汽车专业英语全套教学课件

汽车专业英语AUTOMOTIVEENGINEERINGENGLISH（车辆工程/交通运输/汽车服务工程）授课人：全套可编辑PPT课件课程介绍课程属性——学科选修课课时——36学时课程内容——汽车基础（结构原理）、诊断修理、营销服务、汽车设计制造学习目的1.打好基础：首先掌握必要词汇，熟悉并巩固语法与专业知识，开阔眼界；学好本门课程，对考研亦有一定的帮助2.掌握翻译技巧，提高翻译水平，较熟练笔译专业资料，解决生产实际中的问题3.阅读本专业领域的国外资料，了解和掌握汽车的发展动态和前沿技术，以及汽车设计制造新技术/维修技术/销售服务（任一方向），为研究和创新奠定基础学习方法认真听讲，做好记录，大胆实践参考教材：汽车专业英语，宋进桂，机械工业出版社AUTOMOTIVEENGINEERINGENGLISHForewordSTRUCTURE

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AUTOMOTIVEENGINEERINGENGLISHAutomotiveMaintenanceandRepairAutomotiveBasicsAutomotiveMarketingandServiceAutomotiveDesignandManufacturing课程结构本章学习内容Chapter1GeneralInformation

本章学习内容、目标和重点难点本章学习目标本章难点重点1.BasicPartsofAutomobile1.ClassificationofAutomobile1.掌握汽车组成、主要系统部件的英文名称2.掌握汽车的分类3.了解各个系统的主要组成和功能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1.1.1

NewWordsandPhrasescategory['kætigəri]n.种类，类型，范畴manifold['mænifəuld]a.多种形式的n.多种；歧管styling['stailiŋ]n.花[式]样streamlined['stri:mlaind]a.流线型的,现代化的chassis['∫æsi]n.底盘coolant['ku:lənt]n.冷却液，冷却剂lubrication[ֽlu:bri'kei∫ən]n.润滑Chapter1GeneralInformation

1.1BasicPartsofAutomobiletransmission[trænz'mi∫ən]n.变速器，传动,传动系统，传送，发射clutch[klʌt∫]n.离合器hydraulic[hai'drɔ:lik]a.液压的，水压的，水力的manoeuvre[mə'nu:və]=maneuvrev.策划，机动；n.策略,调动drum[drʌm]n.鼓,鼓声；v.击鼓pedal['pedl]n.踏板Chapter1GeneralInformation

1.1BasicPartsofAutomobileignition[ig'ni∫ən]n.点火,点燃ignite[ig'nait]v.点火,点燃carburetor['kɑ:bjuretə]n.化油器combustible[kəm'bʌstəbl]a.易燃的axle['æksl]n.轮轴,车轴suspension[səs'pen∫ən]n.悬架，悬浮,悬浮液,暂停,中止,悬而未决differential[ֽdifə'ren∫əl]n.差速器，微分；a.微分的，差动的Chapter1GeneralInformation

1.1BasicPartsofAutomobilepowerunit动力装置gasolineengine汽油机spark-ignitionengine点燃式发动机dieselengine柴油机compression-ignitionengine压燃式发动机combustiblemixture可燃混合气motoroil发动机油Chapter1GeneralInformation

1.1BasicPartsofAutomobilewindresistance空气阻力，风阻drivingspeed行驶速度powertrain传动系，动力装置propellershaft传动轴rearaxle后桥drivingroadwheel驱动轮torqueconverter液力变矩器driveshaft传动轴Chapter1GeneralInformation

1.1BasicPartsofAutomobileToday'saveragecarcontainsmorethan15,000separate,individualpartsthatmustworktogether.Thesepartscanbegroupedintofourmajorcategories:engine,body,chassisandelectricalequipments，seeFig.1-1.Fig.1-1basicpartsofacarChapter1GeneralInformation

