汽車專業(yè)英語讀譯教程 第3版 課件 7-U4TA Gasoline Direct Injection (GDI) and Throttle-by-wire

UNIT4

GASOLINEFUELINJECTION

TEXTA

GasolineDirectInjection(GDI)

andThrottle-by-wire

PROFESSIONALENGLISH

UNIT3

GASOLINEFUELINJECTION

TEXTA

GasolineDirectInjection(GDI)

andThrottle-by-wire

GasolineDirectInjection

MitsubishiGDI

VolkswagenAG'sdirect-injection(FSI)

ToyotaDIengine

ElectronicThrottle—Throttle-By-Wire

本次課學習內(nèi)容本次課學習目標掌握GDI系統(tǒng)的特點掌握GDI系統(tǒng)的原理掌握電子節(jié)氣門原理NEWWORDSdrastic['dr?stik]a.激烈的，猛烈的GDI

gasolinedirectinjection(汽油直接噴射)forerunner['f?:?r?n?]n.先驅(qū)（者），先鋒，祖先CVT

continuouslyvariabletransmission（無級變速器）characteristics[?k?rikt?'ristik]n.特性（曲線）exotic[eg'z?tik]n.奇異的，外來的，異國情調(diào)的FSI

fuelstraightinjection燃油直接噴射layout['leiaut]n.規(guī)劃，設計（圖案），布置stick[stik]n.棒，棍；v.粘住，粘鐵estate[i'steit]n.狀態(tài)，時期，不動產(chǎn)signature['sign?t∫?]n.簽名，署名，信號acronym['?kr?nim]n.只取首字母的縮寫linchpin['lint∫pin]n.關鍵NEWWORDSjustice['??stis]n.正義，正當，公平，欣賞，審判effervescent[ef?'ves?nt]a.冒泡的，興奮的superb[sju:'p?:b]n.壯麗的，華美的，最上等的，無比的drawback['dr?:b?k]n.缺點，障礙brilliant['brili?nt]a.燦爛的，閃耀的DI

directinjected,directinjection直接噴射crucial['kru:∫(?)l]a.至關緊要的nitrogen['naitr??(?)n]n.氮lean-burn['li:n-b?:n]a.稀薄燃燒incorporate[in'k?:p?reit]v.合并，混合，組成公司；a.合并的，一體化的lip[lip]n.嘴唇，唇緣helical['helik(?)l]a.螺旋狀的quintessential[kwinti'sen∫?l]a.精髓的，精萃的，典范的，本質(zhì)的stratify['str?tifai]v.使成層NEWWORDSpromote[pr?'mout]v.促進，加速，激勵，提升vicinity[vi‘siniti]n.附近，臨近，接近homogeneous[?h?m?’?i:nj?s]a.相似的，均勻的crossover['kr?s?ouv?]n.跨越，交叉，交迭，穿過throttle-by-wire['θr?tlbai'wai?]線控節(jié)氣門servomotor['s?:voumout?]n.伺服電動機，輔助電動機，伺服傳動裝置ASR

anti-slipregulator或accelerationslipregulation防滑調(diào)節(jié)裝置ABS

anti-lockbrakingsystem防抱死制動系統(tǒng)takeoff['teik?f]n.起飛，開始beat[bi:t]n.敲打，拍子;v.打，打敗trust[tr?st]v.&n.信任，信賴limp-home[limp-'houm]n.跛行回家

PHRASESANDEXPRESSIONS

makeup補充，修理，整理，形成allbut幾乎，差不多turbolag增壓滯后inconjunctionwith連同…一起volumetricefficiency容積效率VVT-i(VariableValveTiming,intelligent)智能型可變氣門定時cruisecontrol巡航控制tractioncontrol牽引控制laydown設計，制定，主張GasolineDirectInjectionConventionalgasolineenginesaredesignedtouseanelectronicfuelinjectionsystem,replacingthetraditionalmechanicalcarburetionsystem.Multi-pointinjection(MPI),wherethefuelisinjectedthrougheachintakeport,iscurrentlyoneofthemostwidelyusedsystems[1].AlthoughMPIprovidesadrasticimprovementinresponseandcombustionquality,itisstilllimitedduetofuelandairmixingpriortoenteringthecylinder.Tofurtherincreaseresponsetimeandcombustionefficiency,whileloweringfuelconsumptionandincreasingoutput,systemsmayusedirectinjection.

