Hydraulically actuated fuel injection valve for combustion engine

摘要

The valve has a housing (13) in which there is an actuator bore (26). A movable actuator rod (9) is arranged in the bore (26). This has a nozzle needle (40). When the valve is closed, the needle (40) is pressed against a valve seat (41). The latter has an injection opening. A control bore (25) is connected to the actuator bore (26). A movable control piston (3) is disposed in the control bore (25). A spring element (10) is arranged between the actuator rod (9) and the control piston (25) such that a control chamber (7) is formed between the piston and the actuator rod (9). An inlet (1) is disposed in the housing (13). The inlet is in connection with the control chamber (7) via lines (2,29,4,5,6,30) and is in connection with an outlet (34) via a control valve (8). The lines have an annular channel (2) in the edge region of the control piston (3). The annular channel (2) is in connection with a pressure chamber (5) inside the control piston (3) via an inlet bore (29,4). The pressure chamber (5) is in connection with the outlet (34) and the control chamber (7). the control piston (3) is pressed by the spring element (10) against a seal seat (11) in the housing (13). This seat (11) seals the annular channel from the control chamber. The control piston (3) is movable against the spring force of the spring element (10) making a direct connection between the annular channel (29) and the control chamber (7).