(新版)汽車專業(yè)英語(yǔ)課件：Engine components

Project3Enginecomponents12

掌握發(fā)動(dòng)機(jī)的總體結(jié)構(gòu)、工作原理、基本術(shù)語(yǔ)，分類

掌握常用術(shù)語(yǔ)的表達(dá)方法,了解相關(guān)其它專業(yè)術(shù)語(yǔ)知識(shí)目標(biāo)能讀懂發(fā)動(dòng)機(jī)工作原理相關(guān)英文材料,能熟記相關(guān)專業(yè)詞匯能讀懂發(fā)動(dòng)機(jī)總體構(gòu)造和分類的英文材料，能熟練掌握發(fā)動(dòng)機(jī)基本術(shù)語(yǔ)和概念的英語(yǔ)表達(dá)方式能對(duì)發(fā)動(dòng)機(jī)各機(jī)構(gòu)和系統(tǒng)組成中的常見(jiàn)零部件的英語(yǔ)表達(dá)準(zhǔn)確識(shí)別能熟記常見(jiàn)的發(fā)動(dòng)機(jī)專業(yè)術(shù)語(yǔ)

縮寫形式能看圖寫出零件名稱能力目標(biāo)

Project3Enginecomponents3Task1

EnginePrinciplesandStructure

1.Newwordsandexpressions知識(shí)準(zhǔn)備principle

[?prins?pl]n.原則，原理convert

[k?n?v?:t,?k?nv?:t]v.(使)轉(zhuǎn)變(化)combustion[k?m'b?st??n]n.燃燒gasoline['ɡ?s?li:n]n.汽油stroke[str?uk]

n.沖程spark[spɑ:k]n.火花;火星；vi.發(fā)出火星;發(fā)出閃光compress[k?m?pr?s]vt.壓緊,壓縮cylinder[?s?l?nd?]n.圓筒,圓柱,圓柱體,汽缸,泵體plug[pl?ɡ]n.插頭,插座；塞子,栓diesel

[?diz?l,-s?l]

n.柴油；柴油機(jī)機(jī)車(或船等),內(nèi)燃機(jī)車inject[?n?d??kt]vt.給…注射（藥物等）,給…注射（液體）高職高專41.Newwordsandexpressionssufficiently[s??f???ntl?]adv.足夠地,充分地ignite[?ɡ?na?t]vt.點(diǎn)燃;引發(fā),（使）燃燒,著火piston['p?stn]n.〈機(jī)〉活塞cycle['saikl]n.循環(huán),周期,自行車inlet[‘inlet]n.

進(jìn)口，入口exhaust[iɡ'z?:st]vt.用盡；使非常疲倦;n.排氣裝置,排氣管[孔]；廢氣valve[v?lv]n.閥,活門,閥門,氣門suction['s?k??n]n.吸,抽吸revolution[,rev?'lu:??n]n.革命；徹底改變,重大變革；旋轉(zhuǎn);運(yùn)行,公轉(zhuǎn)induction[?n'd?k??n]n.就職,入伍；吸入；(電或磁的)感應(yīng)；歸納(法),吸入propel

[pr??pel]vt.推進(jìn)，推動(dòng)block[bl?k]n.街區(qū),街段；大塊(木料、石料、金屬、冰等)；知識(shí)準(zhǔn)備5知識(shí)目rod[r?d]n.竿,桿,棒part[pɑ:t]n.一部分;局部；零件；角色component[k?m'p?un?nt]n.成分,組成部分,部件,元件circular['s?:kjul?]adj.圓形的,環(huán)形的;循環(huán)的n.通知,通告gas-tight氣密的，不透氣的swivel['sw?v?l]n.轉(zhuǎn)節(jié),轉(zhuǎn)環(huán);旋軸;旋轉(zhuǎn)接頭vt.&vi.(使)旋轉(zhuǎn);在樞軸上轉(zhuǎn)動(dòng)gudgeon['ɡ?d??n]n.易騙的人;舵鈕;舵栓pin[pin]n.大頭針,別針；飾針；鎖,釘,插頭,閂；腿coupling['k?pli?]n.連接；連接器;(尤指列車等的)車鉤,掛鉤formula

