Broadband pressure-resistant hydrophone

Abstract

The present application relates to hydrophone technical field, it relates to a kind of wideband pressure-resistant hydrophone, including base, cover, piezoelectric sheet, damping liquid and sealing plug, base one end surface is equipped with slot, cover is sealed and connected at slot, piezoelectric sheet is fixed on the outer surface of cover, cavity filled with damping liquid is formed between cover and slot;Liquid injection hole is opened on the outer surface of base, and the inner wall or bottom of slot is equipped with communication hole, and liquid injection hole is communicated with communication hole through communication channel;Damping liquid uses incompressible insulating liquid, damping liquid is filled into cavity through liquid injection hole, communication channel, communication hole, and liquid injection hole is sealed through sealing plug;When liquid pressure acts on piezoelectric sheet, liquid pressure makes piezoelectric sheet produce extrusion deformation towards damping liquid direction, at this time, damping liquid generates a reverse thrust to piezoelectric sheet, the present application has the advantages of simple structure, can guarantee signal band width, high sensitivity and high pressure resistance.

Description

Technical Field

[0001] This invention relates to the field of hydrophone technology, specifically a broadband pressure-resistant hydrophone. Background Technology

[0002] A hydrophone is a transducer that senses changes in external liquid pressure, generates electrical charge on its surface, and outputs an electrical signal, thus converting mechanical energy into electrical energy. Common hydrophones often employ piezoelectric crystals with a thin, circular wafer structure, which allows for a wider bandwidth.

[0003] To prevent the thin, circular piezoelectric crystal from breaking under pressure during use, it is typically bonded to a copper substrate using conductive adhesive, with the interior of the copper substrate designed as a cavity, forming a drum-like structure. In this structure, the wall thickness from the bonding surface of the piezoelectric crystal to the bottom of the cavity has a crucial impact on the hydrophone's performance. A thicker wall results in less deformation of the copper substrate under the same pressure fluctuations, leading to less deformation of the piezoelectric crystal and making it less prone to breakage; however, this results in lower output sensitivity. Conversely, a thinner wall allows for greater deformation of the copper substrate under the same pressure fluctuations, significantly improving the hydrophone's sensitivity. However, the thinner substrate also reduces the upper pressure limit, meaning the hydrophone can only withstand lower hydrostatic pressures; it is impossible to achieve both high sensitivity and high pressure resistance in a hydrophone. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a broadband pressure-resistant hydrophone with a simple structure that can guarantee signal bandwidth, high sensitivity and high pressure resistance.

[0005] The technical solution adopted by this invention to solve its technical problem is: A broadband pressure-resistant hydrophone, characterized in that it includes a base, a cover, a piezoelectric sheet, a damping fluid, and a sealing plug. The base has a slot on one end face, the cover is sealed to the slot, the piezoelectric sheet is fixed to the outer surface of the cover, and a cavity filled with damping fluid is formed between the cover and the slot. The base has an injection hole on its outer surface and a connecting hole on the inner wall or bottom of the groove. The injection hole and the connecting hole are connected by a connecting channel. The damping fluid is an incompressible insulating liquid. The damping fluid is filled into the cavity through the injection hole, the connecting channel, and the connecting hole. The injection hole is sealed with a sealing plug. When liquid pressure is applied to the piezoelectric sheet, the liquid pressure causes the piezoelectric sheet to deform in the direction of the damping liquid. At this time, the damping liquid generates a reverse thrust on the piezoelectric sheet. By filling the cavity with damping fluid to balance the pressure inside and outside the base, a thinner cover wall can be designed. With a thin-walled structure, the piezoelectric sheet can still maintain a large deformation range in response to pressure fluctuations, ensuring the hydrophone has high sensitivity. At the same time, under high pressure, the damping fluid supports the piezoelectric sheet through internal pressure, keeping it within its elastic deformation range without deformation damage. This allows the hydrophone to maintain the wide frequency characteristics of the piezoelectric sheet while also achieving high sensitivity and high pressure resistance. The separate structure of the cover and base facilitates processing and assembly, and also allows for the design of a thin-walled cover to ensure high sensitivity. The injection hole on the base forms a damping fluid injection path located inside the base, avoiding the need to open the cover for injection, protecting the piezoelectric sheet structure, and facilitating operation and maintenance.

