互换性与测量技术汉英双语资料.ppt

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1、Tolerancesandfits.Thisbookincludestablesandcalculationsforeasyoptionoffitsofmachinepartsanddeterminationoftheirdimensionaltolerancesanddeviations.Usingthistoolthefollowingtaskscanbesolved:Selectionofsuitablefitsofmachinepartsaccordingtotheinternationalstanda

2、rdISO286.DeterminationofdimensionaltolerancesanddeviationsofmachinepartsaccordingtotheinternationalstandardISO286.SelectionofpreferredfitsofmachinepartsanddeterminationoftheirdimensionaltolerancesanddeviationsaccordingtoANSIB4.1.Determinationofnon-prescribed

3、limitdeviationsoflinearandangulardimensionsaccordingtoISO2768.Automaticdesignofafitforthegivenclearanceorfitinterferencerespectively.Basicterms.Itisnecessarythatthedimensions,shapeandmutualpositionofsurfacesofindividualpartsofmechanicalengineeringproductsare

4、keptwithinacertainaccuracytoachievetheircorrectandreliablefunctioning.Routineproductionprocessesdonotallowmaintenance(ormeasurement)ofthegivengeometricalpropertieswithabsoluteaccuracy.:Actualsurfacesoftheproducedpartsthereforedifferfromidealsurfacesprescribe

5、dindrawings.Deviationsofactualsurfacesaredividedintofourgroupstoenableassessment,prescriptionandcheckingofthepermittedinaccuracyduringproductionDimensionaldeviationsShapedeviationsPositiondeviationsSurfaceroughnessdeviationsMoreTerminology•NominalSize-Genera

6、lidentificationinfractions(ex.1-1/2for1.500).•BasicSize-Generalidentificationindecimal(ex.1.500).[d=D...basicsize]•ActualSize-Measuredsize.Limits-Maximumandminimumsizesindicatedbythetolerancedimensions.[Dmax,Dmin...limitsofsizeforthehole][dmax,dmin...limitso

7、fsizefortheshaft]ES...holeupperdeviation EI...holelowerdeviationes...shaftupperdeviationei...shaftlowerdeviationES=Dmax-DEI=Dmin-Des=dmax-dei=dmin-dToleranceisthetotalamountaspecificdimensionispermittedtovary(differencebetweenthemaximumandminimumlimits).•Th=

8、Dmax-Dmin=ES-EITs=dmax-dmin=es-eies=14.996-15=-0.004ei=14.993-15=-0.007Ts=dmax-dmin=es-ei=0.003Thedimensionbelowhasatoleranceof0.003MaximumMaterialCondition•Whenspecifyingtolerancedimensions,the