1.1BasicPartsofAutomobile1.1.2

Text

Theengineactsasthepowerunit.Therearetwotypesofengine:gasolineengine(alsocalledaspark-ignitionengine)anddieselengine(alsocalledacompression-ignitionengine).Allengineshavefuel,exhaust,cooling,andlubricationsystems.Gasolineenginesalsohaveanignitionsystem.Theignitionsystemsuppliestheelectricsparkneededtoignitetheair-fuelmixtureinthecylinders.Thefuelsystemstoresliquidfuelanddeliversittotheengine.Thefuelismixedwithairtoformacombustiblemixtureinthecarburetor,themanifold,orthecylindersthemselves.Thecoolingsystemremovesexcessiveheatfromtheengine.Airandacoolantareusedtocarryawaytheheat.Thelubricationsystemisimportantinkeepingtheenginerunningsmoothly.Motoroilisthelubricantusedinthesystem.Chapter1GeneralInformation

1.1BasicPartsofAutomobile1.Engine

Anautomobilebody(Fig.1-2)providesaprotectivecoveringfortheengine,passengers,andcargo.Thebodyisdesignedtokeeppassengerssafeandcomfortable.Thebodystylingprovidesanattractive,colorful,modernappearanceforthevehicle.Itisstreamlinedtolessenwindresistanceandtokeepthecarfromswayingatthedrivingspeeds.Chapter1GeneralInformation

1.1BasicPartsofAutomobile2.BodyFig.1-2Anautomobilebody3.ChassisThechassisincludesthepowertrain,suspension,steering,andbrakesystems.Thepowertrainsystemcomprisesclutch,transmission,propellershaft,rearaxleanddifferentialandthedrivingroadwheels.Theclutchortorqueconverterhasthetaskofdisconnectingandconnectingtheengine'spowerfromandtothedrivingwheelsofthevehicle.Themainpurposeofthetransmissionorgearboxistoprovideaselectionofgearratiosbetweentheengineanddrivingwheels,sothatthevehiclecanoperatesatisfactorilyunderalldrivingconditions.Gearselectionmaybedonemanuallybythedriverorautomaticallybyahydrauliccontrolsystem.Chapter1GeneralInformation

1.1BasicPartsofAutomobile要点分析：drivingwheels参考译文：驱动轮从动轮是什么？是Drivenwheels!Drivenwheels还有“驱动轮”（被发动机驱动）的意思。只有联系上下文确定其具体指什么。

知识拓展Thefunctionofthepropeller(drive)shaftistotransmitthedrivefromthegearboxtotheinputshaftoftherearaxleanddifferentialassembly.Flexiblejointsallowtherearaxleandwheelstomoveupanddownwithoutaffectingoperation.Therearaxleanddifferentialunittransmitstheengine'srotationalpowerthrough90°frompropellershafttoaxleshafttoroadwheels.Afurtherfunctionistoalloweachdrivingwheeltoturnatadifferentspeedwhencornering.Athirdfunctionistointroduceanothergearratiofortorquemultiplication.Chapter1GeneralInformation

1.1BasicPartsofAutomobile

Thebasicjobofthesuspensionsystemistoabsorbtheshockscausedbyirregularroadsurfacesthatwouldotherwisebetransmittedtothevehicleanditsoccupants,thushelpingtokeepthevehicleonacontrolledandlevelcourse,regardlessofroadconditions.

Chapter1GeneralInformation

1.1BasicPartsofAutomobile

Thebasicjobofthesuspensionsystemistoabsorbtheshockscausedbyirregularroadsurfacesthatwouldotherwisebetransmittedtothevehicleanditsoccupants,thushelpingtokeepthevehicleonacontrolledandlevelcourse,regardlessofroadconditions.难点提示：

1）thatwouldotherwisebetransmittedtothevehicleanditsoccupants是shocks的定语从句；2）thushelping…现在分词短语作主句的状语，并非定语从句的构成部分；3）tokeepthevehicleonacontrolledandlevelcourse不定式短语的含义是“使汽车保持在可以控制的、笔直的行驶路线上。”参考译文：悬架系统的基本作用是吸收路面不平引起的冲击和振动，使其不会传递给车辆和乘员，这样，不管路况如何，都能使车辆具有可控制的、笔直的行驶路线。难点分析Thesteeringsystemprovidesthemeansbywhichthefrontwheelsaredirectionallyturned.Thesteeringsystemmaybepowerassistedtoreducetheeffortrequiredtoturnthesteeringwheelandmakethevehicleeasiertomanoeuvre.

