Patent ID: 8555694

Claim:
A bending apparatus that includes a first jig and a second jig coupled so as to be rotatable about a rotary shaft, and that bends a prescribed material attached to the first jig and the second jig as the first and second jigs rotate relatively to each other about the rotary shaft, wherein the first jig rotates about the rotary shaft, and has a suppressing section that is arranged on a side opposite to a rotating direction and suppresses a displacement of the material, and a bending section that is arranged offset by a prescribed amount from a center axis of the rotary shaft to a rotating side of the material, and has a partially cylindrical surface having a radius of curvature substantially identical with a radius of curvature of an inner peripheral surface of the material at least after the bending of the material, the second jig rotates about the rotary shaft, and has a suppressing section that is arranged on the side opposite to the rotating direction and suppresses the displacement of the material, and a bending center of the material is arranged at a position that is distant from the center axis of the rotary shaft of the first and second jigs toward the rotating side so that the material is not displaced relative to the first and second jigs when the material is bent, wherein the bending apparatus is configured to have a positional relationship between the rotary shaft, the bending section and the suppressing section such that before the bending: (a-1) the bending section is arranged so that the material is held between the bending section and the suppressing section; and (a-2) a center of curvature of the partially cylindrical surface of the bending section is arranged to be offset by a prescribed amount from the center axis of the rotary shaft toward the rotating side of the material, and wherein after the bending the center of curvature of the partially cylindrical surface of the bending section coincides with the bending center.