1、1 Unit 1 Automotive Basics Automobiles, trucks, and buses are essential forms of transportation. They are complex machines made up of many parts. These parts can be grouped into a number of systems. An understanding of how the system work will help you understand how the automobile works. 轿车、卡车和客车是交
2、通运输的重要组成部分。它们都是由许多部件组成的复杂机器。这些部件可以归类为汽车的几个组成系统。了解这些各个小系统是如何工作的将有助于我们理解整个汽车系统是如何工作。 An automobile can be divided into two basic parts: a body and a chassis. The body is the enclosure that houses the engine, passengers, and cargo. It is the part of the automobile that you see. The chassis is that part
3、 of the automobile beneath the body. 汽车可以分为两个基本部分：车身和底盘。车身包围发动机、乘客和行李，它是汽车你所看到的部分。而车身以下的部分就是底盘。 1.1 THE BODY An 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 engine, passengers, and cargo. The body is des
4、igned to keep passengers safe and comfortable. For example, insulation in the body reduces noise and protects against heat and cold. The body styling provides an attractive, colorful, modern appearance for the vehicle. It is streamlined to lessen wind resistance and to keep the car from swaying at d
5、riving speeds. 轿车车身是一个钣金件壳体，它上面有车窗、车门、发送机罩和行李舱门等部件，它给发动机、乘客和行李提供防护。车身设计来确保乘客乘坐的安全和舒适。比如：车身绝热层可以减少噪音和抵御冷热。车身造型设计使得汽车有一个华美、现代、吸引人的外观。车身的流线型设计可以减少风阻，防止汽车行驰过程中发生摆动。 The automobile body has two basic parts-the upper body and the under body. 车身有两个基本部分 -车身上部和车身下部。 1.2 The chassis The chassis is an assembly
6、 of those systems that are the major operating parts of a vehicle. The chassis includes everything except the body. The three important parts of the chassis are the frame, the engine, and the power train (also called the drive train). Each of these three parts is made up of a number of systems. A sy
7、stem is a mechanical or electrical unit that performs a specific function. Thus, each system (such as steering, brake, or fuel) has a certain job to do in running a vehicle. We shall look at each of these parts and systems to see how they fit together to form the automobile chassis. 底盘集中了汽车大部分的运动组件，
8、它包括除了车身以外的所有部件。底盘有三个重要的系统：车架、发动机和传动系统。这三个系统又都有许多个完成某一个特定功能的机械或电气系统组成。为了保证汽车正常运转，每个系统（比如：转向、制动或燃油系统）都要实现一定的功能。下来我们看看这些系统和组件是如何相互连接从而组成汽车底盘的 。 1.2.1 The frame The first major part of the chassis is the frame. It is made from tough steel sections welded, riveted, or bolted together. The frame looks lik
9、e a steel ladder, though it sometime has an X shape for extra strength. It forms a foundation for the car body and the parts of the several systems. The body is joined to the frame with bolts. Rubber shock mounts or washers are used at each joint. These reduce vibration and road noise. In most moder
10、n cars the frame is built into the body. A car with the frame built into the body has a unitized body or unibody. The frame supports the suspension system, steering system, and the braking system. 底盘最重要的部分就是车架。车架由钢件通过焊接、铆接或螺栓联接而成，看上去就像一架钢梯。有时为了得到额外的强度，车架做成了 X 形状。车架为车身和很多系统部件提供了底2 座。车身和车架使用螺栓联接。每个联接使
11、用橡胶防震支架或垫圈来减振降噪。现代轿车车架和车身做在了一起。采用这个形式的汽车车身叫做承载式车身。车架支撑悬架、转向和刹车系统。 The front and rear wheels are attached to the chassis by a suspension system. This system is made up of springs, shock absorbers, control arms, and stabilizers. These support the vehicle and cushion it from road bumps for better ride
12、and handling. 前后轮通过悬架系统和底盘相连。悬架系统由弹簧、减振器、控制臂和横向稳定杆组成。它们支撑着车身，并减缓由于路面不平引起的颠簸，以获得更好的乘坐舒适性和操作稳定性。 The steering system controls the cars direction of travel. It includes a wheel and column, steering gears, rods, and linkages. As the steering wheel is turned, its motion is transferred to the idler arm an