Chapter1GeneralInformation

1.1BasicPartsofAutomobile

Thebrakingsystemonavehiclehasthreemainfunctions.Itmustbeabletoreducethespeedofthevehicle,whennecessary;itmustbeabletostopthecarinasshortadistanceaspossible;itmustbeabletoholdthevehiclestationary.Eachwheelhasabrakeassembly,ofeitherthedrumtypeorthedisctype,hydraulicallyoperatedwhenthedriverappliesthefootbrakepedal.Chapter1GeneralInformation

1.1BasicPartsofAutomobile

4.ElectricalEquipmentTheelectricalsystemsupplieselectricityfortheignition,horn,lights,heater,andstarter.Theelectricitylevelismaintainedbyachargingcircuit.Thiscircuitconsistsofabattery,andanalternator(orgenerator).Thebatterystoreselectricity.Thealternatorchangestheengine'smechanicalenergyintoelectricalenergyandrechargesthebattery.Chapter1GeneralInformation

1.1BasicPartsofAutomobile

Chapter1GeneralInformation

1.2

ClassificationofAutomobile

sedan[si'dæn]n.轿车,轿子enclosed[in'klouzd]a.封闭的,密闭的pick-up['pikʌp]n.拾波器，皮卡（轻型货车），传感器gross[grous]a.总的,毛重的;n.总额coach[kout∫]n.四轮大马车,长途客车,教练rigid['ridʒid]a.刚硬的,刚性的,严格的axle['æksl]n.轮轴,车轴articulated[ɑ:'tikjuleitid]a.铰接(的),有关节的1.2.1

NewWordsandPhrasesChapter1GeneralInformation

1.2

ClassificationofAutomobile

capacity[kə'pæsiti]n.容量,生产量,才能,能力commuter[kə'mju:tə]n.长期月票使用者luxurious[lʌg'zjuəriəs]a.奢侈的,豪华的passengercar乘用车commercialvehicle商用车multi-purposevan多用途厢式车Chapter1GeneralInformation

1.2

ClassificationofAutomobile

Motorvehiclescanbeclassifieddependingonthefollowingfeatures:

·Usesofvehicle.Motorvehiclescanbedividedintopassengercarsandcommercialvehicles.Passengercarsareprimarilyintendedforuseintransportingpeople,aswellastheirluggageandothersmallcargo.Thenumberofseats,includingthatofthedriver,isrestrictedtonine.Commercialvehiclesaredesignedtotransportpeopleandcargoandforpullingtrailers,seeFig.1-3.

1.1.2TextApassengercarsorcommercialvehicle?判断是乘用车还是商用车？SedanCoupeMPVSUVPassengervehicle(numberofseatsismorethan9)PickupCrossoverGreencar（低污染或无污染汽车。不确定，但多属于乘用车，如EV、HEV）知识拓展

Chapter1GeneralInformation

1.2

ClassificationofAutomobile

知识拓展英文“货车”、“重型货车”、“轻型货车”Truck,lorry=goodscar=goodsvehicle=goods-carryingvehicleHeavy（heavyduty）truck=heavygoodsvehicleLighttruckChapter1GeneralInformation

1.2

ClassificationofAutomobile

·Bodyshapes.Asedanhasanenclosedbodywithamaximumof4doorstoallowaccesstothepassengercompartment.Thedesignalsoallowsforstorageofluggageorothergoods.Asedancanalsobereferredtoasasaloonandtraditionallyhasafixedroof.Therearesoft-topversionsofthesamebodydesignexceptforhaving2doors,andthesearecommonlyreferredtoasconvertibles(Fig.1-4).1.1.2TextFig.1-4Bodyshapes

Chapter1GeneralInformation

1.2

ClassificationofAutomobile

Multi-purposevans(MPV)canbebasedoncommonsedandesignsorredesignssothatmaximumcargospaceisavailable.Thepick-upcarriesgoods.Usuallyithasstrongerchassiscomponentsandsuspensionthanasedantosupportgreatergrossvehiclemass.Thebodiesofcommercialvehiclesthattransportgoodsaredesignedforthatspecificpurpose.

