STRUCTURE of the Professional English,Automotive Maintenance and Repair,Section 1 Automotive Basics 第一篇 汽车基础,Chapter 1 General Information Basic Parts Classification Chapter 2 Internal Combustion Engine Operation Classifications Block And Head Piston And Connecting Rod Crankshaft Valve System Fuel Injection Direct Injection Common Rail Cooling Lubrication Chapter 3 Power Train Clutch M/T A/T CVT AMT DCT Chapter 4 Steering and Suspension Systems Chapter 5 Braking Systems Chapter 6 Electrical And Electronic Systems Power Sourse Startor Alternator Lights Signals Anti-theft Air-conditioning,本部分讲授内容,New Words,1.1 Basic Parts of Automobile 1.1.1 Engine,New Words,1.1 Basic Parts of Automobile 1.1.1 Engine,New Words,1.1 Basic Parts of Automobile 1.1.1 Engine,Todays average car contains more than 15,000 separate, individual parts that must work together. These parts can be grouped into four major categories: engine, body, chassis and electrical equipments，see Fig.1-1.,Fig.1-1 basic parts of a car,1.1 Basic Parts of Automobile 1.1.1 Engine,The engine acts as the power unit. There are two types of engine: gasoline engine (also called a spark-ignition engine) and diesel engine (also called a compression-ignition engine). All engines have fuel, exhaust, cooling, and lubrication systems. Gasoline engines also have an ignition system. The ignition system supplies the electric spark needed to ignite the air-fuel mixture in the cylinders. The fuel system stores liquid fuel and delivers it to the engine. The fuel is mixed with air to form a combustible mixture in the carburetor, the manifold, or the cylinders themselves. The cooling system removes excessive heat from the engine. Air and a coolant are used to carry away the heat. The lubrication system is important in keeping the engine running smoothly. Motor oil is the lubricant used in the system.,1.1 Basic Parts of Automobile 1.1.1 Engine,An automobile body (Fig.1-2) provides a protective covering for the engine, passengers, and cargo. The body is designed to keep passengers safe and comfortable. The body styling provides an attractive, colorful, modem appearance for the vehicle. It is streamlined to lessen wind resistance and to keep the car from swaying at the driving speeds.,1.1.2 Body,1.1 Basic Parts of Automobile,Fig.1-2 An automobile body,The chassis includes the power train, suspension, steering, and brake systems. The power train system comprises clutch, transmission, propeller shaft, rear axle and differential and the driving road wheels. The clutch or torque converter has the task of disconnecting and connecting the engines power from and to the driving wheels of the vehicle. The main purpose of the transmission or gearbox is to provide a selection of gear ratios between the engine and driving wheels, so that the vehicle can operate satisfactorily under all driving conditions. Gear selection may be done manually by the driver or automatically by a hydraulic control system. The function of the propeller (drive) shaft is to transmit the drive from the gearbox to the input shaft of the rear axle and differential assembly. Flexible joints allow the rear axle and wheels to move up and down without affecting operation. The rear axle and differential unit transmits the engines rotational power through 90 from propeller shaft to axle shaft to road wheels. A further function is to allow each driving wheel to turn at a different speed when cornering. A third function is to introduce another gear ratio for torque multiplication.,1.1 Basic Parts of Automobile 1.1.3 Chassis,The basic job of the suspension system is to absorb the shocks caused by irregular road surfaces that would otherwise be transmitted to the vehicle and its occupants, thus helping to keep the vehicle on a controlled and level course, regardless of road conditions. The steering system provides the means by which the front wheels are directionally turned. The steering system may be power assisted to reduce the effort required to turn the steering wheel and make the vehicle easier to manoeuvre. The braking system on a vehicle has three main functions. It must be able to reduce the speed of the vehicle, when necessary; it must be able to stop the car in as short a distance as possible; it must be able to hold the vehicle stationary. Each wheel has a brake assembly, of either the drum type or the disc type, hydraulically operated when the driver applies the foot brake pedal.,1.1 Basic Parts of Automobile 1.1.3 Chassis,The 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 a battery, and an alternator (or generator). The battery stores electricity. The alternator changes the engines mechanical energy into electrical energy and recharges the battery.,1.1 Basic Parts of Automobile 1.1.4 Electrical Equipment,Chapter 1 General