| 摘要 |
PROBLEM TO BE SOLVED: To prevent a lowering of the fuel flow injected from a fuel injection hole, by plating an inner face of the fuel injection hole, so that carbon or the like generated in a cylinder is hardly attached to the inner face of the fuel injection hole, and the change of the fuel injection shape can be prevented. SOLUTION: The high pressure fuel introduced from a fuel supply tube, is flown to a revolving body from a duct between a valve body 9 and a needle valve 12, when a gap is formed by separating a point end of the needle valve 12 from a valve seat 11, and flown into an inner peripheral circular groove in the tangent direction thereof, to form a spiral current. Then the fuel is entered into an injection hole 10 of the valve seat 11, to be sprayed from the point outlet thereof. A plated part K is formed on the fuel infection hole inner face 11b of the valve seat 11. As the plated part K, for example, a chrome plating is formed by the thickness of not more than 10μm. Thereby the carbon or the like generated in the cylinder, is hardly attached to the fuel injection hole inner face 11b, the change of the fuel spraying shape can be prevented, and the lowering of the fuel flow injected from the fuel injection hole 10, can be prevented.
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