Underwater acoustic transducer

Abstract

The utility model provides an underwater acoustic transducer, which relates to the technical field of ultrasound and comprises a shell, a base, a pressing plate, a piezoelectric ceramic piece, an emitting surface and a sealing ring. The top of the shell is connected with a watertight joint and the bottom is provided with an opening; the base and the emitting surface are integrally formed, the base is in threaded connection with the bottom wall of the edge of the opening of the shell through screws, and a sealing ring is arranged between the base and the shell so that the shell and the base can surround to form a closed cavity; the pressing plate is laid on the upper layer of the piezoelectric ceramic piece, a threaded blind hole is formed in the upper surface of the base, a vertically-through through hole is formed in the pressing plate, and the pressing plate is fixedly installed on the base through a screw which penetrates through the through hole and then is in threaded connection with the threaded blind hole; and the cavity is filled with a fluid medium. According to the utility model, the technical problems of easy generation of bubbles, incapability of timely adjustment and repair, difficult emission surface cleaning, poor acoustic performance and easy aging caused by integral molding of the housing and the emission surface of the underwater acoustic transducer in the prior art are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrasonic, in particular to an underwater acoustic transducer. Background Art

[0002] An underwater acoustic transducer can convert electrical energy into acoustic energy or acoustic energy into electrical energy in an underwater environment by using the piezoelectric effect or magnetostrictive effect. For example, in an underwater environment, a piezoelectric material deforms under the action of an electric field to generate sound waves, realizing the conversion of electrical energy into acoustic energy. The commonly used piezoelectric material is a piezoelectric ceramic sheet. The structure of a traditional underwater acoustic transducer using a piezoelectric ceramic sheet mainly includes a housing and a piezoelectric ceramic sheet and a transmitting surface arranged inside the housing. The whole housing includes a main housing and an upper cover. The main housing is integrally processed from stainless steel or titanium alloy or rubber or silica gel materials. The upper cover can be opened, and a watertight connector is installed on the upper cover. One side of the piezoelectric ceramic sheet is a positive electrode surface and the other side is a negative electrode surface. The watertight connector is connected to the lead-out cable connecting the two electrodes of the piezoelectric ceramic sheet. The transmitting surface is in contact with the piezoelectric ceramic sheet and is integrally formed with the bottom wall of the main housing. The cavity of the main housing is filled with a foaming material. The traditional underwater acoustic transducer using a piezoelectric ceramic sheet has the following problems:

[0003] (1) The housing (main housing) and the transmitting surface are integrally formed by casting or injection molding processes, resulting in: ① Bubbles are easily generated during the forming process, affecting the performance of the transducer; ② During the forming process, if there is a problem with the internal encapsulation or the piezoelectric ceramic sheet is damaged during processing, it cannot be adjusted and repaired, and can only be discarded, with a high scrap rate; ③ It is difficult to clean the transmitting surface;

[0004] (2) The recoil force generated instantaneously when the piezoelectric ceramic sheet emits acts on the reflecting surface, generating a reverse echo signal interference, reducing the authenticity of the transmitted echo;

[0005] (3) Using a foaming material as the filling medium has the following disadvantages: ① It cannot fill the entire cavity, and the filling effect is poor; ② The foaming material is a porous material, which will absorb some sound waves, affecting the directional emission and reception of sound waves; ③ The acoustic impedance of the foaming material does not match the acoustic impedance of water, affecting the transmission efficiency of sound waves and the performance of the transducer; ④ It is easy to age, and its durability will also deteriorate in an environment of long-term underwater pressure;

[0006] (4) The housing material is made of stainless steel or titanium alloy, which is corrosion-resistant and has high structural strength. However, it has a relatively high hardness and is likely to wear the mesh body (underwater structure, such as a mesh-structured facility or monitoring network) when contacting it. Using rubber or silica gel, although it is relatively soft and will not damage the mesh body, its corrosion resistance is poor, and its structural strength is weak, making it easy to be squeezed and damaged. Moreover, the material density of stainless steel, titanium alloy, rubber or silica gel is not very uniform, which is likely to affect the acoustic wave emission effect. Currently, there is a need to find a material with better corrosion resistance and pressure resistance and relatively uniform density to make the housing to overcome this problem. Summary of the Invention

[0007] The purpose of the present invention is to provide an underwater acoustic transducer to alleviate the above-mentioned technical problems existing in the prior art.

