SU978952A1 - Apparatus for focusing ultrasonic oscillations - Google Patents

Description

(54) DEVICE FOR FOCUSING ULTRASOUND VIBRATIONS

one

This invention relates to an ultrasound technique using focused acoustic fucking,. and can be used primarily for studying the physicomechanical properties of materials and products, measuring vibrations and displacements, as well as in ultrasonic defectoscage, medi-diagnostics and physiotherapy.

Ultrasonic focusing devices in the form of piezoelectric isogated emitters with focusing on a point and line til are known. The disadvantage of such focusing emitters is the difficulty of manufacturing large wave hemispheric active surfaces due to the insufficient strength of the piezoelectric ceramics and the limitations on the accuracy of the thickness of the active double curvature layer.

It is also known a device for focusing ultrasonic vibrations, containing a cylindrical radiator and a parabolic reflector 2.

The disadvantages of this device are manufacturing complexity and limited scope.

Closest to the present invention is an apparatus for focusing ultrasonic vibrations, containing a cylindrical emitter and an axially symmetric reflector with a curvilinear generatrix located coaxially inside it (the reflector is made in the form of a flat parabolic cone of solid material)

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However, this device has a limited scope and is difficult to manufacture.

The purpose of the invention is to expand the scope and simplify the manufacture of the device.

Claims (3)

The goal is achieved by the fact that the device is equipped with a pressure regulator, a rigid base, an emphasis installed in the center of the base with the possibility of axial movement, while the reflector is made in the form of a membrane397 of elastic material, tightly fixed on the edges of the base and resting on the center the end of the anvil, and in the base there is a channel connecting the submembrane space with the pressure regulator. The elastic membrane is filled with a variable radial thickness. : On -fig. 1 shows a device for focusing ultrasonic vibrations, a general view, {in section); in fig. 2 is a cross section of the diaphragm with a thickening in the center; in fig. 3 - the same, but with a thickening at the edges. The device contains a cylindrical emitter. 1, an electroacoustic protective screen 2, with supply electrodes 3 and a rigid base 4 placed inside the radiator and coaxially with it, an emphasis 5, installed in the center of the base, and an elastic membrane 6. The membrane on the satr & the perimeter of the base 4, forming a sealed volume 7, the outer surface of which is the outer side of the membrane and is a second-order surface. At the base there is a channel 8 connecting the submembrane space with the pressure regulator 9, the device operates as follows. When energizing electric voltage is applied to the electrodes 3 of the radiator 1, the latter emits ultrasonic oscillations which, spreading in the environment, reach the membrane 6, are reflected from it and are focused at the point P, where the high intensity ultrasound is reached. If, however, the stop 5 is displaced along the axis or by means of the pressure regulator 9, the pressure inside the hermetic volume 7 is changed, both the character of the reflecting surface of the membrane and the degree of its curvature can be changed. This is achieved due to the degree of tension of individual sections of the membrane. For example, when it is weak. Stretching the shape of the reflective surface is close to spherical. This picture takes place even in the case when the pressure inside the volume 7 is equal to the pressure of the environment. 24 Meng pressure in the volume, you can upepichivat or reduce the radius of curvature of the surface. In the general case, it is possible to obtain a reflective surface of various profiles (spherical, parabolic, hyperbolic, logarithmic, etc.) with varying degrees of curvature. The choice of one or another specific variant is made depending on the tasks of the device, by interchanging the stop 5, selecting the membrane 6 of the desired cross section and selecting the pressure inside the volume 7. This greatly expands the field of application of the device. Claim 1. Device for focusing ultrasound xybans containing a cylindrical emitter and an axisymmetric reflector with a curvilinear generator, coaxially placed inside it, characterized in that, in order to expand the scope and simplify the design, the device is equipped with a pressure regulator, a rigid base and an emphasis in the center of the base with the possibility of axial movement, while the reflector is made in the form of a membrane) of elastic material, tightly fixed on the edges of the base New And support by the dentrum on the end face of the support, and at the base is a blue channel connecting the submembrane space with the pressure regulator. 2 A device according to claim 1, wherein the membrane is designed with a variable radial thickness. Sources of information taken into account during the examination 1. Kanevsky I. I. Focusing of sound and ultrasound Vogg. M., Science, 1977, p. 324-329. . . 2. US patent No. 2617874, cl. 340-11, 1952. 3. USSR author's certificate number 697920, cl. G01N 9/04, 1979. (reg. yy