Lead-free piezoelectric sounder

Abstract

This utility model provides a lead-free piezoelectric sound device, including a housing, a back cover, a piezoelectric sheet, and a connecting wire. A sound outlet is provided in the center of the front side of the housing. The piezoelectric sheet is fixed to the inner side of the housing. A wire outlet is provided on the side wall of the housing. One end of the connecting wire is fixed to and electrically connected to the piezoelectric sheet, and the other end of the connecting wire extends out of the housing through the wire outlet. The piezoelectric sheet is made of lead-free piezoelectric ceramic material. A supporting step is provided on the inner side wall of the rear end of the housing. The back cover is embedded in the inner side of the rear end of the housing and abuts against the supporting step. Several ribs are spaced circumferentially on the side wall of the supporting step, and these ribs abut against the rear side of the outer edge of the back cover to press the back cover firmly onto the supporting step. This utility model has the advantage of convenient assembly of the back cover and the housing, which facilitates the production of piezoelectric sound devices. Furthermore, using lead-free piezoelectric ceramic to make the piezoelectric sheet improves the piezoelectric performance and sound pressure level of the piezoelectric sheet.

Description

Technical Field

[0001] This utility model relates to the field of piezoelectric sound technology, and more specifically, to a lead-free piezoelectric sound. Background Technology

[0002] A piezoelectric buzzer, also known as a buzzer, is a device used to convert electrical signals into sound signals. Currently, commercially available piezoelectric buzzers mainly consist of a housing, a back cover, a piezoelectric element, and a connecting wire. The housing has a sound outlet in the center of its front side, the piezoelectric element is fixed to the inside of the housing, and a wire outlet is located on the side wall of the housing. One end of the connecting wire is fixed to the piezoelectric element and electrically connected, while the other end extends out of the housing through the wire outlet. The back cover is glued to the rear end of the housing using a circular adhesive application method. In this piezoelectric buzzer structure, because the back cover is glued to the rear end of the housing using a circular adhesive application method, there is a disadvantage to the assembly of the back cover and the housing, which means that the production of piezoelectric buzzers is inconvenient. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a lead-free piezoelectric sound device, which has the advantage of easy assembly of the back cover and the housing, thus facilitating the production of piezoelectric sound devices. Furthermore, by using lead-free piezoelectric ceramics to make the piezoelectric sheet, the piezoelectric performance and sound pressure of the piezoelectric sheet can be improved.

[0004] This utility model provides a lead-free piezoelectric sound device, including a housing, a back cover, a piezoelectric sheet, and a connecting wire; a sound outlet is provided in the middle of the front side of the housing, the piezoelectric sheet is fixed to the inner side of the housing, a wire outlet is provided on the side wall of the housing, one end of the connecting wire is fixed to the piezoelectric sheet and electrically connected, and the other end of the connecting wire extends out of the housing through the wire outlet; the piezoelectric sheet is made of lead-free piezoelectric ceramic material; a support step is provided on the inner side wall of the rear end of the housing, the back cover is embedded in the inner side of the rear end of the housing and abuts against the support step, and a number of ribs are provided circumferentially at intervals on the side wall of the support step, and the ribs abut against the rear side of the outer edge of the back cover to press the back cover tightly onto the support step.

[0005] By adopting the above-described structure, this utility model has the advantage of convenient assembly between the back cover and the housing, since the back cover is embedded in the inner side of the rear end of the housing and is pressed onto the support step by several protruding ribs. Compared with the traditional method of fixing the back cover to the housing by applying glue around the entire circle, the back cover is convenient to assemble with the housing, which can facilitate the production of piezoelectric sound devices. In addition, by using the above-described lead-free piezoelectric ceramic to make the piezoelectric sheet, the piezoelectric performance and sound pressure of the piezoelectric sheet can be improved, which can improve the performance of the piezoelectric sound device.

[0006] In one possible implementation, the outer edge of the back cover abuts against the inner wall of the support step; after the back cover is installed inside the rear end of the housing, the outer edge of the back cover abuts against the inner wall of the support step, thereby achieving radial limiting of the back cover and the housing, so as to avoid radial displacement of the back cover relative to the housing, that is, to improve the reliability of the back cover and the housing after assembly.

[0007] In one possible implementation, a circumferential limiting structure is provided between the back cover and the housing. With this structure, after the back cover is fitted into the inner side of the rear end of the housing, the circumferential limiting structure can achieve circumferential limiting of the back cover and the housing, thereby preventing the back cover from rotating relative to the housing, which can improve the reliability of the back cover and the housing after assembly.

[0008] In one possible implementation, the circumferential limiting structure includes a limiting block disposed at the outer edge of the rear cover, and a limiting groove disposed on the side wall of the rear end of the housing, with the limiting block fitting into the limiting groove. By adopting this structure, after the rear cover is fitted into the inner side of the rear end of the housing, the limiting block can fit into the limiting groove, thereby achieving circumferential limiting of the rear cover and the housing, and improving the reliability of the rear cover and the housing after assembly.

[0009] In one possible implementation, a plurality of grooves are provided circumferentially at intervals on the rear sidewall of the outer edge of the back cover. The grooves are used to fill adhesive to bond and fix the back cover to the inner sidewall of the housing. With this structure, after the back cover is inserted into the inner side of the rear end of the housing, the back cover can also be bonded and fixed to the inner sidewall of the housing by the adhesive filled in the grooves, thereby further improving the firmness and reliability of the back cover and the housing after fixation. In addition, since the adhesive is only filled in the grooves, the back cover and the housing do not need to be fixed by applying adhesive around the entire circle, which has the advantage of facilitating further fixation of the back cover and the housing.

[0010] In one possible implementation, an annular step is provided on the inner wall of the housing, and the outer edge of the piezoelectric sheet is supported on and bonded to the annular step. Gaps are left between the piezoelectric sheet and the front inner wall of the housing and the front end face of the rear cover. With this structure, the piezoelectric sheet can be reliably supported on and fixed to the annular step, that is, the piezoelectric sheet can be reliably fixed inside the housing. And because gaps are left between the piezoelectric sheet and the front inner wall of the housing and the front end face of the rear cover, the piezoelectric sheet can reliably vibrate and produce sound when energized, that is, interference with the piezoelectric sheet can be avoided when the piezoelectric sheet vibrates. Attached Figure Description

[0011] Figure 1 This is the first three-dimensional structural schematic diagram of the present invention; Figure 2 This is a second three-dimensional structural schematic diagram of the present invention; Figure 3 This is a partially exploded three-dimensional structural diagram of the present invention; Figure 4 This is a cross-sectional structural diagram of the present invention. Detailed Implementation

[0012] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0013] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0014] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0015] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0016] See Figure 1-4As shown in the figure, this application discloses a lead-free piezoelectric sound device, including a housing 1, a rear cover 2, a piezoelectric sheet 3, and a connecting wire 4; a sound outlet 11 is provided in the middle of the front side of the housing 1, the piezoelectric sheet 3 is fixed to the inner side of the housing 1, a wire outlet 12 is provided on the side wall of the housing 1, one end of the connecting wire 4 is fixed to and electrically connected to the piezoelectric sheet 3, and the other end of the connecting wire 4 extends out of the housing 1 through the wire outlet 12; the piezoelectric sheet 3 is made of lead-free piezoelectric ceramic material; a support step 13 is provided on the inner side wall of the rear end of the housing 1, the rear cover 2 is embedded in the inner side of the rear end of the housing 1 and abuts against the support step 13, the support step A plurality of ribs 14 are arranged circumferentially on the side wall of 13. The plurality of ribs 14 abut against the rear side of the outer edge of the rear cover 2 to press the rear cover 2 onto the support step 13. The piezoelectric sheet mentioned above is made of a KNN-based lead-free piezoelectric ceramic and its preparation method disclosed in Chinese Patent Publication No. CN115286384B. It is prior art and will not be described in detail here. By using the above-mentioned KNN-based lead-free piezoelectric ceramic to make the piezoelectric sheet, the piezoelectric performance and sound pressure of the piezoelectric sheet can be improved, that is, the performance of the piezoelectric sound device can be improved. In addition, the piezoelectric sheet has the advantage of being environmentally friendly.

[0017] The outer edge of the back cover 2 abuts against the inner wall of the support step 13. After the back cover is installed inside the rear end of the housing, the outer edge of the back cover abuts against the inner wall of the support step, thereby achieving radial limiting of the back cover and the housing, so as to avoid radial displacement of the back cover relative to the housing, which can improve the reliability of the back cover and the housing after assembly.

