Patent attributes
A hydroforming seal and method includes a nozzle having both a radially expandable O-ring seal and a conical tapered surface for separately sealing with the bore of the tube. The O-ring seal is expanded to seal the tube and pressurized fluid is added sufficient to support the interior of the tube while the dies are closed so that the tube is thereby bent and forced into the die cavity without collapse or injury to the tube. The O-ring seal is then contracted to a non-sealing position and the conical tapered surface provides metal-to-metal sealing while the higher hydroforming pressure is applied to expand the tube. The nozzle also has a radial shoulder that engages the end face of the tube so that advance of the nozzle feeds the tube into the die.
