冲裁件的工艺设计毕业课程设计外文文献翻译

1、英文：TechnologicaldesignofblankingworkpieceThetechnologicaldesignoftheblankingworkpiececonsistsoftheanalysisofthetechnologicalpropertiesandthedeterminationofthetechnologyscheme.Theexcellenttechnologicalpropertiesoftheworkpieceandreasonabletechnologyschemewouldcutdownthematerialexhausted,operationnumbe

2、randproductiontime.Itwouldalsosimplifythedieconstructionandincreasethedielife,thusresultinginreducingthemanuallabourandthecostoftheworkpiece.Thelattertwofactorsarethemainindexesforjudgingthedesignoftheblankingprocess.1. Calulationofblankingforceandmethodstodecreaseblankingforce(1) calculationofblank

3、ingforceThepurposeofthecalculationoftheblankingforceistochooseasuitablepressmachine,todesignthedie,andtocheckthediestrength.thetoncapacityofthepressmachineshouldbehigherthantheblankingforce.(2) hodstodecreaseblankingforceInpractice,inordertomeetthedemandoftheequipmentcondition,andtoreducevibrationan

4、dnoise,followingmethodsareusedtodecreasetheblankingforce.1) Blankingwithheatin.Theshearingstrengthofmaterialcanbesignificantlydecreasedwhenheated,sotodecreasetheblankingforce.Thedisadvantageofthismethodisthatalayerofoxidewouldbeproducedonthesurfaceofthematerialafterheating,andtheworkingconditiongett

5、ingworse.Consequently,thismethodisonlyusedwiththickplateortheworkpiecewithouthighdeamandsonsufacequalityandtolerancegrage.2) Multi-punchsteppedblanking.Ifthereismorethanonepunchinblanking,thebottomsurfaceoftheplunchedgecanbearrangedinsteps.Whileblankingbymulti-punchwithoutstep,totalblankingforceisth

6、esumofeachpunchforce;ifthepunchesarearrangedinsteps,theblankisprocessedinsequence,thusthetotalshearingareaandthetotalblankingforceatarbitrarymomentisdeceased.Whenthepunchesarearrangedinsteps,thefollowingdemandsshouldbetakinginmind.Thesteppedpunchmustbearrangedsymmetricallyinordertoavoideccentricload

7、.Toavoidextrusionforceinfluencecausedbymaterialflowingonsmallpunchwhenpunchinglargehole,itisbettertopunchlargeholefirst,andthenthesmallone.Itisalsoconducivetodecreasethelengthofthesmallpunch.3) Blankingwithinclinededgedie.Thebottomsurfaceoftheordinarydieisaplane,whichisperpendiculartothedieaxis.When

8、thebottomsurfaceofdieisdesignedinslantwithcertainincludedangletothedieaixs,thediedegepenetratesintotheblankgradually,sotheshearingareaandtheblankingforceascomparedwiththeflatedgeblankingisreducedatanyarbitrarytime.Theblankingforcecanbedecreasedfrom50%to75%.Inordertogetaflatworkpiece,thedieedgeisdesi

9、gnedasaninclinedplaneforblanking.Onontrary,thepunchedgeisdesignedasaninclinedplaneforpunching.Forblankingacurvedshapepart,aroundheadpunchisusuallyused.Blankingwithone-sidedinclinededgeisonlyapplicableforthelancingwithbending.Whenthepunchanddieisdesignedwithinclinedblankingedge,theinclinededgeshouldb

10、earrangedsymmetricallyinordertopreventtheedgedamagecausedbytheoffsetofthepunchordieduetothesidepressureinone-sidedirection.Theinclinededgeisinconvenientforworkpiecewithcomplexshape.Theforcereductiondependsontheheightoftheinclinededgeandtheangles.Themaindisadvantagesoftheinclinededgeblankingincludeth

11、edifficultiesinthedieedgemanufacturingandrepairing,thequickwearingofthedieedge,andtheunflantnessoftheworkpiece.Therefore,thismethodisonlysuitableforblankinglargepartorthickplate.(3) Calculationofstripping,pushingandejectingforcesAfterblanking,theworkpieceorwawteseparatedformtheblankmayjaminthediecav

