| 摘要 |
PURPOSE:To manufacture a bellows having excellent characteristic easily by forming wavelike pitches on a roughly formed unit tube of bellows structure and after piling up required quantity of such tubes and welding, subjecting to necessary heat treatment. CONSTITUTION:A circular plate 1 is blanked by press working and formed to a tubular body 2 by deep drawing. Next, a roughly formed tube 3 of unit bellows structure is made by hydraulic forming. Then, after forming wavelike pitches or V-shaped pitches and precision working, preliminary treatment for welding is made on joined end part of the roughly formed tube 3. At the same time, inner diameter part 3b is welded. Next, two roughly formed tubes are piled to make respective joined end parts opposite to each other and the joined parts and outer diameter part are welded. After that, heat treatment is made to remove residual stress and to make material quality uniform. Thus, manufacture of the bellows is completed. |
