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impulse is transmitted to the engine ... . As the ... moves downward on the power

... , it continues to transmit turning effort to the shaft.

d. The Exhaust Stroke.

As the piston reaches ... again, the exhaust valve ... . The piston moves upward on the exhaust stroke, forcing the burned gases out of the ... through the

... ... . At the instant that the piston once more reaches ... , the exhaust valve closes and the ... ... opens so that, when piston begins to move downwards on the intake stroke, a fresh charge of ... ... and air can be drawn into the ... .

Задание 8. Образуйте производные слова от глаголов:

Текст 12

Задание 1. Слушайте и повторяйте:

Задание 2. Найдите соответствующий вариант перевода каждого английского словосочетания:

A). The combustion chamber; the burning of the gas; design characteristics; the head of the piston; the explosion stroke; the compression ratio; water jacket; anti-detonation qualities.

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B). Горение газа; степень сжатия; камера сгорания; головка цилиндра; такт взрыва; противодетонационные качества; конструкционные характеристики; водяная рубашка.

Задание 3. Прочтите текст и найдите в нем следующие предложения.

1.Мощность зависит от используемого топлива.

2.Причиной шума является вибрация стенок камеры сгорания.

3.Алюминиевые поршни и головки цилиндра могут работать в условиях большей степени сжатия по сравнению с чугунными и стальными.

COMBUSTION CHAMBER

The combustion chamber is the space within the cylinder above the piston where the burning of the gas occurs.

Since early days of the industry research is continued on the design characteristics of the combustion chamber.

The trend in design has been, and is, to concentrate as much of the expansive force as possible directly on the head of the piston and avoid dissipation of the expansive force in directions that do not produce power.

Another trend is towards the creation and control of turbulence or movement of the air and gasoline mixture within the cylinder to create a more uniform and better mixture of the gasoline and air. It has been recognized for many years that the more the explosive mixture is compressed within the cylinder before it is ignited, the more power will be developed by the explosion stroke.

The amount of power depends also upon the characteristics of the fuel used. One of these characteristics is the tendency of the fuel "to ping" or "knock" as the compression pressure is raised. This knocking, known as detonation, is attributed to irregular and to rapid expansion of explosion of the gasoline and air mixture.

The noise comes from vibration of the walls of the combustion chamber. The material of which the combustion chamber is made and the efficiency of the cooling system also has a distinct bearing on the compression ratio that

can be used in a given engine.

For example, aluminium pistons and aluminium cylinder heads can operate at higher compression ratios than could cast iron or steel.

One reason for this is perhaps that the heat of combustion is dissipated more rapidly to the cooling water due to the superior heat conducting ability of aluminium. Aluminium can be used for cylinder heads as the cylinder heads in practically all modern engines are detachable.

Aluminium would not be suitable for the engine cylinders as it is too soft

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to wear well. In the early days individual cylinders were sometimes made of cast iron with a copper outer jacket or water jacket attached to them, as copper is also an excellent conductor of heat. This construction was expensive and would also be impractical for modern engines, where cylinders are cast in blocks.

It is entirely practical to make the cylinder casting including the water jacket out of aluminium and insert a cast iron cylinder sleeve or barrel inside the aluminium. This is an ехсellent arrangement where the cost of aluminium makes this construction economically feasable. An aluminium cylinder block with cast iron sleeves in combination with aluminium cylinder head and aluminium pistons provides excellent heat dissipation and anti-detonation qualities.

Задание 4. Закончите следующие предложения, используя текст.

1.The combustion chamber is...

2.Since early days the industry research is continued on…

3.The trend in design is to concentrate as much of the expansive force as possible directly on...

4.Another trend is toward the creation and control of...

5.The amount of power depends also upon...

6.The material of which the combustion chamber is made and the efficiency of the cooling system also have a distinct bearing on...

7.Aluminium would not be suitable for the engine cylinders as...

Задание 5. Образуйте существительные от следующих глаголов:

burn, continue, concentrate, dissipate, produce, create, move, mix, develop, depend, tend, press, detonate, vibrate, conduct, detach, combine.

Задание 6. Найдите ответ, соответствующий содержанию тек-

ста.

1.What do we call a combustion chamber?

2.For what purpose is the turbulence within the cylinder created?

3.What is the relation between the compression and the power?

4.Upon what does the amount of power depend?

5.Of what material can cylinders be made?

Задание 7. Передайте содержание текста на английском языке, используя следующий план.

1.The purpose of the combustion chamber.

2.The ways of the developing power

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a)design characteristics;

b)compression ratio;

c)characteristics of the fuel;

d)the material of which the combustion chamber is made;

e)the efficiency of the cooling system.

При ответе используйте следующие выражения:

the text is about...; the text deals with the problem of...; the main problem of the text is...; it should be noted that...; I know, that...; it is worth mentioning.

Текст 13

Задание 1. Слушайте и повторяйте:

Задание 2. Найдите соответствующий вариант перевода каждого английского словосочетания.

A). Flexible “piston rings”; fitting closely; to transmit the force of the explosion; mechanical and thermal conditions; installed with the utmost care; to avoid excessive inertia forces; to generate excessive friction.

B). Передавать силу взрыва; установленный с предельной точностью; эластичные поршневые кольца; механические и температурные условия; создавать чрезмерное трение; избегать избыточных сил инерции; прилегающий плотно.

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vided. The amount of clearance depends upon the design of the engine cylinders and cooling system, the piston design and material and to a certain extent the service conditions under which the engine operates. Surface treatment will also have a bearing on the piston clearance.

The clearance between cylinders and piston is measured in most саsеs by means of a feeler gauge inserted between the piston and cylinder.

Задание 4. Закончите следующие предложения, используя текст

"Piston".