[?f?:mjul?]n.原則，方案；公式，方程式；配方bearing['b??ri?]n.舉止,風(fēng)度；方向；軸承offset['?fset]vt.抵消,補(bǔ)償;adj.偏（離中）心的，抵消的crankcase['kr??kkeis]n.曲軸箱知識(shí)準(zhǔn)備6知識(shí)目gasket['ɡ?skit]n.束帆索,墊圈,襯墊pump[p?mp]n.泵,打氣筒vt.&vi.用抽水機(jī)汲水;給…打氣pulley['p?li:]n.滑輪(組);滑車；皮帶輪drain[drein]vt.&vi.(使)流干,(使)逐漸流走;n.排水溝,排水管bolt[b?ult]n.螺栓；(門或窗)插銷,閂;crush[kr??]vt.&vi.壓碎,壓壞;vi.擠進(jìn),擠入ring[ri?]n.戒指,指環(huán)；環(huán)狀物,圓圈；團(tuán)伙,幫派；鈴聲；打電話；特性grommet['ɡr?mit]n.金屬扣眼,索環(huán)distributor[d?'str?bj?t?]n.批發(fā)公司;批發(fā)商；(汽車上的)配電器filter['filt?]n.過(guò)濾,過(guò)濾器vt..透過(guò),過(guò)濾vi.(消息等)走漏manifold['m?n?,f??ld]adj.多種多樣的;n.具有多種形式的東西；多支管volume['v?lju:m]n.卷,冊(cè),書卷；體積;容積,容量；音量,響度知識(shí)準(zhǔn)備7知識(shí)目radius['reidj?s]n.半徑(距離)；用半徑度量的圓形面積;半徑范圍diameter[dai'?mit?]n.直徑；放大率displacement[d?s'ple?sm?nt]n.移置,代替;排量torque[t?rk]n.扭矩clearance['kli?r?ns]n.凈空,余隙；許可,批準(zhǔn)self-contained自給的internalcombustionengine內(nèi)燃機(jī)sparkplug火花塞resultin導(dǎo)致，致使，引起知識(shí)準(zhǔn)備8知識(shí)目consistof由…組成upanddown上上下下connectingrod連桿fuelsystem燃油供給系ignitionsystem點(diǎn)火系coolingsystem冷卻系lubricationsystem.潤(rùn)滑系TopDeadCenter(TDC)上止點(diǎn)BottomDeadCenter(TDC)下止點(diǎn)displacementvolume排量compressionratio壓縮比sweptvolume工作容積clearancevolume燃燒室容積知識(shí)準(zhǔn)備9Engineworkingprinciples任務(wù)實(shí)施Theengineisaself-containedpowerunitwhichconvertstheheatenergyoffuelintomechanicalenergyformovingthevehicle.Inbrief,theburningofthefuelcausesarapidriseincylinderpressurewhichisconvertedtousefulmechanicalenergybythepistonandthecrankshaft.Themajorityofenginesinautomobiletodayarefour-stroke,spark-ignitioninternalcombustionengines.InpetrolEngine,theair-fuelmixtureafterbeingcompressedintheenginecylindertoahighpressureisignitedbyanelectricsparkfromasparkplug.Indieselengine,dieselisinjectedintotheenginecylindercontainingaircompressedtoaveryhighpressure.Theairtemperatureissufficientlyhightoignitethefuel.Thatiswhythereisnosparkplugusedindieselengine.10Engineworkingprinciples任務(wù)實(shí)施Thefour-strokecycle(Figure3.1.1)forapetrolengine(sparkignition)isverysimilarinprincipletothatofadieselengine(compressionignitionorCI).Tocompletethecycle,fourstrokesofthepistonareneeded.StartingwiththepistonatTDC,asthecrankshaftrotates,thenextfourstrokesofthepistonwillresultinanumberofdifferentprocessesandactionstakingplace.Suctionstroke

