2. Перекладіть українською текст “General Structure of Automobiles”

Automobile - Engine

The engine operates on internal combustion; that is, the fuel used for its power is burnt inside the engine. This burning occurs inside cylinders. Within the cylinder is a piston. When the fuel is burnt, it creates an explosive force that causes the piston to move up and down. The piston is attached, via a connecting rod, to a crankshaft, where the up and down movement of the piston converts to a circular motion. When bicycling, the upper part of a person's leg is akin to the pis-ton. Power from the leg is passed through the pedal in order to turn the crank.

Gasoline is the most common automobile fuel. It is pulled into the cylinder by the vacuum cre-ated as the piston moves down through the cylinder. The gasoline is then compressed up into the cylinder by the next movement of the piston. A spark is introduced through a spark plug placed at the end of the cylinder. The spark causes the gasoline to explode, and the explosion drives the piston down again into the cylinder. This movement, called the power stroke, turns the crank-shaft. A final movement of the piston upward again forces the exhaust gases, the byproducts of the fuel's combustion, from the cylinder. These four movements—intake, compression, power, and exhaust—are called strokes. The four-stroke engine is the most common type of automobile engine.

Most automobiles have from four to eight cylinders, although there are also two-cylinder and 12-cylinder automobiles. The cylinders work together in a sequence to turn the crankshaft, so that while one cylinder is in its intake stroke, another is in the compression stroke, and so forth. Generally, the more cylinders, the more smoothly the engine will run. The size of the automobile will affect the number of cylinders the engine uses. Smaller cars generally have the smaller four-cylinder engine. Mid-sized cars will generally require a six-cylinder engine, while larger cars ne-ed the power of an eight-cylinder engine.

The number of cylinders, however, is less important to the level of an engine's power than is its displacement. Displacement is a measure of the total volume of fuel mixture moved by all the pistons working together. The more fuel burned at one time, the more explosive the force, and thus, the power will be. Displacement is often expressed as cubic centimeters (cc) or as liters. A smaller engine will displace 1,200 cc (1.2 L) for 60 horsepower, while a larger engine may dis-place as much as 4,000 cc (4 L), generating more than 100 horsepower. Horsepower is the mea-surement of the engine's ability to perform work. The size and weight of the car also affects its power. It takes less work to propel a lighter car than a heavier car, even if they have the same en-gine, just as a horse carrying a single rider can go faster with less effort than a horse drawing a cart.

Automobile - Fuel System

Gasoline must be properly mixed with air before it can be introduced into the cylinder. The combination of gasoline and air creates a more volatile explosion. The fuel pump draws the ga-soline from the gas tank mounted toward the rear of the car. The gasoline is drawn into a carbu- retor on some cars, while it is fuel-injected on others; both devices mix the gasoline with air (ap-proximately 14 parts of air to one part of gasoline) and spray this mixture as a fine mist into the cylinders. Other parts of the fuel system include the air cleaner, which is a filter to ensure that the air mixed into the fuel is free of impurities; and the intake manifold, which distributes the fu-el mixture to the cylinders.

Automobile - Exhaust System

After the fuel is burned in the pistons, the gases and heat created must be discharged from the cylinder to make room for the next infusion of fuel. The exhaust system is also responsible for reducing the noise caused by the explosion of the fuel.

Exhaust gases are discharged from the cylinder through an exhaust valve. The exhaust gathers in an exhaust manifold before eventually being channeled through the exhaust pipe and muffler and finally out the tailpipe and away from the car. The muffler is constructed with a maze of what are called baffles, specially developed walls that absorb energy, in the form of heat, force, and sound, as the exhaust passes through the muffler.

The burning of fuel creates additional byproducts of hazardous gases –hydrocarbons, carbon monoxide, and nitrogen oxide—which are harmful both to the engine’s components and to the environment. The emission control system of a car is linked to the exhaust system, and functions in two primary ways. The first is to re-duce the levels of unburned fuel. This is achieved by re-turning the exhaust to the fuel-air mixture injected into the cylinders to burn as much of the ex-haust as possible. The second method is through a catalytic converter. Fitted before the muffler, the catalytic converter contains precious metals that act as catalysts. That is, they increase the rate of conversion of the harmful gases to less harmful forms.

3. Дайте відповіді на питання. 1. What is the most common automobile fuel? 2. What is the measurement of the engine's ability to perform work? 3. What additional byproducts of hazardous gases do you know?