Patent ID: 6779741
Filing Date: 2004-08-24
Classification: F02M

Abstract:
A fuel injection apparatus for an internal combustion engine, comprisinga high-pressure fuel pump (10) and a fuel injection valve (12) connected to a high pressure pump for each cylinder of the engine, the high-pressure fuel pump (10) having a pump piston (18), which the engine sets into a stroke motion and which defines a pump working chamber (22), the working chamber being supplied with fuel from a fuel tank (24), which also is a relief chamber (24), the fuel injection valve (12) having a pressure chamber (40) connected to the pump working chamber (22) and an injection valve member (28) which controls at least one injection opening (32) and which the pressure prevailing in the pressure chamber (40) can move in an opening direction (29), counter to a closing force, in order to unblock the at least one injection opening (32), a first control valve (68) that controls a connection (66) between the pump working chamber (22) and the relief chamber (24), a second control valve (70) that controls a connection (64) between a control pressure chamber (52) of the fuel injection valve and the relief chamber (24), wherein the pressure prevailing in the control pressure chamber (52) at least indirectly acts on the injection valve member (28) and the control pressure chamber (52) is connected to the pump working chamber (22), and a control piston (50) contained in the control pressure chamber (52), the control piston (50) being connected to the injection valve member (28) and dividing the control pressure chamber (52) into two separate partial chambers (54, 56) that are connected to each other via a throttle restriction (55), whereby, that when the second control valve (70) is closed and the control pressure chamber (52) is disconnected from the relief chamber (24), a lower pressure acts on the control piston (50) in a closing direction of the injection valve member (28) than when the second control valve (70) is open.