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1、1,汽车的四大组成部分,2,车身,发动机,底盘,电器系统,英语怎么表示？,3,engine,chassis,body,electrical system,图示：The basic components of an automobile,3.车 身,2.底 盘,1.发动机,4.电气系统,4,例句分析：,There are four basic components of the automobile : engine , chassis , body and electrical system .中文：basic component - 基本组成；问题：汽车共四个组成部分：_、 _、_ _ 。,
2、engine 发动机,chassis 底盘,body 车身,electrical system 电气系统,5,The Question (问题),Which is called the “heart” of Automobile?,be called of - (被叫做-)；,中文：哪部分被称作是汽车的心脏？,heart (心脏)；,发动机,6,Part one Automobile Engine 汽车发动机,一、发动机的分类,Clissified by fuel（按燃料不同分类）汽油机和柴油机；Clissfiled by working progress（按工作行程分类）四冲程发动机和二冲程
3、发动机；Clissfiled by cooled ways（按冷却方式分类）水冷发动机和风冷发动机；Clissfiled by number of cylinder（按气缸数量分类）单缸发动机和多缸发动机,7,Clissified by fuel（按燃料不同分类）,8,汽油发动机gasoline enginegasolinegslin n. 汽油,点燃方式（点燃式）,9,柴油发动机diesel enginedieseldi:zl n. 柴油 ，柴油机,点燃方式（压燃式）,Clissfiled by working progress（按工作行程分类）,10,二冲程发动机Two stroke en
4、ginestrokestrk n. 冲程，行程；,活塞反复运动一次，曲轴转动一周，两个冲程完成一个工作循环。,11,四冲程发动机Four stroke enginestrokestrk n. 冲程，行程；,活塞反复运动两次，曲轴转动两周，四个冲程完成一个工作循环。,12,四冲程发动机的四大行程,进气行程 intake stroke排气行程 exhaust stroke压缩行程 compression stroke做功行程 working stroke,13,Exhaust排放,Intake 进气,Compression压缩,Power/working做功,Stroke . /struk / n
5、. 打击；中风；笔画；冲程；尝试；轻抚,发动机的四大工作行程,14,水冷却式发动机Water coolet engine,水箱，通过水泵作用，水通过水道流通整个汽缸体，进行降温。,Clissfiled by cooled ways（按冷却方式分类）,15,风冷却式发动机air coolet engine,风冷，通过空气气流与风扇作用，空气/风通过发动机整个汽缸体，进行降温。,Clissfiled by number of cylinder（按气缸数量分类）,16,单缸发动机Single cylinder enginecylinder slnd n. 气缸,我只有一个气缸，一组气门；,17,多缸
6、发动机Multi cylinder enginecylinder slnd n. 气缸,我有多个气缸，多组气门；,二、发动机的基本组成,18,汽油机包含几大系统？,冷却系 cooling system润滑系 lubrication system起动系 starting system点火系 ignition system燃油供给系 fuel supply system进气系统 intake system排气系统 exhaust system,19,20,Cooling system (冷却系统),Starting system (起动系统),21,Lubrication system (润滑系统
7、),Ignition system (点火系统),22,Fuel supply system (燃油供给系统),intake system (进气系统),例句分析：,Engine system includes ：_、_、_、_. 中文：include vt.包括，包含； 译文：发动机系统包括：_、 _、_、 _。,23,ignition system,starting system,lubrication system,cooling system,点火系统,起动系统,润滑系统,冷却系统,汽油机包括哪两大系统？,24,Crank-connecting rod mechanism,曲 柄,连杆
8、,机构,配气机构,25,Valve mechanism,气 门,机 构,三、发动机的四大工作行程,26,Intake 进气,Compression压缩,Exhaust排放,Power做功,Stroke . /struk / n. 打击；中风；笔画；冲程；尝试；轻抚,27,发动机分类,一台汽车发动机往往具有3个以上的汽缸，对于汽车发动机主要的分类方式是根据汽缸的布局及排列方式来划分。一般有直列L型、V型、W型以及水平对置B型等几种。,28,直列发动机(Line Engine),29,V型排列六缸发动机(V-shape),30,W型发动机(W-shape),31,水平对置发动机(Horizonta
9、lly Opposed,四、发动机的布置形式,32,发动机前置前轮驱动,发动机前置后轮驱动,发动机后置后轮驱动,33,Engine is a self-contained power unit which converts heat energy of fuel into mechanical energy for moving the vehicle. All automobile engines, both gasoline and diesel, are classified as internal combustion engines because the combustion or
10、 burning that creates energy takes place inside the engine. In the internal combustion engine, air-fuel mixture is introduced into a closed cylinder where it is compressed and then ignited. The burning of the fuel causes a rapid rise in cylinder pressure which is converted to useful mechanical energ
11、y by the piston and crankshaft （Fig.1-1）.,Text:One.The Internal Combustion Engine,34,The majority of engines in motor vehicles today are four-stroke piston engine. These four strokes are intake stroke, compression stroke, power stroke and exhaust stroke.,35,Two. Four Strokes,1The Intake StrokeThe in
12、take stroke begins with the piston at the Top Dead Center （TDC）. The crankshaft rotates through the connecting rod, forces the piston to move downward. This downward movement of the piston creates a vacuum, a difference in pressure, in the space above the piston.,36,. Camshaft forces the intake valv
