| 摘要 |
PROBLEM TO BE SOLVED: To suppress sudden increase of actual injection quantity accompanying open of a second injection hole 8 opened later in a variable injection hole type fuel injection nozzle 1 including a first and the second injection hole 7, 8 opened in front and rear two stage. SOLUTION: When second back pressure fuel applying pressure on a second valve element 11 in a close hole direction is discharged for opening the second injection hole 8, discharge flow rate is regulated by a second orifice 36 formed in a second supply discharge flow passage 35. Consequently, reduction of second close hole energizing force always energizing the second valve element 11 in the close hole direction is suppressed, rising speed of the second valve element 11 can be reduced. Consequently, since sudden increase of a second effective gap area formed between a second seat part 31 and a seat surface 19 is suppressed, increase rate of injection rate can be made loose. As a result, sudden increase of actual injection quantity accompanying open of the second injection hole can be suppressed. COPYRIGHT: (C)2006,JPO&NCIPI
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