JPS54160547A - Control of plate thickness and shape in continuous rolling mill - Google Patents

Abstract

PURPOSE: To keep the shape of steel plate constant throughout its whole length by controlling the rolling load and outlet plate thickness of the third stand to constant level by the predictive controlling of the second stand on the basis of predetermined detected value of the first stand in a continuous rolling mill with more than 3 stands.

CONSTITUTION: In the case of a continuous rolling mill with six stands A₁, A₂, .... A₆, in which the stand A₄ corresponds to the first stand and also the stands A₅ and A₆ correspond to the second and third stands, respectively, the rolling load detector B₄ provided to the first stand A₄ sends out the information (▵P₁) on the rolling load P to the plate thickness controller D₄ and also the drafting position detector C₄ sends out the information (▵S₁) on the drafting position S to the controller D₄. And, in case where the stand A₄ is fixed with screw, for example, the plate thickness controller D₄ predictively calculates the variation ▵P₂ of rolling load at the second stands A₅ in accordance with a fixed formula by using the value ▵P₁ alone, and then sends out the value so calculated to the plate thickness controller D₅ for the second stand A₅ in keeping with the movement of the steel plate E. Thus, it is possible to keep the rolling load P₃ and outlet plate thickness h₃ constant at the third stand A₆.

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