A transceiving integrated mortise and tenon type underwater acoustic transducer

Abstract

The application discloses a transceiving integrated mortise and tenon type underwater acoustic transducer, and belongs to the field of piezoelectric materials and sensors thereof. The transducer comprises a mortise and tenon type piezoelectric module, a backing layer, a multi-core cable, a rear end cover and a water-tight layer. The mortise and tenon type piezoelectric module is mainly composed of a tenon unit, a mortise unit, an electrode unit and a rubber unit. The tenon unit is connected with the mortise unit through the rubber unit; the rigid tenon module and the rigid mortise module are stacked along the longitudinal direction through the rubber unit, so that the multi-mode bandwidth is expanded. The backing layer is fixed at the bottom of the mortise and tenon type piezoelectric module and plays a supporting role for the piezoelectric module and a role in absorbing clutter; the multi-core cable is fixed at the bottom of the backing layer, one end of the cable is connected with all the lead wires, and the other end of the cable is led out from the inner side of a slot hole of the rear end cover. The water-tight layer wraps the mortise and tenon type piezoelectric module, the backing layer and the top end surface of the rear end cover. The mortise and tenon type piezoelectric module contains an air gap unit, the air gap unit does not contain any polymer material, the coupling between piezoelectric columns is reduced to the minimum, and the sensitive receiving performance of the transducer can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a transceiving integrated mortise and tenon type underwater acoustic transducer, belonging to the field of piezoelectric materials and their sensors. BACKGROUND

[0002] An underwater acoustic transducer is a device that can convert acoustic signals and electrical signals to each other, widely used in underwater detection, communication, measurement and monitoring fields. Its working principle is to convert electrical signals into sound waves through a vibrating element, and convert sound waves back into electrical signals. Underwater acoustic transducers play an important role in marine science, military detection, environmental monitoring and other fields, and with the progress of science and technology and the increasing demand for applications, higher requirements are put forward for its performance.

[0003] In the design and manufacture of underwater acoustic transducers, 1-3 type piezoelectric composite materials have attracted much attention due to their excellent electroacoustic performance. This composite material is composed of two phases of piezoelectric ceramic and polymer, which has the following advantages: first, 1-3 type piezoelectric composite material has high electromechanical coupling coefficient, which can effectively improve the conversion efficiency of acoustic energy of the transducer; second, the material has high stability, which can maintain good performance under different environmental conditions, and adapt to the complex underwater environment; in addition, the low acoustic impedance characteristic of 1-3 type composite material can effectively reduce the reflection of sound waves in water, and improve the effectiveness of signal transmission. Therefore, these advantages make 1-3 type piezoelectric composite material often used to develop high-performance underwater acoustic transducers.

[0004] However, the current 1-3 type underwater acoustic transducer still has some shortcomings in practical application, especially in the aspects of transmission bandwidth and integration of transducer transmission and reception. Traditional underwater acoustic transducers are mostly single function, i.e. only used for transmission or reception, which leads to low efficiency and limited performance of the system in complex signal processing. The existing transducer has small transmission bandwidth, which limits its application ability in a wide frequency range, which is particularly prominent in some scenarios that require high-precision positioning and detection. Therefore, it is urgent to develop a new type of underwater acoustic transducer that integrates transmission and reception functions to improve overall performance and application flexibility. Through innovative materials and design concepts, the transmission and reception functions can be effectively integrated to achieve higher system integration, improve transmission efficiency and signal quality, and promote the widespread application of underwater acoustic transducers in various applications.

[0005] In summary, with the progress of technology, the design and manufacture of underwater acoustic transducers face new opportunities and challenges, especially in the aspects of material selection and function integration. Future research should focus on improving the transmission bandwidth and integration of 1-3 type underwater acoustic transducers to meet the growing market demand and application scenarios. SUMMARY

[0006] In order to solve the problems of low transmitting bandwidth and low integration of transmitting and receiving of the existing 1-3 type underwater acoustic transducer, the application provides a transceiving integrated mortise and tenon type underwater acoustic transducer, which adopts a mortise and tenon type piezoelectric module as a sensitive unit, and can simultaneously have the performances of wideband transmitting and high sensitive receiving.

[0007] The application is realized by the following technical scheme:

[0008] The application discloses a transceiving integrated mortise and tenon type underwater acoustic transducer, which comprises a mortise and tenon type piezoelectric module, a backing layer, a multi-core cable, a rear end cover and a watertight layer.

[0009] The mortise and tenon type piezoelectric module mainly comprises a tenon unit, a mortise unit, an electrode unit and a rubber unit.

