汽车专业英语课件-5cha

复习,提问EFI分类提问（教师说EFI系统汉语部件名称，同学回答英文名称）GDI原理,学习内容,本次课学习内容、目标和重点难点,学习目标,难点重点,DieselfuelsystemsandCRsystemCooling,lubricationsystems3.Emissioncontrolsystem,1.掌握柴油机喷油系统主要组成、CR系统部件的英文名称；掌握CR系统原理和排放系统控制原理2.了解冷却、润滑和排放控制系统的组成,1.重点为记忆英文专业术语2.难点需要记忆的生词偏多3.汉译准确表达也是难点,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,2.8.1NewWordsandPhrases,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Typicaldieselsystemcomponentsincludethefueltank,fuelpump,fuelfilter,injectionpump,injectors,andthenecessaryfuellines(Fig.2-18).ThesysteminFig.2-19istypicalofnewersystemsthatutilizeacomputer-controlledelectronicfuelinjectionpump.,2.8.2Text,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Fig2-18Aconventionaldieselfuelinjectionsystem,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Fig2-19.Ancomputercontrolleddieselfuelinjectionsystemwithaxial-pistondistributorinjectionpump,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,FuelFilter.Dieselfuelmustbekeptcleantoavoidinjectorsystemtrouble.Verysmallparticlesareenoughtocloginjectornozzles.Dieselfuelsystemstypicallyuseoneormorefilterstotrapdirtandotherdeposits.InjectionPump.Duetothehighcompression(around22:1)usedindieselengines,thedieselinjectionpumpmustbecapableofproducinghighpressures.Thereareanumberofinjectionpumpdesigns.Themostcommonlyusedautomobileandlighttruckdieselinjectionpumpsareclassifiedasinlineordistributor.Theinlineinjectionpump（Figure12-18）usesaseparatecylinderplunger-camunit（Fig.2-20）foreachcylinder.Theseunitsarecontainedinastraightrowinacommonhousing.,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Figure2-20.Pumpplungerconstruction.Whenthecontrolrackismoved,theplungerwillbeforcedtorotatebythesegmentedgearsleeveactingontheplungerflange.,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Fig.2-21Cutawayviewofadistributortypeinjectionpump.,ThedistributorinjectionpumpisshowninFigure2-21.Youwillnotethatasingle,double-plungertypepumpservesallinjectoroutlets.Asingledeliveryvalveislocatedintherotor.AdistributortypefuelinjectionpumpwitchiselectronicallycontrolledisshowninFig.2-22.,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Fig.2-22Aelectronicallycontrolleddistributortypefuelinjectionpump.Fuelshutoffsolenoidiscontrolledbythepowertraincontrolmodule(PCM).Whenenergized,itisdesignedtocompletelystopthefuelflowintotheinjectionpump.,Chapter2InternalCombustionEngine2.8DieselFuelInjectionSystem,Injector.Therearemanydifferentinjectordesigns,butallareavariationoftwobasictypes-inwardopeningandoutwardopening.Dieselspraypatternswillvarydependinguponenginedesign.GlowPlugandIntakeAirHeaters.Toaidinignitingthecompressedair-fuelmixduringcoldstarting,dieselenginesuseglowplugsandintakeairheaters.Theglowplugisanelectricallyoperateddevicethatprotrudesintotheprecombustionchamber.Onlaterengines,theglowplugsareturnedonandoffautomatically.Intakeairheaterswarmtheairasitpassesthroughonitswaytotheintakemanifold.Theheaterelementisawiremeshthatiselectricallyheated.Thecomputerenergizestheheaterelementbeforecranking.,Chapter2InternalCombustionEngine2.9Commonrailinjectionsystems,2.9.1NewWordsandPhrases,Chapter2InternalCombustionEngine2.9Commonrailinjectionsystems,Newerdieselenginesareequippedwithcommonrailinjectionsystems(Fig.2-23toFig.2-26).Commonrailsystemsaredirectinjection(DI)systems.Theinjectorsnozzlesareplacedinsidethecombustionchamber.Thepistontophasadepressionwhereinitialcombustiontakesplace.Theinjectormustbeabletowithstandthetemperatureandpressureinsidethecylinderandmustbeabletodeliverafinesprayoffuelintothoseconditions.Thesesystemshaveahighpressurefuelrailconnectedtoindividualinjectors.,2.9.2Text,Chapter2InternalCombustionEngine2.9Commonrailinjectionsystems,Theinjectorsarecontrolledbyacomputerthatattemptstomatchinjectoroperationtotheoperatingconditionsoftheengine.Therearetwotypesofinjectors:solenoid-typeandpiezoelectric(Fig.2-27andFig.2-28).Newerdieselfuelinjectorsrelyonstackedpiezoelectriccrystalsratherthansolenoids.Piezoelectric-crystalsquicklyexpandwhenelectricalcurrentisappliedtothem.Thecrystalsallowtheinjectorstorespondveryquicklytotheneedsoftheengine.Withthisnew-styleinjector,dieselenginesarequieter,morefuelefficient,cleaner,andhavemorepower.,Chapter2InternalCombustionEngine2.9Commonrailinjectionsystems,Fig.2-23Commonrail(CR)system,Chapter2InternalCombustionEngine2.9Commonrailinjectionsystems,Fig.2-24Boschthirdgenerationcommonrailwithpiezoelectricinlineinjectors,Fig.2-25Lucasdieselcommonrail(LDCR),2.9Commonrailinjectionsystems,Fig.2-26CommonrailinjectionsystemasusedwithaV-8engine,Fig.2-27Solenoid-typeinjector,Chapter2InternalCombustionEngine2.9Commonrailinjectionsystems,Fig.2-28Boschsthirdgenerationcommonrailinwhichtheinjectoractuatorsconsistofpiezo-crystals.,Chapter2InternalCombustionEngine2.10CoolingSystem,2.10.1NewWordsandPhrases,Chapter2InternalCombustionEngine2.10CoolingSystem,Thepurposeoftheenginescoolingsystemistoremoveexcessheatfromtheengine,tokeeptheengineoperatingatitsmostefficienttemperature,andtogettheengineuptothecorrecttemperatureassoonaspossibleafterstarting.Ideally,thecoolingsystemkeepstheenginerunningatitsmostefficienttemperaturenomatterwhattheoperatingconditionsare.Fuelburningenginesproduceenormousamountsofheat;temperaturescanreachupto4,000Fwhentheair-fuelmixtureburns.However,normaloperatingtemperatureisabout2,000F.,Chapter2InternalCombustionEngine2.10CoolingSystem,2.10.2Text,Theexhaustsystemtakesawaymuchoftheheat,butpartsoftheengine,suchasthecylinderwalls,pistons,andcylinderhead,absorblargeamountsoftheheat.Ifapartoftheenginegetstoohot,theoilfilmfailstoprotectit.Thislackoflubricationcanruintheengine.Ontheotherhand,ifanenginerunsattoolowatemperature,itisinefficient,theoilgetsdirty(addingwearandsubtractinghorsepower),depositsform,andfuelmileageispoor-nottomentionexhaustemissions!Forthesereasons,thecoolingsystemisdesignedtostayoutoftheactionuntiltheengineiswarmedup.,Chapter2InternalCombustionEngine2.10CoolingSystem,Therearetwotypesofcoolingsystems:liquidcoolingandaircooling.Mostautoenginesarecooledbytheliquidtype;aircoolingisusedmorefrequentlyforairplanes,motorcyclesandlawnmowers.Thecoolingsystemofawater-cooledengineconsistsoftheengineswaterjacket,athermostat,awaterpump,aradiatorandradiatorcap,acoolingfan(electricorbelt-driven),hoses,andusuallyanexpansion(overflow)tank(Figure2-23).,Chapter2InternalCombustionEngine2.10CoolingSystem,Fig.2-23Thecoolingsystemofawater-cooledengine,2.11.1NewWordsandPhrases,Chapter2InternalCombustionEngine2.11LubricationSystem,Chapter2InternalCombustionEngine2.11LubricationSystem,Reducingfrictiontominimizewearandlossofpoweristheprimaryjobalubricationsystemmustperform.Residualoilonenginepartsalsoprovideslubricationforenginestart-up.Theengineoilformsasealbetweenthepistons,rings,andcylinders.Italsohelpstocoolengineparts.Withoutthecleaningactionofthelubricatingsystem,carbonandvarnishbuildupwouldbeexcessive.Theengineoilalsoabsorbstheshockanddampensthenoiseofmovingparts.,Chapter2InternalCombustionEngine2.11LubricationSystem,Howsuccessfulthelubricationsystemisinperformingallthesefunctionsdependsonanumberoffactorsandconditions.Theremustbeanadequatesupplyofgood-qualitylubricantdeliveredtoallmovingenginepartsundersufficientpressuretoprovidehydrodynamiclubricationforrotatingpartsandoiladhesiontosurfacesubjecttoslidingfriction.Figure2-24showsaengineslubeoilcircuitschematic.,Chapter2InternalCombustionEngine2.11LubricationSystem,Fig.2-24Engineslubeoilcircuitschematic,Fig.2-25Thepartsofthelubricationsystem,Chapter2InternalCombustionEngine2.12EmissionControlSystems,2.12.1NewWordsandPhrases,Chapter2InternalCombustionEngine2.12EmissionControlSystems,Thepurposeoftheemissioncontrolsystemisjustthatitcontrolstheemissionsandexhaustfromavehicle.Theideaistoturntheharmfulgasesacarmanufacturesintoharmlessonesthatdontruintheenvironment,orpersons.Someoftheproblemgasesare:1)hydrocarbons(unburned)2)carbonmonoxide3)nitrogenoxidesTherearefivepopularsystemsusedtoreduceemissions:thecrankcaseventilationsystem,theevaporativeemissioncontrolsystem,theExhaustGasRecirculation(EGR)system,theairinjectionsystemandthecatalyticconvertersystem.,Chapter2InternalCombustionEngine2.12EmissionControlSystems,2.12.2Text,Inadditiontotheseemissionsystems,modernvehiclesincorporateanelectronicallycontrolledfuelinjectionsystem,whichfurtherreducesemissions.Note:Notallvehiclesareequippedwiththeseemissionsystems.Thepurposeofthepositivecrankcaseventilation(PCV)systemistotakethevaporsproducedinthecrankcaseandpistonblow-by,andredirectthemintotheair/fuelintakesystemtobeburnedduringcombustion.Exhaustgasrecirculation(EGR)systemsreducetheamountofoxidesofnitrogenproducedduringthecombustionproces