第8-9次課 UNIT 11 Lathe and Turning.

1、 w 1.The lathe and its construction w 2. Lathe Cutting Tools w 3. Lathe Operations w 4.Cutting Speed and Feed 1.The lathe and its construction w The Lathe and Its Construction w 車床及其結(jié)構(gòu)車床及其結(jié)構(gòu) w A lathe is a machine tool used primarily for producing surfaces of revolution and flat edges. w 車床是主要用于生成旋轉(zhuǎn)

2、表面和平整邊緣的車床是主要用于生成旋轉(zhuǎn)表面和平整邊緣的機(jī)床機(jī)床。 w Based on their purpose, construction, number of tools that can simultaneously be mounted, and degree of automation, lathes-or, more accurately, lathe-type machine tools can be classified as follows: w 根據(jù)它們的使用目的、結(jié)構(gòu)、能同時(shí)被根據(jù)它們的使用目的、結(jié)構(gòu)、能同時(shí)被安裝安裝刀具的數(shù)刀具的數(shù) 量和自動(dòng)化的程度，車床量和自動(dòng)化的

3、程度，車床或更確切地說(shuō)是車床類的或更確切地說(shuō)是車床類的 機(jī)床，可以被分成以下幾類：機(jī)床，可以被分成以下幾類： 1.The lathe and its construction 1.The lathe and its construction w (1)Engine lathes普通車床普通車床 w (2)Toolroom lathes萬(wàn)能車床萬(wàn)能車床 w (3)Turret lathes轉(zhuǎn)塔車床轉(zhuǎn)塔車床 w (4)Vertical turning and boring mills立式車削立式車削 和鏜床和鏜床 w (5)Automatic lathes自動(dòng)車床自動(dòng)車床 w (6)Special

4、-purpose lathes特殊車床特殊車床 1.The lathe and its construction w In spite of that diversity of lathe-type machine tools, they all have common features with respect to construction and principle of operation. These features can best be illustrated by considering the commonly used representative type, the e

5、ngine lathe. Following is a description of each of the main elements of an engine lathe, which is shown in Fig.11.1. w 雖然車床類的機(jī)床多種多樣，但它們?cè)诮Y(jié)構(gòu)和雖然車床類的機(jī)床多種多樣，但它們?cè)诮Y(jié)構(gòu)和操作原操作原 理理上具有共同特性。這些特性可以通過(guò)上具有共同特性。這些特性可以通過(guò)普通車床普通車床這一這一 最常用的代表性類型來(lái)最好地說(shuō)明。下面是關(guān)于圖最常用的代表性類型來(lái)最好地說(shuō)明。下面是關(guān)于圖 11.1所示所示普通車床普通車床的主要部分的描述。的主要部分的描述。 1.The l

6、athe and its construction w Lathe bed. The lathe bed is the main frame, involving a horizontal beam on two vertical supports. It is usually made of grey or nodular cast iron to damp vibrations and is made by casting. w 車床床身：車床床身是包含了在兩個(gè)車床床身：車床床身是包含了在兩個(gè)垂直支柱垂直支柱上上水平水平 橫梁橫梁的主骨架。為減振它一般由灰鑄鐵或的主骨架。為減振它一般由灰鑄

7、鐵或球墨鑄鐵球墨鑄鐵鑄鑄 造而成。造而成。 w It has guideways to allow the carriage to slide easily lengthwise. The height of the lathe bed should be appropriate to enable the technician to do his or her job easily and comfortably. w 它上面有能讓它上面有能讓溜板溜板輕易縱向滑動(dòng)的導(dǎo)軌。車床床身的輕易縱向滑動(dòng)的導(dǎo)軌。車床床身的 高度應(yīng)適當(dāng)以讓技師容易而舒適地工作。高度應(yīng)適當(dāng)以讓技師容易而舒適地工作。 1.T

8、he lathe and its construction w Headstock. The headstock is fixed at the left hand side of the lathe bed and includes the spindle whose axis is parallel to the guideways (the slide surface of the bed). The spindle is driven through the gearbox, which is housed within the headstock. w 主軸箱主軸箱：主軸箱固定在車床

