汽车专业英语全套教学教程

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汽车专业英语VocabularyStudyTranslationSkillsExercisesChapterOneEngine

Unit1EngineMechanicalUnit2EFISystemUnit3EngineCoolingandLubricationSystemUnit4EngineIgnition,StartingandChargingSystemUnit5EngineDiagnosisSystem

Unit1EngineMechanical

1.CylinderBlock

Theengineblockisthemainsupportingstructuretowhichallotherenginepartsareattached.Fig.1-1-1showsacylinderblock.Ithastwomainsections:thecylindersectionandthecrankcasesection.Thecrankcasesectionisusedtohousethecrankshaft,oil

pan.Coolingpassagewaysarebuiltwithintheblock.Thesepassageways,alsoknownaswatersockets,surroundthecylinders.Theyallowcoolanttocirculatethroughoutthecylinderareatokeeptheenginecool.Thereisalsoadrilledpassagewaywithinsomeblocksforthecamshaft.Manyoilholesaredrilledinternallysothatenginepartscanbeadequately

lubricated.engine发动机block气缸体cylinder气缸crankcase曲轴箱house安装crankshaft曲轴camshaft凸轮轴coolant冷却液oilpan机油盘watersocket水套internally内部地adequately充分地lubricate润滑

Four-CylinderEngineCylinderBlock

(四缸发动机气缸体)

Fig.1-1-1

1-cylinderblock(气缸体)2-cylinder(气缸)3-crankcasearea（曲轴箱部分）2.CylinderLinersThepurposeofusingalineristhat,ifthecylinderisdamaged,thelinercanberemovedandreplacedrathereasily.Therearetwotypesofsleeves－wetanddry.

Sealsmustbeusedonthetopandbottomofthewetsleeveinordertokeepthecoolantfromleakingoutofthecoolingsystem.3.CylinderHeadTheCylinderheadisusedtoholdthevalves,andithasportstoallowair,fuelandexhausttomovethroughtheengine.Inaddition,ithascoolantpassages.Fig.1-1-2showsacylinderhead.Afterthecylinderheadhasbeencast,someareasmustbemachinedsothatintakeandexhaustmanifoldscanbeattached,valvescanbeseated,spark

plugsandinjectorscanbeinstalled,andagoodsealcanbeprovidedtotheblock.liner（发动机)气缸套remove拆下replace取代seal密封，封条leak使渗漏valve气门；阀port孔管道exhaust排气inaddition另外intake进气，吸入manifold歧管spark火花plug塞子injector喷油器install安装

CylinderHead（气缸盖）

Fig.1-1-21-cap(盖)2-cylinderheadbolt（气缸盖螺栓）3-exhaustmanifoldgasket（排气歧管垫）4-cylinderheadgasket（气缸盖垫片）5-intakemanifoldgasket(进气歧管垫)6-cylinderhead(气缸盖)7-cylinderheadcovergasket(气缸盖罩垫片)8-cylinderheadcover(气缸盖罩）4.PistonandConnectingRodAssemblyThepistonandconnectingrodassemblytransmitsthepowerfromcombustiontothecrankshaft.ShowninFig.1-1-3,itmainly

consistsofpiston,compressionrings,oilcontrolrings,pistonpinandconnectingrod.(1)piston:Pistonfitscloselywithintheenginecylinderorlinerandisabletomovealternately

upanddowninthecylinder.(2)pistonrings:Therearetwotypesofpistonrings：compressionandoilcontrolrings.Thecompressionringsareusedtosealthepressuresofcompressionandpower.Theoilcontrolringsareemployedtoscrapeoilfromthecylinderwalls.(3)pistonpin:Itisusedtoconnectpistontoconnectingrod.(4)connectingrod:itisusedtoconnectpistontocrankshaftandchangesthereciprocating

motiontotherotarymotion.piston活塞connectingrod连杆combustion燃烧consistsof

由...组成compression压缩pin销fit使配合closely紧密地alternately交替地upanddown上上下下compressionring

