专业英语2124.docx

1、专业英语212421. The latheVocabulary:lathe 车床ordinary 普通的carry out 完成, 实现, 执行versatile 通用的workshop 车间capable 有能力的component 成分headstock 主轴箱tailstock 尾架tool-post 刀架，刀座cross-slide横向拖板job 工件matter 有关系, 要紧sidewards 横着, 向旁边地saddle 溜板箱carriage 溜板箱accommodate 提供turret 转动架，转塔revolve 旋转twist 扭曲incorporate 合并center

2、 顶尖spindle 主轴largely 主要地matter 有关系, 要紧taper 锥形nose 前端firmly 稳固的uniform 统一的rough 粗糙的chuck 卡盘lead-scerw 丝杠feed-shaft 进给杆finishing cut 精加工finish 光洁度、粗糙度front-plate 花盘jaw 夹爪drill 钻孔bore 镗孔thread 螺纹transverse 横向的engage 连结，接合，啮合pitch 螺距alter 改变reverse 反向的reversing lever 反向手柄original 最初的Text:The lathe is o

3、ne of the most useful and versatile machine in the workshop, and is capable of carrying out a wide variety of machining operations.The main components of the lathe are the headstock and tailstock at opposite ends of a bed, and a tool-post between them which holds the cutting tool. The tool-post stan

4、ds on a cross-slide which enables it to move sidewards across the saddle or carriage as well as along it depending on the kind of job it is doing.The ordinary center lathe can accommodate only one tool at a time on the tool-post, but a turret lathe is capable of holding five or more tools on the rev

5、olving turret. The lathe bed must be very solid to prevent the machine from bending or twisting under stress.The headstock incorporates the driving and gear mechanism, and a spindle which holds the workpiece and causes it to rotate at a speed which depends largely on the diameter of the workpiece. A

6、 bar of large diameter should naturally rotate more slowly than a very thin bar; the cutting speed of the tool is what matters.Tapered center in the hollow nose of the spindle and of the tail-stock hold the work firmly between them.A feed-shaft from the headstock drives the tool-post along the saddl

7、e, either forwards or backwards, at a fixed and uniform speed. This enables the operator to make accurate cuts and to give the work a good finish. Gears between the spindle and the feed-shaft control the speed of rotation of the shaft, and therefore the forward or backward movement of the tool-post.

8、 The gear which the operator will select depends on the type of metal which he is cutting and the amount of metal he has to cut off. For a deep or roughing cut the forward movement of the tool should be less than for a finishing cut.Centers are not suitable for every job on the lathe. The operator c

9、an replace them by various types of chucks, which hold the work between jaws, or by a front-plate, depending on the shape of the work and the particular cutting operation. He will use a chuck, for example, to hold a short piece of work, or work for drilling, boring or screw-cutting. A transverse mov

10、ement of the tool-post across the saddle enables the tool to cut across the face of the workpiece and give it a flat surface. For screw cutting, the operator engages the lead-screw, a long screwed shaft which runs a long in front of the bed and which rotates with the spindle. The lead-screw drives t

11、he tool-post forwards along the carriage at the correct speed, and this ensures that the threads on the screw are of exactly the right pitch. The operator can select different gear speeds, and this will alter the ratio of spindle and lead-screw speeds and therefore alter the pitch of threads. A reve

12、rsing lever on the headstock enables him to reverse the movement of the carriage and so bring the tool back to its original position.Appending:Lathe, Milling Machine, Planer, and Shaper A selection of basic machine tools shows a variety of functions and methods of crafting a workpiece. The job at ha

13、nd usually determines which tool will be used. For instance, a person making a rounded handle would use a lathe, while a person making a breadboard would use a planer. In order to use power tools efficiently and safely, either the workpiece or the actual tool must be stationary. A planer is an examp

14、le of a stationary machine tool because the workpiece is moved, or fed, into it. To use the shaper, the workpiece must be kept stationary while the tool is moved across it.Conventional machine tools prepare workpieces for further fitting and use. Drills, grinders, punch presses, surface grinders, an

15、d boring machines are used extensively in industry. Particularly useful in large-scale production, these power tools produce uniform holes and smooth surfaces far faster and more accurately than they could be produced by hand.22. Milling, Shaper, Planer and Grinding MachinesVocabulary:mill 铣削arbor 刀

