| 摘要 |
PURPOSE: To easily form partial irregularities on inner and outer surfaces of a cylindrical body such as a rubber hose and a thermoplastic tube without generating flaws on the cylindrical body and flashes. CONSTITUTION: Into a center hole of a predetermined part of a cylindrical body 1, a core material 3 having a predetermined shape is inserted. On its outer periphery, a ring-like hollow body consisting of a cylindrical regulating member 40 and a cylindrical soft band body 41 is arranged. A fluid is led into a hollow 43 at a plastic deformation area of the cylindrical body 1 so as to expand it, and the cylindrical body 1 is pressed inwardly in the diametric direction and pressed to the surface of the core material 3 so as to give a pattern. As the patterning is performed with the expanding force of the soft band body 41, the patterning can be done uniformly and easily without generating flashes. |
