Chapter 7 The Application of Computer in Design and Manufacture of Mold and Die（计算机在模具设计与制造中的应用）.ppt

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1、Chapter 7 The Application of Computer in Design and Manufacture of Mold and Die（计算机在模具设计与制造中的应用）（计算机在模具设计与制造中的应用）Lesson 24 Computers and CAD/CAMLesson 24 Computers and CAD/CAMlComputers first appeared in the 1940 x.The early inventions were bulky,cumbersome to use and performed computations rather s

2、lowly in comparison to modern digital computers.They advanced from mechanical relays to vacuum tubes to transistors to silicon chips.Computers today are more compact,faster and less expensive than their predecessors.Today some microcomputers can handle the computations of early day main-frames.Techn

3、ological advances in this field have been truly dramatic.BACKNEXTLesson 24 Computers and CAD/CAMlThe application areas of computers have also grown rapidly.Computers are widely used in the fields of engineering,business,education and medicine.However,the most spectacular growth has been in the area

4、of CAD/CAM-Computer Aided Design and Computer Aided Manufacture.This new technology,which emerged within the last decade or so,has helped to increase engineering productivity tremendously.Higher productivity is probably the primary consideration that influences most potential users to acquire a CAD/

5、CAM system.CAD/CAM provides the integration of design,analysis andBACKPREVNEXTLesson 24 Computers and CAD/CAMlmanufacturing functions into a system which is available to the user at his fingertips.In addition,other routine and monotonous(but important)tasks such as the preparation of bills of materi

6、als,costing,production scheduling,etc.may be performed automatically using the same computer network.Another major benefit in the use of CAD/CAM is reduced lead time from concept to design to manufacture.Product development cost can also be reduced dramatically because analysis such as the finite el

7、ement method can be interfaced with design to arrive at the optimum design within a very short time.BACKPREVNEXTLesson 24 Computers and CAD/CAMlCAD/CAM and Analysis are best used in an interactive,computer graphics environment to provide solutions to engineering problems as illustrated in Fig.24-1.T

8、he geometry and topology of the part and other parameters such as material properties are stored in a common data baselwhich can be accessed by any one of the functions.Analysis such as finite element methods,upper bound methods and slab analysis is carried out on the initial product geometry.lResul

9、ts which are often displayed in colour will either automatically or with user interventions alter the designBACKPREVNEXTLesson 24 Computers and CAD/CAMlparameters so as to satisfy the various design criteria.This process is repeated until an optimum solution is obtained.Thereafter manu-facturing and

10、 other related functions can be performed either automatically or with user intervention.lAny CAD/CAM system consists of hardware,such as the central processing unit(CPU),disk storage facilities,display units,tablets,etc.and software,which is the brain behind the system.Sometimes it is harder to mak

11、e a clear distinction between the two,when hardware is built-in with appropriate software.This is often referred to as“firmware.”BACKPREVNEXTLesson 24 Computers and CAD/CAMlA typical CAD/CAM system configuration is illustrated in Fig.24-2.The heart of the system is the central processing unit(or the

12、 computer),which coordinates all the functions within the CAD/CAM system.The user interacts with the system through the work station.A typical work station is shown in Fig.24-3.It consists of a graphic display(or two,as in this case)which provides visual output of the system to the user.The user can

13、 communicate with the system through the keyboard or a tablet(with menu).The dual-screen work-station has numerous advantages.It can be used to view the product being designed at two or moreBACKPREVNEXTLesson 24 Computers and CAD/CAMlangles.The zoom command may be used to zoom up a certain feature o

14、f the product on one screen for detail view while the other screen can be used to view the whole part.Text may be entered on any one of the screens.Other vendors have systems with graphic display and an alpha-numeric display for text.lThe work stations are intelligent,in that they do useful local op

15、erations such as zoom,rotate,etc,without tying up the CPU for these operations.The current trend is to increase the power of the work station,thus freeing the CPU for other more demanding tasks.Many CAD/CAMBACKPREVNEXTLesson 24 Computers and CAD/CAMlsystems have a“menu”of commands to choose from a t

16、ablet or digitizer board,The menus can be changed depending upon the applications.Some CAD/CAM systems use a push-button menu to select certain commands.A typical menu used in a CAD/CAM system is shown in Fig.24-3。Notes:l1.The early inventions were bulky,cumbersome to use and performed computations

17、rather slowly in comparison to modern digital computers.BACKPREVNEXTLesson 24 Computers and CAD/CAMl译文译文:最早发明的计算机大而笨重最早发明的计算机大而笨重,它们的计算速度相对于它们的计算速度相对于今大的数字计算机要慢得多。今大的数字计算机要慢得多。l解析解析:in comparison to:与与相比较。相比较。l2.However,the most spectacular growth has been in the area of CAD/CAM-Computer Aided Desig

18、n and Computer Aided Manufacture.l译文译文:然而然而,最快的发展在最快的发展在CAD(计算机辅助设计计算机辅助设计)和和CAM(计算机辅助制造计算机辅助制造)领域。领域。l3.This new technology,which emerged within the last decade or so,has helped to increase engineering productivity tremendously.BACKPREVNEXTLesson 24 Computers and CAD/CAMl译文译文:这种大约在这种大约在10年前出现的新技术已经

