汽车专业英语2.docx
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汽车专业英语2
Unit2
TheBasicPrincipleofEngine
TextAClassificationandMainComponentsofEngine
游海龙Theinternalcombustionengineisanengineinwhichthecombustionoffueloccurswithoxygen(usuallyair)inacombustionchamber,asshowninFig.2.1.
Fig.2.1InternalCombustionEngine
1—thecapofthecylinderhead2—valve3—engineblock4—flywheel
5—crankshaft6—oilpan7—pulley8—cylinder9—timinggear
ClassificationofEngine
Theenginecanbeclassifiedinfollowingways:
¶ByFuelSystem李鹏
Gasolineengineanddieselengineareused.Inagasolineengine,theair-fuelmixtureisexplodedintheengine.Adieselengineusesdieselfuel.Itgenerateshighpoweratlowspeeds.Thefuelefficiencyisbetterthanthatofagasolineengine.
¶ByCylinderArrangement曾昭昕
Mostcarshavemorethanonecylinder.Four,sixandeightcylindersarecommonused.Inamulti-cylinderengine,thecylindersareusuallyarrangedinoneofthreeways:
in-line,V-type,orflat(Fig.2.2).Todaythenumberofcylindersisgrowing,thecylindersalsocanbearrangedasW-type.
(a) flat(b) V-type(c) in-line
Fig.2.2CylinderArrangement
¶ByCoolingSystem梁松雨
Liquid-cooledenginesandair-cooledenginesarebeingused.Liquid-cooledenginesarethemostcommonintheengineindustry.
Therearealsootherwaystoclassifytheengines.Despiteoftheseclassifications,thestructureoftheengineisbasicallythesame.
MainComponents
曾润泽Theengineconsistsofseveraldifferentmechanismsandsystemsincludingcylinderblock,crankshaftandconnectingrodmechanism,valvemechanism,fuelsupplysystem,lubricationsystem,coolingsystem,ignitionsystemandstartingsystem.
张永德¶CylinderBlock
Thecoreoftheengineisthecylinder,withthepistonmovingupanddowninsidethecylinder.
¶CrankshaftandConnectingRodMechanism
Thecrankshaftchangesthelinearmovementofthepistonintoarotationalmovementviaaconnectingrod.Theconnectingrodconnectsthepistontothecrankshaft.Itcanrotateatbothendssothatitsanglecanchangeasthepistonmovesandthecrankshaftrotates.
张进¶ValveMechanism
Avalvemechanismisagroupofcomponentsthatopensandclosestheintakeandexhaustvalvesinthecylinderheadattheappropriatetime.Themainfunctionsofthevalvegeararetoprovidetimelyadmissionofthefreshchargeintothecylindersandexhaustofspentgasesfromthem.
夏磊¶FuelSupplySystem
Thefuelsystemsuppliesfueltotheengine.Italsohasthefunctionstoregulatethevolumeoffuelsupply.Thefuelsystemsindieselandgasolineenginesaredifferent.
于晨雪¶LubricationSystem
Thelubricationsystemusesanoilpumptocontinuouslysupplyengineoilthroughouttheinsideoftheengine.Thissystemreducesfrictionbetweenpartswithafilmofoil.Iftheengineisrunwithoutoil,thefrictioncancausepoorrunning,orcauseevenmeltdown.Inadditiontolubrication,engineoilcoolsandcleanstheengine.
滕兆磊¶CoolingSystem
Thecoolingsystemregulatestheenginetemperaturetoanoptimallevel(80℃to90℃atcoolanttemperature)bycirculatingthecoolantthroughouttheengineunderalloperatingconditionsandduringallseasonsoftheyear.Thecoolingfancoolsthecoolantintheradiatorandwaterpumpcirculatesthecoolantthroughthecylinderheadandthecylinderblock.
吕庆怡¶IgnitionSystem
Internalcombustionenginesrequireignitionofthemixture,eitherbysparkignition(SI)orcompressionignition(CI).