9、：主軸箱固定在車床床身床身的左側(cè)，它的左側(cè)，它 包括軸線平行于包括軸線平行于導(dǎo)軌導(dǎo)軌的主軸。主軸通過(guò)裝在的主軸。主軸通過(guò)裝在 主軸箱內(nèi)的主軸箱內(nèi)的齒輪箱齒輪箱驅(qū)動(dòng)。驅(qū)動(dòng)。 1.The lathe and its construction w The function of the gearbox is to provide a number of different spindle speeds (usually 6 up to 18 speeds). Some modern lathes have headstocks with infinitely variable spindle spe

10、eds, which employ frictional ,electrical ,or hydraulic drives. w 齒輪箱的功能是給主軸提供若干不同的速度齒輪箱的功能是給主軸提供若干不同的速度( 通常是通常是6到到18速速)。有些現(xiàn)代車床具有采用摩擦。有些現(xiàn)代車床具有采用摩擦 、電力或液壓驅(qū)動(dòng)的、電力或液壓驅(qū)動(dòng)的無(wú)級(jí)調(diào)速無(wú)級(jí)調(diào)速主軸箱。主軸箱。 1.The lathe and its construction w The spindle is always hollow, i.e., it has a through hole extending lengthwise. Bar

11、stock can be fed through that hole if continuous production is adopted. w 主軸往往是主軸往往是中空的中空的，即縱向有一通孔。如果采取連續(xù)，即縱向有一通孔。如果采取連續(xù) 生產(chǎn)，棒料能通過(guò)此孔進(jìn)給。生產(chǎn)，棒料能通過(guò)此孔進(jìn)給。 w Also, that hole has a tapered surface to allow mounting a plain lathe center. The outer surface of the spindle is threaded to allow mounting of a chuc

12、k, a face plate, or the like. w 同時(shí)，此孔為同時(shí)，此孔為錐形表面錐形表面可以安裝普通車床頂尖。主軸可以安裝普通車床頂尖。主軸 外表面是螺紋可以外表面是螺紋可以安裝卡盤安裝卡盤、花盤或類似的裝置。、花盤或類似的裝置。 1.The lathe and its construction w Tailstock. The tailstock assembly consists basically of three parts, its lower base, an intermediate part, and the quill. The lower base is a

13、 casting that can slide on the lathe bed along the guideways, and it has a clamping device to enable locking the entire tailstock at any desired location, depending upon the length of the workpiece. w 尾架：尾架總成基本包括三部分，尾架：尾架總成基本包括三部分，底座、尾架體底座、尾架體和和套套 筒軸筒軸。底座是能在車床床身上沿導(dǎo)軌滑動(dòng)的。底座是能在車床床身上沿導(dǎo)軌滑動(dòng)的鑄件鑄件，它，它 有一定位裝

14、置能讓整個(gè)尾架根據(jù)工件長(zhǎng)度鎖定在任何有一定位裝置能讓整個(gè)尾架根據(jù)工件長(zhǎng)度鎖定在任何 需要位置。需要位置。 1.The lathe and its construction w The intermediate part is a casting that can be moved transversely to enable alignment of the axis of the tailstock with that of the headstock. The third part, the quill, is a hardened steel tube, which can be mov

15、ed longitudinally in and out of the intermediate part as required. w 尾架體尾架體為一能為一能橫向橫向運(yùn)動(dòng)的鑄件，它可以調(diào)整運(yùn)動(dòng)的鑄件，它可以調(diào)整 尾架尾架軸線與軸線與主軸箱主軸箱軸線成一直線。第三部分軸線成一直線。第三部分 ，套筒軸套筒軸是一淬硬鋼管，它能根據(jù)需要在尾是一淬硬鋼管，它能根據(jù)需要在尾 架體中架體中縱向縱向進(jìn)出移動(dòng)。進(jìn)出移動(dòng)。 1.The lathe and its construction w This is achieved through the use of a handwheel and a screw

16、, around which a nut fixed to the quill is engaged. The hole in the open side of the quill is tapered to enable mounting of lathe centers or other tools like twist drills or boring bars. The quill can be locked at any point along its travel path by means of a clamping device（夾持機(jī)構(gòu)）（夾持機(jī)構(gòu)）. w 這通過(guò)使用這通過(guò)使

