汽车专业英语课文翻译4
ESP汽车英语中英对照Unit4passageA高等教育出版社
速箱可以不发生换档冲击的情况下很容易地实现变档。离合器的 滑移允许在接合于断开时实现平滑的操作。
When a clutch is engaged, the driven plate is squeezed between the flywheel and a pressure plate assembly that is bolted to the flywheel. Since the input shaft of the transmission is splined to the hub of the driven plate, the engaging of the clutch provides a direct mechanical connection between the engine and the transmission.
squeezed 压榨，挤； splined 花键，用花键联接
当离合器处于接合状态，从动片被飞轮和一个被装配到飞轮上的 压板总成压挤。因为变速箱的输入轴被是以花键连接到从动片的 轮毂上，离合器的接合提供发动机和变速箱之间的直接机械连结。
Transmissions
An engine develops a specific amount of torque at a given rpm point on its torque-brake horsepower curve. At low speeds, the torque is low. As the speed of the engine increases, the torque also increases, and it reaches a peak and begins to taper off before the maximum speed is reached.
汽车专业外文翻译(中英文翻译)
附录1外文翻译Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses”connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Frictionbetween the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels. At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotating disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluidpressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initial position, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock braking systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the b rakes like a driver might but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around thewinding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The cont rol unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.译文汽车制动系统制动系统是汽车中最重要的系统。
汽车专业英语翻译
INTERNAL COMBUSTION ENGINE引擎燃烧室1. principle of operation 原理Engine 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 place 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 pressure 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.译:引擎和能量:引擎为汽车提供能量，燃料的化学能通过燃烧，转化为热能，这个过程叫燃烧。
汽车实用英语课文翻译
汽车实用英语课文翻译汽车实用英语课文翻译《汽车实用英语》是一本图文并茂介绍汽车构造、维修保养和技术应用的通俗专业英语教材。
全书共分16个单元，每个单元由看图说话、课文、阅读材料、应用写作或科技英语知识组成。
以下是小编整理的汽车实用英语课文翻译，欢迎阅读。
汽车实用英语课文翻译1For many people, driving is A peaceful and easy way to get from point A to point B. Unfortunately, it often takes only a second to turn into a driver's nightmare. As traffic accidents continue to happen on the road, the point is not to go somewhere, but to get somewhere safely.Because of its weight and speed, cars always need to be handled carefully. The number of cars on the road is increasing, and accidents are on the rise. In fact, the Numbers that can be described are already staggering. In Canada, more than 450, 000 traffic accidents are reported every year. Perhaps most disturbing is the main cause of these accidents: about 90 per cent are caused by human error.Car makers share responsibility with drivers who are responsible for keeping roads safe. For years, car makers have designed vehicles to improve. Many of the devices in the vehicle are used to ensure passengers' safety. Braking system, this is the most common kind of safety device. In addition, windscreen is also a safety device. And then the seatbelts, airbags, reverse radar, and so on.When the driver encountered an emergency, he should brake to stop the car. This, of course, is the simplest way to protect a car's passengers. Windscreen, usually a curved glass or othertransparent shielding material, placed in front of the car owner's position to prevent wind. As the basic safeguard equipment of automobile safety, the main function of seat belt is to limit the position of the driver or crew member when the accident occurs, and reduce the injury degree of the accident to the personnel. After special sensors to detect the impact of a very short time, is located in the steering wheel or the airbag will pop up on the dashboard, in order to prevent the people directly by wheels, fender or windshield. Reverse radar, also known as parking ancillary system, or reverse computer warning system. It is when the car parking or reversing safety auxiliary processing it more intuitive to voice or show told the driver around obstructions, lifted the driver parking, before and after the detection of problems, while backing eliminate blind spot, enhance the security of driving.Other traffic safety in the performance of the device are: padded dashboard and masks, built-in fixed child seats, concave type plate, anti-lock braking system, daytime lamp, energy absorption bumper. Every year, new vehicles are introduced, and manufacturers have to stabilize the new system to ensure the safety of driving.对于许多人来说开车是件平静而轻松的从A地到B地的方式。
汽车专业英语翻译
