汽车专业英语project3Enginecomponents

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1、Project 3 Engine components,1,东北大学出版社,改革创新示范教材,2,掌握发动机的总体结构、 工作原理、 基本术语，分类 掌握常用术语的表达方法, 了解相关其它专业术语,知识目标,能读懂发动机工作原理相关英文 材料, 能熟记相关专业词汇 能读懂发动机总体构造和分类的 英文材料，能熟练掌握发动机基本 术语和概念的英语表达方式 能对发动机各机构和系统组成中 的常见零部件的英语表达准确识别 能熟记常见的发动机专业术语 缩写形式 能看图写出零件名称,能力目标,Project 3 Engine components,改革创新示范教材,3,Task1 Engine Princi

2、ples and Structure,1.New words and expressions,principle prinspl n. 原则，原理 convert knv:t, knv:t v. (使)转变(化) combustion kmbstn n. 燃烧 gasoline sli:n n.汽油 stroke struk n. 冲程 spark sp:k n. 火花; 火星； vi.发出火星; 发出闪光 compress kmprs vt. 压紧, 压缩 cylinder slnd n. 圆筒, 圆柱, 圆柱体, 汽缸, 泵体 plug pl n.插头, 插座；塞子, 栓 diesel d

3、izl, -sl n.柴油 ；柴油机机车(或船等), 内燃机车 inject ndkt vt. 给注射（药物等）,给注射（液体）,高职高专改革创新示范教材,4,1.New words and expressions,sufficiently sfntl adv.足够地, 充分地 ignite nat vt.点燃; 引发,（使）燃烧, 着火 piston pstn n.机活塞 cycle saikl n.循环, 周期, 自行车 inlet inlet n.进口，入口 exhaust iz:st vt. 用尽；使非常疲倦; n.排气装置, 排气管孔；废气 valve vlv n. 阀, 活门, 阀

4、门, 气门 suction skn n.吸, 抽吸 revolution ,revlu:n n.革命；彻底改变, 重大变革；旋转; 运行, 公转 induction ndkn n.就职, 入伍；吸入；(电或磁的)感应；归纳(法), 吸入 propel prpel vt. 推进，推动 block blk n.街区, 街段；大块(木料、石料、金属、冰等)；,改革创新示范教材,5,知识目,rod rd n.竿, 杆, 棒 part p:t n.一部分; 局部；零件；角色 component kmpunnt n. 成分, 组成部分, 部件, 元件 circular s:kjul adj.圆形的, 环形

5、的; 循环的 n.通知, 通告 gas-tight 气密的，不透气的 swivel swvl n.转节, 转环;旋轴;旋转接头vt. adj. 偏（离中）心的，抵消的 crankcase krkkeis n.曲轴箱,改革创新示范教材,6,知识目,gasket skit n.束帆索,垫圈,衬垫 pump pmp n.泵, 打气筒 vt. 容积, 容量；音量, 响度,改革创新示范教材,7,知识目,radius reidjs n.半径(距离)；用半径度量的圆形面积; 半径范围 diameter daimit n.直径；放大率 displacement dsplesmnt n.移置,代替; 排量 to

6、rque trk n.扭矩 clearance klirns n.净空, 余隙；许可, 批准 self-contained 自给的 internal combustion engine 内燃机 spark plug 火花塞 result in 导致，致使，引起,改革创新示范教材,8,知识目,consist of 由组成 up and down 上上下下 connecting rod 连杆 fuel system 燃油供给系 ignition system 点火系 cooling system 冷却系 lubrication system. 润滑系 Top Dead Center(TDC) 上止

7、点 Bottom Dead Center(TDC) 下止点 displacement volume 排量 compression ratio 压缩比 swept volume 工作容积 clearance volume 燃烧室容积,改革创新示范教材,9,Engine working principles,任务 实施,The engine is a self-contained power unit which converts the heat energy of fuel into mechanical energy for moving the vehicle. In brief, the

8、 burning of the fuel causes a rapid rise in cylinder pressure which is converted to useful mechanical energy by the piston and the crankshaft. The majority of engines in automobile today are four-stroke, spark-ignition internal combustion engines. In petrol Engine, the air-fuel mixture after being c

9、ompressed in the engine cylinder to a high pressure is ignited by an electric spark from a spark plug. In diesel engine, diesel is injected into the engine cylinder containing air compressed to a very high pressure. The air temperature is sufficiently high to ignite the fuel. That is why there is no

10、 spark plug used in diesel engine.,改革创新示范教材,10,Engine working principles,任务 实施,The four-stroke cycle (Figure 3.1.1) for a petrol engine (spark ignition) is very similar in principle to that of a diesel engine (compression ignition or CI). To complete the cycle, four strokes of the piston are needed.

