METHOD FOR JOINING PLANAR MEMBER

PROBLEM TO BE SOLVED: To provide an effective technique for firmly joining both joining parts of planar member at low cost. SOLUTION: A cylindrical product 100 is produced by working in order of a blanking work, bending work, cylinder-forming work and die-pressing work to a flat plate material 10 by using press-formation to each of the works. In the blanking work, a plurality of engaging pieces 210, 310 and engaging grooves 220, 320, are respectively formed to both joining parts 200, 300 of the flat plate material 10. In the bending work, both sides of the engaging pieces 210, 310, are bent. In the cylinder-forming work, the flat plate material 10 is formed into an intermediate cylindrical body through a forming die. In the die-pressing work, the mutually faced engaging pieces 210, 310 and engaging grooves 220, 320, are fitted, respectively and the intermediate cylindrical body is die-pressed from both faces. In this way, both joining parts 200, 300 can be joined with the high joined strength at a low cost by using the press-formation. COPYRIGHT: (C)2004,JPO