SU1434362A1 - Ultrasonic echo-pulse flaw detector - Google Patents

Abstract

The invention relates to non-destructive testing and can be used for flaw detection by the echo-pulse method. The purpose of the invention is to increase the resolution due to the possibility of detecting defects close to the surface and the bottom of the product. The excitation pulse generator 6 is triggered by a signal from the trigger 5. The acoustic transducer 7 then radiates ultrasonic vibrations into the product, which are reflected from the defects and the bottom of the product and again converted into an electric signal by the converter. This signal is amplified and the counter 10 counts the number of pulses corresponding to the number of defects in the product. When a positive pulse appears at the inverse output of synchronizer 1, a 3 gating pulse generator is triggered, which opens the coincidence element 9, through which the signal received from the product passes. The frequency of synchronizer 1 in this scheme depends on the possibility of detecting defects closely located to the surface of the product, and on the pyrins of the strobe pulse the possibility of detecting defects closely located to the bottom of the product. 2 Il. (L

Description

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The invention relates to the ultrasonic testing of materials without their destruction and can be used during flaw detection of products and materials.

Stand,

The purpose of the invention is to increase the resolution of the flaw detector due to the possibility of detecting defects close to the surface and to the product.

Fig, 1 shows the structural scheme of the proposed flaw detector; on |) 2 - time diagrams device

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I The ultrasonic pulse echo pulse detector contains a sequentially connected synchronizer 1, a matching element j2, a strobe pulse generator 3, a single vibrator 4, a trigger 5, a pulse generator 6, and a combined acoustic transducer 7, the output of which is connected to a circuit connected in series elements from amplifier 8, coincidence element, counter 10, register 11, selector 12 and recorder 13, the device also contains an AND 14 ,, element; connected between the direct output of the syncronizer 1 and the installation inputs; the trigger 5 and the counter 10, the Second | Input of the match element 14 is connected to the output of the trigger 5, the input and the other output of which are connected respectively to the second and third input of the element 2 of the match. The generator output | 3 gating pulses is connected to (the second input of the coincidence element 9 and the setting input of register 1,

The timing diagrams of FIG. 2 jio show voltages:

 a - at the output of an adjustable syncro: nizator 1;

: b - in the code of element 14, match;

in - at the output of the generator 6 excitation pulses;

r on the output of the acoustic transducer 7;

d - at the output of the amplifier 8; e - on the inverse output of the adjustable synchronizer 1;

W - at the output of the element 2 coincidence;

, and - at the output of the regulated generator 3 gating pulser; to - on. the output of the one-shot 4; l - at the direct output of the trigger 5; : m - on the inverse trigger output 5

and - at the output of coincidence element 9.

Ultrasonic echo pulse flaw detector works as follows.

A positive differential signal from the output of trigger 5 triggers a generator of excitation pulses 6 and generates a zeroing potential at the output of element 14 when there is a resolving potential from the output of adjustable synchronizer 1, Pulse counter 10 and trigger 5 are zeroed, and the zeroing pulse from output of coincidence element 14 stops . From the output of the excitation pulses generator 6, the probe pulse arrives at the acoustic finder transducer 7, which emits an ultrasonic wave, receives a reflection from the bottom of the product and from defects, converts it into an electrical signal that is amplified by the amplifier 8 and arrives at the first input of the coincidence element 9. Adjustable synchronizer 1 controls the transmission time of the probe pulse and reception of the reflected signal. When a positive pulse appears at the inverted output of the adjustable synchronizer 1, the generator of 3 gating pulses is triggered, the pulse from the output of which arrives at the second input of coincidence element 9. stop gating pulses are written to the static register 11, and the output of the decoder 12 is sent to the recorder 13. On the falling edge, the one-shot 4, the cathode ing determines the delay time of the trigger 5 and next forming the probe pulse generator of ge- 6 excitatory pulses. To eliminate the premature operation of the generator 3 of the gating pulses, the inhibiting potentials from the output of the single-vibrator 4 and the trigger 5, enter the second and third inputs of the coincidence element 2,

The frequency of the adjustable synchronizer 1 determines the position of the upper boundary of the zone of control of defects in the product, and the width (tolecin) of the zone of control, and hence the lower limit of the zone (thickness) of control in the product, depends on the width of the gating pulse. The duration of the strobe pulse of the adjustable oscillator 3 of the strobe pulses is chosen such that all signals reflected from the bottom of the product do not fall into the defect control band. The number of defects is one less in consideration of reflection from the bottom of the product.

The use of the invention allows, by simple means, to determine the defects throughout the entire volume of the moving material, and the regulation of the boundaries of the control zone with high accuracy to determine the location of the defect.

Claims (1)

Invention Formula An ultrasonic pulse echo flaw detector containing a synchronizer and series-connected excitation pulses and a combined acoustic transducer, an amplifier connected in series, the input of which is connected to the output of the combined acoustic driver, and a coincidence element, a gating generator, the output of which is connected to the second input 0 five. 0 5 A matching element, and a recorder, characterized in that, in order to increase the resolution, it is equipped with a second coincidence element, connected between the synchronizer output and the gate generator input, and the one-vibration connected in series, whose input is connected to the gate pulse generator, trig - heroes, the third element of the match, the counter, the register and the decoder, the output of which is connected to the recorder, the second input of the counter is connected to the output of the first element of the match, the first output One trigger is connected to the input of the excitation pulse generator, and the second output is connected to the second input of the second coincidence element, the third input of which is connected to the single-vibrator output, the output of the gating pulse generator is connected to the control input of the register, and the forward synchronizer output is connected with the second input of the third match element, the input code of which is connected to the trigger setup input.