| 摘要 |
PURPOSE:To improve roundness and thickness accuracy of a cylindrical member by making sizing process and lateral pressing process of a cylindrical member of butted type made by incurvating a square plate almost simultaneously. CONSTITUTION:A cylindrical member 1 made by incurvating a square plate and butting both ends is attached to the core 5 of a punch 4, and pressed in the bore 3 of a die 2 by force P. Since the diameter D2 of the core 5 is formed greater than the inner diameter D4 of the member 1 before working, force is applied to the member 1 by the core 5 pressed in the direction of expanding the diameter. At the same time, axial compressive force is loaded by insertion of the punch 4 on the member 1 through the punch 4 and a knock out punch 6. Accordingly, the member 1 is strongly pressed against the inner circumferential face of the bore 3 and the outer circumferential face of the core 5 which are made beforehand at high roundness by pressing force in the direction of expanding diameter and axial compressive force working almost simultaneously and particularly excellent roundness and thickness accuracy are given to the member 1. |
