外文翻譯--基本的加工工序—切削，鏜削和銑削

1、<p><b>　　英文原文</b></p><p>　　Basic Machining Operations</p><p>　　Machining tools have evolved from the early foot –powered lathe Egyptians and John Wilkinson’s boring mill. They a

2、re designed to provide rigid support for both the workpiece and the cutting tool and cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically,

3、in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the from of a severely deformed chip</p><p>　　Most machine operations produce

4、 parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is produced, an

5、d the operation is called turning. If a hollow tube is on the machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface of uniformly varying diameter is called tape

6、r turning. If the tool point </p><p>　　Flat or plane surface are frequently required. They can be generated by radial turning or facing, in which the tool point moves normal to the axis of rotation. In other

7、 cases, it is more convenient to hole the workpiece steady and reciprocate the tool across , it is series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called plannin

8、g and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpi</p><p>　　Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for hol

9、es with depths up to 5 to 10 times the drill diameter. Whether the drill turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary

10、cutter with a number of cutting edges engages the workpiece, which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter an</p><p>　　Ba

11、sic Machine Tools</p><p>　　Machine tools are used to part of a specified geometetrical shape and precise size by removing metal from a ductile material in the form chips. The latter are a waste product and v

12、ary from long continuous ribbons of a disposal point of view, to easily handed well-broken chips resulting from cast iron. Machine tools perform five basic metal-remove processes: turning, planning, drilling, milling, an

13、d grinding. All other metal-removal processes are modifications of these five basic processes. For e</p><p>　　The amount and rate of material removed by the various machining processes may be large, as in he

14、avy turning operations, or extremely small, as in lapping or superfinishing operations where only the high spots of a surface are removed.</p><p>　　A machining tool performs three major functions: 1. it rigi

15、dly supports the workpice or its holder and the cutting tool; 2. it provides relative motion between the workpice and the cutting tool; 3. it provides a range of feeds and speeds usually ranging from 4 to32 choices in ea

16、ch case.</p><p>　　Speed and Feeds in Machining </p><p>　　Speeds, feeds, and depth pf cut are the three major variables for economical machining. Other variables are the work and tool materials,

17、coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables.</p><p>　　The depths of cut, feed, and cutting speed are machine setting that

18、must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed

19、(V) is represented by the velocity of the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance of the needle radially inward per revolution, or is the differenc</p&g

20、t;<p>　　Turning on lathe centers</p><p>　　The basic operations operations performed on an engine lathe are illustrated in fig. 11-3. those operations performed on external surfaces with a single poin

21、t cutting tool are called turning. Except for drilling, reaming, and tapping, the operations on internal surfaces are also performed by a single point cutting tool.</p><p>　　All machining operate, including

22、turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing operation is to remove the bulk of the material as rapidly and as efficiently as possible, while leaving a smal

23、l amount of material on the work-piece for the finishing operation. Finishing operations are performed to obtain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will prece

24、de the finishing operation </p><p>　　Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in th

25、e end of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while end near the headstock may be supported by a head

26、stock center or held in a chuck. The headstock end of the workpiece may be held in a four-jaw chuck, or in a c</p><p>　　Very precise results can be obtained by supporting the workpiece between two centers.

27、 A lathe dog is clamped to the workpiece; together they are driven by the driver plate mounted on the spindle nose. One end of the workpiece is machined; then the workpiece can be turned around in the lathe to machine to

28、 other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece and to resist the cutting forces. After the wor</p><p>　　Whil

29、e very large diameter workpiece are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaws to obtain the smooth power transmission; moreover, large lathe dogs that are adequate

30、to transmit the power not generally available, although they can be made as a special. Faceplate jaws are like chuck jaws except that they are mounted on a faceplate, which has less overhang from the spindle bearings tha

31、n a large chuck would have.</p><p><b>　　Boring</b></p><p>　　The objective of boring a hole in a lathe is:</p><p>　　1、To enlarge the hole </p><p>　　2、To mach

