| 摘要 |
PURPOSE:To prevent lack of thickness of a flange part, and to form a hub part with high accuracy, by constituting in advance so that the projecting height of the hub part is low and the volume is thick, and subsequently, executing the expansion of prescribed size in width and the straighten-shaping, in case of ring-rolling. CONSTITUTION:A steel billet 4 heated to a prescribed temperature is brought to rough face forging by an upper and a lower die 5, 6, and subsequently, ring- rolling is executed by a main roll 7, a pusher roll 8 and upper and lower edging rolls 9, 10. In this case, formation of a flange part is mainly set to almost complete size, and as for a hub part 3, it is not expanded to much in the axial direction and is smaller than full width in the complete size, and accordingly, the projecting height is low, thickness in the radial direction is thickened by that portion, and especially, surplus thickness inclined to the inside diameter side is formed. Subsequently, this base material 4A is formed by a punch and a die 13, 14 and an expanding punch 15, the hub part is expanded to full width H of the prescribed complete size, and also distortion is straightened. |
