雨课堂学堂在线学堂云Interchangeability and Measurement Technology(长安大学)单元测试考核答案

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