| 摘要 |
PURPOSE:To improve productivity by arranging concentrically outside and inside mandrels, forming a plain part and recessed part of a rim with a spinning roll and next executing a final forming of the recessed part with a different mandrel. CONSTITUTION:The ends of an outside mandrel 14 and inside mandrel 16 are arranged to coincide with each other, and a work 23 is inserted into both the madrels 14, 16. A press plate 22 is pressed to the work 23 via a cylinder 32 and the mandrels 14, 16 are rotated. Next by feeding a spinning roll 41 several times from right to left along the axis line of a spinning machine while pressing the roll 41 to the work 23, the end of an opening of the work 23 is formed. Then the 2nd stage is executed by sliding the inside mandrel 16 to right, and similarly with a different mandrel 42, a work is executed to the necessary finishing shape at the 3rd stage. With this method the cutting work time is shortened and productivity is elevated. |
