专业夹具设计外文翻译

1、译文标题精密机械加工工原文标题PrecisionMachiningTechnology作者PeterJ.Hoffman译名彼行,J,作夫曼国籍美国原文出处CengageLearning译文：在机械加工过程中，工件受到切削力、离心力、惯性力等的作用，为了保证在这些外力作用下，工件仍能在夹具中保持已由定位元件确定的加工位置，而不致发生振动或位移、夹具结构中应设置夹紧装置将工件可靠夹牢。一、夹紧装置的组成夹紧装置的种类很多，但其结构均由两部分组成。1 .动力装置火紧力的来源，一是人力；二是某种装置所产生的力。能产生力的装置称为火具的动力装置。常用的动力装置有：气动装置、液压装置、电动装置、电磁装置、

2、气一液联动装置和真空装置等。由于手动夹具的夹紧力来自人力，所以它没有动力装置。2 .夹紧部分接受和传递原始作用力使之变为夹紧力并执行夹紧任务的部分，一般由下列机构组成：1）接受原始作用力的机构。如手柄、螺母及用来连接气缸活塞杆的机构等。2）中间递力机构。如银链、杠杆等。3）夹紧元件。如各种螺钉压板等。其中中间递力机构在传递原始作用力至夹紧元件的过程中可以起到诸如改变作用力的方向、改变作用力的大小以及自锁等作用。二、夹紧装置的基本要求在不破坏工件定位精度，并保证加工质量的前提下，应尽量使夹紧装置做到：1 .火紧力的大小适当。既要保证工件在整个加工过程中其位置稳定不变、振动小,又要使工件不产生过大

3、的夹紧变形。2 .工艺性好。夹紧装置的复杂程度应与生产纲领相适应，在保证生产效率的前提下，其结构应力求简单，便于制造和维修。3 .使用性好。夹紧装置的操作应当方便、安全、省力。三、基本夹紧机构原始作用力转化为夹紧力是通过夹紧机构来实现的。在众多的夹紧机构中以斜楔、螺旋、偏心以及由它们组合而成的夹紧机构应用最为普遍。（一）斜楔夹紧机构采用斜楔作为传力元件或夹紧元件的夹紧机构称为斜楔夹紧机构。直接采用斜楔夹紧时，斜楔的自锁条件是：斜楔的开角小于斜楔与工件、斜楔与夹具体之间的摩擦角之和。即：:-12为保证自锁可靠，手动夹紧机构一般取口=6©8代用气压或液压装置驱动的斜楔不需要自锁，可取2=

4、15535*。斜楔夹紧具有结构简单，增力比大，自锁性能好等特点，因此获得广泛应用。（二）螺旋夹紧机构采用螺杆作中间传力元件的夹紧机构统称为螺旋夹紧机构。由于它结构简单、夹紧可靠、通用性好，而且由于螺旋升角小，螺旋夹紧机构的自锁性能好，夹紧力和夹紧行程都较大，是手动夹具上用得最多的一种夹紧机构。1 .简单螺旋夹紧机构最简单的螺旋夹紧机构由于直接用螺钉头部压紧工件，易使工件受压表面损伤，或带动工件旋转。因此常在头部装有摆动的压块。由于压块与工件间的摩擦力矩大于压块与螺钉间的摩擦力矩，压块不会随螺钉一起转动。夹紧动作慢、工件装卸费时是单个螺旋夹紧机构的另一个缺点。为克服这一缺点，可采用快速夹紧机构。

5、2 .螺旋压板夹紧机构在夹紧机构中，螺旋压板的使用非常普遍，常见的螺旋压板典型结构其结构尺寸均已标准化，设计者可参考有关国家标准和夹具设计手册进行设计。（三）偏心夹紧机构用偏心件直接或间接夹紧工件的机构，称为偏心夹紧机构。偏心件有两种形式,即圆偏心和曲线偏心，其中，圆偏心机构因结构简单、制造容易而得到广泛应用。偏心夹紧加工操作方便、夹紧迅速，缺点是夹紧力和夹紧行程都小。一般用于切削力不大、振动小、没有离心力影响的加工中。1 .圆偏心轮的工作原理2 .圆偏心轮的夹紧行程及工作段3 .偏心轮的自锁条件amaxWM+蚓推导得：f1>2e/D当f=0.1时，e/D30当f=0.15时，e/D当4

