StampingandPunchingDiesCompoundDieDesignAcompounddieperformsonlycuttingoperations(usuallyblankingandpiercing)whicharecompletedduringasinglepressstroke.Acharacteristicofcompounddiesistheinvertedpositionoftheblankingdieandblankingpunchwhichalsofunctionsasthepiercingdie.Thedieisfastenedtotheuppershoeandtheblankingpunchhavingataperedholeinitandinthelowershoeforslugdisposalismountedonthelowershoe.Theguidepins,orposts,aremountedinthelowershoes.Theuppershoescontainsbushingwhichslideontheguidepins.Theassemblyoftheloweranduppershoeswithguidepinsandbushingisadieset.Diesetsinmanysizesanddesignsarecommerciallyavailable.Ontheupstrokeofthepressslide,theknockoutrodofthepressstrikestheejectorplate,forcingtheejectortierodandshedderdownward,thuspushingthefinishedworkpieceoutoftheblankingdie.Fourspecialshoulderscrews(stripperbolts),commerciallyavailable,guidethestripperinitstravelandretainitagainstthepreloadofitssprings.Theblankingdieaswellasthepunchpadisscrewedanddoweledtotheuppershoe.1、BendingDieBendingistheuniformstrainingofmaterial,usuallyflatsheetorstripmetal,aroundastraightaxiswhichliesintheneutralplaneandnormaltothelengthwisedirectionofthesheetorstrip.Metalflowtakesplacewithintheplasticrangeofthelengthwisedirectionofthebendretainsapermanentsetafterremovaloftheappliedstress.Theinnersurfaceofabendisincompression；theoutersurfaceisintension.Apurebendingactiondoesnotreproducetheexactshapeofthepunchanddieinthemetal；suchareproductionisoneofforming.Theneutralaxisistheplaneareainbendmetalwhereallstrainiszero.2、BendingMethodsMetalsheetorstrip,supportedbyaVbending,producesabendhavinganincludedanglewhichmaybeacute,obtuse,orof90.Frictionbetweenaspring-loadedknurledpinintheVeeofadieandthepartwillpreventorreducesidecreepofthepartduringitsbending.OthermethodsareZ-bendingedgebendingandU-bendingetc.3、DrawingDieDrawingisaprocessofchangingaflat,precutmetalblankintoahollowvesselwithoutexcessivewrinkling,thinning,orfracturing.Thevariousformsproducedmaybecylindricalorbox-shapedwithstraightortaperedsidesorsidesoracombinationofstraight,tapered,orcurvedsides.Thesizeofthepartsmayvaryfrom0.25mmdiameterorsmaller,toaircraftorautomotivepartslargeenoughtorequiretheuseofmechanicalhandingequipment.4、Single-actionDieThesimplesttypeofdrawdiesisonewithonlyapunchanddie.Onetypeofdrawingdieuseinasingle-actionpressisshowninFig.3-4.Thisdieisplainsingle-actiontypewherethepunchpushesthemetalblankintothedie,usingaspring-loadedpressurepadtocontrolthemetalflow.Thepunchhasanairventtoeliminatesuctionwhichwouldholdthecuponthepunchanddamagethecupwhenitisstrippedfromthepunchbythepressurepad.Thesketchshowsthepressurepadfittingthestoppin,whichactsasaspacerthatanevenandproperpressureisexertedontheblankatalltimes.Ifthespringpressurepadisusedwithoutthestoppin,themorethespringsaredepressed,thegreaterthepressureexertedontheblank,therebylimitingthedepthofdrawing.Becauseoflimitedpressuresobtainable,thistypeofdieshouldbeusedwithlight-gagestockandshallowdepths.MoldCavitiesandCoresThecavityandcoregivethemoldingitsexternalshapesrespectively,theimpressionimpartingthewholeoftheformtothemolding.Whenthenproceededtoindicatealternativewaysbywhichthecavityandcorecouldbeincorporatedintothemoldandwefoundthatthesealternativesfellundertwomainheadings,namelytheintegermethodandtheinsertmethod.Anothermethodbywhichthecavitycanbeincorporatedisbymeansofsplitinsertsorsplits.Whenthecavityorcoreismachinedfromalargeplateorblockofsteel,oriscastinonepiece,andusedwithoutbolsteringasoneofthemoldplates,itistermedanintegercavityplateorintegercoreplate.Thisdesignispreferredforsingle-impressionmoldsbecauseofcharacteristicsofthestrength,smallersizeandlowercost.Itisnotusedasmuchformulti-impressionmoldsasthereareotherfactorssuchasalignmentwhichmustbetakenintoconsideration.Ofthemanymanufacturingprocessesavailableforpreparingmoldsonlytwoarenormallyusedinthiscase.Thereareadirectmachiningoperationonaroughsteelforgingorblankusingtheconventionalmachinetool,ortheprecisioninvestmentcastingtechniqueinwhichamasterpatternismadeofthecavityandcore.Thepatternisthenusedtoprepareacastingofthecavityorcorebyorspecialprocess.A4.25%nickel-chrome-molybdenumsteel(BS970-835M30)isnormallyspecifiedforintegermoldplateswhicharetobemadebythedirectmachiningmethod.Theprecisioninvestmentcastingmethodusuallyutilizesahigh-chromesteel.Formoldscontainingintricateimpressions,andformulti-impressionmolds,itisnotsatisfactorytoattempttomachinethecavityandcoreplatesfromsingleblocksofsteelaswithintegermolds.Themachiningsequencesandoperationwouldbealtogethertoocomplicatedandcostly.Theinset-bolsterassemblymethodisthereforeusedinstead.Themethodconsistsinmachiningtheimpressionoutofsmallblocksofsteel.Thesesmallblocksofsteelareknown,aftermachining,asinserts,andtheonewhichformsthemalepartistermedthecoreinsertand,conversely,theonewhichformsthefemalepartthecavityinserts.Thesearetheninsertedandsecurelyfittedintoholesinasubstantialblockorplateofsteelcalledabolster.Theseholesareeithersunkpartwayoraremachinedrightthroughthebolsterplate.Inthelattercasetherewillbeaplatefastenedbehindthebolsterandthissecurestheinsertinposition.Boththeintegerandtheinsert-bolstermethodshavetheiradvantagesdependinguponthesize,theshapeofthemolding,thecomplexityofthemold,whetherthesingleimpressionoramulti-impressionmoldisdesire,thecostofmakingthemold,etc.Itcanthereforebesaidthatingeneral,oncethecharacteristicsofthemoldrequiredtodoaparticularjobwhichhavebeenweighedup,thedecisionastowhichdesigntoadoptcanbemade.Someoftheseconsiderationshavealreadybeendiscussedundervariousbroadheadings,suchascost,buttoenablethereadertoweighthemupmoreeasily,whenfacedwithaparticularproblem,thecomparisonoftherelativeadvantagesofeachsystemisdiscussedunderanumberofheadings.Unquestionably,forsingleimpressionmoldsintegerdesignistobepreferredirrespectiveofwhetherthecomponentformisasimpleoracomplexone.Theresultingmoldwillbestronger,smaller,lesscostly,andgenerallyincorporatealesselaboratecoolingsystemthantheinsert-bolsterdesign.Itshouldbeborneinmindthatlocalinsertscanbejudiciouslyusedtosimplifythegeneralmanufactureofthemoldimpression.Formulti-impressionmoldsthechoiceisnotsoclear-cut.Inthemajorityofcasestheinsert-bolstermethodofconstructionisused,theeaseofmanufacture,moldalignment,andresultinglowermoldcostsbeingheoverridingfactorsaffectingthechoice.Forcomponentsofverysimpleformitisoftenadvantageoustouseonedesignforoneofthemoldplateandthealternativedesignfortheother.Forexample,consideramulti-impressionmoldforabox-typecomponent.Thecavityplatecouldbeoftheintegerdesigntogaintheadvantagesofstrength,therebyallowingasmallermoldplate,whilethecoreplatecouldbeofinsert-bolsterdesignwhichwillsimplifymachiningoftheplateandallowforadjustmentsformoldalignment.1DiepositioninindustrialproductionMoldisahigh-volumeproductswiththeshapetool,isthemainprocessofindustrialproductionequipment.Withmoldcomponents,withhighefficiency,goodquality,lowcost,savingenergyandrawmaterialsandaseriesofadvantages,withthemoldworkpiecespossesshighaccuracy,highcomplexity,highconsistency,highproductivityandlowconsumption,othermanufacturingmethodscannotmatch.Havealreadybecomeanimportantmeansofindustrialproductionandtechnologicaldevelopment.Thebasisofthemodernindustrialeconomy.Thedevelopmentofmodernindustrialandtechnologicalleveldependslargelyonthelevelofindustrialdevelopmentdie,sodieindustrytonationaleconomicandsocialdevelopmentwillplayanincreasingrole.March1989theStateCouncilpromulgatedonthecurrentindustrialpolicydecisionpointsinthemoldasthemachineryindustrytransformationsequenceofthefirst,productionandcapitalconstructionofthesecondsequence(afterthelarge-scalepowergenerationequipmentandthecorrespondingpowertransmissionequipment),establishtoolingindustryinanimportantpositioninthenationaleconomy.Since1997,theyhavetomoldanditsprocessingtechnologyandequipmentincludedinthecurrentnationalfocusonencouragingthedevelopmentofindustries,productsandtechnologiescatalogandtoencourageforeigninvestmentindustrydirectory.ApprovedbytheStateCouncil,from1997to2000,morethan80professionalmoldfactoryowned70%VATrefundofpreferentialpoliciestosupportmoldindustry.AllthesehavefullydemonstratedthedevelopmentoftheStateCouncilandstatedepartmentstoolingindustryattentionandsupport.Moldaroundtheworldaboutthecurrentannualoutputof60billionU.S.dollars,Japan,theUnitedStatesandotherindustrializedcountriesdieofindustrialoutputvalueofmorethanmachinetoolindustry,beginningin1997,Chinasindustrialoutputvaluehasexceededthemoldmachinetoolindustryoutput.Accordingtostatistics,homeappliances,toysandotherlightindustries,nearly90%ofthepartsareintegratedwithproductionofchopsticks；inaircraft,automobiles,agriculturalmachineryandradioindustries,theproportionexceeded60%.Suchasaircraftmanufacturing,theuseofacertaintypeoffighterdiesmorethan30,000units,ofwhichthehost8000sets,2000setsofengines,auxiliary20000sets.Fromtheoutputofview,sincethe80s,theUnitedStates,Japanandotherindustrializedcountriesdieindustryoutputvaluehasexceededthemachinetoolindustry,andtherearestillrising.Productiontechnology,accordingtotheInternationalAssociationpredictsthatin2000,theproductbestpiecesofrough75%,50%willbefinishedmoldcompleted；metals,plastics,ceramics,rubber,buildingmaterialsandotherindustrialproducts,mostofthemoldwillbecompletedinmorethan50%metalplates,morethan80%ofallplasticproducts,especiallythroughthemoldinto.2ThehistoricaldevelopmentofmoldTheemergenceofmoldcanbetracedbackthousandsofyearsago,potteryandbronzefoundry,butthelarge-scaleuseiswiththeriseofmodernindustryanddeveloped.The19thcentury,withthearmsindustry(gunsshell),watchindustry,radioindustry,diesarewidelyused.AfterWorldWarII,withtherapiddevelopmentofworldeconomy,itbecameamassproductionofhouseholdappliances,automobiles,electronicequipment,cameras,watchesandotherpartsthebestway.Fromaglobalperspective,whentheUnitedStatesintheforefrontofstampingtechnology-manydieofadvancedtechnologies,suchassimplemold,highefficiency,mold,dieandstampingthehighlifeautomation,mostlyoriginatedintheUnitedStates；andSwitzerland,fineblanking,coldinGermanyextrusiontechnology,plasticprocessingoftheSovietUnionareattheworldadvanced.50s,moldindustryfocusisbasedonsubscriberdemand,productioncanmeettheproductrequirementsofthemold.Multi-diedesignruleofthumb,referencehasbeendrawingandperceptualknowledge,onthedesignofmoldpartsofalackofrealunderstandingoffunction.From1955to1965,isthepressureprocessingofexplorationanddevelopmentofthetimes-themaincomponentsofthemoldandthestressstateofthefunctionofamathematicalsub-bridge,andtocontinuetoapplytoon-sitepracticalknowledgetomakestampingtechnologyinallaspectsofaleapindevelopment.Theresultissummarizedmolddesignprinciples,andmakesthepressuremachine,stampingmaterials,processingmethods,plumwithastructure,moldmaterials,moldmanufacturingmethod,thefieldofautomationdevices,anewlooktothepracticaldirectionofadvance,sothatpressingprocessingapparatuscapableofproducingqualityproductsfromthefirststage.Intothe70stohighspeed,launchtechnology,precision,security,developmentofthesecondstage.Continuetoemergeinthisprocessavarietyofhighefficiency,businesslife,high-precisionmulti-functionalautomaticschooltohelpwith.Representedbythenumberofworkingplacesasmuchasotherprogressivedieanddozensofmulti-stationtransferstationmodule.Onthisbasis,hasdevelopedbothacontinuouspressingstationtherearemoreslideformingstationofthepress-bendingmachine.Inthemeantime,theJapanesestandtotheworldslargest-themoldintothemicron-levelprecision,dielife,alloytoolsteelmoldhasreachedtensofmillionsoftimes,carbidesteelmoldtoeachofhundredsofmillionsoftimespminutesforstampingthenumberofsmallpressesusually200to300,upto1200timesto1500times.Inthemeantime,inordertomeetproductupdatesquickly,withtheshortduration(suchascarsmodified,refurbishedtoys,etc.)needavarietyofeconomic-typemold,suchaszincalloydiedown,polyurethanerubbermold,diesteelskin,alsohasbeenverygreatdevelopment.Fromthemid-70ssofarcanbesaidthatcomputer-aideddesign,supportingthecontinuousdevelopmentofmanufacturingtechnologyofthetimes.Withtheprecisionandcomplexityofmoldrising,acceleratingtheproductioncycle,themoldindustry,thequalityofequipmentandpersonnelarerequiredtoimprove.Relyoncommonprocessingequipment,theirexperienceandskillscannotmeettheneedsofmold.Sincethe90s,mechanicalandelectronictechnologiesincloseconnectionwiththedevelopmentofNCmachinetools,suchasCNCwirecuttingmachine,CNCEDM,CNCmilling,CNCcoordinategrindingmachineandsoon.Theuseofcomputerautomaticprogramming,controlCNCmachinetoolstoimprovetheefficiencyintheuseandscope.Inrecentyears,hasdevelopedacomputertotime-sharingbythewayagroupofdirectmanagementandcontrolofCNCmachinetoolsNNCsystem.Withthedevelopmentofcomputertechnology,computershavegraduallyintothemoldinallareas,includingdesign,manufacturingandmanagement.InternationalAssociationfortheStudyofproductionforecaststo2000,asameansoflinksbetweendesignandmanufacturingdrawingswillloseitsprimaryrole.AutomaticDesignofdiemostfundamentalpointistoestablishthemoldstandardanddesignstandards.Togetridofthepeopleofthepast,andpracticalexperiencetojudgethecompositionofthedesigncenter,wemusttakepastexperiencesandwaysofthinking,forseries,numericalvalue,thenumberoftype-based,asthedesigncriteriatothecomputerstore.Componentsaredrybecauseofmoldconstitutesamillionotherdifferences,tocomeupwithacanadapttovariouspartsofthedesignsoftwarealmostimpossible.Butsomeproductsdonotchangetheshapeofparts,moldstructurehascertainrules,canbesummedupfortheautomaticdesignofsoftware.IfaJapanesecompanysCDMsystemforprogressivediedesignandmanufacturing,includingtheimportationofpartsofthefigure,roughstart,striplayout,determinethesizeandstandardtemplates,assemblydrawingandparts,theoutputNCprogram(forCNCmachiningCenterandlinecuttingprogram),etc.,usedin20%ofthetimebyhand,reducetheirworkinghoursto35hours；fromJapanintheearly80swillbethree-dimensionalcad/camsystemforautomotivepaneldie.Currently,thephysicalpartsscanninginput,maplinesanddatainput,geometricform,display,graphics,annotationsandthedataisautomaticallyprogrammed,resultingineffectivecontrolmachinetoolcontrolsystemofpost-processingdocumentshavereachedahighlevel；computerSimulation(CAE)technologyhasmadesomeachievements.Athighlevels,CAD/CAM/CAEintegration,thatdataisintegrated,cantransmitinformationdirectlywitheachother.Achievenetwork.Present.Onlyafewforeignmanufacturerscandoit.3ChinasmoldindustryanditsdevelopmenttrendDie&MouldIndustryStatusDuetohistoricalreasonsfortheformationofclosed,bigandcompleteenterprisefeatures,mostenterprisesinChinaareequippedwithmoldworkshop,infactorymatchingstatussincethelate70shaveamoldtheconceptofindustrializationandspecializationofproduction.Productionefficiencyisnothigh,pooreconomicreturns.Moldproductionindustryissmallandscattered,cross-industry,capital-intensive,professional,commercialandtechnicalmanagementlevelarerelativelylow.Accordingtoincompletestatistics,therearenowspecializedinmanufacturingmold,theproductsupportingmoldfactoryworkshop(factory)near17000,about600000employees,annualoutputva