阅读说明：本技术 一种安防报警器及其制作方法 (Security alarm and manufacturing method thereof ) 是由 商亚锋 于 2019-11-07 设计创作，主要内容包括：本发明涉及一种安防报警器,包括壳体以及盖板,所述壳体的一端设有发音孔,另一端与盖板固定连接,所述壳体与盖板合围形成发音腔,所述壳体内固定有压电片,所述压电片将发音腔分隔成前腔与后腔,所述发音孔与前腔连通,所述盖板上固定有线路板,所述线路板设有伸出壳体的外接引线,所述线路板上固定有与压电片连接的引线,所述压电片上朝向发音孔的一面刻有调音槽,所述调音槽呈“B”形,所述调音槽的深度为0.1-0.15mm,调音槽的面积为24.5-25mm2,本发明能够实现在产品组装完成后对频率的调整,避免产生机械挤压和机械应力,不影响产品本身。(The invention relates to a security alarm, which comprises a shell and a cover plate, wherein one end of the shell is provided with a sound emitting hole, the other end of the shell is fixedly connected with the cover plate, the shell and the cover plate surround to form a sound emitting cavity, a piezoelectric sheet is fixed in the shell, the sound emitting cavity is divided into a front cavity and a rear cavity by the piezoelectric sheet, the sound emitting hole is communicated with the front cavity, a circuit board is fixed on the cover plate, the circuit board is provided with an external lead extending out of the shell, a lead connected with the piezoelectric sheet is fixed on the circuit board, a tuning groove is engraved on one surface of the piezoelectric sheet facing the sound emitting hole, the tuning groove is in a 'B' shape, the depth of the tuning groove is 0.1-0.15mm, and the area of the tuning groove is 24.5-25mm 2.)

1. The utility model provides a security alarm which characterized in that: the sounding device comprises a shell and a cover plate, wherein a sounding hole is formed in one end of the shell, the other end of the shell is fixedly connected with the cover plate, a sounding cavity is formed by encircling the shell and the cover plate, a piezoelectric sheet is fixed in the shell and divides the sounding cavity into a front cavity and a rear cavity, the sounding hole is communicated with the front cavity, a circuit board is fixed on the cover plate, an external lead extending out of the shell is arranged on the circuit board, a lead connected with the piezoelectric sheet is fixed on the circuit board, a tuning groove is formed in one surface, facing the sounding hole, of the piezoelectric sheet in a B shape, the depth of the tuning groove is 0.1-0.15mm, and the area of the tuning groove is 24.5-25mm 2.

2. The security alarm of claim 1, wherein: the depth of the tuning groove is 0.13mm, and the area of the tuning groove is 24.75mm 2.

3. A manufacturing method of a security alarm is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

step 1, fixedly mounting a piezoelectric patch in a shell, fixedly mounting a circuit board on a cover plate, connecting a piezoelectric patch welding lead with the circuit board, and welding the circuit board with an external lead extending out of the shell;

step 2, fixing the cover plate on the shell to obtain a product;

step 3, passing laser through the sound emitting hole to the piezoelectric plate, scanning the laser on the piezoelectric plate to form a B-shaped tuning groove, wherein the depth of the tuning groove is 0.1-0.15mm, and the area of the tuning groove is 24.5-25mm 2;

and 4, carrying out frequency test on the product, and if the vibration frequency of the piezoelectric plate is too low, continuing to deepen the depth of the tuning groove through laser scanning, so as to improve the vibration frequency of the piezoelectric plate until the resonance frequency of the product is controlled to be F0 +/-150 HZ.

4. The manufacturing method of the security alarm according to claim 3, wherein the manufacturing method comprises the following steps: in the step 3, the depth of the tuning groove is 0.13mm, and the area of the tuning groove is 24.75mm 2.

Technical Field

The invention relates to the field of buzzers, in particular to an anti-security alarm and a manufacturing method thereof.

Background

The security alarm is generally made of a buzzer, the traditional buzzer is influenced by accumulated tolerance of a piezoelectric ceramic piece process and various materials, the resonance frequency of the manufactured buzzer is F0 +/-300 Hz, the consistency of sound pressure is poor, the adjustment frequency of the traditional piezoelectric piece is different according to the mode of supporting a piezoelectric piece vibration plate, the total thickness of the piezoelectric piece is changed to adjust the frequency in a lifting mode, the mode can be only carried out before the piezoelectric piece is installed, if the piezoelectric piece still needs to be continuously debugged after being installed, the piezoelectric piece needs to be detached, time and labor are wasted, the safety alarm is inconvenient, mechanical extrusion and mechanical stress are easily generated, and the performance of a product is influenced.

Disclosure of Invention

The invention aims to provide a security alarm which can effectively and quickly adjust the frequency of a piezoelectric plate, avoid mechanical extrusion and mechanical stress and does not influence the product and a manufacturing method thereof.

The technical scheme for realizing the purpose of the invention is as follows:

a security alarm comprises a shell and a cover plate, wherein one end of the shell is provided with a sounding hole, the other end of the shell is fixedly connected with the cover plate, the shell and the cover plate are surrounded to form a sounding cavity, a piezoelectric sheet is fixed in the shell and divides the sounding cavity into a front cavity and a rear cavity, the sounding hole is communicated with the front cavity, a circuit board is fixed on the cover plate, the circuit board is provided with an external lead extending out of the shell, a lead connected with the piezoelectric sheet is fixed on the circuit board, a tuning groove is carved on one surface of the piezoelectric sheet facing the sounding hole, the tuning groove is B-shaped, the depth of the tuning groove is 0.1-0.15mm, and the area of the tuning groove is 24.5-25mm 2.

