The common rail fuel injection system officially entered the practical stage in the mid-1990s. This kind of electronic control system can be divided into: accumulator type electronic fuel injection system, hydraulic supercharged electronic fuel injection system and Common rail type electronic fuel injection system. The Common rail system can realize the functions that cannot be realized in the traditional fuel injection system. Its advantages are:

a. The fuel injection pressure in the common rail system is flexible and adjustable, which can determine the optimal injection pressure required for different working conditions, thereby optimizing the overall performance of the diesel engine.

b. It can independently and flexibly control the fuel injection timing, combined with high injection pressure (120MPa~200MPa), and can simultaneously control NOx and particulate matter (PM) within a small value to meet emission requirements.

c. Flexible control of fuel injection rate changes, achieving ideal fuel injection patterns, easy to achieve pre injection and multiple injections, which can reduce diesel engine NOx while ensuring excellent power and economy.

d. Controlled by an electromagnetic valve for fuel injection, its control accuracy is high, and there will be no bubbles or zero residual pressure in the high-pressure oil circuit. Therefore, within the operating range of the diesel engine, the cyclic fuel injection quantity changes little, and the uneven fuel supply of each cylinder can be improved, thereby reducing the vibration of the diesel engine and reducing emissions.

Because the Common rail system has the above advantages, now domestic and foreign diesel engine research institutions have invested a lot of energy in its research.

The design criterion for the fuel supply of the high-pressure oil pump is to ensure the sum of the fuel injection and control fuel of the diesel engine under any circumstances

The demand for and the demand for fuel changes during start-up and acceleration. Due to the lack of fuel injection pressure during the fuel injection process in the common rail system

Off, and the injection timing is not guaranteed by the cam of the high-pressure oil pump, so the pressure cam of the high-pressure oil pump can minimize the peak torque

Design cams based on the principles of minimum contact stress and maximum wear resistance.