| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce a material by manufacturing a bearing surface of a bearing on the inner periphery of a boss and its end part and the flange part on both ends of the outer periphery of a cylindrical core part in a forging stage and to reduce the amount of machining in an internal cutting of the inner periphery of the boss part, the outer periphery and the frictional surface of the cylindrical core part by improving concentricity. <P>SOLUTION: A primary formed article including a disk-like frictional surface 2a, the boss part 2b and a cylindrical core part 2c is formed by simultaneous working of drawing, ironing and backward extrusion of a base stock 1 and a secondary formed article 3 is formed by forming the bearing surface 3bb of the bearing having a bearing surface end 3bt at the lower end of the inner periphery of the boss part 3b by ironing the inner periphery of the boss part 2b and the outer periphery of the cylindrical core part 2c and projecting and leaving the flange part 3cf at the lower end of the outer periphery of the cylindrical core part 3c. After positioning the secondary formed article by restraining the outer periphery excepting the frictional surface 3a, a space between the boss part 3b and the cylindrical core part 3c and the upper end part of the cylindrical core part 3c from the radial directions, the flange part 4cf is projected on the outer periphery on the upper end side of the cylindrical core part 4c by swaging the outer peripheral part of the outer end of the cylindrical core part 3c. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
