機(jī)械外文翻譯

1、外文資料Herbert W. Yankee Manufacturing Processes M Prentice-Hall Inc., 1979Medium-Production Lathes Duplicating Lathe: Duplicating (or tracer) lathes are designed to produce duplicate parts by semiautomatic means. Except f tape-controlled lathes (discussed in Chapter 21), the operator is required to lo

2、ad and unload the work pieces and to start the automatic operation for each cutting cycle. One single-point cutting tool is used. Straight, tapered, and contoured turned or faced surfaces and bored holes are repetitively produced by the motion of a stylus as it follows the outline of a low-cost temp

3、late. The template is generally mounted at the rear of the machine. The movements of the stylus are actuated by mechanical, air, hydraulic, or electrical methods. Work may be held between centers or chucked. Duplicating or tracer attachments are generally factory-installed on a standard engine lathe

4、, although special machines are also available. Turret Lathe: Turret lathes are semiautomatic machine tools which can produce parts in greater quantities, to closer tolerances, faster, and as a result more economically than is possible by conventional engine lathes. Unlike the engine lathe, the turr

5、et lathe is not restricted to a single cutting tool. A leading advantage is that several operations may be performed on a work pace at a given time. It should be noted, however, that the range and types of turret lathe operations are essentially the same as those associated with the engine lathe.FIG

6、URE 16-6 Turret lathe production part (Courtesy, Jones Lamson) Figure 16-6 illustrates examples of turret lathe production parts. To offset the need for frequent tool changes, a six-sided turret is used in place of a tailstock. The turret may easily be indexed so that any desired cutting tool may co

7、ntact the work piece. Additional cutting tools may be placed in square turrets on the cross slide and may be readily indexed to machine other surfaces. Unlike a cutting tool used on an engine lathe, once turret lathe tools have been properly inserted in one of the various tooling stations, they need

8、 not be remove until they require sharpening or after the production run has been completed. Finally, there is also available a single tool holder on a turret lathe which is mounted with a cutting tool on the rear of the cross slide. Full advantage of the versatility and adaptability of the engine l

9、athe can be obtained only in cases where the services of a highly skilled machinist are available. Skilled labor is expensive. Parts produced by engine lathe operations are usually more costly than similar parts produced on a turret lathe. Turret lathe production costs are often minimized by using s

10、killed setup men whose job it is to set and adjust the tools, leaving the simple and repetitive operations for the lower-pay-scale machine operators.FIGURE 16-7 Ram-type universal turret lathe( Courtesy, Jones Lamson) Turret lathes may be classified as horizontal and vertical. The two leading types

11、of horizontal turret lathes are ram type, shown in Figure 16-7, and the saddle type. Both types are suited to bar(cylindrical turning) and chucking work. The ram-type turret lathe is best suited for light bar work and small chucking jobs, while the saddle-type turret lathe is primarily used for long

12、er bar work and for heavier chucking work pieces. Figure 16-8 shows a numerically controlled four-axis turret lathe. Ideal for bar and chucking work, they can also handle between-centers shaft work.FIGURE 16-8 A four-axis numerically controlled turret lathe( Courtesy, Giddings Lewis-Bickford Machine

13、 Compangy) Vertical turret lathes are designed for considerably larger and heavier work than is commonly associated with either type of horizontal turret lathes. Vertical machines are utilized solely for complex chucking work, particularly for boring operations, and are not adapted to bar work. An e

14、xample of a vertical turret is shown in Figure 16-9. FIGURE16-9 A vertical turret lathe with a 36 in. diameter table (Courtesy, The Bullard Company)High-Production Lathes It is difficult to precisely classify the various types of turning machines strictly according to their production output, Machin

15、es previously discussed are all reasonably similar, in that each type requires operator attention to an extent that varies form “considerable” to “only occasional.” The types of high-production lathes selected for following discussion are those that run almost continuously. Sones are fully automatic

16、 and require only occasional operator attention. Automatics Screw Machines: Automatic screw machines (or automatic bar machines) were originally designed for the high production of screws and various other threaded fasteners. The basic beginnings of this machine date back to the 1880s, when the firs

17、t machine was developed. The machine is essentially an advanced form of a turret lathe which fashions a wide range of parts is large quantities form bar stock. High output of intricate mechanisms designed to automatically feed single and continuous lengths of stock, index the turret for the desired

18、sequence of the proper cutting tools, and retract the tool after cutting. Contrary to the designation “screw machine,” production is not limited to threaded parts. The process is adaptable to the economical production of turned and formed parts of almost unlimited configuration, as shown in Figure 1

19、6-10.FIGURE 16-10 Typical Brown Sharp produced on a screw machine ( Courtesy, e Manufacturing Co.)parts FIGURE 16-11 A single spindle screw machine (Courtesy. Brown Sharpe Manufacturing Co.)FIGURE 16-12 A close-up view of cutting tools in a six-station turret ( Courtesy, Brown Sharpe Manufacturing C

