| 摘要 |
PURPOSE:To obtain the proper response speed and the valve opening lift by executing the actual opening and closing of an injection valve and preservation of said state by a hydraulic pressure only by using an electric-strain type actuator as a trigger for opening and closing the valve. CONSTITUTION:A little negative voltage is applied onto an electric-strain type actuator 2 when fuel injection is started, and a voltage of 500V is removed, then said electric-strain type actuator 2 contracts, and a pump piston 12 is raised by a belleville spring 13, and a pump chamber 28 is enlarged, and a negative pressure is generated, and the pressure acting onto the upper edge surface of a nozzle needle 3 through a discharge hole 27 is reduced. Therefore, the nozzle needle 3 is pushed-up by the fuel pressure (200atm) in a fuel sump 23, and the upper edge surface is closely attached with the lower edge surface of a distant piece 14. In this state, the nozzle needle 3 is stopped at the position of the upper edge, and an injection port 26 communicates to the fuel sump 23, and fuel injection is permitted. |
