Hydroformed structural member with varied wall thickness

摘要

A method for hydroforming a tubular structural member of generally polygonal, flat walled cross section in which the various walls in the final part do not have the same thickness. A cylindrical tubular blank is extruded in which the outer surface is round, but in which the inner surface is asymmetrical, providing several contiguous angular sectors or portions of varying width and thickness. Each individual angular portion is tailored as to thickness and width to correspond to a respective wall in the final part. The blank is oriented between in a die cavity so as to align each angular portion with a respective wall of the finished part, and hydroformed in conventional fashion.