| 摘要 |
PROBLEM TO BE SOLVED: To prevent fuel injection after a valve is closed in a fuel injection nozzle which changes the number of injection holes gradually in response to a lift quantity of a needle 3. SOLUTION: A nozzle body 2 includes a first injection hole 9 opening to a seat surface 7 and a second injection hole 10 opening to an inner peripheral surface of a sack chamber 8. The needle 3 is provided with a small diameter shaft part on a lower stream of a seat part 11. The small diameter shaft part includes a cutoff part 12 and a guide part 13. The cutoff part 12 is engaged with the sack chamber 8, and closes the second injection hole 10 by an outer peripheral surface of the cutoff part when the valve is closed. After a needle lift, of a first step, the cutoff part 12 is drawn out from the sack chamber 8 by a needle lift of a second step. The guide part 13 lefts a half lower stream side of the guide part 13 in the sack chamber 8, and a half upper stream side of the guide part 13 is drawn out from the sack chamber 8 at a time of the needle lift of the second step. Thereby, a fuel passage passing to the second injection hole 10 is formed between a cut surface 13a and the inner peripheral surface of the sack chamber 8.
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