汽车专业英语翻译Unit 1 Automotive BasicsAutomobiles, 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 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，它是汽车你所看到的部分。
而车身以下的部分就是底盘。
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 designed 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 driving speeds.轿车车身是一个钣金件壳体，它上面有车窗、车门、发送机罩和行舱门等部件，它给发动机、乘客和行提供防护。
汽车专业英语课文翻译4
Fuel Supply System of Gasoline EngineAll the gasoline engines have substantially identical fuel systems and run on a mixture consisting of fuel vapor and air. The fuel system comprises the units designed to store, clear and deliver fuel, the units intended to clean air and a unit for preparing a mixture from fuel vapor and air.In a fuel system different components are used to supply fuel from the fuel tank into the engine cylinder. Some of the important components are fuel tank, fuel pump, fuel filter, carburetor, intake manifold and fuellines or tubes connecting the tank, pump and the carburetor.The fuel tank is a fuel container used for storing fuel. It is made of sheet metal. It is attached to the vehicle frame with metal traps and is located at the rear of the vehicle. They are mounted in a boot or boot-floor pan in case of front-engined cars and small commercial vehicles. In order to strengthen the tank as well as to prevent surging of fuel when the vehicle rounds a curve of suddenly stops, baffle plates are attached to the inside of the tank.A cap is used to close the filler opening of the tank. The fuel line is attached at or near the bottom of the tank with a filtering element placed at the connection. The other components of the fuel tank are the fuel gauge sending unit, a vent pipe, receiving unit. To prevent the dirt and water from entering the luggage compartment, a sealing strip is fitted between the fuel tank and boot floor pan. Moreover to limit the transmission of frame distortion to the tank giving rise to squeaking as the metal parts get rubbed together, rubber or felt pads are often fitted between the mountings and the tank. Provision is also made against drumming of the tank by these mountings. The tank may be placed at the side of the chassis frame for convenience in case of large commercial vehicles. The length of the connecting lines or tubes from the tank to the carburetor is also restricted by this at the same time.A porous filter is attached to the outlet lines. By drawing fuel from the tank through the filter, any water in the bottom of the tank as well as any dirt into the fuel gathers on the surface of the filter. To keep the fuel always under atmospheric pressure, the filter pipe or tank is vented.In order to prevent dirt in the fuel from entering the fuel pump or carburetor, fuel filters and screens are used in the fuel system. If the dirt is not removed from the fuel, the normal operation of these units will be prevented. The engine performance will also be reduced.The filter is either fitted inside the fuel tank and pump or operates as a separate unit connected between the fuel tank and pump or between pump and carburetor into the fuel lines. Carburetors are also provided filter screens while a filter element is provided in the fuel tank.The fuel filter used is generally a sediment bowl made of glass or metal and a strainer screen. When the fuel drawn from the tank passes through the filter (through the bowl and strainer screen), particles of dirt and water settle in the bottom of the bowl. In certain vehicles, a separate filter either of the disk or ceramic type is used. It is either located between the fuel pump and carburetor or in the fuel line.For connecting the fuel tank to the fuel pump, metallic tubes or synthetic rubber hose used are called fuel lines. They are usually positioned with metallic clips along the frame side members. The tubing or fuel lines are also used to connect fuel pump to the carburetor. In order to absorb vibration as well as prevent breakage of the fuel lines, a short flexible line is used between the fuel pump and the tank.In order to meter and caution the driver of the motor vehicle about the quantity of fuel consumed and left in the tank, a fuel gauge is used. It is generally fitted on dash board for easy reading of the fuel. It is usually a balancing coil type having construction similar to that of an oil gauge. It is generally electrically operated.It consists of a sending unit mounted on the fuel tank and a receiving unit having a caliberated gauge mounted on the instrument panel.A sending unit consists of a float controlled thermostat or variable resistor. With a float and the float arm extending into the fuel tank, the whole unit is mounted on it. The