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外文翻译--发动机冷却系统.doc

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外文翻译--发动机冷却系统.doc

外文翻译11SummarizeOutlineusesamorecompactdesignalongwiththeengineandhasinabigway,theengineproducesthewasteheatdensityalsoobviouslyincreasesalongwithit.Someessentialregions,ifaroundarowoftyrevalveradiatesthequestiontohavefirsttoconsider,thecoolingsystemevenifappearsthesmallbreakdownalsopossiblytocreatethedisasterinsuchregionconsequence.Theenginecoolingsystemradiationabilitygenerallyshouldsatisfywhentheenginefullloadradiationdemand,becausethistimeengineproducesthequantityofheatisbiggest.However,whenpartialloads,thecurrentcapacitywhichthecoolingsystemcanhavethepowerloss,whichthewaterpumpingstationprovidestherefrigerantcurrentcapacitysurpassesneeds.Wehopedstartsthestartingtimetobeasfaraspossibleshort.Becauseenginetimedischargespollutantmore,theoilconsumptionisalsobig.Thecoolingsystemstructurehasamoretremendousinfluencetotheenginecoldstartingtime.2CharacteristicsofmodernenginecoolingsystemModernenginesseriescharacteristictraditioncoolingsystemfunctionreliablyprotectstheengine,butalsoshouldhavethefunctionwhichtheimprovementfueleconomyandreducesdischarges.Therefore,themoderncoolingsystemmustsynthesizeundertheconsiderationthefactorEngineinteriorfrictionlossCoolingsystemwaterpumppowerBurningboundarycondition,likecombustionchambertemperature,completedensity,completetemperature.Theadvancedcoolingsystemusessystematized,themodulardesignmethod,theoverallplanconsideredeachinfluencefactor,causesthecoolingsystembothtoguaranteetheenginenormalwork,andenhancestheengineefficiencyandthereductiondischarges.2.1ThetemperaturessetpointTemperatureshypothesesfiringinburstsmotiveoperatingtemperaturelimitvaluearedecidedbyarowoftirevalvetheperipheralregionmaximumtemperature.Themostidealsituationisaccordingtothemetaltemperaturebutisnottherefrigeranttemperaturecontrolcoolingsystem,likethiscanprotecttheenginewell.Becausethecoolingsystemhypothesiscoolingtemperatureisbythefullloadtimemostisbigisthefoundation,therefore,engineandcoolingsysteminpartialloadstimeisatnottootheperfectcondition,whenurbandistricttravelandlowspeedtravel,canhavethehighoilconsumptionanddischarge.Supposesthefixedpointthroughthechangerefrigeranttemperaturetobepossibletoimprovetheengineandthecoolingsysteminpartialloadstimeperformance.Accordingtoarowoftyrevalvetheperipheralregiontemperaturelimitvalue,mayelevateeitherreducetherefrigerantorthemetaltemperaturesupposesthefixedpoint.Elevatesorreducedtemperatureallrespectivelyhasthecharacteristic,thisisdecidedthegoalwhichachievedtothehope.2.2EnhancesthetemperatureEnhancesthetemperaturetosupposethefixedpointenhancementoperatingtemperaturetosupposethefixedpointisonekindofcomparisonthemethodwhichwelcome.Enhancesthetemperaturetohavemanymerits,itdirectlyaffectstheenginelossandthecoolingsystemeffectaswellastheenginedischargingformation.WillenhancetheoperatingtemperaturetoenhancetheengineMacreducetheenginetorubwears,reducestheenginefueloilconsumption.Theresearchindicatedthat,theengineoperatingtemperaturetorubsthelosstohavetheverytremendousinfluence.Dischargesthetemperaturetherefrigeranttoenhanceto150℃,causesthecylindertemperaturetoelevateto195℃,theoilconsumptiondrops46.Maintainstherefrigeranttemperaturein90115℃scope,causestheenginemachineoilthemaximumtemperatureis140℃,thenoilconsumptioninpartialloadstimedrops10.Enhancestheoperatingtemperaturealsoobviousinfluencecoolingsystemthepotency.Enhancestherefrigerantorthemetaltemperaturecanimprovetheengineanddispersethesteamheattransfertransmissiontheeffect,reducestherefrigerantthespeedofflow,reducesthewaterpumptheratedpower,thusreducestheenginethepowerdissipation.Inaddition,mayselectthedifferentmethod,furtherreducestherefrigerantthespeedofflow.2.3ReducethetemperaturessetpointReducedtemperaturessupposethefixedpointtoreducethecoolingsystemtheoperatingtemperaturetobepossibletoenhancetheenginechargeefficiency,reducestheinlettemperature.Thistothecombustionprocess,thefueloilefficiencyanddischargesadvantageously.Thereducedtemperaturesupposesthefixedpointtobe外文翻译2allowedtosavetheenginemovementcost,enhancesthepartservicelife.Theresearchindicated,ifthecylinderheadtemperaturereducesto50℃,theignitionangleofadvancemay3℃Abutnothavetheengineknockaheadoftime,thechargeefficiencyenhances2,theengineoperationalfactorimprovement,ishelpfultotheoptimizedcompressionratioandtheparameterchoice,obtainsthebetterfueloilefficiencyanddischargestheperformance.2.4PrecisecoolingsystemPrecisecoolingsystemsprecisecoolingsystemmainlymanifestsinthecoolingjacketstructuraldesignandintherefrigerantspeedofflowdesign.Inprecisecoolingsystem,hotessentialarea,ifaroundarowoftyrevalve,therefrigeranthasangreaterspeedofflow,theheattransferefficiencyishigh,therefrigerantgradientoftemperaturechangesslightly.Sucheffectcomesfromtoreducetheseplacerefrigerantchannelsthelateralsection,enhancesthespeedofflow,reducesthecurrentcapacity.Theprecisecoolingsystemdesignkeyliesinthedeterminationcoolingjacketthesize,thechoicematchcoolingwaterpump,guaranteedthesystemtheradiationabilitycansatisfywhenthelowspeedbigloadessentialregionoperatingtemperaturedemand.Theenginerefrigerantspeedofflowrangeofvariationisquitebig,fromtime1m/stomaximumworkratetime5m/s.Thereforeshouldconsideredthecoolingjacketandthecoolingsystemwholethat,mutuallysupplemented,displaybiggestpotential.Theresearchindicatedthat,usestheprecisecoolingsystem,intheengineentireworkrotationalspeedscope,therefrigerantcurrentcapacitymaydrop40.Coversthecoolingjackettotheaircylindertheprecisedesign,maymaketheordinaryspeedofflowtoenhancefrom1.4m/sto4m/s,greatlyenhancesthecylindercoverorcapthermalconductivity,cylindercoverorcapmetaltemperaturedropto60℃.2.5DivergencestypescoolingsystemDivergencestypescoolingsystemdivergencetypecoolingsystemforotheronekindofcoolingsystem.Inthiskindofcoolingsystem,thehineoiltemperature,willcylindercoverorcapfriendlycylinderbodycoolsbyrespectivereturnroute,thecylindercoverorcapfriendlycylinderbodyhasthedifferenttemperature.Thedivergencelikecoolingsystemhastheuniquesuperiority,maycauseengineeachparttosupposethefixedpointworkatthemostsuperiortemperature.Thecoolingsystemoverallefficiencyachievesinabigway.Eachcoolingreturnroutewillsupposeunderthefixedpointorthespeedofflowinthedifferentcoolingtemperatureworks,willcreatetheidealenginetemperaturedistribution.Theidealenginehotactivestatusisthecylinderheadtemperaturelowerbuttheaircylinderbodytemperaturerelativeishigher.Thecylinderheadtemperatureislowermayenhancethechargeefficiency,increases.Thetemperatureislowalsogreatlymaypromotecompletelytoburn,reducesCO,HCandtheNOxformation,alsoenhancestheoutput.Thehigheraircylinderbodytemperaturecanreducethefrictiontolose,directlyimprovesthefueloilefficiency,indirectlyreducesinthecylinderthepeakvaluepressureandthetemperature.Thedivergencetypecoolingsystemmaycausethecylindercoverandthecylinderbodytemperaturediffers100℃.Thecylindertemperaturemayreachashighas150℃,butthecylindercovertemperaturemayreduce50℃,reducesthecylinderbodytorubloses,reducestheoilconsumption.Thehighercylinderbodytemperaturecausestheoilconsumptiontoreduce46,whenpartialloadsHCreduces2035.Whenthedamperallopens,thecylindercoverandthecylinderbodytemperaturesupposesthedefinitevaluetobepossibletomoveto50℃and90℃,improvesthefueloilconsumption,thepoweroutputfromthewholeanddischarges.2.6ControllablecoolingsystemControllableenginecoolingsystemtraditionenginecoolingsystembelongstothepassiveform,thestructuresimpleorthecostislow.Thecontrollablecoolingsystemmaymakeupatpresentcoolingsystemtheinsufficiency.Nowthecoolingsystemdesignstandardsolvestimethefullloadradiationproblem,thuspartiallyshoulderstimetheoversizedradiationabilitywillcausetheenginepowerwaste.Thistothelightvehiclesaidespeciallyobvious,thesevehiclesmajoritytimeallunderthepartialloadsgointheurbandistrict,onlyusesthepartialenginepower,causesacoolingsystemhigherloss.Inordertosolvetheenginetogetdownthehotquestioninthepeculiarcircumstance,thepresentcoolingsystemvolumewasbigger,causestheevaporationefficiencytoreduce,hasincreasedthecoolingsystempowerdemand,lengthenedtheengine外文翻译3duringwarmmachinehour.Thecontrollableenginecoolingsystemgenerallyincludesthesensor,theexecutionandtheelectricallycontrolledmodule.Thecontrollablecoolingsystemcanactaccordingtotheengineworkingconditionadjustmentcoolingquantity,reducestheenginepowerloss.Inthecontrollablecoolingsystem,theexecutionforthecoolingwaterpumpandthethermostat,generallyandthecontrolvalveiscomposedbytheelectricallyoperatedwaterpump,mayactaccordingtorequeststoadjustthecoolingquantity.Temperaturesensorforasystempart,butrapidlybequeathstheenginehotconditionthecontroller.Controllableinstallment,iftheelectricallyoperatedwaterpump,maysupposethetemperaturethefixedpointfrom90℃toenhanceto110℃,saves25fueloil,COreduces20,HCreduces10.Whensteadystate,themetaltemperatureratiotraditioncoolingsystemishigh10℃,thecontrollablecoolingsystemhasthequickerresponseability,maycoolthetemperaturetomaintainissupposingthefixedpoint±2℃thescope.From110℃dropsto100℃onlyneeds2s.Theengineduringwarmmachinehourreduces200s,thecoolingsystemoperatingregiondrawsclosetotheworklimitregion,canreducetheenginecoolingtemperatureandthemetaltemperatureundulationscope,reducescirculatesthefatigueofmetalwhichthehotloadcreates,lengthensthecomponentlife.3ConclusionInfrontof3conclusionsintroducedseveralkindofadvancedcoolingsystemshavetheimprovementcoolingsystemperformancethepotential,canenhancethefueloilefficiencyanddischargetheperformance.Thecoolingsystemcancontrolthenatureisimprovesthecoolingsystemthekey,canthecontrollingexpressiontotheenginestructureprotectionessentialparameter,likethemetaltemperature,therefrigeranttemperatureandthemachineoiltemperatureandsooncancontrol,guaranteestheenginetoworkinthesafetymarginscope.Thecoolingsystemcanmaketherapidreactiontothedifferentoperatingmode,themostearthsavesthefuel,reducesdischarges,butdoesnotaffecttheengineoverallperformance.Lookedfromthedesignandtheoperationalperformanceanglethat,divergencetypecoolingandprecisecoolingunifieshastheverygoodprospectsfordevelopment,bothcanprovidetheidealengineprotection,andcanenhancethefueloilefficiencyanddischargethenature.Thiskindofstructureisadvantageoustoformingtheengineidealtemperaturedistribution.Directlytoacylindercoverorcaprowoftyrevalvearoundthesuppliesrefrigerant,reducedthecylinderheadtemperaturechange,causesthecylindercovertemperaturedistributiontobeevener,alsocanmaintainsthemachineoilandthecylinderbodytemperatureatthedesignoperatingregion,hasalowerfrictiontodamagethepollutionwithdrawal.■coolingsystemfunctionandmaintenancemaintenancemethodasfollows1st,thecoolingsystemfunction,ispartofquantityofheatswhichabsorbstheenginepartcarriesoff,guaranteedthedieselenginevariouscomponentsmaintaininthenormaltemperaturerange.2nd,thecoolingwatershouldbedoesnotcontaindissolvestheXiesaltthesoftwater,likecleanriverwater,rainwaterandsoon.Donotusehardwaterandsoonthewellwater,waterseepageorseawater,guardsagainstproduces,causestheenginetoradiatenotgood,questionoccurrenceandsoonaircylinderheat.3rd,withthefunnelwhenjoinsthecoolingwaterthewatertank,mustpreventthewatersplashestoontheengineandtheradiator,preventedontheradiatorfinandtheorganismaccumulatesthedust,smears,affectsthecoolingeffect.4th,ifwhentheenginelacksthewatercausesthehyperpyrexia,cannotimmediatelyaddwater,shouldcausetheengineidlingspeedtorevolve10□15minutes,aftertheuniformtemperatureslightlyreduces,slowlydoesnotjointhecoolingwaterintheenginesituation.5th,thewinter,thewatertankplantedagentaddsthehotwater.Afterthestartshouldsurpass40degreehourtheslowrevolutiontothewatertemperaturetobeabletowork.Aftertheworkhadended,mustputthecompletelycoolingwater.6th,mustregularlyeliminateinthewatertank,mustfrequentlyscourthesludgetotheforcedaircoolingengineradiatorfin,dirtyisfilthy.Theradiatorfincannotdamage,afterifdamagesmustpromptlyreplace,inordertoavoidinfluenceradiationeffect.4Lathes外文翻译4Lathesaremachinetoolsdesignedprimarilytodoturning,facingandboring,Verylittleturningisdoneonothertypesofmachinetools,andnonecandoitwithequalfacility.Becauselathesalsocandodrillingandreaming,theirversatilitypermitsseveraloperationstobedonewithasinglesetupoftheworkpiece.Consequently,morelathesofvarioustypesareusedinmanufacturingthananyothermachinetool.Theessentialcomponentsofalathearethebed,headstockassembly,tailstockassembly,andtheleadscrewandfeedrod.Thebedisthebackboneofalathe.Itusuallyismadeofwellnormalizedoragedgrayornodularcastironandprovidessheavy,rigidframeonwhichalltheotherbasiccomponentsaremounted.Twosetsofparallel,longitudinalways,innerandouter,arecontainedonthebed,usuallyontheupperside.SomemakersuseaninvertedVshapeforallfourways,whereasothersutilizeoneinvertedVandoneflatwayinoneorbothsets,Theyareprecisionmachinedtoassureaccuracyofalignment.Onmostmodernlathesthewayaresurfacehardenedtoresistwearandabrasion,butprecautionshouldbetakeninoperatingalathetoassurethatthewaysarenotdamaged.Anyinaccuracyinthemusuallymeansthattheaccuracyoftheentirelatheisdestroyed.Theheadstockismountedinafoxedpositionontheinnerways,usuallyattheleftendofthebed.Itprovidesapoweredmeansofrotatingthewordatvariousspeeds.Essentially,itconsistsofahollowspindle,mountedinaccuratebearings,andasetoftransmissiongearssimilartoatrucktransmissionthroughwhichthespindlecanberotatedatanumberofspeeds.Mostlathesprovidefrom8to18speeds,usuallyinageometricratio,andonmodernlathesallthespeedscanbeobtainedmerelybymovingfromtwotofourlevers.Anincreasingtrendistoprovideacontinuouslyvariablespeedrangethroughelectricalormechanicaldrives.Becausetheaccuracyofalatheisgreatlydependentonthespindle,itisofheavyconstructionandmountedinheavybearings,usuallypreloadedtaperedrollerorballtypes.Thespindlehasaholeextendingthroughitslength,throughwhichlongbarstockcanbefed.Thesizeofmaximumsizeofbarstockthatcanbemachinedwhenthematerialmustbefedthroughspindle.Thetailsticdassemblyconsists,essentially,ofthreeparts.Alowercastingfitsontheinnerwaysofthebedandcanslidelongitudinallythereon,withameansforclampingtheentireassemblyinanydesiredlocation,Anuppercastingfitsontheloweroneandcanbemovedtransverselyuponit,onsometypeofkeyedways,topermitaligningtheassemblyisthetailstockquill.Thisisahollowsteelcylinder,usuallyabout51to76mm2to3inchesindiameter,thatcanbemovedseveralincheslongitudinallyinandoutoftheuppercastingbymeansofahandwheelandscrew.Thesizeofalatheisdesignatedbytwodimensions.Thefirstisknownastheswing.Thisisthemaximumdiameterofworkthatcanberotatedonalathe.Itisapproximatelytwicethedistancebetweenthelineconnectingthelathecentersandthenearestpointontheways,Thesecondsizedimensionisthemaximumdistancebetweencenters.Theswingthusindicatesthemaximumworkpiecediameterthatcanbeturnedinthelathe,whilethedistancebetweencentersindicatesthemaximumlengthofworkpiecethatcanbemountedbetweencenters.Enginelathesarethetypemostfrequentlyusedinmanufacturing.Theyareheavydutymachinetoolswithallthecomponentsdescribedpreviouslyandhavepowerdriveforalltoolmovementsexceptonthecompoundrest.Theycommonlyrangeinsizefrom305to610mm12to24inchesswingandfrom610to1219mm24to48inchescenterdistances,butswingsupto1270mm50inchesandcenterdistancesupto3658mm12feetarenotuncommon.Mosthavechippansandabuiltincoolantcirculatingsystem.Smallerenginelatheswithswingsusuallynotover330mm13inches–alsoareavailableinbenchtype,designedforthebedtobemountedonabenchonabenchorcabinet.Althoughenginelathesareversatileandveryuseful,becauseofthetimerequiredforchangingandsettingtoolsandformakingmeasurementsontheworkpiece,thyarenotsuitableforquantityproduction.Oftentheactualchipproductiontineislessthan30ofthetotalcycletime.Inaddition,askilledmachinistisrequiredforalltheoperations,andsuchpersonsarecostlyandofteninshortsupply.However,muchoftheoperatorstimeisconsumedbysimple,repetitiousadjustmentsandinwatchingchipsbeingmade.Consequently,toreduceoreliminatetheamountofskilledlaborthatisrequired,turretlathes,screwmachines,

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