机械专业毕业设计外文翻译Word格式.doc

机械专业毕业设计外文翻译Word格式.doc

《机械专业毕业设计外文翻译Word格式.doc》由会员分享，可在线阅读，更多相关《机械专业毕业设计外文翻译Word格式.doc（8页珍藏版）》请在冰点文库上搜索。

机械专业外文翻译

ApplicationofanintegratedCAD/CAE/CAMsystemforstampingdiesforautomobiles

Bor-TsuenLin&

Chun-ChihKuo

Abstract

Theglobalizationandcompetitionintheautomobileindustrymakesitnecessarytoreducethetimespentonproductdevelopment.Therefore,computeraidedproductdevelopmenthasbecomeoneofthemostimportanttechniquesintheautomobileindustry.Accordingtotheconcurrentengineeringconcept,anintegratedCAD/CAE/CAMsystemforautomobilestampingdiedevelopmentisestablished.Thesystemisbasedon3DsurfaceconstructionCADsoftwareSTRIM,CAD/CAEsoftwareCATIA,stampingformabilityanalysissoftwareDYNAFORM,CAMsoftwareCADCEUS,astampingdesignknowledge-basedsystem,andaproductdatabase.Thispaperusesthedevelopmentoftrunklidouterpanelsasanexampletoshowcasethepowerofthesystem,inwhichthedifferentdevelopmentstagescanbeperformedsimultaneously.Thesystemcangreatlyreducethedevelopmenttimeandcost,improvetheproductquality,andpushproductsintothemarketinarelativelyshorttime.

1Introduction

Sincestampingpartshaveconsiderablepotentialbecauseoftheircompetitiveproductivityandperformance,theyhavebeenwidelyusedintheautomotiveindustry.However,themanufacturingindustryhasthreemajorgoals:

toimproveproductquality,toreducedevelopmentcost,andtoreducethetimespentondevelopment.Inordertoachievethesegoals,weneedtobringinnewtechnologies.

Fromthemanufacturingviewpoint,themajorrequirementformostapplicationsofsheetmetalisgoodformability[1].Giventhatpartsurfaceshavebecomemoreandmorecomplexandsharp-edged,weneedtotakeadvantageofformabilityanalysistounderstandtheirstampingproperties.In1963,KeelerandBackofen[2]introducedtheconceptofforminglimitdiagrams（FLDs）.

Theyanalyzedtheshapeandsizeforanetchedcircle-gridofsheetmetalafterithadbeenstamped.Thistechniquehasbeenwidelyusedinsheetmetalformabilityanalysissincethen.Recently,softwarethatusesafiniteelementmethodhasbeenusedtoanalyzeandsimulatesheetmetal

formability.ChenandLiu[3]combinedcircle-gridanalysiswithformabilityanalysistoidentifyanoptimaldieface,sothatthesplitdefectatthedrawn-cupwallintherearfloorpanelcouldbeavoided.Makinouchi[4]usedformabilityanalysissoftwaretoanalyzefourstampingparts—fenders,

trunklidouterpanels,sideframeouterpanels,andtirediskwheels—andtopredicttheirblankgeometry,springback,sheetthickness,residualstress,andcommondefectsafterstamping.Bigotetal.[5]developedamethodologytovalidatethemodelingofanaluminumformingprocessbasedondimensionalcharacterizationandfiniteelementcomparison.Takingadvantageofartificialneuralnetwork,knowledgebasedsystemsandfiniteelementanalysis,Pilanietal.[6]proposedamethodforautomaticallygeneratinganoptimaldiefacedesignbasedondiefaceformabilityparameters.

Sincediestructuresarebecomingmoreandmorecomplexandlarge-sized,wemustuseasolidmodelindiedesigntoavoidanypotentialinterferenceamongthevariouscomponents.Moreover,thesolidmodelcanbeusedforbuildingdissolvemodelsandestimatingthefragilesectionofdiestructures.Therefore,itisnecessarytousea3DCAD/CAE/CAMsystemtobuildsolidmodels,to

developCNCtoolingpathprograms,andtoanalyzethestressofdiestructureswhendevelopingstampingdies.NahmandIshikawa[7]utilizedtheset-baseddesignapproachwiththeparametricmodelingtechniquetohandletheuncertaintiesthatareintrinsicatearlystagesofthedesign.Parketal.[8]combinedaCAD/CAMsystemwithaknowledge-basedsystemtodevelopdeepdrawingdiesof

themotorhousing.Chengetal.[9]usedVisualC++programmingtocreateCADsoftwarefortheconceptualdesignofthescrollcompressor,andfabricatearealorbitingscrollpartonaCNCmachiningcenter.

Theglobalizationandcompetitionintheautomotiveindustrymakesitnecessarytoreducethetimespentonproductdevelopment.Networksarewidelyusednowadays.Asaresult,KaoandLin[10]designedasystemthatusesalocalareanetworkandtheInternettoallowtwogeographically

dispersedCAD/CAMuserstosimultaneouslyworkonthedevelopmentofproducts.Kongetal.[11]developedanInternet-basedcollaborationsystemforapressdiedesignprocessforautomobilemanufacturerstosheardesignmodelsandanalysisresults.Moreover,anintegratedCAD/CAE/CAMsystemcantremendouslyimproveproductivity.XuandWang[12]usedthemulti-modeltechnologyandanintegratedCAD/CAE/CAMsystemtodevelopcylinderhead.Yueetal.[13]tookadvantageoftheconcurrentengineeringconceptanddevelopedanintegratedCAD/CAE/CAMsystemtodevelopdiecastingdiesforwaterpumps,whichsuccessfullyreducethedevelopmenttimeandcost,andimproveproductquality.Ferreira[14]developedanintegratedCAD/RP/FEAsystemtoimprovethemanufacturingprocessforZncasting.

