To improve efficiency of fuel consumption in automotive industry, high tensile strength steels become to be used for automotive body parts. High strength sheets, however, induce large springback in press working, and a variation in bending angle becomes also large as the bending angle and springback increase. To reduce the variation in bending high strength sheets, a servo press was employed and carried out two-stage V bending. SUS304 stainless steel sheets with a thickness of 1 mm was used for specimen. The objective bending angle was set to 90 degrees. From the experimental results, the bending angle in the first stage bending for obtaining minimum variation was 80 degrees. The bending angle in the second stage bending could be predicted from the results of the bending angle in the first stage bending and the stroke was adjusted to get the objective angle. This feedback control enabled to reduce the variation of the bending angle.
