Fuel injector with a piezoelectric actuator housed in an insulated chamber

A fuel injector (1; 101; 201) having a piezoelectric actuator (9; 109; 209), which activates a shutter (6; 106; 206) to move the shutter (6; 106; 206) in a work direction (3; 103; 203) between a closed position and an open position; the piezoelectric actuator (9; 109; 209) is housed inside a casing (7; 107; 207) having an inner chamber (8; 108; 208) insulated from the fuel, and an outer surface (10; 110; 210) wet by the fuel.