Classification of engines

1. Depending on the fuel used

According to the different fuel used, automobile engines can be divided into gasoline engine, diesel engine, CNG engine, LPG engine, dual fuel engine and so on five kinds

A. An internal combustion engine that uses gasoline as fuel is called a gasoline engine; Gasoline engine has high speed, low quality, low noise, easy starting and low manufacturing cost.

B. An internal combustion engine that uses diesel as fuel becomes a diesel engine. Diesel engine has higher compression ratio, higher thermal efficiency, better economic performance and emission performance than gasoline.

C. Combustion engines that use compressed natural gas (CNG) as fuel are called CNG engines. Natural gas, which is mainly composed of methane and is burned to produce carbon dioxide and water, is a very safe and environmentally friendly energy source.

D. An internal combustion engine that uses liquefied petroleum gas (LPG) as fuel is called LPG engine. LPG has the characteristics of high calorific value, full combustion, and low content of carbon monoxide, hydrocarbons and sulfide in the exhaust.

E. Internal combustion engines that can use both fuels are called dual fuel engines, such as hydrogen/gasoline engines, LPG/ gasoline engines, CNG/ gasoline engines, and so on.

2. Classification by stroke

According to the different working stroke of the engine, the automobile engine can be divided into four stroke engine and two stroke engine.

A. The internal combustion engine in which the crankshaft turns twice (720°) and the piston moves up and down in the cylinder for four strokes to complete one working cycle is called the four-stroke internal combustion engine, which is widely used in automobile engines.

B. The crankshaft rotates once (360°) and the piston reciprocates two strokes in the cylinder to complete one working cycle of the internal combustion engine called the two-stroke internal combustion engine.

3. Classified by cooling method

According to different engine cooling methods, automobile engines can also be divided into water – cooled engines and air – cooled engines.

A. The water-cooled engine is cooled by using the coolant circulating in the cylinder body and the cover cooling water jacket as the cooling medium. Water-cooled engine is widely used in modern automobile engine because of its uniform cooling, reliable operation and good cooling effect.

B. The air-cooled engine is cooled by using the air flowing between the cylinder body and the radiator on the outer surface of the cylinder head as the cooling medium.

4. Classify according to the number of cylinders

According to the number of engine cylinder block cylinder, the engine can be divided into single cylinder, double cylinder and multi-cylinder engine.

An engine with only one cylinder is called a single cylinder engine; An engine with more than two cylinders is called a multi-cylinder engine, such as three cylinders, four cylinders, five cylinders, six cylinders, eight cylinders, twelve cylinders are all multi-cylinder engines. Modern car engine uses four cylinder, six cylinder, eight cylinder engine.

5. Classification by cylinder arrangement

According to the arrangement of engine cylinders, there are five common forms of automobile engines, which are in-line, oblique, opposed, V and W.

The cylinders of an in-line engine are arranged in a row, usually vertically, but in order to reduce the height, the cylinders are sometimes arranged to tilt or even level; A double-row engine arranges the cylinders in two rows. The Angle between the two rows is less than 180° (generally 90°), called a V-engine. If the Angle between the two rows is equal to 180°, it is called an opposing engine.

6. Classified according to whether the intake system adopts supercharging mode

According to whether supercharged can be divided into non-supercharged and supercharged two categories, gasoline engine more natural inspiratory type; In order to increase the power, the diesel engine adopts supercharging.

7. Sort the piston according to its working mode

According to the piston working mode, the engine can be divided into two categories: reciprocating piston type and rotor piston type. A reciprocating piston engine, referred to as a piston engine, is an engine that uses one or more pistons to convert pressure into rotational kinetic energy. Reciprocating piston engine, the reciprocating linear motion of the piston in the cylinder, through the crankshaft to convert the linear motion of the piston into the rotation of the crankshaft, general engines are used in this form.

The rotor piston engine is referred to as the rotor engine, which drives the engine spindle to rotate through the rotation of the piston in the cylinder.

8. Type by fuel supply

Gasoline engines can also be divided into carburetor and electric injection according to different fuel supply methods.

The carburetor relies on the negative pressure formed by the intake air flow of the engine to absorb and atomize gasoline for combustion work; Carburetor engine fuel supply is the use of the throat set above the throttle, air flow through the throat to produce negative pressure, the gasoline from the main nozzle continuous suction, into the engine intake manifold, into the cylinder.

Its ejector engine is called electronically controlled gasoline injection engine, which consists of intake system, fuel system, electronic control system and so on. It is based on the sensor installed in the near term system of the engine and the body of the sensor perceived information, provided to the computer control system, accurate calculation of the fuel supply required by the engine in various conditions, and to provide the required pulse width to the fuel injector, and then there will be a certain pressure of fuel through the injector into the intake manifold or cylinder. It has much stronger environmental protection than carburetor engine, but also improve the engine inflation efficiency, increase the engine power and torque.