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CONTENTS ● Lesson 1 Introduction to Machinery Design ● Lesson 2 Mechanisms ● Lesson 3 Machine Parts (I) ● Lesson 4 Machine Parts (II) ● Lesson 5 Engineering Graphic in the Thirdangle Projecti

on ● Lesson 6 Introduction to CAD/CAM/CAPP ● Lesson 7 A Discussion on Modern Design Optimization ● Lesson 8 Using Dynamic Simulation in the Development of Construction Machinery ● Lesson 9 Engineering Tolerance ● Lesson 10 Numerical Control

● Lesson 11 Introduction to Heat Pipe Technology in Machining Process ● Lesson 12 Introduction to Material Forming ● Lesson 13 Material Forming Processes ● Lesson 14 Introduction to Mould ● Lesson 15 Mould Design and Manufacturing ● Lesson 16 Heat Treatment of Metal ● Lesson 17 Virtual Manufacturing ● Lesson 18 Fluid and Hydraulic System ● Lesson 19 Product Test and Quality Control ● Lesson 20 Introduction of Automobile Engine

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Lesson Lesson Lesson Lesson Lesson Lesson Lesson

21 22 23 24 25 26 27

The Automobile Components Mechatronics Industrial Robots An Army of Small Robots Introduction to MEMS Dialogue—At CIMT Virtual Manufacturing

● Lesson
●1.1

1

Introduction to Machinery Design

Text

[1]Machinery design is either to formulate an engineering plan for the satisfaction of a specified need or to solve an engineering problem. It involves a range of disciplines in materials, mechanics, heat, flow, control, electronics and production.

Machinery Components The major part of a machine is the mechanical system. [3]And the mechanical system is decomposed into mechanisms, which can be further decomposed into mechanical components. In this sense, the mechanical components are the fundamental elements of machinery. On the whole, mechanical components can be classified as universal and special components. Bolts, gear, and chains are the typical examples of the universal components, which can be used extensively in different machines across various industrial sectors.

Mechanical Design Process Product design requires much research and development. Many concepts of an idea must be studied, tried, refined, and then either used or discarded. Although the content of each engineering problem is unique, the designers follow the similar process to solve the problems. The complete process is often outlined as in Fig.1.1.

Fig.1.1 Design Process Model

Recognition of Need Sometimes, design begins when a designer recognizes a need and decides to do something about it. The need is often not evident at all; recognition is usually triggered by a particular adverse circumstance or a set of random circumstances, which arise almost simultaneously. Identification of need usually consists of an undefined and vague problem statement.

Definition of Problem Definition of problem is necessary to fully define and understand the problem, after which it is possible to restate the goal in a more reasonable and realistic way than the original problem statement. Definition of the problem must include all the specifications for the thing that is to be designed. Obvious items in the specifications are the speeds, feeds, temperature limitations, maximum range, expected variation in the variables, and dimensional and weight limitations.

Synthesis The synthesis is one in which as many alternative possible design approaches are sought, usually without regard for their value or quality. This is also sometimes called the ideation and invention step in which the largest possible number of creative solutions is generated. The synthesis activity includes the specification of material, addition of geometric features, and inclusion of greater dimensional detail to the aggregate design.

Analysis Analysis is a method of determining or describing the nature of something by separating it into its parts. In the process the elements, or nature of the design, are analyzed to determine the fit between the proposed design and the original design goals.

Evaluation Evaluation is the final proof of a successful design and usually involves the testing of a prototype in the laboratory. Here we wish to discover if the design really satisfies the needs. The above description may give an erroneous impression that this process can be accomplished in a linear fashion as listed. On the contrary, iteration is required within the entire process, moving from any step back to any previous step.

Presentation Communicating the design to others is the finial, vital presentation step in the design process. Basically, there are only three means of communication. These are the written, the oral, and the graphical forms. A successful engineer will be technically competent and versatile in all three forms of communication. The competent engineer should not be afraid of the possibility of not succeeding in a presentation. In fact, the greatest gains are obtained by those willing to risk defeat.

Contents of Machinery Design Machinery design is an important technological basic course in mechanical engineering education. Its objective is to provide the concepts, procedures, data, and decision analysis techniques necessary to design machine elements commonly found in mechanical devices and systems; to develop engineering students’ competence of machine design that is the primary concern of machinery manufacturing and the key to manufacture good products.

● 1.2

Words and phrases

machinery trivial mechanism chain turbine blade crankshaft propeller discard recognition trigger

n. adj. n. n. n. n. n. v. n. v.

[总称] 机器,机械 琐细的,平常的,微不足道的 机构 链(条),镣铐,一连串,一系列 涡轮机叶片 曲轴 推进者, 推进物, 尤指轮船、飞 机上的螺旋推进器 丢弃, 抛弃 识别 引发, 引起, 触发

vague synthesis ideation aggregate prototype erroneous iteration competent versatile

adj. n. n adj. n. adj. n. adj. adj.

含糊的, 不清楚的 综合 构思能力,思维能力,构思过程 合计的, 集合的 样机,原型 错误的, 不正确的 反复 有能力的, 胜任的 通用的, 万能的, 多才多艺的

● 1.3

Complex Sentence Analysis

[1] Machinery design is either to formulate an engineering plan for the satisfaction of a specified need or to solve an engineering problem. ① either?or?:或??或?? ② formulate:明确地表达,阐明 机械设计用以阐明满足某种特殊需要的工程计划或解决 具体的工程问题。 [2] It is important that the designer begins by identifying exactly how he or she will recognize a satisfactory alternative, and how to distinguish between two satisfactory alternatives in order to identify the best. 对于设计者来说,一开始就能准确判定出令人满意的设 计方案,并能加以区别以选择最好的,这一点很重要。

[3] And the mechanical system is decomposed into mechanisms, which can be further decomposed into mechanical components. ① be decomposed into:被分解为 ② which 引导一个定语从句,在从句中做主语,指前 面的 mechanisms。 机械系统可以分解为机构, 机构又可以进一步分解为 机械零件。

● 1.4 Exercise 1.4.1Translate the Following Paragraphs The practice of design can be one of the most exciting and fulfilling activities that an engineer can undertake. There is a strong sense of satisfaction and pride in seeing the results of one’s creative efforts emerge into actual products and processes that benefit people. To do design well requires a number of characteristics.

1.4.2 Choose the proper answer to fill in the blank and translate the sentences 1.They are using a ( ) shovel to clear up the streets. 2.Many products are made by ( ). 3.There is not a ( ) who hasn’t had this problem. 4.Machinery design involves a range of disciplines in materials, ( ), heat, flow, control, electronics and production. 5.The Allies finally smashed the Nazi war ( ).

● Lesson
●2.1

2

Mechanisms

Text

A mechanism is the members combination more than two or two connections with the members to realize the regulation motion made up by way of the activity. They are the component of machinery. Activity connections between two members that have the relative motion are called the motion pairs.

Fig.2.1 Types of Cams

● 2.2

Words and phrases

mechanism motion pairs disposition machine frame coordinate motivity member parameter driven member free degree categorize category planar spherical spatial loci

n. n.

n.
n. v. n. adj. adj. adj. n.

机构 运动副 配置;排列 机座,机架 坐标 原动件 参变量 从动件 自由度 分类 种类,逻辑范畴 平面的,平坦的 球的,球形的 空间的 [locus的复数形式] 点的轨迹

● 2.3

Complex Sentence Analysis

[1] The motion specific property of mechanism chiefly depends on the relative size between the member, and the character of motion pairs, as well as the mutual disposition method etc. 机构的运动特性主要取决于构件间的相对大小、运动副 的性质以及相互配置方式等。 ① specific property:特性 ② as well as:不但??而且;和??一样;和;也, 表示递进或并列关系。 [2] The criterion which distinguishes the groups, however,is to be found in the characteristics of the motions of the links. 然而,区别分类的标准在于连杆装置的运动特性。

① which引导定语从句,修饰criterion ② to be found为不定式被动语态。 ③ 1inks译为“连杆装置”。 [3] This characteristic makes it possible to represent the locus of any chosen point of a planar mechanism in its true size and shape on a single drawing or figure. 有了这一特点,就能够在单个图形或图像上,以实际 的尺寸和形状来绘出平面机构的任意选择点的轨迹。 ① makes it possible:使??可能 ② represent:描绘,展现 ③ planar mechanism:平面机构。 ④ in size and shape:在大小和形状方面

● 2.4 Exercise:Translate the lineate phrases and fill in the brackets.

该机构为平面四连杆机构( ), 1为机架( ),2为原动件( ), 3、4为从动件( ),A为回转副( ), 属于低副( ),B为固定连接( )。 构件( )4中的焊接符号( )表示4为 一个构件。 该机构的自由度数( )必须等于原动件数, 才能实现确定的运动( )。

● Lesson
●3.1

3

Machine Parts (I)

Text

Gears

Gears are direct contact bodies,operating in pairs, that transmit motion and force from one rotating shaft to another, or from a shaft to a slide (rack),by means of successively engaging projections called teeth.
V-belt The rayon and rubber V-belt are widely used for power transmission.Such belts are made in two series: the standard V-belt and the high capacity V-belt.The belts can be used with short center distances and are made endless so that difficulty with splicing devices

is avoided.

Chain Drives The first chain-driven or “safety” bicycle appeared in 1874, and chains were used for driving the rear wheels on early automobiles. [4]Today, as the result of modern design and production methods, chain drives that are much superior to their prototypes are available, and these have contributed greatly to the development of efficient agricultural machinery, well-drilling equipment, and mining and construction machinery. Since about 1930 chain drives have become increasingly popular, especially for power saws, motorcycle, and escalators etc.

● 3.2

Words and phrases
齿轮 凸出 摆线的 摆线轮廓 渐开线的 渐开线轮廓 共轭的 小齿轮 量纲 啮合 啮合 接触 齿节

Gear n. projection n. cycloidal adi. cycloidal profile involute adi. involute profile conjugate adi. pinion n. dimension n. mate v. engagement n. tangency n. pitch n.

intersect disposition helical gear spur gear worm bevel gear hourglass V-belt splice pulley groove tractive

v . n. n. n n. n. n. adi.

相交,交叉 排列,配置 螺旋齿轮 正齿轮,直齿轮 蜗轮,蜗杆 伞形齿轮,锥齿轮 沙漏 V型带 连接 (皮带)轮 沟,槽 牵引的

clearance n. chain drive prototype n. saw n. escalator n. roller chain bead chain bushing n. sprocket n. strand n. venetian blind

间隙 链传动 模型,原型机 锯 自动扶梯 套筒滚子链条,滚子链 滚珠链条 套筒 链轮 排,列 威尼斯百叶窗,软百叶窗

● 3.3

Complex Sentence Analysis

[1] Gears are direct contact bodies,operating in pairs,that transmit motion and force from one rotating shaft to another,or from a shaft to a slide (rack),by means of successively engaging projections called teeth. ① operating in pairs: 分词短语,修饰前面的Gears。 ② that引导的从句,修饰前面的Gears。 ③ by means of表示“借助”、“通过”的意思 齿轮是直接接触的实体,成对使用,在称为齿的凸起的 连续啮合作用下,齿轮将运动和力从一根转轴传递到另一 根转轴上,或者将运动和力从一根轴传递到滑块(齿条)上。

[2] If an involute spur pinion were made of rubber and twisted uniformly so that the ends rotated about the axis relative to one another, the elements of the teeth,initially straight and parallel to the axis,would become helices. 假设一渐开线直齿轮是用橡胶制成的,并且能够均 匀扭转,那么,两端就会绕着轴线做相对的转动,这样, 开始是直的并平行于轴线的小齿轮上的齿,就变成了螺 旋形。 ① were made of:“由??组成” ② so that引导结果状语从句 ③ parallel to:“平行于??”

[3] Sufficient clearance must be provided at the bottom of the groove to prevent the belt from bottoming as it becomes narrower from wear. ① at the bottom of?“在??的底部” ② prevent?from wear“防止磨损” [4] Today, as the result of modern design and production methods, chain drives that are much superior to their prototypes are available, and these have contributed greatly to the development of efficient agricultural machinery, well-drilling equipment, and mining and construction machinery. 如今,随着现代设计和制造方法的改进,链传动的应 用越来越广泛,大大提高了农业机械、钻探设备、矿业和 建筑机械的效率。 ① superior to表示“优于”的意思。 ② and引导的是一句并列句。

● 3.4 Exercise: 3.4.1 Translate the Following Paragraphs

A gear having tooth elements that are straight and parallel to its axis is known as a spur gear. A spur pair can be used to connect parallel shafts only. Parallel shafts, however, can also be connected by gears of another type, and a spur gear can be mated with a gear of a different type.

● 3.4 Exercise: 3.4.2 Write the name of the following parts and brief description of the roller chain on the structure and assembly relations.

Fig.3.1

Structure

● Lesson

4

Machine Parts (II)

●4.1 Text Fastener [1]Fasteners are devices which permit one part to be joined to a second part and, hence, they are involved in almost all designs. There are three main classifications of fasteners, which are described as follows: (1) Removable. This type permits the parts to be readily disconnected without damaging the fastener. An example is the ordinary nut-and-bolt fastener. (2) Semi permanent. For this type, the parts can be disconnected, but some damage usually occurs to the fastener. One such example is a cotter pin. (3) Permanent. When this type of fastener is used, it is intended that the parts will never be disassembled. Examples are riveted joints and welded joints.

Shaft Virtually all machines contain shafts. The most common shape for shafts is circular and the cross section can be either solid or hollow (hollow shafts can result in weight savings).

Bearing A bearing can be defined as a member specifically designed to support moving machine components. The most common bearing application is the support of a rotating shaft that is transmitting power from one location to another. Since there is always relative motion between a bearing and its mating surface, friction is involved. In many instances, such as the design of pulleys, brakes, and clutches, friction is desirable. However, in the case of bearings, the reduction of friction is one of the prime considerations:Friction results in loss of power, the generation of heat, and increased wear of mating surfaces.

Fig.4.1 Journal Bearing

● 4.2

Words and phrases 器件;设备;装置 紧固件,紧固零件 分类,类别 可移动的,可拆的 半永久性的 开口销,开尾销 拆开,分散 铆钉;v. 铆;铆接 焊接,熔接 障碍,损害 发出喀啦声,硬物质的撞 击声 螺帽 螺钉,螺栓 v. 用螺栓连接

device [di5vais] n. fastener n. classification n. removable adi. semipermanent adj. cotter pin n. disassemble v rivet n. weld v. nuisance n. rattle v.& n
nut bolt

n n.

screw lock washer resilience aluminum shaft bearing gear cam clutch cold-roll forge flexible

n. 螺钉,螺旋丝杆 n. 锁紧垫圈,止动垫圈,防松垫圈 n. 弹力,弹性 n. 铝(金属元素符号) n. 轴 n. 轴承,支承 n. 齿轮 n. 凸轮,靠模 v.& n. 抓住,离合器 v.& n 冷轧,冷轧机 v.& n 锻造,打制 adj. 柔软的,适用性强

friction brake wear arrangement contaminant sealing arrangement hostility appreciation interference

n. 摩擦 v. 破坏,折断,损坏 v.& n 磨损,耗损 n. 布置,排列 n. 杂质,污染物质 n. 密封装置 n. 敌意,恶劣 n. 评价,欣赏 n. 干涉,过盈

fretting n. 微振磨损 corrosion n. 腐蚀 abut v. 邻接,倚靠 stress concentration 应力集中 shoulder n. 轴肩 chamfer v.& n.倒角,倒圆,开槽 journal bearing n. 滑动轴承 cylinderical adj. 圆筒状的,柱状的 lubricant n. 润滑剂,润滑材料 compatible adj. 相适用,和谐的,一致的

● 4.3

Complex Sentence Analysis

[1] Fasteners are devices which permit one part to be joined to a second part and, hence, they are involved in almost all designs. 紧固件可以将一个零件与另一个零件相连接。因此,几 乎在所有的设计中都要用到紧固件。 ① which引导定语从句修饰devices。 ② to be joined to a second part第一个不定式to表 示目的。be joined to是介词词组,to表示“到”的意思。 ③ are involved in表示“涉及”、“包括”的意思。 [2] This change in the length of the bolt can be caused by a number of factors-creep in the bolt, loss of resilience, difference in thermal expansion between the bolt and the bolted members, or wear.

这种螺栓长度的变化可由多种因素引起——螺栓内 部蠕变、弹性丧失、螺栓与被连接件间的热膨胀差异或 磨损。 ① factors-creep是复合词,表示“引起蠕动的因素”。 ② loss of resilience表示“弹性丧失”。 [3] In general, the bending deflection of a shaft should not exceed 0.01 in. per ft of length between bearing supports. 一般来说,在两个轴承支承之间,轴在每英尺长度 上的弯曲变形不应该超过0.01英寸。 ① 0.01 in. per ft表示“每英尺长度上为0.01英寸”。 ft是foot(英尺)的简写;in是inch(英寸)的简写。 ② between bearing supports中between表示两者之间, 可译为在两轴承支承之间。

[4] Where speeds are high special cooling arrangements become necessary which may increase frictional drag. 在高转速场合下需要有专门的冷却装置,这可能会 增大摩擦阻力。 ① where引导非限制性定语从句,表示“在哪里”。 ② which may increase frictional drag修饰主语 cooling arrangements,因为谓语比较短而放在谓语最 后。

● 4.4

Exercise:Translate the Following Paragraphs

A bearing is a connector that permit the connected members to either rotate or translate (more to and from) relative to one another but prevents them from separating in the direction in which loads are applied. In many cases one of the members is fixed, and the bearing acts as a support for the moving member.