[0010] The height of the middle part matrix of the tenon unit is higher than the height of the peripheral matrix, and the high part is referred to as a rigid tenon module; the remaining part is referred to as an air gap unit; a rigid polymer is filled between the rigid tenon module arrays; the end surface of the tenon unit is covered with the electrode unit; the rigid tenon module is covered with a first electrode plate; the air gap unit is covered with a second electrode plate; and the electrode units are respectively led out by lead wires.

[0011] The height of the middle part matrix of the mortise unit is lower than the height of the peripheral matrix, and the recessed part is referred to as a rigid mortise module; the remaining part is referred to as an air gap unit; a rigid polymer is filled between the rigid mortise module arrays; the end surface of the mortise unit is covered with the electrode unit; the rigid mortise module is covered with a first electrode plate; the air gap unit is covered with a second electrode plate; and the electrode units are respectively led out by lead wires.

[0012] The tenon unit and the mortise unit are connected through the rubber unit; the rigid tenon module and the rigid mortise module are stacked in the longitudinal direction through the rubber unit, so that the multi-mode bandwidth is expanded.

[0013] The backing layer is fixed at the bottom of the mortise and tenon type piezoelectric module, and plays a role of supporting the piezoelectric module and absorbing clutter; the multi-core cable is fixed at the bottom of the backing layer, and one end is connected with all the lead wires, and the other end is led out from the inside of the rear end cover slot hole.

[0014] The watertight layer wraps the top end surface of the mortise and tenon type piezoelectric module, the backing layer and the rear end cover.

[0015] As a preferred embodiment, the rigid tenon module and the rigid mortise module serve as the transmitting unit of the transducer, enabling the transducer to transmit with high mechanical strength and broadband speed; the air gap unit of the tenon unit and the mortise unit serves as the receiving unit of the transducer, enabling the transducer to receive with high sensitivity and fulfilling the transceiver function.

[0016] Preferably, the tenon and mortise units are made of PZT ceramic or PMN-PT single crystal to ensure high-intensity emission and high-sensitivity reception performance; and the pillars in the array have exactly the same structural parameters.

[0017] Preferably, the rigid polymer material is epoxy resin or PMMA, used to separate the pillars between the piezoelectric arrays while improving the stability and compressive strength of the piezoelectric arrays.

[0018] Preferably, the aspect ratio of the piezoelectric post in the rigid tenon module and the rigid mortise module is not less than 4:1; the ratio of the width of the piezoelectric post to the width of the array gap is between 0.24 and 0.35, so as to ensure that the volume fraction of the piezoelectric phase is controlled within the range of high electromechanical conversion capability of the material.

[0019] Preferably, the tenon and mortise units are stacked along the thickness direction, wherein the protruding part of the rigid tenon module should completely fit the recessed part of the rigid tenon structure.

[0020] Preferably, the rubber unit is made of decoupling material rubber with low Young's modulus; the thickness of each connecting unit does not exceed 1 mm, and its external dimensions are adapted to the tenon and mortise units.

[0021] Preferably, the electrode unit includes a first electrode plate and a second electrode plate; the electrode unit is made of metal material and has a thickness of no more than 0.5 mm.

[0022] Preferably, the backing layer is made of a foam material with high hardness and a high porosity. "High hardness" means the hardness exceeds a preset hardness threshold, and "high porosity" means the porosity exceeds a preset pore number threshold.

[0023] Preferably, the watertight layer is made of polyurethane material with strong matching and good sound transmission; the thickness of the watertight layer is controlled within 1 / 4 to 3 / 4 of the wavelength.

[0024] Preferably, the multi-core cable is used to connect the electrode unit leads.

[0025] Preferably, the rear end cover is made of metal and its dimensions are adapted to the dimensions of the backing layer.

[0026] Beneficial effects:

[0027] 1. This invention discloses a transceiver integrated tenon-and-mortise type underwater acoustic transducer. Using a tenon-and-mortise structure piezoelectric module as the vibration element enables dual-resonance coupling bandwidth extension, effectively improving the bandwidth of traditional transducers. Furthermore, the tenon-and-mortise piezoelectric module effectively separates the transmitting and receiving units, ensuring both the transducer's wideband transmission performance and its high-sensitivity receiving performance.

[0028] 2. The present invention discloses a transceiver integrated tenon and mortise type underwater acoustic transducer, which adopts a tenon and mortise integrated structure to realize the transmission and reception functions of the transducer, and has the advantages of light weight, small size and high integration. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a transceiver-type underwater acoustic transducer with an integrated mortise and tenon joint structure.

[0030] Figure 2 This is a schematic diagram of the blasting of a transceiver-receiver integrated tenon-and-mortise type underwater acoustic transducer.

