机械专业中英文文献翻译普通全钢冲模的冲压精度分析.docx

机械专业中英文文献翻译普通全钢冲模的冲压精度分析.docx

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机械专业中英文文献翻译普通全钢冲模的冲压精度分析

GeneralAll-steelPunchingDie’sPunchingAccuracy

Accuracyofpanelpunchingpartisdisplaythepressaccuracyofthedieexactly.Buttheaccuracyofanypunchingparts’lineardimensionandpositionalaccuracyalmostdependontheblankingandblankingaccuracy,.Sothatthecompoundmouldofcompoundpunching’saccuracy,istypicalnessandrepresentationinthemajority.

Analyseofthedie’saccuracy

Fortheanalyseofpracyicableinaccuracyduringproductionofdiestoinactivation,wecouldgetthetendencywhenitisaugmentationinmosttime.Fromthiswecouldanalysetheelements.Whenthenewpunchdiesptintoproductiontothefirstcuttergrinding,theinaccuracyproducedcalledinitialerror;ifthediegrindingmorethantwentytimes,untilit’sdiscard,theinaccuracycalledconventionalerror;andbeforethediesdiscard,thelargesterrorofthelastbatchpermit,calledlimitingerror.atjobsite,theevidencetoconfirmlifeofsharpeningisthehigheroftheblanking,punchedholeorpunchedparts.Becauseallfinishedpartshadbeenblanked,soitisespeciallyforthecompounddies.Therefore,theanalyseofburrandmeasurementisespeciallyimportantwhendothemasenterprisestandardizationorcheckedwith<>.

Theinitialerrorusuallyistheminimalthroughthewholelifeofdie.Itsmagnitudedependontheaccuracyofmanufacture,quality,measureofthepunchingpart,thicknessofpanel,magnitudeofgapanddegreeofhomogeneity.Theaccuracyofmanufacturedependonthemanufactureprocess.Forthe1mmthickedcompoundpunchingpartmadeinmediumsteel,theexperimentalresultandproductivepracticeallprovethattheburrofdieswhichproducedbysparkcuttingarehigher25%~~30%thanproducedbygrinder,NCorCNC.ThereasonisthatnotonlythelatterhavemoreexactmachiningaccuracybutalsothevalueofroughnessRaislessoneorderthantheformmer,itcanbereached0.025μm.Therefore,thedie’sinitialblankedaccuracydependsontheaccuracyofmanufacture,qualityandsoon.

Thenormalerrorofthepunchdieisthepracticableerrorwhenthefistcuttergrindingandthelastcuttergrindingbeforethedieproducethelastqualifiedproduct.Astheincreaseofcuttergrinding,causedthemeasurethenaturewearofthediesaregradualincreasing,theerrorofpunchingpartincreasealso,sothepartsareblewproof.Andthediewillbeunused.Theholeonthepartandinnerbecausethemeasureofwearwillbesmallandsmallgradually,anditsoutsideformwillbelagerinthesamereason.Therefore,theholeandinnerforminthepartwillbemademouldaccordingtoone-waypositivedeviationornearlyequaltothelimitmaxmeasure.Inlikemanner,thepunchingpart’sappearancewillbemademouldaccordingtoone-waynegativedeviationornearlyequaltolimitminimeasure.Forthiswillbebroadenthenormalerror,andthecuttergrindingtimeswillbeincreased,thelifewillbelong.

Thelimiterrorinpunchingpartsarethemaxdimensionerrorwhichpracticableallowedinthepartswithlimiterror.Thiskindofpartsusuallyarethelastqualifiedproductsbeforethediediscard.

Fortheallclassesofdies,ifweanalysethefluctuate,tendencyofincreaseanddecreaseandlawwhichappearedinthedie’swholelife,wewillfindthatthemasteroftheerrorarechangeless;theerrorthatbecausetheabradeofthecutterandimpressionwillbeasthecuttergrindingtimesincreasedatthesametime.Andthatwillcausetheerroroversizegradually;andalsohaveanotherparterrorareunconventional,unforeseen.Therefore,everydie’serrorarecomposedoffixederror,systemerror,accidenterrorandsoon.

1.fixederror

AtthewholeprocesswhentheNewpunchingdiebetweenjustinputproductiontodiscard,thechangelessmastererrorthatinqualifiedpartarecalledfixederror.It’smagnitudeisthedeviationwhenthedieproductionqualifiedproductsbeforethefirstcuttergrinding.Alsoistheinitialerror,butthediehaveinitialpunchingaccuracyatthistime.Becauseoftheabradeofparts,thedieaftergrindingwillbechangethedimensionerror.Andtheincrementofdeviationwilloversizeasthetimesofcuttergrinding.Sothepunchingaccuracyaftercuttergrindingalsocalled“grindingaccuracy”andlowertaninitialaccuracy.Thefixederrordependontheelementsfactorasfollowed:

（1）thematerial,sorts,structure,（form）dimension,andthickofpanel

themagnitudeofpunchinggapanddegreeofhomogeneityarehaveaimportanteffectforthedimensionaccuracy.Differentpunchingprocess,material,thickofpanel,havecompletelydifferentgapandpunchingaccuracy.AgearH62whichmadeinyellowbrasswiththesamemodenumberm=0.34,2mmthickandhadacenterhole,whenthegapgetC=0.5%t（singleedge）,andpunchedwithcompoundpunchingdie,andthedimensionaccuracyreachedIT7,theparthaveaflatsurface,theverticalityoftangentplanereached89.5°,itsroughnessRamagnitudeare12.5μm,heightofburrare0.10mm;andthepunchingpartarepunchedwithprogressivedie,thegapC=7%t（singleedge）,initialaccuracyareIT11,andhaveanmoreroughsurface,evencanseethegapwitheyes.Intheusualsituation,flushesamaterialanditsthicknesstistheselectionpunchinggapmainbasis.Oncethedesignationgaphaddeterminedflushestheplanesizethefixederrormainbody;Flushesthestructurerigidityandthethree-dimensionalshapeaffectsitsshapepositionprecision.