16、杆spacer 垫块bushing 套筒yoke 支座，支架kneel 升降台column 立柱elevating screw 升降丝杠index head 分度头table 工作台foot stock 底座arbor yoke 刀杆支座lever 杆right 垂直的，直角的swivel 旋转transverse slide横滑板peel 削，剥chip 屑片shaper 牛头刨床planer 龙门刨床reciprocating 往复的perpendicular 垂直的normal 法向的，垂直的apron 挡板ram 滑枕stroke 行程vise 台钳，虎钳fixture 夹具rocke

17、r 摇杆regulate 调节clamp 夹紧pawl 棘爪notch 槽口ratchet 棘齿crossrail 横梁fasten 拴紧, 使固定tool head 刀架grind 磨削cylindrical 圆柱的conical 圆锥形的accurately 精确地surplus 剩余的external 外部的internal 内部的principal 主要的longitudinally 纵向地，经度地respectively 各自地concentricity 同心periphery 外围ground work 基准axis 轴心线finish 粗糙度milling machine 铣床m

18、illing cutter 铣刀universal milling machine 万能铣床cutter grinder 工具磨床surface grinder 平面磨床centerless grinder 无心磨床external grinder 外圆磨床internal grinder 内圆磨床Text:Milling machinesThe milling machine is a machine that removes metal from work with a revolving milling cutter as the work in fed against it.The m

19、illing cutter is mounted on an arbor where it is held in place by spacers or bushing. The arbor is fixed in the spindle with one end, while the other end of the arbor rotates in the bearing mounted on the arbor yoke.The most important parts of the milling machine are: 1) starting levers; 2) spindle;

20、 3) column; 4) knee; 5) elevating screw; 6) table; 7) index head; 8) speed levers; 9) feed levers; 10) table movement levers; 11) foot stock; 12) arbor yoke.The spindle of the milling machine is driven by an electric motor through a train of gears mounted in the column.The table of the plain milling

21、 machine may travel only at right angles to the spindle while the Universal Milling Machine is provided with a table that may be swiveled on the transverse slide for milling gear teeth, threads, etc.Shaper and PlanerThe machine tools of this group are generally used for machining flat surfaces, whic

22、h is usually performed by a cutter that peels the chip from the work. The main motion is reciprocating and the feed is normal (perpendicular) to the direction of the main motion.The tool and the apron of a shaper are located on the ram. A chip is peeled off the work on the forward stroke. An adjusta

23、ble table with T-slots holds work, vise, and other fixtures for holding the work.The shaper has a rocker arm which drives the ram, and a mechanism for regulating the length of the stroke. The ram supports the tool head. The head carries the downfeed mechanism and will swivel from side to side to per

24、mit the cutting of angles. This is generally a hand feed, but some shapers are required with a power downfeed in addition to the regular hand downfeed.The table of the shaper is of box form with T-slots on the top and sides for clamping the work. The cross rail is bolted directly to the frame or col

25、umn of the shaper with bolts.The automatic feed or power feed is obtained by a pawl which engages in a notched wheel or ratchet.The main parts of the planer include the bed, the table that moves back and forth, the column, the crossrail which moves up and down on the column, and the tool heads that

26、are fastened to the crossrail.Grinding machinesA grinding machine is a machine which employs a grinding wheel for producing cylindrical, conical or plane surfaces accurately and economically and to the proper shape, size, and finish. The surplus stock is removed by feeding the work against the revol

27、ving wheel or by forcing the revolving wheel against the work.There is a great variety of grinding machines. The machines that are generally used are cutter grinder, surface grinder, centerless grinder, external grinder, internal grinder.Principal parts of a Plain Grinding Machine:1. Base. The main

28、casting of a plain grinding machine is a base that rests on the floor.2. Tables.A sliding table, which is mounted on ways at the front and top of the base, may be moved longitudinally by hand or power to feed workpieces past the face of the grinding wheel.3. Headstock and Tailstock. A motor-driven h

29、eadstock and a tailstock are mounted on the left and right ends, respectively, of the swivel table for holding workpieces on centers. The headstock center on a grinder is a dead center, that is both centers are dead to insure concentricity of the periphery of ground work with its axis.4. Wheel head. A wheel head that carries a grinding wheel and its driving motor is mounted on a slide at the top and rear of the base. The wheel head may be moved per