汽车专业英语课件-5cha.ppt

《汽车专业英语课件-5cha.ppt》由会员分享，可在线阅读，更多相关《汽车专业英语课件-5cha.ppt（46页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、复习o提问EFI分类o提问（教师说EFI系统汉语部件名称，同学回答英文名称）oGDI原理学习内容学习内容本次课学习内容、目标和重点难点本次课学习内容、目标和重点难点学习目标学习目标难点重点难点重点1.Diesel fuel systems and CR system2.Cooling,lubrication systems3.3.Emission control system1.1.掌握柴油机喷油系统主要组成、掌握柴油机喷油系统主要组成、CRCR系统部系统部件的英文名称；掌握件的英文名称；掌握CRCR系统原理和排放系统系统原理和排放系统控制原理控制原理2.2.了解冷却、润滑和排放控制系统的组成

2、了解冷却、润滑和排放控制系统的组成1.1.重点为记忆英文专业术语重点为记忆英文专业术语2.2.难点需要记忆的生词偏多难点需要记忆的生词偏多3.3.汉译准确表达也是难点汉译准确表达也是难点Chapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System particlep:tikln.微粒，微粒，颗颗粒粒clogklgv.&n.阻塞，堵塞阻塞，堵塞nozzlenz()ln.喷喷嘴嘴traptrpn.圈套，陷阱，捕集器圈套，陷阱，捕集器plungerplnn.柱塞，活塞柱塞，活塞rackrkn.齿齿条条barrelbr()ln

3、.桶；桶；v.装入桶内装入桶内helixhi:liks n.螺旋，螺旋状物螺旋，螺旋状物cutawayktweia.切去一部分的，剖面的切去一部分的，剖面的 New Words and PhrasesChapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System variationverieinn.变变化，化，变变更，更，变变种，种，变调变调solenoidsulinidn.螺螺线线管，管，电电磁磁线线圈圈铁铁，阀阀，开关，开关shutofft:fn.中断，切断，关中断，切断，关闭闭energizeendaizv.供供给

4、给能量，通能量，通电电，励磁，励磁 Chapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System Typical diesel system components include the fuel tank,fuel pump,fuel filter,injection pump,injectors,and the necessary fuel lines(Fig.2-18).The system in Fig.2-19 is typical of newer systems that utilize a comput

5、er-controlled electronic fuel injection pump.2.8.2 Text Chapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System Fig2-18 A conventional diesel fuel injection system Chapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System Fig2-19.An computer controlled diesel fuel injection s

6、ystem with axial-piston distributor injection pump Chapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System Fuel Filter.Diesel fuel must be kept clean to avoid injector system trouble.Very small particles are enough to clog injector nozzles.Diesel fuel systems typically use one or more f

7、ilters to trap dirt and other deposits.Injection Pump.Due to the high compression(around 22:1)used in diesel engines,the diesel injection pump must be capable of producing high pressures.There are a number of injection pump designs.The most commonly used automobile and light truck diesel injection p

8、umps are classified as inline or distributor.The inline injection pump（Figure 12-18）uses a separate cylinder plunger-cam unit（Fig.2-20）for each cylinder.These units are contained in a straight row in a common housing.Chapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System Figure 2-20.Pu

9、mp plunger construction.When the control rack is moved,the plunger will be forced to rotate by the segmented gear sleeve acting on the plunger flange.Chapter 2 Internal Combustion Engine2.8 Diesel Fuel Injection System Fig.2-21 Cutaway view of a distributor type injection pump.The distributor inject

10、ion pump is shown in Figure 2-21.You will note that a single,double-plunger type pump serves all injector outlets.A single delivery valve is located in the rotor.A distributor type fuel injection pump witch is electronically controlled is shown in Fig.2-22.Chapter 2 Internal Combustion Engine2.8 Die

11、sel Fuel Injection System Fig.2-22 A electronically controlled distributor type fuel injection pump.Fuel shutoff solenoid is controlled by the powertrain control module(PCM).When energized,it is designed to completely stop the fuel flow into the injection pump.Chapter 2 Internal Combustion Engine2.8

12、 Diesel Fuel Injection System Injector.There are many different injector designs,but all are a variation of two basic types-inward opening and outward opening.Diesel spray patterns will vary depending upon engine design.Glow Plug and Intake Air Heaters.To aid in igniting the compressed air-fuel mix

13、during cold starting,diesel engines use glow plugs and intake air heaters.The glow plug is an electrically operated device that protrudes into the precombustion chamber.On later engines,the glow plugs are turned on and off automatically.Intake air heaters warm the air as it passes through on its way

14、 to the intake manifold.The heater element is a wire mesh that is electrically heated.The computer energizes the heater element before cranking.Chapter 2 Internal Combustion Engine2.9 Common rail injection systems piezoelectricpaii:zuilektrika.压电压电的的efficientifinta.有效的，效率高的有效的，效率高的 New Words and Phr

