| 摘要 |
PURPOSE:To obtain a product having a high strength, and to simplify the process by working simultaneously in an enclosed metallic mold a socket hole and a projecting part, in a spherical part of a forming base material having a spherical body which has formed three faces of flat parts in the shaft end, and its opposite part, respectively. CONSTITUTION:A forming base material which has formed flat faces 12a, 12b and 12c on a spherical part 12 formed in the end part of a shaft part is enclosed and fitted in a mold 13, and the spherical part 12 is brought to a punch working by punches 14, 15. In the upper and the lower dies 16a, 16b, cylindrical hollow parts 16ab, 16bb are connected and provided to the extent that the spherical part 12 can be fitted when the dies have been superposed. In case of the punch working, a socket hole 12d is formed and also a projecting part 12e is provided projectingly on a hollow part 16ac side. By executing the working in such a way, a flow line can be formed regularly, and the strength of a product can be improved. |
