Robert Boschgmbh

Rainer Lorenz

Gerd Loesch

Rainer Haeberer

Siegfried Ruthardt

Markus Rueckle

Sandro Soccol

Helmut Clauss

Erhard Faix

A fuel injection system has a low-pressure pump for withdrawing fuel from a tank and a high-pressure pump, which is supplied by the low-pressure pump and has camshaft-actuated pump elements. An on-off valve is connected on the inlet side to the pressure side of the low-pressure pump and on the outlet side, is connected on the one hand to a camshaft chamber of the high-pressure pump and on the other hand, is connected to the suction side of the low-pressure pump. At a first pressure threshold, a spring-loaded valve piston of the on-off valve opens a connection between the low-pressure pump and the camshaft chamber and at a relatively higher second pressure threshold, opens a connection between the pressure side and the suction side of the low-pressure pump. A throttle bore in the bottom of the valve piston serves to ventilate the low-pressure system.

On-off valve in a fuel injection system for internal combustion engines

The invention relates to a radial piston pump for high-pressure fuel delivery in fuel injection systems of internal combustion engines, particularly in a common rail injection system. The pump includes a drive shaft that is supported in a pump housing and is embodied eccentrically or has a number of cam-like projections in the circumference direction. A number of pistons that are disposed radially with regard to the drive shaft are each disposed in a respective cylinder chamber and are set into a reciprocating motion in the radial direction in the cylinder chamber upon rotation of the drive shaft. Each respective cylinder chamber is sealed on the radial outside in relation to the drive shaft by a valve plate that has an intake side check valve and a high-pressure side check valve. In order to increase the efficiency of the pump, the intake side check valve has a tappet that passes through the valve plate and this tappet, on an end oriented toward the cylinder chamber has a valve disk that is placed in a sealed fashion against a sealing seat of the valve plate. On a side of the valve plate remote from the cylinder chamber, a device is provided, which pre-stresses the tappet in the closing direction.

Radial piston pump for high-pressure fuel delivery

Growing community of inventors

Korntal-Muenchingen, Germany

Rainer Lorenz