HYDROFORMING METHOD AND HYDROFORMING DEVICE

摘要

A hydroforming method capable of easily producing a hydroformed product which has a complex shape and is formed so that the axis of the hydroformed product includes a bend. A hydroforming method is configured in such a manner that no axially pressing cylinder is disposed on one end side (3a) of a metallic pipe (3) installed within dies (11, 13) but an axially pressing cylinder (31) is provided only on the other end (3c) side, and in such a manner that the metallic pipe (3) is pressed in the axial direction thereof by the axially pressing cylinder (31), and a pressure medium is supplied to the inside of the metallic pipe (3), which has both ends closed, to apply the inner pressure to the metallic pipe (3). The metallic pipe (3) is installed within the dies (11, 13), and an independent punch (21) is mounted to said end side (3a) of the metallic pipe (3). When closing the dies (11, 13), the independent punch (21) is advanced in the axial direction of the pipe utilizing the force which closes the dies (11, 13). As a result, the metallic pipe (3) is pressed in the axial direction thereof while said end of the metallic pipe (3) is sealed by the independent punch (21).