[0031] Figure 3 This is a schematic diagram of the tenon unit structure of a transceiver-integrated mortise and tenon type underwater acoustic transducer.

[0032] Figure 4 This is a schematic diagram of a tenon-and-mortise type underwater acoustic transducer with integrated transceiver and mortise and tenon joints.

[0033] Figure 5 This is a top view of a rigid tenon module / rigid mortise module for an integrated transceiver mortise and tenon type underwater acoustic transducer.

[0034] Figure 6 Finite element simulation modeling of a transceiver-receiver integrated tenon-and-mortise type underwater acoustic transducer.

[0035] Figure 7 The simulation results show the electrical admittance of a transceiver-mounted tenon-and-mortise type underwater acoustic transducer.

[0036] Figure 8 The simulation results show the transmit voltage response of a transceiver unit with a tenon-and-mortise joint design.

[0037] Figure 9 The simulation results show the receiving voltage sensitivity of a transceiver unit with a tenon-and-mortise joint type underwater acoustic transducer.

[0038] In the figure, 1—watertight layer, 2—tenon-shaped unit, 3—first electrode plate, 4—electrode lead, 5—second electrode plate, 6—second rubber unit, 7—first rubber unit, 8—mortise-shaped unit, 9—backing layer, 10—rear end cover, 11—multi-core cable, 12—piezoelectric post, 13—rigid polymer, 14—air gap, 15—piezoelectric substrate. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0040] Figure 1 This is a three-dimensional structural diagram of a transceiver-receiver integrated tenon-and-mortise type underwater acoustic transducer. Visually, the tenon-and-mortise piezoelectric module is formed by stacking tenon-shaped and mortise-shaped units. The rubber unit in the middle connects the upper and lower tenon-and-mortise piezoelectric modules and also serves a decoupling function. Figure 2 for Figure 1 A detailed explosion diagram of the structure. A three-dimensional structure of a transceiver-receiver mortise and tenon type underwater acoustic transducer consists of a watertight layer 1, a tenon unit 2, a first electrode plate 3, an electrode lead 4, a second electrode plate 5, a second rubber unit 6, a first rubber unit 7, a mortise unit 8, a backing layer 9, a rear end cover 10, a multi-core cable 11, a piezoelectric post 12, a rigid polymer 13, an air gap 14, and a piezoelectric substrate 15. The watertight layer 1 tightly wraps around the composite consisting of tenon-and-mortise piezoelectric modules 1 and 2, electrode plates 3 and 5, electrode leads 4, rubber units 6 and 7, backing layer 9, and rear end cover 10 to achieve sound transmission and waterproofing. The electrode leads 4 are respectively fixed to the electrode plates 3 and 5 of the tenon-shaped unit and the electrode plates 3 and 5 of the mortise-shaped unit, and are used to conduct the vibration generated by the piezoelectric component and external electrical signals. The rubber units 6 and 7 are fixed between the first electrode plate 3 and the second electrode plate 5 between the tenon-and-mortise units 2 and 8. The backing layer 9 is fixed between the rear end cover 10 and the tenon-and-mortise units 2 and 8, serving as mechanical support and eliminating back noise signals. The multi-core cable 11 is fixed in the slot of the rear end cover, and the cable contains multiple strands of leads for connecting and leading out all the electrode leads 4.

[0041] Figure 3 This is a three-dimensional structural diagram of the tenon unit 2. The tenon unit 2 has an inwardly convex structure and consists of a first electrode plate 3, a second electrode plate 5, a piezoelectric post 12, a rigid polymer 13, an air gap 14, and a piezoelectric substrate 15. The first electrode plate 3, the piezoelectric post 12, the rigid polymer 13, and the piezoelectric substrate 15 together constitute the rigid tenon module in the tenon unit 2. This module, under the combined action of the rigid polymer 13 and the piezoelectric substrate 15, has high compressive strength, enabling the transducer to meet the requirements of a high-strength mechanical emission unit.

[0042] Figure 4 This is a three-dimensional structural diagram of the mortise unit 8. The mortise unit 8 has a concave structure, which can be mechanically matched with the convex tenon unit 2. Similarly, the mortise unit 8 is also composed of a first electrode plate 3, a second electrode plate 5, a piezoelectric post 12, a rigid polymer 13, an air gap 14, and a piezoelectric substrate 15. Except for the difference in shape, it is configured the same as the tenon unit.

