| 摘要 |
<P>PROBLEM TO BE SOLVED: To manufacture a spiral steel pipe excellent in forming accuracy stably and at low cost by suppressing the generation of gaps which are apt to be formed in a butted part in the end part of a plate bent into a spiral shape. Ž<P>SOLUTION: In a method of manufacturing the spiral steel pipe, a steel strip sent out from an uncoiler passes through a forming stand which comprises three forming rolls of an outside inlet-side roll, an inside forming roll, and an outside outlet-side roll to be bent, and after that, the abutted part in the edge of the steel strip is weld. All shafts of the outside inlet-side roll 1a, the inside forming roll 1b and the outside outlet-side roll 1c are made into vertical, the steel strip sent out from the uncoiler is pulled out vertically upward through the forming stand. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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