《汽车实用英语(第二版)》(项目二)课件.pptx

1、汽车实用英语项目二 掌握汽车发动机的构造和工作原理Master the Structure and Operating Principle of Automobile Engine01学习汽车发动机的总体构成02学习发动机曲柄连杆机构03学习发动机配气机构04学习发动机点火系统05学习发动机燃油系统06学习发动机冷却系统07学习发动机润滑系统08学习发动机起动系统09了解电动车的动力系统01学习汽车发动机的总体构成Learn the Overall Structure of Automobile EngineTask 1知 识 目 标 掌握汽车燃油发动机及四冲程发动机相关术语的基本含义：cra

2、nkshaftconnecting rodCrankshaft and Connecting RodMechanism engine block piston flywheelvalve Valve Mechanism intake valve exhaust valvecylinder Fuel System Cooling System coolantLubrication System Ignition System intake stroke compression strokepower stroke exhaust strokespark plug 掌握燃油发动机的总体构成。掌握四

3、冲程发动机的四个活塞冲程。理解四冲程发动机的工作原理。Task 1技 能 目 标 能准确对燃油发动机的两大机构和五大系统术语进行中英文互译。能准确对四冲程发动机的四个活塞冲程进行中英文互译。能用精简的英语叙述四冲程发动机的工作原理。Task 1任 务 描 述（1）学习“知识储备”中的内容，掌握本任务的重点词汇。（2）在第一步的基础上学习“畅享阅读”部分“燃油发动机构造”与“四冲程发动机”，掌握汽车燃油发动机构造，理解四冲程发动机的工作原理。学习小贴士：建议首先阅读正文左侧的英文内容。如遇生词，可先根据上下文猜测词意；猜测不出来的生词可用笔标记出来。如果影响理解，再通过查询生词或参考右侧的译文辅

4、助阅读。（3）在教师的组织下完成本任务的“任务检测”。Task 1知 识 储 备1.generate /denret v.使形成2.mechanism /meknzm n.机械装置；机件3.crankshaft /krkft/n.曲轴，曲柄轴4.connecting rod /rd/连杆 Crankshaft and Connecting Rod Mechanism 曲柄连杆机构5.engine block /blk 发动机机体6.piston /pstn n.活塞7.flywheel /flawil n.飞轮；惯性轮8.thermal /ml adj.热的；热量的9.valve /vlv n

5、.气门；阀门 Valve Mechanism 配气机构10.intake/ntek/valve 进气门11.exhaust/zst/valve 排气门12.periodically /pridkli/adv.定期地；周期性地Task 1知 识 储 备bustible /kmbstbl/adj.易燃的；可燃的14.mixture /mkst(r)/n.混合物；混合剂15.cylinder /slnd(r)/n.气缸16.discharge /dstd v.排放17.Fuel System 燃油系统18.sprayed /spred adj.喷雾的；雾化的19.gasoline /slin n.汽

6、油20.considerable /knsdrbl/adj.相当大的；重要的21.Cooling System 冷却系统22.absorb /bzb v.吸收；吸引23.medium /midim n.媒介；中间物24.coolant /kulnt n.冷却剂25.Lubrication/lubrken/System 润滑系统Task 1知 识 储 备26.sufficient /sfnt adj.足够的；充分的27.friction /frkn n.摩擦；摩擦力28.resistance /rzstns n.阻力；电阻29.consumption /knsmpn n.消耗；耗费30.wear

7、 /we(r)/n.磨损 v.用旧；耗损31.alleviate /liviet v.减轻，缓和32.reliability /rlablti n.可靠性33.durability /djrblti n.耐久性34.Ignition/nn/System 点火系统35.voltage /vltd n.电压36.sequence /sikwns n.顺序；次序pressed /kmprest/adj.被压缩的38.adjust /dst v.调整；校准Task 1知 识 储 备39.accurate /kjrt adj.精确的40.Starting System 起动系统41.limiting /

8、lmt adj.限制的42.limit /lmt n.限度；界线43.TDC(top dead center)上止点44.BDC(bottom dead center)下止点45.intake stroke 进气冲程pression stroke 压缩冲程47.power stroke 做功冲程48.exhaust stroke 排气冲程49.trap /trp v.使受限制Task 1知 识 储 备50.revolve /rvlv v.（使）循环51.volume /vljum n.容量52.spark plug /pl 火花塞53.gap /p n.间隔；间隙bustion chamber

