JPH062898U - Piezoelectric electroacoustic transducer - Google Patents

Abstract

(57) [Summary] [Construction] The case 12 is formed of a conductive thin plate, and the piezoelectric ceramic plate 11 is adhered to the case 12.
2 is configured so as to act as a resonance chamber 16, a recess 14 is formed on the entire circumference of the side surface of the case 12, and an O-ring 15 is fitted in the recess 14. A piezoelectric electroacoustic transducer. . [Effect] By fitting the O-ring 15 fitted in the case 12 into the groove portion 19a formed in the attached device 18a, the piezoelectric electroacoustic transducer 10 is simply and reliably attached and fixed to the attached device 18a. You can
Further, the O-ring 15 can prevent moisture from entering from the outside. Furthermore, in addition to the resonance chamber 16 formed inside the piezoelectric electroacoustic transducer 10, a new acoustic space 17 can be formed between the device 18a and the case 12, thus further increasing the sound pressure. You can

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a piezoelectric electroacoustic transducer using a piezoelectric ceramic plate.

[0002]

[Prior art]

 FIG. 3 is a schematic cross-sectional view showing a conventional piezoelectric electroacoustic transducer and the vicinity of a mounting portion of a device to which the piezoelectric electroacoustic transducer is attached. In the figure, 11 indicates a piezoelectric ceramic plate. The piezoelectric ceramic plate 11 is adhered to a conductive thin plate 22 formed of, for example, a metal plate, and the conductive thin plate 22 is made of resin using an adhesive 25 such as an epoxy resin having excellent adhesive strength and water resistance. The piezoelectric ceramic acoustic plate 11, the conductive thin plate 22, and the case 23 are bonded to the inside of a case 23 made of a piezoelectric ceramic acoustic transducer 20. The outer surface of the upper part of the case 23 and the mounting surface of the device 28 to be mounted are adhered by an adhesive 25 so as to prevent moisture from entering (hereinafter referred to as a watertight state).

[0003]

[Problems to be solved by the device]

 In the above-described conventional piezoelectric electroacoustic transducer, it is necessary to bond the conductive thin plate 22 and the case 23, and the case 23 and the device 28 with the adhesive 25 so as to be watertight. Therefore, there is a problem in that the adhesive 25 is applied uniformly over the entire bonding portion, the bonding surface is closely attached to the bonding portion 25, and the adhesive 25 is held until the adhesive 25 is hardened. It was

There is also a problem that moisture may enter the inside of the device if the adhesion is not sufficient even a little.

The present invention has been made in view of the above problems, and a piezoelectric electroacoustic transducer that can be easily and watertightly mounted on a device requiring waterproofing without using an adhesive. Is intended to provide.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the piezoelectric electroacoustic transducer according to the present invention has a case formed of a conductive thin plate, and a piezoelectric ceramic plate is adhered to the case so that the whole case acts as a resonance chamber. In the piezoelectric electroacoustic transducer configured as described above, the case is characterized in that a recess is formed around the entire side surface of the case, and an O-ring is fitted in the recess.

[0007]

[Action]

 There is a small and light hollow cylindrical object and a frame body having an opening slightly larger than the outer diameter of the cylindrical body, and a concave portion is formed on the entire circumference of the side surface of the cylindrical object. Fit a rubber O-ring of specified thickness. When the cylindrical object is fitted into the opening of the frame, the O-ring elastic repulsive force causes the O-ring and the recess of the cylindrical object and the opening of the frame to come into close contact with each other without a gap, resulting in a watertight state. In addition, the columnar object and the frame body are fixed via an O-ring.

According to the piezoelectric electroacoustic transducer of the present invention, since a small and light hollow cylindrical case has a concave portion formed on the entire side surface and an O-ring is fitted in the concave portion, it is waterproof. It will be possible to easily and watertightly attach to equipment that requires it without using an adhesive.

[0009]

【Example】

 Embodiments of a piezoelectric electroacoustic transducer according to the present invention will be described below with reference to the drawings. It should be noted that components having the same functions as those of the conventional example are designated by the same reference numerals.

