1、機(jī)械工程專業(yè)英語 電子工業(yè)出版社Chapter55.1 Introduction Conventional machining is the group of machining operations that use single- or multi-point tools to remove material in the form of chips. Metal cutting involves removing metal through machining operations. Machining traditionally takes place on lathes, drill

2、 presses, and milling machines with the use of various cutting tools. Most machining has very low set-up cost compared with forming, molding, and casting processes. However, machining is much more expensive for high volumes. Machining is necessary where tight tolerances on dimensions and finishes ar

3、e required.5.1 譯文 傳統(tǒng)機(jī)械加工是一組利用單刃或者多刃刀具以切屑形式去除材料的加工方式。金屬切削意味著通過機(jī)械加工去除金屬。傳統(tǒng)的機(jī)械加工都是利用不同的刀具在車床、鉆床和銑床上進(jìn)行的。與成型加工、鍛壓和鑄造工藝相比，大多數(shù)機(jī)械加工的生產(chǎn)準(zhǔn)備成本都較低，然而如果是大批量生產(chǎn)，其成本要高得多。當(dāng)對零件的尺寸公差和光潔度要求較高時(shí)，機(jī)械加工是很有必要的。5.2 Turning and Lathe Turning is one of the most common of metal cutting operations. In turning, a workpiece is rotat

4、ed about its axis as single-point cutting tools are fed into it, shearing away excess material and creating the desired cylindrical surface. Turning can occur on both external and internal surfaces to produce an axially-symmetrical contoured part. Parts ranging from pocket watch components to large

5、diameter marine propeller shafts can be turned on a lathe. Apart from turning, several other operations can also be performed on lathe.axially 'æksili adv.軸向地 symmetrical si'metrikl a. 對稱的cylindrical si'lindrikl a.圓柱形的 contoured 'kntud a.顯示輪廓的，與某種形體輪廓相吻合的譯文:在金屬切削加工操作中，車削是最常見的一種。

6、在車削過程中，工件繞其軸線回轉(zhuǎn)，單刃車刀沿工件進(jìn)給，切除掉多余的材料，最后形成要求的圓柱形表面。車削可以加工外面和內(nèi)表面以形成具有軸對稱的成形工件。從懷表的零件到大直徑的船用螺旋槳軸都可以在車床上加工。 除了車削，還有另外幾種加工操作都可以在車床上進(jìn)行。Boring and internal turning. Boring and internal turning are performed on the internal surfaces by a boring bar or suitable internal cutting tools. If the initial workpiece

7、is solid, a drilling operation must be performed first. The drilling tool is held in the tailstock, and the latter is then fed against the workpiece. When boring is done in a lathe, the work usually is held in a chuck or on a face plate. Holes may be bored straight, tapered, or to irregular contours

8、. Boring is essentially internal turning while feeding the tool parallel to the rotation axis of the workpiece.譯文: 利用鏜桿或合適的內(nèi)圓車刀可以進(jìn)行鏜削和車內(nèi)圓。如果工件毛坯是實(shí)心的，首先要鉆孔。鉆頭安裝在尾架上，后者向工件進(jìn)給。如果在車床上進(jìn)行鏜削加工，工件通常裝夾在卡盤或者花盤上。鏜出的孔可以是直孔、錐孔或者不規(guī)則輪廓。當(dāng)將刀具沿工件的回轉(zhuǎn)軸線平行進(jìn)給時(shí)，鏜削實(shí)際上就是車內(nèi)圓。Facing. Facing is the producing of a flat surface a

9、s the result of a tools being fed across the end of the rotating workpiece. Unless the work is held on a mandrel, if both ends of the work are to be faced, it must be turned around after the first end is completed and then the facing operation repeated. The cutting speed should be determined from th

10、e largest diameter of the surface to be faced.Facing may be done either from the outside inward or from the center outward. In either case, the point of the tool must be set exactly at the height of center of rotation. Because the cutting force tends to push the tool away from the work, it is usuall

11、y desirable to clamp the carriage to the lathe bed during each facing cut to prevent it from moving slightly and thus producing a surface that is not flat. In the facing of casting or other materials that have a hard surface, the depth of the first cut should be sufficient to penetrate the hard mate