15、ases Chapter 2 Internal Combustion Engine 2.9 Common rail injection systems Newer diesel engines are equipped with common rail injection systems(Fig.2-23 to Fig.2-26).Common rail systems are direct injection(DI)systems.The injectors nozzles are placed inside the combustion chamber.The piston top has

16、 a depression where initial combustion takes place.The injector must be able to withstand the temperature and pressure inside the cylinder and must be able to deliver a fine spray of fuel into those conditions.These systems have a high pressure fuel rail connected to individual injectors.Text Chapte

17、r 2 Internal Combustion Engine2.9 Common rail injection systems The injectors are controlled by a computer that attempts to match injector operation to the operating conditions of the engine.There are two types of injectors:solenoid-type and piezoelectric(Fig.2-27 and Fig.2-28).Newer diesel fuel inj

18、ectors rely on stacked piezoelectric crystals rather than solenoids.Piezoelectric-crystals quickly expand when electrical current is applied to them.The crystals allow the injectors to respond very quickly to the needs of the engine.With this new-style injector,diesel engines are quieter,more fuel e

19、fficient,cleaner,and have more power.Chapter 2 Internal Combustion Engine2.9 Common rail injection systems Fig.2-23 Common rail(CR)system Chapter 2 Internal Combustion Engine2.9 Common rail injection systems Fig.2-24 Bosch third generation common rail with piezoelectric inline injectors Fig.2-25 Luc

20、as diesel common rail(LDCR)2.9 Common rail injection systems Fig.2-26 Common rail injection system as used with a V-8 engine Fig.2-27 Solenoid-type injector Chapter 2 Internal Combustion Engine2.9 Common rail injection systems Fig.2-28 Boschs third generation common rail in which the injector actuat

21、ors consist of piezo-crystals.Chapter 2 Internal Combustion Engine 2.10 Cooling System New Words and Phrasescylindersilindn.(发动发动机的机的)气缸气缸 lubricationlu:brikeinn.润润滑滑horsepowerhrspaun.马马力力(功率功率单单位位)depositdipzitn.沉淀物沉淀物;Mileagemailidn里程里程thermostat:msttn.恒温器恒温器,节节温器温器pumppmp n.泵泵radiatorredieitn.散散热

22、热器器Chapter 2 Internal Combustion Engine 2.10 Cooling System cylinder wall气缸壁气缸壁cylinder head气缸盖气缸盖oil film油膜油膜fuel mileage燃油燃油经济经济性性water jacket水套水套water pump水水泵泵expansion(overflow)tank膨膨胀胀（溢流）箱（溢流）箱radiator cap散散热热器盖器盖The purpose of the engines cooling system is to remove excess heat from the engin

23、e,to keep the engine operating at its most efficient temperature,and to get the engine up to the correct temperature as soon as possible after starting.Ideally,the cooling system keeps the engine running at its most efficient temperature no matter what the operating conditions are.Fuel burning engin

24、es produce enormous amounts of heat;temperatures can reach up to 4,000 F when the air-fuel mixture burns.However,normal operating temperature is about 2,000 F.Chapter 2 Internal Combustion Engine 2.10 Cooling System TextThe exhaust system takes away much of the heat,but parts of the engine,such as t

25、he cylinder walls,pistons,and cylinder head,absorb large amounts of the heat.If a part of the engine gets too hot,the oil film fails to protect it.This lack of lubrication can ruin the engine.On the other hand,if an engine runs at too low a temperature,it is inefficient,the oil gets dirty(adding wea

26、r and subtracting horsepower),deposits form,and fuel mileage is poor-not to mention exhaust emissions!For these reasons,the cooling system is designed to stay out of the action until the engine is warmed up.Chapter 2 Internal Combustion Engine 2.10 Cooling System There are two types of cooling syste

27、ms:liquid cooling and air cooling.Most auto engines are cooled by the liquid type;air cooling is used more frequently for airplanes,motorcycles and lawnmowers.The cooling system of a water-cooled engine consists of the engines water jacket,a thermostat,a water pump,a radiator and radiator cap,a cool

28、ing fan(electric or belt-driven),hoses,and usually an expansion(overflow)tank(Figure 2-23).Chapter 2 Internal Combustion Engine 2.10 Cooling System Fig.2-23 The cooling system of a water-cooled engineprincipleprinspln.法法则则,原原则则,原理原理frictionfriknn.摩擦摩擦,摩擦力摩擦力minimizeminimaizvt.将将.减到最少减到最少v.最小化最小化resi

