| 摘要 |
PROBLEM TO BE SOLVED: To uniformize a nozzle port hole diameter of an injection valve at mass production time over the whole length of a nozzle port by putting the nozzle port hole diameter of a fuel injection valve and a length of its hole in the specific relationship. SOLUTION: When an inclination θ of a laser beam 10 to the central axis is set in the same degree as an accuracy error angle of finishing at parallel laser beam irradiating time, in a hole diameter of a nozzle port 7 after a finishing process by a laser beam work method, a cylindrical nozzle port having a uniform hole diameter such as hole diameters ϕda and ϕdb of an inlet side (a) part and an outlet side (b) part of the nozzle port 7 become (θda≈ϕdb) over the total length of the hole up to reaching an outlet (b) part from its inlet (a) part, can be obtained. In order to perform a round chamfer on corner parts of the inlet side (a) part and the outlet side (b) part of the cylindrical hole 7, specifications of the nozzle port 7 are set in the relationship being (Φd/l<=1) when a hole diameter is denoted by Φd and a length is denoted by l. This is because an effective orifice length cannot be secured if it is set in the reverse relationship. |
