SU1555662A1 - Apparatus for checking quality articles - Google Patents

Abstract

This invention relates to non-destructive testing using acoustic emission signals. The purpose of the invention is to increase the reliability of the control during the operation of products under the conditions of periodic noise generated by the mechanisms stationary in relation to the object of control, by taking into account periodic signals of the same amplitude in the total number of acoustic emission pulses. In a product quality control device, a signal of the same amplitude is checked for periodicity, the number of periodic noise pulses is determined, which is then subtracted from the total number of received acoustic pulses. Signal analysis is performed by the device in real time. 2 Il.

Description

The invention relates to the field of non-destructive testing using acoustic emission signals and can be used to diagnose the mechanical state of products during their operation.

The aim of the invention is to increase the reliability of the control during the operation of products under the conditions of periodic noise generated by the mechanisms stationary in relation to the object of control, by taking into account periodic signals of the same amplitude in the total number of acoustic emission pulses.

FIG. 1 shows a block diagram of the device; in fig. 2 is a schematic diagram of a subtracting pulse driver.

The device for quality control of products (Fig. 1) contains a piezo transducer 1, an amplifier 2, an envelope shaper 3, a comparator 4 and a shaper 5 normalized pulses, a generator 6 sequentially connected, the first counter 7 and the first register block 8, the second input of which is connected to the output shaper 5 normalized pulses, serially connected via a data bus analog-to-digital Converter 9, the input of which is connected to the output of the shaper envelope 3, the second block of 10 registers, the second the input of which is connected to the output of the generator of 5 normalized pulses, the first comparison unit 11, the block 12 of the circuits And, the second inputs of which are connected via the data bus to the outputs of the first block of 8 registers, the subtraction unit 13, the second comparison block 14 and the imager 15 of the subtractors

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pulses, the second counter 16, the input of the direct counting of the latter is connected to the output of the imager 5 normalized pulses, and the reverse counting - with the output of the imager 15 subtractive pulses.

The shaper 15 subtractive pulses, designed to work with eight pulses of periodic interference (figure 2), contains 16 elements AND-NOT 17-32, element OR 33 and the counter 34. The first inputs of the first six elements AND-NOT 17-22 are interconnected and connected to the output of the subtractive pulse generator, performed on the AND-NE 30-32 elements, resistor B. and capacitor C, and the second inputs are respectively the inputs of the subtracting pulse generator 15. The outputs of the first six elements AND-NOT 17-22 are connected respectively to the inputs of the element OR 33, the output of which is connected to the direct input of the counter 34 and is the output of the subtracting pulse generator 15. The outputs of the counter 34 are connected respectively to the inputs of the decoder, performed on the elements AND-NOT 23-28, the outputs of the latter are connected respectively to the third inputs of the first six elements AND-NOT 17-22, the output of the last element AND-NOT 28 of the decoder is connected via an inverter element AND NOT 29 with reset inputs of counter 34.

The device quality control product works as follows.

The acoustic emission signals are received by the piezoelectric transducer 1 and amplified by the amplifier 2. At the output of the imaging unit 3, an electric signal envelope is generated, which is fed to the inputs of the comparator 4 and the analog-digital converter 9 In the comparator 4 and the imaging unit 5, the normalized impulses carry out discrimination of the signals according to amplitude and shaping normalized rectangular pulses arriving at the gate inputs of the first 8 and second 10 blocks of registers, and the input of the direct count of the second counter 16, where It is their total score. The signal from the output of the generator of 5 normalized pulses in the corresponding register of the first block of 8 registers records the time of occurrence of the next pulse, the digital code of which is supplied from the output

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the first counter 7. At the same time, the digital amplitude code of the received pulse, written from the output of the analog-digital converter 9, is recorded in the corresponding register of the second register block 10. Thus, the sequential receipt of pulses leads to the sequential filling of the first and second blocks of registers with digital time codes arrival and amplitude of received signals. In the first comparison block 11, the digital amplitude codes of the received signals are compared. In case of equality of digital codes at the three outputs of the first block of 10 registers, the level of the logical unit is formed at the first output of the first block 1 1. In case of equality of digital codes on four or more outputs of the first block of 10 registers in the first block of comparison 11, the level of the logical unit is formed, respectively, on the first two, first three, and so on its outputs.

