SU1101726A2 - Device for electromagnetic checking of mechanical properties of moving ferromagnetic materials - Google Patents

Abstract

DEVICE FOR ELECTROMAGNETIC CONTROL OF MECHANICAL PROPERTIES OF MOVING FERROMAGNETIC MATERIALS by author. St. No. .696369, characterized in that, in order to increase the control accuracy, it is equipped with two logarithmic and anti-logarithmic converters, each logarithmic converter is connected between the reading converter and the adder, and the anti-logarithm converter - between the output of the adder and the recorder.

Description

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N5 Y 1110 The invention relates to non-destructive testing and can be used to determine the mechanical properties of ferromagnetic materials in any branch of engineering. According to the main auth. No. 696369 discloses a device for electromagnetic control of mechanical properties of moving ferromagnetic materials containing magnetizing elements and reading transducers, whose outputs are connected to an adder, and a recorder connected to an adder. The magnetizers and readout transducers are arranged symmetrically with respect to the product being monitored. The controlled material is brought to saturation by magnetizing elements. The signal taken by the readout transducers is equal to the doubled signal from one transducer. When the material deviates towards one of the transducers, the signal in it increases, in the second transducer it decreases, but for a material with the same mechanical properties along its entire length, the sum of these signals will remain constant (with small vibration amplitudes) G13. A disadvantage of the known device is the impossibility of detuning from vibration oscillations within wide limits and with high accuracy. This is due to the fact that the magnitude of the signal of the reading transducer depends on the change in the gap nonlinearly and quasi-exponentially; therefore, in case of material displacement towards one of the transducers, the signal in it will increase by a larger amount than decreases in the second transducer. As a result, the sum signal is always larger than if there is no offset. This reduces the accuracy of control and reduces the limits of the detuning from the vibration displacements of the material in the process of control. The aim of the invention is to improve the accuracy of the control. The goal is achieved by the fact that the device is equipped with two logarithmic and anti-logarithmic converters, each logarithmic converter is connected between the matching converter and the adder, and the anti-logarithmic converter is between the output of the adder and the recorder. FIG. 1 shows a block diagram of a device on the figure. 2 shows the dependence of the output signal of the readout transducer (flux-gate-gradiometer) on the distance to the control surface for three steel products, for example, sheets with different mechanical properties in FIG. 3 the dependence of the logarithm of the output signal of the read converter on the change in the gap to the surface of the control for the same products in FIG. 4 shows the dependence of the output signal of the read converter for the known and proposed devices when changing the gap for three samples with different mechanical properties. The device contains magnetizing elements 1 and 2 and read converters 3 and 4, connected to it logarithmic converters 5 and 6, connecting | 1nn to them adder 7, anti-log converter 8, connected between the output of adder 7 and recorder 9. Read converters 3 and 4 placed behind the magnetizing elements 1 and 2 in the course of the controlled material 10. The device operates as follows. The controlled material 10 moves in the gap between the magnetizing elements 1 and 2 and the reading transducers 3 and 4. The magnetizing elements at some time intervals are applied to the material 10 magnetic labels, carrying information about its mechanical properties. The magnitude of the magnetized impulses is chosen such as to bring the material up to our performance. The magnetic marks are then passed near the reading transducers 3 and 4 and induce signals into them, the voltage levels of which are constant and proportional to the magnitude of the magnetic field. When the controlled material is shifted towards one of the transducers, the signals of the read transducers will become unequal, for example, SG and Uj. These signals are fed to the inputs of logarithmic converters 5 and 6, converting according to the law Ugbix IJex E110 The signals converted in this way are fed to the input of the adder 7, the output signal of which is equal to half the sum of the signals at the inputs (U of the code of the adder 7 8, the signal at the output of which ..-. 0 gUex, As a result of the described signal processing of the reading transducers U and LL, the signal i-c, enU2) is input to the input of perHCTpopopa 9, the value of this signal is judged by mechanical voystvah test material. Since the signals U and (ij depend on the distance between the reading transducers 3 and 4 and the material: 10 is non-linear (Fig. 2), and the dependence of the logarithms of these signals and and is almost linear (Fig. 3),

The 264 signal processing by the formula (1) allows to obtain results on vibration detuning better than the known device, where the signals are summed and the signal on the recorder is equal to I (q) (2). Moreover, the sensitivity to mechanical properties does not decrease, and when comparing formulas (1) and (2), the result is the same. The use of the proposed device will allow more than three times to reduce the error of control of mechanical properties, for example, rolled steel in the stream, associated with its inevitable vibration shifts and, therefore, significantly increase the accuracy of control. Any other conversion will not provide superior control results.

Claims (1)

(5'7) DEVICE FOR ELECTROMAGNETIC CONTROL OF MECHANICAL PROPERTIES OF MOVING FERROMAGNETIC MATERIALS according to ed. St. No. 696369, characterized in that, in order to increase the accuracy of control, it is equipped with two logarithmic and anti-logarithmic transducers, each logarithmic transducer is connected between the read transducer and the adder, and the anti-logarithmic transducer is between the output of the adder and the recorder.