汽車專業(yè)英語(yǔ)翻譯及課后答案--黃韶炯(全部單元都有)課案

1、Unit1AutomotiveBasicsAutomobiles,trucks,andbusesareessentialformsoftransportation.Theyarecomplexmachinesmadeupofmanyparts.Thesepartscanbegroupedintoanumberofsystems.Anunderstandingofhowthesystemworkwillhelpyouunderstandhowtheautomobileworks.轎車、卡車和客車是交通運(yùn)輸?shù)闹匾M成部分。它們都是由許多部件組成的復(fù)雜機(jī)器。這些部件可以歸類為汽車的幾個(gè)組成系統(tǒng)。了解

2、這些各個(gè)小系統(tǒng)是如何工作的將有助于我們理解整個(gè)汽車系統(tǒng)是如何工作。Anautomobilecanbedividedintotwobasicparts:abodyandachassis.Thebodyistheenclosurethathousestheengine,passengers,andcargo.Itisthepartoftheautomobilethatysee.Thechassisisthatpartoftheautomobilebeneaththebody.汽車可以分為兩個(gè)基本部分：車身和底盤。車身包圍發(fā)動(dòng)機(jī)、乘客和行李，它是汽車你所看到的部分。而車身以下的部分就是底盤。1.1

3、THEBODYAnautomobilebodyisasheetmetalshellwithwindows,doors,ahood,andatrunkdeckbuiltintoit.Itprovidesaprotectivecoveringfortheengine,passengers,andcargThebodyisdesignedtokeeppassengerssafeandcomfortable.Forexample,insulatioinnthebodyreducesnoiseandprotectsagainstheatandcold.Thebodystylingprovidesanat

4、tractive,colorful,modernappearanceforthevehicle.Itisstreamlinedtolessenwindresistanceandtokeepthecarfromswayingatdrivingspeeds.轎車車身是一個(gè)鈑金件殼體，它上面有車窗、車門、發(fā)送機(jī)罩和行李艙門等部件，它給發(fā)動(dòng)機(jī)、乘客和行李提供防護(hù)。車身設(shè)計(jì)來(lái)確保乘客乘坐的安全和舒適。比如：車身絕熱層可以減少噪音和抵御冷熱。車身造型設(shè)計(jì)使得汽車有一個(gè)華美、現(xiàn)代、吸引人的外觀。車身的流線型設(shè)計(jì)可以減少風(fēng)阻，防止汽車行馳過(guò)程中發(fā)生擺動(dòng)。Theautomobilebodyhastwobasic

5、parts-theupperbodyandtheunderbody.車身有兩個(gè)基本部分-車身上部和車身下部。1.2 ThechassisThechassisisanassemblyofthosesystemsthatarethemajoroperatingpartsofavehicle.Thechassisincludeseverythingexceptthebody.Thethreeimportantpartsofthechassisaretheframe,theengine,andthepowertrain(alsocalledthedrivetrain).Eachofththreepar

6、tsismadeupofanumberofsystems.Asystemisamechanicalorelectricalunitthatperformsaspecificfunction.Thus,eachsystem(suchassteering,brake,orfuel)hasacertaintodoinrunningavehicle.Weshalllookateachofthesepartsandsystemstoseehowtheyfittogethertoformtheautomobilechassis.底盤集中了汽車大部分的運(yùn)動(dòng)組件，它包括除了車身以外的所有部件。底盤有三個(gè)重要的

7、系統(tǒng)：車架、發(fā)動(dòng)機(jī)和傳動(dòng)系統(tǒng)。這三個(gè)系統(tǒng)又都有許多個(gè)完成某一個(gè)特定功能的機(jī)械或電氣系統(tǒng)組成。為了保證汽車正常運(yùn)轉(zhuǎn)，每個(gè)系統(tǒng)(比如：轉(zhuǎn)向、制動(dòng)或燃油系統(tǒng))都要實(shí)現(xiàn)一定的功能。下來(lái)我們看看這些系統(tǒng)和組件是如何相互連接從而組成汽車底盤的。1.2.1TheframeThefirstmajorpartofthechassisistheframe.Itismadefromtoughsteelsectionswelded,riveted,orboltedtogether.Theframelookslikeasteelladder,thoughitsometimehasanXshapeforextrastre

8、ngth.Itformsafoundationforthecarbodyandthepartsoftheseveralsystems.Thebodyisjoinedtotheframewithbolts.Rubbershockmountsorwashersareusedateachjoint.Thesereducevibrationandroadnoise.Inmostmoderncarstheframeisbuiltintothebody.Acarwiththeframebuiltintothebodyhasaunitizedbodyorunibody.Theframesupportsthe

