《汽车专业英语》课件第2章

2.1EngineClassification2.2HowanEngineWorks2.3EngineComponents(1)2.4EngineFuelSystems2.5EngineCoolingSystems2.6engineLubricationSystemPARTⅡAUTOMOBILEENGINESPART ⅡAUTOMOBILEENGINES学习目标

通过本章的学习，你应当能够：了解汽车发动机构造的相关知识，掌握有关词汇词组。掌握汽车发动机相关术语的英语表达方法。能查阅与汽车知识有关的英文资料。能借助字典翻译汽车构造方面的文章。

Internalcombustiongasolineengines(SeeFig.2.0.1)runonamixtureofgasolineandair.

Theidealmixtureis14.7partsofairtoonepartofgasoline(byweight.)

Sincegasweighsmuchmorethanair,wearetalkingaboutawholelotofairandatinybitofgas.Onepartofgasthatiscompletelyvaporizedinto14.7partsofaircanproducetremendouspowerwhenignitedinsideanengine.

Let’sseehowthemodernengineusesthatenergytomakethewheelsturn.

Fig.2.0.1

Internalcombustiongasolineengines

Airenterstheenginethroughtheaircleanerandproceedstothethrottleplate.Youcontroltheamountofairthatpassesthroughthethrottleplateandintotheenginewiththegaspedal.

Itisthendistributedthroughaseriesofpassagescalledtheintakemanifold,toeachcylinder.

Atsomepointaftertheaircleaner,dependingontheengine,fuelisaddedtotheair-streambyeitherafuelinjectionsystemor,inoldervehicles,bythecarburetor.

Themajorityofenginesinmotorvehiclestodayarefour-stroke,spark-ignitioninternalcombustionengines.

2.1EngineClassification

Theenginescanbeclassifiedinthefollowingseveralways:(1)operatingcycle,(2)pistonaction,(3)pistonconnection,(4)cylinderarrangement,(5)methodoffuelinjection,and(6)speed.

(1)Operatingcycle

Dieselandgas-burningenginescanbedividedintotwogroupsbasedonthenumberofpistonstrokespercycle,eitherfourortwo.Anenginewhichneedsfourstrokestocompleteonecycleisafour-strokecycleengineor,forshort,afour-cycleengine.Ifitneedsonlytwostrokestocompleteacycle,itiscalledatwo-strokecycleengineor,forshort,atwo-cycleengine.Thus,atwo-cycleenginefirestwiceasoftenasafour-cycleengine.

(2)Pistonaction

Anengine’spistonactionmaybeclassifiedas(a)single-action,(b)double-action,or(c)opposed-piston.

Single-actingenginesuseonlyoneendofthecylinderandonefaceofthepistontodeveloppower.Thisworkingspaceisattheendawayfromthecrankshaft,thatis,attheupperendofaverticalengine.

Double-actingenginesusebothendsofthecylinderandbothfacesofthepistontodeveloppowerontheupstrokeaswellasonthedownstroke.Theconstructioniscomplicated;therefore,double-actingenginesarebuiltonlyinlargeandcomparativelylow-speedunits,generallytopowermotorships.

Anopposed-pistonenginehascylindersineachofwhichtwopistonstravelinoppositedirections.Thecombustionspaceisinthemiddleofthecylinderbetweenthepistons.Therearetwocrankshafts：theupperpistonsdriveone,thelowerpistonstheother.Notethateachpistonissingle-acting;thatis,itdevelopspowerwithonlyonefaceofthepiston.

(3)pistonconnection

Thepistonmaybeconnectedtotheupperendoftheconnectingrodeitherdirectly(“trunkpiston”type),orindirectly(“crosshead”type).

Intrunk-pistonengines,ahorizontalpinwithinthepistonisencircledbytheupperendoftheconnectingrod.Thisbyfarthemostcommonconstruction.

Incrosshead-typeengines,thepistonfastenstoaverticalpistonrodwhoselowerendisattachedtoaslidingmembercalleda“crosshead”,whichslidesupandowninguides.Thecrossheadcarriesacrossheadpinwhichisencircledbytheupperendoftheconnectingrod.Thismorecomplicatedconstructionisrequiredindouble-actingengines.Itisalsousedinsomelarge,slow-speed,single-actingengines.

