机制毕业论文翻译(镗孔刀具的改进技术)中英双语完整版

1、毕业设计（论文）英文翻译年级、姓学指导专业名:张李婷口 号:312009080301310师:张晓洪黄伟忠教年级：09级专业：制造工程学号：312009080301310 姓名：张李婷镗孔刀具的技术改进摘自国际金属加工06年3月刊镗削加工通常被认为是适合在各种不同尺寸和形状工件上加工精密孔的 理想加工方式。为了适应不断提高生产率的需要，镗孔刀具的设计也在不断创新 改进。近年来，镗孔刀具的技术改进主要体现在以下四个方面。、采用数显读数屏的精密镗头自数控（NC）技术间世以来，数字显示技术已在 CNC机床和坐标测量机上 大量应用。此外，数显千分尺、数显卡尺等数显量具也已得到广泛使用。但是， 数显技术

2、在精密螳刀上的应用却一直进展缓慢， 其制约因素主要是键孔加工中使 用的冷却液和镗头的高速旋转。过去，在加工中心上进行镗孔加工时必须非常小心， 尽量避免四处飞溅的冷 却液进人锻头数显装置的电子元件中。 如今，采用内冷却设计的新型镗刀已能较 好解决这一问题。由于冷却液可通过刀具内部的通道直接到达切削部位，从而实现了冷却液与镗头数显装置的完全隔离。此外，新型数控镗刀的外部进行了良好密封， 可有效防止冷却液与数显装 置中的电子元件接触。在高速镜削加工中，镜头的高速旋转。离心力以及镗头本身的不平衡都可能 引起较大振动，从而损坏灵敏的数显装置。新型镗头通过采用一种内置平衡机构， 可以在高速镗削时减小或消除

3、有害的振动。目前 ，带数显读数屏的精密镗头已能 够用于转速达16000r/min的高速镗削加工。新型镗头的数宇显示屏可直接显示出镗刀滑块的位移量，而不必通过调整刀 具螺杆的转动量来确定位移量。由于锥杆直接安装在镗刀滑块上，因此镗头的数 显读数值可真实反映出锤刀的位移量，而不会受到螺杆空程误差的影响。数显镗 头这一特点使其可以更快速、更精密地调整镗孔直径，并可实现对加工偏差或刀 具磨损的误差补偿。大多数镗刀都需要通过试切一测量操作来确定其设定尺寸，即首先对一小部分被加工孔进行试切镗削，然后测量其加工孔径。通常，这就意味着需要将镗刀 从机床卜卸下来，再安装到一台对刀仪上对镗刀尺寸进行微调修正， 以

4、获得正确 的孔径尺寸。这种预调操作之所以必要，是因为直接在机床上对普通镗头的游标 刻度盘进行读数和预调相当困难，但是，这种操作方式可能造成镗孔尺寸超差或损 坏工件。由于在机床上安装镗刀时难以预测其刀尖偏差，因此需要采用试切一测量操作来预调刀具。如果采用易于读数的新型数显镗刀，则可能实现直接在机床主轴 上对刀具镗孔直径进行微调，其尺寸调整范围可达0.0001 （0.00254mm）。即使因为机床主轴的进刀限制，必须将镗刀从机床上卸下来进行孔径尺寸凋整，新型数显镗刀的调刀过程也更快速、更精确。二、采用铝结构的镗刀体铝的重量较轻，是制造刀体的常用材料。随着当今CNC机床的加工速度越来越高，许多机床的

5、重量也越来越轻，减轻刀具的重量就显得至关重要。大部分数控机床的换刀机械手对刀具的重量都有一定限制。采用铝结构的 镗刀既可确保刀具重量不超过换刀机械手的限重标准，同时又能加工直径尺寸大于4 （约100mm的孔，（一般来说，加工孔径小于4的镗刀，无论采用铝结构还 是钢结构,其重量均不会超过换刀机械手的限重标准）。镗刀重量的减轻可以减小 机床主轴的误差，从而提高镗孔精度。此外，镗刀的重量越轻，机床主轴本身的 磨损和破坏也越小。在数控机床上装卸大型、重型镗刀时，由于钢结构镗刀的重量往往超过了机 床换刀机械手的限重标准，因此不得不采用手工装卸或利用高架起重臂进行吊 装，既费时又费力。如果采用重量较轻的铝

6、结构镗刀，这一问题可迎刃而解。例 如，美国堪萨斯州一家工厂原来所用的加工孔径14（355.6mm的钢结构镗刀重约40磅,需要使用起重臂才能安装到机床上，换用了一把同样规格的铝结构镗刀后 其重量还不到25磅,可利用换刀机械手自动装刀，从而大大提高了生产率。铝结构镗刀在高拴切削时的平衡性能上也更具优势。由于铝结构镗刀的非 对称质量比传统的钢结构镗刀小得多， 因此在用相同的制造工艺进行加工时， 可 以大大减少或消除刀具不平衡带来的问题。铝结构镗刀的耐用性是人们始终关注的一个问题。不过，通过在刀具表面涂 覆氧化铝硬涂层，这一问题可以得到圆满解决。采用一种特殊的酸性电解液氧化 涂层工艺，可以将刀具表面的

