JPS6127276Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a piezoelectric speaker using a piezoelectric diaphragm as a driving source.

FIG. 1 shows a conventional piezoelectric speaker. In the figure, 1 is a cone-shaped bracket, and a circular opening is provided in the center of the bracket. Reference numeral 2 denotes a disk-shaped piezoelectric diaphragm made by laminating a piezoelectric material plate to a thin brass plate, and its outer periphery matches the opening edge of the bracket 1 and is fixed with an adhesive 3. Reference numeral 4 designates a dome-shaped escutcheon diaphragm, which is made of, for example, a polyethylene film on which aluminum is vapor-deposited, and whose outer periphery is adhesively fixed together with the piezoelectric diaphragm 2 to the opening edge of the bracket 1. This escutcheon diaphragm 4 covers the front surface of the piezoelectric diaphragm 2, and forms an airtight chamber A between it and the piezoelectric diaphragm 2.

In such a piezoelectric speaker, by applying an acoustic signal to the piezoelectric diaphragm 2, the piezoelectric diaphragm 2 bends and vibrates, and this vibration drives the escutcheon diaphragm 4 using the air in the airtight chamber A as a medium. It is something. However, as mentioned above, the outer edges of the piezoelectric diaphragm 2 and the escutcheon diaphragm 4 are bonded 3.
In the fixed configuration, it is difficult to uniformly apply the adhesive 3, so incomplete adhesion occurs, and there is a risk that chattering noise due to bending vibration of the piezoelectric diaphragm 2 may occur at these locations. Ta. Furthermore, the bonding process using adhesive 3 requires drying time, resulting in an increase in manufacturing costs.

The present invention was devised in view of such circumstances, and will be described in detail below.

FIG. 2a shows a sectional view of an embodiment of the piezoelectric speaker of the present invention, and FIG. 2b shows an exploded perspective view thereof. In these figures, 10 is a cone-shaped bracket having an opening in the center, and an annular inner projection 11 and an annular rear projection 12 projecting rearward of the bracket 10 are formed at the edge of the opening. Further, this rear projection 12 is provided with an annular outer protrusion 13. 50 is the bracket 1
a cap elastically fitted to the opening edge of 0;
An annular inner protrusion 52 that is elastically engaged with the outer protrusion 13 of the bracket 10 is formed at the end of the cylindrical portion 51 that protrudes forward from its outer peripheral edge. An annular front projection 53 facing the rear surface of the inner projection 11 of the bracket 10 is provided at an inward location of the bracket 10. The peripheral portion of the bracket 10 and the peripheral portion of the cap 50 are connected by a hinge 15, and the bracket 10 and the cap 50 are integrally molded from styrene resin or polypropylene having appropriate elasticity. There is. 20 and 40 are a piezoelectric diaphragm and an escutcheon diaphragm having the same shape as the conventional speaker shown in FIG.
In this state, their outer peripheral edges are elastically held between the inner protrusion 11 of the bracket 10 and the front protrusion 53 of the cap 50. still,
Cutouts 54 and 55 are formed in the cylindrical portion 51 and the front projection 53 of the cap 50 as shown in FIG. Lead wires 21 and 22 for applying signals are drawn out to the outside.

In a piezoelectric speaker having such a configuration, the escutcheon diaphragm 40 and the piezoelectric diaphragm 20 are sequentially placed from the rear of the bracket 10 onto the annular inner protrusion 11 at the opening edge of the bracket 10, and then the cap is placed. 50
By elastically fitting into the rear projection 12 of the bracket 10, the outer peripheral edges of both the diaphragms 40 and 20 are fixed together.

3 and 4 respectively show other embodiments of the piezoelectric speaker of the present invention. In the piezoelectric speaker of FIG. The structure is such that it connects the two. The piezoelectric speaker shown in FIG. 4 is constructed so that the annular front projection 53' of the cap 50 is press-fitted into the annular rear projection 12' of the bracket 10.

As is clear from the above description, the piezoelectric speaker of the present invention is provided with an annular protrusion at the edge of the opening at the center of the bracket, and is fitted with a cap that is fitted into the bracket to face the annular protrusion of the bracket. The ring-shaped projection of the bracket and the ring-shaped projection of the cap integrally sandwich the outer periphery of the circular piezoelectric diaphragm and the outer periphery of the dome-shaped escutcheon diaphragm. The outer periphery of the diaphragm can be securely fixed, eliminating any chattering noise. In addition, since there is no need to use adhesives like in conventional speakers, the piezoelectric diaphragm and the escutcheon diaphragm can be easily attached at the same time, reducing the time required for this attachment process. It is hoped that the manufacturing cost will be reduced.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional piezoelectric speaker, Figure 2 is a cross-sectional view of a conventional piezoelectric speaker.
Figures a and b are sectional views and exploded perspective views of one embodiment of the piezoelectric speaker of the present invention, and Figures 3 and 4 are sectional views of different embodiments of the piezoelectric speaker of the present invention, respectively. 1, 10... Bracket, 2, 20... Piezoelectric diaphragm, 4, 40... Escutcheon diaphragm, 11
... Inner projection, 12 ... Posterior projection, 50 ... Cap, 51 ... Cylindrical portion, 53 ... Anterior front projection.

Claims (1)

[Scope of Claim for Utility Model Registration] A piezoelectric type in which the outer periphery of a disk-shaped piezoelectric diaphragm is fixed to the opening edge at the center of the bracket, and a dome-shaped escutcheon diaphragm is attached to the front of this piezoelectric diaphragm. In the speaker, an annular protrusion is provided at the opening edge at the center of the bracket, and an annular protrusion for fitting is provided on the cap to be fitted to the bracket, and the annular protrusion is opposed to the annular protrusion of the bracket. A piezoelectric speaker characterized in that the outer periphery of the piezoelectric diaphragm and the escutcheon diaphragm are integrally held together by an annular projection of the bracket and an annular projection of the cap.