汽车工程专业英语(2.1-2.4).ppt

1、2.1 Principle of Operation 2.2 Engine Block and Cylinder Head 2.3 Piston, Connecting Rod and Crankshaft 2.4 Engine and Transmission Mounting 2.5 Valve System 2.1 工作原理 2.2 发动机体和气缸盖 2.3 活塞、连杆和曲轴 2.4 发动机和变速器组件 2.5 气门系统,Chapter 2 Internal Combustion Engine,2.6 Gasoline Fuel System 2.7 Diesel Engine 2.8

2、Engine Cooling 2.9 Engine Lubrication 2.10 Emission 2.6 汽油燃料系统 2.7 柴油发动机 2.8 发动机的冷却 2.9 发动机的润滑 2.10 排放,第二章 内燃机,Chapter 2 Internal Combustion Engine,2.1 Principle of Operation 2.1.1 Energy and power: Energy is used to produce power. The chemical energy in fuel is converted to heat by the burning of t

3、he fuel at a controlled rate. This process is called combustion. 21 工作原理 211 能源和动力 能源用于产生动力。燃料以控制的速率燃烧，燃料中的化学 能转换为热能。这个过程叫做燃烧。,Chapter 2 Internal Combustion Engine,If engine combustion occurs within the power chamber, the engine is called an Internal combustion Engine. If engine takes place outside

4、the cylinder, the engine is called an external combustion engine. 如果发动机燃烧发生在动力室内，这种发动机叫做内燃机。 如果燃烧发生在气缸外，这样的发动机叫做外燃发动机。,Chapter 2 Internal Combustion Engine,Engines used in automobiles are internal combustion heat engines. Heat energy released in the combustion chamber raises the temperature of the c

5、ombustion gases within the chamber. 汽车使用的发动机是内燃热发动机。在燃烧室内释放的热能 提高了室内燃烧气体的温度。,Chapter 2 Internal Combustion Engine,The increase in gas temperature causes the pressure of the gases to increase. The pressure developed within the combustion chamber is applied to the head of a piston to produce a usable

6、mechanical force, which is then converted into useful mechanical power. 气体温度的增加使气体的压力增加。在燃烧室内产生的压力 作用于活塞的顶部，产生机械力，这个力转换成有用的机械 动力。,Chapter 2 Internal Combustion Engine,2.1.2 Engine terms Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn. The

7、 power stroke uses up the gas, so means must be provided to expel the burnt gas and recharge the cylinder with a fresh petrol-air mixture: this control of gas movement is the duty of the valves; 活塞通过连杆和曲轴连接，使得气体带动曲轴旋转半圈。作功 冲程耗尽了所有的气体，这样就必须采取相应的措施排出废气 以及向气缸内充入新鲜的可燃混合气：气体的运动由气门来控 制.,Chapter 2 Internal

8、 Combustion Engine,2.1.2: Engine Terms TDC（top dead center）: the position of the crank and piston when the piston is farther away from the crankshaft. BDC（bottom dead center）: the position of the crank and piston when the piston is nearest away from the crankshaft.,Chapter 2 Internal Combustion Engi

9、ne,Chapter 2 Internal Combustion Engine,swept volume: the volume between TDC and BDC. Clearance volume: the volume of space above the piston when it is at TDC. Engine capacity: this is the swept volume of all cylinders.,Chapter 2 Internal Combustion Engine,2.1.3: The four strokes Spark-ignition Engi

10、ne cycle Intake (induction) stroke Compression stroke Power stroke Exhaust stroke,Chapter 2 Internal Combustion Engine,Chapter 2 Internal Combustion Engine,2.1.4:Engine Overall Mechanics Crankshaft and connecting rods system Valve system Fuel system Ignition system Cooling system Lubrication system

11、Starting system,2.2： Engine block and cylinder head,Chapter 2 Internal Combustion Engine,2.2.1: Engine block: The engine block is the basic frame of the engine. All other engine parts either fit inside it or fasten to it. It holds the cylinders, water jackets, and oil galleries. The engine block als

12、o holds the crankshaft, which fastens to the bottom of the block. 气缸体是发动机的基体。发动机其它的部件都安装在缸体内或 固定在缸体上，它包容了气缸、水套和油道，以及固定在缸体 底部的曲轴等。,Chapter 2 Internal Combustion Engine,2.2.1: Engine block: The camshaft also fits inside the block, except on overhead-cam engine (OHC). In most cars, this block is made o

13、f gray iron, or an alloy (mixture) of gray iron and other metals, such as nickel or chromium. Engine blocks are casting.,Chapter 2 Internal Combustion Engine,2.2.1: Engine block: Some engine block, especially those in smaller cars, are made of cast aluminum. This metal is much lighter than iron. How

14、ever, iron wears better than aluminum. Therefore, the cylinders in most aluminum engine are lined with iron or steel sleeves. These sleeves are called cylinder sleeves. Some engine blocks are made entirely of aluminum.,Chapter 2 Internal Combustion Engine,2.2.1: Engine block:,Chapter 2 Internal Comb

15、ustion Engine,2.2.2: Cylinder sleeve: The dry sleeve can be cast in or pressed into a new block or used to recondition badly worn or damaged cylinders that cannot easily be rebored. 干式缸套可以铸进或压入新气缸体中， 或者用于严重磨损或损 坏而又不易重镗的缸体的修复。,Chapter 2 Internal Combustion Engine,2.2.3: Cylinder head: The cylinder he

