| 摘要 |
PURPOSE:To make flange working of a high flange by supporting plural rolls allowing free rotation on their axes in a tapered mandrel and moving so that the small rolls expand a preliminary hole successively by rotation of the mandrel. CONSTITUTION:The left end of a mandrel 3 is connected to a driving source. Plural small rolls 1A, a slider 7, a supporting plate 8, a connecting plate 9 are joined in a body with a bolt 10 to form a small roll unit and attached to the small diameter side of the mandrel 3. A plate 4 in which a preliminary hole 5 is made beforehand is inserted in the small roll unit and each small roll 1A is brought into contact with the hole 5 of the plate. When the mandrel is rotated, the small roll 1A and the plate 4 rotate in the direction shown by the arrow. With rotation of the mandrel 3, the small roll unit moves to the large diameter side of the mandrel 3. Accordingly, the small roll 1A expands in radial direction and the hole 5 in the plate 4 is expanded. Thus, working of a flange 5a having a large flange height is effected. |