32、ine the hole to the desired diameter</p><p>　　3、To accurately locate the position of the hole </p><p>　　4、To obtain a smooth surface finish in the hole</p><p>　　The motion of the bo

33、ring tool is parallel to the axis of the lathe when the carriage is moved in the longitudinal direction and the work piece revolves about the axis of the lathe. When these two motions are combined to bore a hole, it will

34、 be concentric with the axis of rotation of the lathe. The position of the hole can be accurately located by holding the work piece in the lathe so that the axis about which the hole is to be machined coincides with the

35、axis of rotation of the lathe. When the </p><p>　　The boring tool is held in a boring bar which is fed through the hole by carriage. Variations of this design are used, depending on the job to be done. The l

36、ead angle used, if any, should always be small. Also, the nose radius of the boring tool must not be too large. The cutting speed used for boring can be equal to the speed for turning. However, when the spindle speed of

37、the lathe is calculated, the finished, or largest, bore diameter should be used. The feed rate for boring is usually somewh</p><p>　　The boring operation is generally performed in two steps; namely, rough bo

38、ring and finish boring. The objective of the rough-boring operation is to remove the excess metal rapidly and efficiently, and the objective of the finish-boring operation is to obtain the desired size, surface finish, a

39、nd location of the hole. The size of the hole is obtained by using the trial-cut procedure. The diameter of the hole can be measured with inside calipers and outside micrometer calipers. Basic Measuring Ins</p>&l

40、t;p>　　Cored holes and drilled holes are sometimes eccentric with respect to the rotation of the lathe. When the boring tool enters the work, the boring bar will take a deeper cut on one side of the hole than on the ot

41、her, and will deflect more when taking this deeper cut, with the result that the bored hole will not be concentric with the rotation of the work.. This effect is corrected by taking several cuts through the hole using a

42、shallow depth of cut. Each succeeding shallow cut causes the resultin</p><p>　　Shoulders, grooves, contours, tapers, and threads are also bored inside of holes. Internal grooves are cut using a tool that is

43、similar to external grooving tool. The procedure for boring internal shoulder is very similar to the procedure for turning shoulders. Larger shoulders are faced with the boring tool positioned with the nose leading, and

44、using the cross slide to feed the tool. Internal contours can be machined using a tracing attachment on a lathe. The tracing attachment is mounted on th</p><p><b>　　Milling</b></p><p&g

45、t;　　Milling is a machining process for removing material by relative motion between a workpiece and a rotating cutter having multiple cutting edges. In some applications, the workpiece is held stationary while the rotati

46、ng cutter is moved past it and a given feed rate (traversed). In other applications, both the workpiece and cutter are moved in relation to each other and in relation to the milling machine. More frequently, however, the

47、 workpiece is advanced at a relatively low rate of movement or f</p><p>　　Since both the workpiece and cutter can be moved relative to one another, independently or in combination, a wide variety of operatio

48、ns can be performed by milling. Applications include the production of flat or contoured surfaces, slots, grooves, recesses, threads, and other configurations. </p><p>　　Milling is one of the most universal,

49、 yet complicated machining methods. The process has more variations in the kinds of machines used, workpiece movements, and types of tooling than any other basic machining method. Important advantages of removing materia

50、l by means of milling include high stock removal rates, the capability of producing relatively smooth surface finishes, and the wide variety if cutting tools that are available. Cutting edges of the tools can be shaped t

51、o form any complex surf</p><p>　　The major milling methods are peripheral and face milling; in addition, a number of related methods exist that are variations of these two methods, depending upon the type of

52、 workpiece or cutter. </p><p>　　Peripheral Milling </p><p>　　On peripheral milling, sometimes called slab milling, the milled surface generated by teeth or inserts located in the periphery of th

53、e cutter body is generally in a plane parallel to the cutter axis. Milling operations with form-relieved and formed profile cutters are included in this class. The cross section of the milled surface corresponds to the o

