SU899154A1

SU899154A1 - Apparatus for exciting frequency modulated ultrasonic oscillation

Info

Publication number: SU899154A1
Application number: SU802936973A
Authority: SU
Inventors: Анатолий Николаевич Ивакин; Александр Ефимович Коренцвит; Александр Тимофеевич Косилов
Original assignee: Предприятие П/Я В-8828
Priority date: 1980-03-28
Filing date: 1980-03-28
Publication date: 1982-01-23

Description

1one

Изобретение относитс к технической акустике и может быть использовано дл возбуждени модулированного по частоте акустического сигнала в твердых объектах, в частности при дефектоскопии изделий ультразвуковым способом.The invention relates to technical acoustics and can be used to excite a frequency-modulated acoustic signal in solid objects, in particular during the inspection of products by an ultrasonic method.

Известно устройство дл формировани частотно-модулированных ультразвуковых колебаний, включающее ультразвуковой пъезоэлектрический преобразователь и электрический генератор частотно-модулированного сигнала 1 A device for generating a frequency-modulated ultrasonic oscillations, comprising an ultrasonic piezoelectric transducer and an electric generator of a frequency-modulated signal 1, is known.

Недостатком известного устройства вл етс искажение возбуждаемого сигнала ввиду узкополосности преобразовател .A disadvantage of the known device is the distortion of the excited signal due to the narrowband transducer.

Известно также .устройство, включающее ультразвуковой пъезоэлектрический преобразователь, электрический генератор и согласующий элемент,It is also known a device comprising an ultrasonic piezoelectric transducer, an electric generator and a matching element,

включенный между преобразователем и генератором 2,included between converter and generator 2,

Недостатком этого устройства вл етс мала амплитуда возбуждаемых колебаний.The disadvantage of this device is the small amplitude of the excited oscillations.

Наиболее близким по технической сущности к предлагаемому вл етс устройство, включающее генератор, модулирующий элемент, ультразвуковой The closest in technical essence to the present invention is a device including a generator, a modulating element, an ultrasonic

10 преобразователь, подключенный к выходу генератора и установленный на одном из концов модулирующего элемента , а также модулирук ций преобразователь и генератор модулирующей 10 converter connected to the output of the generator and mounted on one of the ends of the modulating element, as well as modulation of the converter and generator of the modulating

«5 частоты, при этом модулирующий элемент выполнен в виде кюветы, заполненной рабочей жидкостью. На стенках кюветы установлен модулирующий преобразователь в виде поршневых виб20 раторов, подключенных к генератору модулирующей частоты З “5 frequencies, while the modulating element is designed in the form of a cuvette filled with working fluid. A modulating converter in the form of piston vib20 rators connected to a generator of modulating frequency 3 is installed on the walls of the cell.

Claims

A disadvantage of the known device is the low power of the excited 3 vibrations, especially when working with solid media. The purpose of the invention is to increase the power of the excited oscillations. This goal is achieved by the fact that in a device for exciting frequency-modulated ultrasonic vibrations, including a generator, a modulating element, an ultrasound transducer connected to the output of a generator and mounted on one end of a modulating element, a modulating converter and a modulating frequency generator, modulating element made in the form of a rod made of a single crystal of an alloy with a thermoelastic phase transformation, equipped with a loading mechanism. The drawing shows schematically the proposed device. The device contains an ultrasonic transducer 1, a generator 2 a modulating element 3 radiating a pad 4, a generator 5 modulating frequencies, a loading mechanism 6 of a modulating element, a modulating converter 7, matching waveguides 8 and 9, phase boundary 10, phase ji 11, phase ji 12 The device works as follows. In the ultrasonic transducer 1, oscillations are excited at the frequency of its own electromechanical resonance using a generator 2. Ultrasonic oscillations through a matching waveguide 8 enter a modulating element 3 which is transferred by a mechanism 6 to a super elastic region with a single interface 10 j5 and jS. A single crystal of an alloy with a thermoelastic phase transformation from which the modulating element 3 is made, undergoes a thermoelastic g transformation. Moreover, the phase transformation in the core sample, starting in one place of the single crystal under the action of loading, spreads over the entire sample by moving the boundary separating the different-phase regions. The removal of the load leads to the transformation of ji, un, respectively, to the opposite movement of the interphase boundary, up to the complete disappearance of the α phase. That is, the transformation is reversible, and under the action of an alternating load, the phase boundary will move in phase with the load. The modulating element 3 is driven by an alternating force using a modulating converter 7 operated by a generator of modulating frequency 5. A modulated l ultrasonic signal outputting from the modulating element 3 is transmitted to a radiating pad k by means of a coherent waveguide 9. The frequency and amplitude of the modulating converter oscillations can adjust the depth and frequency of modulation of the output signal. As an ultrasonic transducer, an element from piezoceramics can be used, for example, PZT. The modulating transducer 7 may be magnetostrictive or electromagnetic. As the modulating element 3 using a single crystal, for example, from an alloy of Cu-Af-Ni. The use of the invention allows to change the parameters of the ultrasonic signal and increase the power of the excited oscillations, especially when working with solid media. Apparatus for driving frequency-modulated ultrasonic vibrations, comprising a generator, a modulating element, an ultrasonic transducer connected to the output of the generator and installed at one end of the modulating element, a modulating converter and a modulating frequency generator, characterized in that, in order to increase the power of the emitted oscillations, the modulating element is made in the form of a rod from a single crystal alloy with thermoelastic phase transformation, equipped with a mechanism loading. Sources of information taken into account in the examination 1. USSR author's certificate number, cl. B 06 B 1/06, 197.

2. USSR author's certificate number 59263, cl. B 06 B 1/06, 1973.

3. USSR author's certificate number 1472636, cl. B 06 B 1/06, 1972 (prototype),