High precision acoustic receiver structure for tubing leak detection

Abstract

This invention relates to the field of oil pipe leak detection technology, and discloses a high-precision acoustic receiver structure for oil pipe leak detection. The structure includes a housing mechanism, which, along with a bidirectional rigid shell, sound-absorbing layer, sound-insulating layer, and sealing ring, constructs an acoustic isolation environment and filters out background noise. An Ω-shaped corrugated diaphragm is internally installed to absorb the displacement of the waveguide column through elastic deformation. An acoustic receiving mechanism is used to capture the oil pipe leak signal from the waveguide column and its cooperating piezoelectric ceramic stack. A pre-tightening mechanism, using a wedge sleeve, a pusher block, and a force-transmitting slider, converts the radial displacement of the waveguide column under pressure into an axial thrust on the piezoelectric ceramic stack, ensuring tight contact with the waveguide column. An auxiliary mechanism is used to construct an adaptive thermal compensation system that combines the rigid sound transmission of the acoustic pad with the flexible force distribution of the disc spring. This invention, through the synergy of multiple mechanisms, significantly improves the signal-to-noise ratio and detection accuracy, avoids damage to core components, and ensures long-term stable operation under wide temperature range and strong vibration conditions. It is suitable for oil and gas pipeline leak detection.

Description

Technical Field

[0001] This invention relates to the field of oil pipe leak detection technology, specifically a high-precision acoustic receiver structure for oil pipe leak detection. Background Technology

[0002] Oil pipelines are core infrastructure for the long-distance transportation of energy media such as crude oil and natural gas, and their operational safety is directly related to the stability of energy supply and the safety of the ecological environment. Acoustic wave detection technology, due to its advantages such as fast response speed, high detection accuracy, and early leak warning, has become one of the mainstream technologies for oil pipeline leak detection. The acoustic wave receiver is the core component of this technology system, capturing high-frequency acoustic emission signals from leaks and realizing the sound-to-electric conversion. Existing acoustic wave receivers are mostly composed of a shell, a waveguide force transmission mechanism, and a piezoelectric sensing element. The waveguide component contacts the oil pipeline wall to capture vibration signals, which are then transmitted through the force transmission structure to the piezoelectric element and converted into electrical signals. These signals are then combined with subsequent processing to determine leaks, and the technology is widely used in safety monitoring scenarios for various oil and gas pipelines.

[0003] Existing acoustic receivers rely solely on single protection or post-processing filtering to suppress low-frequency mechanical and environmental noise, failing to construct a comprehensive acoustic isolation system. Weak leakage signals are easily submerged, leading to misjudgments. Stable bonding between the waveguide and piezoelectric ceramic stack cannot be achieved solely through bolt pre-tightening, resulting in significant acoustic energy transmission loss. Furthermore, the lack of reliable thermal compensation and buffer protection structures makes the ceramic components susceptible to gaps caused by thermal expansion and contraction or damage from hard impacts under conditions such as high-temperature medium transport or vibration and shock. This leads to drift in detection sensitivity, failure of core components, and shortened device lifespan. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-precision acoustic receiver structure for oil pipe leak detection, solving the problems of complex noise interference, low acoustic transmission efficiency, and poor long-term operational stability in existing technologies.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a high-precision acoustic receiver structure for oil pipe leak detection, including a housing mechanism, which includes a bidirectional rigid shell, a sound-absorbing layer, a sound-insulating layer, a sealing ring, and an Ω-shaped corrugated diaphragm, for constructing an acoustic isolation environment and filtering out background noise and absorbing displacement; An acoustic wave receiving mechanism, comprising a waveguide column and a piezoelectric ceramic stack, is used to capture signals of oil pipe leaks; The pre-tightening mechanism includes a wedge sleeve, a pusher block, and a force-transmitting slider, which is used to convert the radial displacement of the waveguide column after it is compressed into an axial thrust on the piezoelectric ceramic stack and make it fit tightly against the waveguide column. The lubrication assembly includes a first lubrication channel and a second lubrication channel, which are used to lubricate the inclined mating parts between the wedge sleeve and the push block, and between the push block and the force transmission slider, and to store, replenish and distribute the lubricating oil. The auxiliary mechanism, which includes a sound-conducting pad and a disc spring, is used to construct an adaptive thermal compensation for rigid sound transmission and flexible force application.