气环scrape把...刮除pistonpin活塞销reciprocatingmotion

往复运动rotary旋转的

PistonandRodAssembly

（活塞和连杆总成）

Fig.1-1-3

1-piston(活塞)2-pistonrings(活塞环)3-pistonpin(活塞销)4-connectingrod(连杆)5-connectingrodbolts(连杆螺栓)6-connectingrodcap(连杆盖)7-connectingrodbearing(连杆轴瓦)5.CrankshaftAssemblyItisboltedtothebottomofthecylinderblock.Thecrankshaftassemblyincludesthecrankshaft,bearings,flywheel,harmonicbalancer,timing

gear,andfrontandrearseals.Fig.1-1-4showscrankshaftassembly.6.CamshaftAssemblyThecamshaftisdrivenbythecrankshaftandusedtoopenandclosethevalves.Thecamshaftassemblyincludesthecamshaft,camshafttiminggear,camshaftbearing,andtimingchain,belt（ifused）.harmonicbalancer扭转减震器timing

gear正时齿轮chainbelt链(条)传动带7.ValveDriveMechanismItisusedtotransferthecamshaftliftThevalvedrivemechanismconsistsofthelifters,thepushrodsandtherockerarmsLifterschangetherotarymotionofthecamshafttoreciprocatingmotiontoopenandclosethevalve.Hydraulicliftersareusedtoreducenoiseandcontrolthevalveclearanceonmanyengines.Theyabsorbthevalvetrainclearancebyusingoilpressureinsidethelifterbody.Pushrodsareusedonlyonenginesthathavethecamshaftplacedwithintheblock.Overheadcamshaftsdonotneedpushrods.Rockerarmsaredesignedtochangethedirectionofthecamliftingforce.liftern.

挺柱pushrodn.

推杆rockerarm

摇臂hydraulicadj.

液压的clearancen.间隙liftingforce举升力

CrankshaftAssembly（曲轴总成）

Fig.1-1-41-front(前端)2-mainbearing（主轴颈）3-connectingrodbearing（连杆轴颈）4-crank（曲柄）5-counterweight（平衡重）6-rearflange（后端法兰）7-camshaftassembly（凸轮轴总成）8.ValveAssemblyThevalveassembly,showninFig.1-1-5,includesthevalves,valveguides,valveseats,valvesprings,springretainersandseals.

(1)valves:Theintakevalvesandtheexhaustvalvesarelocatedwithinthecylinderheadonmostenginestoday.Theexhaustvalvesareusuallysmallerindiameterthantheintakeones,becauseontheexhauststrokethegasesmovemoreeasilyforthepressureofthepistonforcingthemout.(2)valveguides:Thevalveguidessupportthevalveinthecylinderhead.(3)valveseats:Theseatsprovideasurfacefortheintakeandexhaustvalvestosealthecombustionchamber.Theyarepressedintothecylinderheadandgroundtothecorrectangle.(4)valvesprings,keepersandretainers:Thevalvespringskeepthevalvesclosedwhenthecamshaftisnotliftingthevalves.Keepersandretainersaredesignedtokeepthevalvespringsecuredtothevalvestem.valveguide气门导管valveseat气门座springretainer弹簧座圈diameter直径combustionchamber燃烧室ground.

