Research On The Horizontal Vibration Of Four Roller Of Cold Rolling Mill

The vibration of rolling mill is a cross subject of plastic mechanics,dynamics and surface engineering,the research on the vibration theory and vibration phenomenon of rolling mill has become an important obbject in the design and safe use of modern rolling mill.In this paper,the vertical vibration and torsional vibration of the rolling mill are considered as the original input excitation,induced horizontal vibration response as output,Through the rational simplification of four roller of cold rolling mill,the nonlinear dynamic model of the rolling mill is established to reveal the mechanism of the horizontal vibration of four roller of cold rolling mill under different working conditions.Firstly,the horizontal vibration of the working roller caused by the vertical vibration of the press-down system is studied.The vibration characteristics of the working roller under the interaction of the parameters in the vertical direction and the parameters in the horizontal direction are obtained;Secondly,the horizontal vibration of the working roller caused by the torsional vibration of the torsion system is studied.The vibration characteristics of the working roller under the interaction of the parameters in the twist direction and the parameters in the horizontal direction are obtained;Finally,the combined resonance characteristics of the working roller are obtained by taking the action of the vertical vibration in the vertical direction and the torsional vibration in the twist direction into account.I.By analyzing the influence of different parameters on the horizontal main resonance characteristics of the working roller,it is concluded that the damping and stiffness in the horizontal direction have a great influence on the horizontal vibration;the fluctuation amplitude of rolling force has a great influence on the main resonance amplitude in the horizontal direction of the working roller;the smaller the eccentricity of the roller,the smaller the resonance zone and the larger the resonance amplitude;the larger the eccentricity is the opposite.II.Using the singularity theory,according to the bifurcation characteristics of different regions,the amplitude of the system is smooth and slow,when the parameter is in the region(1).?.By analyzing the influence of boundary disturbance on the dynamic characteristics of the system,when the parameters such as the frequency ?,the frequency ratio?,the amplitude of the boundary disturbance ? and the floating amplitude of the rolling force F are changed,the change rule of the motion path and the change mechanism of the vibration characteristic of the system are obtained.IV.Considering the influence of the additional force caused by the torsional vibration of the main drive system on the horizontal vibration of the working roller,when the parameters such as the frequency?,the cubic damping c3,the primary damping c1,the additional horizontal force F,the primary stiffness k1,and the cubic stiffness k3 are changed,the change rule of the motion path and the change mechanism of the vibration characteristic of the system are obtained.V.The nonlinear characteristics of the system in the horizontal direction of the working roller are analyzed by using the method of multiple scales,which is excited by the 2?1+?2?1 and ?1+?2?1 forms of combined resonance of two excitations.?.Based on the Mathieu equation,the stability of the rolling system is analyzed,and the influence of different rolling process parameters on the stability of the system is obtained.The research results of this paper can provide some guiding significance for the design of four roller of cold rolling mill system and the vibration control in the rolling process.