SU1368771A1 - Device for ultrasonic checking of articles - Google Patents

Abstract

The invention relates to non-destructive testing of products and can be used in various industries. The aim of the invention is to increase the reliability of control by eliminating the influence of the quality of acoustic contact and reducing the size of the uncontrolled zone. The first bottom pulse, separated by the second time selector 22, is fed through the second memory circuit 23 to the analog input of the second digital-to-analog converter 24, which generates an increasing step voltage. The first input of the first amplitude discriminator 16 is received by the first time selector 14 through the first memory 15 scheme of the amplitude of echoes in the time interval between the first and second bottom pulses, and the second input is controlled by the converter 24, and a comparison is made. Counter 18 captures this value. The first digital-to-analog converter 19 and the second amplitude discriminator. 20 serve to ensure that the presence of a defect is detected by the magnitude of the amplitude of the response voltage of the first amplitude discriminator 16.5 Il. 13 9 ko Sde 9d eo h

Description

 .13687712

The invention relates to the field of chick 18, the first digital-to-analogue pre-nondestructive testing of ultrasonic puller 19, the second amplitude extraction method and the discriminator 20 can be used, the second input of which is used to control the products in the machine-building industry and others. The industrial voltage thresholds of the threshold voltage and the circuit are OR 21, the second input is connected. The purpose of the invention is to reach the output of the first circuit AND 8, and to verify the control quality by eliminating the input to the third input of the second circuit. ow and neither the quality of the acoustic circuit, I 12, connected in series with the measure and the decrease in the magnitude of the noncontact second time selector 22, the first to be rotated. The input connected to the output of the second

Fig. 1 shows a block diagram of an oscillator 5 of gating pulses, solutions for ultrasonic control and a second input to the output of amplification products; Figures 2 to 5 are diagrams, 15 liters, 3, a second memory circuit 23, and a second memory device for explaining the operation of the device. A digital-to-analog converter 24,

The device contains a second input connected to the output but electro-acoustically connected counter 18, and vspod to the second high frequency generator 1, the piezo input of the first amplitude discriminant converter 2 and amplifier 3, the monitor 16, delay circuit 25, the input consequently connected to the first 4 and connected to the output of the second time-second 5 generator gating the selector 22, and the output - to the pulses, the first amplitude-time input of the generator 17 pulses discriminator 6, the first input of which is a, and the third generator 26 is directly connected to the output of the second generator of 25 coal pulses, the input is connected to strobe pulses, the second input to the output of the second amplitude-time discriminator is intended for substitution discriminator 9, and the output is the source to the threshold napa to the third input of the circuit OR 21. Positions and, the first generator 7, on the order of 27–50, indicate the signals from the angular pulses and the first circuit AND 30 strokes of the device elements. 8, the second amplitude-time disk- The device operates as follows as the transmitter 9, the first input is connected. at once.

The output of the whole circuit to the output of the 4th generator 4 is set by the impulse pulses, the second input pulses 27 produced by synchronization which is intended to connect the high frequency generator 1 to the source of the threshold voltage Uj, P1 pulses 28 taken from the output of the second generator 10 rectangular high-frequency rarator 1, excites pulses, the input connected to the converter 2. The signals received by the signal of the first generator 4, gates 29, amplified by amplifier 3, the positive pulses, and the output to the second 40 The first inputs of the amplitude input of the first circuit And 8, sequential discriminators 6 and 9, and the connected pulse sources of the selectors 14 and 22 are fed. The power generator 11 and the second circuit 12, the tori 4, 5 and 13 of the gate pulses the second input connected to the syncro are assembled according to the scheme of the waiting multivibration output of the generator 1 of the shooters, form rectangular frequency frequencies, and the output is intended for pulses whose duration is determined to be connected to the recorder, the necessary time intervals . The inputs of the first 6 and second 9 amps are fed to the second input of the second amplitude-tense-time discriminators of the time discriminator 9, connected to the output of the amplifier 3, after the output of the first generator 4, the strongly connected third generation signal pulses 30, Rotor 13 of gating pulses, the input of which corresponds to the damage connected to the output of the second genetic gap between the echo pulse generator 5 gating pulses, mi 29 from the front face P and the bottom of the first time selector 14, the second 55 D Lee D. Thus, at the output an input connected to the output of the amplification of the second amplitude-time discriminator 3, the first memory circuit 15, perminator 9 appear rectangular amplitude discriminator 16, the pulses 31 only when the amp - generator 17 counting pulses, the echo echo count gj in time

the interval between pulses from the edge and bottom of the product is greater than the threshold level Uj.

