SU1446559A1 - Ultrasonic echo-pulse flaw detector - Google Patents

Abstract

The invention relates to a measurement technique and can be used in the ultrasonic testing of products. The purpose of the invention is to increase the reliability of control by:; , improved resolution of selection of defects. The echo signal reflected from the defect enters electrically in video amplifier 6, yes

Description

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further to the peak detector 7 and through the analog-to-digital converter 8 to the register 9 for measuring the amplitude of the defect signal. On the leading edge from the imaging unit 5 of the control zone, the counter 18 starts counting pulses, the number of which is proportional to the depth of the defect. A control circuit of a series-connected reference signal unit 11, a comparison unit 12, a one-shot 13, a coincidence element 14, and a driver 15 generates a recording signal in the memory block 21. 2 Il.

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The invention relates to ultrasonic testing of products and can be used to create automated installations for controlling materials and products in mechanical engineering, power engineering and other industries, and can also be used to control the porosity of materials, sorting, predicting the mechanical properties of materials and products in a non-destructive way. .

The aim of the invention is to increase the reliability of control by increasing the destructive ability of the selection of defects.

FIG. 1 shows a block diagram of an ultrasonic flaw detector; in f fig. 2 - timing diagrams for the operation of the device. Na.1fig. 2 marked: a - the echo signal from the defect; b - peak output signal

detector;

in - a strobe pulse of a control zone; g is the clock frequency or frequency of the analog-to-digital conversion (ADC); d is the signal at the output of the reference unit; e is a single-output signal.

Torah;

k is the signal at the output of the first element of the match; n is the signal at the output of the control signal generator; T - the duration of the frequency period

oscillations of ultrasonic pie transducer;

Tj is the duration of the pulse produced by the single vibrator, (,);

T is the reset time of the peak detector;

T is the delay between the amplitude recording signal in the first register of storing equivalent amplitude and the write pulse in the block

memory;

Tj - recording signal duration

in the memory block;

TTCIKT is the duration of the ADC frequency conversion period.

0 The device contains a synchronizer 1 connected in series, a generator 2, ultrasonic transducer 3 mounted on a controlled article 4, and a driver 5.

5 control zones; video amplifier 6 connected in series: an input connected to a converter 3, a peak detector 7, an analog-to-digital converter B and a register 9 remembering the equivalent signal amplitude, a coincidence element 10, a first input connected to a control unit 5, and an output analog converter 8, serially connected by the reference signal block 11, comparison block 12, the second input connected to the output of the analog-digital converter 8, the one-oscillator 13, coincidence element 14, the output of which The driver of the control signal 15, the second input of the register 9 for storing the equivalent of the amplitude of the signal and the second input of the peak detector 7, element 16

 matches, the first input connected to the former 5 of the control zone, the second input to the comparison unit 12, and the output to one of the inputs of the coincidence element 14, sequentially connected to the crystal oscillator 17, the counter 18, the second input connected to the output of the former 5 of the control zone , a memory register 19 equivalent of the depth of the defect, the first input connected to the output of the comparison unit 12, serially connected counter 20, the input connected to the output of the comparison unit 12, the memory unit 21, the first input connected to f a control signal damper 15, a second input with register 9 for storing the amplitude equivalent, a third input for register 19 for storing the depth of the defect, and a recorder 22, the quartz oscillator 17 connected to the second inputs of the first element-15 with the strobe -pulse of contat zone 14 coincidence and coincidence element 10.

Ultrasonic pulse echo gating flaw detector works as follows.

Synchronizer 1 generates sync pulses to start generator 2 .. The latter excites ultrasonic transducer 3, which sends

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The ultrasonic pulse in the controlled detector 7 was able to charge up to my product 4. The signals reflected from material homogeneity are received by converter 3 and are received to the input of video amplifier 6 and the former 5 of the control zone (Fig. 2, a). The latter forms a strobe-pulse of the control zone (Fig. 2, c), which enables the operation of the analog-digital npet generator 8 (hereinafter the ADC) and the counter 18. From the output of video amplifier 6, the amplified signals are sent to the bee detector 7, From the output of the latter arrive at the second input of the ADC 8 (figure 2, b). At the first input of the ADC 8, the clock frequency from the quartz oscillator 17 (Fig. 2, d) is supplied through the second input of the coincidence element 10 if there is a control zone at the first input of the unlocking strobe pulse.

