第1題Inordertoachieveinterchangeability,thegeometricparametersofthepartswiththesamespecificationsshouldbecompletelyconsistent.第2題Interchangeabilityisproposedformassproduction,andthereisnointerchangeabilityforasinglesmallnumberofparts.第3題InterchangeablepartsshouldbeAsamespecificationsBshapeandsizeareexactlythesameCfitwitheachotherDdifferentspecifications第1題Theroleofinterchangeabilityinmachinerymanufacturinginthedesignaspect:thedrawingandcalculationjobswillbedecreased,andthedesigningtimeissavedandcomputeraideddesigncanbeused.第2題Theroleofinterchangeabilityinmachinerymanufacturinginthemanufactureaspect:largenumbersofstandardmachineelementscanbemade,thendistributionalmanufacturescanbeadoptedandautomaticmanufacturelinescanbeused,resulttothecostofthesestandardmachineelementsislower.1.2.1Standardization第1題Theenterprisestandardislowerthanthenationalstandardlevel,andthestandardrequirementscanbeslightlylowerthanthenationalstandard.第2題Inthenationalstandard.Mandatorystandardsmustbeimplemented,anditdoesnotmatterwhetherrecommendedstandardsareimplementedornot.第3題Amongthefollowingstandardsissuedbyourcountry,()standardhasthehighestgrade.ANationalstandardsBIndustrystandardsCLocalstandardsDEnterprisestandards1.2.2SeriesofPreferredValues第1題Anynumberintheprecedencenumbersystemistheprecedencenumber.第2題Theprioritynumbersystemconsistsofarithmeticsequences,code-namedR.第3題Ifourdesignconstrainsdemandthatthetwoscrewsinourgadgetshouldbeplacedbetween19mmand31mmapart,wemakeit().A19mmB25mmC30mmD40mm2.1GeneralOverview第1題Sizetoleranceandfitareimportantbasicstandardsinmechanicalaccuracydesign.第2題Thefittingwithsmallclearanceorsmallinterferenceisusuallyadoptedtransitionfitting.第3題Theapplicationofholeandshaftfitsisverywide.Indifferentoccasions,therequirementsforfitsaredifferent.2.2SizeofHoleandShaft第1題Fromthebasictermsanddefinitionsoflimitsandfits,holesandaxesonlyrefertocircularones.第2題Allfeaturesindicatedinthemechanicaldrawingaregeometricalfeature.2.3DeviationandTolerance第1題Theillustrationofsizetoleranceintervaliscomposedoffundamentaldeviationcodeandstandardtolerancegrade.第2題Whenselectingtolerancezones,theyshouldbeselectedintheorderofpriority,commonandgeneraltolerancezones.第3題Zerolineinillustrationofsizetoleranceintervalis()AActualsizeBLocalsizeCNominalsizeDLimitsize2.4FitTypesandBasicSystemofFit第1題Holesandshaftsthatfiteachothermustbeofthesamenominalsize.第2題Iftheremaybegapsinthefit,thefitnaturemustbelongtothegapfit.第3題Whentheupperlimitdeviationoftheholeislessthanthelowerlimitdeviationofthematchedaxis,thefitis().AclearancefitBinterferencefitCtransitionfitDuncertain2.5StandardsofTolerancesandFits第1題Thenthetolerancevaluesarerelevanttotwofactors:tolerancegradesandnominalsizes.第2題Whenthenominalsizeisfixed,thecoefficientoftolerancegradeistheonlyparameterthesizeofstandardtolerance.第3題Determinetheaccuracyofthetwosizesthatarenotinthesamesizesegment,accordingtothe()ofthetwosizes.AtolerancegradeBfundamentaldeviationClimitdeviationDactualdeviation2.6FundamentalDeviationSeries第1題Thebasicdeviationvalues,codenamedHandh,areequaltozero.第2題Thebaseholesystemisasysteminwhichthebasicdeviationoftheholeisfixedandvariouscombinationsareformedbychangingthebasicdeviationoftheshaft.