A low frequency wideband bending disc transducer driven by a combination of moving coil and piezoelectric ceramics

Abstract

The application discloses a low-frequency wide-band bending disc transducer driven by a moving coil-piezoelectric ceramic hybrid mode, which comprises a shell, a sealing groove is formed in the top end of the shell; a transducer vibration assembly is detachably connected above the shell; an axial-radial composite magnetic circuit assembly is connected below the shell; a plug is connected below the shell in communication; a water-tight cable joint is detachably connected to the plug; wherein the transducer vibration assembly is in contact with the water-tight cable joint through piezoelectric ceramic sheet wires and moving coil wires to realize electrical connection. The low-frequency acoustic performance of the transducer is good, the working frequency band is wide, the size is small, the weight is light, two vibration modes can be coupled, and low-frequency and wide-band sound wave emission of the transducer can be realized.

Description

Technical Field

[0001] This invention relates to a transducer, specifically a low-frequency broadband curved disk transducer driven by a moving coil-piezoelectric ceramic hybrid, belonging to the field of underwater acoustic transducer technology. Background Technology

[0002] As a core component of sonar, underwater acoustic transducers enable underwater electro-acoustic energy conversion. Low-frequency sound waves have the significant advantage of long transmission distance underwater and are widely used in underwater target detection, underwater acoustic communication, underwater acoustic countermeasures, marine geological exploration, and marine resource development. They have important research value and military significance in national economy and defense technology.

[0003] Generally speaking, the operating frequency of a transducer is inversely proportional to its physical parameters such as size and weight; that is, the lower the operating frequency, the larger and heavier the transducer. Common low-frequency underwater acoustic transducers mainly include piezoelectric transducers such as inlaid ring transducers, bent tension transducers, bent disc transducers, and bent rod transducers, as well as moving coil transducers. Among them, piezoelectric transducers have disadvantages such as large size and heavy weight in order to achieve low-frequency acoustic emission. For example, the HX-554 bent rod piezoelectric transducer is about 1 meter in diameter, about 2 meters long, and weighs 2.3 tons. Bent disc transducers need to form an array using the mutual radiation principle to achieve low-frequency acoustic emission, which not only has disadvantages such as large size and heavy weight, but also poor adaptability and narrow operating frequency band. Moving coil transducers have good low-frequency acoustic performance, but have disadvantages such as poor resistance to hydrostatic pressure and low radiation sound source level.

[0004] As people's technical requirements for underwater vehicles in terms of endurance, size, and weight increase, underwater acoustic transducers, as acoustic loads, are developing towards low frequency, broadband, and high power. Transducers using traditional single-mode drive cannot simultaneously meet the requirements of low frequency, broadband, high power, small size, and light weight.

[0005] The invention patent application with publication number CN111083611A provides a small-sized moving-coil ultra-low frequency underwater acoustic transducer. It includes a radially arranged magnetic circuit system structure and a corresponding radiation system structure installed within a watertight housing. When current flows through the coil, a driving force is generated in the air gap of the magnetic circuit under the action of the magnetic field, driving the radiation system to vibrate according to a certain pattern, radiating sound waves outward from the radiating plate. This invention has advantages such as small size, light weight, ease of use, and good adaptability. However, the small-sized moving-coil ultra-low frequency underwater acoustic transducer proposed in this invention is a single-drive type, mainly utilizing the mode of longitudinal vibration of the transducer's radiating plate. Above a certain frequency, the coil reactance increases, leading to an increase in the transducer's reactive power and a relatively low electroacoustic conversion efficiency.

[0006] The invention patent application CN110021285A provides an underwater acoustic transducer comprising a watertight shell with openings at the top and bottom, an upper pressure plate, a lower pressure plate, an upper radiating surface, a lower radiating surface, an upper pressure plate, a lower pressure plate, an electromagnetic drive mechanism, an upper spring assembly, a lower spring assembly, an upper watertight rubber assembly, and a lower watertight rubber assembly. It features high conversion efficiency, low energy consumption, small size, light weight, ultra-low frequency operation, high power output, and a simple structure. The difference between this patent and CN111083611A is that CN111083611A uses an electromagnetic drive method, which can achieve high-power acoustic emission at low frequencies. However, due to the larger mass of the vibrating structure and higher quality factor, this design can only operate within a narrower frequency band.

[0007] The invention patent with authorization announcement number CN107580274B proposes a pieced-together curved disc underwater acoustic transducer, comprising a metal core, an insulating ceramic sheet, and a pieced-together piezoelectric ceramic ring. It features low frequency response, high transmission voltage response, simple structure, and light weight. The inventiveness of this invention lies primarily in overcoming the shortcomings of traditional curved transducers, such as low transmission voltage response. Curved disc transducers also suffer from a high quality factor, leading to a narrow operating frequency range; compared to moving-coil transducers, the lower limit of the operating frequency is not low enough, and a single curved disc cannot achieve low-frequency acoustic emission in the tens of hertz range.

