车床手柄座（831015）加工工艺及关键工序工装设计【钻φ14孔】【说明书+CAD】
车床手柄座（831015）加工工艺及关键工序工装设计【钻φ14孔】【说明书+CAD】,钻φ14孔,说明书+CAD,车床手柄座（831015）加工工艺及关键工序工装设计【钻φ14孔】【说明书+CAD】,车床,手柄,831015,加工,工艺,关键,工序,工装,设计,14,说明书,CAD
南京理工大学泰州科技学院
毕业设计(论文)外文资料翻译
系 部： 机械工程系
专 业： 机械工程及自动化
姓 名： 陈游
学 号： 05010113
(用外文写)
外文出处： http://www.mapeng.net
附 件： 1.外文资料翻译译文；2.外文原文。
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附件1：外文资料翻译译文
车床与铣削加工
车床
用与车外圆、端面和镗孔等加工的机床叫车床。车削很少在其他种类的机床上进行，某些机床不能像车床那样方便地进行车削加工。由于车床除了用于车外圆外还能用于镗孔、车端面、钻孔和铰孔，车床的多功能性可以使工件在一次定位安装中完成多种加工。这就是在生产中普遍使用各种车床比其他种类的机床都要多的原因。
很早就已经有了车床。现代车床可以追溯到大约17世纪，那时亨利·莫德斯利发明了一种具有丝杠的车床。这种车床可以控制工具的机械进给。聪明的英国人还发明了一种把主轴和丝杠相连接的变速装置，这样就可以切削螺纹。
车床的主要部件：床身、主轴箱组件、尾架组件、拖板组件、变速齿轮箱、丝杠和光杠床身是车床的基础件。它通常是由经过正火处理的灰铸铁或者球墨铸铁制成，它是一个坚固的刚性框架，所有其他主要部件都安装在床身上。通常在床身上面有内外两组平行的导轨。一些制造厂生产的四个条导轨都采用倒“V”形，而另一些制造厂则将倒“V”形导轨和平面导轨相结合。由于其他的部件要安装在导轨上或在导轨上移动，导轨要经过精密加工，以保证其装配精度。同样地，在操作中应该小心，以避免损伤导轨。导轨上的任何误差，常常会使整个机床的精度破坏。大多数现代车床的导轨要进行表面淬火处理，以减小磨损和擦伤，具有更大的耐磨性。主轴箱安装在床身一端内导轨的固定位置上。它提供动力，使工件在各种速度下旋转。它基本上由一个安装在精密轴承中的空心主轴和一系列变速齿轮，通过变速齿轮，主轴可以在许多种转速下旋转。大多数车床有8—18种转速，一般按等比级数排列。在现代车床上只需扳动2～4个手柄，就能得到全部挡位的转速。目前发展的趋势是通过电气的或机械的装置进行无级变速。
由于车床的精度在很大程度上取决于主轴，因此主轴的结构尺寸较大，通常安装在紧密配合的重型圆锥滚子轴承或球轴承中。主轴中有一个贯穿全长的通孔。主轴孔的大小是车床的一个重要尺寸，因为当工件通过主轴孔供料时，它确定了能够加工棒料毛坯的最大外径尺寸。
主轴的内端从主轴箱中凸出，其上可以安装多种卡盘、花盘和挡块。而小型的车床常带有螺纹截面供安装卡盘之用。很多大车床使用偏心夹或键动圆锥轴头。这些附件组成了一个大直径的圆锥体，以保证对卡盘进行精确地装配，并且不用旋转这些笨重的器件就可以锁定或松开卡盘和花盘。
主轴由电动机经V带或无声链装置提供动力。大多数现代车床都装有5—15马力的电动机，为硬质合金和金属陶瓷合金刀具提供足够的动力，进行高速切削。
尾座组件主要由三部分组成。底座与床身的内侧导轨配合，并可以在导轨上做纵向移动，底座上有一个可以使整个尾座组件夹紧的装置。尾座安装在底座上，可以沿键槽在底座上横向移动，使尾座与主轴箱中的主轴对正并为切削圆锥体提供方便。尾座组件的第三部分是尾座套筒，它是一个直径通常在2～3英寸之间的钢制空心圆柱轴。通过手轮和螺杆，尾座套筒可以在尾座体中纵向移入和移出几英寸。活动套筒的开口一端具有莫氏锥度，可以用于安装顶尖或其他刀具。通常在活动套筒的外表面刻有几英寸长的刻度，以控制尾座的前后移动。锁定装置可以使套筒在所需要的位置上夹紧。
拖板组件用于安装和移动切削工具。拖板是一个相对平滑钓H形铸件，安装在床身外侧导轨上，并可在上面移动。大拖板上有横向导轨，使横向拖板可以安装在上面，并通过丝杠使其运动，丝杠由一个小手柄和刻度盘控制。横拖板可以带动刀具垂直于工件的旋转轴线切削。
铣削加工