（2）punchingcraftandmolderstructuretype

Usesthedifferentrammingcraft,flushesaprecisionandthefixederrordifferenceisreallybig.Exceptthattheabovepiecegearexampleshowed,theessenceflushesthecraftandordinarypunchingflushesaprecisionandthefixederrordiffersoutsideamagnitude,evenifinordinarypunchingcenter,usesthedifferentgappunching,thefixederrordifferenceveryisalsobig.Forexamplematerialthickt=1.5mmH62brasspunching,selectsC<=the40%tunilateralIkindofsmallgappunchingcomparedtoselectC<=8%t（unilaterally）IIIkindofbiggappunching,willflushafixederrortoenlarge40%~60%,theprecisionatleastwillfallalevel.Sideinaddition,whetherthereispicksbuildsarowoftypeside,flushesaerrortohavefartobebiggerthanhasbuildsarowoftypetoflush.Sidenotbuildsarowoftypetoflush.SidenotbuildsarowoftypetoflushaprecisiontobelowerthantheIT12levelside,butmosthasbuildsarowoftypetoflushaprecisioninIT11between~IT9level,materialthickt>4mmflushes,thesizeprecisioncanlowersome.Differentdie’sstructuretype,becauseissuitabletherammingmaterialtobethickandthemanufactureprecisiondifference,causestoflushafixederrortohaveleaves.Compounddiecenter,multi-locationscontinuoustypecompounddiebecauseflushescontinuouslytoduplicatethelocalizationtoaddonthepatternmakingerrortobebigger,thereforeitflushesafixederrorcompoundpunchingdietowantcomparedtothesinglelocationBig1~2levels

（3）thecraftofpunchingdie’smanufacture

themainworkofpunchingdienamelyareraised,theconcavemoldprocessingprocedure,tooperatesonthespecificationnottobehigh,cantimeformamorecomplexcavity.Butitsprocessingsurfaceapproximatelyisthick>0.03~0.05mmisthehightemperatureablationremainingfurcatedausteniteorganization,degreeofhardnessmayreachashighasHRC67~70,hasthemicrocrack,easilywhenpunchingappearsbrokethecutterorflaking.TheItalianCorradaCorporation''srelatedmemoircalled"thelinecuttheprocessingcontructiontohavethedisadvantageousinfluencetothesuperficialgold,infactalreadychangedthegoldcontruction.WemustusetheJin''gangstonepowdertogrindorthenumericalcontrolcontinualpathcoordinatesrubtruncate（cuttoline）tomaketheprecisionwork".InrecentyearscountryandsoonSwitzerlandandJapan,hasconductedthethoroughresearchtotheelectricalfinishingequipmentandabiggerimprovement,makesfunctioncompletehighaccuracyNCandtheCNClinecutter,theprocessingprecisionmayreach±0.005~0.001mm,evenissmaller.TheprocessingsurfaceroughnessRavaluecanachieve0.4mum.Accordingtotherecentyearstothedomestic12productionlinescutterfactoryinvestigationandstudy,thedomesticallyproducedlinecutterprocessingprecisiondifferentfactorydifferentmodellinecuttermightreach±0.008~±0.005mm,generallyallin±0.01mmorbiggersomewhat,wasindividualalsocanachieve±0.005mm,theprocessingsurfaceroughnessRavaluewasbiggerthan1.6μm.However,theelectricalfinishingablationmetalsurfacethusthechangeandthedamagemachinedsurfacementalstructurecharactercannotchange,onlyifwithrubstruncatesorotherwaysremovesthisharmfullevel.Therefore,merelyuseselectricitymachining,includingthesparkcuttingandtheelectricityperforation,achieveswithdifficultypunching,especiallyhighaccuracy,highlifepunchingdietosizeprecisionandworkcomponentssurfaceroughnessRavaluerequest.

Withpreciselyrubstruncatesthelawmanufacturepunchingdie,speciallymakesthehighaccuracy,thehighlifepunchingdie,suchas:

Thinmaterialsmallgapcompoundpunchingdie,multi-locationscontinuoustypecompounddieandsoon,hasthesizeprecisionhigh,theworkcomponentsmachinedsurfaceroughnessRavalueissmall,themoldlifehighercharacteristic.Itsprocessingcraftatpresentchangedtheelectricalfirebythepastordinaryenginebedroughmachiningsparkcuttingortheelectricitypuncherroughmachining,finallypreciselyrubstruncates,alsofromtakesshaperubs,opticscurverubs,themanualgridreferencerubsgraduallyfiltersthecontinualpathgrid