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1、chapter 1 automotive basics(汽车基础)(1) today s average car contains more than 15,000 separate, individual parts that must work together. these parts can be grouped into four major categories: body, engine, chassis and electrical equipment。当今的车辆一般都由15000多个分散、独立且相互配合的零部件组成。这些零 部件主要分为四类:车身、发动机、底盘和电气设备。1.
2、1 body (车身)(2) the body is designed to keep passengers safe and comfortable. thebody styling provides an attractive, colorful, modern appearance for the vehicle.车身的设计要保证乘客安全舒适。车身的款式使得汽车看起来漂亮迷人、色彩斑斓、时尚前卫。1.2 engine (发动机)(3)the internal combustion engine is most common:this obtains 让s power by burning
3、 a liquid fuel inside the engine cylinder. there are two types of engine: gasoline and diesel . both engines are called heat engines;the burning 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 .内燃机
4、是最常见的,其动力来自气缸里液体燃料的燃烧。 发动机有汽油机和柴油 机两种,都称为热机燃料燃烧产生热量, 使得气缸内气体压力升高,从而提供动 力,带动连接变速器的轴旋转.1.3 chassis (底盘)1.3.3 suspension(悬架)(4) the purpose of the complete suspension system is to isolate thevehicle body from road shocks and vibrations, which will otherwise be transferred to the passengers and load. it
5、 must also keep the tires in contact with the road regardless of road surface.整个悬架系统的作用是隔离来自路的冲击和振动对车身的影响,防止它们传递给 乘客和货物。另外不论路面如何,悬架系统都应该保持轮胎和路的接触。1.3.4 braking (制动)(5) drumbrakes have a drum attached to the wheel hub, and braking occurs by means of brake shoes expanding against the inside of the dru
6、m. withdisc brakes, a disc attached to the wheel hub is clenched between two brake pads.在鼓式制动器上,制动鼓和轮毂连接,制动蹄张开压紧制动鼓内侧从而产生制动。 在盘式制动器上、连着轮毂的制动盘,被紧紧夹在两个制动块之间。1.4 electrical system(电气系统)(6) the electrical system supplies electricity for the starter, ignition, lights and heater. the electricity level is
7、maintained by a charging circuit.电器系统为起动机、点火系、照明和加热设备提供电流。电流的大小由充电电路来维持。chapter 2 internal combustion engine(内燃机)2.1.2 engine terms(发动机条款)2) linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn. the power stroke "uses up” the gas, so mean
8、s 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;活塞通过连杆和轴连接, 使得气体带动轴旋转半圈。作功冲程耗尽了所有的气体,样就必须采取相应的措 施排出废气以及向气缸内再充入新鲜的可燃混合气:气体的运动由气门来控。2.2.1 engine block(发动机缸体)1) the engine block is the basic fram
9、e of the engine. all other engineparts either fit inside it or fasten to it. it holds the cylinders, water jackets, and oil galleries. the engine block also holds the crankshaft, which fastens to the bottom of the block.缸体是发动机的基体。发动机具它的部件都安装或固定在缸体上,包括气缸、水套和油道,以及固定在缸体底部的曲轴等。2.2.2 cylinder sleeves (气缸
10、套)2) cylinder sleeves are used in engine blocks to provide a hard wearing material for pistons and piston rings. the block can be made of one kind of iron that is light and easy to cast while the sleeves uses another that is better able to stand up wear and tear. there are two main types of sleeves:
11、 dry and wet.缸体中的气缸套为活塞和活塞环提供了一种坚硬耐磨的 材料。缸体可以采用某种重量轻且易铸造的铁来制造,而缸套使用的却是另一种 更加耐磨损的材料成。主要有两种类型的气缸套:干缸套和湿缸套。2.2.3 cylinder head(缸盖)3) the 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. in-line engine