[0008] Therefore, developing a water acoustic transducer that is small in size, low in frequency, wide in bandwidth, and lightweight is the key to solving the above technical problems. Summary of the Invention

[0009] In view of the many defects and deficiencies in the above-mentioned background technology, the present invention has made improvements and innovations, aiming to provide a low-frequency broadband curved disk transducer driven by a moving coil-piezoelectric ceramic hybrid drive, which can couple two vibration modes to realize low-frequency, broadband acoustic wave emission of the transducer.

[0010] Another objective of this invention is that the provided transducer has the advantages of good low-frequency performance, wide operating bandwidth, small size, and light weight, and can be used as an underwater acoustic load or directly as a general-purpose underwater low-frequency sound source.

[0011] To solve the above problems and achieve the above-mentioned objectives, the present invention provides a low-frequency broadband curved disk transducer driven by a moving coil-piezoelectric ceramic hybrid system, which is achieved by adopting the following design structure and the following technical solution:

[0012] A low-frequency broadband curved disk transducer driven by a dynamic coil-piezoelectric ceramic hybrid drive includes: a housing (1), and a sealing groove is provided at the top of the housing (1);

[0013] Transducer vibration assembly (2) is detachably connected to the top of housing (1);

[0014] Axial-radial composite magnetic circuit assembly (3) is connected to the lower part of the housing (1);

[0015] Plug (4), plug (4) is connected to the bottom of the shell (1);

[0016] Watertight cable connector (5), which is detachably connected to the plug (4);

[0017] The transducer vibration assembly (2) is electrically connected to the watertight cable connector (5) through the piezoelectric ceramic sheet wire (21) and the moving coil wire (28).

[0018] Preferably, the top of the housing (1) is provided with an opening, and a sealing groove and several mounting holes are provided circumferentially at the top of the housing (1), and a radiating plate O-ring (11) is installed in the sealing groove;

[0019] The plug (4) has a connecting groove circumferentially opened on the outer side and inward, and an O-ring seal (41) for the plug is installed in the connecting groove;

[0020] The upper end of the plug (4) is connected to the lower end of the housing (1) through the opening, and the lower end of the plug (4) is connected to the middle of the bottom of the housing (1) by fasteners.

[0021] In this invention, the top of the housing (1) is provided with an opening, and the acoustic radiation thin plate (22) and the housing (1) are sealed on the contact surface by a radiation plate O-ring (11).

[0022] Preferably, a mounting base is provided between the plug (4) and the watertight cable connector (5). The mounting base is tightly connected to the middle of the plug (4). One end of the mounting base has a toothed annular groove structure, and the other end has a threaded structure.

[0023] In this invention, the toothed structure reduces the risk of water molecules penetrating the transducer along the bonding surface; the threaded structure of the mounting base is used for threaded connection with other external equipment.

[0024] Preferably, the transducer vibration assembly (2) is used to convert electrical energy into mechanical energy and radiate sound waves outward; the transducer vibration assembly (2) includes:

[0025] A sound radiation thin plate (22) is provided with several shell connection holes in the circumference of the sound radiation thin plate (22), and a winding frame connection hole is provided in the middle of the sound radiation thin plate (22);

[0026] An external piezoelectric ceramic sheet (23) is circumferentially connected to the outer surface of the acoustic radiation thin plate (22);

[0027] An internal piezoelectric ceramic sheet (24) is circumferentially connected to the inner surface of the acoustic radiation thin plate (22);

[0028] The upper end of the winding frame (25) is connected to the winding frame connection hole in the middle of the acoustic radiation thin plate (22) by a locking member, and the winding frame (25) is wound with enameled wire (26);

[0029] The positive and negative electrode surfaces of the internal piezoelectric ceramic sheet (24) are electrically connected to the watertight cable connector (5) through the piezoelectric ceramic sheet wire (21) to drive the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) to vibrate.

[0030] In this invention, the acoustic radiation plate (22) is made of a lightweight and high-strength material with an insulating surface to prevent it from being connected to the electrodes of the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24). It is preferably made of titanium alloy or aluminum alloy. The acoustic radiation plate (22) is fastened to the winding frame (25) by a locking member (coil fixing screw) to ensure that the driving force generated by the coil is effectively transmitted to the acoustic radiation plate (22). The acoustic radiation plate (22) is fastened to the housing (1) along the outer circumference by a radiation plate mounting screw.

[0031] Before installation, both the coil fixing screws and the radiation plate mounting screws need to be coated with thread-locking adhesive to prevent the transducer from loosening or even falling off during operation and causing damage.

[0032] Preferably, a protective layer (27) is provided on the outer side of the external piezoelectric ceramic sheet (23). The protective layer (27) is made of sound-permeable rubber, which can provide watertight insulation and improve the transmission response.

[0033] The external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) are respectively bonded to two surfaces in the thickness direction of the acoustic radiation thin plate (22) by adhesive. The electrode polarities of the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) are consistent with those of the contact surface with the acoustic radiation thin plate (22), and the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) are connected in parallel.