● Lesson

5

Engineering Graphic in the Third-angle Projection

●5.1

Text

[1]Graphics comes to our vocabulary from the Greek word grapho, whose extended meaning is “drafting” or “drawing”, the drawing is the primary medium for developing and communicating technical ideas. Engineering drawings provide an exact and complete description of objects. In addition to a description of the shape of an object, an engineering drawing gives all further information needed to manufacture the object drawn, such as dimensions, tolerances, and so on. So it is often said the engineering drawing is the common language of engineering. Every engineer must master this language.

Formation of Three-projection Views Three projection planes system: Since it is impossible to determine the position of a point with its only one projection, more projection planes are added. Usually, three projection planes perpendicular to each other are used in orthographic projection. They are horizontal projection plane, frontal projection plane and profile projection plane, denoted by H, V, W, respectively.

The third-angle projection: Three projection planes divide space into eight parts or quadrants numbered from 1 to 8, as shown in Fig.5.1. [2]According to the Chinese National Standard of Technical Drawings, the first-angle projection is used to make engineering drawings while in some other countries, such as in the USA and Canada, the third-angle projection is used. In this paper we focus on the third-angle projection.

Formation of three-projection views: In first angle, an object is placed in quadrant 1, and observer always looks through the object towards the projection plane. But in third-angle, the object is placed in quadrant 3, and observer always looks through the projection plane towards the object. In third-angle projection, projection plane is assumed transparent, so form into views. The symbols of the first-angle and the third-angle projection in the following Fig. 5.2.

Fig.5.1 Projection planes

The first-angle projection The third-angle projection Fig.5.2 The Symbols of the Different Angle Projection

Composite Objects Drawing three views: (1) Analyzing-shape method: Any composite object can be broken into a combination of some primary geometric object. Any of these basic shapes can be positive, classified to the superposition style and the cutting style. (2) Select the projection: Because the front view is the most important one in the three views, it is very important to select adequate projection direction to form the front view. (3) Drawing steps: Locate the axis lines, centerlines of symmetry and base lines; draw the base with H pencil; check the drawing and darken the lines.

Methods to read views: (1) Analyzing shape method: Break the object down into its basic geometric solids. (2) Analyzing lines and planes method: Break the object into various surfaces and lines. For example, like the following Fig.5.3, the three views of a Composite Object.

Fig.5.3 Three Views of Composite Object

Detail Drawings Detail drawings: It is a drawing that indicates the construction, size, and technical requirements of a part. It describes its shape, gives the dimensions, provide all the information needed to make the part. The contents of a detail drawing: (1) A sufficient number of views to give a complete shape description of the exterior and interior constructions of the part. (2) All the dimensions needed for manufacturing the part. (3) Technical requirements including tolerances, geometric tolerances, surface roughness, material specification, heat treatments, and so on.

Assembly Drawings Assembly drawings: A drawing that shows the parts of a machine or machine unit assembled in their relative working position is called an assembly drawing. The contents of an assembly drawing are as follows: (1) A set of views showing the positional relationship and mutual operation of the parts being assembled. (2) A few dimensions that are needed to show the positional relationship between critical parts, the positioning of the product at site, etc. (3) Technical requirements including all the information necessary for assembling, checking, and maintaining the machine. (4) Item numbers for each part, the item list, and the title block.

● 5.2

Words and phrases

graphics n. drafting n. drawing n. projection n. dimension n. spatial analysis spatial visualization horizontal projection frontal projection profile projection quadrant n. center-lines of symmetry composite object detail drawing assembly drawing phantom line

制图,图学 草图,制图 绘图,制图,图样 投影 尺寸;v. 给??标注尺寸 空间分析 空间想象 水平投影 正投影 侧投影 象限 对称中心线 组合体 零件图 装配图 假想线

● 5.3

Complex Sentence Analysis

[1] Graphics comes to our vocabulary from the Greek word grapho, whose extended meaning is “drafting” or “drawing”, the drawing is the primary medium for developing and communicating technical ideas. 图学一词来源于希腊语grapho,其延伸意义为“绘图” 或“图样”。图样是开发和交流技术思想的主要工具。 [2] According to the Chinese National Standard of Technical Drawings, the first-angle projection is used to make engineering drawings while in some other countries, such as in the USA and Canada, the third-angle projection is used. 依据中国机械制图国家标准,制图采用第一角投影, 而其他一些国家像美国和加拿大则采用第三角投影。

[3] Special conventions: Representation of making the cut along joint face or taking some parts apart; representation of showing parts separately; representation of using phantom lines; exaggerated representation; simplified representation. 特殊规定:沿结合面剖切或把某些零件拆开的画法; 单独表示零件画法;使用假想线画法;夸大画法;简化 画法。

● 5.4

Exercise:Translate the Following Paragraphs

Similar to an offset in that the cutting-plane line staggers, however, it differs in that the cutting-plane line is offset at some angle other than 90°. When the section is taken the sectional view is drawn as if the cutting-plane is rotated to the plane perpendicular to the line of sight. This is why the right side sectional view may sometimes be elongated (depending on the shape). Exercise: Drawing the front view to aligned section. The Fig. 5.4 is the topic and Fig. 5.5 is the answer.

Fig.5.4 The Topic

Fig.5.5 The Answer

● Lesson
●6.1

6

Introduction to CAD/CAM/CAPP

Text

Throughout the history of our industrial society, many inventions have been patented and whole new technologies have evolved. [1]Perhaps the single development that has impacted manufacturing more quickly and significantly than any previous technology is the digital computer. Computers are being used increasingly for both design and detailing of engineering components in the drawing office.

[2]Computer-aided design (CAD) is defined as the application of computers and graphics software to aid or enhance the product design from conceptualization to documentation. CAD is most commonly associated with the use of an interactive computer graphics system, referred to as a CAD system. Computer-aided design systems are powerful tools and are used in the mechanical design and geometric modeling of products and components.

There are several good reasons for using a CAD system to support the engineering design function: (1) To increase the productivity. (2) To improve the quality of the design. (3) To uniform design standards. (4) To create a manufacturing data base. (5) To eliminate inaccuracies caused by handcopying of drawings and inconsistency between drawings.

Models in CAD can be classified as being twodimensional models, two-and-halfdimensional models, or three-dimensional models. A 2-D model represents a flat part and a 3-D model provides representation of a generalized part shape(as shown in Fig.6.1). A -D model can be used to represent a part of constant section with no side-wall details. [3]The major advantage of a -D model is that it gives a certain amount of 3-D information about a part without the need to create the database of a full 3-D model.

After a particular design alternative has been developed, some form of engineering analysis must often be performed as a part of the design process. [4]The analysis may take the form stress-strain calculations, heat transfer analysis, dynamic simulation etc. Some examples of the software typically offered on CAD systems are mass properties and Finite Element Method (FEM) analysis. Mass properties involve the computation of such features of a solid object as its volume, surface area, weight, and center of gravity. FEM analysis is available on most CAD systems to aid in heat transfer, stressstrain analysis, dynamic characteristics, and other engineering computations. Presently, many CAD systems can automatically generate the 2-D or 3-D FEM meshes which are essential to FEM analysis.

(a) Wire-frame Model

(b)

Surface Model

Fig.6.1 Three-dimension Models

CAM can be defined as computer aided preparation manufacturing including decision-making, process and operational planning, software design techniques, and artificial intelligence, and manufacturing with different types of automation (NC machine, NC machine centers, NC machining cells, NC flexible manufacturing systems), and different types of realization (CNC single unit technology, DNC group technology). The CAM covers group technology, manufacturing database, automated and tolerance. Fig.6.2 illustrates the general scope of CAM.

Fig.6.2 The General Scope of CAM

When a design has frozen, manufacturing can begin. Computers have an important role to play in many aspects of production. Modern shipbuilding fabricates structures from welded steel plates that are cut from a large steel sheet. Computer-controlled flame cutters are often used for this task and the computer is used to calculate the optimum layout of the components to minimize waste metal.

● 6.2

Words and phrases

evolve v. (使)发展,(使)进展,(使)进化 conceptualization n. 化为概念,概念化 documentation n. 文件 inconsistency n. 不兼容性 NC. Numerical Control 数字控制 CNC. Computer Numerical Control 计算机数字控制 interactive adj. 交互式的 wire-frame models 线框模型 surface models 表面模型 solid models 实体模型 stress-strain 应力-应变 fabricate v. 构成,伪造,虚构 incorporate adj. 合并的,一体化的

● 6.3

Complex Sentence Analysis

[1] Perhaps the single development that has impacted manufacturing more quickly and significantly than any previous technology is the digital computer. ① that has impacted manufacturing more quickly and significantly than any previous technology是定 语从句,修饰development。 ② 全句可翻译成:与以前出现的任何科学技术相比,对 工程制造业冲击最快、影响更大的是数字计算机。 [2] Computer-aided design (CAD) is defined as the application of computers and graphics software to aid or enhance the product design from conceptualization to documentation. ① be defined as: 定义成,定义为。

例如,Teachers are defined as those who do some teaching at school。 ② to aid or enhance the product design from conceptualization to documentation 为本句的目的状语; from conceptualization to documentation 为介词短语作定 语修饰前面的design,其字面的解释是从概念到文件,其实指 的就是产品设计过程。 [3] The major advantage of a -D model is that it gives a certain amount of 3-D information about a part without the need to create the database of a full 3-D model. ① that引导的是表语从句。 ② without引导的介词短语在整个句子中充当状语,例如: I wouldn’t have accomplished the designated task without your help.

[4] The analysis may take the form stress-strain calculations, heat transfer analysis, dynamic simulation etc. Some examples of the software typically offered on CAD systems are mass properties and Finite Element Method (FEM) analysis. ① 这里的take应译为,包括,包含。 ② stress-strain:应力—应变;dynamic simulation: 动力学仿真,simulation:仿真,计算;Finite Element Method (FEM):有限元方法,是一种对物体进行物理特性 分析的方法,目前被广泛地应用在机械学、传热学、电磁 学等领域。

[5] Lower level strategies only use computers for storage and retrieval of the data for the process plans which will be constructed manually by process planners, as well as for supplying the data which will be used in the planner’s new work. ① as well as:也,又,介词性词组,常引导名词, 代词,或相当于名词性的短语; ② for supplying the data which will be used in the planner’s new work,与for storage and retrieval of the data for the process plans which will be constructed manually by process planners作 用相当,都是use computers的目的。

[6] The database in a CAPP system based on the highest level strategy will be directly integrated with conjunctive systems, e.g. CAD and CAM. based on the highest level strategy,过去分词短语 作定语前面的system;based on,基于,建立在,在句中 可作状语或定语,试比较: based on the experimental results, it could be inferred that a heat pipe has a strong ability to transfer heat. We do believe the facts based on the experiments.

● 6.4

Exercise:Translate the Following Paragraphs

AutoCAD is a computer-aided drafting and design system implemented on a personal computer. It supports a large number of devices. Device drivers come with the system and include most of the digitizers, printer/plotters, video display boards, and plotters available on the market. AutoCAD supports 2-D drafting and 3-D wire-frame models. The system is designed as a single-user CAD package. The drawing elements are lines, poly-lines of any width, arcs, circles, faces, and solids. There are many ways to define a drawing element. For example, a circle can be defined by the center and its radius, three points, and two end points of its diameter. The system always prompts the user for all options.

● Lesson
●7.1

7 A Discussion on Modern Design Optimization

Text

The integration of optimization techniques with Finite Element Analysis (FEA) and CAD is having pronounced effects on the product design process. [1]This integration has the power to reduce design costs by shifting the burden from the engineer to the computer. Furthermore, the mathematical rigor of a properly implemented optimization tool can add confidence to the design process. Generally, an optimization method controls a series of applications, including CAD software as well as FEA automatic solid meshers and analysis processors. This combination allows for shape optimizations on CAD parts or assemblies under a wide range of physical scenarios including mechanical and thermal effects.

Modern optimization methods perform shape optimizations on components generated within a choice of CAD packages. Ideally, there is seamless data exchange via direct memory transfer between the CAD and FEA applications without the need for file translation. Furthermore, if associativity between the CAD and FEA software exists, any changes made in the CAD geometry are immediately reflected in the FEA model. In the approach taken by ALGOR, the design optimization process begins before the FEA model is generated. The user simply selects which dimension in the CAD model needs to be optimized and the design criterion, which may include maximum stresses, temperatures or frequencies. The analysis process appropriate for the design criteria is then performed.

The results of the analysis are compared with the design criterion, and, if necessary without any human intervention, the CAD geometry is updated. [2]Care is taken such that the FEA model is also updated using the principle of associativity, which implies that constraints and loads are preserved from the prior analysis. The new FEA model, including a new high-quality solid mesh, is now analyzed, and the results are again compared with the design criterion. This process is repeated until the design criterion is satisfied. Fig.7.1 shows the procedure of shape optimization.

Introduction The typical design process involves iterations during which the geometry of the part(s) is altered. In general, each iteration also involves some form of analysis in order to obtain viable engineering results. Optimal designs may require a large number of such iterations, each of which is costly, especially if one considers the value of an engineer’s time. The principle behind design optimization applications is to relieve the engineer of the laborious task by automatically conducting these iterations. At first glance, it may appear that design optimization is a means to replace the engineer and his or her expertise from the design loop.

Design optimization applications tend to be numerically intensive because they must still perform the geometrical and analysis iterations. [3]Fortunately, most design optimization problems can be cast as a mathematical optimization problem for which there exist many efficient solution methods. The drawback to having many methods is that there usually exists an optimum mathematical optimization method for a given problem. This complexity should be remedied by the design optimization application by giving the engineer not only a choice of methods, but also a suggestion as to which approach is most appropriate for his or her design problem.

Fig.7.1 Procedure of Shape Optimization

Background and Theory In this section, we focus on the theory underlying some of the mathematical methods employed by design optimization procedures. But, first we describe how the optimization problem arises. Consider a three-step process: (1) Generation of geometry of part or assembly in CAD; (2) Creation of FEA model of part or assembly; (3) Evaluation of results of FEA models.

Benefits and Drawbacks The elimination or reduction of repetitive manual tasks has been the impetus behind many software applications. Automatic design optimization is one of the latest applications used to reduce man-hours at the expense of possibly increasing the computational effort. It is even possible that an automatic design optimization scheme may actually require less computational effort than a manual approach. This is because the mathematical rigor on which these schemes are based may be more efficient than a human-based solution. Of course, these schemes do not replace human intuition, which can occasionally significantly shorten the design cycle.

● 7.2

Words and phrases

optimization n. 最佳化,最优化 finite element analysis (FEA) 有限元分析 computer aided design(CAD) 计算机辅助设计 burden n. 担子,负担,责任,义务 rigor n. 严格,严密,精确 mesh n. 网孔,网格,网状物 scenario n. [意大利语]方案,情况 seamless adj. 无缝的,无伤痕的 criterion n. 标准,规范,准则,判据 iteration n. 反复,迭代 geometry n. 几何学,几何图形,表面形状 gauge v. 判断,测试,测定,测量

intensive cast assembly variable
warrant yield underlying linear function constraint impetus scheme

adj. 强化的,加强的 v. 计算,派(角色),分类整理 n. 组合,装配,部件,汇编 n. 可变物,变量 adj. 可变的,变量的 v. 成为??的证据,保证,
证明??是正确的 v. 产出,产生,提供,给予 adj. (做)基础的,根本的 adj. 线的,直线的,线性的 n. 功能,作用,[数]函数 n. 约束,强制,局促 n. 推动力,促进,刺激,激励 n. 计划,阴谋,方案,图解

● 6.3

Complex Sentence Analysis

[1] This integration has the power to reduce design costs by shifting the burden from the engineer to the computer. ① power:能力,has the power to翻译成“能够”。 ② 注意power在作为“能力”时和ability的区别,和 ability相比power更强调“本能,智能和体能”,试比较: Some animals have the power to see in the dark. He has a strong ability to deal with the business. [2] Care is taken such that the FEA model is also updated using the principle of associativity, which implies that constraints and loads are preserved from the prior analysis. ① 主句很短,such that引导状语从句。 ② which引导非限定性定语从句,which代表前面这个句子 的意思。

③ 此外上述句子,还可写成以下两种形式: Care is taken such that the FEA model is also updated using the principle of associativity, as implies that constraints and loads are preserved from the prior analysis. As implies that constraints and loads are preserved from the prior analysis, Care is taken such that the FEA model is also updated using the principle of associativity. [3] Fortunately, most design optimization problems can be cast as a mathematical optimization problem for which there exist many efficient solution methods. ① cast:派(角色),此处be cast as转译为“看成”。 ② for which?:介词+ which引导的定语从句修饰其前 面的problem。试比较:

At an instant, the energy in the control volume includes the rate at which thermal and mechanical energy enters and leave through the control surface. [4] One definite advantage of automated methods over manual approaches is that software applications, if implemented correctly, should consider all variable possibilities. ① advantage?over?:与??相比的优越性 ② that引导表语从句,其中if implemented correctly 是插入短语。

● 7.4

Exercise:Translate the Following Paragraphs

Optimization is concerned with finding the best possible solution, formally referred to as the optimal solution, to a particular problem (for example, a design problem). The term optimization is often used very loosely in general speech, for our purposes it has a precise meaning: the action of finding the best possible solution to a problem as defined by an unambiguous criterion: the cost function.

● Lesson

8 Using Dynamic Simulation in the Development of Construction Machinery ●8.1 Text

Introduction
[1]The general motives for “Virtual Prototyping” are probably familiar to all engineers: Stricter legal requirements (e.g. with regard to exhaust emissions and sound) and tougher customer demands (e.g. with regard to performance and handling) lead to more advanced, complex systems, which are harder to optimize. With traditional methods, development will cost more and need more time. In contrast to this, increased competition demands lower development cost and shorter project times.

