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

2、 internal 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

3、 fuel 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

4、 the 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 in

5、cludes 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 dow

6、n the 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 altern

7、ator 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 動力安裝internal combustion engine 內(nèi)燃機 cylinder 汽缸gasoline 汽油 spark 火ignition 點燃，點火 diesel 柴油機compression 緊縮 shaft 軸transmiss

8、ion 傳動系 sheet metal 金屬板shell 外殼 hood 發(fā)動機罩trunk deck 行李艙蓋 cargo 貨物styling 款式 assembly 總成，裝配suspension 懸掛，懸置 shock 沖擊steering 轉(zhuǎn)向，支配 brake 剎車，制動器clutch 離合器 gearbox 變速器 driveshaft 傳動軸 final drive 主減速器，后橋 differential 差速器 slow down 使慢下來，減速horn 喇叭 starter 起動機 charge 充電 alternator 交流發(fā)電機Review QuestionsList

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

10、 and power 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 p

11、lace outside 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 p

12、ressure of 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 ga

13、s to rotate 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 rig

14、ht time 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 neares

15、t to the 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

16、two liters(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 rev

17、olution 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 co

18、mplete 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

19、 vacuum, 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 c

20、ompression 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 t

21、he compressed, 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 grea

22、t force.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

23、 opens. 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, co

24、nnecting 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

25、 WORDPiston 活塞 Connecting rod 連桿Crankshaft 曲軸 Power stoke 活塞行程Expel 排出 Valve 氣閥inlet(intake) valve 進氣閥 exhaust valve 排氣閥term 術(shù)語 TDC 上止點BDC 下止點 Bore 缸徑swept volume 有效容積 engine capacity 發(fā)動機排量clearance volume 余隙容積,熄滅室容積 compression ratio 緊縮比revolution 旋轉(zhuǎn),轉(zhuǎn)數(shù) every other 每隔一個cycle 循環(huán) spread over 分布,普及int

26、ake stroke 進氣行程 compression stroke 緊縮行程knock 敲缸,敲打 exhaust stroke 排氣行程engine block 發(fā)動機缸體 lubrication 光滑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 jac

27、kets, and oil galleries. 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 ni

28、ckel or chromium. Engine 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

29、sleeves are called 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

30、 the hemi, wedge, and 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 directl

31、y into the cylinder 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 betw

32、een the block and the 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 pressur

33、es within the engine.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

34、 all working parts 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 oil gallery 油道 camshaft 凸輪軸overhead-cam(OHC) 頂置凸輪 gray

35、 iron 灰鑄鐵 alloy 合金nickel 鎳 chromium 鉻 casting 鑄件head cover 汽缸蓋罩 intake manifold 進氣總管 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 準半球形 rocker 搖臂 push-rod 推桿gasket 襯墊 high-tensile 高強度的 stud 螺栓gas-tight 密封的 asbestos 石棉 crankcase 曲軸箱，曲柄箱encase

36、封鎖，把包起來 drain off 排出，流出Review QuestionWhat do TDC, BDC, stroke, compression ratio and engine capacity stand for?How do you calculate swept volume and compression ratio?What controls the length of the stroke?List the main parts of the engine overall mechanics?What are the main function of the engine

37、block?2.3 Piston Connecting 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 t

38、urns the crankshaft .Thin, 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 th

39、e piston to the connecting 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,

40、 since it travels at high 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 par

41、t is the skirt The sections 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 diffe

42、rent shapes.2.3.3Piston RingsAs 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 som

43、etimes had four rings, or 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 comp

44、ression rings. The lower one 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 p

45、ower stoke , combustion pressure 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

46、 bottom of the ring groove. 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 connecti

47、ng rod. The top end of is 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 p

48、lace in the center of the 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 cranksh

49、aft . 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 the connecting rod fits the crankshaft journal . This is called the big end . For this big-end bearing , steel-backed lead or tin shell bear

50、ing are used . These are the 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

51、the connecting rod , coverts 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 th

52、e connecting rods .At the 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

53、 the stroke . The stroke is 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 str

54、okes it also carries the clutch , 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

55、 WordsComprise 由。組成，包含 Inter 慣性，慣量 Radius 半徑，范圍Circular 圓形的 Steel band 鋼圈 Fit into 放入，放進Groove 凹槽 Piston pin 活塞銷 Pin boss 活塞銷凸臺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 外表鍍銀的 Untwist 朝相反方向的

56、 In place 在適當位置Chrome-plated 鍍鉻的 Forge 偽造，仿造 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，分別 In conjunction with 連同 Reciprocating motion 往復運動Rotary 旋轉(zhuǎn)的 Carbon steel 碳鋼 Journal 軸頸Align with 匹配 Overlap 重疊 Timing gear 正時齒輪Throw 擺幅 Vice verse 反之亦然

57、Impulse 脈沖Space out 隔開，分隔 Through out 普及 Diagram 圖表Firing order 點火順序 Companion 成對 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 .2.4.1 Valve Operation To coordinate the four-stroke cycle , a group parts called t

58、he valve train opens and closes the valves ( moves them down and up , respectively ) . These valve movements must take place at exactly the right moments . The opening of each valve is controlled by a camshaft .1. Camshaft(OHC) Valve Train OverheadThe cam is an egg-shaped piece of metal on a shaft t

59、hat rotates in coordination with the crankshaft . The metal shaft , called the camshaft , typically has individual cams for each valve in the engine . As the camshaft rotates , the lobe , or high spot of the cam , pushes against parts connected to the stem of the valve . This action forces the valve

60、 to move downward . This action could open an inlet valve , or open an exhaust valve for an exhaust stroke . As the camshaft continues to rotate , the high spot moves away from the valve mechanism . As this occurs , valve spring pull the valve tightly closed against its opening , called the valve se