Low noise high sensitivity port hydrophone with integrated shield

Abstract

The utility model provides a low noise high sensitivity port water listener with integrated shielding layer, include: oscillator assembly, first rubber layer, second rubber layer and metal shielding net, first rubber layer and second rubber layer are covered in the oscillator assembly outside from inside to outside in proper order, the density of first rubber layer is greater than the density of second rubber layer, and the metal shielding net is located between first rubber layer and second rubber layer. The utility model discloses a low noise high sensitivity port water listener with integrated shielding layer, acoustically, form the sound impedance decrement gradient, maximize sound energy transmission efficiency, improve the sensitivity of hydrophone. Electromagnetically, shielding net ground, import external electromagnetic noise into the earth, eliminate environmental electromagnetic noise coupling path, improve the signal to noise ratio of received signal. In addition, the composite damping structure formed by double layer rubber and metal shielding net can dissipate vibration, reduce the influence of outside flow noise and structure vibration on the hydrophone.

Description

Technical Field

[0001] This utility model relates to the field of hydrophones, and in particular to a low-noise, high-sensitivity port hydrophone with an integrated shielding layer. Background Technology

[0002] As critical national infrastructure, ports and docks require real-time monitoring of their underwater safety and hydrological environment. This includes tasks such as detecting and identifying unauthorized intruding submarine targets and underwater obstacles, conducting acoustic monitoring and assessment of port infrastructure, and monitoring underwater noise pollution, biological activity, and other marine ecological environments. However, the core equipment for achieving these monitoring tasks—hydrophones—faces severe challenges in the unique and complex environments of ports and docks.

[0003] Traditional piezoelectric hydrophones are commonly used in port detection due to their simple structure, low cost, and ease of mass production. However, the complex environment of ports and wharves is not only pollutants such as oil and silt, but also subject to strong electromagnetic interference from ships, cranes, power transmission and transformation stations, and communication facilities. The long cables and internal piezoelectric elements of hydrophones are susceptible to interference from these environmental electromagnetic fields, introducing noise that drowns out weak target sound signals, leading to a sharp drop in the signal-to-noise ratio. Furthermore, port waters are often corroded by hydrocarbon pollutants such as fuel oil and lubricating oil. Traditional hydrophones generally use a single-material sheath, such as polyurethane or ordinary neoprene rubber. This sheath design makes it difficult to simultaneously meet the comprehensive requirements of water resistance, oil resistance, aging resistance, and excellent sound transmission. In other words, a sheath with excellent protection often has poor sound transmission, affecting hydrophone sensitivity, while a sheath with good sound transmission generally lacks durability and protection.

[0004] Therefore, there is an urgent need for a hydrophone that combines high sensitivity and strong resistance to electromagnetic interference, while also being highly protective and adaptable to various environments. This would meet the urgent need for long-term reliable monitoring in complex waters such as ports and docks, and provide reliable technical support for tasks such as underwater security, navigation support, and infrastructure monitoring. Utility Model Content

[0005] This invention provides a low-noise, high-sensitivity port hydrophone with an integrated shielding layer, which can effectively suppress electromagnetic interference and has good sound transmission while providing excellent protection.

[0006] A low-noise, high-sensitivity port hydrophone with an integrated shielding layer includes: a vibrator assembly, a first rubber layer, a second rubber layer, and a metal shielding mesh; The oscillator assembly can convert acoustic signals in water into electrical signals. The first rubber layer and the second rubber layer are sequentially wrapped around the outside of the oscillator assembly from the inside to the outside. The density of the first rubber layer is greater than that of the second rubber layer. The metal shielding mesh is disposed between the first rubber layer and the second rubber layer.

[0007] Furthermore, it also includes a rubber fusion layer, wherein the metal shielding mesh has a plurality of mesh openings, and the first rubber layer and the second rubber layer are fused together at the mesh openings to form the rubber fusion layer.

[0008] Furthermore, the first rubber layer is chloroprene rubber, and the second rubber layer is nitrile rubber.

[0009] Furthermore, the mesh size of the metal shielding mesh is 20 to 60 meshes.

[0010] Furthermore, the oscillator assembly includes a metal frame and a cork pad, an insulating pad, and a piezoelectric ceramic ring fitted on the metal frame. The cork pad is disposed in the radial gap between the piezoelectric ceramic ring and the metal frame, and the insulating pad is disposed in the axial gap between the piezoelectric ceramic rings.