第3題Whenthebasicdeviationoftheholeistheupperlimitdeviation,thecalculationformulaforthevalueofthelowerlimitdeviationis().AES=EI+ITBEI=ES+ITCEI=ES-ITDei=es-IT2.7DrawingMarkingForm第1題Thelocationoftoleranceintervalrelativetozerolineisdeterminedbyfundamentaldeviation,andthesizeoftoleranceintervalisdeterminedbystandardtolerancegrade.第2題Thefitsymbolsaremainlymarkedontheassemblydrawing.第3題Marktoleranceintervalsymbolandlimitdeviationvalues,therearedrawingnominalsize,toleranceintervalsymbolandlimitdeviationvalues.2.8StandardizationofToleranceGradeandFit第1題Alargenumberoftolerancegradesofdifferentsizesandlocationscanbeobtainedbycombininganyfundamentaldeviationwithanystandardtolerance.第2題Thestandardsprovidegeneral,commonandprefertoleranceintervalsandcommonpreferfits.第3題Thenationalstandardalsorecommendsthecombinationoftoleranceintervalsymbolsforshaftsandholes.2.9GeneralTolerance第1題Unmarkedtolerancesforlineardimensionsaretolerancesthatareeconomicallypossibletoobtainaccuracyunderordinaryprocessconditionsintheworkshop,sothereisnoneedtospecifytolerancelevels.第2題Thevalueofthelimitdeviationofholeorshaftadoptsthetolerancezonewithsymmetricaldistribution.2.10SelectionofTolerancesandFits第1題Ifmatingwithstandardparts,standardpartsshouldbetakenasdatumpartstodeterminewhetherbasisholesystemorbasisshaftsystemisadopted.第2題Ifthetolerancegradeistoohigh,themanufacturingprocessissimple,andthenthecostincreases.第3題Iftheholeandshafthaverelativemotionrequirements,theclearancefitmustbeselected.3.1GeneralOverview第1題Theprocesssystemerrorcomposedofmachiningtools,fixture,toolandworkpiecewillnotaffectthegeometricerroroftheworkpiece.第2題Theeffectsofthegeometricalerrorsonperformancedoesnotincludethefollowingaspects().AeffectonassemblabilityBeffectonfitpropertiesCeffectonotherfunctionDaestheticcomfortofparts3.2MarkingofGeometricTolerances第1題Ifthetolerancezoneiscircularorcylindrical,addasymbolφbeforethetolerancevalue.Ifthetolerancezoneissphere,addSφbeforethetolerancevalue.第2題Whenthedatumfeatureisacontourlineorsurface,thesmallblackisoscelestriangleofthedatumsymbolisclosetothecontourlineoritsextensionlineofthedatumfeature.第3題Iftolerancesoflocation,orientationorprofileareprescribedforafeatureoragroupoffeatures,thesizesdeterminingthetheoreticallyexactlocation,orientationorprofilerespectivelyarecalledTheoreticallyExactDimension.3.3FormTolerance第1題Dimensionaltolerancelimitsthedeviationofafeaturefromitsgeometricalideallineorsurfaceform.第2題Straightnesstoleranceisusedtolimittheshapeerrorofthestraightlineinplaneorspace.Themeasuredfeaturecanbeaintegralfeatureoraderivedfeature.第3題Formtolerancedoesnotincludewhichofthefollowingparts？AStraightnesstolerancesBFlatnesstolerancesCCircularitytolerancesDParallelismTolerance3.4OrientationTolerance第1題Theorientationtoleranceistheallowablevariationoftherelatedactualfeaturestothedatuminthedirection.第2題Theorientationtolerancezonedoesnothasacleardirectionrelativetothedatumandhasthefunctionofcontrollingthedirectionandshapeofthemeasuredfeatureatthesametime.第3題Thedirectiontoleranceincludeswhichofthefollowingparts？AParallelismTolerancesBPerpendicularityTolerancesCAngularityTolerancesDConcentricityandCoaxialityTolerances正確答案：ABC3.5LocationTolerance第1題Locationtolerancesisrelatedtodatum.