数控专业英语教案.docx

1、数控专业英语教案数控专业英语电子教案适用班级：10级数控技术 李柏华2012年9月 课题一一、章节：lesson 1 Five Basic Techniques of Machining Metal 二、教学目的： 让同学们了解和掌握五种基本的金属加工工艺方法 三、教学方法：讲授 四、教学重点： 金属成型的5种方法 五、教学难点：车削和镗削 六、使用教具： 七、课后作业：Translation 八、课后小结： lesson 1 Five Basic Techniques of Machining MetalNew words:1. variety n. 种类，变化，多样化2. unlimite

2、d adj.无限的3. bench n. 工作台4. house v. 安装，容纳5. solid adj. 坚固的，固体的，实心的n. 固体，实体6. slot n. 缝, 槽， 狭槽 v. 开槽7. slotting machine 插床8. slotter n. 插床，铣槽机9. straight adj. 直的, 整齐的10. circle v., n. 环绕，旋转，圆圈 Tranlations:Machine tools are made in a great many types and sizes. The variety of machine tools today is al

3、most unlimited. Some are small enough to be mounted on a bench. Others are so large that they require special building to house them.1Some are rather simple, while others are very complicated in construction and their controls.Large or small, simple or complicated, machine tools can be categorized i

4、nto five major classifications, identified as the five basic techniques of shaping metal.(1) Drilling. Drilling is the operation of producing holes in solid metal. A rotating drill called a twist drill is used. Machine tools for drilling holes are called drilling machines. There are many types and s

5、izes of drilling machines. These machines can perform other operations besides drilling. The workpiece is held stationary, that is,clamped in position, and as the drill rotates, it is fed into the workpiece 2(Fig. 1-1).(2) Turning and Boring. The engine lathe is the most common type of machine tool

6、for turning work. Turning is the operation of cutting or removing metal from a wokpiece. A cutting tool is fed into or along the work while the workpiece revolves (Fig. 1-2).Boring is the operation of enlarging or machining a hole that has been drilled or cast into the metal. Boring in a lathe is do

7、ne by feeding a single-point cutting tool into the work as it revolves3(Fig. 1-3 ).(3) Milling. Milling is the operation of removing metal by means of a rotating cutting tool, which has multiple cutting edges and is called a milling cutter (Fig. 1-4).(4) Grinding. Grinding is the operation of cuttin

8、g or removing metal by means of an abrasive wheel called a grinding wheel. Grinding finishes work very accurately and smoothly. When grinding round work, the workpiece revolves as it is fed against the turning wheel. When grinding flat work, the workpiece is passed back and forth under the turning w

9、heel (Fig. 1-5). The grinding process is often used for the final finishing to close dimensions of a part that has been heat-treated to make it very hard.(5) Shaping, Planing and Slotting. These operations are done to produce or machine flat, accurate surface using single-point cutting tools. We sho

10、uld understand the difference between the shaper, the planer and the slotting machines. On a shaper, the cutting tool moves back and forth over the work while the work is fed against the cutting tool (Fig. 1-6).On a planer, the work moves back and forth under the cutting tool while the cutting tool

11、is fed into or against the workpiece (Fig. 1-7).Slotting is an Operation similar to the operation performed on a shaper. A slotting machine is really a vertical shaper, the cutting tool of which moves up and down. 4In this case, the work is fed against the cutting tool in a straight line or in a cir

12、cle, depending upon the type of work being machined.Slotter, or vertical shaper, are used principally to c课题二一、章节：LESSON2 The Machine Control Computer二、教学目的： 让同学们了解和掌握工控机的结构与功能 三、教学方法：讲授 四、教学重点： 工控机的结构与功能 五、教学难点：工控机的结构与功能 六、使用教具： 七、课后作业： 八、课后小结： New words1. execution n. 实行, 完成, 执行,制作2. hence adv. 因此

13、, 从此3. alter v. 改变4. load n.负载, 加载vt. 装载,使5. controller n. 控制器 6. hardware􀱷 n. (电脑的)硬件7. software n.软件8. monitor n.显示器，监视器v.监控9. general term n. 总括, 通称，统称10. processor n. 处理机, 处理器11. volatile memory 非永久性存储器, 易失存储器12. switch n.开关,转换vt.转换13. RAM(random access memory)n.计 随机(存取)存储器14. battery n

14、.电池15. ROM(Read Only Memory) n.只读存储器 TranslationsThe computer on numerically controlled machines controls the program execution, hence this computer is known as the machine control computer or controller (Fig. 2-1). This computer performs tasks similar to a personal computer, such as loading the pro