[0043] The rigid tenon structure in tenon unit 2 and the rigid mortise structure in mortise unit 8 together form a transducer transmitting unit (both composed of piezoelectric pillars 12, rigid polymer 13, and piezoelectric substrate 15), as shown in the top view below. Figure 5 As shown. Both structures belong to type 1-3 in terms of their interconnected structure, exhibiting good thickness vibration modes and stability. Similarly, the air gap units in tenon-shaped unit 2 and mortise-shaped unit 8 form the receiving units of the transducer (both composed of piezoelectric pillars 12, air gaps 14, and piezoelectric substrates 15). Using air gaps as filler reduces acoustic energy loss caused by lateral coupling, resulting in a more concentrated thickness mode.

[0044] Example 1:

[0045] like Figure 1 and Figure 2 As shown, the tenon-and-mortise type underwater acoustic transducer disclosed in this embodiment consists of a watertight layer 1, a tenon-and-mortise piezoelectric module, a backing layer 9, a rear end cover 10, and a multi-core cable 11.

[0046] like Figure 2 As shown, the tenon-and-mortise piezoelectric module consists of tenon unit 2, mortise unit 8, electrode units (3 and 5), and rubber units (6 and 7). This module, as the core part of the transducer, can be used to generate sound waves. The tenon unit 2 includes a rigid tenon module, an air gap unit, and an electrode unit; the tenon unit has a centrally protruding structure, specifically characterized in that the thickness of the rigid tenon module is greater than that of the air gap unit.

[0047] like Figure 3 As shown, the rigid tenon module is composed of a first electrode plate 3, a piezoelectric post 12, a rigid polymer 13, and a piezoelectric substrate 15.

[0048] The piezoelectric pillars 12 and the piezoelectric substrate 15 are made of the same material, such as PZT ceramics and PMN-PT single crystals with good piezoelectricity, to ensure high-intensity emission and high-sensitivity reception performance; the piezoelectric pillars 12 are a uniform periodic array and have the same structural parameters.

[0049] The rigid polymer 13 can be made of epoxy resin or PMMA material with high hardness, used to separate the small pillars between the piezoelectric arrays while improving the stability and compressive strength of the piezoelectric arrays.

[0050] The piezoelectric substrate 15 is used to connect all the piezoelectric posts 12 to further improve the stability and compressive strength of the rigid tenon module; the piezoelectric substrate 15 has two end faces, a piezoelectric surface and an electrode surface, wherein the piezoelectric surface is used to connect all the piezoelectric posts, and the electrode surface is used to transfer and receive charges; in addition, the aspect ratio of the piezoelectric posts 12 is not less than 4:1.

[0051] The ratio of the gap to the width of the piezoelectric pillar 12 is between 0.24 and 0.35 to ensure that the volume fraction of the piezoelectric phase is controlled within the range of high electromechanical conversion capability of the material.

[0052] The thickness of the piezoelectric substrate 15 is within 10% of the total thickness of the tenon unit 2, which not only greatly weakens the lateral coupling, but also preserves the compressive strength of the piezoelectric material.

[0053] The air gap unit is composed of piezoelectric pillars 12 and piezoelectric substrates 15. The piezoelectric pillars 12 and piezoelectric substrates 15 in the air gap unit are made of the same material as the piezoelectric pillars 12 and piezoelectric substrates 15 of the rigid tenon module, but do not contain the rigid polymer 13.

[0054] like Figure 4 As shown, the mortise unit 8 includes a rigid mortise module, an air gap unit, and an electrode unit; the mortise unit 8 has a concave structure in the middle, specifically characterized in that the thickness of the rigid mortise module is less than that of the air gap unit.

[0055] The piezoelectric substrate 15 of the mortise unit and the piezoelectric substrate 15 of the tenon unit use the same material and structural parameters. Preferably, the thickness of the piezoelectric substrate of the mortise unit is within 10% of the total thickness of the mortise unit.

[0056] The rigid mortise module is composed of a piezoelectric column 12, a rigid polymer 13, and a piezoelectric substrate 15.

[0057] The piezoelectric post 12 in the rigid mortise module and the piezoelectric post 12 in the rigid tenon module are made of the same piezoelectric material; the rigid polymer 13 of the rigid mortise module and the rigid polymer 13 of the rigid tenon module are exactly the same.

[0058] The air gap unit of the mortise unit 8 and the air gap unit of the tenon unit 2 have the same configuration, including materials and structure.

[0059] The rigid tenon module and the rigid mortise module serve as the transmitting unit of the transducer, enabling high mechanical strength broadband transmission. The air gap units of the tenon unit 2 and the mortise unit 8 serve as the receiving unit of the transducer, enabling high-sensitivity reception and fulfilling the transducer's integrated transmitting and receiving function. Preferably, the piezoelectric pillars 12 in the rigid mortise module are arranged periodically, similar to those in the rigid tenon module, with a height-to-width ratio of not less than 4:1 and the same structural dimensions.

