Unit 2汽車專業(yè)英語(發(fā)動(dòng)機(jī))

Unit2-1

MainComponentsofEngine

ContentsⅠ．Pre-questionsII.Text

ExplanationIII.ExercisesPre-questionsTheheartofautomobileWhatimpressionoftheengine?complicatedpowerPre-questionsWhatarethetypesoftheengine?electricmotors,steamengines,andinternalcombustionenginesWhat’stheinternalcombustionengine?

burnsfuelwithinthecylindersandconvertstheexpandingforceofthecombustionintorotaryforceusedtopropelthevehicle.Pre-questionsWords&phrasesIntakemanifold[‘m?n?f??ld]進(jìn)氣管throttle

[‘θr?t(?)l]valve[v?lv]節(jié)氣門Cylinder[‘s?l?nd?]headcover氣缸蓋罩Distributor

[d?‘str?bj?t?]分電器Cylindercover氣缸蓋Vent-pipe

[‘ventpaip]排氣管Cylinderblock氣缸體Sparkplug

[pl?g]火花塞timingdrivingroomcover正時(shí)傳動(dòng)室蓋Timingbelt正時(shí)齒輪帶Words&phrasesCamshaft

[‘k?m?ɑ?ft]凸輪軸Campulley[‘p?l?]凸輪帶輪Crankshaft

[‘kr??k?ɑ?ft]曲軸Crankshafttimingbeltgearwheel曲軸正時(shí)齒形帶輪Flywheel飛輪Waterjacket水套Piston['p?st(?)n]活塞Sump[s?mp]油底殼Mechanism

[‘mek(?)n?z(?)m]機(jī)械裝置，原理Connectingrod連桿lubricating

[‘lu:brikeiti?]

system潤(rùn)滑系統(tǒng)Single-cylinderenginecylinderpistonPistonpinConnectingrodcrankshaftOilpipeIntakevalveExhaustvalveTiminggearOilpumpwhatisthepowersourceofautomobileandhowtoproduce?pistonpistonpinconnectingrodcrankshaftEnginePowerisproducedbythelinearmotionofapistoninacylinder.

Theconnectingrodtransmitstheup-and-downmotionofthepistontothecrankshaft,whichchangesitintorotarymotion.

Pre-questionsTheenginecomprisestwomechanismandfivesystems,whatarethey?crankshaftandconnectingrodmechanism（曲軸連桿裝置）,valvegear(閥動(dòng)裝置）,coolingsystem,lubricatingsystem,fuelsystem,startingsystem,ignitionsystemPre-questions9connectingrodflywheelcrankshaftpistonintakevalveexhaustvalvepushrodtappettiminggears■

Valvegear

■

Connectingrod

EnginecoolingsystemEnginelubricatingsystemFuelsupplysystemValvegearpistoncrankshaftdistributorsumptiminggearcrankshaftandconnectingrodmechanismvalvegearfuelsystemSparkplugexhaustmanifoldIII.ExercisesTranslatethefollowingexpressionsintoChinese.活塞曲軸分電器油底殼正時(shí)齒輪曲柄連桿機(jī)構(gòu)配氣機(jī)構(gòu)燃油系統(tǒng)火花塞排氣歧管1-cylinderheadcover2-piston3-timingbelt4-waterpump5-sump6-oilpump7-crankshaft8-flywheel9-distributor10-valveIII.ExercisesReadingHowanEngineWorksTheinternalcombustionengine,asitsnameindicates,burnsfuelwithinthecylindersandconvertsexpandingforceofthecombustionintorotaryforceusedtopropelthevehicle.Theactionstakingplaceintheenginecylindercanbeclassifiedintofourstages,orstroke.“stroke”referstopistonmovement;pel[pr?‘pel]v.推動(dòng)，驅(qū)動(dòng)limitingposition極限位置Theinternalcombustionengine,asitsnameindicates,burns

fuelwithinthecylindersandconvertstheexpandingforceofthecombustionintorotaryforceusedtopropelthevehicle.譯文：內(nèi)燃機(jī)，顧名思義，就是燃料在氣缸內(nèi)部燃燒，并且把燃燒時(shí)的膨脹力轉(zhuǎn)化為驅(qū)動(dòng)車輛的旋轉(zhuǎn)力。II.TextExplanationConvert…..into….①轉(zhuǎn)變；變換Thatbuildinghasbeenconvertedintoaschool.那座樓房改成學(xué)校了。②兌換IwanttoconvertsomeHongKongdollarsintoAmericandollars.我想把一些港元換成美元。③改變信仰、黨派或意見等Shemanagedtoconverthimtoheropinion.她終于設(shè)法說服了他接受她的意見。II.TextExplanationReadingHowanEngineWorks.Theactionstakingplaceintheenginecylindercanbeclassifiedintofourstages,orstroke.發(fā)動(dòng)機(jī)氣缸內(nèi)的工作過程可以分為四個(gè)過程或沖程。beclassifiedinto….①分類為、被分成Memorycan