6、四、定心夹紧机构当工件被加工面以中心要素（轴线、中心平面等）为工序基准时，为使基准重合以减少定位误差，需采用定心夹紧机构。定心夹紧机构具有定心和夹紧两种功能，如卧式车床的三爪自定心卡盘即为最常用的典型实例。定心夹紧机构按其定心作用原理有两种类型，一种是依靠传动机构使定心夹紧元件等速移动，从而实现定心火紧，如螺旋式、杠杆式、楔式机构等；另一种是利用薄壁弹性元件受力后产生均匀的弹性变形（收缩或扩张），来实现定心夹紧,如弹簧筒夹、膜片卡盘、波纹套、液性塑料等。1 .螺旋式定心夹紧机构螺杆两端的螺纹旋向相反，螺距相同。当其旋转时，使两个V形钳口作对向等速移动，从而实现对工件的定心夹紧或松开。V形钳口可

7、按工件不同形状进行更换。这种定心夹紧机构的特点是：结构简单、工作行程大、通用性好，但定心精度不高，主要适用于粗加工或半精加工中需要行程大而定心精度要求不高的场合。2 .杠杆式定心夹紧机构杠杆式三爪自定心卡盘中，滑套作轴向移动时，圆周均布的三个钩形杠杆便绕轴转动，拨动三个滑块沿径向移动，从而带动其上卡爪将工件定心并夹紧或松开。这种定心夹紧机构具有刚性大、动作快、增力倍数大、工作行程也比较大等特点，但其定心精度较低。一般为0.1mm左右，它主要用于工件的粗加工。由于杠杆机构不能自锁，所以这种机构自锁要靠气压或其它机构。3 .楔式定心夹紧机构机动的楔式夹爪自动定心机构中，当工件以内孔及左端面在夹具上

8、定位后，汽缸通过拉杆使六个夹爪左移，由于本体上斜面的作用，火爪左移的同时向外胀开，将工件定心夹紧；反之，夹爪右移时，在弹簧卡圈的作用下使夹爪收拢，将工件松开。这种定心夹紧机构的结构紧凑，定心精度一般可达0.02mm0.07mm比较适用于工件内孔作定位基面的半精加工工序。4 .弹簧筒夹式定心夹紧机构这种定心夹紧机构常用于安装轴套类工件。弹性定心夹紧机构的结构简单、体积小、操作方便迅速，因而应用十分广泛。其定心精度可稳定在0.04mm0.010mm之间。除上述介绍的定心夹紧机构外，常用的还有膜片卡盘机构、波纹套定心夹紧机构以及液性塑料夹紧机构等。夹具是机械加工中不可缺少的部件，在机床技术向高速、高

9、效、精密、复合、智能、环保方向发展的带动下，夹具技术正朝着高精、高效、模块、组合、通用、经济方向发展。一、高精随着机床加工精度的提高，为了降低定位误差，提高加工精度对火具的制造精度要求更高高精度夹具的定位孔距精度高达±0.5夹具支撑面的垂直度达0.01mm/300mm平行度高达0.01mm/500mm瑞士EROWA性夹具的重复定位精度高达25微米。机床夹具的精度已提高到微米级，世界知名的夹具制造公司都是精密机械制造企业。为了适应不同行业的需求和经济性，火具有不同的型二、高效为了提高机床的生产效率，双面、四面和多件装夹的夹具产品越来越多。为了减少工件的安装时间，各种自动定心夹紧、精密平