[0006] The injection hole of the present invention includes an upper connecting section and a lower internal thread section; The sealing plug adopts a screw structure, including an upper sealing section and a lower external thread section. The lower external thread section of the sealing plug is threadedly connected to the lower internal thread section of the injection hole. The upper sealing section of the sealing plug is sealed to the upper connecting section of the injection hole via a sealing ring. The screw structure of the sealing plug can provide an adjustable preload when tightened. This preload is transmitted to the damping fluid in the cavity, generating an outward pre-pressure effect on the internal damping fluid. The reverse thrust generated by this pre-pressure effect can balance the inward squeezing effect of the external pressure on the cover when the hydrophone is working, so that the deformation range of the piezoelectric sheet is controlled within a safe range, effectively preventing damage to the piezoelectric sheet due to excessive deformation. At the same time, the screw structure is convenient for installation and maintenance.

[0007] The cover of this invention adopts a cylindrical structure, including a base plate and a surrounding plate arranged along the outer periphery of the base plate. The surrounding plate is fixedly connected to the base plate. An annular sealing groove is formed on the outer surface of the base plate, and an O-ring is installed in the sealing groove. The cover is placed over the groove, and the inner wall of the surrounding plate is sealed to the outer surface of the base through the O-ring. The cover and the base are assembled by axial fitting, forming a radial sealing fit. The radial seal has self-tightening characteristics in deep water and high pressure environments, ensuring the reliability of the seal. At the same time, the axial fitting method is simple to operate and easy to maintain.

[0008] The cover of the present invention also includes a pressing edge plate, which is disposed at the end of the surrounding plate away from the bottom plate and is fixedly connected to the surrounding plate. A pressing edge groove is provided on the base. After the cover is placed over the groove, the pressing edge plate is bent and embedded in the pressing edge groove. The embedded cooperation between the pressing edge plate and the pressing edge groove realizes the locking of the cover position. The structure is simple, no additional fasteners are required, and it is easy to install and disassemble.

[0009] The cover of the present invention is made of conductive material, the base is made of insulating material, and a lead-out electrode one and a lead-out electrode two are fixed on the outer surface of the base. The lead-out electrode one is connected to an external positive lead wire, and the lead-out electrode two is connected to an external negative lead wire. The outer surface of the piezoelectric sheet is connected to the first lead-out electrode via an inner lead one, and the cover is connected to the second lead-out electrode via an inner lead two; By setting lead electrodes on the base as intermediate transition terminals, direct connection between external leads and piezoelectric sheets is avoided, thus preventing damage to the piezoelectric sheets caused by pulling of external leads.

[0010] The base of the present invention has a screw hole one and a screw hole two on its outer surface. The lead-out electrode one is pressed onto the outer surface of the base by screw one being threadedly connected to screw hole one, and the lead-out electrode two is pressed onto the outer surface of the base by screw two being threadedly connected to screw hole two. This achieves reliable fixing of the position of the lead-out electrode and facilitates installation and maintenance.

[0011] The base of the present invention adopts a cylindrical structure, and a lead wire groove is formed on the outer surface of the base. The bottom of the lead wire groove is machined into a plane, and screw hole one and screw hole two are formed on the bottom of the lead wire groove. The base adopts a cylindrical structure to ensure minimal disturbance to the water flow and effectively reduce self-noise.

[0012] The groove described in this invention adopts a cylindrical structure to ensure uniform stress distribution and no stress concentration points when subjected to hydrostatic pressure.

[0013] The base of the present invention has a slot one on one end face and a slot two on the other end face. The cover body includes a cover body one and a cover body two. The cover body one is sealed and connected to the slot one, and the cover body two is sealed and connected to the slot two. Two piezoelectric sheets are provided, including piezoelectric sheet one and piezoelectric sheet two. Piezoelectric sheet one is fixed on the outer surface of cover one, and piezoelectric sheet two is fixed on the outer surface of cover two. Both slot one and slot two are filled with damping fluid; By setting piezoelectric sheets at both ends, interference signals caused by the acceleration of the hydrophone in the liquid can be canceled, reducing acceleration sensitivity and further improving the hydrophone sensitivity. At the same time, a backup structure is formed, so that if one piezoelectric sheet fails, the other piezoelectric sheet can still output a valid signal, improving the overall reliability and service life of the device.