13、e open automatically at or slightly before the piston starts down. The air-fuel mixture is drawn into the cylinder. At the same time, the exhaust valve remains closed during this downward movement. This valve closure prevents the entering air-fuel charge from escaping through the exhaust port. After
14、 the piston reaches the Bottom Dead Center （BDC） of its first stroke, the cylinder is practically full of an air-fuel charge. The drawing of an air-fuel charge into the cylinder in this manner, during the downward movement of the piston, constitutes the intake stroke （Fig.1-2a,37,2The Compression St
15、rokeAfter piston reaches the BDC, the intake valve closes and the exhaust valve remains closed. The piston is beginning to move upward again, compresses the trapped air-fuel mixture that was brought in by the intake stroke. As piston reaches the TDC again during its upward travel, the compression st
16、roke of the piston is over（Fig.1-2b）.,38,3The Power StrokeNow, both valves remain closed during the power stroke. Before piston reaches the TDC on the compression stroke, the spark plug fires, igniting the compressed air-fuel mixture which produces a powerful expansion of the vapor. The combustion p
17、rocess pushes the piston down the cylinder with great force turning the crankshaft to provide the power to propel the vehicle （Fig.1-2c）.,39,4The Exhaust StrokeNear the end of the downward movement of the power stroke, the camshaft opens the exhaust valve, but the intake valve remains closed. Althou
18、gh much of the gas pressure has expended itself driving the piston downward, some pressure still remains when the exhaust valve opens. So, this remaining pressurized gas flows comparatively free from the cylinder through the passage opened by the exhaust valve.,40,Then, as the piston again moves up
19、in the cylinder, it drives any remaining gases out of the cylinder past the open exhaust valve. As the piston travels through the TDC position and starts downward again in the cylinder, a new operating cycle begins. This four strokes are continuously repeated in every cylinder as long as the engine
20、remains running （Fig.1-2d）.,41,The single-cylinder engine just described as above provides only one power stroke during every two crankshaft revolutions or delivers power only one-fourth of the time. To provide a more even and continuous flow of power, automobile have engines with four, six, eight o
21、r twelve cylinders.,Three. The Multiple-cylinder Engine,42,Four. The Classification of the Engine,For identification purposes, manufacturers classify automobile engines by their cylinder arrangement, valve arrangement, and type of cooling system.Automobile engines have their cylinders arranged in fo
22、ur distinct ways：in-line, V-shape, W-shape, or horizontally opposed （Fig.1-3）.,43,Automobile engines have their valves arranged in one of three ways：the valves in the engine block; one valve in the cylinder head and the other in the engine block; both valves in the cylinder head. Modern automotive e
23、ngines utilize the third type of valve arrangement.Manufacturers also classify engines as being either air-cooled or water-cooled.,课堂小结,需要记住的单词：发动机底盘车身电器系统汽油柴油冲程,44,EngineChassisBodyElectrical systemGasolineDieselstroke,45,46,单独的，独立的气缸曲柄连杆机构配气机构润滑系统点火系统启动系统冷却系统进气系统排气系统,47,SinglecylinderCrank-connect
24、ing rod machanismValve machanismLubrication systemIgnition systemStarting systemCooling systemIntake systemExhaust system,需要记住的句子,There are four basic components of the automobile : engine , chassis , body and electrical system .译：汽车有四个基本组成部分，发动机， 底盘，车身和电气系统。Engine system includes ： ignition system，lubrication system, cooling system, starting system.译：发动机系统包括：点火系，润滑系，冷却系，起动系。,48,布置任务,将需要记住的单词和句子记录在笔记本上；将需要记住的单词每个写3遍，1遍汉语意思；完成教材p7课后习题；预习第二节课的内容；,49,50,Thank You !,
