机电专业英语课件Unit Nine CNC.ppt

机电专业英语,呼枫 / 主编 牛存超 于春元 / 副主编,人民邮电出版社 北京,Unit Nine CNC,Focus Section One Warming -up Section Two Real World: What do you know NC technology? Section Three Brighten Your Eyes: Features of CNC Section Four Translation Skills Section Five Writing: Certifcate Section Six Grammar: Adverbial Clause II,Section Two Real World Listen and role-play the following dialogue which is about NC technology. What do you know about NC technology? Lucas: Since your major is NC technology, I’m sure you know a lot about numerical control. Jessica: Numerical control is a method of automatically controlling machine tool movements with the aid of a number language.,Lucas: When was the first NC machine invented? Jessica: The first NC machine was developed by MIT in 1952. It was a retroftted milling machine. The first generation of NC machine used large vacuum-tube-based controllers. Lucas: I heard that those controllers consumed a great deal of electrical power, generated a lot of heat, took up a large area of space, and was lacking in reliability.,Jessica: Yes, you’re right. Thus, the second-generation models replaced the vacuum tubes with transistors for higher reliability, lower power consumption and less space.,Lucas: What about the third generation of NC machines? Jessica: The third generation models featuring integrated circuit and modular circuit design reduced costs and increased reliability still further. Lucas: Thanks to those NC machines, it is possible and much easier to produce large quantities of identical parts.,Words relating to numbers automatically [ɔ:tə mætɪklɪ] adv. 自动地；机械地 in a reflex manner movement [ mu:vmənt] n. 整个活动； 运动；移动 a change of position retrofit [ retrəufɪt] vt. 给机器设备装配（新部件）；翻新 the act of adding a component or accessory to something that did not have it when it was manufactured,generation [dʒenə reɪʃn] n. （产品类型的）代 all members of any developing class of things at a certain stage base [beis] vt. 以……作基础place or establish; provide with a base or centre controller [kən trəulə(r)] n. 控制器 a mechanism that controls the operation of a machine consume [kən sju:m] vt. 消耗use especially eagerly or in large amounts generate [ dʒenəreɪt] vt. 产生 produce especially heat or electricity,reliability [rɪˌlaɪə’bɪlətɪ] n. 可靠性 the quality of being dependable or reliable transistor [træn zɪstə(r)] n. 晶 体 管a small electrical apparatus,especially used in radios, televisions, etc. consumption [kən sʌmpʃn] n. 消费；消耗 the act of consuming or an amount consumed identical [aɪ dentɪkl] adj. 同一的；相同的the same with the aid of 借助于；通过……的帮助 number language 数字语言 take up 占据 lack in 缺少，缺乏 large quantities of 大量的,Proper Names MIT(Massachusetts Institute of Technology) 麻省理工学院（美国） NC (Numerical Control) 数控 machine tool 机床 milling machine 铣床 vacuum-tube 电子管 electrical power 电力 integrated circuit 集成电路 modular circuit 模块电路,Section Three Brighten Your Eyes Pre-reading questions: 1． Are you familiar with the features of CNC? 2． Do you know how to operate a CNC machine?,Features of CNC CNC means Computer Numerical Control. This means a computer converts the design into numbers that the computer uses to control the cutting and shaping of the material. A CNC production facility needs of three pieces of equipment: 1. A computer. It is used to draw the design.However, the design is only a picture. The computer software can convert the picture into numbers that the CNC machine can use when it starts to cut and shape the material.,2. An interface. The computer is connected to the surface. This converts the signals from the computer to a form that the CNC machine understands. 