Such a simple carburetor can not meet the requirements of the mixture composition of internal combustion engines in various working conditions.Therefore, the carburetor used in general internal combustion engine, especially automobile internal combustion engine, also needs other systems, including main oil system, idle system, thickening system, acceleration system and starting system.
The main oil system
The main oil system is the main oil supply system of the carburetor.There are three commonly used main oil system correction (compensation) methods:
1, with infiltration air compensation;
2, oil needle to change the main hole area;
3. Change the area of the throat and the main measuring hole at the same time.
Among them, the first method is widely used.
The air compensation method is to add the main air volume hole and foam pipe between the main volume hole and the nozzle, thus infiltrating the air, in order to reduce the vacuum of the main volume hole, so as to control the fuel flow, can get the required mixture composition.In order to make the mixture composition stable, the float chamber has a through hole communicated with the atmosphere, and the float controls the oil inlet needle valve to keep the liquid level of the fuel in the float chamber stable.The liquid level is usually 5 to 6 mm lower than the nozzle to prevent fuel spillover when the internal combustion engine tilts.The shape and size of the nozzle determine the air velocity and vacuum degree, thus affecting the internal combustion engine's charging capacity, main oil supply and fuel atomization.In order to get high speed airflow to make atomization good, and at the same time to increase the volume of air, can use double or triple throat.The main oil system can only meet the requirements of the mixture in most operating conditions.In special working conditions, the auxiliary system is also needed.