“Virtual Prototyping” has been generally adopted in the vehicle industry as a major step towards solving this conflict both on the consumer side (cars) and on the commercial side (trucks and buses as shown in Fig .8.1). Having started with simulation of sub-systems, the state-of the- art is simulation of complete vehicles, mostly for evaluation of handling, comfort, and durability but also for crash-tests.

Fig.8.1 Multi-body Model of a Volvo L220E Loader, Loading Gravel

Wheel

Design Process and Visualization The aim of the present project is evolution of the current product development process, rather than revolution by means of Design Science. The research question is therefore how to augment the existing design process with dynamic simulation. [3]As mentioned before, the focus is on analysis and optimization of overall performance and related aspects. The revised design process has to fulfil the following non-optional targets: Lead to development of compared with today. Saved resources (time, money, and people) can then be spent on optimizing one or all of the aspects mentioned in the first item in the list.

Fig.8.2 Initial Calculation Loop for Balancing the Main System

Fig.8.3 Dynamic Torque Curve of a Modern, Turbo—Charged Diesel Engine

Conclusion and Outlook This paper presented the joint research by Volvo Wheel Loaders and Link?ping University on simulation of complete machines for analysis and optimization of overall performance. The motivation on the side of the industrial partner is to develop products of equally high performance, efficiency and operatability, but with more robustness regarding these aspects, in a shorter time and at a lower total development cost. A revised product development process (with regard to the research topic) has been proposed. Examples of areas for future research have also been presented. Research in the immediate future will focus on a definition of operatability (including quantification), as well as practical simulation problems.

● 8.2

Words and phrases

dynamic simulation 动态仿真 Virtual Prototyping 虚拟原型机 off-road adj. 道路之外的,越野的 lag v. 缓缓而行,滞后; v. 落后于,加上外套 amortization n. 摊销,分期偿付 topologically adv. 拓扑地 optimization n. 最佳化,最优化 hydrodynamic adj. 水压的,液力的,流体动力学的 augment v. 增加,增大;n. 增加

operatability robustness proprietary downscale reiteration checkpoint jerky concurrent scenario perspective

n. 操作性能 n. 耐用,坚固 adj. 专利的,独占的,私有的 v. 缩减??规模;按比例缩减,减少 n. 重复,反复 n. 关卡,公路检查站,检查点 adj. 急拉的,急动的 adj. 同时,兼,并行地 n. 游戏的关,某一特定情节 n. 透视图,远景,观点,观察

● 8.3

Complex Sentence Analysis

[1] The general motives for “Virtual Prototyping” are probably familiar to all engineers. be familiar to = be known to (某人或某物)对??是 熟悉的 e.g. The food and the climate here are familiar to me. 我对这儿的饮食和气候比较熟悉。 试比较:be familiar with (某人)熟悉??。 [2] One reason for the off-road equipment industry lagging behind can be found in the size of these companies. 该句中lagging behind作定语修饰前面的 industry,意 思是“落后,滞后”。

[3] As mentioned before, the focus is on analysis and optimization of overall performance and related aspects. 此句中,as替代the focus is on analysis and optimization of overall performance and related aspects。 [4] Only if the deviation is too high will a new static calculation loop need to be started (with the original product targets as input). 当only引导副词、副词性词组和状语句子时,后面所跟 的主句一般需倒装。 试比较:Only then did I realize made such a big mistake. 只是在那时,我才认识到我犯了一个多么大的错误。 Only when one loses health does he know its value. 只有当人们身体不好时才认识到健康的重要性。

[3] As mentioned before, the focus is on analysis and optimization of overall performance and related aspects. 此句中,as替代the focus is on analysis and optimization of overall performance and related aspects。 [4] Only if the deviation is too high will a new static calculation loop need to be started (with the original product targets as input). 当only引导副词、副词性词组和状语句子时,后面所跟 的主句一般需倒装。 试比较:Only then did I realize made such a big mistake. 只是在那时,我才认识到我犯了一个多么大的错误。 Only when one loses health does he know its value. 只有当人们身体不好时才认识到健康的重要性。

● 8.4

Exercise:Translate the Following Paragraphs

As shown earlier, off-road equipment consists of systems from various domains, and most of them need to be taken into account when simulating performance of complete machines,which is usually a collaborative activity. As noted by many researchers, engineers have often already chosen one domain-specific simulation program that they are familiar with. Instead of forcing migration to one monolithic simulation system that can be used in several domains (but offers only limited functionality in the individual domain), a better approach is to couple the specialized, single-domain tools. This has the advantage that both pre- and postprocessing are done decentralized, in the engineer’s domain-specific tools.

● Lesson
●8.1

8

Heat Treatment of Metal

Text

The generally accepted definition for heat treating metals and metal alloys is “heating and cooling a solid metal or alloy in a way so as to obtain specific conditions and I or properties.” Heating for the sole purpose of hot working (as in forging operations) is excluded from this definition.Likewise,the types of heat treatment that are sometimes used for products such as glass or plastics are also excluded from coverage by this definition.

● Lesson
●9.1

9

Engineering Tolerance

Text

Introduction

A solid is defined by its surface boundaries. Designers typically specify a component’s nominal dimensions such that it fulfils its requirements. In reality, components cannot be made repeatedly to nominal dimensions, due to surface irregularities and the intrinsic surface roughness. [2]Some variability in dimensions must be allowed to ensure manufacture is possible. However, the variability permitted must not be so great that the performance of the assembled parts is impaired. The allowed variability on the individual component dimensions is called the tolerance.

Component Tolerances Control of dimensions is necessary in order to ensure assembly and interchangeability of components. Tolerances are specified on critical dimensions that affect clearances and interferences fits. One method of specifying tolerances is to state the nominal dimension followed by the permissible variation, so a dimension could be stated as 40.000mm0.003mm. [3]This means that the dimension should be machined so that it is between 39.997mm and 40.003mm. Where the variation can vary either side of the nominal dimension, the tolerance is called a bilateral tolerance.

Standard Fits for Holes and Shafts A standard engineering task is to determine tolerances for a cylindrical component, e.g. a shaft, fitting or rotating inside a corresponding cylindrical component or hole. The tightness of fit will depend on the application. [5]For example, a gear located onto a shaft would require a“tight” interference fit, where the diameter of the shaft is actually slightly greater than the inside diameter of the gear hub in order to be able to transmit the desired torque. Alternatively, the diameter of a journal bearing must be greater than the diameter of the shaft to allow rotation.

Fig.9.1 The Definitions Used in Conventional Tolerance

● 9.2

Words and phrases

tolerance

n.

nominal adj. intrinsic adj. normal distribution weld bead fillet n. spigot n. interference fit broach n. gauge n. deviation

n.

公差; v. 给机器部 件等规定公差 公称的,标称的,额定的 固有的,内在的,本质的 正态分布 焊缝 圆角,倒角 插销,塞子,阀门 干涉配合,过盈配合 拉刀; v. 拉削 (电线等的)直径;(金属 板的)厚度;量具 偏差,偏移

● 9.3

Complex Sentence Analysis

[1] Designers typically specify a component’s nominal dimensions such that it fulfils its requirements. such that = so that 以便于、以至于,通常后面跟 can(could) + 动词原形。 [2] Some variability in dimensions must be allowed to ensure manufacture is possible. 在这个句子中,to ensure manufacture is possible 是Some variability的主语补足语,同时,manufacture is possible为ensure的宾语从句。 e.g. A lot of students will be allowed to do whatever is good for them. 人们允许大多数学生做对他们有益的事情。

[3] This means that the dimension should be machined so that it is between 39.997mm and 40.003mm. 在该句中,mean的中文意思是“意味着”。实际上,当 mean为动词时需注意以下两个结构。 ① mean to do something:计划做某事、打算做某事, 主语通常是人。 e.g. I meant to have seen you, but I was too busy at that time. 我原打算去看你的,但是那时实在太忙。 ② mean doing something:意味着做某事,主语通常是 物。 e.g. What he said at the meeting meant his finishing the task given by himself。 他在会上的发言意味着他将独自地完成所分配的任务。

[4] When specifying a tolerance for a component, reference can be made to previous drawings or general engineering practice. 在这个句子中,When specifying a tolerance for a component相当于When we are specifying a tolerance for a component, 由于specify 的逻辑主 语就是主句的主语,同时该时间状语的主要谓语动词是 be,按照英语语法规则,可将we are省去。

[5] For example, a gear located onto a shaft would require a “tight” interference fit, where the diameter of the shaft is actually slightly greater than the inside diameter of the gear hub in order to be able to transmit the desired torque. ① 在这个句子中,located onto a shaft为过去分词 短语作定语,其作用相当于一个定语从句。 ② where the diameter of the shaft is actually slightly greater than the inside diameter of the gear hub in order to be able to transmit the desired torque为非限定性定语从句修饰前面的a “tight” interference fit。

e.g. The man followed by a lot of students is a professor studying simulation technology. 有许多学生跟着的那名男子是一位从事仿真技术研究的 教授。 I like living in Hefei,where a lot of universities are located. 我喜欢生活在合肥,那儿有许多大学。 [6] Given that it is not economically possible to manufacture components to exact dimensions, some variability in sizes of both the shaft and hole dimension must be specified.

在Given that it is not economically possible to manufacture components to exact dimensions, some variability in sizes of both the shaft and hole dimension must be specified 中,Given=provided, 其中文解释是“假定”。 e.g. Given that all we want has been prepared, what on earth should we do next? 假定我们所需要的一切都准备好了,那么下一步我们究 竟应该做些什么呢?

● 9.4

Exercise:Translate the Following Paragraphs

Computers are used extensively in most engineering functions. Engineering is a profession in which a knowledge of the natural sciences is applied with judgment to develop ways of using the materials and forces of nature. Typical engineering functions using CAPACS(computer-aided production and control systems) are design, process planning, analysis and optimization, synthesis, evaluation and documentation, simulation, modeling, and quality control planning. Using CAPACS in engineering increases the productivity of engineers and improves the quality of designs.

● Lesson
●10.1

10

Numerical Control

Text

Numerical control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers,letters,and other symbols.The numbers,letters,and symbols are coded in an appropriate format to define a program of instructions for a particular workpart or job. The instructions are provided by either of the two binary coded decimal systems: the Electronic Industries Association (EIA) code, or the American Standard Code for Information Interchange (ASCII).

Basic Components of NC A numerical control system consists of the following three basic components: (1) Program instructions (2) Machine control unit (3) Processing equipment The program instructions are the detailed step by step commands that direct the processing equipment.[3]In its most common form,the commands refer to positions of a machine tool spindle with respect to the worktable on which the part is fixed.More advanced instructions include selection of spindle speeds,cutting tools,and other functions.

Types of NC There are two basic types of numerical control systems:point to point and contouring. Point to point control system, also called positioning, are simpler than contouring control system.Its primary purpose is to move a tool or workpiece from one programmed point to another. Usually the machine function,such as a drilling operation,is also activated at each point by command from the NC Program.Point to point systems are suitable for hole machining operations such as drilling, countersinking,counterboring, reaming,boring and tapping. Hole punching machines,spotwelding machines,and assembly machines also use point to point NC systems.

Programming for NC [4]A program for numerical control consists of a sequence of directions that causes an NC machine to carry out a certain operation, machining being the most commonly used process. Programming for NC may be done by an internal programming department, on the shop floor, or purchased from an outside source. Also, programming may be done manually or with computer assistance.

DNC and CNC The development of numerical control was a significant achievement in batch and job shop manufacturing,from both a technological and a commercial viewpoint.There have been two enhancements and extensions of NC technology, including: (1) Direct numerical control (2) Computer numerical control

● 10.2

Words and phrases
数字控制 指令 二进制 车床 铣 钻 镗 磨 转盘 冲床 (电)火化 线切割

numerical control instruction binary lathe mill drill bore grind turret punch flame wire-cutting

n. adj. n. v. v. v. v. n. n. n.

pipe bender spindle contour workpiece countersink counterbore ream tapping spotwelding

n. n. n. n. n. n. n.

弯管机 主轴 轮廓 工件 钻(沉头)孔 镗(沉头)孔 铰孔 攻丝 点焊

synchronization interpolation parabolic compensation pertain coolant clamping miniaturization dedicated

n. n. adj. n. v. n. n. n. adj.

同步 插补 抛物线的 补偿 合适 冷却液 夹紧 小型化 专用的

● 10.3 Complex Sentence Analysis [1] Numerical control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers,letters, and other symbols. 数控技术是一种利用程序实现自动控制的技术,加工制造 设备采用数控技术后能由数字、字符和符号等进行控制。 ① a form of?“一个??的形式” ② in which?引导的是定语从句,修饰前面的 programmable automation ③ by means of “通过??”,“使用??方法” [2] Automation operation by NC is readily adaptable to the operation of all metalworking machines. Lathes, milling machines, drill presses, boring machines, grinding machines, turret punches, flame or wirecutting and welding machines, and even pipe benders are available with numerical controls.

数控加工制造目前已经广泛地应用于几乎所有的金 属加工机床:车床,铣床,钻床,镗床,磨床,回转冲 床,电火花或线切割机床以及焊接机床,甚至弯管机也 可采用数控加工技术。 ① is adaptable to? “可适用于??” ② are available with? “用??有效” [3] In its most common form,the commands refer to positions of a machine tool spindle with respect to the worktable on which the part is fixed. 最常用的指令形式可以使机床刀具主轴位于工作台 上的具体位置,工作台是用于固定加工零件的。 ① refer to?表示 “指??”的意思 ② with respect to?表示 “相对于??”的意思 ③ on which引导的是定语从句,修饰前面的worktable

[4] A program for numerical control consists of a sequence of directions that causes an NC machine to carry out a certain operation, machining being the most commonly used process. 数控系统(NC)的程序包括使数控(NC)机床进行操作 和机加工中最常用的一系列指令。 ① consist of表示为“包含”的意思 ② that引导的从句修饰前面的directions ③ machining是一个名词,表示 “制造”的意思 ④ being是一个分词短语结构形式

● 10.4

Exercise:Translate the Following Paragraphs

Numerical control may be defined as a method of accurately managing the movement of machine tools by a series of programmed numerical data which activate the motors of the machine tool. There is nothing complex or magical about this system. It is based on the simple fundamental that combines automatic measurement of machine table slide will move with a series of programmed instructions.

● Lesson

11

Introduction to Heat Pipe Technology in Machining Process

●11.1

Text

Forging
In any machining processes, most of the input energy is converted into heat in the cutting zone. This results in increases in tool and work-piece temperatures. Elevated temperature can significantly shorten the tool life. Excessive heat accumulated in the tool and work-piece can contribute to thermal distortion and poor dimensional control of the workpiece. In addition, high tool temperatures promote the formation of BUE (built-up edge) on the tool tip.

(a)

(b) Fig.11.1 (a) Schematic of a Heat Pipe, (b) Location of Heat Pipe Inside Drill

Fig.11.2 Drilling Temperatures in the Tip

Fig.11.3 Effect of l/L Ratio

Fig.11.4 Effect of change of d/D

● 11.2

Words and phrases
切削区域 工件,工作件 热变形,热扭曲 切削液 附加的,添加的; 添加剂 [化]硫磺;vt. 用硫磺处理 [化]氯 [化]磷 乳状液; [摄]感光乳剂 低温学的,低温存储的 半月板,(液柱的)弯月面

cutting zone workpiece thermal distortion cutting fluid additive sulfur chlorine phosphorus emulsion cryogenic meniscus

n. adj. n. n. n. n. n. adj. n.

● 11.3

Complex Sentence Analysis

[1] In a drilling process, tool temperatures are particularly important because the chips, which absorb much of the cutting energy, are generated in a confined space and remain in contact with the tool for a relatively long time compared with any other machining operation. ① which absorb much of the cutting energy,非限 制性定语从句修饰chips。 ② compared with any other machining operations, 过去分词作定语修饰time,试比较: The approaches proved by the experiments in the lab have been widely employed in industries.

[2] In order for machining process to run dry, an effective cooling method, other than flooding by a coolant, is desirable to remove the heat accumulated in drill tool. ① machining process to run dry,干式机械加工过程,run 为连系动词,dry作表语。 ② other than:与??不同;与??不同方式 You can’t get there other than by swimming. [3] From the heat transfer point of view, the authors Jen et al. did much work to prove the feasibility and effectiveness of the heat pipe in the drilling operation. ① From the heat transfer point of view:从传热的角度。 ② From?point of view:从??的角度。试比较,froma static point of view, from dynamic point of view.

● 11.4

Exercise:Translate the Following Paragraphs

The operation of a heat pipe can be analyzed using a fundamental thermodynamic cycle for the working fluid, in which the thermal energy is converted to kinetic energy. The basic thermodynamic cycle can be studied using a temperature-entropy diagram. As expected from the second law, the conversion of the thermal energy to kinetic energy is associated with heat rejection at a temperature below the high temperature reservoir in the system where the efficiency is less than 100%. Note that a heat pipe can never be completely isothermal because this would violate the second law.

● Lesson
●12.1

12

Introduction of Material Forming

Text

Material Forming Processes as a System

The term material forming refers to a group of manufacturing methods by which the given shape of a workpiece (a solid body) is converted to another shape without change in the mass or composition of the material of the workpiece.

Cold Forming and Hot Forming [2]By applying a stress that exceeds the original yield strength of metallic material, we have strain hardened or cold worked the metallic material,while simultaneously deforming it. This is the basis for many manufacturing techniques, such as wire drawing. Fig.12.1 illustrates several manufacturing processes that make use of both cold-working and hot-working processes.

