Micro-tension control system and method

Abstract

The invention discloses a micro-tension control system and method. In the hot continuous rolling process, when a rolled piece enters a current machine frame and is stably bitten, the current machine frame is kept under speed control, speed control of main motors of machine frames on the upstream of the current machine frame is switched to constant torque control, on the basis, the torque and the rolling force of a main motor of the current machine frame are sampled to calculate the initial length of a rolling force arm, and the tension measurement calculating accuracy is improved. Each machine frame is provided with a pressure measuring head device to directly detect the rolling force, and consideration is given to the situation that the length of the rolling force arm is changed along with changes of the rolling force. Tension between the machine frames is obtained in real time through tension calculating models to form micro-tension closed-loop control to adjust the speeds of the machine frames so as to correct the tension deviations between the machine frames. As for a serial type universal rolling mill, the speed of the E machine frame serves as a standard, the rolling speed of the E machine frame is kept unchanged while speed set values of the other machine frames are adjusted, and real-time control is carried out on dynamic instantaneous values of the tension difference of the E machine frame before and after the adjustment process to guarantee micro-tension rolling of series universal rolling.

Description

Technical field [0001] The invention relates to a system and method for controlling the dimensional accuracy of rolling pieces in the process of hot rolling of section steel, in particular to a system and method for micro-tension control in the tandem universal rolling process of high-speed steel rail production. Background technique [0002] When metal products are continuously rolled between the stands of the rolling mill and the preset speed is not ideal, the rolling pieces meshed in the multiple continuously running stands will appear tensile stress. If the downstream stand pulls the upstream stand, the rolling stock between the stands will be stretched. If the upstream stand pushes the downstream stand through the rolling stock, the rolling stock between the stands is compressed. Stress is caused when the difference between the speed of the upstream stand of the rolling stock and the speed of the next adjacent stand does not match. When the exit speed of the upstream rack i...

AI Technical Summary

Problems solved by technology

[0004] 1) Due to large fluctuations in the tension at the head and tail of the rail, the size deviation of the head and tail of the rail is too large, resulting in a longer head and tail. For example, the head and tail dimensions of a high-speed rail produced by a production plant are 3 to 7 meters out of tolerance;

[0005] 2) The micro-tension control link is unstable, and the rack vibration phenomenon is prone to occur, especially the vibration of the universal rolling E rack

[0007] 1) Due to the large and unstable tension between the racks and the unstable dynamic AGC of the TCS process control system, it is difficult to eliminate the rail size changes caused by the temperature and thickness deviations of the rails. When putting into static AGC function

[0008] 2) The stability of the tension will affect the accuracy of the overall length of the rail

[0009] 3) When the steel biting speed is increased to the rolling speed, the tension will also fluctuate, resulting in fluctuations in the size of the rail

With the rapid development of my country's high-speed railways, the quality requirements for high-speed rails are constantly increasing. However, the existing tandem universal rolling mill MTC micro-tension control technology in my country has an impact on the size of high-speed rails, and there are deficiencies

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