板带轧机液压压下-垂直振动特性研究

考虑板带轧机垂直振动对液压压下系统中四通伺服电磁阀非线性流量的影响，推导出非线性流量变化下的液压缸的非对称分段弹簧力，并建立了板带轧机液压压下-垂直振动动力学方程.运用平均法求解出该轧机振动系统的幅频响应方程，并利用奇异性理论求解了轧机在动态轧制过程的分岔特性，得到4组不同的转迁集及其对应的分岔图，分析了开折参数对轧机分岔特性的影响.最后以实际轧机参数为例，通过仿真发现系统幅频曲线在分段处出现拐弯特性，调整伺服阀响应时间可降低系统振幅不稳定频率区域，通过调整外激励幅值与阻尼比等参数可有效改善系统共振情况，为进一步抑制轧机辊系振动提供理论参考.

Research on Hydraulic Screw down-Vertical Vibration Characteristics of Strip Rolling Mill

Considering the effect of the vertical vibration of the strip mill on the non-linear flow rate of the four-way servo solenoid valve in the hydraulic system， the asymmetric segmented spring force of the hydraulic screw down cylinder under the non-linear flow rate change is derived. The dynamic equations of hydraulic screw down-vertical coupling vibration of the strip mill are established. The averaging method is used to solve the amplitude-frequency response equation of the coupled vibration system of the rolling mill， and the bifurcation characteristics of the rolling mill in the dynamic rolling process are solved using the singularity theory. Four different transition sets and their corresponding bifurcation diagrams are obtained. The effect of the unfolding parameters on the bifurcation characteristics of the rolling mill are analyzed. Finally， based on the actual rolling mill parameters， it is found through simulation that the amplitude-frequency curve of the system has turning characteristics at the section. Adjusting the response time of the servo valve can reduce the unstable frequency area of the coupling system. By adjusting the external excitation amplitude and damping ratio and other parameters， the resonance of the coupled system can be effectively improved. This can provide a theoretical reference for further suppressing the vibration of the roll system of the rolling mill.