Study On The Electro-hydraulic Pressure Control System Of Temper Mill

The accuracy of strip Thickness and strip flatness is two quality targets of strip production. With the development of rolling and control theory and its application, it has been improvised greatly. But there are still many questions to resolve in practice. The temper mill is the core facility of cold rolling mill line. The machining feature of strip, the mass of temper mill and the efficiency of production are all related with the appropriate design of the temper mill. This article carries on the comparatively in-depth study into the hydraulic automatic gauge control (AGC) system of the temper mill. The main contents of this article include the following parts.1) This article firstly has discussed the principle of eliminate thickness error, and analyzed the concept of equivalent stiffness and variable stiffness. In combination with the research object of this subject, the thesis concretely analyzes the related control strategy, control principle and the basic algorithm of this AGC system.2) According to the physical model of the real model system, the mathematic model of the AGC system is established. Then the mathematic model of AGC is simulated with the SIMULINK Blackest in MATLAB, analyses the influence to the system response characteristics of main parametric variation in hydraulic automatic position control (APC) system. It provided the theoretical basis for the system designing and debugging.3) On base of the boundary conditions on the contacting surface between the strip and rolls, the balancing differential equation of unit pressures established. Considering of elastic deformation of the plaiting strip, the deformation zone is divided into elastic deformation area and plastic deformation area. The distribution formulation and the surface balance formula of strip. The length of contact arc between the strip and rolls is calculated with boundary conditions, and the total force equals integration of the rolling force in all deformation areas.4) This article established a dual-pressure hydraulic cylinder system mathematical model; Dual hydraulic cylinders were installed in the roll on both sides. then the mathematical model of this system is simulated with the SIMULINK, the result is compared with actual field data to verify the correctness of the mathematical model. At the same time, it take into account the mill mechanical error, incoming changed and roller wear in mill roll to impact of both sides of the rolling force changed. It provided a theoretical basis for rolling force control.