29、dualrizdu:ladj.剩余的剩余的,残留的残留的sealsiln.封条封条;vt.封封,密封密封pistonpistnn.机机活塞活塞cylindersilindn.气缸气缸varnishv:nin.清漆清漆,光光泽泽面面,掩掩饰饰v.修修饰饰 New Words and PhrasesChapter 2 Internal Combustion Engine 2.11 Lubrication System carbonk:bnn.化化碳碳excessiveiksesivadj.过过多的多的,过过分的分的,额额外外absorbbs:bvt.吸收吸收,吸引吸引adequatedikwita

30、dj.适当的适当的,足足够够的的deliverdilivvt.递递送送,陈陈述述,释释放放,发发表表hydrodynamic,haidroudainmikadj.水力的水力的slidingslaidiadj.滑行的滑行的,变变化的化的buildupbildpn.组组合合,集集结结,累累积积,形成形成Chapter 2 Internal Combustion Engine 2.11 Lubrication System Reducing friction to minimize wear and loss of power is the primary job a lubrication sys

31、tem must perform.Residual oil on engine parts also provides lubrication for engine start-up.The engine oil forms a seal between the pistons,rings,and cylinders.It also helps to cool engine parts.Without the cleaning action of the lubricating system,carbon and varnish buildup would be excessive.The e

32、ngine oil also absorbs the shock and dampens the noise of moving parts.Chapter 2 Internal Combustion Engine 2.11 Lubrication System How successful the lubrication system is in performing all these functions depends on a number of factors and conditions.There must be an adequate supply of good-qualit

33、y lubricant delivered to all moving engine parts under sufficient pressure to provide hydrodynamic lubrication for rotating parts and oil adhesion to surface subject to sliding friction.Figure 2-24 shows a engines lube oil circuit schematic.Chapter 2 Internal Combustion Engine 2.11 Lubrication Syste

34、m Fig.2-24 Engines lube oil circuit schematicFig.2-25 The parts of the lubrication systemmanufacture,mnjufkt vt.制造，生制造，生产产；n.制造；制制造；制成品，成品，产品；品；environmentinvairnmntn.环境境nitrogennaitrdnn.氮氮crankcasekrkkeisn.曲曲轴箱箱injectionindeknn.注射注射Chapter 2 Internal Combustion Engine 2.12 Emission Control Systems

35、New Words and Phrasescatalytic,ktlitikn.催化催化剂tailpipeteilpaipn.n.尾管尾管mufflerm fln.消声器，消音器消声器，消音器manifoldmnifoldn.歧管（汽歧管（汽车引擎用于引擎用于进气或排气）气或排气）chamberteimbn.室室Chapter 2 Internal Combustion Engine 2.12 Emission Control Systems The purpose of the emission control system is just that it controls the emis

36、sions and exhaust from a vehicle.The idea is to turn the harmful gases a car manufactures into harmless ones that dont ruin the environment,or persons.Some of the problem gases are:1)hydrocarbons(unburned)2)carbon monoxide 3)nitrogen oxidesThere are five popular systems used to reduce emissions:the

37、crankcase ventilation system,the evaporative emission control system,the Exhaust Gas Recirculation(EGR)system,the air injection system and the catalytic converter system.Chapter 2 Internal Combustion Engine 2.12 Emission Control Systems 2.12.2 TextIn addition to these emission systems,modern vehicle

38、s incorporate an electronically controlled fuel injection system,which further reduces emissions.Note:Not all vehicles are equipped with these emission systems.The purpose of the positive crankcase ventilation(PCV)system is to take the vapors produced in the crankcase and piston blow-by,and redirect

39、 them into the air/fuel intake system to be burned during combustion.Exhaust gas recirculation(EGR)systems reduce the amount of oxides of nitrogen produced during the combustion process.Chapter 2 Internal Combustion Engine 2.12 Emission Control Systems The function of the fuel evaporative control sy

40、stem is to trap and store evaporative emissions from the gas tank and carburetor.A charcoal canister is used to trap the fuel vapors.The fuel vapors adhere to the charcoal,until the engine is started,and engine vacuum can be used to draw the vapors into the engine,so that they can be burned along wi

41、th the fuel/air mixture.The catalytic converter looks like a muffler.It is located in the exhaust system ahead of the muffler.As hydrocarbons or carbon monoxide in the exhaust are passed over the catalyst,it is chemically oxidized or converted to carbon dioxide and water.Chapter 2 Internal Combustio

42、n Engine 2.12 Emission Control Systems Fig.2-26 Exhaust systemFig.2-27 Positive crankcase ventilation(PCV)systemFig.2-28 Evaporative emission control(EVAP)systemFig.2-29 Exhaust gas recirculation(EGR)systemoFig.2-30 Air injection(AIR)systemFig.2-31 Three-way catalytic converter(TWC)system with ceramic substrateso自学补充内容，熟悉排放物控制原理小结与作业o冷却、润滑和排放控制系统主要部件的英文名称和有关术语 o阅读并记住黑体字专业词汇；