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

GF07.02-P-3010P Component Description For High Pressure Pump
ENGINE 642.8 in MODEL 463.3 up to 31.5.12
- as of model year 2011
ENGINE 642.9 in MODEL 203.2, 164.8, 203.0, 164.1, 251.0, 221.0, 251.1, 221.1, 204.0 /2 up to model year 2008
/YoM 07
ENGINE 642.9 in MODEL 211.2 /0, 219.3, 209.4 /3, 211.6
ENGINE 642.9 /8 in MODEL 461.3
ENGINE 642.9 in MODEL 463.3 up to 31.5.12





19 High-pressure pump
Y94 Quantity control valve

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 set at 120°, which compresses the fuel sup plied by the fuel pump (M3) and thus generates the rail pressure.





19/1 High-pressure line to rail
19/3 High-pressure port
19/4 Eccentric disk
19/5 Eccentric shaft
19/6 Fuel feed to pump element
19/9 Piston
19/15 Ball valve
19/16 Return flow
19/19 Valve
19/21 Annular passage

E Fuel from quantity control valve
F High pressure
G Return flow

Low-pressure side function
The fuel supplied by the fuel pump arrives at the high-pressure pump flange and from here is 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 passage to the 3 pump elements of the high-pressure pump (fuel feed to high-pressure elements).
To lubricate the pump elements when the quantity control valve is closed (deceleration mode), fuel from the fuel feed is fed directly into the annular passage.

The fuel pressure relief valve limits the fuel pressure at the quantity control valve to about 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 to the eccentric shaft as lubricant.
Any air entrained by the fuel is passed through the fuel pressure relief valve into the high-pressure pump to the return line.





19/3 High-pressure port
19/4 Eccentric disk
19/5 Eccentric shaft
19/6 Fuel feed to pump element
19/8 Valve spring
19/9 Piston
19/10 Piston spring
19/15 Ball valve
19/19 Valve
19/20 High-pressure pump flange
19/21 Annular passage

A Filling the piston
B Producing high pressure

High pressure side
With its eccentric disk, 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 through the annular passage and fuel feed, and against the valve spring force through the valve into the cylinder. The ball valve prevents fuel from flowing back through the high pressure channel into the fuel tank.

High pressure production
The piston is moved upward by the upward movement of the eccentric shaft. This compresses the fuel. The valve closes the delivery volume against the fuel feed. Once the fuel pressure in the cylinder rises above the pressure in the high-pressure circuit, the ball valve opens and the fuel is delivered into the high pressure circuit.