13、d tie rods. These cause the front wheels to turn to the right of left. On some cars, a power unit (called power steering) makes steering easier. 转向系统控制车辆行驰的方向。它包括方向盘、转向管柱、转向器、转向拉杆和转向传动装置。当转动方向盘，方向盘的运动被传递到随动臂和横拉杆，从而使得前轮向左或向右转动。有些车辆使用助力转向装置，从而使得转向更加轻便。 The brake system gives the automobile its stoppin
14、g power. Hydraulic brakes are found on all modern cars. As the brake pedal is pushed with the foot, brake fluid is forced through brake lines into cylinders that press the brake shoes against a drum. This stops the motion of the car. Power units (power brakes) are used to make braking easier. Most m
15、odern cars have disc brakes on the front wheels. (Some have them on both the front and rear wheels.) Disc brakes work like a pair of pliers squeezing a rotating disc. Drum brakes are also used. 制动系统给车辆制动的动力。现代轿车都使用液压制动。当踩下制动踏板，制动液通过制动管路流入制动缸，强迫制动蹄接触制动鼓，从而阻止车辆运动。为了使刹车更加轻便，车辆也使用助力制动。现代轿车在前轮装备盘式制动器。（一些
16、轿车在前后轮都使用盘式制动器。）盘式制动器工作原理类似一对钳子夹住旋转的盘片。也有前后轮都使用鼓式制动器的汽车。 1.2.2 The engine The engine provides power to move the automobile. The most common type of automobile engine is the gasoline-burning piston engine. It is found in most automobiles. Diesel-fuel burning engines are also used in modern passenger
17、cars, as well as in large trucks. All engines have fuel, exhaust, cooling, and lubrication systems. Gasoline engines also have an ignition system. 发动机给汽车提供动力。最常见的发动机是汽油机。大多数汽车都使用它。现代客车和大型卡车使用柴油机。所有的发动机都具有燃油、排放、冷却和润滑系统。汽油发动机还有一套点火系统。 The ignition system supplies the electric spark needed to ignite th
18、e air-fuel mixture in the cylinders. When the ignition switch is turned on, current flows from the 12 -volt storage battery to the ignition coil. The coil boosts the voltage to produce the strong spark of 20,000V needed to ignite the engine fuel. The distributor directs the electrical current to the
19、 right spark plug at the right time. Diesel engines use the heat caused by engine compression to ignite the fuel charge. These engines are called compression ignition engines. 点火系统提供点燃气缸内油气混和物的电火花。当打开点火开关，电流从 12V 电池流向点火线圈。点火线圈升高电压，产生用于点火的 20000V 尖峰电压。分电器引导电流在正确的时刻流向正确的火花塞。柴油机使用压缩发动机产生的热量来点燃燃料，因此被称为压
20、燃式发动机。 The automobile supplies all the electricity it needs through its electrical system. For example, the 3 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, a
21、lternator (or generator), and the regulator. The battery stores electricity. The alternator changes the engines mechanical energy into electrical energy and recharge the battery. The regulator prevents damage to the system by regulating the maximum voltage in the circuit 汽车通过自身的电气系统给自身供电。比如：电气系统给点火系
22、统、喇叭、灯光、供暖系统和起动器供电。系统电压通过充电系统保持稳定。充电系统由电池、发电机和调节器组成。电池储存电能。发电机将发动机的机械能转变为电能，并给电池充电。调节器调节电气系统的最大电压，提供过压保护。 The fuel system stores liquid fuel and delivers it to the engines. The fuel is stored in the tank, which is connected to a fuel pump by a fuel line. The fuel is pumped from the fuel tank through
23、 the fuel lines. It is forced through a filter (which removes moisture and dirt) into the carburetor, where it is mixed with air, or into the fuel injection system. The fuel is mixed with air to form a combustible mixture in the carburetor, the manifold, or the cylinders themselves. 燃油系统储存液态燃料，并且把燃料
24、送至发动机。燃料储存在通过油管与油泵连接的油箱里。油泵通过油管将油箱内的油泵出，并通过滤清器（去除湿气和杂污）送达化油器与空气混合或者喷油系统。燃油在化油器、歧管或气缸自身内与空气混合，形成可燃混和物。 The exhaust system has four jobs: 1. To collect burned gases from the engines. 2. To remove dangerous emission that pollutes the air. 3. To reduce exhaust noises. 4. To get rid of the exhaust gases.