Busesandcoachesareusually4-wheelrigidvehicles,butalargenumberofwheelsandaxlescanbeused.Sometimesarticulatedbusesareusedtoincreasecapacity.Busesandcoachescanbesingle-deckordouble-deck.Busesarecommonlyusedincitiesascommutertransportswhilecoachesaremoreluxuriousandusedforlongdistances.小结与作业Mainparts,classification阅读并记住黑体字专业词汇；提出疑难问题掌握汽车组成和分类术语复习1.Discribethemainpartsofacar?说明汽车的主要组成部件（系统）有哪些？2.Vehicleclassificatin汽车分类提问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PrincipleofOperationClassificationsMainpartsandsystems1.掌握内燃机的分类英文术语2.掌握机体、曲柄连杆机构、配气机构的英文术语2.了解各个系统的主要功能1.重点为记忆分类和主要部件英文专业术语2.难点需要记忆的生词偏多3.准确汉译表达也是难点Chapter2InternalCombustionEngine

2.1PrincipleofOperation

NicolausAugustOtto尼古拉斯·奥古斯特·奥托GottliebDaimler戈特利布·戴姆勒associate[ə'səu∫ieit]n.伙伴，同事，合伙人pioneer[¸paiə'niə]n.拓荒者，先驱者,开拓者；v.开辟，倡导combustion[kəm'bʌs∫ən]n.燃烧stroke[strouk]n.冲程piston['pistən]n.活塞cylinder['silində]n.气缸2.1.1

NewWordsandPhrasesChapter2InternalCombustionEngine

2.1PrincipleofOperation

valve[vælv]n.气门，阀门，阀exhaust[ig'zɔ:st]n.排气，废气intake['inteik]n.进气，进（引，吸）入compression[kəm'pre∫ən]n.压缩crankshaft['kræŋk∫ɑ:ft]n.曲轴cylinder['silində]n.气缸，圆筒charge[t∫ɑ:dʒ]n.充气，充量，充电；v.充电，增压□descend[di'send]v.

下降，下倾，下斜，下行Chapter2InternalCombustionEngine

2.1PrincipleofOperation

aspirate['æspəreit]v.吸气，抽吸throttle['θrɔtl]n.节气门，节流阀，油门，风门depression[di'pre∫ən]n.萧条(期)，凹地，洼地，低（气）压atomise['ætəmaiz]v.使雾化，喷雾，粉化innermost['inəməust]a.最内的，最内部的，最深处的，内心深处的outermost['autəməust]a.最外边的，离中心最远的maybe['meibi]ad.大概,或许,可能Chapter2InternalCombustionEngine

2.1PrincipleofOperation

aspirate['æspəreit]v.吸气，抽吸throttle['θrɔtl]n.节气门，节流阀，油门，风门depression[di'pre∫ən]n.萧条(期)，凹地，洼地，低（气）压atomise['ætəmaiz]v.使雾化，喷雾，粉化innermost['inəməust]a.最内的，最内部的，最深处的，内心深处的outermost['autəməust]a.最外边的，离中心最远的maybe['meibi]ad.大概,或许,可能Chapter2InternalCombustionEngine

2.1PrincipleofOperationmotorvehicle汽车，机动车petrolengine汽油机flammablemixture可燃混合气spark-ignition(S.I.)engine点燃式（S.I.）发动机cylinderhead气缸盖inletvalve进气门exhaustvalve排气门inductionstroke进气行程Chapter2InternalCombustionEngine

2.1PrincipleofOperationatmosphericpressure大气压力naturallyaspirated自然吸气normallyaspirated自然吸气compressionstroke压缩行程air-and-petrolcharge空气与汽油的混合气powerstroke做功行程exhauststroke排气行程spark-plug火花塞Chapter2InternalCombustionEngine