10、口钳、杠杆夹紧、凸轮夹紧、气动和液压夹紧等，快速夹紧功能部件不断的推陈出新。新型的电控永磁夹具，夹紧和松开工件只用1、2秒，夹具结构简化，为机床进行多工位、多面和多件加工创造了条件。采用美国杰金斯公司的球锁装夹系统，1分钟内就能将夹具定位和锁紧在机床工作台上，球锁装夹系统用于柔性生产线上更换夹具，起到缩短停机时间，提高生产效率的作用。三、模块组合夹具元件模块化是实现组合化的基础。利用模块化设计的系列化、标准化夹具元件，快速组装成各种夹具，已成为夹具技术开发的基点。省工、省时、节材、节能，体现在各种先进夹具系统的创新之中。模块化设计为夹具的计算机辅助设计与组装打下了基础。应用CA成术，可建立元件

11、库、典型夹具库、标准和用户使用档案库，进行夹具优化设计，为用户三维实体组装夹具。模拟仿真刀具的切削过程，既能为用户提供正确、合理的夹具与元件配套方案，又能积累使用经验，了解市场需求，不断的改进和完善夹具系统。四、通用经济夹具的通用性直接影响其经济性。采用模块、组合式的夹具系统，一次性投资比较大，只有夹具系统的可重组性、可重构性及可扩展性功能强，应用范围广，通用性好，夹具利用率高，收回投资快，才能体现出经济性好。原文:Inthemachiningprocesstheworkpiecebythecuttingforce,centrifugalforce,inertiaforce,suchasthe

12、roleof,inordertoensurethattheseexternalforce,theworkpiececanremaininthefixturebythepositioningoftheprocessingtodeterminethelocationofcomponents,andshouldbenovibrationordisplacement,fixturestructureshouldbesetureliableworkpiececlampingdevicefolderwillbeinprison.First,thecompositionofclampingdevicesMa

13、nydifferenttypesofclampingdevices,buttheirstructuresarecomposedoftwoparts.1. PowerplantThesourceofclampingforce,onehuman;secondisgeneratedbyapowerdevice.Thedevicecangeneratepowerasthepowerunitfixture.Commonlyusedipowerplantare:pneumaticdeviceshydraulicdeviceselectricaldeviceselectromagneticdevicesga

14、s-liquidinteractiondevicesandvacuumdevices.Fixtureasaresultofmanualclampingforcefromthehumansoitdoesnotpowerplants.2. ClampingpartReceiveandimpartintotheoriginalclampingforcetoclampthetaskforceandpartoftheimplementationofthegeneralcompositionofthefollowingagencies:1) toaccepttheoriginalforceofbodies

15、.Suchashandlesnutsandusedtoconnectthinstitutionssuchascylinderpistonrod.2) Forcethemiddleofdelivery.Suchashingesleversandsoon.3) Clampingcomponents.Suchasplatesuchasscrews.Forcedeliveryoftheminthemiddleoftheoriginaltransmissionofforcetotheprocessofclampingdevicescanplaysuchaschangesinthedirectionoff

16、orcetochangethesizeofforcesaswellastheroleofself-lockingandsoon.SecondthebasicrequirementsforclampingdeviceWithoutdamagingtheworkpiecepositioningaccuracyandqualityassuranceprocessunderthepremiseofclampingdevicesshouldbeenabledto:1. Thesizeoftheappropriateclampingforce.Itisnecessarytoensurethatthewor

17、kpieceinthewholeprocessofitsstablepositionvibrationsmallbutalsosothattheworkpiecedoesnotproduceexcessiveclampingdeformation.2. Technologyisgood.ThecomplexityoftheclampingdeviceshouldbesuitedtotheproductionoftheProgramtoensureproductionefficiencyitsstructureshouldbekeptsimpleeasytomanufactureandmaint

18、enance.3. Gooduse.Theoperationofclampingdeviceshouldbeconvenientsafeandlabor-saving.ThirdthebasicClampTheoriginalforceintoaclampingforcethroughtheclampingbodytoachieve.Amongthemanyinstitutionsintheclampingwedgeobliquespiralandbytheireccentriccombinationofthemostcommonapplicationofclamping.(A) WedgeC