[0011] Furthermore, it also includes a housing and a shielded cable. The housing has a through cavity. One end of the metal frame and the shielded cable enter the cavity from both ends of the cavity, and one end of the metal frame is connected to the shielding layer of the shielded cable inside the cavity. The other end of the metal frame is a mounting rod. The cork pad, the insulating pad, and the piezoelectric ceramic ring are all fitted on the mounting rod. The end of the mounting rod is electrically connected to the metal shielding mesh.

[0012] Furthermore, the oscillator assembly also includes a support head, the end of the mounting rod is threaded, and the piezoelectric ceramic ring is pressed together by the nut and the support head. An insulating pad is provided between the support head and the piezoelectric ceramic ring.

[0013] This utility model discloses a low-noise, high-sensitivity port hydrophone with an integrated shielding layer. Acoustically, it forms a decreasing acoustic impedance gradient from "oscillator assembly → first rubber layer (high density) → second rubber layer (low density) → seawater," maximizing sound energy transfer efficiency and improving the hydrophone's sensitivity. Electromagnetically, the shielding mesh is grounded, guiding external electromagnetic noise to the ground, eliminating environmental electromagnetic noise coupling paths, and improving the signal-to-noise ratio of the received signal. Furthermore, the composite damping structure formed by the double-layer rubber and metal shielding mesh dissipates vibrations, reducing the impact of external flow noise and structural vibrations on the hydrophone. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a low-noise, high-sensitivity port hydrophone with an integrated shielding layer disclosed in an embodiment of this utility model. Figure 2 This is a cross-sectional schematic diagram of the hydrophone disclosed in the embodiments of this utility model; Figure 3 for Figure 2 A magnified view of part A in the middle; Figure 4 This is a schematic diagram of the metal skeleton structure disclosed in the embodiments of this utility model; Figure 5 This is a cross-sectional schematic diagram of the metal skeleton disclosed in the embodiments of this utility model; In the picture: 1. Oscillator assembly; 11. Metal frame; 12. Cork pad; 13. Insulating pad; 14. Piezoelectric ceramic ring; 15. Support head; 16. Nut; 2. First rubber layer; 3. Second rubber layer; 4. Metal shielding mesh; 5. Shell; 6. Shielded cable; Detailed Implementation To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0016] like Figure 1-3 As shown, this embodiment discloses a low-noise, high-sensitivity port hydrophone with an integrated shielding layer, comprising: a vibrator assembly 1, a first rubber layer 2, a second rubber layer 3, and a metal shielding mesh 4; The oscillator assembly 1 can convert acoustic signals in water into electrical signals. The first rubber layer 2 and the second rubber layer 3 are sequentially wrapped around the outside of the oscillator assembly 1 from the inside to the outside. The density of the first rubber layer 2 is greater than the density of the second rubber layer 3. The metal shielding mesh 4 is disposed between the first rubber layer 2 and the second rubber layer 3.

[0017] This utility model discloses a low-noise, high-sensitivity port hydrophone with an integrated shielding layer. Acoustically, it forms a decreasing acoustic impedance gradient from "oscillator assembly 1 → first rubber layer 2 (high density) → second rubber layer 3 (low density) → seawater," creating a gradient transition structure where the acoustic impedance gradually decreases from the piezoelectric sensitive element to the external seawater, maximizing sound energy transfer efficiency and improving the hydrophone's sensitivity. Electromagnetically, the shielding mesh is grounded, guiding external electromagnetic noise to the ground, eliminating environmental electromagnetic noise coupling paths, and improving the signal-to-noise ratio of the received signal. Furthermore, the composite damping structure formed by the double-layer rubber and metal shielding mesh 4 dissipates vibrations, reducing the impact of external flow noise and structural vibrations on the hydrophone.

[0018] Furthermore, it also includes a rubber fusion layer, wherein the metal shielding mesh 4 has a plurality of mesh holes, and the first rubber layer 2 and the second rubber layer 3 are fused together at the mesh holes to form the rubber fusion layer.

[0019] Adding extra structures to a hydrophone can interfere with its acoustic performance. This application incorporates a rubber fusion layer and a metal shielding mesh 4, which are integrated to ensure the protective and anti-interference effects of the rubber layer while minimizing the impact of the structure on the acoustic performance.

[0020] In this embodiment, the first rubber layer 2 is chloroprene rubber, and the second rubber layer 3 is nitrile rubber.

[0021] Furthermore, the metal shielding mesh 4 has a mesh size of 20 to 60 meshes.

