JP2000350279A - Horn speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sound characteristics of a loudspeaker which uses a piezoelectric diaphragm. SOLUTION: The piezoelectric diaphragm 20 has its center support on one side of a sound diaphragm 22, a horn 12 is provided spreading outward from the other side of the sound diaphragm 22, and an equalizer 14 is provided at the center part of the horn 12 along the center axis of the piezoelectric diaphragm 20 to constitute a horn speaker 10. A throat part 12 formed between the horn 12 and equalizer 14 is formed of an elastic material 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a horn type speaker using a piezoelectric vibrator.

[0002]

2. Description of the Related Art A sound generator having a piezoelectric diaphragm as a sound source of a speaker system is known. For example, Japanese Utility Model Registration No. 3037167 by the applicant of the present application discloses a speaker structure using a piezoelectric element such as a bimorph as a sound source of a speaker system. This speaker is
A piezoelectric diaphragm is attached to an acoustic diaphragm made of a fiber-reinforced plastic such as carbon fiber to use as a sound source of a speaker.

[0003]

The sound generator as a sound source used in the speaker having the structure disclosed in the above-mentioned utility model registration has particularly excellent high-frequency characteristics but has room for improvement.

[0004]

According to the present invention, a piezoelectric vibrating plate is supported at one side on one side of an acoustic diaphragm, and a horn which expands outward from the opposite side of the acoustic diaphragm is provided. A horn-type speaker having an equalizer provided along a central axis of the piezoelectric vibrating plate at a center portion, wherein a throat portion formed between the horn and the equalizer is formed of an elastic material. The speaker is the gist.

[0005]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, referring to FIG. 1 which is an axial cross-sectional view of the first embodiment, a horn-shaped speaker 10 has a piezoelectric vibrator supported centrally on one side of a generally conical cone 22 as an acoustic diaphragm. Board 20
Is provided. On the opposite side of the cone 22 is a horn 12
Is provided so as to expand outward. An equalizer 14 is provided at the center of the horn 12 along the center axis of the cone 22. An enclosure 16 is connected to the horn 12 by a suitable fastening means such as a screw. A piezoelectric vibration plate 20 and a cone 22 are housed in an internal space defined by the horn 12 and the enclosure 16.

The equalizer 14 can be separated and fixed in a radial direction with respect to the horn 12 by, for example, a plurality of connecting members (not shown) extending radially, and a cone 22 is provided between the horn 12 and the equalizer 14. A throat portion 12a, which is a passage of the sound generated by the sound, is formed. In the present embodiment, an elastic member 26 such as silicone rubber is provided particularly at the throat portion 12a.

The cone 22 can be formed in a generally conical shape from a plastic such as polypropylene, for example.
It is attached to the enclosure 16 with its peripheral edge. A mounting portion for mounting the circular piezoelectric vibration plate 20 is formed at the vertex of the cone 22. The mounting portion is passed through the center hole of the piezoelectric vibration plate 20 and heat and pressure are applied from the outside to fix the mounting portion. By tightening, the piezoelectric vibrating plate 20 is
2 is fixed. Further, the cone 22 is provided with the equalizer 14.
Are spaced apart from the tail end of the horn 12 and a part of the horn 12, and a gap Ga is formed therebetween. The gap Ga can be formed so as to preferably expand at a predetermined angle from the center to the periphery.

The piezoelectric vibrating plate 20 may be, for example, a bimorph in which ceramic layers are formed on both surfaces of a metal layer such as aluminum, and an amplifier (see FIG. 1) is provided between the metal layer and the ceramic layer via a lead wire 20a. (Not shown), the piezoelectric diaphragm 20 repeatedly bends in the front-rear direction, that is, in the vertical direction in FIG. 1 in response to the audio signal. In addition, the enclosure 16
It has a hole 16a for drawing out the lead wire 20a to the outside, and the hole 16a is closed by a resin, an adhesive, solder or the like after passing through the lead wire 20a. By closing the hole 16a, the piezoelectric vibrating plate 20 is
And in the space surrounded by the cone 22.

