| 摘要 |
A manufacturing method for a bent product which can guarantee a high working accuracy and which can provide a large bending angle without damage to the surface condition of a metal material when a widely varying bent shape is desired or when it is necessary to perform bending of a high strength metal material. A bent product having a three-dimensionally bent portion intermittently or continuously in the lengthwise direction is manufactured by supporting a steel pipe 1 at a first position A while feeding it in the lengthwise direction, locally heating the steel pipe 1 being fed at a second position B, cooling the heated portion of the steel pipe 1 at a third position C, and varying the position of a gripping means 15, which grips the steel pipe 1 in a region D downstream of the third position C, in a three-dimensional direction including the feed direction of the steel pipe 1 in a workspace including a space on the upstream side of the third position C in the feed direction of the steel pipe 1 to impart a bending moment to the heated portion of the is steel pipe 1. |
