| 摘要 |
PURPOSE:To allow rapid closure of a needle valve by releasing the remaining fuel in a fuel reservoir in which the needle valve is disposed to a low pressure zone simultaneously upon completion of fuel injection, thereby reducing oil pressure. CONSTITUTION:Pressure increased fuel remains in the fuel reservoir 12 of an injection nozzle unit 1 when fuel injection is completed, but the slot 59a of a remaining pressure removing unit 50 is shut off from the first pressurizing chamber 56 having high pressure, a piston 58 is displaced leftwardly to communicate a central hole 59b with the second hole 64, and the remaining fuel of the reservoir 12 is thus returned into a fuel tank 31 through the first hole 63, slot 59a, hole 59c, central hole 59b, gap 62 and the second hole 64. Accordingly, when a pressure piston 6 is pressurized in next cycle, the downward movement of the valve body 7 is not disturbed, thereby rapidly closing an injection port 4. |