3. CNC Machine: the signals from the interface control the motors on the CNC machine. The signals not only determine the way the vice moves but also control the speed of the cutting tool.,How to use a typical CNC machine: 1. The design is loaded into the computer, which changes the design into a special code (numerical) that controls the way the CNC cuts and shapes the material. 2. The material to be shaped is taped on to a block with double-sided tape. 3. The block is then placed in the vice, inside the CNC. When the machine starts working, the vice moves up, down,right and left according to the design.,4. The guard is placed in proper position. Otherwise, the motor will not start. 5. The CNC is turned on and the shape is cut from the material. When the cutting tool has stopped, the shaped material can be removed from the vice.,Words have a direct and important effect on vice [vaɪs] n. 台虎钳 plier,typical [ tɪpɪkl] adj. 特有的；典型的；有代表性的 having the distinctive qualities of a particular type of person or thing load [ləud] v. [ 计算机 ] 装入；装载 put (a load) on or in (a vehicle,structure, computer, etc.) tape [teɪp] vt. 用带子捆起来；用胶布粘 fasten or tie with tape block [blɔk] n. 大块 a big heavy piece of sth. with flat sides guard [ga:d] n. 防护装置；护板 keep from danger, watchfulness,tape [teɪp] vt. 用带子捆起来；用胶布粘 fasten or tie with tape block [blɔk] n. 大块 a big heavy piece of sth. with flat sides guard [ga:d] n. 防护装置；护板 keep from danger, watchfulness position [pə zɪʃn] n. 位置 a place where sb./sth. is or stands, especially in relation to other objects, places, etc. remove [rɪ mu:v] vt. 消 除； 脱 掉 take away from a place or take to another place; get rid of,be used to 被用于 connect to 连接；相连 not only.but also. 不仅；而且 load in 装入 according to 按照；根据；取决于 turn on 打开；发动 Proper Names CNC 计算机数控 cutting tool 刀具,Section Four Translation Skills 科技英语的翻译方法与技巧——被动语态的翻译 科技英语中大量使用被动语态，这是因为文章需要客观地叙述事理，而不是强调动作的主体。 The clutch controls the direction of spindle rotation. 离合器控制主轴旋转方向。,The direction of spindle rotation is controlled by the clutch. 主轴旋转方向由离合器控制。 在第一句中，动词的主语 the clutch 实施动词表示的动作，这个动词处于“主动语态”；在第二句中，动词的动作被施加到主语上，该动词处于“被动语态”。 只有及物动词（其后可跟一个宾语）可用于被动语态。主动形式的宾语，通常是被动形式的主语。,1．被动语态的种类 （1）一般现在时的被动语态 Computer is used in business, governments and institutions. 计算机用于商业、政府和公共机构。 （2）现在进行时的被动语态 Computers are being used in machine tool control. 计算机 正用于机床的控制。,（3）过去进行时的被动语态 The hard-wired NC was being used widely in 1960s. 20 世纪 60 年代时，硬线数控应用很广。 （4）不定式的被动语态 If a large amount of stock is to be removed, it is advisable to take one or more roughing cuts and then take light finishing cuts at relatively light speed. 如果毛坯切削量很大，建议进行一次以上的粗切削，然后以相对高速进行少量精切削。,（5）带情态动词的被动语态 Finishing cuts are generally very light; therefore, the cutting speed can be increased since the chip is thin. 精切削一般量很小，由于切屑很薄，因此可以提高切削速度。 （6）短语动词的被动语态 The documents attached to the machine should be taken good care of.必须妥善保管这些随机资料。,2．被动语态的翻译方法 把英语被动句译成汉语时，一般可以采用下列处理方法。 （1）译成汉语被动句 用“被”“由”“受”“靠”“给”“遭”等汉语中表达被动概念的介词引导出施动者。 The power feed is engaged by the longitudinal just as . ， so. ; A is to B what /as X is to Y; no .more than; not A so much as B 1. as . as 和……一样 Jack is as tall as Bob. 杰克和汤姆一样高。 2. not so(as) . as . 和……不一样 She is not so (as) outgoing as her sister. 她不如她姐姐外向。 3. more . than （比……更……） This book is more instructive than that one. 这本书比那本书更有教育意义。,五、方式状语从句 常用引导词： as, as if, as though 特殊引导词： the way When in Rome, do as the Roman do. 入乡随俗。,She behaved as if she were the boss. 她表现得好像她是老 板。 as if, as though 两者的意义和用法相同，引出的状语从句的谓语多用虚拟语气， 表示与事实相反；有时也用陈述语气，表示所说情况是事实或 实现的可能性较大。汉语常译作“仿佛……似的”，“好像…… 似的”，例如： He looks as if (as though) he had been hit by lighting. 他那样子就像被雷击了似的。（与事实相反，谓语用虚拟语气。） It looks as if the weather may pick up very soon. 看来天 气很快就会好起来。（实现的可能性较大，谓语用陈述语气。）,