[0060] The ratio of the gap to the width of the piezoelectric post 12 in the rigid mortise module is between 0.24 and 0.35 to ensure that the volume fraction of the piezoelectric phase is controlled within the range of high electromechanical conversion capability of the material.

[0061] The thickness difference between the piezoelectric post 12 of the rigid mortise module and the piezoelectric post 12 of the rigid tenon module does not exceed 1 mm.

[0062] The tenon unit 2 and mortise unit 8 are stacked along the thickness direction, wherein the protruding part of the rigid tenon module should completely fit the recessed part of the rigid tenon structure.

[0063] The rubber unit is divided into a first rubber unit 6 and a second rubber unit 7, both of which are made of decoupling material rubber with low Young's modulus, such as cork rubber, silicone rubber, etc. The first rubber unit 6 is a square solid structure used to connect the rigid tenon module and the rigid mortise module. The second rubber unit 7 is a hollow square structure used to connect the air gap unit in the tenon unit 2 and the mortise unit 8.

[0064] The thickness of each rubber unit does not exceed 1 mm, and its external dimensions are adapted to the tenon unit 2 and the mortise unit 8.

[0065] The electrode unit includes a first electrode plate 3, a second electrode plate 5, and electrode leads 4. The electrode unit can be made of a metal material with good conductivity, such as silver, copper, or platinum, with a thickness not exceeding 0.5 mm. The two-dimensional planar dimensions and structure of the first electrode plate 3 and the second electrode plate 5 are the same as those of the first rubber unit 6 and the second rubber unit 7, respectively. The top surfaces of the rigid tenon module and the rigid mortise module are covered by the first electrode plate 3, and the air gap units of the tenon unit 2 and the mortise unit 8 are covered by the second electrode plate 5. The electrode leads 4 are fixed to the surfaces of the first electrode plate 3 and the second electrode plate 5, respectively, for transmitting and transmitting current through the electrode unit, and can be made of a metal material with good conductivity.

[0066] The backing layer 9 is made of a foam material with high hardness and many pores, which can support the tenon-shaped piezoelectric module and filter out noise generated on the back of the transducer.

[0067] The watertight layer 1 is made of polyurethane material with strong matching and good sound transmission, which can effectively reduce the reflection of sound wave energy; the thickness of the watertight layer 1 is within 1 / 4 to 3 / 4 of the wavelength.

[0068] The multi-core cable 11 is used to connect the electrode leads 4 to realize independent control of each module of the tenon-and-mortise piezoelectric module.

[0069] The rear cover 10 is used to lead out the multi-core cable 11. It can be made of metal and its size is similar to that of the backing layer 9.

[0070] Example 2:

[0071] Type 1-3 underwater acoustic transducers urgently need breakthroughs in bandwidth expansion due to their limited operating frequency range, making them unsuitable for the detection and communication needs of complex underwater environments. Broadband underwater acoustic transducers can cover a wider range of frequencies, thereby improving signal transmission quality, reducing the impact of multipath effects, and enhancing data transmission reliability, which is particularly important for marine exploration and underwater communication. Furthermore, there is a growing market demand for integrated transmitter and receiver transducers. This integrated design not only reduces equipment size and system complexity but also improves response speed and signal processing efficiency. Therefore, this invention proposes the development of an integrated underwater acoustic transducer that combines broadband transmission and high-sensitivity reception using a mortise and tenon structure, aiming to solve existing technical challenges. The specific design process is as follows:

[0072] The general range of underwater acoustic high-frequency transducers is around 200kHz to 400kHz. Given that the frequency constant of the PZT-epoxy composite unit is approximately 1500, the thickness of the composite unit should be within the range of 3.75mm to 7.5mm. In this example, the tenon-shaped unit 2 has a thickness of 6.0mm, and the mortise-shaped unit 8 has a thickness of 5.5mm. The piezoelectric material is PZT-5A ceramic, which is both transceiver and has good hardness. The rigid polymer 13 is made of 618 epoxy resin with good stability. The rubber units (6 and 7) are made of 704 silicone rubber with strong adhesion and good decoupling. The electrode units (3 and 5) are both made of thin-layer copper foil (0.1mm).

[0073] A piezoelectric substrate 15 of a certain thickness can improve the stability of piezoelectric composite materials and give them a certain compressive strength. However, if the percentage of the substrate is too high, it will lead to strong lateral coupling, thereby significantly reducing the electromechanical coupling coefficient. In this invention, the ceramic substrates of the tenon unit 2 and the mortise unit 8 are both designed to be 0.5 mm thick, and neither exceeds 10%.