[0034] In this invention, the protective layer (27) is a sound-permeable rubber layer, and the outer piezoelectric ceramic sheet (23) is covered with sound-permeable rubber, which isolates the outer piezoelectric ceramic sheet (23) from the working water medium, prevents electrical conduction, and achieves the effects of watertight insulation and improved transmission response; the sound-permeable rubber can also increase the damping of the moving coil-piezoelectric ceramic hybrid drive transducer, optimize the quality factor, and make the transmission voltage response curve of the transducer flatter; furthermore, if the material of the protective layer (27) is neoprene rubber, it is formed by high temperature and high pressure vulcanization; if the material of the protective layer (27) is JA-2S polyurethane rubber, it is formed by casting.

[0035] The external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) are respectively bonded to the two surfaces of the acoustic radiation thin plate (22) in the thickness direction by epoxy resin adhesive.

[0036] Preferably, the contact surfaces of the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) with the acoustic radiation plate (22) are both negative, so as to avoid the transducer failing to work properly underwater when the insulation of the acoustic radiation plate (22) fails.

[0037] Preferably, several layers of enameled wire (26) are wound on the cylindrical surface of the winding frame (25).

[0038] The surface of the winding frame (25) is insulated; the enameled wire (26) is wound and pasted onto the winding frame (25) with adhesive.

[0039] In this invention, to ensure that the enameled wire (26) is reliably wound on the surface of the winding frame (25), an impregnation process or a thermally conductive epoxy resin adhesive is used for bonding, preventing the enameled wire (26) from separating or falling off from the winding frame (25) and improving the reliability of the winding of the enameled wire (26); preferably, the winding frame (25) is made of lightweight and high-strength non-metallic or metallic materials; furthermore, if the winding frame (25) is made of metallic materials, it needs to undergo surface insulation treatment to prevent the enameled wire (26) from breaking off under extreme conditions. 6) Electrically connected to the winding frame (25); furthermore, the winding frame (25) has an even number of winding layers, usually two, four or six layers; the winding frame (25) is made of ultra-hard aluminum alloy to ensure that the moving coil has the characteristics of being lightweight and high-strength, and the surface of the winding frame (25) is anodized to improve the insulation of the contact surface between the winding frame (25) and the enameled wire (26); the enameled wire (26) can be made of copper core wire, aluminum core wire or copper-clad aluminum wire, etc., and the cross-section of the enameled wire (26) can be round wire or flat wire.

[0040] Preferably, the axial-radial composite magnetic circuit assembly (3) includes a magnetic cup (32), a radially oriented permanent magnet (33), a magnetic ring (34), and a magnetic post (35) arranged coaxially and circumferentially within the housing (1) from the outside to the inside. It also includes an axially oriented permanent magnet (31), which is arranged circumferentially inside the magnetic cup (32) and located outside the magnetic post (35) and below the radially oriented permanent magnet (33) and the magnetic ring (34).

[0041] In this invention, the axial-radial composite magnetic circuit assembly (3) is used to provide a magnetic field with high intensity, high uniformity and large magnetic circuit air gap space for the moving coil, so as to increase the thrust of the moving coil and improve the electro-acoustic energy conversion efficiency of the moving coil drive transducer.

[0042] The magnetic cup (32) and the magnetic column (35) are used to conduct and control the magnetic lines of force of the permanent magnet, so that the magnetic lines of force converge in the working air gap of the coil and reduce the leakage of magnetic field energy.

[0043] The radially oriented permanent magnet (33) mainly provides a large-size, highly uniform magnetic field for the working air gap of the coil;

[0044] The magnetic ring (34) is used to optimize the magnetic field contribution of the radially oriented permanent magnet (33) and the axially oriented permanent magnet (31) to the working air gap of the coil. Through the reasonable design of the magnetic ring (34), the direction and distribution uniformity of the magnetic field lines in the working air gap of the coil can be improved.

[0045] The axially oriented permanent magnet (31) strengthens the magnetic field of the working air gap of the coil and increases the magnetic field strength.

[0046] Preferably, the outer side of the radially oriented permanent magnet (33) is connected to the inner wall of the magnetic cup (32) by an adhesive, the inner side of the radially oriented permanent magnet (33) is connected to the outer side of the magnetic ring (34) by an adhesive, the upper end of the axially oriented permanent magnet (31) is connected to the radially oriented permanent magnet (33) and the magnetic ring (34) by an adhesive, and the lower end of the axially oriented permanent magnet (31) is connected to the inner upper surface of the magnetic cup (32).

[0047] In this invention, the magnetic cup (32), magnetic ring (34), and magnetic column (35) can be made of materials such as high-saturation soft magnetic alloy, permalloy, electrical pure iron, or low-carbon steel; preferably, considering both economic and technical parameters, the magnetic cup (32), magnetic ring (34), and magnetic column (35) can be made of different magnetic materials in combination.

