轴瓦工艺工装设计-外文翻译讲解

1、麻花钻。麻花钻是最普通的一类钻刀麻花钻有两条切削刃和两条螺旋线形的出钻削与镗削Addis on-Wesley pub.Co.摘要：通过驱动刀具能在工件上钻出通孔或盲孔， 钻刀是正对着工件绕着自己的轴线 旋转。当然，刀具从其轴线向外的切削距离应和需加工的孔的半径相等。 在实际生产 中，是采用关于同一轴线对称的两切削刀刃的刀具。 钻削既可被应用于手工也可用于 钻床中。钻床在尺寸和结构上有所不同。然而，当工件被牢固地安装好后，钻刀总是 绕着自己的轴线旋转。这是和在车床上钻孔是相反的。镗孔是扩大以前钻削或镗削好 了的孔。镗孔能够消除钻空加工时孔所产生的偏心， 使孔扩大到需铰削的尺寸。下面 是对钻削、钻

2、床分类和镗孔的简要介绍。关键词：钻削、镗削、钻床、钻削刀具、镗刀、钻床的分类钻削刀具在钻削操作中，采用的是一种柱形的螺旋式刀具， 被称之为钻刀。钻刀有一条或 两条切削刃和相应的出屑槽，出屑槽呈直线或螺旋线形。出屑槽的作用是为在钻削过 程中产生的切屑提供一个通道，同时也是便于润滑剂和冷却剂到达钻刀的切削刃和工 件的被加工表面。以下是普通刀具的概括论述：图4.1屑槽，出屑槽连续地围绕分布在整个钻体上（如图4.1 ）。钻刀除了钻体部分，还有钻颈和钻柄，钻柄可以是圆柱形，也可以是锥行。在后者的情况下，钻柄是通过柄舌的楔形作用安装在主轴的锥形钻套中， 柄舌是安装在主轴钻套的狭槽中，这样钻刀和刀刃主轴形成

3、一个整体来传递旋转运动。在另一方面，圆柱形钻柄是被安装在钻夹头里， 然后，以安装锥形钻柄的方法将其安装进主轴的钻套中从图4.1可以看出，两条切削边被称为刀刃，两条切削刃是通过楔子连接在一起。麻花钻还有两条刃带，其能在钻削操作中对刀具起正确的导向和定位的作用。两条刀刃形成钻刀的顶角，顶角大小的选择是依据被加工材料的特性。工业生产中经常 使用的钻刀的顶角是118，其适合钻削低碳钢和铸铁。对于硬度和刚度较高的金属， 譬如，硬刚，黄铜和青铜，宜选用稍大顶角（130。或140 ）的钻刀。常用麻花钻 的出屑槽的螺旋角是范围是在24 -30。之间。当在钻削铜或软塑材料时，推荐使用螺旋角较大的刀具（35 -4

4、5。之间）钻颈倒棱钻体钻柄图4.2空心钻。空心钻是由倒棱，钻体，钻颈和钻柄组成，如图4.2所示。此类的空心钻有三条或四条出屑槽和相应数量的刃带保证良好的导向来获得高的加工精度。从图4.2还可以看出空心钻有一平断，倒棱可能有三条或四条切削边，或称为刀刃， 顶角可在90-120范围内变化。空心钻是用来扩大先前已有的孔，它不是用来钻削新 的孔的。空心钻有高的生产率，高的加工精度和能钻削出高质量的表面的特性。枪孔钻。枪孔钻是用来加工深孔的。所有的枪孔钻的出屑槽都是直的，只有一单 条切削刃。在枪钻的钻体上有一个孔，其起着导管的作用，冷却剂在较的压力下通过 该孔流到枪钻的顶尖部位。现有两种枪钻，即，用来加

5、工盲孔的中心钻和套筒钻。 套筒钻的中心有一个圆柱 形孔，钻孔时可在工件上形成一个芯子，当钻头连续进给进行钻孔时，芯子对钻起导 向作用。平钻。平钻是用于钻削大于7/2英寸的孔（90mm乃至更大的孔。该类的钻易于 磨削。镗刀镗孔是扩大以前钻削或镗削好了的孔。镗孔能够消除钻空加工时孔所产生的偏心，使孔扩大到需铰削的尺寸平底扩孔是指扩大一个钻孔的末端。 这个扩大的孔的底部是平的，它与原来的孔 是同轴的。刀具与导向销一起使用，导向销装进已钻好的孔中，用于切削刃对中。平 底扩孔主要用于在上面安装螺栓下面安装螺钉的孔的加工。在一个已加工好的孔上加 工一个小的平面，该面称之为刮孔平面。在粗糙的表面上为螺栓提供

