| 摘要 |
PURPOSE:To prevent the generation of cracks due to fatigue and to eliminate the deformation of wheel by making a rim and disc in an integral construction using a piece of blank. CONSTITUTION:The bowl shaped member 9 having a flange 8 on the peripheral edge part is formed by forming with bulging the center part of a circular plate shaped blank 7 by a press work. The bulging part having the smaller diameter d than the diameter D of the bulging part is then formed by forming with bulging by a press work the bottom part of the bowl shaped member 9, namely from the opposite direction to the bulging direction. The outer peripheral edge part 10 is formed in cylindrical shape by rising with a press work the flange 8 provided on the outer peripheral edge part further. The outer peripheral part 10 is then formed in recessed curved face shape by a roll work. A forming work is then performed further so as to make the outer peripheral part in the prescribed rim shape with further roll work and the wheel 13 for automobile of an integral construction having a rim part 11 and disc part 12 is formed. |