[0048] The radially oriented permanent magnet (33) and the axially oriented permanent magnet (31) can be permanent magnet materials such as neodymium iron boron, samarium cobalt, and ferrite. The radially oriented permanent magnet (33) is oriented radially, and the axially oriented permanent magnet (31) is oriented axially. Furthermore, the radially oriented permanent magnet (33) and the axially oriented permanent magnet (31) can be made by integral molding or unit splicing according to the size and process.

[0049] In this invention, the magnetic bowl (32), magnetic ring (34), and magnetic column (35) are all made of high-saturation soft magnetic alloy 1J22; the radially oriented permanent magnet (33) and the axially oriented permanent magnet (31) are both made of N45SH neodymium iron boron. The radially oriented permanent magnet (33) is made of multiple tile units spliced ​​together, and the axially oriented permanent magnet (31) is also made of circular segment units with the same number of tiles as the radially oriented permanent magnet (33) spliced ​​together.

[0050] Preferably, the lower end of the winding frame (25) is disposed between the magnetic ring (34) and the magnetic post (35).

[0051] The working principle is as follows: Before use, the operator uses a hoisting device to hoist the present invention to the underwater unmanned submersible (6) that needs to be equipped with the existing structure and install it to form an integral whole. After installation and inspection and testing, it can be put into use. When the dynamic coil-piezoelectric ceramic hybrid drive transducer of this design structure is working, it is driven by two parts to radiate sound waves outward. In the frequency band near f1, the excitation electrical signal in the enameled wire (26) is transmitted to the sound radiation thin plate (22) through the winding frame (25) under the interaction of magnetic field and current, and the lower frequency sound waves are radiated outward. In the frequency band near f2, the "triple-layer" curved disk transducer composed of the sound radiation thin plate (22), the outer piezoelectric ceramic sheet (23) and the inner piezoelectric ceramic sheet (24) is excited by the electrical signal and subjected to the inverse piezoelectric effect. The outer piezoelectric ceramic sheet (23) and the inner piezoelectric ceramic sheet (24) drive the sound radiation thin plate (22) to vibrate and radiate higher frequency sound waves outward. On the one hand, the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) serve as the vibrating components driven by the moving coil, which can increase the mass and thus reduce the resonant frequency of the moving coil driven bending disk. On the other hand, due to the difference in driving principle and working mode, the resonant frequency of the moving coil driven bending disk is f1, and the resonant frequency of the piezoelectric ceramic driven bending disk is f2. The vibration modes corresponding to the resonant frequencies f1 and f2 of the moving coil-piezoelectric ceramic hybrid drive transducer can realize low-frequency, broadband sound wave radiation.

[0052] The beneficial effects of this invention compared to the prior art are:

[0053] 1. This invention proposes a low-frequency broadband curved disk transducer scheme driven by a hybrid dynamic coil and piezoelectric ceramic, which cleverly utilizes the driving principles of the dynamic coil and piezoelectric ceramic, as well as the difference between the working resonant frequency and mode, to couple the two vibration modes and realize the low-frequency, broadband acoustic wave emission of the transducer;

[0054] 2. Compared with the traditional "triple-plate" piezoelectric bent disk transducer, the present invention has a lower operating frequency and a wider operating bandwidth;

[0055] 3. This invention utilizes piezoelectric ceramic sheets to increase the weight of the vibrating component and reduce the resonant frequency of the moving coil drive. Compared with traditional moving coil transducers, it has a higher transmission voltage response and a wider operating bandwidth.

[0056] 4. This invention has the advantages of good low-frequency performance, wide operating bandwidth, small size and light weight. It can be used as an underwater acoustic load or directly as a general underwater low-frequency sound source. Attached Figure Description

[0057] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0058] Figure 1 This is one of the usage state diagrams of the present invention;

[0059] Figure 2 This is one of the usage state diagrams of the present invention;

[0060] Figure 3 This is a schematic diagram of the overall structure of the present invention;

[0061] Figure 4 This is a cross-sectional schematic diagram of the present invention;

[0062] Figure 5 This is a cross-sectional schematic diagram of the present invention;

[0063] Figure 6 This is one of the partial exploded view diagrams of the present invention;

[0064] Figure 7 This is the second partially exploded schematic diagram of the present invention;

[0065] Figure 8 This is a cross-sectional schematic diagram of the transducer vibration assembly component of the present invention;

[0066] Figure 9 This is a cross-sectional structural schematic diagram of the axial-radial composite magnetic circuit assembly component of the present invention;

[0067] Figure 10 This is a schematic diagram of the voltage response curve transmitted by the present invention;

[0068] In the figure, the numbers are: 1—shell, 11—radial plate O-ring seal;

[0069] 2—Transducer vibration assembly; 21—Piezoelectric ceramic sheet wire; 22—Acoustic radiation plate; 23—Outer piezoelectric ceramic sheet; 24—Inner piezoelectric ceramic sheet; 25—Winding frame; 26—Enamelled wire; 27—Protective layer; 28—Moving coil wire.

