Patent ID: 7575180

Claim:
Method of operating an injection valve comprising the steps of: storing fuel at high pressure in a fuel line; supplying the high pressured fuel from the fuel line via a bypass throttle to a valve chamber and from the fuel line via an inlet throttle to a control chamber, for controlling a nozzle needle; guiding a coupling piece of the nozzle needle through a first guide hole; guiding a control piston of the nozzle needle through a second guide hole; controlling the pressure in the control chamber through a servo valve and an outlet throttle coupling the valve chamber and the control chamber, wherein the control chamber comprises the control piston which is connected to a rod of the nozzle needle, and the rod of the needle nozzle extends through a rod chamber to the coupling piece of the nozzle needle, wherein the pressure between the valve chamber and the control chamber controls the movement of the control piston; coupling a nozzle chamber with the fuel line, wherein the nozzle needle is arranged within the nozzle chamber; and coupling the fuel line with the rod chamber via at least one groove in the first guide hole extending between the rod chamber and the nozzle chamber.