| 摘要 |
PROBLEM TO BE SOLVED: To achieve a method of manufacturing by which a second flange portion 4a to be formed later can be finished flat. SOLUTION: As shown in (B), that part of the second axial end portion of an intermediate material 2 at which the second flange portion 4a is to be formed is bent axially in the direction opposite to the prescribed direction to form a curved portion 9. The curved portion 9 is then folded radially inward to form the second flange portion 4a. The deformation by bending for forming the curved portion 9 and the deformation by folding for forming the second flange portion 4a are mutually offset, so that the flange portion 4a can be finished into a flat shape. COPYRIGHT: (C)2009,JPO&INPIT
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