| 摘要 |
PURPOSE:To improve the size accuracy of a bellows by providing a flow stop mechanism for fixing one end of a cylindrical member, and also pressing the other end of the cylindrical member against the flow stop mechanism side. CONSTITUTION:A flow stop mechanism 8 for forming one end of a cylindrical member 3 is provided on one end of an inner die 4. A pressing mechanism 9 for pressing the end of the member 3 against the flow stop mechanism side is provided on the other side of the member 3. The pressing mechanism 9 is constituted of a hydraulic cylinder 10, a thrust bearing 11, a fixing member 12 of the cylinder 10, and a radial bearing 13. By this mechanism, a pressing force is always applied to one end of the cylindrical member 3 through the thrust bearing 11. Accordingly, it can be prevented that a material of the first crest is retracted at the time of forming of the second crest. According to this method, the size accuracy of a bellows 2 is improved. |
