Patent AT-E400377-T1: [Translated] HYDROFORMING PRESS FOR PRODUCING MOLDED PARTS BY INTERNAL HIGH PRESSURE FORMING

A hydroform press has shrink-joined outer (3) and inner (4) pipes. The inner pipe has a two-part (7, 8) tool mount (6) for an upper (10) and lower (11) tool (9) with a work piece (13) form chamber (12). Short stroke cylinders (14, 15) are located between the tools and tool mounts, and close the tools during the forming process. A pressure cushion (20, 21) is located between the short stroke cylinder pressure pistons (18, 19), the upper and lower tools respectively. The cushions compensate the form chamber (12) inner pressure on the pistons (18, 19) and tools (10, 11). The cushions are integrated in the pistons (18, 19) and/or in the upper and lower tools. Cushion pressure is regulated in accordance with form chamber (12) pressure.