6、平滑的沉头座的 操作是很普遍的。如果把一个已加工控切成斜边以便适合一个平底螺栓的圆锥座，该操作称为锪锥面。刀具用于卧式镗床或是被安装在一个大型杆上或是作一个镗前头，它们依次排布在机床的主轴上。绝大多数镗孔操作是使用具有一个单齿的镗刀，如图4.3所示，因为他们易于安装和维修。镗杆的作用是将来机床自轴的动力传递到刀具上和保持在 切削过程中的刚性，在加工过程中，工件通常不动，刀具在孔中作旋转进给运动。如 图所示，通常需给镗杆提供附加支撑。镗杆必须足够的长以达到末端支撑和为机床操 作提供一定的纵向空间。图4.3在铣床、坐标镗床、或钻床上进行精密镗削时，有必要使用一种带有千分尺调整 的工具。这种工具安装

7、在刀具头上并作旋转运动。因此任何孔径的增加必须通过调整 工具半径来获得。图4.3b所示的是最常见的组合式双镗刀布置形式，他包括两个相对 的刀具夹在沟槽中。螺柱是用来在指定位置锁紧刀具和调整他们的位置。整体装进一 个矩形狭槽中，且锁在固定位置。刀具固定在滑行刀架里，且与顶尖成一条直线。刀具 的精度取决与刀具车间的全体人员而不是操作者.通常用于小型机床譬如车床的镗刀是单齿镗刀,他是被以其能进入孔内的方式支承着。图4.4a所示刀具的末端事实锻造的，然后通过磨削成型。它是安装在一个单 独的支承杆上，该支承杆是安装在车床的刀架上。对于转塔车床所用的是类似于图4.4b所示的刀具，只是刀杆稍有不同。刀具的修

8、改是镗杆部分，如图4.4c所示，它被设计成在镗杆的末端拥有一个小型高速钢刀具。镗杆的刚度强，其长度可根据孔的长度作相应的调整。尽管这些刀具的间隙、斜度和切削角应该接近那些在车床操作中 推荐使用的相近，但如果孔较小的话，这些角度是不能使用的。在加工工件中，普遍使用多切削刃的镗刀。如图 4.4f，这些表面类似筒形绞刀 的刀具，但具有镶齿铣刀，它们被调整成补偿磨损和直径变化。 这种类型的镗刀比单 刃刀具有较长的寿命，因此在加工中更经济。如图 4.4e所示的带有导向销的以保证 同轴度的平底扩孔刀具是用来扩大孔的末端。钻床的分类便携式的小机床上可实现钻削操作，一般的机床上也可以实现钻削操作。一般的 机床

9、在形状和尺寸上不同于便携式小机床，但它们也有共同的特征。例如，它们都拥 有一根或更多根的麻花钻，当在加工以被固定装好了的工件时，每根麻花钻绕着自己 的轴作旋转运动。这和在车床上工件被夹紧并随着卡盘作旋转运动而进行的钻削是相 反的。下面是对一些普通式钻床的概述。台式钻床。台式钻床通常是被放在工作台上的普通加工用途的小型机床。这种钻床包括一个动力来源的电动机，动力是通过滑轮和皮带传递到装有刀具的主轴上。进给运动是通过降低操纵杆，由操纵杆带动主轴的下降（或上升）来实现的。台钻的主 轴在套筒内自由旋转（套筒由操纵杆通过齿轮齿条系统驱动， 但不随主轴一起旋转）。加工工件时，工件是被放在机床的工作台上，有

10、时需要一个特殊的花钳来固定。被加工工件的最大厚度是受机床主轴与工作台之间的间隙限制d)图4.4的工作台上，此时，该机床被称之为排式钻床。这种机床特别地适用于几种需连续进摇臂立柱主轴底座立式钻床。立式钻床可被用于轻度、中等、甚至相对重负何强度的工作，这主要 取决于立式钻床的尺寸。立式钻床与台式钻床基本相似，主要的不同点是里是立式钻床的底座上装有一较 长的圆柱形支柱。在支柱上附加安装了一个可以锁定在任一想要高度的滑动工作台。 当立式钻床用于中等强度的工作时，其所需的动力要比台式钻床的多。在立式钻床里有比较的的钻床。因此，这大的钻床有一个箱柱和较高的动力，以 此满足重负荷。此外，它是采用齿轮箱为主轴

