SU824024A1 - Automated ultrasonic checking device - Google Patents

Description

The invention relates to an ultrasonic nondestructive testing method and can be used for quality control of the materials during manufacturing _ ^e bilateral access thereto.

Well-known ultrasonic flaw detector? comprising a synchronizer, a probe pulse generator and converters, gate pulse generators, a coincidence cascade, and an OR circuit [1].

A disadvantage of the known flaw detector is the low reliability of control. fifteen

The closest to the invention of the technical essence and the achieved result is a device for automated ultrasonic testing of products, containing in series 20 synchronizer, a probe pulse generator, a main finder located on one side of the product, and an amplifier, gating units for surface and 25 bottom signals, the first the inputs of which are connected to the output of the synchronizer, and the second to the input of the amplifier, the shaper of the control zone, the first input of which is connected to the output of the 0 gating surface signal, coincidence cascade AND, the first input of which is connected to the output of the amplifier, the second - to the output of the shaper of the control zone, OR logic element, the first input of which is connected to the output of the cascade of matches, the AND-NOT circuit, the output of which is connected to the second input of the OR gate (2].

The disadvantages of this device are the low reliability of control and the inability to control the thickness of the products.

The purpose of the invention is to increase the reliability of control and expand the scope of application of the device.

The goal is achieved by that. that the device is equipped with an additional finder with an acoustic delay, located on the opposite side of the product coaxially with the main source *. a catheter and connected to the output of the probe pulse generator and amplifier, an adjustable delay unit connected between the gating unit of the bottom signal and the shaper of the control zone, a reset unit whose input is connected to the output of the synchronizer, and the output to the second input of the shaper of the control zone, the first input. AND NOT connected to the output of the amplifier, and the second to the output of the synchronizer.

In FIG. 1 presents a block diagram of the proposed device; on the ,

FIG. 2 - temporary diagrams explaining the ³ operation of the circuit.

The device comprises a synchronizer 1 connected in series, a probe pulse generator 2, a main finder 3 located on one side of the product, an additional finder 4 with an acoustic delay 5, located on the opposite side of the product coaxially with the main finder 3 and connected to the output generator 2 probe pulses, and amplifier 6, blocks 7 and 8 of the gating surface and bottom signals, respectively, the first inputs of which are connected to the output of the synchronizer 1, and the second to the output of the amplifier b ,. shaper 9 of the control zone, the first input of which is connected to the output of block 7 of the gating of the surface signal, cascade 10 matches 25, and the first input of which is connected to the output of amplifier 6, the second to the output of Shaper 9 of the control zone, logical element 11 OR, the first input of which connected to the 3Q output of the coincidence cascade 10, the AND-NOT circuit 12, the output of which is connected to the second input of the OR logic element, the first input to the output of amplifier b, and the second to the output of synchronizer 1, jj adjustable delay unit 13 connected between block 8 straw ation and the bottom signal generator 9.

control zone, and a reset unit 14, the input of which is connected to the output of the synchronizer 1, and the output to the second input of the shaper 9 of the control zone.

The device operates as follows.

Searchers 3 and 4, installed from * two opposite sides on the controlled product, scan its surface in the control process. The synchronizer 1 starts the generator 2 of the probe pulses and at the time instant (Fig. 2, plot 15) excites the finders 3 and 4.

At time t2, a bottom pulse appears at the output of amplifier 6. radiated and received by the searcher 3. 55 The time interval t ^ -t ^ is equal to twice the transit time of the ultrasound in the product 2T _met ·

At a moment in time, an impulse appears at the output of amplifier b, emitted and received by both finders 3 and 4, while the interval -q is equal to the ultrasound transit time in acoustic delay 5, i.e., 17 _met +

At a time at the output of amplifier b, a pulse appears, emitted and received by the finder 4, with ^t 4 ^{= 2T} met

It is necessary to fulfill the condition ^{>, from} years · ^for normal operation of the device.

The pulse 16, allocated at the time point by the AND-NOT circuit 12, is used to control any extended defects, including those located in the vicinity of the surface of the products.

At the output of the AND-NOT circuit and the first input of the OR gate 11, a signal appears when the shadow pulse disappears from the strobe.

The pulse 17 from the surface of the product, gated by block 7 at the time by the trailing edge, triggers the shaper 9 of the control zone, and the bottom pulse 19, received at time t _a and gated by block 8, by the leading edge breaks the pulse 18 of the shaper 9 of the control zone, passing through, block 13 adjustable delay. The gate pulse of the control zone from the output of the shaper 9 is fed to one of the inputs of the coincidence cascade 10, to the other input of which pulses 15 come from the output of the amplifier. from the output of the coincidence stage 10, the pulse 20 is fed to the input of the logic element. 11 OR. In the absence of defects in the product, its thickness within the tolerance, there are no signals at the inputs and outputs of the logic element.

In the presence of local defects in the product that do not interfere with the passage of the shadow signal, reflected echo signals appear in the time intervals tj -t _a and at the output of the logical OR element.

When extended defects appear in the product that impede the passage of the shadow signal, they are recorded both from the output of the coincidence cascade 10 and the AND-NOT circuit 12.

- In the event that the defect in the product prevents the reception of a bottom signal at time t ₄ , the control zone is cut off at time tg 7 by a signal from the reset unit 14. ⁵

The present invention permits to identify both ¹ local and extended directly at the surfaces. products and expand the functions of the device, providing simultaneous control of the thickness of the products.

Claims (2)

1. USSR author's certificate According to the application 2448709/28, cl. G 01 N 29/04, 1977. 2. Authors certificate of the USSR W 495602, cl. G 01 N 29/04, 1973 (prototype). 0 3 t- AVNL S ffoSAАОН s P ifi & t9. Sac .. ZtoK.iu /five & f6 P Lal sh f4 FIG. 2 Ae9 AND CSft.iad-Hlax.t Lj. J