17、用手輪手輪和和螺桿螺桿來(lái)達(dá)到，與螺桿嚙合的是一固來(lái)達(dá)到，與螺桿嚙合的是一固 接在套筒軸上的接在套筒軸上的螺母螺母。套筒軸開(kāi)口端的孔是錐形的，。套筒軸開(kāi)口端的孔是錐形的， 能安裝車床頂尖或諸如能安裝車床頂尖或諸如麻花鉆麻花鉆和和鏜桿鏜桿之類的工具。套之類的工具。套 筒軸通過(guò)筒軸通過(guò)定位裝置定位裝置能沿著它的移動(dòng)路徑被鎖定在任何能沿著它的移動(dòng)路徑被鎖定在任何 點(diǎn)。點(diǎn)。 1.The lathe and its construction w The carriage. The main function of the carriage is mounting of the cutting tools

18、and generating longitudinal and/or cross feeds. It is actually an H-shaped block that slides on the lathe bed between the headstock and tailstock while being guided by the V-shaped guideways of the bed. w 大拖板：大拖板的主要功能是安裝刀具和產(chǎn)大拖板：大拖板的主要功能是安裝刀具和產(chǎn) 生縱向和生縱向和/或橫向進(jìn)給。它實(shí)際上是一由車床或橫向進(jìn)給。它實(shí)際上是一由車床 床身床身V形導(dǎo)軌引導(dǎo)的、能在車床

19、床身主軸箱和形導(dǎo)軌引導(dǎo)的、能在車床床身主軸箱和 尾架之間滑動(dòng)的尾架之間滑動(dòng)的H形滑塊。形滑塊。 1.The lathe and its construction w The carriage can be moved either manually or mechanically by means of the apron and either the feed rod or the lead screw. w 大拖板能手動(dòng)或者通過(guò)大拖板能手動(dòng)或者通過(guò)溜板箱溜板箱和光桿和光桿(進(jìn)給桿進(jìn)給桿) 或絲桿或絲桿(引導(dǎo)螺桿引導(dǎo)螺桿)機(jī)動(dòng)。機(jī)動(dòng)。 1.The lathe and its construc

20、tion w When cutting screw threads, power is provided to the gearbox of the apron by the lead screw. In all other turning operations, it is the feed rod that drives the carriage. The lead screw goes through a pair of half nuts, which are fixed to the rear of the apron. w 在切削螺旋時(shí)，動(dòng)力通過(guò)絲桿提供給在切削螺旋時(shí)，動(dòng)力通過(guò)絲桿

21、提供給溜板箱溜板箱 上的齒輪箱。在其余車削作業(yè)中，都由上的齒輪箱。在其余車削作業(yè)中，都由光桿光桿 驅(qū)動(dòng)大拖板。絲桿穿過(guò)一對(duì)固定在驅(qū)動(dòng)大拖板。絲桿穿過(guò)一對(duì)固定在溜板箱后溜板箱后 部部的剖分螺母。的剖分螺母。 1.The lathe and its construction w When actuating a certain lever, the half nuts are clamped together and engage with the rotating lead screw as a single nut, which is fed, together with the carria

22、ge, along the bed. When the lever is disengaged, the half nuts are released and the carriage stops. w 當(dāng)開(kāi)動(dòng)特定當(dāng)開(kāi)動(dòng)特定操作桿操作桿時(shí)，剖分螺母時(shí)，剖分螺母夾在一起夾在一起作作 為單個(gè)螺母與旋轉(zhuǎn)的絲桿嚙合，并帶動(dòng)拖板為單個(gè)螺母與旋轉(zhuǎn)的絲桿嚙合，并帶動(dòng)拖板 沿著床身提供進(jìn)給。當(dāng)沿著床身提供進(jìn)給。當(dāng)操作桿操作桿脫離時(shí)，剖分脫離時(shí)，剖分 螺母釋放同時(shí)大拖板停止運(yùn)動(dòng)。螺母釋放同時(shí)大拖板停止運(yùn)動(dòng)。 1.The lathe and its construction w On the other hand

