| 摘要 |
PURPOSE:To make the heights of projection lines on a steel-sheet surface to be formed by calibers uniform, by changing at least one of the width, pitch, and angle of plural calibers, in the roll-axis direction stepwise or gradually from its center to both ends. CONSTITUTION:The width (l), pitch (p), and caliber angle theta of a caliber, in a roll having plural calibers are changed stepwise or successively in the roll-axis direction from its central part to both ends. When the width (l) is increased, the projection 2 to be formed in the surface of a steel sheet 1 tends to increase in size, and the same tendency about the caliber angle theta is ascertained. Further, when the pitch (p) is decreased, the projection 2 tends to increase in size; therefore, plural projections having the desired and uniform heights can be formed in the surface of steel sheet 1 by changing, stepwise or gradually at least one of the width (l), angle (theta), and pitch (p) of the caliber in the roll-axis direction from its center to its end. |
