SU1569581A1 - Method of vibration acoustic diagnosis of articles - Google Patents

Abstract

The method of vibroacoustic diagnostics of products relates to a measurement technique, in particular to vibroacoustic diagnostics of electrical machines. The aim of the invention is to improve the reliability of diagnosing electrical equipment containing a winding, by creating non-standard modes of operation and diagnosing a product at higher harmonics of the fundamental frequency. A positive effect is achieved due to the fact that the winding of the product is excited by a broadband electric signal, and the component of the noise of the product itself and the background and only the background are measured, which allows monitoring of products in industrial conditions. 2 Il.

Description

The invention relates to a measuring technique, in particular to the vibro-acoustic diagnostics of electric machines.

 The aim of the invention is to improve the reliability of diagnosing electrical equipment containing a winding, by creating non-standard modes of operation and diagnosing the product at higher harmonics of the fundamental frequency.

Fig. 1 shows a block diagram of a device implementing a method of vibro-acoustic diagnostics of products; figure 2 - block diagram of the logical block of the device.

The device of vibroacoustic diagnostics contains a sequence-5- but connected generator 1 of stimulating signals connected with a key 2 to the winding of the product being diagnosed 3, a vibration converter 4, a sound meter 5, to the output of which two keys 6 and 7 are connected in parallel and 9 and two analog storage devices 10 and 11, the output of the first storage device is connected to the inverting input of the adder 12, and the output of the second to its non-inverting input, the output of the accumulator 12 is loaded on the connected parallel flax indicator 13 and a comparator 14 'to the second input of the comparator 14 is fed a reference voltage. The input of logic block 15 is connected to one of the outputs of the generator 1 stimulating pulses, and the outputs to the inputs of keys 2, 6 and 7. Logic unit 15 controls the operation of the keys and is a functional complete system that contains a zero-body 16, counter 17 with variable division factor and two D-flip-flops 18 and 19

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The method is implemented as follows.

A broadband stimulating signal (for example, a square wave) from generator J through key 2 is fed to the diagnosed product 3. Vibro-acoustic oscillations of the product using vibrator 4 and sound level meter 5 are converted into an electrical signal and measured. In the time period t, t, the noise meter 5 measures the background component and the acoustic noise of the product. Key 6 is open, the sum signal is rectified by detector 8 and stored on the first storage device 10. During time, keys 2 and 6 are turned off, key 7 is opened. Sound level meter measures background noise, the proportional signal is rectified by detector 9 and the second memory 11 is stored a signal that corresponds only to the background noise. Signals from memory devices 10 and 11 are fed to adder 12 and are stored, forming a total voltage.

UBux5 c + t) -U, - Uc,

3

where.UA is the background component;

Is - acoustic noise. From the output of the adder 12, the indicator 13 is given a signal proportional to the magnitude of the noise, the frequency range of which is determined by the vibroacoustic noise of the product and may be limited by the octave sound level meter filters (not shown in Fig. 1). Parallel to the indicator 13, a comparator 14 is connected, which, by comparing the output voltage of the adder with the reference voltage, allows the product to be rearranged by vibro-acoustic noise according to the principle of fit - reject.

The operation of the keys 2, 6 and 7 is controlled by a logic unit 15, generating

5 0 5 0 5

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control commands for the signals of the zero-organ 16 and the counter 17. The zero-organ captures the moments of the signal transition from the generator 1 through the zero level, providing the possibility of supplying and removing a stimulating signal to the diagnosed product 3 without extracurrents. Counter 17 allows you to set the specified periods of exposure to the diagnosed product 3. The control signals from counter 17 are sent to D-triggers 18 and 19, and from their outputs, control commands are received to keys 2, 6 and 70

The method allows to speed up the process of diagnosing products by vibroacoustic noise, improves the quality and reliability of diagnostics in the workshop conditions of serial production by compensating for the background component of vibroacoustic noise, increases the reliability of detecting potentially faulty products by using heat due to increased losses in the magnetic system of such products0

Claims (1)

Invention Formula The method of vibroacoustic diagnostics of products, which consists in measuring the parameters of mechanical vibrations of the product, according to which the state of the diagnosed product is judged, characterized in that, in order to increase the reliability of diagnostics of electrical equipment containing a winding, an electric broadband signal is applied to the winding of the product The mechanical vibration parameters are measured at the time of the electrical signal and without it, and the state of the product is judged by the difference in the measured vibration parameters. y. 1 Om1 sixteen 77 1B nineteen