Whenthepistonmovesdownthecylinder,theinletportisopenandtheexhaustportisclosed,afreshchargeisdrawnintothecylinder.Mostpetrolenginesdrawinamixtureofairandfuel,howeveradieselenginedrawsinachargeofaironly.Attheendofthestroke,theinletcloses.11Engineworkingprinciples任務(wù)實(shí)施12Engineworkingprinciples任務(wù)實(shí)施CompressionstrokeThenthepistonmovesbackuptocompressthisair-fuelmixture.Thecompressionforcesthefuelintoclosercombinationwithair.Justalittlebeforetheendofcompressionstroke,themixtureisignitedbyasparkproducedbysparkplug.Duringthisstrokesuctionandexhaustvalveremainclosed.Whenthemixtureinsidethecylinderiscompressed,pressureandtemperatureriseatthesametime.Powerstroke

Whenthepistonreachesthetopofitsstroke,thesparkplugemitsasparktoignitethegasoline.Thegasolinechargeinthecylinderexplodes,drivingthepistondown.Thecombustionprocesspushesthepistondownthecylinderwithgreatforceturningthecrankshafttoprovidethepowertopropelthevehicle.Eachpistonfiresatadifferenttime,determinedbytheenginefiringorder.Atthistime,intake,exhaustvalveisstillclosed.13Engineworkingprinciples任務(wù)實(shí)施Bythetimethecrankshaftcompletestworevolutions,eachcylinderintheenginewillhavegonethroughonepowerstroke.However,foradieselengine,thedieselfuelisinjectedathighpressureintothehotcompressedairandmixestoformacombustibleair/fuelmixture.Theheatoftheairignitesthefuelmixture.ExhauststrokeTherotationofthecrankshaftcausesthepistontoreturnupthecylinder.Theinletportremainsclosedbuttheexhaustportisnowopened.Themovementofthepistontowardsthetopofthecylinderthereforeforcestheburntgasesoutofthecylinderviatheexhaustport.Attheendoftheexhauststroke,theexhaustportclosesandtheinletportre-opensforthenextinductionstroke.14Engineworkingprinciples任務(wù)實(shí)施Engineoverallstructure

Theengineconsistsofalargenumberofparts(shownasFig.3.1.2).Themaincomponentsofenginearecylinderblock,pistons,connectingrods,crankshaftandvalves.

