RU2795944C1 - Horn phased electro-acoustic transducer - Google Patents

Abstract

FIELD: acoustics; horn electro-acoustic transducers.

SUBSTANCE: acoustic piezoceramic transducer, containing a housing in which a membrane is fixed around the circumference, having a flat and internal convex part, at the base of which a bimorph piezoblock with two piezoelectric disks connected to electrical conductors is fixed; a facility reflecting acoustic vibrations is fixed above the convex and the flat part of the membrane. Two acoustic piezoceramic transducers are also installed in the transduce; its membranes featuring a flat and a convex part are fixed around the circumference inside flat annular holders, which ensure their counter-directional fastening on the flat sides of the truncated cones forming a circular horn, between which an acoustic reflecting waveguide is positioned with the radius greater than the wavelength of the emitted acoustic vibrations; electrical conductors from piezoceramic disks of bimorph piezoblocks are connected to a source of electrical vibrations so that acoustic vibrations from acoustic piezoceramic transducers are added at the output of the horn phased electroacoustic transducer, increasing the acoustic pressure, forming a circular toroidal radiation pattern.

EFFECT: creation of a circular toroidal radiation pattern.

1 cl, 3 dwg

Description

The present invention relates to electro-acoustic transducers operating in the range of sound and ultrasonic acoustic waves. Designed for use in phased arrays of long-range acoustic annunciators with a circular pattern, high efficiency, long duration of continuous operation, an increased number of conditional acoustic signals.

Sound annunciators with a circular pattern are widely used as sound sirens for giving alarm signals to the Ministry of Emergency Situations and the Ministry of Defense of the Russian Federation. But they have low efficiency and increased power consumption. Due to the inertia in the set of engine revolutions and its braking, the siren is not able to give more than three conditional signals.

Widely used in transport, electrodynamic sirens have a higher efficiency and a large number of conditional acoustic signals, but they are prone to failures during long-term operation.

The highest efficiency and low power consumption are distinguished by electro-acoustic transducers based on piezoceramics used in acoustic annunciators for various purposes. However, they have a narrow radiation pattern.

The objective of the invention is to create an electro-acoustic transducer, based on piezoceramics, with high efficiency, circular toroidal radiation pattern, increased number of conditional acoustic signals supplied, including those supplied using Morse code. The design of the electro-acoustic transducer should ensure its use in long-range acoustic annunciators.

Close in principle to the claimed invention is an electro-acoustic transducer described in the patent for invention PU No. 2647509, in which an acoustic reflective screen is used, partially covering the membrane emitting acoustic vibrations, which increases the sound pressure at the output of the electro-acoustic transducer and improves efficiency. However, the radiation pattern does not exceed 80 degrees.

The closest in terms of technical characteristics is the electro-acoustic transducer described in the patent for the invention RU No. 2716287 in which, to increase the efficiency, the acoustic reflective screen completely covers the membrane emitting acoustic vibrations. But, it narrowed the radiation pattern. However, taking into account that electroacoustic transducers of this design have the best technical characteristics, it was decided to develop an electroacoustic transducer with a circular toroidal directivity pattern based on them. For this purpose, instead of an acoustic reflective screen, an acoustic reflective waveguide is used, the radius of which should be greater than the wavelength of the applied acoustic vibrations. Under such conditions, an acoustic wave, consistent with the air environment, from the center of the acoustic reflective waveguide, evenly propagates to its periphery, which makes it possible to direct it into a horn having a circular pattern, consisting of two truncated cones. On the surfaces of truncated cones, interconnected by holders, two oppositely directed electroacoustic transducers are fixed, separated by an acoustic reflective waveguide. In the internal cavities of truncated cones, closed with covers, you can install the necessary equipment. During field tests, an acoustic pressure of at least 125 dB was obtained. per meter with a toroidal radiation pattern shown in the section in FIG - 3.

To narrow the radiation pattern and increase the range, a composite phased array is used, consisting of the required number of phased electro-acoustic transducers FIG - 2.

To improve clarity when studying the principle of operation of the device, the attachment points of the elements of the circular horn in the figures are not indicated.

DESIGN OF A HORN PHASED ACOUSTIC TRANSDUCER,

FIG - 1 shows the design of a horn phased electro-acoustic transducer, consisting of two truncated cones 1, forming a circular horn. Oppositely directed electro-acoustic transducers 2 are installed on the tops of the cones, separated, with a gap, a common acoustic reflective waveguide 3. Electro-acoustic transducers consist of a flat annular body, on which a membrane 4 is fixed, having a flat and central convex part, at the base of which a bimorph piezoblock 5 is fixed with two piezoceramic discs 6 connected to electrical conductors 7 for in-phase excitation of bimorph piezoblocks.

OPERATING PRINCIPLE OF HORN PHASED ACOUSTIC TRANSDUCER.

When applying resonant electrical vibrations through the electrical conductors 7 to the piezoceramic disks 6, mechanical vibrations are excited in the bimorph piezoblocks 5, which arrive at the membranes 4, which excite acoustic vibrations, which, using the acoustic reflective waveguide 3, are consistent with the air environment and are directed to the circular horn 1, where in phase add up, increasing the acoustic pressure at its output, forming a circular toroidal radiation pattern.

Claims (1)

Acoustic piezoceramic transducer, containing a housing in which a membrane is fixed around the circumference, having a flat and internal convex part, at the base of which a bimorph piezoblock with two piezoelectric disks connected to electrical conductors is fixed, a means reflecting acoustic vibrations is fixed above the convex and flat part of the membrane, characterized in that two acoustic piezoceramic transducers are installed in the horn phased electro-acoustic transducer, the membranes of which, having a flat and convex part, are fixed around the circumference inside flat annular holders, providing their counter-directional fastening on the flat sides of the truncated cones forming a circular horn, between which an acoustic reflective waveguide is placed with a gap, the radius of which is greater than the wavelength of the emitted acoustic vibrations, the electrical conductors from the piezoceramic disks of the bimorph piezoblocks are connected to the source of electrical vibrations in such a way that the acoustic vibrations from the acoustic piezoceramic transducers add up at the output of the horn phased electroacoustic transducer, increasing the acoustic pressure, forming a circular toroidal radiation pattern.

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