12、s of light vehicles have just one cylinder head for all cylinders; larger in-line engines can have two or more.气缸盖安装在缸体的顶部,就像安在房子上的屋顶一样。缸盖的下方和活塞顶部形成燃烧室。轻型车上使用的直列发动机,所有气缸仅有一个气缸盖,较大的直 列发动机有两个或更多缸盖。2.2.5 oil pan or sump (油盘或油底盖)4) the oil pump in the lubricating system draws oil from the oil pan and se
13、nds it to all working parts in the engine. the oil drains off and runs downinto the pan. thus, there is constant circulation of oil between the pan and the working pats 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就有机油定向循环流动。2.3.2 piston assembly(活塞总成)1) most pistons
14、are madefrom 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.大多数活塞由专吕铸造而成。通过连杆的作用,活塞把可燃混合气燃烧产生的力传递给曲轴, 带动曲轴旋转。2) in diesel engines, the combustion chamber may be formed totally。门n part i
15、n the piston crown, depending on method of injection. 柴油机发动机根据喷油方法不同, 活塞头部可以形成全部燃烧室, 也可以是燃烧不" 一部分.3 ) piston rings (活塞环)in modern engines, each piston has three rings. (piston in older engines gas rings sometimes had four rings, or even five.) the inside surface of the ring fits in the groove o
16、n the piston. the ring's 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,每个活塞有四个甚至五个活塞环)环的内侧装 在活塞的环槽里,环的外表面紧压在气缸壁上。4) 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 o
17、f the connecting rod fit the crankshaft journal. this is called the big end.连杆小头与活塞销连接,连接处有像青铜这样软金属制成 的衬套,连杆下端连接在曲柄轴径上,称为连杆大头。5) n.b. no.4 piston is always performing the companion stroke to no.1: when the inlet valve inno.4 cylinder is fully open, no.1cylinder inletvalve is fully closed - this feat
18、ure is useful toremember whenchecking valve clearances. 注意4号活塞和1号活塞总是成对运行:1号气缸 进气门全闭时,4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。6) as each cylinder fires, it causes the crank throw to speed up. the inertia of the rest of shaft causeit to stay slightly behind, resultingin a twisting action on the crankshaft.当一气缸点火时
19、,使拐的转速提高,而轴的其它部分由于惯性作用,有所滞后,从而导致曲轴扭转。2.5: valve system (气门系统)1 ) it is apparent from this description that the exhaust valve stays open for a short period of time during which the intake valve is also open. in other words, the end of the exhaust stroke and the beginning of the intake stoke overlap f
20、or a short period of time. this is called valve overlap. valve timing and valve overlap vary on different engines.由上显而易见,排气门在进气门打开的一小段时间内也打开着。换句话说, 排气冲程终了和进气冲程初期有一小段时间的重叠,这称为气门重叠。不同的发 动机,其配气正时和气门重叠是不一样的。2 ) each cam must revolve once during the four-stroke cycle to opena valve. a cycle, remember, co
21、rresponds with two revolutions of the crankshaft. therefore, the camshaft must revolve at exactly half the speed of the crankshaft. this is accomplished with a 2:1 gear ratio. a gear connected to the camshaft has twice the number of teeth as a gear connected to the crankshaft.在一个四冲程的循环里,每个凸轮转动一次来打开一
22、个气门。在一个循环里曲轴是转动两圈的。因此,凸轮轴必须以曲轴转速的一半旋转,这是由2:1的传动比来实现的。连接凸轮轴的齿轮齿数是连接曲轴的齿轮齿数的2倍。2.6 gasoline fuel system(汽油燃烧系统)1) gasoline must vaporize easily. this characteristic, called volatility, is important. however, it must not vaporize too easily, or it will turn to vapor inside the fuel tank or fuel lines.
