| 摘要 |
PURPOSE:To improve a combustion condition through prevention of diesel knocking, reduction of a noise level, etc., by arranging valve opening pressure of a fuel injection nozzle to a changeable state and changing the opening pressure of the nozzle in accordance with conditions of speed, load, etc. of an engine. CONSTITUTION:A nozzle main unit 3 comprises the first oil accumulating chamber 8, for a tapered part between a nozzle needle seat part 7 and the first nozzle needle guide 5, the second oil accumulating chamber 9, corresponding to a tapered part between the first nozzle needle guide 5 and the second nozzle needle guide 6, feed passages 10 and 11, feeding fuel to the first oil accumulating chamber 8 and the second oil accumulating chamber 9, and a selector valve 13, opening and closing the feed passage 11 and communicating an injection pump to the second oil accumulating chamber 9 while the passage 11 is opened. In accordance with the condition of an engine, the selector valve 13 is opened. Here high pressure fuel from the injection pump is guided to the first and second oil accumulating chambers 8, 9 to increase pressure receiving area of the needle guides and change valve opening pressure. |
