Configuration Principle And Elastic Dynamics Of Dual-source Seven-rod Oscillatorfor Continuous Casting Mold

The mold is the core of efficient continuous casting,and the continuous casting mold oscillation system is the key equipment to ensure the non-sinusoidal oscillation of the mold.Aiming at the performance defects of the current electric servo oscillation system of continuous casting machine mold,a dual-source seven-link oscillation device that can run smoothly in harsh working environment was designed,and considering the member elasticity and hinge clearance,the elastic dynamics of the system was studied.Firstly,in view of the defect that the single eccentric shaft non-sinusoidal oscillation system cannot adjust the amplitude on-line,a seven-rod oscillation system driven by dual servo motors was proposed.The composition and motion principle of the dual-source sevenlink oscillation mechanism of the continuous casting mold were expounded,the kinematics equation of the system was deduced,and a unified expression of the non-sinusoidal oscillation of the mold was established by using the Fourier function approximation characteristics.And a kinematic analysis was carried out.Considering the elastic deformation of the mechanism components,the lumped parameter method was used to establish the elastic dynamic model of the equivalent component and the dual-source seven-link oscillation system.The oscillation response of the system was solved by using the Runge-Kutta method,and the evolution law of the oscillation characteristics of the system with the oscillation parameters was analyzed.The results show that the fundamental frequency of the eccentric shaft is the main reason for the superharmonic resonance of the system and has the greatest impact on the system error;the increase of the fluctuation coefficient and the decrease of the phase angle difference enhance the elastic oscillation of the system;the elastic error of the system increases with the frictional force of the slab increases linearly with the increase of the external oscillation.Further considering that the hinges between the connecting rods generate gaps under long-term operation,a nonlinear dynamic model of the gaps of the dual-source oscillation system was established.The numerical solution of the equation was obtained by the RungeKutta method.The results show that gaps affect the non-sinusoidal oscillation of the mold.With the increase of the gap value,the mold received more impact force.The motion state of the system has gone through the state of period-period-doubling-chaos-period-doubling.Finally,according to the principle of the dual-source oscillation mechanism,a test prototype was designed and manufactured,and a oscillation test experimental platform was built to test the oscillation signals of the dual-source oscillation system under different process parameters.The original measurement data was preprocessed by the noise reduction method and compared with the theoretical value.The results of the experiment and the theoretical analysis were basically consistent,which proves that the dual-source oscillation system proposed in this paper can achieve accurate online control of all parameters and the dynamic analysis method is reasonable.