Fig.12.1 Metal Forming Processes That Make Use of Cold Working As Well As Hot Working

Principles of Plastic Forming Plasticity theory is the foundation for the numerical treatment of metal forming processes. Materials science and metallurgy can explain the origins of the plastic state of metallic bodies and its dependence on various parameters,such as process speed,prior history,temperature,and so on. The essentially older plasticity theory deals with the calculation of stresses,forces,and deformation.

Methods Used in Material Forming The following classification of the deformation methods into five groups is based mainly on the important differences in effective stresses. No simple descriptions of stress states are possible since,depending on the kind of operation,different stress states may occur simultaneously,or they may change during the course of the deforming operation. Therefore,the predominant stresses are chosen as the classification criteria.

● 12.2

Words and phrases

synonymously cohesion

adv. 同义地 n. 结合,凝聚,[物理]内聚力结

合 subassembly n. 部件,组件 impregnate v. 使充满,注入,灌输 galvanise v .& n. <英=galvanize > 电镀 foil n. 箔,金属薄片,烘托,衬托;v. 贴箔于??,衬托,阻止 substrate n. (=substratum)底层,下层, [地]底土层,基础 deliberately adv. 有目的地,故意地 metallurgy n. 冶金, 冶金学,冶金术 macroscopically adv. 宏观上

recovery n. 回复 recrystallization n. 再结晶 tangled adj 紊乱的;复杂的 dislocation n. 位错 polygonized subgrain structure 多边形亚晶结构 grain growth 晶粒长大 predominant adj. 支配的,主要的,突出的 shearing stress 剪应力

● 12.3

Complex Sentence Analysis

[1] These methods include changing the orientation of micro-particles as well as their introduction and removal,such as by diffusion, that is,rearranging,adding,or removing particles ① as well as:和、还有 这些方法包括改变微粒的取向,以及通过扩散产生或消 除这些微粒,即重排、增加或消除微粒。 ② rearranging:重排

[2] By applying a stress that exceeds the original yield strength of metallic material,we have strain hardened or cold worked the metallic material,while simultaneously deforming it. ① have strain hardened:产生形变硬化 ② while simultaneously:而同时 [3] Plasticity is the capacity of a material to change its shape permanently under the action of forces when the corresponding stress state reaches a material-dependent critical magnitude called yield strength or initial flow stress ① under the action of:在??作用下 ② critical magnitude:临界值 ③ flow stress:流变应力

● 12.4

Exercise:Translate the Following Paragraphs

The so-called ceramic group of cutting tools represents the most recent development in cutting tool materials. They consist mainly of sintered oxides, usually aluminum oxide, and are almost invariably in the form of clamped tips. Because of the comparative cheapness of ceramic tips and the difficulty of grinding them without causing thermal cracking, they are made as throw-away inserts.

Ceramic tools are a post-war introduction and are not yet in general factory use. Their most likely applications are in cutting metal at very high speeds, beyond the limits possible with carbide tools. Ceramics resist the formation of a built-up edge and in consequence produce good surface finishes. Since the present generation of machine tools is designed with only sufficient power to exploit carbide tooling, it is likely that, for the time being, ceramics will be restricted to highspeed finish machining where there is sufficient power available for the light cuts taken. The extreme brittleness of ceramic tools has largely limited their use to continuous cuts, although their use in milling is now possible.

● Lesson

13

Material Forming Processes

●13.1 Text In this section, a short description of the process examples about material forming will be given. But assembly and joining processes are not described here. Forging Forging can be characterized as: mass conserving, solid state of work material (metal), and mechanical primary basic process-plastic deformation. [1]Technically, forging may be defined as the process of giving metal increased utility by shaping it, refining it, and improving its mechanical properties through controlled plastic deformation under impact or pressure.

Rolling Rolling can be characterized as: mass conserving, solid state of material, mechanical primary basic process-plastic deformation. Rolling is extensively used in the manufacturing of plates, sheets, structural beams, and so on. Fig.13.1 (b) shows the rolling of plates or sheets. An ingot is produced in casting and in several stages it is reduced in thickness, usually while hot. Since the width of the work material is kept constant, its length is increased according to the reductions. After the last hot-rolling stage, a final stage is carried out cold to improve surface quality and tolerances and to increase strength. In rolling, the profiles of the rolls are designed to produce the desired geometry.

Powder Compaction Powder compaction can be characterized as: mass conserving, granular state of material, mechanical basic process-flow and plastic deformation. In this context, only compaction of metal powders is mentioned, but generally compaction of molding sand, ceramic materials, and so on, also belong in this category. Casting Casting can be characterized as: mass conserving, fluid state of material, mechanical basic processfilling of the die cavity. Casting is one of oldest manufacturing methods and one of the best known processes. The material is melted and poured into a die cavity corresponding to the desired geometry [as shown in Fig. 13.1(d)].

Fig.13.1 Mass-conserving Processes in the Solid State of the Work Material

Turning Turning can be characterized as: mass reducing, solid state of work material, mechanical primary basic process-fracture. The turning process, which is the best known and most widely used mass-reducing process, is employed to manufacture all types of cylindrical shapes by removing material in the form of chips from the work material with a cutting tool [as shown in Fig.13.2(a)]. The work material rotates and the cutting tool is fed longitudinally. The cutting tool is much harder and more wear resistant than the work material. A variety of types of lathes are employed, some of which are automatic in operation. The lathes are usually powered by electric motors which, through various gears, supply the necessary torque to the work material and provide the feed motion to the tool.

EDM Electrical discharge machining (EDM) can be characterized as: mass reducing, solid state of work material, thermal primary basic process-melting and evaporation [as shown in Fig.13.2 (d)]. In EDM, material is removed by the erosive action of numerous small electrical discharges (sparks) between the work material and the tool (electrode), the latter having the inverse shape of the desired geometry. [3]Each discharge occurs when the potential difference between the work material and the tool is large enough to cause a breakdown in the fluid medium, fed into the gap between the tool and work piece under pressure, producing a conductive spark channel. The fluid medium, which is normally mineral oil or kerosene, has several functions.

ECM Electrochemical machining (ECM) can be characterized as:mass reducing, solid state of work material, chemical primary basic process-electrolytic dissolution [as shown in Fig.13.2 (e)]. Electrolytic dissolution of the work piece is established through an electric circuit, where the work material is made the anode, and the tool, which is approximately the inverse shape of the desired geometry, is made the cathode. The electrolytes normally used are waterbased saline solutions (sodium chloride and sodium nitrate in 10%~30% solutions).

Flame Cutting Flame cutting can be characterized as: mass reducing, solid state of work material, chemical primary basic process-combustion [as shown in Fig.13.2 (f)]. In flame cutting, the material (a ferrous metal) is heated to a temperature where combustion by the oxygen supply can start. Theoretically, the heat liberated should be sufficient to maintain the reaction once started, but because of heat losses to the atmosphere and the material, a certain amount of heat must be supplied continuously. A torch is designed to provide heat both for starting and maintaining the reaction. Most widely used is the oxyacetylene cutting torch, where heat is created by the combustion of acetylene and oxygen.

Fig.13.2 Mass-reducing Processes in the Solid State of the Work Material

Fine Blanking Fine blanking is a technique used for production of blanks perfectly flat and with a cut edge which is comparable to a machined finish. This quick and easy process is worthy of serious thought when the number of parts justifies the cost of a blanking tool especially when consideration is given to the fact that operations such as shaving are eliminated.

● 13.2

Words and phrases

squeeze ingot profile ceramic sintering oxidation solidification longitudinal erosive dissolution electrolyte sodium chloride sodium nitrate ferrous oxyacetylene

v. 压榨,挤,挤榨 n. [冶]锭铁,工业纯铁 n. 剖面,侧面,外形,轮廓 adj. 陶器的 v. 烧结 n. [化]氧化 n. 凝固 adj. 经度的,纵向的 adj. 侵蚀性的,腐蚀性的 n. 分解,解散 n. 电解,电解液
氯化钠 硝酸钠 adj. 含铁的,[化]亚铁的 adj. [化]氧乙炔的

acetylene combustible plasma fine blanking cut edge clearance shaving punch

n. [化]乙炔,电石气 adj. 易燃的 n. [物]等离子体,等离子区
精密冲裁 剪切刃 n. 间隙;(公差中的)公隙 n. 刨削;修整 n. 冲头,凸模; 冲压机,冲床,打孔机 vt. 冲孔,打孔 n. 落料件 冲孔 n. 模具;凹模

blank producing hole die

● 13.3

Complex Sentence Analysis

[1] Technically, forging may be defined as the process of giving metal increased utility by shaping it, refining it, and improving its mechanical properties through controlled plastic deformation under impact or pressure. ① be defined as:被定义为?? ② under impact or pressure:在冲击力或压力的作用 下 [2] Excess material is squeezed out between the die faces at the periphery as flash, which is removed in a later trimming process. ① which:引导定语从句,修饰excess material。 ② flash:飞边。 ③ trimming process:切边、清理过程。

[3] Each discharge occurs when the potential difference between the work material and the tool is large enough to cause a breakdown in the fluid medium, fed into the gap between the tool and work piece under pressure, producing a conductive spark channel. ① when:引导时间状语从句修饰occurs。 ② fed into?:从句修饰fluid medium。

● Lesson
●14.1

14

Introduction to Mould

Text

Mould is a fundamental technological device for industrial production. Industrially produced goods are formed in moulds which are designed and built specially for them. The mould is the core part of manufacturing process because its cavity gives its shape. There are many kinds of mould, such as casting & forging dies, ceramic moulds, die-casting moulds, drawing dies, injection moulds, glass moulds, magnetic moulds, metal extruding moulds, plastic and rubber moulds, plastic extruding moulds, powder metallurgical moulds, compressing moulds, etc.

Compression Moulding Compression moulding is the least complex of the moulding processes and is ideal for large parts or low-quantity production. For lowquantity requirements it is more economical to build a compression mould than an injection mould. Compression moulds are often used for proto-typing, where samples are needed for testing fit and forming into assemblies. This allows for further design modification before building an injection mould for high-quantity production. Compression moulding is best suited for designs where tight tolerances are not required.

Fig.14.1 A Compression Mould 1. top plate;2. opening bar slot;3. handle; 4. dowel pin & bushing;5. flash & tear trim gate; 6. part cavity;7. bottom plate.

Injection Moulding Injection moulding is the most complex of the moulding processes. Due to the more complex design of the injection mould, it is more expensive to purchase than a cast or compression mould. [1]Although tooling costs can be high, cycle time is much faster than other processes and the part cost can be low, particularly when the process is automated. [2]Injection moulding is well suited for moulding delicately shaped parts because high pressure (as much as 29 000psi) is maintained on the material to push it into every corner of the mould cavity.

(a) Horizontal Type (b) Vertical Type Fig.14.2 An Injection Mould
1. injection runner;2. nozzle bushing;3. stripper bolt; 4. top plate;5. sprue;6. opening bar slot; 7. bottom plate;8. flash & tear trim gate; 9. part cavity;10. dowel pin and bushing; 11. ejector;12. fixed plate;13. movable plate.

Cast Moulding There are two types of casting, open casting and pressure casting. With open casting, the liquid mixture is poured into the open cavity in the mould and allowed to cure. With pressure casting, the liquid mixture is poured into the open cavity, the cap is put in place and the cavity is pressurized. Pressure casting is used for more complex parts and when moulding foam materials.

Extrusion Moulding Although extrusion moulds are quite simple the extrusion moulding process requires great care in the setting up and manufacture and final processing to ensure consistency of product. Pressure is forced through the die plate that has the correct profile cut into it. Variations in feed rate, temperature and pressure need to be controlled.

● 14.2

Words and phrases

mould n. 模具,模(型),模塑,压模 cavity n. 模腔,型腔,空洞 die n. 模(子,片,具),压模,塑模 casting & forging die 铸、锻模 ceramic mould 陶瓷模 die-casting mould 压铸模 drawing die 拉丝模 injection mould 注塑模 magnetic mould 磁铁成形模 extruding mould 挤压成形模 powder metallurgical mould 粉末冶金模 compressing mould 冲压模 moulding n. 成型

proto-typing assembly tolerance affordable fasten secure ejector runner sprue parting line core cure

n. n. adj. v. v. n. n. n. n. v.

初始制模 装配件,组件 公差,容许 提供得起的 连接,固定,夹紧 固定,紧固 脱模销,推顶器 浇道,流道 流道,浇道 合模线,拼缝线 模芯,中间层 固化,塑化

urethane n. abrasion n. flex fatigue insert n. pin n. tool steel maraging steel porosity n. venting hole evacuate v. autoclave n. salt bath curing system silicone extrusion

聚氨酯 磨蚀,磨损 弯曲疲劳 插件,嵌件 销,杆 工具钢 马氏体时效钢 多孔性,有孔性 排气孔,通风孔 排出,抽空 高压釜 盐浴固化系统 硅橡胶挤压

● 14.3

Complex Sentence Analysis

[1] Although tooling costs can be high, cycle time is much faster than other processes and the part cost can be low, particularly when the process is automated. ① tooling costs:模具成本 ② particularly when the process is automated:条 件状语从句放在后面,用于进一步说明,译为:尤其当工 艺过程为自动操作时 [2] Injection moulding is well suited for moulding delicately shaped parts because high pressure (as much as 29000psi) is maintained on the material to push it into every corner of the mould cavity.

① is well suited for:最适合用于 ② delicately shaped parts:外形精致的零件 ③ psi:英制压力单位,磅/平方英寸 [3] Since the mould materials have no natural porosity and the molten metal rapidly flows into the mould during injection, venting holes and passageways must be built into the moulds at the parting line to evacuate the air and gases in the cavity.

① since引导状语从句,表示原因,译为由于?? ② venting hole:排气孔 ③ parting line:合模线 [4] Although extrusion moulds are quite simple the extrusion moulding process requires great care in the setting up and manufacture and final processing to ensure consistency of product. ① in the setting up and manufacture and final processing:在建立、制造和最终加工过 程中 ② to ensure consistency of product:以确保产品 的一致性,表示目的

● 14.4

Exercise:Translate the Following Paragraphs

The most common types of moulds used in industry today are (1) two-plate moulds, (2) three-plate moulds, (3) side-action moulds, and (4) unscrewing moulds. A two-plate mould consists of two active plates, into which the cavity and core inserts are mounted. In this mould type, the runner system, sprue, runners, and gates solidify with the part being moulded and are ejected as a single connected item. Thus the operation of a two-plate mould usually requires continuous machine attendance.

● Lesson
15.1 Text

15

Mould Design and Manufacturing

CAD and CAM are widely applied in mould design and mould making. [1]CAD allows you to draw a model on screen, then view it from every angle using 3-D animation and, finally, to test it by introducing various parameters into the digital simulation models. CAM, on the other hand, allows you to control the manufacturing quality. The advantages of these computer technologies are legion: shorter design times (modifications can be made at the speed of the computer), lower cost, faster manufacturing, etc. This new approach also allows shorter production runs, and to make last-minute changes to the mould for a particular part. Finally, also, these new processes can be used to make complex parts.

Computer-Aided Design (CAD) of Mould Traditionally, the creation of drawings of mould tools has been a time-consuming task that is not part of the creative process. Drawings are an organizational necessity rather than a desired part of the process. Computer-Aided Design (CAD) means using the computer and peripheral devices to simplify and enhance the design process. CAD systems offer an efficient means of design, and can be used to create inspection programs when used in conjunction with coordinate measuring machines and other inspection equipment. CAD data also can play a critical role in selecting process sequence.

A CAD system consists of three basic components: hardware, software, users. The hardware components of a typical CAD system include a processor, a system display, a keyboard, a digitizer, and a plotter. The software component of a CAD system consists of the programs which allow it to perform design and drafting functions. The user is the tool designer who uses the hardware and software to perform the design process.

Detailing the functional components and adding the standard components complete the mould (as shown in Fig.15.1). This all happens in 3-D. Moreover, the mould system provides functions for the checking, modifying and detailing of the part. Already in this early stage, drawings and bill of materials can be created automatically.

Fig.15.1 3-D Solid Model of Mould

Through the use of 3-D and the intelligence of the mould design system, typical 2-D mistakes— such as a collision between cooling and components/cavities or the wrong position of a hole—can be eliminated at the beginning. [2]At any stage a bill of materials and drawings can be created—allowing the material to be ordered on time and always having an actual document to discuss with the customer or a bid for a mould base manufacturer.

Computer-Aided Manufacturing (CAM) of Mould One way to reduce the cost of manufacturing and reduce lead-time is by setting up a manufacturing system that uses equipment and personnel to their fullest potential. The foundation for this type of manufacturing system is the use of CAD data to help in making key process decisions that ultimately improve machining precision and reduce non-productive time. This is called as computer-aided manufacturing (CAM). [3]The objective of CAM is to produce, if possible, sections of a mould without intermediate steps by initiating machining operations from the computer workstation.

