Liutenko L. MAGNETIC-PULSE EXPANSION OF TUBULAR WORKPIECES by MEANS OF MAGNETIC FIELD PULSES «CUT» by A CONTROLLED VACUUM SWITCH

The dissertation on competition of a scientific degree of the candidate of technical sciences on a speciality 05.09.13 – technique of strong electric and magnetic fields (14 - Electrical engineering) – National technical university «Kharkiv polytechnic institute» of the Ministry of Education and Science of Ukraine, Kharkiv, 2021. Dissertation devoted to determining the shape, dimensions and method for producing pulses of external magnetic field to ensure dilation of the metal cylindrical tube workpiece with an external inductor. Analytical solutions to the problems of penetration of «cut» pulses of the external magnetic field into thin-walled cylindrical metal workpiece are obtained, by means of which a criterion analysis of the influence of the pulse shape on the electrodynamic forces acting on the workpiece is carried out. The probability of the appearance of «cut» pulses in the discharge circuit of magnetic forming installation with a controlled vacuum switch has been experimentally investigated. The reliability of the results obtained was confirmed by experiments on a low-voltage generator of pulse currents and by performing technological operations on a magnetic forming unit based on expanding tubular workpieces using an external inductor. Practical recommendations for finding the parameters of magnetic forming installation with a controlled vacuum switch to obtain «cut» pulses of discharge current and perform the necessary technological operations of expansion of thin-walled metal workpiece by an external inductor are worked out. Key words: magnetic forming installation, controlled vacuum switch, «cut» pulse of current, probability of the appearance of «cut» pulse, external inductor, expansion of tubular workpiece.