与水平面成keeper锁片secure紧固stem杆，柄TranslationSkill(1)

科技英语翻译的标准与方法一、翻译的标准科技英语的翻译标准可概括为“忠实、通顺”四个字。忠实，指忠实于原文内容。通顺，指译文语言必须通俗易懂，符合规范。例如：1.Theelectricresistanceismeasuredinohms.误译：电的反抗是用欧姆测量的。正译：电阻的测量单位是欧姆。

2.Themomentthecircuitiscompleted,acurrentwillstartflowingthecoil.误译：电路被完成的片刻，一个电流将开始流向这个线圈。正译：电路一旦接通，电流开始流向线圈。二、翻译的方法翻译的方法一般来说有直译（literaltranslation）和异译（freetranslation）两种。直译，指“既忠实于原文内容，又忠实于原文的形式”的翻译。异译，指忠实于原文的内容，但不拘泥原文的形式。例如：Manyoilholesaredrilledinternallysothatenginepartscanbeadequatelylubricated.直译：有许多油孔在内部被钻出，以使发动机能够被充分的润滑。异译：发动机内部钻有许多油道，可使其得到充分的润滑。Unit2EFISystem

EFIsystemiscomposedof3basicsub–systems:Fuel,AirInductionandElectronicControlSystems.AnEFIsystemisshowninFig.1-2-11.ElectronicControlSystemTheEngineElectronicControlSystemconsistsofvarioussensors,switchesandactuators.Thevarioussensorsdetecttheintakeairpressure,enginespeed,oxygen

densityintheexhaustgas,enginecoolanttemperature,intakeairtemperatureandatmosphericpressureetc,andconverttheinformationintoanelectricalsignal,whichissenttotheECM.Basedonthesesignals,theECMdeterminestheinjectionvolume(timing)andcalculatestheoptimum

ignitiontimingforthecurrentconditions.TheECMnotonlycontrolsthefuelinjectiontiming,butalsotheselfdiagnosticfunctionwhichrecordstheoccurrenceofamalfunction,ignitiontimingcontrol,idlespeedcontrolandEGRcontrol.induction(发动机)进气actuator执行器density浓度oxygen[化]氧atmospheric大气的determine决定injection喷射optimum最适宜的ignition点火current当前的diagnostic诊断occurrence发生malfunction故障

Fig.1-2-1AEFISystem（燃油系统）1-ignitionswitch2-EFImainreplay3-vehiclespeedsensor4-terminalTE15.PNPswitch6-A/Ccompressor7-starter8-headlightswitch9-defoggerswitch10-MAPsensor11-intakeairtemp.sensor12-IACvalve13-throttlepositionsensor14-enginecoolanttemperaturesensor15-knocksensor16-EGRvalve17-VSVforEGR18-distributorW/ignitioncoil19-igniter20-battery21-malfunctionindicatorlamp22-circuitopeningrelay23-fueltank24-fuelpump25-fuelfilter26-fuelpressurepulsationdamper27-fuelpressureregulator28-injector29-mainoxygensensor30-suboxygensensor(1)TheECMcontrolsthefollowingfunctions:①OptimumAir–FuelRatio

TheECMreceivessignalsfromvarioussensorsindicatingchangingengineoperationconditions.Suchas:intakemanifoldpressure,intakeairtemperature,enginecoolanttemperature,enginespeed,throttlevalveopeningangle,exhaustoxygencontentetc.ThesignalsareutilizedbytheECMtodeterminetheinjectiondurationnecessaryforanoptimumair–fuelratio.②ElectronicSparkAdvance(ESA)TheECMisprogrammedwithdataforoptimumignitiontimingunderalloperatingconditions.Usingdataprovidedbysensorswhichmonitorvariousenginefunctions(RPM,enginecoolanttemperature,etc.),themicrocomputer(ECM)triggersthesparkatpreciselytherightinstant.content含量utilize利用duration持续（时间）monitor监控RPM=RevolutionPerMinute

