JPH0968986A - Piezoelectric sounding body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized and thin piezoelectric sounding body which is usable as a single piezoelectric sounding body as well, is usable in spite of integral assembly into the set body side of an apparatus and has excellent versatility. SOLUTION: This piezoelectric sounding body includes a piezoelectric diaphragm 3 which is formed by adhering a piezoelectric ceramic plate 12 to a metallic diaphragm 13, a case body 2 which is formed with a stepped part 5 to be placed with the piezoelectric diaphragm 3 and a spring terminal 4 which is arranged between the case body 2 and the piezoelectric diaphragm 3 and comes into elastic contact with the electrodes formed on the inside surface of the case body 2 and the piezoelectric ceramic 12. The piezoelectric sounding body 1 is constituted by forming one connecting terminal 14 to the peripheral edge 13 of the metallic diaphragm and another connecting terminal 15 to the end of the spring terminal 4, respectively, and fitting both connecting terminals 14, 15 to the case body 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a piezoelectric sounding body,
More specifically, the present invention relates to a piezoelectric sounding body having a reduced size and a reduced thickness by improving the structures of a diaphragm and terminals.

[0002]

2. Description of the Related Art A piezoelectric sounding body is used as a small buzzer for calling mobile communication devices such as mobile phones and wireless phones, and has a pin type structure. It's been there for a long time.

As such a pin-type piezoelectric sounding body, for example, Japanese Utility Model Laid-Open No. 6-59897 discloses a piezoelectric vibrating plate, a case body for accommodating the piezoelectric vibrating plate, and a piezoelectric vibrating plate which is electrically connected to the piezoelectric vibrating plate and is drawn out of the case body. A pair of connection terminals are provided, and at the inner end position of each connection terminal, a contact piece that elastically contacts the piezoelectric diaphragm is formed, and the contact piece is positioned and supported by elastically contacting the inner surface of the case body. A piezoelectric buzzer is disclosed which is characterized by forming a support piece.

According to this, since the contact piece formed at the inner end position of each connection terminal is supported by the case body via the support piece, the contact state of each contact piece with the piezoelectric vibrating plate is stabilized. Therefore, each contact piece is in contact with the piezoelectric vibrating plate while maintaining an appropriate contact pressure, and the reliability of the contact can be ensured.

This piezoelectric sounding body is assembled by inserting the piezoelectric vibrating plate into the case body, incorporating the connection terminals having the contact pieces and the support pieces as pin terminals, and then pressing the back cover into the case body. It was

[0006]

However, the piezoelectric speaker disclosed in Japanese Utility Model Laid-Open No. 6-59897 has good assemblability during manufacturing and is suitable for mass production. Since the case body needs to have a predetermined length in the thickness direction, there is a problem that it is difficult to reduce the thickness of the piezoelectric sounding body.

In particular, when miniaturization is required such as a ringing buzzer used in a portable telephone, which is rapidly in demand in recent years, a case body of a piezoelectric sounding body is built in a casing of the telephone. Although it has been found that the size and weight of the piezoelectric sounding body can be further reduced by the integration, there is a problem that the piezoelectric sounding body having the above-described structure cannot cope with the size and weight reduction by such integration.

In addition, the piezoelectric sounding body having another structure also
There is also a problem that it is difficult to integrate it into a set body such as a mobile phone because there is no structure suitable for being small and thin.

The present invention has been completed by the present inventor to solve the above problems, and an object thereof is to reduce the size and thickness by improving the piezoelectric vibrating plate and the terminal structure.
To provide a compact and thin piezoelectric sounding body excellent in versatility that can be used as a single piezoelectric sounding body by covering a case, or by making a portion corresponding to the case into a set body side and integrally incorporating it. It is in.