[0014] The outer surface of the piezoelectric sheet of the present invention is connected to the lead-out electrode 1 via an inner lead 1, and the cover body 1 is connected to the lead-out electrode 2 via an inner lead 2. The outer surface of the second piezoelectric sheet is connected to the first lead electrode via the third inner lead, and the second cover is connected to the second lead electrode via the fourth inner lead. This allows the piezoelectric sheets to form a parallel structure, resulting in superposition of signal charges and further improving sensitivity.

[0015] The beneficial effects of this invention are as follows: By filling the cavity with damping fluid to balance the pressure inside and outside the base, the wall thickness of the cover can be designed to be thinner. Under the thin-walled structure, the piezoelectric sheet can still maintain a large deformation range in response to pressure fluctuation signals, ensuring that the hydrophone has high sensitivity. At the same time, under high pressure, the damping fluid supports the piezoelectric sheet through internal pressure, keeping it within the elastic deformation range without deformation damage. This allows the hydrophone to maintain the wide frequency characteristics of the piezoelectric sheet while also taking into account high sensitivity and high pressure resistance. The separate structure of the cover and the base facilitates processing and assembly, and also makes it easy to design the cover as a thin-walled structure to ensure high sensitivity. The liquid injection hole on the base forms a damping fluid injection path located inside the base, avoiding the need to open the cover for injection, protecting the piezoelectric sheet structure, and making operation and maintenance convenient. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention at an inclined angle (including the fit between the base and the cover and the connection of the lead wires).

[0017] Figure 2 This is the main view of the overall structure of the present invention.

[0018] Figure 3 This is a cross-sectional view of the overall structure of the present invention (including the fit between the base and the cover, and the fit between the internal damping fluid and the sealing plug).

[0019] Figure 4 This is a schematic diagram of the tilt angle of the base structure of the present invention.

[0020] Figure 5 This is a cross-sectional view of the base of the present invention.

[0021] Figure 6 This is a schematic diagram of the tilt angle of the cover structure of the present invention.

[0022] Figure 7 This is a side view of the cover of the present invention.

[0023] Reference numerals: Base-1, Slot 1-1011, Connecting Hole 1-10111, Slot 2-1012, Connecting Hole 2-10121, Injection Hole 1-1021, Upper Connecting Section 1-10211, Lower Internal Thread Section 1-10212, Injection Hole 2-1022, Upper Connecting Section 2-10221, Lower Internal Thread Section 2-10222, Connecting Channel 1-1031, Connecting Channel 2-1032, Sealing Ring Groove 1-1041, Sealing Ring Groove 2-1042, Edge Pressing Groove 1-1051, Edge Pressing Groove 2-1052, Lead Wire Groove-106, Screw Hole 1-1061, Screw Hole 2-1062; Cover 1-201, Base Plate 1-2011, Enclosing Plate 1-2012, Edge Pressing Plate 1-2013, Cover 2-202, Base Plate 2-2021, Enclosing Plate 2-2022, Edge Pressing Plate 2-2023; Piezoelectric sheet 1-301, piezoelectric sheet 2-302; O-ring 1-401, O-ring 2-402; Damping fluid-5; Sealing plug 1-601, sealing plug 2-602; Sealing ring 1-701, sealing ring 2-702; Lead-out electrode 1-801, lead-out electrode 2-802; Screw 1-901, Screw 2-902; Inner lead 1-1001, Inner lead 2-1002, Inner lead 3-1003, Inner lead 4-1004; External positive lead-1101, external negative lead-1102. Detailed Implementation

[0024] The present invention will now be described in conjunction with the accompanying drawings and embodiments.

