JPS6228160Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to damping of a piezoelectric speaker, particularly a piezoelectric vibrator.

In a conventional piezoelectric speaker using a piezoelectric vibrator as a driving source, damping of resonance of the piezoelectric vibrator is configured as shown in FIG.

That is, a braking plate 3 having a diameter larger than the diameter of the circular through hole 4a and a piezoelectric vibrator 2 having a diameter smaller than the diameter of the through hole 4a are stacked at the center of the bottom surface of the frame 4 in the shape of an inverted truncated cone with a bottom, and the piezoelectric vibrators are stacked. The top of the cone-shaped diaphragm 1 was connected to the center of the upper surface of the child 2, and the peripheral edge of the diaphragm 1 was adhered to the frame to perform electrical and acoustic conversion. In a piezoelectric speaker with such a configuration, the Q of each order of resonance can be lowered by the damping plate 3, but when assembling the piezoelectric speaker in mass production, the damping plate 3, piezoelectric vibrator 2, It is difficult to accurately assemble the diaphragms 1 in a predetermined mutual positional relationship, and the mutual positional relationship often becomes out of order, resulting in slight stress on the brake plate. This minute stress often corresponds to the region A of the stress-strain curve of the brake plate 3 shown in Fig. 3, and this region A corresponds to the curved part of the stress-strain curve, so it causes harmonics in the reproduced sound pressure. It had the disadvantage of causing distortion and, in turn, variations in quality.

This invention eliminates the above-mentioned conventional drawbacks.

Examples of this invention are shown in Figures 2 and 3 of the drawings below.
This will be explained with figures.

FIG. 2 shows an embodiment of this invention. Reference numeral 12 denotes a disk-shaped piezoelectric vibrator. The top of a cone-shaped diaphragm 11 is adhesively bonded to the center of the upper surface of the piezoelectric vibrator 12, and the diameter of the piezoelectric vibrator 12 is bonded to the lower surface of the piezoelectric vibrator 12. Strip-shaped brake plate 1 with larger dimensions
3 are adhesively bonded to each other, and these are attached to the cup-shaped frame 1.
A bending stress is applied to both ends of the rectangular braking plate 13 in the inside of the cup-shaped frame 14 to lock it to the inner surface of the cup-shaped frame, and the peripheral edge of the cone-shaped diaphragm 11 is attached to the edge of the cup-shaped frame 14 for storage. It has been done. Therefore, the bending stress at both ends of the strip-shaped brake plate 13 passes through the region A of minute strain in the stress strain curve of the brake plate shown in FIG. 3, and does not reach the region C showing plastic deformation due to rubber elastic deformation. Set to the range of area B that indicates.

In this way, when the bending stress is set at both ends of the strip-shaped damping plate 13 within the range B that shows rubber elastic deformation, the strip-shaped damping plate 13 will be applied to the disc-shaped piezoelectric vibrator 1
The sound pressure reproduction frequency characteristics are flattened by lowering the Q value of each order of resonance. Since the bending stress at both ends of the strip-shaped damping plate 13 is within a wide range of rubber elastic deformation, the occurrence of harmonic distortion caused by the strip-shaped braking plate 13 can be eliminated, and as a result, a high-quality piezoelectric speaker can be produced. Can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a piezoelectric speaker as a conventional example, and FIG. 2 is a sectional view and a plan view of the piezoelectric speaker of this invention. Fig. 3 is a stress strain curve diagram of a brake plate, 11... cone-shaped diaphragm, 12... disk-shaped piezoelectric vibrator, 13... strip-shaped brake plate, 14... cup-shaped frame.

Claims (1)

[Scope of utility model registration request] In a piezoelectric speaker in which the periphery of a cone-shaped diaphragm is suspended within a cup-shaped frame, and the center portion of a disk-shaped piezoelectric vibrator is fixed to the top of the diaphragm, the bottom surface of the disk-shaped piezoelectric vibrator is A piezoelectric speaker characterized in that a rectangular braking plate having a size larger than the diameter of the piezoelectric vibrator is fixed, and the braking plate is locked or fixed to the frame by applying bending stress to both ends of the braking plate.