23、inside the fuel line, fuel vapor may block the flow of liquid gasoline. this is called vapor lock. vapor lock is common in fuel lines where the inlet side of the pump is exposed to high temperatures.汽油容易蒸发,这个重要的特性称为挥发性。但是汽油也不能挥发得过快, 不然它会在油箱或油管里转变为蒸气。在油管中油蒸气会阻碍液态油的流动,这 称为气阻。汽油泵的入口处易受高温,就经常出现气阻。2) inc
24、reasing the pressure of the fuel mixture in the combustionchamber before ignition helps to increase the power of an engine. thisis done by compressing the fuel mixture to a smaller volume. highercompression ratios not only boost power but also give more efficient power. but as the compression ratio
25、goes up, knocking tendency increases.在点火前增加燃烧室内可燃混合气的压力有助于提高发动机的功率,这是通过把可燃混合气压缩到一个极小的体积来实现的。高的压缩比不仅可以增加功 率,而且会带来更多的有功率。但随着压缩比的增加,爆震的可能性也会增加。3 ) fuel pump: most cars today have a mechanical fuel pump. this pumps fuel out of the tank and through the fuel lines to the carburetor or injection system. in
26、 most cars, the pump is mounted on the engine block. some cars have an electric fuel pump. this pump mounts in the fuel tank with the fuel pickup and the fuel-gauge-sending unit.当前大多数车采用机械油泵,油泵从油箱抽出油,通过油管送到化油器或喷 射系统。大部分车的油泵安装在缸体上。一些车采用电动油泵,油泵安装在油箱 上,附带有油量传感器和燃油表油量传送装置。4 ) a carburetor delivers fuel
27、in proportion to the amount of airflowing through it. as you press on the accelerator pedal, the throttle valve opens wider to draw more air through the carburetor the carburetor provides richer or leaner mixtures, depending on a number of factors: engine speed, load, temperature, and throttle posit
28、ion. to meet complicated demands, a carburetor is a highly intricate device, with many internal passages and parts.化油器输送的燃油与流经化油器的空气量成一定比例。踩下加速踏板、节气 门开度变大,化油器吸入的空气增加。化油器可提供较浓或较稀的混合气,这取决于发动机转速、负荷、温度和油门开度等因素。为满足复杂的要求,化油器的 结构也很复杂,其上有很多内部通道和部件。5 ) the throttle mechanismcontrols the flow of the air- fuel
29、 mixture. the throttle has several parts, including the throttle shaft and the throttle plate. by opening and closing, the throttle plate controls the flow of the air-fuel mixture into the engine. more air flows in as the plate opens; less air flows in as the plate closes.节气门机构捽制着可燃混合气的流量:包括节气门轴和节气门
30、等部件。 节气门的开启和关闭控制着进入发动机的可燃混合气流量。节气门开启,空气流量增 加;节气门关闭,空气流量减少。2.7 diesel engine(柴油机)1 ) diesel engine gets this namefrom the pioneer work done by dr rudolf diesel. the diesel is used for the majohty of heavy vehicles and the excellent fuel economy makes it an attractive alternative to the petrol engine
31、for light commercial vehicles, delivery vans and taxis.柴油发动机的名称来源于 rudolf diesel博士所完成的开拓性工作。大多数 重型车辆使用柴油,优良的燃油经济性使得柴油机成为具有吸引力的替代品,来代替轻型商用车、厢式运输货车和出租车上汽油机。2 ) at exhaust-gas turbo-charging, the exhaust-gas energy which would have been lost is used to drive a turbine. this turbine drives a compressor
32、which aspirates the combustion air and supplies it pre-compressed to the engine. in this way, more fuel can be supplied to the larger air mass and the engine power is increased. a positive effect is also exerted on the combustion process.在废气涡轮增压中,原本要丧失的废气能量用来驱动涡轮,涡轮驱动压缩机,压缩机吸入助燃空气,预压缩后送给发动机。这样,空气量多,
33、供油也多,发动 机功率就会增加,对燃烧过程也会带来积极作用。2.8.2 thermostat circulation(温控器循环)1 ) when the engine is cool, the thermostat remains closed so that coolant cannot circulate through the radiator. instead,coolant isrecirculated within the engine block and cylinder head untilthe coolantreaches a predetermined temperat