铣削是机械加工的一个基础方法。在这一加工过程中，当工件沿垂直于旋转刀具轴线方向进给时，在工件上去除切屑从而逐渐地铣出表面。有时候，工件是固定的，而刀具处于进给状态。在大多数情况下，使用多齿刀具，金属切削量大，只需一次铣削就可以获得所期望的表面。在铣削加工中使用的刀具称做铣刀。它通常是一个绕轴线旋转并且周边带有同间距齿的圆柱体，铣刀齿间歇性接触并切削工件。在某些情况下，铣刀上的刀齿会高出圆柱体的一端或两端。
由于铣削切削金属速度很快，并且能产生良好的表面光洁度，故特别适合大规模生产加工。为了实现这一目的，已经制造出了质量一流的铣床。并且在机修车间和工具模具加工中也已经广泛地使用了非常精确的多功能通用的铣床。车间里拥有一台铣床和一台普通车床就能加工出具有适合尺寸的各种产品。
铣削操作类型：铣削操作可以分成两大种类，每一类又有多种类型。
1．圆周铣削在圆周铣削中，使用的铣刀刀齿固定在刀体的圆周面上，工件铣削表面与旋转刀具轴线平行，从而加工表面。使用这种方法可以加工出平面和成型表面，加工中表面横截面与刀具的轴向外轮廓相一致。这种加工过程常被称为平面铣削。
2．端面铣削铣削平面与刀具的轴线垂直，被加工平面是刀具位于周边和端面的齿综合作用形成的。刀具周边齿完成铣削的主要任务，而端面齿用于精铣。
圆周铣削和端面铣削的基本概念，圆周铣削通常使用卧式铣床，而端铣削则既可在卧式铣床又可以在立式铣床上进行。
铣削面的形成：铣削时可以采用两种完全不同的方法。应注意的是，在逆向铣削时，铣刀旋转方向与工件进给方向相反，而在顺铣时铣刀旋转与工件进给方向相同。在逆铣过程中，当铣刀齿刚切人工件时，切屑是非常薄的，然后渐渐增厚，在刀齿离开工件的地方，切屑最厚。在两种铣削方法中，切屑的形成是不同的，逆铣过程中，刀具有推动使工件从工作台提升的趋势，这种作用有助于消除铣床工作台进给螺杆和螺母间的间隙，从而形成平稳的切削。然而，这种作用也有造成工件与夹紧装置之间的松动的趋势，这时应施加更大的夹紧力。此外，铣削表面的平整度主要取决于切削刃的锋利程度。
顺铣时，最大切屑厚度产生于靠近刀具与工件接触点处。由于相对运动把工件拉向铣刀，如果采用顺铣法，要消除工作台进给时螺杆可能产生的松动。因此，对于不能用于顺铣的铣床，应不采用顺铣方法。因为在铣刀结束切削时，处于切线方向的被切材料发生屈服，所以与逆铣相比，顺铣的被加工表面没有什么切痕。顺铣的另一个优势是切削力趋于将工件压紧在工作台上，因此对工件的夹紧力可以小于逆铣。这一优势可以用于铣削较薄的工件或进行强力切削。顺铣的弱点是铣刀齿刚一切削每片铁屑时，刀齿会撞击工件的表面。如果工件表面坚硬，像铸件，就会使刀齿迅速地变钝。
铣刀
铣刀分类有多种方法，一种方法是根据刀具后角将铣刀分为两大类：
1．仿形铣刀每个刀齿在切削刃的背面磨了一个很小的棱面形成后角，切削刃可以是直线或曲线的。
2．凸轮形后角铣刀每个齿的横截面在切削刃的背面呈偏心曲线状，以产生后角。偏心后角的各面与切削刃平行，具有切削刃的相同形状。这种类型的铣刀仅需磨削齿的前刀面就可以变得锋利，只要切削刃的外形保持不变，铣刀的另一种分类方法是根据铣刀安装的方法进行分类。心轴铣刀带有一个中心孔以使铣刀安装在心轴上。带柄铣刀有一锥柄或直柄轴，含锥形轴柄的铣刀可以直接安装在铣床的主轴上，而直柄轴的铣刀则是夹持在卡盘里。平面铣刀通常用螺栓固定在刀轴的末端上。
根据这种分类方法，通用型的铣刀可分类如下：
心轴铣刀：圆柱形铣刀，角度铣刀，侧刃铣刀，嵌齿铣刀，错齿铣刀，凸轮形后角铣刀，开槽铣刀，高速切削刀。
带柄铣刀：端面铣刀，T形槽铣刀，整体式铣刀，半圆键座铣刀，套式铣刀，高速切削刀，空心铣刀。
铣刀的类型圆柱形铣刀是在圆周上有直的或螺旋形的齿的圆柱形或盘形铣刀。它们可以用来铣削平面，这种铣削称做平面铣削。螺旋形的铣刀上的每个齿是逐渐地接触工件，在给定的时间内，一般有多齿进行铣削，这样可以减少震动，获得一个较平滑的表面。因此，与直齿铣刀相比，这种类型的铣刀，通常使用得更多。
侧刃铣刀的齿除了在圆柱刀体的一端或两端向径向延伸之外，与圆柱形铣刀是相似的。侧刃铣刀的刀齿既可以是直线的，也可以是螺旋形的，这种铣刀一般较窄小，具有盘形的形状。在跨式铣削加工中，常常将两个或更多的侧刃铣刀同时相间地安装在一个刀杆上同步并行切削。
双联槽铣刀是由两个侧刃铣刀组成，但是在铣槽时，作为一组铣刀进行操作。在两个铣刀之间添加一些薄垫片，以调整之间的间距。