25、 排放系统要实现四个功能： 1、收集发动机的废气。 2、去除污染空气的排放物。 3、减少排放噪音。 4、排出废气。 Exhaust gases contain carbon monoxide, unburned hydrocarbons, and oxides of nitrogen. Since all of these are harmful, the exhaust system is designed to reduce them as much as possible. In the United Stares all modern automobiles have emission
26、 control systems. 汽车废气包含一氧化碳，未燃烧的碳氢化合物和氮氧化合物。所有的这些都是有害的，排放系统设计要尽可能多减少这些有害物质。美国所有的现代车都配备了排放系统。 The cooling system removes excessive heat from the engine. The temperature in engine combustion chambers is about 1094C. Since steel melts at around 1354C, this heat must be carried away to prevent engine d
27、amage. Air and a coolant are used to carry away the heat. The radiator is filled with a coolant. The water pump circuits this coolant through the engine and the walls of the engine block and head. Heat also is removed by the radiator fan, which draws air through the narrow fins of the radiator. This
28、 system also supplies heat to the passenger compartment and the window defroster. 冷却系统去除发动机多余的热量。发动机燃烧室的温度可以达到 1094 摄氏度。钢的熔点大约是 1354 摄氏度，发动机多余的热量必须消除来防止发动机过热。空气和冷却剂用来带走这个热量。散热器内装满了冷却剂。水泵使冷却剂在发动机、发动机壳体和发动机盖循环流动。也可以使用冷却风扇来降温。冷却风扇将风从散热器狭窄的孔径吹出，从而带走热量。这个系统可以给乘客舱和车窗除霜器提供热量。 The lubrication system is impo
29、rtant in keeping the engine running smoothly. Motor oil is the lubricant used in the system. The lubrication system has four functions: 1. It cuts down friction by coating moving parts with oil. 4 2. It produces a seal between the piton rings and the cylinder walls. 3. It carries away sludge, dirt,
30、and acids. 4. It cools the engine by circulating the motor oil. 润滑系统非常重要，它使得发动机平滑工作。润滑系统使用机油作为润滑剂。润滑系统有四个功能： 1、通过运动部件油膜，它可以减小摩擦。 2、它在活塞环和气缸壁之间产生油封。 3、它可以带走金属碎屑、杂污和酸。 4、通过机油的循环，它可以冷却发动机。 To keep this system working effectively, oil filters and motor oil must be change regularly. All other moving part
31、s in an automobile must also be lubricated. These include the transmission, differential, wheel bearings, and steering linkage. 为了使得润滑系统有效工作，机油滤清器和机油必须定期更换。汽车内所有的运动部件都必须要润滑，这包括变速器、差速器、轮轴轴承和转向传动机构。 1.2.3 The power train The power train, or drive system, delivers power from the engine to the wheels. T
32、he power from the engine moves through the transmission. Transmissions are either standard, with a manual shift lever and foot clutch, or automatic. 传动系统将发动机动力传给车轮。来自发动机的动力传递给变速器。变速器可以是一个带手动换档杆和离合器的手动变速器或者自动变速器。 The transmission has gears that control the amount of power delivered to the wheels. The
33、 transmission increases the power (torque) to start the car moving. This torque is reduced when the transmission changes gears at higher speeds. The transmission also contains a set of gears that can reverse the direction of the wheels. The transmission delivers the power to the differential. A driv
34、e (or propeller) shaft with universal joints at either end of the drive shaft allows axle movement of front-engine, rear-wheel drive cars. These flexible universal joint prevent the drive shaft from breaking. The differential delivers power to the wheels through axle. Certain gears allow one wheel t
35、o turn faster than the other wheel when the vehicle is turning a corner. 变速器使用齿轮来控制传递到车轮力矩的大小。当车辆起步时， 变速器增大扭矩。当车速增大，变速器改变齿轮来减小扭矩。变速器还有一套使得车轮反向运动的齿轮。变速器将扭矩传递给差速器。发动机前置后轮驱动轿车的驱动轴两侧装有万向节，可允许产生轴向运动。万向节防止驱动轴断裂。差速器通过半轴将扭矩传递给车轮。当车辆转弯时，齿轮使得一侧车轮比另一侧车轮旋转得更快。 These are the basic systems of the automobile. Each
36、 of the systems is designed for a specific job. 以上就是汽车的基本系 统。每个系统都为了一个专门的功能而设计。 1 Exercises The automobiles further development will be determined by already existing and steadily increasing requirements, by additional further requirements and by the technical possibilities for meeting these require
37、ments. The following focal points for development and research efforts can be discerned: 汽车的进一步发展取决于已经存在的、目前稳定增长和未来的需求以及为了满足这些需求的技术。下来给出发展研究的几个要点： Further improvements of the automobile through products innovation in all classis functions, i. e. performance, fuel economy, environmental impact, safet
