| 摘要 |
<p>A method of forming a tubular member, comprising a preliminary forming method for expanding (bulging) and bending a tubular raw material (Pa) by first and second metal molds (M1, M2) and a final forming method for collapsing a preliminarily formed tube (Pc) in a specified cross sectional shape by a third metal mold (M3), wherein the preliminary forming is performed by the first and second metal molds (M1, M2) heated to the recrystallization temperature of the tubular raw material or higher, and the final formation is performed by the third metal mold (M3) heated to the recrystallization temperature of the tubular raw material or below, whereby the tubular member of modified cross-section having expanded tube parts and bent parts can be accurately formed of an aluminum alloy tubular raw material with high quality, and the productivity thereof can be remarkably improved.</p> |