11、 Starting with the piston at TDC, as the crankshaft rotates, the next four strokes of the piston will result in a number of different processes and actions taking place. Suction stroke When the piston moves down the cylinder, the inlet port is open and the exhaust port is closed, a fresh charge is d

12、rawn into the cylinder. Most petrol engines draw in a mixture of air and fuel, however a diesel engine draws in a charge of air only. At the end of the stroke, the inlet closes.,改革创新示范教材,11,Engine working principles,任务 实施,改革创新示范教材,12,Engine working principles,任务 实施,Compression stroke Then the piston

13、 moves back up to compress this air-fuel mixture. The compression forces the fuel into closer combination with air. Just a little before the end of compression stroke, the mixture is ignited by a spark produced by spark plug. During this stroke suction and exhaust valve remain closed. When the mixtu

14、re inside the cylinder is compressed, pressure and temperature rise at the same time. Power stroke When the piston reaches the top of its stroke, the spark plug emits a spark to ignite the gasoline. The gasoline charge in the cylinder explodes, driving the piston down. The combustion process pushes

15、the piston down the cylinder with great force turning the crankshaft to provide the power to propel the vehicle. Each piston fires at a different time, determined by the engine firing order. At this time, intake, exhaust valve is still closed.,改革创新示范教材,13,Engine working principles,任务 实施,By the time

16、the crankshaft completes two revolutions, each cylinder in the engine will have gone through one power stroke. However, for a diesel engine, the diesel fuel is injected at high pressure into the hot compressed air and mixes to form a combustible air/fuel mixture. The heat of the air ignites the fuel

17、 mixture. Exhaust stroke The rotation of the crankshaft causes the piston to return up the cylinder. The inlet port remains closed but the exhaust port is now opened. The movement of the piston towards the top of the cylinder therefore forces the burnt gases out of the cylinder via the exhaust port.

18、 At the end of the exhaust stroke, the exhaust port closes and the inlet port re-opens for the next induction stroke.,改革创新示范教材,14,Engine working principles,任务 实施,Engine overall structure The engine consists of a large number of parts (shown as Fig. 3.1.2). The main components of engine are cylinder

19、block, pistons, connecting rods, crankshaft and valves. The cylinder with the simplest form, is circular tube, which is closed at one end. The piston fits closely inside the cylinder. Ideally it would be perfectly gas-tight yet perfectly free to move up and down inside the cylinder. The connecting r

20、od connects the piston to the crankshaft. At the piston end of connecting rod is a swivel pin called the gudgeon pin. The gudgeon pin is fitted into holes in the piston and the connecting rod, thus coupling them together. The crankshaft is the main shaft of the engine and is carried in bearings in t

21、he crankcase. Offset from the main part of the shaft is the crankpin to which the connecting rod is fitted and is free to turn. The other parts are joined together to form systems. These systems are the fuel system, valve system, ignition system, cooling system, lubrication system. Each of them has

22、a definite function.,改革创新示范教材,15,Engine working principles,任务 实施,Engine size The usual method of indicating the size of an engine is to state the volume of air and fuel taken into the engine for each cycle of operations. This means the volume contained in that part of the cylinder between the TDC an

23、d BDC positions of the piston. The volume of a cylinder is given by the formula V=r2h or V=d2h/4. Where V is the volume of the cylinder, r is the radius, d the diameter and h the height or length. The internal diameter of the engine cylinder is called the bore, whilst the distance the piston moves b

24、etween TDC (Top Dead Center) and BDC (Bottom Dead Center) is called the stroke (shown in figure 3.1.3). Representing these by d and l, respectively, the above formula can be written: V=d2l/4. Since this is the volume displaced or swept by the piston, it is called the displacement volume or swept vol

25、ume of the cylinder. If the engine has several cylinders, as most have，the total swept volume of the engine is swept volume per cylinder multiplied by the number of cylinders.,改革创新示范教材,16,Engine working principles,任务 实施,Compression ratio It is an important parameter of an engine cylinder. When the p

26、iston is at TDC, a space is left between its top and the end of the cylinder: the volume contained in this space is called the clearance volume. The volume enclosed above the piston at BDC consists of the clearance volume plus the swept volume and is called the total volume.,改革创新示范教材,17,Engine worki

