2015-02-04
5357
1. The engine is the source of power that makes the car move. It is usually called an internal combustion engine because gasoline is burned within its cylinders or combustion chambers. Most automobile engines have six or eight cylinders.
The operating cycle of the four-stroke engine that takes place in the engine cylinder can be divided into four strokes. The upper limit of the piston movement is called the top dead centre. The lower limit of piston movement is called the bottom dead centre. A stroke is the piston movement from the top dead centre to the bottom dead centre or from bottom dead centre to the top dead centre. In other words, the piston the completes a stroke each time it changes the direction of its motion.
3. Where the entire cycle of events in the cylinder requires four strokes (two crankshaft revolutions), the engine is called a four-stroke cycle engine. The four strokes are: intake, compression, power and exhaust.
4. Two-cycle engines have also been made, and in such engines the entire cycle of events is completed in two strokes or one revolution of the crankshaft.
5. On the intake stroke the intake valve is opened. The mixture of air and vaporized gasoline is delivered into the cylinder through the inlet valve. On the compression stroke the inlet valve is closed so that the mixture can be compressed. On the power stroke both valves (inlet and exhaust) are closed in order to raise pressure during the mixture combustion. On the exhaust stroke the exhaust valve is opened to exhaust the residual gas.
4. Переведите на русский язык в письменной форме абзацы 2 и 5.
5. Найдите соответствующие ответы на вопросы и напишите их в той последовательности, в которой заданы вопросы:
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Вопросы
1. What is the top dead centre?
2. What is the bottom dead centre?
3. When the engine is called a four-stroke cycle engine?
4. When the engine is called a two-cycle engine?
5. What kind of strokes can the events in the engine cylinder be divided into?
Ответы
a. When the entire cycle of events is completed in two strokes.
b. The lower limit of the piston movement.
с. The upper limit of the piston movement.
d. When the entire cycle of events in the cylinder is completed in four strokes.
e. Intake, compression, power and exhaust strokes.
6. Закончите предложения, выбрав соответствующий вариант окончания:
1. An internal combustion engine is called so because gasoline is burned....
a) inside the combustion chamber
b) outside the combustion chamber
2. The upper limit of the piston movement is called...
3. The lower limit of the piston movement is called....
a) the bottom dead centre
b) the top dead centre
4. The four-cycle engine requires....
a) two strokes of piston movement
b) four strokes of piston movement
5. The mixture of air and gasoline is delivered into the cylinder....
a) on the power stroke
b) on the exhaust stroke
c) on the intake stroke
d) on the compression stroke.