1.Gas tightness is secured by means of...

2.Conventional pistons for internal combustion engines are shaped like...

3.The pistons are usually made of...

4.Pistons operate under...

5.The amount of clearance depends upon...

6.The clearance between cylinder and piston is measured...

Задание 5. Найдите ответ, соответствующий содержанию тек-

ста.

1.What form has a piston?

2.By means of what is the gas tightness of a piston secured?

3.Of what metal are pistons usually made?

4.Why can semi-steel be well used for making pistons?

5.Under what conditions must pistons operate?

6.What purposes do engine pistons serve?

Задание 6. Посмотрите на схему на с. 204 и скажите:

With the help of what parts of the engine is the force of the explosion transmitted to the flywheel?

Задание 7. Передайте содержание текста на английском языке, используя вопросы задания 5 как план пересказа.

При ответе используйте следующие выражения:

the text is about...; the text deals with the problem of...; the main subject of the test is...; I know, that ...; it is worth mentioning…; it is known, that ...; it should be noted... .

Текст 14

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Задание 1. Слушайте и повторяйте:

Задание 2. Найдите соответствующий вариант перевода каждого английского словосочетания.

A). A flywheel is mounted; the rear main bearing; to idle smoothly; heavy and light flywheels; to balance with great care; centrifugal forces of rotation; critical speeds.

B). Задний коренной подшипник; работать плавно на холостом ходу; критические скорости; центробежные силы вращения; тяжелое и легкое маховое колесо; маховое колесо закреплено; балансировать с особой тщательностью.

Задание 3. Прочтите текст"Flywheel", найдите ответы на следующие вопросы.

1.Для чего необходимо маховое колесо?

2.В каких двигателях используется легкое, а в каких - тяжелое маховое колесо?

3.Что такое критические скорости?

FLYWHEEL

A flywheel is ordinarily mounted near the rear main bearing, which is the longest and sometimes the largest of any of the main bearings in order to support the weight of the flywheel. The flywheel permits the engine to idle smoothly by carrying the pistons through those parts of the stroke cycle when power is not being produced.

The heavier the engine flywheel is the smoother the engine will idle. However an excessively heavy flywheel because of its inertia will cause the engine to accelerate and decelerate slowly.

For these reasons, heavy-duty or truck engines have large and heavy flywheels and racing car or high speed engines have light flywheels.

Because of the forces acting on the flywheel and crankshafts and the

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speed at which they revolve, it is necessary to balance them with great care. They are first balanced statically and then balanced dynamically. To ob-

tain static balance, the weight must be equal in all directions from the centre when the crankshaft is at rest.

Dynamic balance means balance while the crankshaft is turning. Dynamic balance is attained when centrifugal forces of rotation are equal in all directions at any point. The balancing operation requires special machinery and involves removal of metal at the heavy points or addition of metal at the light point.

But no matter how carefully the crankshaft and the parts attached to it are balanced, there will be certain speeds, at which vibration will occur. These are known as critical speeds are caused to occur at speeds outside the working speeds of the engine.

Задание 4. Закончите следующие предложения, используя текст

“Flywheel”.

1.A flywheel is ordinarily mounted...

2.The flywheel permits the engine...

3.To obtain static balance, the weight must...

4.Dynamic balance means...

5.Critical speeds are caused to occur...

Задание 5. Дайте антонимы к следующим словам.

Long, heavy, usual, mount, rear, main, accelerate, slow, high speed, static, equal, at rest, often, near, outside.

Задание 6. Найдите ответ, соответствующий содержанию текс-

та.

1.Where is a flywheel usually mounted?

2.What is the function of a flywheel in an automobile?

3.What flywheels have heavy-duty vehicles?

4.Why must the flywheel and crankshaft be balanced with great care?

5.What are critical speeds?

Задание 7. Посмотрите на схему на с. 204 и ответьте на вопросы.

1.То what mechanism dоеs the flywheel refer?

2.What other parts are included into this mechanism?

Задание 8. Передайте содержание текста на английском языке, используя вопросы задания 6 как пункты плана пересказа.

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1.Сколько кулачков имеет распределительный вал многоцилиндрового двигателя?

2.Для чего служит кулачок?

CAMSHAFT

A camshaft in its simplest form is a straight shaft with an eccentric lobe or cam on it. For one cylinder four cycle poppet valve engine it would have two cams on it -one for the inlet valve and another for the exhaust valve. These cams would be located at different places around the perimeter of the shaft as the valves need to be opened at different times. For a multiple cylinder engine there are ordinarily as many cams as there are valves to be operated.

The cam is designed to lift the valve at precisely the correct instant of piston travel and hold it long enough to obtain the most efficient filling and emptying of the cylinder and thus exerts considerable control over the volumetric efficiency of the engine. In any car engine the ram of the cams are designed to open the valve smoothly and gradually.

The location of the cams around the camshaft along with the design of the crankshaft determines the firing order of the engine.

At one time cams were pinned or keyed to the crankshaft, but they are now forged in one piece and it is not possible to get them mixed up. When they are worn out of shape, it is necessary to replace the entire camshaft.

Задание 5. Закончите следующие предложения, используя текст.

1.A camshaft is a… .

2.Fоr a multiple cylinder engine there are ordinarily as many cams as... .

3.In any car engine the ram on the cams are designed… .

4.The location of the cams determines… .

Задание 6. Образуйте существительные от следующих глаголов.

Replace; locate; place; operate; determine; mix.

Задание 7. Найдите ответ, соответствующий содержанию тек-

ста.

1.What is the camshaft?

2.On what does the quantity of cams on the camshaft depend?

3.What is the function of a cam?

4.What determines the firing order?

5.What must be done if the cams are worn out of shape?

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