[0010]

The piezoelectric sounding body of the present invention comprises:
A piezoelectric vibrating plate formed by adhering a piezoelectric vibrating plate having electrodes formed on both main surfaces to a metal vibrating plate, a case body having a stepped portion on which the piezoelectric vibrating plate is mounted, the case body, and A spring terminal that is disposed between the piezoelectric diaphragm and is elastically contacted with the inner surface of the case body and one of the electrodes, and has one connection terminal at the peripheral edge of the metal diaphragm and an end of the spring terminal. The other connecting terminal is formed in each part, and both connecting terminals are fitted in the case body.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION According to the piezoelectric sounding body of the present invention, the piezoelectric vibrating plate and the spring are arranged by placing the piezoelectric vibrating plate on the case body and arranging the spring terminals between them to elastically contact them. The terminals are pressure-connected to each other, and one of the pair of connection terminals is formed on the periphery of the metal diaphragm of the piezoelectric diaphragm, and the other is formed on the end of the spring terminal. The piezoelectric sounding body can be made very thin and small by fitting the piezoelectric sounding body.

The piezoelectric sounding body of the present invention can be made into a single piezoelectric buzzer by covering the case body with a cap case having a predetermined cavity so as to cover the piezoelectric vibrating plate. Further, by forming a predetermined cavity on the set body side of a device incorporating the piezoelectric sounding body and fitting the cavity into the cavity, a built-in piezoelectric buzzer having a very small installation space can be obtained.

As described above, the piezoelectric sounding body of the present invention has excellent versatility, and can respond to various frequencies by changing the size and shape of the cap case. It will be possible to unify and make a lineup.

Further, according to the piezoelectric sounding body of the present invention, the connection terminal is fitted in the case body, so that the connection terminal goes around the side surface or the lower surface of the case body and extends along those surfaces. Become. Therefore, the connection with the external circuit (driving circuit) can correspond to various connection methods such as soldering to a mounting board, soldering of lead wires, and pressure contact connection by contact.

The piezoelectric sounding body of the present invention will be described below in detail with reference to the drawings. 1 is a sectional view showing an embodiment of a piezoelectric speaker according to the present invention, and FIG. 2 is a top view thereof.

As shown in FIGS. 1 and 2, in the piezoelectric speaker 1 of the present invention, 2 is a case body, 3 is a piezoelectric diaphragm, and 4 is a spring terminal. In FIG. 2, the piezoelectric vibrating plate 3 is shown by a chain line so that the arrangement of the spring terminals 4 can be easily understood.

The case body 2 is made of ABS or PBT and has a width of 10 to 20 mm, a length of 10 to 20 mm, and a thickness of 1.0 to 1.
The size is about 5 mm, and the shape thereof may be square or circular other than the octagon shown, and is not particularly limited.

At the center of the case body 2, there is a recess 6 in which a step 5 for mounting the piezoelectric vibrating plate 3 is formed. Further, a bulge 7 is formed at a height of such a level that it does not contact the piezoelectric vibrating plate 3 at the center of the bottom surface of the recess 6, and the spring terminal 4 is inserted in the center of the bulge 7 for positioning thereof. The groove 8 is formed. This raised portion 7 is provided mainly for the purpose of securing the strength of the case body 2, but it is not necessarily provided if the case body 2 has sufficient strength, and it is assumed that only the groove 8 is formed on the bottom surface of the recessed portion 6. Good.

Further, connection terminal fitting portions 10 and 11 into which connection terminals to be described later are fitted are formed on two opposing sides of the eight sides around the case body 2 shown in FIG. An input signal from an external circuit (driving circuit) is applied via a pair of connection terminals attached to these. If the connection terminal fitting portions 10 and 11 are formed on two opposite sides as shown in the drawing, the connection terminals are securely fixed when soldered to a circuit board or the like, or the connection electrodes on the board side are provided on both sides. Therefore, there is an advantage that a stable connection and fixation can be obtained by sandwiching the connection terminal. In addition, the connection terminal fitting portions 10 and 11 may be formed on, for example, two sides in a direction of approximately 90 degrees, which makes it possible to cope with circuit boards having various circuit arrangements. There are advantages.

Further, on the four sides of the eight sides around the case body 2 shown in FIG. 2, there are stepped portions 9 for attaching a cap case to be described later or for assembling into a cavity on the set body side of the device. Although each is formed, it may be appropriately set according to the shape of the case body 2, the cap case or the cavity, or the required mounting structure.