[0070] 3—Axial-radial composite magnetic circuit assembly; 31—Axially oriented permanent magnet; 32—Magnetic cup; 33—Radially oriented permanent magnet; 34—Magnetic ring; 35—Magnetic column;

[0071] 4—Plug, 41—Plug O-ring seal;

[0072] 5—Watertight cable joint;

[0073] 6—Unmanned underwater vehicle. Detailed Implementation

[0074] To make the technical means, inventive features, objectives, and effects of this invention readily understandable, the technical solution of this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0075] See attached document Figure 1 and attached Figure 2 This embodiment provides a low-frequency broadband curved disk transducer driven by a dynamic coil-piezoelectric ceramic hybrid, which can be used as an acoustic load for underwater unmanned submersibles and is conformally mounted with the hull of the submersible.

[0076] See attached document Figure 3 and attached Figure 4 This embodiment provides a low-frequency broadband curved disk transducer driven by a hybrid dynamic coil-piezoelectric ceramic, comprising a housing 1, a transducer vibration assembly 2, an axial-radial composite magnetic circuit assembly 3, a plug 4, and a watertight cable connector 5. The housing 1 has a sealing groove at its top. The transducer vibration assembly 2 is detachably connected to the top of the housing 1. The axial-radial composite magnetic circuit assembly 3 is connected to the lower part of the housing 1. The plug 4 is connected to the lower part of the housing 1. The watertight cable connector 5 is detachably connected to the plug 4. The transducer vibration assembly 2 is electrically connected to the watertight cable connector 5 through piezoelectric ceramic sheet wires 21 and dynamic coil wires 31.

[0077] Furthermore, the top of the housing 1 has an opening, and a sealing groove and several mounting holes are circumferentially formed at the top of the housing 1. A radial plate O-ring seal 11 is installed in the sealing groove. The plug 4 has a connecting groove circumferentially formed on its outer side, and a plug O-ring seal 41 is installed in the connecting groove. The upper end of the plug 4 is connected to the lower end opening of the housing 1, and the lower end of the plug 4 is connected to the middle of the bottom end of the housing 1 by fasteners. The top of the housing 1 has an opening, and a seal is achieved at the contact surface with the housing 1 by the radial plate O-ring seal 11. A mounting seat is also provided between the plug 4 and the watertight cable connector 5. The mounting seat is tightly connected to the middle of the plug 4. One end of the mounting seat has a toothed annular groove structure, and the other end has a threaded structure.

[0078] See attached document Figure 5 Appendix Figure 6 Appendix Figure 7 and attached Figure 8The transducer vibration assembly 2 provided in this embodiment is used to convert electrical energy into mechanical energy and radiate sound waves outward. It includes a sound radiation plate 22, an outer piezoelectric ceramic sheet 23, an inner piezoelectric ceramic sheet 24, and a winding frame 25. The sound radiation plate 22 has several housing connection holes circumferentially, and a winding frame connection hole is located in the middle of the sound radiation plate 22. The outer piezoelectric ceramic sheet 23 is circumferentially connected to the outer surface of the sound radiation plate 22; the inner piezoelectric ceramic sheet 24 is circumferentially connected to the inner surface of the sound radiation plate 22; the upper end of the winding frame 25 is connected to the winding frame connection hole in the middle of the sound radiation plate 22 via a locking member, and enameled wire 26 is wound on the winding frame 25. The positive and negative electrode surfaces of the inner piezoelectric ceramic sheet 24 are electrically connected to a watertight cable connector 5 via piezoelectric ceramic sheet wires 21 to drive the vibration of the outer piezoelectric ceramic sheet 23 and the inner piezoelectric ceramic sheet 24.

[0079] Furthermore, the acoustic radiation plate 22 is made of a lightweight and high-strength material with an insulating surface to prevent conduction between it and the electrodes of the external piezoelectric ceramic sheet 23 and the internal piezoelectric ceramic sheet 24. It is preferably made of titanium alloy or aluminum alloy. The acoustic radiation plate 22 is fastened to the winding frame 25 by a locking device (coil fixing screw) to ensure that the driving force generated by the coil is effectively transmitted to the acoustic radiation plate 22. The acoustic radiation plate 22 is fastened to the housing 1 along the outer circumference by radiation plate mounting screws. Before installation, both the coil fixing screw and the radiation plate mounting screw need to be coated with thread glue on the thread surface to prevent the transducer from loosening or even falling off during operation and causing damage to the transducer.

[0080] See attached document Figure 8 The outer piezoelectric ceramic sheet 23 is also provided with a protective layer 27. The protective layer 27 is made of sound-permeable rubber, which can provide watertight insulation and improve the transmission response. The outer piezoelectric ceramic sheet 23 and the inner piezoelectric ceramic sheet 24 are respectively bonded to the two surfaces of the acoustic radiation thin plate 22 in the thickness direction by adhesive. The electrode polarities of the outer piezoelectric ceramic sheet 23 and the inner piezoelectric ceramic sheet 24 are consistent with those of the contact surface with the acoustic radiation thin plate 22. The outer piezoelectric ceramic sheet 23 and the inner piezoelectric ceramic sheet 24 are connected in parallel.

