Automated Device for Magnetic Control of Products of Complex Forms Made from Electrotechnical Steels

Abstract

This study proposes the device for indirect measurement of magnetic induction, with the given value of magnetic field strength, in electrotechnical steel samples of complex form with application of two permeameters. The testing of enclosed form samples requires preliminary labor-intensive coiling of magnetization and measuring windings, which is not suitable for automation of express testing. Express testing of products from electrotechnical steels is usually related to the measurement of not absolute values, but the values of deviation, taking into account the sign of the selected conventional «standard» value. Therefore, for such measurements implementation it is necessary to apply methods of comparison with the measure. The most suitable for this purpose is a differential measurement method. Comparing the increase of accuracy of testing in comparison with analogues, the design of a permeameter implies coiling of the measuring winding of four sections and their placement on the magnetic circuit on both sides of the zones of contact with the controlled pro-duct.Besides that, the windings in each pair of sections are connected in series, and the pairs of coils themselves — in series in accordance. This allows to measure the voltage on the terminals of the measuring winding, which only depends on the working magnetic flux passing through the cross section of the sample. This does not take into account magnetic dispersion flows from the magnetic circuit, which are sources of errors. This constructive technique achieves one more objective — increasing the sensitivity of the permeameter, which is adjustable since its value depends on the number of turns of the measuring winding. Obtained results allow to solve the problem of automation of the routine magnetic control of products of complex form from thin-sheet electrical steel in conditions of its mass production.