| 摘要 |
PURPOSE:To obtain an annular member which is capable of ideal fitting at all times even if an error exists in the inside diameter of a cylindrical case, by constituting so that a part of a ring of an annular member provided with a burring on the inside circumferential edge of the annular outside circumferential part lacks discontinuously. CONSTITUTION:A work B obtained by working cylindrically a strip-like work A by means of roll forming, etc. is placed on a base 12. In this case, there is a step difference between a circumference supporting member 14 and the base 12, therefore, as for the work B, its outside circumferential face is supported by the member 14. Subsequently, when a ram 19 is lowered, the lower end face of a reserve bend die 21 is made to press-conact with the member 14, depresses it, an engaging face 24 is engaged with the work B, and a tapered work C is formed. Subsequently, a bend die 25 is made to press- contact with the work C, depresses the base 12 and presses by piching the work together with the base 12. In this case, the work is lowered together with the base 12 and the die 25, therefore, the circumferential edge part in the work interfaces with a bend punch 11, is bent upwards and is subjected to burring F work. Thereafter, when the ram 19 is lifted, the base 12 also is lifted by a spring 13, therefore, a work D is lifted up, is dropped down onto the base 12 from the lifting member such as the die 21, etc., and an annular member R is obtained. |
