汽車構(gòu)造(英文版)

1、CHAPTER 1 AUTOMOTIVE BASICS1.1 Principal ComponentsTodays average car contains more than 15,000 separate, individual parts that must work together. These parts can grouped into four major categories: engine, body, chassis and electrical equipment.1.2 EngineThe engine acts as the power unit. The inte

2、rnal combustion engine is most common: this obtains its power by burning a liquid fuel inside the engine cylinder. There are two types of engine :gasoline(also called a spark-ignition engine) and diesel(also called a compression-ignition engine).Both engines are called heat engines; the burning fuel

3、 generates heat which causes the gas inside the cylinder to increase its pressure and supply power to rotate a shaft connected to the transmission.1.3 BodyAn automobile body is a sheet metal shell with windows, doors, a hood, and a trunk deck built into it. It provides a protective covering for the

4、engine, passengers, and cargo. The body is designed to keep passengers safe and comfortable. The body styling provides an attractive, colorful, modern appearance for the vehicle.1.4 ChassisThe chassis is an assembly of those systems that are the major operating part of a vehicle. The chassis include

5、s the transmission, suspension, steering, and brake systems.Transmission systems conveys the drive to the wheels. The main components are clutch, gearbox, driveshaft, final drive, and differential.Suspension absorbs the road shocks.Steering controls the direction of the movement.Brake slows down the

6、 vehicle.1.5 Electrical EquipmentThe electrical system supplies electricity for the ignition, horn, lights, heater, and starter. The electricity level is maintained by a charging circuit. This circuit consists of the battery, alternator (or generator). The battery stores electricity. The alternator

7、changes the engines mechanical energy into electrical energy and recharges the battery.New WordsPrincipal component 主要部件category 種類，類型body 車身chassis 底盤layout 布置power unit 動(dòng)力裝置internal combustion engine 內(nèi)燃機(jī)cylinder 汽缸gasoline 汽油spark 火花ignition 點(diǎn)燃，點(diǎn)火diesel 柴油機(jī)compression 壓縮shaft 軸transmission 傳動(dòng)系shee

8、t metal 金屬板shell 外殼hood （發(fā)動(dòng)機(jī)）罩trunk deck 行李艙蓋cargo 貨物styling 樣式assembly 總成，裝配suspension 懸掛，懸置shock 沖擊steering 轉(zhuǎn)向，操縱brake 剎車，制動(dòng)器clutch 離合器gearbox 變速器driveshaft 傳動(dòng)軸final drive 主減速器，后橋differential 差速器slow down （使）慢下來，減速horn 喇叭starter 起動(dòng)機(jī)charge 充電alternator 交流發(fā)電機(jī)Review Questions1. List the main parts of

9、 an automobile?2. What are the common types of a vehicle according to body styling?3. Which systems does a chassis include and what are the main functions of the chassis?4. Why are suspension systems used on vehicles?CHAPTER2 INTERNAL COMBUSTION ENGINE2.1 principle of operation 2.1.1 Engine and powe

10、r Engine is used to produce power. The chemical energy in fuel is converted to heat by the burning of the fuel at a controlled rate. This process is called combustion. If engine combustion occurs with the power chamber. ,the engine is called internal combustion engine. If combustion takes place outs

11、ide the cylinder, the engine is called an external combustion engine. Engine used in automobiles are internal combustion heat engines. Heat energy released in the combustion chamber raises the temperature of the combustion gases with the chamber. The increase in gas temperature causes the pressure o

12、f the gases to increase. The pressure developed within the combustion chamber is applied to the head of a piston to produce a usable mechanical force, which is then converted into useful mechanical power.2.1.2 Engine Terms Linking the piston by a connecting rod to a crankshaft causes the gas to rota

13、te the shaft through half a turn. The 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 ;an inlet valve allows the new mixture to enter at the right time

14、and an exhaust valve lets out the burnt gas after the gas has done its job. Engine terms are : 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 to the

15、 crankshaft. Stroke : the distance between BDC and TDC; stroke is controlled by the crankshaft. Bore : the internal diameter of the cylinder. Swept volume : the volume between TDC and BDC. Engine capacity : this is the swept volume of all the cylinder e.g. a four-stroke having a capacity of two lite

