| 摘要 |
PURPOSE:To raise the productivity, and to reduce a cost, by forming a poly-V- pulley having a poly-V-groove and a rib on the circumferential wall part and the inside face side, respectively, by pressing and rolling. CONSTITUTION:A cuplike blank material 24 having a circumferential wall part 23 and a bottom wall part 22 is formed by pressing a disk 21 of a prescribed radius, which is punched from a sheet metal blank material. Subsequently, a boss part 26 is formed by pressing the center part of this bottom wall part 22. Also, flange parts 28, 29 and a rib 30 for reinforcement are formed by pressing the tip part and the inside face side of said circumferential wall part 23. Also, a V-groove 33 is formed on the outside face side of the circumferential wall side 23 by a rolling roll 16. According to this method, a poly-V-pulley provided with a small-sized rib is produced efficiently, and the cost is reduced. |