7、铝转化为氧化铝。氧化层深度可达0.008 （约0.02mm）,其表面硬度可达 56HRC.铝结构镗刀的表面硬涂层可以有效防止因切屑磨擦和腐蚀对刀具的损 害。由于精镗加工的切屑一般较为细碎， 对刀体的撞击力也较小，切屑磨擦对刀 具的影响有限。因此，经过表面涂层处理的铝结构镗刀在精镗加工中具有良好的 耐磨损性，但在耐冲击性方面则可能不如钢结构镗刀。刀体表面涂覆了氧化铝硬涂层的铝结构镗刀，在易形成长切屑或磨蚀性切屑 的工件材料上粗镗加工大孔径（8.07 40 1533，2051020mm）时也具有明 显的优势（小孔径粗镗刀通常采用钢结构），流畅的排屑（可减小切屑对刀具的 冲击和磨损）与刀具表面硬涂层

8、相结合，可使刀具在粗镗加工此类材料时刀体不 会过快磨损。三、具有粗、精镗功能的复合式镗刀传统的镗孔加工通常需要经过从粗镗到精镗（有时精镗前还需进行半精镗） 的多道工序才能完成，虽然这种多工序加工方式可保证加工的可靠性，但却相当 耗费工时。随着近净成形铸造（near- net-sharp cast in gs）技术尤其是铝模铸造技术的出 现，工件毛坯质量提高，加工余量减小，多工序加工的必要性也随之减少甚至消 除。在许多情况下，孔的粗镗与精镗加工可以在同一台机床上完成，这样，对被 加工孔的加工余量和偏心量的技术要求可以大幅度降低。为此，复合式镗刀的应用引起了人们的广泛关注。复合式镗刀将粗镗与精镗两

9、种切削刃集成于同一把镗刀上，通过一次走刀操作即可完成孔的全部镗削加工。首先由粗镗切削刃切除大部分加工余量， 然后由 精镗切削刃加工孔径至要求尺寸。粗镗刀片与精镗刀片之间工作寿命的差异可以 通过在刀夹中安装不同牌号硬质合金刀片来加以调节。精镗切削刀片装夹在一个可调刀夹上， 刀夹位置可利用精密螺杆和传统的游 标刻度进行调节。通过一次走刀操作，即可加工出公差为 0.001（ 0.0254mm） 的精密孔径。虽然复合式加工必须根据加工需要设定进给率， 但由于省略了粗镗 或半精镗工序，因此可大幅度提高生产率。四、适合高速切削的自平衡镗刀人们很早就已认识到镗刀的平衡性能对于镗削加工质量的重要性。在如今的高

10、速切削条件下，镗刀的平衡问题显得比以往更为突出，即使是很小的刀具不平 衡量都可能对被加工孔径的尺寸、表面光洁度、圆度以及刀具寿命造成很大影响。 此外，刀具的不平衡还可能引起切削振颤。 近年来，许多标准镗刀上都加装了平 衡机构，这种机构通常由可移动的配重块组成， 由于镗刀的不平衡状态主要是由 加工孔径变化引起的，因此可以根据镗刀设定的加工孔径对刀具的配重进行调 节。这种方法对于保持刀具平衡虽然有效，但却相当耗费工时。此外，这种平衡 装置位于刀具外部，暴露于冷却液、切屑和油污中，很容易受到损坏。内部安装有自平衡机构的新型镗刀则可较好解决这一问题。 当装夹刀片的可 调刀夹向某一方向移动以调节孔径时，

11、镗头内一个与之机械连接的平衡配重块则 同时向相反方向移动，以保持镗刀的平衡。该内置自平衡机构密封在镗头内， 可 与冷却液和切屑完全隔离。这种自平衡镗刀可应用于现代 CNC机床的高速加工，对于大多数加工任务， 均可获得相当不错的刀具平衡效果。如果某项加工任务对于刀具平衡的技术要求 特别高，也可将这种镗刀作为一个组件在高精密平衡机上进行平衡。对于桥式镗刀（不管是铝结构还是钢结构），通常都是利用平衡配重块进行手动平衡。上述几项设计技术（带数显读数屏的精密镗头、铝结构镗刀体、复合式镗刀和自平衡镗刀）均有助于加工制造商大幅度地提高镗削加工生产率。虽然这些技 术创新还不能称为革命性”的技术发展，但已足以对