9、 /temb(r)/燃烧室55.expansive /kspnsv adj.膨胀的；扩张的56.rotate /rtet v.旋转；使旋转57.expel /kspel v.排出；喷出58.time and again adv.屡次；常常Task 1畅 享 阅 读Task 1畅 享 阅 读发动机构造 发动机是汽车不可或缺的动力装置，主要将燃料燃烧所产生的热能转化为机械能，并通过底盘的传动系统驱动汽车行驶。通常，燃油发动机由两大机构、五大系统构成。Engine forms an integral component of a vehicle.It mainly converts the heat

10、 generated1 by fuel combustion into mechanical energy,and drive a vehicle through the chassis transmission system.Generally,the combustion engine is composed of two mechanisms2 and five systems.The Construction of EngineTask 1畅 享 阅 读 曲柄连杆机构 曲柄连杆机构是燃油发动机的能量转换装置。在这个机构中，它的主要组件，如发动机机体组、活塞连杆组、曲轴飞轮组，协同工作，

11、把热能转化为机械能，从而推动汽车行驶。配气机构 配气机构的功用是根据发动机的工作程序，定时开启和关闭进气门和排气门，使可燃混合气或空气进入气缸，并使废气从气缸内排出，实现换气。Crankshaft3 and Connecting Rod4 Mechanism The crankshaft and connecting rod mechanism is the energy conversion device of a combustion engine.In this mechanism,all of the major units,such as the engine block5 grou

12、p,the piston6 and connecting rod group,and the crankshaft and flywheel7 group,work together to convert thermal8 energy into mechanical energy to drive the vehicle.Valve9 Mechanism The function of the valve mechanism is to open and close the intake valve10 and exhaust valve11 periodically12 according

13、 to the working sequence and process of the engine,so that the combustible13 mixture14 or air enters the cylinder15,and the exhaust gas is discharged16 from the cylinder to realize the air exchange.Task 1畅 享 阅 读 燃油系统 燃油系统的功用是根据发动机运转工况的需要，向发动机供给一定数量的、清洁的、雾化良好的汽油，以便与一定数量的空气混合形成可燃混合气。同时，燃油系统还需要储存相当数量的汽

14、油，以保证汽车有相当远的续驶里程。冷却系统 冷却系统的功用是将受热零件吸收的部分热量及时散发出去，保证发动机在最适宜的温度状态下工作。发动机的冷却系统有风冷系统和水冷系统之分。风冷系统以空气为冷却介质，水冷系统以冷却液为冷却介质。Fuel System17 The function of the fuel system is to supply a certain amount of clean,well-sprayed18 gasoline19 to the engine according to the needs of the engine operating conditions,so

15、 as to mix with a certain amount of air to form combustible mixture.At the same time,the fuel system also needs to store a considerable20 amount of gasoline to ensure that the car has a considerable driving range.Cooling System21 The function of the cooling system is to transmit some heat absorbed22

16、 by the heated parts in time to ensure that the engine works at the most suitable temperature.The cooling system of the engine is divided into air cooling system and water cooling system.Air cooling system takes air as cooling medium23,and water cooling system takes coolant24 as cooling medium.Task

17、1畅 享 阅 读 润滑系统 润滑系统的功用是在发动机工作时连续不断地把数量足够、温度适当的洁净机油输送到全部传动件的摩擦表面，并在摩擦表面之间形成油膜，实现液体摩擦，从而减小摩擦阻力，降低功率消耗，减轻机件磨损，提高发动机工作可靠性和耐久性。Lubrication System25 The function of the lubrication system is to continuously transport the clean oil with sufficient26 quantity and proper temperature to the friction27 surface

18、of all the transmission parts while the engine is working,and then form an oil film between the friction surfaces to realize liquid friction.Therefore,friction resistance28 is reduced,power consumption29 is reduced,wear30 of parts is alleviated31,and the working reliability32and durability33 of engi

19、ne are improved.Task 1畅 享 阅 读 点火系统 点火系统主要有两个功能：一是将电源的低电压变为高电压，再按照发动机点火顺序轮流送至各气缸，点燃压缩混合气；二是适应发动机工作状况和使用条件的变化，自动调节点火时刻，实现可靠而准确的点火。起动系统 起动系统为发动机提供动力，使发动机起动直至其可以在自身动力下运转。为完成这项任务，起动机从电池中接收电能，并将这些电能转化为机械能。机械能通过传动装置传给发动机飞轮。Ignition System34 The ignition system has two basic functions.One is to change the l