16、ad fastens to the top of the block, just as a roof fits over a house. The underside forms the combustion chamber with the top of the piston. In- line engines of light vehicles have just one cylinder head for all cylinders; larger in-line engines can have two or more. 气缸盖扣在缸体的顶部，就像屋顶安在房子上一样。缸盖的下 方和活塞

17、顶部形成燃烧室。轻型车的直列发动机所有缸仅有一 个气缸盖，较大的直列发动机有两个或更多缸盖。,Chapter 2 Internal Combustion Engine,The cylinder head carries the valves, valve springs and the rockers on the rocker shaft, this part of the valve gear being worked by push- rods. 缸盖上有气门、气门弹簧和摇臂轴上的摇臂，推杆推动这部 分气门传动机构工作。,Chapter 2 Internal Combustion Eng

18、ine,Chapter 2 Internal Combustion Engine,2.2.4:Gasket,Chapter 2 Internal Combustion Engine,2.2.5: Oil pan or Sump: The oil pump in the lubricating system draws oil from the oil pan and sends it to all working parts in the engine. Theoil drains off and runs down into the pan. Thus, there is constant

19、circulation of oil between the pan and the working parts of the engine. 润滑系的机油泵从油底壳抽出机油，并把机 油输送给发动机的所有工作部件。机油从油 底壳流进流出。因而在油底壳和发动机的工 作部件之间有机油定向循环流动。,Chapter 2 Internal Combustion Engine,2.3: Piston, connecting Rod and Crankshaft,Chapter 2 Internal Combustion Engine,2.3.2: Piston assembly Most pistons

20、 are made from cast aluminum. The piston, through the connecting rod, transfers to the crankshaft the force created by the burning fuel mixture. This force turns the crankshaft. 大多数活塞由铝铸造而成。 通过连杆，活塞把可燃混合 气燃烧所产生的力传递给曲 轴，并带动曲轴旋转。,Chapter 2 Internal Combustion Engine,1.Piston,Chapter 2 Internal Combust

21、ion Engine,2. Piston Rings In modern engines, each piston has three rings. (Piston in older engines sometimes had four rings, or even five.) The inside surface of the ring fits in the groove on the piston The rings outside surface presses against the cylinder walls. 在新型发动机上，每个活塞有三个活塞环。（在老式发动机 上，每个活塞

22、有四个甚至五个活塞环。）环的内边面紧贴在活 塞的环槽里，环的外表面紧压在气缸壁上。,Chapter 2 Internal Combustion Engine,3. Piston Pin,Chapter 2 Internal Combustion Engine,2.3.3 Connecting Rod The connecting rod little end is connected to the piston pin. A bush made from a soft metal, such as bronze, is used for this joint. The lower end of

23、 the connecting rod fit the crankshaft journal. This is called the big end. 连杆小头与活塞销连接，小头孔处压有诸如青铜这种较软材料 所制成的衬套，连杆下端连接在曲轴的连杆轴径处，称为连杆 大头。,Chapter 2 Internal Combustion Engine,Connecting Rod,Chapter 2 Internal Combustion Engine,Connecting Rod,Chapter 2 Internal Combustion Engine,2.3.4 Crankshaft,Chapte

24、r 2 Internal Combustion Engine,2.3.5 Cylinder number and firing order: Crank arrangement of engines: four cylinders six cylinders,Chapter 2 Internal Combustion Engine,Cylinder number and firing order: No.4 piston is always performing thecompanion stroke to No.1: when the inlet valve in No.4 cylinder

25、 is fully open, No.1 cylinder inletvalve is fully closed - this feature is useful to remember when checking valve clearances. 注意4号活塞和1号活塞总是成对运行：4号气缸进气门全闭 时，1号气缸进气门全开这个特点在检查气门间隙时是很有 用的。,Chapter 2 Internal Combustion Engine,2.3.6 Flywheel,Chapter 2 Internal Combustion Engine,2.3.7 Torsional vibration

26、balancer: As each cylinder fires, it causes the crank throw to speed up. The inertia of the rest of shaft cause it to stay slightly behind, resulting in a twisting action on the crankshaft. 当一缸点火时，使曲轴摆幅的速度提高，而其它轴的惯性阻碍 它，使其滞后，从而导致曲轴扭转。,Chapter 2 Internal Combustion Engine,The inertia ring is bonded t

27、o the hub through a flexible elastomer (rubber compound) insert. The inertial ring moves slightly in relation to crankshaft rotation as each cylinder fires, thereby dampening the torsional vibration of the crankshaft over a wide range of engine speed. 惯性盘通过一层由橡胶合成的可变形人造橡胶层与减振器圆盘 相连在每个汽缸点火时，惯性盘相对于曲轴运

28、动做微小转 动，用以削减发动机较大速度范围.,Chapter 2 Internal Combustion Engine,Chapter 2 Internal Combustion Engine,汽车英语专业词组 2.1 chemical energy 化学能 internal combustion engine 内燃机 inlet valve 进气阀 exhaust valve 排气阀 TDC 上止点 BDC 下止点 swept volume 有效/工作容积 engine capacity 发动机排量 clearance volume 燃烧室容积 compression ratio 压缩比,Chapter 2 Internal Combustion Engine,汽车英语专业词组 2.1 kinetic energy 动能 induction/i