排氣控制系統(tǒng)-中英文翻譯

PAGEPAGE7英文資料翻譯EmissionControlSystemsThepurposeoftheemissionsystemisjustthatitcontrolstheemissionandexhaustfromavehicle.Theideaistoturntheharmfulgasesacarmanufacturesintoharmlessonesthatdon'truintheenvironment,orpersons.Someofproblemgasesare:hydrocarbons（unburned）.Carbonmonoxide.CarbondioxideNitrogenoxide.Sulfurdioxide.Phosphorus.Leadandothermetal.Therearefivepopularsystemsusedtoreduceemissions:thecrankcaseventilationsystem,theevaporativeemissionscontrolsystem,theexhaustgasrecirculationsystemandthecatalyticconvertersystem.Inadditionaltotheseemissionssystem,somevehiclesincorporateanelectronicallycontrolledfuelsystem,whichfurtherreducesemissions.Note:Notallvehiclesareequippedwiththeseemissionsystems.CrankcaseventilationsystemSincetheearly1960s,allcarshavebeenequippedwithcrankcaseventilationsystem.Whentheengineisrunning,asmallportionofthegaseswhichareformedinthecombustionchamberleakpasthepistonringsandenterthecrankcase.Sincethesegasesareunderpressure,theytendtoescapefromthecrankcaseandentertheatmosphere.ifthesegasesareallowedtoremaininthecrankcaseforanylengthoftime,theycontaminatetheengineoilandcausesludgetobuildupinthecrankcase.Ifthegasesareallowedtoescapetotheatmosphere,theypollutetheairwithunburnedhydrocarbons.Thejobofthecrankcaseventilationsystemistorecycletheegasesbackintotheenginecombustionchamberwheretheyarere-burned.Thecrankcasegasesarerecycledastheengineisrunningbydrawingcleanfilteredairthroughtheairfilterandintothecrankcase.Astheyarepassesthroughthecrankcase,itpicksupthecombustiongasesandcarriesthemoutofthecrankcase,throughtheoilseparator,throughthePCVvalveororifice,andintotheinductionsystem.astheyentertheintakemanifold,theyaredrawnintothecombustionchamberwheretheyarere-burned.ThemostcriticalcomponentinthesystemisthePCVvalvethatcontrolstheamountofgasesthatarerecycled.Atlowenginespeedincreases,thevalveopenstoadmitgreaterquantitiesofairtotheintakemanifold.SomesystemsdonotuseaPCVvalve.Theysimplyusearestrictorororificeintheventilationhosetometerthecrankcasegases.IfthePCVvalvebecomesblockedorplugged,thegasescannotbeventedfromthecrankcase.Sincetheyareunderpressure,theyillfindtheirownwayoutofthecrankcase.Thisalternaterouteisusuallyaweakoilsealorgasketintheengine.Asthegasescapesbythegasket,itusuallycreatesanoilleak.Besidescausingoilleaks,acloggedPCVvalvealsoallowsthesegasestoremaininthecrankcaseforanextendedperiod,promotingtheformationofsludgeintheengine.EvaporativeemissioncontrolsystemTheevaporativeemissioncontrolsystemisdesignedtopreventfueltankandcarburettorbowlvapoursfrombeingemittedintotheatmosphere.Fuelvapoursareabsorbedandstoredbyafuelvapourcharcoalcanister.Thecanisterstoresthemuntilcertainengineconditionsaremetandthevapourscanbepurgedandburnedbytheengine.Thecharcoalcanisterpurgecycleiscontrolleddifferentways:eitherbyathermostaticvacuumswitch,asolenoidorbyatimedvacuumsource.Thethermostaticswitchisinstalledinthecoolantpassageandpreventscanisterpurgewhentheengineisbelowacertaintemperature.Thesolenoidisusuallycontrolledbyacomputerandisusedonfeedbackfuelsystems.Thecomputerdetermineswhencanisterpurgeisappropriate.Dependingonthesystem,thiscanbeengineoperatingtemperature,enginespeed,evaporativesystempressureoranycombinationofthese.Thetimedvacuumsourceusesamanifoldvacuumcontrolleddiaphragmocontrolcanisterpurge.Whentheengineisrunning,fullmanifoldvacuumisappliedtothetoptubeofthepurgevalvewhichliftsthevalvediaphragmandopensthevalve.Aventlocatedinthefueltank,allowsfuelvapourstoflowtothecharcoalcanister.atankpressurecontrolvalve,usedonsomehighaltitudeapplications,preventscanisterpurgewhentheengineisnotrunning.Thefueltankcapdoesnotnormallyventtotheatmosphere,butisdesignedtoprovidebothvacuumandpressurerelief.AirinjectionsystemIntroducingacontrolledamountofairintotheexhaustsystempromotesfurtheroxidationofthegases.Thisinturnreducestheamountofcarbonmonoxideandwater,theharmlessby-productsofcombustion.Somesystemuseanairpump,whileotherusenegativeexhaustpulsestodrawair.Theairpump,usuallydrivenbyabelt,simplypumpsairunderapressureofonlyafewpoundsintoeachexhaustport.Betweenthenozzlesandthepumpisacheckvalvetokeepthehotexhaustgasesfromflowingbackintothepumpandhosestherebydestroyingthem.Mostpumpsalsoutilizeagulpvalveoradivertervalve.Earlysystemusedagulpvalvewhilelatersystemsusedivertervalves.Theybothoperateonthesameprinciple.Duringdeceleration,asthethrottleisclosed,theexplosionintheexhaustsystemcouldoccurthatcouldblowthemufflerapart.Duringdeceleration,theairiseitherdivertedintotheatmosphereorintotheintakesystem.Onpulseairsystem,cleanairisdrawnthroughasilencer,thecheckvalveandthenintotheexhaustports.Thenegativeexhaustpulsesopensthereedvalveinthecheckvalveassembly,allowingairtoflowintotheexhaustport.Somefeedback-controlledvehiclesutilizeanoxidizingcatalyticconverter.Undercertainoperatingconditions,theairisdivertedintothecatalyticconvertertohelpoxidizetheexhaustgases.Exhaustgasre-circulationsystemTheEGRsystem'spurposeistocontroloxidesofnitrogenwhichareformedduringthecombustionprocess.NOxemissionsatlowcombustiontemperaturesarenotsevere,butwhenthecombustiontemperaturesgoover2,500F,theproductionofNOxinthecombustionchambersshootswayup.Theendproductsofcombustionarerelativelyinertgasesderivedfromtheexhaustgases.theseareredirected,(undercertainconditions)throughtheEGRvalveandbackintothecombustionchamber.Theseinertgasesdisplaceacertainamountofoxygeninthechamber.Sincenotasmuchchamber.Theseinertgasesdisplaceacertainamountofoxygeninthechamber.Sincenotasmuchoxygenispresent,theexplosionisnotashot.Thishelpslowerpeakcombustiontemperatures.TheEGRvalvecaneitherbeactuatedbyavacuumdiaphragm,asolenoidorsteppermotor.Onfeedbackcontrolledvehicles,theEGRsystemiscontrolledbythecomputer.CatalyticconverterThecatalyticconverterisamuffler-likecontainerbuiltintotheexhaustsystemtoaidinthereductionofexhaustemissions.Thecatalystelementiscoatedwithanoblemetalsuchasplatinum,palladium,rhodiumoracombinationofhem,whentheexhaustgasescomeintoharmlesssubstancessuchaswaterandcarbondioxide,oxidizingcatalystsintoH2OandCO2.Whilecatalyticconvertersarebuiltinavarietyofshapesandsizes,theyallfallintotwogeneraltypes,thepellet,orbeadtypeandthemonolithictype.Constructionmaydifferslightly,buttheobjectisthesame-topresentthelargestpossiblesurfaceareatopassingexhaustgases.Oldervehiclesusebeadtypeconverters.Theexhaustgasmustpassthroughabedofthesepellets.Thistypeofconverterisratherrestrictive.Thecross-sectionofamonolithictypeconverterresemblesahoneycomb.Theexhaustgasesareexposedtoagreateramountofsurfaceareaintheseconverters;asaresulttheyaremoreefficient.Theyalsotendtobelessrestrictive.DualexhaustsystemTheadvantageofadualexhaustsystemisthattheengineexhaustsmorefreely,therebyloweringthebackpressure,whichisinherentinanexhaust.withadualexhaustsystem,asizableincreaseinenginehorsepowercanbeobtainedbecausethebreathingcapacityoftheengineisimproved,leavinglessexhaustgasesintheengineattheendofeachexhauststroke.Thisinturn,leavesmoreroomforanextraintakeoftheair-fuelmixture.HyperboloidgearOnthepassengervehiclemaingearboxusesthehyperboliccurvegeargenerally.Thisisbecausethehyperboliccurvegearandthespiralbevelgearcompare,formerrevolutionnoisefew,worksteadier,turnsthetoothintensityhigh,moreoveralsohasthedrivegearspoolthreadtobepossibletherelativedrivengeardisalignmentcharacteristic,thispointtobeextremelyimportantregardingtheautomobiletechnicalperformance,engineermayinnotchangetheenginethepositionsizetobepossibletochangethedrivingaxledirectlythegroundclearance,alsoischangestheentirevehiclethegroundclearance.someautomobilesmaingearboxhyperboliccurvegearoff-setsamountstomorethan30millimeters,inthemaintenancecertaingroundclearancesituation,mayreducethedrivegearandthedriveshaftposition,causestheautomobilebodycenterofgravitytoreduce,isadvantageousinenhancestheautomobilehighspeedtravelthestability.TwogearsspoolthreadsintersectiondrivingpulleydisplacestounderSomeautomobilesproducethepassengervehicleandmovementontheidenticalframe,itschassisparametertransformationalsohasusedhyperboliccurvegearthischaracteristic.Becausehasthesemerits,atpresenttheautomobiledrivingaxlealreadytendedtousesthehyperboliccurvegear,infactrecentyearsimportedtheautomobilebasicallywasusesthehyperboliccurvegear,thedomesticallyproducedautomobilealsohasmanyvehicletypestousethehyperboliccurvegear,andalreadymoreandmoreweremanyincenter,ontheheavyfreightvehicleobtainstheuse.Whenthehyperboliccurvegearworks,betweenthetoothfacecanhaveinabigwayskidsrelatively,alsothetoothfacepressureisverybig,thetoothfacelubricantfilmiseasilydestroyed.Inordertoreducethefriction,enhancestheefficiency,musthavetouseincludesguardsagainsttheabrasionchemicaladditivethespecial-purposehyperboliccurvegearoil,cannotuseothergearoiltoreplace,otherwisewillcausethetoothfacerapidattritionandtheabrasion,seriouslywillaffecttheautomobiletherunningstatus.FurtherdevelopmentManufacturersaroundtheworldareseekingsignificantimprovementsinconventionalautomotivetechnologies,andChinesemanufacturersriskfallingbehindiftheyfailtosustaincomparableresearcheffortsonconventionalpowertrainsystems.TheChineseautomotiveindustryalsoshouldstrengthenitseffortstodevelopimproveddieselandsparkignitiontechnologyincooperationwithitsjointventurepartners.Researchersshouldfocuson.amongotherthings,advancedgasolineanddieselenginetechnologies,anultra-low-emissiongasolineenginesystem,dieselparticulatefilters,de-NOcatalysts,selectivecatalyticreduction(SCR),andimprovedin-enginecombustionmanagement.Industrymustdevelopthecapabilitytomodelthevehiclepowertrainsysteminordertooptimizeitsoverallperformance,includingfueleconomy,andvehicledrivability.Theautomobile'sfurtherdevelopmentwillbedeterminedbyalreadyexistingandsteadilyincreasingrequirements,byadditionalfurtherrequirementsandbythetechnicalpossibilitiesformeetingtheserequirements.Thefollowingfocalpointfordevelopmentandresearcheffortscanbediscerned.Furtherimprovementoftheautomobilethroughproductinnovationisinallclassicfunctions,performance,fueleconomy,environmentalimpact,safety,comfort,andreliability.

中文翻譯排氣控制系統(tǒng)排放控制系統(tǒng)的目的只是為了控制車輛廢氣的排放。這個想法是把有汽車排放的有害氣體變?yōu)闊o害，從而不破壞環(huán)境，或影響人們的健康。這些有害氣體是：1.未完全燃燒的碳?xì)浠衔铮?.一氧化碳；3.二氧化碳；4.氮氧化物；5.二氧化硫；6.磷；7.鉛和其他金屬。通常有5類系統(tǒng)用來減少排放量：曲軸箱通風(fēng)系統(tǒng)，燃油蒸發(fā)排放控制系統(tǒng)，廢氣再循環(huán)系統(tǒng)和催化轉(zhuǎn)換器系統(tǒng)。除了這些排放系統(tǒng)，將一些車輛的電子控制燃油系統(tǒng)，從而進(jìn)一步降低排放量。注意：并非所有的車輛都配備了這些排放系統(tǒng)。曲軸箱通風(fēng)系統(tǒng)自1960年代初以來，所有車輛都配備了曲軸箱通風(fēng)系統(tǒng)。當(dāng)發(fā)動機運行時，一小部分在燃燒室形成的氣體從活塞環(huán)泄漏從而進(jìn)入曲軸箱。由于這些氣體的處高壓力下，他們往往擺脫曲軸箱，進(jìn)入大氣層。如果這些氣體被允許留在曲軸箱一段時間，它們將污染機油，造成污泥，集聚在曲軸箱。如果氣體逃脫到大氣中，他們中的未燃盡碳?xì)浠衔飳⑽廴究諝?。曲軸箱通風(fēng)系統(tǒng)的作用是回收氣體進(jìn)入發(fā)動機燃燒室，使其重新燃燒。曲軸箱泄露的氣體被回收利用，當(dāng)發(fā)動機運行時采用用清潔過濾使空氣通過空氣過濾器進(jìn)入曲軸箱。當(dāng)它們通過曲軸箱時，它通過分油器，通過強制式通風(fēng)閥或孔，將燃燒氣體帶離曲軸箱，進(jìn)入循環(huán)系統(tǒng)。他們由進(jìn)氣歧管卷入燃燒室，在那重新被燃燒。該循環(huán)系統(tǒng)最重要的組成部分是強制式通風(fēng)閥，它用來控制廢氣的循環(huán)利用量。在低時隨著轉(zhuǎn)速的增加，閥打開接納更多的空氣的進(jìn)入進(jìn)氣歧管。有些循環(huán)系統(tǒng)不使用強制式通風(fēng)閥。他們只是使用或孔板節(jié)流的通風(fēng)管，以控制曲軸箱氣體。如果強制式通風(fēng)閥被攔截或堵塞，氣體無法從曲軸箱通風(fēng)。從而導(dǎo)致他們在高壓下，通過密封間隙逃離曲軸箱。這種氣體的泄露通常是由于引擎內(nèi)一個薄弱油封或墊圈。隨著氣體通過墊圈逸出，它通常伴隨著油的泄漏。除了造成油泄漏污染，阻塞強制式通風(fēng)閥也將導(dǎo)致這些氣體留在曲軸箱的時間延長，從而導(dǎo)致形成發(fā)動機油泥污染。燃油蒸發(fā)排放控制系統(tǒng)燃油蒸發(fā)排放控制系統(tǒng)的設(shè)計，是為防止油箱和化油器的氣體被排放到大氣中。燃油蒸汽吸收并儲存在活性炭罐中。當(dāng)某些發(fā)動機條件得到滿足時油氣混合蒸汽將被凈化并通過發(fā)動機燃燒。活性炭罐凈化系統(tǒng)以幾種不同的方式控制：要么由一個恒溫真空開關(guān)，電磁或定時真空源控制。恒溫開關(guān)安裝在冷卻通道，防止罐清洗發(fā)動機時低于某一溫度。電磁通常是由計算機控制的，用于燃油系統(tǒng)的反饋。計算機決定何時罐清洗是適當(dāng)?shù)?。通過這些系統(tǒng)反饋，這可能是發(fā)動機的工作溫度，發(fā)動機轉(zhuǎn)速，蒸發(fā)系統(tǒng)壓力或任何這些條件的組合。定時真空源使用多種真空控制隔膜控制活性罐。當(dāng)發(fā)動機運行時，只夠的企管真空壓力作用于進(jìn)氣閥門頂端，并使閥門膜片升起從而打開閥門。一個位于油箱的通風(fēng)口，使燃油蒸汽流向活性炭罐。油箱壓力控制閥，用于在一些高海拔地區(qū)的應(yīng)用，防止發(fā)動機未運行時活性碳罐工作。油箱蓋通常不會朝大氣開合，但能提供真空和可靠的壓力條件?？諝鈬娚湎到y(tǒng)將一定控制量的空氣導(dǎo)入排氣系統(tǒng)促進(jìn)氣體的進(jìn)一步氧化。這反過來又減少了一氧化碳和碳?xì)浠衔?，無害的燃燒副產(chǎn)品。有些系統(tǒng)使用的空氣泵，而其他使用排氣脈沖提來吸取空氣。

空氣泵，通常由皮帶帶動，只要在只有少數(shù)磅的空氣壓力下就能傳送空氣到每個排氣口。位于噴嘴和泵之間的是一個止回閥保持熱廢氣流回到泵和軟管從而破壞它們。大多數(shù)泵還利用補氣閥或橫向閥。早期的系統(tǒng)使用了補氣閥而后來系統(tǒng)使用橫向閥。他們都基于同樣的原理。在減速時，因為油門是封閉的，燃油混合氣變得越來越多。如果混合氣繼續(xù)增多，爆在排氣系統(tǒng)中就可能發(fā)生爆炸，可能使消聲器分離。在減速期間，空氣要么改行到大氣中或到進(jìn)氣系統(tǒng)。

在脈沖空氣系統(tǒng)中，來自空氣濾清器的清潔空氣經(jīng)過消聲器，止回閥，然后到排氣口。排氣負(fù)脈沖打開止回閥的簧片閥，使空氣流入