12、ityduetoelasticexpansioninradialdiorection.Meanwhile,theholeremainingintheblankmayhooponthepunchduetoelasticshrinkinginradialdirection.Theforcetostripthesheetmetalhooparoundthepunchiscalledstrippingforceandtheforcethatpushesdownorejectupthesheetmetaljammedinthediecavityiscalledpushingorejectingforce

13、,respectively.Thestripping,pushingandejectingforcesareobtainedbyutilizingthepushingandejectingdevicesofthepressaswellasthatofthepunchanddie.Itisnecessarytocalculatethestripping,pushingandejectingforcesbyconsideringthediestructurewhenselectingthepressanddesigningthepunchanddie.Therearemanyfactorsinfl

14、uencetheseforces,includingthemechanicpropertiesandthicknessoftheblank,theshapeanddimensionoftheworkpiece,theclearancebetweenthepunchanddie,thescrapsizeandthelubricationcondition.2. TechnologicalpropertiesanalysisofblankingworkpieceTheanalysisofthetechnologicalpropertiesofblankingworkpieceistheadapta

15、bilityoftheblankingworkpiecetoblankingprocess,namely,whethertheshape,thedimensionandthetoleranceoftheblankingworkpiecemeetthedemandoftheblankingprocessornot.Whetherthetechnologicalpropertiesoftheblankingworkpieceisreasonableornot,hasagreatinfluenceonthequalityoftheblankingworkpiece,thedielifeandthep

16、roductivity.Theblankingworkpiecemustmeetthefollowingdemands:(1) shapeoftheblankingworkpieceTheshapeoftheblankingworkpiecemustbesimpleandsymmetrical,withlesswasteinblanklayout.Ifonlythedistancebetweenthethreeholesshouldbekept,andtheoutershapeoftheworkpieceisnotsoimportant,theworkpiececanberedesignedt

17、oadoptblanklayoutwithoutwastewithsucharrangement,thematerialutilizationratiomayincreaseby40%.Moreover,therearetwoworkpiecesproducedinoneblanking,sotheblankingproductivityisdoubledandtheproductioncostisdecreased.Obviouslythetechnologypropertyoftheimprovedblankingworkpieceisbetterthanthatoftheoriginal

18、one.(2) RoundnessradiusoftheblankingworkpieceSharpcornershouldbeavoidedintheblankingworkpieceexceptwhenadoptinglesswastearrangementorusinginsertdie.Asuitableroundnessradiusshouldbeadopted.(3) WidthanddepthofthelocalprotrusiveorincurvateregionoftheblankingworkpieceThewidthoftheprotrusiveorincurvatere

19、gionoftheblankingworkpieceshouldnotbetoosmall.Thelancingandgroove,shouldnotbetoonarrowandtoolong,otherwisethedielifeandtheworkpiecequalitywouldbedecreased.(4) AperturedimensionoftheblankingworkpieceIftheaperturedimensionistoosmall,thepunchwouldfractureorbendeasilyundercompression.Theminimumdimension

20、oftheaperturepuncheddependsonthemechanicalpropertiesofthematerial,thepunchstrengthandthediestructure.Inthecaseofpunchingsmallaperture,ifaprotectingjacketisused,thepunchwouldnotbedamagedeasilyanditsstabilitycanalsobeimproved;therefore,theminimumdimensionoftheaperturepunchedcanbedecreased.(5) Distance

21、betweenholesintheblankingworkpieceThedistancesbetweenholesorbetweentheholeandedgeshouldnotbetoosmall.Otherwise,thematerialbetweentheholesmaytwist.Inthecaseofcompoundblankingprocess,thediemaybreakeasilyduetothematerialispulledintodieeasily;inthecaseofblankingsmallholeswithsmalldistancebetweenthem,the

22、phenomenathatthepunchjammedindiealwayshappensduetothebendingofthepunch.Iftheedgeofthepunhedholedoesnotparalleltotheedgeoftheworkpieceoutline,thedistancebetweenthemshouldbelangerthant;onthecontrary,thedistancebetweenthemshouldbelangerthan1.5t.3. DeterminationoftechnologyschemeinblankingAccordingtothe

23、characteristicsoftheblankingworkpiece,thetechnologyschemeoftheblankingisdeterminedbasedontheanalysisoftheblankingprocess(1) CombinationoftheblankingprocessBlankingprocesscanbedividedintosingleblanking,compoundblankingandprogressiveblanking.Thecompoundblankingisthattwoormorethantwoprocessesaredoneint

