Fuel injection nozzle for internal combustion engines

Fuel injection nozzle for pilot and main injection, with an inwardly opening valve needle (22) and a fuel chamber (45), which is defined by a deflection piston (32), which is pressed by spring force against a valve seat (42), which encloses a fuel passage (24, 44) opening into the fuel chamber (45) and lifts off from this when the fuel pressure at the end of a pilot injection phase has attained a predetermined value. According to the invention, the deflection piston (32) is displaceably supported in a cylinder bore (30) of the valve needle (22) and at the end of its deflection stroke comes to bear on the intermediate disc (12) arranged between nozzle body (10) and nozzle holder (16), which disc also limits the opening lift of the valve needle (22). This results in a compact construction in the longitudinal axis of the injection nozzle, which without additional parts suffices for guiding and limiting the stroke of the deflection piston (32). In addition, when the deflection piston (32) lifts off from its valve seat (42), the fuel contact surface on the valve needle (22) acting in the opening direction is reduced so that at the end of the pilot injection phase the said needle temporarily returns to its valve seat (20) on the nozzle body (10) and in so doing briefly interrupts the injection.