汽车专业英语课件 Module 2

Module2EnginePartⅠReadingMaterialsPartⅡSkillTrainingPartⅢExercisesPartⅣListeningandSpeaking学习目标(１)能够用英语介绍发动机曲柄连杆机构部件(２)能够用英语描述发动机曲柄连杆机构的作用和工作原理(３)能够用英语介绍发动机配气机构部件(４)能够用英语描述发动机配气机构的作用和工作原理(５)能够用英语介绍发动机润滑系统部件(６)能够用英语描述发动机润滑系统的作用和工作原理(７)能够用英语介绍发动机冷却系统部件(８)能够用英语描述发动机电控系统电路图的组成和作用学习目标建议课时10课时。PartⅠReadingMaterialsPassage1Crank-connectingRodmechanism请指出图2-1所示发动机曲柄连杆机构部件中文名称及其相应英文名称。PartⅠReadingMaterialsThecrank-connectingrodmechanismisthemainmechanismofareciprocatingenginefortransformingthermalenergyintomechanicalenergy.Ittransformsthereciprocatinglinearmotionofthepistonunderactionofpressureintothecircularmotionofthecrankshafttodeliverpowertotheexternalcomponents.译文：曲柄连杆机构是往复活塞式发动机将热能转换为机械能的主要机构，其功用是将燃气作用在活塞顶上的压力转变为曲轴旋转运动而对外输出动力。PartⅠReadingMaterialsThecrank-connectingrodmechanismconsistsofthepistonandconnectingrodgroupandthecrankshaftandflywheelgroup.Thepistonandconnectingrodgroupincludesmainlythepiston,pistonrings,pistonpin,andconnectingrod.Thecrankshaftandflywheelgroupincludesmainlythecrankshaft,flywheel,pulley,andtiminggear.译文：曲柄连杆机构由活塞连杆组和曲轴飞轮组两部分组成。活塞连杆组主要包括活塞、活塞环、活塞销、连杆等零部件。曲轴飞轮组包括曲轴、飞轮、带轮、正时齿轮等零部件。PartⅠReadingMaterials.Whentheengineisrunning,thepressureofgasesproducedfromfuelburningisdirectlyappliedtothepistoncrown.Thepistonishencedriventoreciprocatealongastraightline.Thepowerappliedbythepistonisdeliveredviathepistonpinandtheconnectingrodtothecrankshaft.Thereciprocatinglinearmotionofthepistonistransformedintothecircularmotionofthecrankshaft.Largeportionofthepowerproducedbytheengineisdeliveredtothedrivelineviatheflywheelinstalledattherearendofthecrankshaft.Thepoweristhendeliveredtothedrivewheelsofthevehicle,viathedriveline.Anotherportionofthepowerproducedbytheengineisusedtodrivetheaccessoriesoftheengineitselfandothersystems,viathegearandthepulleyinstalledatthefrontendofthecrankshaft.PartⅠReadingMaterials译文：发动机工作过程中，燃料燃烧产生的气体压力直接作用在活塞顶上，推动活塞作往复直线运动。活塞作用力经活塞销、连杆传给曲轴，将活塞的往复运动转换为曲轴的旋转运动。发动机产生的动力大部分由曲轴后端的飞轮传给底盘的传动系统，再经过传动系统传给汽车的驱动轮；还有一部分动力通过曲轴前端的齿轮和带轮驱动发动机自身的其他机构和系统。PartⅠReadingMaterialsPassage2Valvemechanism请指出图2-2所示发动机配气机构部件中文名称及其相应英文名称。PartⅠReadingMaterialsThevalvemechanismclosesandopenstheintakevalvesandexhaustvalvesaccordingtothefiringorderofthecylinders,sothatfreshair-fuelmixture(inthecaseofagasolineengine)orair(inthecaseofadieselengine)cantimelyenterthecylinders,andwastegasesresultingfromcombustioncantimelygooutofthecylinders.译文：配气机构的功用是按照发动机各缸的工作循环和做功次序，定时地将各个气缸的进、排气门开启和关闭，以便使新鲜的可燃混合气（汽油机）或空气（柴油机）及时进入气缸，并将各气缸中燃烧后的废气及时排出。PartⅠReadingMaterialsThevalvemechanismconsistsofthevalvegroupandthevalvetraingroup.Thevalvegroupincludesmainlythevalves(intakevalvesandexhaustvalves),valvesprings,valveseats,andvalveguides.Thevalvetraingroupincludemainlythecamshafts,timingpulleys(orgear,orsprocket),timingbelt(ortimingchain),andvalvetappets.