Patent ID: 8919171

Claim:
A method for three-dimensionally bending a metal material as a workpiece comprising: feeding the workpiece by a feeding unit which is provided at an upstream side of the workpiece; supporting the workpiece by a supporting unit at a downstream side of the feeding unit; and processing the workpiece by: (a) a clamping step to clamp the workpiece with a three-dimensionally movable unit that is provided at the downstream side of the supporting unit; the three-dimensionally movable unit comprising two rolls, three rolls, or four rolls; (b) a heating a local part of the workpiece by a heating unit that is provided at an upstream side of the three-dimensionally movable unit in a temperature range which allows quenching to be performed, (c) applying bending moments in three dimensions to said heated local part of the workpiece by the three-dimensionally movable unit in association with the supporting position and/or the moving speed of the workpiece after the step (b); and (d) rapidly cooling down the heated portion by a cooling unit that is provided between the heating unit and the three-dimensionally movable unit in order to perform quenching after the step (c).