The function of the fuel injection pump is to deliver high-pressure diesel oil to the injector according to the working order and load of Bai engine. The function of the fuel injection Dao is to spray the high-pressure diesel oil supplied by the fuel injection pump into the combustion chamber with a certain pressure.

The requirements are as follows:

(1) uniform atomization;

(2) certain injection pressure and range

(3) proper injection cone angle;

(4) rapid fuel cut-off and no dripping phenomenon

Ordinary diesel engine is driven by the engine camshaft, with the help of high-pressure oil pump to deliver diesel to the fuel chambers of each cylinder. This mode of fuel supply changes with the change of engine speed, so it can not achieve the best fuel supply under various speeds.

The common rail injection fuel supply system is composed of high-pressure oil pump, common oil supply pipe, injector, electronic control unit (ECU) and some pipeline pressure sensors. Each injector in the system is connected with the common oil supply pipe through its own high-pressure oil pipe, and the common oil supply pipe plays a role of hydraulic pressure storage for the injector. When working, the high-pressure oil pump delivers the fuel to the common oil supply pipe with high pressure. The high-pressure oil pump, pressure sensor and ECU work in a closed-loop manner, which can accurately control the oil pressure in the common oil supply pipe, and completely change the phenomenon that the fuel supply pressure changes with the engine speed

Its main characteristics are as follows:

1. The fuel injection timing and fuel metering are completely separated, and the injection pressure and injection process are timely controlled by ECU.

2. According to the working conditions of the engine, the injection pressure, injection starting point and duration can be adjusted to achieve the best control point.

3. It can realize high injection pressure and pre injection of diesel.