To suppress generation of irregular deformation within a face of a workpiece in a roll bending device for the workpiece.
A roll bending forming device includes: a first forming roll 1A in which a rotating shaft is disposed vertically to the longitudinal direction of a workpiece 2; a second forming roll 1B; and a third forming roll 1B. The first forming roll 1A includes: a columnar small diameter part 10A with which the workpiece 2 comes into surface contact with; and large diameter parts 11A installed on both side faces of the small diameter part 10A and having a large diameter. A load applying tool 41 for pressing the large diameter part 11A installed movably in the rotating shaft direction of the first forming roll 1A is installed. When the workpiece 2 is sent while brought into contact with the columnar small diameter part 10A of the first forming roll 1A, the load applying tool 41 presses the movable large diameter part 11A to apply a load to the side face of the workpiece 2 via the large diameter part 11A.
UENO SHIGEYASU
SATO KAZUNARI
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