JPH02312399A - Piezoelectric sounder - Google Patents

Abstract

PURPOSE:To eliminate soldering and sticking process by engaging and fixing a piezoelectric diaphragm to a groove in the peripheral wall of an outer case so that a piezoelectric element faces downward and conductively bringing the piezoelectric element into contact with the contact tip of a metallic terminal. CONSTITUTION:The piezoelectric diaphragm 5 and the outer case 12 are engaged and fixed to the groove 8 provided on the inner peripheral of the side wall 9 of the outer case 12 so that the piezoelectric element 2 faces downward and a piezoelectric sounder 1 is constituted. Since the piezoelectric element 2 is contact-connected with the contact tip 10 of the metallic terminal 11, the need of soldering is eliminated by elastic force of the metallic terminal 11 itself. Thus, the soldering process and the adhering process with the silicone of the piezoelectric diaphragm can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a piezoelectric sounder (so-called piezoelectric buzzer) that drives a diaphragm to generate sound by deforming a piezoelectric element bonded to the diaphragm.

(Prior Art) As a conventional piezoelectric sounder, for example, one whose cross section is shown in FIGS. 2 and 3 is well known.

The piezoelectric sounder 21 in FIG. 2 is composed of a piezoelectric diaphragm 24 and an exterior case 30.
consists of a metal diaphragm 23 to which a piezoelectric element 22 is bonded on one side, and the exterior case 30 has a bottom 27 with an opening 26 in the center, and a bottom part 27 that rises upward from the periphery of the bottom part 27, and has a metal diaphragm 23 on the inside that surrounds the piezoelectric diaphragm 24. It consists of a peripheral wall 29 provided with a stop portion 28.

The piezoelectric diaphragm 24 is bonded to a locking portion 28 provided on a peripheral wall 29 of the outer case 30 with a recon 25. Further, the peripheral wall 29 has a portion on its outer side that fixes a metal terminal 32 extending toward the piezoelectric element 22 with a rivet 31 or the like.
is electrically connected to the piezoelectric element 22 by solder 33.

Although not shown, the terminal connected to the other metal diaphragm 23 may be soldered and pulled out to the outside, or may be directly connected to the metal diaphragm 23 depending on the form of use. You may. When an electric signal is applied between the above two terminals, the piezoelectric element 22 deforms and the metal diaphragm 2
3 is driven and a sound is generated. The generated sound is radiated outward from the opening 26 formed in the outer case 30.

The piezoelectric sounder 41 shown in FIG. 3 includes a piezoelectric diaphragm 24,
It is composed of an exterior case 30 and a lid member 35.

The structure of the outer case 30 is almost the same as that of the piezoelectric sounder 21 shown in FIG. It has become.

The piezoelectric diaphragm 24 is fixed by being held between a downward protrusion 36 provided on the lid member 35 and a locking portion 28 inside the exterior case 30. Furthermore, since the metal terminal 32 is pressed against the piezoelectric element 22 by the lid member 35, the metal terminal 32 and the piezoelectric element 22 are connected with solder 33 as in the piezoelectric sounder 21 in FIG. It is no longer necessary.

(Problem to be solved by the invention) However, in the piezoelectric sounder 21 of FIG.
Soldering and silicone bonding are required, and the piezoelectric sounder 41 shown in FIG. 3 requires a lid member, and furthermore, the thickness of the product increases, making it difficult to miniaturize.

Therefore, the purpose of the present invention is to reduce the soldering process and the silicon bonding process of the piezoelectric diaphragm, eliminate the need for mounting the M member, reduce manufacturing costs, and make it possible to make the product smaller and thinner. The purpose is to provide a piezoelectric sounder with a high quality.

