汽车专业英语课件-与汽车专业英语读译教程课件、参考译文7-U4TA

UNIT4GASOLINEFUELINJECTIONTEXTAGasolineDirectInjection(GDI)andThrottle-by-wire,PROFESSIONALENGLISH,UNIT3GASOLINEFUELINJECTIONTEXTAGasolineDirectInjection(GDI)andThrottle-by-wireGasolineDirectInjectionMitsubishiGDIVolkswagenAGsdirect-injection(FSI)ToyotaDIengineElectronicThrottleThrottle-By-Wire,本次课学习内容,本次课学习目标,掌握GDI系统的特点掌握GDI系统的原理掌握电子节气门原理,NEWWORDS,drasticdrstika.激烈的，猛烈的GDI=gasolinedirectinjection(汽油直接喷射)forerunnerf:rnn.先驱（者），先锋，祖先CVT=continuouslyvariabletransmission（无级变速器）characteristicskriktristikn.特性（曲线）exoticegztikn.奇异的，外来的，异国情调的FSI=fuelstraightinjection燃油直接喷射layoutleiautn.规划，设计（图案），布置stickstikn.棒，棍；v.粘住，粘铁estateisteitn.状态，时期，不动产signaturesigntn.签名，署名，信号acronymkrnimn.只取首字母的缩写linchpinlintpinn.关键,justicestisn.正义，正当，公平，欣赏，审判effervescentefvesnta.冒泡的，兴奋的superbsju:p:bn.壮丽的，华美的，最上等的，无比的drawbackdr:bkn.缺点，障碍brilliantbrilinta.灿烂的，闪耀的DI=directinjected,directinjection直接喷射crucialkru:()la.至关紧要的nitrogennaitr()nn.氮lean-burnli:n-b:na.稀薄燃烧incorporateink:preitv.合并，混合，组成公司；a.合并的，一体化的liplipn.嘴唇，唇缘helicalhelik()la.螺旋状的quintessentialkwintisenla.精髓的，精萃的，典范的，本质的stratifystrtifaiv.使成层,promoteprmoutv.促进，加速，激励，提升vicinityvisinitin.附近，临近，接近homogeneoushmi:njsa.相似的，均匀的crossoverkrsouvn.跨越，交叉，交迭，穿过throttle-by-wirertlbaiwai线控节气门servomotors:voumoutn.伺服电动机，辅助电动机，伺服传动装置ASR=anti-slipregulator或accelerationslipregulation防滑调节装置ABS=anti-lockbrakingsystem防抱死制动系统takeoffteikfn.起飞，开始beatbi:tn.敲打，拍子;v.打，打败trusttrstv.&n.信任，信赖limp-homelimp-houmn.跛行回家,makeup补充，修理，整理，形成allbut几乎，差不多turbolag增压滞后inconjunctionwith连同一起volumetricefficiency容积效率VVT-i(VariableValveTiming,intelligent)智能型可变气门定时cruisecontrol巡航控制tractioncontrol牵引控制laydown设计，制定，主张,PHRASESANDEXPRESSIONS,GasolineDirectInjection(GDI)andThrottle-by-wireGasolineDirectInjectionConventionalgasolineenginesaredesignedtouseanelectronicfuelinjectionsystem,replacingthetraditionalmechanicalcarburetionsystem.Multi-pointinjection(MPI),wherethefuelisinjectedthrougheachintakeport,iscurrentlyoneofthemostwidelyusedsystems1.AlthoughMPIprovidesadrasticimprovementinresponseandcombustionquality,itisstilllimitedduetofuelandairmixingpriortoenteringthecylinder.Tofurtherincreaseresponsetimeandcombustionefficiency,whileloweringfuelconsumptionandincreasingoutput,systemsmayusedirectinjection.Gasolinedirectinjectionenginesareengineeredtoinjectthegasolinedirectlyintothecylinderinamannersimilartodieseldirectinjectionengines.,Directinjectionisdesignedtoallowgreatercontrolandprecision,resultinginbetterfueleconomy.Thisisaccomplishedbyenablingcombustionofanultra-leanmixtureundermanyoperatingconditions.Directinjectionisalsodesignedtoallowhighercompressionratios,deliveringhigherperformancewithlowerfuelconsumption.Currently,directinjectiongasolineenginesarebeingdeployedthroughouttheworldinpassengercars.,MitsubishiGDIMitsubishiMotorsisaimingtoachievebothlowfuelconsumptionandhighoutput.MMCisaworldforerunnerinthedevelopmentofdirectcylinderinjectiongasolineengines,knownasGDI,whichwerefirstintroducedinthe1996Galant.GDIsuppliesfueldirectlytotheinsideofthecylinder.Avarietyofair-fuelmixturescanbecreatedaccordingtochangesinthefuelinjectiontiming.UsingmethodsandtechnologiesuniquetoMitsubishi,theGDIengineprovidesbothlowerfuelconsumptionandhigheroutput.Thisseeminglycontradictoryanddifficultfeatisachievedwiththeuseoftwocombustionmodes.Putanotherway,injectiontimingschangetomatchengineload.,Ultra-leanCombustionModeUndermostnormaldrivingconditions,uptospeedsof120km/h,theMitsubishiGDIengineoperatesinultra-leancombustionmode,resultinginlessfuelconsumption.Inthismode,fuelinjectionoccursatthelatterstageofthecompressionstrokeandignitionoccursatanultra-leanair-fuelratioof30:40(35:55,includingEGR).SuperiorOutputModeWhentheGDIengineisoperatingwithhigherloadsorathigherspeeds,fuelinjectiontakesplaceduringtheintakestroke.Thisoptimizescombustionbyensuringahomogeneous,coolerair-fuelmixturewhichminimizesthepossibilityofengineknocking.ThesetwomodesarerepresentedinFigure4-1.ThepistonoftheGDIengineisshowninFigure4-2.,Fig.4-1TwocombustionmodesoftheGDI,Fig.4-2ApistonofMitsubishiGDIengine,Inaddition,theGDI-CVTintroducedinthe2000LancersignificantlyreducesenergylossbyintegratedcontrolthatmakesthemostofGDIcharacteristics3.High-precisiontorquecontrolandlargerangeforlowfuelconsumptionaswellastheCVTcharacteristicsofquickandcontinuouscontrolofthelargegearchangeratiosenabletopclasslevelfueleconomyandanexceptionallysmoothride4.BorschMED-MotronicMED-Motronic(D=directinjection)isaMotronicsystemwhichisderivedfromME-Motronicandadaptedtotheparticularconditionsandrequirementsofdirectinjection(Fig.4-3).ThefollowingoperatingmodescanbeusedwithMED-Motronicgasolinedirectinjection:Stratified-chargeoperationHomogeneous-chargeoperationHomogeneousleanoperation,HomogeneousstratifiedoperationHomogeneousknock-protectionmodeStratified-catalyst-heatingoperationTheseoperatingmodesarematchedtoeachothersoastoprovideoptimalmixtureformationandcombustionineveryoperatingstate.Thecontrolsystemmustensurethatduringvehicleoperationneitherpowernortorquejumpsareperceptiblewhenswitchingfromoneoperatingstatetoanother.Stratified-chargeoperation.Stratified-chargeoperationispossibleinthelowertorqueandspeedrangeuptoapprox.3,000rpm.Herethefuelisinjectedduringthecompressionstrokeintothecombustionchambershortlybeforethemomentofignition.Becauseoftheshorttimeperioduntilitignites,thefuelcannotmixuniformlywiththeairinthecombustionchamber.,Thefuelistransportedinacloudtothesparkplugbyanairswirlprevailinginthecombustionchamber(Fig.4-4).Insidethemixturecloudthemixtureratioisapprox.0.95-1.Outsidethecloudthemixtureisverylean.AlargeamountofexhaustgasisrecirculatedintothecombustionchamberinordertoreducethecreationofNOxbythealtogetherleanmixture.Sincethethrottlevalveisfullyopenduringstratified-chargeoperation,thetorqueisgeneratedduringstratified-chargeoperationbyqualityregulation.Ifthetorquedemandweretobecometoohighinthisoperatingstate,theincreasedinjectionwouldcauseparticlestoform.Excessivelyhighspeedsgiverisetoturbulencesinthecombustionchamber,whichnolongerpermitasteadymixturecloudof=1.Consequences:faultycombustion,misfiring.,Homogeneous-chargeoperation.Athightorqueorhighspeedtheengineisoperatedwithahomogeneousmixtureof=1or,toachievemaximumpower,of1.Forthispurpose,thestartofinjectionismovedtotheinductionstroke(Fig.4-5).Theperiodoftimethusavailableuntilthefuel-airmixtureignitesallowsthefueltomixthoroughlywiththeinductedairandspreaduniformlywithinthecombustionchamber.Inhomogeneous-chargeoperationthetorqueisgeneratedbyquantityregulation.Inotherwords,thequantityofinductedairisregulatedbythethrottlevalve.Mixtureformationandcombustiontakeplaceaccordinglyasinmanifoldinjection.Homogeneousleanoperation.Theenginecanbeoperatedwithahomogeneousleanmixtureinatransitionrangebetweenstratified-andhomogeneous-chargeoperations.Withoperationat11.2,fuelconsumptionisreducedincomparisonwithhomogeneous-chargeoperationat=1.,Homogeneousstratifiedoperation.Inthisoperatingmodeahomogeneousleanmixtureisformedinthecombustionchamberbyadvancedinjection(approx.75%ofthefuel)intheinductionstroke.Asecondinjectiontakesplaceinthecompressionstroke(doubleinjection),whichcreatesazoneofrichermixtureintheareaaroundthesparkplug.Thismixtureishighlyflammableandensurescompletecombustioninthecombustionchamber.Thisoperatingmodeischosensothatthetorquecanbebettersetduringthechangeoverfromhomogeneous-tostratified-chargeoperation.Homogeneousknock-protectionmode.Thankstodoubleinjectionatfullloaditispossibletodispensewithretardingthemomentofignitioninordertoavoidknocking.Chargestratificationpreventsthedangerousphenomenonoffuelauto-ignition.,Fig.4-3BorschMED-Motronicgasolinedirectinjection,Stratifiedcatalyst-heatingoperation.Anotherformofdoubleinjectionallowsthecatalysttobequicklyheated.Aleanmixtureisformedhereasinstratified-chargeoperation.Afterthefuelhasignited,fuelisinjectedonceagainduringthepowerstroke.Thisshareoffuelburnsverylateandheatsuptheexhaust-systembranchintensively.,Fig.4-4Stratified-chargeoperation,Fig.4-5Homogeneousstratifiedoperation,ElectronicThrottleThrottle-By-WireSomeofthenewestMotronicsystemshaveanelectronicthrottle(alsoknownasathrottle-by-wiresystem).Theelectronicthrottlehasnomechanicallinkbetweentheacceleratorpedalandthethrottlevalve.Instead,asshowninFig.4-6,anacceleratorsensorpicksupyourmovementorpositionoftheacceleratorpedal.Itsignalsthecontrolunitaboutpedalmovement,andthecontrolunitsignalstheservomotoronthethrottleshafttoopen.Theelectr