[0006] Preferably, the sound-absorbing layer is attached to the inner wall of the bidirectional rigid shell, and the sound-insulating layer is fixedly connected to the inner side of the sound-absorbing layer and forms a core cavity.

[0007] Preferably, the sealing ring is fitted at the position where the waveguide column penetrates the bidirectional rigid outer shell, and the outer edge of the Ω-shaped corrugated diaphragm is connected to the inner wall of the shell mechanism, and the inner edge is connected to the outer peripheral surface of the waveguide column.

[0008] Preferably, the rear end of the waveguide is tapered, and the front end of the waveguide is equipped with a contact, which is a hemispherical shape and extends through the side wall of the bidirectional rigid shell to the outside. The piezoelectric ceramic stack is located at the other end of the waveguide.

[0009] Preferably, the wedge sleeve is fixedly sleeved on the waveguide post and located behind the Ω-shaped corrugated diaphragm. The inner surface of the rear end of the wedge sleeve is provided with an inclined surface, and the push block is distributed in two annular shapes at the top and bottom.

[0010] Preferably, the inclined surface of the front end of the push block abuts against the inclined surface of the wedge sleeve, the force transmission slider is conical, the inner surfaces of the rear ends of both push blocks are provided with inclined surfaces, the inclined surface of the rear end of the push block abuts against the surface of the force transmission slider, and the force transmission slider is movably connected to the rear end of the piezoelectric ceramic stack.

[0011] Preferably, an oil storage cavity is installed on the outer surface of the bidirectional rigid shell, one end of the oil storage cavity is connected to an oil filling port, and an oil outlet is provided at the connection between the oil storage cavity and the bidirectional rigid shell. The first lubrication channel is opened inside the wedge-shaped sleeve, and the second lubrication channel is opened inside the push block.

[0012] Preferably, there are multiple sound guide pads and disc springs, and the front end of the force transmission slider is provided with multiple countersunk holes.

[0013] Preferably, there are multiple disc springs, one end of each disc spring is connected to the interior of the corresponding countersunk hole, the sound guiding pad is connected to the rear end of the piezoelectric ceramic stack, and the multiple sound guiding pads are respectively installed at the other end of the corresponding disc spring.

[0014] Preferably, the disc spring is composed of multiple mating discs, and the sound guide pad and the countersunk hole form a clearance fit that slides axially.

[0015] This invention provides a high-precision acoustic receiver structure for oil pipe leak detection. It offers the following advantages: 1. This invention reflects most external vibration noise through a bidirectional rigid shell, and converts the acoustic energy of residual noise into heat energy through the porous structure of the sound-absorbing layer. Combined with the inert gas or vacuum environment inside the sound insulation layer and the acoustic damping effect of the sealing ring, the propagation path of noise through the shell sidewall to the core component is completely cut off. At the same time, the Ω-shaped corrugated diaphragm can absorb the displacement of the piezoelectric ceramic stack through elastic deformation, filtering out low-frequency mechanical vibration interference generated by the operation of oil pipe pumps, etc. The synergistic effect of multiple protection mechanisms significantly improves the signal-to-noise ratio of the core cavity, ensuring that the receiver accurately captures only leakage characteristic signals and avoids interference signals from falsely triggering detection alarms.

[0016] 2. This invention utilizes a multi-stage inclined force transmission linkage structure consisting of a waveguide column, a wedge sleeve, a pusher block, and a force transmission slider. After the front contact of the waveguide column is pressed against the oil pipe wall, the axial pressure can be automatically converted into a forward thrust on the piezoelectric ceramic stack. In conjunction with the built-in lubrication components, the first and second lubrication channels opened inside the wedge sleeve and the pusher block squeeze out lubricating oil during the force transmission process, reducing frictional loss at the inclined mating parts. This forces the piezoelectric ceramic stack to fit tightly against the conical tail of the waveguide column, establishing a zero-gap, high-efficiency sound transmission channel.

[0017] 3. This invention constructs an adaptive thermal compensation unit that combines rigid sound transmission with flexible force application by adding a disc spring and a high-stiffness sound-guiding pad between the force-transmitting slider and the piezoelectric ceramic stack. Utilizing the thermosensitive properties of the bimetallic material, it automatically compensates for dimensional deviations caused by thermal expansion and contraction, ensuring that the piezoelectric ceramic and waveguide maintain a constant dynamic zero-gap contact across a wide temperature range, effectively preventing sensitivity drift. Simultaneously, the nonlinear elastic properties of the disc spring absorb the instantaneous energy during installation pre-tensioning or external impacts, converting rigid thrust into flexible loading and preventing the brittle ceramic from cracking. Combined with the high-stiffness pad serving as an acoustic backing, it protects the core components while ensuring efficient sound wave transmission, improving the physical reliability and service life of the device. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the housing mechanism of the present invention; Figure 3 This is a schematic diagram of the pre-tightening mechanism of the present invention; Figure 4 This is a schematic diagram of the lubrication assembly of the present invention; Figure 5 This is a schematic diagram of the auxiliary mechanism of the present invention.

[0019] The components include: 1. Shell structure; 11. Bidirectional rigid shell; 12. Sound-absorbing layer; 13. Sound-insulating layer; 14. Sealing ring; 15. Ω-shaped corrugated diaphragm; 2. Sound wave receiving mechanism; 21. Waveguide column; 22. Contact; 23. Piezoelectric ceramic stack; 3. Pre-tightening mechanism; 31. Wedge sleeve; 32. Push block; 33. Force transmission slider; 34. Lubrication assembly; 341. Oil reservoir; 342. Oil filling port; 343. Oil outlet; 344. First lubrication channel; 345. Second lubrication channel; 4. Auxiliary mechanism; 41. Sound guiding gasket; 42. Disc spring; 43. Countersunk hole. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see the appendix Figure 1 - Appendix Figure 5 The present invention provides a high-precision acoustic receiver structure for oil pipe leakage detection, including a housing mechanism 1, which is used to construct an acoustic isolation environment and filter out background noise by a bidirectional rigid shell 11, a sound-absorbing layer 12, a sound-insulating layer 13 and a sealing ring 14, and is provided with an Ω-shaped corrugated diaphragm 15 for elastic deformation to absorb the displacement of the waveguide column 21. Acoustic wave receiving mechanism 2, which is used to capture oil pipe leakage signals by waveguide column 21 and piezoelectric ceramic stack 23 that cooperates with its tail; The lubrication assembly 34 includes a first lubrication channel 344 and a second lubrication channel 345, which are used to lubricate the inclined mating parts between the wedge sleeve 31 and the push block 32 and between the push block 32 and the force transmission slider 33, and to store, replenish and distribute the lubricating oil. The pre-tightening mechanism 3 is used by the wedge sleeve 31, the push block 32 and the force transmission slider 33 to convert the radial displacement of the waveguide column 21 after being compressed into the axial thrust on the piezoelectric ceramic stack 23 and to make it fit tightly against the waveguide column 21. Auxiliary mechanism 4 is used to construct an adaptive thermal compensation system that combines the rigid sound transmission of the sound guide pad 41 with the flexible force-bearing of the disc spring 42.