错齿铣刀是较薄的圆柱形铣刀，刀上有相互交错的刀齿，相邻刀齿具有相反的螺旋角。这种铣刀经研磨后仅用于周铣，在每个齿突出的一边，留有供切屑排出的缝隙。这种类型的铣刀可用于高速切削，在铣削深槽时可以发挥独特的作用。
开槽铣刀是一种薄型的圆柱形铣刀，厚度一般为1／32—3／16英寸。这种铣刀的侧面呈盘状，有间隙，可以防止粘连。与圆柱形铣刀相比，这种类型的铣刀每英寸直径上的齿数更多，通常用于铣削较深的、狭窄的槽，并可用于切割加工。
附件2：外文原文（复印件）
LATHE AND MILLING
The basic machines that are designed primarily to do turning, facing and boring are called lathes. Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathe can do boring, facing, drilling, and reaming in addition to turning, their versatility permits several operations to be performed with a single setup of the workpiece. These accounts for the fact that lathes of various types are more widely used in manufacturing than any other machine tool.
Lathes in various forms have existed for more than long long age. Modem lathes date from about 1797, when Henry Maudsley developed one with a lea&crew. It provided controlled, mechanical feed of the tool. This ingenious Englishman also developed a changegear system that could connect the motions of the spindle and lea&crew and thus enable threads to be cut.Lathe Construction. The essential components of a lathe are depicted in the block diagram.
These are the bed, headstock assembly, tailstock assembly, carriage assembly, quick-change gear box, and the lea&crew and feed rod.The bed is the backbone of a lathe. It usually is made of well-normalized or aged gray or nodular cast iron and provides a heavy, rigid frame on which all the other basic components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets. Because several
other components are mounted and/or move on the ways they must be made with precision to assure accuracy of alignment. Similarly, proper precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed. The ways on most modem lathes are surface
hardened to offer greater resistance to wear and abrasion.