16、rs(2000cm) has a cylinder swept volume of 50cm. Clearance volume: the volume of the space above the piston when it is at TDC. Compression ratio = (swept vol + clearance vol)(clearance vol) Two-stroke : a power stroke every revolution of the crank. Four-stroke : a power stroke every other revolution

17、of the crank.2.1.3 The Four-stroke Spark-ignition Engine Cycle The spark-ignition engine is an internal-combustion engine with externally supplied in ignition , which converts the energy contained in the fuel to kinetic energy. The cycle of operations is spread over four piston strokes. To complete

18、the full cycle it takes two revolutions of the crankshaft.The operating strokes are : This stroke introduces a mixture of atomized gasoline and air into the cylinder. The stroke starts when the piston moves downward from a position near the top of the cylinder. As the piston moves downward, a vacuum

19、, or low-pressure area, is created. During the intake stroke, one of the ports is opened by moving the inlet valve. The exhaust valve remains tightly closed.Compression strokeAs the piston moves upward to compress the fuel mixture trapped in the cylinder, the valves are closed tightly. This compress

20、ion action heats the air/fuel mixture slightly and confines it within a small area called the combustion chamber.Power strokeJust before the piston reaches the top of its compression stroke, an electrical spark is introduced from a spark plug screwed into the cylinder head.The spark ignites the comp

21、ressed, heated mixture of fuel and air in the combustion chamber to cause rapid burning. The burning fuel produces intense heat that causes rapid expansion of the gases compressed within the cylinder. This pressure forces the piston downward. The downward stroke turns the crankshaft with great force

22、.Exhaust strokeJust before the bottom of the power stroke, the exhaust valve opens. This allows the piston, as it moves upward, to push the hot, burned gases out through the open exhaust valve.Then, just before the piston reaches its highest point, the exhaust valve closes and the inlet valve opens.

23、 As the piston reaches the highest point in the cylinder, known as TDC, it starts back down again. Thus, one cycle ends and another begins immediately.2.1.4 Engine Overall Mechanics The engine has hundreds of other parts . The major parts of engine are engine block , engine heads, pistons, connectin

24、g rods, crankshaft and valves. The other parts are joined to make systems. These systems are the fuel system, intake system, ignition system, cooling system, lubrication system and exhaust system. Each of these systems has a definite function. These systems will discussed in detail later. NEW WORDPi

25、ston 活塞Connecting rod 連桿Crankshaft 曲軸Power stoke 活塞行程Expel 排出Valve 氣閥inlet(intake) valve 進(jìn)氣閥exhaust valve 排氣閥term 術(shù)語TDC 上止點(diǎn)BDC 下止點(diǎn)Bore 缸徑swept volume 有效容積engine capacity 發(fā)動(dòng)機(jī)排量clearance volume 余隙容積,燃燒室容積compression ratio 壓縮比revolution 旋轉(zhuǎn),轉(zhuǎn)數(shù)every other 每隔一個(gè)cycle 循環(huán)spread over 分布,遍及intake stroke 進(jìn)氣行程 c

26、ompression stroke 壓縮行程knock 敲缸,敲打exhaust stroke 排氣行程engine block 發(fā)動(dòng)機(jī)缸體lubrication 潤(rùn)滑2.2 Engine Block and Cylinder Head2.2.1 Engine BlockThe 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 galle

27、ries. The engine block also holds the crankshaft, which fastens to the bottom of the block. The camshaft also fits inside the block, except on overhead-cam engines (OHC). In most cars, this block is made of gray iron, or an alloy (mixture) of gray iron and other metals, such as nickel or chromium. E

28、ngine blocks are castings.Some engine blocks, especially those in smaller cars, are made of cast aluminum. This metal is much lighter than iron. However, iron wears better than aluminum. Therefore, the cylinders in most aluminum engines are lined with iron or steel sleeves. These sleeves are called

29、cylinder sleeves. Some engine blocks are made entirely of aluminum.2.2.2 Cylinder HeadThe cylinder head 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. The most common cylinder head types are the hemi, wedge, a

