Patent ID: 6772963
Filing Date: 2004-08-10
Classification: F02M

Abstract:
A fuel injector having a piezoelectric actuator (9; 109; 209); a first casing (7; 107; 207) housing the piezoelectric actuator (9; 109; 209); and a shutter (6; 106; 206) which is activated by the piezoelectric actuator (9; 109; 209) to move, in a work direction (3; 103; 203), between a closed position and an open position; the injector (1; 101; 201) being characterized in that the first casing (7; 107; 207) comprises an inner chamber (8; 108; 208) insulated from the fuel, housing the piezoelectric actuator (9; 109; 209), and having an outer surface (10; 110; 210) wet by the fuel; said shutter (6; 106; 206) being activated by the piezoelectric actuator (9; 109; 209) and regulating fuel supply flowing in said work direction (3; 103; 203); a mechanical transmission (20; 120; 220) being interposed between the piezoelectric actuator (9; 109; 209) and the shutter (6; 106; 206), so that expansion of the piezoelectric actuator (9; 109; 209) moves the shutter (6; 106; 206) from a closed position to an open position in the work direction (3; 103; 203) and in a sense (V1) opposite the fuel outflow sense (V2); said mechanical transmission (20; 120; 220) inverting the sense of the movement produced by expansion of the piezoelectric actuator (9; 109; 209) in said work direction (3; 103; 203), so that a first movement produced by expansion of the piezoelectric actuator (9; 109; 209) in the work direction (3; 103; 203) corresponds to a second movement of the shutter in the work direction (3; 103; 203) and in the opposite sense to said first movement.