2.1PrincipleofOperation

Thefirstinternal-combustionenginetooperatesuccessfullyonthefour-strokecycleusedgasasafuelandwasbuiltin1876byNicolausAugustOtto,aself-taughtGermanengineerattheGas-motoreufabrikDeutzfactorynearCologne,formanyyearsthelargestmanufacturerofinternal-combustionenginesintheworld.ItwasoneofOtto’sassociates–GottliebDaimler–wholaterdevelopedanenginetorunonpetrolwhichwasdescribedinpatentnumber4315of1885.Healsopioneereditsapplicationtothemotorvehicle.Petrolenginestakeinaflammablemixtureofairandpetrolwhichisignitedbyatimedsparkwhenthechargeiscompressed.Theseenginesarethereforesometimescalledspark-ignition(S.I.)engines.2.1.2

TextChapter2InternalCombustionEngine

2.1PrincipleofOperation

Theseenginesrequirefourpistonstrokestocompleteonecycle:anair-and-fuelintakestrokemovingoutwardfromthecylinderhead,aninwardmovementtowardsthecylinderheadcompressingthecharge,anoutwardpowerstroke,andaninwardexhauststroke.

Inductionstroke.Theinletvalveisopenedandtheexhaustvalveisclosed.Thepistondescends,movingawayfromthecylinderhead(Fig.2-1(a)).Thespeedofthepistonmovingalongthecylindercreatesapressurereductionordepressionwhichreachesamaximumofabout0.3barbelowatmosphericpressureatone-thirdfromthebeginningofthestroke.Thedepressionactuallygeneratedwilldependonthespeedandloadexperiencedbytheengine,butatypicalaveragevaluemightbe0.12barbelowatmosphericpressure.Chapter2InternalCombustionEngine

2.1PrincipleofOperation

Thisdepressioninduces(sucksin)afreshchargeofairandatomisedpetrolinproportionsrangingfrom10to17partsofairtoonepartofpetrolbyweight.Anenginewhichinducesfreshchargebymeansofadepressioninthecylinderissaidtobe‘normallyaspirated’or‘naturallyaspirated’.

Compressionstroke.Boththeinletandtheexhaustvalvesareclosed.Thepistonbeginstoascendtowardsthecylinderhead(Fig.2-1(b)).Theinducedair-and-petrolchargeisprogressivelycompressedtosomethingoftheorderofone-eighthtoone-tenthofthecylinder’soriginalvolumeatthepiston’sinnermostposition.Thiscompressionsqueezestheairandatomised-petrolmoleculesclosertogetherandnotonlyincreasesthechargepressureinthecylinderbutalsoraisesthetemperature.Chapter2InternalCombustionEngine

2.1PrincipleofOperation

Typicalmaximumcylindercompressionpressureswillrangebetween8and14barswiththethrottleopenandtheenginerunningunderload.Powerstroke.Boththeinletandtheexhaustvalvesareclosedand,justbeforethepistonapproachesthetopofitsstrokeduringcompression,aspark-plugignitesthedensecombustiblecharge(Fig.2-1(c)).Bythetimethepistonreachestheinnermostpointofitsstroke,thechargemixturebeginstoburn,generatesheat,andrapidlyraisesthepressureinthecylinderuntilthegasforcesexceedtheresistingload.Theburninggasesthenexpandandsochangethepiston’sdirectionofmotionandpushittoitsoutermostposition.Thecylinderpressurethendropsfromapeakvalueofabout60barsunderfullloaddowntomaybe4barneartheoutermostmovementofthepiston.Chapter2InternalCombustionEngine

2.1PrincipleofOperation

Exhauststroke.Attheendofthepowerstroketheinletvalveremainsclosedbuttheexhaustvalveisopened.Thepistonchangesitsdirectionofmotionandnowmovesfromtheoutermosttotheinnermostposition(Fig.2-1(d)).Mostoftheburntgaseswillbeexpelledbytheexistingpressureenergyofthegas,butthereturningpistonwillpushthelastofthespentgasesoutofthecylinderthroughtheexhaust-valveportandtotheatmosphere.Chapter2InternalCombustionEngine