¶StartingSystem
Thestartingsystemforcestheenginetocrankwithanelectricmotor,andstartstheengine.
TextBEngineOperatingPrinciples
[zhuangjihui]Afour-strokeengine,alsoknownasfour-cycle,isaninternalcombustionengineinwhichthepistoncompletesfourseparatestrokes:
intake,compression,powerandexhaust—duringtwoseparaterevolutionsoftheengine’scrankshaft,andonesinglethermodynamiccycle.ThemainpartsinfourstrokeengineareshowninFig.2.3.
Fig.2.3MainPartsinFourStrokeEngine
1—intakevalve2—sparkplug3—exhaustvalve4—combustionchamber5—pistonhead
[wangxiaolong]Astheirnameimplies,four-strokeinternalcombustionengineshavefourbasicstepsthatrepeatwitheverytworevolutionsofthecrankshaft:
①Intakestroke②Compressionstroke,③Powerstroke,④Exhauststroke.ThefourstrokeswillbeillustratedinFig.2.4.
[liyang]Theydrawinanair-fuelmixturetothecylinders,compressit,igniteandcombustit,thendischargeit.Repeatingthesefouractionsgivesgasolineenginestheirpower.ThecyclebeginsatTopDeadCentre(TDC),whenthepistonisfarthestawayfromthecrankshaft.AcyclereferstothefulltravelofthepistonfromTDCtoBottomDeadCentre(BDC).
[renwenjie]¶IntakeStroke
Ontheintakestrokeofthepiston,thepistondescendsfrom(TDC,BDC)to(TDC,BDC),reducingthepressureinsidethecylinder.Amixtureoffuelandair,orjustairinadieselengine,isforcedbyatmosphericpressureintothecylinderthroughtheintakeport.Theintakevalve(s)then(open,close).
[zhangshuai]¶CompressionStroke
Withbothintakeandexhaustvalves(open,close),thepistonreturnstothetopofthecylindercompressingthefuel-airmixtureintothecombustionchamberofthecylinderhead.
[zhantianbao]¶PowerStroke
Itisalsonamedascombustionstroke.Whilethepistoniscloseto(TDC,BDC),thecompressedair–fuelmixtureisignited.Theresultingmassivepressurefromthecombustionofthecompressedfuel-airmixtureforcesthepistonbackdowntoward(TDC,BDC).
[zhangzhikai]¶ExhaustStroke
Duringtheexhauststroke,thepistononceagainreturnsto(TDC,BDC)whiletheexhaustvalveis(open,close).Thisactionevacuatestheburntproductsofcombustionfromthecylinderbyexpellingthespentfuel-airmixtureoutthroughtheexhaustvalve(s).
.
(1) intake
(2) compression(3) power(4) exhaust
Fig.2.4FourStrokeCycle
[heguangbin\youhailong]NEWWORDSANDPHRASES
principle[]
n.原理,法则
classification[]
n.种类,类别
configuration[]
n.布局,构造
oxygen[]
n.氧气
combustion[]
n.燃烧
chamber[]
n.室,房间
component[]
n.成分,部件,零件
force[]
n.力
gasoline[]
n.汽油
diesel[]
n.柴油;柴油机
explode[]
n.爆炸,爆发
rotational[]
adj.旋转的
in-line[]
adj. (汽缸)直列的
flat[]
adj. (汽缸)水平对置
coolingsystem
冷却系
liquid-cooled
水冷
air-cooled
风冷
cylinderblock
汽缸体
crankshaft[]
n.曲柄轴,机轴
connectingrod
连杆
valvemechanism[]
配气机构
fuelsupplysystem
燃油供给系
lubrication[]
润滑
lubricationsystem
润滑系
ignitionsystem
点火系
startingsystem
起动系
linear[]
adj.线性的
piston[]
n.活塞
intake[]
n.吸入;进气口,入口
exhaust[]
n.排气;废气
valve[]
n.气门,阀门
oilpump
机油泵
friction[]
n.摩擦(力)
part[]
n.零件,部位
appropriate[]
adj.恰当的,适当的
volume[U.S.]
