Dynamic features of functioning of the plug mill of the pipe-rolled unit

The results of the study of the refined mathematical dynamic model of the working stand of the plug mill of the pipe-rolling unit (TPA) are presented. The spatial coordinate system in the center of mass of the working stand is selected and the initial dynamic model of the mechanical system is transformed into a simplified mechanical system of rigid bodies, which are interconnected in a certain way in the supporting nodes by elastic elements. The spatial position of the mechanical system in the process of oscillation of the working stand of the plug mill is represented by the corresponding coordinates in the selected reference system. Taking into account certain initial and boundary conditions, the task is presented in the formulation of the problem of the dynamics of a mechanical system. Assuming that the legs of the bed and the pedestals (tires) that hold the working stand of the plug mill on the support mechanisms are deformed, the kinetic and potential energies of the system are determined for a simplified mechanical system with four degrees of freedom. The differential equations of the movement of the working stand and the units of the mechanism of holding the bed on the support nodes of the pipe-roled unit were compiled using the Lagrange equation of the second kind. Pictures of the vibroactivity of the elements of the working stand and supporting units of the mechanism for holding the mechanical system with four degrees of freedom are obtained. A numerical solution of the system of differential equations is given, and by the example of calculating the dynamics of the working stand of the plug mill TPA-350, the features of the functioning of the mechanical system with four degrees of freedom are established. The parameters of the dynamism of the working stand of the plug mill and the mechanism of its retention on the reference planes, affecting the difference wall thickness of the rolled shells, are established. A scheme has been proposed to modernize the mechanism for holding the working stand of an plag mill TPA-350.