54、utline or contour of the milling cutter or combination of cutters used. </p><p>　　Peripheral milling operations are usually performed on milling machines with the spindle positioned horizontally, however, th

55、ey can also be performed with end mills on vertiasl-spindle machines. The milling cutters are mounted on an arbor which is generally supported at the outer end for increased rigidity, particularly when, because of the co

56、nditions of the setup, the cutter or cutters are located at some distance from the nose of the spindle. Peripheral milling should generally not be done if </p><p>　　Face Milling </p><p>　　Face m

57、illing is done on both horizontal and vertical milling machines. The milled surface resulting from the combined action of cutting edges located on the periphery and face of the cutter is generally at right angles to the

58、cutter axis. The milled surface is flat, with no relation to the contour of the teeth, except when milling is done to a shoulder. Generally, face milling should be applied wherever and whenever possible.</p><p

59、>　　Chip thickness in conventional (up) face milling varies from a minimum at the entrance and exit of the cutter tooth to a maximum along the horizontal diameter. The milled surface is characterized by tooth and revol

60、ution marks, as in the case of peripheral milling cutters. The prominence of these marks is controlled by the accuracy of grinding the face cutting edge of the teeth, or by the accuracy of the body/insert combination in

61、indexable cutters and of mounting the cutter so that it runs true </p><p>　　In face milling, it is important to select a cutter with a diameter suited to the proposed width of cut if best results are to be o

62、btained. Cuts equal in width to the full cutter diameter should be avoided, if possible, since the thin chip section at entry of the teeth results in accelerated tooth wear abrasion plus a tendency for the chip to weld o

63、r stick to the tooth or insert and be carried around and recut. This is detrimental to surface finish. A good ratio of cutter diameter to the width o</p><p><b>　　中文譯文</b></p><p>　　基本

64、的加工工序—切削，鏜削和銑削</p><p>　　機(jī)床是從早期的埃及人的腳踏動力車床和約翰.威爾金森的鏜床發(fā)展而來的。它們用于為工件和刀具兩者提供剛性支撐并且可以精確控制它們的相對位置和相對速度。一般來說，在金屬切削中用一個(gè)磨尖的楔形工具以緊湊螺紋形的切屑形式從有韌性工件表面上去除一條很窄的金屬。切屑是廢棄的產(chǎn)品，與其工件相比，它相當(dāng)短但是比未切削的部分厚度有相對的增加。機(jī)器表面的幾何形狀取決于刀具的形狀以及加工

65、過程中刀具的路徑。</p><p>　　不同的加工工序生產(chǎn)出不同幾何形狀的部件。如果一個(gè)粗糙的柱形工件繞中心軸旋轉(zhuǎn)而且刀具穿透工件表面并沿與旋轉(zhuǎn)中心平行的方向前進(jìn)，就會產(chǎn)生一個(gè)旋轉(zhuǎn)面，這道工序叫車削。如果以類似的方式加工一根空心管的內(nèi)部，則這道工序就叫鏜削。制造一個(gè)直徑均勻變化的錐形外表面叫做錐體車削。如果刀具尖端以一條半徑可變的路徑前進(jìn)，就可以制造出象保齡球桿那種仿形表面；如果工件足夠短而且支撐具有足夠的剛性，

66、仿形表面可以通過用一個(gè)垂直于旋轉(zhuǎn)軸的仿形刀具來制造。短的錐面或柱面也可以仿形切削。</p><p>　　常常需要的是平坦的或平的表面。它們可以通過徑向車削或端面車削來完成，其中刀具尖端沿垂直于旋轉(zhuǎn)軸的方向運(yùn)動。在其他情況下，更方便的是固定工件不動，以一系列直線方式往復(fù)運(yùn)動刀具橫過工件，在每次切削行程前具有一定橫向進(jìn)給量。這種龍門刨削和牛頭刨削是在刨床上進(jìn)行的。大一些的工件很容易保持刀具固定不動，而像龍門刨削那樣在

67、其下面拉動工件，再每次往復(fù)進(jìn)給刀具。仿形面可以通過使用仿形刀具來制造。</p><p>　　也可以使用多刃刀具。鉆削使用兩刃刀具，深度可達(dá)鉆頭直徑的5-10倍。不管是鉆頭轉(zhuǎn)動還是工件轉(zhuǎn)動，切削刃與工件之間的相對運(yùn)動都是一個(gè)重要因素。在銑削作業(yè)中，有許多切削刃的旋轉(zhuǎn)銑刀與工件相接合，這種工件相對銑刀運(yùn)動緩慢。根據(jù)銑刀的幾何形狀和進(jìn)給的方式，可以加工出平面和仿形面?？梢允褂盟交虼怪毙D(zhuǎn)軸，工件可以沿三個(gè)坐標(biāo)方向中的

68、任意一個(gè)進(jìn)給。</p><p><b>　　基本的機(jī)床</b></p><p>　　機(jī)床用于以切屑的形式從韌性材料上去除金屬來加工特殊幾何形狀和精密尺寸的部件。切屑是廢品，其變化形狀從像鋼這樣的韌性材料的長的連續(xù)帶狀屑到鑄鐵形成的易于處理、徹底斷掉的切屑，從處理的觀點(diǎn)來講，不想要長的連續(xù)帶狀屑。機(jī)床完成5種基本的金屬切削工藝：車削、刨削、鉆削、銑削和磨削。其他所有金屬

69、切削工藝都是這5種基本工藝的變形。例如：鏜削是內(nèi)部車削；鉸削、錐體車削和平底锪孔則修改鉆孔，與鉆削有關(guān)；滾齒與切齒是基本銑削作業(yè)；弓鋸削和拉削是銑削和磨削的一種形式；而研磨、超精加工、拋光和磨光是磨削和研磨切削作業(yè)的各種變化形式。因此，僅有4種使用專用可控幾何形狀的刀具基本機(jī)床：1、車床，2、刨床，3、鉆床，4、銑床。磨削工藝形成碎屑，但是磨粒的幾何形狀不可控制。</p><p>　　不同加工工藝切削的材料的數(shù)量

70、和速度卻不相同?？赡軜O大，如大型車削作業(yè)；或者極小，如磨削和超精加工作業(yè)，只有表面高出的點(diǎn)被去除。</p><p>　　機(jī)床完成3種主要功能：1、剛性支撐工件或工件夾具以及切削刀具；2、提供工件與切削刀具之間的相對運(yùn)動；3、提供了一定范圍的速度進(jìn)給，通常每種有4-32種選擇。</p><p><b>　　切削速度和進(jìn)給</b></p><p>

71、　　切削速度、進(jìn)給量和切削深度是切削加工的3個(gè)主要變量，其他變量還有工件和工具材料、冷卻劑以及切削刀具的幾何形狀。金屬切削的速率和加工所需的功率就決定于這些變量。</p><p>　　切削深度、進(jìn)給量和切削速度是任何金屬切削作業(yè)中必須都建立的變量。它們都影響切削力、功率和對金屬切削的速率?？梢酝ㄟ^把它們與留聲機(jī)的唱針和唱片相比較給出定義。切削速度（V）由任意時(shí)刻唱片表面相對于拾音器支臂內(nèi)部的唱針的速度來表示；進(jìn)給

72、量由唱針每圈徑向向內(nèi)的前進(jìn)量或者由兩個(gè)相鄰槽的位置差來表示。切削深度是唱針進(jìn)入的量或者是槽的深度。</p><p><b>　　切削</b></p><p>　　那些在外表面上用單刃刀具完成的工序叫車削。除鉆削、鉸削和錐體車削外，在內(nèi)表面的作業(yè)也由單刃刀具完成。</p><p>　　包括車削和鏜削在內(nèi)的所有加工工序都可以分為粗加工、精加工和半精