发动机转速microcomputer微电脑trigger触发precisely精确地instant片刻③IdleAirControl(IAC)TheECMisprogrammedwithtargetidlingspeedvaluestorespondtodifferentengineconditions(enginecoolanttemperature,airconditioningON/OFF,etc.).SensorstransmitsignalstotheECMwhichcontrolstheflowofairthroughthebypassofthethrottlevalveandadjustsidlespeedtothetargetvalue.④DiagnosisTheECMdetectsanymalfunctionsandabnormalitiesinthesensornetworkandlightsamalfunctionindicatorlampinthecombinationmeter.Atthesametime,troubleisidentifiedandadiagnostictroublecodeisrecordedbytheECM.ThediagnostictroublecodecanbereadbythenumberofblinksofthemalfunctionindicatorlampwhenterminalsTE1andE1areconnected.⑤Fail–SafefunctionIntheeventofthesensormalfunction,aback–upcircuitwilltakeovertoprovideminimaldrivability,andthemalfunctionindicatorlampwillilluminate.targetvalue目标值bypass旁路abnormality反常indicator指示器combinationmeter组合仪表identify确认diagnostictroublecode=DTC

故障码blink闪烁fail-safe失效保护illuminate

照明(2)InputsignalTheavailableinputsignalsofavehicleincludethefollowing:1)Airflow

Sensor

2)IntakeAirTemperatureSensor(IAT)3)ThrottlePositionSensor4)CamshaftPositionSensor5)CrankshaftPositionSensor6)VehicleSpeedSensor7)OxygenSensor8）EngineCoolantTemperature(ECT)Sensor9）ManifoldAbsolutePressure(MAP)Sensor10)

EGRGasTemperatureSensor11)

KnockSensor12)

Park/NeutralPosition(PNP)Switch

13)EngineCrankingSignal14)BrakeLightSwitchSignal15)AirConditioning(A/C)Switch16)BatterySignalAirflowSensor空气流量计IntakeAirTemperatureSensor进气温度传感器ThrottlePositionSensor节气门位置传感器EGR=ExhaustGasRecirculation废气再循环KnockSensor爆震传感器Park/NeutralPosition(PNP)Switch驻车/空挡位置开关Cranking起动equip装备list列出idle-up

怠速提升VacuumSolenoidValve

真空电磁阀

fuelpump燃油泵injector喷油器igniter点火器pressureup增压

(3)OutputsignalsVehiclesareequippedwithdifferentcombinationsofcomputer-controlledcomponents.Notallcomponentslistedbelowareusedoneveryvehicle.TheECMreceivesinputsignalsfromsensorsandswitchestocontrolthefollowingcomponentsandsub-systems.Theavailableinputsignalsofavehicleincludethefollowing:1)A/CIdle-UpSystem.2)IdleAirControlValve(IACV)3)EGRVacuum

SolenoidValve(VSV)4)ElectronicSparkAdvanceSystem.5)EVAPVacuumSolenoidValve(VSV)6)

Fuel

Pump7)

Injector8)

Igniter9)FuelpressureupVSV10)Self-DiagnosticSystem.11)CircuitOpeningRelay2.FuelSystemThefuelsystemconsistsofafueltank,electricfuelpump,afuelfilter,fuelfeedandreturnlines,fuelpressureregulator,thepulsation

damperandinjectors.Fig.1-2-2showsthepartsofafuelsystem.(1)ElectricfuelpumpElectricfuelpumpismountedinthefueltank.Itdrawsfuelfromthefueltankandsendsittothefuelrail,whichdistributesfuelevenlytoallinjectors.(2)FuelpressureregulatorThefuelpressureregulatoradjuststhepressureofthefuelfromthefuelline(highpressureside)toaconstantpressurehigherthanthepressureinsidetheintakemanifold,andexcessfuelisreturnedtothefueltankthroughthereturnpipe.(3)PulsationdamperThepulsationdamperabsorbstheslightfluctuationsinfuelpressurecausedbyfuelinjectorfromtheinjector.(4)InjectorsTheinjectorsinjectameteredquantityoffuelintotheintakeportinaccordancewithsignalsfromtheECM(EngineControlModule).filter

