| 摘要 |
At the downstream-side face of an injection hole plate, a plurality of concaves are arranged corresponding to a plurality of injection holes; at least part of an injection hole outlet opens at the plain of the concave; the rest of the outlet opens at the downstream side face of the injection hole plate or contacts the inner surface of the concave. In a flow path formed by the injection hole, there is provided a cylindrical portion, whose cross section is the radially minimum cross section of the injection hole, from the upstream side face of the injection hole plate to the plain of the concave. Where D1 denotes the diameter of the injection hole and D2 denotes the diameter of the concave or the diameter of the concave in the circumferential direction of the virtual circle, the relationship 1.1<(D2/D1)<3.0 is satisfied.
|
