| 摘要 |
PURPOSE: An actual punch for hydroforming is provided to improve sealing property with the front part of a tube which is a material to be formed by installing a sealing ring that is expandably operated by hydraulic pressure on the front outer circumference of the actual punch. CONSTITUTION: In an actual punch for hydroforming which is interposed between an upper die(5) and a lower die(1) to supply the liquid pressure to the front part of both sides of a tube(3) to be hydroformed by a liquid pressure, the actual punch for hydroforming comprises a ring groove(15) which is constructed at the front of the actual punch that is inserted between the upper die(5) and the lower die(1) so that the ring groove(15) is formed along the outer circumferential surface of one side of an insert part(13) that is inserted into the front part of both sides of the tube(3); a sealing ring(17) which is inserted into the ring groove(15); and a plurality of oil pipes(19) supplying a liquid pressure into the ring groove(15) so that the liquid pressure is acted on the sealing ring(17) inside the ring groove(15) by connecting the ring groove(15) to a main liquid pressure pipeline(11), wherein the sealing ring(17) is made of a rubber material which is easily expanded by the liquid pressure supplied through the oil pipes(19). |