27、ng principles,任务 实施,Torque and power When engines are discussed, there are usually two terms used to indicate how powerful an engine is: torque and power. Although there is a relationship between torque and power, they are in fact different measurements of what an engine can achieve. The values of t

28、orque and power provide indications of the performance that can be expected from an engine. Torque is generally associated with strong pulling power, which would be typically required in a vehicle that has to pull heavy loads such as a large commercial vehicle or heavy goods vehicle. Power is genera

29、lly associated with engines that are intended to produce high vehicle speeds. Racing cars and sports cars would generally have high-power engines.,改革创新示范教材,18,Task2 Crank - connecting rods and valve mechanism,1.New words and expressions,mechanism mknzm n. 机械装置 、构造, 机制 fulfill fulfil t. 履行(诺言等)、完成(任务

30、等)、实现 ；执行(命令等)、服从；达到(目的) potential ptenl adj. 潜在的, 有可能的 rotary rutri adj. (机器或设备) 转动的； (运动 ) 旋转的、绕轴转动的 severe sivi adj. 极为恶劣的、 十分严重的；精确的；严谨的 withstand wistnd vt. 经受, 承受 corrosion krn n. 腐蚀、侵蚀、受腐蚀的部位 ；腐蚀生成物如绣等、衰败 crankcase krkkeis n.曲轴箱 constitute knstitju:t vt. 构成、组成 ；建立、 制定 backbone bkbn n. 脊骨、脊柱；骨

31、干、支柱、主力、中坚、基础 accessory ksesri n. 附件、配件、附属物 ；,改革创新示范教材,19,sufficient sfint adj. 足够的、 充足的 film film n.影片, 电影；胶片, 胶卷；薄层, 薄膜 stiffness stfns n. 刚度 attachment ttmnt n.附着, 附属；附属物, 附件 valve vlv n.阀、 活门；真空管 emission imin n.发出，发光，放射物 simultaneously 同时地 punctually pktl adv. 如期地,准时地 tappet tpit n. 梃杆, 凸子 rock

32、er rk n. (摇椅等底部)弯形摇臂、摇滚青年 inefficiency nfns n. 无效率;无能 无效率事例 retainer ritein n. 护圈, 定位器 belt belt n.腰带、 带子、区域、地带 chain tein n. 链、锁链、一系列的事物、连锁店或旅馆、束缚 cylindrical slndrkl adj. 圆柱形的、圆筒状的、气缸(或滚筒)的 intermediate ,ntmi:djt adj.中间的、中级的 reliability rlablt n. 可靠、可信赖,改革创新示范教材,20,durability djrblt n. 耐久性、 耐用性 ca

33、m km n. 凸轮 compression ring 压缩环（气环） pressure-tight 耐压密闭的 align with 使一致；使密切合作 be subjected to 经过、易于、遭受 valve stem 气门杆 valve guide 阀导承、阀杆导承、气阀导管、气门导管 locking plate 锁紧木片、锁片、防松板、定闹盘 push rod 制动缸推杆、顶杆、挺杆、推杆 chain drive 链传动 with regard to 关于 timing gear 正时齿轮 Variable Valve Timing 可变气门正时,改革创新示范教材,21,Crank

34、 and connecting rod mechanism,任务 实施,The combination of crank and connecting rod in an internal combustion engine forms a kind of mechanism that can fulfill working cycle and convert the potential energy of the fuel into the kinetic energy which rotates the crankshaft. Its function is to achieve ener

35、gy conversion to transmit force and change the reciprocating motion of the piston into the rotary motion of the crankshaft. The working condition in this mechanism is rather severe due to withstanding high temperature, high pressure, high-speed and chemical corrosion.,改革创新示范教材,22,Automobile category

36、,任务 实施,The crank and connecting rod mechanism can be divided into three groups, such as the engine body, piston - connecting rod and crankshaft - flywheel group. Among them, the body constitutes the backbone of the engine, which is regarded as a base on the internal and external installation of all

37、the major parts and accessories in an engine. The body must have sufficient strength and stiffness because it is subjected to various loads. It is mainly composed of the cylinder block, crankcase, cylinder head, cylinder gasket and other parts (shown as the figure.3.2.1). This group about piston-con

