1、Unit 26 The Roles of Engineers in ManufacturingContentslNew Words&Expressions lText&TranslationlComplex Sentence AnalysislKey to ExercisesNew Words&Expressions lfabrication fbrikein n.制作，构成lthe processing or fabrication of materials 材料的加工制造ldesign engineer 设计工程师laccomplish kmpli v.完成，实现lassumption s
2、mpn n.假设，设想ldictate dikteit v.强行规定，限定lsequence si:kwns n.顺序，程序，序列ldetract ditrkt v.转移，毁损，减损lcoordinate ku:dnit v.调整，整理New Words&Expressions ltooling tu:li n.工具，刀具，工艺装备lprocess capabilities工艺能力loverload uvlud v.（使）超载，超重，过负荷linterrelationship int(:)rileinip n.相互关系，相互联系 lthe properties of the materials
3、 材料性能lproportion prp:n n.比率，比例llow-cost manufacture 低成本制造New Words&Expressions linterdependent intdipendnt adj.相互依赖ltooling selection 工艺设备选择lexpenditure ikspendit n.消费，支出ladvent dvnt n.到来，出现，来临lwith the advent of 随着的出现lcentral data base 中央数据库linspection inspekn n.检验，检查lcomputer aided testing and ins
4、pection 计算机辅助检验与检测lever-accelerating adj.不断加速的Text&Translationl1Many engineers have as their function the designing of products that are to be brought into reality through the processing or fabrication of materials.In this capacity they are a key factor in the material selectionmanufacturing procedu
5、re.A design engineer,better than any other person,should know what he or she wants a design to accomplish.2He knows what assumptions he has made about service loads and requirements,what service environment the product must withstand,and what appearance he wants the final product to have.In order to
6、 meet these requirements he must select and specify the materials to be used.In many instances,the selection of a specific material may dictate what processing must be used.Text&TranslationlAt the same time,when certain processes are to be used,the design may have to be modified in order for the pro
7、cess to be utilized effectively and economically.Certain dimensional tolerances can dictate the processing.In any case,in the sequence of converting the design into reality,such decisions must be made by someone.In most instances they can be made most effectively at the design stage,by the designer
8、if he has a reasonably adequate knowledge concerning materials and manufacturing processes.3Otherwise,decisions may be made that will detract from the effectiveness of the product,or the product may be needlessly costly.It is thus apparent that design engineers are a vital factor in the manufacturin
9、g process,and it is indeed a blessing to the company if they can design for producibility that is,for efficient production.Text&TranslationlManufacturing engineers select and coordinate specific processes and equipment to be used,or supervise and manage their use.Some design special tooling that is
10、used so that standard machines can be utilized in producing specific products.These engineers must have a broad knowledge of machine and process capabilities and of materials,so that desired operations can be done effectively and efficiently without overloading or damaging machines and without adver
11、sely affecting the materials being processed.These manufacturing engineers also play an important role in manufacturing.Text&TranslationlA relatively small group of engineers design the machines and equipment used in manufacturing.They obviously are design engineers and,relative to their products,th
12、ey have the same concerns of the interrelationship of design,materials,and manufacturing processes.4However,they have an even greater concern regarding the properties of the materials that their machines are going to process and the interreaction of the materials and the machines.Text&TranslationlSt
13、ill another group of engineersthe materials engineersdevote their major efforts toward developing new and better materials.They,too,must be concerned with how these materials can be processed and with the effects the processing will have on the properties of the materials.lAlthough their roles may b
14、e quite different,it is apparent that a large proportion of engineers must concern themselves with the interrelationship between material and manufacturing processes.Low-cost manufacture does not just happen.There is a close and interdependent relationship between the design of a product,selection o
15、f materials,selection of processes and equipment,and tooling selection and design.Text&TranslationlEach of these steps must be carefully considered,planned,and coordinated before manufacturing starts.This lead time,particularly for complicated products,may take months,even years,and the expenditure
16、of large amount of money may be involved.Typically,the lead time for a completely new model of an automobile is about 2 years,for a modern aircraft,it may be 4 years.Text&TranslationlWith the advent of computers and machines that can be controlled by computers,we are entering a new era of production