[0008] To achieve the above purpose, the embodiments of the present invention adopt the following technical solutions:

[0009] The embodiments of the present invention provide an underwater acoustic transducer, which includes a housing, a base, a pressing plate, a piezoelectric ceramic sheet, a transmitting surface and a sealing ring. Specifically, a watertight joint is connected to the top of the housing, and an opening is provided at the bottom. The base is integrally formed with the transmitting surface, and the base is threadedly connected to the bottom wall of the opening edge of the housing by screws. A sealing ring is provided between the base and the housing so that the housing and the base enclose a sealed cavity. The pressing plate is laid on the upper layer of the piezoelectric ceramic sheet. Moreover, a threaded blind hole is provided on the upper surface of the base, and a through hole penetrating up and down is provided on the pressing plate. The pressing plate is fixedly installed on the base by screws passing through the through hole and threadedly connected to the threaded blind hole. A fluid medium is filled inside the cavity.

[0010] In the underwater acoustic transducer provided in this embodiment, the layer structure of the piezoelectric ceramic sheet and its connection method with the watertight joint through the outgoing cable are exactly the same as those in the prior art, and will not be elaborated here.

[0011] For the above structure of this embodiment, compared with the prior art, the main improvements are as follows:

[0012] (1) The housing is divided into a housing and a base, and the two are detachably connected by screws and sealed by a sealing ring. Since the transmitting surface and the base are of an integral structure, the base can be detached from the housing by screws, which is equivalent to detaching the transmitting surface from the housing. This can: ① avoid the generation of air bubbles during the production by the integral molding process, which may affect the performance of the transducer; ② adjust the distance between the piezoelectric ceramic sheet and the transmitting surface to ensure that there is no gap between them, which is convenient for adjustment and control, and improves the production efficiency and production qualification rate of the transducer; ③ facilitate the cleaning of the transmitting surface.

[0013] (2) Using a fluid medium such as oil as the filling medium, ① it can completely fill the cavity, playing the roles of electrical isolation and buffering; ② the fluid medium will not absorb acoustic energy like porous foaming materials, thus maintaining the integrity and intensity of the sound wave, being able to transmit acoustic energy more effectively, reducing the loss of energy during transmission, and moreover, the acoustic wave propagation effect of the fluid medium in the low-frequency range is significantly better than that of the foaming material; ③ the acoustic impedance of the fluid medium is closer to that of water, which helps to improve the efficiency of acoustic wave transmission between the inside of the transducer and the water medium; ④ there is no aging problem and it is little affected by the underwater environment.

[0014] (3) By setting the pressure plate, it is ensured that there is no gap between the piezoelectric ceramic sheet and the emission surface, improving the authenticity of the emitted echo.

[0015] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the fluid medium is oil.

[0016] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the pressure plate includes a metal plate and a wooden plate stacked from top to bottom. The metal plate is provided with a through hole penetrating up and down. The metal plate is fixedly installed on the base through a screw that passes through the through hole and is threadedly connected to the threaded blind hole. The lower plate surface of the wooden plate fits with the upper surface of the piezoelectric ceramic sheet.

[0017] Further optionally, the metal plate is an aluminum plate.

[0018] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the base includes a body and a disc-shaped protrusion integrally formed on the lower surface of the body.

[0019] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the base includes a body, and a limiting sunk groove matching the shape of the piezoelectric ceramic sheet is integrally formed on the upper surface of the body. The piezoelectric ceramic sheet is fixed inside the limiting sunk groove.