译文：配气机构由气门组和气门传动组两部分组成。气门组包括气门（进气门、排气门）、气门弹簧、气门座、气门导管等零部件。气门传动组包括凸轮轴、正时带轮（或齿轮、链轮）、正时带（或正时链条）、气门挺柱等零部件。PartⅠReadingMaterialsThevalvemechanismconsistsofthevalvegroupandthevalvetraingroup.Thevalvegroupincludesmainlythevalves(intakevalvesandexhaustvalves),valvesprings,valveseats,andvalveguides.Thevalvetraingroupincludemainlythecamshafts,timingpulleys(orgear,orsprocket),timingbelt(ortimingchain),andvalvetappets.译文：配气机构由气门组和气门传动组两部分组成。气门组包括气门（进气门、排气门）、气门弹簧、气门座、气门导管等零部件。气门传动组包括凸轮轴、正时带轮（或齿轮、链轮）、正时带（或正时链条）、气门挺柱等零部件。PartⅠReadingMaterialsPassage3Lubricationsystem请指出图2-3所示发动机润滑系统部件中文名称及其相应英文名称。PartⅠReadingMaterialsWhentheengineworks,manypartsmoverelativelywithotherpartsinasmallroom,suchasthemainjournalofthecrankshaftandthemainbearing;therodjournalandtherodbearing;piston,pistonringandcylinderwall;thecamshaftandcamshaftbearingetc.Ifthesurfacesofthesepartsarenotlubricated,severefrictionhappensandexpeditesthepartswearandfinallymakesitimpossiblefortheenginetorun.Sothelubricationsystemisimportanttoguaranteealongoperationoftheengine.译文：发动机工作时，很多零件都是在很小的间隙下与另一个零件作相对运动，如曲轴主轴颈与主轴承，连杆轴颈与连杆轴承，活塞、活塞环与气缸壁，凸轮轴与凸轮轴轴承等。如果没有对这些零件表面进行润滑，必然会产生强烈的摩擦，加速磨损，最终导致发动机无法运转。因此，润滑系统是保证发动机能长期正常运转的重要系统。PartⅠReadingMaterialsThefunctionofthelubricationsystemistocontinuouslydeliveradequatecleanoilinrighttemperaturetothefrictionsurfacesofallmovingparts,andtoformtheoilfilmbetweenthefrictionsurfacesforliquidfriction,soastoreducethefrictionresistance,powerconsumptionandpartsweartoimprovetheengine’sreliabilityanddurability.Italsohelpsincoolingandcleaningofenginepartsastheoilcirculates.译文：润滑系统的功用是在发动机工作时连续不断地把数量足够、温度适当的洁净机油输送到全部运动件的摩擦表面，并在摩擦表面之间形成油膜，实现液体摩擦，从而减小摩擦阻力、降低功率消耗、减轻机件磨损，以达到提高发动机工作可靠性和耐久性的目的。PartⅠReadingMaterialsThelubricationsystemofgasolineengineisnormallycomposedofoilpump,suctionfilter,filtercleaner,pressure-limitingvalve,by-passvalveandoilpipelineetc.andsomehaveoilcoolertoo..译文：汽油机润滑系统一般由机油泵、集滤器、机油滤清器、限压阀、旁通阀和机油管道等组成，有些汽油机润滑系统中还设有机油冷却器。PartⅠReadingMaterialsWhentheengineruns,theoilpumpsucksintheengineoilfromtheoilpanthroughthesuctionfilterwhichpreventstheentryofbigmechanicalimpuritiesintotheoilpumpandlubricatingcircuit.Theengineoilpumpedoutflowsthroughthefiltercleanerintothemainoilpassageofthecylinderandthenthroughthetransverseoilpassageinthecrankcaseintothemainjournalofthecrankshaft.Thenitflowsfromthemainjournal,passesthroughtheslantingoilpassageinthecrankshaft,andthenenterstherodjournalwherealittleportionoftheengineoilspraystothepistonandcylinderwalltolubricatethemthroughtheorificeonthebigendoftherod.Andsomeoftheengineoilflowstotheoilpassageonthecylindercoverthroughtheoilpassageonthecylinderbodyandthenentersthecamshaftbearingtolubricatethejournalofthecamshaftbearing.Furthermore,thelubricatingoilflowsalsothroughrelevantoilpassageororificetothetimingchainanditsautomatictensioner(whentheenginewithtimechaindistributionmechanismisused),camsurfaceofthecamshaft,hydraulictappet(whentheenginewithhydraulictappetisused)andsoontolubricateorworkastheservicefluidforthehydraulicparts.PartⅠReadingMaterials译文：当发动机工作时，机油泵将油底壳中的机油经集滤器吸入，集滤器可防止大的机械杂质进入机油泵和润滑油路中。被机油泵压出的机油经机油滤清器过滤后流入缸体上的主油道中，并通过曲轴箱中的横向油道进入曲轴主轴颈，再通过曲轴中的斜向油道从主轴颈处流向连杆轴颈，进入连杆轴颈中的小部分机油通过连杆大头上的机油喷孔喷向活塞和气缸壁，以润滑活塞和气缸。另有一部分机油经缸体上的油道到达气缸盖油道，进入凸轮轴轴承，润滑凸轮轴轴颈。此外，润滑油还经过相关的油道或喷嘴到达正时链条和正时链条自动张紧器（使用正时链条配气机构的发动机）、凸轮轴的凸轮表面、液力挺柱（使用液力挺柱的发动机）等，执行润滑任务或作为液压部件的工作介质。PartⅠReadingMaterialsPassage4Coolingsystem请指出图2-4所示发动机冷却系统部件中文名称及其相应英文名称。PartⅠReadingMaterialsThefunctionofthecoolingsystemistomaketheenginegetnormalworkingtemperatureasquicklyaspossibleandstayatthebestworkingtemperatureinthewholeworkingprocess.译文：冷却系统的功用就是使发动机尽快地达到正常的工作温度，并使发动机在工作过程中始终处于最佳的工作温度范围内。PartⅠReadingMaterialsTheengineshouldbecooleddowntotherightextent.Withundercooling,theengineisoverheatedtoleadtothedecreaseoftheintakeefficiencyandahighertendencyofpreignationandconflagration,whichcausestheenginepowerreduction;overheatedenginealsoreducestheclearancebetweenthemovingpartsoftheengine,makingthepartsunabletomovenormallyorevenstuckorbroken;what’smore,overheatingalsodecreasesthelubricatingoilviscosityandmakestheoilfilmbreakeasily,intensifyingthepartswear.Andalsofuelconsumptionincreasesduetoprematurecombustion.译文：发动机冷却要适度。若冷却不足，会使发动机过热，从而造成充气效率下降，早燃和爆燃倾向加大，致使发动机功率下降；过热还会使发动机运动零件间的间隙变小，导致零件不能正常运动，甚至卡死、损坏；或使零件因强度下降而导致变形和损坏；同时，过热还会使润滑油黏度减小，润滑油膜易破裂而使零件磨损加剧。PartⅠReadingMaterialsWithovercooling,theengineistoocoldandthemixedgasortheairenteringthecylinderhasatoolowtemperatureandishardtoignite,leadingtothereductionoftheenginepowerandtheincreaseoftheoilconsumption.Thelubricatingoilhasahigherviscositytoo,weakeningthelubricationandincreasingthepartswear.Furthermore,thefueloilwhichisnotclassifieryetduetothelowtemperatureshallwashagainsttheoilfilmonthefrictionsurfacesofthecylinderandpistonetc.Andasthemixedgascontactsthecoolercylinderwall,theclassifierfueloilshallcondenseagainandflowintothecrankcase,whichshallnotonlyincreasetheoilconsumptionbutalsomaketheoilthinandaffectthelubrication,decreasingtheenginepowerandintensifyingthepartswear.译文：若冷却过度，会使发动机过冷，导致进入气缸的混合气或空气温度低而难以点燃混合气，造成发动机功率下降、油耗上升。还会使润滑油黏度增大，造成润滑不良而加剧零件磨损。此外，因温度低而未气化的燃油会冲刷气缸、活塞等摩擦表面上的油膜，同时因混合气与温度较低的气缸壁接触，使其中原已汽化的燃油又重新凝结而流入曲轴箱内，不仅增加了油耗，而且使机油变稀而影响润滑，从而导致发动机功率下降，磨损加剧。