Thecylinderwiththesimplestform,iscirculartube,whichisclosedatoneend.Thepistonfitscloselyinsidethecylinder.Ideallyitwouldbeperfectlygas-tightyetperfectlyfreetomoveupanddowninsidethecylinder.Theconnectingrodconnectsthepistontothecrankshaft.Atthepistonendofconnectingrodisaswivelpincalledthe‘gudgeonpin’.Thegudgeonpinisfittedintoholesinthepistonandtheconnectingrod,thuscouplingthemtogether.Thecrankshaftisthemainshaftoftheengineandiscarriedinbearingsinthecrankcase.Offsetfromthemainpartoftheshaftisthecrankpintowhichtheconnectingrodisfittedandisfreetoturn.Theotherpartsarejoinedtogethertoformsystems.Thesesystemsarethefuelsystem,valvesystem,ignitionsystem,coolingsystem,lubricationsystem.Eachofthemhasadefinitefunction.15Engineworkingprinciples任務(wù)實(shí)施EnginesizeTheusualmethodofindicatingthesizeofanengineistostatethevolumeofairandfueltakenintotheengineforeachcycleofoperations.ThismeansthevolumecontainedinthatpartofthecylinderbetweentheTDCandBDCpositionsofthepiston.ThevolumeofacylinderisgivenbytheformulaV=πr2horV=πd2h/4.WhereVisthevolumeofthecylinder,ristheradius,dthediameterandhtheheightorlength.Theinternaldiameteroftheenginecylinderiscalledthebore,whilstthedistancethepistonmovesbetweenTDC(TopDeadCenter)andBDC(BottomDeadCenter)iscalledthestroke(showninfigure3.1.3).Representingthesebydandl,respectively,theaboveformulacanbewritten:V=πd2l/4.Sincethisisthevolumedisplacedorsweptbythepiston,itiscalledthedisplacementvolumeorsweptvolumeofthecylinder.Iftheenginehasseveralcylinders,asmosthave，thetotalsweptvolumeoftheengineissweptvolumepercylindermultipliedbythenumberofcylinders.16Engineworkingprinciples任務(wù)實(shí)施CompressionratioItisanimportantparameterofanenginecylinder.WhenthepistonisatTDC,aspaceisleftbetweenitstopandtheendofthecylinder:thevolumecontainedinthisspaceiscalledtheclearancevolume.ThevolumeenclosedabovethepistonatBDCconsistsoftheclearancevolumeplusthesweptvolumeandiscalledthetotalvolume.17Engineworkingprinciples任務(wù)實(shí)施TorqueandpowerWhenenginesarediscussed,thereareusuallytwotermsusedtoindicatehow‘powerful’anengineis:torqueandpower.Althoughthereisarelationshipbetweentorqueandpower,theyareinfactdifferentmeasurementsofwhatanenginecanachieve.Thevaluesoftorqueandpowerprovideindicationsoftheperformancethatcanbeexpectedfromanengine.Torqueisgenerallyassociatedwithstrongpullingpower,whichwouldbetypicallyrequiredinavehiclethathastopullheavyloadssuchasalargecommercialvehicleorheavygoodsvehicle.Powerisgenerallyassociatedwithenginesthatareintendedtoproducehighvehiclespeeds.Racingcarsandsportscarswouldgenerallyhavehigh-powerengines.18Task2

Crank-connectingrodsandvalvemechanism

1.Newwordsandexpressionsmechanism[?m?k??n?z?m]n.機(jī)械裝置、構(gòu)造,機(jī)制fulfill[ful?fil]t.履行(諾言等)、完成(任務(wù)等)、實(shí)現(xiàn)；執(zhí)行(命令等)、服從；達(dá)到(目的)potential[p??ten??l]adj.潛在的,有可能的rotary[?r?ut?ri]adj.(機(jī)器或設(shè)備)轉(zhuǎn)動(dòng)的；(運(yùn)動(dòng))旋轉(zhuǎn)的、繞軸轉(zhuǎn)動(dòng)的severe[si?vi?]adj.極為惡劣的、十分嚴(yán)重的；精確的；嚴(yán)謹(jǐn)?shù)膚ithstand[wie?st?nd]vt.經(jīng)受,承受corrosion[k??r????n]n.腐蝕、侵蝕、受腐蝕的部位；腐蝕生成物如繡等、衰敗crankcase['kr??kkeis]n.曲軸箱constitute[?k?nstitju:t]vt.構(gòu)成、組成；建立、制定backbone[?b?k?b??n]n.脊骨、脊柱；骨干、支柱、主力、中堅(jiān)、基礎(chǔ)accessory[?k?ses?ri]n.附件、配件、附屬物；知識(shí)準(zhǔn)備19sufficient[s??fi??nt]adj.足夠的、充足的film[film]n.影片,電影；膠片,膠卷；薄層,薄膜stiffness[?st?fn?s]n.剛度attachment[?'t?t?m?nt]n.附著,附屬；附屬物,附件valve[v?lv]n.閥、活門；真空管emission