12、rial to avoid excessive tool wear. mandrel 'mændrl n.車床心軸 clamp klæmp v. 夾緊，夾住carriage kærid n.大刀架，拖板 penetrate 'penitreit v. 穿透，滲透tool wear 刀具磨損譯文: 車端面可以加工出一個平面，它是當(dāng)車刀沿回轉(zhuǎn)工件的端面橫向進(jìn)給的結(jié)果。除非工件固定在心軸上，如果工件兩端都要車端面，必須將一端加工完成后，將工件調(diào)頭，重復(fù)進(jìn)行車端面加工。車削速度必須由所加工表面的最大直徑來決定。車端面可以由外向內(nèi)也可以由中心向外進(jìn)行。無論哪

13、種情況，刀尖必須準(zhǔn)確地與回轉(zhuǎn)中心對正。由于切削力有將車刀推離工件的趨勢，通常最可行的就是在車端面時(shí)將拖板卡緊在床身上以避免車刀輕微移動造成加工表面不平整。在對具有硬質(zhì)表面的鑄件或其他材料進(jìn)行車端面加工時(shí)，首次切深要足以穿透硬質(zhì)材料從而避免過度的刀具磨損。Parting. Parting is the operation by which one section of a workpiece is severed from the remainder by means of cutoff tool. Because cutting tools are quite thin and must ha

14、ve considerable overhang, this process is less accurate and more difficult. The tool should be set exactly at the height of axis of rotation, be kept sharp, have proper clearance angles, and be fed into the workpiece at a proper and uniform feed rate. remainder ri'meind剩余物 ，余數(shù) overhang 'uv&#

15、39;hæ vt.懸于.之上 n.伸出;突出 uniform 'ju:nif:m a.相同的,一致的 n.制服;軍服 clearance angles 后角 譯文: 切斷是一種利用切斷刀（割刀）將工件的一部分與其剩余部分脫離的加工方法。由于切斷刀非常薄而且處于懸臂狀態(tài)，因此這種加工方法不太精確而且加工起來常常比較困難。切斷刀必須準(zhǔn)確地對正回轉(zhuǎn)軸，保持鋒利，具有合適的后角，以合適、不變的進(jìn)給率沿工件進(jìn)給。Threading. Threading can be considered as turning since the path to be travelled by the

16、cutting tool is helical. However, there are some major differences between turning and threading. While in turning, the interest is in generating a smooth cylindrical surface, in threading the interest is in cutting a helical thread of a given form and depth which can be calculated from the formulae

17、. 譯文: 車螺紋可以看作是車削，只是車刀所形成的加工軌跡是螺旋線。但二者也存在一些不同之處。車削主要考慮能否生成光滑的圓柱形表面，而車螺紋注重的是能否切出具有按公式計(jì)算出來的規(guī)定形狀和深度的螺旋線。There are two basic requirements for thread cutting. An accurately shaped and properly mounted tool is needed because thread cutting is a form-cutting operation. The resulting thread profile is determ

18、ined by the shape of the tool and its position relative to the workpiece. The second by requirement is that the tool must move longitudinally in a specific relationship to the rotation of workpiece, because this determines the lead of the thread. This requirement is met through the use of the lead s

19、crew and the split unit, which provide positive motion of carriage relative to the rotation of spindleform-cutting operation 成形加工 longitudinally l:di'tju:dinli adv.縱向lead screw 絲杠 split unit 開合機(jī)構(gòu)譯文: 車螺紋有兩個基本要求：首先，由于車螺紋是一種成形加工，因此車刀必須具有準(zhǔn)確的形狀而且要安裝合適。所切出的螺紋外形是由車刀形狀和它與工件的相對位置決定的。其次，車刀的縱向進(jìn)給與工件的回轉(zhuǎn)運(yùn)動具有特

20、定的關(guān)系，因此這決定了螺紋的導(dǎo)程。這個條件可以通過采用絲杠和開合機(jī)構(gòu)得到滿足，它們可以實(shí)現(xiàn)拖板相對于主軸回轉(zhuǎn)運(yùn)動的精確可靠的運(yùn)動1. Engine lathes 普通車床 2. Vertical lathes 立式車床 3. Turret lathes 轉(zhuǎn)塔車床5. Contouring lathes 仿形車床 6. Universal lathes 萬能車床Lathe bed is foundation of the engine lathe, which heavy, rugged casting is made to support the working parts of the la

