| 摘要 |
PROBLEM TO BE SOLVED: To provide a retainer of good accuracy capable of being manufactured in good productivity and assuring a dop of the cost and establish a method for manufacturing such retainers. SOLUTION: A retainer is shaped into an M-form by a rolling process, consisting of a groove pushing process to mold the middle part in axial direction of a cylindrical workpiece 1A so as to have a trapezoidal section and a flange bending process to form flanges 2 at the two ends of the work 1A. The groove pushing process is performed using an inside shape mandrel 11, outside shape mandrel 12, a pair of guide rolls 11, and a backup roll 14, while the flange bending process is conducted using a drive chuck 15 having an inner surface shape corresponding to the outside shape of the work 1A subjected to groove pressing, a mandrel 16 for the flank, and width rolls 17 and 18. |
