Apparatus and method for the stretch forming of elongated hollow metal sections

摘要

Disclosed is apparatus and a method for the stretch forming of an elongated hollow metal section, such as an aluminum extrusion. The apparatus and method uses one or more constraining means secured to the forming die and a die extension to constrain and support the walls of the elongated hollow metal section against the forces produced by air pressure within the interior of the hollow metal section. The apparatus and methods disclosed herein prevent the formation of wrinkles, crimps and bulges in the walls of the elongated hollow metal section during the stretch forming and reshaping thereof.