From the outputs of the first block of 8 registers, the digital inputs of the arrival times of the received signals are sampled at the inputs of the block 12 of the circuits, where only those of equal amplitudes are sampled. These digital codes are fed to the corresponding inputs of subtraction unit 13, in which the differences in arrival times of signals with the same amplitudes are determined. The analysis of received signals for periodicity is carried out by comparing the differences obtained in the second comparison unit 14. In case of equality of digital codes on two or more inputs of this block, the level of a logical unit is formed, respectively, on the first, first two, first three, and so on its outputs. Signs of periodic interference arrive at the corresponding inputs of the imaging unit 15 subtractive pulses.

The shaper 15 subtractive pulses operates as follows.

In the initial state, the counter 34 is reset, therefore, at the third inputs of the first six elements NAND-17-22, the levels of the logical unit are set. Assume that the device has received three pulses of periodic noise. In this case, at the second input of the first element IS-NOT 17, a logic level is set.

units permitting the passage of generator pulses on the AND-NE 30-32 elements to the input of the direct counting of the counter 34 and to the input of the imaging unit 15 of the subtractive pulses. When the third pulse is generated on the counter 34, a digital code of number 3 is formed, which is converted by the decoder on the AND-NE elements 23-28 to the logical zero level on the third input of the first AND-17 element. This level blocks the AND-NE 17 element and the generation of the subtractive pulses is terminated. Upon receipt of the next next interfering pulse, the generator pulses pass to the input of the direct counting of the counter 34 through the second IS-HE 18, as a result, another subtractive pulse is generated at the output of the imaging unit 15 of the subtracting pulses. At the same time, the next element AND-NOT is locked at the entrance to the formate

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AE, taking into account the periodic disturbance pulses produced by fixed mechanisms in relation to the object of control, as a result of which the reliability of the control is increased.

Claims (1)

Invention Formula A device for quality control of products containing a converter and an amplifier connected to it, a generator connected in series, a first counter and a first block of registers connected in series to a comparator, a driver of normalized pulses and a second counter, and a block of circuits I, the output of the driver of normalized pulses are connected to a gate input the first block of registers, characterized in that, in order to increase the reliability of the control, it is equipped with an envelope former; l The operation cycle of the imaging unit extended via the data bus is analogous until the reception of the eighth periodic disturbance pulse, when the levels of the logical unit are set at all six inputs of the imaging unit 15 of the subtracting pulses. When the eighth subtractive pulse is generated, the logical unit level is formed at the output of the IS-NOT element 29, which flushes the contents of the counter 34, after which the subtracting pulse generator 15 changes to the initial state, the operation cycle repeats. Subtractive pulses are fed to the countdown input of the second counter 16, where acoustic emission pulses are counted. Thus, the device checks the signals of the same amplitude for periodicity and corrects the total count. the digital converter, the second block of registers and the first comparison block, and the subtracting pulse driver, the driver input The envelope 30 is connected to the amplifier output, and the output is connected to the inputs of the comparator and the analog-digital converter, the gate input of the second register block is connected to the output of the normalized pulse generator, the outputs of the first comparison block are connected to the first group of inputs of the U block, the second group of inputs of which are connected co4Q responsibly with the outputs of the first block of registers, the outputs are connected respectively to the inputs of the subtractor, and the output of the subtracting pulse former is connected to the second input of the second with etchika. 35 via the data bus analog the digital converter, the second block of registers and the first comparison block, and the subtracting pulse driver, the driver input the envelope is connected to the amplifier output, and the output is connected to the inputs of the comparator and analog-digital converter, the gate input of the second register block is connected to the output of the normalized pulse generator, the outputs of the first comparison block are connected respectively to the first group of inputs of the P block, the second group of inputs of which are connected respectively with the outputs of the first block of registers, the outputs are connected respectively to the inputs of the subtraction unit, and the output of the subtracting pulse shaper is connected to the second input of the second account ika. Phie.1