PLATE THICKNESS MONITOR TYPE AUTOMATIC PLATE THICKNESS CONTROLLING METHOD OF CONTINUOUS ROLLING MILL

摘要

PURPOSE:To control a variation of a shape, a crown and a strip passing property by maintaining not only a plate thickness but also a rolling load ratio of each rolling stand to a total rolling load of all rolling stands, to a value of a lock-on timing. CONSTITUTION:First of all, in a lock-on timing, a plate thickness lock-on contact 24 and a rolling load ratio lock-on contact 52 are closed simultaneously, and lock-on of a ratio to a total rolling load SIGMAFi of all rolling stands of a plate thickness (hi) and the i-th rolling stand rolling load Fi is executed. Thereafter, at every sampling processing of each rolling data, the rolling load ratio is calculated, and in accordance with a deviation from a ratio in their lock-on timing, a plate thickness monitor quantity DELTAhmi is increased or decreased from a lock-on plate thickness correcting quantity operator 42. As a result, a plate thickness of a strip 14 can be controlled to a target plate thickness without exerting a bad influence on a shape, a crown, a strip passing property, etc. extending over the overall length of the strip 14.