19、在工程上帮助年前出现的新技术已经在工程上帮助我们极大地提高了生产力。我们极大地提高了生产力。l解析解析:which引导的是一个非限制性定语从句引导的是一个非限制性定语从句,修饰中心词修饰中心词technology;句中的句中的or so意为意为“大约大约”。l4.CAD/CAM provides the integration of design,analysis and manufacturing functions into a system which is available to the user at his fingertips.l译文译文:CAD/CAM为用户提供了一个集设计、

20、分析、制造功能为用户提供了一个集设计、分析、制造功能于于-体的系统体的系统,用户只需动动手指就能使用。用户只需动动手指就能使用。l解析解析:provide into:提供。提供。be available to:可用的可用的,可得到可得到的。的。BACKPREVNEXTLesson 24 Computers and CAD/CAMl5.In addition,other routine and monotonous(but important)tasks such as the preparation of bills of materials,costing,production schedu

21、ling,etc.may be performed automatically using the same computer network.l译文译文:此外此外,其他一些日常的单调的其他一些日常的单调的(但是重要的但是重要的)任务任务,比比如说材料清单的准备、成本计算、生产调度等也许可以通如说材料清单的准备、成本计算、生产调度等也许可以通过使用同过使用同-电脑网络自动执行。电脑网络自动执行。l6.Analysis such as finite element methods,upper bound methods and slab analysis is carried out on th

22、e initial product geometry.BACKPREVNEXTLesson 24 Computers and CAD/CAMl译文译文:像有限元法、上限元法和板坯分析法等分析都在初像有限元法、上限元法和板坯分析法等分析都在初始的产品几何形状上进行。始的产品几何形状上进行。l解析解析:carry out:执行。执行。l7.Results which are often displayed in colour will either automatically or with user interventions alter the design parameters so as

23、to satisfy the various design criteria,This process is repeated until an optimum solution is obtained.l译文译文:通常用彩色显示出来的结果既可以自动也可以通过通常用彩色显示出来的结果既可以自动也可以通过用户的介入来改变设计参数用户的介入来改变设计参数,以满足各种设计标准以满足各种设计标准,这个过这个过程可以不断地重复下去程可以不断地重复下去,直到获得最优的解决方案为止。直到获得最优的解决方案为止。BACKPREVNEXTLesson 24 Computers and CAD/CAMl8.Any

24、 CAD/CAM system consists of hardware,such as the central processing unit(CPU),disk storage facilities,display units,tablets,etc.and software,which is the brain behind the system.l译文译文:任何任何CAD/CAM系统都包括硬件系统都包括硬件如中央处理器如中央处理器(CPU),磁盘存储器、显示器、写字板等等磁盘存储器、显示器、写字板等等,以及软件以及软件它它是整个系统的大脑。是整个系统的大脑。l9.The heart o

25、f the system is the central processing unit(or the computer),which coordinates all the functions within the CAD/CAM system.l译文译文:系统的核心是中央处理器系统的核心是中央处理器,它可以协调它可以协调CAD/CAM系系统中的各项功能。统中的各项功能。BACKPREVNEXTLesson 24 Computers and CAD/CAMl10.The user interacts with the system through the work station that c

26、onsists of a graphic display(or two,as in this case)which provides visual output of the system to the user.l译文译文:用户通过工作站与系统交互作用用户通过工作站与系统交互作用,工作站由一个给用工作站由一个给用户提供可视化输出的图像显示器户提供可视化输出的图像显示器(或两个或两个,如图如图)所构成。所构成。l解析解析:interact with=(of two things)to have an effect on each other:两个事物间相互作用。两个事物间相互作用。l11.Th

27、e user can communicate with the system through the keyboard or a tablet(with menu).l译文译文:用户可以通过键盘或写字板用户可以通过键盘或写字板(带有菜单带有菜单)与系统交流。与系统交流。l解析解析:communicate with:交流交流,沟通。沟通。BACKPREVNEXTLesson 24 Computers and CAD/CAMl12.The work stations are intelligent,in that they do useful local operations such as zo

28、om,rotate,etc,without tying up the CPU for these operations.l译文译文:工作站是智能的工作站是智能的,因为它们可以在没有与因为它们可以在没有与CPU联系的联系的情况下进行一些有用的局部操作情况下进行一些有用的局部操作,如放大、旋转等。如放大、旋转等。l解析解析:tie up缠住某人缠住某人,使某人脱不了身。使某人脱不了身。l13.Many CAD/CAM systems have a“menu”of commands to choose from a tablet or digitizer board.The menus can be

29、 changed depending upon the applications.l译文译文:许多许多CAD/CAM系统有一个来自写字板或数字转换系统有一个来自写字板或数字转换板的命令板的命令“菜单菜单”可选择菜单可以根据应用而变化。可选择菜单可以根据应用而变化。BACKPREVFig.24-1 Interactive computer graphics environmentBACKFig.24-2 Typical CAD/CAM system configurationBACKFig.24-3 Typical CAD/CAM menu(Courtesy of Intergraph Corp)BACK