PartⅠReadingMaterialsThewater-cooledcoolingsystemuseswater(orcoolingliquid)asthecoolant.Theheatfromtheheatedenginepartsistransferredtothecoolantfirstandthendissipatestotheairthroughtheradiator.Theengineadoptingthewater-cooledcoolingsystemisalsocalledwater-cooledengine.Itscoolingsystemincludesradiator,waterpump,fan,coolingwaterjacketandthermostatetc.Waterpumpisusedinthissystemtoforcethecoolanttocirculateinthesystemtodissipatetheheat.译文：水冷式冷却系统是以水（或冷却液）为冷却介质，先将发动机受热零件的热量传给冷却液，再通过散热器散发到大气中去。采用水冷式冷却系统的发动机也称为水冷式发动机。其冷却系统由散热器、水泵、风扇、冷却水套和节温器等组成（见图2-4），利用水泵强制冷却液在冷却系统中进行循环流动而达到散热的目的。PartⅠReadingMaterialsBoththecylindercoverandthecylinderbodyofthewater-cooledenginehaveinsidethecastedwaterjacketmutuallyconnected.Withthepumpfunction,thecoolingwaterintheradiatorispressedandflowsthroughtheinletonthecylinderbodyintotheengine,andthenthroughthewaterjacketinthecylinderbodyandcovertoabsorbheatandreturnsafterwardsfromtheoutletonthecylindercovertotheradiatoralongthewaterchannel.Duetotheautospeedandthepowerfulsuctionbythefan,theairpassesthroughtheradiatoratahighspeedfromthefronttotherear.So,whentheheatedcoolingwaterflowsthroughtheradiatorcore,heatdissipatesconstantlyintotheair.Thecooledwaterflowstotheradiatorbottomandthenispumpedoutandpressedintothewaterjacketoftheengineandcyclesrepeatedlyinthisway.Theheatiscontinuouslytransportedtotheairtocooldowntheenginetoguaranteethenormaloperationoftheengine.PartⅠReadingMaterials水冷式发动机的气缸盖和气缸体中都铸有相互连通的水套。在水泵的作用下，散热器内的冷却水被加压后通过气缸体进水孔进入发动机，流经气缸体及缸盖的水套而吸收热量，然后从气缸盖的出水口沿水管流回散热器。由于汽车行驶的速度及风扇的强力抽吸，空气由前向后高速通过散热器。因此，受热后的冷却水在流过散热器芯的过程中，热量不断地散发到大气中去，冷却后的水流到散热器的底部，又被水泵抽出，再次压送到发动机的水套中，如此不断循环，把热量不断地送到大气中去，使发动机不断地得到冷却，从而保证发动机正常工作。PartⅡSkillTrainingHaveatryFaultphenomenon:Theidlingspeedofengineistoohigh.Descriptionofthefaultphenomenon:Theenginekeepsafastidlespeedafterstarting.ProbableCause？

PartⅢExercisesExercise1：TranslatethefollowingphrasesintoChineseorEnglish.1. crankshaft2.凸轮轴 3. cylinder4.活塞环 5. journal6.连杆 7. valveseat8.润滑系统 9. thermostat10.飞轮 PartⅢExercisesExercise2：MarkthefollowingstatementswithT（True）orF（False）accordingtothepassage..()1.Accordingtothepassagecrankandconnectingrodmechanismconsistsofthepistonandconnectingrodgroupandthecrankshaftandflywheelgroup.()2.Thevalvesonthecylinderheadareusedtoopentheintakeandexhaustportsofeachcylinder.()3.Lubricationsystemcancontinuouslydeliveradequatecleanfuelinrighttemperaturetothefrictionsurfacesofallmovingparts.()4.Whentheheatedcoolingwaterflowsthroughtheradiatorcore,heatdissipatesconstantlyintotheair.()5.Generally,anautomotiveengineconsistsoftwomechanismsandfivesystems. PartⅢExercisesExercise3：TranslatethefollowingparagraphintoChinese.Generally,anautomotiveengineconsistsofthefollowingmechanismsandsystems:enginebody,crankandconnectingrodmechanism,valvemechanism,lubricationsystem,coolingsystem,fuelsystem,ignitionsystem,andstartingsystem.Furthermore,a