20、ow voltage35 of the power supply into high voltage,and then send it to the cylinders in turn according to the ignition sequence36 of the engine to ignite the compressed37 mixture.The other is to adjust38 the ignition time automatically according to the change of engine working condition and operatin

21、g condition,so as to realize reliable and accurate39 ignition.Starting System40 The starting system provides power to turn the engine over until it can be operated under its own power.To perform this task,the starter receives electrical power from the battery and then converts this energy into mecha

22、nical energy,which transmits through the drive mechanism to the engines flywheel.Task 1畅 享 阅 读四冲程发动机 发动机气缸内的工作过程可以称作冲程。冲程是指活塞的运动，即活塞从某一限定位置到另一限定位置的运动。活塞运动的上限称为上止点，下限称为下止点。一个冲程就是活塞从上止点到下止点，或从下止点到上止点的运动。换句话说，活塞每完成一个冲程，就改变一次运动方向。四冲程发动机的四个活塞冲程分别是：进气冲程、压缩冲程、做功冲程和排气冲程。The actions taking place in the engin

23、e cylinder can be called as strokes.Stroke refers to piston movement;a stroke occurs when the piston moves from one limiting41 position to another.The upper limit42 of piston movement is called TDC43(top dead center).The lower limit of piston movement is called BDC44(bottom dead center).A stroke is

24、piston moves from TDC to BDC or from BDC to TDC.In other words,the piston changes its direction of motion every time it completes a stroke.The four strokes of four-stroke engine are intake stroke45,compression stroke46,power stroke47 and exhaust stroke48.Four-Stroke EngineTask 1畅 享 阅 读 进气冲程 活塞向下移动，进

25、气门打开。活塞下行时，可燃混合气进入气缸。当活塞到达下止点时，进气门关闭，将可燃混合气封闭于气缸中。压缩冲程 活塞到达下止点后开始向上运动。这时，进气门关闭，排气门保持关闭。由于活塞向上运动（由转动的曲轴和连杆推动），可燃混合气被压缩。当活塞到达上止点时，可燃混合气被压缩到只有原体积的1/10，甚至更少。Intake Stroke The piston moves down,and the intake valve opens.As the piston moves down,the air-fuel mixture is drawn into the cylinder.When the pi

26、ston reaches the BDC,the intake valve closes,trapping49 the air-fuel mixture in the cylinder.Compression Stroke After the piston reaches BDC,it begins to move upward.As this happens,the intake valve closes and the exhaust valve remains closed.Since the piston moves upward(pushed now by the revolving

27、50 crankshaft and connecting rod),the air-fuel mixture is compressed.When the piston reaches TDC,the mixture has been compressed to as little as one tenth of its original volume51,or even less.Task 1畅 享 阅 读 做功冲程 当活塞在压缩行程结束时接近上止点时，进气门和排气门都被关闭。电火花在火花塞间隙跳动，点燃混合气。当混合气燃烧时，燃烧室内会产生高温和高压。燃烧气体产生的膨胀力向下推动活塞顶部。

28、连杆将这种推力传递给曲轴，曲轴从上止点经180旋转到下止点。Power Stroke As the piston nears TDC at the end of the compression stroke,both the intake and exhaust valves are closed.An electric spark jumps at the spark plug52 gap53 and ignites the mixture.As the mixture burns,high temperatures and pressure are created in the combu

29、stion chamber54.The expansive55 force generated by combustion gases pushes down on the top of the piston.The connecting rod transmits this force to the crankshaft,which rotates56 through another 180 from TDC to BDC.Task 1畅 享 阅 读 排气冲程 当活塞再一次到达下止点时，排气门打开，废气在较强的推力作用下排出气缸。此时，活塞到达上止点，废气全部排出后，排气门关闭。气缸活塞的四

30、个冲程不断重复，推动汽车前进。四冲程发动机工作原理见图2-1。Exhaust Stroke As the piston reaches BDC again,the exhaust valve opens.And the exhausted gas is expelled57 with a strong force.The piston travels up to the top of the cylinder,pushing all the exhaust out before closing the exhaust valve.The four-stroke cycle of piston

31、within the cylinder is repeated time and again58 to put the vehicle forward.See the working principle of four-stroke engine in Figure 2-1.Task 1畅 享 阅 读Task 1畅 享 阅 读 Figure 2-1 How Four-Stroke Engine Works图2-1 四冲程发动机工作原理02学习发动机曲柄连杆机构Learn the Crankshaft and Connecting Rod MechanismTask 2知 识 目 标 掌握汽车曲