[0025] As shown in the attached figure, a broadband pressure-resistant hydrophone includes a base 1, a cover, a piezoelectric sheet, a damping fluid 5, and a sealing plug. One end face of the base is provided with a groove, the cover is sealed and connected to the groove, the piezoelectric sheet is fixed to the outer surface of the cover, and a cavity filled with damping fluid 5 is formed between the cover and the groove. The base 1 has an injection hole on its outer surface and a connecting hole on its inner wall or bottom. The injection hole and the connecting hole are connected by a connecting channel. The damping fluid 5 can be an incompressible liquid with good fluidity and electrical insulation, such as silicone oil or mineral oil; the damping fluid 5 is filled into the cavity through the injection hole, the connecting channel, and the connecting hole, and the injection hole is sealed with a sealing plug; When liquid pressure is applied to the piezoelectric sheet, the liquid pressure causes the piezoelectric sheet to be squeezed and deformed in the direction of the damping liquid 5. At this time, the damping liquid 5 generates a reverse thrust on the piezoelectric sheet. By filling the cavity with damping fluid 5, the pressure inside and outside the base 1 is balanced, allowing for a thinner cover wall design. With this thin-walled structure, the piezoelectric sheet maintains a large deformation range in response to pressure fluctuations, ensuring high sensitivity of the hydrophone. Simultaneously, under high pressure, the damping fluid 5, through internal pressure support, keeps the piezoelectric sheet within its elastic deformation range without deformation or damage. This allows the hydrophone to maintain the wideband characteristics of the piezoelectric sheet while also achieving high sensitivity and high pressure resistance. The separate structure of the cover and base facilitates processing and assembly, and also allows for a thin-walled cover design to ensure high sensitivity. The injection hole on the base forms a damping fluid injection path inside the base, avoiding the need to open the cover for injection, protecting the piezoelectric sheet structure, and facilitating operation and maintenance.

[0026] In this embodiment, the hydrophone can be used in insulating liquids (such as silicone oil or mineral oil). If it is placed in a conductive liquid (such as water), a waterproof layer or insulating encapsulation needs to be added to the outside of the hydrophone.

[0027] In this embodiment, the piezoelectric sheet can be a thin-sheet piezoelectric crystal or a piezoelectric ceramic.

[0028] The injection hole includes an upper connecting section and a lower internal thread section; The sealing plug adopts a screw structure, including an upper sealing section and a lower external thread section. The lower external thread section of the sealing plug is threadedly connected to the lower internal thread section of the injection hole. The upper sealing section of the sealing plug is sealed to the upper connecting section of the injection hole via a sealing ring. The screw structure of the sealing plug can provide an adjustable preload when tightened. This preload is transmitted to the damping fluid in the cavity, generating an outward pre-pressure effect on the internal damping fluid. The reverse thrust generated by this pre-pressure effect can balance the inward squeezing effect of the external pressure on the cover when the hydrophone is working, so that the deformation range of the piezoelectric sheet is controlled within a safe range, effectively preventing damage to the piezoelectric sheet due to excessive deformation. At the same time, the screw structure is convenient for installation and maintenance.

[0029] The cover includes a base plate and a surrounding plate arranged along the outer periphery of the base plate. The surrounding plate is fixedly connected to the base plate. An annular sealing groove is formed on the outer surface of the base 1, and an O-ring is installed in the sealing groove. The cover is placed over the groove, and the inner wall of the surrounding plate is sealed to the outer surface of the base through the O-ring. The cover and the base are assembled by axial insertion, forming a radial sealing fit. The radial seal has self-tightening characteristics in deep water and high pressure environments, ensuring the reliability of the seal. At the same time, the axial insertion method is simple to operate and easy to maintain.

[0030] The cover also includes a pressing edge plate, which is disposed at the end of the surrounding plate away from the bottom plate and is fixedly connected to the surrounding plate. A pressing edge groove is provided on the base. After the cover is placed over the groove, the pressing edge plate is bent and embedded in the pressing edge groove. The embedded cooperation between the pressing edge plate and the pressing edge groove realizes the locking of the cover position. The structure is simple, requires no additional fasteners, and is easy to install and disassemble.

[0031] The cover is made of conductive material, the base 1 is made of insulating material, and lead-out electrode 1 801 and lead-out electrode 2 802 are fixed on the outer surface of the base. Lead-out electrode 1 801 is connected to the external positive lead wire 1101, and lead-out electrode 2 802 is connected to the external negative lead wire 1102. The outer surface of the piezoelectric sheet is connected to the lead-out electrode 801 via an inner lead 1001, and the cover is connected to the lead-out electrode 802 via an inner lead 2 1002. By setting lead electrodes on the base 1 as intermediate transfer terminals, direct connection between external leads and piezoelectric sheets is avoided, thus preventing damage to the piezoelectric sheets caused by pulling of external leads.