73、加工。粗加工工序的目的是盡可能迅速且高效地去除大量的材料，在工件上只留下少量的材料給精加工工序。精加工工序用以獲得工件最終的大小、形狀和表面粗糙度。有時(shí)，在精加工工序前進(jìn)行半精加工作業(yè)以便在工件上留下少的、預(yù)定的和均勻量的原材料供精加工去除。</p><p>　　通常，較長的工件是在一個(gè)或兩個(gè)車床頂尖的支撐下進(jìn)行的。用于安裝車床頂尖的錐形孔叫做頂尖孔，它是在工件的端部鉆出的——通常沿著柱形部件的軸心。與尾架鄰近的

74、工件端部總是由尾架頂尖支撐，而挨著主軸箱的一端則由主軸箱頂尖支撐或裝在卡盤內(nèi)。工件的主軸箱一端可以裝在一個(gè)四爪卡盤或套爪卡盤內(nèi)。這種方法牢固地夾持工件并且把功率平穩(wěn)地傳送到工件上；由卡盤提供的額外支撐減少了車削作業(yè)時(shí)發(fā)生震動的傾向。如果仔細(xì)地將工件精確的固定在卡盤上，用這種方法將獲得精密的結(jié)果。</p><p>　　通過將工件支撐在兩個(gè)頂尖之間可以獲得非常精確的結(jié)果。一個(gè)車床夾頭夾在工件上；然后由安裝在主軸前端的

75、撥盤一起帶動。先加工工件的一端，然后可以在車床上將工件掉頭加工另一端。工件上的頂尖孔是用作精確定位面以及承受工件重量和抵抗車削力的支撐面。在工件被拆下后，頂尖孔可以精確地將其裝回機(jī)床。工件千萬不要同時(shí)通過卡盤和頂尖安裝在主軸箱一端。雖然這樣似乎是一種快捷方法，但是這樣做使得工件受力不均勻，頂尖的對正作用不能維持，而且爪的壓力可能損壞頂尖孔、車床頂尖甚至車床主軸。幾乎被獨(dú)自用在大量生產(chǎn)工件上的補(bǔ)償或浮動爪式卡盤是上述的一個(gè)例外。這些卡盤是

76、自動偏心夾緊卡盤不能起到普通三爪或四爪卡盤同樣的作用。</p><p>　　直徑非常大的工件雖然有時(shí)安裝在兩個(gè)頂尖上，但是最好用花盤把它們固定在主軸箱端以獲得流暢的動力傳輸；此外，可以把它們制造成專用部件，但是一般不能提供足夠大的車床夾頭來傳輸動力。除非是安裝在花盤上，其主軸軸承上的外伸要比大卡盤上的少一些。</p><p><b>　　鏜削</b></p>

77、;<p>　　在車床上鏜孔的目的是：</p><p><b>　　1、擴(kuò)孔；</b></p><p>　　2、把孔加工到所需直徑；</p><p>　　3、精確的為孔定位；</p><p>　　4、在孔內(nèi)獲得好的表面粗糙度。</p><p>　　當(dāng)?shù)毒邚较蛄锇蹇v向移動而工件繞車床的軸

78、線旋轉(zhuǎn)時(shí)，鏜刀的運(yùn)動平行于車床上的軸線。當(dāng)兩種運(yùn)動結(jié)合起來鏜孔時(shí)，就會與車床的旋轉(zhuǎn)軸同心。通過把工件固定在車床上可以精確定位孔的位置以使待加工孔所環(huán)繞的軸與車床的旋轉(zhuǎn)軸一致。當(dāng)鏜削工序與用于車削和刮削工序的設(shè)置相同時(shí)，實(shí)際上可以達(dá)到理想的同心與垂直。</p><p>　　鏜刀固定在一根通過刀具徑向溜板進(jìn)給的鏜桿上。根據(jù)待做的工作來使用這一設(shè)計(jì)的變化形式。如果有的話，所用的倒角總是應(yīng)該小些。而且，鏜刀前端的半徑一定

79、不能太大。用于鏜孔的切削速度可以等于車削速度。但是，在計(jì)算車床主軸速度時(shí)，應(yīng)當(dāng)使用完成后的或最大的孔徑。鏜削的進(jìn)刀速度通常比車削的小一點(diǎn)以補(bǔ)償鏜桿剛性的不足。</p><p>　　鏜削工序一般分兩步完成，即粗鏜和精鏜。粗鏜工序的目的是快速、高效地去除多余的金屬；而精鏜工序的目的是獲得所需的尺寸、表面粗糙度和孔的位置?？椎某叽缤ㄟ^試切來獲得?？椎闹睆娇梢杂脙?nèi)卡尺和千分尺測量。測量儀表或內(nèi)千分卡尺直接測量直徑。<

80、;/p><p>　　型心孔和要鉆的孔有時(shí)相對于車床的旋轉(zhuǎn)是偏心的。當(dāng)鏜刀進(jìn)入工件時(shí)，鏜桿在孔的一邊切口比另一邊深，當(dāng)采用這深切口時(shí)就會更偏斜，結(jié)果鏜的孔與工件旋轉(zhuǎn)不同心。這一影響通過利用淺切口在整個(gè)孔加工中進(jìn)行幾次加工來糾正。因?yàn)槊總€(gè)淺切口形成的孔比使用深切口形成的孔更加同心。在完工前，進(jìn)行精加工，孔應(yīng)該與工件的旋轉(zhuǎn)同心以確保完工時(shí)孔能精確定位。</p><p>　　肩、溝槽、輪廓、錐度和螺紋

81、也應(yīng)該在孔內(nèi)鏜出。內(nèi)槽是用與外部開槽工具相似的工具切削。鏜削內(nèi)槽的步驟非常類似于車削肩部的步驟。大的肩部使用前導(dǎo)裝置定位的鏜刀進(jìn)行刮削，使用橫向滑板進(jìn)給工具。內(nèi)部輪廓使用車床上的描摹附件加工。仿行板附件安裝在橫向滑板上，靠模指跟隨標(biāo)準(zhǔn)剖面板的輪廓線運(yùn)動。這使刀具對應(yīng)于標(biāo)準(zhǔn)剖面樣板的輪廓線的路徑進(jìn)行移動。這樣標(biāo)準(zhǔn)剖面樣板的輪廓就在孔內(nèi)得到復(fù)制。標(biāo)準(zhǔn)剖面樣板精確安裝在一個(gè)專用的滑板上，滑板可以在兩個(gè)方向上進(jìn)行精確調(diào)整以使刀具與工件以正確的關(guān)

82、系對正。這臺車床有一個(gè)偏心夾型的主軸前端，允許在任意一方向旋轉(zhuǎn)時(shí)進(jìn)行切削。正常的車削是在主軸逆時(shí)針轉(zhuǎn)動時(shí)進(jìn)行的；鏜削切削是在主軸順時(shí)針方向或“向后”轉(zhuǎn)動時(shí)進(jìn)行的。這允許在孔的“后側(cè)”進(jìn)行鏜削切削，在車床前面，從操作者的位置易于看到后孔。在具有螺紋主軸前端的車床上不應(yīng)這么做，因?yàn)榍邢髁Φ淖饔脮煽ūP。</p><p><b>　　銑削</b></p><p>　　銑削