9、suspensionsystem,steeringsystem,andthebrakingsystem.底盤最重要的部分就是車架。車架由鋼件通過(guò)焊接、鉚接或螺栓聯(lián)接而成，看上去就像一架鋼梯。有時(shí)為了得到額外的強(qiáng)度，車架做成了X形狀。車架為車身和很多系統(tǒng)部件提供了底座。車身和車架使用螺栓聯(lián)接。每個(gè)聯(lián)接使用橡膠防震支架或墊圈來(lái)減振降噪?，F(xiàn)代轎車車架和車身做在了一起。采用這個(gè)形式的汽車車身叫做承載式車身。車架支撐懸架、轉(zhuǎn)向和剎車系統(tǒng)。Thefrontandrearwheelsareattachedtothechassisbyasuspensionsystem.Thissystemismadeupof

10、springs,shockabsorbers,controlarms,andstabilizers.Thesesupportthevehicleancushionitfromroadbumpsforbetterrideandhandling.前后輪通過(guò)懸架系統(tǒng)和底盤相連。懸架系統(tǒng)由彈簧、減振器、控制臂和橫向穩(wěn)定桿組成。它們支撐著車身，并減緩由于路面不平引起的顛簸，以獲得更好的乘坐舒適性和操作穩(wěn)定性。Thesteeringsystemcontrolsthecar'sdirectionoftravel.Itincludesawheelandcolumn,stegears,rods,andl

11、inkages.Asthesteeringwheelisturned,itsmotionistransferredtotheidlarmandtierods.Thesecausethefrontwheelstoturntotherightofleft.Onsomecars,apowunit(calledpowersteering)makessteeringeasier.轉(zhuǎn)向系統(tǒng)控制車輛行馳的方向。它包括方向盤、轉(zhuǎn)向管柱、轉(zhuǎn)向器、轉(zhuǎn)向拉桿和轉(zhuǎn)向傳動(dòng)裝置。當(dāng)轉(zhuǎn)動(dòng)方向盤，方向盤的運(yùn)動(dòng)被傳遞到隨動(dòng)臂和橫拉桿，從而使得前輪向左或向右轉(zhuǎn)動(dòng)。有些車輛使用助力轉(zhuǎn)向裝置，從而使得轉(zhuǎn)向更加輕便。Thebrakes

12、ystemgivestheautomobileitsstoppingpower.Hydraulicbrakesarefoundonallmoderncars.Asthebrakepedalispushedwiththefoot,brakefluidisforcedthroughbrakelinintocylindersthatpressthebrakeshoesagainstadrum.Thisstopsthemotionofthecar.Poweunits(powerbrakes)areusedtomakebrakingeasier.Mostmoderncarshavediscbrakeso

13、nthefrontwheels.(Somehavethemonboththefrontandrearwheels.)Discbrakesworklikeapairoplierssqueezingarotatingdisc.Drumbrakesarealsoused.制動(dòng)系統(tǒng)給車輛制動(dòng)的動(dòng)力?，F(xiàn)代轎車都使用液壓制動(dòng)。當(dāng)踩下制動(dòng)踏板，制動(dòng)液通過(guò)制動(dòng)管路流入制動(dòng)缸，強(qiáng)迫制動(dòng)蹄接觸制動(dòng)鼓，從而阻止車輛運(yùn)動(dòng)。為了使剎車更加輕便，車輛也使用助力制動(dòng)。現(xiàn)代轎車在前輪裝備盤式制動(dòng)器(。一些轎車在前后輪都使用盤式制動(dòng)器。)盤式制動(dòng)器工作原理類似一對(duì)鉗子夾住旋轉(zhuǎn)的盤片。也有前后輪都使用鼓式制動(dòng)器的汽車。1.2.2

14、 TheengineTheengineprovidespowertomovetheautomobile.Themostcommontypeofautomobileengineisthegasoline-burninpgistonengine.Itisfoundinmostautomobiles.Diesel-fuelburningenginesarealsousedinmodernpassengercars,aswellasinlargetrucks.engineshavefuel,exhaust,cooling,andlubricatiosnystems.Gasolineenginesals

15、ohaveanignitionsystem.發(fā)動(dòng)機(jī)給汽車提供動(dòng)力。最常見(jiàn)的發(fā)動(dòng)機(jī)是汽油機(jī)。大多數(shù)汽車都使用它?，F(xiàn)代客車和大型卡車使用柴油機(jī)。所有的發(fā)動(dòng)機(jī)都具有燃油、排放、冷卻和潤(rùn)滑系統(tǒng)。汽油發(fā)動(dòng)機(jī)還有一套點(diǎn)火系統(tǒng)。Theignitionsystemsuppliestheelectriscparkneededtoignitetheair-fuemlixtureinthecylinders.Whentheignitionswitchisturnedon,currentflowsfromthe12-voltstoragebatterytheignitioncoil.Thecoilbooststhev

16、oltagetoproducethestrongsparkof20,000Vneededtoignitetheenginefuel.Thedistributordirectstheelectricalcurrenttotherightsparkplugarighttime.Dieselenginesusetheheatcausedbyenginecompressiontoignitethefuelcharge.Theseenginesarecalledcompressionignitionengines.點(diǎn)火系統(tǒng)提供點(diǎn)燃?xì)飧變?nèi)油氣混和物的電火花。當(dāng)打開(kāi)點(diǎn)火開(kāi)關(guān)，電流從12V電池流向點(diǎn)火線圈。點(diǎn)

