Abstract: A method for hemming a workpiece having an upturned edge, wherein the workpiece is composed of an outer panel having a peripheral upturned edge turned substantially at a right angle, and an inner panel having a peripheral edge superimposed on the outer panel adjacent the upturned edge. The upturned edge of the outer panel is bent preliminarily by a hem roller which is held on a guide surface of a lower die. The guide surface is so formed that when the hem roller is rotated on the guide surface, the hem roller abuts against the outer periphery of the upturned edge of the outer panel at a point at least a distance 2TO+TI apart from the lower end of the upturned edge toward the distal end thereof, wherein TO is thickness of the outer panel and TI is thickness of the inner panel. The hem roller is then shifted by a robot hand to a second position in which the hem roller is parallel to the superimposed portion of the inner panel.

Abstract: A method and apparatus are presented for hemming a workpiece having an upturned edge, wherein the workpiece is composed of an outer panel having a peripheral upturned edge turned substantially at right angles, and an inner panel having a peripheral edge to be superimposed on the outer panel adjacent the upturned edge. The upturned edge of the outer panel is bent preliminarily by a hem roller which is held on a guide surface of a lower die. The guide surface is so formed that when the hem roller is rotated on the guide surface, the hem roller abuts against the outer periphery of the upturned edge of the outer panel at a point at least a distance 2TO+TI apart from the lower end of the upturned edge toward the distal end thereof, wherein TO is thickness of the outer panel and TI is thickness of the inner panel. The hem roller is then shifted by a robot hand to a second position in which the hem roller is parallel to the superimposed portion of the outer panel and the inner panel.