83、是一種通過工件與多刃旋轉(zhuǎn)銑刀間的相對運(yùn)動去除材料的加工工藝。在一些應(yīng)用中，工件固定而旋轉(zhuǎn)的銑刀以一定進(jìn)給速度移過工件（橫向進(jìn)給）；在其他應(yīng)用中，工件與銑刀既彼此相對運(yùn)動，又相對銑床運(yùn)動。但是，更常見的是工件以一個(gè)相對較低的運(yùn)動速度或進(jìn)給速度朝正在高速旋轉(zhuǎn)的銑刀前進(jìn)，而銑刀軸保持在一個(gè)固定位置。銑削工藝特有的性能是每個(gè)銑刀齒都以小的單個(gè)切屑的形式切去一部分原料?？梢栽谠S多不同的機(jī)器上進(jìn)行銑削作業(yè)。</p><p>

84、　　由于工件和銑刀都可以彼此相對運(yùn)動，銑削可以獨(dú)立的或以組合方式完成各式各樣的作業(yè)。各種應(yīng)用包括平面或仿行面、窄槽、槽、退刀槽、螺紋和其他外形的加工。</p><p>　　銑削是一種最為通用而又復(fù)雜的加工方法。該工藝比任何其他基本加工方法在所用機(jī)器的種類、工件運(yùn)動以及加工工具種類方面都具有更多的變化。利用銑削去除材料的重要優(yōu)點(diǎn)包括原料切削速度高，能形成相對光滑的表面粗糙度以及可應(yīng)用的刀具更為多樣。刀具的切削刀刃可

85、以仿行以形成任何復(fù)雜的表面。</p><p>　　主要的銑削方法有周銑和端銑，此外，還有許多相關(guān)方法，他們屬于這2種方法的變化形式，這些變化形式取決于工件或刀具的類型。</p><p><b>　　周銑</b></p><p>　　在周銑（有時(shí)也叫平面銑削）中，由位于銑刀主體外周上的尺或刀片銑削的面一般在一個(gè)與銑刀軸平行的平面上。使用鏟齒銑刀和

86、成形銑刀完成的銑削工序包括在這一類。銑削面的界面與所使用的銑刀或刀具組合的輪廓線或輪廓相符。</p><p>　　周銑作業(yè)通常在帶有水平定位主軸的銑床上進(jìn)行。但也可以在帶有端面銑刀的主軸銑床上進(jìn)行。銑刀安裝在心軸上，尤其是由于設(shè)置的條件，銑刀或者若干銑刀位于距主軸前端一定距離處時(shí)，心軸一般在外端得到支撐來提高剛性。如果部件可以端銑，一般不應(yīng)進(jìn)行周銑。</p><p><b>　　

87、端銑</b></p><p>　　端銑在臥式銑床和立式銑床上進(jìn)行。由位于銑刀外周和端面的切削刃聯(lián)合銑削所形成的銑削面一般與銑刀軸成直角。除了在肩部銑削時(shí)外，銑削面是平的，與齒的輪廓形狀無關(guān)。一般來講，無論何時(shí)何地，只要可能就應(yīng)使用端銑。</p><p>　　傳統(tǒng)（上）端銑中切屑厚度是變化的，在銑刀齒進(jìn)入和退出處最薄，而在沿水平直徑處最大。銑削面由齒和專屬轉(zhuǎn)速痕跡表現(xiàn)其特征，這與

88、周銑銑刀情況相同。這些痕跡的起伏度由齒的端面切削刃的磨削精度或由刀體/刀片在可以指標(biāo)化的刀具內(nèi)組合精度以及刀具安裝精度來控制，以使刀具在主軸上精確運(yùn)動。起伏度還由機(jī)器及工件本身的剛性來控制。當(dāng)端面切削刃的長度短于每轉(zhuǎn)的進(jìn)給量（或銑刀每轉(zhuǎn)一圈工件的移動量）時(shí)，在銑面上就會形成一系列的環(huán)形凹槽或環(huán)紋。當(dāng)后齒在工件的銑面上拖動時(shí)，也會產(chǎn)生類似的標(biāo)記，這叫齒根拖動。</p><p>　　在端銑中，如果想獲得最佳結(jié)果，重要