17、火線圈升高電壓，產(chǎn)生用于點(diǎn)火的20000V尖峰電壓。分電器引導(dǎo)電流在正確的時(shí)刻流向正確的火花塞。柴油機(jī)使用壓縮發(fā)動(dòng)機(jī)產(chǎn)生的熱量來(lái)點(diǎn)燃燃料，因此被稱為壓燃式發(fā)動(dòng)機(jī)。Theautomobilesuppliesalltheelectricityitneedsthroughitselectricalsystem.Forexample,electricaslystemsupplieselectricitfyortheignitionh,orn,lightsh,eater,andstarterT.heelectricitylevelismaintainedbyachargingcircuit.Thisci

18、rcuitconsistsofthebattery,alt(orgenerator)a,ndtheregulatorT.hebatterystoreselectricitTyh.ealternatorchangestheengine'msechanicalenergyintoelectricaelnergyandrechargethebattery.Theregulatorpreventsdamagetothesystembyregulatingthemaximumvoltageinthecircuit汽車通過(guò)自身的電氣系統(tǒng)給自身供電。比如：電氣系統(tǒng)給點(diǎn)火系統(tǒng)、喇叭、燈光、供暖系統(tǒng)和起

19、動(dòng)器供電。系統(tǒng)電壓通過(guò)充電系統(tǒng)保持穩(wěn)定。充電系統(tǒng)由電池、發(fā)電機(jī)和調(diào)節(jié)器組成。電池儲(chǔ)存電能。發(fā)電機(jī)將發(fā)動(dòng)機(jī)的機(jī)械能轉(zhuǎn)變?yōu)殡娔?，并給電池充電。調(diào)節(jié)器調(diào)節(jié)電氣系統(tǒng)的最大電壓，提供過(guò)壓保護(hù)。Thefuelsystemstoresliquidfuelanddeliversittotheengines.Thefuelisstoredinthetanwhichisconnectedtoafuelpumpbyafuelline.Thefuelispumpedfromthefueltankthroughthefuellines.Itisforcedthroughafilter(whichremovesmoist

20、ureanddirt)intothecarburewhereitismixedwithair,orintothefuelinjectionsystem.Thefuelismixedwithairtoforcombustiblemixtureinthecarburetor,themanifold,orthecylindersthemselves.燃油系統(tǒng)儲(chǔ)存液態(tài)燃料，并且把燃料送至發(fā)動(dòng)機(jī)。燃料儲(chǔ)存在通過(guò)油管與油泵連接的油箱里。油泵通過(guò)油管將油箱內(nèi)的油泵出，并通過(guò)濾清器(去除濕氣和雜污)送達(dá)化油器與空氣混合或者噴油系統(tǒng)。燃油在化油器、歧管或氣缸自身內(nèi)與空氣混合，形成可燃混和物。Theexhaust

21、systemhasfourjobs:1. Tocollectburnedgasesfromtheengines.2. Toremovedangerousemissionthatpollutestheair.3. Toreduceexhaustnoises.4. Togetridoftheexhaustgases.排放系統(tǒng)要實(shí)現(xiàn)四個(gè)功能：1、收集發(fā)動(dòng)機(jī)的廢氣。2、去除污染空氣的排放物。3、減少排放噪音。4、排出廢氣。Exhaustgasescontaincarbonmonoxide,unburnedhydrocarbons,andoxidesofnitrogen.Sinceallofthesea

22、reharmful,theexhaustsystemisdesignedtoreducethemasmuchaspossible.IntheUnitedStaresallmodernautomobileshaveemissioncontrolsystems.汽車廢氣包含一氧化碳，未燃燒的碳?xì)浠衔锖偷趸衔?。所有的這些都是有害的，排放系統(tǒng)設(shè)計(jì)要盡可能多減少這些有害物質(zhì)。美國(guó)所有的現(xiàn)代車都配備了排放系統(tǒng)。Thecoolingsystemremovesexcessiveheatfromtheengine.Thetemperatureinenginecombustionchambersisabou

23、t1094°C.Sincesteelmeltsataround1354°C,thisheatmustbecarriedawaytopreventenginedamage.Airandacoolantareusedtocarryawaytheheat.Theradiatorisfilledwithacoolant.Thewaterpumpcircuitsthiscoolantthroughtheengineandtwallsoftheengineblockandhead.Heatalsoisremovedbytheradiatorfan,whichdrawsairthroug