● 15.2

Words and phrases

animation n. 动画 digital simulation model 数字模拟模型 legion n. 多,大批,无数 peripheral adj. 外围的,周边的 split adj. 分割的,对分的 run-off n . 流出口,流放口 shut-off n. 截流,断流 ejection system 脱模系统,缷料装置 collision n. 打击,碰撞 tedious adj. 沉闷的 lead-time n. 研制周期 tool-path n. 方法路径 CNC 计算机数字控制 redundant adj. 多余的,冗余的 in a nutshell 总之

● 15.3 Complex Sentence Analysis [1] CAD allows you to draw a model on screen, then view it from every angle using 3-D animation and, finally, to test it by introducing various parameters into the digital simulation models (pressure, temperature, impact, etc.). ① draw,view和test表示3个并列的操作。 ② digital simulation model:数字模拟模型。 [2] At any stage a bill of materials and drawings can be created—allowing the material to be ordered on time and always having an actual document to discuss with the customer or a bid for a mould base manufacturer. ① a bill of materials:材料清单。 ② allowing和having引导两个现代分词短语,做伴随状 语。

[3] The objective of CAM is to produce, if possible, sections of a mould without intermediate steps by initiating machining operations from the computer workstation. ① if possible:插入语,译成:如可能,是if it is possible的省略语,试比较: If possible, I will visit you in Chicago next month. I will lend you some money to help you with the present difficulty if possible. ② by:通过??方式。

[4] With the emphasis in the mould making industry today on producing moulds in the most efficient manner while still maintaining quality, mould makers need to keep up with the latest software technologies-packages that will allow them to program and cut complex moulds quickly so that mould production time can be reduced. ① with:译为:随着??,引导的介词短语作状语,修 饰整个句子。试比较: With the development of the economy in China, the people around the country are living a happy life. ② in the most efficient manner饰producing moulds。 ③ keep up with:紧跟。 ④ that:在这里引导了一个宾语从句,修饰前面的 software technologies-packages。

● 15.4

Exercise:Translate the Following Paragraphs

A key decision early in mold making process is determining what machining operations will be used and in what order. Machining considerations should be analyzed during the development of the CAD model. If this isn’t done, the programmer may not be able to use certain machining strategies. Each of the processes has advantages and disadvantages when producing a close tolerance mould. The proper selection of process and sequence of process will not only result in more precise dimensional control, but also will reduce manufacturing time by reducing bench work.

● Lesson
16.1 Text

16

Heat Treatment of Metal

The generally accepted definition for heat treating metals and metal alloys is “heating and cooling a solid metal or alloy in a way so as to obtain specific conditions and/or properties.” Heating for the sole purpose of hot working (as in forging operations) is excluded from this definition. Likewise, the types of heat treatment that are sometimes used for products such as glass or plastics are also excluded from coverage by this definition.

Transformation Curves The basis for heat treatment is the timetemperature-transformation curves or TTT curves where, in a single diagram all the three parameters are plotted. Because of the shape of the curves, they are also sometimes called Ccurves or S-curves. To plot TTT curves, the particular steel is held at a given temperature and the structure is examined at predetermined intervals to record the amount of transformation taken place. [1]It is known that the eutectoid steel (T8) under equilibrium conditions contains, all austenite above 727℃, whereas below, It is pearlite.

Classification of Heat Treating Processes In some instances, heat treatment procedures are clear cut in terms of technique and application. whereas in other instances, descriptions or simple explanations are insufficient because the same technique frequently may be used to obtain different objectives. For example, stress relieving and tempering are often accomplished with the same equipment and by use of identical time and temperature cycles. The objectives, however, are different for the two processes.

The following descriptions of the principal heat treating processes are generally arranged according to their interrelationships.

Fig.16.1 Isothermal Decomposition Diagram of T8 Steel

● 16.2

Words and phrases

forge eutectoid austenite pearlite martensitic stress relieving tempering normalizing ferrous alloy transformation still full annealing notably austenitize denote

v. 锻造 adj. 共析的 n. 奥氏体 n. 珠光体 adj. 马氏体的
消除应力,低温退火 n. 回火 n. 常化,正火 铁合金 n. 变换,转换,相变 adj. 不动的,静止的 完全退火 adv. 显著地,特别是 v. 奥氏体化,使成奥氏体 v. 指示,表示,概述

machinability facilitation in-process qualification quenching brine caustic aqueous warp glossary quench-hardened process annealing fog quenching hot quenching

n. 切削加工性,机械加工性能 n. 便于 adj. (加工、处理)过程中的 n. 资格,条件,限制,限定 n. 淬火 n. 盐水 adj. 腐蚀性的,碱性的 adj. 水的,水成的 n. 翘曲,变形 n. 词汇表,术语汇编 adj. 淬火硬化的
工序间退火,中间退火 喷雾淬火 高温淬火,热淬火

● 16.3

Complex Sentence Analysis

[1] It is known that the eutectoid steel (T8) under equilibrium conditions contains, all austenite above 727℃, whereas below, it is pearlite. 共析钢(T8)在平衡条件下,在727℃以上时全为奥氏体, 低于此温度则为珠光体。 ① that:引导主语从句。 ② eutectoid steel:共析钢。 ③ below指低于727℃。 [2] These points are then plotted on a graph with time and temperature as the axes. with time and temperature as the axes:以时间和 温度为坐标轴。

● 16.4

Exercise:Translate the Following Paragraphs

Carburizing consists of absorption and diffusion of cartoon solid ferrous alloys by heating to some temperature above the upper transformation temperature of the specific alloy. Temperatures used for carburizing are generally in the range of 1650°F of to 1900°F (900℃ to 1040℃). Heating is done in a carbonaceous environment (liquid, solid, or gas). This produces a carbon gradient extending inward from the surface, enabling the surface layers to be hardened to a high degree either by quenching from the carburizing temperature or by cooling to room temperature followed by reaustenitizing and quenching.

● Lesson
17.1 Text

17

Virtual Manufacturing

What is Virtual Manufacturing [1]Virtual manufacturing (VM) is an integrated, synthetic manufacturing environment exercised to enhance all levels of decision and control in a manufacturing enterprise. VM can be described as a simulated model of the actual manufacturing setup which may or may not exist. It holds all the information relating to the process, the process control and management and product specific data. It is also possible to have part of the manufacturing plant be real and the other part virtual. Virtual manufacturing is the use of computer models and simulations of manufacturing process to aid in design and production of manufactured products.

What is the Significance of VM VM aims at providing an integrated environment for a number of isolated manufacturing technologies such as Computer Aided Design, Computer Aided Manufacturing, and Computer Aided Process Planning, thus allowing multiple users to concurrently carry out all or some of these functions without the need for being physically close to each other. For example, a process planning engineer and a manufacturing engineer can evaluate and provide feedback to a product designer, who may be physically located in another state or country, at the same time as the design is being conceived.

Applications of VM Application of VM encompass the entire life cycle of a product. Reported developments include a virtual space decision support system by Imamura and Nomura[1994] at the Matsushita company in Japan. This system applied towards the marketing and sales of kitchen furniture, allows customers to experience a kitchen environment and evaluate alternatives and select the best combination according to preferences. Their preferences are stored as drawings and subsequently transferred to the company’s production facilities.

● 17.2

Words and phrases
虚拟制造 adj. 人造的,综合的,假想的 n. 范例,式样 虚拟现实 adv. 反(重)复,迭代 虚拟企业 v. 使成形,装配,配置 adj. (有关)多种学科的 n. 撞,冲突,抵触 adj. 人类工程(学),人机学的 n. 基础(结构),基本设施 n. 履带(式)车,履带式挖土机 n. 推土机

virtual manufacturing synthetic paradigm Virtual Reality iteratively Virtual Enterprise configure multi-disciplinary collision ergonomic(al) infrastructure caterpillar bulldozer

● 17.3

Complex Sentence Analysis

[1] Virtual manufacturing (VM) is an integrated, synthetic manufacturing environment exercised to enhance all levels of decision and control in a manufacturing enterprise. Exercised:运用的:使用的,做后置定语,修饰 environment。 [2] Design-centered VM:provides designers with the tools to design products that meet design criteria such as design for X. ① to design products that meet design criteria such as design for X 动词不定式短语做定语修饰tools。 ② provide A with B同provide B for A:把B提供给A。 e.g. Parents provide us with food and clothing. 父母亲向我们提供吃、穿所用的一切。

[3] Control-centered VM:allows the evaluation of product design, production plans, and control strategy and a means to iteratively improve all of them through the simulation of the control process. Means:方法,手段,即可指单数,又可指复数;如果作 主语,应根据意思来决定其谓语动词用单数还是用复数。 All means have been tried. 所有的办法都尝试过了。 [4] The principal advantage of this technology is its ability to provide a multi-media environment, enhancing communication at all levels in a product’s life cycle. ① to provide a multi-media environment作定语修饰 前面的ability。 ② enhancing communication at all levels in a product’s life cycle为现在分词短语做目的状语。

● 17.4

Exercise:Translate the Following Paragraphs

Kinematic simulation or animation can be an important CAD/CAM capability in certain settings. Through animation, users can design a product or a process that involves moving components and analyze its behavior without having to build prototypes and conduct live trial runs. For example, mechanical linkage designs have historically been difficult because testing their actual behavior has required engineers to build models or prototypes. In such a setting, engineers frequently resort to building cardboard or wooden models, a time-consuming process. With animation, a computer model can be quickly built and displayed. By watching the computer screen, the engineer can easily see how the linkage performs. Other useful applications of animation are in analyzing the performance of a robot in a cell or automated guided vehicles (AGV) on the shop floor. By simulating the planned behavior of a robot or an AGV, engineers and manufacturing personnel can spot and correct problems before implementing a live setting.

● Lesson
●18.1

18

Fluid and Hydraulic system

Text

The history of hydraulic power is a long one, dating from man’s prehistoric efforts to harness the energy in the world around him. The only sources readily available were the water and the wind—two free and moving streams. The watermill, the first hydraulic motor, was an early invention. One is pictured on a mosaic at the Great Palace in Byzantium, dating from the early fifth century. The mill had been built by the Romans. But the first record of a watermill goes back even further, to around 100 BC, and the origins may indeed have been much earlier.

Fig.18.1 gives a diagrammatic presentation of the components of a hydraulic installation. [4]Electrically driven oil pressure pumps establish an oil flow for energy transmission, which is fed to hydraulic motors or hydraulic cylinders, converting it into mechanical energy. The control of the oil flow is by means of valves. The pressurized oil flow produces linear or rotary mechanical motion. The kinetic energy of the oil flow is comparatively low, and therefore the term hydrostatic driver is sometimes used. There is little constructional difference between hydraulic motors and pumps. Any pump may be used as a motor .The quantity of oil flowing at any given time may be varied by means of regulating valves (as shown in Fig.18.1) or the use of variable-delivery pumps.

Fig.18.1 Speed-control Methods for Hydraulic Motors

The application of hydraulic power to the operation of machine tools is by no means new, though its adoption on such a wide scale as exists at present is comparatively recent. It was in fact the development of the modern self-contained pump unit that stimulated the growth of this form of machine tool operation. Hydraulic machine tool drive offers a great many advantages. One of them is that it can give infinitely-variable speed control over wide ranges. In addition, they can change the direction of drive as easily as they can vary the speed. As in many other types of machine, many complex mechanical linkages can be simplified or even wholly eliminated by the use of hydraulics

● 18.2

Words and phrases
液压系统 位移,转移,置换 层,层次 切线的,切向的 牛顿的,牛顿学说的 非线性的,非直线的 旋转的,转动的,循环的 可压缩的,可压榨的 帕斯卡定律 入口,进口,进入量 油箱,水箱,池塘 蓄水池,水箱,蓄能器

hydraulic system displacement layer tangential Newtonian nonlinear rotational compressible Pascal’s law intake tank reservoir

n. n. adj. adj. adj. adj. adj. n. n. n. n.

atmospheric discharge

adj. 大气的,空气的 n. 卸货,出料,流出; vi.

pressurize prehistoric harness watermill mosaic domestication preference compact diagrammatic

v. adj. v. n. n. n. n. adj. adj.

卸下,放出 增压,给??加压 史前的,很久以前的 利用(风等)作动力,治理,控 制 水车,水磨 镶嵌细工,马赛克 家养,驯养 优先选择 紧凑的,紧密的,简洁的 图表的,概略的

intersect disposition helical gear spur gear worm bevel gear hourglass V-belt splice pulley groove tractive

v . n. n. n n. n. n. adi.

交叉 排列,配置 螺旋齿轮 正齿轮 蜗轮,蜗杆 伞形齿轮 沙漏 V型带 连接 (皮带)轮 沟,槽 牵引的,曳引的

oil pressure pump hydraulic motor hydraulic cylinder kinetic energy hydrostatic driver variable-delivery pump by no means self-contained adj. stimulate v. hydraulics n. resilience n. virtue n. detriment n. regrind v.

油泵 液压电机 油缸 动能 静压传动 变量泵 决不?? 独立的,配套的,整体的 促进,激励 水力学,液压系统 跳回,恢复力,回弹 优点,效力,功能 损害,不利 重磨

stimulate hydraulics resilience virtue detriment regrind

v. n. n. n. n. v.

促进,激励 水力学,液压系统 跳回,恢复力,回弹 优点,效力,功能 损害,不利 重磨

● 18.3

Complex Sentence Analysis

[1] The history of hydraulic power is a long one, dating from man’s prehistoric efforts to harness the energy in the world around him. ① dating from: 从什么时候开始 ② prehistoric efforts:很久以前的努力 [2] In Newtonian fluid there is a linear relation between the magnitude of applied shear stresses and the resulting rate of angular deformation. ① between:在两者之间 ② applied shear stresses:作用的剪切应力 ③ the resulting rate:总的合率(量)

[3] All hydraulic systems depend on Pascal’s law, named after Braise Pascal, who discovered the law. ① depend on:遵循于 ② named after:根据??命名的 ③ who discovered the law. 是非限定性定语从句, 修饰Braise Pascal [4] Electrically driven oil pressure pumps establish an oil flow for energy transmission, which is fed to hydraulic motors or hydraulic cylinders, converting it into mechanical energy. ① which is fed to hydraulic motors or hydraulic cylinders中的which是指oil flow ② converting?into?指“转换(形式)”的意思

● 18.4

Exercise:Translate the Following Paragraphs

Compressors are used in petrochemical plants to raise the static pressure of air and process gases to levels required to overcome pipe friction, effect a certain reaction at the point of final delivery, or to impart desired thermodynamic properties to the medium compressed. These compressors come in a variety of sizes, types, and models, each of which fulfills a given need and is likely to represent the optimum configuration for a given set of requirements.

● Lesson 19 Product Test

Fluid and Hydraulic system

Product test can be thought of as the culmination of all process control work. It can also be thought of as a quality check of the inspection process itself. If the quality plan is adequate and carried out properly, then the product’s performance should have been verified and a total test is redundant. For this reason, a test of the completed product is often nothing more than a contractual requirement that must be performed before the customer accepts the product. But product test is also more than proving. And testing to whole is equal to the sum of the parts. [1]It allows for gathering data that support the design theory of the product, for interpretations to be made for further improvements in design so that future products will be better than present ones, and for evaluation of design evolution toward better performance costs. In addition, it is a means of verifying design, since not all design parameters can be fully calculated or predicted. Product test engineers work closely with design engineers to provide useful data for testing. They must also work in close harmony with engineers all other phases of manufacturing. Not infrequently, product testing will turn up deficiencies in design that requires major revisions in manufacturing processes. This is particularly true if the company produces many prototypes and has short production runs. Therefore, manufacturing engineers are as interested in product test’s results as are design engineers. For complex products, product test becomes a very important part of the total process control function. It gives the company a high degree of confidence that the product will perform as the customer expects it to, and this is a valuable marketing tool as it helps to establish the proper reputation with the customers.

Geometric Errors
Geometric errors are defined here as errors in form of individual machine components (e.g., straightness of motion of a linear bearing). Geometric errors are concerned with the quasistatic accuracy of surface, which bear upon the moving relative of the surfaces. Geometric errors can be smooth and continuous (systematic) or they can exhibit hysteresis (e.g., backlash) or random behavior. [2]Many factors affect geometric errors including: surface straightness (see Fig.19.1), surface roughness, bearing preload, kinematics versus elastic design principles and structural design philosophies.

Fig.19.1 Straightness Errors Caused by Surface Form and Finish Errors

Quality Planning
This is the planning and strategy activity of process control, and is sometimes referred to as process planning or inspection planning. The engineers involved develop the plans for checking the adequacy of performance of shop operations to ensure that the final product performs as designed. Using plans and methods produced by measurement of productivity and work measurement (MP&WM) as a guide, quality-planning engineers determine where inspections and nondestructive tests will be specified during the manufacturing process. They also specify the type of inspection or test to be conducted and, based on design engineering requirements, determine what will constitute acceptance or rejection. Normal manufacturing activities produce a certain percentage of deviations from drawing. Some are important, some of little consequence. It is the quality planning engineers’ responsibility to evaluate these deviations and determine what the proper corrective action will be. They then ensure through MP&WM that the corrective actions are factored into manufacturing planning for rework. As the arbiter of quality via the deviation from drawing procedure, quality planning has the database to evaluate performance of the various shop and support functions. A score-keeping function is possible and desirable; in this way quality planning can report to management whether quality levels are improving or declining. Quality status can be reported by statistically evaluating the numbers of deviations and their seriousness. This leads naturally to an evaluation of the cost of doing the repair work caused by the deviation. Repair work, which constitutes manufacturing losses, is an important measurement of organizational quality levels. Manufacturing losses are a significant measure of the adequacy of attention to detail of the operators and their foremen. High losses indicate a poorly managed operation. Quality planning engineers are responsible for setting the manufacturing losses, budgets, and measurements policy.