[0022] In this embodiment, the first rubber layer 2 is made of neoprene rubber with a density of approximately 1.4 g / cm³, providing strong adhesion to the piezoelectric ceramic and excellent water resistance, forming the first transition step of the acoustic impedance matching network.

[0023] The second rubber layer 3 is made of nitrile rubber with a density of approximately 1.0 g / cm³-1.2 g / cm³, providing excellent oil resistance and mechanical protection, and forming a second transition step for acoustic impedance matching.

[0024] The metal shielding mesh 4 is a layer of woven metal mesh, preferably tin-plated copper mesh or Monel alloy mesh, with a sparse mesh structure of 20-60 meshes (the mesh size is much smaller than the wavelength of the main sound waves being detected). This shielding mesh is embedded between two rubber layers, forming a continuous Faraday cage with the internal metal skeleton 11 to achieve electromagnetic shielding, while the sparse mesh design ensures efficient sound wave transmission.

[0025] The hydrophone manufacturing process in this embodiment is as follows: First, a neoprene inner layer is molded onto the oscillator assembly 1 to form a first rubber layer 2. Then, a metal braided shielding mesh is tightly wrapped around the incompletely vulcanized first rubber layer 2. Finally, nitrile rubber is molded to form a second rubber layer 3. During the vulcanization process, the inner and outer rubber layers fuse through the mesh openings to form a fused rubber layer, permanently encapsulating and fixing the metal shielding mesh 4.

[0026] Furthermore, the oscillator assembly 1 includes a metal frame 11 and a cork pad 12, an insulating pad 13, and a piezoelectric ceramic ring 14 sleeved on the metal frame 11. The cork pad 12 is disposed in the radial gap between the piezoelectric ceramic ring 14 and the metal frame 11, and the insulating pad 13 is disposed in the axial gap between the piezoelectric ceramic rings 14.

[0027] An insulating pad 13 is also provided between the piezoelectric ceramic ring 14 and the metal frame 11. The insulating pad 13 and the cork pad 12 can insulate and isolate the piezoelectric ceramic ring 14, optimize the acoustic performance of the piezoelectric ceramic ring 14, and ensure the normal operation of the piezoelectric ceramic ring 14.

[0028] In this embodiment, the pressure-sensitive element of the oscillator assembly 1 is an even number of piezoelectric ceramic rings 14, or a piezoelectric single crystal ring. The piezoelectric ceramic rings 14 are connected in parallel in the circuit.

[0029] Furthermore, it also includes a housing 5 and a shielded cable 6. The housing 5 has a through cavity. One end of the metal frame 11 and the shielded cable 6 enter the cavity from both ends of the cavity, and one end of the metal frame 11 is connected to the shielding layer of the shielded cable 6 inside the cavity. The other end of the metal frame 11 is a mounting rod. The cork pad 12, the insulating pad 13, and the piezoelectric ceramic ring 14 are all sleeved on the mounting rod. The end of the mounting rod is electrically connected to the metal shielding mesh 4.

[0030] The shielded cable 6 is introduced from one end of the cavity of the housing 5. The shielded cable 6 and the housing 5 are sealed by vulcanization with watertight rubber to ensure that the connection is firmly bonded and the seal is durable.

[0031] The output cable of the hydrophone is a coaxial shielded cable, and its shielding layer is electrically connected to the metal braided shielding mesh to ensure the continuity of the overall shielding.

[0032] like Figure 4 and Figure 5 As shown, one end of the metal frame 11 that extends into the housing 5 has an opening, such as... Figure 2 and Figure 3As shown, the insulating pad 13 has through holes, through which the bonding wire can pass and be laid along the cork pad 12 and the piezoelectric ceramic ring 14. It is then connected to the shielded cable 6 through an opening in the metal frame 11 to transmit the electrical signal from the piezoelectric ceramic. When the hydrophone is working, external sound waves act on the piezoelectric ceramic ring 14, and the piezoelectric effect of the ring converts the sound signal into a voltage signal. This signal is transmitted to the back-end acquisition system via a coaxial shielded cable to complete the acoustic detection.

[0033] The shell 5 is made of stainless steel, titanium alloy or aluminum alloy, with high structural strength, good corrosion resistance and excellent protection.

[0034] Furthermore, the oscillator assembly 1 also includes a support head 15, the end of the mounting rod is threaded, and the piezoelectric ceramic ring 14 is pressed together by the nut 16 and the support head 15. The insulating pad 13 is provided between the support head 15 and the piezoelectric ceramic ring 14.

