System and method for controlling hydraulic tension of straight-pull cold rolling experiment machine

Abstract

The invention discloses a system and method for controlling the hydraulic tension of a straight-pull cold rolling experiment machine, and belongs to the technical field of cold rolling tension. The system comprises a left tension hydraulic cylinder, a right tension hydraulic cylinder, a hydraulic pump, a constant-backpressure control unit, a left tension control unit and a right tension control unit. Compared with the prior art, in the system for controlling the hydraulic tension, the overflow amount of a proportional overflow valve on the outlet side and the overflow amount of a proportional overflow valve on the inlet side can be greatly reduced, and therefore the tension control accuracy can be greatly improved; when the proportional overflow valves work, nonlinear areas and dead zones can be effectively avoided, the performance of the proportional overflow valves can be easily achieved, and the tension control accuracy can be improved; according to the tension control system, the forward slip rate and the backward slip rate do not need to be predicted, the high-accuracy tension control is achieved by presetting the control amount of servo valves in cooperation with pressure control of the proportional overflow valves, and finally the robustness of the tension control system is improved.

Description

technical field [0001] The invention belongs to the technical field of cold rolling tension control, in particular to a hydraulic tension control system and method for a straight-pull cold rolling test machine. Background technique [0002] The straight-pull cold rolling test machine is the key experimental equipment for the research and development of cold rolling process and rolled products. The tension hydraulic cylinders on the left and right sides of the cold rolling test machine apply tension to the rolled parts and perform constant tension rolling. . [0003] However, it is not easy to achieve constant tension rolling. First, the precision of tension control must be guaranteed, and there are many factors that affect the precision of tension control, including the time-varying nature of the control object during the rolling process, nonlinearity, and left and right tension. Due to the strong coupling between them, it will become very difficult to achieve high-precisio...

AI Technical Summary

Problems solved by technology

In the cold rolling process, there are many factors that affect the front slip rate and the back slip rate, including the reduction rate, the thickness of the rolled piece, the friction coefficient, the roll diameter and the tension factor, etc. For different materials and different rolling processes, it will also affect the front slip rate. slip rate and back slip rate, which makes it very difficult to predict the front slip rate and back slip rate with high precision

Although during the rolling process, the forward slip rate and the rear slip rate can be calculated and corrected by the actual movement speed of the left and right tension hydraulic cylinders and the actual rotational speed of the rolling mill, but at the moment of starting the rolling process, the calculation has not yet started, and it is necessary to Set an initial prediction value for the front slip rate and rear slip rate, and the initial prediction value has uncertainty, which greatly affects the tension control accuracy in the start-up stage

[0006] It can be seen that the robustness of the existing technology is not strong, which directly affects the precision of tension control. Therefore, a method that can effectively enhance the robustness of the tension control system is urgently needed to improve the precision of tension control

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