Patent ID: 6085719
Filing Date: 2000-07-11
Classification: F02M

Abstract:
A fuel injection system for internal combustion engines, which comprises a high-pressure fuel source (1) from which a fuel injection valve (9) is supplied with fuel, said injection valve has an injection valve member (14) for controlling an injection opening (12) and has a control chamber (24), which is defined by a movable wall (22), said movable wall is at least indirectly connected to the injection valve member (14), said control chamber has an inflow conduit (26) arriving from a high-pressure fuel source (1), and an outflow conduit (29) that leads to a relief chamber, pressure in the relief chamber is controlled by a control valve (31), which controls the inflow conduit (26, 126) or an outflow conduit (29, 49) and is actuated by a piezoelectric actuator (41), the control valve (31) has a control valve member (34) with a valve tappet (35), said valve tappet is guided in a housing and a valve head (37, 137) on an end that protrudes into a valve chamber (30), said valve head includes a valve head sealing face (51) that points toward a valve seat (52) and controls an outflow cross section of an outflow conduit (49), the valve chamber (30, 130) communicates with the control chamber (24) and is exposed to a pressure of the high-pressure fuel source (1) when the outflow cross section is closed, and by means of the control valve, two outflow cross sections of different size are opened successively.