23、, when the feed rod is used, it supplies power to the apron through a worm gear. The latter is keyed to the feed rod and travels with the apron along the feed rod, which has a keyway extending to cover its whole length. w 另一方面，當(dāng)使用另一方面，當(dāng)使用光桿光桿時(shí)則通過(guò)蝸輪給溜板時(shí)則通過(guò)蝸輪給溜板 箱提供動(dòng)力。箱提供動(dòng)力。 蝸輪用鍵連接在光桿上，并與蝸輪用鍵連接在光桿上，并與

24、 溜板箱溜板箱一起沿光桿運(yùn)動(dòng)，光桿全長(zhǎng)范圍開(kāi)有一起沿光桿運(yùn)動(dòng)，光桿全長(zhǎng)范圍開(kāi)有 鍵槽。鍵槽。 1.The lathe and its construction w A modern lathe usually has a quick-change gearbox located under the headstock and driven from the spindle through a train of gears. It is connected to both the feed rod and the lead screw and enables selecting a variet

25、y of feeds easily and rapidly by simply shifting the appropriate levers. w 現(xiàn)代車床一般在主軸箱下裝備快速變換齒輪現(xiàn)代車床一般在主軸箱下裝備快速變換齒輪 箱，通過(guò)一系列齒輪由主軸驅(qū)動(dòng)。它與箱，通過(guò)一系列齒輪由主軸驅(qū)動(dòng)。它與光桿光桿 和和絲桿絲桿連接，能容易并快速地通過(guò)簡(jiǎn)單轉(zhuǎn)換連接，能容易并快速地通過(guò)簡(jiǎn)單轉(zhuǎn)換 適當(dāng)?shù)牟僮鳁U選擇各種進(jìn)給。適當(dāng)?shù)牟僮鳁U選擇各種進(jìn)給。 1.The lathe and its construction w The quick-change gearbox is employed in plain

26、turning, facing and thread cutting operations. Since that gearbox is linked to the spindle, the distance that the apron (and the cutting tool) travels for each revolution of the spindle can be controlled and is referred to as the feed. w 快速變換齒輪箱可用于快速變換齒輪箱可用于普通車削普通車削、端面切削端面切削 和和螺旋切削螺旋切削作業(yè)中。由于這種齒輪箱與主軸

27、作業(yè)中。由于這種齒輪箱與主軸 相連，主軸每轉(zhuǎn)相連，主軸每轉(zhuǎn)一圈溜板箱一圈溜板箱(和切削刀具和切削刀具)運(yùn)動(dòng)運(yùn)動(dòng) 的距離能被控制，這距離就可以被認(rèn)為是進(jìn)的距離能被控制，這距離就可以被認(rèn)為是進(jìn) 給。給。 w 1.The lathe and its construction w 2. Lathe Cutting Tools w 3. Lathe Operations w 4.Cutting Speed and Feed 2. Lathe Cutting Tools w Lathe Cutting Tools w 車床切削刀具車床切削刀具 w The shape and geometry of the

28、 lathe tools depend upon the purpose for which they are employed. w 車床刀具的形狀和幾何參數(shù)取決于它們的使用目的。車床刀具的形狀和幾何參數(shù)取決于它們的使用目的。 w Turning tools can be classified into two main groups, namely, external cutting tools and internal cutting tools. Each of these two groups include the following types of tools: w 車削刀具可

29、以分為兩個(gè)主要組別，即外部切削刀具和車削刀具可以分為兩個(gè)主要組別，即外部切削刀具和 內(nèi)部切削刀具。這兩組中的每一組都包括以下類型刀內(nèi)部切削刀具。這兩組中的每一組都包括以下類型刀 具：具： 2. Lathe Cutting Tools Common Cutting tools 2. Lathe Cutting Tools w Turning tools. Turning tools can be either finishing or rough turning tools. Rough turning tools have small nose radius and are employed

30、when deep cuts are made. w 車削刀具：車削刀具可以是精車刀具或粗車車削刀具：車削刀具可以是精車刀具或粗車 刀具。粗車刀具刀具。粗車刀具刀尖半徑刀尖半徑較小，用于深切削較小，用于深切削 。 2. Lathe Cutting Tools w On the other hand, finishing tools have larger nose radius and are used for obtaining the final required dimensions with good surface finish by making slight depths of