Quality Control
Quality control has traditionally been the liaison between manufacturing and design. This function interprets design’s specifications for manufacturing and develops the quality plan to be integrated into manufacturing engineering’s methods and planning instructions to operations. Quality control is also responsible for recommending to management what level of manufacturing losses can be tolerated. This is based on the complexity of the product design; specifically the degree of preciseness necessary in tolerances. Quality control traditionally monitors manufacturing losses by setting a negative budget that is not to be exceeded, and establishes routines for measurement and corrective action. Within the past decade or two, quality control has become increasingly involved with marketing and customers in establishing documentation systems to ensure guaranteed levels of product quality. This new role has led to the new title quality assurance, to differentiate it from traditional in-house quality control. Quality assurance strives through documentation of performance and characteristics at each stage of manufacture to ensure that the product will perform at the intended level. Whereas quality control is involved directly with manufacturing operations, quality assurance is involved with the customer support responsibilities generally found within the marketing function. Many industrial organizations have chosen to establish an independent quality assurance sub-function within the manufacturing function and have placed the technical responsibilities of quality control, namely process control, within the manufacturing engineering organization.

● 19.2 Words and Phrases

culmination

n. n.

顶点 缺乏,不足 准静态的

contractual
deficiency quasi-static

adj. 契约的

hysteresis
clearance fit interference fit

n. 滞后作用,[物]磁滞现象
间隙配合 过盈配合

transition fit
liaison n.

过渡配合
联络,(语音)连音

● 19.3 Complex Sentence Analysis [1] It allows for gathering data that support the design theory of the product, for interpretations to be made for further improvements in design so that future products will be better than present ones, and for evaluation of design evolution toward better performance costs. ① it为形式主语,代替support the design theory

② 两个for引导的介词短语引导状语从句
[2] Many factors affect geometric errors including: surface straightness, surface roughness, bearing preload, kinematics versus elastic design principles and structural design philosophies. ① surface straightness表示“平面度”。 ② surface roughness表示“表面粗糙度”。

③ versus elastic design principles(相对于弹性设计原理)介词短 语修饰kinematics(运动学)

● 19.4 Exercise:Translate the Following Paragraphs
Machine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so it will fit into any other machine or mechanism of the same type. To make the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools become worn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For example, a part might be made 6 in. long with a variation allowed of 0.003 in, above and below this size. Therefore, the part could be 5.997 in. to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance.A tolerance is the total permissible variation in the size of a part.The basic size is that size from which limits of size are derived by the application of allowances and tolerances. Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral tolerance is a system of dimensioning where the tolerance (that is variation) is shown in only one direction from the nominal size. Unilateral tolerance allows the changing of tolerance on a hole or shaft without seriously affecting the fit.

● Lesson
●20.1

20

Introduction of Automobile Engine

Text

It is well-known that the automobile is composed of four sections such as engine, chassis, body and electrical system. The engine which is called the “heart” of a vehicle is used to supply power for an automobile. There are various types of engines such as electric engine (motor), steam engine and internal combustion engine (ICE). Generally, an automobile is operated by internal combustion engine. It includes the fuel, lubricating, cooling, ignition and starting systems.

In general, the location relations of engine and driving wheels fall into these: (1) Engine lies in the front of automobile and driving wheels are rear drive type; (2) Engine lies in the front of automobile and driving wheels are front drive type; (3) Engine lies in the rear of automobile and driving wheels are rear drive type; (4) Engine lies in the middle of automobile and driving wheels are rear drive type; (5) full-wheeldrive, etc.

(a) State I (b) State II Fig.20.1 Rotary (Piston) Engine

Fig.20.2 Inline Four-Cylinder Gasoline Engine

● 20.2

Words and phrases
底盘 燃烧 内燃机 点火;点燃 推进, 驱使 点燃式发动机 压燃式发动机 煤油 冲程 奥托循环发动机 进气 转子 内齿圈

chassis n. combustion n. internal combustion engine(ICE) ignition n. propel v. spark-ignition engine compression-ignition engines kerosene n. stroke n. the Otto cycle engine intake n. rotor n. internal ring gear

spark plug stationary pinion eccentric apex seal seal spring crankshaft crank mechanism connecting rod valve train push-rod timing gear camshaft rettery

火花塞 固定齿轮 adj. 古怪;偏心的,偏执的; n. 行为古怪的人 顶端密封条 密封条弹簧 n. 曲轴 曲柄连杆机构 连杆 配气机构 n. 推杆 正时齿轮 n. 凸轮轴 n. 化油器

intake manifold(pipe) muffler(silencer) spout governor radiator distributor cutaway view four-cylinder intake air tank throttle valve catalytic converter jacket oil pan(oil sump) timing belt pulley timing belt cover

n. n. n. n. n.

n.

进气歧管,进气管 消声器 喷口;喷嘴 调速器 散热器 分电器 剖视图 四缸 进气室 节气门 催化转化器 [机]水套 油底壳 正时齿带轮 正时齿带罩

● 20.3

Complex Sentence Analysis

[1] The internal combustion engine burns fuel within the cylinders and converts the expanding force of the combustion or “explosion” into rotary force used to propel the vehicle. ① within the cylinders:作burns的状语 ② convert?into?:把??转换成?? ③ of the combustion or“explosion”:修饰the expanding force [2] In a reciprocating engine, the motion produced from the energy within the fuel moves parts up and down. ① within the fuel moves parts up and down:修饰 energy;up and down上下 ② produced from?:产生于??

● 20.4

Exercise:Translate the Following Paragraphs

Ford’s latest concept car gives shape to the ideas being explored by the New Generation Vehicle Program-the effort by a U.S. consortium to develop the so-called “super car”. The goal is to create an 80-mpg, full-size affordable family sedan and make it available in the coming decade. The car is called Synergy 2010. It’s aluminum body saves some 400 pounds over a comparable-size steel body, bringing curb weight down to about 2200 pounds. The car’s low profile and aerodynamic “fences” (vertical fenders) reflect the need to cut drag to about one-third that of today’s sedans. Power comes from a direct-injection diesel turbo alternator, which uses a flywheel to store energy for acceleration. Electric current produced by the system powers a separate electric motor in each wheel hub, while regenerative braking recharges the flywheel during deceleration. The flywheel-based hybrid drive concept has been under investigation for decades, even at Ford, but problems remain with building a production flywheel system. Likewise the wheel-in-hub motors, which are easy to package but present safety problems in the event of a single-motor failure.

● Lesson
●21.1

21

The Automobile Components

Text

Engine The engine is a power plant, which provides power to drive the automobile. In most automobile engines, the explosive power of the mixture of air and gasoline drives the pistons. The pistons turn a crankshaft to which they are attached. The rotating force of the crankshaft makes the automobile’s wheels turn.

Lubrication System An engine has many moving parts which eventually develop wear, as they move against each other. The engine circulates oil between these moving parts to prevent the metal-to-metal contact that results in wear. Parts that are oiled can move more easily with less friction and hence power loss due to friction is minimized. The secondary function of lubricant is to act as a coolant and also as a sealing medium to prevent leakages. Finally, a film of lubricant on the cylinder walls helps the rings in sealing and thus improves the engine’s compressions.

Cooling System Due to the combustion of fuel with air inside the cylinder, the temperature of the engine parts increases. This increase of temperature directly affects the engine performance and the life of the engine parts. The cooling system keeps the engine operating at the efficient temperature. Whatever the driving conditions, the system is designed to prevent both overheating and overcooling.

Fuel System The main function of the fuel supply system is to provide fuel to the carburetor or injection system at a rate and pressure sufficient to meet engine demands under all conditions of load, speed and gradients encountered by the vehicle. The fuel system must also have enough reserve fuel for several miles of vehicle operation.

Ignition System The purpose of the ignition system is to provide assistance for the combustion of fuel either by a high voltage spark or selfignition in each of the engine’s cylinder at the right time so that the air-fuel mixture can burn completely. The fuel supplied to the combustion chamber must be ignited to deliver power. In a sparkignition engine an electric spark is used for this purpose. The compression-ignition engine does not require a separate ignition system because the ignition is affected by compression of the mixture to a high pressure.

Electrical System The engine’s electrical system provides energy to operate a starting motor and to power all the accessories. The main components of the electrical system are a battery, an alternator, a starting motor, ignition coil and heater.

Frame The frame provides a foundation for the engine and the body of the vehicle. The frame is constructed from square or box-shaped steel members strong enough to support the weight of the body and other components. The automobile frame is usually made up of a number of members welded or riveted together to give the final shape. The engine is mounted on the frame with rubber pads which absorb vibrations and also provide damping of these vibrations. Absorption and damping of vibrations protects passengers from discomfort caused by shocks.

Suspension System The function of the suspension system is to absorb vibrations due to the up and down motion of wheels, caused by the irregularities in the road surface. The springs, connecting linkages, and shock absorber comprise the suspension system of a vehicle. The suspension system is of two types: (1)Rigid system. (2)Independent system. In the rigid system, the road springs are attached to a rigid beam axle. It is mostly used in the front axle of commercial vehicles and in the car axle of all types of vehicles.

Power Train The power train carries the power that the engine produces to the car wheels. It consists of the clutch (on cars with a manual transmission), transmission (a system of gears that increases the turning effort of the engine to move the automobile), drive shaft, differential and rear axle. Clutch A clutch is required with the manual transmission system to temporarily disconnect the engine from wheels. [2]Such disengagement of the power train from the engine is essential while changing the gear ratio or while stopping the vehicle.

Transmission The main function of the transmission is to provide the necessary variation to the torque applied by the engine to the wheels. This is achieved by changing the gearing ratio between the engine output shaft and the drive shaft. Drive Shaft The drive shaft or propeller shaft connects the gearbox and the differential unit. The drive shaft has universal joints at its ends.

Differential The function of the differential is to split the power received from the propeller shaft to the rear axle shaft. It allows the rear wheels to be driven at different speeds when the vehicle takes a bend or falls into a ditch. Axles Axles are the shafts on which road wheels are mounted. The road wheels are provided with the required drive through these axles. Wheels The automobile wheels take the load of the vehicle and also produce tractive force to move the vehicle. The wheels are also used for retardation and for stopping the vehicle.

● 21.2

Words and phrases

accessory circulate coolant leakage sufficient gradient combustion chamber component alternator damping beam power train differential disengagement retardation

n. 附件 v. (使)运行,(使)循环 n. 冷却剂,冷冻剂 n. 漏,泄漏,渗漏 adj. 充分的,足够的 adj. 倾斜的;n. 倾斜度
燃烧室 n. 成分;adj. 组成的 n. 交流发电机 n. 阻尼,减幅,衰减 n. 梁,横梁 动力传动系 n. 差速器,差动装置 n. 脱离 n. 延迟,障碍物,制动

● 21.3

Complex Sentence Analysis

[1] Finally, an electrical system is required to operate the cranking motor that starts the engine and to provide electrical energy to power engine accessories. ① that 引导的定语从句修饰motor。 ② to operate 和to provide 并列作目的状语。 [2] Such disengagement of the power train from the engine is essential while changing or while stopping the vehicle. ① while 引导时间状语从句。 ② gear ratio 表示“速比”

[3] The major requirements in any steering mechanism are that it should be precise and easy to handle, and that the front wheels should have a tendency to return to the straight-ahead position after a turn. ① 两个that引导的是并列表语从句。 ② steering mechanism 表示“转向机制”。 [4] As the load on the vehicle and the vehicle speed has increased according to recent trends, in modern days, the importance of the brake system has also increased and power brakes are now being preferred. ① according to表示“按照”的意思。 ② as引导时间状语从句。

● 21.4

Exercise:Translate the Following Paragraphs

Brakes are required for slowing down or stopping a moving vehicle. The braking system may be operated mechanically or hydraulically. 95 percent of the braking systems in use today are of the hydraulic type. All brakes consist of two members, one rotating and the other stationary. There are various means by which the two members can be brought in contact, thus reducing the speed of the vehicle. The major components of the braking system are: brake pedal, master cylinder,wheel cylinder,brake drum,brake pipe, brake shoes,brake packing plant and linkages. [4]As the load on the vehicle and the vehicle speed has increased according to recent trends, in modern days, the importance of the braking system has also increased and power brakes are now being preferred. Power brakes utilize vacuum and air pressure to provide most of the brake—applying effort.

● Lesson

22

Mechatronics

●22.1 Text Mechatronics was originally coined in 1970s from the integration of two engineering disciplines—mechanics and electronics. [1]More recently, with spectacular advancements in the areas of control and communications, the word mechatronics has been adapted as the synergetic integration of three disciplines:mechanics, control and electronics and is aimed at the study of mainly manufacturing machines controlled by electronics. It is also being viewed as the fusion of mechanical engineering with electronics and intelligent computer control in the design and manufacture of industrial products and processes.

Mechatronics paradigm [3]Mechatronics paradigm deals with benchmarking and emerging problems in engineering, science, and technologies which have not been attacked and solved. This reflects obvious trends in fundamental, applied, and experimental research as well as curriculum changes in response to long-standing unsolved problems, engineering and technological enterprise and entreaties of steady evolutionary demands. Mechatronics is an integrated comprehensive study of intelligent and high performance electromechanical system (mechanisms and processes), intelligent and motion control through the use of advanced microprocessors and DSPs, power electronics and ICs, design and optimization, modeling and simulation, analysis and virtual prototyping, etc.

Fig.22.1 Mechatronics Integrates Electrical, Mechanical and Computer Engineering

Mechatronics paradigm One of the most challenging problems in mechatronics systems design is the development of system architecture,e.g.,selection of hardware and Attempts to design state-of-the-art man-made mechatronics systems and to guarantee the integrated design can be pursued through analysis of complex patterns and paradigms of evolutionary developed biological systems. Recent trends in engineering have increased the emphasis on integrated analysis, design and control of advanced mechanical systems. The scope of mechantromics system has continued to expand, and in addition to actuators, sensors, power electronics, ICs microprocessors, DSPs, as well as input/output devices, many other subsystems must be integrated, even through the basic foundations have been developed, some urgent areas have been downgraded, less emphasized and covered.

The study of high-performance electromechanical systems should be considered as the unified cornerstone of the engineering curriculum through mechatronics. The unified analysis of actuators and sensors, power electronics and ICs, microprocessors and DSPs, advanced hardware and software, have barely been introduced in the engineering curriculum. Mechatronics, as a breakthrough concept in design and analysis of conventional, micro- and nano-scale electromechanical system, was introduced to attack, integrate and solve a great variety of emerging problems. Mechatronics systems, as shown in Fig.22.2, can be classified as (1) conventional mechatronics systems, (2) MEMS, and (3) NEMS.

Fig.22.2 Classification and Fundamental Theories Applied in Mechatronics Systems

● 22.2 Words and Phrases
mechatronics synergetic 机电一体化 adj. 协同的,合作的

fusion
Notion Interdisciplinary paradigm benchmark evolutionary DSP (Digital Signal Processing)

n. 融合
n. 概念,想法 adj. 学科间的 n. 范例 n. 基准,标准 adj. 发展的,演化的 数字信号处理

IC (Integrated Circuit)
Consensus augment

集成电路
n. 一致 v. 增加,扩大

unify
cornerstone

v. 成为一体,统一
n. 基石,基础

● 22.3 Complex Sentence Analysis [1] More recently,with spectacular advancements in the areas of control and communications, the word mechatronics has been adapted as the synergetic integration of three disciplines: mechanics, control and electronics and is aimed at the study of mainly manufacturing machines controlled by electronics. 最近随着控制工程和通信领域的迅猛发展,机电一体化 这个术语已经用于描述机械工程学、控制工程学和电子学 三大学科的集成,其目标主要是研究由电子学所控制的机 械产品的制造。 ① 句中的with表示“随着”的意思。 ② is aimed at表示“目的为”的意思。

[2] In engineering terms, what can be made to emerge is a new and previously unattainable set of performance characteristics. 在工程上,一个新诞生的术语肯定是新的、以前不具有 的一系列性能特征的组合。 ① In engineering terms表示“工程上来说”的意思。 ② what can be made to emerge是一个主语从句。 [3] Mechatronics paradigm deals with benchmarking and emerging problems in engineering, science, and technologies which have not been attacked and solved. 机电一体化范例是处理工程、科学和技术上出现的还没 有破解和解决的基准程序技术和新兴的问题。 ① deals with 表示“处理”的意思。 ② which have not been attacked and solved是一个 定语从句,修饰前面的problems。

[4] Attempts to design state-of-the-art man-made mechatronics systems and to guarantee the integrated design can be pursued through analysis of complex patterns and paradigms of evolutionary developed biological systems. 通过分析复杂的模型和高级的生物系统的范例来设计具 有艺术特性的人造的机电一体化系统,并保证这一集成设 计能继续深入。 ① attempts to 表示“??方面的尝试、??方面的努 力”的意思。 ② state-of-the-art man-made 表示“具有艺术特性的 人造的”的意思。

● 22.4

Exercise:Translate the Following Paragraphs

A mechatronics product such as modern SLR cameras, viedo recorders, music synthesizers, automobiles with engine management systems etc. cannot be designed by a single person; it is simply too complex. Nor can it be designed by a large number of persons with different specializations unless these persons operate in a team manner. It used to be the case that a product containing some mechanical functionality, some electronic sensing and control would be designed sequentially. First the basic mechanical structure would be designed and made by the mechanical engineers. It would then become the job of the electronics engineers to fit it with the appropriate transducers and actuators. Finally the control engineers would be given the job of finding effective controller structures and algorithms to drive it. There are a number of striking examples of the disastrous consequences of this design philosophy when the product is of a high degree of complexity.

● Lesson 23 23.1 Text

Industrial Robots

A robot is an automatically controlled, reprogrammable, multipurpose, manipulating machine with several reprogrammable axes, [1]which may be either fixed in place or mobile for use in industrial automation applications. The key words are reprogrammable and multipurpose because most singlepurpose machines do not meet these two requirements. The term “reprogrammable” implies two things: The robot operates according to a written program, and this program can be rewritten to accommodate a variety of manufacturing tasks. The term “multipurpose” means that the robot can perform many different functions, depending on the program and tooling currently in use.