As described above, when an audio signal is applied to the piezoelectric diaphragm 20, the piezoelectric diaphragm 20 repeatedly bends in the front-rear direction in response to the audio signal, and the vibration of the piezoelectric diaphragm 20 is reduced. The light is transmitted to the cone 22, passes through the throat portion 12a from the cone 22, and propagates from the horn 12 to external air as sound waves.

Referring now to FIG. 2, a horn-type speaker 100 according to a second embodiment of the present invention has a piezoelectric vibration center supported on one side of a cone 122 as an acoustic diaphragm similarly to the first embodiment. A plate 120 is provided. Cone 1
A horn (not shown) similar to the horn 12 of the first embodiment is provided on the opposite side of the horn 22 so as to expand outward. An equalizer 114 is provided at the center of the horn along the central axis of the cone 122. Further, an enclosure 116 is connected to the horn, and the piezoelectric diaphragm 120 and the cone 122 are housed in an internal space defined by the horn and the enclosure 116. The horn and equalizer 114
A throat portion 112a, which is a passage of the sound emitted by the cone 122, is formed between the throat portion 112a and the throat portion 112a. In the present embodiment, in the equalizer 114, in particular, the conical or hemispherical tail end portion 114a facing the cone 116 is formed with a number of contour-shaped grooves that change the wave number characteristics of the sound emitted by the cone 116. .

The cone 122 can be formed, for example, in a generally conical shape from a plastic such as polypropylene, and is attached to the enclosure 16 with a peripheral edge 112b. At the apex of the cone 122, a mounting portion 124 for mounting a circular piezoelectric vibration plate 120 is formed.
The piezoelectric vibration 120 is fixed to the cone 122 by applying heat and pressure from outside and crimping the mounting portion.

The piezoelectric vibrating plate 120 may be a bimorph in which ceramic layers 132 are formed on both sides of a metal layer 130 of, for example, aluminum, and a lead wire 120 a is provided between the metal layer 130 and the ceramic layer 132. An audio signal from an amplifier (not shown) is applied, and the piezoelectric vibrating plate 120 is vibrated in the front-back direction as described above. The enclosure 116 has a hole 116a for drawing out the lead wire 120a to the outside.
a is closed by a resin, an adhesive, solder or the like after passing through the lead wire 120a. By closing the hole 116a, the piezoelectric vibration plate 120 is sealed in a space surrounded by the enclosure 116 and the cone 122.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Horn type speaker 12 ... Horn 14 ... Equalizer 16 ... Enclosure 20 ... Piezoelectric diaphragm 22 ... Cone 26 ... Elastic member

Claims (5)

[Claims] 1. A piezoelectric vibrating plate is centrally supported on one side of an acoustic vibrating plate, and a horn that expands outward from the opposite side of the acoustic vibrating plate is provided. A horn-shaped speaker provided with an equalizer along a central axis, wherein a throat portion formed between the horn and the equalizer is formed of an elastic material. 2. The horn-type speaker according to claim 1, wherein the acoustic diaphragm is formed in a substantially conical shape, and the piezoelectric diaphragm is attached to a vertex on an outer surface of the acoustic diaphragm. . 3. The equalizer has a substantially conical or substantially hemispherical tail end, and the acoustic diaphragm is provided between a tail end of the equalizer and an inner surface of the conical acoustic diaphragm. The horn-type speaker according to claim 2, wherein the horn-type speaker is arranged so as to form a gap. 4. The outer surface of the tail end of the equalizer,
The horn-type speaker according to claim 3, wherein a plurality of grooves are formed along the contour line. 5. The horn-type loudspeaker according to claim 4, wherein an angle between a tail end of the equalizer and the acoustic diaphragm expands from a center to a peripheral edge.