[0032] In this embodiment, the cover is made of copper or other conductive metals, and the base is made of insulating materials such as nylon and polyoxymethylene.

[0033] The outer surface of the base 1 is provided with screw hole 1061 and screw hole 1062. Lead-out electrode 801 is threadedly connected to screw hole 1061 by screw 901 and pressed onto the outer surface of the base 1. Lead-out electrode 802 is threadedly connected to screw hole 1062 by screw 902 and pressed onto the outer surface of the base 1. This achieves reliable fixing of the lead-out electrode position and facilitates installation and maintenance.

[0034] In this embodiment, lead-out electrode one and lead-out electrode two adopt a conductive sheet structure, such as a copper sheet or other conductive metal sheet.

[0035] In this embodiment, the cover is cylindrical and the base 1 is cylindrical to ensure minimal disturbance to the water flow and effectively reduce self-noise.

[0036] In this embodiment, to facilitate the stable installation of the copper sheet, a lead wire groove 106 is formed on the outer surface of the base 1. The bottom of the lead wire groove 106 is machined into a flat surface, and screw holes 1061 and 1062 are formed on the bottom of the lead wire groove 106 to ensure that the copper sheet can be horizontally fixed on the bottom plane of the groove.

[0037] In this embodiment, two piezoelectric sheets are symmetrically arranged.

[0038] As attached Figure 4 and attached Figure 5As shown, the base 1 has a slot 1011 on one end face and a slot 2 1012 on the other end face. The cover includes a cover 201 and a cover 202. The cover 201 is sealed to the slot 1011 and the cover 202 is sealed to the slot 2 1012.

[0039] The bottom of the first slot 1011 is provided with a connecting hole 10111, the bottom of the second slot 1012 is provided with a connecting hole 2 10121, and the outer surface of the base 1 is provided with a liquid injection hole 1021 and a liquid injection hole 2 1022. The liquid injection hole 1021 and the connecting hole 10111 are connected by a connecting channel 1031, and the liquid injection hole 2 1022 and the connecting hole 2 10121 are connected by a connecting channel 2 1032.

[0040] In this embodiment, slot 1011 and slot 2 1012 adopt a cylindrical structure to ensure uniform stress distribution and no stress concentration points when subjected to hydrostatic pressure.

[0041] The injection hole 1021 includes an axially connected upper connecting section 10211 and a lower internal thread section 10212. The bottom of the lower internal thread section 10212 is connected to the connecting channel 1031. The outer diameter of the upper connecting section 10211 is larger than the outer diameter of the lower internal thread section 10212. A horizontal limiting surface is formed between the upper connecting section 10211 and the lower internal thread section 10212.

[0042] The injection hole 2 1022 includes an axially connected upper connecting section 2 10221 and a lower internal thread section 2 10222. The bottom of the lower internal thread section 2 10222 is connected to the connecting channel 2 1032. The outer diameter of the upper connecting section 2 10221 is larger than the outer diameter of the lower internal thread section 2 10222. A horizontal limiting surface 2 is formed between the upper connecting section 2 10221 and the lower internal thread section 2 10222.

[0043] The sealing plug adopts a cylindrical head screw structure, including sealing plug one 601 and sealing plug two 602. Sealing plug one 601 includes an axially connected upper sealing section one (cylindrical head) and a lower external thread section one. The outer diameter of the upper sealing section one matches the inner diameter of the upper connecting section one 10211 of the injection hole one 1021. The upper sealing section one has an annularly arranged sealing groove one along the circumference. A sealing ring one 701 is provided in the sealing groove one. The lower external thread section one of the sealing plug one 601 is threadedly connected to the lower internal thread section one of the injection hole one 1021. The upper sealing section one of the sealing plug one 601 is squeezed and sealed with the upper connecting section one 10211 of the injection hole one 1021 through the sealing ring one 701. The lower end face of the sealing plug 602 abuts against the horizontal limiting surface 1; the sealing plug 602 includes an axially connected upper sealing section 2 (cylindrical head) and a lower external thread section 2. The outer diameter of the upper sealing section 2 matches the inner diameter of the upper connecting section 2 10221 of the injection hole 2 1022. The upper sealing section 2 is provided with an annular sealing groove 2 along the circumference. The sealing groove 2 is provided with a sealing ring 2 702. The lower external thread section 2 of the sealing plug 602 is threadedly connected to the lower internal thread section 2 10222 of the injection hole 2 1022. The upper sealing section 2 of the sealing plug 602 is squeezed and sealed with the upper connecting section 2 10221 of the injection hole 2 1022 through the sealing ring 2 702. The lower end face of the upper sealing section 2 abuts against the horizontal limiting surface 2.