24、hthenarrowfinsoftheradiatorT.hissystemalsosuppliesheattothepassengercompartmentandthewindowdefroster.冷卻系統(tǒng)去除發(fā)動(dòng)機(jī)多余的熱量。發(fā)動(dòng)機(jī)燃燒室的溫度可以達(dá)到1094攝氏度。鋼的熔點(diǎn)大約是1354攝氏度，發(fā)動(dòng)機(jī)多余的熱量必須消除來(lái)防止發(fā)動(dòng)機(jī)過(guò)熱?？諝夂屠鋮s劑用來(lái)帶走這個(gè)熱量。散熱器內(nèi)裝滿了冷卻劑。水泵使冷卻劑在發(fā)動(dòng)機(jī)、發(fā)動(dòng)機(jī)殼體和發(fā)動(dòng)機(jī)蓋循環(huán)流動(dòng)。也可以使用冷卻風(fēng)扇來(lái)降溫。冷卻風(fēng)扇將風(fēng)從散熱器狹窄的孔徑吹出，從而帶走熱量。這個(gè)系統(tǒng)可以給乘客艙和車窗除霜器提供熱量。Thelubricatiosny

25、stemisimportantinkeepingtheenginerunningsmoothly.Motoroilisthelubricantusedinthesystem.Thelubricationsystemhasfourfunctions:1. Itcutsdownfrictionbycoatingmovingpartswithoil.2. Itproducesasealbetweenthepitonringsandthecylinderwalls.3. Itcarriesawaysludge,dirt,andacids.4. Itcoolstheenginebycirculating

26、themotoroil.潤(rùn)滑系統(tǒng)非常重要，它使得發(fā)動(dòng)機(jī)平滑工作。潤(rùn)滑系統(tǒng)使用機(jī)油作為潤(rùn)滑劑。潤(rùn)滑系統(tǒng)有四個(gè)功能：1、通過(guò)運(yùn)動(dòng)部件油膜，它可以減小摩擦。2、它在活塞環(huán)和氣缸壁之間產(chǎn)生油封。3、它可以帶走金屬碎屑、雜污和酸。4、通過(guò)機(jī)油的循環(huán)，它可以冷卻發(fā)動(dòng)機(jī)。Tokeepthissystemworkingeffectiveloyi,lfilterasndmotoroilmustbechangeregularlyA.llothermovingpartsinanautomobilemustalsobelubricatedT.heseincludethetransmission,differentia

27、l,wheelbearings,andsteeringlinkage.為了使得潤(rùn)滑系統(tǒng)有效工作，機(jī)油濾清器和機(jī)油必須定期更換。汽車內(nèi)所有的運(yùn)動(dòng)部件都必須要潤(rùn)滑，這包括變速器、差速器、輪軸軸承和轉(zhuǎn)向傳動(dòng)機(jī)構(gòu)。1.2.3 ThepowertrairfThepowertrain,ordrivesystem,deliverspowerfromtheenginetothewheels.ThepowerfromtheenginemovesthroughthetransmissionT.ransmissionasreeitherstandard,withamanualshiftleverandfootclu

28、tch,orautomatic.傳動(dòng)系統(tǒng)將發(fā)動(dòng)機(jī)動(dòng)力傳給車輪。來(lái)自發(fā)動(dòng)機(jī)的動(dòng)力傳遞給變速器。變速器可以是一個(gè)帶手動(dòng)換檔桿和離合器的手動(dòng)變速器或者自動(dòng)變速器。Thetransmissionhasgearsthatcontroltheamountofpowerdeliveredtothewheels.Thetransmissionincreasesthepower(torque)tostartthecarmoving.Thistorqueisreducedwhenthetransmissionchangesgearsathigherspeeds.Thetransmissionalsocontain

29、sasetofgearsthatcanreversethedirectionofthewheels.Thetransmissiondeliversthepowertothedifferential.Adrive(orpropeller)shaftwithuniversaljointsateitherendofthedriveshafaxlemovementoffront-engine,rear-wheeldrivecars.Theseflexibleuniversaljointpreventthedriveshaftfrombreaking.Thedifferentidaelliverpsow

30、ertothewheelsthroughaxle.Certaingearsallowonewheeltoturnfasterthantheotherwheelwhenthevehicleisturningacorner.變速器使用齒輪來(lái)控制傳遞到車輪力矩的大小。當(dāng)車輛起步時(shí)，變速器增大扭矩。當(dāng)車速增大，變速器改變齒輪來(lái)減小扭矩。變速器還有一套使得車輪反向運(yùn)動(dòng)的齒輪。變速器將扭矩傳遞給差速器。發(fā)動(dòng)機(jī)前置后輪驅(qū)動(dòng)轎車的驅(qū)動(dòng)軸兩側(cè)裝有萬(wàn)向節(jié)，可允許產(chǎn)生軸向運(yùn)動(dòng)。萬(wàn)向節(jié)防止驅(qū)動(dòng)軸斷裂。差速器通過(guò)半軸將扭矩傳遞給車輪。當(dāng)車輛轉(zhuǎn)彎時(shí)，齒輪使得一側(cè)車輪比另一側(cè)車輪旋轉(zhuǎn)得更快。Thesearethebasic

31、systemsoftheautomobile.Eachofthesystemsisdesignedforaspecificjo以上就是汽車的基本系統(tǒng)。每個(gè)系統(tǒng)都為了一個(gè)專門的功能而設(shè)計(jì)。1 ExercisesTheautomobile'fsurtherdevelopmentwillbedeterminedbyalreadyexistingandsteadilyincreasingrequirements,byadditionalfurtherrequirementsandbythetechnicalpossibilitiesfmeetingtheserequirements.Thefo

