To prevent stoppage by biting and flare phenomenon at a tube end and obtain a beautiful product in outer surface property by arranging non-driven roller guides facing to each other in the adjacent position to rolling rolls on a pass line imparting a prescribed inclined angle or a crossed angle.
The roller guides 2, 3 are arranged on the inlet side and outlet side of roll bite of the rolling rolls, 1 facing to each other on both sides of the pass line. The shapes, sizes of the roller guides 2, 3, crossed angle γ and inclined angle θ are decided so that the interval between the rolling roll 1 and the roller guides 2, 3 becomes smaller in the vicinity of the roll bite taking the shape of the rolling roll 1, inclined angle θ and corssed angle γ of the rolling roll or the like, that is, the circumferential speeds of the rolling roll 1 and roller guides 2, 3 or the like into consideration. Rolling is executed setting the min. gap between a pair of the roller guides 8, 8 on the inlet side of the roll bite in the range of 115-130% of the min. value of the rolling-roll gap. When the roller guide is used under such a shape setting condition, sticker and flare phenomena are prevented as the roller guides are non-driven.
YAMAMOTO SHUJI
HAMAUZU SHUICHI