[0022] The housing mechanism 1 serves as the overall installation foundation and protective carrier, constructing a multi-layered acoustic isolation environment through the bidirectional rigid outer shell 11, sound-absorbing layer 12, sound-insulating layer 13, and sealing ring 14. This effectively reflects and dissipates external environmental noise and low-frequency mechanical vibration noise from the oil pipe, filtering out background interference. An Ω-shaped corrugated diaphragm 15 is also fixedly installed inside the housing mechanism 1. This Ω-shaped corrugated diaphragm 15 absorbs the displacement of the waveguide column 21 under pressure and vibration conditions through its own elastic deformation, preventing displacement from being transmitted to the core sensing components and causing signal distortion. The acoustic wave receiving mechanism 2 is the core of signal capture, used to capture the high-frequency acoustic emission signal generated by oil pipe leakage through the waveguide column 21 and the piezoelectric ceramic stack 23 precisely matched to its tail, converting mechanical energy into identifiable signals. Electrical signal; the pre-tightening mechanism 3 is used to convert the axial displacement of the waveguide column 21 after it is pressed against the oil pipe wall into an axial pre-tightening thrust on the piezoelectric ceramic stack 23 through a multi-stage inclined force transmission structure consisting of a wedge sleeve 31, a push block 32, and a force transmission slider 33, ensuring that the tail of the waveguide column 21 is tightly fitted with the piezoelectric ceramic stack 23 and establishing a zero-gap sound transmission channel; the oil outlet 343 is used to guide the lubricating oil in the oil storage chamber 341 to the first lubrication channel 344 and the second lubrication channel 345; the first lubrication channel 344 is used to deliver lubricating oil to the inclined surface of the wedge sleeve 31 and the push block 32 when they move relative to each other; the second lubrication channel 345 is used to deliver lubricating oil to the inclined surface of the push block 32 and the force transmission slider 33 when they move relative to each other. The auxiliary mechanism 4 is used to construct an adaptive thermal compensation unit that integrates rigid sound transmission and flexible force bearing through the sound guide pad 41 and the disc spring 42. This ensures efficient sound wave transmission and automatically compensates for thermal expansion and contraction deviations, buffers impact energy, and ensures stable operation of the core components.

[0023] The sound-absorbing layer 12 is attached to the inner wall of the bidirectional rigid shell 11, and the sound insulation layer 13 is located inside the sound-absorbing layer 12 and forms a core cavity.

[0024] See appendix Figure 2 The sound-absorbing layer 12 is made of porous aluminum foam or high-damping polyurethane. It has an overall ring structure and is completely attached to the inner wall of the bidirectional rigid shell 11. It is used to cause residual noise that penetrates the bidirectional rigid shell 11 to undergo multiple diffuse reflections through its porous structure, converting sound energy into heat energy for dissipation and achieving noise attenuation. The sound insulation layer 13 is made of thin-walled stainless steel and is located inside the sound-absorbing layer 12 and is tightly attached to the sound-absorbing layer 12. The sound insulation layer 13 surrounds the sound wave receiving mechanism 2, the pre-tightening mechanism 3 and the auxiliary mechanism 4 to form a sealed core cavity. The core cavity is filled with dry inert gas or vacuumed to further block the noise propagation path.

[0025] The sealing ring 14 is fitted at the position where the waveguide post 21 penetrates the bidirectional rigid shell 11. The outer edge of the Ω-shaped corrugated diaphragm 15 is connected to the inner wall of the shell mechanism 1, and the inner edge is connected to the outer circumferential surface of the waveguide post 21.

[0026] See appendix Figure 2 The sealing ring 14 is made of fluororubber and has a ring structure. It is tightly fitted at the position where the waveguide post 21 penetrates the bidirectional rigid shell 11. The inner ring of the sealing ring 14 is interference-fitted with the outer circumferential surface of the waveguide post 21, and the outer ring is interference-fitted with the inner wall of the through hole of the bidirectional rigid shell 11. This achieves high gas tightness and also forms acoustic damping through its own viscoelasticity, blocking noise from propagating along the gap between the waveguide post 21 and the shell. The Ω-shaped corrugated diaphragm 15 is a stainless steel thin-walled rotating body structure. Its outer edge is fixed to the inner wall step of the sound insulation layer 13 of the shell mechanism 1 by argon arc welding, and its inner edge is fixed to the outer circumferential surface of the waveguide post 21 by laser spot welding. It is located in front of the wedge sleeve 31. It absorbs the radial and axial displacement of the waveguide post 21 through the elastic deformation of its own corrugated structure, avoiding the displacement from affecting the signal acquisition accuracy of the piezoelectric ceramic stack 23.

[0027] The rear end of the waveguide post 21 is conical, and a contact 22 is installed on the top of the waveguide post 21. The contact 22 is hemispherical and located outside the front end of the bidirectional rigid shell 11. The piezoelectric ceramic stack 23 is located at the rear end of the waveguide post 21.

