车辆工程专业英语PPT课件-UNIT-2--ENGINE-MECHANICAL-TEXT-A

No.10039UNIT2ENGINEMECHANICALTEXTAOperation,MainComponentsandClassificationoftheEnginePROFESSIONALENGLISHNo.10039UNIT2ENGINEMECHANICALTEXTAOperation,MainComponentsandClassificationoftheEnginePrincipleofOperationMainEngineComponentsEngineClassification本次课学习内容No.10039本次课学习目标掌握发动机主要部件的英文名称掌握各中发动机的英文名称掌握常用术语（phrasesandexpressions）了解相关术语（relatedterms）较熟练翻译与发动机工作原理相关的英文文章NEWWORDScombustion[kəm'bʌs∫ən]n.燃烧stroke[strouk]n.冲程piston['pistən]n.活塞cylinder['silində]n.气缸valve[vælv]n.气门，阀门，阀exhaust[ig'zɔ:st]n.排气，废气intake['inteik]n.进气，进（引，吸）入compression[kəm'pre∫ən]n.压缩crankshaft['kræŋk∫ɑ:ft]n.曲轴swirl[swə:l]n.漩涡，涡流，紊流；v.涡动churn[t∫ə:n]v.搅拌，搅动foundation[faun'dei∫ən]n.基础，基地，基金，机座camshaft['kæm∫ɑ:ft]n.凸轮轴accessory[æk'sesəri]n.附属品，附件，辅助装置clutch[klʌt∫]n.离合器housing['hauziŋ]n.外壳bolt[boult]n.螺栓；v.用螺栓连接core[kɔ:]n.芯，核心，铁心，型芯，沙芯，（电缆）芯线aluminum['əlju:minəm]n.铝liner['lainə]n.衬套，衬里，衬板oversize['ouvəsaiz]n.&a.加大尺寸heavy-duty['hevi'dju:ti]a.重型的，重载的oscillate['ɔsileit]v.振荡，振动，波动，动摇bearing['bəriŋ]n.轴承journal['ʤə:nəl]n.轴颈throw[rou]n.&v.投掷，扔；n.投掷距离，偏心距离，摆幅；（pl.）曲柄attach[ə'tæt∫]v.附着，连接，固定（to）reciprocating[ri'siprəkeitiŋ]a.往复的mount[mɑunt]v.安装，固定；n.安装件，支架，机座rim[rim]n.边缘，轮缘，轮辋，齿圈heat-resistant[hi:t-ri'zistənt]a.耐热的clearance['kliərəns]n.间隙lifter['liftə]n.挺杆harden['hɑ:dən]v.硬化，变硬，淬硬revolution[revə'lu:∫ən]n.转，回转，大变革inline['in'lain]a.直列式的，在一条直线上的bank[bæŋk]n.（气缸）列，排，银行rigidity[ri'ʤiditi]n.刚性profile['proufail]n.外形，轮廓conducive[kən'dju:siv]a.有助于…的，促进…的（to）sacrifice['sækrifais]n.牺牲（品），损失liquefy['likwifai]v.液化propane['proupein]n.丙烷carburetion[kɑ:bju're∫ən]n.汽化carburetor[kɑ:bju'retə]n.化油器internalcombustionengine内燃机four-strokecycle四冲程循环sparkplug火花塞intakestroke进气行程powerstroke作功行程compressionstroke压缩行程exhauststroke排气行程connectingrod连杆automatictransmission自动变速器torqueconverter液力变矩器PHRASESANDEXPRESSIONSinsertbearing镶入式轴承valveseat气门座valveguide气门导管valvetrain气门机构，气门组hydraulicvalvelifter液力挺杆TEXTAOperation,MainComponentsandClassificationoftheEngineTheautomotiveengineisessentiallyaheatengine.Theheatenginesusedinautomobilesareinternalcombustionengines.1.PrincipleofOperationThespark-ignitionengineisaninternal-combustionenginewithexternallysuppliedinignition.Thegasolineengineisakindofspark-ignitionengines.Thefour-stroke-cyclegasolineenginecycleisspreadoverfourpistonstrokes.Theoperationstrokesare(figure2-1):Fig.2-1Theoperationofafour-stroke-cyclegasolineengineThefirststrokeinyourengineiscalledtheintakestroke.Insteadofopeningtheintakevalveafteryouhavedrawnthepistondown,youwillfinditbettertoopentheintakevalveasthepistonstartsdown[1].Thisallowstheairtodrawfuelintheentiretimethepistonismovingdown.Remember,theintakestrokestartswiththepistonatthetopofthecylinder(intakevalveopenandexhaustvalveclosed)andstopswiththepistonatthebottomofitstravel[2].Thisrequiresone-halfturnofthecrankshaft.