level of fuel in the tank varies the position of the float. The amount of electrical resistance within the variable resistor for controlling the amount of current sent to receiving unit on the instrument panel is determined by the float position.The receiving unit mounted on the dash board indicates the amount of fuel in the tank on a caliberated gauge by the amount of current received from the sending unit.On modern automobiles, two types of fuel gauges; thermostatic type and an electromagnetic type are used.In order to prevent the rapid wear and tear of engine operating components causing reduced performance air cleaner is fitted to the carburetor air intake, it is mounted on thecarburetor air-horn for trapping dirt. Before entering the carburetor, the air must pass through it.To reduce the noise produced by the air rushing into the carburetor, a silencing chamber is built into the air cleaner. In case the engine misfires back through the carburetor, it acts as the flame arrestor.There are in general three types of the air cleaners used in modern automobiles. They are (a) oil bath cleaner (b) oil-wetted mesh air cleaner (c) dry type air cleaner. The first two are also known as heavy duty air cleaner while the third is known as light duty air cleaner.Fuel pumps are the devices used to supply fuel from the fuel tank to the carburetor. There are in general two main types of fuel pumps used in automobiles. They are main types of fuel pumps used in automobiles. They are (a) mechanical fuel pump (b) electric fuel pump.汽油发动机的燃料供给系统所有的汽油发动机具有基本相同的燃料系统和运行的燃料蒸气和空气组成的混合物中。
汽车专业英语全文翻译
汽车工程专业英语全文翻译一当今的汽车一般都由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。
Body：车身Engine：发动机Brakes：制动器Power train ：传动系Steering：转向系Electrical：电器及电子设备Suspension：悬架Layout of a passenger car：乘用车总布置Layout of a commercial vehicle ：商用车总布置1.1 车身汽车车身是由车窗、车门、发动机罩和行李箱盖焊接在金属板外壳发动机发动机作为动力装置。
最常见的发动机气缸的排列方式称为发动机配置。
直列式发动机的汽缸呈一列布置。
这个设计创造了一个简单的发动机缸体铸造。
在车辆应用中，汽缸数一般是2-6 缸，汽缸中心线与水平面垂直。
当汽缸数增多时，发动机尺寸和曲轴就成为一个问题。
解决这个问题的办法就是采用V 形（汽缸呈两列布置，且两列气缸之间夹角为V 形）发动机。
这个设计使发动机尺寸和曲轴都变得更短且更坚硬。
前置发动机纵向安装，既可前轮驱动也可后轮驱动。
后置发动机是将发动机安装在后轮后面。
发动机可横置或纵置，一般情况下为后轮驱动。
1.4 电气系统电气系统为起动机、点火系统、照明灯具、取暖器提供电能。
该电平由一个充电电路维护。
1.4.1 充电充电系统为所有汽车电子元件提供电能。
充电系统主要包括：蓄电池，交流发电机，电压调节器，即通常是交流发电机上不可或缺的，充电警告或指示灯和金属丝连成一个完整电路。
蓄电池为起动提供电能 ,然后发动机工作，交流发电机就为所有的电子元件提供电能。
同时也给蓄电池充电即用来使发动机起动。
电压调节器有过充保护作用。
1.4.2 起动起动系统包括：蓄电池、电缆、起动机、飞轮和换向器。
起动时，有两个动作同时运行，该起动机齿轮与飞轮齿圈啮合，并起动电机，然后运行传输到发动机曲轴。
起动机电机将起动机安装在发动机缸体上并由电池供电。
《汽车专业英语读译教程》参考译文-课文A-UNIT 4 TEXT B
第4单元课文B Motronic系统的工作原理在这一部分中，我们来考察一下Motronic系统的工作情况，从而理解Motronic系统是怎样控制喷油、点火和怠速旁通系统，以便获取理想的发动机管理效果的。
1.起动控制1）起动时的燃油控制在大多数Motronic系统中，起动加浓燃油由进气道喷油器而不是单独的起动喷油器/温控定时开关来提供的。
对于起动控制，重要的输入有转速和发动机温度。
控制单元监视着起动转速，还监视着起动开始之后转动的圈数。
喷油脉冲比通常情况下要长些。
而在发动机低温时，控制单元对每一转都要输送几个较短的喷油脉冲，以便改善起动性能。
记住，在一个脉冲周期（即曲轴转动200ms的时间）中有10个毫秒级脉冲。
为了防止溢油，在经过精确的圈数之后，或者在发动机达到与温度相关的一定起动转速（如200~300r/min）之后，燃油量将会下降。
2）起动时的点火正时控制一台低温发动机以低转速起动，其点火正时将会控制在上止点（TDC）附近。
对于正常的起动转速，大的点火提前角会使发动机点火过早，从而损坏起动机。
另外，如果能起动的话，起动也将会很困难。
然而，一台低温发动机以较高转速起动，为了更好地起动，要将点火正时提前。
对于热起动，或在高的进气温度下起动，由于在活塞以起动转速下上升时，热的气缸就能着火，所以应该推迟点火正时。
推迟点火能够防止高压缩比发动机出现爆燃，这种爆燃在起动时会被起动机噪声所掩盖。
3）起动时的空气控制就像在L-Jetronic系统中一样，由于闭合角信号的加长，通常怠速稳定器的开度会加大，以便提供冷态起动所需的额外空气。
2.起动后控制起动后阶段（即在松开钥匙，使钥匙转离“起动”位置之后，发动机保持运转的5~30s 时间）受发动机温度以及控制单元内的定时电路的控制。
发动机温度越低，喷油量就越大。
发动机温度越低，喷油定时越早。
根据起动温度和起动后经过的时间，起动后校正加浓逐渐减小。
怠速稳定器维持转速不变。
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Fuel Supply System of Gasoline Engine(UNIT SEVEN)All the gasoline engines have substantially identical fuel systems and run on a mixture consisting of fuel vapor and air. The fuel system comprises the units designed to store, clear and deliver fuel, the units intended to clean air and a unit for preparing a mixture from fuel vapor and air.In a fuel system different components are used to supply fuel from the fuel tank into the engine cylinder. Some of the important components are fuel tank, fuel pump, fuel filter, carburetor, intake manifold and fuellines or tubes connecting the tank, pump and the carburetor.The fuel tank is a fuel container used for storing fuel. It is made of sheet metal. It is attached to the vehicle frame with metal traps and is located at the rear of the vehicle. They are mounted in a boot or boot-floor pan in case of front-engined cars and small commercial vehicles. In order to strengthen the tank as well as to prevent surging of fuel when the vehicle rounds a curve of suddenly stops, baffle plates are attached to the inside of the tank.A cap is used to close the filler opening of the tank. The fuel line is attached at or near the bottom of the tank with a filtering element placed at the connection. The other components