Fuel Injection Valve for Combustion Engines

A fuel injection valve for intermittent injection of fuel into the combustion chamber of an internal combustion engine, having

• a housing (12), which has a housing body (14) and a nozzle body (16) with an injection valve seat (18),
• a high-pressure space (26), which is arranged in the housing (12) and extends from a high-pressure fuel inlet (24) to the injection valve seat (18),
• an injection valve member (56), which is arranged movably in the housing (12) and interacts with the injection valve seat (18),
• a compression spring (62), which is supported, on the one hand, on the injection valve member (56) and subjects the latter to a closing force directed toward the injection valve seat (18) and, on the other hand, is supported in a fixed manner relative to the housing (12),
• a guiding part (64), in which a control plunger (68) of the injection valve member (56) is guided with a sliding fit,
• an intermediate part (66), which, together with the guiding part (64) and the control plunger (68), delimits a control space (70),
• a control device (72) for controlling the axial movement of the injection valve member (56) by varying the pressure in the control space (70), having an intermediate valve (83), the mushroom-shaped intermediate valve member (78) of which has a stem (76), which is guided with a sliding fit in a guide passage (74) of the intermediate part (66), and a head (80), the sealing surface (116) of which, which extends at a radial distance around the stem (76), rests, in the closed position of the intermediate valve member (78), against an annular intermediate valve seat (82) formed on the intermediate part (66), thereby forming an annular sealing surface (122),
• an annular space (120), which is delimited by the intermediate part (66), the stem (76) and the head (80) and has an inner annular space (108) extending around the stem (76), into which inner annular space (108) a high-pressure fuel feed (86) connected to the high-pressure fuel inlet (24) opens,
• wherein the intermediate valve (83) cuts off the high-pressure fuel feed (86) and the annular space (120) from the control space (70) in the closed position of the intermediate valve member (78) and otherwise opens the connection from the annular space (120) and the high-pressure fuel feed (86) to the control space (70), and the intermediate valve member (78) continuously cuts off the control space (70) from a valve space (44)—apart from a restrictor passage (90), and
• an electrically actuated actuator arrangement (38) for connecting the valve space (44) to and cutting the valve space (44) off from a low-pressure fuel return (46),
• wherein the annular space (120) has an annular gap space (118), which adjoins the inner annular space (108) and which is formed by a gap between the intermediate part (66) and the head (80) in the closed position of the intermediate valve member (78).