[0044] The damping fluid 5 enters the slot 1011 through injection hole 1021, connecting channel 1031, and connecting hole 10111, and enters the slot 2 1012 through injection hole 2 1021, connecting channel 2 1032, and connecting hole 2 10121.

[0045] The base 1 has an annular sealing ring groove 1041 and a pressing edge groove 1051 arranged sequentially from the outside to the inside on the outer periphery of the end near the first groove 1011, and an O-ring 401 is installed in the sealing ring groove 1041. The base 1 has an annular sealing ring groove 1042 and a pressing edge groove 1052 arranged sequentially from the outside to the inside on the outer periphery of the end near the second groove 1012, and an O-ring 402 is installed in the sealing ring groove 1042.

[0046] In this embodiment, cover body one 201 and cover body two 202 are cylindrical, as shown in the attached figure. Figure 6 and attached Figure 7As shown, cover body 1 201 includes a base plate 1 2011, an annular surrounding plate 1 2012 and an annular pressing plate 1 2013 arranged around the outer periphery of the base plate 1. One end of the surrounding plate 1 2012 is fixedly connected to the base plate 1 2011, and the other end is fixedly connected to the pressing plate 1 2013. The thickness of the pressing plate 1 2013 is less than the thickness of the surrounding plate 1 2012, which facilitates bending and embedding into the pressing groove 1 1051. Cover body 2 202 includes a base plate 2 2021, an annular surrounding plate 2 2022 and an annular pressing plate 2 2023 arranged around the outer periphery of the base plate 2 2021. One end of the surrounding plate 2 2022 is fixedly connected to the base plate 2 2021, and the other end is fixedly connected to the pressing plate 2 2023. The thickness of the pressing plate 2 2023 is less than the thickness of the surrounding plate 2 2022, which facilitates bending and embedding into the pressing groove 2 1052.

[0047] The piezoelectric sheet includes a first piezoelectric sheet 301 and a second piezoelectric sheet 302. The first piezoelectric sheet 301 is bonded and fixed to the outer surface of the first base plate 2011 with conductive adhesive and is located in the middle of the outer surface of the first base plate. The second piezoelectric sheet 302 is bonded and fixed to the outer surface of the second base plate 2021 with conductive adhesive and is located in the middle of the outer surface of the second base plate.

[0048] As attached Figure 1 As shown, the outer surface of the piezoelectric sheet 301 is connected to the lead-out electrode 801 via the inner lead 1001, and the cover 201 is connected to the lead-out electrode 802 via the inner lead 1002. The outer surface of the piezoelectric sheet 302 is connected to the lead-out electrode 801 via the inner lead 3 1003, and the cover 202 is connected to the lead-out electrode 802 via the inner lead 4 1004. Lead-out electrode 1 801 is connected to the external positive lead 1101, and lead-out electrode 2 802 is connected to the external negative lead 1102; By setting piezoelectric sheets at both ends, interference signals caused by the acceleration of the hydrophone in the liquid can be canceled, reducing acceleration sensitivity. The two piezoelectric sheets form a parallel structure, and the signal charges are superimposed, further improving sensitivity. At the same time, a backup structure is formed, so that if one piezoelectric sheet fails, the other piezoelectric sheet can still output a valid signal, improving the overall reliability and service life of the device.

