| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel injection device that can generate good spray immediately after a start of lift of a needle.SOLUTION: A fuel injection device includes a nozzle body 26 provided with a nozzle hole 40 and a seat 34 positioned at the upstream side rather than the nozzle hole 40; a circular passage 36 positioned at the upstream side rather than the seat 34 and for circulating fuel introduced to the nozzle hole 40; a needle 24 arranged in the nozzle body 26 in a freely slidable manner and seated on the seat 34; and a piezoelectric element 42 that, from a start of lift of the needle 24 over a predetermined period, maintains an exit area of the circular passage 36 which is smaller than an exit area corresponding to a lift amount at the passage of the predetermined period, and sets the exit area of the circular passage as the exit area corresponding to the lift amount after the passage of the predetermined period. |
