公差原则ppt课件

4.3公差原则ToleranceprinciplesGB/T4249-1996,1,基本内容：Basiccontents:公差原则1.Toleranceprinciples有关术语及定义2.Relatedtermsanddefinitions相关原则3.Relatedprinciples难点内容：Aporiacontents:相关原则的应用Theapplicationsofrelatedprinciples,2,一.公差原则1.Toleranceprinciples处理形位公差和尺寸公差之间关系的规定。Theregulationstosolvetherelationshipsbetweengeometricaltolerancesanddimensionaltolerances,独立原则公差原则包容要求相关原则最大实体要求最小实体要求,Toleranceprinciples,Independenceprinciples,Enveloperequirements,Maximummaterialrequirements,Leastmaterialrequirements,3,1.独立原则Independenceprinciples,定义：Definitions:图样上给定的每一个尺寸公差和形位公差要求，均是独立的，各自满足要求。Eachsizetoleranceandgeometricaltolerancerequirementsgivenonthedrawingsarebothindependentandsatisfytherequirements标注：Label:不需加注任何符号Thereisnoneedtoaddlabelinganysymbol,4,5,6,2.相关原则Relativeprinciples,定义图样上给定的形位公差与尺寸公差相互有关的公差要求。DefinitionThetolerancerequirementsthatthegivengeometricaltolerancesondrawingsrelatetosizetolerances.,7,二.有关术语及定义Relatedtermsanddefinitions,1体外作用尺寸Externalmatingsizes,Dfe：在被测要素的给定长度上，与实际内表面体外相接的最大理想面的直径或宽度。Themaximumidealsurfacesdiameterorwidthonthegivenlengthofmeasuredelementsandconnectswithactualinternalsurfaceexternally.,External,Internal,8,dfe：在被测要素的给定长度上，与实际外表面体外相接的最小理想面的直径或宽度。Theminimumidealsurfacesdiameterorwidthonthegivenlengthofmeasuredelementsandconnectswithactualexternalsurfaceexternally.,External,Internal,9,10,2最大实体状态（尺寸）Maximummaterialcondition(Size),最大实体状态（MMC）：Maximummaterialcondition(MMC)实际要素在给定长度上,处处位于极限尺寸之间，并具有实体最大时的状态.Thestatethatactualelementsareonthegivenlengthes.Andeachpositionisbetweenthelimitsizesthuscontainingthemaximummaterial.最大实体尺寸（MMS）：Maximummaterialsize实际要素在最大实体状态下的极限尺寸.ThelimitsizethattheactualelementsareinthemaximummaterialconditionDM=DmindM=dmax实体最大：占有材料量最多Actualmaterialismaximum:Thepossessedmaterialvolumeisthemost.,11,3最小实体状态（尺寸）Leastmaterialcondition(size),最小实体状态（LMC）：Leastmaterialcondition(LMC)实际要素在给定长度上,处处位于极限尺寸间，并具有实体最小时的状态.Thestatethatactualelementsareonthegivenlengthes.Andeachpositionisbetweenthelimitsizesthuscontainingtheminimummaterial.最小实体尺寸（LMS）：Leastmaterialsize(LMS)实际要素在最小实体状态下的极限尺寸.ThelimitsizethattheactualelementsareintheminimummaterialconditionDL=DmaxdL=dmin实体最小：占有材料量最少Actualmaterialisminimum:Thepossessedmaterialvolumeistheleast.,12,4最大实体实效状态（尺寸）Maximummaterialvirtualcondition(Size),MMVC：给定长度上，实际要素处于最大实体状态，且该要素轴线、中心平面的形位误差等于给出公差值时的综合极限状态.MMVC:Thecomprehensivelimitstatewhenthegeometricaldeviationsofthiselementaxisandmidplaneequaltothegiventolerancevaluesandtheactualelementsareinmaximummaterialconditionsongivenlengthes.MMVS：最大实体实效状态下的体外作用尺寸MMVS:Exteraleffectsizesinmaximummaterialvirtualcondition.dMV=dmax+tDMV=Dmin-t,13,最大实体实效尺寸Maximummaterialvirtualsize,14,最大实体实效尺寸Maximummaterialvirtualsize,15,5最小实体实效状态（尺寸）Leastmaterialvirtualcondition(Size),LMVC：给定长度上，实际要素处于最小实体状态，且该要素轴线、中心平面的形位误差等于给出公差值时的综合极限状态Thecomprehensivelimitconditionthatactualelementsareinleastmaterialconditionongivenlengthandthegeometricalerrorsofaxisandcentralplaneequaltothegiventolerancevalues.LMVS：最小实体实效状态下的体外作用尺寸ExternalmatingsizesunderleastmaterialvirtualconditiondLV=dmin-tDLV=Dmax+t,L,L,16,4.形状公差（t）与尺寸公差（T）的关系：Therelationshipsbetweengeometricaltolerancesandsizetolerances,最大实体状态时：形状公差tmin=0Wheninmaximummaterialcondition:Formtolerancestmin=0最小实体状态时：形状公差tmax=TWheninleastmaterialcondition:condition:Formtolerancestmax=T,中心轴线Centralaxis垂直度Verticality,17,小结：Summary:,尺寸公差ThTs与形状公差tSizetolerancesThTsandformtolerancest尺寸公差具有双重职能：控制尺寸公差和形状公差Sizetolerancescontaindualfunctions:Controlingsizetolerancesandformtolerances.,dminDmax,dmaxDmin,18,5.最大实体要求应用举例（一）Applicationexamplesofmaximummaterialrequirements(1),该轴应满足下列要求：Thisshaftshouldsatisfythefollowingrequirements:实际尺寸：9.98510Actualsize:边界：实际轮廓不超出最大实体实效边界Boundary:Actualcamdoesntoversteppingmaximummaterialvirtualboundary.dMV=dM+t1=10+0.005=10.005mm即体外作用尺寸：Externalmatingsizedfe10.005,A,10h7,A,0.005M,19,合格条件：Acceptancecondition:轴：dfedMVdmax+t1=10.005Shaft9.985da10,尺寸公差：Ts=0.015Sizetolerance:形状公差：Formtolerance:When:当：dM=dmax=10t=t1=0.005When:当：dL=dmin=9.985t=t1+t2=t1+Ts=0.005+0.015=0.02,直线度Straightness,da,9.985,10（dM）,10.005(dMV),0.005,0.02,-0.3,动态公差图Dynamictolerancechart,20,1.尺寸公差ThTs与形位公差t的关系：TherelationshipsbetweensizetolerancesThTsandgeometricaltolerancest.当Da=Dminda=dmax：允许形位公差t=tmin=t1