GasolineDirectInjection(GDI)

andThrottle-by-wire

GasolineDirectInjection(GDI)

andThrottle-by-wireGasolinedirectinjectionenginesareengineeredtoinjectthegasolinedirectlyintothecylinderinamannersimilartodieseldirectinjectionengines.Directinjectionisdesignedtoallowgreatercontrolandprecision,resultinginbetterfueleconomy.Thisisaccomplishedbyenablingcombustionofanultra-leanmixtureundermanyoperatingconditions.Directinjectionisalsodesignedtoallowhighercompressionratios,deliveringhigherperformancewithlowerfuelconsumption.Currently,directinjectiongasolineenginesarebeingdeployedthroughouttheworldinpassengercars.GasolineDirectInjection(GDI)

andThrottle-by-wireMitsubishiGDIMitsubishiMotorsisaimingtoachievebothlowfuelconsumptionandhighoutput.MMCisaworldforerunnerinthedevelopmentofdirectcylinderinjectiongasolineengines,knownas"GDI",whichwerefirstintroducedinthe1996Galant.GDIsuppliesfueldirectlytotheinsideofthecylinder.Avarietyofair-fuelmixturescanbecreatedaccordingtochangesinthefuelinjectiontiming.UsingmethodsandtechnologiesuniquetoMitsubishi,theGDIengineprovidesbothlowerfuelconsumptionandhigheroutput.Thisseeminglycontradictoryanddifficultfeatisachievedwiththeuseoftwocombustionmodes.Putanotherway,injectiontimingschangetomatchengineload.GasolineDirectInjection(GDI)

andThrottle-by-wireUltra-leanCombustionModeUndermostnormaldrivingconditions,uptospeedsof120km/h,theMitsubishiGDIengineoperatesinultra-leancombustionmode,resultinginlessfuelconsumption.Inthismode,fuelinjectionoccursatthelatterstageofthecompressionstrokeandignitionoccursatanultra-leanair-fuelratioof30:40(35:55,includingEGR).GasolineDirectInjection(GDI)

andThrottle-by-wireSuperiorOutputModeWhentheGDIengineisoperatingwithhigherloadsorathigherspeeds,fuelinjectiontakesplaceduringtheintakestroke.Thisoptimizescombustionbyensuringahomogeneous,coolerair-fuelmixturewhichminimizesthepossibilityofengineknocking.ThesetwomodesarerepresentedinFigure4-1.ThepistonoftheGDIengineisshowninFigure4-2.Fig.4-1TwocombustionmodesoftheGDIGasolineDirectInjection(GDI)

andThrottle-by-wireFig.4-2ApistonofMitsubishiGDIengineGasolineDirectInjection(GDI)

andThrottle-by-wireInaddition,theGDI-CVTintroducedinthe2000LancersignificantlyreducesenergylossbyintegratedcontrolthatmakesthemostofGDIcharacteristics[3].High-precisiontorquecontrolandlargerangeforlowfuelconsumptionaswellastheCVTcharacteristicsofquickandcontinuouscontrolofthelargegearchangeratiosenabletopclasslevelfueleconomyandanexceptionallysmoothride[4].BorschMED-MotronicMED-Motronic(D=directinjection)isaMotronicsystemwhichisderivedfromME-Motronicandadaptedtotheparticularconditionsandrequirementsofdirectinjection(Fig.4-3).GasolineDirectInjection(GDI)

andThrottle-by-wireGasolineDirectInjection(GDI)

andThrottle-by-wireThefollowingoperatingmodescanbeusedwithMED-Motronicgasolinedirectinjection:·Stratified-chargeoperation·Homogeneous-chargeoperation·Homogeneousleanoperation·Homogeneousstratified·operation·Homogeneousknock-protectionmode·Stratified-catalyst-heatingoperationGasolineDirectInjection(GDI)

