外文翻译--发动机冷却系统.doc

外文翻译-1-1SummarizeOutlineusesamorecompactdesignalongwiththeengineandhasinabigway,theengineproducesthewasteheatdensityalsoobviouslyincreasesalongwithit.Someessentialregions,ifaroundarowoftyrevalveradiatesthequestiontohavefirsttoconsider,thecoolingsystemevenifappearsthesmallbreakdownalsopossiblytocreatethedisasterinsuchregionconsequence.Theenginecoolingsystemradiationabilitygenerallyshouldsatisfywhentheenginefullloadradiationdemand,becausethistimeengineproducesthequantityofheatisbiggest.However,whenpartialloads,thecurrentcapacitywhichthecoolingsystemcanhavethepowerloss,whichthewaterpumpingstationprovidestherefrigerantcurrentcapacitysurpassesneeds.Wehopedstartsthestartingtimetobeasfaraspossibleshort.Becauseenginetimedischargespollutantmore,theoilconsumptionisalsobig.Thecoolingsystemstructurehasamoretremendousinfluencetotheenginecoldstartingtime.2CharacteristicsofmodernenginecoolingsystemModernenginesseriescharacteristictraditioncoolingsystemfunctionreliablyprotectstheengine,butalsoshouldhavethefunctionwhichtheimprovementfueleconomyandreducesdischarges.Therefore,themoderncoolingsystemmustsynthesizeundertheconsiderationthefactor:Engineinteriorfrictionloss；Coolingsystemwaterpumppower；Burningboundarycondition,likecombustionchambertemperature,completedensity,completetemperature.Theadvancedcoolingsystemusessystematized,themodulardesignmethod,theoverallplanconsideredeachinfluencefactor,causesthecoolingsystembothtoguaranteetheenginenormalwork,andenhancestheengineefficiencyandthereductiondischarges.2.1ThetemperaturessetpointTemperatureshypothesesfiringinburstsmotiveoperatingtemperaturelimitvaluearedecidedbyarowoftirevalvetheperipheralregionmaximumtemperature.Themostidealsituationisaccordingtothemetaltemperaturebutisnottherefrigeranttemperaturecontrolcoolingsystem,likethiscanprotecttheenginewell.Becausethecoolingsystemhypothesiscoolingtemperatureisbythefullloadtimemostisbigisthefoundation,therefore,engineandcoolingsysteminpartialloadstimeisatnottootheperfectcondition,whenurbandistricttravelandlowspeedtravel,canhavethehighoilconsumptionanddischarge.Supposesthefixedpointthroughthechangerefrigeranttemperaturetobepossibletoimprovetheengineandthecoolingsysteminpartialloadstimeperformance.Accordingtoarowoftyrevalvetheperipheralregiontemperaturelimitvalue,mayelevateeitherreducetherefrigerantorthemetaltemperaturesupposesthefixedpoint.Elevatesorreducedtemperatureallrespectivelyhasthecharacteristic,thisisdecidedthegoalwhichachievedtothehope.2.2EnhancesthetemperatureEnhancesthetemperaturetosupposethefixed-pointenhancementoperatingtemperaturetosupposethefixedpointisonekindofcomparisonthemethodwhichwelcome.Enhancesthetemperaturetohavemanymerits,itdirectlyaffectstheenginelossandthecoolingsystemeffectaswellastheenginedischargingformation.WillenhancetheoperatingtemperaturetoenhancetheengineMacreducetheenginetorubwears,reducestheenginefueloilconsumption.Theresearchindicatedthat,theengineoperatingtemperaturetorubsthelosstohavetheverytremendousinfluence.Dischargesthetemperaturetherefrigeranttoenhanceto150,causesthecylindertemperaturetoelevateto195,theoilconsumptiondrops4%-6%.Maintainstherefrigeranttemperaturein90-115scope,causestheenginemachineoilthemaximumtemperatureis140,thenoilconsumptioninpartialloadstimedrops10%.Enhancestheoperatingtemperaturealsoobviousinfluencecoolingsystemthepotency.Enhancestherefrigerantorthemetaltemperaturecanimprovetheengineanddispersethesteamheattransfertransmissiontheeffect,reducestherefrigerantthespeedofflow,reducesthewaterpumptheratedpower,thusreducestheenginethepowerdissipation.Inaddition,mayselectthedifferentmethod,furtherreducestherefrigerantthespeedofflow.2.3ReducethetemperaturessetpointReducedtemperaturessupposethefixedpointtoreducethecoolingsystemtheoperatingtemperaturetobepossibletoenhancetheenginechargeefficiency,reducestheinlettemperature.Thistothecombustionprocess,thefueloilefficiencyanddischargesadvantageously.Thereducedtemperaturesupposesthefixedpointtobe外文翻译-2-allowedtosavetheenginemovementcost,enhancesthepartservicelife.Theresearchindicated,ifthecylinderheadtemperaturereducesto50,theignitionangleofadvancemay3Abutnothavetheengineknockaheadoftime,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.Thedivergence-likecoolingsystemhastheuniquesuperiority,maycauseengineeachparttosupposethefixed-pointworkatthemostsuperiortemperature.Thecoolingsystemoverallefficiencyachievesinabigway.Eachcoolingreturnroutewillsupposeunderthefixedpointorthespeedofflowinthedifferentcoolingtemperatureworks,willcreatetheidealenginetemperaturedistribution.Theidealenginehotactivestatusisthecylinderheadtemperaturelowerbuttheaircylinderbodytemperaturerelativeishigher.Thecylinderheadtemperatureislowermayenhancethechargeefficiency,increases.Thetemperatureislowalsogreatlymaypromotecompletelytoburn,reducesCO,HCandtheNOxformation,alsoenhancestheoutput.Thehigheraircylinderbodytemperaturecanreducethefrictiontolose,directlyimprovesthefueloilefficiency,indirectlyreducesinthecylinderthepeakvaluepressureandthetemperature.Thedivergencetypecoolingsystemmaycausethecylindercoverandthecylinderbodytemperaturediffers100.Thecylindertemperaturemayreachashighas150,butthecylindercovertemperaturemayreduce50,reducesthecylinderbodytorubloses,reducestheoilconsumption.Thehighercylinderbodytemperaturecausestheoilconsumptiontoreduce4%-6%,whenpartialloadsHCreduces20%-35%.Whenthedamperallopens,thecylindercoverandthecylinderbodytemperaturesupposesthedefinitevaluetobepossibletomoveto50and90,improvesthefueloilconsumption,thepoweroutputfromthewholeanddischarges.2.6ControllablecoolingsystemControllableenginecoolingsystemtraditionenginecoolingsystembelongstothepassiveform,thestructuresimpleorthecostislow.Thecontrollablecoolingsystemmaymakeupatpresentcoolingsystemtheinsufficiency.Nowthecoolingsystemdesignstandardsolvestimethefullloadradiationproblem,thuspartiallyshoulderstimetheoversizedradiationabilitywillcausetheenginepowerwaste.Thistothelightvehiclesaidespeciallyobvious,thesevehiclesmajoritytimeallunderthepartialloadsgointheurbandistrict,onlyusesthepartialenginepower,causesacoolingsystemhigherloss.Inordertosolvetheenginetogetdownthehotquestioninthepeculiarcircumstance,thepresentcoolingsystemvolumewasbigger,causestheevaporationefficiencytoreduce,hasincreasedthecoolingsystempowerdemand,lengthenedtheengine外文翻译-3-duringwarmmachine-hour.Thecontrollableenginecoolingsystemgenerallyincludesthesensor,theexecutionandtheelectricallycontrolledmodule.Thecontrollablecoolingsystemcanactaccordingtotheengineworkingconditionadjustmentcoolingquantity,reducestheenginepowerloss.Inthecontrollablecoolingsystem,theexecutionforthecoolingwaterpumpandthethermostat,generallyandthecontrolvalveiscomposedbytheelectricallyoperatedwaterpump,mayactaccordingtorequeststoadjustthecoolingquantity.Temperaturesensorforasystempart,butrapidlybequeathstheenginehotconditionthecontroller.Controllableinstallment,iftheelectricallyoperatedwaterpump,maysupposethetemperaturethefixedpointfrom90toenhanceto110,saves2%-5%fueloil,COreduces20%,HCreduces10%.Whensteadystate,themetaltemperatureratiotraditioncoolingsystemishigh10,thecontrollablecoolingsystemhasthequickerresponseability,maycoolthetemperaturetomaintainissupposingthefixedpoint±2thescope.From110dropsto100onlyneeds2s.Theengineduringwarmmachine-hourreduces200s,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.coolingsystemfunctionandmaintenancemaintenancemethodasfollows:1st,thecoolingsystemfunction,ispartofquantityofheatswhichabsorbstheenginepartcarriesoff,guaranteedthedieselenginevariouscomponentsmaintaininthenormaltemperaturerange.2nd,thecoolingwatershouldbedoesnotcontaindissolvestheXiesaltthesoftwater,likecleanriverwater,rainwaterandsoon.Donotusehardwaterandsoonthewellwater,waterseepageorseawater,guardsagainstproduces,causestheenginetoradiatenotgood,questionoccurrenceandsoonaircylinderheat.3rd,withthefunnelwhenjoinsthecoolingwaterthewatertank,mustpreventthewatersplashestoontheengineandtheradiator,preventedontheradiatorfinandtheorganismaccumulatesthedust,smears,affectsthecoolingeffect.4th,ifwhentheenginelacksthewatercausesthehyperpyrexia,cannotimmediatelyaddwater,shouldcausetheengineidlingspeedtorevolve1015minutes,aftertheuniformtemperatureslightlyreduces,slowlydoesnotjointhecoolingwaterintheenginesituation.5th,thewinter,thewatertankplantedagentaddsthehotwater.Afterthestartshouldsurpass40degree-hourtheslowrevolutiontothewatertemperaturetobeabletowork.Aftertheworkhadended,mustputthecompletelycoolingwater.6th,mustregularlyeliminateinthewatertank,mustfrequentlyscourthesludgetotheforced-aircoolingengineradiatorfin,dirtyisfilthy.Theradiatorfincannotdamage,afterifdamagesmustpromptlyreplace,inordertoavoidinfluenceradiationeffect.4Lathes外文翻译-4-Lathesaremachinetoolsdesignedprimarilytodoturning,facingandboring,Verylittleturningisdoneonothertypesofmachinetools,andnonecandoitwithequalfacility.Becauselathesalsocandodrillingandreaming,theirversatilitypermitsseveraloperationstobedonewithasinglesetupoftheworkpiece.Consequently,morelathesofvarioustypesareusedinmanufacturingthananyothermachinetool.Theessentialcomponentsofalathearethebed,headstockassembly,tailstockassembly,andtheleadscrewandfeedrod.Thebedisthebackboneofalathe.Itusuallyismadeofwellnormalizedoragedgrayornodularcastironandprovidessheavy,rigidframeonwhichalltheotherbasiccomponentsaremounted.Twosetsofparallel,longitudinalways,innerandouter,arecontainedonthebed,usuallyontheupperside.SomemakersuseaninvertedV-shapeforallfourways,whereasothersutilizeoneinvertedVandoneflatwayinoneorbothsets,Theyareprecision-machinedtoassureaccuracyofalignment.Onmostmodernlathesthewayaresurface-hardenedtoresistwearandabrasion,butprecautionshouldbetakeninoperatingalathetoassurethatthewaysarenotdamaged.Anyinaccuracyinthemusuallymeansthattheaccuracyoftheentirelatheisdestroyed.Theheadstockismountedinafoxedpositionontheinnerways,usuallyattheleftendofthebed.Itprovidesapoweredmeansofrotatingthewordatvariousspeeds.Essentially,itconsistsofahollowspindle,mountedinaccuratebearings,andasetoftransmissiongears-similartoatrucktransmissionthroughwhichthespindlecanberotatedatanumberofspeeds.Mostlathesprovidefrom8to18speeds,usuallyinageometricratio,andonmodernlathesallthespeedscanbeobtainedmerelybymovingfromtwotofourlevers.Anincreasingtrendistoprovideacontinuouslyvariablespeedrangethroughelectricalormechanicaldrives.Becausetheaccuracyofalatheisgreatlydependentonthespindle,itisofheavyconstructionandmountedinheavybearings,usuallypreloadedtaperedrollerorballtypes.Thespindlehasaholeextendingthroughitslength,throughwhichlongbarstockcanbefed.Thesizeofmaximumsizeofbarstockthatcanbemachinedwhenthematerialmustbefedthroughspindle.Thetailsticdassemblyconsists,essentially,ofthreeparts.Alowercastingfitsontheinnerwaysofthebedandcanslidelongitudinallythereon,withameansforclampingtheentireassemblyinanydesiredlocation,Anuppercastingfitsontheloweroneandcanbemovedtransverselyuponit,onsometypeofkeyedways,topermitaligningtheassemblyisthetailstockquill.Thisisahollowsteelcylinder,usuallyabout51to76mm(2to3inches)indiameter,thatcanbemovedseveralincheslongitudinallyinandoutoftheuppercastingbymeansofahandwheelandscrew.Thesizeofalatheisdesignatedbytwodimensions.Thefirstisknownastheswing.Thisisthemaximumdiameterofworkthatcanberotatedonalathe.Itisapproximatelytwicethedistancebetweenthelineconnectingthelathecentersandthenearestpointontheways,Thesecondsizedimensionisthemaximumdistancebetweencenters.Theswingthusindicatesthemaximumworkpiecediameterthatcanbeturnedinthelathe,whilethedistancebetweencentersindicatesthemaximumlengthofworkpiecethatcanbemountedbetweencenters.Enginelathesarethetypemostfrequentlyusedinmanufacturing.Theyareheavy-dutymachinetoolswithallthecomponentsdescribedpreviouslyandhavepowerdriveforalltoolmovementsexceptonthecompoundrest.Theycommonlyrangeinsizefrom305to610mm(12to24inches)swingandfrom610to1219mm(24to48inches)centerdistances,butswingsupto1270mm(50inches)andcenterdistancesupto3658mm(12feet)arenotuncommon.Mosthavechippansandabuilt-incoolantcirculatingsystem.Smallerenginelathes-withswingsusuallynotover330mm(13inches)alsoareavailableinbenchtype,designedforthebedtobemountedonabenchonabenchorcabinet.Althoughenginelathesareversatileandveryuseful,becauseofthetimerequiredforchangingandsettingtoolsandformakingmeasurementsontheworkpiece,thyarenotsuitableforquantityproduction.Oftentheactualchip-productiontineislessthan30%ofthetotalcycletime.Inaddition,askilledmachinistisrequiredforalltheoperations,andsuchpersonsarecostlyandofteninshortsupply.However,muchoftheoperatorstimeisconsumedbysimple,repetitiousadjustmentsandinwatchingchipsbeingmade.Consequently,toreduceoreliminatetheamountofskilledlaborthatisrequired,turretlathes,screwmachines,