| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel injection device having high responsiveness of a valve opening operation with a simple configuration. SOLUTION: An injector 10 includes a needle 23 movably housed in a valve body 14. In the needle 23, a second inclined face 23d that receives fuel pressure in the downstream side of a seat 23 to be in contact with and separated from the valve seat 54 of the valve body 14, is formed. The injector 10 includes a throttling channel 57 at a flow section between the seat 23c and an injection hole 53, the throttling channel having a smaller channel area toward the injection hole 53. Thereby, when a fuel channel 51 is opened to allow the fuel to flow from the seat 23c to the injection hole 53, the throttling channel 57 on the downstream side of the seat 23c is formed, which relatively decreases the flow speed on a second inclined face channel located on the upstream side of the throttling channel 57 and between the second inclined face 23d and the valve seat 54, and relatively increases the pressure of the fuel applied to the second inclined face 23d. Thus, the injector 10 has high responsiveness to the valve opening operation with the simple configuration. COPYRIGHT: (C)2013,JPO&INPIT |