After the structure is adopted, after the product is assembled, the laser penetrates through the sounding hole to sweep out the B-shaped tuning groove from the back of the piezoelectric sheet, so that the local thickness of the piezoelectric sheet is reduced, the frequency of the piezoelectric sheet is improved, the frequency of the piezoelectric sheet is close to or even identical to that of the sounding cavity, the resonant frequency of the product is controlled to be F0 +/-150 HZ, and the integral sound pressure of the product is improved.

Preferably, in order to optimize the resonant frequency of the product, the tuning groove has a depth of 0.13mm and an area of 24.8mm 2.

A manufacturing method of a security alarm comprises the following steps,

step 1, fixedly mounting a piezoelectric patch in a shell, fixedly mounting a circuit board on a cover plate, connecting a piezoelectric patch welding lead with the circuit board, and welding the circuit board with an external lead extending out of the shell;

step 2, fixing the cover plate on the shell to obtain a product;

step 3, passing laser through the sound emitting hole to the piezoelectric plate, scanning the laser on the piezoelectric plate to form a B-shaped tuning groove, wherein the depth of the tuning groove is 0.1-0.15mm, and the area of the tuning groove is 24.5-25mm 2;

and 4, carrying out frequency test on the product, and if the vibration frequency of the piezoelectric plate is too low, continuing to deepen the depth of the tuning groove through laser scanning, so as to improve the vibration frequency of the piezoelectric plate until the resonance frequency of the product is controlled to be F0 +/-150 HZ.

After the steps are adopted, the back of the piezoelectric sheet is swept by laser after the product is assembled, a B-shaped tuning groove is formed on the back of the piezoelectric sheet, the local thickness of the piezoelectric sheet is reduced, the frequency of the piezoelectric sheet is improved, the frequency of the piezoelectric sheet is close to or even identical to that of the sounding cavity, the resonant frequency of the product is controlled to be F0 +/-150 HZ, and the integral sound pressure of the product is improved.

Preferably, in order to improve the efficiency of frequency adjustment, the depth of the tuning groove in step 3 is 0.13mm, and the area is 24.75mm 2.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural diagram of a tuning slot of the present invention.

In the figure: the structure comprises a shell 1, a cover plate 2, a sounding hole 3, a front cavity 41, a rear cavity 42, a piezoelectric plate 5, a circuit board 6, a lead 7, a tuning groove 8 and an external lead 9.

Detailed Description

As can be seen from fig. 1 and 2, the security alarm of the present invention comprises a housing 1 and a cover plate 2, wherein one end of the housing is provided with a sounding hole 3, the other end of the housing is fixedly connected with the cover plate, the housing and the cover plate surround to form a sounding cavity, a piezoelectric plate 5 is fixed in the housing, the sounding cavity is divided into a front cavity 41 and a rear cavity 42 by the piezoelectric plate, the sounding hole is communicated with the front cavity, the cover plate is fixed with a circuit board 6, the circuit board is provided with an external lead 9 extending out of the housing, the circuit board is fixed with a lead 7 connected with the piezoelectric plate, a tuning groove 8 is engraved on one surface of the piezoelectric plate facing the sounding hole, the tuning groove is B-shaped, the depth of the tuning groove is 0.1-0.15mm, and the area of the tuning groove is 24.5-25mm 2.

After the structure is adopted, after the product is assembled, the laser penetrates through the sounding hole to sweep out the B-shaped tuning groove from the back of the piezoelectric sheet, so that the local thickness of the piezoelectric sheet is reduced, the frequency of the piezoelectric sheet is improved, the frequency of the piezoelectric sheet is close to or even identical to that of the sounding cavity, the resonant frequency of the product is controlled to be F0 +/-150 HZ, and the integral sound pressure of the product is improved.

Preferably, in order to optimize the resonant frequency of the product, the tuning groove has a depth of 0.13mm and an area of 24.75mm 2.

A manufacturing method of a security alarm comprises the following steps,

step 1, fixedly mounting a piezoelectric patch in a shell, fixedly mounting a circuit board on a cover plate, connecting a piezoelectric patch welding lead with the circuit board, and welding the circuit board with an external lead extending out of the shell;

step 2, fixing the cover plate on the shell to obtain a product;

step 3, passing laser through the sound emitting hole to the piezoelectric plate, scanning the laser on the piezoelectric plate to form a B-shaped tuning groove, wherein the depth of the tuning groove is 0.1-0.15mm, and the area of the tuning groove is 24.5-25mm 2;

and 4, carrying out frequency test on the product, and if the vibration frequency of the piezoelectric plate is too low, continuing to deepen the depth of the tuning groove through laser scanning, so as to improve the vibration frequency of the piezoelectric plate until the resonance frequency of the product is controlled to be F0 +/-150 HZ.

Preferably, in the step 3, the depth of the tuning groove is 0.13mm, and the area of the tuning groove is 24.75mm 2.

After the steps are adopted, the back of the piezoelectric sheet is swept by laser after the product is assembled, a B-shaped tuning groove is formed on the back of the piezoelectric sheet, the local thickness of the piezoelectric sheet is reduced, the frequency of the piezoelectric sheet is improved, the frequency of the piezoelectric sheet is close to or even identical to that of the sounding cavity, the resonant frequency of the product is controlled to be F0 +/-150 HZ, and the integral sound pressure of the product is improved.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.