滤清器regulator

调节器pulsation

脉动damper

衰减器mount

安放draw吸收rail油轨evenly

平稳地excess

过量的fluctuation波动metered

计量的

ThePartsofAFuelSystem

（燃油系统部件）

Fig.1-2-21-fuelpressurepulsationdamper(燃油压力脉动衰减器)2-injectors(喷油器)3-fuelpressureregulator(燃油压力调节器)4-fuelfilter(燃油滤清器)5-fuelpump(燃油泵)3.AirInductionSystemTheairinductionsystemprovidessufficientairforengineoperation.Fig.1-2-3showsthepartsofaairinductionsystem.Airisfilteredthroughtheaircleanerandtheamountflowingtotheairintakechamberisdeterminedaccordingtothethrottlevalveopeninginthethrottlebodyandtheenginespeed.Intakeaircontrolledbythethrottlevalveopeningisdistributedfromtheairintakechambertothemanifoldofeachcylinderandisdrawnintothecombustionchamber.AtlowtemperaturestheIACvalveopensandtheairflowsthroughtheIACvalveandthethrottlebody,intotheairintakechamber.Duringenginewarmingup,evenifthethrottlevalveiscompletelyclosed,airflowstotheairintakechamber,therebyincreasingtheidlespeed(firstidleoperation).Theairintakechamberpreventspulsationoftheintakeair.Italsopreventsintakeairinterferenceineachcylinder.sufficient足够的combustionchamber

燃烧室IACvalve(IdleAirControl)

怠速空气控制阀warmup

暖机interference

干扰ThePartsofAAirInductionSystem

（进气系统部件）

Fig.1-2-3

1-intakeaircontrolvalve(进气控制阀)2-VSVforACIS(进气控制阀真空开关阀)3-vaccumtank(真空罐)4-aircleaner(空气滤清器)5-MAFmeter(空气流量计)6-IACvalve(怠速控制阀)7-throttlebody(节气门体)TranslationSkill(2)

词义的选择一、根据词类选择词义选择某个词的词义时，首先要确定这个词在句中应属于哪一种词类，然后再进一步去定其词义。下面以“current”为例。例如：

1.TheECMdeterminestheinjectionvolumeandcalculatestheoptimumignitiontimingforthecurrentconditions.译：ECM确定喷油量并计算当前工况下的最佳点火时间。（current为形容词）2.Thebuttonswitchesthecurrenton.译：这个按钮接通电流。（current为名词）二、同一词类表达不同词义英语中同一个词，同一类词，在不同的场合，往往具有不同的含义。此时，必须根据上下文的联系及整个句子的意思加以判断和翻译。例如“as”这一连词。例如：

1.Thevolumevariesasthetemperatureincreases.译：体积随着温度增加而变化。（as引导时间状语从句）2.Asheatmakesthingsmove,itisaformofenergy.译：因为热能使物体运动，所以热是能的一种形式。Unit3

EngineCoolingandLubricationSystem

1.EngineCoolingSystemThecoolingsystemisusedtokeeptheengineatthemostefficientoperatingtemperature.Thecoolingsystemiscomposedofthewaterjacket(insidethecylinderblockandcylinderhead),radiator,waterpump,thermostat,fan,hosesandothercomponents.Fig1-3-1showsthepartsofacoolingsystem.efficient效率高的waterjacket水套radiator散热器，水箱waterpump水泵thermostat节温器hose软管CoolingSystem

（冷却系统）

Fig.1-3-11-radiator(散热器)2-securingclip（固定夹）3-securingrubber（固定橡胶）4-uppercoolanthose（上部冷却液软管）5-rubberwasher（橡胶垫）6-radiatorfan（冷却风扇）7-fanring（风扇罩壳）8-lockingbolt（紧固螺栓）9-nut（螺母）10-2pinconnector（双头插式插头）11-lowercoolanthose（下部冷却液软管）12-Oring（O型圈）13-connector（连接插头）14-radiatorfanthermoswitch（散热风扇的热敏开关）15-seal(密封圈)16–drainscrew（排水螺栓）(1)RadiatorandFanTheradiatorperformsthefunctionofcoolingthecoolantwhichhaspassedthroughthewaterjacketandbecomehot,anditismountedinthefrontofthevehicle.Afanismountedbehindtheradiatortoassisttheflowofairthroughtheradiator.Thefanoperateswhentheenginecoolanttemperaturebecomeshighinordertopreventitfrombecomingtoohigh.(2)RadiatorCapArelief

