| 摘要 |
PURPOSE:To aim at lowering the injection rate of fuel in an initial stage of fuel injection, as well at lowering engine noise and at enhancing the reliability of the fuel injection device in order to restrain the generation of nitrogenoxide, and to reduce the minimum fuel injection amount, by providing a restrictor which restricts fuel stream counterflowing through a spill port. CONSTITUTION:Along with the progress of fuel injection, the pressure of fuel compressed in an accumulating chamber 12 continuously lowers so that an injection terminating control valve 13 is depressed by a spring 14 to open, and therefore, the fuel in the accumulating chamber 12 counter-flows into passages 3a, 4a through passages 4b, 3b. At this time a suction return valve 20 is in its closed condition so that fuel does not overflow from a spill port 18, and therefore, the pressure of the fuel passage 4a is naturally made equal to the pressure in the accumulating chamber 12, resulting in a needle valve 8 tending to close. Since a restrictor 3f is disposed in a part of the passage 3a between the passage 3b and the suction return valve 20, the needle valve 8 initiates to close in a short time by pressure waves of fuel counter-flowing from the passage 3b. |
