JPH0419918Y2 - - Google Patents

Description

[Detailed description of the invention] "Purpose of the invention" (Field of industrial application) The present invention relates to a piezoelectric speaker, and particularly to a speaker whose drive source is an actuator made of stacked piezoelectric elements, which can be easily configured and assembled. Regarding the speakers.

(Conventional technology) Conventionally, piezoelectric speakers are shown in Fig. 2 A and B.
As shown in FIG.
Alternatively, a dome-shaped diaphragm 23 or the like is directly attached and the diaphragm is driven by the piezoelectric element 21, or as shown in FIG. 2C, both ends 24a of the piezoelectric film 24 are fixed and the piezoelectric film 24 is energized. There are devices that use the film as a diaphragm by utilizing the principle that the film expands by doing so.

However, in general, piezoelectric elements themselves have shortcomings such as low sound pressure and can only be used in a narrow frequency band due to their low performance. A device equipped with a diaphragm has also been proposed.

(Problems to be solved by the invention) However, since the above-mentioned drive arm mechanism is one in which the fixing part and the drive arm part are integrally molded and the thin hinge part is used as a support fulcrum, it is structurally and molded technically. It becomes complicated and has the disadvantage that an ideal drive arm mechanism cannot be realized especially when multiple stages of drive arm sections are provided.Also, the amplification degree increases as the drive arm section reaches the final stage. Therefore, there was a risk that material fatigue would occur in the thin hinge portion and the supporting fulcrum would break.

The purpose of this invention is to eliminate the above-mentioned conventional drawbacks,
It is an object of the present invention to provide a piezoelectric speaker in which a drive arm part can be easily assembled, an ideal drive arm mechanism can be obtained, and a support fulcrum is not likely to be damaged.

"Structure of the invention" (Means for solving the problems) A piezoelectric speaker according to the invention uses an actuator made of stacked piezoelectric elements as a drive source, and is designed to amplify the movement of the actuator. A drive arm mechanism is arranged in the drive arm mechanism, and the drive arm mechanism is constructed by arranging a plurality of drive arm members each consisting of independent parts each having a support fulcrum for utilizing the lever principle. be.

(Function) An actuator made of stacked piezoelectric elements is used as a drive source, and the movement of this piezoelectric element is amplified by a drive arm mechanism and acoustically converted by a diaphragm attached to the drive arm. In other words, it is constructed by assembling a plurality of drive arm members made up of independent parts each having a support fulcrum for utilizing the lever principle. In this case, each drive arm member is easy to manufacture and easy to assemble, and there is no fear that the supporting fulcrum of each drive arm member will be damaged due to material fatigue or the like.

(Example) An example of a piezoelectric speaker according to the present invention will be described based on FIG. 1, which shows a cross-sectional view.

In the figure, 1 indicates the entire piezoelectric speaker,
The drive source is an actuator 2 made of stacked piezoelectric elements, and is composed of a fixed frame 3, a drive arm mechanism 4 disposed on the fixed frame 3, and a diaphragm 5.

The drive arm mechanism 4 is constructed by superimposing drive arm members 6, 7, and 8 that move on a lever principle in order to sequentially amplify the movement of the actuator 2. The actuator 2 is disposed between the fixed frame 3 and the fixed frame 3 . These drive arm parts 6, 7, 8
are formed of independent parts, and also serve as a knife edge portion and a receiving portion.
0, 11, 12, and 13.

That is, the lowermost (frontmost) drive arm section 6 has a knife edge section 6a protruding near the position of the actuator 2, which abuts a receiving section 3a provided on the fixed frame 3, and a knife edge section 6a on the tip side. A knife edge portion 6b is formed and abuts on a receiving portion 7a formed on the proximal end side of the drive arm portion 7.

A receiving portion 7b is formed on the upper surface of the proximal side of the drive arm portion 7 to be disposed in the middle stage, slightly shifted from the receiving portion 7a, and a knife edge portion 3b protruding from one end of the fixed frame 3. Is receiving.
Further, a knife edge 7c is formed on the distal end side of the drive arm portion 7, and abuts on a receiving portion 8a formed at the base end portion of the drive arm portion 8. A receiving portion 8b is formed on the upper surface side of the drive arm portion 8 at a slightly shifted position from the receiving portion 8a, and receives a knife edge portion 3c projecting from the other end of the fixed frame 3. A rising portion 18 is provided at the tip of the drive arm portion 8, and a diaphragm mounting portion 14 is formed thereon, and an anti-arch shaped portion is formed between it and the other diaphragm mounting portion 15 formed on the fixed frame 3. A diaphragm 5 is attached.

In order to prevent the support fulcrums 9, 11, and 13 from separating, the fixed frame 3 and the drive arms 6, 7 are provided with hooks 19 as shown in the figure, and a spring 20 is applied to the hooks 19.

To describe an example of its operation based on the above-described configuration, when the actuator 2 is energized, it extends;
This movement is transmitted to the drive arm part 6 supported by the support fulcrum 9, and the movement of this drive arm part 6 is transmitted to the drive arm part 7 supported by the support fulcrums 10 and 11. The movement of part 7 is transmitted to 8 supported by support fulcrums 12 and 13, and vibrates the diaphragm 5 attached to the tip side of 8.

"Effect of the invention" According to the piezoelectric speaker according to the invention, an actuator made of stacked piezoelectric elements is used as a driving source,
The sound is amplified by the drive arm mechanism and converted by the diaphragm attached to the final stage drive arm, but the drive arm mechanism is made up of independent parts each having a support fulcrum to utilize the lever principle. Since the drive arm member is constructed by assembling a plurality of stages of drive arm members, each drive arm member is easy to manufacture and easy to assemble. In addition, there is no risk that the supporting fulcrum of each drive arm member will be damaged due to material fatigue, etc., so it is possible to create a piezoelectric speaker with a large amplitude.
The advantages of a speaker using piezoelectric elements can be fully demonstrated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a piezoelectric speaker according to the present invention. Figures 2A to C show examples of conventional piezoelectric speakers, where A is a sectional view of an example in which a cone-shaped diaphragm is attached to a piezoelectric element, and B is a side view of an example in which a dome-shaped diaphragm is attached to a piezoelectric element. , C is a side view showing an example of a configuration in which a piezoelectric film is used as a diaphragm by fixing both ends of the film and applying electricity to the film. DESCRIPTION OF SYMBOLS 1... Entire piezoelectric speaker, 2... Actuator, 3... Fixed frame, 4... Drive arm mechanism, 5... Vibration plate, 6, 7, 8... Drive arm portion, 9-13... Support fulcrum .

Claims (1)

[Claims for Utility Model Registration] 1. In a piezoelectric speaker whose drive source is an actuator formed by laminating piezoelectric elements, a drive arm mechanism is disposed to amplify the movement of the actuator, and the drive arm mechanism is equipped with a lever. 1. A piezoelectric speaker characterized in that it is constructed by arranging a plurality of drive arm members each made up of independent parts each having a support fulcrum for utilizing the principle of the above. 2. The piezoelectric speaker according to claim 1, wherein the support fulcrum has a knife edge bearing structure. 3. The piezoelectric speaker according to claim 1 of the utility model registration, characterized in that a spring is disposed to prevent the support fulcrum from separating.