The piezoelectric vibrating plate 3 is formed by adhering a piezoelectric ceramic plate 12 having electrodes (not shown) formed on both main surfaces to a metal vibrating plate 13, and the periphery of the metal vibrating plate 13 is formed. One connection terminal 14 is formed by bending into a structure to be fitted into one connection terminal fitting portion 10 of the case body 2.

The piezoelectric ceramic plate 12 is made of lead zircon titanate or the like and has a disk shape with a diameter of 7 mm and a thickness of 0.05 mm.
Electrodes such as are formed and polarized.

The metal vibrating plate 13 is made of 42 alloy or the like, and its size and shape are larger than the piezoelectric ceramic plate 12 by about 2 mm in diameter, for example, 8.5 to 9.0 mm in diameter × 0.
It shall be a disc or square plate with a size of about 08 mm. The metal vibrating plate 13 and the piezoelectric ceramic plate 12 are electrically connected to the electrodes of the piezoelectric ceramic plate 12 by an epoxy or acrylic adhesive or the like, and are mounted on the case body 2 when the piezoelectric ceramic is placed. The plate 12 is adhered to the bottom side of the recess 6.

The spring terminal 4 is an elongated conductive member made of a metal having a spring property such as phosphor bronze plated with Ag, and its main part is provided on the bottom surface of the recess 6 of the case body 2. It is placed in the groove 8 and is disposed between the case body 2 and the piezoelectric ceramic plate 12 of the piezoelectric vibrating plate 3, and is located on the inner surface of the case body 2, that is, the bottom surface of the recess 6 and the main surface of the piezoelectric ceramic plate 12. It is in elastic contact with one of the electrodes due to the elasticity of the material and shape.

At the end of the spring terminal 4, the other connecting terminal 15 is formed by bending the connecting terminal fitting portion 11 of the case body 2 into a structure. The other end has a shape in which the tip portion 16 that contacts the electrode of the piezoelectric ceramic plate 12 is divided into two parts, and the vicinity of the center of the main portion of the spring terminal 4 contacts the bottom surface of the recess 6 of the case body 2. As a result, elastic contact is made between the electrode and the bottom surface. With such a shape, reliable contact can be obtained with an appropriate spring pressure, which is preferable.

The shape of the spring terminal 4 in the piezoelectric speaker 1 of the present invention is not limited to that shown in FIG. 1 and FIG.
16 may be brought into contact with the bottom surface of the concave portion 6, and the vicinity of the center of the main portion may be brought into contact with the electrodes of the piezoelectric ceramic plate 12.

In assembling the piezoelectric sounding body 1 having the above-mentioned structure, first, the connection terminal fitting portion 11 of the case body 2 is fitted with the connection terminal 15 of the spring terminal 4, and the main portion of the spring terminal 4 is a case. It is assembled so as to enter the groove 8 on the bottom surface of the concave portion 6 of the body 2.

Next, after applying an adhesive such as silicone resin or epoxy resin to the step portion 5 of the case body 2, the piezoelectric vibrating plate 3 is placed on the step portion 5. At this time, the connection terminals 14 formed on the peripheral edge of the metal diaphragm 13 are fitted to the connection terminal fitting portion 10 of the case body 2 and assembled. In addition, metal diaphragm
A gap 17 is secured between 13 and the connection terminal 15 side of the spring terminal 4 so that they do not come into contact with each other.

Then, an adhesive such as a silicone resin or an epoxy resin is applied so that the piezoelectric vibrating plate 3 is fixed to the step portion 5 of the case body 2, and the adhesive is cured by heat treatment or the like.

The piezoelectric sounding body 1 assembled in this way is not only very thin and small, but also the connection terminals 14 and 15 to be fitted into the case body 2 are formed as shown in FIG. The external circuit (driving circuit) is connected to the side surface of the body 2 from the side surface to the bottom surface by soldering the lead wire to the side surface or the side surface or the mounting surface to the mounting board. Alternatively, various connection methods such as pressure contact connection by contact on the lower surface can be supported.