n.容量,容积
afilmofoil
一层油膜
meltdown[]
n.熔毁
optimal[]
adj.最佳的,最优的
coolant[]
n.冷却液,冷冻剂
radiator[]
n.散热器
waterpump
抽水机,水泵
sparkignition(SI)
火花点火
compression[]ignition(CI)
压缩点火
four-stroke
四冲程的(内燃机)
power[]
n.做功
illustrate[]
vt.说明,阐明
revolution[]
n.旋转(一周)
sparkplug
火花塞
discharge[]
vt.释放;排出
TopDeadCentre(TDC)
上止点
BottomDeadCentre(BDC)
下止点
descend[]
vi.下降,降临
evacuate[]
vi.散离,释放
NOTESTOTHETEXT
1.Theinternalcombustionengineisanengineinwhichthecombustionoffueloccurswithoxygen(usuallyair)inacombustionchamber.
内燃机是一种由燃料和氧气(通常是空气)在燃烧室中燃烧而产生动力的发动机。
2.Theengineconsistsofseveraldifferentmechanismsandsystemsincludingcylinderblock,crankshaftandconnectingrodmechanism,valvemechanism,fuelsupplysystem,lubricationsystem,coolingsystem,ignitionsystemandstartingsystem.
发动机由不同的机构和系统构成,包括汽缸体、曲轴和连杆机构、配气机构、燃油供给系、润滑系、冷却系、点火系和起动系。
3. Thecrankshaftchangesthelinearmovementofthepistonintoarotationalmovementviaaconnectingrod.
曲轴把活塞的线性运动通过连杆转换成旋转运动。
4. Afour-strokeengine,alsoknownasfour-cycle,isaninternalcombustionengineinwhichthepistoncompletesfourseparatestrokes,intake,compression,powerandexhaust—duringtwoseparaterevolutionsoftheengine’scrankshaft,andonesinglethermodynamiccycle.
四冲程发动机也叫做四循环发动机,这种内燃机在发动机曲轴转两周和一个热力学循环中完成四个独立的冲程即进气、压缩、做功和排气。
5. WhilethepistonisclosetoTopDeadCenter,thecompressedair–fuelmixtureinagasolineengineisignited,usuallybyasparkplug,orfuelisinjectedintothedieselengine,whichignitesduetotheheatgeneratedintheairduringthecompressionstroke.
活塞接近上止点时,汽油机中的压缩空气与燃料混合气通常被火花塞点燃,而柴油机中燃油直接喷入发动机,由压缩冲程压缩空气产生的热量压燃。
6. Theydrawinanair-fuelmixturetothecylinders,compressit,igniteandcombustit,thendischargeit.
空气与燃料混合气被吸入汽缸里,被压缩,点燃、燃烧,然后被排出。
EXERCISES
1. TranslatethefollowingwordstoEnglish.
发动机工作原理
发动机结构
内燃机
起动系
曲轴和连杆机构
配气机构
燃油供给系统
上止点
四冲程发动机
空燃混合气
活塞
汽缸排列
水冷
多缸发动机
柴油机
上下运动
润滑系统
冷却系统
点火系
油膜
2. TranslatethefollowingsentencestoChinese.
(1) Inaninternalcombustionengine,theexpansionofthehigh-temperatureandhigh-pressuregasesproducedbycombustionapplydirectforcetosomecomponentoftheengine.
(2) Theair-fuelmixtureisexplodedintheengine,andthisforceisconvertedintoarotationalmovementtomovethevehicle.
(3) Inamulti-cylinderengine,thecylindersusuallyarearrangedinoneofthreeways:
inline,V-typeorflat.
(4) Thecrankshaftchangesthelinearmovementofthepistonintoarotationalmovementviaaconnectingrod.
(5) Almostallcarscurrentlyusewhatiscalledafour-stroke