GF07.02-P-3010P Component Description For the High Pressure Pump

GF07.02-P-3010P Component Description For The High Pressure Pump







Location
The high pressure pump is mounted on the cylinder head at the left front.

Task
The high pressure pump is a radial piston pump with 3 pump elements arranged at an angle 120° which compresses the fuel supplied by the fuel pump (M3) and thus generates the rail pressure.







Function Low pressure side
The fuel supplied by the electrical fuel pump arrives at the high- pressure pump flange and is then sent on to the quantity control valve and to the fuel pressure relief valve.

The quantity control valve controls the volume of fuel fed through the annular port to the 3 pump elements of the high pressure pump (fuel feed to the high-pressure elements).

In order to lubricate the pump elements when the quantity control valve is closed (overrun mode), fuel from the fuel feed is fed directly into the annular port.

The fuel pressure relief valve limits the fuel pressure which exists at the quantity control valve to approx. 5 bar. If this value is exceeded, the fuel pressure relief valve opens and passes the excess fuel back through the return line to the fuel tank.

The fuel pressure relief valve also sends some of the fuel for lubrication to the eccentric shaft.

Any air entrained by the fuel is passed through the fuel pressure relief valve to the return flow of the high pressure pump.







High pressure side
With its eccentric plate, the eccentric shaft moves the piston back and forth against the piston spring.

Filling the piston
The piston is moved down as a result of the piston spring. The fuel supplied by the fuel pump flows along the annular port, the fuel feed and, by overcoming the force of the valve spring, through the valve into the cylinder. The ball valve prevents fuel from flowing back through the high pressure duct into the fuel tank.

Producing high pressure
The piston is moved upward by the upward movement of the eccentric shaft. This compresses the fuel. The valve closes off the delivery volume to the fuel feed. Once the fuel pressure in the cylinder rises beyond the pressure which exists in the high pressure circuit, the ball valve opens and the fuel is pumped into the high pressure circuit.