| 摘要 |
PURPOSE:To improve a response characteristic in control of a nozzle needle and prevent its vibration, by separately arranging an oil hydraulic system, for controlling the nozzle needle to be opened and closed, from a fuel system for injecting fuel. CONSTITUTION:An electrostrictive actuator 102 lifts by its contraction a pump piston 111, spreading a pump chamber 128 so as to reduce a pressure applied to the upper end surface of a nozzle needle 101. Accordingly, the actuator, lifting the nozzle needle 101 by the pressure of oil in an oil reservoir 121, causes a jet 102 to communicate with a fuel reservoir 122 and continue to inject fuel. While a feed pump 10, starting its action when a system is started, performs a delivery stroke by simultaneously energizing a three way valve 12 for 3sec while a suction stroke in a pump chamber 207 thereafter by stopping the energizing for 3sec. If the system repeats these actions about several times, the pressure of oil in a reservoir 13 reaches a certain value, opening a pressure switch 14. |