34、ure. at that temperature a wax-like pellet expands inside the thermostat to open it and allow the coolant to flow. today, most original-equipment thermostats open at approximately 85oc to 900c. in hotter climates, a "cooler " thermostat maybe used to help avoid overheating.当发动机温度较低时,节温器保持关
35、闭,冷却水不能流通散热器进行循环, 而是在发动机缸体和缸盖之间循环流动,一直到冷却水达到预定的温度为止。在 该温度下,节温器中的蜡芯膨胀,从而打开节温器,使得循环水流经节温器。目 前,多数原装节温器的开启温度大约在8590oc气温较高时,可采用低温节温器防止发动机过热。2 ) the purpose of the lubrication system is to circulate oil through the engine. an engine must have a good lubrication system. without it, the friction heat from t
36、he contact of the moving parts would wear the parts and cause power loss.oil, whenplaced between two moving parts, separates them with a film. this oil film prevents the parts from rubbing against each other. this oil film also cushions the parts, giving quieter and smoother engine operation.润滑系统的作用
37、是使机油在发动机里循环流动。j动机必须要有良好的润滑 系统,不然移动部件相互接触摩擦而产生的热量 磨损发动机部件,并损失发动 机功率。机油位于两个移动部件之间,通过油膜隔开两部件。油膜防止部件之间 的相互摩擦。它垫在部件之间,使得发动机工作安静、平稳可靠。3 ) three types of harmful emission (hc, co, nox): there are manycausesfor emissions. some emissions are caused by poor air quality. otheremissions are caused by engine fue
38、ls, such as diesel fuel or gasoline.these are hydrocarbon fuels, made up primarily of hydrogen and carbon. emissions are colorless and odorless. sunlight, though, will transform them into smog.产生排放的原因有很多,一部分排放物是由于空气质量差引起的,另一部分是由柴油或汽油等发动机燃料产生的。这些碳氢化合物燃料主要由碳和氢两种元素组成。这些排放物是无色无味的,在阳光的作用下转变为烟雾。2.10 emiss
39、ion control(排放控制装置)1) exhaust-gas recirculation is a method of reducing emissions ofoxides of nitrogen that has been known and applied for years. in itsessential components, engine exhaust is an inert gas, i.e. a non-combustible gas.废气再循环可降低氮氧化合物的排放,这种技术早已为人所知并应用多年。 发动机废气的基本成分是一种惰性气体,也就是一种不易燃烧的气体。ch
40、apter 3 power tra n 动系统)1) when a vehicle is to be moved from rest the clutch must engage a stationary gearbox shaft with the engine; this must be rotating at a high speed to provide sufficient power or else the 10ad will be too great and the engine will stall (come to rest).当汽车原地起步时,离合器要将静止的变速器轴同发动
41、机接合起来,此时发动机必须高速旋转以提供足够大的功率,否则载荷过大将引起发动机熄火。2) the driving member(主动部分)the driving member consists of two parts: the flywheel and the pressure plate. the flywheel is bolted directly to the engine crankshaft and rotates when the crankshaft turns. the pressure plate is bolted to the flywheel. the result
42、 is that both flywheel and pressure plate rotate together. (p74)主动部分由飞轮和压盘两部件组成。飞轮用螺栓直接连接到发动机曲轴上, 随曲轴旋转而旋转。压盘与飞轮连接,这样飞轮和压盘一起旋转。3) the driven member(从动部分)the driven member, or clutch disc, is located between the flywheeland pressure plate. the disc has a splined hub that locks to the splined input sh
43、aft on the gearbox. any rotation of the clutch disc turns the input shaft.从动部分(或从动盘)位于飞轮和压盘之间。从动盘上有花键毂、连接着变 速器上花键的输入轴。从动盘的旋转动变速器输入轴随之转动。4) operating members(操纵机构)these are the parts that release pressure from the clutch disc. the operating members consist of the clutch pedal, clutch return spring,cl
44、utch linkage, clutch fork, and throwout bearing. the clutch linkage includes the clutch pedal and a mechanical or hydraulic system to move the other operating members.操纵机构释放离合器盘的压力。操纵机构由离合器踏板、回位弹簧、离合器杆系、分离叉和分离轴承等组成。离合器杆系包括离合器踏板以及用来移动其它 操纵部件的机械或液压操纵系统。5) 4 universal joints (uj 万向节)1) the suspension c
