| 摘要 |
PURPOSE:To prevent a clutch drum from wrikling and cracking and improve its production accuracy, by drawing a blank, then effecting flange-making work and then effecting tooth-shaping finish work. CONSTITUTION:A circular blank 11 is drawn so that a dish-shaped workpiece 12 having protrusions 12c and recesses 12d is provided. Rough serration work is then effected by a press so that the flange 12b of the workpiece 12 is drawn downward to make a cylindrical wall 14 continuous to the wall 12a of the workpiece and a single groove 15 is provided on the center of each protrusion 12c on the side wall 14 and pairs of rough teeth 16 are also provided. After that, finish work is effected on the rough teeth 16 to provide teeth 13. |
