| 摘要 |
PURPOSE:To minimize the deformation of a metallic substrate due to the shrinkage of molding member and the like and consequently highly accurately keep the flatness of the substrate by a method wherein a molding part, which deforms itself so as to make the substrate convex on one surface side, and molding parts, each of which deforms itself so as to make the substrate convex on the other surface side, are combined. CONSTITUTION:A sheet metal 11 within the portion laying between through holes 12 and 13 is deformed to be convex upwards due to the contraction of a molding part 16e, which lies between the through holes 12 and 13, in the lower side molding part 16d of a molding member 16. On the other hand, the central portion of the sheet metal 11 is bent by the molding portion 16f, which lies between through holes 13 and 14, in the lower side molding part 16d and by a molding part 16b. In this case, the sheet metal 11 bends convex downwards, because the cross-sectional area of the molding part 16b is larger than that of the molding part 16f. Accordingly, as for the sheet metal 11 ranging between the through holes 12 and 14, if the condition represented by the formula (I) is satisfied, the deformation of the sheet metal 11 as a whole is suppressed and the deterioration of the flatness of the sheet metal can be eliminated. In other words, by making the bending developed by the contraction of the molding member 16 into a wavy shape, the deformation of the sheet metal is suppressed and consequently the deterioration of the flatness of the sheet metal becomes small. |