[0049] When assembling this practical wideband pressure-resistant hydrophone: Piezoelectric sheet 301 is bonded to the center of the outer surface of base plate 2011 with conductive adhesive, and piezoelectric sheet 302 is bonded to the center of the outer surface of base plate 2021 with conductive adhesive. Install O-ring 401 into sealing groove 1041 and O-ring 402 into sealing groove 1042. Cover body 201 is placed on the slot 1011 along the axial direction of base 1. The inner surface of bottom plate 2011 is pressed against the opening of slot 1011. The surrounding plate 2012 is sealed to the side wall of base 1 by O-ring 401. The pressing plate 2013 is deformed by tooling and embedded into pressing groove 1051 to fix the position of cover body 201. Cover body 202 is placed on the slot 1012 along the axial direction of base 1. The inner surface of bottom plate 2021 is pressed against the opening of slot 1012. The surrounding plate 2022 is sealed to the side wall of base 1 by O-ring 402. The pressing plate 2023 is deformed by tooling and embedded into pressing groove 1052 to fix the position of cover body 202. Damping fluid 5 is injected into injection hole 1021. Damping fluid 5 enters slot 1011 through injection hole 1021, connecting channel 1031, and connecting hole 10111. After the damping fluid 5 is filled, sealing ring 701 is installed in the sealing groove of the upper sealing section of sealing plug 601. The lower external thread section of sealing plug 601 is threadedly connected to the lower internal thread section of injection hole 1021. Injection hole 1021 is sealed with sealing plug 601 through sealing ring 701. Damping fluid 5 is injected into injection hole 2 1022. Damping fluid 5 enters slot 2 1012 through injection hole 2 1022, connecting channel 2 1032, and connecting hole 2 10121. After the damping fluid 5 is filled, sealing ring 2 702 is installed in the sealing groove 2 of the upper sealing section 2 of sealing plug 2 602. The lower external thread section 2 of sealing plug 2 602 is threadedly connected to the lower internal thread section 2 of injection hole 2 1022. Injection hole 2 1022 is sealed and fitted with sealing plug 2 602 through sealing ring 2 702. The lead-out electrode 801 with a central opening is placed in the screw hole 1061 of the lead slot 106. The screw 901 passes through the central opening of the lead-out electrode 801 and is inserted into the screw hole 1061, where it is threaded and connected to the screw hole 1061. This achieves the result of the lead-out electrode 801 being pressed and fixed by the cylindrical head of the screw. The lead-out electrode 802 with a central opening is placed in the screw hole 1062 of the lead slot 106. The screw 902 passes through the central opening of the lead-out electrode 802 and is inserted into the screw hole 1062, where it is threaded and connected to the screw hole 1062. This achieves the result of the lead-out electrode 802 being pressed and fixed by the cylindrical head of the screw. One end of the inner lead 1001 is soldered to the outer surface of the piezoelectric sheet 301, and the other end is soldered to the lead electrode 801. One end of the inner lead 1002 is soldered to the cover 201, and the other end is soldered to the lead electrode 802. One end of the inner lead 1003 is welded to the outer surface of the piezoelectric sheet 302, and the other end is welded to the lead electrode 801. One end of the inner lead 1004 is welded to the cover 202, and the other end is welded to the lead electrode 802. One end of the external positive lead 1101 is soldered to the lead-out electrode 801, and the other end is connected to the positive signal output electrode. One end of the external negative lead 1102 is soldered to the lead-out electrode 802, and the other end is connected to the negative signal output electrode.

[0050] The order of the above steps can be adjusted according to actual assembly needs.

[0051] When this hydrophone is used in a liquid: When liquid pressure is applied to the piezoelectric sheet, the liquid pressure causes the piezoelectric sheet to deform in the direction of the damping fluid. At this time, the pre-tightening force of the sealing plug is transmitted to the incompressible damping fluid, which generates a reverse thrust on the piezoelectric sheet, reducing the deformation range of the piezoelectric sheet and ensuring that the deformation of the piezoelectric sheet is always within its elastic range, without deformation damage, and can withstand greater pressure.

[0052] Specifically, when the hydrophone moves along the axial direction of the base in the liquid, the inertial force acts on both piezoelectric sheet one and piezoelectric sheet two simultaneously. The two piezoelectric sheets are subjected to the same thrust in the same direction. One of them is compressed and deformed, while the other is stretched and deformed. The two piezoelectric sheets output charges of opposite polarities, and the interference signals cancel each other out, effectively reducing the acceleration sensitivity of the hydrophone. At the same time, the acoustic pressure will compress the two piezoelectric sheets simultaneously, causing them to output charges of the same polarity. After superposition, the signal is enhanced, and the cancellation of acceleration interference does not affect the normal output of the underwater acoustic signal.