[0074] When the aspect ratio of piezoelectric materials is less than 3:1, lateral coupling will occur, resulting in sound energy loss. Therefore, the width of the piezoelectric post 12 is set to 1 / 4 (4:1) of the thickness, i.e., 1 mm. Similarly, in order to obtain a higher electromechanical coupling coefficient, the ratio of the gap to the width of the piezoelectric post 12 of the rigid tenon module should be between 0.24 and 0.35 to ensure that the volume fraction of the piezoelectric phase is controlled within the range of high electromechanical conversion capability of the material. Therefore, the slit width is set to 0.3 mm.

[0075] To ensure the uniformity of the composite material, the thickness of the air gap unit should be half the overall thickness of the tenon unit 2 and the mortise unit 8, i.e., 5.25 mm. At the same time, to ensure uniformity, its slit width is also set to 0.3 mm.

[0076] Considering that the thickness of the rubber units (6 and 7) does not exceed 1mm and their external dimensions are compatible with the tenon unit 2 and the mortise unit 8, the thickness of the silicone rubber gasket is set to 0.5mm to ensure effective coupling of the tenon and mortise structure.

[0077] The manufacturing method of the integrated tenon-and-mortise type underwater acoustic transducer disclosed in this embodiment is as follows:

[0078] Part 1, Preparation of Tenon Unit 2:

[0079] Step 1: Prepare the ceramic cutting skeleton. Take a 105mm×105mm×6mm piezoelectric material and fix it on the sample stage of the cutting machine. Set the cutting depth to 5.5mm and the step size to 1.3mm. Make the cutting blade cut along the horizontal and vertical directions respectively, leaving a 0.5mm piezoelectric substrate to form the ceramic cutting skeleton.

[0080] Step 2: Fill with epoxy resin (rigid polymer 13). Prepare a certain amount of epoxy resin solution according to the ratio of epoxy resin: softener: curing agent = 10:1:1, and fill it evenly into the gaps of the cut skeleton. After vacuuming to remove air bubbles, cure and shape to produce a 1-3-2 rigid piezoelectric composite material.

[0081] Step 3: Prepare the tenon structure. Measure the position of the rigid tenon module on the 1-3-2 rigid piezoelectric composite material using a ruler. Cover this position with an opaque mask, exposing the rest of the composite material. Fix the masked sample in the cutting machine again, set the cutting step to 1 / 3 of the blade width, and grind away 0.25mm of thickness with the cutting blade to form the tenon structure.

[0082] Step 4: Fabrication of air gap units. Remove the mask, clean the composite material with tenon structure prepared in Step 3 with ethanol, and then fix it again onto the sample stage of the cutting machine. Set the cutting depth to 5.25 mm and the step size to 1.3 mm, so that the cutting blade removes the epoxy resin outside the tenon structure along the horizontal and vertical directions to form air gap units. At this point, the tenon unit 2 has the following characteristics: a raised rigid tenon module in the middle, surrounded by a uniform array of piezoelectric pillars 12, with air gaps 14 between the arrays;

[0083] Step 5: Electrode Coating. Take the customized square copper foil plate (first electrode plate 3) and the U-shaped copper foil plate (second electrode plate 5), and attach them to the top surface of the rigid tenon module and the top surface of the air gap unit, respectively. Then, weld leads to both end faces. At this point, the tenon unit 2 is complete.

[0084] Part Two, Preparation of the mortise-shaped unit 8:

[0085] Step 1: Prepare the ceramic cutting skeleton. Take a 105mm×105mm×5.5mm piezoelectric material and fix it on the sample stage of the cutting machine. Set the cutting depth to 5mm and the step size to 1.3mm. Make the cutting blade cut along the horizontal and vertical directions respectively, leaving a 0.5mm piezoelectric substrate 15 to form the ceramic cutting skeleton.

[0086] Step 2: Fill with epoxy resin. Prepare a certain amount of epoxy resin solution according to the ratio of epoxy resin: softener: hardener = 10:1:1. Fill the gaps in the cut skeleton evenly with the epoxy resin solution, remove air bubbles by vacuuming, and then cure to form a 1-3-2 rigid piezoelectric composite material.

[0087] Step 3: Prepare the mortise structure. Measure the position of the rigid mortise module on the 1-3-2 rigid piezoelectric composite material using a ruler. Use an opaque mask to cover the part outside the rigid mortise module. Fix the masked sample in the cutting machine again, set the cutting step to 1 / 3 of the blade width and the cutting depth to 0.25mm, and use the cutting blade to grind the exposed part in the middle of the material to form the mortise structure.