[0020] Further optionally, an electrode groove is provided on the bottom wall of the limiting sunk groove, and the positive electrode solder joints on the piezoelectric ceramic sheet are arranged inside the electrode groove.

[0021] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the base includes a body, and the upper end of the body is inserted into the inside of the housing from the opening of the housing. An annular groove is provided on the radial circumferential outer wall surface of the part where the body is inserted into the inside of the housing, and the sealing ring is installed inside the annular groove.

[0022] Further optionally, the base further includes an annular protrusion integrally formed on the upper surface of the body. The annular protrusion is inserted into the inside of the housing from the opening of the housing, and the annular groove is provided on the outer ring surface of the annular protrusion.

[0023] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the housing and the base are made of ultra-high molecular weight polyethylene material. Description of the Drawings

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Is an axonometric view of the overall structure of the underwater acoustic transducer provided in the embodiment of the present invention;

[0026] Figure 2 Is a front view of the underwater acoustic transducer provided in the embodiment of the present invention;

[0027] Figure 3 Is a bottom view of the underwater acoustic transducer provided in the embodiment of the present invention;

[0028] Figure 4 Is an axonometric exploded view of the overall structure of the underwater acoustic transducer provided in the embodiment of the present invention;

[0029] Figure 5 Is a front cross-sectional view of the overall structure of the underwater acoustic transducer provided in the embodiment of the present invention;

[0030] Figure 6 Is Figure 5 A partial enlarged view of part A in

[0031] Figure 7 Is a front cross-sectional view of the overall structure of the base in the underwater acoustic transducer provided in the embodiment of the present invention;

[0032] Figure 8 Is Figure 7 A partial enlarged view of part B in

[0033] Reference Signs: 1 - housing; 2 - base; 21 - body; 211 - limiting sink; 212 - electrode groove; 22 - disc-shaped protrusion; 23 - annular protrusion; 231 - annular groove; 3 - pressing plate; 31 - metal plate; 32 - wooden board; 4 - piezoelectric ceramic sheet; 5 - sealing ring; 6 - watertight joint. Detailed Embodiments

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. The components of the embodiments of the present utility model described and illustrated herein can be arranged and designed in a variety of different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0036] It should be noted that like reference numerals and letters denote like items in the drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0037] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0038] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0039] The following will describe in detail some embodiments of the present utility model with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0040] This embodiment provides an underwater acoustic transducer. Refer to Figures 1 to 8, the underwater acoustic transducer includes a housing 1, a base 2, a pressing plate 3, piezoelectric ceramic sheets 4, a transmitting surface, and a sealing ring 5. Specifically, a watertight connector 6 is connected to the top of the housing 1, and an opening is provided at the bottom of the housing 1. The base 2 is integrally formed with the transmitting surface, and the base 2 is threadedly connected to the bottom wall of the opening edge of the housing 1 by screws. A sealing ring 5 is provided between the base 2 and the housing 1 so that the housing 1 and the base 2 enclose a sealed cavity. The pressing plate 3 is laid on the upper layer of the piezoelectric ceramic sheets 4. Moreover, threaded blind holes are provided on the upper surface of the base 2, and through holes penetrating up and down are provided on the pressing plate 3. The pressing plate 3 is fixedly installed on the base 2 by screws that pass through the through holes and are threadedly connected to the aforementioned threaded blind holes. Oil or other fluid media are filled inside the above cavity.

[0041] In the underwater acoustic transducer provided in this embodiment, the layer structure of the piezoelectric ceramic sheets 4 and the connection mode thereof to the watertight connector 6 through outgoing cables (not shown) are exactly the same as those in the prior art, and will not be elaborated here.

