外文翻译--普通全钢冲模的冲压精度分析.doc
外文翻译专业名称机械设计制造及其自动化班级学号学生姓名指导教师填表日期2011年1月17日Generalall-steelpunchingdiespunchingaccuracyAccuracyofpanelpunchingpartisdisplaythepressaccuracyofthedieexactly.Buttheaccuracyofanypunchingpartslineardimensionandpositionalaccuracyalmostdependontheblankingandblankingaccuracy,.Sothatthecompoundmouldofcompoundpunchingsaccuracy,istypicalnessandrepresentationinthemajority.AnalyseofthediesaccuracyFortheanalyseofpracyicableinaccuracyduringproductionofdiestoinactivation,wecouldgetthetendencywhenitisaugmentationinmosttime.Fromthiswecouldanalysetheelements.Whenthenewpunchdiesptintoproductiontothefirstcuttergrinding,theinaccuracyproducedcalledinitialerror;ifthediegrindingmorethantwentytimes,untilitsdiscard,theinaccuracycalledconventionalerror;andbeforethediesdiscard,thelargesterrorofthelastbatchpermit,calledlimitingerror.atjobsite,theevidencetoconfirmlifeofsharpeningisthehigheroftheblanking,punchedholeorpunchedparts.Becauseallfinishedpartshadbeenblanked,soitisespeciallyforthecompounddies.Therefore,theanalyseofburrandmeasurementisespeciallyimportantwhendothemasenterprisestandardizationorcheckedwith<<theheightofpunchingpart>>.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)punchingcraftandmolderstructuretype