[1]Insteadofopeningtheintakevalveafteryouhavedrawnthepistondown,youwillfinditbettertoopentheintakevalveasthepistonstartsdown.Insteadof…的意思是“而不是…”，“代替着…”。draw…down的意思是“将…向下移”。better为副词，意思为“更好”，“更多”，“更加”，修饰动词不定式短语toopentheintakevalve。本句译为：在活塞下行之后，进气门不只是已经打开，而是随着活塞的下移，开度还在进一步增大。[2]Remember,theintakestrokestartswiththepistonatthetopofthecylinder(intakevalveopenandexhaustvalveclosed)andstopswiththepistonatthebottomofitstravel.With后面的宾语接有现在分词、过去分词、形容词,甚至是副词，with后面的宾语与现在分词、过去分词、形容词之间具有“主谓”关系。这时整个with短语说明附带情况，或者交待细节。本句译为：记住，进气行程在活塞位于气缸顶部（进气门开启，排气门关闭）时开始，在活塞到达其行程的底部时结束。Asthecrankshaftcontinuestomove,thepistonisforcedupthroughthecylinder.Ifyoukeepbothvalvesclosed,thefuelmixturewillbesqueezed,orcompressed,asthepistonreachesthetop.Thisiscalledthecompressionstroke.It,too,requiresahalfturnofthecrankshaft.Thecompressionstrokeservestobreakupthefuelintoevensmallerparticles.Thishappensduetothesuddenswirlingandchurningofthemixtureasitiscompressed.Whentheair-fuelmixtureissubjectedtoasuddensharpcompressionforce,itstemperaturerises.Thisincreaseintemperaturemakesthemixtureeasiertoigniteandcausesittoexplodewithgreaterforce.Asthepistonreachesthetopofitstravelonthecompressionstroke,ithasreturnedtotheproperpositiontobepushedbackdownbytheexplosion.Remember,thecompressionstrokestartswiththepistonatthebottomofthecylinder(bothvalvesclosed)andstopswiththepistonatthetopofthecylinder.Thisrequiresanadditionalhalfturnofthecrankshaft.Asthepistonreachesthetopofthecompressionstroke,themixtureisbrokenintotinyparticlesandheatedup.Whenignited,itwillexplodewithgreatforce.Thisistherighttimetoexplodethemixture.Asparkplugprovidesasparkinsidethecombustionchamber.Thesparkproducedattheplugisformedbytheignitionsystem.ThiswillbediscussedinUnit6.Justimaginethatahotsparkhasbeenprovidedinthefuelmixture.Themixturewillexplodeand,inturn,forcethepistondownintothecylinder.Thisgivesthecrankshaftaquickandforcefulpush.Thisisthepowerstroke.Bothvalvesmustbekeptclosedduringthepowerstrokeorthepressureoftheburningfuelwillsquirtoutthroughthevalvepods.Remember,thepowerstrokestartswiththepistonatthetopofthecylinder(bothvalvesclosed)andstopswiththepistonatthebottomofthecylinder.Thisrequiresanotherhalfturnofthecrankshaft.Whenthepistonreachesthebottomofthepowerstroke,t