Patent ID: 6726128
Filing Date: 2004-04-27
Classification: F02M

Abstract:
In a unit injector (1) for injecting fuel into the combustion chamber of a self-igniting internal combustion engine, having a pump part (2), a nozzle part (3) and a final control element (5) that is followed downstream by a hydraulic coupler (38, 39) by way of which a valve needle (24) of a 2/2-way valve inside a nozzle body (23) is actuatable, the improvement wherein the final control element (5) comprises a piezoelectric crystal array (7) acting on the hydraulic coupler (38, 39) which acts upon one face end (40) of the valve needle (24) to put the valve needle (24) into a first position (41) that enables a pressure buildup, and a second position (42) of the valve needle (24) that enables the opening of a nozzle needle (29), whereby the pressure buildup and the valve opening are adjustable independently.