[0018] A circumferential limiting structure is provided between the back cover 2 and the housing 1. With this structure, after the back cover is inserted into the inner side of the rear end of the housing, the circumferential limiting structure can achieve circumferential limiting of the back cover and the housing, thereby preventing the back cover from rotating relative to the housing, which can improve the reliability of the back cover and the housing after assembly.

[0019] The circumferential limiting structure includes a limiting block 21 disposed at the outer edge of the rear cover 2, and a limiting groove 15 disposed on the side wall of the rear end of the housing 1, in which the limiting block 21 is fitted. With this structure, after the rear cover is fitted into the inner side of the rear end of the housing, the limiting block can fit into the limiting groove, thereby achieving circumferential limiting of the rear cover and the housing, so as to improve the reliability of the rear cover and the housing after assembly.

[0020] The rear sidewall of the outer edge of the back cover 2 is provided with several grooves 22 spaced apart circumferentially. The grooves 22 are used to fill glue so that the back cover 2 is bonded and fixed to the inner sidewall of the housing 1. With this structure, after the back cover is inserted into the inner side of the rear end of the housing, the back cover can also be bonded and fixed to the inner sidewall of the housing by the glue filled in the grooves, thereby further improving the firmness and reliability of the back cover and the housing after fixation. In addition, since the glue is only filled in the grooves, the back cover and the housing do not need to be fixed by applying glue around the entire circle, which has the advantage of facilitating further fixation of the back cover and the housing.

[0021] An annular step 16 is provided on the inner wall of the housing 1. The outer edge of the piezoelectric sheet 3 is supported on the annular step 16 and bonded to the annular step 16. A gap is left between the piezoelectric sheet 3 and the front inner wall of the housing 1 and the front end face of the rear cover 2. With this structure, the piezoelectric sheet can be reliably supported on the annular step and fixed to the annular step, that is, the piezoelectric sheet can be reliably fixed to the inner side of the housing. And because a gap is left between the piezoelectric sheet and the front inner wall of the housing and the front end face of the rear cover, the piezoelectric sheet can reliably vibrate and produce sound when energized, that is, interference with the piezoelectric sheet can be avoided when the piezoelectric sheet vibrates.

[0022] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A lead-free piezoelectric sound device, comprising a housing (1), a rear cover (2), a piezoelectric element (3), and a connecting wire (4); a sound outlet (11) is provided in the middle of the front side of the housing (1), the piezoelectric element (3) is fixed to the inner side of the housing (1), a wire outlet (12) is provided on the side wall of the housing (1), one end of the connecting wire (4) is fixed and electrically connected to the piezoelectric element (3), and the other end of the connecting wire (4) extends out of the housing (1) through the wire outlet (12); characterized in that: The piezoelectric sheet (3) is made of lead-free piezoelectric ceramic material; a support step (13) is provided on the inner side wall of the rear end of the housing (1); the rear cover (2) is embedded in the inner side of the rear end of the housing (1) and abuts against the support step (13); a number of ribs (14) are provided circumferentially on the side wall of the support step (13); the number of ribs (14) abut against the rear side of the outer edge of the rear cover (2) to press the rear cover (2) onto the support step (13).

2. The lead-free piezoelectric sound device according to claim 1, characterized in that: The outer edge of the rear cover (2) abuts against the inner wall of the supporting step (13).

3. The lead-free piezoelectric sound device according to claim 1 or 2, characterized in that: A circumferential limiting structure is provided between the rear cover (2) and the shell (1).

4. The lead-free piezoelectric sound device according to claim 3, characterized in that: The circumferential limiting structure includes a limiting block (21) disposed at the outer edge of the rear cover (2), and a limiting groove (15) is provided on the side wall of the rear end of the housing (1), and the limiting block (21) is fitted into the limiting groove (15).

5. The lead-free piezoelectric sound device according to claim 1, 2, or 4, characterized in that: The rear sidewall of the outer edge of the rear cover (2) is provided with a plurality of grooves (22) spaced apart circumferentially. The grooves (22) are used to fill glue so that the rear cover (2) is bonded and fixed to the inner sidewall of the housing (1).

6. The lead-free piezoelectric sound device according to claim 5, characterized in that: An annular step (16) is provided on the inner wall of the housing (1). The outer edge of the piezoelectric sheet (3) is supported on the annular step (16) and bonded to the annular step (16). A gap is left between the piezoelectric sheet (3) and the front inner wall of the housing (1) and the front end face of the rear cover (2).

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