32、柄连杆机构各零件术语的基本含义：crankcylinder block cylinder headcylinder gasketoil pan water jacket camshaftpistonPin piston crown piston ring piston landpiston skirt cylinder wall compression ring oil ringconnecting rod small end connecting rod big end snap ringRod journal timing gear ring gear 熟悉汽车曲柄连杆机构各零件所在位置。

33、理解曲柄连杆机构的工作原理。Task 2技 能 目 标能通过看图或实体准确识别汽车曲柄连杆机构各零件。能准确对曲柄连杆机构各零件名称进行中英互译。能阅读发动机曲柄连杆机构相关英文材料。Task 2任 务 描 述（1）学习“知识储备”中的内容，掌握本任务的重点词汇。（2）在第一步的基础上学习“畅享阅读曲柄连杆机构”，掌握汽车曲柄连杆机构的结构，理解其工作原理。学习小贴士：建议首先阅读正文左侧的英文内容。如遇生词，可先根据上下文猜测词意；猜测不出来的生词可用笔标记出来。如果影响理解，再通过查询生词或参考右侧的译文辅助阅读。（3）学习并分角色扮演“畅谈汽车”下的对话场景。（4）在教师的组织下完成本任

34、务的“任务检测”。Task 2知 识 储 备1.reciprocating /rsprket/adj.往复的；交互的2.rotational /rtenl adj.转动的3.output /atpt v.输出4.outwards /atwdz adv.向外地5.inertia /n n.惯性；惰性6.crank /krk n.曲柄7.cylinder block 气缸体8.cylinder head 气缸盖9.cylinder gasket /skt 气缸垫10.oil pan /pn 油底壳11.subassembly /sbsembli n.组件；部件12.grade /red n.硬度1

35、3.alloy /l v.把铸成合金 n.合金Task 2知 识 储 备14.aluminum /ljmnim n.铝15.cast /kstv.铸造，浇铸16.water jacket 水套17.camshaft /kmft n.凸轮轴18.cavity /kvtin.腔，洞，凹处19.mount /mant v.镶嵌；安置20.sleeve /sliv n.套筒，套管21.fasten /fsn v.系牢，扎牢，扣紧22.exhaust /zst n.废气23.micro-pore /makrp/n.微孔24.joint /dnt n.接合处，接合点25.leakage /likd n.泄

36、漏；渗漏26.cylinder head cover 气缸盖罩Task 2知 识 储 备27.cylinder head cover gasket 气缸盖罩垫28.oil pan gasket 油底壳垫29.piston pin /pn 活塞销30.cylindrical /slndrkl adj.圆筒状的31.hollow /hl adj.中空的；空心的32.piston crown /kran 活塞顶部33.piston ring /r 活塞环34.piston land 活塞环岸35.piston skirt 活塞裙部36.piston pin bore 活塞销座37.piston ri

37、ng groove /ruv/活塞环槽38.cylinder wall 气缸壁39.classify /klsfa v.将分类或归类Task 2知 识 储 备pression/kmpren/ring 气环41.oil ring 油环42.deposite /dpzt v.放置；沉积43.connecting rod small end 连杆小头44.connecting rod bushing 连杆衬套45.connecting rod shank /k 连杆杆身46.connecting rod big end 连杆大头47.connecting rod bearing half shell

38、 /el/连杆轴瓦48.connecting rod cap 连杆盖49.snap ring 卡环50.connecting rod bolt 连杆螺栓prise /kmpraz v.包括52.crankshaft bearing 曲柄轴承Task 2知 识 储 备53.main bearing journal /dnl/主轴承轴颈54.rod journal 连杆轴颈55.counter-balanced weight 平衡重56.flywheel end 飞轮端57.bolt /blt v.用螺栓把固定在一起58.rear /r(r)/adj.后面的；后部的59.torsional vib

39、ration damper/tnl vabrendmp(r)/扭转减振器60.timing gear 正时齿轮61.start claw /kl/起动爪62.ring gear 齿圈/环形齿轮Task 2畅 享 阅 读Task 2畅 享 阅 读曲柄连杆机构 曲柄连杆机构是往复式内燃机中的动力传递系统，是发动机实现工作循环，完成能量转换的主要运动部分。在做功冲程中，曲柄连杆机构将燃料燃烧产生的热能转换为推动活塞做直线运动的机械能，将活塞往复运动转变为曲轴旋转运动，并向外输出动力；在其他冲程中，则依靠曲柄和飞轮的转动惯性，通过连杆带动活塞上下运动，为下一次做功冲程创造条件。曲轴连杆机构主要由发动机