2.1PrincipleofOperation

Fig2-1Four-stroke-cyclepetrolengineChapter2InternalCombustionEngine

2.2EngineClassifications

Fig2-1Four-stroke-cyclepetrolengineChapter2InternalCombustionEngine

2.2EngineClassifications

complicated['kɔmplikeitid]a.复杂的，难懂的，结构复杂的valvetrain['vælv'trein]n.气门机构，配气机构，气门组camshaft['kæmʃɑ:ft]n.凸轮轴diesel['di:zəl]n.柴油gasoline['gæsəli:n]n.汽油methanol['meθənəul]n.甲醇propane['prəupein]n.丙烷four-stroke-cycleengine四冲程（循环）发动机2.2.1

NewWordsandPhrasesChapter2InternalCombustionEngine

2.2EngineClassifications

roadvehicle道路车辆flat(horizontal-opposed)engine水平对置式发动机inlineengine直列式发动机V-typeengineV型发动机overheadcamshaft(OHC)顶置凸轮轴（OHC）overheadvalve(OHV)顶置气门（OHV）doubleoverheadcamshaft(DOHC)engine双顶置凸轮轴（DOHC）发动机air-cooledengine风冷发动机liquid-cooledengine水冷发动机Chapter2InternalCombustionEngine

2.2EngineClassifications

Today’sautomotiveenginescanbeclassifiedinseveralwaysdependingonthefollowingdesignfeatures:·Operationalcycles.Therearetwo-strokeandfour-strokecycles.Four-stroke-cycleenginesarewidelyusedonroadvehicles.However,afewoldercarshaveusedandsomecarsinthefuturewilluseatwo-strokeengine.·Numberofcylinders.Currentenginedesignsinclude3-,4-,5-,6-,8-,10-,and12-cylinderengines.·Cylinderarrangement.Anenginecanbeflat(horizontal-opposed),inline,orV-type.Othermorecomplicateddesignshavealsobeenused.Seefigure2-2.2.2.2Text

Fig.2-2CylinderarrangementsChapter2InternalCombustionEngine

2.2EngineClassifications

·Valvetraintype.Enginevalvetrainscanbeeithertheoverheadcamshaft(OHC)typeorthecamshaftin-blockoverheadvalve(OHV)type(Figure2-3).Someenginesseparatecamshaftsfortheintakeandexhaustvalves.ThesearebasedontheOHCdesignandarecalleddoubleoverheadcamshaft(DOHC)engines.V-typeDOHCengineshavefourcamshafts—twooneachside.Figure2-3(a)Overheadcamshaft（OHC）

Chapter2InternalCombustionEngine

2.2EngineClassifications

·Valvetraintype.Enginevalvetrainscanbeeithertheoverheadcamshaft(OHC)typeorthecamshaftin-blockoverheadvalve(OHV)type(Figure2-3).Someenginesseparatecamshaftsfortheintakeandexhaustvalves.ThesearebasedontheOHCdesignandarecalleddoubleoverheadcamshaft(DOHC)engines.V-typeDOHCengineshavefourcamshafts—twooneachside.Figure2-3(b)Overheadvalve(OHV)engines

Chapter2InternalCombustionEngine

2.2EngineClassifications·Ignitiontype.Therearetwotypesofignitionsystems:sparkignitionandcompressionignition.Gasolineenginesuseasparkignitionsystemandaresortedtosparkignitionengines.Inasparkignitionengine,theair-fuelmixtureisignitedbyanelectricalspark.Dieselengines,orcompressionignitionengines,havenosparkplugs.Anautomotivedieselenginereliesontheheatgeneratedasairiscompressedtoignitetheair-fuelmixtureforthepowerstroke.

