SUBSTANTIALLY CYLINDRICAL POWER COMPACT AND POWER DIE DEVICE

摘要

The cross-sectional shape of a main part except for both end portions is generally divided into a lower arc surface (12) extending along a base circle (P) and an upper arc surface (12) of which a top portion corresponds to the base circle (P). Side edge portions (15) extending inward from the base circle (P) are formed on both side surfaces (14) of the upper arc surface (12). Curved edge portions (15a) which concavely curves upward from the side edge portions (15) to end surfaces (10) and continues to the end surfaces (10) and chamfer portions (16) extending from the end surfaces (10) to the side surfaces (14) which planes the edges and curves so that width thereof gradually narrows, are formed on both ends in a longitudinal direction.