搜索
汽车工程专业英语李俊玲罗永革版（原文与翻译）today'saveragecarcontainsmorethan15000separate,individualpartsthatmustworktogether.thesepartscanbegroupedintofourmajorcategories:body,engine,chassisandelectricalsystem.现在的汽车一般都由15000多个分散、独立且相互配合的零部件组成。这些零部件只要分为四类：车身、发动机、底盘和电气设备。anautomobilebodyisasheetmetalshellwithwindows,ahoodandatrunkdeckbuiltintoit.itprovidesaprotectivecoveringfortheengine,passengersandcargo.thebodyisdesignedtokeeppassengerssafeandcomfortable.thebodystylingprovidesanattractive,colorfulmodernappearanceforthevehicle.轿车车身是一个钣金件壳体，它上面有车窗、车门、发动机罩和行李舱门等部件，它给发动机、乘客和行李提供防护。车身设计是为了确保乘客乘坐的安全和舒适。车身造型设计使得汽车有一个华美、现代、吸引人的外观。asedanhasanenclosedbodywithamaximumof4doorstoallowaccesstothepassengercompartment.thedesignalsoallowsforstorageofluggageorothergoods.asedancanalsobereferredtoasasaloonandtraditionallyhasafixedroof.therearesoft-topversionsofthesamebodydesignexceptforhaving2doors,andtherearecommonlyreferredtoasconvertibles.轿车车身为封闭式，轿车最多有4个车门，乘员通过车门进出。另外车身的设计还应考虑行李和货物的存放。传统的轿车都是硬顶车身。活顶乘用车（敞篷车）的车顶是软顶，车身设计与普通轿车类似，但只有两个车门。theutilityorpick-upcarriesgoods.usuallyithasstrongerchassiscomponentsandsuspensionthanasedantosupportgreatergrossvehiclemass.皮卡一般用来运载货物。为能承载更大的总质量，皮卡的底盘部件和悬架比轿车更结实。lightvehiclevanscanbebasedoncommonsedandesignsorredesignssothatmaximumcargospaceisavailable.轻型货车一般是基于普通轿车设计的，或是重新设计使可用载货空间最大化。thebodiesofcommercialvehiclesthattransportgoodsaredesignedforthatspecificpurpose.tankerstransportfluids,tipperscarryearthorbulkgrains,flatbedsandvansareusedforgeneralgoodstransport.用于运输货物的商用车车身必须满足具体要求，例如运输液体的油罐车、运输泥土或散装谷物的自卸车、运输一般货物的平板车或货车。busesandcoachesareusually4-wheelrigidvehices,butalargenumberofwheelsandaxlescanbeused.sometimesarticulatedbusesareusedtoincreasecapacity.busesandcoachescanbesingle-deckordouble-deck.busesarecommonlyusedincitiesascommutertransportswhilecoachesaremoreluxurioususedforlongdistances.客车和长途汽车一般是有4个车轮的整体式车辆，也能配备更多的车轮和车桥。为了增加客车的载客量往往使用由铰链连接的客车。公共汽车和长途汽车有单层和双层两种。公共汽车一般用城市内公共交通，而长途汽车一般用于长距离的旅行。1.2EngineTheengineactsasthepowerunit.Theinternalcombustionengineismostcommon:thisobtainsitspowerbyburningaliquidfuelinsidetheenginecylinder.Therearetwotypesofengine:gasoline(alsocalledaspark-ignitionengine)anddiesel(alsocalledacompression-ignitionengine).Bothenginesarecalledheatengines;theburningfuelgeneratesheatwhichcausesthegasinsidethecylindertoincreaseitspressureandsupplypowertorotateashaftconnectedtothepowertrain.发动机作为动力设备，常见的类型是内燃机，其原理是通过发动机缸内的液体燃料燃烧而产生能量。发动机可分为两类：汽油机（点燃式）和柴油机（压燃式），都属于热力发动机。燃料燃烧产生热量使缸内气体气压上升，从而产生能量，驱动与动力传动系相连接的轴旋转。