(4)Cylinderarrangement (SeeFig.2.1.1)

Thefourbasiccylinderarrangementsofadieselorgas-burningengineare:(a)cylinder-in-line,(b)v-arrangement,(c)flat,and(d)radial.Fig.2.1.1Typicalcylinderarrangements

Acylinder-in-linearrangement.Thisisthesimplestandmostcommonarrangement,withallcylindersarrangedverticallyinline.Thisconstructionisusedforengineshavingupto12cylinders.Enginesarealsobuiltwithhorizontalcylinders,usuallyoneortwo,inafewcaseswiththreecylinders.

Ifanenginehasmorethaneightcylinders,itbecomesdifficulttomakeasufficientlyrigidframeandcrankshaftwithanin-linearrangement.Also,theenginebecomesquitelongandtakesupconsiderablespace.Thev-arrangement,withtwoconnectingrodsattachedtoeachcrankpin,permitsreducingtheenginelengthbyalmostone-half,thusmakingitmuchmorerigid,withastiffcrankshaft.Italsocostslesstomanufactureandinstall.Thisisacommonarrangementforengineswitheight,twelve,andsixteencylinders.Cylinderslyinginonelinearecalleda“bank”,andtheanglebetweenthebanksmayvary,inmanufacturingpractice,from30°to120°,themostcommonanglesbeingbetween40°and75°. (Acompletecircleis360°)

Aflatengineisav-enginewiththeanglebetweenthebanksincreasedto180°.Thisarrangementisusedwherethereislittleheadroom,asintrucks,buses,andrailcars.Flatenginesarealsocalled“opposed-cylin-der”engines.

Inaradialengineallthecylindersaresetinacircleandallpointtowardthecenterofthecircle.Theconnectingrodsofallthepistonsworkonasinglecrankpin,whichrotatesaroundthecenterofthecircle.Sucharadialengineoccupieslittlefloorspace.Byattachingtheconnectingrodstoamasterdisksurroundingthecrankpin,asmanyastwelvecylindershavebeenmadetoworkonasinglecrankpin.

(5)Methodoffuelinjection

Dieselenginesaredividedintoair-injectionenginesandsolidormechanicalinjectionengines.Air-injectionenginesuseablastofhighlycompressedairtoblowthefuelintothecylinder.Airinjectionwascommonlyuseonearlydieselenginesbutwiththedevelopmentofsolid-injectionsystemstheair-injectionengineisrapidlydisappearing.

(6)Speed

Alldieselandgas-burningenginesmaybedividedintothreeclassesaccordingtospeed;low-speed,medium-speed,andhigh-speedengines.Automotivedieselenginesoftenrunfasterthan1,200rpm,butthegreatmajorityofotherenginesrunbetween350and1,200rpmandaretermedmedium-speedengines.TechnicalWordscomplete vt. 完成，结束

single-acting adj. 单动的，单作用的

develop v. 发展，发出，产生

crankshaft n. 曲轴，曲柄轴

vertical adj. 垂直的，直立的

upstroke n. (活塞)上行程

downstroke n. (活塞)下行程complicated adj.复杂的，结构复杂的motorship n. 内燃机船，汽船crosshead n. 十字头，滑块horizontal adj. 水平的，卧式的，地平的encircle vt. 环绕，包围，围绕considerable adj. 相当大(多)的crankpinn.曲柄销，曲轴(拐轴)销manufacture v.；n. 制造，生产，加工；制造， 生产，加工bank n. 一排，组，机组rigid adj. 刚性的，刚硬的，不易弯的stiff adj. 刚性的，坚硬的，非弹性的vary vt. 变化，使多样化，改变rotate vt. 旋转，转动，使旋转occupy vt. 占有，占据，拥有blast n. 一阵，一股，气流medium adj. 中间的，中等的，适中的PhrasesandExpressions

fuelinjection 燃油喷射

divideinto… 分成……，分为……

bebasedon… 以……为基础，根据……

pistonstroke 活塞行程，冲程

forshort 简称，为简略起见

(be)awayfrom 离开……，远离，不在……处trunk-pistonengine 筒状活塞式发动机byfar (用以修饰比较级，最高级) 最……，……得多gas-burningengine 汽油(发动)机，可燃气体发动机cylinder-in-line 直列式气缸asufficientlyrigidframe 足够刚性的机架radialengine 径向式发动机，星形发动机asmanyas 多达……，达……之多thegreatmajorityof 大部分……，大多数……NotesontheText