32、llowingfocalpointsfordevelopmentandresearcheffortscanbediscerned:汽車的進(jìn)一步發(fā)展取決于已經(jīng)存在的、目前穩(wěn)定增長(zhǎng)和未來(lái)的需求以及為了滿足這些需求的技術(shù)。下來(lái)給出發(fā)展研究的幾個(gè)要點(diǎn)：Furtherimprovementsoftheautomobilethroughproductsinnovationinallclassisfunctions,i.performance,fueleconomy,environmentalimpact,safety,comfortandreliability.Furtherdevelopmentofne

33、wtechnologiesuchaselectricasl,ternativmeaterialsn,ewtestandproductionmethods.Long-rangesolutionsfortraffipcroblemssuchashighwaycongestion,smogincitiesandcarbondioxideenrichmentofouratmosphere.傳統(tǒng)功能的產(chǎn)品革新，比如：性能、燃油經(jīng)濟(jì)性、環(huán)境友好、安全、舒適性和可靠性。新技術(shù)的發(fā)展，比如：電氣、替代材料、新型測(cè)試和生產(chǎn)技術(shù)。解決交通問(wèn)題的技術(shù)，比如：交通擁堵，城市煙霧和溫室效應(yīng)。Unit2Automotiv

34、eengine2.1 PurposeandlocationsofenginhepurposeofanautomobileengineistosupplythepowerneededtomovethevehicleT.heengineproducesthispowerbyburningfuelinsideit.Becausetheengineburnsfuelinside,orinternally,theengineisknownasaninternalcombustiengine(ICE).汽車發(fā)動(dòng)機(jī)的功用是提供汽車行馳所需的動(dòng)力。發(fā)動(dòng)機(jī)通過(guò)發(fā)動(dòng)機(jī)內(nèi)部燃燒燃料來(lái)產(chǎn)生這個(gè)動(dòng)力。由于燃料燃燒在發(fā)動(dòng)

35、機(jī)內(nèi)部進(jìn)行，這種發(fā)動(dòng)機(jī)被稱作內(nèi)燃機(jī)。MostautomobileenginesarelocatedatthefrontofthevehicleM.anyenginesdrivetherearwheels.Thisrequiresalongdriveshaftextendingfromthefrontwheelstotherearwheels.Othenginesdrivethefrontwheels.Intherear-wheel-drivaerrangement,theenginesitslongitudinally.Itslongdimensionisfromfronttoback.對(duì)于大

36、多數(shù)汽車，發(fā)動(dòng)機(jī)布置在汽車前部。許多發(fā)動(dòng)機(jī)驅(qū)動(dòng)后輪，這就要求從前輪到后輪的長(zhǎng)驅(qū)動(dòng)軸。其余發(fā)動(dòng)機(jī)驅(qū)動(dòng)前輪。對(duì)于后輪驅(qū)動(dòng)的汽車而言，發(fā)動(dòng)機(jī)由前到后縱向布置。Inthefront-wheel-drivaerrangement,theenginesitscrosswise,transverselyW.itheitherarrangement,thepoweriscarriedtothedrivewheels(rearorfront)bygearsandshafts.對(duì)于前輪驅(qū)動(dòng)的布置，發(fā)動(dòng)機(jī)橫置。無(wú)論哪種布置方式，能量都是通過(guò)齒輪和傳動(dòng)軸傳到驅(qū)動(dòng)輪(前輪或后輪)。Somecarshavetheengi

37、nemountedinbackofthefrontseat.Thisiscalledamid-enginearrangement.Othercarshavebeenbuiltwiththeenginemountedattherear,inbackofrearseaTheVolkswagen“beettle”isanexampleofrear.有些汽車的發(fā)動(dòng)機(jī)位于前排座椅的后面。這種布置被稱為發(fā)動(dòng)機(jī)中置。還有些汽車的發(fā)動(dòng)機(jī)位于后部，安置在后排座椅后面。大眾汽車的甲殼蟲(chóng)就是發(fā)動(dòng)機(jī)后置的一個(gè)例子。2.2 EnginetypeSariouskindsofengineareusedinautomotiv

38、evehicles.Thetwomajortypesare:Thepistonengineinwhichpistonsmoveupanddown,orreciprocate,intheenginecylinder.Thisistheengineusedinallcarestoday,exceptforsomemodelsofMazda.2. TheWankelrotaryengineinwhichrotate,orspin.TheMazdaMotorCorporationofJapanisthemajormanufacturerofthisengine.汽車上使用著不同種類的發(fā)動(dòng)機(jī)。它們可以分

