SU509825A1 - Ultrasonic flaw detector - Google Patents

Description

one

The invention relates to ultrasonic flaw detection and can be used to obtain visible imaged defects.

An ultrasonic flaw detector is known, containing a series-connected continuous oscillator, an ultrasound finder, a receiving amplifier, a continuous balance oscillator and a hologram forming unit, a unit of forming an uninterrupted reference oscillator, which is turned on by a generator and

the mixer. . :. ..

The disadvantage is that the limiting device has low accuracy of measuring the coordinates of the defect and its dimensions in the event that the defect lies in the depth of the material under study.

In order to improve the accuracy of determining the coordinates and sizes of defects, the proposed device is equipped with a follower. but connected through an ultrasonic finder by a pulse oscillator.

| nii, the second receiving amplifier and ba-; lanovym mixer pulse oscillations;

SRI, switched on generator and balanced pulse oscillator, reference pulse generation unit, first adder and gating unit, whose inputs are connected to balanced mixer outputs, and the second adder, one input of which is connected to a balanced pulse oscillation mixer, second input of unit output gating, and the output is with a Hologram forming unit.

The drawing shows the block diagram of the proposed ultrasonic defect, Osprey.

The flaw detector contains generators 1,

2 continuous and pulsed ultrasound of new vibrations, connected through blocks 3, 4 of the formation of reference oscillations with balanced mixers 5, 6, respectively

stately. Mixers 5, b are connected to receiving amplifiers 7, 8 of ultrasonic vibrations. Ultrasound Finder

9, in contact with the test medium

10 is connected to generators 1, 2 and forces 7, 8. The output of a mixer 5 of continuous ultrasonic vibrations is connected to an adder 11 of continuous and impulse. fluctuations, as well as to block 12 construction; | continuous signals, the mixer 6 pulse signals are connected to the adder 11, gating unit 12, and also to the adder 13 pulsed and gated continuous ultrasonic vibrations. The outputs of sug-makers 11, 13 are connected to a device 14 for forming holograms. Device 14 contains a dual-beam oscilloscope 15 and a tape-testing device 16 with a flap. The flaw detector operates in two modes: the defect mating mode and the hologram 4 mode, the first mode is operated only by the pulse part of the device. In the second mode, after receiving the reflected pulse (in case of detection of a defect), the continuous vibration oscillator 1 and the f-6 tape device start up. Continuous oscillations with a wavelength. From the generator 1 of continuous ultrasonic sound oscillations and pulsed probing signals with a wavelength I from generator 2 are transmitted to the radiation 9. Continuous and pulsed ultrasonic oscillations propagate in the controlled medium 10 and are reflected from nus in the presence of inhomogeneities. Reflected-continuous signals are fed to the input of the receiver 7 tuned to the wavelength I, and then to the mixer 5, where they are multiplied with the supports of the oscillations coming from unit 3, as a result of the relative alternation of the controlled medium 1O and scanning of the searcher 9 at the output Mixer 5 extracts a low-frequency component of the signal, characterizing interference relief created in the transmitter's scanning width 9 with discontinuous signals, scattered defects. The reflected pulse signals are fed to the input of the amplifier 8, tuned to the wavelength Y, and then to the mixer 6, where they multiply with the reference oscillations coming from block 4. The continuous signals from the output of the mixer 5 jH are summed from adder 11. From the output of summer 11, the signals arrive at the first channel of the sweep of the dual-beam oscilloscope 15, and this channel is started synchronously with the start of scanning of the radiator 9. Theme. on the tape itself, on the screen of the oscilloscope 15 using a tape recorder device 16, they form a hologram, one coordinate of which is collie-. nearna vector of the relative speed of the controlled medium 1O relatively flaw, and other kodlinearna BeKtopy speed skanirorani j radiator 9. Hologram The generated by total nepreryvnTm iimpul} waist signals tfedstavl is a sum / Continuous hologram sfork5irovannoy wavelength ji and discrete holograms formed on the wavelength I. Over the image, reconstructed from such a total hologram due to the difference in wavelengths, interference bands are superimposed. The distance difference between the bands is determined by the ratio () The position of the interferential bands determine the size and configuration of the defect in the scanning plane of the radiator 9. Pulse signals from the output of the mixer 6 feed to the gating unit 12, which simultaneously receive continuous signals from the output of the mixer 5 . In block 12, the gating of continuous signals. The pulsed signals are cut out: equal in duration to the pulse signals coming from the output of the electric mixer 6. From the gated signals from the output of the block 12 to They are added to the adder 13, where they are summed with the pulsed signals of the mixer output 6. The total signals are sent to the second sweep channel of the two-beam oscillator 15, and Torog is launched to the probe pulse of the generator 2. At the same time, a hologram is formed, one coordinate of which is collinear the velocity vector and displacement of the controlled medium 1O with respect to the flaw detector, and the other is parallel to the direction of the maximum radiation; The search pattern of the seeker 9. A hologram formed in a similar way is a sum of discrete holograms formed on the waves' Alines, I, and D "The image reconstructed from such a hologram is observed in the plane formed by the vector of the velocity of the object and. By breaking the radiation maximum of the suit of bodies 9, i.e. it is observed from the side. Its position in the b-space determines the removal of the defect from the scanning plane.

Due to the difference in the wavelengths of the formation of a total hologram, I impose a reconstructed image on the reconstructed image; 1 interlacing stripes, according to which you can be aware of the sizes; And the configuration of the defect under observation;

: Fixed holograms are produced on one tape. For both holograms of the coordinate, collinear - the velocity vector 1 of the available motion of the controlled medium 10, the beam is the same as the direction of the tape on which the hologram is recorded. The axis, the strap in the direction of maximum radiation of the searcher 9, is deposited to one side from the middle of the tape, and the axis collinear to the scan vector of the searcher 9, to the other side from the middle of the tape. With such arrangements of the holograms on the tape, the image is restored simultaneously, with one image being the defa (em in the plane parallel to the scanning plane of the finder 9, and the other image in the plane perpendicular to the scanner's Flaring plane 9,

Claims (1)

The invention The ultrasonic flaw detector containing a series-connected continuous oscillation generator, an ultrasound finder, a receiving amplifier, a continuous vibration oscillator and a hologram formation unit, a continuous reference oscillation shaping unit connected between the generator and the mixer, which distinguishes so that, in order to improve the accuracy of determining the coordinates and sizes of defects, it is equipped with series-connected {through an ultrasonic finder a pulse generator -oscillations, priemnp second amplifier and a balanced mixer pulsed vibrations included between | dy oscillator and a balanced mixer unit oscillation pulse formation J "and the reference pulse oscillations, the first adder and the gating unit, whose inputs are connected to the outputs of balanced mixers, and the second adder, one input of which is connected to the balance5; nominal impulse mixer; and the second input to the output of the strobe unit; and the output is with a hologram forming unit.