| 摘要 |
<p>A metal tube is cold formed into a stamped member by filling the tube with a liquid change-of-state material, freezing the change-of-state material, sealing the tube containing the solid change-of-state material, and stamping the tube in a die. The change-of-state material compresses during the stampi ng step to force the walls of the tube to conform to the die cavity, eliminatin g the need to pressurize the tube prior or subsequent to stamping. Additionall y, the solid within the tube provides support to the wall of the tube during a piercing step to form a hole in the tube having less deformation surrounding the hole than a comparative tube pierced without having the solid fill. Afte r the stamping or piercing steps, the change-of-state material is melted and drained from the tube. Further, a tube is pierced by forming an outwardly bulged area and piercing the tube in the outwardly bulged area while simultaneously depressing the tube to substantially flatten the outwardly bulged area.</p> |