45、onnects the final drive assembly to the car body. thefinal drive movesup and downin relation to the engine and transmission. a coupling is needed that permits movement between the final drive and transmission. the universal joints provide this coupling.悬架连接着主减速器(后桥)总成和车身。主减速器相对于发动机和变速器上 下运动,这样在主减速器和
46、变速器之间就需要万向节这种连接装置来允许其相 对运动。2 ) a shaft which receives the drive from a cross type joint varies its speed during rotation; the greater the drive angle the greater the speed variation. a constant rotational speed can be restored by fitting a second joint in a way such that when the first joint increas
47、es its speed the second joint decreases its speed.传动轴接收十字轴式万向节传来的动力,转动时其速度发生变化。传动角越 大,速度变化越大。要实现等速,必须以某种方式安装第二个万向节,这样第一 个万向节使转速增大,第二个万向节就使转速减少。3 ) planetary gears are used mainly in final drives, rear- mountedsplitter boxes and, above all, in automatic transmissions. the simplest form of planetary g
48、ear (the planetary-gear train) consists of sun gear, ring gear and arm with planet gears. each of the three elements may act as drive, output or may be at rest. therefore, great variation is possible as regards the transmission ratio, ranging as far as a reversal of the direction of rotation. the pa
49、rallel meshing of several gears under load permits a compact construction.行星齿轮系主要应用在主减速器、后置副变速器和自动变速器上。最简单的 行星齿轮系统由太阳轮、齿圈和行星轮组成。三部件中任意一个都可作输、 输出 或保持静止。这样,依照变速比的不同可得到较大的变速范围, 汽车的倒行也能 实。承载齿轮的平行啮合使行星轮系结构较紧凑。4 ) whena vehicle is cornered the inner wheel moves through a shorter distance than the outer wh
50、eel. this means that the inner wheel must slow downand the outer wheel must speed up. during this period it is desirable that each driving wheel maintains its driving action. the differential performs these two tasks.当汽车转弯时,内侧车轮比外侧车轮行驶的距离要短,这说明内侧车轮比外侧车轮转得要慢。在此期间,维持每个驱动车轮的行驶状态是很重要的。这两个任务由差速器来完成另:重点词句
51、重点词语i.power train: 传动系统 2.suspension: 悬架 3.cylinder: 气缸 4.transmission:变速器 5.gasoline: 汽油机 6.final drive:主减速器,后桥 7.leaf spring: 钢板弹簧 8.piston:活塞9.tdc:上止点10.lubrication:润滑 11.muffler: 消声器 12.planetary gear:行星齿轮13.disc brake:盘式制动器 14.venting system:通风系统 15.hybrid: 混合动力重点句子1 gasoline and diesel are cal
52、led heat engines, the burning fuel generates heat which causes the gas inside the cylinder to increase its pressure and supply power to rotate a shaft connected to the power train.汽油机和柴油机被称为热机,车用燃料产生热量使得气缸里的气体压力升高,为传动系统的曲轴提供动力。2 an automatic transmission performs similar functions to a manual transm
53、ission except that gear selection is controlled either htdraulically or electronically.自动变速器选择档位由液压或者电控方式控制,其余方面,自动变速器和手动变速器的功能类似。3 the purpose of the complete suspension system is to isolate the vehicle body from road shocks and vibrations, which will otherwise be transferredto the passengers and l
54、oad. 悬架系统的功能是隔离、缓减路面冲击和振动避免传递到车身 , 影响乘客和货物的舒适性和安全性。4 all vehicles must fitted with at least 2 independent brake systems.they were once called the service brake and the emergency brake. 所有汽 车都必须配备两套独立的制动系统,即行车制动和紧急制动。5 the pressure developed within the combustion chamber is applied to the head of a p
55、iston to produce a usable mechanical force.燃烧室内的压力作用在活塞顶部产生有用的机械功。6 the valve system is made up of those parts needed to open and closethe valves at just the right time.气门系统由那些在正确时间开启和关闭气门的零部件组成。7 the burned gases removed from the combustion chamber contain such harmful emissions as hydrocarbons,carbon monoxide and nitrous oxides.从燃烧室里排除的
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