beclassifiedinto

short-termandlong-termmemory.記憶可分為長(zhǎng)期記憶和短期記憶。II.TextExplanationReadingHowanEngineWorks“Stroke”referstopistonmovement;astrokeoccurswhenthepistonmovesfromonelimitingpositiontotheother.“沖程”指的是活塞的運(yùn)動(dòng)。當(dāng)活塞從一個(gè)極限位置移動(dòng)到另一個(gè)極限位置，即完成了一次沖程。ReadingTheupperlimitofpistonmovementiscalledTDC(topdeadcenter).ThelowerlimitofpistonmovementiscalledBDC(bottomdeadcenter).AstrokeispistonmovementfromTDCtoBDCorfromBDCtoTDC.活塞運(yùn)動(dòng)的上極限位置被稱為TDC（上止點(diǎn)）。活塞的下極限位置被稱為BDC（下止點(diǎn)）。一個(gè)沖程是指活塞從上止點(diǎn)運(yùn)動(dòng)到下止點(diǎn)或者從下止點(diǎn)運(yùn)動(dòng)到上止點(diǎn)。ReadingInotherwords,thepistoncompletesastrokeeachtimeitchangesitsdirectionofmotion.換句話說，活塞每完成一次沖程就會(huì)改變運(yùn)動(dòng)方向。Inotherwords

Inotherwords,theyremainrelativelyconstantorstatic.

換句話說，它們相對(duì)的穩(wěn)定、靜止。

Inotherwords,wehaveadheredtoscientificsocialism.

也就是說，我們堅(jiān)持了科學(xué)社會(huì)主義ReadingWheretheentirecycleofeventsinthecylinderrequiresfourstrokes(ortwocrankshaft

revolutions),theengineiscalledafour-stroke-cycleengine.Thefourpistonstrokesareintake,compression,powerandexhaust.氣缸內(nèi)的全部循環(huán)運(yùn)動(dòng)需要四沖程（或稱為二次曲軸轉(zhuǎn)動(dòng)），這種發(fā)動(dòng)機(jī)稱為四沖程循環(huán)發(fā)動(dòng)機(jī)?；钊乃臎_程分別為進(jìn)氣行程、壓縮行程、做功行程和排氣行程。ReadingIntakestroke.Ontheintakestroke,theintakevalvehasopened,thepistonismovingdownward,andamixtureofairandvaporizedgasolineisenteringthecylinderthroughthevalveport.Themixtureofairandvaporizedgasolineisdeliveredtothecylinderbythefuelsystemandcarburetor.Vaporized[‘ve?p?ra?zd]adj.汽化的carburetor[,kɑ?bj?‘ret?]n.汽化器ReadingOntheintakestroke,theintakevalvehasopened,thepistonismovingdownward,andamixtureofairandvaporizedgasolineisenteringthecylinderthroughthevalveport.“在進(jìn)氣行程中，進(jìn)氣門打開，活塞向下移動(dòng)，可燃混合氣通過進(jìn)氣門進(jìn)入氣缸。ReadingThemixtureofairandvaporizedgasolineisdeliveredtothecylinderbythefuelsystemandcarburetor.適當(dāng)濃度的可燃混合氣是由燃料系統(tǒng)和化油器提供的。Compressionstroke.AfterthepistonreachesBDC,orthelowerlimitofitstravel.Itbeginstomoveupwards.Asthishappens,theintakevalvecloses.Theexhaustvalveisalsoclosed,sothatthecylinderissealed.Asthepistonmovesupward(pushednowbytherevolvingcrankshaftandconnectingrod),theair-fuelmixtureiscompressedtoaslittleasone-tenthofitsoriginalvolume,orevenless.Whentheair-fuelmixtureiscompressed,notonlydoesthepressureinthecylindertoup,butthetemperatureofthemixturealsoincreases.revolving[r?‘v?lv??]adj.旋轉(zhuǎn)的volume

