Ответьте на вопросы по тексту
1. What phases does the production of the automobile comprise?
2. What requirements must the automobile meet?
3. Why are cars subjected to road tests
4. What qualities are required of the automobile?
5. Why is it important for the specialists in automobile industry to know computing methods?
3. Закончите предложения, выбрав соответствующий вариант окончания:
1. The cars are subjected to road tests in order…
1. to shorten the time between designing and manufacturing
2. to meet up-to-date requirements
3. to work out new technological processes
2. The car must have the following units….
1. high efficiency, long service life, driving safety and pleasant appearance
2. smooth acting clutch, silent gearbox, dependable brakes and steering system
3. The car must have the following qualities….
1. high efficiency, long service life, driving safety and pleasant appearance
2. smooth acting clutch, silent gearbox, dependable brakes and steering system
Components of Automobile
Basically, the automobile consist of three parts: the power plants, or the engine, the chassis and body. To these may be added the accessories: the heater, lighter, radio, speedometer and other devices. The power plant or engine is the source of power that makes the wheels rotate and the car move. It includes electric, fuel, cooling and lubricating systems. Most automobile engines have six or eight cylinders.
The chassis consists of a power train, frame with axles, wheels and springs. The chassis includes brakes and steering system.
The power train carries the power from the engine to the car wheels and contains the clutch, gearbox, propeller or cardan shaft, differential and the final drive. The clutch is a friction device connecting (or disconnecting) the engine crankshaft to the gears in the gearbox. It is used for freeing the gearbox from the engine and is controlled by the clutch pedal. Brakes are important mechanisms of the car. They are used to slow or to stop the car. Most braking systems in use today are hydraulic. They are operated by the brake pedal. When the driver pushes down on the brake pedal, they are applied and the car stops.
Задания:
1. Переведите на русский язык встречающие в тексте интернациональные слова:
Automobile, chassis, speedometer, electric, system, cylinder, cardan, control, hydraulic, pedal, accessories, differential
|
|
|
2. Подберите соответствующие ответы на вопросы и напишите их в той последовательности, в которой заданы вопросы.
1. What are the main basic parts of the automobile?
2. What does the chassis consist of?
3. What units does the power train contain?
4. What is the function of the clutch?
5. Why are brakes needed?
Ответы . 1.The clutch, gearbox, cardan shaft and the final drive
2. Freeing the engine from the gearbox
3. The power plant, the chassis and the body
4. A power train, frame with axles, wheels and springs
5. To slow or stop the car.
3. Закончите предложения, выбрав соответствующий вариант:
1. The mechanism used for stopping the car is…
1. Clutch 2. Gearbox 3. brakes
2. The mechanism used for changing the speed is…
1) clutch 2. gearbox 3. brakes
3. The mechanism used for connecting the engine from the gearbox is…
1. в rakes 2. с lutch 3. steering system
4. The unit carrying the power from the engine to the car wheels is…
1. power plant 2. power train 3. chassis
5. The instrument measuring the speed of the car is…
1. heater 2. lights 3. speedometer
Cooling system
When an internal-combustion engine operates, the parts coming in contact with hot gases are strongly heated. If the temperature of the pistons, cylinder heads, valves and cylinders becomes too high, undesirable effects appear such as deterioration of cylinder filling, power reduction, ignition of fuel. Very often the oil burns out and loses its lubricating properties.
If the engine is excessively cooled, the portion of heat that goes for useful work diminishes and the power of the engine drops.
The cooling system consists of the aggregate of all the devices ensuring the required thermal duty of the engine.
A water cooling system operates in the following manner: the water present between the cylinder walls and the cylinder heads cools the heated inner walls and become heated itself in the process. It often flows to the radiator, where it is cooled down by air. The cooled water is again redirected to the engine water jacket.
|
|
|
Forced cooling, when the water is circulated by a pump, is most common in modern engines. Cooling systems may be open or closed. In the first case, the volume of the system is not closed tightly. In the second case the plug of the cooler is provided with a two-way steam-air valve, which is opened by an excess pressure of steam in the system and also when the pressure in the cooler drops below atmospheric by 0.05-0.02 kg/cm2.
To enable the engine to operate normally, the temperature of the cooling water should be maintained at 80-90 irrespective of the load and the temperature of the environment. For this purpose and also to speed up the warming of the engine in starting, provision is made for adjusting the cooling rate which can be varied by changing the volume of the air stream passing through the cooler and also by changing the rate of water circulation.
In addition to water cooling, modern international-combustion engines, especially low-power types, often air-cool the ribbed cylinder surfaces with the aid of fans.
Задания:
Дата добавления: 2020-01-07; просмотров: 4375; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!