Unit 2-1(Main Components of Engine )

1、Unit 2-1Automobile Engines ContentsPre-questionsII. Text ExplanationIII. ExercisesI.Pre-questionsThe heart of automobile What impression of the engine?complicated powerI. Pre-questions What are there types of the engine? electric motors, steam(蒸汽蒸汽) engines, and internal combustion engines Whats the

2、 internal combustion engine? burns fuel within the cylinders and converts the expanding force of the combustion into rotary force used to propel the vehicle.I.Pre-questionsSingle-cylinder enginecylinderpistonPiston pinConnecting rodcrankshaftOil pipeIntake valveExhaust valve Timing gearOil pump what

3、 is the power source of automobile and how to produce?piston piston pin connecting rod crankshaft EnginePower is produced by the linear motion of a piston in a cylinder. The connecting rod transmits the up-and-down motion of the piston to the crankshaft, which changes it into rotary motion. I.Pre-qu

4、estions The engine comprises two mechanism and five systems, what are they ? crankshaft and connecting rod mechanism, valve gear, cooling system, lubricating system, fuel system, starting system, ignition system I.Pre-questionsconnecting rodflywheelcrankshaftpistonintake valveexhaust valvepush rodta

5、ppettiming gears Valve gear Connecting rod Engine cooling systemEngine lubricating systemFuel supply systemValve gear Whats the function of the crankshaft and connecting rod mechanism? Its function is to convert heat energy into mechanical energy used to drive the vehicles. I. Pre-questions The inte

6、rnal combustion engine, as its name indicates, burns fuel within the cylinders and converts the expanding force of the combustion into rotary force used to propel the vehicle. 译文：译文：内燃机，内燃机，顾名思义顾名思义，就是燃料在气缸内部，就是燃料在气缸内部燃烧，并且把燃烧时的膨胀力转化为驱动车辆的燃烧，并且把燃烧时的膨胀力转化为驱动车辆的旋转力。旋转力。II. Text ExplanationOf all autom

7、obile components, an automobile engine is the most complicated assembly with dominant effects on the function of an automobile. complicated kmplikeitid adj.复杂的复杂的, 难解的难解的dominance dmnns n.优势优势, 统治统治译文：译文：汽车发动机是一切汽车部件中结构最复杂，汽车发动机是一切汽车部件中结构最复杂，对汽车功能起支配作用的一个总成。对汽车功能起支配作用的一个总成。II. Text Explanation Its f

8、unction is to convert heat energy into mechanical energy used to drive the vehicles. Convertinto. 转变；变换转变；变换 译文：译文：它的作用就是将热能转换成机械能用来驱它的作用就是将热能转换成机械能用来驱动汽车动汽车 。II. Text Explanation Co. 转变；变换转变；变换 That building has been converted into a school. 那座楼房改成学校了。那座楼房改成学校了。 兑换兑换 I want to convert som

9、e Hong Kong dollars into American dollars. 我想把一些港元换成美元。我想把一些港元换成美元。 改变信仰、党派或意见等改变信仰、党派或意见等 She managed to convert him to her opinion. 她终于设法说服了他接受她的意见。她终于设法说服了他接受她的意见。II. Text Explanation Power is produced by the linear motion of a piston in a cylinder. linear lini adj. 线的线的, 直线的直线的, 线线 性的性的 piston p

10、istn n.活塞活塞II. Text Explanation The piston attached to the top of a connecting rod by a pin, called a piston pin or wrist pin. attach to v. 连接连接 connecting rod 连杆连杆 piston pin = wrist pin 活塞销活塞销II. Text Explanation The connecting rod transmits the up-and-down motion of the piston to the crankshaft,

11、which changes it into rotary motion. transmitto 把把传到传到 which changes it into rotary motion 定语从句定语从句II. Text Explanationdiesel engineswater pumpthe ignition distributoroil pantiming gearcrankshaft and connecting rod mechanismvalve gearfuel systemexhaust pipeexhaust manifoldIII. ExercisesTranslate the

12、 following expressions into Chinese.u柴油发动机u水泵u分电器u油底壳u正时齿轮u曲柄连杆机构u配气机构u燃油系统u排气管u排气歧管1-cylinder head cover 2-piston3-timing toothed belt4-water pump5-oil pan6-oil pump7-crankshaft8-flywheel9-distributor10-valveIII. Exercises The crankshaft represents the final link in the conversion of reciprocating

13、motion at the piston to one of rotation at the flywheel. In the cast of the multi-cylinder engine, the crankshaft has to control the relative motions of the pistons, while receiving their own impulses. A one-piece construction is most commonly used for the motor-vehicle crankshaft, which extends the

14、 whole length of the engine and must therefore possess considerable rigidity . III. Exercises The timing-drive for the engine valve mechanism is taken from the front end of the crankshaft as is the pulley and belt drive for the engine auxiliaries, such as the cooling fan and the alternator for elect

15、rical system. attached to the rear end of the crankshaft is the engine flywheel .III. Exercises I. Translate the following sentences into Chinese. 1Engine is the power source of the automobile. Power is produced by the linear motion of a piston in a cylinder. 发动机是汽车的动力源发动机是汽车的动力源.它通过汽缸内的活塞线它通过汽缸内的活塞

16、线性运动产生的性运动产生的. 2The fuel system works according to the requirements of the engine as it provides an air-fuel mixture which must be in proportion to the speed and load placed on the engine. 燃油系统的作用是根据发动机的转速和负荷提燃油系统的作用是根据发动机的转速和负荷提供一定比例的可燃混合气以满足发动机的需求。供一定比例的可燃混合气以满足发动机的需求。III. Exercises 3The valve gea

17、r provides timely admission of the fresh charge into the cylinders and exhaust of spent gases from them. 配气机构机构可定时的将新鲜气体充入气缸，并配气机构机构可定时的将新鲜气体充入气缸，并且将废气排放出去。且将废气排放出去。III. Exercises 1发动机主要有两大机构五大系统组成。发动机主要有两大机构五大系统组成。 An engine is mainly composed of two mechanisms and five systems. 2曲柄连杆机构主要包括机体组，活塞连曲柄连杆机构主要包括机体组，活塞连杆组和曲轴飞轮组。杆组和曲轴飞轮组。 The crankshaft and connecting rod mechanism mainly consists of the engine crankcase and cylinder block, the piston and connecting rod, the crankshaft and flywheel. III. ExercisesII. Translate the following sentences into English. 3水泵工作时，可以将冷却液在发动机水水泵工作时，可以将冷却液