RU2647509C1 - Electroacoustical transducer - Google Patents

Abstract

FIELD: acoustics.

SUBSTANCE: invention relates to acoustics, particularly to a piezoelectric electroacoustical transducers. Electroacoustical transducer comprises an alternating voltage generator, a cylindrical body coaxially disposed therein, a circular bimorph with two piezoelements, fastened with a convex membrane above it and a common flat annular holder, is equipped, over the convex membrane, with an acoustic reflective screen with peripheral nodes to coaxially fasten the transducer to the cylindrical body.

EFFECT: technical result is increased acoustic pressure by 2, narrowing of acoustic oscillation emission pattern, increased efficiency, increased action range.

1 cl, 2 dwg

Description

The invention relates to piezoelectric electro-acoustic transducers and can be used as a source of acoustic vibrations with increased acoustic pressure, for example, in sound warning systems, security and fire alarms, long-range acoustic oscillators and for other purposes.

Known electro-acoustic transducer containing an alternating voltage generator, a cylindrical body (not mentioned as an attribute insignificant for it, only its base is shown), a circular piezoelectric element coaxially located in it (it can be a piezoelectric unit, for example a bimorph with two piezoelectric elements), bonded with a convex membrane above it, and a holder (RU 2014758 C1 5, H04R 17/00, 06/15/94).

A technical drawback of the known electro-acoustic transducer: it does not have a sufficiently high acoustic pressure of the emitted vibrations due to the loss of mechanical vibrations when the central part of the piezoelectric element is mounted on the housing, it emits acoustic vibrations with a radiation pattern width of more than 30 g.

The closest to the claimed invention by its technical nature and the problem to be solved is an electro-acoustic transducer containing an alternating voltage generator, a cylindrical body, a round bimorph coaxially arranged in it with two piezoelectric elements, fastened with a convex membrane above it and a common flat ring holder (RU 71496 U16, H04R 17/00, 03/10/2008).

The technical disadvantage of the known electro-acoustic transducer: insufficient acoustic pressure, a wide radiation pattern of emitted acoustic vibrations, insufficient efficiency (efficiency) and range, does not have mechanical protection of the convex membrane and the common flat ring holder from external mechanical influences.

The technical problem: increasing the acoustic pressure of the emitted vibrations, narrowing the radiation pattern of acoustic vibrations, increasing efficiency, increasing the range, increasing the mechanical strength of the body and the protection of the convex membrane and the common flat ring holder from external mechanical influences.

According to the invention, an electro-acoustic transducer comprising an alternating voltage generator, a cylindrical body, a circular bimorph with two piezoelectric elements coaxially located therein, fastened with a convex membrane above it and a common flat ring holder, provided with an acoustic reflective screen with peripheral nodes for coaxially attaching it to the cylindrical membrane case.

In FIG. 1 shows an electro-acoustic transducer, a general view in diametrical section AA of FIG. 2.

The electro-acoustic transducer contains an alternating voltage generator 1, a cylindrical housing 2, a circular bimorph 3 with two piezoelectric elements coaxially located in it, fastened with a convex membrane 4 above it and a common flat ring holder 5 (simultaneously acts as a membrane), and above the convex membrane 4, an acoustic a reflective screen 6 (shown flat, but may be concave or in the form of a cone) with peripheral nodes of the coaxial mount 7 (for example, petals, in Fig. 1 are not shaded as fasteners) it is to indricheskomu housing 2. The plurality of convex membrane 4 and the acoustic reflective screen 6 form a round tube, guiding The phased acoustic vibrations to the output electroacoustic transducer.

In the initial state, the alternator 1 is turned off. The device does not emit acoustic vibrations.

Electro-acoustic transducer operates as follows.

From the alternating voltage generator 1, the electrical signals arrive at a bimorph 3 with two piezoelectric elements, which simultaneously excites mechanical vibrations on the surface of the convex membrane 4 and the common flat ring holder 5. By acting on the air in the acoustic transducer, the convex membrane 4 excites acoustic vibrations in it directed along axis 8. Due to the fact that the acoustic vibrations from the convex membrane 4 and the planar ring holder 5 are different in phase, their resulting amplitudes cause lowering the acoustic pressure at the output of the piezoelectric transducer. This disadvantage is eliminated by the acoustic reflective screen 6, which directs the acoustic vibrations from the convex membrane 4 towards the common flat annular holder 5 and thereby provides phased interaction of the acoustic vibrations from the convex membrane 4 and the common flat annular holder 5, which increases the acoustic pressure at the output of the transducer.

According to experimental studies, this invention increases the acoustic pressure at the output of electro-acoustic conversion by 2 times (and even slightly higher), narrows the radiation pattern of acoustic vibrations, increases efficiency, increases the range, increases the mechanical strength of the body and the protection of the convex membrane and the common flat ring holder from external mechanical influences.

Thus, the technical problem has been solved: increasing the acoustic pressure of the emitted oscillations, narrowing the radiation pattern, increasing efficiency, increasing the range, increasing the mechanical strength of the body and the protection of the convex membrane and the common flat ring holder from external mechanical influences.

Claims (1)

An electro-acoustic transducer containing an alternating voltage generator, a cylindrical body, a circular bimorph with two piezoelectric elements coaxially located therein, fastened with a convex membrane above it and a common flat ring holder, characterized in that it is equipped with an acoustic reflective screen with peripheral coaxial attachment nodes over the convex membrane him to the cylindrical body.

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