Die null for revolution hammering

摘要

PURPOSE: To reduce frictional resistance by providing a bearing between a lower die and an upper die. ;CONSTITUTION: A die insert 1b is coaxially fitted to a bottom die 1a and the lower die 1 consists of the bottom die 1a and die insert 1b. The recessed part of a lower die 1 is formed on the inner circumferential surface of die insert 1b and a rolling bearing 3 is coaxially fitted to the inner circumferential surface. A collar 4 consisting of sintered hard alloy is coaxially fitted to the inner ring 3a of bearing 3. The upper die 6 is arranged above the lower die 1 confronting the lower die 1. The upper die 6 consists of a small diameter cylindrical part 6a and a large diameter cylindrical part 6b which is formed coaxially with and integrally connected to the upper end part of the small diameter cylindrical part 6a. The projecting part is formed of the small diameter cylindrical part 6a.;COPYRIGHT: (C)1995,JPO