| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a forming method of a nozzle body having high strength, high rigidity, and low cost for a long nozzle-type fuel injection valve. Ž<P>SOLUTION: In the forming method of a nozzle body, a material for the nozzle body is formed to have: a large diameter cylindrical part 151 situated at an end of the nozzle body and having the largest outer and inner diameters; a small diameter cylindrical part 152 situated at the other end thereof and having the smallest outer and inner diameters; and an intermediate diameter cylindrical part 153 situated in between the large diameter cylindrical part 151 and the small diameter cylindrical part 152 and having outer and inner diameters intermediate therebetween. In a first forming step, a hollow blank is backwardly extruded to thereby mold the large diameter cylindrical part 151, and the hollow blank is forwardly extruded to thereby mold the intermediate diameter cylindrical part 153. In a second forming step, the extrusion-molded intermediate diameter cylindrical part 153 is ironed for reducing the inner diameter thereof to thereby obtain the small diameter cylindrical part 152. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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