| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently manufacture a spiral pipe having a straight pipe part on both ends in high dimensional accuracy, in a manufacturing method of a spiral pipe for continuously forming a spiral groove by rolling a molding roll in pressure contact on its outer peripheral surface, while sending a pipe material forward.SOLUTION: Processing operation is started in a state of loading and setting a pipe material (p) of the set length L0 by positioning by allowing the rear end to abut on a rear end stopper 10 so that a spiral groove molding starting end is positioned in the rear by the set length L1 from its front end, and the processing operation is automatically stopped by detecting that the front end of the pipe material (p) sent out forward by executing grooving, reaches a state of positioning the tail end of a spiral groove forward by the set length L2 from the rear end of the pipe material (p), by front end position detection means.</p> |
