| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a bent pipe with a helical groove capable of preventing projecting portions on the inner bend side from being brought close to each other or interfered with each other, or projecting portions on the outer bend side from being too low, reliably obtaining a desired sectional shape after the bend, and easily and reliably drawing a core from the bent pipe with the helical groove. SOLUTION: In the method for manufacturing the bent pipe with the helical groove, a core 2 having a helical projecting bar 3a formed thereon is arranged inside the pipe 1 with the helical groove, and the pipe is bent to form the bent pipe with the helical groove. Then, the pipe and the core are relatively inverted and detached from each other. COPYRIGHT: (C)2006,JPO&NCIPI
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