20、o.) A automatic screw machines may be classified as single-spindle automatics，multiple-spindle automatics, and automatic chucking machines. An example of a single-spindle bar automatic screw machine is shown in Figure 16-11. Bar stock (ranging from round, square , hexagonal, or other cross-sectional

21、 shapes) is fed through a revolving hollow spindle at the beginning of each cycle of operation. The stock is stopped at a predetermined distance and held during the cutting operations in a cullet. Cutting tools are mounted around a six-station turret shown in Figure 16-12, which rotates in a vertica

22、l plane in a Ferris wheel motion. The turret is fixed to a slide which gives it longitudinal movement. There is a cross slide on which additional tools may be mounted in positions on the front as well as to the rear. The various cutting tool movements are obtained by means of cams mounted on shafts

23、which are geared together on three sides of the machine. Mounted “dogs” engage various trip levers to control the sequence of operations on the machine.FIGURE 16-13(a) A Vertical chucking machine ( Courtesy, The Bullard Co.)FIGURE 16-13(b) A horizontal chucking machine ( Courtesy, The Warner Swazi C

24、o.)The principles that apply to the tolling arrangement of single-spindle-bar automatic screw revolving work spindle. The spindle carrier indexes and automatically moves the stock from one cutting station to another. The required cutting operations are machines apply ascrew machines. Instead of a si

25、ngle spindle, however, spindle machines may havlso to multiple-spindle-bar automatic e four, five, six, or eight hollow spindles. Bars of stock are loaded into each continuously performed on the stock in progressive stages as the work piece proceeds from one station to another, ending with the compl

26、eted part as it is cut off from its original bar. Figure 16-13a and illustrates two types of chucking machines designed for machining castings, forgings, pressed parts, and other shapes that cannot be machined from bar stock. Automatic chucking machines are capable of performing most of the operatio

27、ns normally associated with the multiple-spindle-bar automatics machine. A numerically controlled two-axis twin-turret bar chucker is shown in Figure 16-14. It is common practice for an operator to handle or service two or more automatic machines once they have been properly tooled. Figure 16-15 ill

28、ustrates some typical parts machined on a vertical chucking machine.FIGURE 16-14 Two-axis twin bar checkers are well suited for either bar or chucking work This machine has a 14 tool capacity that inherently reduces tool-changing time. ( Courtesy, Giddings Lewis-Bickford Machine Co.) FIGURE 16-15 Ty

29、pical parts machined on a vertical chucking machine . (Courtesy, The Warner Swasay Co.)FIGURE 16-16 A Swiss-automatic screw machine (Courtesy, American Belcher Corporation)FIGURE 16-17 A close-up view showing the tooling and the slides on a Swiss automatic screw machine ( Courtesy, American Belcher

30、Corporation) Swiss-Type Automatic Screw Machine：An example of a Swiss-type automatic screw machine is shown in Figure 16-16, with a close up in the tooling and slides in Figure 16-17.It differs widely in design and function from other types of screw machines. A revolving piece of stock is fed throug

31、h a carbide-lined guide bushing into the path of five radically, mounted tools which are individually cam-controlled. edges of the single-point cutting tools which are used in this process are set to contact the stock as close as a few thousands of an inch but never more than in (0.794 mm) away from

32、 the end of the guide bushing. Accurate parts may be produced in this manner because the firmly held work is prevented from springing away form the cutting tool. Special combining such as tapers and multiple diameters are possible by combining the forward or dwell movements of the headstock and the

33、in and out tool movements.FIGURE 16-18 Examples of Swiss automatic machine production parts ( Courtesy, American Belcher Corporation ) 中文譯文中等生產(chǎn)率的車(chē)床 仿形車(chē)床: 仿形車(chē)床是為了通過(guò)半自動(dòng)的方法生產(chǎn)完全一樣的零件而被設(shè)計(jì)的，除了程序控制車(chē)床（詳見(jiàn)21章），裝上、卸下工件以及每個(gè)切割周期自動(dòng)運(yùn)轉(zhuǎn)的啟動(dòng)是需要由操作員完成的。使用一個(gè)單切削刀具，模板通常裝在機(jī)器的后部。通過(guò)機(jī)械、空氣、水壓、或者電的方法促使觸針的移動(dòng)，盡管專(zhuān)門(mén)的機(jī)床也是可以的，但是仿形車(chē)床的