21、the. The size and mass of the bed gives the rigidity necessary for accurate engineering tolerances required in manufacturing. On top of the bed are machined slideways that guide and align the carriage and tailstock, as they are move from one end of the lathe to the other. rugged adj. 健壯，堅(jiān)固 mass n. 質(zhì)

22、量 slideways n.導(dǎo)軌 床身是普通車床的基礎(chǔ)，它是由沉重而堅(jiān)固的鑄件制作而成的，其目的是為了支撐車床的工作部件。床身的尺寸和質(zhì)量要使車床具有足夠的剛性以保證制造過程中獲得所需的工程公差。床身上的導(dǎo)軌可以引導(dǎo)和對準(zhǔn)拖板和尾座，使它們可以從車床的一端移動到另一端。 Headstock is clamped atop the bed at left-hand end of the lathe and contains the motor that drives the spindle whose axis is parallel to the guideways through a ser

23、ies of gears housed within the gearbox. The function of gearbox is to generate a number of different spindle speeds. atop adv. 在()頂上 gearbox 齒輪箱床頭箱（主軸箱）緊固在床身上面的左端，內(nèi)裝有電機(jī)，它通過變速箱內(nèi)的一組齒輪來驅(qū)動主軸轉(zhuǎn)動，主軸的軸線平行于導(dǎo)軌。變速箱的功能是可以產(chǎn)生不同的主軸轉(zhuǎn)速。A spindle gear is mounted on the rear of the spindle to transmit power through th

24、e change gears to the feeding box that distributes the power to the lead screw for threading or to the feed rod for turning. on the rear of 在的尾部change gears 掛輪lead screw 絲杠feed rod 光杠 主軸齒輪安裝在主軸的尾部，通過掛輪把動力傳遞到進(jìn)給箱，如果是車螺紋，進(jìn)給箱將動力分配到絲杠上；如果是車削，就將動力分配到光杠上。The spindle has a through hole extending lengthwise

25、through which bar stocks can be fed if continuous production is used. The hole can hold a plain lathe center by its tapered inner surface and mount a chuck, a face plate or collet by its threaded outer surface. taper n.坡度，錐形 v.錐度加工collet n.夾頭主軸有一個縱向通孔，如果連續(xù)加工棒料，通孔就用來實(shí)現(xiàn)棒料的送料。這個通孔具有一個內(nèi)錐面，可以安裝普通車床的中心頂尖。

26、主軸的外表面車有螺紋，可以安裝卡盤，花盤或夾頭。Carriage assembly is actually an H-shaped block that sits across the guideways and in front of lathe bed. The function of the carriage is to carry and move the cutting tool longitudinally. It can be moved by hand or by power and can be clamped into position with a locking nut

27、. The carriage is composed of the cross slide, compound rest, tool saddle, and apron. 拖板組件實(shí)際上是一個H形的鑄件，位于床身的前端并橫跨在導(dǎo)軌上。拖板的功能帶動刀具縱向移動，這個可以通過手動或者自動完成。利用鎖緊螺母可以將其卡緊在所需位置。拖板組件由橫拖板，小刀架，刀架鞍板和溜板箱組成。The cross slide is mounted on the dovetail guideways on the top of the saddle and it moved back and forth at 90&

28、#176;to the axis of the lathe by the cross slide lead screw. The lead screw can be hand or power activated. dovetail 燕尾槽橫拖板安裝在刀架鞍板上部的燕尾槽導(dǎo)軌上。它利用橫拖板絲杠于車床軸線成90度夾角的方向上前后移動。絲杠可以手動或者自動驅(qū)動。The compound rest is mounted on the cross slide and can be swiveled and clamped at any angle in a horizontal plane. The

29、 compound is typically used for cutting chamfers or tapers, but must also be used when cutting thread. The compound rest can only be fed by hand. There is no power to compound rest. The cutting tool and tool holder are secured in the tool post which is mounted directly to the compound rest. swivel &