[0042] For the above structure of this embodiment, compared with the prior art, the main improvements are as follows:

[0043] (1) The outer shell is divided into a housing 1 and a base 2, and the two are detachably connected by screws and sealed by a sealing ring 5. Since the transmitting surface and the base 2 are of an integral structure, the base 2 can be detached from the housing 1 by screws, which is equivalent to detaching the transmitting surface from the housing 1. In this way, it can: ① avoid the generation of bubbles during the production process of the perfusion integral molding process, which affects the performance of the transducer; ② adjust the distance between the piezoelectric ceramic sheets 4 and the transmitting surface to ensure that there is no gap between the two, which is convenient for adjustment and control, and improves the production efficiency and production qualification rate of the transducer; ③ facilitate the cleaning of the transmitting surface;

[0044] (2) Using fluid media such as oil as the filling medium, ① it can completely fill the cavity and play the role of electrical isolation and buffering; ② the fluid medium will not absorb sound wave energy like porous foaming materials, thus maintaining the integrity and intensity of the sound wave, being able to transmit sound wave energy more effectively, reducing the loss of energy during the transmission process, and moreover, the sound wave propagation effect of the fluid medium in the low-frequency range is significantly better than that of the foaming material; ③ the acoustic impedance of the fluid medium is closer to that of water, which helps to improve the transmission efficiency of sound waves between the inside of the transducer and the water medium; ④ there is no aging problem and it is hardly affected by the underwater environment;

[0045] (3) By providing the pressing plate 3, it is ensured that there is no gap between the piezoelectric ceramic sheets 4 and the transmitting surface, and the authenticity of the transmitted echo is improved.

[0046] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the pressing plate 3 includes a metal plate 31 and a wooden plate 32 stacked from top to bottom. The metal plate 31 is provided with a through hole penetrating up and down. The metal plate 31 is fixedly installed on the base 2 by screws that pass through the through hole and are threadedly connected to the blind threaded hole. The lower plate surface of the wooden plate 32 is attached to the upper surface of the piezoelectric ceramic sheet 4. In this alternative solution, a relatively soft wooden plate 32 and a metal plate 31 with relatively high structural strength are combined. The piezoelectric ceramic sheet 4 is fixed by the metal plate 31, and the wooden plate 32 is used as an insulating material to isolate the positive electrode of the piezoelectric ceramic sheet, and buffer the recoil force caused by the instantaneous emission of the transducer, avoiding the generation of reverse echoes, so as to improve the authenticity of the emitted echo. In this alternative solution, further optionally, the metal plate 31 is an aluminum plate to reduce the weight of the transducer.

[0047] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the base 2 includes a main body 21 and a disc-shaped protrusion 22 integrally formed on the lower surface of the main body 21. The disc-shaped protrusion 22 can not only strengthen the structural strength of the base 2 to protect the stability of the piezoelectric ceramic sheet 4, but also facilitate the embedded assembly of the base 2 and other structures.

[0048] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the base 2 includes a main body 21. A limiting sunk groove 211 matching the shape of the piezoelectric ceramic sheet 4 is integrally formed on the upper surface of the main body 21. The piezoelectric ceramic sheet 4 is fixed inside the limiting sunk groove 211. By providing the limiting sunk groove 211, the piezoelectric ceramic sheet 4 can be limited to prevent shaking between the piezoelectric ceramic sheet 4 and the base 2, and improve the installation stability.

[0049] Further optionally, an electrode groove 212 is provided on the bottom wall of the above-mentioned limiting sunk groove 211, and the positive electrode solder joints on the piezoelectric ceramic sheet 4 are arranged inside the electrode groove 212 to protect the positive electrode solder joints on the piezoelectric ceramic sheet 4 through the electrode groove 212.

[0050] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the base 2 includes a main body 21. The upper end of the main body 21 is inserted into the interior of the housing 1 from the opening of the housing 1. An annular groove 231 is provided on the radial circumferential outer wall surface of the part where the main body 21 is inserted into the interior of the housing 1. The sealing ring 5 is installed inside the annular groove 231. Further optionally, the base 2 further includes an annular protrusion 23 integrally formed on the upper surface of the main body 21. The annular protrusion 23 is inserted into the interior of the housing 1 from the opening of the housing 1, and the above-mentioned annular groove 231 is provided on the outer ring surface of the annular protrusion 23. The above structure has good sealing performance, which can ensure that the cavity is in a closed state and ensure the stable operation of the ultrasonic transducer.

