外文翻译--普通全钢冲模的冲压精度分析.doc

Generalall-steelpunchingdiespunchingaccuracyAccuracyofpanelpunchingpartisdisplaythepressaccuracyofthedieexactly.Buttheaccuracyofanypunchingpartslineardimensionandpositionalaccuracyalmostdependontheblankingandblankingaccuracy,.Sothatthecompoundmouldofcompoundpunchingsaccuracy,istypicalnessandrepresentationinthemajority.AnalyseofthediesaccuracyFortheanalyseofpracyicableinaccuracyduringproductionofdiestoinactivation,wecouldgetthetendencywhenitisaugmentationinmosttime.Fromthiswecouldanalysetheelements.Whenthenewpunchdiesptintoproductiontothefirstcuttergrinding,theinaccuracyproducedcalledinitialerror；ifthediegrindingmorethantwentytimes,untilitsdiscard,theinaccuracycalledconventionalerror；andbeforethediesdiscard,thelargesterrorofthelastbatchpermit,calledlimitingerror.atjobsite,theevidencetoconfirmlifeofsharpeningisthehigheroftheblanking,punchedholeorpunchedparts.Becauseallfinishedpartshadbeenblanked,soitisespeciallyforthecompounddies.Therefore,theanalyseofburrandmeasurementisespeciallyimportantwhendothemasenterprisestandardizationorcheckedwith.Theinitialerrorusuallyistheminimalthroughthewholelifeofdie.Itsmagnitudedependontheaccuracyofmanufacture,quality,measureofthepunchingpart,thicknessofpanel,magnitudeofgapanddegreeofhomogeneity.Theaccuracyofmanufacturedependonthemanufactureprocess.Forthe1mmthickedcompoundpunchingpartmadeinmediumsteel,theexperimentalresultandproductivepracticeallprovethattheburrofdieswhichproducedbysparkcuttingarehigher25%30%thanproducedbygrinder,NCorCNC.ThereasonisthatnotonlythelatterhavemoreexactmachiningaccuracybutalsothevalueofroughnessRaislessoneorderthantheformmer,itcanbereached0.025m.Therefore,thediesinitialblankedaccuracydependsontheaccuracyofmanufacture,qualityandsoon.Thenormalerrorofthepunchdieisthepracticableerrorwhenthefistcuttergrindingandthelastcuttergrindingbeforethedieproducethelastqualifiedproduct.Astheincreaseofcuttergrinding,causedthemeasurethenaturewearofthediesaregradualincreasing,theerrorofpunchingpartincreasealso,sothepartsareblewproof.Andthediewillbeunused.Theholeonthepartandinnerbecausethemeasureofwearwillbesmallandsmallgradually,anditsoutsideformwillbelagerinthesamereason.Therefore,theholeandinnerforminthepartwillbemademouldaccordingtoone-waypositivedeviationornearlyequaltothelimitmaxmeasure.Inlikemanner,thepunchingpartsappearancewillbemademouldaccordingtoone-waynegativedeviationornearlyequaltolimitminimeasure.Forthiswillbebroadenthenormalerror,andthecuttergrindingtimeswillbeincreased,thelifewillbelong.Thelimiterrorinpunchingpartsarethemaxdimensionerrorwhichpracticableallowedinthepartswithlimiterror.Thiskindofpartsusuallyarethelastqualifiedproductsbeforethediediscard.Fortheallclassesofdies,ifweanalysethefluctuate,tendencyofincreaseanddecreaseandlawwhichappearedinthedieswholelife,wewillfindthatthemasteroftheerrorarechangeless；theerrorthatbecausetheabradeofthecutterandimpressionwillbeasthecuttergrindingtimesincreasedatthesametime.Andthatwillcausetheerroroversizegradually；andalsohaveanotherparterrorareunconventional,unforeseen.Therefore,everydieserrorarecomposedoffixederror,systemerror,accidenterrorandsoon.1.fixederrorAtthewholeprocesswhentheNewpunchingdiebetweenjustinputproductiontodiscard,thechangelessmastererrorthatinqualifiedpartarecalledfixederror.Itsmagnitudeisthedeviationwhenthedieproductionqualifiedproductsbeforethefirstcuttergrinding.Alsoistheinitialerror,butthediehaveinitialpunchingaccuracyatthistime.Becauseoftheabradeofparts,thedieaftergrindingwillbechangethedimensionerror.Andtheincrementofdeviationwilloversizeasthetimesofcuttergrinding.Sothepunchingaccuracyaftercuttergrindingalsocalled“grindingaccuracy”andlowertaninitialaccuracy.Thefixederrordependontheelementsfactorasfollowed:(1)thematerial,sorts,structure,(form)dimension,andthickofpanelThemagnitudeofpunchinggapanddegreeofhomogeneityarehaveaimportanteffectforthedimensionaccuracy.Differentpunchingprocess,material,thickofpanel,havecompletelydifferentgapandpunchingaccuracy.AgearH62whichmadeinyellowbrasswiththesamemodenumberm=0.34,2mmthickandhadacenterhole,whenthegapgetC=0.5%t(singleedge),andpunchedwithcompoundpunchingdie,andthedimensionaccuracyreachedIT7,theparthaveaflatsurface,theverticalityoftangentplanereached89.5,itsroughnessRamagnitudeare12.5m,heightofburrare0.10mm；andthepunchingpartarepunchedwithprogressivedie,thegapC=7%t(singleedge),initialaccuracyareIT11,andhaveanmoreroughsurface,evencanseethegapwitheyes.Intheusualsituation,flushesamaterialanditsthicknesstistheselectionpunchinggapmainbasis.Oncethedesignationgaphaddeterminedflushestheplanesizethefixederrormainbody；Flushesthestructurerigidityandthethree-dimensionalshapeaffectsitsshapepositionprecision.(2)punchingcraftandmolderstructuretypeUsesthedifferentrammingcraft,flushesaprecisionandthefixederrordifferenceisreallybig.Exceptthattheabovepiecegearexampleshowed,theessenceflushesthecraftandordinarypunchingflushesaprecisionandthefixederrordiffersoutsideamagnitude,evenifinordinarypunchingcenter,usesthedifferentgappunching,thefixederrordifferenceveryisalsobig.Forexamplematerialthickt=1.5mmH62brasspunching,selectsC=the40%tunilateralIkindofsmallgappunchingcomparedtoselectC4mmflushes,thesizeprecisioncanlowersome.Differentdiesstructuretype,becauseissuitabletherammingmaterialtobethickandthemanufactureprecisiondifference,causestoflushafixederrortohaveleaves.Compounddiecenter,multi-locationscontinuoustypecompounddiebecauseflushescontinuouslytoduplicatethelocalizationtoaddonthepatternmakingerrortobebigger,thereforeitflushesafixederrorcompoundpunchingdietowantcomparedtothesinglelocationBig12levels(3)thecraftofpunchingdiesmanufactureThemainworkofpunchingdienamelyareraised,theconcavemoldprocessingprocedure,tooperatesonthespecificationnottobehigh,cantimeformamorecomplexcavity.Butitsprocessingsurfaceapproximatelyisthick0.030.05mmisthehightemperatureablationremainingfurcatedausteniteorganization,degreeofhardnessmayreachashighasHRC6770,hasthemicrocrack,easilywhenpunchingappearsbrokethecutterorflaking.TheItalianCorradaCorporationsrelatedmemoircalledthelinecuttheprocessingcontructiontohavethedisadvantageousinfluencetothesuperficialgold,infactalreadychangedthegoldcontruction.WemustusetheJingangstonepowdertogrindorthenumericalcontrolcontinualpathcoordinatesrubtruncate(cuttoline)tomaketheprecisionwork.InrecentyearscountryandsoonSwitzerlandandJapan,hasconductedthethoroughresearchtotheelectricalfinishingequipmentandabiggerimprovement,makesfunctioncompletehighaccuracyNCandtheCNClinecutter,theprocessingprecisionmayreach0.0050.001mm,evenissmaller.TheprocessingsurfaceroughnessRavaluecanachieve0.4mum.Accordingtotherecentyearstothedomestic12productionlinescutterfactoryinvestigationandstudy,thedomesticallyproducedlinecutterprocessingprecisiondifferentfactorydifferentmodellinecuttermightreach0.0080.005mm,generallyallin0.01mmorbiggersomewhat,wasindividualalsocanachieve0.005mm,theprocessingsurfaceroughnessRavaluewasbiggerthan1.6m.However,theelectricalfinishingablationmetalsurfacethusthechangeandthedamagemachinedsurfacementalstruc