DFMEA全解

1設計失效模式及效应分析DesignFailureMode&EffectAnalysis(DFMEA)2FMEADefinition/FMEA定义AnFMEAcanbedescribedasasystemizedgroupofactivitiesintendedto:失效模式及效应分析是一组有系统的行为,其目的是:(a)Recognizeandevaluatethepotentialfailureofaproduct/processanditseffects辨别与评估产品及其工艺的潜在失效模式,以及由此产生的效应(b)Identifyactionswhichcouldeliminateorreducethechanceofthepotentialfailureoccurring,and找出行动方案来避免潜在失效的发生,或降低其可能性(c)Documenttheprocess将以上过程记录在案3FMEAFlow/FMEA流程BoundaryDiagramInterfaceMatrixP-DiagramFMEA(withRobustnessLinkage)Robustness&ReliabilityChecklistDesignValidationPlan(DVP)QualifiesandclarifiestherelationshipsbetweensystemsIdentifiesandquantifiesthestrengthofsysteminteractionsIdentifiesnoiseandcontrolfactorsanderrorstatesSummarizeserrorstates,noisefactors,andassociatedesigncontrol4MagnaClosuresRequiredFMEARelatedDocuments•BoundaryDiagram•P-Diagram•CC/SC/KC•ProductCharacteristicMatrix•FMEAChecklist•InterfaceMatrix•DFMEA•ProcessFlowDiagram•PFMEA•DVP&R5ABoundaryDiagramExample(U204LiftgateLatchingSystem)LiftgateLatchAssemblyAjarSwitchBrainplateLockActuatorPlasticSecurityShieldGlassLatchO/SHandleAssemblyw/RodWireHarnessGEMAssemblyPlantOwner/OperatorVehicleBodyInnerDoorTrimWaterShieldDoorSealSystem(dooreffort)StrikerAssemblyC-pillarsheetmetalwithpaintFastenersWindowGlassclearanceSheetMetalOuterFCSD(Service)Fasteners6AP-DiagramExample(U204LiftgateLatchingSystem)U204LiftgateLatchingSystemSignalFactors1)DoorSlamEngergy2)HandlereleaseeffortLiftgate3)HandlereleasetravelLiftgate4)HandlereleaseeffortGlass5)HandlereleasetravelGlass6)OutsidereleasehandlecyclingControlFactorsLatchmaterialselections-Frameplate-Housing-Ratchet&PawlRatchet&pawlheattreat:36-42HRCComponentfinishSpringmaterialselectionIdealFunctionResponse1)Latchreleases2)LatchretainsstrikerfullyErrorStateResponse1)Latchnofunction2)Strikernotalignedwithlatch3)Strikernotproperlyengaged4)Gapissueswithtrim5)High/lowreleaseeffort6)High/lowreleasetravel7)Inside/outsidereleasehandlenotfunctioningNoiseFactorsPiecetopiece:1)Handleeffort68.6NMax2)Handletravel20–29mm3)Doorpanelholetolerance4)Doordimensionalvariation5)Releaserod6)4-waylocatorbodyCustomerUsage:1)Handlecycleloads/Abuse2)DoorslamspeedSub-systeminteraction:1)Inner/outersheetmetal2)Latchassembly3)Outsidereleasehandleassy4)Linkage5)ElectricalconnectorAging/WearEffect:1)Fatigue2)Creek3)Impactdurability4)CorrosionEnvironment:1)Temperature2)Humidity3)Dust4)Vibration5)Ice7AnInterfaceMatrixExample(Headlamp)InterfaceMatrix:ExampleofHeadLamp-1-2-1-12-2-1-2-1-1-1-1-1-1-1-122-2-1-12HeadlampHeadlampHousingHoodGrillOpeningPanelBodyConnectorWiring/ElectricalSystemScrew/FastenerScrew/FastenerWiring/ElectricalSystemConnectorBodyGrillOpeningPanelHoodHeadlampHousingHeadlampPEIMP:PhysicaltouchingE:EnergyExchangeI:InformationExchangeM:MaterialExchangeNumbersineachcornerrepresenttheaboveinterfacetypes,withvaluedenotingthefollowing:+2:Interactionisnecessaryforfunction+1:Interactionisbeneficial;butnotabsolutelynecessaryforfunctionality0:Interactiondoesnotaffectfunctionality-1:Interactioncausesnegativeeffectsbutdoesnotpreventfunctionality-2:InteractionmustbepreventedtoachievefunctionalityNegativevaluesareanalyzedforrecommendedfunctions.8DFMEA设计失效模式及效应分析DesignPotentialFMEAis:设计潜在失效模式及效应分析是:•ananalyticaltechniqueusedprimarilybyDesign-ResponsibleEngineer/Team由负责设计的工程师/小组采用的分析技术•toidentifypotentialfailuremodes用作辨别潜在失效模式•toidentifyassociatedcause/mechanisms辨别相关原因/机理•tosupportthedesignprocessinreducingtheriskoffailures支持设计过程,减少失效风险•applytosystem,subsystem,andcomponent应用于系统、子系统及部件9CustomerofDFMEA顾客的定义CustomerforaDesignFMEA顾客的定义•Enduser通常是指“最终使用者”•Manufacturing/Process-responsibleengineer也可以是更高一层设计司，制造或装配生产工程司10TeamEffort小组的努力•Design设计•Manufacturing制造•Quality品质•Material材料•Reliability可靠性•Sub-contractor分供方11DFMEA设计失效模式及效应分析DesignFMEAisLIVINGdocumentandshould设计FMEA是一份动态的文件•beinitiatedbeforeoratdesignconceptfinalization在一个设计概念最终形成之时或之前开始•becontinuallyupdated在产品开发的各个阶段,发生更改或获得更多的信息时,持续予以更新•befundamentallycompletedbeforeproductiondrawingrelease在产品加工图样完工之前全部完成12DFMEA设计失效模式及效应分析•Assumption:Designwillbemanufactured/assembled假设:该设计将按此意图进行生产•Potentialfailuremodesduringproduction“NeedNot”but“MayBe”included制造的失效模式“不需”但“也可能”包括•DFMEAnotrelyonprocesscontrolstoovercomedesignweaknessDFMEA不依靠过程控制来克服潜在的设计缺憾•DFMEAconsiderstechnicallimitsofmanufacturingDFMEA考虑制造的限制–Molddrafts拔模斜度–Assemblingspace装配空间–Tolerances/capability公差/过程能力13DevelopmentofaDesignFMEA设计FMEA的开始FirstStepofDFMEA:IDENTIFYDESIGNINTEND第一步:确定设计意图“Listingofwhatdesignisexpectedtodoandwhatisexpectednottodo”“列出设计期望做什么和不期望做什么?14DevelopmentofaDesignFMEA设计FMEA的开始Sourceofinformation资料来源•QFD质量功能展开•ProductRequirement产品要求•Manufacturingrequirement生产要求“DesignIntent”“设计意图”15BlockDiagram框图DFMEARecommendedtool:BlockDiagramDFMEA建议工具:框图Tounderstand明白Housing灯罩•inputtotheblock输入Slipfit•functionoftheblock功能Batteries电池plate弹簧Compressivefit压紧装接•outputformtheblock输出Snapfit卡扣连接滑动配合16Page__________of___________________Component_________________________DesignResponsibility_________________________Preparedby________________________ModeYear(s)/Vehicle(s)________________