ThispaperillustratesanintegratedCAD/CAE/CAMsystemfordesigningstampingdiesoftrunklidouterpanelsforautomobilesusingconcurrentengineering（CE）.

2Proceduresfordevelopingstampingdiesforautomobiles

Oncereceivingthesurfacemodelofastampingpartfromanautomobilemanufacturer,thediemanufacturerinitializesthedevelopmentprocess,whichisshowninFig.1.

DiefacedesignisaprocessthatusesCADsoftwaretocreate3Ddiefaces,whichincludestampingpartsurfaces,addendums,drawbeadsandbinderfaces,andanalyzestheirstampingpropertiesusingformabilityanalyzingsoftware.Takingpossiblecommondefectsintoconsideration,designerskeepmodifyingthe3Dsurfacesuntiltheyobtainanoptimaldrawingdieface,whichwillbeusedindesigningdiesanddesigningNCprogramsforprocessingdiefaces.

Layoutdiagramdesignistheprocessofdevelopingthedielayoutdiagrambasedonitssurfacemodel,whichincludesthefollowingsub-tasks:

identifyingthecentralreferencepoint,identifyingthepressdirection,identifyingtheresponsibilitiesofeachprocess,designingdrawingdiefaces,suggestingdieheightandindicatingpresslines.

Sinceautomotivestampingdiescanbeverylargeinsize,theyareprocessedbycastinginordertominimizetheirweightandcost.3DCAD/CAEsoftwaremustbeusedtodesignthesolidmodeltoavoidanypotentialinterferenceamongvariouscomponents,whichincludescavity,punch,

strengthenedribs,functionalunitsand/orstandardpartsforupperandlowerdiesets,andblank-holder（BH）.

Afterthediedesignprocessisfinished,designerswillperformmotionandinterferenceanalysisonthe3Dsolidmodelsandmodifythemifanyproblemisidentified.Moreover,thestampingforceisverylarge,modificationandenhancementshouldbemadetothediestructuralmodelswherenecessarythroughstructuralanalysis.

Diemanufactureincludesdissolvediesmanufacture,diedimensionmanufactureanddiefacemanufacture.Dissolvediesareneededbecausediebodiesareprocessedbycasting.Afteridentifyingtheinformationneededtoconstruct3Dsolidmodels,designersshoulddevelopNCtoolingpath

programstomakedissolvediesusingCNCmachines.Then,thediebodiesarecastthroughdissolvedies.

Diedimensionmanufactureisresponsibleformakingallreferenceplanesandholes,suchasdiebaseplanes,guidingplanes,stopperplanes,assemblingplanes,positioningholesandboltholes.Diefacemanufacturegeneratesallsurfacesthatwillbecompletedinallsubsequentsub-tasks.Designers

use3DCAMsoftwaretodesigntoolingpaths,includingroughing,finishing,andcornerfinishingpaths.Moreover,cuttingsimulationneedstobeconductedtoensurethefeasibilityoftheprocess.Afterthetoolingpathshavebeenidentified,theywillbepostedintoNCcodetoallowfurtherprocessingbyCNCmachines.

Whenthedieshavebeenmanufacturedandassembled,CMM（coordinatemeasuringmachines）willmeasurethedimensionsofthedies.Ifnofaultsarefound,dietryoutswillbeproduced.Ifthetryoutsmeetallrequirementsandspecifications,massproductionensues.

3TheintegratedCAD/CAE/CAMsystems

Figure2showstheschemeoftheintegratedCAD/CAE/CAMsystemforstampingdies.ThissystemincludesasetofCADdiefacedesignsoftware,asetofstampingformabilityanalyzingsoftware,asetofCAD/CAEsoftware,asetofCAMsoftware,astampingdiedesignknowledge-basedsystem,andaproductdatabase.

Diefacedesignistheprocessofdesigningvarioussupportingsurfacesaroundthestampingpartsurfaces.Thesesupportingsurfacesarenotpartofthestampingpartsurfaces.Therefore,thediemanufacturerisresponsibleforthediefacedesign.Inordertoensureconsistencybetweenthestampingpart’ssurfacesanditssupportingsurfaces,specializedsurfacedesignCADsoftwaremustbeused.CommonlyusedcommercialsoftwareincludesIcemSurfbyIcem,STRIMbySGI,andCATIAbyDassault.

Thesurfacesofautomotivepartsareverycomplexandsharp-edged.Theirformabilitycannotbepredictedusingpreviousexperience.Inordertoensureproductquality,designersneedtoperformformabilityanalysisondiefacesbeforedesigningstampingdie.Currently,thiskindofsoftwareincludesDYNAFORMbyETA,PAM-STAMPbyEDS,andAUTOFORMbyAFE.

Automotivestampingdiestructuresincludestructuralsubcomponents,suchaspunch,cavity,strengthenedribs,functionalunits,andcammechanisms,whichareusedtochangethestampingdirectionandreducediesizes.Thediefacesofpunchandcavityaremadeupof