| 摘要 |
PROBLEM TO BE SOLVED: To fix fixed legs to the bottom surface of a bottom plate with a sufficient strength without fixing the same through welding, screwing or riveting. SOLUTION: Fixed legs 2, having the thickness of 1.0-1.2 mm, are connected to a bottom plate 1, having the thickness of 0.8-1.0 mm, through this connecting structure. The bottom plate 1 and the fixed legs 2 are caulked so as to form substantially cylindrical caulked parts 3, projected toward the upper surface side of the bottom plate 1, by press work employing a dice having the depth (h) of 5.4-5.8 mm and a punch having the diameter (d) of 7.8-8.2 mm. In this case, the caulking thickness (t) in a recessed part 30 at the upper end center of the caulked part 3 is specified so as to be within the range of 0.60-0.85 mm. A coated steel sheet, in which coating is applied on a hot-dip aluminum-zinc alloy plated steel sheet, a hot-dip zinc plated steel sheet or the like, for example, is employed for the material of the bottom plate 1 and the fixed legs 2. |
