FUEL-INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES

A fuel injection valve with a valve member (10), which cooperates with a valve seat (16) to control injection openings (20). The valve member (10) is guided, in a portion remote from the combustion chamber, in a bore (7) and is surrounded by a pressure chamber (12), which can be filled with fuel at high pressure. The valve member (10) is urged by a spring (27) disposed in a spring chamber (25) and having a closing force in the direction of the valve seat (16), and in an appropriate opening pressure in the pressure chamber (12), as a result of the hydraulic pressure on a pressure shoulder (11), embodied on the valve member (10), the valve member lifts from the valve seat (10) and thus opens the injection openings; the injection of the fuel is effected separately in a main injection and a subsequent postinjection. The pressure chamber (12) and the spring chamber (25) communicate via a throttle connection, so that the pressure in the otherwise closed-off spring chamber (25) rises during the main injection and via the additional hydraulic force on the valve member (10) raises the opening pressure of the postinjection; the pressure in the spring chamber (25) has reached the initial value again by the onset of the next injection cycle (FIG. 1).