多源激励下CSP轧机主传动扭振问题研究

Research on Torsional Vibration of Main Drive System under Multi-source Excitation in CSP Rolling Mill

为研究薄板坯连铸连轧CSP轧机在轧制高强薄带钢时出现强烈振动这一普遍难题,利用轧机在线监测系统获取振动信号,分析得出CSP轧机存在电气驱动、机械传动及辊系压下耦合振动且振动信号表现出非线性谐波特征。以F3轧机主传动扭振问题为研究对象,通过建立传动等效非线性2自由度系统模型,将电气驱动谐波和轧制力谐波作为外扰激励施加到模型求解,结果显示轧机主传动在多源激励下存在超谐、亚谐及组合共振等多态特征。以w_1-w_2≈w-n型组合共振为例求解获得振动响应幅值随阻尼一次、三次项减小和刚度三次项、初始加载及谐波激励增大而增大的结论。由此制定利用抑制电气驱动电流谐波和轧制力谐波来抑制轧机传动扭振方案,试验结果表明振动幅值降低75%,取得显著效果。本文研究内容对深入认识传动非线性动力学特性与轧机系统耦合振动机理以及振动抑制提供参考。

For study the vibration of CSP mill of thin slab continuous casting and rolling mill when it roll high strength thin strip, the on-line monitoring system is used to obtain the vibration signal. Through signal analysis the coupling vibration exist in the electric drive, mechanical drive and the screw down system of CSP rolling mill, and it present nonlinear harmonic characteristics. The torsional vibration appearing on main drive of F3 rolling mill is regarded as the research object. By building the equivalent nonlinear two-DOF model, then, as external disturbance excitation, the harmonics of electromagnetic torque and rolling force are applied on the model. The solving result is that the polymorphism characteristics including ultraharmonic, subharmonic, and combination resonance are displayed on main drive system under multi-source excitation. For the case of combination resonance “”, the simulation show that vibration amplitude increases with the reduction of the one-time or three-times damping and the increase of three-times stiffness, initial load and harmonic excitation. Thus the project is implemented to suppress the torsional vibration by use of inhibition of harmonic excitation of electric drive and rolling force. The vibration amplitude value reduce 75% of the original and good results are obtained. This research can provide reference for vibration suppression, deep understanding of nonlinear dynamic characteristics and coupling vibration mechanism in rolling mill.