17、 planning.The integration of the design function and the manufacturing function through the computer is called CDA/CAM.The design is used to determine the manufacturing process planning and the programming information for the manufacturing processes themselves.Detailed drawings can also be made from
18、 the central data base used for the design and manufacture,and programs can be generated to make the parts as needed.In addition,extensive computer aided testing and inspection(CATI)of the manufactured parts is taking place.There is no doubt that this trend will continue at ever-accelerating rates a
19、s computers become cheaper and smarter.Text&Translationl许多工程师的职责是进行产品设计，而产品是通过对材料的加工制造而产生出来的。设计工程师在材料选择制造方法等方面起着关键的作用。一个设计工程师应该比其他的人更清楚地知道他的设计需要达到什么目的。他知道对产品的使用荷载和使用要求所做的假设，产品的使用环境，产品应该具有的外貌特征。为了满足这些要求，他必须选择和规定用哪种材料。在许多情况下，选择某种特定的材料，可能意味着已经确定了某种必须采取用的加工方法。同时，当决定采用某种加工方法后，很可能需要对设计进行修改，以使这种加工方法能够被有效而经
20、济地应用。某些尺寸公差可以决定产品的加工方法。Text&Translationl总之，在将设计转变为产品的过程中，必须有人做出这些决定。在大多数情况下，如果设计人员在材料和加工方法方面具有足够的知识，他会在设计阶段做出最为合理的决定。否则，做出的决定可能降低产品的性能，或者使产品变得过于昂贵。显然，设计工程师是制造过程中的关键因素，如果他们能够进行面向生产（即可以进行高效率的生产）的设计，就会给公司带来效益。Text&Translationl制造工程师们选择和调整所采用的加工方法和设备，或者监督和管理这些加工方法和设备的使用。一些工程师进行专用工艺装备的设计，以使通过机床能够用来生产特定的产品
21、。这些工程师们在机床、工艺能力和材料方面必须具有渊博的知识，以使机器在没有过载和损坏，而且对被加工材料没有不良影响的情况下，更为有效地完成所需的加工工序。这些制造工程师们在制造业中也起到重要作用。Text&Translationl少数工程师们设计在制造业中使用的机床和设备。显然，他们是设计工程师。而且对于他们的产品而言，他们同样关心设计、材料和制造工艺之间的相互关系。然而，他们更多地关心他们所设计的机床将要加工的材料的性能和机床与材料之间的相互作用。l还有另外一些工程师材料工程师，他们致力于研制新型的和更好的材料，他们也应该关心这些材料的加工方法和加工对材料性能的影响。Text&Transla
22、tionl尽管工程师所起的作用可能会有很大差别，但是，大部分工程师都必须考虑材料与制造工艺之间的相互关系。低成本制造并不是自动产生的。在产品设计，材料选择，加工方法和设备的选择，工艺装备选择和设计之间都有非常密切的相互依赖关系。这些步骤中的每一个步，都必须在开始制造前仔细地加以考虑、规划和协调。这种从产品设计到实际生产的准备工作，特别是对于复杂产品，可能需要数月甚至数年的时间，并且所产生的费用很高。通常，对于一款全新的汽车，从设计到投产所需要的时间大约为2年，而一种现代化飞机则可能需要4年。Text&Translationl随着计算机和计算机控制的自动化机器的出现，我们进入了一个生产计划的新时
23、代。采用计算机将产品的设计功能与制造功能集成，被称为CAD/CAM（计算机辅助设计/计算机辅助制造）。这种设计用来制定加工工艺规程和提供加工过程本身的编程信息。根据供设计与制造使用的中央数据库内的信息，我们可以绘制零件图；可以生成加工这些零件所使用的程序，此外，对加工后的零件进行计算机辅助检验与检测，也得到了广泛的应用。随着计算机价格的降低和性能的提高，毫无疑问，这种趋势将会继续快速发展。Complex Sentence Analysisl1 Many engineers have as their function the designing of products that are to
24、be brought into reality through the processing or fabrication of materials.许多工程师的职责是进行产品设计，而产品是通过对材料的加工制造而产生出来的。l此句可理解为：Many engineers have the designing of products that are to be brought into reality through the processing or fabrication of materials as their function.文中之所以没有这样写，是由于have后面跟的宾语太长，为了
25、避免整个句子头重脚轻，所以将“the designing of products that are to be brought into reality through the processing or fabrication of materials”这个宾语后置，放到了“as their function”的后面l have.as:把作为l“that are to be brought into reality through the processing or fabrication of materials”为限制性定语从句，修饰先行词products.Complex Sentenc
26、e Analysisl2 He knows what assumptions he has made about service loads and requirements,what service environment the product must withstand,and what appearance he wants the final product to have.l他知道对产品的使用荷载和使用要求所做的假设、产品的使用环境、产品应该具有的外貌特征。l句子的主语为he，谓语为 knows,后面三个并列的what 引导的名词性从句做其宾语.Complex Sentence
27、Analysisl3 Otherwise,decisions may be made that will detract from the effectiveness of the product,or the product may be needlessly costly.否则，做出的决定可能降低产品的性能，或者使产品变得过于昂贵。l detract from:有损于l that will detract from the effectiveness of the product：限制性定语从句，修饰先行词decisions.Complex Sentence Analysisl4 Howe
28、ver,they have an even greater concern regarding the properties of the materials that their machines are going to process and the interreaction of the materials and the machines.然而，他们更多地关心他们所设计的机床将要加工的材料的性能和机床与材料之间的相互作用。lregarding：关于lthat their machines are going to process：由that引导的限制性定语从句，修饰先行词mater
29、ials；句子中the properties of the materials和the interreaction of the materials and the machines为并列关系.Key to Exercisesl.Translate the following phrases into Chinese or English.l1.材料的加工制造l2.manufacturing process l3.工艺能力l4.the properties of the materials l5.低成本制造l6.tooling selection l7.随着的出现l8.central data
30、 base l 9.除此之外puter aided testing and inspection Key to Exercisesl.Mark the following statements with True(T)or False(F)according to the text.l1.Fl2.Fl3.Tl4.Fl5.FKey to Exercisesl.Fill in the blanks with the suitable words or phrases given below.l1.specific processesl2.supervisel3.utilizedl4.efficie
31、ntlyl5.damagingl6.play an important roleKey to Exercisesl.Translate the Chinese parts given in the brackets into English.l1.the processing or fabrication of materials l2.the selection of a specific material l3.the interreaction of the materials and the machines l4.entering a new era of production planning l5.The integration of the design function and the manufacturing functionlThe end!
