科技英语课件 4.ppt

1、 教程 EX: VI, P.61, 教程 EX: VIII, P. 62, 教程 EX: IX, P.62, 教程 EX: X, P. 62-63, 教程 EX: IV, P.60, 教程 EX: V, P60-61,Comprehension,Vocabulary,Translation,上一页,下一页,Mark the following statements with T (true) or F (false) according to the passage （ ）1. In a typical NC system the numerical data which is require

2、d for producing a part is maintained on a punched tape and is called the part program （ ）2. Dimensional information and the contour form are taken from computer system. （ ）3. The part dimensions are expressed in part programs by integers. （ ）4.The CNC machine tool is the servo actuator of the CAD/CA

3、M technology figuratively. （ ）5. Numerical Control (NC) was the forerunner of todays Computer Numerical Control.,上一页,下一页,T,F,T,F,T,6. It is enough for the part programmer to possess knowledge in mechanical engineering fields. 7. NC machines were first developed after World War . 8. To calculate the

4、position command in NC, the actual length is divided by the BLU value. 9. GE had its NC 550 workhorse for many years until they came out with their first CNC in August 1974. 10. Operators of NC machine tool must be skilled machinists. 6. F 7. F 8. T 9. T 10. F,II. Give brief answers to the following

5、 questions 1. What is the definition of NC equipment given by the Electronic Industries Association? 2. What are essential qualifications of a good NC operator according to the text? 3. What is the driving device of NC machine tool? 4. What are differences between conventional machine tool and NC ma

6、chine tool? 5. Why Mylar (or polyester) tapes became popular?,1. A system in which actions are controlled by the direct insertion of numerical data at some point. The system must automatically interpret at least some portion of this data.” 2. The operator works with a sophisticated and expensive sys

7、tem, intelligence, clear thinking, and especially good judgment are essential qualifications of a good NC operator. 3. The driving device may be a DC motor, a hydraulic actuator, or a stepping motor. 4. Compared with a conventional machine tool, the NC system replaces the manual actions of the opera

8、tor. In conventional machining a part is produced by moving a cutting tool along a workpiece by means of handwheels, which are guided by an operator. 5.Because of their high durability and quality.,III. Match the items listed in the following two columns,workpiece manual Forerunner contour execute s

9、egment inherent Dimensional Sophisticated conventional,measurement of any sort (breadth, length, thickness, height) b. outward curve of sth or sb thought of as defining its shape c. follow an order, plan, or instruction d. any of the parts into which something may be divided e. person or thing that

10、prepares the way for the coming of sb. or something else more important f. things to be worked on with a tool or machine g. following accepted customs and standards, sometimes too closely h. done with or controlled by the hands i. naturally present in a person or thing, and not able to be thought of

11、 as separate j. complicated and refined,上一页,下一页,IV. Translate the following expressions 1. part program 2. punched tape 3. hydraulic actuator 4. dimensional information 5. Computer Numerical Control 6. 电子工业协会 7. 基本长度单位 8. 以的形式 9. 伺服驱动器 10. 步进电机,上一页,下一页,1.零件程序 2. 穿孔纸带 3. 液压制动器 4. 空间信息 5. 计算机数控 6. EIA

12、 7. basic length-unit 8. in the form of 9. servo actuator 10. stepping motor,V. Translate the following sentences into Chinese 1. In a typical NC system the numerical data which is required for producing a part is maintained on a punched tape and is called the part program. 2. Compared with a conven

13、tional machine tool, the NC system replaces the manual actions of the operator.,上一页,下一页,1.在典型的数控系统中，制造零件所需的数值数据，即零件程序，被保存在穿孔带上。 2.和传统的机床相比，数控系统取代了操作员的手工操作。,3. Part programmers must be familiar with the function of NC machine tools and machining processes, and have to decide on the optimal sequence o

14、f operations. 4. The DNC is the advanced technologies in manufacturing, which includes the numerical control, communication, computer network and database. 5. The driving device may be a DC motor, a hydraulic actuator, or a stepping motor. The type selected is determined mainly by the power requirem

15、ents of the machine.,上一页,下一页,3.工件程序设计员必须熟悉数控机床的功能和加工工艺，并且决定最佳的操作顺序。 4.DNC技术是目前制造业的先进技术 ,是数控技术、通信技术、计算机网络和数据库等技术的综合应用。 5.该驱动装置可能是一个直流电动机，液压致动器，或步进电机。对驱动装置类型的选择主要取决于机器对电源的要求,VI. Translate the following sentences into English 1. 由于操作员是在精密昂贵的系统中工作，因此健全的智力，清晰的思维和良好的判断力是好的数控操作员的必备素质。 2. 零件的尺寸在加工程序中用整数来表达。

16、,上一页,下一页,1. Since the operator works with a sophisticated and expensive system, intelligence, clear thinking, and especially good judgment are essential qualifications of a good NC operator. 2. The part dimensions are expressed in part programs by integers.,VI. Translate the following sentences into

17、 English 3. 在20世纪60年代，数控机床为计算机数字控制（CNC）机床所取代。 4. 使用计算机的优点主要在于节省编程时间。 5. 他们手工书写工件程序或使用计算机辅助语言，如APT（自动程序设计工具）来完成。,上一页,下一页,3. In the 1960s, NC machines largely gave way to CNC, or computer numerical control machines. 4.The advantage of using computer lies principally in the savings of programming time.

18、 5. They write the part program manually or by using a computer-assisted language, such as APT., 教程 EX: IV, 69, 教程 EX: V, P70,Comprehension,上一页,下一页,I. Mark the following statements with T (true ) or F (false) according to the passage （ ）1.VNC involves written communication of the machining procedure

19、 to a voice-input NC tape-preparation system. （ ）2. To perform the part programming process s with VNC, the operator must speak into a telephone. （ ）3. Communication of programming instructions only involves providing dimensional and coordinate data. （ ）4. Before it can be used, the voice-input syst

20、em needs some training to recognize and accept the programmers voice pattern. （ ）5. The entire vocabulary for the Threshold system contains about 1000 words.,F,F,F,T,F,上一页,下一页,Mark the following statements with T (true ) or F (false) according to the passage （ ）6. In talking to the system, the progr

21、ammer must pause before and after each word. （ ）7. The pause before and after each word allows the speech recognition to identify the pronunciation for the uttered command. （ ）8. Typical word input rates under the restriction are claimed to be about 70 per hour. （ ）9. As the words are spoken, a CRT terminal in front of the operator verifies each command and prompts the operator for the next command. （ ）10. Some of the benefits of VNC are improvements in accuracy and lower compu