MODELING OF A CONTROLLED ELECTROMAGNETIC VIBRATION DRIVE WITH A VARIABLE RESONANT FREQUENCY

The technology for the production of high-quality concrete products includes the vibration of the concrete mixture at various frequencies. For this, an electromagnetic vibration drive can be used, which has high reliability, durability and controllability. For its effective application, it is necessary to adjust the resonance frequency of the oscillating system in order to ensure the near-resonance mode of operation at different frequencies. This is possible by using devices with adjustable stiffness, in particular, controlled dynamic vibration absorbers with nonlinear elastic elements. In the article the electromagnetic, electromechanical, mechanical, and energy processes in a controlled vibration system, which includes an electromagnetic vibrator and a vibration absorber with conical springs, the stiffness of which is regulated by compression using a press, have been investigated. Using the circle-field method, a mathematical and simulation model of electromagnetic and electromechanical processes in the vibrator has been developed. For this purpose, numerical calculations of the magnetic field in the vibrator have been performed and, based on the obtained results, the functional dependences between the electromagnetic force, magnetic flux, magnetomotive force and the size of the air gap have been determined. A model of the mechanics of the oscillating system, processes in the vibration absorber press drive and processes in the control system has been also developed. The built simulation models were combined into a general model in the Simulink environment, by means of which the time diagrams of the processes have been obtained. The modeling results show that the system provides a smooth transition from one vibration frequency to another while maintaining the specified amplitude of the working body oscillations and near-resonance mode with high energy efficiency. References 12, figures 10, tables 3.