30、#39;swvl v.旋轉(zhuǎn)小刀架安裝在橫拖板上，它可以在水平面內(nèi)轉(zhuǎn)動或夾緊在任意角度位置。小刀架主要用來倒角和加工錐面，在車削螺紋時(shí)也必須用到小刀架。小刀架只能手動進(jìn)給，沒有動力傳到小刀架上。刀具和刀夾被卡緊在直接安裝在小刀架上的刀座上。The tool saddle is an H shaped casting mounted on the top of the guideways and houses the cross slide and compound rest. It makes possible longitudinal, cross and angular feeding of

31、 the tool bit. 刀架鞍板是一個安裝在導(dǎo)軌上部的H形鑄件，容納有橫拖板和小刀架。它可以實(shí)現(xiàn)刀尖的縱向、橫向和斜向進(jìn)給。The apron is attached to the front of the carriage and contains the gears and feed clutches which transmit motion from the feed rod or lead screw to carriage and cross slide. When cutting screw threads, power is provided to the gearbox

32、 of the apron by the lead screw. In all other turning operations, it is the feed rod that drives the carriage. 溜板箱位于拖板的前端，里面裝有齒輪和將運(yùn)動從光杠或絲杠傳遞至拖板或橫向拖板的進(jìn)給離合器。當(dāng)切制螺紋時(shí)，動力通過絲杠傳遞到溜板箱中的變速齒輪箱。在其它車削加工時(shí)，依靠光杠來驅(qū)動拖板。Tailstock is composed of a low base and the movable part of the tail-stock proper, the transverse a

33、djustments being made with a cross screw furnished with a square head. The two parts are hold together by the holding-down bolts which secure the tailstock to the bed.transverse adj. 橫向的，橫切的； n. 橫軸holding-down bolts 壓緊螺栓尾座由底座和尾座體的可移動部件組成。課移動部件的橫向調(diào)整有帶有四方頭的橫向絲杠來完成。底座和可移動部分通過壓緊螺栓連接在一起并將尾座固定在床身上。Chapter

34、 66.1Traditional or conventional machining, such as turning, milling, and grinding etc.，uses mechanical energy to shear metal against another substance to create holes or remove material. Non-tradition machining processes are defined as a group of processes that remove excess 傳統(tǒng)或傳統(tǒng)的加工,如車削、銑削、磨削等,使用機(jī)

35、械能剪切金屬反對另一種物質(zhì)來創(chuàng)建洞或刪除材料。非傳統(tǒng)加工過程被定義為一組進(jìn)程,去除多余material by various techniques involving mechanical, thermal,electrical or chemical energy or combinations of these energies but do not use a sharp cutting tool as it is used in traditional manufacturing processes. 1 材料的各種技術(shù)涉及機(jī)械、熱、電力或化學(xué)能源或組合這些能量但不使用鋒利的刀具,因?yàn)?/p>

36、它是用在傳統(tǒng)的制造過程。1Extremely hard and brittle materials arc difficult to be machined by traditional machining processes. Using traditional methods to machine such materials means increased demand for time and energy and therefore increases in costs; in some cases traditional machining may not be feasible.

37、 Traditional machining also results in tool wear and loss of quality in the product owing to induced residual stresses during machining. 極高的硬度、脆性材料電弧很難通過傳統(tǒng)加工過程的加工。使用傳統(tǒng)方法來機(jī)這樣的材料意味著需求增加的時(shí)間和精力,因此增加的成本;在某些情況下傳統(tǒng)加工可能不可行。傳統(tǒng)的加工刀具的磨損,也會導(dǎo)致失去質(zhì)量的產(chǎn)品由于誘導(dǎo)殘余應(yīng)力在加工過程中。Non-traditional machining processes, also called

38、unconventional machining process or advanced manufacturing processes, are employed where traditional machining processes are not feasible, satisfactory or economical due to special reasons as outlined below: 非傳統(tǒng)加工過程,也稱為非常規(guī)加工過程或先進(jìn)的生產(chǎn)工藝,采用傳統(tǒng)加工過程不可行,滿意或經(jīng)濟(jì)因特殊原因如下所示:1. Very bard fragile materials difficu