31、cut. Rough turning tools can be right-hand or left-hand types, depending upon the direction of feed. They can have straight, bent, or offset shanks. w 而精車刀具而精車刀具刀尖半徑刀尖半徑較大，用于通過(guò)微量進(jìn)刀深度來(lái)較大，用于通過(guò)微量進(jìn)刀深度來(lái) 獲得具有較好表面光潔度的最終所需尺寸。粗車刀具獲得具有較好表面光潔度的最終所需尺寸。粗車刀具 按其進(jìn)給方向可以是右手型的或是左手型的。它們可按其進(jìn)給方向可以是右手型的或是左手型的。它們可 以有直的、彎的或

32、以有直的、彎的或偏置的刀桿偏置的刀桿。 2. Lathe Cutting Tools w Facing tools. Facing tools are employed in facing operations for machining plane side or end surfaces. There are tools for machining left-hand-side surfaces and tools for right-hand-side surfaces. Those side surfaces are generated through the use of the c

33、ross feed, contrary to turning operations, where the usual longitudinal feed is used. w 端面刀具：端面刀具用在端面刀具：端面刀具用在端面作業(yè)端面作業(yè)中加工平板側(cè)面或中加工平板側(cè)面或 端部表面，也有加工左右側(cè)表面之分。與一般采用縱端部表面，也有加工左右側(cè)表面之分。與一般采用縱 向進(jìn)給的向進(jìn)給的車削作業(yè)車削作業(yè)相反，那些側(cè)表面通過(guò)采用橫向進(jìn)相反，那些側(cè)表面通過(guò)采用橫向進(jìn) 給產(chǎn)生。給產(chǎn)生。 2. Lathe Cutting Tools w Cutoff tools. Cutoff tools, which are

34、 sometimes called parting tools, serve to separate the workpiece into parts and/or machine external annular grooves. w 切斷刀具：切斷刀具，有時(shí)也稱為切斷刀具：切斷刀具，有時(shí)也稱為分割刀具分割刀具 ，用于將工件分割成若干部分和，用于將工件分割成若干部分和/或加工外部或加工外部 環(huán)形槽環(huán)形槽。 2. Lathe Cutting Tools w Thread-cutting tools. Thread-cutting tools have either triangular, sq

35、uare, or trapezoidal cutting edges, depending upon the cross section of the desired thread. Also, the plane angles of these tools must always be identical to those of the thread forms. w 螺紋切削刀具：螺紋切削刀具根據(jù)所需螺紋切削刀具：螺紋切削刀具根據(jù)所需螺紋螺紋 的的橫截面橫截面，有，有三角形三角形的、的、矩形的矩形的或或梯形梯形的切的切 削刃。同時(shí)，這些刀具的平面角必須始終與削刃。同時(shí)，這些刀具的平面角必須

36、始終與 螺紋形狀螺紋形狀的平面角保持一致。的平面角保持一致。 2. Lathe Cutting Tools w Thread-cutting tools have straight shanks for external thread cutting and are of the bent- shank type when cutting internal threads. w 車外螺紋的螺紋切削刀具為車外螺紋的螺紋切削刀具為直刀桿直刀桿，而車內(nèi)，而車內(nèi) 螺紋的螺紋切削刀具則是螺紋的螺紋切削刀具則是彎刀桿彎刀桿。 2. Lathe Cutting Tools w Form tools. For

37、m tools have edges especially manufactured to take a certain form, which is opposite to the desired shape of the machined workpiece. w 成形刀具：成形刀具有專門制成特定形狀的成形刀具：成形刀具有專門制成特定形狀的 刀刃，這種刀刃形狀與被加工工件所需外形刀刃，這種刀刃形狀與被加工工件所需外形 正好相反。正好相反。 2. Lathe Cutting Tools w An HSS(High-Speed -Steel) tool is usually made in t

