SPEED CONTROLLER OF TANDEM ROLLER

PURPOSE:To provide a speed controller for a tandem roller which satisfies a law of constant mass flow and can always keep a plate thickness on the outlet side of the mill at a fixed value against the variation of the the plate thickness on the inlet side to the mill. CONSTITUTION:The target value of roll peripheral speeds of the mills 101,201 in which the law of constant mass flow is satisfied by the plate speed measured value on the outlet side of the mill, the plate thickness measured value on the outlet side of the mill, the plate thickness measured value on the inlet side of the mill is determined dynamically with the peripheral speed of a reference mill 301 set by a rolling schedule as reference. In this way, places requiring setting of parameters in a rolling process can be reduced and a product having a desired plate thickness can be obtained even by steel material ununiform in quality stably and at a high quality.