The leading edge of the pulse 31 is triggered by the third generator 26 of the direct coal pulses and creates at the out. de rectangular impulse 32 of a certain duration. To the second input of the first amplitude-time discriminator 6 t of the output of the second generator 5 gating pulses, a signal 33 is transmitted, which propagates the first bottom pulse. Thus, at the input of the first amplitude-time discriminator 6, a rectangular pulse 34 appears only when the amplitude of the first bottom pulse E is greater than the threshold level

Uf.

The leading edge of the pulse 34 starts the first generator of 7 rectangular pulses, which form an inverse signal 35 of a certain length

telnosti. From the back of the pulse 25 pulse. This is a stepped voltage.

Amplitude of the first bottom mpul.sa

41D, is memorized by the second memory circuit 23 and is supplied as a reference

42 to the analog input of the second digital-to-analog converter 24, which is controlled by the binary code from the outputs of the counter 18. With the arrival of the first bottom pulse, through the delay time determined by the delay circuit 25.

U

a counting pulse generator 17 is launched, generating a sequence of square pulse 43. These pulses are considered to be counter 18 and are fed to the digital inputs of digital-to-analog converters 19 and 24 in binary code. In accordance with the number of counting pulses, the second digital-to-analog converter 24 generates an increasing step voltage 44 with the increment value ai, where N is the digit-to-analog converter size;

ten

- amplitude of the first bottom to them

30, a second generator of 10 rectangular pulses is triggered and generates an inverse signal 36 at the output, the duration of which is regulated. At the output of the first AND 8 circuit, a high level is formed only if both inputs have a high level. Therefore, at the output of the first circuit And 8 an inverse pulse 37 is formed, the duration of which is determined by the pulse 36 if the level of the first bottom signal D is less than the threshold level and, or the pulse 35 if the level of the first bottom pulse D is greater than the threshold level Uj.

The first time selector 14 selects the echo pulses 39 in the time / interval with the first D and the second Bottom pulses, since a pulse 38 is output to its second input from the output of the third generator 13 of the gating pulses, the duration of which determines this time interval, the amplitude of the largest echo pulse 39 The gg or gj is memorized by the first memory circuit 15, which forms a constant level 40. The magnitude of the level 40 mA corresponds to the amplitude of the memory 44 compared to the level 40 on the first amplitude discriminator 16. Once a step This voltage 44 will exceed level 40, the first amplitude discriminator I4 W triggers 30 using signal 45 to stop the generation of 17 counting pulses, and thus the counter 18, at whose digital outputs the number of counting pulses in the binary code remains.

oD)

Using the first digital-to-analog converter 19, the number of count pulses is converted into an increasing step voltage of 46 s.

40 by the increment of D U / 2. This voltage 46 is compared with the threshold level and with the help of the second amplitude discriminator 20. If voltage 46 is greater than the threshold level

45 n Uj, then the second amplitude discriminator 20 is triggered and generates a high level 47 at the output. Thus, signals 32, 37 and 47 arrive at the OR 12 circuit. The OR circuit 12 you

5Q gives a high level of 48, if at least one of the inputs has a high level. Record 50 is made only during the time determined by the duration of the pulsed echo pulse. The second time 55 power source 11 and the long-distance selector 22 select the first one, the pulse bottom 27. The threshold levels

impulse 41 D ,, as on its second U - U

the input is impulse 33, setting

the required time span. control,

1 set according to the required sensitivity.

