HEMMING METHOD

PURPOSE:To carry out hemming with precision and to reduce the costs of die and equipment by forming the almost straight part with a forming roller, and forming the corner part with a forming die. CONSTITUTION:A jig 1 for receiving a work is provided, and die driving devices 3 for driving a forming die 2 are respectively provided outside the four corners corresponding to the work corners of the jig 1. An articulated robot 5 traveled by a conveyor 4 along the almost straight part of the work is furnished on the outside of the one side of the jig 1, and the jig 1 is fixed to the tip of a robot arm 6 of the robot 5 through a roller holder 7. Accordingly, when the work is formed, the almost straight part having a large radius of curvature is traveled by pressing the forming rollers 8 from the upper part. Meanwhile, the circular-arcuate corners having a small radius of curvature are respectively press-formed by the forming die 2. As a result, the whole die need not be exchanged in accordance with the kind of the work, only the forming die at the corner is exchanged, and hence the costs of the die and equipment can be reduced.