39、成兩大類：1、往復(fù)活塞式發(fā)動(dòng)機(jī)：發(fā)動(dòng)機(jī)在氣缸內(nèi)作上下往復(fù)運(yùn)動(dòng)。除了馬自達(dá)公司的幾款以外，現(xiàn)今幾乎全部轎車都采用這種發(fā)動(dòng)機(jī)。2、轉(zhuǎn)子發(fā)動(dòng)機(jī)：活塞在氣缸內(nèi)作旋轉(zhuǎn)運(yùn)動(dòng)。日本的馬自達(dá)公司是這類發(fā)動(dòng)機(jī)的主要生產(chǎn)商。Therearetwotypesofpistonengines-sparkignition(SI)andcompressionignition(CI).Spark-ignitionenginesuseanelectricsystemwithsparkplugs.Electricsparksatthesparkpluignite,orsetfire,thefuelintheenginecylin

40、ders.Thecombustionofthefuelmakestheengirunandproducepower.Thisistheengineusedinmostproducepower.Thisisthetypeofengineusedinmostautomotivevehicles.活塞式發(fā)動(dòng)機(jī)可以分為兩類：點(diǎn)燃式和壓燃式。點(diǎn)燃式發(fā)動(dòng)機(jī)使用帶火花塞的點(diǎn)火系統(tǒng)?；鸹ㄈ碾娀鸹c(diǎn)燃發(fā)動(dòng)機(jī)氣缸內(nèi)的燃料。燃料燃燒驅(qū)動(dòng)發(fā)動(dòng)機(jī)，并做功。這是大多數(shù)動(dòng)力源采用的發(fā)動(dòng)機(jī)，也是大多數(shù)汽車采用的發(fā)動(dòng)機(jī)形式。Thecompression-ignitieongineusestheheatofcompressio

41、ntoignitethefuel.Whenairiscompressed,itgetsveryhot.Inthedieselengine,theairiscompressedsomuchthatitstemperaturegoesupto538degreesCelsiusorhigher.Thedieselfuelissprayedintothisveryairandisignitedbtyheheat.Someautomobileshavedieselengines.Manyheavy-dutytrucksandbusesarepoweredbydieselengines.壓燃式發(fā)動(dòng)機(jī)使用壓

42、縮產(chǎn)生的熱量來(lái)點(diǎn)燃燃料。當(dāng)空氣被壓縮，它可以達(dá)到非常高的溫度。對(duì)于柴油式發(fā)動(dòng)機(jī)，壓縮空氣可以使得空氣溫度達(dá)到538度或者更高。此時(shí)，柴油被噴射到這熾熱的空氣中，被空氣的熱量點(diǎn)燃。一些轎車使用柴油發(fā)動(dòng)機(jī)。重型卡車和客車普遍使用柴油發(fā)動(dòng)機(jī)。Thereareotherenginesstillintheexperimentalstagethatmightsomedaybecomeimportant.Theseincludegas-turbineengines,steamengines,Stirlingengines,andelectricmotors.還有一些目前尚且處于試驗(yàn)階段，但未來(lái)可能會(huì)非常重要

43、的發(fā)動(dòng)機(jī)，比如：燃?xì)鉁u輪機(jī)、蒸汽機(jī)、斯特靈發(fā)動(dòng)機(jī)和電動(dòng)機(jī)。2.3BasicenginesystemsAspark-ignitiomjginerequirefourbasicsystemstorun.Dieselenginesrequiresthreeofthesesystems.Theyarefuelsystem,ignitiosnystem(expectdiesel),lubricatinsgystemandcoolingsystem.Eachperformsabasicjobinmakingtheenginerun.Thesearedescribedbrieflybelow.點(diǎn)燃式發(fā)動(dòng)機(jī)運(yùn)

44、轉(zhuǎn)需要4個(gè)基本系統(tǒng)，而柴油發(fā)動(dòng)機(jī)需要3個(gè)基本系統(tǒng)。它們是燃油系統(tǒng)、點(diǎn)火系統(tǒng)(柴油發(fā)動(dòng)機(jī)不需要)，潤(rùn)滑系統(tǒng)和冷卻系統(tǒng)。每個(gè)系統(tǒng)實(shí)現(xiàn)一個(gè)基本功能來(lái)使得發(fā)動(dòng)機(jī)運(yùn)轉(zhuǎn)。下文將簡(jiǎn)短介紹這些系統(tǒng)。2.3.1 fuelsystemThefuelsystemsuppliesgasolineordieselfueltotheengine.Thisfuelismixedwithairtomakeacombustiblemixture(amixturethatwillrun).Eachcylinderisrepeatedlyfillewdiththemixture.Then,themixtureisignitedor

45、burned,producinghighpressure.Thehighpressuremakesthepistonmove(orrotorsspin).Thisturnsshaftsthatrotatthewheels,causingthevehicletomove.燃油系統(tǒng)給發(fā)動(dòng)機(jī)提供汽油或柴油燃料。燃油與空氣混合形成可燃混合氣。發(fā)動(dòng)機(jī)的每個(gè)氣缸重復(fù)充滿這種可燃混合氣，然后它們被點(diǎn)燃或壓燃，產(chǎn)生高壓。這個(gè)高壓使得發(fā)動(dòng)機(jī)活塞運(yùn)動(dòng)(或者轉(zhuǎn)子旋轉(zhuǎn))，驅(qū)動(dòng)軸來(lái)旋轉(zhuǎn)車輪，從而使得汽車行駛。2.3.2 ignitionsystemEverytimethefuelsystemdeliversair/fu