1．Anopposed-pistonenginehascylindersineachofwhichtwopistonstravelinoppositedirections.对置式发动机的每个气缸中都有两个活塞沿相反方向运动。

2．Therearetwocrankshafts：theupperpistonsdriveone,thelowerpistonstheother.有两根曲轴：上面的活塞驱动一根，下面的活塞驱动另一根。

3．Incrosshead-typeengines,thepistonfastenstoaverticalpistonrodwhoselowerendisattachedtoaslidingmembercalleda“crosshead”,whichslidesupanddowninguides.在十字头型发动机中，活塞连接在一根垂直的活塞杆上，活塞杆的下端又连接在一个叫做“十字头”的滑动构件上，十字头在导轨中上下滑动。

4．Thev-arrangement,withtwoconnectingrodsattachedtoeachcrankpin,permitsreducingtheenginelengthbyalmostone-half,thusmakingitmuchmorerigid,withastiffcrankshaft.

V形排列，由于每个曲柄销上有两根连杆，所以可使发动机的长度几乎缩短一半，这样就使发动机的刚性更大，曲轴也更坚固。

5．Thisarrangementisusedwherethereisalittleheadroomasintrucks,buses,andrailcars.这种气缸排列通常用在头部空间很小的机动车上，如货车、公共汽车以及有轨电车上。

6．Byattachingtheconnectingrodstomasterdisksurroundingthecrankpin,asmanyastwelvecylindershavebeenmadetoworkonasinglecrankpin.通过把连杆连接到包住曲柄销的一个主盘上，十二个气缸便可在同一个曲柄销上工作。Exercises

Ⅰ. PutthefollowingexpressionsintoChinese.

1．burnitsfuelwithintheengineproper

2．asparktoignitethefuel

3．piston-typeinternalcombustionengines

4．air-cooledengine

5．singlecylinderdieselengine

6．multicylinderengine

7．connecttotheupperendoftheconnectingrod

8．sparkignitionengine

9．four-stroke-cycledieselengine

10．horizontalopposedcylinderdieselengine

Ⅱ. Completingthesentences:Thesentencesbelowareincomplete.Aftereachsentence

therearefourwordsorphrases,onlyoneofwhichwillcorrectlycompletethesentence,selectingtheproperwordorphrasetocompleteitcorrectly.

1．Incarburetorengines,theair/fuelmixtureis＿＿byaspark.

A.developedB.producedC.ignitedD.blownout

2．Theconnectingrodisattachedtothepistonbythe____.  A.rodcapB.pistonpinC.capboltsD.capbearing

3．Thefourstrokesintheengineare,inorderofoccurrence:____.  A.intake,power,exhaust,andcompression  B.intake,exhaust,power,andcompression  C.intake,compression,power,andexhaust  D.intake,power,compression,andexhaust

4．Enginescanbedividedinto____bythenumberofpistonstrokesinonecompletecycle.  A.twogroupsB.threekindsC.fourclassesD.six

5．Accordingtothemethodofignitionoftheairfuelmixture,enginesaredividedinto____.  A.gasengineandsteamengine  B.gasolineengineanddieseslengine  C.externalcombustionengineandcompressionignitionengine  D.internalcombustionengineanddieselengine

6．Inthestandardengine,eachcylinderhas____.A.onevalveB.twovalvesC.threevalvesD.fourvalves

Ⅲ. TranslatethefollowingsentencesintoChinese.

1．Ifthepistonismovedupanddowninthecylinder,thisup-and-down,orreciprocating,motionofthepistonischangedintotherotarymotionofthecrankshaftbytheconnectingrodandthecrankoftheshaft.

2．Theadvantageofthedieselisitsgreaterpullingor“lugging”powerwhenitslowsdownunderaheavyload,inotherwords,thedieselloseslesspoweratreducedspeedthanthegasolineengine.

3．Additionaladvantagesofthedieselenterintocertainspecialapplicationssuchasisolatedservicestations,railwaywaterstations,vacationresorts,lumbercamps,minepowerplants,oil-welldrilling,andemergencypowerplants.