11、提供不同的旋转速度和轴向进给量， 通 过齿轮箱可以预先设置任何想要的主轴转速和进给速率。多轴钻床。多轴钻床的结构坚固，其工作时需要很强的动力，每台多轴钻床能同 时钻削很多孔。为满足加工要求，不同的刀具是可以调整的，同时根据需要，整个床 头箱部分（带有主轴和刀具）是可以倾斜的。这类的钻床主要用于批量生产且拥有很多孔的零件的加工。例如汽缸体。排式钻床。当几个独立的钻头（每个都有一个单独主轴）排列在一个单独的普通行的操作图4.5摇臂钻床。摇臂钻床，特别地适合那些不便于安装在立式钻床上的大型和重型工件进行钻孔。在图4.5可以看出，摇臂钻床有一安装在底座上的立柱。 摇臂钻床的摇臂带着钻床的床头箱主轴和刀

12、具移动， 该摇臂能够沿立柱上升或下降，并可以锁紧在任一所需的位置上。床头箱沿着摇臂滑动并使主轴作旋转运动和轴向进给运动。 此外,.钻床的床头箱斗摇臂能够摆动，因此刀具可移动到圆柱坐标系统的任一位置。转塔钻床 。归属于转塔钻床类的机床， 或是半自动或是全自动控制的。 转塔机床 的一个普遍的设计特征是用转塔代替原来机床的主轴，转塔上装有几把钻削、镗削 和螺纹切削刀具。 因此，几种连续的操作只需要在一次初安装下就可以完成， 在两种 操作之间不需要再次装夹工件。如今，由数字或计算机控制系统控制的自动转塔钻床是相当的普遍了。在这种情 况下， 人的工作只是对工件进行初安装和对其进行监控。 这类机床就空间要

13、求 （机床 的物理尺寸）和工件装夹次数而言比排式钻床有优越性。长孔钻床 。长孔钻床是一类特殊的被用作钻削长孔的机床，譬如，枪管的长孔就 是用此类机床加工。 通常长孔钻在使用时对工件的进给速度是较慢的。 这类机床在工 作时，工件作旋转运动，而刀具不作旋转运动。长孔钻床有立式结构也有卧式结构。 然而，这两种结构的共同特征是在钻削过程中工件的精确导向和刚性支承。坐标镗床 。这类机床是为获得高的精确性和精密性而特别设计的。这类机床不但 钻孔而且能够给孔定位，因为工作台的运动由电子测量装置监控着。DRILLING AND BORINGAddison-Wesley pub.Co.Abstract: Dri

14、lling involves producing through or blind holes in a workpiece by forcing a tool, which rotates around its axis, against the workpiece.Consequently, the range of cutting from that axis of rotation is equal to the radius of the required hole. In practice, two symmetrical cutting edges that rotate abo

15、ut the sameaxis are employ. Drilling operations can be carried out by using either hand drills or drilling machine. The latter differ in size and construction. Nevertheless, the tool always rotates around its axis while the workpiece is kept firmly fixed. This is contrary to drilling on a lathe.Bori

16、ng is enlarging holes previously drilled or bored. Drilled holes are frequently bored to eliminate any possible eccentricity and to enlarge the hole to a reaming size. Following is a survey of drilling, drilling machine tool and boring.Keyword: drilling boring drilling machine tool classification of

17、 drilling machine cutting tool for drilling operations cutting tool for boring operationsCUTTING TOOL FOR DRILLING OPERATIONSIn drilling operations, a cylindrical rotary-end cutting tool, called a drill, is employed. The drill can have either one or more cutting edges and corresponding flutes, which

18、 can be straight or helical. The function of the flutes is to provide outlet passages for the chips generated during the drilling operation and also to allow lubricants and coolants to reach thecutt ing edges and the surface being mach in ed. Follow ing is a survey of the common ly used drills.Twist

19、 drill. The twist drill is the most commortype of drill. It has two cutting edges and two helical flutes that continue over the length of the drill body, as shown in Fig.4.1. The drill also consists of a neck and a shank that can be either straight or tapered. In the latter case, the shank is fitted

20、 by the wedge acti on into the tapered socket of the spin dle and has a tang, which goes into a slot in the spindle socket, thus acting as a solid means for transmitting rotation. On theother hand, straight-shank drillsare heldin a drill chuck that is,in turn,fitted intothe spindle socket inthe same

