| 摘要 |
PURPOSE:To provide a method for manufacturing an equal or unequal angle bar having a prescribed internal or external apex angle on a corner radius by cold rolling after bending a steel sheet. CONSTITUTION:This method is a cold rolling method for an angle bar 1 composed of a blank bending stage to bend a blank in an L shape and a cold finishing stage to finish an L shape intermediate member obtained in the blank bending stage in a cold state. In the finishing stage, at the same time that an internal apex angle part is rolled in a prescribed radius by using a horizontal roll 4 to roll an internal apex angle part 37 made by an inside surface 31 and an inner lower surface 32 into a prescribed radius, a vertical left roll 5 abutting on the outside surface 33 of the intermediate member, a horizontal lower roll 6 abutting on the outer lower surface 34 of the intermediate member and a vertical right roll 7 to work a lower end face 36 of the intermediate member in an orthogonal state, each side part of both or one of the end face 35 of the upper part and the end face of the lower part or each side part of the L shape part is pressed down and rolling is performed to cover the shortage of the thickness of the external apex angle. |