46、elmixturetoacylinder,theignitionsystemfollowsupbyadeliveringanelectricspark.Thisignitethemixturewhichcreathehighpressurethatmovesthepistonsandturnsthecarwheels.Theactionisrepeatedmanytimeseachsecondwhiletheengineisrunning.每當(dāng)燃油系統(tǒng)將可燃混合氣送至氣缸，點(diǎn)火系統(tǒng)接著就發(fā)出電火花來(lái)點(diǎn)燃缸內(nèi)的可燃混合氣，從而產(chǎn)生高壓，使得活塞運(yùn)動(dòng)和汽車行駛。當(dāng)發(fā)動(dòng)機(jī)運(yùn)轉(zhuǎn)時(shí)，每秒鐘要點(diǎn)火多次。T

47、heignitesystemtakesthelowvoltageofthebatteryandbuildsituptoaveryhighvoltage:highas47,000voltsinsomesystems.Thishighvoltagejumpsthegapsinthesparkplugs,producingthesparksthatignitetheair/fuelmixtureintheenginecylinders.點(diǎn)火系統(tǒng)將電池的低電壓升壓到高壓。對(duì)于某些系統(tǒng)，可以達(dá)到47000伏。這個(gè)高壓擊穿火花塞間隙，產(chǎn)生電火花，點(diǎn)燃發(fā)動(dòng)機(jī)氣缸內(nèi)的可燃混合氣。2.3.3Thelubrica

48、tiisystemTheenginehasmanymovingmetalparts.Ifmetalpartsrubagainsteachother,theywillwearrapidly.Topreventthis,engineshavelubricatingoil.Theoibetweenthemetalpartssotheyslideontheoil,andnotoneachother.發(fā)動(dòng)機(jī)有許多運(yùn)動(dòng)金屬部件。如果這些金屬部件相互摩擦，那它們磨損就會(huì)很快。為了防止這種情況，發(fā)動(dòng)機(jī)使用潤(rùn)滑油。潤(rùn)滑油在金屬部件之間，使得金屬部件在油膜上滑動(dòng)，而不是彼此之間的摩擦。Thelubricatins

49、gystemhasanoilpanatthebottomoftheenginewhichholdsseveralquarts(liters)ofoil.Anoilpump,drivenbytheengine,sendsoilfromthisreservoirthroughtheenAftercirculatingthroughtheengine,theoildropsbacktotheoilpan.Theoilpumpcontinuescirculatetheoilaslongastheengineisrunning.發(fā)動(dòng)機(jī)潤(rùn)滑系統(tǒng)在發(fā)動(dòng)機(jī)底部有一個(gè)儲(chǔ)存幾升汽油的油底殼。由發(fā)動(dòng)機(jī)驅(qū)動(dòng)的油泵將油

50、從油底殼泵到發(fā)動(dòng)機(jī)循環(huán)流動(dòng)。在發(fā)動(dòng)機(jī)循環(huán)后，潤(rùn)滑油流回到油底殼。只要發(fā)動(dòng)機(jī)在運(yùn)轉(zhuǎn)，油泵就始終使?jié)櫥脱h(huán)流動(dòng)。2.3.4CoolingsystemWherethereisfire(combustion)thereisheat.Burningoftheair/fuelmixtureraisesthetemperatureinsidetheenginecylinderseveralthousanddegrees.Someofthisheatproducesthehighpressurethatmovesthepistonstoproducepower.Someoftheheatleavesthec

51、ylinderswiththeexhaustgas.Theexhaustgasiswhatisleftaftertheair/fuelmiburns.Itisclearedoutofthecylindersafterthecombustioniscomplete.哪里有燃燒，哪里就有熱量?？扇蓟旌蠚獾娜紵沟冒l(fā)動(dòng)機(jī)氣缸內(nèi)溫度上升數(shù)千度。部分熱量產(chǎn)生高壓來(lái)驅(qū)動(dòng)活塞產(chǎn)生動(dòng)力。部分熱量伴隨排放氣體被帶出氣缸。排放氣體指的是可燃混合氣燃燒后剩余物。當(dāng)燃燒結(jié)束，排放氣體被排出氣缸。Someoftheheatisremovedbythecirculatingoil.Afterthehotoildropsd

52、ownintotheoilpatheoilgivesupsomeofthisheattotheairpassingundertheoilpan.Therestoftheheatisremovedbythecoolingsystem.部分熱量被循環(huán)油帶走。當(dāng)溫度較高的油流回到油底殼，熱量通過(guò)油底殼下流動(dòng)的空氣帶走。剩余的熱量就要使用冷卻系統(tǒng)來(lái)帶走。2.3.50therenginesystemAnenginewillrunwiththefourbasicsystemsdescribedabove-fuel,ignitionl,ubricatinagndcooling.However,threeot

