METHOD AND APPARATUS FOR HIGH-PRESSURE INTERNAL SHAPING

摘要

A method using high interior pressure to reshape structural section of continuously bounded overall cross-section, whereby the overall cross-section can be provided with extra walls or chambers and a stopper is forced radially against each end of the piece. The object is to reduce wear on the stopper while ensuring that any walls or chambers in addition to its overall cross section will buckle or bulge only at their ends. Either any walls (2 & 3) that partition the chambers (4, 5, & 6) and any independent wall (7) are provided with slots (17) at the ends of the piece that parallel the inner surface (18) and outer surface of the piece or the stopper (8) itself is provided with grooves (19) adjacent to and matching the shape of the walls.