valve(pressurizationvalve)andavacuumvalve(negativepressurevalve)arebuiltintotheradiatorcap.Itisusedtomaintainthecorrectandconstantpressureonthecoolingsystem.(3)WaterjacketThewaterjacketistheopenspaceswithinthecylinderblockandcylinderheadthroughwhichcoolantpasses.perform执行assist帮助reliefvalve

泄压阀pressurization维持大气压水平vacuumvalve

真空阀negativepressure负压(4)WaterPumpThewaterpumpisusedtocirculatethecoolantthroughthecoolingsystem.Itismountedonthefrontofthecylinderblockanddrivenbyatimingbelt.(5)ThermostatThethermostatisoneofthemostimportantpartsofthecoolingsystem,andusedtokeeptheenginecoolantatthemostefficienttemperature.Ifthecoolantremainscold,itwillbeclosed.Inthiscase,alargeamountofcoolantgoestotheby-passtubewithoutbeingcooled.Theremainingcoolantpassesthroughtheradiatortobecooled.Ifthecoolanttemperaturerisestotheopeningpoint,thethermostatopensslightly.Asthetemperatureincreasesfurther,thethermostatopensmore.Whentheengineisunderfullload,thethermostatwillbefullyopen.Themaximumamountofcoolantwillbesenttotheradiatorforcooling,andasmallamountwillcontinuetoflowthroughtheby-passtube.timingbelt正时皮带by-passtube旁通管openingpoint开启点slightly轻微地load负荷2.EngineLubricationSystemLubricationsystemhasbeenadoptedtosupplyoiltothemovingpartsofthisengine.Thelubricationsystemconsistsofanoilpan,oilpump,oilfilter,oilcoolerandpressurereliefvalve.Fig1-3-2showsthepartsofalubricatingsystem.(1)OilpanTheoilpanislocatedonthebottomoftheengineandholdstheexcessoilduringoperationandnorunningconditions.Apluginthebottomoftheoilpanisusedtodraintheoil.(2)OilpumpTheoilpumpislocatedinthecrankcaseareasothatoilcanbedrawnfromtheoilpanandsentintotheengine.(3)OildrainplugOilpressurereliefvalveisusedtokeepthepressurewithintheoilsystemataconstantmaximumvalue.lubrication

润滑adopt采用supply供给oilpan

油底盘drain排放draw抽吸LubricatingSystem

（润滑系统）Fig.1-3-21-gasket（密封垫片）2-cap（加油口盖）3-dipstick（机油标尺）4–guide（机油标尺导管口）5-oilfilterbracket（机油滤清器支架）6-oilpressureswitch（机油压力开关）7-O-ring（O形圈）8-oilcooler（机油冷却器）9-oilfilter（机油滤清器）10-cap（密封盖）11-drivegear（驱动齿轮）12-gears（齿轮）13-oilpumpcoverwithpressurereliefvalve（带泄压阀的机油泵盖）14-baffleplate（挡油板）15-oildrainplug（放油螺栓）16-seal（密封圈）17-oilpan（机油盘）18-gasket（机油盘垫片）19-suctionline（吸油管）20-Oring（O形圈）(4)OilfilterOilFilterisadoptedtocleanthedirtparticlesoutofthelubricatingsystem.Astheoilanddirtflowthefilterunit,contaminantsaretrappedinsidethefilterunit.(5)OilcoolersOiltemperatureforanengineshouldbeincertainrangeofdegrees.Undernormalconditions,oiliscooledbytherightamountofoilintheoilpan.Whenexcesstemperaturesoccurs,suchassomeheavy-duty