34、附件出廠時(shí)一般都安裝在一個(gè)標(biāo)準(zhǔn)的普通車(chē)床上。 轉(zhuǎn)塔車(chē)床：轉(zhuǎn)塔車(chē)床是半自動(dòng)的機(jī)床，它比常規(guī)的發(fā)動(dòng)機(jī)車(chē)床生產(chǎn)的零件數(shù)量更大，公差更小，速度快所以經(jīng)濟(jì)要更好。不同于發(fā)動(dòng)機(jī)車(chē)床，轉(zhuǎn)塔車(chē)床不局限于單一的切削工具。他最主要的優(yōu)點(diǎn)是有些操作可以在給足時(shí)間完成工件的加工。圖16-6 轉(zhuǎn)塔機(jī)床生產(chǎn)零件（經(jīng)瓊斯和拉姆森同意轉(zhuǎn)載） 圖16-6是轉(zhuǎn)塔車(chē)床生產(chǎn)零件的實(shí)例。用一個(gè)方面的小塔代替尾座，是為了抵消頻繁換刀。然而，應(yīng)該注意的是轉(zhuǎn)塔車(chē)床操作范圍和類(lèi)型與發(fā)動(dòng)機(jī)車(chē)床基本上是相同的。最后轉(zhuǎn)塔車(chē)床上的單一工具架也可以帶著切削工具安裝在后部的橫向滑塊上。普通車(chē)床的通用性和適應(yīng)性只有在熟練的機(jī)械師的情況下能被充分利用，熟練工

35、是昂貴的。有發(fā)動(dòng)機(jī)車(chē)床操作下生產(chǎn)的零件比轉(zhuǎn)塔車(chē)床生產(chǎn)相同的零件花費(fèi)要多。將轉(zhuǎn)塔車(chē)床生產(chǎn)成本減到最少的方法是讓熟練的安裝工人設(shè)置和調(diào)整工具，讓低工資等級(jí)的機(jī)器操作員進(jìn)行簡(jiǎn)單重復(fù)的操作。轉(zhuǎn)塔車(chē)床可分為臥式和立式兩類(lèi)。臥式轉(zhuǎn)塔車(chē)床的兩種主要類(lèi)型是鞍座式和滑塊式（見(jiàn)圖16-7）兩種類(lèi)型都適合車(chē)削和卡盤(pán)工作。滑塊式轉(zhuǎn)塔車(chē)床最合適于輕的棒狀加工以及小的卡盤(pán)工作而鞍座式轉(zhuǎn)塔車(chē)床主要用于加工較長(zhǎng)的棒狀工件以及較重的卡盤(pán)的工件。圖16-8是四軸數(shù)控轉(zhuǎn)塔車(chē)床。理想的棒狀以及卡盤(pán)的車(chē)削加工是它們也可以操作中心與軸之間的工作。塊從一個(gè)站到另一個(gè)收益,以完成的部分,因?yàn)樗乔袛嗔藦脑瓉?lái)的地點(diǎn)計(jì)的機(jī)器加工鑄件、鍛件、擠壓

36、零件和其他形狀,不能加工棒料。圖16-7常規(guī)的滑塊式轉(zhuǎn)塔車(chē)床（經(jīng)瓊斯和拉姆森同意轉(zhuǎn)載） 圖16-8 四軸數(shù)控轉(zhuǎn)塔車(chē)床（經(jīng)吉丁斯和劉易斯比其福德公司同意轉(zhuǎn)載） 立式車(chē)床是為了較大和較重的工作而被設(shè)計(jì)的，它與臥式車(chē)床的兩周類(lèi)型有關(guān)聯(lián)。立式車(chē)床可以單獨(dú)完成復(fù)雜的卡盤(pán)工作，特別是鉆孔操作，不適應(yīng)棒狀物的操作。圖16-9是立式車(chē)床的實(shí)例。 36mm工作臺(tái)的立式車(chē)床（經(jīng)布拉得公司同意轉(zhuǎn)載）高產(chǎn)車(chē)床 嚴(yán)格按照不同的產(chǎn)品輸出是很難準(zhǔn)確劃分機(jī)床的類(lèi)型。前面討論的機(jī)器都是相當(dāng)類(lèi)似的，因?yàn)槟持茴?lèi)型的機(jī)器都需要操作員注意到從“可觀的”到“偶爾”的程度。下面選擇討論的高產(chǎn)車(chē)床的類(lèi)型幾乎是可以連續(xù)運(yùn)行的。有些是全自動(dòng)的，只需要操作員偶爾注意。 自動(dòng)螺紋車(chē)床：自動(dòng)螺紋車(chē)床最初是被設(shè)計(jì)用于高產(chǎn)量的螺釘和其他螺紋緊固件的生產(chǎn)。自動(dòng)螺紋車(chē)床的開(kāi)發(fā)可以追溯到19世紀(jì)80年代。自動(dòng)螺紋車(chē)床基本上是轉(zhuǎn)塔車(chē)床的高級(jí)形式，它可以把棒料形成大批量且范圍廣的零件?？苫Q的高輸出可能是由于被設(shè)計(jì)用來(lái)自動(dòng)單次和連續(xù)送料的復(fù)雜的機(jī)械裝