Fuel injector

The fuel injection system (1) has a piezoelectric actuator (30) pushing upward on a plate (32) attached to a piston rod (33). The piston (38) slides in a sharp-edged sleeve (39) in contact with a channel plate (4). Fuel flows through a bore (45) from a first chamber (47) into a second chamber (46) and presses on a piston (18) in one piece with a needle valve (10) with a tip (14,16) which can seal off the injector nozzle (12).