21、way as tapered sha nk drills.Fig.4.1 The twist drillAs can be seen in Fig.4.1, the two cutting edges are referred to as thelips, and are connected together by a wedge, which is a chisel-like edge. The twist drill also has two margi ns, which en able proper guida nee and locati ng of the drill while

22、it is in operation. The tool point angle (TPA) is formedby the two lips and is chosen based on the properties of the material to becut. The usual TAP for commercial drills is 118, which is appropriate fordrilli nglow-carb on steels and cast irons. For harder and tougher metals, suchas harde ned stee

23、l, brass and bron ze, larger TAPs (130or 140) give betterperforma nee. The helix an gle of the flutes of the commo nly used twist drillsranges between 24 and 30 . Whendrilling copper or soft plastics, higher values for the helix an gle are recomme nded (betwee n35 and 45).Core drills. A core drill c

24、onsists of the chamfer, body, neck, and shank, as show n in Fig.4.2.This type of drill may have either three or four flutes and an equal number of margins, which ensure superior guidanee, thus resulting in high machining accuracy. It can also be seen in Fig.4.2 that a core drill has flat end. The ch

25、amfer can have three or four cutt ing edges, or lips, and the lip angle may vary between 90 and 120 . Core drills are employed for enlarging previously madeholes and not for originating holes. This types of drill is characterized by greater productivity, high machining accuracy, and superior quality

26、 of the drilled surfaces.Gun drills. Gun drills are used for drilli ng deep holes. All gun drills are straight-fluted, and each had a sin gle cutt ing edge. A hole in the body acts as a conduit to transmit coolant underconsiderable pressure to the tipof the drill.There are two kinds of gun drills, n

27、amely, the center-cut dill used for drilling blind holes and the trepanning drill. The latter has a cylindrical groove at its cen ter, thus gen erat ing a solid core, which guides the tool as it proceeds during the drilling operation.Spade drill.Spadedrills are used for drilling large holes of 7/2in

28、. (90mm)or more. Their which results in a marked saving in cost of the tool as well as a tan giblereduct ion in its weight, which facilitates itshan dli ng.Moreover, this type of drill is easy to grind.BORING TOOLSBori ng is enlarging holes previously drilled or bored. Drilled holes arefreque ntly b

29、ored to elimi nate any possible ecce ntricity and to enl arge the hole to a ream ing size.Coun terbori ng is enlarging one end of a dilled hole. The enl arged hole, which is 譚口宫1凸Fig.4.2 The core drillconcentric with the original one, is flat on the bottom. The tool is provided with a pilot pin that

30、 fits into the drilled hole to center the cutting edges. Counterboring is used principally to set bolt heads and nuts below the surface. To finish off a small surface around a drilled hole is known as spot facing. This is a customary practice on tough surface to provide smooth seats for bolt heads.

31、If the top of a drilled hole is beveled to accommodate the coni cal seat pf a flat-head screw, the operatio n is called coun ters inking.CutLers.Fig.4.3Tools used in horiz on tal bori ng mach ines are moun ted in either a heavybar or a bori ng head, which in tur n is conn ected to the main spin dle

32、of the machine. Most boring operations use a single-pointcutter as shown in Fig.4.3,because they are simple to set up and maintain. The bar serves to tran smit power from the machine spindle to the cutter as well as to hold it rigidly duri ng the cutt ing operati on. The workpiece is no rmally stati

33、 on ary a nd the rotating cutter is fed through the hole. It is often necessary to provide additional support for the bar as shown in the figure. The bar must be long eno ugh to reach the end support and also must provide the n ecessary Iongitudinal traverse for the machining operation.For precision

34、 boring work on millingmachines, jig bore, or drill presses,it is n ecessary to use a tool hav ing micrometer adjustme nt. Such tools are held in a cutter head and rotate. Hen ce, any in crease in hole size must beobtained by adjusting the tool radially from its center.The most popular double-cutter

35、 arrangement is the block type shown in Fig.4.3b, which consists of two opposing cutters resting in grooves on the block. Screws are provided to lock the cutters in positi on as well as to adjust them. The entire assembly fits into a rectangular slot in the cutters in position as well as to adjust t

36、hem. The en tire assembly fits into a recta ngular slot in the bar and is keyed in place. Cutters are ground while assembled in the block and are held in alig nment by the cen ter holes provided. The resp on sibility for tool accuracy and setup belongs to the toolroom personnel rather than the opera

37、tor.The boring tool commonly use in small machines such as lathes is a single -po in ted tool,supported in a manner that permits its entry into a hole. Thistool, show n in Fig.4.4a is forged at the end and the n ground to shape. It is supported in a separate holder that fits into a lathe tool post.

