To provide an edge wave measuring method capable of eliminating the vertical movement component of an edge part of an open pipe and the vibration component of the edge part, and capable of measuring only the edge wave component immediately before the welding.
In a method for measuring the edge wave to be generated by the buckling generated in an edge part of an open pipe by a displacement meter when a welded tube is manufactured, the position of installation of the displacement meter is determined so that the edge wave generated in the edge part of the open pipe is measured in the range to satisfy the inequality, Lf≤{[0 D/21]-Bt} [Df+Bt-(OD/2)]}1/2, where Lf is the distance in the axial direction of the welded tube to be manufactured from the center of a squeeze side roll, OD is the outside diameter of the welded tube, Df is the outside diameter of a flange of the squeeze side roll, Bt is the outside diameter of the flange of the squeeze side roll subtracted from the center distance of the squeeze side roll divided by two.
UEI SEISHI
MIHARA YUTAKA
NAGAHAMA YUTAKA
SATO AKIO
IWASAKI KENICHI
SEKINE YUKIO
TAKAHASHI MASANOBU