4．Thefundamentaldifferencebetweenpetrolanddieselenginesisthatinthepetrolthesourceofheatforignitingthecharge,namely,anelectricspark,isgeneratedoutsidetheengine,andistaken,asitwere,intothewaitingchargeattherequiredinstant.

5．Atanearlystageintheevolutionofthehighspeeddieselengineavariabletimingdevicewasintroducedinthepumpdrivecoupling,takingtheformofahelicallysplinedsleevebymeansofwhichtheangularrelationbetweendrivinganddrivenshaftscouldbevariedbymanualorautomaticcontrol.ReadingMaterialEnginemaintenance

Asoundengineshoulddevelopfullpower,runsteadilyunderfull-loadandno-loadconditions,withoutoverheating,smoking,oilorcoolantleakage.Sometroublescanbeidentifiedbytheirsymptomswithoutdisassemblingtheengine.

Thesymptomsindicativeofsometroubleswiththecrankgearincludeforeignnoiseandknocks,lossofpower,excessiveoilandfuelconsumption,smokyexhaust.

Noiseandknocksintheenginearecausedbythewearofitsbasicpartsleadingtoexcessiveclearancebetweenitsmatingparts.

Ifthepistonandcylinderarewornandtheclearancebetweenthemisexcessive,aclearmetallicknockingappears,whichismostvividwhentheenginerunscold.Asharpmetallicknockingatallspeedsindicatesanincreasedclearancebetweenthepistonpinandtheconnectingrodbush.Iftheknockinggrowswhentheengineissharplythrottledup,themainorcrankpinbearingshellsareworn,thedullerknockssymptomizingthewearofthemainbearings.Sharpcontinuousknockingintheengineaccompaniedbytheoilpressuredropisanevidenceofmeltingoutofbearings.Theengineknockscanbelistenedtowiththeuseofstethoscope.

Lossofenginepowerstemsfromthedropofcompressionwhichmayoccurwhenthecylinderblockheadnutsaretightenednonuniformlyorinsufficiently,ortheheadgasketisdamaged,thepistonringsarestuckinthegroovesowingtocarbonorlacquerdeposit;theringsareworn,brokenorlosttheirresilience;thecylindersareworn.

Thecompressioncanbecheckedwithacompressiongaugeorbyhand.Tocheckthecompressionbyhand,driveoutthesparkplugsfromallthecylindersbuttheonebeingchecked.Whilerotatingthecrank,estimatethecompressionbytheresistancetotherotation.Thecompressioninothercylindersischeckedinasimilarway.

Tocheckthecompressionwithacompressiongauge,warmuptheengine,driveoutthesparkplugs,fullyopenthethrottleandchokevalves.Installarubbernippleofthecompressiongaugeintotheplughole,turnthecrankshaft8or10timesandcheckthegaugereading.Afterthecrankshaftisturned,thepressureinthegoodcylindershouldbe7.0~7.8kgf/cm2(0.7～0.78MPa).Thisprocedureshouldbeusedtocheckthecompressionconsecutivelyinallthecylindersoftheengine.

Excessivefuelandoilconsumptionandsmokygrayexhaust(theoillevelinthecrankcasebeingnormal)areusuallyattributedtothestickingorwearofthepistonrings.Stickingcanberemediedwithoutdisassemblingtheengine;forthispurpose,mixequalpartsofdenaturedalcoholandkeroseneandpour20gofthemixtureintoeachcylinderthroughthesparkplughole,leavingitthereovernight.Inthemorningstarttheengine,runitfor10to15minutes,shutdownandchangetheoil.

Carbonizationoftheengine,i.e.depositionofcarbononthepistoncrownsandcombustionchambers,impairsheattransferandleadstooverheating,lossofpowerandexcessivefuelconsumption.Toremovethecarbondeposit,drainthecoolant,removetheunitsmountedonthecylinderhead,undothenutsanddetachthecylinderheadcarefullysoasnottodamagethegasket.Ifthegaskethasstucktotheheadorblock,separateitwithabluntknifeorawideandthinstripofmetal.

Removethecarbondepositwithscrapersmadeofwoodorsoftmetaltoavoiddamagingthepistoncrownsorcombustionchamberwalls.Insodoing,covertheadjacentcylinderswithcleanrags.Thecarbondepositgoesoffeasieraftersofteningbyapplyingkerosene-soakedrags.