gasolineenginesandmanydieselengines,oilcoolersareusedtokeeptheoilcool.(6)OilpressuresensorsandgaugesOilpressuresensorsareusedtosensetheoilpressureinthelubricatingsystem.Oilpressureisusuallysenseddirectlyfromthemainoilgallery.Thevalueissenttothedashboardonthevehicleandtheoperatorcanreadit.Thesystemscommonlyusedareapressuregaugeandanoilindicatorlight.Thepressuregaugereadstheoilpressurewithinthesystem.Theoilindicatorlightgoesonwhenoilpressureislowerthanacertainvalue.(7)Markingonoil

dipstick（Fig.1-3-3）particle粒子contaminant

污染物trap收集heavy-duty

大功率gasoline

汽油diesel柴油sense感觉

gallery通道dashboard(汽车等的)仪表板gauge仪表dipstick油尺

Dipstick（机油尺）Fig.1-3-31-Max.mark2-Min.marka-Areaabovehatchedfielduptomax.mark:Donottop-upwithengineoil!b-Oillevelwithinhatchedfield:canbetopped-upwithengineoilc-Areafrommin.markuptohatchedfield:fillwithmax.0.5liter.ofengineoil!

TranslationSkill(3)

词义的引申英汉两种语言在表达上有很大差别。翻译时，有些词或词组不能直接搬用词典中的释义，若生搬硬套，会使译文生硬晦涩，难以看懂，甚至造成误解。所以，要在弄清原文内涵的基础上，根据上下文的逻辑关系和汉语的搭配习惯，对词义加以引申。若遇到有关专业方面的内容，必须选用专业方面的术语。引申后的词义虽然同词典中的释义稍有不同，但能更确切地表达原文意义。1.However,colorscangivemoreforcetotheformoftheproduct.欠佳译法：然而，色彩能给与产品更多的力量。引申译法：然而，色彩能使产品外形增添美感。2.Neverheatrefrigerantcontainerorexposeittonakedflame.欠佳译法：永远不要加热制冷剂贮液罐或将它暴露在裸露的火焰中。引申译法：绝对不要直接加热制冷剂贮液罐或者与明火接触。3.Whenexcesstemperaturesoccurs,suchassomeheavy-dutygasolineenginesandmanydieselengines,oilcoolersareusedtokeeptheoilcool.欠佳译法：当过剩的温度发生时，如某些重责任的汽油机和许多柴油机，使用机油冷却器使机油冷却。引申译法：当温度过高时，如某些大功率汽油机和许多柴油机上，使用机油冷却器冷却机油。4.Duringthefirstpartofhislife,Wattstudiedweatherandstorm.欠佳译法：在他生命的第一部分，瓦特研究过天气和风暴。引申译法：瓦特年轻时研究过天气和风暴。Unit4

EngineIgnition,Starting

andChargingSystem1.EngineIgnitionSystem

Theignitionsystemisusedtoignitetheairandfuelinthecylinder.Inordertodothisaveryhighvoltageisneededtoforcetheelectricalcurrenttojumpacrossthesparkpluggapandcauseanelectricalspark.However,thereisonly12-voltbatterywithintheautomobile.Theignitionsystemisdesignedtoincreasethevoltagetothenecessaryamountattherighttimeforthesparktooccur.Inaddition,thetimeofsparkmustbealteredasspeedandloadincreaseordecrease.voltage电压，伏特数electricalcurrent电流jumpacross击穿sparkpluggap火花塞间隙automobile汽车alter变化Theignitionsystemmaybeclassifiedasfollows:(1)Conventionalignitionsystemwithcontactbreaker(2)Electronicignitionsystemusingsemiconductorsortransistors(3)Computer-controlledignitionsystemThecomputer-controlledignitionsystemiscomposedofElectronicControlModule(ECM),varioussensors,battery,theignitionswitch,igniter,ignitioncoil,distributorandthesparkplugs.Fig.1-4-1showsaignitionsystem.asfollows如下，如次contactbreaker触点断电器semiconductor半导体Transistor晶体管