第2題Locationtolerancesareusedtolimitthelocationdeviationofrelatedfeaturerespectedtodatum,whichincludecoaxiality(concentricity),symmetryandposition.3.6Run-outTolerance第1題Run-outtoleranceisthemaximumallowablerun-outwhentheactualfeaturerotatesaroundthedatumshaftforonecycleorcontinuously.Therun-outisthedifferencebetweenthemaximumandminimumindicationvalues.第2題Accordingtothemeasuringdirection,thecircularrun-outisdividedintoradialrun-out,axialrun-outandslantrun-out.第3題Thetolerancefeaturesofrun-outtoleranceusuallyarecylindricalsurface,conesurfaceandendplane.Thedatumfeatureisashaft.3.7BasicTermsandDefinitionofTolerancePrinciples第1題Boundaryistheperfectlimitenvelopesurface(cylinderortwoparallelplane)specifiedatdesigning.Thewidthordiameteroftheperfectlimitenvelopesurfaceistheboundarysize.第2題Maximummaterialconditionisthestateoftheconsideredfeatureofsizeinwhichthefeatureiseverywhereatthelimitofsizewherethematerialofthefeatureisatitsmaximum,e.g.minimumholediameterandmaximumshaftdiameter.第3題Maximummaterialvirtualconditionisacollectivestateoftheconsideredfeatureofsizeinwhichthefeatureisatitsmaximummaterialconditionanditsderivedfeaturegeometricaldeviationisequaltoitsgeometricaltolerancespecifiedonengineeringdrawing.3.8IndependencyPrincipleandEnvelopeRequirement第1題Theextractedintegralfeatureshouldnotexceedthemaximummaterialboundary,anditsextractedlocalsizeshouldnotexceedtheleastmaterialsize.第2題Theenveloperequirement,specifiesthatthesurfaceofanindividualfeatureofsizeshouldnotviolatetheimaginaryenvelopeofperfect(geometricalideal)formatmaximummaterialsize.3.9MaximumMaterialRequirement第1題Assemblydependsontheconceptoftherelationshipbetweenthelocalactualsizeofthepartandthegeometricerror,whichisthetheoreticalbasisforestablishing.第2題Whenthemaximummaterialrequirementisappliedtothemeasuredfeature,theactualcannotourofthemeasuredfeatureshouldnotexceedthemaximummaterialvirtualboundaryatanygivenlength.3.10SelectionofGeometricalTolerance第1題Principleofunifyingdatum:thedatumfeaturesshouldbethesamewithfeaturesofdesigningdatum,locationdatumandtheassemblydatum.第2題Theselectionofdatummainlyaccordingtothefunctionanddesignrequirementsofworkpiece,andtheaspectsshouldbeconsideredatthesametimesuchastheprincipleofunifyingdatumandthestructurepropertiesofworkpiece.第3題Followingaspectsshouldnotbeconsideredwhengeometricalcharacteristicsareselected().AStructurepropertiesofworkpiecesBFunctionalrequirementsofworkpiecesCPropertiesofgeometricalcharacteristicsDColoroftheworkpieces4.1BasicConceptofSurfaceRoughness第1題Theformationofsurfaceroughnessismainlyduetothefrictionbetweensurfacesoftoolsandparts,plasticdeformationandmetaltearingduringchipseparation,andhighfrequencyvibrationintheprocessingsystem.第2題Generallyspeaking,therougherthesurface,thegreaterthefrictionalresistanceandtheslowerthewearoftheparts.4.2EvaluationofSurfaceRoughness第1題Thesamplinglengthreferstothelengthinthex-axisdirectionusedtodistinguishtheirregularfeaturesoftheevaluatedprofile.Itisthelengthofadatumlinespecifiedinthemeasurementorevaluationofsurfaceroughness,whichcontainsatleastfiveprofilepeaksandprofilevalleys.第2題Thedirectionofthesamplinglengthlrisconsistentwiththedirectionoftheprofile,thatis,thedirectionofthx-axisisconsistentwiththedirectionofthespacing.第3題Theevaluationlengthisusedtojudgethelengthinthex-axisdirectionoftheevaluatedcontour.Duetotheunevensurf