·Coolingsystems.Therearebothair-cooledandliquid-cooledenginesinuse.Nearlyalloftoday’sengineshaveliquid-coolingsystems.·Fueltype.Severaltypesoffuelcurrentlyusedinautomobileenginesincludegasoline,naturalgas,methanol,diesel,andpropane.Themostcommonlyusedisgasolinealthoughnewfuelsarebeingtested.Chapter2InternalCombustionEngine

2.2EngineClassificationsChapter2InternalCombustionEngine

2.3Engineblockandhead

foundation[faun'dei∫ən]n.基础，基地，基金，机座，基础件accessory[æk'sesəri]n.附属品，附件，辅助装置clutch[klʌt∫]n.离合器housing['hauziŋ]n.外壳，bolt[boult]n.螺栓；v.用螺栓连接core[kɔ:]n.核心，铁心，型芯，沙芯，（电缆）芯线aluminum[ælju'miniəm]n.铝liner['lainə]n.衬套，衬里，衬板2.3.1

NewWordsandPhrasesChapter2InternalCombustionEngine

2.3Engineblockandheadengineblock气缸体cylinderblock气缸体clutchhousing离合器壳castiron铸铁cylindersleeve气缸套combustionchamber燃烧室lightvehicle轻型汽车Chapter2InternalCombustionEngine

2.3Engineblockandhead

2.3.1EngineblockTheengineblock(orcylinderblock)servesasarigidmetalfoundationforallpartsofanengine(Fig.2-4).Itcontainsthecylindersandsupportsthecrankshaftandcamshaft.Accessoryunitsandtheclutchhousingareboltedtoit.Blocksaremadeofeithercastironoraluminum.

2.3.2

TextChapter2InternalCombustionEngine

2.3Engineblockandhead

Thecylinderisaroundholeformedintheblock.Itformsaguideforthepistonandactsasacontainerfortakingin,compressing,firing,andexhaustingtheair-fuelcharge.Cylindershavebeenmadeofbothsteelandcastiron.Castironisbyfarthemostpopular.Whensteelcylindersaredesiredinanaluminumblock,theyareinstalledintheformofcylindersleeves(round,pipe-likeliners).Thesesleevesmaybeeithercastorpressedintotheblock.Someenginesuseremovablecylindersleeves.Whenthecylinderbecomesworn,theoldsleevescanbepulledoutandnewsleevescanbepressedin.

Chapter2InternalCombustionEngine

2.3Engineblockandhead2.3.2CylinderheadThecylinderheadfastenstothetopoftheblock(Fig.2-4).Theundersideformsthecombustionchamberwiththetopofthepiston.In-lineenginesoflightvehicleshavejustonecylinderheadforallcylinders;largerin-lineenginescanhavetwoormore.Justaswithengineblocks,cylinderheadscanbemadeofcastironoraluminumalloy.

Chapter

2InternalCombustionEngine

2.3EngineblockandheadFig.2-4Cylinderblock,cylinderheadandcamshaft小结与作业Mainengineparts,classification阅读并记住黑体字专业词汇；提出疑难问题掌握发动机工作原理、主要组成和分类术语复习提问（教师说发动机汉语部件名称，同学回答英文名称）用英语说明内燃机分类方式和类别Whatarefourstrokesinafour-stroke-cycleengine?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2.4Pistons,ConnectingRodsandCrankshaft2.5ValveSystem1.掌握曲柄连杆机构主要组成、零件英文名称；2.了解VVT系统的主要功能1.重点为记忆曲柄连杆机构主要组成、零件英文专业术语2.难点需要记忆的生词偏多3.汉译准确表达也是难点Chapter2InternalCombustionEngine

2.4Pistons,ConnectingRodsandCrankshaft

bearing['bεəriŋ]n.轴承journal['ʤə:nəl]n.轴颈throw[θrou]n.&v.投掷，扔；n.投掷距离，偏心距离，摆幅；（pl.）曲柄attach[ə'tæt∫]v.附着，连接，固定（to）reciprocating[ri'siprəkeitiŋ]a.往复的2.4.1

