| 摘要 |
PURPOSE:To obtain a titled device that prevents damage of sealing material and can eliminate necessity of correction of tube end after bulge forming by constituting with a compression holding the tube end between a seal ring provided in the cylinder and a punch provided at the tip of a piston rod. CONSTITUTION:Tube end of a double layered tube 9 is fitted and held by a seal ring 28 provided in an opening in a bottomed cylindrical cylinder 15, and a piston rod 29 provided movably in the cylinder 15 is shifted to the opening side of the cylinder 15 applying oil pressure to a piston 17. Tube end of the double layered tube 9 is widened by the slanted face 33 of a punch 32 made of hard material attached to small diameter part 31 at the tip of the piston rod 29, and pressure held on the face of the seal ring 28 and bulge pressure water supplied through a water supply port 25, a through hole 24, an anuular groove 23, a through hole 30 of the piston rod 29 etc. is sealed. Thus, forming can be done applying pressure by the bulge pressure water to the tube end without damaging the sealing material by burrs at the tube end. |