38、he form of a single piece, contrary to cemented carbides or ceramic, which are made in the form of tips. The latter are brazed or mechanically fastened to steel shanks w 高速鋼刀具通常以單件形式制造，而硬質(zhì)合高速鋼刀具通常以單件形式制造，而硬質(zhì)合 金或陶瓷刀具則以金或陶瓷刀具則以刀尖刀尖形式制造。后者用形式制造。后者用銅銅 焊焊或機(jī)械方法固定于鋼質(zhì)刀桿上?；驒C(jī)械方法固定于鋼質(zhì)刀桿上。 2. Lathe Cutting Tool

39、s w Fig.11.2 indicates an arrangement of this latter type, which includes the carbide tip, the chip breaker, the pad, the clamping screw (with a washer and a nut), and the shank. w 圖圖11.2所示為機(jī)械式固定布置方式，它包括了所示為機(jī)械式固定布置方式，它包括了 硬質(zhì)合金刀尖硬質(zhì)合金刀尖、斷屑槽斷屑槽、襯墊襯墊、卡裝螺桿卡裝螺桿(帶帶 有墊圈和螺母有墊圈和螺母)及及刀桿刀桿。 2. Lathe Cutting Too

40、ls w As the name suggests, the function of the chip breaker is to break long chips every now and then, thus preventing the formation of very long twisted ribbons that may cause problems during the machining operation. w 顧名思義，斷屑槽的功能就是不時(shí)地折斷長(zhǎng)顧名思義，斷屑槽的功能就是不時(shí)地折斷長(zhǎng) 切屑，以防形成很長(zhǎng)的可能會(huì)在機(jī)加工操作切屑，以防形成很長(zhǎng)的可能會(huì)在機(jī)加工操作 中引

41、起問(wèn)題的纏繞中引起問(wèn)題的纏繞切屑條切屑條。 2. Lathe Cutting Tools w The carbide tips (or ceramic tips) can have different shapes, depending upon the machining operations for which they are to be employed. The tips can either be solid or with a central through hole, depending on whether brazing or mechanical clamping is

42、employed for mounting the tip on the shank. w 硬質(zhì)合金刀尖硬質(zhì)合金刀尖(或陶瓷刀尖或陶瓷刀尖)根據(jù)采用它們的機(jī)根據(jù)采用它們的機(jī) 加工操作，可以有不同的形狀。根據(jù)將刀尖加工操作，可以有不同的形狀。根據(jù)將刀尖 裝配在刀桿上是通過(guò)用裝配在刀桿上是通過(guò)用銅焊銅焊還是還是機(jī)械卡裝機(jī)械卡裝， 刀尖可以是實(shí)心的或是帶有中心通孔的。刀尖可以是實(shí)心的或是帶有中心通孔的。 w 1.The lathe and its construction w 2. Lathe Cutting Tools w 3. Lathe Operations w 4.Cutting Speed

43、 and Feed 3. Lathe Operations w Lathe Operations w 車床操作車床操作 w In the following section, we discuss the various machining operations that can be performed on a conventional engine lathe. w 在下面這節(jié)中，要討論的是能在傳統(tǒng)普通車在下面這節(jié)中，要討論的是能在傳統(tǒng)普通車 床上進(jìn)行的各種機(jī)加工作業(yè)。床上進(jìn)行的各種機(jī)加工作業(yè)。 3. Lathe Operations w It must be borne in mind

44、, however, that modern computerized numerically controlled lathes have more capabilities and can do other operations, such as contouring, for example. Following are conventional lathe operations. w 然而，必須記住現(xiàn)代計(jì)算機(jī)數(shù)控車床具有更然而，必須記住現(xiàn)代計(jì)算機(jī)數(shù)控車床具有更 多的功能并且可以進(jìn)行其它操作，例如仿型多的功能并且可以進(jìn)行其它操作，例如仿型 。下面是傳統(tǒng)車床的操作。下面是傳統(tǒng)車床的操作。

45、3. Lathe Operations w Cylindrical turning. Cylindrical turning is the simplest and the most common of all lathe operations. A single full turn of the workpiece generates a circle whose center falls on the lathe axis; this motion is then reproduced numerous times as a result of the axial feed motion