38、For turret lathes, slightlydifferent holders and forged tools similar to the one shownin Fig.4.4b are used. A modification of this tool is the boring bar shown in Fig.4.4c, which is desig ned to hold a small high-speed steel tool bit at the end. The bar support ing the tool is rigid and may be adjus

39、ted accord ing to the hole len gth. Although the cleara nee, rake, and cutt ing an gles cannot be used if the tools should be similar to those recommendedfor lathe work, these an gles cannot be used if the holes are small.In product ion work, bori ng cutters with multiple cutt ing edges are widely u

40、sed. These cutters, show n in Fig.4.4f resemble shell reamers in appeara nee but are usually provided with inserted-tooth cutters that may be adjusted radially to compensate for wear and variations of diameter. Boring tools of this type have longer life than single-pointed tools and hence are more e

41、conomical for production jobs. The counterboring tool shown in Fig.4.4 Types of bori ng toolsFig.4.4e provided with pilots to ensure concentric diameters. Is designed to recess or enlarge one end of a hole.CLASSIFICATION OF DRILLING MACHINESDrilling operations can be carried out by employing either

42、portable small machines or appropriate machine tools. The latter differ in shape and size, although they have commonfeatures. For instance, they all involve one or more twist drills, each rotating around its own axis while the work piece is kept firmly fixed. This is contrary to the drilling operati

43、on on a lathe, where the work piece is held in and rotates with the chuck,. Following is a survey of the commonly used types of drilling machines.Beach-type drilling machines. Beach-type drilling machines are general-purpose, small machine tools that are usually placed on benches. This type of drill

44、ing machine includes an electric motor asthe source of motion,which is transmitted via pulleys and belts to the spindle, where the tool is mounted. The feed is manually generated by lowering a lever handle, which is designed to lower (or raise) the spindle. The latter rotates freely inside a sleeve

45、(which is actuated by the lever through a rackpinion system but does mot rotate with the spindle ).The workpiece is mounted on the machine table, although a special vise is sometimes used to hold, the workpiece. The maximum height of a workpiece to be machined is limited by the maximumgap between th

46、e spindle and the machine table.Upright drilling machines. Depending upon the size, upright drilling machine tools can be used for light, medium, and even relatively heavy jobs. It is basically similar to bench-type machines, the main difference being a longer cylindrical column fixed to the basic.

47、Along that column is anSpindleadditi on al, slid ing table for fixing the workpiece which can be locked inposition at any desired height. The power required for this type is more than that for ben ch-type drilli ngmach in es, since this type is employed inperform ing medium-duty job.There are also l

48、arge drilling machines of the upright type. In this case the mach ine has a box colu mn and a higher power to deal with large jobs. Moreover, gear boxes are employed to provide differe nt rotati onal spin dle speeds as well as the axial feed moti on, which can be preset at any desired rate.Multisp i

49、n dle drilli ng machi nes.Multisp in dle drilli ng mach ines havesturdy construction and require high power; each is capable of drilling many holes simultaneously. The positions of the different tools (spindles)can beadjusted as desired. Also, the whole head (which carries the spindles and tools) ca

50、n sometimes be titled, as required.This type of drillingmachine is used mainly for massproduction in jobs havingmany holes, such as cyli nder blocks.Gang drilli ng mach in es.Whe n several separate heads (each with a sin glespin dle)are arran ged on a sin gle com mon table, the mach ine tool is the

51、nreferred to as a gang drillingmachine. This type of machine tool isparticularly suitable where several operations are to be performed in successi on.Radial drill. A radial drill is particularly suitable for drilling holes in large and heavy workpiece that are inconvenient to mount on the table of a

52、n upright drilling machine. As you can see in Fig.4.5, a radial drilling machine has a main column, which is fixed to base. The cantilever guide arm, which carries the drilling head spindle and tool, can be raised or Fig.4.5 A Sketch of radial drill.can Mrinp: I* ICTE “ristii?4Eki疋lowered along the

53、column and clamped at any desired position. The drill head slides along the arm and provides rotary motion and axial feed motion. Again, the cantilever guide arm can be swung, thus enabling the tool to be moved in all directions according to a cylindrical coordinate system.Turret drilling machines.

54、Machines tools that belong to the turret drilling machines are either semi-or fully automatic. A commondesign feature is that the main spindle is replaced by a turret, which carries several drilling, boring, reaming, and threading tools. Consequently, several successive operations can be carried out with only a single initial setup and without the need for setting up