[i?mi??n]n.發(fā)出，發(fā)光，放射物simultaneously同時(shí)地punctually['p??kt???l?]adv.如期地,準(zhǔn)時(shí)地tappet['t?pit]n.梃桿,凸子rocker['r?k?]n.(搖椅等底部)彎形搖臂、搖滾青年inefficiency[?n?'f???ns?]n.無(wú)效率;無(wú)能無(wú)效率事例retainer[ri'tein?]n.護(hù)圈,定位器belt[belt]n.腰帶、帶子、區(qū)域、地帶chain[t?ein]n.鏈、鎖鏈、一系列的事物、連鎖店或旅館、束縛cylindrical[s?'l?ndr?k?l]adj.圓柱形的、圓筒狀的、氣缸(或滾筒)的intermediate[,?nt?'mi:dj?t]adj.中間的、中級(jí)的reliability[r?la??b?l?t?]n.可靠、可信賴知識(shí)準(zhǔn)備20durability['dj?r?b?l?t?]n.耐久性、耐用性cam[k?m]n.凸輪compressionring壓縮環(huán)（氣環(huán)）pressure-tight耐壓密閉的alignwith使一致；使密切合作besubjectedto經(jīng)過(guò)～、易于～、遭受valvestem氣門桿valveguide閥導(dǎo)承、閥桿導(dǎo)承、氣閥導(dǎo)管、氣門導(dǎo)管lockingplate鎖緊木片、鎖片、防松板、定鬧盤pushrod制動(dòng)缸推桿、頂桿、挺桿、推桿chaindrive鏈傳動(dòng)withregardto關(guān)于timinggear正時(shí)齒輪VariableValveTiming可變氣門正時(shí)知識(shí)準(zhǔn)備21Crankandconnectingrodmechanism

任務(wù)實(shí)施Thecombinationofcrankandconnectingrodinaninternalcombustionengineformsakindofmechanismthatcanfulfillworkingcycleandconvertthepotentialenergyofthefuelintothekineticenergywhichrotatesthecrankshaft.Itsfunctionistoachieveenergyconversiontotransmitforceandchangethereciprocatingmotionofthepistonintotherotarymotionofthecrankshaft.Theworkingconditioninthismechanismisrathersevereduetowithstandinghightemperature,highpressure,high-speedandchemicalcorrosion.22Automobilecategory

任務(wù)實(shí)施Thecrankandconnectingrodmechanismcanbedividedintothreegroups,suchastheenginebody,piston-connectingrodandcrankshaft-flywheelgroup.Amongthem,thebodyconstitutesthebackboneoftheengine,whichisregardedasabaseontheinternalandexternalinstallationofallthemajorpartsandaccessoriesinanengine.Thebodymusthavesufficientstrengthandstiffnessbecauseitissubjectedtovariousloads.Itismainlycomposedofthecylinderblock,crankcase,cylinderhead,cylindergasketandotherparts(shownasthefigure.3.2.1).Thisgroupaboutpiston-connectingrodconsistsofpiston,pistonring,pistonpin,connectingrodanditsbearinghalfshells(illustratedinFigure3.2.2).Thegroupofcrankshaft-flywheelismainlycomposedofcrankshaft,flywheelandotheraccessories(shownasFigure.3.2.3)23AutomobileClassification任務(wù)實(shí)施2425Valveoperatingmechanism任務(wù)實(shí)施Thevalveoperatingmechanismisusedtocontroltheintakeandexhaustports,whichprovidestimelyadmissionofthefreshchargeintothecylindersandemissionofexhaustgases.Simultaneously,thevalvespunctuallyopenandclosethoseportsinthecylinderheadthroughwhichthecylinderscommunicatewiththeintakeandexhaustmanifoldaccordingtotheignitionorderofthecylinderandtheprocessrequirements.Thevalvegeariswidelyappliedinthefour-strokeengines.2627Valveoperatingmechanism任務(wù)實(shí)施Thevalvegeariscomposedoftwoparts,includingthevalvegroupandthevalvedrivegroup(showninFig.3.2.4).Eachgroupcontainssomecomponentsorparts,suchasvalves,valvebosses,valveguides,valvesprings,lockingplate,retainer,camshaft,tappet,pushrod,rockerarmetc..Accordingtothedifferentlocationofvalvesandcamshafts,thelayoutwillbedifferent.Forexample,valvesarelocatedonthetoporthesideofthecylinder.Camshaftsaresetonthebeneath,themidortheoverhead(showninFig.3.2.5).Thesearrangementsarerespectivelyusedindifferentengines.Duetotheinefficiencyofside-valveengines,vehiclemanufacturesnolongerusethislayout.2829Valveoperatingmechanism任務(wù)實(shí)施Asforthecamshaftdrive,therearethreewayssuchasbeltdrive,chaindriveandgeardrive(showninfigure3.2.6).Generallyspeaking,themechanismwithboththebeneathcamshaftandthemidcamshaftismostlyadoptedthecylindricaltiminggeardrive.Itusuallyneedsjustapairoftiminggearsfromcrankshafttocamshaft.Ifthegeardiameteristoolarge,anintermediategearmaybeadded.Thechaindriveissuitablefortheoverheadcamshaft,butthereliabilityandthedurabilityofthedriveisnotasgoodasthatofthegeardrive.Inrecentyears,thetoothedbeltwithlownoiseandlowcostiswidelyusedinhigh-speedcarengineinsteadofthedrivechain.3031Task3ElectronicFuelInjectionsystem

