DEVICE FOR INJECTING A LIQUID, IN PARTICULAR A FUEL, WITH AN ELECTROACTIVE ACTUATOR

摘要

The invention relates to a liquid injection device that comprises a tubular body (11), a needle (12) having an end with a head (120) defining a valve on a seat (110) of the tubular body (11). An actuator with an electroactive material is capable of triggering a movement of the head (120) of the needle (12) so as to open the valve. A supply duct (111) supplies the liquid about the needle (12) up to the head (120). A hydraulic chamber (17) is defined by an actuator piston (101) moved by the actuator (10) and a needle piston (121), the needle piston (121) being carried by the end of the needle (12) opposite the head (120). The hydraulic chamber (17) is supplied with fluid by the supply duct (111) via a capillary (18).