15、gram, searching through the program, altering and deleting information, and executing the program (program run).1Fig. 2-1A CNC vertical machining center equipped with a modern control that utilizes 32-bit logic for on-screen programming, foreground/background operations, maintenance and standard fun

16、ctions for program editing, and program execution.The machine control computer consists of two main components: hardware, which is any physical component in a computer system, such as the processor, monitor, memory, and input/output devices; and software, which is a general term for programs stored

17、in the memory in electronic form.2The CNC programs are stored in computer memory, which also holds the software needed to run the control compute. To change and alter data, the programmer and the operator need to write into and read from memory. The main memory of a computer is RAM (Random Access Me

18、mory). RAM is volatile memory, the programmer and theoperator can easily change the content of this memory by writing over the old programs and replacing them with new ones.3On a CNC machine control computer, this is where the programmer and the operator store the CNC programs and read and write as

19、they like. When the power to the machine is turned off, the content of this memory is lost. To save data in memory when the machine is turned off, the machine uses itsbatteries. The machine switches to batteries automatically. When the batteries weaken, a light on the control panel lights up, warnin

20、g the operator to change the batteries. This should be done within a month, or the data stored in RAM will be lost permanently. 4Besides RAM, the computer has ROM (Read Only Memory). This memory allows reading from it, but writing to it is not normally possible. The computer must have ROM in order t

21、o store some important information, which is system, not user, related. Since the user cannot write into ROM, he or she cannot change its content. The content of ROM does not change when the power is turned off. Various CNC software ( such as canned cycles ) is stored in this memory for permanent us

22、e.课题三一、章节：LESSON3 The Evolution of CNC 二、教学目的： 为了让学生了解计算机数字控制的发展趋势 三、教学方法：讲授 四、教学重点： 计算机数字控制 五、教学难点：计算机数字控制 六、使用教具： 七、课后作业： 八、课后小结： New words1. allocate v.分配，配给2. consist of 由组成3. conjunction 􀱻 n.连词，结合，同时发生4. interchangeably () adv.可交换地，可互换地5. stabilize v.稳定，沉稳6. evolve v.(使)逐渐形成，进化7. belt

23、n.传送带8. pulley n.滑轮组9. cam n.凸轮10. attempt to 尝试，努力，试图11. industrialist n.工业家，实业家12. retrofit n.式样翻新, 花样翻新13. machinist n. 操作机器的工人，机械师14. ballistic n.弹道学15. trajectory n.轨道，轨迹16. vacuum n.真空 ,空间17. subcontract v.订立分契，转契18. the University of Pennsylvania 宾夕法尼亚州大学19. the Massachusetts Institute of Tec

24、hnology 马萨诸塞州技术学院，麻省理工学院TranslationsIntroductionComputer numerical control (CNC) is the process of manufacturing machined parts. Production is controlled and allocated by a computerized controller. The controller uses motors to drive each axis of a machine tool and actually regulates the direction,

25、speed, and length of time each motor rotates. A programmed path is loaded into the machines computer by the operator and then executed. The program consists of numeric point data in conjunction with specialized machine control commands and function codes1. Numerical control (NC) is the original term

26、 given to this technology and is still often used interchangeably with CNC.The evolution of NC The principal of NC manufacturing has been evolving since the Industrial Revolution, although the actual procedures involved have developed with technology. Early attempts to automate production made use o

27、f belts, pulleys, and cams.However, manual labor was by far more cost effective than were the development and operation of big, new machines.Not until World War II did industrialists realize that they couldnt meet both quantity and quality requirements at the same time. Machinists of the day could p

28、roduce superior quality parts but not at high volumes. As the quantity of a certain product increased, the quality decreased due to the human factors involved.During World War II the United States Army Ballistic Research Lab and the University of Pennsylvania collaborated on development of ENIAC, th

29、e worlds first digital computer. This was an extremely large vacuum tube computer, which was usedto calculate ballistic trajectory tables for artillery. Programming involved setting hundreds of switches and cables manually prior to having the machine sequence through the settings(Fig.3-1)3.In the ea

30、rly 1950s the Massachusetts Institute of Technology developed a more advanced vacuum tube computer called the Whirlwind. This improved computational device was capable of executing thousands of times more instructions per second than ENIAC.To ensure that all U.S. military airplanes were manufactured identically, the United States Air Force invited several companies to develop and manufacture numerical control systems that could handle the volume and repeatability.The specific goals of developing NC were to：1. Increase production;2. Improve the qua