30、nd semi-hemi. All three of these terms refer to the shape of the engines combustion chamber. The cylinder head carries the valves, valve springs and the rockers on the rocker shaft, this part of the valve gear being worked by the push-rods. Sometimes the camshaft is fitted directly into the cylinder

31、 head and operates on the valves without rockers. This is called an overhead camshaft arrangement. Like the cylinder block, the head is made from either cast iron or aluminum alloy.2.2.3 GasketThe cylinder head is attached to the block with high-tensile steel studs. The joint between the block and t

32、he head must be gas-tight so that none of the burning mixture can escape. This is achieved by using cylinder head gasket. This is a sandwich gasket, i.e. a sheet of asbestos between two sheets of copper, both these materials being able to withstand the high temperature and pressures within the engin

33、e.2.2.4 Oil Pan or SumpThe oil pan is usually formed of pressed steel. The oil pan and the lower part of the cylinder block together are called the crankcase; they enclose, or encase, the crankshaft. The oil pump in the lubricating system draws oil from the oil pan and sends it to all working parts

34、in the engine. The oil drains off and runs down into the pan. Thus, there is constant circulation of oil between the pan and the working parts of the engine.New Wordsengine block 缸體cylinder head 氣缸蓋fasten 使固定water jacket 水套o(hù)il gallery 油道camshaft 凸輪軸overhead-cam(OHC) 頂置凸輪gray iron 灰鑄鐵alloy 合金nickel 鎳

35、chromium 鉻casting 鑄件head cover 汽缸蓋罩intake manifold 進(jìn)氣總管distributor 分電器oil pan 油底殼aluminum 鋁be lined with 鑲有cylinder sleeve 氣缸套hemi 半球形wedge 楔型，楔入semi-hemi 準(zhǔn)半球形rocker 搖臂push-rod 推桿gasket 襯墊high-tensile 高強(qiáng)度的stud 螺栓gas-tight 密封的asbestos 石棉crankcase 曲軸箱，曲柄箱encase 封閉，把包起來drain off 排出，流出Review Question1.

36、What do TDC, BDC, stroke, compression ratio and engine capacity stand for?2. How do you calculate swept volume and compression ratio?3. What controls the length of the stroke?4. List the main parts of the engine overall mechanics?5. What are the main function of the engine block?2.3 Piston Connectin

37、g Rod and Crankshaft2.3.1 Piston Assembly The piston is an important part of a four-stroke cycle engine. Most pistons are made from cast aluminum. The piston , through the connecting rod, transfers to the crankshaft the force create by the burning fuel mixture. This force turns the crankshaft .Thin,

38、 circular , steel bands fit into grooves around the piston to seal the bottom of the combustion chamber. These bands are called piston rings. The grooves into which they fit are called ring grooves. A piston pin fits into a round hole in the piston . The piston pin joins the piston to the connecting

39、 rod . The thick part of the piston that holds the piston is the pin boss.The piston itself , its rings and the piston pin are together called the piston assembly. 2.3.2.PistonTo withstand the heat of the combustion chamber, the piston must be strong. It also must be light, since it travels at high

40、speeds as it moves up and down inside the cylinder. The piston is hollow. It is thick at the top where it take the brunt of the heat and the expansion force. It is thin at the bottom, where there is less heat. The top part of the piston is the head , or crown . The thin part is the skirt The section

41、s between the ring grooves are called ring lands.The piston crown may be flat , concave ,dome or recessed . In diesel engine , the combustion chamber may be formed totally or in part in the piston crown , depending on the method of injection . So they use pistons with different shapes.2.3.3Piston Ri

42、ngsAs Fig.2-9 shows , piston rings fit into ring grooves near the of the piston. In simplest terms, piston rings are thin, circular pieces of metal that fit into grooves in the tops of the pistons. In modern engines ,each piston has three rings. (Piston in older engines sometimes had four rings, or

43、even five.) The rings outside surface presses against the cylinder walls. Rings provide the needed seal between the piston and the cylinder walls. That is, only the rings contact the cylinder walls. The top two rings are to keep the gases in the cylinder and are called compression rings. The lower o

