Patent attributes
The configuration comprises a shaping member 3 having a substantially rectangular shape and shaping the inner surface side of a bent portion 1b, a worm gear 2 slidably linked with the shaping member 3 and gradually reducing the distance between the shaping members 3 for sequentially feeding the shaping member 3 from one side to the other side, and a reference member 4 arranged so that the upper end surface of the bent portion 1b comes into contact with its reference surface, and the distance between the shaping members 3 is gradually reduced to a predetermined fin pitch and the upper end surface of the bent portion 1b is shaped into a predetermined shape by rotating the worm gear 2 after the plurality of bent portions 1b are arranged at the shaping members 3. Due to this, it is possible to shape the bent portion into a continuous and stable shape.