39、lt to clamp for traditional machining; 1。非常脆弱的材料很難夾巴德傳統(tǒng)加工;2. When the workpiece is too flexible or slender, 2。當(dāng)工件太靈活或苗條,3. When the shape of the part is too complex; 3。當(dāng)形狀的部分是過于復(fù)雜;4. Parts without producing buns or inducing residual stresses. 4。部分沒有生產(chǎn)面包或誘導(dǎo)殘余應(yīng)力。Traditional machining can be defined as

40、 a process using mechanical (motion) energy. 傳統(tǒng)加工可以被定義為一個流程使用機(jī)械(運(yùn)動)能量。Non-traditional machining utilizes other forms of energy; the three main forms of energy 非傳統(tǒng)加工利用其他形式的能源;三種主要形式的能量used in non-traditional machining processes are as follows: 用于非傳統(tǒng)加工過程如下:1. Thermal energy; 1。熱能;2. Chemical energy-,

41、2?；瘜W(xué)能源-,3. Electrical energy. 3。電能。Several types of non-traditional machining processes have been developed to meet extra required machining conditions. When these processes are employed properly, they offer many advantages over traditional machining processes. The common non-traditional machining p

42、rocesses are described in the following section. 幾種類型的非傳統(tǒng)加工過程已經(jīng)被開發(fā)出來,以滿足額外的要求加工條件。當(dāng)這些流程是正確使用,他們提供了許多優(yōu)點(diǎn)比傳統(tǒng)的加工過程。常見的非傳統(tǒng)加工過程是下一節(jié)描述。6.2 Electrical Discharge Machining (EDM) 6.2電火花加工(EDM)Electrical discharge machining (EDM) sometimes is colloquially referred to as spark machining, spark eroding, burning,

43、 die sinking or wire erosion. It is one of the most widely used non-traditional machining processes. The main attraction of EDM over traditional machining processes such as metal cutting using different tools and grinding is that this technique utilizes thermoelectric process to erode undesired mate

44、rials from the workpiece by a series of rapidly recurring discrete- electrical sparks between workpiece and electrode. 2 電火花加工(EDM)有時(shí)是通俗地稱為電火花加工、電火花侵蝕,燃燒,開?；蜾摻z侵蝕。這是一個最廣泛使用的非傳統(tǒng)加工過程。主要的吸引力比傳統(tǒng)的電火花加工過程,如金屬切削使用不同的工具和磨削是這種技術(shù)利用熱電過程侵蝕無用的材料工件的一系列迅速反復(fù)出現(xiàn)的離散-電火花工件和電極之間。2The traditional machining processes rely

45、on harder tool or abrasive material to remove the softer material whereas non-traditional machining processes such as EDM uses electrical spark or thermal energy to erode unwanted material in order to create desired shapes. So, the hardness of the material is no longer a dominating factor for EDM pr

46、ocess. 傳統(tǒng)的加工流程依賴?yán)щy工具或研磨材料去除軟材料而非傳統(tǒng)加工如EDM使用電火花或熱能侵蝕多余的材料以創(chuàng)建所需的形狀。所以,硬度的材料不再是一個主要因素電火花放電加工。EDM removes material by discharging an electrical current, normally stored in a capacitor bank, across a small gap between the tool (cathode) and the workpiece (anode) typically in the order of 50 volts/l0 amps.

47、 As shown in Fig-6. 1, at the beginning of EDM operation, a high voltage is applied across the narrow gap between the electrode and the workpiece. This high voltage induces an electric field in the insulating dielectric that is present in narrow gap between electrode and workpiece. This cause conduc

48、ting particles suspended in the dielectric to concentrate at the points of strongest electrical field. When the potential difference between the electrode and the workpiece is sufficiently high ,the dielectric breaks down and a transient spark discharges through the dielectric fluid, removing small

49、amount of material from the workpiece surface. The volume of the material removed per spark discharge is typically in the range of 10-5 to 10-6 mm3. The gap is only a few thousandths of an inch, which is maintained at a constant value by the servomechanism that actuates and controls the tool feed. 除

