Modeling of Deformation Zone during Plate Stock Molding in Three-Roll Plate Bending Machine

In this paper, the roller (three-roll) molding of a plate stock, based on elastoplastic bending, is investigated. Physical models of the deformation zone during the interaction of the workpiece with rolls are presented considering two stages: when the upper roll is moved without rotating the rolls and when all three rolls are rotated without moving the upper roll. The results of an experimental study of the deformation zone parameters are obtained, and they are used to determine the profile of the tubular billet during molding on a specialized bending machine, for the two stages of the bending process. The experiments showed that for the first bending stage, the billet in the zone of separation from the upper roll has a complex curvature and symmetrical three-point and four-point contacts with the rolls. The second stage of bending with the rotation of the rolls is characterized by an asymmetric deformation zone during three-point contact. Finally, the regression equations for the geometric parameters of the bent workpiece profile sections are obtained.