汽车专业英语2分析解析.docx

汽车专业英语2分析解析.docx

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汽车专业英语2分析解析

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-strokecombu