Over the past two decades, the robot has been introduced into industry to perform many monotonous and often unsafe operations. Because robots can perform certain basic tasks more quickly and accurately than humans, they are being increasingly used in various manufacturing industries.

Structures of Robots
The typical structure of industrial robots consists of 4 major components: the manipulator, the end effector, the power supply and the control system, as shown in Fig.23.1.

Fig.23.1 Structures of Robots

The manipulator is a mechanical unit that provides motions similar to those of a human arm. It often has a shoulder joint, an elbow and a wrist. It can rotate or slide, stretch out and withdraw in every possible direction with certain flexibility. The basic mechanical configurations of the robot manipulator are categorized as cartesian, cylindrical, spherical and articulated. A robot with a cartesian geometry can move its gripper to any position within the cube or rectangle defined as its working volume. Cylindrical coordinate robots can move the gripper within a volume that is described by a cylinder. The cylindrical coordinate robot is positioned in the work area by two linear movements in the X and Y directions and one angular rotation about the Z axis. Spherical arm geometry robots position the wrist through two rotations and one linear actuation. Articulated industrial robots have an irregular work envelope. This type of robot has two main variants, vertically articulated and horizontally articulated.

The end effector attaches itself to the end of the robot wrist, also called end-of-arm tooling. [2]It is the device intended for performing the designed operations as a human hand can. End effectors are generally custom-made to meet special handling requirements. Mechanical grippers are the most commonly used and are equipped with two or more fingers. The selection of an appropriate end effector for a specific application depends on such factors as the payload, environment, reliability, and cost.

The power supply is the actuator for moving the robot arm, controlling the joints and operating the end effector. The basic types of power sources include electrical, pneumatic, and hydraulic. Each source of energy and each type of motor has its own characteristics, advantages and limitations. An ac-powered or dc-powered motor may be used depending on the system design and applications. These motors convert electrical energy into mechanical energy to power the robot. Most new robots use electrical power supply. Pneumatic actuators have been used for high speed, nonservo robots and are often used for powering tooling such as grippers. Hydraulic actuators have been used for heavier lift systems, typically where accuracy was not also required.
The control system is the communications and information-processing system that gives commands for the movements of the robot. It is the brain of the robot; it sends signals to the power source to move the robot arm to a specific position and to actuate the end effector. It is also the nerves of the robot; it is reprogrammable to send out sequences of instructions for all movements and actions to be taken by the robot. An open-loop controller is the simplest form of the control system, which controls the robot only by following the predetermined step-by-step instructions. This system does not have a self-correcting capability. A close-loop control system uses feedback sensors to produce signals that reflect the current states of the controlled objects.

Classification of Robots
Industrial robots vary widely in size, shape, number of axes, degrees of freedom, and design configuration. Each factor influences the dimensions of the robot’s working envelope or the volume of space within which it can move and perform its designated task. A broader classification of robots can been described as below. Fixed-and Variable-Sequence Robots. The fixed-sequence robot (also called a pick-and place robot) is programmed for a specific sequence of operations. Its movements are from point to point, and the cycle is repeated continuously. The variable-sequence robot can be programmed for a specific sequence of operations but can be reprogrammed to perform another sequence of operation. Playback Robot. An operator leads or walks the playback robot and its end effector through the desired path. The robot memorizes and records the path and sequence of motions and can repeat them continually without any further action or guidance by the operator.

Numerically Controlled Robot. The numerically controlled robot is programmed and operated much like a numerically controlled machine. The robot is servo-controlled by digital data, and its sequence of movements can be changed with relative ease.
Intelligent Robot. [3]The intelligent robot is capable of performing some of the functions and tasks carried out by human beings. It is equipped with a variety of sensors with visual and tactile capabilities.

Robot Applications

The robot is a very special type of production tool; as a result, the applications in which robots are used are quite broad. These applications can be grouped into three categories: material processing, material handling and assembly.
In material processing, robots use tools to process the raw material. For example, the robot tools could include a drill and the robot would be able to perform drilling operations on raw material.

Material handling consists of the loading, unloading, and transferring of workpieces in manufacturing facilities. These operations can be performed reliably and repeatedly with robots, thereby improving quality and reducing scrap losses.
Assembly is another large application area for using robotics. An automatic assembly system can incorporate automatic testing, robot automation and mechanical handling for reducing labor costs, increasing output and eliminating manual handling concerns.

Fig.23.2 SCARA Robot for Automatic Assembly

● 23.2 Words and Phrases

reprogrammable

adj. 可重复编程的,可改编的

manipulate
accommodate Monotonous

v. (熟练地)操作, 使用(机器等), 操纵
v. 供应, 供给, 使适应, 调节, 容纳 adj. 单调的, 无变化的

end effector
Elbow wrist stretch out v. Cartesian cylindrical

n. 终端操作机构
n. 肘 n. 手腕, 腕关节 伸出,伸手, 开始大踏步走 adj. 笛卡儿的 adj. 圆柱的,圆筒形的,柱面的

spherical articulated

adj. 球状的,天体的,圆的 adj. 铰接的,有关节的

gripper
actuation envelope variant custom-made payload pneumatic

n. 抓持器, 夹持器,手爪
n. 活动,激励,动作 n. 封袋,[数]包迹,包络线 n. 变量 adj. 定做的, 订制的 n. 有效载荷 adj. 装满空气的, 气动的, 风力的

discrepancy
designate servocontrol

n. 相差, 差异, 矛盾
v. 指明, 指出, 任命, 指派 n. 伺服控制, 随动控制

tactile

adj. 触觉的, 有触觉的

● 23.3 Complex Sentence Analysis
[1] … which may be either fixed in place or mobile for use in industrial automation applications.

可以固定或移动的方式应用于工业自动化中。
which引导一个定语从句,在从句中作主语,指前面的 reprogrammable axes [2] It is the device intended for performing the designed operations as a human hand can. ① intended for: 用来,目的在于,是过去分词短语作定语,修饰device ② as a human hand can. 是方式状语从句 [3] The intelligent robot is capable of performing some of the functions and tasks carried out by human beings. ① be capable of doing something: 能够做某事 ② carried out:“完成”,是过去分词作定语,修饰functions and tasks

● 23.4 Exercise:Translate the Following Paragraphs
Although the robot has always been a fantastic subject and produces scenes in such movies as “Star War”, and even more fantastic kinds are described in science fiction books, we have found that our modern robots even seem to surpass these in reality, capacity, and development. Humanized robots are possible if a demand for them exists. The only reason we do not have more advanced robots is not because they cannot be developed, but because there has not been a need specified for them. As that need becomes obvious, then they will appear in large number. The future development of robotics depends mostly on the young and young-at heart scientists who are less conservative, who have active and imaginative brains and who have not learned to think in terms of “not practical ” or “not possible”. What robots can do around the home, office, factory and other places remains to be “seem” in their brains. These minds will create more wonderful inventions and adaptations than we have ever dreamed of. So let it be that the future of robotics belongs to the young and the young-at heart.

● Lesson 24

An Army of Small Robots

24.1 Text
A group of terrorists has stormed into an office building and taken an unknown number of people hostage. They have blocked the entrances and covered the windows. No one outside can see how many they are, what weapons they carry or where they are holding their hostages. But suddenly a SWAT team bursts into the room and captures the assailants before they can even grab their weapons. How did the commandos get the information they needed to move so confidently and decisively? The answer is a team of small, coordinated robots. They infiltrated the building through the ventilation system and methodically moved throughout the ducts. Some were equipped with microphones to monitor conversations, others with small video cameras, still others with sensors that sniffed the air for chemical or biological agents. Working together, they radioed this real-time information back to the authorities.

Ant mighty army In principle, lilliputian robots have numerous advantages over their bulkier cousins. They can crawl through pipes, inspect collapsed buildings and hide in inconspicuous niches. A well-organized group of them can exchange sensor information to map objects that cannot be easily comprehended from a single vantage point. They can come to the aid of one another to scale obstacles or recover from a fall. Depending on the situation, the team leader can send in a bigger or smaller number of robots. If one robot fails, the entire mission is not lost; the rest can carry on.

Where Are We? One vital task that requires collaboration is localization: figuring out the team’s position. Larger robots have the luxury of several techniques to ascertain their position, such as Global Positioning System (GPS) receivers, fixed beacons and visual landmark recognition. Moreover, they have the processing power to match current sensor information to existing maps. None of these techniques works reliably for midget robots. They have a limited sensor range; the millibot sonar can measure distances out to about two meters. They are too small to carry GPS units. Dead reckoning— the technique of tracking position by measuring the wheel speed—is frustrated by their low weight.

Chain of Command Obstacles present small robots with another reason to collaborate. By virtue of its size, a little robot is susceptible to the random clutter that pervades our lives. It must deal with rocks, dirt and loose paper. The standard millibot has a clearance of about 15 millimeters, so a pencil or twig can stop it in its tracks. To get around these limitations, we have come up with a newer version of the millibots that can couple together like train cars. Each of these new millibots, about 11 centimeters long and six centimeters wide, looks like a miniature World War Istyle tank. Typically they roam around independently and are versatile enough to get over small obstacles. But when they need to cross a ditch or scale a flight of stairs, they can link up to form a chain.

What gives the chain its versatility is the coupling joint between millibots. Unlike a train couple or a trailer hitch on a car, the millibot coupling joint contains a powerful motor that can rotate the joint up or down with enough torque to lift several millibots. To climb a stair, the chain first pushes up against the base of the stair. One of the millibots near the center of the chain then cantilevers up the front part of chain. Those millibots that reach the top can then pull up the lower ones. Right now this process has to be remotely controlled by humans, but eventually the chain should be able to scale stairs automatically.

One of the ways we envision large-scale control is through hierarchy. Much like the military, robots will be divided into smaller teams controlled by a local leader. This leader will be responsible to a higher authority. Already millibots are being directed by larger, tank like robots whose Pentium processors can handle the complex calculations of mapping and localization. These larger robots can tow a string of millibots behind them like ducklings and, when necessary, deploy them in an area of interest. They themselves report to larger all-terrain-vehicle robots in our group, which have multiple computers, video cameras, GPS units and a range of a few hundred kilometers. The idea is that the larger robots will deploy the smaller ones in areas that they cannot access themselves and then remain nearby to provide support and direction.

● 24.2 Words and Phrases SWAT n. Special Weapons and Tactics 特警队 ventilation n. 通风 diminutive adj. 极小的,微型的 processing power 处理能力 GPS Global Positioning System 全球位置测定系统 midget adj. 小型 millibot n. 毫米机器人 ultrasonic n. 超声的,超声波 odometry n. 测程法 odometer n. 里程计 trilateration n. 三边测量 intervention n. 干 cantilever n. 悬臂梁 military logistics 军事后勤学

● 24.3 Complex Sentence Analysis
[1] On the home front, firefighters and search-and-rescue workers could toss these robots through windows and let them scoot around to look for trapped victims or sniff out toxic materials. 消防队员和搜救人员可以留在大后方,将这些机器人丢进窗内,让它们到处 跑,寻找受困的伤者或是嗅出有毒的物质。 ① home front:大后方,后方支前活动。 ② search-and-rescue workers 搜救人员。 [2] Consequently, their sensors, processing power and physical strength must be distributed among several robots, which must then work in unison. 因此,传感器、处理能力及机械强度必须要分散到几个机器人身上,所以它 们必须通力合作。 ① physical strength:机械强度。 ② in unison:共同,一起。

● 24.4 Exercise:Translate the Following Paragraphs
Man has always used augmenters to increase the powers which nature endowed him. A simple stick, made into a lever to extend his reach and enable him to move heavy objects, may have been his first machine. Slingshots helped him kill food animals that were at greater distances. The wheel eased his movement and his burdens over the ground. But those were simple augmenters for simple tasks. Man has made his world much more complex. With the rapid development of science and technology, man’s augmenters have become much more sophisticated. They are designed not only to do the work of man, but also to do it in much the same way a man would. Some simply amplify the muscular power of their human operators. The “walking truck”being constructed, for example, is a large device that might better be called a walking horse. A man sits inside, moving his arms and legs to make the “horse” move its own four legs and carry far greater loads than the operator could. Another man, wearing a movable mechanical and electrical framework, lifts 1500 pounds six feet in six seconds.

● Lesson 25

Introduction to MEMS

25.1 Text
Development of MEMS MEMS, which called MM (Micro Machine) in Japan, MS (Micro System)in Europe and MEMS (Micro-Electro-Mechanical systems)in USA was only the assumption of scientists 30 years ago. [1]Only when the application of manufacturing technology (semiconductor microprocessing technology) in micro-scale product field created the condition to develop MEMS, and much relative technology such as design, material, measuring, control, sensing, information processing, computer, energy and system integrating got the certain high level achievement, i.e. 1ater 80’s, researchers of University Of California, Berkeley and MIT successfully researched and manufactured electrostatic micro-motor with the diameter of 100, did MEMS begin to be popularly studied and highly thought in worldwide and become one of the newly emerging high technology.

Since it was predicted that micrometer/nanometer technology would lead to industry revolution, many developed countries and areas looked it as the crucial technology in both economic flourishing and national defense. They took it prior project and spent huge sum of money in researching it, which made it rapidly develop and got certain achievement. For example, Stanford University researched and manufactured gemel connecting rod level mechanism with the diameter of 20 and the length of 150, sliding block mechanism with the size of 210×100, micro electrostatic motor with the diameter of 200and pump with the flux of 20ml/min. Tokyo University researched and manufactured micro slope climbing mechanism with the size of 1 cm. [2] Nagoya University researched and manufactured crawling wireless robot used to inspect micro pipe, which movement was controlled by magnetic field generated by circuit loop outside pipe,etc.At the same time, MEMS is also thought highly in our country. Now, the miniaturization technology on mechanical parts, integrated sensor, optics parts and actuator has been studied. Some of them has got certain achievement and turn to application studying.

Basic Characteristic The miniaturizing of MEMS causes the scaling effect problem .i.e. the physical phenomena doesn’t proportionally miniaturize with the size. When the size is certain extent small, the simulation and similarity theory of macro-mechanical is no longer adaptive. So MEMS has following characteristics: (1) The dominant force of MEMS is surface force. We know bulk force (e.g. gravity, electromagnetic force is direct proportion to high power feature size, while surface force (friction force, surface force and electrostatic force) is direct proportion to relatively low power of feature size. MEMS has small bulk, light weight. The ratio of surface force to bulk force relatively increases. Compared with bulk force, the surface force becomes dominant force. So, after miniaturizing, compared to gravity, electrostatic force becomes dominant force (the scaling effect of mechanical miniaturization).So, MEMS often actuated by electrostatic force. Compared to gravity, effect of friction in MEMS is also larger than that in normal machine.

(2)MEMS isn’t the simulative miniaturization of traditional
machine. The complexity of every parts of the traditiona 1 mechanical isn’t equa 1.To geometrically simulatively miniaturize them, the miniaturization of the complicated parts is very difficult, especially of highly intelligent automotive mechanica1.So, to design MEMS needn’t pursue complicated mechanical structure but with a view to multiple single mechanical part (include the parts with sensor and artificial intelligence) which can complete complicated work. (3)Energy supplying. For MEMS which can move and spin, electrical cable is the obstacle of its movement. So, energy supplying usually needn’t cable. Now MEMS often supplying energy by electrostatic force. Besides, often directly bestirring by vibration (piezoelectric, electromagnetic and SMA actuating). So, the development of MEMS needs the direction of new theory and method. With the change of main resistance, new structure principle and control method are needed. With the change of the dominant element of kinematic and kinetic equation, new actuating method is needed. With the miniaturization of structure of MEMS parts, new manufacturing method is needed, etc.

Application of MEMS The rising and development of MEMS synchronously forecasts its widely application prospect. The main field can be concluded as follows: (1) Machine field , micro gearing, micro connecting rod level mechanism ,micro sliding block mechanism etc,which are composed of micro system; (2) Instrument, pressure sensor, acceleration sensor, etc; (3) Hydro-control, micro pump, intelligent pump, etc; (4) Micro optics, optical cable, optical scanner, interferometer, etc; (5) GSI, vacuum manipulator, micro position system, gas precision control system, etc; (6) Information machine, magnetic head, printer head, scanner, etc; (7) Robot in next century, micro robot, multi degree of freedom manipulator, etc, which can be used in minimal environment such as micro pipe inspection and repair.