NewWordsandPhrases

2.4.1PistonandconnectingrodThepistonmustmovedownthroughthecylindertoproduceavacuumtodrawafuelchargeintothecylinder.Itthentravelsupinthecylinderandcompressesthemixture.Whenthemixtureisfired,thepressureoftheexpandinggasistransmittedtothetopofthepiston.Thisdrivesthepistonbackdownthroughthecylinderwithgreatforce,transmittingtheenergyoftheexpandinggastothecrankshaft.Thepistonthentravelsupthroughthecylinderandexhauststheburnedfuelcharge.Pistonsareusuallymadeofaluminum.Often,aluminumpistonsaretin-platedtoallowproperbreak-inwhentheengineisstarted.Aluminumpistonscanbeforged,buttheyaremorecommonlycast.Castironisagoodmaterialforpistonsusedinaslow-speedengine.Ithasexcellentwearcharacteristicsandwillprovidegoodperformance.Chapter2InternalCombustionEngine

2.4Pistons,ConnectingRodsandCrankshaft2.4.2TextFig.2-5Pistons,connectingrodsandcrankshaft

Asthenameimplies,connectingrodsareusedtoconnectpistonstothecrankshaft(Fig.2-5).Theupperendoftherodhasaholethroughitforthepistonpin.Thebottomofthelargeendoftheconnectingrod(Fig.2-6)mustberemovedsotherodcanbeinstalledonthecrankshaftjournal.Thesectionthatisremovediscalledtheconnectingrodcap.Connectingrodsarenormallymadeofalloysteel.Theyaredrop-forgedtoshapeandthenmachined.Fig.2-6ConnectingrodChapter2InternalCombustionEngine

2.4Pistons,ConnectingRodsandCrankshaft

2.4.2CrankshaftTheenginecrankshaft(Fig.2-7)providesaconstantturningforcetothewheels.Ithasthrowstowhichconnectingrodsareattached,anditsfunctionistochangethereciprocatingmotionofthepistontoarotarymotiontodrivethewheels.Crankshaftsaremadeofalloysteelorcastiron.

Thecrankshaftisheldinpositionbyaseriesofmainbearings.Themaximumnumberofmainbearingsforacrankshaftisonemorethanthenumberofcylinders.Itmayhavefewermainbearingsthancylinders.Chapter2InternalCombustionEngine

2.4Pistons,ConnectingRodsandCrankshaft

Mostenginesuseprecisioninsertbearingsthatareconstructedliketheconnectingrodbearings,butaresomewhatlarger.Inadditiontosupportingthecrankshaft,oneofthemainbearingsmustcontroltheforwardandbackwardmovement.Fig.2-7Crankshaft

Chapter2InternalCombustionEngine

2.5ValveSystem

lifter['liftə]n.挺杆clearance['kliərəns]n.间隙2.5.1

NewWordsandPhrases

Thecamshaftmustturnatone-halfcrankshaftspeed.Thecamshaftislinkedwithcrankshaftbyoneofthreeways:beltdrive,chaindriveandgeardrive.Themaincomponentsofthevalvesystemare:

Camshaft.Itisusedtoopenandclosethevalves.Generallyonlyonecamshaftisusedinmostengines.Newerenginesareincreasinglyequippedwithtwoormorecamshafts(Figure2-8).Valves.Eachenginecylinderordinarilyhastwovalves.However,modernenginesoftenusefourvalvespercylinder(twointakevalvesandtwoexhaustvalves).Inordertopreventburning,thevalvemustgiveoffheattothevalveseatandtothevalveguide.Thevalvemustmakegoodcontactwiththeseatandmustrunwithminimumclearanceintheguide.Chapter2InternalCombustionEngine

2.5ValveSystem2.5.2Text

Valvelifters.Mechanicalvalvelifterswereusedinolderengines.Mostvalvetrainsthatcontainmechanicalliftershavesomeprovisionforadjustingclearance.Hydraulicvalveliftersperformthesamejobasmechanicallifters.However,hydraulicliftersareself-adjusting,operatewithnolifter-to-rockerarmclearance,andusesengine