The working principle of high pressure fuel pump

1. Suction stroke

In the process of sucking oil, the downward movement of the pump piston provides the power for sucking oil. At the same time, when the oil inlet valve is opened, the fuel is sucked into the pump cavity. In the pump piston stroke

In the last 1/3 section, the fuel pressure regulating valve is energized, so that the fuel inlet valve is still open to return fuel at the initial stage of the upward movement of the pump piston.

2. Oil return stroke

In order to control the actual fuel supply, the fuel inlet valve is still open at the beginning of the upward movement of the pump piston, and the excess fuel is squeezed back to low pressure by the pump piston

end. The function of the pressure reducer is to absorb the pressure fluctuations generated in this process.

3. Pump oil stroke

At the beginning of the pump stroke, the fuel pressure regulating valve is de-energized, so that the rising pressure of the fuel inlet valve in the pump chamber and the closing spring in the valve work together

Close down.

The pump piston moves upward to generate pressure in the pump chamber. When the pressure exceeds the pressure in the fuel rail, the fuel outlet valve is opened and fuel is pumped into the fuel rail.