What is the working principle of a high-pressure fuel pump?
1 Answers
The working principle of a high-pressure fuel pump consists of three main stages: the suction stroke, the return stroke, and the pumping stroke. Below is a detailed explanation of the working principle of a high-pressure fuel pump: 1. Suction stroke: During the suction process, the downward movement of the pump piston provides the suction force, while the intake valve opens, allowing fuel to be drawn into the pump chamber. In the final third of the pump piston's stroke, the fuel pressure regulator is energized, keeping the intake valve open during the initial upward movement of the pump piston to allow fuel return. 2. Return stroke: To control the actual fuel supply, the intake valve remains open during the initial upward movement of the pump piston, allowing excess fuel to be pushed back to the low-pressure side by the pump piston. The pressure damper absorbs the pressure fluctuations generated during this process. 3. Pumping stroke: At the beginning of the pumping stroke, the fuel pressure regulator is de-energized, causing the intake valve to close under the combined action of the rising pressure in the pump chamber and the closing spring inside the valve. The upward movement of the pump piston creates pressure in the pump chamber, and when this pressure exceeds the pressure in the fuel rail, the outlet valve opens, allowing fuel to be pumped into the fuel rail.