24、hesamediepositioninonepressstroke.Theprogressiveblankingisthatseveralblankingprocessesaredoneatdifferentdiepositionsinonepressstroke.Onworkpiceccanbeproduceineachpressstrokebuttheinitialstrokeistheexceptional.Theproductivityofthecompoundblankingishigherthanthatofthesingleblanking,andthetolerancegrad

25、eofworkpieceofthecompoundblankingisalsohigherthanthatofthesingleblanking.Thecompoundmodeoftheblankingprocessisdeterminedbyfollowingfactors:1) Productionbatch.Generally,thesingleblankingissuitableforsmallbatchortrialproduction,thecompoundorprogressiveblankingissuitableformediumandlargebatchproduction

26、.2) Dimensiontolerancegradeoftheblankingworkpiece.Thetolerancegradeoftheworkpieceproducedthroughthecompoundblankingishigh,becausemulti-timelocatingerrorcanbeavoidedinthisprocess.Ascomparedwithcompoundblanking,thetolerancegradeoftheworkpieceproducedthroughprogressiveblankingislow.3) Dimensionandshape

27、oftheworkpiece.Whenthedimensionoftheworkpieceissmall,thecompoundorprogressiveblankingisusuallyadoptedinviewofinconvenienceandlowproductivityofthesingleblanking.Forworkpieceofmediumdimension,thecombinedblankingisalsousedbecausetomanufactureseveralsimplediesismoreexpensivethanacombineddie.Butifthedist

28、ancebetweentheholesorbetweenholeandedgeistoosmall,itisbettertousepropressiveblankingthancompoundandsingleblanking.Sotheprogressiveblankingcanusedtoproduceabnormalworkpieceswithcomplexshapeandsmallwidth,andtheblankingmaterialthicknessinprogressiveblankingislargerthanthatincompoundblanking.Theprogress

29、iveblankingisrestrictedbytheworkingtabledimensionofpressandthenumberofproess,sothesizeofblankingworkpiececannotbetoobig.4) Manufacture,adjustmentandcostofthedie.Fortheworkpiecewithcomplexshape,itisbettertousethecompoundblankingforthemanufactureandadjustmentofthediewouldbeeasier,andthecostwouldbelowe

30、rthanthatofprogressiveblanking.5) Convenienceandsafetyinoperation.Itisdifficulttopushouttheworkpieceorclearupthewasteincompoundblanking,soitislesssafethaninprogressiveblanking.Uummarizingtheanalysisabove,itisknownthattherearealotoftechnologyschemesforaworkpiece.Itisnecessarytocomparethedifferenttech

31、nologyschemesandselectthebestonewhichisadbantageousinlowmanufacturingcostandlongdielife,convenienceandsafeinoperation,andmeetingthedemandsinworkpiecequalityandproductivity.(2) Arrangementofblankingsequence1) Arrangementofprogressiveblankingsequene2) Punchingorlancingfirst,thenblankingorcutting-offto

32、separatetheworkpieceandblank.Theholepunchedpreviouslycanbeusedasthelocatingholeinlatterprocess.Ifthereishighlocatingdemand,atechnologicalholeforlocatingpurposeshouldbepnchedspecially.3) Whenusingkicker,thetrimmingprocessofthekicderandthefirstpunchingprocessshouldbedonesimulataneouslytocontrolthestep

33、distanceofblankfeeding.Iftwosideedgesareused,itcanbearrangedintandem.4) Arrangementofsingleblankingsequenceformulti-processworkpieceBlankingtoseparatetheworkpieceandblankfirst,thenpunchingornotching.Locatingreferenceofthelaterprocessesshouldbeaccordanttoavoidthelocatingerrorandtheconversionofthedime

34、nsionchain.Whenpunchingtheholeswithdifferenttdimensionsandsmallintervaldistance,inordertodecreasetheholedistortion,thebeggerholeshouldbepunchedfirst,andtenthesmallerone.译文：冲裁件的工艺设计冲裁的工艺设计包含冲裁件的工艺性分析和冲裁工艺方案的确定两方面的内容。良好的工艺性和合理的工艺方案，可以使用最少的材料，最少的工序数量和工时，并使模具结构简单且模具寿命长，能稳定地获得合格的工件，因而可以减少劳动量和冲裁件的工艺成本。劳动量