EngineIgnitionSystem

（发动机点火系统）Fig.1-4-1

1-battery(蓄电池)2-ignitionswitch(点火开关)3-ignitioncoil(点火线圈)4-distributor(分电器)5-sparkplug(火花塞)6-igniter(点火器)7-signalrotor(信号转子)8-ECM(电子控制模块)Componentsintheignitionsystemareasfollows:(1)Thebatteryisusedtoprovideelectricalenergyneededtooperatethesystem.Thenegativesideisgroundedtotheframe,andthepositivesideisfeddirectlytotheignitionswitch.(2)Theignitionswitchconnectsordisconnectstheflowofelectricitytotheignitionsystem.(3)TheignitertemporarilyinterruptstheprimarycurrentwiththeignitionsignalfromtheECMandgeneratessparksatthesparkplug.(4)TheECMmonitorstheengineconditionbysignalsfromeachsensor,calculatestheignitiontimingandsendsanignitionsignaltotheigniter.ground接地，搭铁positive

阳的，正的temporarily

临时的primarycurrent

初级电流monitor监控(5)Theignitioncoilallowsthegenerationofahighvoltagesufficienttocauseasparktojumpacrossthesparkpluggap.(6)Thedistributordistributeshighvoltagetothesparkplugofeachcylinderinthespecifiedignitionorder.Fig.1-4-2showspartsofthedistributor.(7)Thesparkplugwiresareusedtoconnectthehigh-voltagetoeachsparkplug.(8)Thesparkplugsprovideagapwithinthecombustionchambersothateachtimeahigh-voltageisdelivered,aqualitysparkwilloccur.sufficient

充足的specified

规定的sparkplugwires

分缸线deliver传递PartsofTheDistributor

（分电器部件）

Fig.1-4-21-distributorhousing(分电器壳体)2-dustproofcover(防尘罩)3-dustproofseal(防尘罩密封圈)4-rotor(转子)5-packingring(密封圈)6-distributorcap(分电器盖)2.EngineStartingSystemThestartingSystemisusedtostartaengine.Itincludescrankingmotor,solenoid,clutchmechanism,electricalwire,andignitionswitch.Fig.1-4-3showsacompleteelectricalcircuitofthestartingsystem.(1)startingmotorFieldcoilsinastartingmotorisusedtoproducethepoles.Armatureinastartingmotorisarotationalpartthathasmanyloopsofwirewithacommutator.Brushesareusedtomakeelectricalcontactbetweentherotatingarmatureandthestationarybattery.(2)StarterclutchThepurposeoftheclutchistoengageanddisengagethepiniongearfromtheflywheel.Whenthestarteriscranked,thepiniongearslidesonthearmatureshaftandengagestheflywheel.

crankingmotor

起动机solenoid

电磁开关field磁场pole电极armature

电枢loop匝commutator

换向器brush电刷engage啮合disengage

分离TheElectricalCircuitofStartingSystem（起动系统电路）Fig.1-4-3

1-battery(蓄电池)2-starter(起动机)3-starterrelay(起动继电器)4-ignitionswitch(点火开关)5-neutralstartswitch(空挡起动开关)(3)solenoidThesolenoidisanelectromechanicaldevicethatswitcheselectricalcircuitsonandoff.Itisusedtostartandstoptheheavycurrentthatflowstothestartermotorduringcranking.3.EngineChargingSystemThepurposeofthechargingsystemistoprovidetheelectricalenergyneededtochargethebatteryandtopoweralltheelectricalcomponentsandsystemsontheautomobile.Whentheengineisnotrunningandd