[0081] Furthermore, the protective layer 27 is a sound-permeable rubber layer, and the outer piezoelectric ceramic sheet 23 is covered with sound-permeable rubber, which isolates the outer piezoelectric ceramic sheet 23 from the working water medium, prevents electrical conduction, and provides watertight insulation and improves the transmission response. The sound-permeable rubber can also increase the damping of the moving coil-piezoelectric ceramic hybrid drive transducer, optimize the quality factor, and make the transmission voltage response curve of the transducer flatter.

[0082] Further preferably, if the material of the protective layer 27 is chloroprene rubber, it is vulcanized by high temperature and high pressure; if the material of the protective layer 27 is JA-2S polyurethane rubber, it is cured by casting; the external piezoelectric ceramic sheet 23 and the internal piezoelectric ceramic sheet 24 are respectively bonded to the two surfaces in the thickness direction of the acoustic radiation thin plate 22 by epoxy resin adhesive.

[0083] Furthermore, the contact surfaces of the external piezoelectric ceramic sheet 23 and the internal piezoelectric ceramic sheet 24 with the acoustic radiation thin plate 22 are both negative to prevent the transducer from failing to work properly underwater if the insulation of the acoustic radiation thin plate 22 fails.

[0084] Furthermore, several layers of enameled wire 26 are wound on the cylindrical surface of the winding frame 25, and the surface of the winding frame 25 is insulated; the enameled wire 26 is then bonded to the winding frame 25 with adhesive. Preferably, to ensure the enameled wire 26 is reliably wound on the surface of the winding frame 25, an impregnation process or a thermally conductive epoxy resin adhesive is used for bonding, preventing the enameled wire 26 from separating or falling off the winding frame 25 and improving the reliability of the winding of the enameled wire 26; more preferably, the winding frame 25 is made of lightweight and high-strength non-metallic or metallic materials; further preferably, if the winding frame 25 is made of metallic materials, it needs to undergo surface insulation treatment to prevent the enameled wire 26 from conducting electricity with the winding frame 25 under extreme conditions; further preferably, the winding frame 25 has an even number of winding layers, usually two, four, or six layers; the winding frame 25 is made of ultra-hard aluminum alloy to ensure that the moving coil has the characteristics of being lightweight and high-strength, and the surface of the winding frame 25 is anodized to improve the insulation of the contact surface between the winding frame 25 and the enameled wire 26; the enameled wire 26 can be made of copper core wire, aluminum core wire, or copper-clad aluminum wire, and the cross-section of the enameled wire 26 can be round or flat wire.

[0085] See attached document Figure 9 The axial-radial composite magnetic circuit assembly 3 provided in this embodiment includes a magnetic cup 32, a radially oriented permanent magnet 33, a magnetic ring 34, and a magnetic post 35 arranged coaxially and circumferentially within the housing 1 from the outside to the inside. It also includes an axially oriented permanent magnet 36, which is arranged circumferentially inside the magnetic cup 32 and located outside the magnetic post 35 and below the radially oriented permanent magnet 33 and the magnetic ring 34.

[0086] Furthermore, the axial-radial composite magnetic circuit assembly 3 is used to provide a high-intensity, highly uniform magnetic field with a large magnetic air gap space for the moving coil, thereby increasing the thrust of the moving coil and improving the electro-acoustic energy conversion efficiency of the moving coil-driven transducer. The magnetic cup 32 and magnetic post 35 are used to conduct and control the magnetic field lines of the permanent magnets, ensuring that the magnetic field lines converge within the working air gap of the coil and reducing magnetic field energy leakage. The radially oriented permanent magnet 33 primarily provides a large-size, highly uniform magnetic field for the working air gap of the coil; the magnetic ring 34 is used to optimize the magnetic field contribution of the radially oriented permanent magnet 33 and the axially oriented permanent magnet 36 to the working air gap of the coil. Through the rational design of the magnetic ring 34, the direction and distribution uniformity of the magnetic field lines in the working air gap of the coil can be improved; the axially oriented permanent magnet 36 strengthens the magnetic field in the working air gap of the coil, increasing the magnetic field strength.

[0087] Furthermore, the outer side of the radially oriented permanent magnet 33 is connected to the inner wall of the magnetic cup 32 by adhesive, the inner side of the radially oriented permanent magnet 33 is connected to the outer side of the magnetic ring 34 by adhesive, the upper end of the axially oriented permanent magnet 36 is connected to the radially oriented permanent magnet 33 and the magnetic ring 34 by adhesive, and the lower end of the axially oriented permanent magnet 36 is connected to the inner upper surface of the magnetic cup 32. Furthermore, the radially oriented permanent magnet 33 and the axially oriented permanent magnet 36 can be implemented using integral molding or unit splicing methods, depending on the size and process.

