| 摘要 |
PURPOSE:To form a hollow aluminum alloy rim of a light weight to a prescribed annular shape by forming a part or the whole of a section hollow part so that it becomes a little larger than a prescribed finish size by means of extrusion forming of an aluminum alloy, pressing and deforming it by roll-forming, and setting the hollow part to a prescribed shape size. CONSTITUTION:A hollow part 11 can be formed easily by extruding a part or the whole of a hollow rim section hollow part 11 so that it becomes a little larger than a prescribed size by extrusion forming of an aluminum alloy. It is pressed and deformed by roll-forming, and the hollow part 11 is formed to a prescribed shape size, also curved to an annular shape and formed to a butt ring shape. In case of only a conventional extrusion forming, a size section of the hollow part 11 cannot be made so small, the rib becomes large and its conversion to a light weight is insufficient, but according to this method, it is converted to a light weight easily. |
