遥控器后盖的注塑模具设计-抽芯塑料注射模含12张CAD图带开题
收藏
资源目录
压缩包内文档预览:
编号:81003258
类型:共享资源
大小:5.81MB
格式:ZIP
上传时间:2020-05-24
上传人:QQ14****9609
认证信息
个人认证
郭**(实名认证)
陕西
IP属地:陕西
50
积分
- 关 键 词:
-
遥控器
注塑
模具设计
塑料
注射
12
CAD
开题
- 资源描述:
-
遥控器后盖的注塑模具设计-抽芯塑料注射模含12张CAD图带开题,遥控器,注塑,模具设计,塑料,注射,12,CAD,开题
- 内容简介:
-
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.Oneoftheessentialfeaturesofthepartis
- 温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。