Apparatus and method for forming and hydropiercing a tubular frame member

Abstract

A method and apparatus for forming complex shaped frame members from a tubular blank where the blank is transferred from station to station and various tooling are performed on the blank at each station. For example, at a first station the blank is expanded into a tube having a varying cross-section throughout the length of the tube by applying pressure to the interior of the tube and compressive force to the opposed ends of the tube preferably simultaneously. At another station, the expanded tube is preformed by introducing a bend therein. The bend in the preformed tube is then increased at another station. While the expanded tube is being preformed and bent, the flow of material into the die cavity at those stations is controlled to reduce the amount of folding that may occur. The shape of the frame member is finished at another station by introducing a lateral bend and varying the cross-sectional configuration of the bent tube. Holes may then be pierced into the finished frame member at another station by pressurizing the interior of the frame member with hydraulic fluid and striking the frame member with a piercing punch. Final stations crop the ends and flush the interior of the frame member before it is unloaded for further transport.