12、镗削加工的技术进步产生重 大影响。Impro veme nt of bori ng cutter tech no logyfrom the in ter natio nal metal p rocess ing 06 years 3 mon thly.Boring is usually considered to be the ideal way of processing precision machining holes in different sizes and shapes. In order to adapt to the n eed to imp rove p roductivi

13、ty, desig n of bori ng cutter is also in constant improvement and innovation.In recent years, the improvement ofthe tech no logy of the bori ng cutter is mai niy reflected in the followi ng four asp ects.A p recisi on bori ng head, the digital dis play scree nSi nee nu merical con trol (NC) since th

14、e tech no logy world, digital dis play tech no logy has bee n app lied in CNC machi ne tool and coord in ate measuri ng mach ine. In additi on, digital dis play micrometer, cali pers, digitaldis play measuri ng has also bee n widely used. However, app licati onof digitaltech no logy in p recisi on m

15、an tis on the knife has bee n slow, thekey factor is the use of high-s peed rotati ng hole mach ining coola nt and bori ng head.In the past, be very careful for boring machining in machining center, try to avoid the electro niccomponents cooli ng liquid sp lash ing in to theheadi ng in the digital d

16、is play device. Now, using a new type of bori ng cutter cooling design can solve this problem. Because the cooling liquid can be directlyto the cutt ing p ositi on through the tool in side the cha nn el,so as to realize the cooli ng liquid and the bori ng head digital dis play device comp letelyIsol

17、ation.In addition,the new NC boring is a good seal, caneffectively p reve nt the electr onic component con tact cooli ng fluid and digital dis play device.In the high sp eed cutt ing, high sp eed rotat ing lens. The un bala need cen trifugal force and bori ng head itself may cause largevibrati on,th

18、ereby damag ing sen sitive digital dis play device. New bori ng head by using a built-in bala nee mecha ni sm, can reduce or elimi nate the harmfulvibrati on in high sp eed bori ng. At p rese nt, p recisi on bori ng head with digital dis play scree n can be used for high sp eed bori ng sp eed is up

19、to 16000r/min mach ining.Digital dis play type bori ng head can directly show the dis placeme nt of bori ng cutter slider, without accurate po siti oning by rotati ng the adjustme nt screw to shift tool. Si nee the cone rod moun ted directly on the bori ng cutter block, so bori ng head of digital re

20、adi ng value can reflect the dis pl aceme nt of the hammer, and will not be affected by the screw backlash error. The characteristics of digital boring head so that it can be more rap id, more p recisely adjust the bore diameter, and can realize the compen sati on of tool wear machi ning deviati on

21、or error.Most bori ng tools n eeded by test cutt ing a measureme nt op erati on to determ ine the set size, n amely, first a small p orti on of the hole is cut and trialboring, and then measure its processing aperture. Usually, thismea ns that n eed to be uni oaded from the mach ine tool, cutter, an

22、d the n mounted to a tool auto-checkinginstrumentof boring cutter sizehowever, bore sizerefin eme nt, in order to obtai n the correct ap erture size. The p reset op erati on is n ecessary, because the direct mach ine on the vernier dial for ordinary boring head for reading and preset quite difficult

23、, this mode of op eratio n may cause damage to the work piece deviatio n or.p resett ing the directDue to its tip bias is difficult to p redict the in stallati on tool in machine tools, so we need to try to cut a measurement operation cutter. If using a new digitalboring easy reading, mayrealizeto f

24、ine-tune boring tool diameter on the spindle of the machine tool, the size of the adjustme nt range up to 0.0001 (0.00254mm). Eve n if the feed restrict ion of machi ne tool spin dle bori ng, must be uni oaded from the mach ine on the pore size adjustme nt, adjustable p rocess model digital cutter i

25、s also more rap id, more accurate.Two, the cutter body alumi num structureAlu minum is light in weight, is com monly used in manu facturi ng the cutter body. With the CNC machine tool processing speed ismore and morehigh, many mach ine tool weight are also more and more light, reduci ng weight is ve

26、ry imp orta nt tool.The knife manipu lator of cutt ing weight cha nge most of CNC machi ne tools have certain limitations. Using aluminum structure of boring cutter can en sure the weight limit sta ndard tool weightnot exceedi ng toolcha nging manipu lator, while machi ning diameter greater tha n 4

27、in ches(about 100mm)of the hole, (in general, processing diameter of less than 4 bori ng, no matter is made of alu minum or steel structure, its weight will not limit weight sta ndard more tha n tool cha nging manipu lator).Bori ng the reduced weight error can be reduced the machi ne spin dle, so as

28、 to improve the boring accuracy. In addition,boring weight more light,wear and damage the machi ne tool spin dle itself is smaller.In the numerical control machine tool of handling large, heavy boring, because the weight limit sta ndard steel structure bori ng weight ofte n exceeds the machi ne tool