● 25.2 Words and Phrases
micro-processing technology 微加工技术

electrostatic adj. 静电的,静电学的 micrometer/nanometer technology 微/纳米技术 flourishing adj. 繁茂的,繁荣的 simulative adj. 模拟的,假装的 miniaturize vt. 使小型化,使微型化 synchronous adj. 同时的,[物]同步的 micro gearing 微齿轮micro connecting rod level mechanism 微连杆机构micro sliding block mechanism 微滑块机构

● 25.3 Complex Sentence Analysis
[1] Only when the application of manufacturing technology?did MEMS begin to be popularly studied and highly thought in worldwide and become one of the newly emerging high technology. only+从句或短语提前,放在主句的前面,则主句需要倒装。试比较: Only when we broaden our views, can we realize the importance of knowledge. Only in this way can we deal with the matter effectively. [2] Nagoya University researched and manufactured crawling wireless robot used to inspect micro pipe, which movement was controlled by magnetic field generated by circuit loop outside pipe, etc. ① used to inspect micro pipe 过去分词短语做定语,修饰robot。 ② which movement was controlled by magnetic field generated by circuit loop outside pipe, etc. 为非限制性定语从句,修饰robot。

● 25.4 Exercise:Translate the Following Paragraphs
MIT is developing a MEMS-based gas turbine generator. Based on high speed rotating machinery, this l cm diameter by 3 mm thick Sic heat engine is designed to produce 10~20 W of electric power while consuming 10 grams/hr of H2. Later versions may produce up to 100 W using hydrocarbon fuels. The combustor is now operating and an 80 W micro-turbine has been fabricated and is being tested. This engine can be considered the first of a new class of MEMS device, power MEMS, which are heat engines operating at power densities similar to those of the best large scale devices made today. The design of the micro-gas turbine generator presents a considerable challenge to all the disciplines involved. However, progress to date has been quite encouraging. The ability to manufacture MEMS-based high speed rotating machinery opens up a host of possibilities including various thermodynamic machines. MIT is also working on a motor-driven micro compressor and a micro-high pressure liquid rocket motor employing turbo pumps. The concept of MEMS-based, high power density heat engines appears extremely attractive and physically realizable.

lesson 26 Dialogue—At CIMT ●18.1 ●18.2 ●18.3 ●18.4 Text Words and Phrases Complex Sentence Analysis Exercise

● lesson 26 26.1 Text
Introduction
[1]CIMT

Dialogue—At CIMT

is one of the four most important machine tool exhibitions in the world. Engineers and managers from all parts of the world flock to Beijing, where they get the abreast of the latest manufacturing technology and promote their new products. Outside the Hall

Y:You are welcome to this China International Machine Tool Show. The opening ceremony is being performed now.
E:Yes, the scene is lively. Y:What’s your name? E:My name is Esther. Here is my card. Y:And here is my card. Thank you for coming. E:This seems to be a big show.

Y:Exactly. The registered visitors are already about 45,000 from all parts of the world and the number is expected to increase in two or three days.

E:I’m lucky to have this opportunity.
Y:You are right. The show has been very important to China’s machine tool industry. There are about 1 000 new machine tools on display. Delegations representing various countries or regions participate in CIMT’2001.

E:Fantastic! Do you have such a big show every year?
Y:Yes, it has been held in China every 2 years ever since its existence in 1989. And the show has been recognized as one of the top four marketing activities in the world’s machine tool area. E:I’m sure to come next time. Y:You are welcome!

Inside the Hall
E:Look! Aren’t the exhibits spectacular? Y:Sure. This is the exhibition hall 8A. It’s composed of four sections. Here on display are some new homemade machine tools. Many of them have caught up with the technical levels of similar products made abroad. Let me show you around. E:It’s very kind of you! Oh, that’s a big simultaneous five-axis CNC machine. Y:Yes. This new machine reaches the advanced world level. It is suitable for air industry. E:I see. Y:This is mode SV—100 MC (Machining Center). There are 16 tools in the storage, which will make them change automatically. The working table can move forward and backward in a wide scale, which is completely fit for the processing of conventional mold. E:Um.Is this boring-milling machine? Y:That’s right. It is highly recommended in the world because it is economical, easy to operate and outstanding in performance.

E:That sounds interesting. But the size is a bit small.
Y:It is specially designed for small works, and it is stable and efficient. The bigger one is also available. Over there, you see. E:What’s the unit price? Y:Here is our price list and this is the catalogue.

In the Negotiation Booth
Y:How do you do? What kind of equipment are you most interested in?

E:We have studied your catalogue and we have great interest in your boring-milling machine. But your price has been found higher through repeated calculations.
Y:How many would you like to order? E:Our quantity is surely to your satisfaction. We plan to order 15 if the price is moderate. Y:[2]To be frank, such machine was out of stock for a while because we had too many orders. The price on the list now is the same as it was before. [3]But since your order has a size, we would like to have another new partner by reducing the unit price to $20 000 FOB Shanghai. This is our lowest quotation, and no further concession. Actually, we won’t make a profit. We will just use it as an advertisement. E:It seems acceptable. Including freight? Y:Um, OK. E:When can you make the goods ready for shipment? Y:Around August. E:Well, we expect to use them this October Time is too tight. We need to transit the goods at the Singapore since there is no direct steamer from Shanghai to Lagos. Could you get the goods ready for shipment in mid July?

Y:July is OK. By the way, how would you make the payment? E:I’ll pay by installment. Y:[4]What about paying 30% upon signing the contract, and then paying the rest after delivery of the goods? E:According to our practice, we’ll pay 60% after delivery, and pay the additional 10% after three months’ trial use. What about your after-sales services?

Y:We will ensure you “three warranties” (for repair replacement or compensation of faulty products) during one-year period of guarantee. Then we’ll ensure you follow-up services. OK, just now Mr. Jiang said that you also want to buy NC equipment?
E:Yes, we want to buy WFC (Wire Flame Cutter), and EDM (Electric Discharge Machine). Y:We can be your agent.

E:Mr. Yang , We’ll discuss other equipment after we have done this one.
Y:Welcome! E:When can we sign the contract? Y:Tomorrow afternoon.

E:OK .Looking forward to mutual cooperation. See you tomorrow then.
Y:See you tomorrow.

● 26.2 Words and Phrases
opportunity Delegation spectacular negotiation booth n. 机会 n. 代表团 adj. 壮观的 n. 谈判 n. 层位,摊位

catalogue
moderate steamer contract transit cooperation manufacturing technology

n. 产品样本,目录
adj. 适中的 n. 船 n. 合同 n.& v. 运输 n. 合作,协作 制造技术

● 26.2 Words and Phrases
opening ceremony participate in exhibition hall homemade machine tool simultaneous five-axis CNC machine 开幕式 参加 展馆,展厅 国产机床 五轴联动数控机床

boring-milling machine
unit price Lagos direct steamer

镗铣床
单价 n. 拉各斯,尼日利亚首都 直达航运

● 26.3 Complex Sentence Analysis
[1] CIMT is one of the four most important machine tool exhibition in the world. Engineers and managers from all parts of the world flock to Beijing, where they get the abreast of the latest manufacturing technology and promote their new products. CIMT是China International Machine Tool的缩写,代表中国国际机床展览会,是世界4 大机床展之一。其他国际机床展览会分别在美国、欧洲和日本举行。首届中国国际 机床展览会于1989年在上海举行,以后每两年一届。第七届中国国际机床展览会 CIMT’2001于2001年4月19日至25日在北京举行。

[2] To be frank, such machine was out of stock for a while because we had too many orders.
① To be frank:坦白地说,说实话② out of stock: 脱销③ too many:太,过;非常

[3] But since your order has a size, we would like to have another new partner by reducing the unit price to $20 000 FOB Shanghai.
① FOB 是Free on Board的缩写,离岸价。这是国际贸易术语
② have a size:订货达一定数量

[4] What about paying 30% upon signing the contract, and then paying the rest after delivery of the goods?
① what about:怎么样,如何② sign the contract: 签订合同

● 26.4 Exercise:Translate the Following Paragraphs
Interview Place:Personnel Manager’s Office in a company Characters:(Interviewer) Mike Anderson, Personnel Manager of a company (Applicant) Chenzhuo
I:Come in, please. Good morning, I am Mike Anderson, personnel manager of our company. A:How do you do? My name is Chen Zhuo. I:Sit down please and make yourself at home. A:Thank you very much. I:As I know you have applied to work in our company. Would you please introduce yourself? A:I’m 23 years old and was born in Huangshi. I can speak and write English fluently and know how to operate the computer and NC machines. I have been an assistant engineer for half a year in a famous company one year ago. So, I am sure that I am quite efficient in technical work, like NC programming, operation, maintenance and debugging. I:OK,I would infer that you are an excellent student in your college. Could you tell me more details about your major and English courses ? A:All right. Though I am a student in the Department of Mechanical and Electrical Engineering, I studied many English Courses including English Reading and Comprehension, Oral, English, English Writing and professional English. Most of the courses are taught in English, some are even taught by foreign teachers.

I:By the way, do you have any experience as a leader at the school? A:Yes, I was the monitor of our class. I have organized many social activities. I:Besides all these, what do you like to do in your spare time? A:I have a great interest in travel, reading and sports such as swimming, tennis and so on. I: I am very glad to hear that. Travel and sports are also my hobbies. Why do you choose our company? A:Your company is one of the largest NC machine manufacturers in East China. As you see in my resume, I specialized in CAD/CAM in college, so I expect to develop my capabilities in your company. On the other hand, the position for which I applied is quite challenging. That’s the reason why I like to come to your company. I hope to display my talents fully here. I:If I accept you, how much do you expect to be paid? A:At least ? 2000 a month.

I:That will be no problem.
A:OK. When can I get the reply about my application? I:I think you will know the final result within a week. It’s my pleasure to have a talk with you. A:Me too. It takes your much time. Good bye. I:Goodbye.

PART TWO
Lesson 29 How to Write a Scientific Paper ●29.1 ●29.2 ●29.3 ●29.4 Text Words and Phrases Complex Sentence Analysis Exercise

● Lesson 27

How to Write a Scientific Paper

27.1 Text
A scientific paper is a written and published report describing original research results.That short definition must be qualified,however,by noting that a scientific paper must be written in a certain way and it must be published in a certain way. Title In preparing a title for a paper,the author would do well to remember one salient fact:That title will be read by thousands of people.Perhaps few people,if any, will read the entire paper,but many people will read the title,either in the original journal or in one of the secondary (abstracting and indexing) services.Therefore,all words in the title should be chosen with great care,and their association with another must be carefully managed. What is a good title? We can define it with the fewest words that adequately describe the contents of the paper. The title of a paper is a label.It is not a sentence.Because it is not a sentence, with the usual subject,verb,object arrangement,it is really simpler than a sentence (or,at least,usually shorter),but the order of the words becomes even more important.

Abstract An abstract is a concise and precise summary of the paper. The role of the abstract is not to evaluate or explain, but rather to describe the paper.[1]The abstract should include a brief but precise statement of the problem or issue, a description of the research method and design,the major findings and their significance, and the principal conclusion.[2]The abstract should contain the most important words referring to method and contend of the paper:These facilitate access to the abstract by computer research,and enable readers to identify the basic content of a document quickly and accurately,to determine its relevance to their interests, and thus to decide whether they need to read the document in its entirety.

An abstract should be written in complete sentences,rather than in phrases and expressions. Generally,an abstract for a short paper is limited to a maximum of 200~250 words. The abstract should be designed to define clearly what is dealt with in the paper.Many people will read the abstract, either in the original journal or in The Engineering Lndex,Science Citation Index or one of the other secondary publications.
The abstract should never give any information or conclusion that is not stated in the paper. References to the literature must not be cited in the abstract.Because the abstract is not a part of the paper,it is neither numbered nor counted as a page.

lntroduction Now that we have the preliminaries out of the way,we come to the paper itself.I should mention that some experienced writers prepare their title and abstract after the paper is written,even though by placement these elements come first.You should,however,have in mind ( if not on paper) a provisional title and an outline of the paper that you propose to write.You should also consider the level of the audience you are writing for,so that you will have a basis for determining which terms and procedures need definition or description and which do not. The first section of the text proper should,of course,be the introduction.The purpose of the introduction should be to supply sufficient background information and the design idea to allow the reader to properly understand and evaluate the results of the present study without needing to refer to previous publication on the topic.The introduction should also provide the rationale for the present study. Above all,you should state briefly and clearly your purpose in writing the paper.Choose references carefully to provide the most important background information.

Materials and Methods Now,in Materials and Methods you must give the full details.Most of this section should be written in the past tense.The main purpose of the Materials and Methods section is to describe the experimental design and then provide enough detail that a competent worker can repeat the experiments.Many (probably most) readers of your paper will skip this section,because they already know (from the introduction) the general methods you used and they probably have no interest in the experimental detail.However,careful writing of this section is critically important because the cornerstone of the scientific method requires that your results,to be of scientific merit,must be reproducible;and,for the results to be adjudged reproducible,you must provide the basis for repetition of the experiments by others.That experiments that are unlikely to be reproduced are beside the point;the potential for producing the same or similar results must exist, or your paper does not represent good science. When your paper is subjected to peer review,a good reviewer will read the Materials and Methods carefully.If there is serious doubt that your experiments could,he repeated,the reviewer will recommend rejection of your manuscript no matter how awe-inspiring your results. For materials,include the exact technique specifications and qualities and source and method of preparation.Generally,it is necessary to list pertinent chemical and physical properties of specimens (or reagents) used.

Results So now we come to the core of the paper,the data.This part of the paper is called the Results section. There are usually two ingredients of the Results section. First,you should give some kind of overall description of the experiments,providing the“big picture”, without,however,repeating the experimental details previously provided in Materials and Methods.Second,you should present the data. Of course,it isn’t quite easy.How do you present the data? A simple transfer of data from laboratory notebook to manuscript will hardly do.Most important,in the manuscript you should present representative data rather than endlessly repetitive data. The Results need to be clearly and simply stated,because it is the Results that comprise the new knowledge that you are contributing to the world.The earlier parts of the paper (Introduction, Materials and Methods) are designed to tell why and how you got the Results;the later part of the paper (Discussion) is designed to tell what they mean.Obviously,therefore,the whole paper must stand or fall on the basis of the Results.Thus,the Results must be presented with clarity.

Discussion The Discussion is harder to define than the other sections.Thus,it is usually the hardest section to write.And whether you know it or not,many papers are rejected by journal editors because of a faulty Discussion,even though the data of the paper might be both valid and interesting.Even more likely,the true meaning of the data may be completely obscured by the interpretation presented in the Discussion,again resulting in rejection. What are the essential features of a good Discussion? I believe the main components will be provided if the following injunctions are heeded: (1) Try to present the principles,relationships,and generalizations shown by the Results.And bear in mind,in a good Discussion,you discuss—you do not recapitulate the Results. (2) Point out any exceptions or any lack of correlation and define unsettled points.Never take the high-risk alternative of trying to cover up or fudge data that do not quite fit. (3) Show how your results and interpretations agree (or contrast) with previously published work. (4) Don't be shy;discuss the theoretical implications of your work,as well as any possible practical applications.

● 27.2 Words and Phrases
salient adequately citation table of contents retrievable dissertation relevance preliminary provisional rationale adj. n. n. adj . adj. n adj. n. n. adj. 突出的,显著的,卓越的,优质的,明显的 adj. 充分地,适当地 n. 引用 目录 可获取的,可取回的,可重新获得 (学位)论文,专题,论述,学术演讲 关联,关系,适用,中肯 预备的,初步的 暂定的,假定的,暂时的,临时的 基本原理,理论基础,原理的阐述

above all
pertinent cornerstone manuscript

尤其是,最重要的是,首先是
有关的,相干的,中肯的 基石;基础;(建筑)隅石 手稿,原稿

awe-inspiring

令人敬畏的,令人鼓舞的

● 27.2 Words and Phrases
specification specimen reagent chronological ingredient obscure injunction heed recapitulate unsettled n. n. n. adj. n. adj. n. v. n. v. 详述;[常pl.] 规格,说明书;规范;明细表 试样,样品;标本 反应物,反应力,试剂 按时间顺序排列的;按年代顺序排列的 成分,要素,因素,原料 模糊的, 含糊的 v 命令,指令 注意,留心 扼要重述,概括,重现,再演 使……黑暗,使不明显

adj. 不稳定的,不安定的,未解决的,混乱的

correlation
cover up fudge

n.
n.

关联,相关性,相互关系
包裹,隐藏,掩盖 捏造,梦话,胡话,空话;

implication cosmic illuminate spotlight

n. a. v. n.

牵连,受牵累;暗示,隐含;意义,本质 宇宙的,全世界的,广大无边的 照明,照亮,阐明,说明 vi. 照亮 聚光灯,点光源,公众注意中心

buttress
extrapolate evoke verbose

n.
n.

支持物,支柱;v
推断,外推,外插

支持,加强,扶住

v. 唤起,引起,博得,移送 adj. 冗长的,累赘的,喋喋不休的

fancy

adj. 奇特的,美妙的,漂亮的;
n. 想象力,嗜好,爱好

● 27.3 Complex Sentence Analysis
[1] The abstract should include a brief but precise statement of the problem or issue, a description of the research method and design,the major findings and their significance, and the principal conclusion. 摘要应该包括下列内容:论文中问题或论点的简洁而精确的陈述、研究方法及设计思 路的描述、主要发现和它们的意义,以及主要的结论。 句中a brief but precise statement of the problem or issue、a description of the research method and design、 the major findings and their significance及the principal conclusion均 为include的宾语。 [2] The abstract should contain the most important words referring to method and contend of the paper:these facilitate access to the abstract by computer research,and enable readers to identify the basic content of a document quickly and accurately,to determine its relevance to their interests,and thus to decide whether they need to read the document in its entirety.

these facilitate access to…,and enable readers to…entirety一句为并列句,facilitate与 enable为并列的两个谓语。句中to identify…、to determine…及to decide…均为reader的 宾语补足语。

● 27.4 Exercise:Translate the Following Paragraphs
Ductil-Regime Machining Model for Diamond Turning of Brittle Materials Abstract
A new machining model has been developed for single point diamond turning of brittle materials. Experiments using the interrupted cutting method allow model parameters to be determined that provide a quantitative method for determinig the machineability of a material with respect to the rake angle, tool nose radius and machining environment. The model uses two parameters, the critical depth of cut and the subsurface damage depth, to characterize the ductile-regime material removal process. Also includes in the model is a parameter used to set process limit defined as the maximum feed rate. Machining experiments have verified the model, and allow for determination of optimum machining conditions.

New Words
regime heat treatment regime critical depth of cut rake angle tool nose radius parameter characterize limit n. n. n. 方式,规范,范围,领域 热处理规范 临界切削深度 (刀具的)前角 刀尖半径 参数 v. 以……为特征;描写,述说 极限;范围;公差,极限尺寸


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