[0088] Preferably, in this embodiment, the magnetic cup 32, the magnetic ring 34, and the magnetic post 35 are all made of high-saturation soft magnetic alloy 1J22; the radially oriented permanent magnet 33 and the axially oriented permanent magnet 36 are both made of N45SH neodymium iron boron. The radially oriented permanent magnet 33 is assembled from multiple tile units, and the axially oriented permanent magnet 36 is also assembled from circular ring segment units with the same number of tiles as the radially oriented permanent magnet 33.

[0089] See attached document Figure 10 To further explain, when the aforementioned moving-coil-piezoelectric ceramic hybrid drive transducer is working, it is driven by two parts to radiate sound waves outward. Specifically: in the frequency band near f1, the excitation electrical signal in the enameled wire 7, under the interaction of the magnetic field and current, transmits the driving force through the winding frame 6 to the sound radiation thin plate 1, radiating lower frequency sound waves outward; in the frequency band near f2, the "triple-layer" curved disk transducer, composed of the sound radiation thin plate 1, the outer piezoelectric ceramic sheet 2, and the inner piezoelectric ceramic sheet 3, under the excitation of the electrical signal, is subjected to the inverse piezoelectric effect, and the outer piezoelectric ceramic sheet 2 and the inner piezoelectric ceramic sheet 3 drive the sound radiation thin plate 1 to vibrate, radiating higher frequency sound waves outward. Due to the difference in driving principle and working mode, the resonant frequency of the moving-coil driven curved disk is f1, and the resonant frequency of the piezoelectric ceramic driven curved disk is f2. The moving-coil-piezoelectric ceramic hybrid drive transducer couples the vibration modes corresponding to the resonant frequencies f1 and f2, which can realize low-frequency, broadband sound wave radiation.

[0090] The following provides the manufacturing steps for a low-frequency broadband curved disk transducer driven by a moving coil-piezoelectric ceramic hybrid drive according to the present invention.

[0091] Step 1: Preparation of the axial-radial composite magnetic circuit assembly 3. First, after applying adhesive to the lower end face of the axially oriented permanent magnet 36, it is coaxially mounted with the magnetic cup 32. Second, after applying adhesive to the arc surface of the radially oriented permanent magnet 33, it is coaxially mounted with the magnetic cup 32 and contacts the end face of the axially oriented permanent magnet 36. Third, after coaxially mounting the outer cylindrical surface of the magnetic ring 34 with the inner cylindrical surface of the radially oriented permanent magnet 33, the magnetic ring 34 contacts the end face of the axially oriented permanent magnet 36. Finally, after applying adhesive to the bottom surface of the magnetic column 35, it is coaxially placed with the magnetic cup 32 and installed until their end faces contact. After the adhesive cures, the preparation of the axial-radial composite magnetic circuit assembly 3 is complete. The fabricated and installed assembly is then transported manually or using appropriate handling equipment to a designated location for use.

[0092] Step 2: Preparation of transducer vibration assembly 2, i.e., piezoelectric ceramic excitation bending disk assembly. First, the surface of the aluminum alloy acoustic radiation plate 22 is anodized to give it good insulation properties. Second, the surfaces of the outer piezoelectric ceramic sheet 23 and the inner piezoelectric ceramic sheet 24 are cleaned with anhydrous ethanol or acetone and then coated with epoxy resin adhesive. Third, the outer piezoelectric ceramic sheet 23 and the inner piezoelectric ceramic sheet 24 are bonded to both sides of the plane of the acoustic radiation plate 22, and the epoxy resin adhesive is allowed to cure and solidify. Finally, a certain shape of JA-2S polyurethane rubber is poured into the outer piezoelectric ceramic sheet 23, and the mixture is placed in a constant temperature chamber at 80°C for 24 hours to form a protective layer 27, followed by demolding and cleaning. This completes the preparation of transducer vibration assembly 2.

[0093] Step 3: Assembly of the low-frequency broadband curved disk transducer driven by the moving coil-piezoelectric ceramic hybrid. First, the surface of the housing 1 is cleaned, and silicone grease is applied to the surface of the O-ring seal 11 of the radiating plate before it is installed in the sealing groove of the housing 1. The axial-radial composite magnetic circuit assembly 3 prepared in step 1 is then placed into the housing 1. Second, the winding frame 25 with the pre-wound enameled wire 26 is coaxially fitted with the acoustic radiation thin plate 22, and then the two are fastened together by the locking device, which is a coil fixing screw. After that, the winding frame 25 is coaxially fitted with the axial-radial composite magnetic circuit and placed in the air gap between the magnetic ring 34 and the magnetic column 35. The acoustic radiation thin plate 22 is then fastened to the housing 1 by the radiating plate mounting screw. Third, the surface of the plug 4 is cleaned, and silicone grease is applied to the surface of the plug O-ring seal 41 before it is installed in the sealing groove of the plug 4. The watertight cable connector 5 is installed in the plug 4. Finally, the moving coil wire 21 and the piezoelectric ceramic sheet wire 31 are soldered to the corresponding pins of the watertight cable connector 5, and the plug 4 is installed on the housing 1 by the plug screw. This completes the fabrication of the low-frequency broadband curved disk transducer driven by a hybrid dynamic-piezoelectric ceramic system, which is ready for use upon completion.

