《汽车工程专业英语》复习重点.doc

Todays 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 layoutThe body is designed to keep passengers safe and comfortable. The body styling provides an attractive, colorful, modern appearance for the vehicle.1.1汽车车身的设计还应该保证乘员的安全舒适。车身的造型（款式）使得汽车看起来漂亮迷人、色彩斑斓、时尚前卫。The engine acts as the power unit. The 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 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.1.2发动机作为动力设备，常见的类型是内燃机，其原理是通过发动机缸内的液体燃料燃烧而产生能量。发动机可分为两类：汽油机（点燃式）和柴油机（压燃式），都属于热力发动机。燃料燃烧产生热量使缸内气压上升，产生的能量驱动轴旋转，并传递给动力传动系。The chassis includes the power train, steering, suspension, and braking systems.1.3Power train system: conveys the drive to the wheelsSteering system: controls the direction of movementSuspension and wheels absorb the road shocksBraking slows down the vehicleThe purpose of the complete suspension system is to isolate the vehicle body from road shocks and vibrations, which will otherwise be transferred to the passengers and load. It must also keep the tires in contact with the road regardless of road surface. A basic suspension system consists of springs, axles, shock absorbers, arms, rods and ball joints.1.3.3整个悬架系统的作用是隔离来自路面的冲击和振动对车身的影响，防止传递给乘员和货物。另外不论路面如何，悬架系统都应该保持轮胎和路面接触。悬架系统的基本组成包括弹性元件、车桥、减震器、杆系（臂、杆）和球副组成的导向机构。Drum brakes have a drum attached to the wheel hub, and braking occurs by means of brake shoes expanding against the inside of the drum. With disc brakes, a disc attached to the wheel hub is clenched between two brake pads. 1.3.4鼓式制动器的制动鼓和轮毂连接，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。Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn.2.1.2活塞通过连杆和曲轴连接，使得气体带动曲轴旋转半圈。When a vehicle is to be moved from restthe clutch must engage a stationarygearbox shaft with the engine; this must be rotating at a high speed to provide sufficient power or else the load will be too great and the engine will stall(come to rest).3.2.1当汽车原地起步时，离合器要将静止的变速器轴同发动机接合起来，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。The driving member:The driving memberconsists of two parts: the flywheel and the pressure plate. The flywheel is bolteddirectly to the engine crankshaftand rotates when the crankshaft turns. The pressure plate is bolted to the flywheel. The result is that both flywheel and pressure plate rotate together. 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。The driven member:The driven member, or clutch disc, is located between the flywheel and pressure plate. The disc has a splinedhubthat locks to the splined input shaft 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，连接着变速器上带花键的输入轴。从动盘的旋转带动变速器输入轴随之转动。The driven member:The inner part of the clutch disc, called the hub flange, has a number of small coil springs. These springs are called torsional springs. They let the middle part of the clutch disc turn slightly on the hub. Thus, the springs absorb the torsional vibrationsof the crankshaft. When the springs have compressed completely, the clutch moves back until the springs relax. In other words, the clutch absorbs these engine vibrations, preventing the vibrations from going through the drive train. 当从动盘的内侧（毂缘）有一些叫作扭转弹簧的小螺旋弹簧，这些弹簧使得从动盘中部相对从动盘毂能有轻微转动，从而吸收曲轴的扭转振动。压紧弹簧完全压缩时，离合器向后移动直到弹簧开始伸张为止。也就是说，离合器吸收发动机的振动，防止振动传递给传动系。operating members :These are the parts that release pressure from the clutch disc. The operating membersconsist of the clutch pedal, clutch return spring, clutch linkage, clutch fork, and throwout bearing. The clutch linkage includes the clutch pedal and a mechanicalor hydraulicsystem 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操纵其它部件的机械式或液压式操纵系统。operating members : When the clutch pedal is depressed, the clutch linkage operates the clutch fork. The clutch fork, or release fork, moves the throwout bearingagainst the pressure plate release levers. These levers then compress springs that normally hold the clutch disc tightly against the flywheel. 踩下离合器踏板，离合器杆系操纵分离叉。分离叉带动分离轴承压向压盘上的分离杠杆，分离杠杆压缩压紧弹簧。通常情况下，压紧弹簧使从动盘和飞轮紧密接合。operating members : When the clutch pedal is released, the pressure plate forces the clutch disc against the flywheel. The clutch return springhelps raise the pedal. 释放离合器踏板，压盘使从动盘同飞轮接合，回位弹簧使离合器踏板抬起。There are three types of manual transmissions-Sliding-mesh Transmission、Constant-mesh Transmission、Synchro-mesh Transimission。