The headstock is mounted in a fixed position on the inner ways at one end of the lathe bed. It provides a powered means of rotating the work at various speeds. It consists, essentially, of a hollow spindle, mounted in accurate bearings? And a set of transmission gears similar to a truck transmission through which the spindle can be rotated at a number of speeds. Most lathes provide from eight to eighteen speeds, usually in a geometric ratio, and on modem lathes all the speeds can be obtained merely by moving from two to four levers.
An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives.
Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapered roller or ball types, a longitudinal hole extends through the spindle so that long bar stock can be fed through it. The size of this hole is an important size dimension of a lathe because it determines
the maximum size of bar stock that can be machined when the material must be fed through the spinale.
The inner end of the spindle protrudes from the gear box and contains a means for mounting various types of chucks, face plates, and dog plates on it. Whereas small lathes often employ a threaded section to which the chucks are screwed, most large lathes utilize either cam-lock or key-drive taper noses. These provide a large-diameter taper that assures the
accurate alignment of the chuck, and a mechanism that permits the chuck or face plate to be locked or unlocked in position without the necessity of having to rotate these heavy
attachments.
Power is supplied to the spindle by means of an electric motor through a V-belt or silent-chain drive. Most modem lathes have motors of from 5 to15 horsepower to provide adequate power for carbide and ceramic tools at their high cutting speeds.The tailstock assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location. An upper casting fits on the lower one and can be moved transversely upon it on some type of keyed ways. This transverse motion pemfits aligning the tailstock and headstock spindles and provides a method of tuming tapers. The third major component of the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 2 to sinches in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a handwheel and screw. The open end of the quill hole terminates in a morse. Taper in which a lathe center, or various tools such as drills, can be held. A graduated scale, several inches in length, usually is engraved on the outside of the quill to aid in controlling its motion in and out of the
upper casting. A locking device permits clamping the quill in any desired position.
The carriage assembly provides the means for mounting and moving cutting tools. The carriage is a reianvely fiat H-shaped casting that rests and moves on the outer set of ways on the bed. The transverse bar of the carriage contains ways on which the cross slide is mounted and can be moved by means of a feed screw that is controlled by a small handwheel and a
graduated dial. Through the cross slide a means is provided for moving the lathe tool in the direction normal to the axis of rotation of the work.On most lathes the tool post actually is mounted on a compound rest. This consists of a base, which is mounted on the cross slide so that it can be pivoted about a vertical axis, and an .upper casting. The upper casting is mounted on ways on this base .so that it can be moved back and forth and controlled by means of a short lead screw operated by a handwheel and a calibrated dial.
Manual and powered motion for the carriage, and powered motion for the cross slide, is provided by mechanisms within the apron,attached to the front of the carriage. Manual
movement of the carriage along the bed is effected by turning a handwheel on the front of
the apron, which is geared to a pinion on the back side. This pinion engages a rack that is attached beneath the upper front edge of the bed in an inverted position.
MILLING
Milling is a basic machining process in which the surface is generated by the progressive formation and removal of chips of material from the workpiece as it is fed to a rotating cutter in a direction perpendicular to the axis of the cutter. In some cases the workpiece is stationary and the cutter is fed to the work. In most instances a multiple-tooth cutter is used so that the metal removal rate is high, and frequently the desired surface is obtained in a single pass of the work.
The tool used in milling is known as a milling cutter. It usually consists of a cylindrical body which rotates on its axis and contains equally spaced peripheral teeth that intermittently engage and cut the workpiece. 1 In some cases the teeth extend part way across one or both Ends of the cylinder.
Because the milling principle provides rapid metal removal and can produce good surface finish, it is particularly well-suited for mass-production work, and excellent milling machines have been developed for this purpose. However, very accurate and versatile milling Machines of a general-purpose nature also have been developed that are widely used in jobshop and tool and die work. A shop that is equipped with a milling machine and an engine lathe can machine almost any type of product of suitable size.
Types of Milling Operations. Milling operations can be classified into two broad categories, each of which has several variations:
1. In peripheral milling a surface is generated by teeth located in the periphery of the cutter body; the surface is parallel with the axis of rotation of the cutter. Both flat and formed surfaces can be produced by this method. The cross section of the resulting surface corresponds to the axial contour of the cutter. This procedure often is called slab milling.