46、of the tool. w 圓柱面車削：圓柱面車削是所有車床操作中圓柱面車削：圓柱面車削是所有車床操作中 最簡(jiǎn)單也是最普通的。工件旋轉(zhuǎn)一整圈產(chǎn)生最簡(jiǎn)單也是最普通的。工件旋轉(zhuǎn)一整圈產(chǎn)生 一個(gè)圓心落在車床主軸上的圓；由于刀具的一個(gè)圓心落在車床主軸上的圓；由于刀具的 軸向進(jìn)給運(yùn)動(dòng)這種動(dòng)作重復(fù)許多次。軸向進(jìn)給運(yùn)動(dòng)這種動(dòng)作重復(fù)許多次。 3. Lathe Operations w The resulting machining marks are, therefore, a helix having a very small pitch, which is equal to the feed. Cons

47、equently, the machined surface is always cylindrical. w 所以，由此產(chǎn)生的機(jī)加工痕跡是一條具有很所以，由此產(chǎn)生的機(jī)加工痕跡是一條具有很 小節(jié)距的螺旋線，該節(jié)距等于進(jìn)給。因此機(jī)小節(jié)距的螺旋線，該節(jié)距等于進(jìn)給。因此機(jī) 加工表面始終是圓柱形的。加工表面始終是圓柱形的。 3. Lathe Operations w The axial feed is provided by the carriage or the compound rest, either manually or automatically, whereas the depth of

48、 cut is controlled by the cross slide. w 軸向進(jìn)給通過(guò)大拖板或復(fù)式刀架手動(dòng)或自動(dòng)軸向進(jìn)給通過(guò)大拖板或復(fù)式刀架手動(dòng)或自動(dòng) 提供，然而切削深度則由橫向滑板控制。提供，然而切削深度則由橫向滑板控制。 3. Lathe Operations w In roughing cuts, it is recommended that large depths of cuts (up to 0.25in. or 6mm, depending upon the workpiece material) and smaller feeds would be used. On t

49、he other hand, very fine feeds, smaller depths of cut (less than 0.05in, or 0.4mm), and high cutting speeds are preferred for finishing cuts. w 粗車中，推薦使用較大切削深度粗車中，推薦使用較大切削深度(根據(jù)工件材料可達(dá)根據(jù)工件材料可達(dá) 0.25英寸或英寸或6毫米毫米)和較小進(jìn)給。另一方面，精車則最和較小進(jìn)給。另一方面，精車則最 好采用很小的進(jìn)給、較小的切削深度好采用很小的進(jìn)給、較小的切削深度(小于小于0.05英寸或英寸或 0.4毫米毫米)和較高的切削速

50、度。和較高的切削速度。 3. Lathe Operations w Facing. The result of a facing operation is a flat surface that is either the whole end surface of the workpiece or an annular intermediate surface like a shoulder. During a facing operation, feed is provided by the cross slide, whereas the depth of cut is controlle

51、d by the carriage or compound rest. w 端面車削：端面車削操作的結(jié)果是將工件整個(gè)端部表端面車削：端面車削操作的結(jié)果是將工件整個(gè)端部表 面或者像軸肩之類的中間環(huán)形表面加工平整。在端面面或者像軸肩之類的中間環(huán)形表面加工平整。在端面 車削操作中，進(jìn)給由橫向滑板提供，而切削深度則通車削操作中，進(jìn)給由橫向滑板提供，而切削深度則通 過(guò)大拖板或復(fù)式刀架控制。過(guò)大拖板或復(fù)式刀架控制。 3. Lathe Operations w Facing can be carried out either from the periphery inward or from the cen

52、ter of the workpiece outward. It is obvious that the machining marks in both cases take the form of a spiral. w 端面車削既可以從外表面向內(nèi)切削也可以從端面車削既可以從外表面向內(nèi)切削也可以從 工件中心往外切削。很明顯在這兩種情況下工件中心往外切削。很明顯在這兩種情況下 機(jī)加工痕跡都是螺線形式。機(jī)加工痕跡都是螺線形式。 3. Lathe Operations w Usually, it is preferred to clamp the carriage during a facing

