A Brief Discussion on Common Rail Electronic Control Fuel Injection Technology for Diesel Engines

Electronic fuel injection technology has evolved from the initial position-controlled type to the time-controlled type, and the common rail electronic fuel injection equipment technology precisely belongs to the latter. The common rail electronic control system uses various related sensors to collect and transmit the operating status parameters of the diesel engine to the controller (ECU), and the ECU, according to the purpose. The set values calculate the fuel injection volume, fuel injection pressure, fuel injection timing and fuel injection rate, and then issue instructions to the actuator to drive it to operate, keeping the diesel engine in the best condition.

Common rail electronic control injection technology refers to a fuel supply method in which the generation of injection pressure and the injection process are completely separated in a closed-loop system composed of a high-pressure oil pump, pressure sensor and electronic control device (BCU). It is composed of a high-pressure fuel pump that delivers high-pressure fuel to the common fuel supply pipe. Through the oil pressure in the common fuel supply pipe, precise control is achieved, making the pressure in the high-pressure fuel pipe independent of the engine's rotational speed. This can significantly reduce the extent to which the fuel supply pressure of the diesel engine varies with the engine's rotational speed. Therefore, it also reduces the drawbacks of traditional diesel engines. The ECU controls the fuel injection volume of the fuel injector, which depends on the pressure of the fuel track and the duration of the solenoid valve opening.

This technology no longer adopts the traditional principle of pulsating fuel supply by a plunger pump, but instead directly or indirectly forms a constant high-pressure fuel through a common rail. The fuel is distributed to each injector and, with the opening and closing of the high-speed electromagnetic switch valve integrated on each injector, the amount of fuel injected into the diesel engine combustion chamber by the injector is controlled in a timed and quantitative manner, thereby ensuring that the diesel engine achieves the best combustion ratio and good atomization, as well as the optimal ignition time, sufficient energy and the least pollution emissions.

The common rail electronic fuel injection technology for diesel engines integrates computer control technology, modern sensor detection technology and advanced injector structure. It can not only achieve high injection pressure, control injection pressure and fuel injection volume, but also realize pre-injection and post-injection, thereby optimizing fuel injection characteristics, reducing diesel engine noise and significantly reducing exhaust emissions.