2. In face milling the generated flat surface is at right angles to the cutter axis and is the combined result of the actions of the portions of the teeth located on both the periphery and the face of the cutter. 2 The major portion of the cutting is done by the peripheral portions of the teeth with the face portions providing a finishing action.
The basic concepts of peripheral and face milling are illustrated in Fig. 16-1. Peripheral milling operations usually are performed on machines having horizontal spindles, whereas face milling is done on both horizontal- and vertical-spindle machines.
Surface Generation in Mimng. Surfaces can be generated in milling by two distinctly different methods depicted in Fig. 16-2. Note that in up milling the cutter rotates againsi the direction of feed the workpiece, whereas in down milling the rotation is in the same direction as the feed. As shown in Fig. 16-2, the method of chip formation is quite different in the two cases. In up milling the c hip is very thin at the beginning, where the tooth first contacts the work, and increases in thickness, becoming a maximum where the tooth leaves the work. The cutter tends to push the work along and lift it upward from Tool-work relationshios in peripheral and face milling the table. This action tends to eliminate any effect of looseness in the feed screw and nut of the milling machine table and results in a smooth cut. However, the action also tends to loosen the work from the clamping device so that greater clamping forcers must be employed. In addition, the smoothness of the generated surface depends greatly on the sharpness of the cutting edges.
In down milling, maximum chip thickness cecum close to the point at which the tooth contacts the work. Because the relative motion tends to pull the workpiece into the cutter, all possibility of looseness in the table feed screw must be eliminated if down milling is to be used. It should never be attempted on machines that are not designed for this type of milling. Inasmush as the material yields in approximately a tangential direction at the end of the tooth engagement, there is much less tendency for the machined surface to show tooth marks than when up milling is used. Another considerable advantage of down milling is that the cutting force tends to hold the work against the machine table, permitting lower clamping force to be employed. 3 This is particularly advantageous when milling thin workpiece or when taking heavy cuts.
Sometimes a disadvantage of down milling is that the cutter teeth strike against the surface of the work at the beginning of each chip. When the workpiece has a hard surface, such as castings do, this may cause the teeth to dull rapidly.
Milling Cutters. Milling cutters can be classified several ways. One method is to group them into two broad classes, based on tooth relief, as follows:
1. Profile-cutters have relief provided on each tooth by grinding a small land back of the cutting edge. The cutting edge may be straight or curved.
2. In form or cam-reheved cutters the cross section of each tooth is an eccentric curve behind the cutting edge, thus providing relief. All sections of the eccentric relief, parallel with the cutting edge, must have the same contour as the cutting edge. Cutters of this type are sharpened by grinding only the face of the teeth, with the contour of the cutting edge thus remaining unchanged.
Another useful method of classification is according to the method of mounting the cutter. Arbor cutters are those that have a center hole so they can be mounted on an arbor. Shank cutters have either tapered or straight integral shank. Those with tapered shanks can be mounted directly in the milling machine spindle, whereas straight-shank cutters are held in a chuck. Facing cutters usually are bolted to the end of a stub arbor.
The common types of milling cutters, classified by this system are as follows:
Types of Milling Cutters. Hain milling cutters are cylindrical or disk-shaped, having straight or helical teeth on the periphery. They are used for milling flat surfaces. This type of operation is called plai n or slab milling. Each tooth in a helical cutter engages the work gradually, and usually more than one tooth cuts at a given time. This reduces shock and chattering tendencies and promotes a smoother surface. Consequently, this type of cutter usually is preferred over one with straight teeth.
Side milling cutters are similar to plain milling cutters except that the teeth extend radially part way across one or both ends of the cylinder toward the :center. The teeth may be either straight or helical. Frequently these cutters are relatively narrow, being disklike in shape. Two or more side milling cutters often are spaced on an arbor to make simultaneous, parallel cuts, in an operation called straddle milling.
Interlocking slotting cutters consist of two cutters similar to side mills, but made to operate as a unit for milling slots. The two cutters are adjusted to the desired width by inserting shims between them.
Staggered-tooth milling cutters are narrow cylindrical cutters having staggered teeth, and with alternate teeth having opposite helix angles. They are ground to cut only on the periphery, but each tooth also has chip clearance ground on the protruding side. These cutters have a free cutting action that makes them particnlarly effective in milling deep slots.
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