of the fuel tank are the fuel gauge sending unit, a vent pipe, receiving unit. To prevent the dirt and water from entering the luggage compartment, a sealing strip is fitted between the fuel tank and boot floor pan. Moreover to limit the transmission of frame distortion to the tank giving rise to squeaking as the metal parts get rubbed together, rubber or felt pads are often fitted between the mountings and the tank. Provision is also made against drumming of the tank by these mountings. The tank may be placed at the side of the chassis frame for convenience in case of large commercial vehicles. The length of the connecting lines or tubes from the tank to the carburetor is also restricted by this at the same time.A porous filter is attached to the outlet lines. By drawing fuel from the tank through the filter, any water in the bottom of the tank as well as any dirt into the fuel gathers on the surface of the filter. To keep the fuel always under atmospheric pressure, the filter pipe or tank is vented.In order to prevent dirt in the fuel from entering the fuel pump or carburetor, fuel filters and screens are used in the fuel system. If the dirt is not removed from the fuel, the normal operation of these units will be prevented. The engine performance will also be reduced.The filter is either fitted inside the fuel tank and pump or operates as a separate unit connected between the fuel tank and pump or between pump and carburetor into the fuel lines. Carburetors are also provided filter screens while a filter element is provided in the fuel tank.The fuel filter used is generally a sediment bowl made of glass or metal and a strainer screen. When the fuel drawn from the tank passes through the filter (through the bowl and strainer screen), particles of dirt and water settle in the bottom of the bowl. In certain vehicles, a separate filter either of the disk or ceramic type is used. It is either located between the fuel pump and carburetor or in the fuel line.For connecting the fuel tank to the fuel pump, metallic tubes or synthetic rubber hose used are called fuel lines. They are usually positioned with metallic clips along the frame side members. The tubing or fuel lines are also used to connect fuel pump to the carburetor. In order to absorb vibration as well as prevent breakage of the fuel lines, a short flexible line is used between the fuel pump and the tank.In order to meter and caution the driver of the motor vehicle about the quantity of fuel consumed and left in the tank, a fuel gauge is used. It is generally fitted on dash board for easy reading of the fuel. It is usually a balancing coil type having construction similar to that of an oil gauge. It is generally electrically operated.It consists of a sending unit mounted on the fuel tank and a receiving unit having a caliberated gauge mounted on the instrument panel.A sending unit consists of a float controlled thermostat or variable resistor. With a float and the float arm extending into the fuel tank, the whole unit is mounted on it. The level of fuel in the tank varies the position of the float. The amount of electrical resistance within the variable resistor for controlling the amount of current sent to receiving unit on the instrument panel is determined by the float position.The receiving unit mounted on the dash board indicates the amount of fuel in the tank on a caliberated gauge by the amount of current received from the sending unit.On modern automobiles, two types of fuel gauges; thermostatic type and an electromagnetic type are used.In order to prevent the rapid wear and tear of engine operating components causing reduced performance air cleaner is fitted to the carburetor air intake, it is mounted on thecarburetor air-horn for trapping dirt. Before entering the carburetor, the air must pass through it.To reduce the noise produced by the air rushing into the carburetor, a silencing chamber is built into the air cleaner. In case the engine misfires back through the carburetor, it acts as the flame arrestor.There are in general three types of the air cleaners used in modern automobiles. They are (a) oil bath cleaner (b) oil-wetted mesh air cleaner (c) dry type air cleaner. The first two are also known as heavy duty air cleaner while the third is known as light duty air cleaner.Fuel pumps are the devices used to supply fuel from the fuel tank to the carburetor. There are in general two main types of fuel pumps used in automobiles. They are main types of fuel pumps used in automobiles. They are (a) mechanical fuel pump (b) electric fuel pump.汽油发动机的燃料供给系统所有的汽油发动机具有基本相同的燃料系统和运行的燃料蒸气和空气组成的混合物中。