The piezoelectric sounding body 1 of the present invention produced as described above is covered with a cap case having a predetermined cavity so as to cover the piezoelectric vibrating plate 3, and the case body 2 is covered with a single piezoelectric buzzer. Can be
Such an example is shown in an exploded view in FIG.

In FIG. 3, 1 is a piezoelectric sounding body of the present invention, and 19 is a cap case.

In the example of FIG. 3, the cap case 19 has a cylindrical shape in accordance with the shape of the piezoelectric vibrating plate 3, but the outer shape may be rectangular or round. This cap case
19 is made by ABS or PBT.

A predetermined cavity 20 is formed inside the cap case 19, and the cavity 20 and the sound emitting hole 21 provided on the upper surface of the cap case 19 cause a cavity resonance in the cavity 20 to generate a large noise. It can output pressure. And their shape, size, position, etc.
Various types can be designed and combined according to the desired resonance frequency. Further, on the side surface of the cap case 19, the step portion 9 of the case body 2 is fitted and
Claws 22 for attaching 19 are provided at positions corresponding to the respective step portions 9, and by this, the cap case 19 and the case body 2 are integrally assembled to form a single piezoelectric buzzer.

Further, since the piezoelectric sounding body 1 of the present invention is extremely thin and small as described above, a predetermined cavity similar to the cap case 19 is formed on the set body side of a device incorporating the piezoelectric sounding body 1. Then, by fitting the piezoelectric sounding body 1 therein, it is possible to form a built-in piezoelectric buzzer having a very small installation space.

[0036]

As described above, according to the present invention, the piezoelectric vibrating plates are placed on the case body, the spring terminals arranged between them are elastically contacted with each other, and one of the pair of connecting terminals is connected to the piezoelectric plate. By forming the other end of the vibrating plate on the edge of the metal vibrating plate and the end of the spring terminal so that each connecting terminal fits into the case body, a very thin and compact piezoelectric sounding body is provided. We were able to.

Further, according to the present invention, it is possible to form a single piezoelectric buzzer by covering the case body with the cap case, and a predetermined cavity is formed on the set body side of the device and fitted into the cavity. As a result, it was possible to provide a piezoelectric sounding body with excellent versatility, which can be used as a built-in piezoelectric buzzer with a very small installation space.

Further, according to the present invention, a piezoelectric sounding body can be adapted to various frequencies by changing the size and shape of the cap case, and the piezoelectric buzzers having different frequencies can be unified in the product lineup. Could be provided.

Furthermore, according to the piezoelectric sounding body of the present invention,
Since the connection terminals are fitted to the case body and wrap around the side surface or the lower surface of the case body so as to be along those surfaces, the connection with the external circuit (driving circuit) is performed on the mounting board on the side surface or the lower surface. It has become possible to support various connection methods such as soldering to, pressure contact connection by contact, and soldering of lead wires.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a piezoelectric speaker according to the present invention.

FIG. 2 is a top view showing an embodiment of a piezoelectric speaker according to the present invention.

FIG. 3 is an exploded view showing an embodiment of the piezoelectric speaker of the present invention.

[Explanation of symbols]

 1 Piezoelectric Sounder 2 Case 5 Stepped portion 3 Piezoelectric vibrating plate 12 Piezoelectric ceramic plate 13 Metal vibrating plate 14 One connection terminal 4 Spring terminal 15 The other connection terminal

Claims (1)

[Claims] 1. A piezoelectric vibrating plate formed by adhering a piezoelectric vibrating plate having electrodes formed on both main surfaces to a metal vibrating plate, and a case body having a stepped portion on which the piezoelectric vibrating plate is mounted. A spring terminal that is disposed between the case body and the piezoelectric vibrating plate and is in elastic contact with the inner surface of the case body and one of the electrodes; and one connecting terminal on the periphery of the metal vibrating plate. A piezoelectric sounding body, characterized in that the other connection terminal is formed at an end of the spring terminal, and both connection terminals are fitted into a case body.