Principle of Operation of the Four-Stroke Petrol Engine

Week 2

Tasks / Тапсырмалар:

1. Text “Principle of operation of the four-stroke petrol engine”
2. Grammar: Continuous tenses (revision)

Read and translate the text

Principle of Operation of the Four-Stroke Petrol Engine

The internal combustion engine is called so because fuel is burned directly inside the engine itself. Most automobile engines work on a 4-stroke cycle. A cycle is one complete sequence of 4 strokes of the piston in the cylinder. The operating cycle of the four-stroke petrol engine includes: inlet stroke (intake valve opens), compression stroke (both valves closed), power stroke (both valves closed), exhaust stroke (exhaust valve is opened).

To describe the complete cycle, let's assume that the piston is at the top of the stroke (top dead center) and the inlet and the exhaust valves are closed. When the piston moves down the inlet valve opens to intake a charge of fuel into the cylinder. This is called the inlet (intake) stroke. On reaching the lowest position (bottom dead center) the pis­ton begins to move upward into the closed upper part on the cylinder, (he inlet valve is closed and the mixture is compressed by the rising piston. This is called the compression stroke. As the piston again reaches the top dead center the spark plugs ignite the mixture, both valves be­ing closed during its combustion. As a result of burning mixtures the both valves be­ing closed during its combustion. As a result of burning mixtures the gases expand and great pressure makes the piston move back down the cylinder. This stroke is called the power stroke. When the piston reaches the bottom of its stroke, the exhaust valve is opened, pressure is re­leased, and the piston again rises. It lets the burnt gas flow through the exhaust valve into the atmosphere. This is called the exhaust stroke which completes the cycle. So the piston moves in the cylinder down (intake stroke), up (compression stroke), down (power stroke), up (ex­haust stroke).

The heat released by the fuel is transformed into work so that the reciprocating movement of the pistons is converted into rotary move­ment of a crankshaft by means of connecting rods.

1 - intake 2 - compression 3 - power 4 - exhaust

1. intake - такт впуска 3. power — рабочий такт
2. compression — такт сжатия 4. exhaust — такт выхлопа

Answer the questions:

1. Why is the engine called the internal combustion engine?

2. What stroke is called the inlet one?

3. What is a compression stroke?

4. What takes place in the cylinder on power stroke?

5. What takes place on the exhaust stroke?

6. By means of what is the reciprocating movement of the pistons converted into rotary movement of a crankshaft?

Choose the right variant:

1. The internal combustion engine is called so because fuel is burned…

a) outside the engine; b) inside the engine.

2. On the inlet stroke.............

a) the intake valve opens; b) the intake valve is closed; c) the intake and the exhaust valves are closed.

3.On the compression stroke...............

a) the intake valve opens; b) the intake valve is closed; c) the intake and the exhaust valves are closed.

4.On the power stroke...........

a) the intake valve opens; b) the intake valve is closed; c) the intake and the exhaust valves are closed.

5.On the exhaust stroke.............

a) the exhaust valve opens; b) the intake valve is closed; c) the intake and the exhaust valves are closed.

Translate new words into Kazakh and learn them:

as a result assume bottom dead center burn by means of charge of fuel combustion combustion chamber compression stroke connecting rod convert crankshaft cylinder descend describe diesel engine directly engine exhaust stroke four-stroke cycle fuel injection top dead center trace the fault valve

have a look heat ignite ignition intake (inlet) stroke internal combustion engine mixture operating cycle petrol engine piston power stroke pressure reach recharge reciprocating movement residual gas rise rotary movement run down run out of fuel spark plug stroke tank

2. Grammar:

Present Continuous	Past Continuous	Future Continuous
I am reading a newspaper	I was reading a newspaper when he came	I shall be reading a newspaper when he comes.
Мен газет оқып отырмын	Ол келгенде мен газет оқып отырдым	Ол келгенде мен газет оқып отырамын

Exercise 1: Open the brackets

1. We could not go out because it (to rain) hard since early morning. 2. She (to teach) at our school for twenty years now. 3. Ring me up as soon as you (to come) home. 4. He (to begin) to write his composition at three o'clock. It is already eleven, and he still (to write) it. He says he (to finish) it by twelve. 5. We (to help) our librarian to put the books in the right order for three days already, but we (to arrange) only half the books. 6. What you (to do) when I (to come) in? 7. When I (to come) to his house, they (to tell) me that he (to leave) an hour before. 8. On checking up his answers he (to find) out that he (to make) several mistakes. 9. When I (to leave) home, the snow already (to stop), but a strong wind (to blow). 10. You (to read) this book? — Yes, I (to read) it. I (to think) it (to be) very interesting. 11. What the children (to do) now? — Oh, they (to play) the new board game which I (to buy) for them the day before yesterday. 12. They (to reach) the corner of the street by now and (to stand) at the bus stop. 13. After we (to walk) about two hours, we arrived at a picturesque glade covered with fresh grass.

Exercise 2: Open the brackets

1. At last the librarian (to give) me the book which I (to wait) for during two months. I was very glad. I (to go) home and (to begin) reading it at once. 2. Don't speak to him: he (to be) very busy, he (to do) some very urgent work. 3. I did not want him to go there: I (to be) afraid that something (to happen). 4.1 did not notice that my watch (to stop), and when I (to arrive) at the station, my train (to leave) and I (to have) to ask when the next train (to come). 6. He (to wait) for fifteen minutes when at last he (to see) her at the end of the platform. 6. By the end of the year he (to read) about two hundred pages. 7. We were happy when the sun (to rise), for the night (to be) very cold. 8. Where you (to put) my dictionary? I cannot find it anywhere. 9. I (not yet to fall) asleep when the telephone (to ring). 10. What you (to do) from six till nine yesterday? 11. The children (to play) here at eleven o'clock, but now they (to go) home. 12. Go to see your old grandfather as soon as you (to arrive) in Novgorod. 13. You always (to spend) summer at the seaside? — Yes, as a rule. Last summer I (to go) to the mountains, but I (not to find) the rest there as pleasant as near the sea. 14. When they returned, they (to tell) us many interesting things which they (to see) during their journey. 15. When I (to leave) home, it (to rain).

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