44 is compared with level 40 at the first amplitude discriminator 16. As soon as step voltage 44 exceeds level 40, the first amplitude discriminator I4 W is triggered by a signal 45 and the counting pulse generator 17, and thus the counter 18, whose digital outputs have the number of pulses accounts in binary code.

D)

With the help of the first digital-to-analog converter 19, the number of counting pulses is converted into an increasing step voltage 46 with an increment of D U / 2. This voltage 46 is compared with the threshold level and with the help of the second amplitude discriminator 20. If the voltage 46 is greater than the threshold level 5 n Uj, then the second amplitude discriminator 20 is triggered and generates a high level 47 at the output. 32, 37 and 47. The scheme OR 12 youQ gives a high level of 48, if at least one of the inputs has a high level. Record 50 is made only in time, determined by the duration of the operation pulse U

1 set according to the required sensitivity.

The additionally introduced blocks form a relationship channel, which allows, in addition to detecting defects using an echo method and a mirror-shadow method, register the ratio of the amplitudes of the echo pulses in the time interval between the first and second bottom pulses to the amplitude of the first bottom pulse.

The relationship channel operates as follows.

The first bottom pulse, divided by the second time selector 22 and enclosed by the second memory circuit 23, is applied to the analog input of the second digital-to-threshold converter 24, which generates an increasing step voltage from 0 to U X (2 -) / 2N, in increments of

ai / 2, where Uya is the level of the first bottom pulse; N is the digital-to-analog converter width,

At the first input of the first amplitude discriminator 16, the amplitudes of echo signals allocated by the first time selector 14 and stored by the first memory circuit 15 in the time interval between the first and second bottom pulses are received. The 16-step voltage supplied to the second input of the first amplitude discriminator, formed by the second digital-to-analog converter 24, is compared with the constant voltage formed by the first memory circuit 15, proportional to the amplitude of the echoes in the second time interval. The first amplitude discriminator 16 is triggered and, by its output signal, stops the operation of the generator 17 of counting pulses at the moment when the step voltage is compared to the constant voltage

and

3I-U

proportional amplitudes

echoes in the second time interval. The amplitude of this voltage at the time of operation and to- p

and

PG-and

l

or

Usr-j / i.

Yu

1/2

where n is the number of pulses of the generator 17 counted by the counter 18 by the time the first threshold stage 16 is triggered.

The first digital-to-analog converter 19 and the second amplitude discriminator 20 serve to ensure that the presence of a defect in the product is detected by the magnitude of this ratio. The digital inputs of the first digital-to-analog converter 19 receive the number of counting pulses in binary code from the outputs of counter 18. The analog input of the first digital-analog converter 19 is supplied with a reference voltage U The output voltage of this

proportional converter

and Hfjf, p / 2, is fed to the first input

second amplitude discriminator

20 and is compared with the threshold level Uj. In the case of U, U decides on the presence of a defect in the product, with the second amplitude discriminator 20 triggered and

a high level of the output signal to the input of the OR circuit 21. The value of the threshold level Uj is set to the values of the reference voltage Pop Uj K Ug (K с 1). If there is a defect

in the product U U and U., U K;

Thus, the sensitivity of the control over the second time interval is determined by the value of the ratio / Uja By adjusting the value of K, the desired sensitivity of the control can be set.

I

In the case when the product has

defect g, which is recorded in the time intervals between the echo pulse from the front face of the Pu and the first

bottom pulse D; and between the first Du and the second D. bottom pulses, at the output of the amplifier 3 there is the next sequence of signals 29. This triggers the second

the amplitude-time discriminator 9 and pulse 31 triggers the third generator 26 rectangular pulses, which forms a rectangular pulse 32. The first amplitude-time discriminator 6 triggers, starts the first generator 7 rectangular pulses, and a pulse 37 is generated at the output of the first And 8 circuit. A ratio channel is activated, and a high level 47 is formed at the output of the second amplitude discriminator 20. Thus, a pulse 48 is formed at the first input of the second circuit 12 And

The current time 49 of the operation of the pulsed power source 11.

