High Pressure Fuel Injector

The present invention relates to an internal combustion engine having a high pressure fuel injector (1) which is arranged in a common rail arrangement, in order to improve the accuracy over in particular a service life of a high pressure fuel injector (1), comprising at least one nozzle needle (5), which can be pressed with a pressing force against a valve seat (12), and at least one solid-state actuator (3) which acts on an actuating piston (23) and is connected directly to a rail pressure supply (7), wherein at least one hydraulic operative connection (22) between the actuating piston (23) and a differential piston (4), which is operatively connected to the nozzle needle (5), is provided in such a way that an activation of the solid-state actuator (3) acts directly on the actuating piston (23), thereby permitting a pressure increase by means of the actuating piston (23) above a rail pressure, which pressure increase, via the differential piston (4), counteracts the pressing force such that the nozzle needle (5) can be raised from the valve seat (12) and at least one injection opening can be opened.