Patent ID: 8333098

Claim:
A bending method for forming, in a material in which a plurality of straight portions extending in parallel with each other and a first-end side coupling portion and a second-end side coupling portion provided alternately to couple first-end portions and second-end portions, respectively, of adjacent ones of the straight portions with each other are successively formed, folded portions respectively in a pair of the straight portions provided on both sides of the first-end side coupling portion, a length from one of the folded portions to the first-end side coupling portion being different from a length from the other of the folded portions to the first-end side coupling portion, the bending method comprising the steps of: shaping the material such that the first-end side coupling portion is inclined with respect to a direction orthogonal to the pair of the straight portions in accordance with a difference between the lengths of the folded portions to be respectively formed in both the straight portions; and thereafter forming the folded portions in both the straight portions at the same time, the folded portions being bent in the same direction as each other.