Elongation coefficient control method of rewinding straightening and withdrawal unit

Abstract

An elongation coefficient control method of a rewinding straightening and withdrawal unit comprises enabling speed of an exit tension roller unit to serve as a speed standard of the rewinding straightening and withdrawal unit for the exit tension roller unit, and adopting a speed control mode from beginning to end to enable a speed slope setting value Vline of the rewinding straightening and withdrawal unit to serve as the setting speed Vex of the exit tension roller unit; enabling an entrance tension roller unit to adopt the speed control mode in speed-up and speed-down processes of the unit, and achieving elongation coefficient control by adopting a speed difference adjustment mode; enabling the entrance tension roller unit to adopt a tension control mode after the unit enters a constant speed stage, and achieving the elongation coefficient control by adopting a tension adjustment mode; and enabling a tension actual value obtained by feedback at the time to serve as an initial value of the tension setting value when the elongation coefficient is just switched from the speed difference adjustment mode into the tension adjustment mode. The elongation coefficient control method avoids problems of being big in elongation coefficient fluctuation and unstable, and has good dynamic and static state performance.

Description

technical field [0001] The invention relates to a method for controlling the elongation rate of a plate, in particular to a method for controlling the elongation rate of a heavy coil tension leveling machine. Background technique [0002] The finishing process of high-quality cold-rolled sheet products such as automobile sheets and home appliance sheets requires shape correction, edge trimming, and coiling. Combined with technology, the process of straightening, trimming and coiling can be completed on one unit. [0003] In the heavy-coil tension-leveler unit, a tension-tension leveler is usually set up to correct the strip shape. In the process of stretching and leveling, the strip steel relies on the joint action of stretching and bending to make the strip steel produce local plastic extension when the tension it bears is less than the yield limit, so as to achieve the purpose of improving the shape of the strip. The shape defect of the strip steel plate is caused by the...

AI Technical Summary

Problems solved by technology

[0007] After the strip steel has been stretched and leveled, although the quality of the strip is improved, defects often appear on the surface to varying degrees. One of the reasons is that the elongation control accuracy is not high and the tension fluctuation is large.

In the first way, the response characteristics are good when the speed of the unit changes, but the tension between the tension rollers is the data automatically formed by the system in order to obtain the set elongation under a certain pressing amount of the bending rollers, and the tension is an open loop Therefore, the tension fluctuation is slightly larger; in the second method, the tension fluctuation is small in the steady state, and the elongation rate control steady state accuracy is higher, but the initial setting value of the tension is not easy to obtain, and there is a long period before entering the steady state. In the adjustment process, it is easy to oscillate and cause tension fluctuations, and because it is an indirect tension control in the process of unit speed up and down, if the inertia compensation of the tension roller is inaccurate, the closed-loop control of the elongation rate will be more likely to oscillate

Images