[0035] After the piezoelectric ceramic ring 14, cork pad 12 and insulating pad 13 are fully assembled into the metal frame 11 to form the oscillator assembly 1, the electrical connection between the welding wire and the piezoelectric ceramic ring 14 is completed, and the lead wire is set at the end of the mounting rod. Then the first rubber layer 2 completely covers the oscillator assembly 1, and a metal shielding mesh 4 is set. The lead wire and the metal shielding mesh 4 are connected to realize the connection between the metal shielding mesh 4 and the metal frame 11.

[0036] The technical solution disclosed in this embodiment has the following advantages: 1. The metal shielding mesh used in this invention forms a continuous and complete Faraday cage structure, which can effectively block the coupling interference of external complex electromagnetic fields to the internal piezoelectric elements. This significantly improves the signal-to-noise ratio of the hydrophone in strong electromagnetic noise environments such as ports, ensuring the reliability of weak acoustic signal detection.

[0037] 2. The sparse mesh design of the shielding mesh in this invention ensures efficient sound wave transmission. Simultaneously, it constructs a gradient acoustic impedance transition structure from piezoelectric ceramic to neoprene rubber, then to nitrile rubber, and finally seawater. By matching the acoustic impedance at each stage, the reflection loss of sound waves at the transmission interface is minimized, thereby improving the receiving sensitivity of the hydrophone.

[0038] 3. The outer rubber coating of this invention adopts a functional double-layer design. The inner neoprene rubber layer provides excellent water resistance and adhesion, while the outer nitrile rubber layer focuses on resisting oil corrosion and mechanical wear. This synergistic protection system provides comprehensive protection for the internal core piezoelectric components, greatly enhancing the durability and service life of the hydrophone in harsh aquatic environments.

[0039] 4. This utility model utilizes an integrated vulcanization molding process for the rubber and shielding mesh to fuse the various layers of materials into a dense, integral structure. This fundamentally eliminates the risk of interlayer delamination, ensuring the precise fixation and long-term stability of the shielding mesh position, thereby guaranteeing the consistency and reliability of the hydrophone's performance.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A low-noise, high-sensitivity port hydrophone with an integrated shielding layer, characterized in that, include: The oscillator assembly, the first rubber layer, the second rubber layer, and the metal shielding mesh; The oscillator assembly can convert acoustic signals in water into electrical signals. The first rubber layer and the second rubber layer are sequentially wrapped around the outside of the oscillator assembly from the inside to the outside. The density of the first rubber layer is greater than that of the second rubber layer. The metal shielding mesh is disposed between the first rubber layer and the second rubber layer.

2. A low-noise, high-sensitivity port hydrophone with an integrated shielding layer according to claim 1, characterized in that, It also includes a rubber fusion layer, wherein the metal shielding mesh has a plurality of mesh openings, and the first rubber layer and the second rubber layer are fused together at the mesh openings to form the rubber fusion layer.

3. A low-noise, high-sensitivity port hydrophone with an integrated shielding layer according to claim 1, characterized in that, The first rubber layer is chloroprene rubber, and the second rubber layer is nitrile rubber.

4. A low-noise, high-sensitivity port hydrophone with an integrated shielding layer according to claim 1, characterized in that, The mesh size of the metal shielding mesh is 20 to 60 meshes.

5. A low-noise, high-sensitivity port hydrophone with an integrated shielding layer according to claim 1, characterized in that, The oscillator assembly includes a metal frame and a cork pad, an insulating pad, and a piezoelectric ceramic ring fitted on the metal frame. The cork pad is located in the radial gap between the piezoelectric ceramic ring and the metal frame, and the insulating pad is located in the axial gap between the piezoelectric ceramic rings.

6. A low-noise, high-sensitivity port hydrophone with an integrated shielding layer according to claim 5, characterized in that, It also includes a housing and a shielded cable. The housing has a through cavity. One end of the metal frame and the shielded cable enter the cavity from both ends of the cavity, and one end of the metal frame is connected to the shielding layer of the shielded cable inside the cavity. The other end of the metal frame is a mounting rod. The cork pad, the insulating pad, and the piezoelectric ceramic ring are all fitted on the mounting rod. The end of the mounting rod is electrically connected to the metal shielding mesh.

7. A low-noise, high-sensitivity port hydrophone with an integrated shielding layer according to claim 6, characterized in that, The oscillator assembly also includes a support head, and the end of the mounting rod is threaded. The piezoelectric ceramic ring is pressed together by the nut and the support head, and the insulating pad is provided between the support head and the piezoelectric ceramic ring.

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