JPS6127274Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a piezoelectric acoustic device typified by a piezoelectric speaker.

An example of an existing piezoelectric speaker is shown in FIG. In the same figure, 1 is a piezoelectric diaphragm made by bonding a piezoelectric material plate such as ceramics to a metal plate, 2 is a conical paper cone whose top is adhesively fixed to the center of the diaphragm 1, and 3 is a piezoelectric diaphragm made by bonding a piezoelectric material plate such as ceramics to a metal plate; A frame 4, 4, which holds the outer periphery of the cone paper 2 and the periphery of the piezoelectric diaphragm 1, is a terminal fixed to the frame 3, and electricity is connected to the piezoelectric diaphragm 1 via flexible wires 5, 5. It is connected to the target. The flexible wires 5, 5 and the piezoelectric diaphragm 1 are connected to each other by soldering 6, 6.

By applying an electrical signal to terminals 4, 4,
This signal is applied to the piezoelectric diaphragm 1 via the flexible wires 5, 5, and the diaphragm 1 makes a unique mechanical vibration due to the electrostrictive effect. This vibration is transmitted to the paper cone 2 via the central joint, converted into air vibration, and radiated into the air as a sound wave.

In a speaker with such a configuration, the flexible wires 5, 5 are indispensable as a means of transmitting electrical signals from the terminals 4, 4 to the piezoelectric diaphragm 1, and therefore the soldering 6, 6 is also indispensable. is an element of However, the soldering process 6, 6 is the most difficult to put into practical use, and there are problems in the manufacturing process, and there is also the problem of partial polarization deterioration caused by the heat applied to the piezoelectric diaphragm 1 during soldering. It was a problem that could not be avoided.

In addition, in the manufacturing process of such speakers,
In order to hold the periphery of the piezoelectric diaphragm 1, the frame 3 and the periphery of the piezoelectric diaphragm 1 are usually bonded together with an adhesive, but such an adhesion process has also been a factor hindering automation.

The present invention was devised in view of these problems, and will be described in detail with reference to FIG. 2 and subsequent figures.
1, 2, and 3 indicate a piezoelectric diaphragm, a conical paper cone, and a frame as in FIG. The piezoelectric diaphragm 1 has a locking piece 8 erected from the bottom wall 7 of the frame 3,
8, 8 and are held flexibly through a flexible material film 9. The flexible material film 9 is made of foamed urethane foam, foamed polyethylene, Moltoprene, or viscolloid paint, and has a thickness of 1 to 2.
mm is used, and this is provided on the back side of the piezoelectric diaphragm 1. The shape of this material film 9 has a through hole 10 in the center and notches 11, 11, 11 on the outer periphery. 12,1
2 is bent and stands up, and is interposed between each of the locking pieces 8, 8, and the periphery of the piezoelectric diaphragm 1, so that the diaphragm 1 is not adhesively fixed and the flexible material film 9 is It remains soft due to its elasticity. The top of the conical paper cone 2 is bonded to the center of the piezoelectric diaphragm 1, as in the case of FIG. 1, and its outer periphery is fixed to the outer edge of the frame 3. Reference numerals 13 and 13 denote fitting bodies that fit into recesses 15 and 15 provided in the side wall 14 of the frame 3, and are made of an insulating material, and conductive tongue pieces 16 and 16 made of a highly elastic material such as phosphor bronze are inserted thereinto. There is. The inside of the frame 3 of the conductive tongues 16, 16 is curved so as to obtain elastic force, and is in contact with the front and back surfaces of the piezoelectric diaphragm 1 at 11 notches in the flexible material film 9. Electric signal terminals 17, 17 are configured on the outside. Incidentally, the points where the conductive tongues 16, 16 come into contact with the piezoelectric diaphragm 1 are preferably vibration nodes of the diaphragm 1 so as not to interfere with the vibration of the diaphragm 1.

By supplying an electrical signal to the electrical signal terminals 17, 17, the electrical signal is transmitted to the piezoelectric diaphragm 1 via the conductive tongues 16, 16, and the diaphragm 1 vibrates in accordance with the signal. and is emitted from the cone paper 2 as a sound wave.

As is clear from the above description, the piezoelectric acoustic device of the present invention has a single flexible material film having a plurality of protrusions and notches on the periphery on the back side of the piezoelectric diaphragm. The piezoelectric diaphragm can be held flexibly by interposing each protrusion of the material film between each locking piece planted from the frame and the peripheral portion of the piezoelectric diaphragm, and the flexible material film It becomes possible to supply power to the piezoelectric diaphragm through the conductive tongue piece placed at the notch position.

Therefore, not only can the piezoelectric diaphragm be held flexibly and reliably without the need for an adhesive process, but also power can be supplied to the piezoelectric diaphragm without the need for soldering of flexible wires, which was previously required.
The configuration can be simplified and assembly can be easily automated. Moreover, there is no fear of polarization deterioration of the piezoelectric diaphragm due to conventional soldering of flexible wires.

Although the present invention has been described using a piezoelectric speaker as an example, it goes without saying that the invention is not limited to speakers and can be applied to other acoustic devices such as buzzers.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the conventional structure, Fig. 2 is a cross-sectional view of the device of the present invention, Fig. 3 is a top view of the main parts thereof, and Fig. 4 is an exploded perspective view thereof. 2 is a cone paper, 3 is a frame, 8 is a locking piece, 9 is a flexible material layer, and 16 is a conductive tongue piece.

Claims (1)

[Scope of utility model registration request] The periphery of one piezoelectric diaphragm is held by a plurality of locking pieces raised from the frame, and a pair of conductive tongue pieces are provided protruding from the frame, and these conductive tongue pieces are attached to both the front and back sides of the piezoelectric diaphragm. A piezoelectric acoustic device that supplies power to a piezoelectric diaphragm by contact with the piezoelectric diaphragm, wherein a flexible material film having a plurality of protrusions and notches on the periphery is provided on the back side of the piezoelectric diaphragm; A plurality of protrusions of the flexible material film are interposed between the plurality of locking pieces and the peripheral portion of the piezoelectric diaphragm, and the conductive tongue piece is arranged at the notch position of the flexible material film. A piezoelectric acoustic device featuring: