The 4-stroke internal combustion cycle

Before the cycle begins. The cycle begins at top dead centre (TDC). Here the piston is furthest away from the crankshaft. There are 4 strokes of the piston.

Intake stroke. The crankshaft rotates. This makes the piston move down the cylinder, away from the valves. At the same time, the cam above the intake valve rotates. This makes the valve move downwards, which opens the intake port. As the piston moves down, fuel is sucked into the cylinder through this inlet.

Compression stroke. As the crankshaft rotates, it makes the piston move up the chamber towards the valves. Simultaneously, the cam above the intake valve rotates and allows it to close. Both valves are now closed. As the piston moves up towards the valves, it compresses the fuel.

Ignition. Now the piston is once again at TDC. The compressed fuel is ignited by the spark plug and there is a small explosion at the top of the cylinder.

Power stroke. Immediately after this, the gases expand in the cylinder, which pushes the piston downwards. This makes the crankshaft rotate and provides torsion to drive the wheels of the vehicle.

Exhaust stroke. As the crankshaft rotates, it pushes the piston up the cylinder. At the same time, the cam above the exhaust valve pushes the valve downwards. This opens the exhaust port and the burnt gases are pushed out.

The cycle is repeated thousands of times per minute.

7. Study the following information:

When often indicates that two actions happen in sequence, immediately after the other.

(e.g. When the spark plug ignites, the gases explode.)

As often indicates that two actions happen simultaneously, both at the same time.

(e.g. As the piston moves up, it compresses the fuel.)

When or as can sometimes be used with the same meaning when it’s difficult to decide if two actions are simultaneous or in rapid sequence.

(e.g. When / As the brake pedal is pressed, the piston pushes the oil along the brake pipe.)

Now join each group into a single sentence. Use when / as and which. Do not use the words in italics.

e.g. The piston moves up. At the same time, the exhaust valve opens. This lets the burnt gases escape. – As the piston moves up, the exhaust valve opens, which lets the burnt gases escape.

 

a) The spark plug ignites the fuel. Immediately afterwards, there is an explosion. This makes the piston move down with great force.

b) The camshaft rotates. Simultaneously, the cam pushes the intake valve downwards. This allows the fuel to enter the cylinder.

c) The piston moves away from the valve. Immediately after this, it creates a vacuum in the cylinder. This sucks the fuel in.

d) The piston moves up towards the valves. Soon afterwards, it puts the fuel under high pressure. This helps the gases to expand rapidly after ignition.

e) The cam pushes the exhaust valve down. At the same time, the piston moves up towards it. This forces the burnt gases out of the engine.

8. Translate this extract in written form:

As automobiles changed through the years, mechanics or automobile service technicians, as they are now called, have kept them running. The “Big Three” (Ford, GM and Chrysler) automobile makers produced millions of cars for a public eager for freedom and mobility the automobile promised. With the ill-prepared roads suddenly overrun by inexperienced drivers, accidents and breakdowns became common. People were not only unskilled in driving but also were ignorant of the basic maintenance and service the automobile required. It suddenly became apparent that a new profession was in the making.

Automobile service technicians maintain and repair cars, vans, small trucks and other vehicles. Using both hand tools and specialized diagnostic test equipment, they pinpoint problems and make the necessary repairs or adjustments. In addition to performing complex and difficult repairs, they perform a number of routine maintenance procedures, such as oil changes, tire rotation and battery replacement. Technicians interact frequently with customers to explain repair procedures and discuss maintenance needs.

 

Look at the words used to describe shape of car parts. Describe the components from the box below using them.

Square, rectangular, circular, triangular, cuboid, cylindrical, spherical, conical.

 

battery, brake fluid reservoir, engine oil dipstick, engine oil filler cap, windscreen / headlight washer container.

 

What manufacturing company is the most famous in our country? What kind of cars does it produce? Prepare and deliver a short report about one of the companies.

11. Discuss the following famous words:

Research is the answer, if any one should ask why modern cars are so much improved. (Walter P. Chrysler)

The motor car that is thrilling proof of what designers the world over have always known – that the lower a car can be built, the more graceful its lines can be made. (From a Hudson advertisement)

The wheel is one of mankind’s greatest inventions. Why attempt to hide it? (Virgil Exner, Chrysler chief designer)

Modern science and techniques have taught mankind at least one lesson – nothing is impossible. (Lewis Mumfold)

 

Text 5

How has transport changed in the last 100 years? What do you know about the latest innovations in automobile industry?

Do you agree that there will be no more switches, only voice control? Will the car be made of self-cleaning materials? Will the sensors in the car prevent accidents? Would you like to be able to do most of the tasks you usually do in your office – in the car?

THE INSTRUMENT PANEL

Navigation aids, telemetric equipment, audio system features and the standard instruments are all fighting for space on the instrument panel (IP). This creates a challenge for interior designers and engineers who need to keep the IP simple so that the driver is not distracted by too many buttons and instruments. Customers also equate a spacious interior with luxury – another reason why the IP shouldn’t look overcrowded.

Designers deal with the problem in various ways. They reduce the size of ‘space-eaters’ such as heating and cooling systems, or even remove them completely from the IP by putting them under the seat or in the boot. They also put many functions, such as station pre-set buttons for audio systems, on touch screens, which save space on the IP. But there is still the danger of overcrowding the screen, which could distract the driver and thus cause an accident. Another problem is the position: the touch screen needs to be located high on the dashboard so that the driver can use it easily while driving. But if it is too high it can be hard to read because of reflections and the sun ‘washing out’ the screen.

Some engineers see voice recognition as a way to get rid of many manual controls and to simplify the IP. But voice recognition can also be overused. There needs to be an optimal balance between visual displays and voice instructions, so that the driver can deal safely with all the information he or she receives.

 

3. Study the following information:

 

 

Automobile dashboard: the control panel of a car. Contains gauges used to measure speed, distance traveled, etc. It is generally located in front of the driver.

Rearview mirror: mirror used for looking backward.

Cigarette lighter: device used for lighting cigarette.

Vent: opening that allows air to circulate in the passenger compartment.

Glove compartment: storage compartment at the front of passenger compartment.

Radio controls: button used to control the radio.

Heating controls: button used to control the different heating systems of a car.

Steering column: set of mechanisms used for steering a car.

Turn signal level: control that operates the turn signals.

Windshield wiper controls: hand lever controlling the windshield wiper.

Instrument panel: set of dials and pictograms that give information on the state of a vehicle.

Sun visor: movable device that shields against the sun.