50、材料的電火花加工放電電流,通常存儲在電容器銀行,在一個小差距工具(陰極)和工件(陽極)通常在訂單50伏特/ 10安培。圖6所示。1,開始時(shí),一個高壓電火花加工操作是應(yīng)用在狹窄的電極之間的差距和工件。這個高電壓產(chǎn)生電場在絕緣介質(zhì)中存在的差距和工件之間的狹窄電極。這導(dǎo)致導(dǎo)電粒子懸浮在介質(zhì)集中點(diǎn)的最強(qiáng)的電場。當(dāng)潛在的區(qū)別和工件的電極是足夠高,電介質(zhì)分解和瞬時(shí)放電通過電介質(zhì),消除少量的材料從工件表面。材料去除的體積每火花放電通常在10 - 5到10 - 6的范圍mm3。這個差距只有幾英寸的秒這個級別,這是維持在一個恒定值由伺服機(jī)構(gòu),促動和控制工具進(jìn)給。Chapter 77.1 Introduction

51、 7.1引入Quality and accuracy are major considerations in making machine parts or structures. 質(zhì)量和準(zhǔn)確性是主要的考慮因素在制造機(jī)零件或結(jié)構(gòu)。Interchangeable parts require a high degree of accuracy to fit together. With increasing accuracy or less variation in the dimension, the labor and machinery required to manufacture a p

52、art is more cost intensive. l Any manufacturer should have a thorough knowledge of the tolerances to increase the quality and reliability of 'a manufactured part with the least expense. 具有互換性的零件需要一個高精確度來組裝在一起。隨著準(zhǔn)確性或更少的變異在尺寸、勞動和機(jī)械需要制造一個部分是更多的成本密集型。是任何制造商應(yīng)該有一個全面的知識的公差,以便提高質(zhì)量和可靠性的一個制造最少的部分費(fèi)用。An eng

53、ineering drawing must be properly dimensioned in order to convey the designer's intent to the end user. Dimensions of parts given on blueprints and manufactured to those dimensions should be exactly alike and fit properly. Unfortunately, it is impossible to make things to an exact or dimension.

54、Most dimensions have a varying degree of accuracy and a means of specifying acceptable limitations in dimensional variance so that a manufactured part will be accepted and still function. It is necessary that the dimensions, shapes and mutual position of surfaces of individual parts are kept within

55、a certain accuracy to achieve their correct and reliable functioning. Routine production processes do not allow maintenance (or measurement) of the given geometrical properties with absolute accuracy. 2 Actual surfaces of the produced parts therefore differ from ideal surfaces prescribed in drawings

56、. Deviations of actual surfaces are divided into four groups to enable assessment, prescription and checking of the permitted inaccuracy during production: 一個工程圖紙必須得到適當(dāng)?shù)某叽?以傳達(dá)設(shè)計(jì)者的意圖給最終用戶。維度上給出的部分設(shè)計(jì)圖和制造這些維度應(yīng)該完全一樣,恰到好處。不幸的是,它是不可能讓事情一個確切的或維度。大多數(shù)維度有不同程度的準(zhǔn)確性和一種方式來指定可接受的限制在維方差這樣一個人造的部分會被接受,還是函數(shù)。這是必要的,尺寸、形

57、狀和表面的相互位置的各個部分都保持在一定的精度,達(dá)到他們的正確和可靠的功能。日常生產(chǎn)過程不允許維護(hù)(或測量)給定的幾何屬性以絕對的精度。2實(shí)際表面產(chǎn)生部分因此不同于理想的表面在圖紙規(guī)定。偏離實(shí)際的表面分為四組,使評估、處方和檢查錯誤的允許生產(chǎn)過程中:1. Dimensional deviations; 1。尺寸偏差;2. Shape deviations; 2。形狀的偏差;3. Position deviations; 3。位置偏差;4. Surface roughness deviations. 4。表面粗糙度的偏差。As mentioned above, it is principally

58、 impossible to produce machine parts with absolute dimensional accuracy. In fact, it is not necessary or useful. It is quite sufficient that the actual dimension of the part is found between two limit dimensions and a permissible deviation is kept with production to ensure correct functioning of engineering products. The required level of accuracy of the given part is then given by the dimensional tolerance whic