Patent ID: 7210639

Claim:
In a fuel injector for internal combustion engines, having a fuel injection valve ( 10 ) connected to a high-pressure source and having a control valve ( 30 ) that includes a control piston ( 34 ) that is guided in a longitudinally movable fashion in a valve body ( 31 ) and comprises a pressure piston section ( 35 ), which has a first pressure surface ( 38 ) and is guided in a bush ( 33 ), and a control piston section ( 36 ) with a sliding seal that has a control edge ( 45 ); the bush ( 33 ) is contained in a pressure chamber ( 40 ) of the valve body ( 31 ) and is at least partially acted on from the outside with system pressure; in a first valve position, a sealing seat ( 46 ) of the control piston ( 34 ), which sealing seat ( 46 ) is acted on by means of the pressure surface ( 38 ), disconnects a valve chamber ( 47 ) from a low-pressure/return system and in a second valve position, the control edge ( 45 ) of the control piston ( 34 ) disconnects the pressure chamber ( 40 ) from the valve chamber ( 47 ) and simultaneously, via the sealing seat ( 46 ), produces a connection between the valve chamber ( 47 ) and the low-pressure/return system, thus initiating an actuation of the fuel injection valve ( 10 ), the improvement wherein the control piston section ( 36 ) of the control piston ( 34 ) with the control edge ( 45 ) is guided in a control cylinder ( 41 ) that is contained in the pressure chamber ( 40 ) of the valve body ( 31 ) and is separate from the bush ( 33 ).