TEMPERATURE CONTROLLER FOR HOT FINISHING MILL

PURPOSE: To control the temp. of a rolled stock on the outlet side of a rolling mill to the target temp. even in rapid acceleration and deceleration rolling and also to execute high- accuracy temp. control over the entire length of the rolled stock by reducing temp. variation in the tip and tail end parts of the rolled stock. CONSTITUTION: Plural rolled stock cooling devices are provided between the rolling stands of the hot finishing mill and, at the time of changing the number of jets in the rolled stock cooling devices, the rolling speed pattern at each rolling stand is calculated based on the rolling conditions of the rolled stock with a rolling speed arithmetic part 70 before the rolled stock is passed through. The number of jet in the rolled stock cooling devices for making the temp. of the rolled stock on the outlet side of the hot finishing mill into the target temp. is calculated concerning plural positions in the longitudinal direction on the inlet side of the hot finishing mill based on the calculated rolling speed pattern by a calculating part 71 for the number of jets. On the other hand, when respective positions in the longitudinal direction of the rolled stock are tracked during rolling by a rolled stock position tracking part 72, the rolled stock cooling device is turned on/off so that rolled stock is cooled with the rolled stock cooling device having the number of jets calculated with the calculating part for the number of jets while the tracked positions of the rolled stock are passed through the hot finishing mill with the controlling part 73 for the number of jet of the rolled stock cooling device.