| 摘要 |
PROBLEM TO BE SOLVED: To realize high pressure injection, improve combustion efficiency, and reduce a fuel consumption rate by providing an oil chamber wherein an upper surface of a needle valve is faced and an operating shaft for pressurizing the needle valve in the closing direction is housed, and arranging pressure regulating means for regulating operating pressure in the oil chamber. SOLUTION: At the time of operation of an engine, low pressure fuel supplied from a fuel pump is led to a feed passage 3d. In this condition, a plunger 1 is lifted up through a tappet 5 by a returning spring 6 to open the feed passage 3d. When a solenoid device 12 is excited and a poppet valve 2 is opened, fuel in the feed passage 3d is led into a plunger chamber 3a. When the poppet 2 is closed and pressure in a fuel reservoir 11c overcomes the sum of oil pressure in the oil chamber 40 and a set load of a needle valve spring 8, the needle valve 10 is opened, and fuel is injected. In this case, oil pressure in the oil chamber 40 is regulated by an opening/closing valve 41 serving a piezoelectric element 42 as a driving source, and injection control is performed.
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