Wheninstallingthecylinderblockheadgasket,wipeitwithpowderedgraphite.

Cracksinthewallsofthecylinderblockandheadmayresultfromfreezingofwaterorfillingcoldwaterintoahotengine.

Themaintroublescharacteristicofthevalvegearareimproperseatingorincompleteopeningofthevalves.

Improperseatingissymptomizedbypoorcompression,poppingintheinletandexhaustmanifolds,lossofpower.Improperseatingmaybecausedbycarbondepositonthevalvesintheguides,absenceofclearancebetweenthevalvestemandtherocker.

Incompleteopeningofthevalvesischaracterizedbyknockingintheengineandlossofpower.Thisderangementstemsfromexcessiveclearancebetweenthevalvestemandtherocker.

Thevalvegeartroublesalsoincludewearofthecrankshaftgears,tappets,guides,excessiveendplayofthecamshaft,wearofrockerbushingsandfulcrums.

Toadjusttheclearancebetweenthevalvestemandtherocker,removethevalvecover,firstdetachingallthepartsmountedonit;shiftthepistontoTDConthecompressionstrokesothatthevalvesareclosed;checktheclearanceandadjustit,ifnecessary,asfollows:undothelock-nutontherockeradjustingscrew,settherequiredclearancebyrotatingtheadjustingscrew,tightenthelock-nutholdingthescrewwiththescrewdriverandrechecktheclearance.PhrasesandExpressions

beidentifiedby 用……来确定，用……来作标志

beindicativeof 表现出，有……征兆，有……的征兆

smokyexhaust 有烟排气

matingparts 配合件，相配构件，配件

connectingrodbush 连杆轴套

crankpinbearingshells 曲柄销轴瓦(轴承壳套)withtheuseofstethoscope 利用听诊器stemfrom 由……引起，产生于……rubbernipple 橡胶接头，橡皮套(be)attributedto 起因于，被认为是……所造成的denaturedalcohol 变性酒精impairheattransfer 减弱传热becharacterizedby ……的特点在于，在……上有 明显区别rockeradjustingscrew 摇臂调整螺钉2.2HowanEngineWorks

Sincethesameprocessoccursineachcylinder,wewilltakealookatonecylindertoseehowthefourstrokeprocessworks.

ThefourstrokesareIntake,Compression,PowerandExhaust.ThepistontravelsdownontheIntakestroke,upontheCompressionstroke,downonthePowerstrokeandupontheExhauststroke.• Intake (SeeFig.2.2.1)

AsthepistonstartsdownontheIntakestroke,theintakevalveopensandthefuel-airmixtureisdrawnintothecylinder(similartodrawingbacktheplungeronahypodermicneedletoallowfluidtobedrawnintothechamber).

Whenthepistonreachesthebottomoftheintakestroke,theintakevalvecloses,trappingtheair-fuelmixtureinthecylinder. Fig.2.2.1iNTAKE

• Compression

Thepistonmovesupandcompressesthetrappedairfuelmixturethatwasbroughtinbytheintakestroke.Theamountthatthemixtureiscompressedisdeterminedbythecompressionratiooftheengine.Thecompressionratioontheaverageengineisintherangeof8∶1to10∶1.

Thismeansthatwhenthepistonreachesthetopofthecylinder,theair-fuelmixtureissqueezedtoaboutonetenthofitsoriginalvolume.

• Power

Thesparkplugfires,ignitingthecompressedair-fuelmixturewhichproducesapowerfulexpansionofthevapor.Thecombustionprocesspushesthepistondownthecylinderwithgreatforceturningthecrankshafttoprovidethepowertopropelthevehicle.Eachpistonfiresatadifferenttime,determinedbytheenginefiringorder.Bythetimethecrankshaftcompletestworevolutions,eachcylinderintheenginewillhavegonethroughonepowerstroke.

• Exhaust

Withthepistonatthebottomofthecylinder,theexhaustvalveopenstoallowtheburnedexhaustgastobeexpelledtotheexhaustsystem.Sincethecylindercontainssomuchpressure,whenthevalveopens,thegasisexpelledwithaviolentforce(thatiswhyavehiclewithoutamufflersoundssoloud.)Thepistontravelsuptothetopofthecylinderpushingalltheexhaustoutbeforeclosingtheexhaustvalveinpreparationforstartingthefourstrokeprocessoveragain.

