Patent ID: 7455244

Claim:
A fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, the injector comprising, an injector body, a nozzle holder, an injection valve member movably received in the nozzle holder, the injection valve member having a seat that opens or closes injection openings, a piezoelectric actuator, a first booster piston directly actuated by the piezoelectric actuator, and a second booster piston guided in the first booster piston and connected to the injection valve member for varying pressure inside a control chamber, wherein the piezoelectric actuator is received inside a pressure chamber, embodied in the injector body, which chamber has an inlet for fuel at system pressure and wherein the control chamber is defined by a control chamber sleeve, an annular face of the first booster piston, an annular face of the second booster piston, and a plane face of the nozzle holder.