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How much do you know about internal combustion engines

The engine that burns fuel (gasoline, diesel, kerosene) inside the cylinder, the expanding gas pressure drives the piston up and down to produce power.

The working cycle

The working cycle of an internal combustion engine is composed of intake, compression, combustion and expansion, exhaust, and other processes. In these processes, only the expansion process is the process of external work, and all other processes are the processes that need to be done to achieve the process of achievement. According to the number of trips to achieve a work cycle, the work cycle can be divided into four strokes and two strokes.

A four-stroke internal combustion engine

The crankshaft rotates 720 rounds to complete the pressure absorption and detonation row, a working cycle, called the four-stroke internal combustion engine. Four-stroke refers to the completion of a working cycle within the four strokes of intake, compression, work (expansion), and exhaust, where the crankshaft rotates twice. When the intake stroke, the inlet valve opens and the exhaust valve closes. Air flowing through the air filter, or combustible mixture formed by mixing with gasoline by the carburetor, enters the cylinder through the intake pipe and inlet door; During the compression stroke, the gas in the cylinder is compressed, the pressure is increased and the temperature is increased; The expansion stroke is to spray oil or ignition before the compression stop point, so that the mixture combustion, produce high temperature, high pressure, push the piston down and work hard; During the exhaust stroke, the piston pushes the exhaust gas in the cylinder through the exhaust valve. Then start with the intake stroke and go on to the next work cycle.

Two-stroke internal combustion engine

The crankshaft turns a circle of 360, completing the pressure absorption and explosion row, a working cycle, called the two-stroke internal combustion engine. A second stroke refers to the completion of a work cycle within two trips, during which the crankshaft rotates one circle. When the piston is lower, the inlet and outlet are opened, and the fresh charge is filled into the cylinder by the air inlet, and the exhaust gas in the cylinder is swept out of the outlet; Then the piston goes up, the inlet and outlet are closed, and the filling in the cylinder begins to be compressed until the piston is close to the upper and lower point, ignition or oil injection, so that the combustible mixture in the cylinder combustion; Then the gas inside the cylinder expands and pushes the piston to do work; When the piston goes down to open the vent, the exhaust gas is discharged from it, and the piston continues to fall down to the lower stop point, that is, a work cycle is completed. LandTopMall is a professional engine parts supplier with many years of experience.  Recently, the sales of the thrust film suitable for Yanmar 4tnv106 in our store are very good. The Yanmar engine has superb quality if there is a need, welcome to consult to buy.

How much do you know about internal combustion engines


An internal combustion engine from the appearance of the body, cylinder cover, gear room, and flywheel, from the perspective of the interior, is composed of two structures, three systems, and two equipment, two structures refer to the crankshaft connecting rod mechanism (it is the main component of power generation), and the engine distribution mechanism. Three series refer to the fuel system, lubrication system, and cooling system. The second piece of equipment refers to electrical equipment and hydraulic equipment.

How the internal combustion engine works

The piston goes down from the top stop point, the inlet valve opens, and the fresh air is inhaled into the cylinder. The piston goes up from the bottom stop point. Certain pressure will be very thin fog diesel gas into the gas, produce an explosion, push the piston down, link to push the crankshaft, generate power, piston continues to move up, exhaust valve open, exhaust gas out of the cylinder, complete a work cycle.

Oil supply system

In order to feed fuel into the cylinder, the internal combustion engine is equipped with an oil supply system. The gasoline engine mixes the air with gasoline in a certain proportion (air combustion ratio) by installing it at the inlet end of the inlet pipe and then passes through the intake pipe to the cylinder, which is automatically ignited by the electric spark controlled by the ignition system of the gasoline engine. The fuel of a diesel engine is sprayed into the combustion chamber through the diesel fuel injection system, and it burns by itself at high temperature and high pressure.

Air conditioning process

The exhaust process and intake process of an internal combustion engine are collectively referred to as the ventilation process. The main function of ventilation is to remove the exhaust gas from the previous cycle as clean as possible so that the cycle can be fed as much fresh as possible so that as much fuel can be completely burned in the cylinder, so as to emit greater power. The quality of the ventilation process directly affects the performance of the internal combustion engine. In addition to reducing the flow resistance of the inlet and exhaust system, the main reason is to open and close the inlet and exhaust doors at an appropriate time.

Other matters needing attention

The fuel combustion in the cylinder of an internal combustion engine makes the piston, cylinder liner, cylinder valve, and other parts heated and heated. In order to ensure the normal operation of the internal combustion engine, the above parts must work at the permitted temperature without being damaged by overheating, so the cooling system must be available.

The internal combustion engine cannot go from the parking state to the operating state by itself and must be turned from the external force to make the crankshaft start. This device that produces external forces is called a starting device. The common methods include electric starting, compressed air starting, gasoline engine starts, and human starting.



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