车辆工程专业英语PPT课件-ELECTRONIC-FUEL-INJECTION

No.10039ELECTRONICFUELINJECTION（2）ElectronicThrottle—Drive-By-WireGDI——GasolineDirectInjectionDieselCommonRailInjectionSystemPROFESSONALENGLISH:NEWTECHNOLOGIESNo.10039NewWordsoctane-rating辛烷值takeadvantageof利用运用anti-knockindex抗爆指数scopeset示波器stipulate约定，规定Coastv.滑行blank空白（的）空地空虚的approachev.接近达到stall熄火retard延迟，推迟mask掩盖overswing尖峰突增jerk急拉[动，撞，跳],振动（冲击）颠簸地行进rich富的浓的丰富多彩的enrichment加浓freedom自由(度）灵活性freedomfrom免除（于）turbochargev.(涡轮)增压turbo涡轮涡轮增压器formv.形成n.形式形态形状式样ELECTRONICFUELINJECTIONNo.10039ElectronicThrottle—Drive-By-WireSomeofthenewestMotronicsystemshaveanelectronicthrottle(alsoknownasadrive-by-wiresystem).Theelectronicthrottlehasnomechanicallinkbetweentheacceleratorpedalandthethrottlevalve.Instead,asshownintheFigureonnextpage,anacceleratorsensorpicksupyourmovementorpositionoftheacceleratorpedal.Itsignalsthecontrolunitaboutpedalmovement,andthecontrolunitsignalstheservomotoronthethrottleshafttoopen.Theelectronicthrottle(BoschcallsitEGAS)maysoundlikesomethingnoneofusneeds,butithasmanybenefits.ELECTRONICFUELINJECTIONsoundlike听起来好像No.10039Fig.4-29.ElectronicthrottlesendsacceleratorsignaltoMotroniccontrolunit.DCmotormovesthrottlevalve,modifiedbyenginetemperature,idlerpm,andmaximumrpmELECTRONICFUELINJECTIONNo.10039Thethrottleopeningsignalmaybemodifiedaccordingtoenginerpmandenginetemperature.Itcanprovidesimplifiedcruisecontrol.Itcanalsocontrolminimumrpm,replacingtheidle-speedstabilizer,andcontrolmaximumrpm,replacingthealternate-injectorcut-out.Butthere'smore.Fortractioncontrol,theelectronicthrottlelinkswiththeABS(Anti-lockBrakingSystem).Thesamewheel-speedsensorsofABSalsofeedtheASR(Anti-SlipRegulator).Whenanydrivingwheelstartstoslip,aslightbrakeapplicationpreventsthatwheelfromslippingsomuchthatthedifferentialdeliversnopowertotheotherdrivingwheel.Ifbothdrivingwheelsshowsignsofslipping,theelectronicthrottlecutsbackpowerformaximumtraction.Tractioncontrolgivesthecarthemaxaccelerationthetirescandelivertotheroad.Iflayingdowntiresmokeisyourthing,avoidASR.Butformakingthefastesttakeoff,youcannotbeatit.ELECTRONICFUELINJECTIONlayingdown主张，搁下，放弃beat冲击，敲打trust相信，信赖No.10039Canyoutrusttheelectronicthrottle?Willitprovideunintendedacceleration?Thesystemchecksitssafetycircuitsbeforestart-off,andreportsdefectstothedriver.Ifadefectisfound,alimp-homecircuitmaydisablesomeofthefunctions,butitwillallowyoutogettothehouseortheshop.Itmaywellbemorereliablethansomecableactuatedthrottles.trust相信，信赖defect故障，缺点，毛病limp-home跛行回家ELECTRONICFUELINJECTIONNo.10039GasolineDirectInjectionConventionalgasolineenginesaredesignedtouseanelectronicfuelinjectionsystem,replacingthetraditionalmechanicalcarburetionsystem.Multi-pointinjection(MPI),wherethefuelisinjectedthrougheachintakeport,iscurrentlyoneofthemostwidelyusedsystems.AlthoughMPIprovidesadrasticimprovementinresponseandcombustionquality,itisstilllimitedduetofuelandairmixingpriortoenteringthecylinder.Tofurtherincreaseresponsetimeandcombustionefficiency,whileloweringfuelconsumptionandincreasingoutput,systemsmayusedirectinjection.Gasolinedirectinjectionenginesareengineeredtoinjectthegasolinedirectlyintothecylinderinamannersimilartodieseldirectinjectionengines.ELECTRONICFUELINJECTIONNo.10039Directinjectionisdesignedtoallowgreatercontrolandprecision,resultinginbetterfueleconomy.Thisisaccomplishedbyenablingcombustionofanultra-leanmixtureundermanyoperatingconditions.Directinjectionisalsodesignedtoallowhighercompressionratios,deliveringhigherperformancewithlowerfuelconsumption.Currently,directinjectiongasolineenginesarebeingdeployedthroughouttheworldinpassengercars.MitsubishiGDIMitsubishiMotorsisaimingtoachievebothlowfuelconsumptionandhighoutput.MMCisaworldforerunnerinthedevelopmentofdirectcylinderinjectiongasolineengines,knownasGDI,whichwerefirstintroducedinthe1996Galant.GDIsuppliesfueldirectlytotheinsideofthecylinder(Figure).Avarietyofair-fuelmixturescanbecreatedaccordingtochangesinthefuelinjectiontiming.ELECTRONICFUELINJECTIONNo.10039Fig.4-1MitsubishidirectcylinderinjectiongasolineengineELECTRONICFUELINJECTIONNo.10039ELECTRONICFUELINJECTIONNo.100392.7.4CommonRailInjectionSystem(CRSystem)Allpreviousinjectionsystemshaveonedisadvantageincommon(Fig.2-30):thepressuregenerationandthesupplyoftheinjectionquantityarenotmutuallyindependent.Theresultisthattheinjectionpressureincreaseswiththeenginespeedandalsoincreasesduringinjection(approximatelylinearly).Consequently,smallerinjectionquantitiesareinjectedwithlowpressure.Thepeakpressureisalmosttwiceashighastheaverageinjectionpressure,whichisresponsibleforthequalityofthefuelswirlinthecombustionchamber.ELECTRONICFUELINJECTIONberesponsiblefor对…负责，是…的主要原因，决定着No.10039ELECTRONICFUELINJECTIONNo.10039Aninjectionsystemisdesirableinwhich1)injectionpressureandfuelquantitycanbeadjustedindependently,2)theinjectionpressureisashighandasconstantaspossibleduringtheentireinjectionaftercombustionstart,3)theinjectionquantityorinjectionpressureatthestartofinjection,i.e.Duringtheignitionlagbetweenthestartofinjectionandstartofcombustion(dependingonenginetemperature,severalhundredItsuptoover1ms)is