andThrottle-by-wireTheseoperatingmodesarematchedtoeachothersoastoprovideoptimalmixtureformationandcombustionineveryoperatingstate.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.GasolineDirectInjection(GDI)

andThrottle-by-wireGasolineDirectInjection(GDI)

andThrottle-by-wireExcessivelyhighspeedsgiverisetoturbulencesinthecombustionchamber,whichnolongerpermitasteadymixturecloudofλ=1.Consequences:faultycombustion,misfiring.Homogeneous-chargeoperation.Athightorqueorhighspeedtheengineisoperatedwithahomogeneousmixtureofλ=1or,toachievemaximumpower,ofλ<1.Forthispurpose,thestartofinjectionismovedtotheinductionstroke(Fig.4-5).GasolineDirectInjection(GDI)

andThrottle-by-wireTheperiodoftimethusavailableuntilthefuel-airmixtureignitesallowsthefueltomixthoroughlywiththeinductedairandspreaduniformlywithinthecombustionchamber.Inhomogeneous-chargeoperationthetorqueisgeneratedbyquantityregulation.Inotherwords,thequantityofinductedairisregulatedbythethrottlevalve.Mixtureformationandcombustiontakeplaceaccordinglyasinmanifoldinjection.Homogeneousleanoperation.Theenginecanbeoperatedwithahomogeneousleanmixtureinatransitionrangebetweenstratified-andhomogeneous-chargeoperations.Withoperationat1<λ<1.2,fuelconsumptionisreducedincomparisonwithhomogeneous-chargeoperationatλ=1.Homogeneousstratifiedoperation.Inthisoperatingmodeahomogeneousleanmixtureisformedinthecombustionchamberbyadvancedinjection(approx.75%ofthefuel)intheinductionstroke.Asecondinjectiontakesplaceinthecompressionstroke(doubleinjection),whichcreatesazoneofrichermixtureintheareaaroundthesparkplug.Thismixtureishighlyflammableandensurescompletecombustioninthecombustionchamber.Thisoperatingmodeischosensothatthetorquecanbebettersetduringthechangeoverfromhomogeneous-tostratified-chargeoperation.GasolineDirectInjection(GDI)

andThrottle-by-wireGasolineDirectInjection(GDI)

andThrottle-by-wireHomogeneousknock-protectionmode.Thankstodoubleinjectionatfullloaditispossibletodispensewithretardingthemomentofignitioninordertoavoidknocking.Chargestratificationpreventsthedangerousphenomenonoffuelauto-ignition.Fig.4-3BorschMED-MotronicgasolinedirectinjectionGasolineDirectInjection(GDI)

andThrottle-by-wireStratifiedcatalyst-heatingoperation.Anotherformofdoubleinjectionallowsthecatalysttobequicklyheated.Aleanmixtureisformedhereasinstratified-chargeoperation.Afterthefuelhasignited,fuelisinjectedonceagainduringthepowerstroke.Thisshareoffuelburnsverylateandheatsuptheexhaust-systembranchintensively.Fig.4-4Stratified-chargeoperationFig.4-5HomogeneousstratifiedoperationGasolineDirectInjection(GDI)

andThrottle-by-wireGasolineDirectInjection(GDI)

andThrottle-by-wireElectronicThrottle—Throttle-By-Wire

SomeofthenewestMotronicsystemshaveanelectronicthrottle(alsoknownasathrottle-by-wiresystem).Theelectronicthrottlehasnomechanicallinkbetweentheacceleratorpedalandthethrottlevalve.Instead,asshowninFig.4-6,anacceleratorsensorpicksupyourmovementorpositionoftheacceleratorpedal.Itsignalsthecontrolunitaboutpedalmovement,andthecontrolunitsignalstheservomotoronthethrottleshafttoopen.Theelectronicthrottle(BoschcallsitEGAS)maysoundlikesomethingnoneofus