Fuel injection device for an internal combustion engine

A fuel injection system for an internal combustion engine, having a high-pressure fuel pump (10) with a fuel injection valve (12) connected to it for each cylinder of the engine, wherein the high-pressure fuel pump (10) has a pump piston (18) that is driven into a stroke motion by the engine and defines a pump working chamber (22) that is supplied with fuel from a fuel tank (24), wherein the fuel injection valve (12) has a pressure chamber (40) connected to the pump working chamber (22) and an injection valve element (28) that controls at least one injection opening (32) and the pressure prevailing in the pressure chamber (40) can act on the injection valve element (28) in an opening direction (29) in order to open the at least one injection opening (32), having a first control valve (68) that controls a connection (66) of the pump working chamber (22) to a relief chamber (24), and having a second control valve (70) that controls a connection (64) of a control pressure chamber (52, 54;

• 152, 154) to a relief chamber (24), wherein the control pressure chamber (52, 54;
• 152, 154) is defined by a control piston (50;
• 150), which, when acted on by the pressure prevailing in the control pressure chamber (52, 54;
• 152, 154), acts in a closing direction on the injection valve element (28) and can move together with the injection valve element (28), wherein the control pressure chamber (52, 54;
• 152, 154) has a connection (62) to the pump working chamber (22), characterized in that in a stroke position of the control piston (50;
• 150) in which the injection valve element (28) is in its closed position, the pressure prevailing in the control pressure chamber (52, 54;
• 152, 154) acts on a greater end surface of the control piston (50;
• 150) than in a stroke position of the control piston (50;
• 150) in which the injection valve element (28) is opened by its maximal stroke.