[0094] Before use, the operator uses a hoisting device to hoist the invention to the underwater unmanned submersible that needs to be equipped, installs it, and checks and tests it before putting it into use.

[0095] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid, characterized in that, include: The shell (1) has a sealing groove at its top; The transducer vibration assembly (2) is detachably connected to the top of the housing (1); An axial-radial composite magnetic circuit assembly (3) is connected to the lower part of the housing (1); Plug (4), plug (4) is connected to the bottom of the shell (1); Watertight cable connector (5), which is detachably connected to the plug (4); Among them, the transducer vibration assembly (2) is electrically connected to the watertight cable connector (5) through the piezoelectric ceramic sheet wire (21) and the moving coil wire (28); The transducer vibration assembly (2) is used to convert electrical energy into mechanical energy and radiate sound waves outward; the transducer vibration assembly (2) includes: A sound radiation thin plate (22) is provided with several shell connection holes in the circumference of the sound radiation thin plate (22), and a winding frame connection hole is provided in the middle of the sound radiation thin plate (22); An external piezoelectric ceramic sheet (23) is circumferentially connected to the outer surface of the acoustic radiation thin plate (22); An internal piezoelectric ceramic sheet (24) is circumferentially connected to the inner surface of the acoustic radiation thin plate (22); The upper end of the winding frame (25) is connected to the winding frame connection hole in the middle of the acoustic radiation thin plate (22) by a locking member, and the winding frame (25) is wound with enameled wire (26). Among them, the positive and negative electrode surfaces of the internal piezoelectric ceramic sheet (24) are electrically connected to the watertight cable connector (5) through the piezoelectric ceramic sheet wire (21) to drive the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) to vibrate; The outer piezoelectric ceramic sheet (23) is also provided with a protective layer (27), which is made of sound-permeable rubber and can provide watertight insulation and improve the transmission response. The external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) are respectively bonded to two surfaces in the thickness direction of the acoustic radiation thin plate (22) by adhesive. The electrode polarities of the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) are consistent with those of the contact surface with the acoustic radiation thin plate (22), and the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) are connected in parallel.

2. The low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid according to claim 1, characterized in that, The top of the housing (1) is provided with an opening, and a sealing groove and several mounting holes are provided circumferentially at the top of the housing (1). A radiating plate O-ring (11) is installed in the sealing groove. The plug (4) has a connecting groove circumferentially opened from the outside to the inside, and an O-ring seal (41) for the plug is installed in the connecting groove. The upper end of the plug (4) is connected to the lower end of the housing (1) through the opening, and the lower end of the plug (4) is connected to the middle of the bottom of the housing (1) by fasteners.

3. A low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid according to claim 1, characterized in that, An installation seat is provided between the plug (4) and the watertight cable connector (5). The installation seat is tightly connected to the middle of the plug (4). One end of the installation seat has a toothed annular groove structure, and the other end has a threaded structure.

4. A low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid according to claim 1, characterized in that, The contact surfaces of the external piezoelectric ceramic sheet (23) and the internal piezoelectric ceramic sheet (24) with the acoustic radiation plate (22) are both negative, so as to avoid the transducer failing to work properly underwater when the insulation of the acoustic radiation plate (22) fails.

5. A low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid according to claim 1, characterized in that, Several layers of enameled wire (26) are wound on the cylindrical surface of the winding frame (25). The surface of the winding frame (25) is insulated; the enameled wire (26) is wound and pasted onto the winding frame (25) with adhesive.

6. A low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid according to claim 1, characterized in that, The axial-radial composite magnetic circuit assembly (3) includes a magnetic cup (32), a radially oriented permanent magnet (33), a magnetic ring (34), and a magnetic post (35) arranged coaxially and circumferentially within the housing (1) from the outside to the inside. It also includes an axially oriented permanent magnet (31), which is arranged circumferentially inside the magnetic cup (32) and located outside the magnetic post (35) and below the radially oriented permanent magnet (33) and the magnetic ring (34).

7. A low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid according to claim 6, characterized in that, The outer side of the radially oriented permanent magnet (33) is connected to the inner wall of the magnetic cup (32) by an adhesive, the inner side of the radially oriented permanent magnet (33) is connected to the outer side of the magnetic ring (34) by an adhesive, the upper end of the axially oriented permanent magnet (31) is connected to the radially oriented permanent magnet (33) and the magnetic ring (34) by an adhesive, and the lower end of the axially oriented permanent magnet (31) is connected to the inner upper surface of the magnetic cup (32).

8. A low-frequency broadband curved disk transducer driven by a moving coil and piezoelectric ceramic hybrid according to claim 1, characterized in that, The lower end of the winding frame (25) is disposed between the magnetic ring (34) and the magnetic post (35).

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