3.3.1In the case of a sliding-mesh gearbox, gear changing demands skill if noise is to be avoided. Crashing (or clashing) of the gears as the result of a bad change suggests the reason why this type is often called a crash type gearbox. 3.3.1.1对滑动啮合变速器来说，换挡时要避免噪声是需要技巧的。齿轮打齿是由换挡不当引起的，这也是滑动啮合变速器经常被称为“碰撞”型变速器的原因。MT:Manual TransmissionAMT:Automatic Mannually TransmissionsCVT:Continuously Variable TransmissionsAT:Automatic TransmissionThe suspension connects the final drive assembly to the car body. The final drive moves up and down in relation to the engine and transmission. A coupling is neededthat permits movement between the final drive and transmission. The universal joints (U-joints)and sliding jointsFig.3-8 provide this coupling. 3.4.2悬架连接着主减速器总成和车身。主减速器相对于发动机和变速器上下运动，这样在主减速器和变速器之间就需要万向节和滑动联轴节等连接装置来允许其相对运动。There are two types of universal joints -cross type joint and constant-velocity universal joint.Here two U-shaped pieces are placed perpendicularto one another and joined with a simple crossFig. 3-16. The U-shaped pieces are called yokes. The cross that connects them is called a spider. The arms that extend from the spider are called trunnions. The two yokes are at a 90angle to one another. Most cars have two universal joints, one at each end of the propeller shaft. 两个U形片垂直布置，通过十字叉连接在一起。U形片称为万向节叉，连接万向节叉的十字叉叫作十字轴，从十字轴延伸出的臂叫作耳轴，两个万向节叉成90布置。多数汽车采用两个万向节，在传动轴的每一端各有一个万向节。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 increases 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。Large crown wheelsreduce the ground clearanceunder the differential. In the case of pinion axlesand planetaryhub reduction axles, the differential and the half-shaftscan be made smaller by splitting the reduction. This makes it possible, even in the case of high power outputs, to achieve sufficient ground clearance of the vehicle.从动锥齿轮尺寸大，就降低了汽车的离地间隙。如果采用圆柱齿轮式和行星齿轮式轮边减速器，通过两级减速的形式可极大减小差速器和半轴的尺寸。这样，汽车就可以获得足够大的离地间隙， 即使输出功率要求较大也可以。Planetary gears are used mainly in final drives, rear-mounted splitter boxesand, above all, in automatic transmissions. The simplest form of planetary gear (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 parallel 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入、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，汽车的倒行也能实现。承载齿轮的平行啮合使行星轮系结构较紧凑。When a vehicle is cornered the inner wheel moves through a shorter distance than the outer wheel. This means that the inner wheel must slow down and 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.3.6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。When the vehicle is travelling straight, the lever will divide the driving force equally and both discs will move the same amount.When the vehicle corners, the driving force will still be divided equally but the inner disc will now move through a smaller distance; this will cause the lever to pivotabout its center which will prize forward the outer disc to give it a greater movement. This action shows that the torque applied to each driving wheel is always equal - hence the differential is sometimes called a torque equalizer.汽车直行时，杠杆平均分配驱动力，两个圆盘移动相同的距离。汽车转弯时驱动力仍然会平均分配，但是内侧圆盘移动的距离要小一些，这使得杠杆绕中心转动，推动外侧圆盘使之移动更大的距离。这个过程表明扭矩总是平均分配给每个驱动轮，因此差速器有时也叫做扭矩平衡装置。Energy is required when a vehicle is accelerated from restto a certain speed. A proportion of that energy is now stored in the vehicle and is called kinetic energy. In order to reduce the speed of the vehicle, the brakes have to convert the kinetic energy to heat energy; the speed of conversion governs the rate at which the vehicle slows down.4.1汽车从原地起步加速到某一速度需要能量。储存在汽车中的那部分能量称为动能。要降低车速,制动器必须把汽车的动能转换为热能；转换的速度决定了汽车减速的快慢。A braking system consists of an energy supplying device, a control device, a transmission device and the brake. The three types of braking systems are in use today: service braking system, parking braking system and additional retarding-braking system. 目前使用的制动系统有三种类型：行车制动系，住车制动系和辅助制动系Two types of brakes are used in modern cars:drum brakes and disc brakes.目前使用的制动器有两种类型：鼓式制动器和盘式制动器Two types of hydraulic brake systems are used.1、The manual brake system is the simples. 2、The power brake system.Exposed to the air, disc brakes radiate the heat to the air better than drum brakes: This means that the brake can be operated continuously for a longer period, i.e. they have a greater resistance to fade (fall-off in brake efficiency due to heat).4.2.2由于暴露于空气中，盘式制动器的散热效果比鼓式的要好：这意味着盘式制动器能持续使用更长的时间，也就是说其抗热衰退性（因受热导致制动效能下降）要好得多。