SU896531A1

SU896531A1 - Device for eddy-current inspection of metallic articles

Info

Publication number: SU896531A1
Application number: SU792803162A
Authority: SU
Inventors: Анатолий Яковлевич Тетерко; Валентин Николаевич Учанин; Владимир Николаевич Зыбов
Original assignee: Физико-Механический Институт Ан Укрсср; Специальное Конструкторско-Технологическое Бюро Физико-Механического Института Ан Укрсср
Priority date: 1979-07-30
Filing date: 1979-07-30
Publication date: 1982-01-07

Description

(54) УСТРОЙСТВО ДЛЯ ВИХРЕТОКОВОГО КОНТРОЛЯ МЕТАЛЛИЧЕСКИХ ИЗДЕЛИЙ(54) DEVICE FOR VORTEX CURRENT CONTROL OF METAL PRODUCTS

1one

Изобретение относитс к неразрушающему контролю металлических изделий вихретоковым методом и может найти применение в машиностроении, авиации и других област х техники дл вы влени дефектов и определени их параметров.The invention relates to the non-destructive testing of metal products by the eddy current method and can be used in mechanical engineering, aviation and other fields of technology for detecting defects and determining their parameters.

Известно устройство дл вихретокового контрол металлических изделий, содержащее генераторы основной и вспомогательной частот, подключенные к генератору основной частоты последовательно соединенные сумматор, вихретоковый датчик и предварительный усилитель, последовательно соединенные компенсатор, полосовой фильтр и индикатор , а также подключенные к генератору всломагательной частоты последовательно соединенные фазовращатель и дел-итель напр жени , подключенный к сумматоРУС€Недостатком известного устройства вл етс наличие избирательных усилителей в каждом из частотных каналов. Это приводит к возникновению значительной погрешности , вызванной зависимостью частотных и фазовых характеристик избирательных цепей от внещних воздействий и изменени питани .A device for eddy current testing of metal products is known, comprising primary and auxiliary frequency generators connected to a main frequency generator connected in series an adder, eddy current sensor and preamplifier, a series-connected compensator, a band-pass filter and an indicator, and series-connected phase shifter and voltage del connected to summaRUS € A disadvantage of the known device is Whose selective amplifiers in each of the frequency channels. This leads to a significant error caused by the dependence of the frequency and phase characteristics of the electoral circuits on external influences and changes in the power supply.

Цель изобретени - повышение точности контрол .The purpose of the invention is to improve the accuracy of control.

Эта цель достигаетс тем, что устройство снабжено включенным между предварительным усилителем и компенсатором умножителем , второй вход которого подключен к генератору основной частоты, и каналом компенсации , выполненным в виде последовательно соединенных умножител , фазовращател , и делител , входы у.множител канала компенсации соединены с генератором Ф основной частоты и выходом сумматора, а выход делител канала компенсации подключен к второму входу компенсатора.This goal is achieved by the fact that the device is equipped with a multiplier connected between the preamplifier and the compensator, the second input of which is connected to the fundamental frequency generator, and the compensation channel, made in the form of serially connected multipliers, phase shifters, and divisor, the inputs of the compensation multiplier channel are connected to the generator F main frequency and the output of the adder, and the output of the divider compensation channel connected to the second input of the compensator.

При этом частоты генераторов основнойи вспомогательной частот выбраны из соотношени 1:3, а полосовой фильтр настроен 15 на удвоенную частоту генератора основной частоты.In this case, the frequencies of the main and auxiliary frequency generators are selected from a ratio of 1: 3, and the band-pass filter is tuned 15 to twice the frequency of the main frequency generator.

На чертеже представлена функциональна схема устройства.The drawing shows the functional diagram of the device.

Claims

The device contains a fundamental frequency generator 1, an adder 2 supply voltages, an auxiliary frequency generator 3, generating the triple frequency of the main generator, a phase shifter 4. voltage divider 5, eddy current sensor 6, preamplifier 7, multiplier 8, the second input of which is connected to generator I main frequency. The device also contains a compensator 9. The compensation channel includes a phase shifter 10, a voltage divider 11 and a multiplier 12, the inputs of which are connected to the generator 1 and the output of the adder 2 of the supply voltages. The output of the compensator 9 is connected to a band-pass filter 13 tuned to twice the frequency of the main generator, the output of the filter 13 is connected to the indicator 14. The device operates as follows. The main frequency signal from oscillator 1 is fed to one of the inputs of adder 2. The frequency of the second oscillator 3 is chosen equal to the third harmonic of oscillator 1. The phase and amplitude of this signal fed to the second input of adder 2 are adjusted by the phase shifter 4 and voltage divider 5, respectively. The sum signal is fed to one of the inputs of the multiplier 12 and the excitation winding of the sensor 6. The output signal of the sensor 6 amplified with the aid of the preamplifier 7 is fed to the input of the multiplier 8, the second input of which receives the signal from the main frequency generator 1. Further conversion is performed at twice the frequency of the main generator 1, obtained by multiplying the two signals. From the multiplier output, the signal is fed to the compensator 9, in which the unbalance signal of sensor 6 is compensated. For this, the output signal of multiplier 12, in which the total signal of generators 1 and 3 is multiplied with the signal of the fundamental generator 1, is fed through a phase shifter 10 and a divider 11 voltage to the compensator 9. The total frequency spectrum is fed to the filter 13, tuned to twice the generator frequency; from the output of the filter 13, the signal goes to the indicator 14, which records the amplitude and phase of the voltage received. The proposed device allows to increase the reliability and quality of control of materials. 1. An apparatus for eddy current testing of metal products, comprising primary and auxiliary frequency generators connected to a main frequency generator in series with an adder, eddy current sensor and preamplifier, in series a compensator, band-pass filter and indicator, and also connected to an auxiliary frequency generator in series A coupled phase shifter and voltage divider connected to an adder, characterized in that, in order to increase control accuracy, it is equipped with a multiplier connected between the preamplifier and the compensator, the second input of which is connected to the fundamental frequency generator, and the compensation channel, made in the form of serially connected multipliers, rotator and divider, the multiplier inputs of the compensation channel are connected to the fundamental frequency generator and the output of the adder, and the output of the compensation channel divider is connected to the second input of the compensator.

2. The device according to claim 1, characterized in that the frequencies of the generators are selected from a ratio of 1: 3, and the band-pass filter is tuned to twice the frequency of the fundamental frequency generator. Sources of information taken into account in the examination 1. USSR Author's Certificate No. 169681, cl. G 01 N 27/86, 1963 (prototype).