38、necting rod consists of piston, piston ring, piston pin, connecting rod and its bearing half shells (illustrated in Figure 3.2.2). The group of crankshaft-flywheel is mainly composed of crankshaft, flywheel and other accessories (shown as Figure. 3.2.3),改革创新示范教材,23,Automobile Classification,任务 实施,改革

39、创新示范教材,24,改革创新示范教材,25,Valve operating mechanism,任务 实施,The valve operating mechanism is used to control the intake and exhaust ports, which provides timely admission of the fresh charge into the cylinders and emission of exhaust gases. Simultaneously, the valves punctually open and close those ports

40、in the cylinder head through which the cylinders communicate with the intake and exhaust manifold according to the ignition order of the cylinder and the process requirements. The valve gear is widely applied in the four-stroke engines.,改革创新示范教材,26,改革创新示范教材,27,Valve operating mechanism,任务 实施,The val

41、ve gear is composed of two parts, including the valve group and the valve drive group (shown in Fig.3.2.4). Each group contains some components or parts, such as valves, valve bosses, valve guides, valve springs, locking plate, retainer, camshaft, tappet, push rod, rocker arm etc. According to the d

42、ifferent location of valves and camshafts, the layout will be different. For example, valves are located on the top or the side of the cylinder. Camshafts are set on the beneath, the mid or the overhead (shown in Fig.3.2.5). These arrangements are respectively used in different engines. Due to the i

43、nefficiency of side-valve engines, vehicle manufactures no longer use this layout.,改革创新示范教材,28,改革创新示范教材,29,Valve operating mechanism,任务 实施,As for the camshaft drive, there are three ways such as belt drive, chain drive and gear drive (shown in figure 3.2.6). Generally speaking, the mechanism with bo

44、th the beneath camshaft and the mid camshaft is mostly adopted the cylindrical timing gear drive. It usually needs just a pair of timing gears from crankshaft to camshaft. If the gear diameter is too large, an intermediate gear may be added. The chain drive is suitable for the overhead camshaft, but

45、 the reliability and the durability of the drive is not as good as that of the gear drive. In recent years, the toothed belt with low noise and low cost is widely used in high-speed car engine instead of the drive chain.,改革创新示范教材,30,改革创新示范教材,31,Task 3 Electronic Fuel Injection system,1.New words and

46、 expressions,carburetor k:bjret n. 汽化器, 化油器 sensor sens n. 传感器,灵敏元件 appropriate prupri-it, pruprieit a. (适)恰当的 pressurize pre,raz vt. 对施加压力、给增压 nozzle nzl n. 管嘴、喷嘴 injector indekt n. 喷油器 discharge dist:d vt. 执行、履行 spray sprei vt. & vi. 喷 n. 浪花、飞沫、喷雾 circuit s:kit n. 电路，线路； vibration vaibrein n. 颤动；振

47、动 atomize tmaiz v. 使分裂为原子、将喷成雾状,改革创新示范教材,32,degree of richness 浓度 air-fuel ratio 空燃比 integrate with 与结合在一起 fuel consumption 燃料消耗（量），耗油率 wiring harness 线束 electronic fuel injection(EFI) 电子燃油喷射 throttle body 节气门体 intake manifold 进气歧管,改革创新示范教材,33,Electronic fuel Injection system,任务 实施,On old cars, it i

48、s a carburetor that sends the correct air-fuel mixture to the engine. The carburetor is a mixing device which mixes liquid gasoline with air. The mixture must vary degree of richness continually to suit engine operation conditions. Therefore, the electric fuel injection system has replaced the funct

49、ion of the carburetor in modern car engines. Fuel injection system provides more exact air-fuel ratio control. Thus, engine develops better economy and emission control. Sensors read changes on the engine. A computer interprets the information and sends appropriate instruction to the engines fuel co

50、ntroller. Then the injector sprays a measured amount of fuel down to the engine.,改革创新示范教材,34,Electronic fuel Injection system,任务 实施,The term petrol injection is used to describe any system in which pressurized fuel is forced out of a nozzle in an atomized state to mix with a supply of air. Modern sy

51、stems are controlled electronically because this form of control enables the fuel quantity to be accurately set to suit the engine operating conditions. Strict emission control regulations have demanded precise metering of the fuel, and although petrol injection systems are more expensive than carbu

52、retor fuel systems, they are now used to control the fuelling on all engines. Most petrol injection systems (figure 4.3.1) are integrated with the ignition system into an engine management system, including three systems (fuel delivery, air induction, electronic control).,改革创新示范教材,35,Electronic Fuel

53、 Injection System,任务 实施,A petrol injection system that delivers the correct quantity of highly atomized fuel gives the following advantages: (1) lower exhaust pollution. (2) lower fuel consumption. (3) higher power output. (4) smoother engine operation due to an even power output from each cylinder.