53、herrelatedsystemsarealsonecessary.Thesearetheexhaustsystem,theemission-controlsystem,andthestartingsystem.具備上述的燃油、點(diǎn)火、潤(rùn)滑和冷卻系統(tǒng)，發(fā)動(dòng)機(jī)就可以運(yùn)轉(zhuǎn)。但是，其余相關(guān)的3個(gè)系統(tǒng)也是非常必需的。它們是排放系統(tǒng)、排放控制系統(tǒng)和啟動(dòng)系統(tǒng)。Theexhaustsystemreducesthenoiseoftheburnedgasesleavingtheenginecylindersandcarriestheseexhaustgasessafelyawayfromthepeopleinth

54、ecar.Theemission-controlsystemrequiredbylawtoreducetheairpollutiontheenginecouldproduce.Thestartinsgystemisneededtocranktheengine.Abatteryprovidestheelectricpowertooperatethestartingmotorandtheignitionsystemduringcranking.排放系統(tǒng)減少發(fā)動(dòng)機(jī)氣缸可燃混合氣燃燒時(shí)的噪音，并且將廢氣安全帶走，使其遠(yuǎn)離車廂內(nèi)的人。排放控制系統(tǒng)是法律強(qiáng)制要求的，用來(lái)減少發(fā)動(dòng)機(jī)產(chǎn)生的空氣污染。啟動(dòng)系統(tǒng)是

55、用來(lái)啟動(dòng)發(fā)動(dòng)機(jī)。啟動(dòng)過(guò)程中，由電池給啟動(dòng)電機(jī)和點(diǎn)火系統(tǒng)提供能量。2.4EnergyconversionTheinternaCombustionengineisadeviceusedtoconvertthechemicalenergytothefuel(gasolineordieselfuel)intoheatenergy,andthentoconvertthisheatenergyintousablemechanicalenergy.Thisisachievedbycombiningtheappropriateamountsofairandfuel,andburningthemixturein

56、anenclosedcylinderatacontrolledrate.Amovablepistoninthecylinderisforceddownbytheexpandinggasesofcombustion.發(fā)動(dòng)機(jī)是一個(gè)將燃料(汽油或柴油)的化學(xué)能轉(zhuǎn)化成熱能，再將熱能轉(zhuǎn)化成可利用的機(jī)械能的裝置。實(shí)現(xiàn)這個(gè)能量的轉(zhuǎn)化是通過(guò)混合適當(dāng)?shù)目諝夂腿加?，并在密封的氣缸?nèi)以一個(gè)可控的速率燃燒這個(gè)可燃混合氣來(lái)實(shí)現(xiàn)的。燃燒產(chǎn)生的膨脹氣體強(qiáng)迫氣缸內(nèi)的活塞運(yùn)動(dòng)。Anaverageair/fuelratioforgoodcombustionisabout15partsofairto1partoffuelbywei

57、gThismeansthatforeverygallonofgasolineburned,theoxygenisabout9,000to10,000gallonsofairisrequired.Airisabout21%oxygenand78%nitrogen.可燃燒良好的空燃比，按質(zhì)量大約是15：1。這就意味著燃燒1加侖汽油需要的9000到10000加侖的空氣里的氧氣?？諝獯蠹s有21%的氧氣和78%的氮?dú)狻ieselengineoperateonamuchwiderair/fuelratio,sinceairintakeisnotregulatedonmostdiesels.Ratiosm

58、ayrangefromabout20:1to100:1.Thefact,plusthehighcompressionofthediesel,makesitaveryfuelefficientengine.由于大多數(shù)的柴油機(jī)并不控制進(jìn)氣，柴油機(jī)的空燃比范圍很寬，從20：1到100：1。再加上柴油混合氣具有很高的壓縮比，這使得柴油機(jī)的效率很高。Themovablepistoninthecylinderisconnectedtothetopofaconnectingrod.Thebottomofthconnectingrodisattachedtotheoffsetportionofacranksh

59、aft.Asthepistonisforceddown,forceistransferredtothecrankshaft,causingthecrankshafttorotate.Thereciprocating(bacandforthorupanddown)movementofthepistonisconvertedtorotary(turning)motionofthecrankshaft,whichsuppliesthepowertodrivethevehicle.氣缸內(nèi)的活塞與連桿的上部相連，而連桿的下部與曲軸的偏移部連接。因此，當(dāng)活塞向下運(yùn)動(dòng)時(shí)，這個(gè)運(yùn)動(dòng)傳遞到曲軸，使得曲軸旋轉(zhuǎn)?；钊耐鶑?fù)運(yùn)動(dòng)(前后或者上下)就轉(zhuǎn)化為曲軸的旋轉(zhuǎn)運(yùn)動(dòng)，從而給汽車行駛提供動(dòng)力。Theefficiencyoftheinternalcombustion,reciprocatingpistonengineinconvertingthe