OilingSystem

Oilisthelife-bloodoftheengine.Anenginerunningwithoutoilwilllastaboutaslongasahumanwithoutblood.Oilispumpedunderpressuretoallthemovingpartsoftheenginebyanoilpump.Theoilpumpismountedatthebottomoftheengineintheoilpanandisconnectedbyageartoeitherthecrankshaftorthecamshaft.

Thisway,whentheengineisturning,theoilpumpispumping.Thereisanoilpressuresensorneartheoilpumpthatmonitorspressureandsendsthisinformationtoawarninglightoragaugeonthedashboard.Whenyouturntheignitionkeyon,butbeforeyoustartthecar,theoillightshouldlight,indicatingthatthereisnooilpressureyet,butalsolettingyouknowthatthewarningsystemisworking.Assoonasyoustartcrankingtheenginetostartit,thelightshouldgooutindicatingthatthereisoilpressure.

EngineCooling

Internalcombustionenginesmustmaintainastableoperatingtemperature,nottoohotandnottoocold.Withthemassiveamountsofheatthatisgeneratedfromthecombustionprocess,iftheenginedidnothaveamethodforcoolingitself,itwouldquicklyself-destruct.Majorenginepartscanwarpcausingoilandwaterleaksandtheoilwillboilandbecomeuseless.

Whilesomeenginesareair-cooled,thevastmajorityofenginesareliquidcooled.Thewaterpumpcirculatescoolantthroughouttheengine,hittingthehotareasaroundthecylindersandheadsandthensendsthehotcoolanttotheradiatortobecooledoff.TechnicalWords

compression n. 压缩

plunger n. 柱塞，活塞

hypodermic n. 皮下注射器

muffler n. 消声器，消音器

mount v. 使……固定

self-destruct v. 自我毁坏

warp v. (使某物)弯曲

coolant n. 冷却器

radiator n. 散热器

smother v. 覆盖

vibration n. 振动

flywheel n. 飞轮

torque n. 扭转力

converter n. 变流器，液力变距器

inertia n. 惯性

inherent adj. 内在的，固定的

parallel v. 平行

spin v. 旋转

offset v. 补偿或抵消PhrasesandExpressions

bedrawninto 被卷入

theratioof ……的比例

besqueezedto 挤入

beexpelledto 驱逐

aslongas 只要

beattachedto 系、缚在

smoothout 使某物光滑、平坦NotesontheText

1．AsthepistonstartsdownontheIntakestroke,theintakevalveopensandthefuel-airmixtureisdrawnintothecylinder(similartodrawingbacktheplungeronahypodermicneedletoallowfluidtobedrawnintothechamber.)在进气行程，当活塞开始下行时，进气门打开，空气燃油的混合气被吸入气缸(类似于拉开注射器的柱塞，将液体吸到针管内)。

2．Bythetimethecrankshaftcompletestworevolutions,eachcylinderintheenginewillhavegonethroughonepowerstroke.曲轴转两周，发动机里的气缸完成一个作功行程。

3．Whenyouturntheignitionkeyon,butbeforeyoustartthecar,theoillightshouldlight,indicatingthatthereisnooilpressureyet,butalsolettingyouknowthatthewarningsystemisworking.当你打开点火开关，在启动车子之前油量警示灯亮，表明此时无油压力，同时也让你知道报警系统已开始工作。

4．Thewaterpumpcirculatescoolantthroughouttheengine,hittingthehotareasaroundthecylindersandheadsandthensendsthehotcoolanttotheradiatortobecooledoff.水泵使冷却液在整个发动机形成循环，冷却液流至气缸和气缸盖周围发热的区域，然后水泵把热的冷却液抽到散热器中使之冷却下来。Exercises

Ⅰ.AnswerthefollowingquestionsinEnglish.

1．Pleasetelltheprincipleofthecompressionstroke.

2．What’sthefunctionofamuffler?

3．Whydoestheoilpumpneedanoilpressuresensor?

4．Whathappenedtotheengineifitdidnothaveamethodforcoolingitself?

5．Howmanykindsofenginecooling?