54、 (5) automatic adjustment of the air/fuel ratio to suit all operating conditions. The fuel delivery system（Fig.3.3.2）is to supply the injectors with the fuel. Pressure is provided by an electric fuel pump. Some systems use two pumps: a low-pressure fuel pump that delivers fuel to another pump, which

55、 develops the pressure.,改革创新示范教材,36,Figure 3.3.2 Fuel delivery system,改革创新示范教材,37,Electronic Fuel Injection System,任务 实施,The air supply system (Figure 3.3.3) is to induce the fresh air to form the mixture in the cylinder, consisting of an air cleaner assembly, throttle body, and intake manifold. The

56、 throttle body section contains the throttle valve, which is opened and closed by the driver to control the amount of air entering the intake manifold. On throttle body fuel injection systems, the throttle body also contains the fuel injection components. The intake manifold forms a closed passage b

57、etween the throttle body and the cylinder head.,改革创新示范教材,38,Figure 3.3.3 The air induction system,改革创新示范教材,39,Electronic Fuel Injection System,任务 实施,The electronic control system of an engine is mainly composed of ECU, sensors and actuators (shown in Figure 3.3.4). Engine control computers are const

58、ructed using many different electronic circuits and components. Modern computers control many other engine systems in addition to the fuel injectors. The computer is usually located in a protected area away from engine vibration and heat, and is connected to the rest of the injection system by means

59、 of a sealed wiring harness plug. The computer receives signals from a number of sensors whenever the engine is running. From this input, the computer evaluates engine fuel needs and adjusts injector pulse width accordingly.,改革创新示范教材,40,改革创新示范教材,41,Task 4 The lubrication system,1.New words and expre

60、ssions,circulate s:kjuleit v.(使)循环；(使)流传 friction frikn n.不和，抵触；摩擦(力) lubricant lu:briknt n.润滑剂, 润滑油 minimize minimaiz vt.使减(缩)小到最低 wear w vt.穿(戴)着；磨损 overhaul ,vh:l, v,h:l vt. 彻底检查、大修 n. 检查、大修 splash spl vt. 使(液体)溅起 vi. (指液体)溅落 droplet drplit n. 小滴 mist mist n. 薄雾、视线模糊不清 vt. 滤盆、滤网 quantificationall

61、y kwntfkenl adv. 定量（化）地 grease gri:s n.油脂；润滑油 vt.用油脂涂，加润滑油,改革创新示范教材,42,in detail 详细地 cylinder wall 汽缸壁 splash lubrication 飞溅润滑 main oil gallery 主油道 oil filter (汽车等)机油滤清器 oil pressure regulator 油压调节器 oil strainer 集滤器 relief valve 安全阀、泄压阀 oil cooler 机油冷却器,改革创新示范教材,43,The lubrication system,任务 实施,It is

62、 very important for the lubrication system to be required to lubricate the moving parts of an engine constantly. It is used for collecting, cleaning, cooling and re-circulating oil in the engine. The main function of the lubrication system is to circulate and deliver oil to the surfaces of all the m

63、oving parts in order to reduce friction between them. In detail, the lubricant circulates through the engine moving parts and performs important jobs: (1)To lubricate moving parts to minimize wear. (2)To lubricate moving parts to minimize power loss from friction. (3)To remove heat from engine parts

64、 by acting as a cooling agent. (4)To absorb shocks between bearings and other engine parts, thus reducing the noise and extending the engine life. (5)To form a good seal between piston rings and cylinder walls. (6)To act as a cleaning agent, washing the working surfaces free of chemical deposits, du

65、st and dirt to protect them from corrosion.,改革创新示范教材,44,The lubrication system,任务 实施,To keep a car in good running conditions, a car owner must change the lubricant once every 5000 km. If the lubricating system should fail, not only will the engine stop, but also some parts are likely to be damaged

66、beyond repair. Therefore, when lubrication failure occurs, the engine can seldom be run again without a major overhaul. The main components of the system are oil pump, oil filters, main oil galleries, oil pan, oil pressure regulators, relief valve, oil coolers and so on. Figure 3.4.1 shows the lubrication system layout. The lubrication way comprises three types: splash lubrication, pressure lubrication and regular lubrication. The splash lubr