| 摘要 |
A method of manufacturing a wheel rim for a vehicle includes an ironing step for ironing a tubular material to manufacture a tubular member having a non-constant thickness, using an ironing apparatus provided with a punch, a die whose side surface opposing the punch is a convex and concave surface, and a pressing member. At the ironing step, a flange portion of the tubular material is set at the die, then the pressing member is moved relative to the die thereby to squeeze the flange portion of the tubular material by the pressing member and the die, and then the punch is moved relative to the die to iron at least a portion of the tubular material except the flange portion of the tubular material to manufacture the tubular member having a non-constant thickness. |