1.Newwordsandexpressionscarburetor['kɑ:bj?ret?]n.汽化器,化油器sensor

[?sens?]n.傳感器,靈敏元件appropriate

[??pr?upri-it,??pr?uprieit]a.(適)恰當(dāng)?shù)膒ressurize['pre??,ra?z]vt.對(duì)…施加壓力、給…增壓nozzle['n?z?l]n.管嘴、噴嘴injector[in'd?ekt?]n.噴油器discharge[dis't?ɑ:d?]vt.執(zhí)行、履行spray[sprei]vt.&vi.噴n.浪花、飛沫、噴霧

circuit

[?s?:kit]n.電路，線路；vibration

[vai?brei??n]n.顫動(dòng)；振動(dòng)atomize['?t?maiz]v.使分裂為原子、將…噴成霧狀知識(shí)準(zhǔn)備32degreeofrichness濃度air-fuelratio空燃比integratewith與…結(jié)合在一起fuelconsumption燃料消耗（量），耗油率wiringharness線束electronicfuelinjection(EFI)電子燃油噴射throttlebody節(jié)氣門體intakemanifold進(jìn)氣歧管知識(shí)準(zhǔn)備33ElectronicfuelInjectionsystem

任務(wù)實(shí)施Onoldcars,itisacarburetorthatsendsthecorrectair-fuelmixturetotheengine.Thecarburetorisamixingdevicewhichmixesliquidgasolinewithair.Themixturemustvarydegreeofrichnesscontinuallytosuitengineoperationconditions.Therefore,theelectricfuelinjectionsystemhasreplacedthefunctionofthecarburetorinmoderncarengines.Fuelinjectionsystemprovidesmoreexactair-fuelratiocontrol.Thus,enginedevelopsbettereconomyandemissioncontrol.Sensorsreadchangesontheengine.Acomputerinterpretstheinformationandsendsappropriateinstructiontotheengine’sfuelcontroller.Thentheinjectorspraysameasuredamountoffueldowntotheengine.34ElectronicfuelInjectionsystem任務(wù)實(shí)施Theterm‘petrolinjection’isusedtodescribeanysysteminwhichpressurizedfuelisforcedoutofanozzleinanatomizedstatetomixwithasupplyofair.Modernsystemsarecontrolledelectronicallybecausethisformofcontrolenablesthefuelquantitytobeaccuratelysettosuittheengineoperatingconditions.Strictemissioncontrolregulationshavedemandedprecisemeteringofthefuel,andalthoughpetrolinjectionsystemsaremoreexpensivethancarburetorfuelsystems,theyarenowusedtocontrolthefuellingonallengines.Mostpetrolinjectionsystems(figure4.3.1)areintegratedwiththeignitionsystemintoanenginemanagementsystem,includingthreesystems(fueldelivery,airinduction,electroniccontrol).35ElectronicFuelInjectionSystem任務(wù)實(shí)施Apetrolinjectionsystemthatdeliversthecorrectquantityofhighlyatomizedfuelgivesthefollowingadvantages:(1)lowerexhaustpollution.(2)lowerfuelconsumption.(3)higherpoweroutput.(4)smootherengineoperationduetoanevenpoweroutputfromeachcylinder.