SU967584A1 - Wide band ultrasonic converter - Google Patents

Description

The invention relates to non-destructive means and control methods, and can be used for ultrasonic testing of thin-walled pipes. in the metallurgical industry; 5

Known ultrasonic transducer containing housings which are placed piezoelectric plate of variable thickness, protector and damper [1].

The disadvantage of this converter is. .10 la is a slight absorption of ultrasonic vibrations in the damper, as a result of which false signals are created due to reflection back to the piezoelectric element, · 15

The closest in technical essence to the invention is a broadband ultrasonic transducer containing a piezoelectric element of variable thickness, fixed in the housing, the cavity of which forms a damper + · frying volume [2]. ''

The disadvantage of this converter is its low resolution due to false signals arising in the damper material.

• The aim of the invention is to increase the resolution of the transducer by improving the damping, θ wavelength.

This goal is achieved by the fact that in a broadband ultrasonic transducer containing a piezoelectric ... element of variable thickness, mounted in a housing, the cavity of which forms a damping volume, the latter is formed by reflective surfaces, which ensure parasitic vibrations on the non-working part of the piezoelectric element.,

The drawing schematically depicts a broadband converter.

. It contains, housing 1, damping volume 2, piezoelectric element '3, protector 4, channels 5, screw plugs 6.' • · The transducer works as follows. · Ί Ultrasonic vibrations of the piezoelectric element 3 are emitted through the protector / t 4 in the studied object and into the damping volume 2. The maximum amplitude of the wave emitted into the damper is normal to the surface of the piezoelectric plate, for example, in the region of resonance A. After repeated reflections in the damping volume (the wave path is indicated by number 7), the weakened wave hits the surface of the piezoelectric element in the head edomo nonresonant region B.

To improve the characteristics of the damper, its volume is filled with viscosity3 967584 4 with a bunch of mass with high ultrasound attenuation. ''

The converter has a uniform amplitude-frequency character. tristy in a wide range of frequencies \ from I to · 10 MHz. The absence of parasitic vibrations makes it possible to increase the resolution and information content of the control.

It develops a damping volume, which is related to the fact that, in order to increase the resolving power of the transducer by improving Damping, the body cavity is formed by reflective surfaces, which ensure that parasitic vibrations get on the inoperative part of the piezoelectric element. .

Claims (2)

(54) BROADBAND ULTRASONIC CONVERTER. , G- . , - The invention relates to non-destructive means and methods of control and can be used for ultra sound control of thin-steep tubes in the metallurgical industry. A known ultrasonic transducer containing a corzus, in which a piezoplate of varying thickness is placed, a protector and a damper 1. The disadvantage of this converter is an insignificant the absorption of ultrasonic vibrations in the damper, resulting in the creation of false signals due to reflection back on piezoelemit. The closest to the technical essence of the izbreteniya is a broadband ultrasonic transducer containing a piezoelectric element of variable thickness Fixed in a box, the cavity of which forms a damping volume 2. The low resolution of this transducer is low resolution due to spurious signals originating The material of the damper. The object of the invention is to increase the resolution of the converter by improving the damping. The goal is achieved by the fact that in a broadband ultrasonic transducer containing a piezo. an element of varying thickness, fixed in the housing, the cavity of which forms a damping volume, the latter is formed by the diverting surfaces; but with the help of parasitic oscillations on non-working. part of the piezoelement. In the drawing is a schematic image of a wideband transducer. . It contains body 1, damping-. total volume 2 | piezoelectric element 3, protector 4, channels 5, threaded plugs 6. The converter operates as follows. Ultrasonic oscillations of the piezoelectric element 3 are emitted through the protect / t 4 into the studied object and into the damping volume 2. The maximum amplitude of the wave emitted in the dempfer is normal to the surface of the piezoplate, for example, in the resonance region A. After multiple reflections in the damping volume (path The waves are designated as 7) a weak foam wave hits the surface of the piezoelectric element in a deliberately nonresonant region B. To improve the characteristics of the damper, its volume is filled in a flowing mass with high ultrasound attenuation. The converter has a uniform amplitude-frequency characteristic in a wide range of frequencies; from I to 10 MHz. The absence of parasitic oscillations allows increasing the resolvability and information content of the control. Claims. A broadband ultrasonic transducer containing a piezoelectric element of variable thickness is fixed in the housing, the cavity of which forms a damping volume, so that, in order to increase the resolution of the converter by improving the cement, the housing cavity is formed reflecting the surfaces that provide parasitic vibrations on the non-working part of the piezoelectric element., The sources of information taken into account in the examination 1, USSR Copyright Certificate 592045 ,. CL G 01 N 29/04, 1976. 2. USSR author's certificate №364893, CL. G 01 N 29/04, 1972 (prototype).