Claims

1. A broadband pressure-resistant hydrophone, characterized in that: It includes a base, a cover, a piezoelectric sheet, a damping fluid, and a sealing plug. The base has a slot on one end face, the cover is sealed to the slot, the piezoelectric sheet is fixed to the outer surface of the cover, and a cavity filled with damping fluid is formed between the cover and the slot. The base has an injection hole on its outer surface and a connecting hole on the inner wall or bottom of the groove. The injection hole and the connecting hole are connected by a connecting channel. The damping fluid is an incompressible insulating liquid. The damping fluid is filled into the cavity through the injection hole, the connecting channel, and the connecting hole. The injection hole is sealed with a sealing plug. When liquid pressure is applied to the piezoelectric sheet, the liquid pressure causes the piezoelectric sheet to deform in the direction of the damping liquid. At this time, the damping liquid generates a reverse thrust on the piezoelectric sheet.

2. The broadband pressure-resistant hydrophone according to claim 1, characterized in that: The injection hole includes an upper connecting section and a lower internal thread section; The sealing plug adopts a screw structure, including an upper sealing section and a lower external thread section. The lower external thread section of the sealing plug is threadedly connected to the lower internal thread section of the injection hole, and the upper sealing section of the sealing plug is sealed to the upper connecting section of the injection hole via a sealing ring.

3. A broadband pressure-resistant hydrophone according to claim 1 or 2, characterized in that: The cover adopts a cylindrical structure, including a bottom plate and a surrounding plate arranged along the outer periphery of the bottom plate. The surrounding plate is fixedly connected to the bottom plate. An annular sealing groove is opened on the outer surface of the base, and an O-ring is installed in the sealing groove. The cover is placed over the groove, and the inner wall of the surrounding plate is sealed to the outer surface of the base through the O-ring.

4. A broadband pressure-resistant hydrophone according to claim 3, characterized in that: The cover also includes a pressing edge plate, which is disposed at the end of the surrounding plate away from the bottom plate and is fixedly connected to the surrounding plate. A pressing edge groove is provided on the base. After the cover is placed over the groove, the pressing edge plate is bent and embedded in the pressing edge groove.

5. A broadband pressure-resistant hydrophone according to claim 1, 2, or 4, characterized in that: The cover is made of conductive material, the base is made of insulating material, and lead-out electrode one and lead-out electrode two are fixed on the outer surface of the base. Lead-out electrode one is connected to the external positive lead wire, and lead-out electrode two is connected to the external negative lead wire. The outer surface of the piezoelectric sheet is connected to the first lead electrode via an inner lead, and the cover is connected to the second lead electrode via an inner lead.

6. A broadband pressure-resistant hydrophone according to claim 5, characterized in that: The outer surface of the base is provided with screw hole one and screw hole two. Lead-out electrode one is pressed onto the outer surface of the base by screw one being threadedly connected to screw hole one, and lead-out electrode two is pressed onto the outer surface of the base by screw two being threadedly connected to screw hole two.

7. A broadband pressure-resistant hydrophone according to claim 6, characterized in that: The base adopts a cylindrical structure, and a lead wire groove is formed on the outer surface of the base. The bottom of the lead wire groove is machined into a flat surface, and screw hole one and screw hole two are formed on the bottom of the lead wire groove.

8. A broadband pressure-resistant hydrophone according to claim 1, 2, 4, 6, or 7, characterized in that: The slot is cylindrical in shape.

9. A broadband pressure-resistant hydrophone according to claim 1, 2, 4, 6, or 7, characterized in that: The base has a slot one on one end face and a slot two on the other end face. The cover body includes a cover body one and a cover body two. The cover body one is sealed and connected to the slot one, and the cover body two is sealed and connected to the slot two. Two piezoelectric sheets are provided, including piezoelectric sheet one and piezoelectric sheet two. Piezoelectric sheet one is fixed on the outer surface of cover one, and piezoelectric sheet two is fixed on the outer surface of cover two. Both slot one and slot two are filled with damping fluid.

10. A broadband pressure-resistant hydrophone according to claim 9, characterized in that: The outer surface of the piezoelectric sheet is connected to the lead-out electrode 1 via an inner lead 1, and the cover is connected to the lead-out electrode 2 via an inner lead 2. The outer surface of the piezoelectric sheet II is connected to the lead-out electrode I via the inner lead III, and the cover II is connected to the lead-out electrode II via the inner lead IV.

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