Thewayenginecylindersarearrangediscalledengineconfiguration.In-lineengineshavethecylindersinaline.Thisdesigncreatesasimplycastengineblock.Invehicleapplications,thenumberofcylindersisnormallyfrom2upto6.Usually,thecylindersarevertical.Asthenumberofthecylindersincrease,thelengthoftheblockandcrankshaftcanbecomeaproblem.OnewaytoavoidthisiswithaVconfiguration.Thisdesignmakestheenginesblockandcrankshaftshorterandmorerigid.发动机的布置即发动机气缸的排列方式。发动机缸体按直线排列的即直列式，这种布置使得发动机缸体结构简单。汽车发动机一般为2~6缸，通常气缸是垂直放置的，但气缸数量的增加会导致缸体和曲轴的长度过大，解决问题的措施之一就是采用V型布置，这种布置方式可以使发动机缸体和曲轴长度尺寸更短，从而大大增加刚度。Anenginelocatedatthefrontcanbemountedlongitudinallyandcandriveeitherthefrontortherearwheels.Rearenginevehicleshavetheenginemountedbehindtherearwheels.Theenginecanbetransverseorlongitudinalandusuallydrivestherearwheelsonly.前置发动机可以纵向布置，能够驱动前轮或后轮。后置发动机布置在后轮后侧，发动机即可纵向布置又可横向布置，一般只能驱动后轮。1.3chassis底盘thechassisisanassemblyofthosesystemsthatarethemajoroperatingpartsofavehicle.thechassisincludesthepowertrain,steering,suspension,andbrakingsystems.底盘由汽车的主要操作系统组装而成。包括传动系、行驶系、转向系和制动系四部分。1）Powertrainsystemconveysthedrivetothewheels.传动系-将驱动力传递到车轮。2）Steeringsystemcontrolsthedirectionofmovement.转向系-控制汽车的行驶方向。3）Suspensionandwheelsabsorbstheroadshocks.悬挂系-吸收路面震动4）Brakeslowsdownthevehicle.制动系-使汽车减速缓行。1.3.1powertrainsystem动力传动系统Thepowertraintransfersturningeffortfromtheenginetothedrivingwheels.apowertraincanincludeaclutchmanualtransmissionoratorqueconverterforautomatictransmission,adriveshaft,finaldriveanddifferentialgearsanddrivingaxles.Alternatively,atransaxlemaybeused.Atransaxleisaself-containedunitwithatransmission,finaldrivegearsanddifferentiallocatedinonecasing.传动系把发动机输出的扭矩传递给驱动轮。传动系包括离合器（对应机械变速器）或液力变矩器（对应液力自动变速器）、变速器、驱动轴、主减速器、差速器和驱动桥。另外有些传动系采用由变速器、主减速器和差速器组成的一体式的变速驱动桥。（或者采用一个独立的变速驱动桥，即变速器……在同一个箱体内。）Avehiclewithamanualtransmissionusesaclutchtoengageanddisengagetheenginefromthepowertrain.Enginetorqueistransmittedthroughtheclutchtothetransmissionortransaxle.thetransmissioncontainssetsofgearsthatincreaseordecreasethetorquebeforeitistransmittedtotherestofthepowertrain.thelowerthegearratioselected,thehigherthetorquetransmissioned.avehiclestartingfromrestneedsalotoftorque,butonceitismoving,itcanmaintainspeedwithonlyarelativelysmallamountoftorque.ahighergearratiocanthenbeselected,andenginespeedisreduced.对于采用机械变速器的汽车，其发动机扭矩由离合器传递给变速器或变速驱动桥，并通过离合器来控制发动机和传动系的啮合或分离。变速器包含了不同传动比的齿轮副，能够增加或减小扭矩。选择的齿轮速比越小，传递的扭矩最大。汽车起步时需要较大的扭矩，一旦起动后，仅需要较小的扭矩就可维持速度，此时应该换用较高的档位，以降低发动机转速。aconventionalvehiclewiththeengineatthefrontanddrivingwheelsattherearusesadriveshaft,calledapr