Diesel IC engine fuel injection valve - with valve needle operated via pressure slot sliding relative to cooperating hydraulic piston

摘要

The fuel injection valve has a sliding valve needle (4) continuously acted on by a first closure spring (8b) and acted on by a second closure spring only when it has moved away from the closure position by a given distance. The valve needle (4) is operated via a pressure bolt (5) directly acted on by the first closure spring (8b) and sliding relative to an hydraulic piston (7), acted on by the second closure spring (8a). An intermediate ring (10) which can slide along the pressure bolt (5) acts against the hydraulic piston (7). It has a shoulder (19) facing a corresponding shoulder of the valve needle (4) used to define a distance (d1) corresponding to the valve needle preliminary stroke. ADVANTAGE Maintains min. mechanical tolerances.