19、lampWedgeusedascomponentsortransmissionoftheclampingdeviceclampingbodyknownastheWedgeClamp.heWedgeclampingdirectlytheobliquewedgeoftheself-lockingconditionsare:WedgeanglesmallerthantheworkpieceWedgeWedgeandfoldersbetweentheconcreteandtfrictionangle.Namely:af1+f2Inordertoensureareliableself-lockingma

20、nualclampinggenerallytakea=68:Usingpneumaticorhydraulicdevicedriversdonotneedtheself-lockingobliquewedgeitisdesirabletoa=1535.00Wedgeclampissimpleinstructurethanbylargeself-lockingfeaturessuchasperformanceitiswidelyavailable.(B) HelicalClampUsedasintermediatescrewtransmissioncomponentsarecollectivel

21、yreferredtoastheclampingscrewclampingbodyorgans.Becauseofitssimplestructurereliableclampingcommongoodandasaresultofthesmallhelixanglespiralofself-lockingclampingbodygoodclampingforceandtheclampingitineraryarelargerfixtureonmanualwiththemostaclampingbody.1. SimplescrewclampbodyThesimplestspiralasares

22、ultofthedirectuseofclampingbodiespressedworkpiecescrewheadsoeasytodamagethesurfaceoftheworkpieceunderpressureordrivenrotatingworkpiece.SooftenintheheadwithswingingPress.PresswiththeworkpieceasaresultoffrictionbetweenthePressandthetorqueisgreaterthanthefrictionbetweethescrewtorquescrewtogetherwiththe

23、Presswillnotrotate.Clampingactionslowtime-consumingloadingandunloadingtheworkpieceisasinglespiralAnotherdrawbackoftheClamp.Toovercomethisshortcomingtherapidclampingbodiescanbe.2. ClampscrewplatetoInstitutionsintheclampingtheuseofspiralplateisverycommoncommonstructureofthespiralstructureofatypicalpla

24、tesizehasbeenstandardizedthedesignercanrefertherelevantnationalstandardsandfixturedesignmanualdesign.(C)EccentricClampWitheccentricpieces,directlyorindirectly,theworkpiececlampingbody,knownastheeccentricclampingbody.Therearetwotypesofeccentricpieces,thatis,andthecurVeofeccentricityeccentriccircle,wh

25、ich,duetoaroundeccentricstructureissimpleandeasytomanufactureandiswidelyused.Eccentricclampingprocessingiseasytooperate,rapidclamp,thedisadvantageofclampingforceandclampingtriparesmall.Notgenerallyusedincuttingforce,vibrationsmallthereisnocentrifugalforceoftheimpactoftheprocessing.1. Roundtheworking

26、principleofeccentric2. Eccentricclampingroundtripandparagraph3. Eccentricself-lockingconditionofa<j1+j2Wasderived:f1We/DWhenf=0.1hours,e/D>20,whenf=0.15pm,e/D冒4FourthinstitutionscenteringclampingWhentheworkpieceisprocessedbythecentralelementofsurface(axis,thecenterplane,etc.)forthebaseprocessi

27、nordertoenablethebasetoreducethepositioningerrorofcoincidencetobeusedcenteringclampingbody.Centeringcenteringclampingbodyandclampingthetwofunctionssuchashorizontalself-centeringthree-jawlathechuckisaclassicexampleofthemostcommonlyused.Centeringcenteringclampingtheroleofinstitutionsaccordingtotheirpr

28、inciple,therearetwotypes,oneisrelyingonthetransmissionmechanismsothatmobilespeedcenteringclampingdeviceinordertoachievecenteringclamping,suchasspiralleveragedinstitutionssuchaswedge;theotheristheuseofthin-walledelasticelementforceevenaftertheelasticdeformation(contractionorexpansion),toachievecenter

29、ingclamping,suchasaspringclipdrum,diaphragmchuck,bellowsunits,suchasliquidplastic.1. CenteringclampingbodyspiralRotaryscrewthreadatbothendstothecontrary,thesamepitch.Whenitspins,thetwoV-shapedgagagainsttheconstantmovementinordertoachievethecenteringoftheworkpiececlampingorrelease.V-shapedworkpieceso

30、fdifferentshapescanshutupthereplacement.s.Centeringclampingbodiessuchfeaturesare:simplestructuretheworktripandgeneralgoodbutthecenteringaccuracyisnothighmainlysuitableforroughorsemi-finishedtouroftheneedsoflargeandlessdemandingprecisioncenteringoccasion2. LeveragedinstitutionscenteringclampingThree-

31、jawself-centeringleveragedtradingcards,sleeveforaxialmovementthecirclearethreefabrichookleverwillrotatearoundtheaxis,thethreestrucktheslideralongtheradialmovementofthecardsinordertopromoteitsclawstheworkpiececenteringandclampingorrelease.Thiscenteringclampingrigidbody,andmovefast,byforcemultiplier,a

32、ndtheworktripisalsocharacterizedbyrelativelylarge,butitsrelativelylowprecisioncentering.Generallyabout0.1mmitismainlyusedforroughwork.Sincethebodycannotself-lockinglever,sothatorganizationsrelyonself-lockingairpressureorotheragencies.3. CenteringclampingwedgebodiesWedgemobilefolderautomaticallycente

33、ringbodyclawwhentheworkpiecesurfacewithintheholeandleftthepositioninthefixtureafterthesix-cylinderthroughtherodsothattheleftclawclipduetotheroleofontologyontheslopewhiletheleftclawfoldertotheopenedoutsidethebulgewillbecenteringtheworkpiececlampingtheotherhandclawshiftedtorightfolderintheroleofspring

34、circlecardfolderunderclawtoreleasetheworkpiece.Centeringclampingbodiessuchcompactstructureusuallyrangingfromprecisioncentering0.02mm0.07mmcomparedwiththeholefortheworkpiecesurfaceforpositioningthebaseofthesemi-finishingprocesses.4. Clip-onspring-centeringclampingcylinderbodyThiscenteringclampingslee

35、vebodytypecommonlyusedintheinstallationoftheworkpiece.Elasticcenteringclampingsimplestructure,smallsize,easytooperatequickly,soawiderangeofapplications.Centeringaccuracyofitsstabilityinbetween0.04mm0.010mm.Inadditiontotheabovedescribedcenteringclampingbodies,arecommonlyuseddiaphragmchuckbody,corruga

36、tedcenteringclampingsetsofinstitutions,aswellasfluidbodiessuchasplasticclampingMachiningfixtureisanindispensablecomponentinthemachinetooltechnologytohigh-speed,highefficiency,precision,complex,intelligent,environmentally-friendlydirection,drivenbytechnologyismovingfixturehigh-precision,high-performa

37、nce,modular,mix,generaleconomicdirection.First,high-precisionMachiningwithimprovedaccuracy,inordertoreducethepositioningerrorandimprovemachiningaccuracyofthefixturemanufacturingprecisiondemandinghigh-precisionpositioningjigDistanceaccuracyupto±5pmthebearingsurfaceoftheverticalfixtureachieve0.01

38、mm/300mmuptoparallelism0.01mm/500mm.SwitzerlandduplicationEROWAFlexiblefixturepositioningaccuracyofupto25m.Precisionmachinetoolfixturetothemicronlevelhasbeenraisedtheworldsleadingmanufactureroffixtureisprecisionmachinerymanufacturingenterprises.Itistruethat,inordertomeettheneedsofdifferentindustries

39、andeconomy,folderswithdifferentmodels,aswellasthedifferentgradesfortheaccuracyofthestandardoptions.Second,efficienttoolToimproveproductionefficiency,double-sided,fourandmorethanclamping巾xtureofmoreandmoreproducts.Workpieceinordertoreducetheinstallationtime,allkindsofauto-centeringclamping,precisionf

40、latclamp,clampinglevers,camclamp,suchaspneumaticandhydraulicclamping,rapidclampingnewfeaturesconstantly.Newtypeofelectronicallycontrolledpermanentmagnetfixture,stepupandreleasetheworkpieceonly12seconds,simplifyingthefixturestructureforthemachinetocarryoutstage,facetedandprocessingtocreatethecondition.Americ