SU1541487A1 - Apparatus for resonance testing of articles - Google Patents

Abstract

The invention relates to a testing technique and can be used in the instrumental and engineering industry for resonant testing of products. The purpose of the invention is to improve the accuracy of measuring the number of working modes of the product. Before being measured by the initial setup signal, the device is prepared for operation. Using a controlled oscillator 3 through an electromechanical transducer 4, the product is subjected to the influence of frequency increasing oscillations. When the frequency of the generator 3 corresponds to the resonant frequency (eigenmode) of the product, the device automatically adjusts and keeps oscillator oscillations near this resonant frequency. Such auto-tuning is performed by the first feedback circuit - generator 3 - converter 4 - product - converter 5 - amplitude detector 11 - comparator 12 - matching circuit 13 - actuator 2 - and second feedback circuit - generator 3 - converter 4 - product - converter 5 - phase detector 1. When the resonant frequency region reaches the first feedback circuit, a signal is sent to the generator, reducing the rate of increase of frequency. When the resonant frequency of the re-feedback circuit is reached, a signal passes through the generator, stopping the increase in frequency. At the same time, through the phase mismatch 6, the OR 7 circuit, a resolving signal is fed to the counter 8 and the frequency meter 9, fixing the akurasov629.1.046.089.84463.631.879.62-229.81-1535.8

Sheshunova Nadezhda Mikhailovna

antipin Vladimir Filipovich

Ulitsa Valentin Nikolaevich + 7540138VacUUmElRETRIs FURNace FoR oNe-tIme tneRmaL tReATMeNt oF GRoUp oF artIcLeS11 456226 people of Binsk region. zlatoust11 456209 people of Binsky oblastzlatoust, pr. world 10-25

11 45623

Description

The invention relates to a testing technique and can be used in the instrumental and engineering industry in resonant tests.

The aim of the invention is to improve the accuracy of measuring the working modes of the products by eliminating the error in counting the number and determining the order of the resonant frequencies.

Fig about 1 shows a block diagram of the device; FIG. 2 shows the amplitude and phase characteristics of the test object having at least two resonant frequencies.

A device for resonant testing of products contains a series-connected phase detector 1, an actuating element 2, a controlled generator 3, an electromechanical transducer 4, the output of which is the output of the device, a mechanical electric conductivity converter 5 whose input is the input of the device, and the output is connected to the first the input of the phase detector 1, the second input of which is connected to the output of the controlled generator 3 and the input of the electromechanical converter 4, the converter 6 of the phase mismatch, the input which is connected to the output

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phase detector 1, connected in series with 4ILI circuit 7, the first input of which is connected to the output of phase mismatch converter 6, pulse counter 8 and frequency meter 9, counting inputs of which are connected to the output of controlled generator 3 and second input of phase detector 1, counting trigger 10, etc. my input of which is connected to the second input of the 4ILI circuit 7, the zeroing inlet is connected to the third input of the 4ILI circuit, and the counting input is connected to the output of the frequency meter 9 and the fourth input of the 4ILI circuit 7, serially connected amplitude detail The vector 1I, the input of which is connected to the output of the mechanoelectric converter 5 and the first input of the phase detector 1, the comparator 12S to one of the comparison inputs of which is supplied a predetermined voltage But, and the output is connected to the third input of the circuit 4IL 7, and the matching circuit 13, the output which is connected to the input of the actuating element 2, shifting the register 14, the logic unit 15, made in the form of serially connected ZILIR circuits whose inputs are the inputs of the logic unit 15, and the AND circuit, one of the inputs of which is connected to the input

the shift of the shift register 14 and the direct output of the trigger 10, and the output with the input of the actuating element 2, switches 16-18, installed between the outputs of the shift register 14 and the inputs of the logic unit 15,

The device works as follows.

The appropriate range of the controlled oscillator 3 is preliminarily set and the initial frequency of the signal is lower than the resonant frequency of the tested product. When the device is turned on, the trigger 10 is nullified, and the signal of the logical unit is set at the first output of register 14. The inputs of logic unit 15 are grounded through switches 1b-18. Generator 3 generates a signal whose frequency is controlled by the output signal of the actuator 2.

The output signal of the generator 3 through the converter 4 excites oscillations in the object, which through the converter 5 arrive at the first input of the phase detector 1. The polarity of the output signal of the detector 1 depends on the lag or advance of the oscillation frequency of the object of the generator 3 frequency. polarity leads to an increase in the frequency of the generator 3 o

The output signal of the positive polarity of the amplitude detector 11, depending on the amplitude of the object's oscillations, is compared at the input of the comparator 12 with the given signal U0. When oscillations II are exceeded, the output signal of the comparator 12 has a positive polarity and through the circuit 13 is fed to the input of the actuating element 2, causing an increase in the frequency of the generator 3.

The frequency sweep speed decreases near a certain value oz0 (Fig. 2) with a negative polarity of the output signal of the comparator 12

When the frequency approaches the value of the resonant frequency (J the difference between the phases of the signals at the input of the detector 1 decreases and the input signal of the phase error converter 6 becomes less than the signal of the specified error. At the first input of the circuit 7, the log

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In addition, the prohibition on the counting of a certain number of pulses coming from the generator 3 is lifted from the control input of the counter 8. After the end of the counting, a pulse arrives at the input of the frequency meter 9 allowing the measurement of the resonant frequency of the test object.

This phase locked loop mode is terminated at a frequency that corresponds to a component defined and specified in order in the frequency spectrum of the test product. The order and the number of modes of an object are measured by connecting the outputs of register 14 to the inputs of logic unit 15. For example, if the first output of register 14 is connected via switch 18 to the first input of ZILI circuit 15, then upon reaching the resonant frequency 10 (to the trigger input 10 the output of the frequency meter 9 receives a pulse that sets the state of logic 1 at the output of the trigger 10. From the output of the circuit 15 of the block 15, the input of the element 2 receives a positive polarity signal that ensures the frequency of the generator 3 moves from the first resonant frequency to the stop It increases to a certain frequency OU (at which the polarity of the output signal of the comparator 12 changes from negative to positive, moreover, the trigger 10 is reset, and the logical 1 from the first output of the register 14 is rewritten to the second.

A positive signal from the output of the circuit 13 increases the speed of the generator frequency to the value of EE. At the frequency ctfj, the output signal of the comparator 12 again changes polarity and the process of phase 5 auto-tuning starts at the second resonant frequency u3 (j under the influence of the phase detector 1.

Claims (1)

Thus, by connecting the corresponding outputs of register 14 to the inputs of block 15, it is possible to measure the eigenmodes of the test object in a strictly defined order. The 4ILI circuit 7 performs the function of protecting against false starts of the frequency meter 9 at nonresonant frequencies, as well as re-measuring one frequency. Invention Formula Device for resonant testing of products containing a series of five 0 0 Keu