(5)automaticadjustmentoftheair/fuelratiotosuitalloperatingconditions.Thefueldeliverysystem（Fig.3.3.2）istosupplytheinjectorswiththefuel.Pressureisprovidedbyanelectricfuelpump.Somesystemsusetwopumps:alow-pressurefuelpumpthatdeliversfueltoanotherpump,whichdevelopsthepressure.36Figure3.3.2Fueldeliverysystem37ElectronicFuelInjectionSystem任務(wù)實(shí)施Theairsupplysystem(Figure3.3.3)istoinducethefreshairtoformthemixtureinthecylinder,consistingofanaircleanerassembly,throttlebody,andintakemanifold.Thethrottlebodysectioncontainsthethrottlevalve,whichisopenedandclosedbythedrivertocontroltheamountofairenteringtheintakemanifold.Onthrottlebodyfuelinjectionsystems,thethrottlebodyalsocontainsthefuelinjectioncomponents.Theintakemanifoldformsaclosedpassagebetweenthethrottlebodyandthecylinderhead.38Figure3.3.3Theairinductionsystem39ElectronicFuelInjectionSystem任務(wù)實(shí)施TheelectroniccontrolsystemofanengineismainlycomposedofECU,sensorsandactuators(showninFigure3.3.4).Enginecontrolcomputersareconstructedusingmanydifferentelectroniccircuitsandcomponents.Moderncomputerscontrolmanyotherenginesystemsinadditiontothefuelinjectors.Thecomputerisusuallylocatedinaprotectedareaawayfromenginevibrationandheat,andisconnectedtotherestoftheinjectionsystembymeansofasealedwiringharnessplug.Thecomputerreceivessignalsfromanumberofsensorswhenevertheengineisrunning.Fromthisinput,thecomputerevaluatesenginefuelneedsandadjustsinjectorpulsewidthaccordingly.4041Task4Thelubricationsystem

1.Newwordsandexpressionscirculate

[?s?:kjuleit]v.(使)循環(huán)；(使)流傳friction

[?frik??n]n.不和，抵觸；摩擦(力)lubricant

[?lu:brik?nt]n.潤(rùn)滑劑,潤(rùn)滑油minimize

[?minimaiz]vt.使減(縮)小到最低wear

[w??]vt.穿(戴)著；磨損overhaul[,??v?'h?:l,'??v?,h?:l]vt.徹底檢查、大修n.檢查、大修splash[spl??]vt.使(液體)濺起vi.(指液體)濺落droplet['dr?plit]n.小滴mist[mist]n.薄霧、視線模糊不清vt.&vi.(使)蒙上薄霧gallery['ɡ?l?ri]n.畫廊,美術(shù)館；走廊strainer['stre?n?]n.濾器;濾盆、濾網(wǎng)quantificationally[kw?nt?f?'ke???n?l?]adv.定量（化）地grease

[gri:s]n.油脂；潤(rùn)滑油vt.用油脂涂，加潤(rùn)滑油知識(shí)準(zhǔn)備42indetail詳細(xì)地cylinderwall汽缸壁splashlubrication飛濺潤(rùn)滑mainoilgallery主油道oilfilter(汽車等)機(jī)油濾清器oilpressureregulator油壓調(diào)節(jié)器oilstrainer集濾器reliefvalve安全閥、泄壓閥oilcooler機(jī)油冷卻器知識(shí)準(zhǔn)備43Thelubricationsystem

