Rolling machine, bending method, and workpiece material

Abstract

A bending method feeds a long workpiece material made of metal and having a plurality of thickness portions disposed at different angles between rollers and bends the workpiece material. An initial shape of the workpiece material is a straight line or a bend with a bend radius larger than a target bend radius, a thickness of a cross section of the workpiece material along a bend radius direction is set to increase from an inner side toward an outer side of the bend radius direction, the workpiece material is fed between the rollers and rolled in a way that an amount of rolling in a region corresponding to the outer side of the bend radius direction is larger than an amount of rolling in a region corresponding to the inner side, and the workpiece material is bent to have the target bend radius from the initial shape.

1 . A rolling machine capable of simultaneously rolling two or more of a plurality of thickness portions of a long workpiece material made of metal in a thickness direction, the plurality of thickness portions being disposed at different angles, and the machine comprising:
 a plurality of roller units each including one roller that is pressed against one surface of the thickness portion and another roller that is pressed against another surface of the thickness portion, wherein   at least one of the plurality of roller units rolls in the thickness direction the thickness portion that is different from the thickness portion rolled in the thickness direction by another one of the roller units.   
     
     
         2 . A bending method that feeds a long workpiece material made of metal and having a plurality of thickness portions disposed at different angles between rollers and bends the workpiece material while rolling the workpiece material with the rollers, wherein
 an initial shape of the workpiece material is a straight line or a bend with a bend radius dimension larger than a target bend radius dimension,   a thickness dimension of a cross section of the workpiece material along a bend radius direction is set to increase from an inner side toward an outer side of the bend radius direction,   the workpiece material is fed between the rollers and rolled in a way that an amount of rolling in a region corresponding to the outer side of the bend radius direction is larger than an amount of rolling in a region corresponding to the inner side, and   the workpiece material is bent to have the target bend radius dimension from the initial shape.   
     
     
         3 . The bending method according to  claim 2 , wherein, with regard to the thickness dimension of the cross section of the workpiece material along the bend radius direction, a thickness dimension on an inner peripheral part of a bend radius is set to a target thickness dimension at the completion of bending, and a thickness dimension on an outer peripheral part of the bend radius is set to a dimension obtained by multiplying the target thickness dimension by a value that is obtained by dividing an outer radius dimension of the workpiece material by an inner radius dimension of the workpiece material at the completion of bending. 
     
     
         4 . A workpiece material used when a long workpiece material made of metal is fed between rollers and bent while being rolled by the rollers, wherein
 a thickness dimension of a cross section of the workpiece material along a bend radius direction is set to increase from an inner side toward an outer side of the bend radius direction.