53、operation, since the cutting force tends to push the tool (and, of course, the whole carriage) away from the workpiece. In most facing operations, the workpiece is held in a cTck or on a face plate. w 通常在端面車削作業(yè)時(shí)習(xí)慣于采用夾住大拖板，這是通常在端面車削作業(yè)時(shí)習(xí)慣于采用夾住大拖板，這是 因?yàn)榍邢髁A向于將刀具因?yàn)榍邢髁A向于將刀具(當(dāng)然包括整個(gè)大拖板當(dāng)然包括整個(gè)大拖板)推離推離 工件。在大

54、多數(shù)端面車削作業(yè)中，工件被支撐在卡盤工件。在大多數(shù)端面車削作業(yè)中，工件被支撐在卡盤 或花盤上?；蚧ūP上。 3. Lathe Operations w Groove cutting. In cut-off and groove-cutting operations, only cross feed of the tool is employed. The cut-off and grooving tools, which were previously discussed, are employed. w 開(kāi)槽：在切斷和開(kāi)槽操作中，刀具只有橫向開(kāi)槽：在切斷和開(kāi)槽操作中，刀具只有橫向 進(jìn)給。要采用

55、前面已經(jīng)討論過(guò)的切斷和開(kāi)槽進(jìn)給。要采用前面已經(jīng)討論過(guò)的切斷和開(kāi)槽 刀具。刀具。 3. Lathe Operations w 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 is solid, a drilling operation must be performed first. The drill

56、ing tool is held in the tailstock, and the latter is then fed against the workpiece. w 鏜孔和內(nèi)部車削：鏜孔和內(nèi)部車削通過(guò)鏜桿或合適的鏜孔和內(nèi)部車削：鏜孔和內(nèi)部車削通過(guò)鏜桿或合適的 內(nèi)部切削刀具在內(nèi)表面進(jìn)行。如果初始工件是實(shí)心的內(nèi)部切削刀具在內(nèi)表面進(jìn)行。如果初始工件是實(shí)心的 ，則必須首先進(jìn)行鉆孔作業(yè)。鉆孔刀具安裝在尾架上，則必須首先進(jìn)行鉆孔作業(yè)。鉆孔刀具安裝在尾架上 ，然后對(duì)著工件進(jìn)給。，然后對(duì)著工件進(jìn)給。 3. Lathe Operations w Taper turning. Taper turning

57、is achieved by driving the tool in a direction that is not parallel to the lathe axis but inclined to it with an angle that is equal to the desired angle of the taper. Following are the different methods used in taper-turning practice: w 錐面車削：錐面車削通過(guò)沿著與車床主軸不錐面車削：錐面車削通過(guò)沿著與車床主軸不 平行而傾斜成一個(gè)等于錐面所需角度的方向平行而傾

58、斜成一個(gè)等于錐面所需角度的方向 進(jìn)刀來(lái)實(shí)現(xiàn)。下面是在實(shí)際錐面車削中采用進(jìn)刀來(lái)實(shí)現(xiàn)。下面是在實(shí)際錐面車削中采用 的不同方法：的不同方法： 3. Lathe Operations w (1) Rotating the disc of the compound rest with an angle equal to half the apex angle of the cone. Feed is manually provided by cranking the handle of the compound rest. This method is recommended for taper tur

59、ning of external and internal surfaces when the taper angle is relatively large. w 將復(fù)式刀架盤旋轉(zhuǎn)一個(gè)等于圓錐體頂角一半將復(fù)式刀架盤旋轉(zhuǎn)一個(gè)等于圓錐體頂角一半 的角度。通過(guò)搖動(dòng)復(fù)式刀架操縱柄手動(dòng)提供的角度。通過(guò)搖動(dòng)復(fù)式刀架操縱柄手動(dòng)提供 進(jìn)給。當(dāng)錐角相對(duì)較大時(shí)切削外錐面和內(nèi)錐進(jìn)給。當(dāng)錐角相對(duì)較大時(shí)切削外錐面和內(nèi)錐 面推薦使用這種方法。面推薦使用這種方法。 3. Lathe Operations w (2) Employing special form tools for external, very short

60、, conical surfaces. The width of the workpiece must be slightly smaller than that of the tool, and the workpiece is usually held in a chuck or clamped on a face plate. In this case, only the cross feed is used during the machining process and the carriage is clamped to the machine bed. w 對(duì)很短的外錐面采用特殊