38、y, comfort and reliability. Further development of new technologies such as electrics, alternative materials, new test and production methods. Long-range solutions for traffic problems such as highway congestion, smog in cities and carbon dioxide enrichment of our atmosphere. 5 传统功能的产品革新，比如：性能、燃油经济性
39、、环境友好、安全、舒适性和可靠性。 新技术的发展，比如：电气、替代材料、新型测试和生产技术。 解决交通问题的技术，比如：交通拥堵，城市烟雾和温室效应。 Unit2 Automotive engine 2.1 Purpose and locations of engines The purpose of an automobile engine is to supply the power needed to move the vehicle. The engine produces this power by burning fuel inside it. Because the engine
40、 burns fuel inside, or internally, the engine is known as an internal combustion engine (ICE). 汽车发动机的功用是提供汽车行驰所需的动力。发动机通过发动机内部燃烧燃料来产生这个动力。由于燃料燃烧在发动机内部进行，这种发动机被称作内燃机。 Most automobile engines are located at the front of the vehicle. Many engines drive the rear wheels. This requires a long drive shaft
41、extending from the front wheels to the rear wheels. Other engines drive the front wheels. In the rear-wheel-drive arrangement, the engine sits longitudinally. Its long dimension is from front to back. 对于大多数汽车，发动机布置在汽车前部。许多发动机驱动后轮，这就要求从前轮到后轮的长驱动轴。其余发动机驱动前轮。对于后轮驱动的汽车而言，发动机由前到后纵向布置。 In the front-wheel-
42、drive arrangement, the engine sits crosswise, transversely. With either arrangement, the power is carried to the drive wheels (rear or front) by gears and shafts. 对于前轮驱动的布置，发动机横置。无论哪种布置方式，能量都是通过齿轮和传动轴传到驱动轮（前轮或后轮）。 Some cars have the engine mounted in back of the front seat. This is called a mid -eng
43、ine arrangement. Other cars have been built with the engine mounted at the rear, in back of rear seat. The Volkswagen “beettle” is an example of rear. 有些汽车的发动机位于前排座椅的后面。这种布置被称为发动机中置。还有些汽车的发动机位于后部，安置在后排座椅后面。大众汽车的甲壳虫就是发动机后置的一个例子。 2.2 Engine types Various kinds of engine are used in automotive vehicles
44、. The two major types are:The piston engine inwhich pistons move up and down, or reciprocate, in the engine cylinder. This is the engine used in all cares today, except for some models of Mazda. 2. The Wankel rotary engine in which rotate, or spin. The Mazda Motor Corporation of Japan is the major m
45、anufacturer of this engine. 汽车上使用着不同种类的发动机。它们可以分成两大类： 1、往复活塞式发动机：发动机在气缸内作上下往复运动。除了马自达公司的几款以外，现今几乎全部轿车都采用这种发动机。 2、转子发动机：活塞在气缸内作旋转运动。日本的马自达公司是这类发动机的主要生产商。 There are two types of piston engines-spark ignition (SI) and compression ignition (CI). Spark-ignition engines use an electric system with spark p
46、lugs. Electric sparks at the spark plugs ignite, or set fire, the fuel in the engine cylinders. The combustion of the fuel makes the engine run and produce power. This is the engine used in most produce power. This is the type of engine used in most automotive vehicles. 活塞式发动机可以分为两类：点燃式和压燃式。点燃式发动机使用
47、带火花塞的点火系统。火花塞的电火花点燃发动机气缸内的燃料。燃料燃烧驱动发动机，并做功。这是大多数动力源采用的发动机，也是大多数汽车采用的发动机形式。 The compression-ignition engine uses the heat of compression to ignite the fuel.When air is compressed, it gets very hot. In the diesel engine, the air is compressed so much that its 6 temperature goes up to 538 degrees Celsi
48、us or higher. The diesel fuel is sprayed into this very hot air and is ignited by the heat. Some automobiles have diesel engines. Many heavy-duty trucks and buses are powered by diesel engines. 压燃式发动机使用压缩产生的热量来点燃燃料。当空气被压缩，它可以达到非常高的温度。对于柴油式发动机，压缩空气可以使得空气温度达到 538 度或者更高。此时，柴油被喷射到这炽热的空气中，被空气的热量点燃。一些轿车使用
49、柴油发动机。重型卡车和客车普遍使用柴油发动机。 There are other engines still in the experimental stage that might someday become important. These include gas-turbine engines, steam engines, Stirling engines, and electric motors. 还有一些目前尚且处于试验阶段，但未来可能会非常重要的发动机，比如：燃气涡轮机、蒸汽机、斯特灵发动机和电动机。 2.3 Basic engine systems A spark-ignition engine requires four basic systems to run. Diesel engines requires three of these systems. They are fuel system, ignition system (expect diesel), lubricating system and cooling system. Each performs a basic job in making the engine run