29、 cha nging manipu lator, so had to use manual han dli ng or use of overhead crane for lift ing, which is time-c onsuming and laborious. If the use of alu minum structure bori ng weight lighter, this problem can be smoothly done or easily solved. For example, a factory p rocess ing ap erture in the A

30、merica n state of Kan sas origi nally used 14 (355.6mm) of the steel structure of boring weighs about 40 pounds, need to use the crane to in stall to mach ine tools, were rep laced by a same specificationaluminum structure of boring cutter, its weight is less than25 pounds, can use the automatic too

31、l change manual and automatic knife, which greatly impro ves the p roductivity.Alu minum structure bori ng bala nee p erforma nee in high tied whe n the cutting is more advantage. Because of asymmetric qualityaluminumstructure boring boring than traditionalsteel structure is muchsmaller,so in the pr

32、ocessing by the samemanufacturing process, can greatly reduce or elimi nate the p roblem brought by the un bala need tools.Alumi num structure and cutter durability is a p roblem that people always pay atte nti on to the. However, the tool is coated on the surface of alumina hard coatings, thisprobl

33、em can be solved. The acidicelectrolyte oxidati on coat ing p rocess of a sp ecial tool, can be surface of the aluminum into aluminum oxide. The oxide layer depth of up to 0.008 (about 0.02mm), the surface hard ness of up to 56HRC.Surface hard coated alu minium structure and cutter can effectively p

34、 reve nt the chip due to fricti on and corrosi on on tool damage. Because the cutting precision boring processing in general more finely, the impact force of the knife body is smaller, the chip friction effect on tool co. Therefore, after the aluminum structure boring coating treatmentonbori ng p ro

35、cess ing has good wear resista nee, but the impact may be less than steel cutter.Coated surface of the knife body alumi num structure bori ng alumi na hard coat ing, in the form of chi p or abrasive cutti ng work piece materials on rough mach ining of large ap erture (8.07 40 1533, 2051020mm) hasthe

36、 obvious adva ntage (small ap erture rough bori ng tool usually ado pts steel structure), chi p flow line smooth (which can reduce the impact of cutt ing tool wear and chip) comb ined with the tool surface hard coati ng, can make the cutting tool in machining this material rough boring cutter body n

37、ot excessive wear.Compo site bori ng tool three, with coarse, fine bori ng functionboring also need semi-finishing) the processes process can ensure the machining reliability,Bori ng traditi onal usually n eed to go through from the rough bori ng to fine boring (sometimes to compiete, although this

38、but rather spend time.of near net shape casting(near-net-sharpWith the development cast in gs) tech no logy, esp ecially alumi num cast ing tech no logy, i mprove the quality of the work- piece, the machi ning allowa nee is reduced, the necessity of working procedure processing is reduced and even e

39、liminated. In many cases, bori ng and bori ng hole can be comp leted, in the samemachi ne, requireme nts on the margin and ecce ntric machi ning the hole the amount of tech no logy can greatly reduce. Therefore, app licatio n of compo site cutter caused the wide atte nti on of peop le.The composite

40、boring cutter will be boring and boring two cutting edges are in tegrated in the same bori ng cutters, by one-p ass op erati on can complete all the boring hole machining. First by the rough boring cutting edge removal of most of the machi ning allowa nee, and the n by the fine boring cutting edge p

41、rocessing aperture to the requiredsize. Thedifferenee between the blade and the working life of rough boring boring blade can be adjusted through the in stallati on of differe nt grades of ceme nted carbide in serts in the cutter holder.Fine bori ng cutt ing blade is clamped in an adjustable tool ho

42、lder, the knife clamping position can be adjusted by using precision screw traditi onal vernier scale. By one-p ass op erati on, can be p rocessed out of toleraneeis 0.001 (0.0254mm) precisionaperture.Althoughcomp osite p rocess ing must be set accordi ng to the feed rate mach ining needs, but becau

43、se the rough boring or semi-finishingprocesses, thusgreatly improve the p roductivity.andthecanFour, since the bala nee of bori ng cutter for high sp eed cutt ingnow.It has long recog ni zed the imp orta nee of bala nee p erforma nee for boring boring machining quality. In the high-speed cutting con

44、ditions bala nee bori ng cutter is more prominent tha n ever, eve n if the tool isvery small amount of un bala nee are likely to be greatly affected theprocessing aperture size, surface roughness, roundness and tool life. In additi on, the un bala need tool may also cause the cutt ing chatter. I n r

45、ece nt years, many of the sta ndard bori ng cutter are in stalled bala nee mechanism, this mechanism is usually composedof counterweight block can move, due to the un bala need state of bori ng cutter is mainly caused by p rocess ing ap erture cha nges, it can be adjusted accordi ng to the weightprocessing aperture boring cutter set of tools. This approach to mainta