44、ne prevents the oil splashed onto the cylinder bore from entering the combustion chamber , and is called an oil ring. Chrome-face cast-iron compression rings are commonly used in automobile engines. The chrome face provide a very smooth , wear-resistant surface.During the power stoke , combustion pr

45、essure on the combustion rings is very high. It causes them to untwist . Some of the high-pressure gas gets in back of the rings. This force the ring face into full contact with the cylinder wall. The combustion pressure also holds the bottom of the ring tightly against the bottom of the ring groove

46、. Therefore , high combustion pressure causes a tighter seal between the ring face and the cylinder wall.2.3.4 Piston Pin The piston pin holds together the piston and the connecting rod . This pin fits into the piston pin holes and into a hole in the top end of the connecting rod. The top end of is

47、much smaller than the end that fits on the crankshaft . This small end fits inside the bottom of the piston . The piston pin fits through one side of the piston , through the small end of the rod , and then through the other side of the piston . It holds the rod firmly in place in the center of the

48、piston. Pins are made of high-strengh steel and have a hollow center . Many pins are chrome-plated to help them wear better.2.3.3 Connecting rod The connecting rod is made of forged high-strength steel . It transmits and motion from the piston to the crankpin on the crankshaft . The connecting rod l

49、ittle 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 the connecting rod fits the crankshaft journal . This is called the big end . For this big-end bearing , steel-backed lead or tin shell bearing are used . These are t

50、he same as those used for the main bearings . The split of the big end is sometimes at an angle , so that it is small enough to be withdrawn through the cylinder bore . The connecting rod is made from forged alloy steel .2.3.5 CrankshaftThe crankshaft , in conjunction with the connecting rod , cover

51、ts the reciprocating motion of the piston to the rotary motion needed to drive the vehicle . It is usually made from carbon steel which is alloyed with a small proportion of nickel .The main bearing journals fit into the cylinder block and the big end journals align with the connecting rods .At the

52、rear end of the crankshaft is attached the flywheel , and at the front end are the driving whells for the timing gears , fan , cooling water and alternator . The throw of the crankshaft , the distance between the main journal and the big end centers , controls the length of the stroke . The stroke i

53、s double the throw , and the stroke-length is the distance that the piston travels from TDC to BDC and vice versa .2.3.6 Flywheel The flywheel is the made from carbon steel . It fit s onto the rear of the crankshaft . As well as keeping the engine rotating between power strokes it also carries the c

54、lutch , which transmits the drive to the transmission , and has the starter ring gear around its circumference . There is only one working stroke in four so a flywheel is needed to drive the crankshaft during the time that the engine is performing the non-power strokes .New WordsComprise 由。組成，包含Inte

55、r 慣性，慣量Radius 半徑，范圍Circular 圓形的Steel band 鋼圈Fit into 放入，放進(jìn)Groove 凹槽Piston pin 活塞銷Pin boss 活塞銷凸臺(tái)Withstand 抵抗Hollow 空的Brunt 沖力Crown 活塞頂Skirt 裙部Ring land 環(huán)帶Concave 凹的，凹入的Dome 圓頂Recessed 隱蔽的Cylinder wall 氣缸壁Cylinder bore 缸筒Splash 飛濺chrome-face 表面鍍銀的Untwist 朝相反方向的In place 在適當(dāng)位置Chrome-plated 鍍鉻的Forge 偽造，仿

56、造Crankpin 曲軸銷Bush 軸瓦，套筒Bronze 青銅Crankshaft journal 曲軸軸頸Steel-backed 鋼背的Lead 鉛Tin 錫Splint 切口，中斷，分配，分離In conjunction with 連同Reciprocating motion 往復(fù)運(yùn)動(dòng)Rotary 旋轉(zhuǎn)的Carbon steel 碳鋼Journal 軸頸Align with 匹配Overlap 重疊Timing gear 正時(shí)齒輪Throw 擺幅Vice verse 反之亦然Impulse 脈沖Space out 隔開，分隔Through out 遍及Diagram 圖表Firing order 點(diǎn)火順序Companion 成對(duì)Circumference 圓周2.4 Valve System The valve system is made up of those parts needed to open and close the valves at just the right time