In the case when there is a gross defect in the product, which is recorded in time intervals Between the echoes from the front face P and the bottom of the product D, and between the first A and the second A bottom pulses, as well as reducing the first bottom pulse, does not work the first amplitude-time discriminator 6 and at the output of the first circuit And 8 an inverse pulse 37 is formed smaller

20

thirty

duration. But, since 15 switches to the source of the threshold Nap-second amplitude-time discriminator 9 and the ratio channel are triggered, a pulse 48 is formed at the first input of the second circuit 12 And a defect is recorded.

If the defect in the product is close to the surface of the product and the reflected echo impulse from the defect g is masked against the background of the impulse from the front face P, then in the second, the time interval between the first D and the second D bottom pulses, an echo impulse g from the defect appears 29, since the control method for the second time interval has a smaller dead zone than the echotenic method. In this case, the relationship channel is triggered and the defect is recorded.

If there is a sound diffusing sound defect in the product (accumulations of small slag inclusions or pores) or a gross defect located so close to the surface that the echo pulses from the defect are masked against the background of echoes reflected from the front face of P. and the bottom of the product D, D - TO in this case, the defect is recorded by a decrease in the level of the first bottom signal. At the same time, the second 9 and first 6 amplitude-time discriminators do not work, the ratio channel does not work, and an inverse pulse 37 is formed at the output of the first circuit And 8. In this case, the defect is recorded, but with a lower intensity, since the pulse duration 50 is smaller, what is the time 49 of the operation of the pulsed power source 11.

the first generator of rectangular pulses and the first And circuit, the second amplitude-time discriminator, the first input connected to the output of the first gating pulse generator, the second input of which is intended to connect the threshold voltage to the source, the second rectangular pulse generator connected to to the output of the first generator of gating pulses, and the output to the second input of the first And circuit, the series-connected switching power supply and the second And circuit, the second input is connected It is connected to the recorder, and the third inputs of the first and second amplitude-time discriminators are connected to the output of the amplifier, characterized in that it is equipped with series-connected third generator of gating pulses in order to increase the reliability of control. , the input is connected to the output of the second generator of gating pulses, the first time selector, the second input is connected to the output of the amplifier, the first circuit

35

40

50

memory, first amplitude discriminator, counting pulse generator, counter, first digital-to-analog converter, second amplitude discriminator, the second input of which is intended to connect the threshold voltage to the source and the OR input, the second input connected to the output of the first AND circuit, and the output increase the access to 55 to the third input of the second circuit I, connected in series by the second time selector, the first input connected to the output of the second gating pulse generator, and eye ring

the reliability of the control by eliminating the influence of the quality of the acoustic contact on the results of the control and reducing the size of the uncontrolled zone.

eight

Claims (1)

Invention Formula A device for ultrasonic testing of products containing a series of electro-acoustically connected high-frequency generator, a piezo-transducer and an amplifier, serially connected first and second gating pulse generators, first amplitude-time discriminator, the first input of which is connected to the output of the second gating pulse generator, the second input of the discriminator is designed for under the key to the source threshold the first rectangular pulse generator and the first AND circuit, the second amplitude-time discriminator, the first input connected to the output of the first strobe generator, the second input of which is intended to connect a threshold voltage to the source, the second rectangular pulse generator connected to the output of the first generator of gating pulses, and the output to the second input of the first And circuit, the series-connected switching power supply and the second And circuit, the second input connected It is connected to the recorder, and the third inputs of the first and second amplitude-time discriminators are connected to the output of the amplifier, characterized in that it is equipped with series-connected third generator of gating pulses in order to increase the reliability of control. , the input connected to the output of the second gate generator, the first time selector, the second input connected to the output of the amplifier, the first circuit 50 input to the output of the amplifier, a second memory circuit and a second analog-to-digital converter, a second input connected to the counter output, and an output to the second. - input of the first amplitude discriminator, a delay circuit connected to the output I P guv L  f f. „ „To ShtSh  I j   I lg fie2 the second time selector, and the output to the second input of the counting pulse generator, and the third rectangular pulse generator connected to the output of the second amplitude-time discriminator, and the output to the third input of the OR circuit. fi.3 Fy 27 .L 28 / 42 45  close up