[0051] In an alternative solution of the underwater acoustic transducer provided in this embodiment, the housing 1 and the base 2 are made of ultra-high molecular weight polyethylene material, which has the advantages of corrosion resistance, acid and alkali resistance, good compressive capacity, and uniform density, and has almost no interference with sound wave transmission, and can greatly improve the authenticity of the transmitted echo.

[0052] Finally, it should be noted that the embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same and similar parts among the embodiments can be referred to each other. The above embodiments in this specification are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An underwater acoustic transducer, characterized in that: It comprises a housing (1), a base (2), a pressure plate (3), a piezoelectric ceramic sheet (4), an emitting surface and a sealing ring (5); The shell (1) is connected to a watertight joint (6) at the top and has an opening at the bottom; The base (2) and the emitting surface are integrally formed, and the base (2) is threadedly connected to the bottom wall of the opening edge of the shell (1) by means of screws, and a sealing ring (5) is provided between the base (2) and the shell (1) so that the shell (1) and the base (2) surround and form a closed cavity; The pressing plate (3) is laid on the upper layer of the piezoelectric ceramic sheet (4), and the upper surface of the base (2) is provided with a threaded blind hole, and the pressing plate (3) is provided with a through hole extending vertically, and the pressing plate (3) is fixedly mounted on the base (2) by means of a screw that passes through the through hole and is threadedly connected to the threaded blind hole; The cavity is filled with a fluid medium.

2. The underwater acoustic transducer according to claim 1, characterized in that: The fluid medium is oil.

3. The underwater acoustic transducer according to claim 1, characterized in that: The pressing plate (3) comprises a metal plate (31) and a wooden board (32) stacked from top to bottom, the metal plate (31) is provided with a through hole extending from top to bottom, the metal plate (31) is fixed to the base (2) by means of screws passing through the through hole and then threadedly connected to the threaded blind hole, and the lower surface of the wooden board (32) is in contact with the upper surface of the piezoelectric ceramic sheet (4).

4. The underwater acoustic transducer according to claim 3, characterized in that: The metal plate (31) is an aluminum plate.

5. The underwater acoustic transducer according to claim 1, characterized in that: The base (2) comprises a main body (21) and a disc-shaped protrusion (22) integrally formed on the lower surface of the main body (21).

6. The underwater acoustic transducer according to claim 1, characterized in that: The base (2) comprises a main body (21), the upper surface of the main body (21) is integrally formed with a limiting recessed groove (211) matching the shape of the piezoelectric ceramic sheet (4), and the piezoelectric ceramic sheet (4) is fixed inside the limiting recessed groove (211).

7. The underwater acoustic transducer according to claim 6, characterized in that: The bottom wall of the limiting sink (211) is provided with an electrode groove (212), and the positive electrode welding point on the piezoelectric ceramic sheet (4) is arranged inside the electrode groove (212).

8. The underwater acoustic transducer according to claim 1, characterized in that: The base (2) comprises a main body (21), the upper end of the main body (21) being inserted into the interior of the shell (1) from the opening of the shell (1), an annular groove (231) being provided on the radial circumferential outer wall surface of the portion of the main body (21) inserted into the interior of the shell (1), and the sealing ring (5) being installed inside the annular groove (231).

9. The underwater acoustic transducer according to claim 8, characterized in that: The base (2) further comprises an annular protrusion (23) integrally formed on the upper surface of the body (21); the annular protrusion (23) is inserted into the interior of the shell (1) from the opening of the shell (1); and the annular groove (231) is provided on the outer annular surface of the annular protrusion (23).

10. The underwater acoustic transducer according to claim 1, characterized in that: The shell (1) and the base (2) are made of ultra-high molecular weight polyethylene material.

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