6．Whydoengineersuseoneormorebalanceshafts?

Ⅱ.TranslatefollowingexpressionsintoEnglish.

1．压缩比

2．进气、压缩、作功、排气行程

3．发动机点火顺序

4．油压传感器

5．点火开关

6．废气排出

Ⅲ.TranslatethefollowingsentencesintoEnglish.

1．当活塞到达进气行程的下止点时，空气燃油混合气进入气缸，进气门关闭。

2．每个活塞按不同的点火顺序依次点火。

3．机油靠油泵的作用加压流至发动机的各个部件。

4．发动机必须保持一个相对稳定的工作温度，既不太热也不太冷。

Ⅳ.Pleaseselecttherightwordinthefollowingblockstocompletetheparagraph.

last

pump

mountconnectmonitorsendAnenginerunningwithoutoilwill

aboutaslongasahumanwithoutblood.Oilis

underpressuretoallthemovingpartsoftheenginebyanoilpump.Theoilpumpis

atthebottomoftheengineintheoilpanandis

byageartoeitherthecrankshaftorthecamshaft.Thisway,whentheengineisturning,theoilpumpispumping.Thereisanoilpressuresensorneartheoilpumpthat

pressureand

thisinformationtoawarninglightoragaugeonthedashboard.

Ⅴ.Completethesentences:Thesentencesbelowareincomplete.Aftereachsentencetherearefourwordsorphrases,onlyoneofwhichwillcorrectlycompletethesentence,selectingtheproperwordorphrasetocompleteitcorrectly.

1．Thefour-strokecycleoperatesinwhichorder

.

A.intake,compression,power,exhaust

B.compression,power,intake,exhaust

C.intake,exhaust,power,compression

D.intake,power,exhaust,compression

2．Thecombustionprocesspushesthepistondownthecylinderwithgreatforceturningthecrankshafttoprovidethepowerto

thevehicle.  A.expel

B.enforce C.propel

D.add

3．Withthe_________atthebottomofthecylinder,theexhaustvalveopenstoallowtheburnedexhaustgastobeexpelledtotheexhaustsystem.  A.piston

B.valve

C.camshaft D.crankshaft

4．Thereisan

neartheoilpumpthatmonitorspressureandsendsthisinformationtoawarninglightoragaugeonthedashboard.  A.oilpressuresensor

B.oxygensensor  C.temperaturesensor

D.speedsensor5．Theflywheeluses

tosmoothoutthenormalenginepulses.  A.pressure

B.inertia

C.throttle

D.carburetor

6．Abalanceshaftisaheavyshaftthatrunsthroughtheengine

thecrankshaft.  A.oppositeto

B.subjectto C.upto

D.paralleltoReadingMaterial

Don’tLetTheCarEngineIdle!

OLYMPIA－Here’sapowerfultooljustaboutanydrivercanusetosavemoneyandhelpprotecttheairwebreathe:theignitionswitch.

Idlingyourcarformorethan30secondswastesmoneyanddamagestheenvironment.Turningitoffisasimpleactthatcanmakeabigdifference.“Wedon’tusuallythinkabouthowidlingourcarscausespollution,”saidMaryBurg,whomanagestheairqualityprogramattheDepartmentofEcology(Ecology).“Weletourenginesrunatdrive-upwindows,whenwe’resittingatthemall,whenwe’rewaitingfortrainsorferries,whenwe’relisteningtotheradio.Weevenidleatschools,wherechildrenhavetobreathetheexhaust.”

Childrenbreathe50percentmoreairperpoundofbodyweightthanadults,andvehicleexhaustincreasesmanychildren’sasthmasymptoms.Morethanoneoutofevery10childreninWashingtonhasbeendiagnosedwithasthmaandthenumberisrising–it’sanepidemic.

Contrarytopopularbelief,idlingisn’taneffectivewaytowarmupmostcarengines.Today’sautomobilemanufacturersrecommenddrivingoffrightawayandurgethatdriverswaitnomorethan30secondstobegindriving,evenonthecoldestdays.

Somepeopleworrythatrestartingtheenginemightharmthecar,butfrequentrestartingdoeslittledamage.ResearchersinCanadafoundthatcomponentwearcausedbyfrequentrestartsaddsabout$10peryeartothecostofdriving,