35、和工艺成本是衡量冲裁工艺设计的主要指标。1. 冲裁力的计算及降低冲裁力的方法（ 1）冲裁力的计算计算冲裁力的目的是为了选用合适的压机、设计模具和检验模具强度。压机的吨位必须大于所计算的冲裁力。（ 2）降低冲裁力的方法冲压生产中，由于设备条件以及减少振动、噪声的需要，可以采用以下几种常用方法降低冲裁力。1）加热冲裁。材料在加热状态下抗剪强度有明显下降，所以加热冲裁能降低冲裁力。这种冲裁方法的缺点是，材料加热后产生氧化皮，且因加热劳动条件差，只适用于厚板或工伯表面质量及公差等级要求不高的工作。2）多凸模阶梯布置冲裁。当冲裁模有多个凸模时，可将凸模刃口底平面呈阶梯布置。多凸模冲裁时，总冲裁力是每个凸

36、模冲裁力的叠加，而凸模交款作阶梯形布置后，可以避免各个凸模冲裁力的最大值同时出现，减少了任意冲裁瞬时的剪切面面积，从而降低了冲裁力的峰值。在将多个凸模进行阶梯形布置时，需要注意以下几方面的要求：阶梯形布置需要对称分布，防止偏载；为了避免冲大孔时材料流动的挤压力对小孔冲头的影响，阶梯形应安排先冲大孔、后冲小孔，这样也有利于减少小孔冲头的长度。3）斜刃口模具冲裁。普通模具刃口都是采用与模具轴线相垂直的平面形式。若将凸模（或凹模）刃口平面设计成与轴线倾斜一定的角度进行冲裁时，刃口逐步冲切材料，减少了每一瞬时的剪切面积，从而降低了冲裁力。与平刃冲裁相比，斜刃冲裁的冲裁力可以降低50%-75%为了制取平

37、整的零件，落料时，将凹模设计为斜刃。冲孔时，则相反。冲裁弯曲状工件时，采用有圆头的凸模。单边斜刃冲裁，只适用于折弯的切口。设计斜刃模具时，应注意将斜刃作对称布置，以免冲裁时承受单向侧压力而发生偏移，啃坏刃口。轮廓复杂的工件，不宜采用斜刃。斜刃冲模的减力程度由斜刃高度和角度决定。采用斜刃模具的主要缺点是：刃口制造与修磨比较复杂，刃口极易磨损，工件不够平整，因此一般情况下尽量不用，只用于大型工件及厚料裁。（3）卸料力、推件力与顶件力的计算当冲裁工作完成后，从板料上冲裁下来的工件（或废料）由于径向发生弹性变形而扩张，会卡在凹模模腔内；同时，在板料上冲裁出的孔径则沿着径向发生弹性收缩，会紧箍在凸模上。

38、为了将紧箍在凸模上的板料卸下来所需要的力称为卸料力；将卡在凹模中的板料推出或顶出所需的力分别称为推件力与顶件力。卸料力、推件力与顶件力是同压机和模具的卸料、顶件装置获得的。在选择压机吨位和设计模具时，要根据模具结构来考虑卸料力、推件力与顶件力的大小，并作必要的计算。影响这些力的因素很多，主要有：材料的机械性能和厚度，工件形状和尺寸大小，凸、凹模间隙，排样的搭边大小及润滑情况。2. 冲裁件的工艺性分析冲裁件的工艺性，是指冲裁件对冲裁工艺的适应性，即冲裁件的形状结构、尺寸大小及偏差等是否符合冲裁加工的工艺要求。冲裁件的工艺性是否合理，对冲裁件的质量、模具寿命和生产率有很大的影响。冲裁件应满足如下要求：（ 1）冲裁件的形状冲裁件的形状应尽可能简单、对称、排样废料少。如果工件上只是三个供装配用的孔要求有准确的位置，而外形无关紧要，此时便能采用无废料排样，可使材料利用率提高40%，而且一次能冲出两个工件，生产率提高一倍，降低了工件成本。因此，改进后的冲裁件的工艺性比原工件的工艺性好。（ 2）冲裁件的圆角除在少、无废料排样或采用镶拼模结构时，允许工件有尖锐的清角外，冲裁件的外形或内孔的交角处，