塑料注塑模具并行设计外文文献翻译、中英文翻译

CONCURRENTDESIGNOFPLASTICSINJECTIONMOULDSAbstractTheplasticproductmanufacturingindustryhasbeengrowingrapidlyinrecentyears.Oneofthemostpopularprocessesformakingplasticpartsisinjectionmoulding.Thedesignofinjectionmouldiscriticallyimportanttoproductqualityandefficientproductprocessing.Mould-makingcompanies,whowishtomaintainthecompetitiveedge,desiretoshortenbothdesignandmanufacturingleadingtimesofthebyapplyingasystematicmoulddesignprocess.Themouldindustryisanimportantsupportindustryduringtheproductdevelopmentprocess,servingasanimportantlinkbetweentheproductdesignerandmanufacturer.Productdevelopmenthaschangedfromthetraditionalserialprocessofdesign,followedbymanufacture,toamoreorganizedconcurrentprocesswheredesignandmanufactureareconsideredataveryearlystageofdesign.Theconceptofconcurrentengineering(CE)isnolongernewandyetitisstillapplicableandrelevantintodaysmanufacturingenvironment.Teamworkingspirit,managementinvolvement,totaldesignprocessandintegrationofITtoolsarestilltheessenceofCE.TheapplicationofTheCEprocesstothedesignofaninjectionprocessinvolvesthesimultaneousconsiderationofplasticpartdesign,moulddesignandinjectionmouldingmachineselection,productionschedulingandcostasearlyaspossibleinthedesignstage.Thispaperpresentsthebasicstructureofaninjectionmoulddesign.Thebasisofthissystemarisesfromananalysisoftheinjectionmoulddesignprocessformoulddesigncompanies.Thisinjectionmoulddesignsystemcoversboththemoulddesignprocessandmouldknowledgemanagement.Finallytheprincipleofconcurrentengineeringprocessisoutlinedandthenitsprincipleisappliedtothedesignofaplasticinjectionmould.Keywords:Plasticinjectionmoulddesign,Concurrentengineering,Computeraidedengineering,Mouldingconditions,Plasticinjectionmoulding,Flowsimulation1.IntroductionInjectionmouldsarealwaysexpensivetomake,unfortunatelywithoutamoulditcannotbepossiblehohaveamouldedproduct.Everymouldmakerhashis/herownapproachtodesignamouldandtherearemanydifferentwaysofdesigningandbuildingamould.Surelyoneofthemostcriticalparameterstobeconsideredinthedesignstageofthemouldisthenumberofcavities,methodsofinjection,typesofrunners,methodsofgating,methodsofejection,capacityandfeaturesoftheinjectionmouldingmachines.Mouldcost,mouldqualityandcostofmouldproductareinseparableIntodayscompletiveenvironment,computeraidedmouldfillingsimulationpackagescanaccuratelypredictthefillpatternsofanypart.Thisallowsforquicksimulationsofgateplacementsandhelpsfindingtheoptimallocation.Engineerscanperformmouldingtrialsonthecomputerbeforethepartdesigniscompleted.Processengineerscansystematicallypredictadesignandprocesswindow,andcanobtaininformationaboutthecumulativeeffectoftheprocessvariablesthatinfluencepartperformance,cost,andappearance.2.InjectionMouldingInjectionmouldingisoneofthemosteffectivewaystobringoutthebestinplastics.Itisuniversallyusedtomakecomplex,finishedparts,ofteninasinglestep,economically,preciselyandwithlittlewaste.Massproductionofplasticpartsmostlyutilizesmoulds.Themanufacturingprocessandinvolvingmouldsmustbedesignedafterpassingthroughtheappearanceevaluationandthestructureoptimizationoftheproductdesign.Designersfaceahugenumberofoptionswhentheycreateinjection-mouldedcomponents.Concurrentengineeringrequiresanengineertoconsiderthemanufacturingprocessofthedesignedproductinthedevelopmentphase.Agooddesignoftheproductisunabletogotothemarketifitsmanufacturingprocessisimpossibleortooexpensive.Integrationofprocesssimulation,rapidprototypingandmanufacturingcanreducetheriskassociatedwithmovingfromCADtoCAMandfurtherenhancethevalidityoftheproductdevelopment.3.ImportanceofComputerAidedInjectionMouldDesignTheinjectionmouldingdesigntaskcanbehighlycomplex.ComputerAidedEngineering(CAE)analysistoolsprovideenormousadvantagesofenablingdesignengineerstoconsidervirtuallyandpart,mouldandinjectionparameterswithouttherealuseofanymanufacturingandtime.Thepossibilityoftryingalternativedesignsorconceptsonthecomputerscreengivestheengineerstheopportunitytoeliminatepotentialproblemsbeforebeginningtherealproduction.Moreover,invirtualenvironment,designerscanquicklyandeasilyassesthesensitivityofspecificmouldingparametersonthequalityandmanufacturabilityofthefinalproduct.AlltheseCAEtoolsenablealltheseanalysistobecompletedinameterofdaysorevenhours,ratherthanweeksormonthsneededfortherealexperimentaltrialanderrorcycles.AsCAEisusedintheearlydesignofpart,mouldandmouldingparameters,thecostsavingsaresubstantialnotonlybecauseofbestfunctioningpartandtimesavingsbutalsotheshortensthetimeneededtolaunchtheproducttothemarket.Theneedtomeetsettolerancesofplasticparttiesintoallaspectsofthemouldingprocess,includingpartsizeandshape,resinchemicalstructure,thefillersused,mouldcavitylayout,gating,mouldcoolingandthereleasemechanismsused.Giventhiscomplexity,designersoftenusecomputerdesigntools,suchasfiniteelementanalysis(FEA)andmouldfillinganalysis(MFA),toreducedevelopmenttimeandcost.FEAdeterminesstrain,stressanddeflectioninapartbydividingthestructureintosmallelementswheretheseparameterscanbewelldefined.MFAevaluatesgatepositionandsizetooptimizeresinflow.Italsodefinesplacementofweldlines,areasofexcessivestress,andhowwallandribthicknessaffectflow.Otherfiniteelementdesigntoolsincludemouldcoolinganalysisfortemperaturedistribution,andcycletimeandshrinkageanalysisfordimensionalcontrolandpredictionoffrozenstressandwarpage.TheCAEanalysisofcompressionmouldedpartsisshowninFigure1.TheanalysiscyclestartswiththecreationofaCADmodelandafiniteelementmeshofthemouldcavity.Aftertheinjectionconditionsarespecified,mouldfilling,fiberorientation,curingandthermalhistory,shrinkageandwarpagecanbesimulated.Thematerialpropertiescalculatedbythesimulationcanbeusedtomodelthestructuralbehaviourofthepart.Ifrequired,partdesign,gatelocationandshrinkageandwarpagecanbesimulated.Thematerialpropertiescalculatedbythesimulationcanbeusedtomodelthestructuralbehaviourofthepart.Ifrequired,partdesign,gatelocationandprocessingconditionscanbemodifiedinthecomputeruntilanacceptablepartisobtained.Aftertheanalysisisfinishedanoptimizedpartcanbeproducedwithreducedweldline(knownalsoknitline),optimizedstrength,controlledtemperaturesandcuring,minimizedshrinkageandwarpage.Machiningofthemouldswasformerlydonemanually,withatoolmakercheckingeachcut.ThisprocessbecamemoreautomatedwiththegrowthandwidespreaduseofcomputernumericallycontrolledorCNCmachiningcentres.SetuptimehasalsobeensignificantlyreducedthroughtheuseofspecialsoftwarecapableofgeneratingcutterpathsdirectlyfromaCADdatafile.Spindlespeedsashighas100,000rpmprovidefurtheradvancesinhighspeedmachining.Cuttingmaterialshavedemonstratedphenomenalperformancewithouttheuseofanycutting/coolantfluidwhatsoever.Asaresult,theprocessofmachiningcomplexcoresandcavitieshasbeenaccelerated.Itisgoodnewsthatthetimeittakestogenerateamouldisconstantlybeingreduced.Thebadnews,ontheotherhand,isthatevenwithalltheseadvances,designingandmanufacturingofthemouldcanstilltakealongtimeandcanbeextremelyexpensive.Manycompanyexecutivesnowrealizehowvitalitistodeploynewproductstomarketrapidly.Newproductsarethekeytocorporateprosperity.Theydrivecorporaterevenues,marketshares,bottomlinesandshareprices.Acompanyabletolaunchgoodqualityproductswithreasonablepricesaheadoftheircompetitionnotonlyrealizes100%ofthemarketbeforerivalproductsarrivebutalsotendstomaintainadominantpositionforafewyearsevenaftercompetitiveproductshavefinallybeenannounced(Smith,1991).Formostproducts,thesetwoadvantagesaredramatic.Rapidproductdevelopmentisnowakeyaspectofcompetitivesuccess.Figure2showsthatonly37%oftheproductmixfromtheaverageindustrialorelectronicscompanyislessthan5yearsold.Forcompaniesinthetopquartile,thenumberincreasesto1525%.Forworld-classfirms,itis6080%(Thompson,1996).Thebestcompaniescontinuouslydevelopnewproducts.AtHewlett-Packard,over80%oftheprofitsresultfromproductslessthan2yearsold!(Neel,1997)Figure1Importanceofnewproduct(Jacobs,2000)Withtheadvancesincomputertechnologyandartificialintelligence,effortshavebeendirectedtoreducethecostandleadtimeinthedesignandmanufactureofaninjectionmould.Injectionmoulddesignhasbeenthemainareaofinterestsinceitisacomplexprocessinvolvingseveralsub-designsrelatedtovariouscomponentsofthemould,eachrequiringexpertknowledgeandexperience.Leeet.al.(1997)proposedasystematicmethodologyandknowledgebaseforinjectionmoulddesigninaconcurrentengineeringenvironment.4.ConcurrentEngineeringinMouldDesignConcurrentEngineering(CE)isasystematicapproachtointegratedproductdevelopmentprocess.Itrepresentsteamvaluesofco-operation,trustandsharinginsuchamannerthatdecisionmakingisbyconsensus,involvingallperspectivesinparallel,fromtheverybeginningoftheproductlife-cycle(Evans,1998).Essentially,CEprovidesacollaborative,co-operative,collectiveandsimultaneousengineeringworkingenvironment.Aconcurrentengineeringapproachisbasedonfivekeyelements:（1）.process（2）.multidisciplinaryteam（3）.integrateddesignmodel（4）.facility（5）.softwareinfrastructureFigure2Methodologiesinplasticinjectionmoulddesign,a)Serialengineeringb)ConcurrentengineeringIntheplasticsandmouldindustry,CEisveryimportantduetothehighcosttoolingandlongleadtimes.Typically,CEisutilizedbymanufacturingprototypetoolingearlyinthedesignphasetoanalyzeandadjustthedesign.Productiontoolingismanufacturedasthefinalstep.Themanufacturingprocessandinvolvingmouldsmustbedesignedafterpassingthroughtheappearanceevaluationandthestructureoptimizationoftheproductdesign.CErequiresanengineertoconsiderthemanufacturingprocessofthedesignedproductinthedevelopmentphase.Agooddesignoftheproductisunabletogotothemarketifitsmanufacturingprocessisimpossible.IntegrationofprocesssimulationandrapidprototypingandmanufacturingcanreducetheriskassociatedwithmovingfromCADtoCAMandfurtherenhancethevalidityoftheproductdevelopment.Foryears,designershavebeenrestrictedinwhattheycanproduceastheygenerallyhavetodesignformanufacture(DFM)thatis,adjusttheirdesignintenttoenablethecomponent(orassembly)tobemanufacturedusingaparticularprocessorprocesses.Inaddition,ifamouldisusedtoproduceanitem,therearethereforeautomaticallyinherentrestrictionstothedesignimposedattheverybeginning.Takinginjectionmouldingasanexample,inordertoprocessacomponentsuccessfully,ataminimum,thefollowingdesignelementsneedtobetakenintoaccount:（1）geometry; draftangles,Nonre-entrantsshapes, nearconstantwallthickness, complexity,splitlinelocation,andsurfacefinish,（2）materialchoice;（3）rationalisationofcomponents(reducingassemblies);（4）.cost.Ininjectionmoulding,themanufactureofthemouldtoproducetheinjection-mouldedcomponentsisusuallythelongestpartoftheproductdevelopmentprocess.Whenutilisingrapidmodelling,theCADtakesthelongertimeandthereforebecomesthebottleneck.Theprocessdesignandinjectionmouldingofplasticsinvolvesrathercomplicatedandtimeconsumingactivitiesincludingpartdesign,moulddesign,injectionmouldingmachineselection,productionscheduling,toolingandcostestimation.Traditionallyalltheseactivitiesaredonebypartdesignersandmouldmakingpersonnelinasequentialmanneraftercompletinginjectionmouldedplasticpartdesign.Obviouslythesesequentialstagescouldleadtolongproductdevelopmenttime.Howeverwiththeimplementationofconcurrentengineeringprocessintheallparameterseffectingproductdesign,moulddesign,machineselection,productionscheduling,toolingandprocessingcostareconsideredasearlyaspossibleinthedesignoftheplasticpart.Whenusedeffectively,CAEmethodsprovideenormouscostandtimesavingsforthepartdesignandmanufacturing.Thesetoolsallowengineerstovirtuallytesthowthepartwillbeprocessedandhowitperformsduringitsnormaloperatinglife.Thematerialsupplier,designer,moulderandmanufacturershouldapplythesetoolsconcurrentlyearlyinthedesignstageoftheplasticpartsinordertoexploitthecostbenefitofCAE.CAEmakesitpossibletoreplacetraditional,sequentialdecision-makingprocedureswithaconcurrentdesignprocess,inwhichallpartiescaninteractandshareinformation,Figure3.Forplasticinjectionmoulding,CAEandrelateddesigndataprovideanintegratedenvironmentthatfacilitatesconcurrentengineeringforthedesignandmanufactureofthepartandmould,aswellasmaterialselectionandsimulationofoptimalprocesscontrolparameters.QualitativeexpensecomparisonassociatedwiththepartdesignchangesisshowninFigure4,showingthefactthatwhendesignchangesaredoneatanearlystagesonthecomputerscreen,thecostassociatedwithisanorderof10.000timeslowerthanthatifthepartisinproduction.Thesemodificationsinplasticpartscouldarisefrommouldmodifications,suchasgatelocation,thicknesschanges,productiondelays,qualitycosts,machinesetuptimes,ordesignchangeinplasticparts.Figure3Costofdesignchangesduringpartproductdevelopmentcycle(Rioset.al,2001)Attheearlydesignstage,partdesignersandmouldershavetofinalisepartdesignbasedontheirexperienceswithsimilarparts.Howeverasthepartsbecomemorecomplex,itgetsratherdifficulttopredictprocessingandpartperformancewithouttheuseofCAEtools.Thusforevenrelativelycomplexparts,theuseofCAEtoolstopreventthelateandexpensivedesignchangesandproblemsthatcanariseduringandafterinjection.Forthesuccessfulimplementationofconcurrentengineering,theremustbebuy-infromeveryoneinvolved.5.CaseStudyFigure5showstheinitialCADdesignofplasticspartusedforthesprinklerirrigationhydrantleg.Oneoftheessentialfeaturesofthepartisthattheparthastoremainflatafterinjection;anywarpingduringtheinjectioncausesoperatingproblems.Anotherimportantfeaturetheplasticparthastohaveisahighbendingstiffness.AnumberoffeedersindifferentorientationwereaddedtothepartasshowninFigure5b.Thesefeedersshouldbedesignedinawaythatithastocontributetheweightofthepartasminimumaspossible.Beforethedesignofthemould,theflowanalysisoftheplasticpartwascarriedoutwithMoldflowsoftwaretoenabletheselectionofthebestgatelocationFigure6a.Thefigureindicatesthatthebestpointforthegatelocationisthemiddlefeederatthecentreofthepart.Asthedistortionandwarpageofthepartafterinjectionwasvitalfromthefunctionalitypointofviewandithastobekeptataminimumlevel,thesamesoftwarewasalsoutilisedtoyiledthewarpageanalysis.Figure5bshowstheresultsimplyingthefactthatthewarpagewellafterinjectionremainswithinthepredefineddimensionaltolerances.6.ConclusionsIntheplasticinjectionmoulding,theCADmodeloftheplasticpartobtainedfromcommercial3Dprogramscouldbeusedforthepartperformanceandinjectionprocessanalyses.WiththeaidofCEAtechnologyandtheuseofconcurrentengineeringmethodology,notonlytheinjectionmouldcanbedesignedandmanufacturedinaveryshortofperiodoftimewithaminimisedcostbutalsoallpotentialproblemswhichmayarisefrompartdesign,moulddesignandprocessingparameterscouldbeeliminatedattheverybeginningofthemoulddesign.Thesetwotoolshelppartdesignersandmouldmakerstodevelopagoodproductwithabetterdeliveryandfastertoolingwithlesstimeandmoney.塑料注塑模具并行设计摘要塑料制品制造业近年迅速成长。其中最受欢迎的制作过程是注塑塑料零件。注塑模具的设计对产品质量和效率的产品加工非常重要。模具公司想保持竞争优势,就必须缩短模具设计和制造的周期。模具是工业的一个重要支持行业，在产品开发过程中作为一个重要产品设计师和制造商之间的联系。产品开发经历了从传统的串行开发设计制造到有组织的并行设计和制造过程中,被认为是在非常早期的阶段的设计。并行工程的概念(CE)不再是新的,但它仍然是适用于当今的相关环境。团队合作精神、管理参与、总体设计过程和整合IT工具仍然是并行工程的本质。CE过程的应用设计的注射过程包括同时考虑塑件设计、模具设计和注塑成型机的选择、生产调度和成本中尽快设计阶段。介绍了注射模具的基本结构设计。在该系统的基础上,模具设计公司分析注塑模具设计过程。该注射模设计系统包括模具设计过程及模具知识管理。最后的原则概述了塑料注射模并行工程过程并对其原理应用到设计。关键词:塑料注射模设计、并行工程、计算机辅助工程、成型条件、塑料注塑、流动模拟。1、简介注塑模具总是昂贵的,不幸的是没有模具就不可能生产模具制品。每一个模具制造商都他/她自己的方法来设计模具,有许多不同的设计与建造模具。当然最关键的参数之一,要考虑到模具设计阶段是大量的计算、注射的方法,浇注的的方法、研究注射成型机容量和特点。模具的成本、模具的质量和制件质量是分不开的在针对今天的计算机辅助充型模拟软件包能准确地预测任何部分充填模式环境中。这允许快速模拟实习,帮助找到模具的最佳位置。工程师可以在电脑上执行成型试验前完成零件设计。工程师可以预测过程系统设计和加工窗口,并能获得信息累积所带来的影响,如部分过程变量影响性能、成本、外观等。2、注射成型法注塑成型是最有效的方法之一,将塑料最好的一面呈现。这是普遍用于制造复杂的制件,优点是简单、经济、准确与少浪费。塑料零件的批量生产主要采用模具。产品设计制造过程包括模具的结构必须经过外观评价和结构优化。当设计师创造注射模具组件时，他们面临一个巨大的多种选择，并行工程需要一个工程师考虑制产品在发展阶段时的过程设计。一个好的产品设计为了满足市场其制造过程是不可能太贵的。CAD/CAM整合了过程仿真、快速成形制造能减少风险,进