FIG. 1 is a cross-sectional view schematically showing a piezoelectric electroacoustic transducer according to an embodiment and the vicinity of a mounting portion of a device to which the piezoelectric electroacoustic transducer is attached. A piezoelectric ceramic plate having an outer diameter of about 10 mm and a thickness of about 0.1 mm with electrodes (not shown) formed on the surface is shown. This piezoelectric ceramics plate 11 is bonded to an inner central flat part of a case 12 having an outer diameter of about 14 mm and a height of about 2 mm formed by bending an edge portion of an iron-nickel alloy plate having a thickness of about 0.05 mm. Has been done. A recess 14 having a semicircular cross section with a radius of about 0.3 mm is formed on the entire circumference of the side surface of the case 12, and the recess 14 has a rubber O-ring 15 with an inner diameter of about 13.5 mm and a thickness of about 1.5 mm. Are fitted. On the side of the case 12 facing the piezoelectric ceramics plate 11, a lid 13 made of an iron-nickel alloy plate having a thickness of about 0.05 mm is bonded at the lower peripheral edge of the case 12 so as to form a resonance chamber 16. The piezoelectric type electroacoustic transducer 10 is constituted by the piezoelectric ceramic plate 11, the case 12 and the lid 13 which are fixed. On the other hand, in the attached device 18a, a groove portion 19a having a width of about 0.6 mm, a depth of about 0.3 mm, and a bottom surface of a diameter of about 16.2 mm and having a U-shaped cross section is formed at a position facing the recess 14 of the case 12. .

When the piezoelectric electroacoustic transducer 10 configured as described above is attached to the device 18a, the O-ring 15 fitted to the case 12 is fitted into the groove portion 19a formed in the device 18a. The piezoelectric electroacoustic transducer 10 can be easily and reliably fixed to the device 18a, and the O-ring 15 can prevent the intrusion of moisture from the outside.

Further, in addition to the resonance chamber 16 formed inside the piezoelectric electroacoustic transducer 10, a new acoustic space 17 can be formed between the device 18 a and the case 12, so that the sound pressure is reduced. It can be further enhanced.

FIG. 2 is a cross-sectional view schematically showing a piezoelectric electroacoustic transducer according to another embodiment and the vicinity of a mounting portion of a device to which the piezoelectric electroacoustic transducer is attached. 2 shows a piezoelectric electroacoustic transducer configured similarly to the example. The attached device 18b of the piezoelectric electroacoustic transducer 10 has an L-shaped cross section with a width of about 1.5 mm, a depth of about 0.3 mm, and a bottom diameter of about 16.2 mm at a position facing the recess 14 of the case 12. The groove portion 19b is formed.

When the piezoelectric electroacoustic transducer 10 configured as described above is attached to the device 18b, the O-ring 15 fitted to the case 12 is fitted into the groove portion 19b formed in the device 18b. As in the case of the embodiment, the piezoelectric electroacoustic transducer 10 can be simply and reliably fixed to the device 18b, and the O-ring 15 can prevent moisture from entering from the outside.

[0015]

[Effect of device]

 As described above in detail, in the piezoelectric electroacoustic transducer according to the present invention, the O-ring fitted in the case is fitted into the groove formed in the device to be attached, thereby easily and reliably The piezoelectric electroacoustic transducer can be attached and fixed, and the O-ring can prevent moisture from entering from the outside.

Further, in addition to the resonance chamber formed inside the piezoelectric electroacoustic transducer, a new acoustic space can be formed between the mounting device and the case, so that the sound pressure is further increased. Can be increased.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing the vicinity of a mounting portion of a piezoelectric electroacoustic transducer and an attached device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing the vicinity of a mounting portion of a piezoelectric electroacoustic transducer and an attached device according to another embodiment.

FIG. 3 is a cross-sectional view schematically showing the vicinity of a mounting portion of a conventional piezoelectric electroacoustic transducer and an attached device.

[Explanation of symbols]

 10 Piezoelectric Electroacoustic Transducer 11 Piezoelectric Ceramics Plate 12 Case 14 Recess 15 O-ring

Claims (1)

[Scope of utility model registration request] 1. A piezoelectric electroacoustic transducer in which a case is formed of a conductive thin plate, a piezoelectric ceramics plate is adhered to the case, and the whole case acts as a resonance chamber. A piezoelectric electroacoustic transducer characterized in that a concave portion is formed on the entire circumference of a side surface portion, and an O-ring is fitted in the concave portion.