外文翻譯--凸輪.doc

6.附錄：6.1英文原文CamsVariousmotionscanbeproducedbytheactionofacamagainstafollower.Mamytimingdevicesareoperatedbycanaction.Thepurposeofandycamistoproduceadisplacementofitsfollower；asecondaryfollowerisoften.usedtoproduceadditionaldisplacementinanotherlocation.Themostpopulartypeistheplatecam.Thecylindricaltypeisusedtotransmitlinearmotiontoafollowerasthecamrotates.Three-dimensionalcamaresometimesused；theseprovidesomeunusualfollowermotions,butalsomakefollowerdesigndifficult.Thecamshaftintheautomotiveengineillustratesasimplebutimportantapplicationofalatecam.Thecamassembliesinautomaticrecordplayersillustrateasomewhatmorecomplexapplication.Camprofilesareaccuratelyconstructedbyeitherpraphicalormathematicalmethods.Thetransitiomfromdevelopmentdrawingstoworking(shop)drawingcanbemadeinseveralways:1.Makeafull-scaletemplate.Thisisdesirablefromthemanufacturingstandpoint,butitwillnotguaranteeaccuratecamprofiles.2.Useradialdimensions.Thisisfairlyaccurate,butsometimesproduceslayoutproblemsintheshop.3.Usecoordinatedimensioning.Thisprocedurewillensureaccuracy.Inselecringoneofthesemethods,oneshouldconsiderthefunctionofthecamintermsofdesiredpreciseness.Becausethecamworkoutlinealreadydetermined,thereforethecamstructuraldesignmainlywasdeterminesthecurveoutlineaxialthicknessandthecamandthedriveshaftconnectionway.Whentheworkloadcomparesthehour,curveoutlineaxialthicknessgenerallytakesfortheoutlinecurvebiggestradiusofvector1,/10/5；Regardingastressbiggerimportantsituation,mustwithcarryonthedesignaccordingtothecamcontoursurfacefromthecontactintensity.Whendeterminationcamanddriveshaftjointway,shouldsynthesizetheconsiderationcamtheassemblinganddismantling,theadjustmentandfirmlygradesthequestion.Regardingimplementingagencymoreequipment,betweenitseachexecutioncomponentmovementcoordinationusuallydeterminedbythecycleofmotionchart,thereforeinassemblycamgeartime,thecamcontourcurveinitialstation(pushesregulationstarts)therelativepositiontohaveaccordingtothecycleofmotioncharttocarryontheadjustment,guaranteeseachexecutioncomponenttobeableaccordingtothepre-setsequencesynchronizedaction.Therefore,requeststhecaminthestructuraldesigntobeabletobeoppositetothedriveshaftcarriesontherotationalongthecircumferencedirection,andreliablyperformsfixedly.Thesimplestmethodusestheclampingscrewnailfixedcam,orwithclampingscrewnailpre-fixed,aftertreatsadjustsusesthepintobefixedagain.Fromstructuraldesign:fromstructure:Whendesignmustconsiderfromtheguidanceandpreventedrevolves.Frommovementruledesign:Involvesmanyaspectsfromthemovementruledesignthequestions,besidesconsiderationrigidityimpactandflexibleimpact,butalsoshouldmaximumspeedvmaxwhichhastoeachkindofmovementrule,maximumaccelerationamaxanditstheinfluenceperformsthecomparison.1)vmaxbigger,thenmomentummvisbigger.Iffromissuddenlyprevented,theoversizedmomentumcancausetheenormousimpulse,endangerstheequipmentandthepersonalsafety.Therefore,whenisbiggerfromthequality,inordertoreducethemomentum,shouldchoosethevmaxvaluesmallermovementrule.2)amaxbigger,isbigger.Functioninhighvice-contactplacestressbigger,theorganizationintensityandthewearresistantrequestisalsohigher.Regardinghighspeedcam,inordertoreducetheharm,shouldchoosetheamaxvaluesmallermovementrule.Firststatesseveralkindofmovementsrulesvmax,amax,theimpactcharacteristicandthesuitablesituationfollowingtableregardingswingsfromthecamgear,itsmovementgraphx-coordinateexpressioncamcorner,y-coordinatethenseparatelyexpressesfrom,angularspeedandangleacceleration.Thiskindofmovementgraphhasthestateofmotionandaboveissame.Fromstructuraldesign:fromstructure:Whendesignmustconsiderfromtheguidanceandpreventedrevolves.Frommovementruledesign:Thecamgeardesignbasicquestion1.camgearstypechoice,thedefinitecamshape,withfrommaintainsthehighvice-contactfromtheshapeandthemovementformandthecamtheway2.fromthemovementruledesign,accordingtotheapplicationsituationtofromthetravellingscheduleandthestateofmotionrequest,determinesfromthemovementrule.3.camgearsbasicparameterdesign,determinesfromthetravellingschedule,variousmovementsangle,thecamradius,therollerradius,thecenterdistance,fromthelengthandsoon.4.camcontourscurvedesign.5.camgearsbearingcapacitycomputation.6.camgearsstructuraldesign,planorganizationassemblydrawingandvariouscomponentsshopdrawingFromstructuraldesign:fromstructure:Whendesignmustconsiderfromtheguidanceandpreventedrevolves.Frommovementruledesign:Thecamgeardesignbasicquestion1.camgearstypechoice,thedefinitecamshape,withfrommaintainsthehighvice-contactfromtheshapeandthemovementformandthecamtheway2.fromthemovementruledesign,accordingtotheapplicationsituationtofromthetravellingscheduleandthemovement1,thecamgearapplicationcamgearisincludesthecamthehighvice-organization,thecamgearhasthestructuretobesimple,mayaccuratelyrealizerequestmeritandsoonmovementrule,thusobtainsthewidespreadapplicationintheindustrialproduction,speciallyautomaticdeviceandintheautomaticcontroldevice,obtainsthewidespreadapplication.2nd,thecamgearclassificationaccordingtotwomovestherelativemotioncharacteristicclassificationbetweenthecomponent(1)theplanecamgear1)thediskcam；2)translationcam.(2)spacecamgearaccordingtofrommovementvice-elementshapeclassification(1)apexfrom；(2)rollerfrom(3)flatbasefrom.Note:Classifiesthispartofcontentwhentheintroductioncamgear,shouldpointouteachkindofcamgearthegoodandbadpointsanditstheadaptionsituation,showedeachkindofcamgeartheinnerlink,willbuildthefoundationforthelatertranslationcamandthecolumncamcontourdesign.3rd,thethrowoutlevermovementrule(1)thecamgearcycleofmotionandthebasictermterminologypushtheregulationmovementangle:Withfrompushesthecamcornerwhichtheregulationcorresponds；Farstopstheangle:Withfromfarreststhecamcornerwhichtheregulationcorresponds；Returntripmovementangle:Withcamcornerwhichcorrespondsfromthereturntrip；Nearlystopstheangle:Withfromnearlyreststhecamcornerwhichtheregulationcorresponds；Cam:Takethecamaxlecenterasthecenterofacircle,takeitsoutlineslightlytodiameterr0astheradiuscircle；Fromravellingschedule:Inpushesintheregulationorthereturntripfromthebiggestdisplacement,indicatedwithh；:Thecamcenterofrotationwithfromguideswaythebiasdistance,indicatedwithe.TypesofCamsPlatecamsaresimpletofabricate.Thefollowercanbemovedinvariouspatternswithvariousrise/fallratios.Motionshouldbecontrolledtoavoidabruptchangesinforcetransmittedfromthecamtothefollower.Oneshouldcarefullydeterminehorizontalforcecomponents,sincethesepresentproblemsdesigningthefollowerassemblyguide.CriticalreactionsoccuratpointsAandB.Thesereactionvaluesmustbecomputed.TherelativeverticalpositionofpointAwithrespecttoBneedstoberaisedifthereactionvalueatBisexcessive.ThepositionofBshouldbeasclosetocamaspossibletominimizeflexureintheroller-followersupport.Thistypeproducesreciprocatingmotioninthefollower.Again,dorcesneedtobedeterminedanddimensionschosensoastoavoidexcessivecomponentsizes.Ataperedrollerfollowerisfrequentlyemployed；thegrooveintheperipheryofthecamshouldbeshapedtoaccommodatethefollower.Thistypeofcamisexpensivetoproduce.The