[0088] Step 4: Fabrication of air gap units. Remove the mask, wash the composite material with the mortise structure prepared in Step 3 with ethanol, and then fix it again on the sample stage of the cutting machine. Set the cutting depth to 5.25 mm and the cutting step to 1.3 mm, so that the cutting blade removes the epoxy resin outside the mortise structure along the horizontal and vertical directions to form air gap units. At this point, the mortise-shaped unit 8 has the following characteristics: a concave rigid mortise module in the middle, surrounded by uniform piezoelectric pillars 12, and air gaps 14 between the arrays;

[0089] Step 5: Electrode Coating. Take the customized square copper foil plate (first electrode plate 3) and the U-shaped copper foil plate (second electrode plate 5), and attach them to the top surface of the rigid mortise module and the top surface of the air gap unit, respectively. Then, weld leads to both end faces. At this point, the mortise unit 8 is complete.

[0090] Part Three: Fabricating the Mortise and Tenon Piezoelectric Module:

[0091] Take a square silicone rubber washer (first rubber unit 6) and a U-shaped silicone rubber washer (second rubber unit 7). Secure the square silicone rubber washer to the middle of the square copper foil plates of the tenon unit 2 and the mortise unit 8 using adhesive. Secure the U-shaped silicone rubber washer to the middle of the U-shaped copper foil plates of the tenon unit and the mortise unit using adhesive. At this point, the tenon-mortise piezoelectric module is complete.

[0092] Part Four: Applying the Backing Layer

[0093] The backing layer 9 is attached to the bottom of the tenon-and-mortise piezoelectric module, and all electrode leads 4 are marked and attached to the outside of the backing layer.

[0094] Part 5: Attaching the rear cover and securing the multi-core cable:

[0095] Pass the multi-core cable 11 through the slot in the rear cover 10 and connect it to all the electrode leads 4; then attach and fix the rear cover 10 to the backing layer 9.

[0096] Part 6, Encapsulation Polyurethane (Watertight Layer 1):

[0097] After the adhesive in the fifth part has cured, it is fixed in the sealing mold, polyurethane adhesive is injected and cured, and then it is demolded. At this point, a transceiver-integrated tenon-and-mortise type underwater acoustic transducer is completed.

[0098] The performance of the tenon-and-mortise type underwater acoustic transducer prepared in this embodiment is tested below, taking into account the specific design. In this example, PZT-5A was selected as the piezoelectric material, and 618 epoxy resin and 704 silicone rubber were used as the rigid polymer phase and silicone rubber gasket, respectively. The material parameters are shown in Table 1 below:

[0099] Table 1. Material parameters of PZT-5A, epoxy resin and silicone rubber

[0100]

[0101] The transducer was simulated using finite element analysis. Figure 6 This is a schematic diagram of the transducer's underwater simulation structure in this embodiment. The simulation structure consists of a 200mm far-water area, a 20mm near-water area, an acoustic absorption boundary, and an optimized transducer structure. For ease of calculation and mesh generation, the structural components of the watertight layer 1 and the backing layer 9 were optimized in this example. In the simulation post-processing module, the electrical admittance information of the transducer's transmitting module was read, and the following diagram was generated. Figure 7 The admittance-frequency simulation results are shown below. Figure 7 The admittance results show that the tenon-and-mortise type transducer has two thickness resonant modes. When two piezoelectric units with similar thicknesses are stacked longitudinally, they can effectively excite coupled resonance, and the half-power point bandwidth can be increased to 48kHz, which verifies the rationality of the design concept of this invention.

[0102] At the boundary of the far water area, the sound pressure at the farthest point of the transducer's axial acoustic center is extracted. Substituting this into equations (1) and (2) yields the transducer's emission voltage response (S) in the water. v ) and receiver voltage sensitivity (M v The relationship between frequency and frequency.

[0103]

[0104] In equations (1) and (2) above, P a The value is: ρ = (r - r) / (r - r) = (r - r) / (r - r) = (v - v) / (v - v ...3 f is the transducer frequency.

[0105] Figure 7 The relationship between the transmit voltage response and frequency of the intermediate transmitting unit of the transducer is presented. As the frequency increases, the transmit voltage response of the transducer first increases to a peak value and then decreases, reaching a peak value of 159.3 dB near the resonant frequency of 264 kHz. The curve has a wide bandwidth and a flat trend, indicating good broadband transmit performance. Figure 8 This curve shows the relationship between the receiving voltage sensitivity and frequency of the transducer receiving unit. The curve reaches a peak of -206.0 dB near the transducer's anti-resonance and exhibits a relatively flat trend, demonstrating better receiving performance compared to existing transducers (below -210 dB). In this example, the underwater acoustic transducer designed in this invention utilizes a classic mortise and tenon structure to achieve multi-functionality while maintaining high mechanical strength, wide bandwidth transmission capability, and high sensitivity sensing effect. This provides significant reference value for the development of small-sized transceiver integrated underwater acoustic transducers.