40、机体组、活塞连杆组和曲轴飞轮组组成。The crankshaft and connecting rod mechanism is the power transfer system in reciprocating1 internal combustion engine.It is the main moving part of the engine to realize working cycle and energy conversion.In the power stroke,the crankshaft and connecting rod mechanism converts the

41、 heat energy generated by fuel combustion into the mechanical energy that drives the piston to move in a straight line,converts the reciprocating motion of the piston to the rotational2 motion of the crankshaft,and outputs3 power outwards4.In other strokes,it depends on the rotational inertia5 of th

42、e crank6 and the flywheel and drives the piston up and down through the connecting rod to create conditions for the next power stroke.The crankshaft and connecting rod mechanism is composed of three parts engine block group,the piston and connecting rod group,and crankshaft and flywheel group.Cranks

43、haft and Connecting Rod MechanismTask 2畅 享 阅 读发动机机体组 发动机机体组由气缸体、气缸盖、气缸垫和油底壳等组成。发动机机体组组件如图2-2所示。气缸体 气缸体通常由高强度的铁合金或铝合金制成，是所有安装在发动机上的零件的支撑架。气缸体内铸有气缸，提供活塞上下运动的空间。气缸体内还铸有水套、凸轮轴及安装曲轴的空腔。铝制气缸体内通常安装有铸铁或钢制的缸套。Engine block group consists of cylinder block7,cylinder head8,cylinder gasket9 and oil pan10.Engine

44、block group subassembly11 is shown at Figure 2-2.Cylinder Block The cylinder block is usually made of high-grade12 iron alloy13 or aluminum14 alloy.It is the supporting structure of all engine parts.The cylinders are cast15 into the block,in which the pistons move up and down.The water jackets16,cam

45、shaft17 and cavity18 for mounting19 crankshaft are also cast into the block.In aluminum blocks,the manufacturer usually installs cast-iron or steel cylinder sleeves20.Engine Block GroupTask 2畅 享 阅 读 Figure 2-2 Engine Block Group Subassembly图2-2 发动机机体组组件Task 2畅 享 阅 读 Figure 2-2 Engine Block Group Sub

46、assembly图2-2 发动机机体组组件Task 2畅 享 阅 读气缸盖气缸盖固定在缸体的上部。气缸盖上装有气门，供空气、燃油进入及废气排出。和气缸体一样，气缸盖也由铸铁或铝合金制成。气缸垫气缸垫位于气缸盖与气缸体之间，其功能是填补它们之间的微观孔隙，保证结合面处有良好的密封性，进而保证燃烧室的密封，防止气缸漏气。油底壳油底壳位于发动机底部，是一个非常简单但非常重要的组件，它的功能是储存机油。一般的油底壳是由钢或铝制成的。Cylinder HeadThe cylinder head is fastened21 to the top of the cylinder block.The cyli

47、nder head carries the valves which allow the air,fuel,and exhaust22 moving through the engine.Like the cylinder block,the head is made from either cast iron or aluminum alloy.Cylinder GasketThe cylinder gasket is located between the cylinder head and the cylinder block.Its function is to fill the mi

48、cro-pores23 between them to ensure the good sealing at the joint24 surface,so as to guarantee the sealing of the combustion chamber and prevent cylinder leakage25.Oil PanThe oil pan,located at the bottom of the engine,is a very simple but very important component.It is used to store oil.The ordinary

49、 oil pan is made of steel or aluminum.Task 2畅 享 阅 读活塞连杆组 活塞连杆组由活塞和连杆组成，二者之间通过活塞销连接。活塞连杆组组件如图2-3所示。活塞 活塞是一个中空的圆柱形零件，可在气缸内做上下运动。活塞由活塞顶部、活塞环、活塞环岸、活塞裙部和活塞销座孔组成。活塞组件如图2-4所示。Piston and connecting rod group is composed of piston and connecting rod,which are connected by a piston pin29.Its subassembly is sh

50、own at Figure 2-3.Piston Piston is a cylindrical30 hollow31 part that moves up and down inside the cylinder.It is composed of piston crown32,piston ring33,piston land34,piston skirt35 and piston pin bore36.Piston subassembly is shown at Figure 2-4.Piston and Connecting Rod GroupTask 2畅 享 阅 读 Figure