Rolled product tension control device, rolled product tension control method and hot strip mill

Abstract

The invention relates to a rolled product tension control device, a rolled product tension control method and a hot strip mill, wherein the tension on rolled products can be stably controlled. When a load detection value obtained from a load detection part (28) is normal, a pressure command correction quantity learning part (3) indicates the relation coefficient of the correlativity between a pressure detection value obtained from a pressure detection part (27) and a first pressure command correction quantity calculated through a first pressure command correcting part (24). When the load detection part can not obtain a normal load detection value, a rolled product tension control device (1) switches the pressure command correction quantity adopted by a pressure command calculating part (20) from a first pressure command correction quantity to a second pressure command correction quantity calculated through a second pressure command correcting part (25). Since the above correction quantities are related to each other, the change of the correction quantities during the switching process is not large. Therefore, the tension on rolled products can be stably controlled.

Description

technical field [0001] The present invention relates to a rolling material tension control device for controlling the tension of the rolling material, a rolling material tension control method, and a hot continuous rolling mill equipped with the rolling material tension control device. Background technique [0002] In a hot continuous rolling mill that rolls a rolled material such as a steel plate, keeping the tension applied to the rolled material constant during rolling is extremely important in realizing the stability of the operation of the rolling mill and maintaining the product quality of the rolled material. important. For this reason, in a hot continuous rolling mill, in order to keep the tension applied to the material to be rolled constant, a device called a looper is installed in the middle of the two roll installation positions. The looper has a roll that supports the material to be rolled in the middle of the two rolls, and the tension applied to the material ...

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Problems solved by technology

[0010] However, in the workpiece tension detection device described in Patent Document 1, since the accuracy and performance of the detectors used by the two tension calculators are different, the tensions calculated by the two tension calculators are not necessarily the same.

Therefore, if there is a difference in the tension calculated by the two tension calculators, for example, if a failure or abnormality occurs in the load detector, etc., if the signal switcher converts the signal sent to the tension control device from the calculation result of the second tension calculator When switching to the calculation result of the first tension calculator, the control input signal in the tension control device changes suddenly, and there is a possibility that the tension control becomes unstable.

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