The analog-to-digital converter 8 converts the analog signal from the output of the peak detector 7 into a digital equivalent with a frequency equal to the frequency of the crystal oscillator 17, transmitted to the register 9 to store the equivalent amplitude and to the second input of the comparison unit 12. A digital equivalent of the cutoff level is applied to the first input of the latter via a reference signal block using a well-known programmer (not shown) or in the case of use in computerized control systems using a computer (not shown). When exceeding

The maximum amplitude of the reflected signal, or this duration must be more than one and a half for the period of the oscillation frequency of the ultrasonic transducer 3. Before the signal of the defect strobe pulse at the output of the comparator unit 12 arrives, a low level op arrives at the second input of the first matching element 14. a signal prohibiting its operation, a low signal level will also be output at its output, and the third frequency of the first element 14 of the comparison will receive a clock frequency from the quartz generator 17.

When the output of the strobe-pulse comparison unit 12 appears at the output of the right matching element 16, a high signal level appears, allowing the first element 14 to work, at the first input of which the one-shot 13 sends a delay-low delay gate 1-1m level. On the clock edge, from high to low, the state of the first input of the first element 14 - ... is recorded. As long as the low strobe-pulse level is at its first input, the output level will also be low. A high level appears at the output after the strobe-pulse delay changes from a low state to a high one at the first input

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a digital equivalent at the second input relative to the first input at the output of the comparator unit 12, a strobe-pulse signal of the defect signal is generated (Fig. 2, d). On the first edge of the strobe-pulse of the defect signal, the content of the second counter 20 of defects is increased by one and the contents of the first counter 18 are recorded in the register 19 of storing the equivalent depth of the defect. At the first input of the counter 18, the clock frequency arrives, and the counting begins

a roll that goes to the second input of this counter.

From the first edge of the strobe-pulse signal of the defect, the one-shot 13 forms a strobe-pulse delay, which is fed to the first input of the first coincidence element 14 (FIG. 2, e). The duration of this pulse is chosen so that during this time the pico

0

The 5th detector 7 charged up to

the maximum amplitude of the reflected signal, or this duration must be more than one and a half times the period of the oscillation frequency of the ultrasonic transducer 3, until a strobe-pulse signal appears at the output of the comparison unit 12. The second input of the first element 14 coincides with the low level p. signal prohibiting its operation, while its output will also be a low signal level, and the third input of the first element 14 of the comparison with the crystal oscillator 17 receives a clock frequency.

When a strobe-pulse comparison signal 12 output appears at the output of the right matching element 16, a high signal level appears that permits the operation of the first element 14, to the first input of which the one-shot 13 delivers a delay-low delay gate-1-1m level. On the clock edge, from high to low, the state of the first input of the first element 14 - .. is recorded. match on exit. As long as the low strobe-pulse level is at its first input, the output level will also be low. A high level appears at the output after the strobe-pulse delay at the first input goes from a low to a high state, at the first transition

0

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clock rate from high to low.

On the first front, at the output of the first coincidence element 14, the amplitude is recorded in a digital equivalent in the register 9, which stores the equivalent of amplitude. .

A driver 15 of the control signal from the first edge of the strobe pulse (Fig. 2, k) with a time delay forms a write signal to the memory unit 21 (Fig. 2, n). By this signal, the amplitude and depth of the defect in digital equivalent and the number of defects are recorded in memory block 21.

After resetting the peak detector 7, the gating circuit is ready to receive the next reflected signal from the data capture. The accumulated information in the memory unit 21 is transmitted to the evaluation device, for example, in the recorder 22, and when used in an automated system, the installation is transferred to the EBM.

Claims (1)

Invention Formula Ultrasonic echo pulse flaw detector containing sequentially connected synchronizer, probe pulse generator and ultrasonic transducer, serially connected video amplifier, the input of which is connected to the output of the ultrasonic transducer, peak de- tector and analog-digital converter, driver of the control zone, input of which connected to the output of an ultrasonic transducer, connected in series torus and first counter, serially connected second counter, memory unit and recorder, three elements of coincidence, characterized in that, in order to increase the reliability of control, it is equipped with serially connected signal support unit, a comparison unit, the second input of which is connected to the output an analog-digital converter and a one-shot whose output is connected to the first input of the first matching element, a first register connected between the output of the analog-digital converter and the second input of the memory block, the second register connected between the output of the first counter and the third input of the memory unit, and the control pulse driver, switched on by the output of the first coincidence element and controlling the input of the memory unit, the output of the control zone former, the output of which connected to the control input of the analog-to-digital converter, with the first input of the third match point, the output of which is connected to the second input of the first match element, and with the control input of the first the generator output is connected to the second input of the second match element and the third input of the first match element, the output of the comparison unit is connected to the second input of the third match element, the control input of the second register and the counter input, and the output of the first match element is connected to inputs of the first register and peak detector. "E72 Compiled by L. Kondrykinsky Editor G. Volkova Tekhred L. Serdyukova Proofreader M. Vasilyeva Order 6743/50 Circulation 847 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk nab. j 73 BUT FIG. 2 Subscription