[‘v?lju?m]n.量AfterthepistonreachesBDC,orthelowerlimitofitstravel.Itbeginstomoveupwards.Asthishappens,theintakevalvecloses.Theexhaustvalveisalsoclosed,sothatthecylinderissealed.在活塞到達(dá)下止點(diǎn)時(shí)或者是活塞下限時(shí)，活塞開始向上運(yùn)動(dòng)。同時(shí)，進(jìn)氣門關(guān)閉，排氣門也關(guān)閉，所以這時(shí)的汽缸是封閉的。Asthepistonmovesupward(pushednowbytherevolvingcrankshaftandconnectingrod),theair-fuelmixtureiscompressedtoaslittleasone-tenthofitsoriginalvolume,orevenless.當(dāng)活塞向上運(yùn)動(dòng)時(shí)(這時(shí)是由轉(zhuǎn)動(dòng)的曲軸和連桿推動(dòng)活塞)，可燃混合氣被壓縮。當(dāng)活塞到達(dá)上止點(diǎn)時(shí)，可燃混合氣被壓縮到有原體積的十分之下甚至更少。Whentheair-fuelmixtureiscompressed,notonlydoesthepressureinthecylindertoup,butthetemperatureofthemixturealsoincreases.當(dāng)油氣混合燃料被壓縮時(shí)，不僅汽缸里的壓力上升，可燃混合氣的溫度也隨之增加了。Powerstroke.AsthepistonreachesTDConthecompressionstroke,andelectricsparkisproducedatthesparkplug.Theignitionsystemdeliversahigh-voltagesurgeofelectricitytothesparkplugtoproducethespark.Thesparkignitestheair-fuelmixture.Itnowbeginstoburnveryrapidly,andthecylinderpressureincreasedtoasmuchas3-5MPaorevenmore.Thisterrificpushagainstthepistonforcesitdownward,andapowerimpulseistransmittedthroughtheconnectingrodtothecrankpinonthecrankshaft.Thecrankshaftisrotatedasthepistonispusheddownbythepressureaboveit.AsthepistonreachesTDConthecompressionstroke,andelectricsparkisproducedatthesparkplug.Theignitionsystemdeliversahigh-voltagesurgeofelectricitytothesparkplugtoproducethespark.當(dāng)活塞到達(dá)壓縮行程的上止點(diǎn)時(shí)，火花塞產(chǎn)生電火花。電火花是由點(diǎn)火系統(tǒng)向火花塞提供高壓電脈沖而產(chǎn)生的。

Thesparkignitestheair-fuelmixture.Itnowbeginstoburnveryrapidly,andthecylinderpressureincreasedtoasmuchas3-5MPaorevenmore.

電火花點(diǎn)燃可燃混合氣?？扇蓟旌蠚忾_始發(fā)生劇烈燃燒，氣缸內(nèi)壓力達(dá)到3-5兆帕，甚至更高。Thisterrificpushagainstthepistonforcesitdownward,andapowerimpulseistransmittedthroughtheconnectingrodtothecrankpinonthecrankshaft.Thecrankshaftisrotatedasthepistonispusheddownbythepressureaboveit.作用于活塞上強(qiáng)大的推動(dòng)力推動(dòng)活塞向下運(yùn)動(dòng)，并將這一推力通過連桿傳到曲軸上的連桿軸頸上。因此，當(dāng)活塞受壓向下運(yùn)動(dòng)時(shí)，推動(dòng)曲軸轉(zhuǎn)動(dòng)。Exhauststroke.AsthepistonreachesBDCagain,theexhaustvalveopens.Now,asthepistonmovesupontheexhauststroke,itforcestheburnedgasesoutofthecylinderthroughtheexhaust-valveport.Then,whenthepistonreachesTDC,theexhaustvalveclosedandtheintakevalveopens.Now,afreshchargeofair-fuelmixturewillbedrawnintothecylinderasthepistonmovesdowntowardBDC.Thisfourstrokecycleofpistonwithinthecylinderisrepeatedtimeandagaintoputthevehicleforward.AsthepistonreachesBDCagain,theexhaustvalveopens.Now,asthepistonmovesupontheexhauststroke,itforcestheburnedgasesoutofthecylinderthroughtheexhaust-valveport.當(dāng)活塞再一次到達(dá)下止點(diǎn)時(shí)，排氣門打開。同時(shí)，活塞向上移動(dòng)，把廢氣經(jīng)排氣門排出氣缸。Then,whenthepistonreachesTDC,theexhaustvalveclosedandtheintakevalveopens.Now,afreshchargeofair-fuelmixturewillbedrawnintothecylinderasthepistonmovesdowntowardBDC.隨后活塞達(dá)到上止點(diǎn)，排氣門關(guān)閉，進(jìn)氣門打開。當(dāng)活塞又一次向下移動(dòng)到達(dá)下止點(diǎn)時(shí)，新鮮燃混合氣被吸入氣缸。Thisfourstrokecycleofpistonwithinthecylinderisrepeatedagainandagaintoputthevehicleforward.上述的四個(gè)行程又繼續(xù)重復(fù)，推進(jìn)車輛前進(jìn)。strokeBDCTDCsurgeterrificcrankpinintakestrokeCompressionstrokepowerstrokeexhauststrokefreshcharge行程，沖程；上止點(diǎn)；下止點(diǎn)；沖擊，脈動(dòng)；了不起的，絕妙的；曲柄銷，連桿軸頸；吸氣沖程；壓縮沖程；做功沖程；排氣沖程；吸入的新鮮混合油氣I.TranslatethefollowingsentencesintoChinese.1．Engineisthepowersourceoftheautomobile.Powerisproducedbythelinearmotionofapistoninacylinder.發(fā)動(dòng)機(jī)是汽車的