Bent member and an apparatus and method for its manufacture
A bent member having a bent portion with an extremely small bend radius is manufactured by supporting a rectangular tube by a first support means disposed at a first position A while performing relative feeding of the rectangular tube in its lengthwise direction, locally heating the rectangular tube by a heating means disposed at a second position B, cooling the rectangular tube by a cooling means disposed at a third position C, and at the time of working, applying a shear force to the heated portion of the rectangular tube with a shear force applying means 14 disposed in a downstream region D by moving the device 14 two-dimensionally or three-dimensionally simultaneously in the feed direction of the rectangular tube and in a direction generally parallel to a transverse cross section in the lengthwise direction of the rectangular tube which was heated by the heating means.