任務(wù)實(shí)施Itisveryimportantforthelubricationsystemtoberequiredtolubricatethemovingpartsofanengineconstantly.Itisusedforcollecting,cleaning,coolingandre-circulatingoilintheengine.Themainfunctionofthelubricationsystemistocirculateanddeliveroiltothesurfacesofallthemovingpartsinordertoreducefrictionbetweenthem.Indetail,thelubricantcirculatesthroughtheenginemovingpartsandperformsimportantjobs:(1) Tolubricatemovingpartstominimizewear.(2) Tolubricatemovingpartstominimizepowerlossfromfriction.(3) Toremoveheatfromenginepartsbyactingasacoolingagent.(4) Toabsorbshocksbetweenbearingsandotherengineparts,thusreducingthenoiseandextendingtheenginelife.(5) Toformagoodsealbetweenpistonringsandcylinderwalls.(6) Toactasacleaningagent,washingtheworkingsurfacesfreeofchemicaldeposits,dustanddirttoprotectthemfromcorrosion.44Thelubricationsystem任務(wù)實(shí)施Tokeepacaringoodrunningconditions,acarownermustchangethelubricantonceevery5000km.Ifthelubricatingsystemshouldfail,notonlywilltheenginestop,butalsosomepartsarelikelytobedamagedbeyondrepair.Therefore,whenlubricationfailureoccurs,theenginecanseldomberunagainwithoutamajoroverhaul.Themaincomponentsofthesystemareoilpump,oilfilters,mainoilgalleries,oilpan,oilpressureregulators,reliefvalve,oilcoolersandsoon.Figure3.4.1showsthelubricationsystemlayout.Thelubricationwaycomprisesthreetypes:splashlubrication,pressurelubricationandregularlubrication.Thesplashlubricationisasimplemethodtolubricatethefrictionsurfacesviausingthoseoildropletsoroilmistsplashedupbythemovingpartswhentheengineworks.Pressureorforcedlubricationiscarriedoutbytheoilpumpsupplyingcontinuouslytheoilwithacertainpressuretothemajorityofengineparts,especiallytomainbearingsandconnectingrodbearings.Theregularlubricationisfulfilledbyaddingsomeakindoflubricatinggreaseregularlyandquantificationally.4546Task5Thecoolingsystem

1.Newwordsandexpressionstransfer[tr?ns'f?:]vt.&vi.轉(zhuǎn)移、遷移crack[kr?k]vt.&vi.開裂、破裂n.裂縫、縫隙coolant['ku:l?nt]n.冷凍劑、冷卻液、散熱劑passage['p?sid?]n.通道、過(guò)道、通過(guò)、消逝radiator['re?di:,e?t?]n.(暖氣設(shè)備的)散熱器、汽車引擎的冷卻器、散熱器thermostat['θ?:m?,st?t]n.恒溫(調(diào)節(jié))器hose[h?uz]n.軟管、膠管、水龍頭surround[s?'raund]vt.包圍centrifugal[sen,tr?fj?g?l,-,tr?f?-]adj.離心的fluid['flu:?d]n.液體、流體impeller[im'pel?]n.推進(jìn)者、葉輪plunger['pl?nd??]n.橡膠吸盤、搋子、活塞、柱塞知識(shí)準(zhǔn)備47braze[breiz]vt.銅焊、用黃銅鍍或制造fin[fin]n.(汽車、飛機(jī)、炸彈上的)尾翅flatten['fl?tn]vt.&vi.變平、使(某物)變平surge[s?:d?]n.浪濤般洶涌奔騰vi.(人群等)蜂擁而出regulate['reɡjuleit]vt.控制、管理、調(diào)整、調(diào)節(jié)channel['t??nl]n.通道、途徑bypass['baipɑ:s]vt.繞過(guò)、避開n.旁道withoutdoubt毫無(wú)疑問(wèn)waterjacket水套liquidcooling液體冷卻，液冷centrifugalforce地心引力smallcirculation小循環(huán)知識(shí)準(zhǔn)備48Thecoolingsystem任務(wù)實(shí)施Withoutdoubt,theburningofthefuel/airmixtureinsidethecylindersofanenginewillproduceagreatdealofheat.Iftheheatisnottransferredtimelyoutside,theenginewillnotworknormallyduetotoohightemperature.Somepartswillbesubjectedtoexpandtoomuchandsticktogetherorcrack.ThefunctionofthecoolingsystemistokeeptheengineatitsmostefficientoperatingtemperaturebytransferringtheheattotheItissaidthatab