(Means for Solving the Problems) In order to achieve the above object, a piezoelectric sounder according to the present invention includes a metal diaphragm having a piezoelectric element adhered to one surface, and a periphery of the metal diaphragm that is supported from the outside. a piezoelectric diaphragm consisting of an annular elastic member, a bottom part having an opening in the center, and a circumferential wall that rises upward from the periphery thereof and has a groove in its inner periphery shaped to fit the annular elastic member; and an exterior case in which a metal terminal is insert-molded so that the contact tip protrudes obliquely upward and the other tip protrudes outward when forming the peripheral wall, and the piezoelectric diaphragm is formed so that the piezoelectric element faces downward. The piezoelectric element and the contact tip of the metal terminal are in conductive contact with each other, with the piezoelectric diaphragm being fitted and fixed in a groove in the peripheral wall of the outer case, and the piezoelectric diaphragm or the like being fitted and fixed with the outer case. shall be.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1(a) shows a longitudinal sectional view of a piezoelectric sounder 1 according to the present invention. This piezoelectric sounder 1 is comprised of a piezoelectric diaphragm 5, a partially cutaway perspective view of which is also shown in FIG. 1(b), and an exterior case 12 in which metal terminals 1.1 are insert-molded.

The piezoelectric diaphragm 5 is insert-molded, and the periphery of a disk-shaped metal diaphragm 3 with a piezoelectric element 2 bonded to one surface is supported from the outside by a ring-shaped elastic member 4 made of thick resin, styrofoam, or rubber. The structure that was built is creaking.

The exterior case 12 also has a bottom 7 having an opening 6 in the center.
and a peripheral wall 9 which stands upward from its periphery and has a groove 8 on its inner circumference. Further, when forming the bottom portion 7 and the peripheral wall 9, a metal terminal 11 is insert-molded so that the contact tip 10 projects obliquely upward and the other tip projects outward.

The piezoelectric diaphragm 5 and the exterior case 12 having the above configuration are fitted and fixed in the groove 8 provided on the inner periphery of the peripheral wall 9 of the exterior case 12, thereby forming the piezoelectric sounder 1.

Note that the piezoelectric element 2 and the contact tip 10 of the metal terminal 11 are brought into contact connection by the elastic force of the metal terminal 11 itself, so there is no need for soldering.

Although not shown, if the other metal terminal is insert-molded in the same way as the metal terminal 11 so that the metal diaphragm 3 and the contact tip of the other metal terminal are connected by contact, this will work. There is no need for soldering.

In this way, when an electric signal is applied across the gap between the metal diaphragm 3 and the piezoelectric element 2, the piezoelectric element 2 is deformed, the metal diaphragm 3 is driven, and sound is generated. The generated sound is radiated upward or downward through an opening 6 provided in the outer case 12 in FIG. 1(a).

(Effects of the Invention) By having the configuration described above, the piezoelectric sounder according to the present invention, unlike conventional ones, can omit the soldering and bonding steps, and furthermore, the piezoelectric sounder according to the present invention can omit the soldering and bonding steps. This is not necessary, reduces manufacturing costs, and facilitates miniaturization and thinning of the product.

[Brief explanation of the drawing]

FIG. 1(a) is a longitudinal sectional view of a piezoelectric sounder according to the present invention. FIG. 1(b) is a partially cutaway perspective view of a diaphragm of the piezoelectric sounder according to the present invention. and Fig. 3 are vertical cross-sectional views of a conventional piezoelectric sounder. ■...Piezoelectric sounder 2 - Piezoelectric element 3 - Metal diaphragm 11 - Ring-shaped elastic member 5 - Piezoelectric diaphragm 6...・Opening A...Bottom 8...Groove 9・Peripheral wall 10...Contact tip Ll...Metal terminal 12...Exterior case

Claims (1)

[Claims] (1) A piezoelectric diaphragm consisting of a metal diaphragm with a piezoelectric element adhered to one surface, an annular elastic member that supports the periphery of the metal diaphragm from the outside, a bottom with an opening in the center, and a bottom part with an opening in the center, and It consists of a peripheral wall that stands upward and has a groove on its inner periphery that is shaped to fit an annular elastic member, and when forming the bottom and peripheral wall, the contact tip protrudes obliquely upward, and the other tip protrudes to the outside. The piezoelectric diaphragm is fitted and fixed in a groove in the peripheral wall of the outer case with the piezoelectric element facing downward, and the piezoelectric diaphragm is fitted into a groove in the peripheral wall of the outer case. A piezoelectric sounder characterized in that the piezoelectric element and a contact tip of a metal terminal are in conductive contact with each other in a fixed state.