Disc brakes as used in most passenger cars are slowly beginning to be used in commercial vehicles as well. Aside from their use in fast coaches, current use of disc brakes in commercial vehicles is primarily limited to front-axle brakes for commercial vehicles up to a weight of approx. 7.5 t which are driven in a manner similar to passenger cars.常用在许多乘用车上的盘式制动器正逐渐被用于商用车. 它们除用于快速客车外, 目前盘式制动器在商用车上的用途基本限制在前轴制动, 因为商用车重量约等于7.5吨时驱动方式与乘用车相似.There are two main ways of building automobiles -They are built using body/frame construction and unitized body construction.A separate framemust be light yet strong enough to resist the various loads and road forces. Commercial vehicles normally use a separate steel frame to provide the rigidityneeded to support the various loads. The two long side membersof channel section are rivetedto a number of cross membersto give a low weight frame which offers great resistance to bending, twisting. 4.9分离式车架必须足够轻巧而且结实，以承受变化的载荷和路面作用力。商用车通常使用分离式钢质车架，以获得较好的刚度来承受变化的载荷。两根槽形的长纵梁铆接着很多横梁，这使车架重量较轻，具有较好的抗弯和抗扭能力。Most cars use a unitized body construction, a combined body and frame. Unitized body construction is lighter than body/frame construction, but noisier. Rubber mounts are used between the body section and mechanical parts to absorb vibrations. The floor panis made of sections that support the rear suspension and the transmission.多数轿车采用承载式车身，也就是车身和车架融为一体。承载式车身比非承载式车身质量轻，但噪声大。在车身和机械部件之间安装橡胶块以吸收振动。地板由一些支撑后悬架和变速器的部件组成。The purpose of venting systemsis to draw in fresh air and remove stale airfrom the interior of the car. Fresh air venting systems direct air to two different places. First, they can direct outside air into the heater housing. This air either can bypass the coil or it can be heated by the coil. Second, the air can move directly into the passenger compartment through small vent doorsin the dash panelor at floor level. Venting also can take place by opening the windows.通风系统吸入新鲜的空气，排除车内不新鲜的空气。通风系统将新鲜空气引入两个地方。首先，通风系统将外部空气引入加热器壳里，空气从线圈旁流过或被线圈加热。其次，空气可通过前围板或地板上的小风门直接将空气引入车厢. 打开车窗也可实现通风。The basic steering system in most cars is the same. Thesteering gearof steering boxis the heart of the steeringsystem. This usually is next to the engine. A shaft extends from the back of the steering gear. This shaft is connected to thesteering columnorsteering shaft. Thesteering wheelis at the top of the steering column. Another shaft comes from the bottom of the steering gear. This shaft connects to the arms, rods, and links. Thisparts assembly, called thesteering linkage, connects the steering gear to the parts at the wheels. The wheels and tires mount to thesteering knuckles. As shown in Fig. 5-1, the knuckles are pivoted at the top and bottom. Thus, the wheels and tirescan turn from side to side.5.1多数汽车的转向系基本上是一样的。转向系的核心是转向器，一般位于发动机附近。一根轴从转向器后部伸出，连接着转向柱。方向盘在转向柱的顶端。另一根轴从转向器低端伸出，连接着转向臂、转向拉杆和转向杆系，这些部件总称为转向传动机构，连接转向器和车轮上的部件。车轮和轮胎安装在转向节上。如图5-1所示，转向节的上下端可自由转动，这样车轮可从一侧转到另一侧。While the steering system may look complicated, it works quite simply. When a driver drives a car straight down the road, thesteering gearis centered. The gear holds thelinkagecentered so that the wheels and tires point straight ahead. When the driver turns thesteering wheel, the steering shaftrotates and the steering gear moves toward that side. The shaft coming out the bottom of the steering gear turns, as well. When the shaft turns, it pulls the linkage to one side and makes thesteering knucklesturn slightly about their pivot points. Thus, the steering knuckle,spindle, wheels, and tires turn to one side, causing the car to turn. 转向系看起来复杂，工作原理却很简单。汽车直行时，转向器处于中间位置，转向传动机构也处于中间位置，车轮直行。驾驶员转动方向盘，转向轴旋转，转向器向同侧转动，同时转向器底部的输出轴也会旋转。输出轴转动时，会向一侧拉动拉杆，使得转向节绕其支点旋转。这样，转向节、转向节轴端、车轮和轮胎都会向一侧旋转，汽车实现转向。The suspension covers the arrangement used to connect the wheels to the body.The purpose is to prevent large shocks, caused by the wheels striking bumpsin the road, being passed to the vehicle occupants and components; otherwise discomfort and damage would occur.5.6悬架是车架（车身）与车桥（车轮）之间一切连接传力装置的总称。其目的是防止车轮遇到路面不平产生的巨大冲击传给车内的货物和乘客；否则会产生不舒适的感觉和货物的损坏The suspension system has two subsystemsthe front suspension and the rear suspension. 悬架系统有两个子系统前悬架和后悬架he suspension system has two subsystemsthe front suspension and the rear suspension. The front suspensionis more complicated than the rear suspension. This is because the front wheels must move in several different directions. The