[0106] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A transceiver integrated tenon-and-mortise type underwater acoustic transducer, characterized in that: It includes a tenon-and-mortise piezoelectric module, a backing layer, a multi-core cable, a rear end cover, and a watertight layer; The tenon-and-mortise piezoelectric module is mainly composed of tenon units, mortise units, electrode units, and rubber units; The height of the middle part of the tenon unit matrix is ​​higher than the height of the outer matrix, and the higher part is called the rigid tenon module; the remaining part is called the air gap unit; the rigid polymer is filled between the rigid tenon module array; the end face of the tenon unit is covered with the electrode unit; the rigid tenon module is covered with the first electrode plate; the air gap unit is covered with the second electrode plate; the above electrode units are led out by leads respectively; The height of the middle part of the mortise-shaped unit matrix is ​​lower than the height of the outer matrix matrix, and the recessed part is called the rigid mortise module; the remaining part is called the air gap unit; the rigid polymer fills the space between the rigid mortise module array; the end face of the mortise-shaped unit covers the electrode unit; the rigid mortise module is covered with the first electrode plate; the air gap unit is covered with the second electrode plate; the above electrode units are led out by leads respectively. The tenon unit and the mortise unit are connected by rubber units; the rigid tenon module and the rigid mortise module are stacked longitudinally by rubber units to achieve multi-mode bandwidth expansion; The backing layer is fixed to the bottom of the tenon-and-mortise piezoelectric module, serving to support the piezoelectric module and absorb noise; the multi-core cable is fixed to the bottom of the backing layer, with one end connected to all the above-mentioned leads and the other end led out from the inside of the rear cover slot. The watertight layer encloses the mortise and tenon piezoelectric module, the backing layer, and the top surface of the rear cover; The rigid tenon module and the rigid mortise module serve as the transmitting unit of the transducer, enabling the transducer to transmit with high mechanical strength and broadband speed. The air gap unit of the tenon unit and the mortise unit serves as the receiving unit of the transducer, enabling the transducer to receive with high sensitivity and fulfilling the transceiver function.

2. The transceiver integrated tenon-and-mortise type underwater acoustic transducer as described in claim 1, characterized in that: The tenon and mortise units are made of PZT ceramic or PMN-PT single crystal to ensure high-intensity emission and high-sensitivity reception performance; and the pillars in the array have exactly the same structural parameters.

3. The transceiver integrated tenon-and-mortise type underwater acoustic transducer as described in claim 1, characterized in that: The rigid polymer material is epoxy resin or PMMA, used to separate the small pillars between the piezoelectric arrays while improving the stability and compressive strength of the piezoelectric arrays.

4. The transceiver integrated tenon-and-mortise type underwater acoustic transducer as described in claim 1, characterized in that: The aspect ratio of the piezoelectric post in the rigid tenon module and the rigid mortise module is not less than 4:1; the ratio of the width of the piezoelectric post to the width of the array gap is between 0.24 and 0.35, so as to ensure that the volume fraction of the piezoelectric phase is controlled within the range of high electromechanical conversion capability of the material.

5. The transceiver integrated tenon-and-mortise type underwater acoustic transducer as described in claim 1, characterized in that: The tenon and mortise units are stacked along the thickness direction, wherein the protruding part of the rigid tenon module should completely fit the recessed part of the rigid tenon structure.

6. The transceiver integrated tenon-and-mortise type underwater acoustic transducer as described in claim 1, characterized in that: The rubber unit is made of decoupling material rubber with low Young's modulus; the thickness of the connecting unit does not exceed 1mm, and its external dimensions are adapted to the tenon and mortise units.

7. The transceiver integrated tenon-and-mortise type underwater acoustic transducer as described in claim 1, characterized in that: The electrode unit includes a first electrode plate and a second electrode plate; the electrode unit is made of metal material and has a thickness of no more than 0.5 mm.

8. The transceiver integrated tenon-and-mortise type underwater acoustic transducer as described in claim 1, characterized in that: The backing layer is made of a foam material with high hardness and many pores; "high hardness" means that the hardness is higher than a preset hardness threshold, and "many pores" means that the number of pores is higher than a preset threshold. The rear end cover is made of metal and its dimensions are adapted to the dimensions of the backing layer.

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