[0028] See appendix Figure 3 The waveguide column 21 is made of 45# steel and is long and rod-shaped with a conical structure at its rear end. The conical surface of this structure fits and conforms to the front end of the piezoelectric ceramic stack 23 to ensure efficient transmission of acoustic energy. The top of the waveguide column 21 is fitted with a contact 22 by threaded connection or integral molding. The contact 22 is a hemispherical structure made of wear-resistant alloy material and is located outside the front end of the bidirectional rigid shell 11. It is used to make point contact with the oil pipe wall to reduce noise interference caused by the contact area and improve wear resistance. The piezoelectric ceramic stack 23 is composed of multiple circular piezoelectric ceramic sheets stacked together, with electrode layers set between the sheets. It is located at the rear end of the waveguide column 21 and coaxially arranged with the conical tail of the waveguide column 21. It is used to convert the mechanical vibration transmitted by the waveguide column 21 into an electrical signal.

[0029] The wedge sleeve 31 is fixedly sleeved on the waveguide post 21 and located behind the Ω-shaped corrugated diaphragm 15. The inner surface of the wedge sleeve 31 is provided with an inclined surface, and there are two push blocks 32.

[0030] See appendix Figure 3 The wedge sleeve 31 is made of stainless steel and has a ring structure. It is fixedly sleeved on the waveguide post 21 by interference fit or key connection and is located behind the Ω-shaped corrugated diaphragm 15. It moves axially synchronously with the waveguide post 21. The inner surface of the rear end of the wedge sleeve 31 is provided with an annular inclined surface, which is used to form an adaptive abutment with the inclined surface of the push block 32. There are two push blocks 32, which are symmetrically arranged on both sides of the piezoelectric ceramic stack 23. They are made of high-strength aluminum alloy and have an overall block structure. The front end of the push block 32 is provided with an inclined structure that is adapted to the inclined surface of the wedge sleeve 31.

[0031] The front inclined surface of the push block 32 abuts against the inclined surface of the wedge sleeve 31. The force transmission slider 33 is conical. The inner surface of the rear end of the push block 32 is provided with an inclined surface. The rear inclined surface of the push block 32 abuts against the surface of the force transmission slider 33. The force transmission slider 33 is located at the rear end of the piezoelectric ceramic stack 23.

[0032] See appendix Figure 3 The inclined surface at the front end of the push block 32 abuts tightly against the inclined surface of the wedge sleeve 31. The contact surfaces of both are polished to reduce friction loss and ensure efficient force transmission. The force-transmitting slider 33 is made of stainless steel and has an overall conical structure. Its conical surface matches the inner rear surface of the push block 32. The inner rear surface of the push block 32 has an inclined surface that matches the conical surface of the force-transmitting slider 33. The inclination angle of this inclined surface matches the cone angle of the force-transmitting slider 33, used to convert the radial thrust of the push block 32 into the force-transmitting slider 33. The axial thrust of the 3 pushes the rear inclined surface of the block 32 to abut against the conical surface of the force transmission slider 33. Wear-resistant pads are provided at the abutment to prevent structural wear caused by long-term friction. The force transmission slider 33 is located at the rear end of the piezoelectric ceramic stack 23. Its front end face is in close contact with the rear end face of the piezoelectric ceramic stack 23. The force transmission slider 33 and the piezoelectric ceramic stack 23 are arranged coaxially to ensure that the axial thrust of the force transmission slider 33 is uniformly applied to the piezoelectric ceramic stack 23, pushing the piezoelectric ceramic stack 23 forward and in close contact with the tail of the waveguide column 21.

[0033] An oil storage chamber 341 is installed on the outer surface of the bidirectional rigid shell 11. One end of the oil storage chamber 341 is connected to an oil filling port 342. An oil outlet 343 is opened at the connection between the oil storage chamber 341 and the bidirectional rigid shell 11. The first lubrication channel 344 is opened inside the wedge sleeve 31, and the second lubrication channel 345 is opened inside the push block 32.

[0034] When the wedge sleeve 31, the push block 32 and the force transmission slider 33 are reset, the oil outlet 343 is connected to the first lubrication channel 344 and the second lubrication channel 345. The lubricating oil in the oil storage chamber 341 enters the first lubrication channel 344 and the second lubrication channel 345 through the oil outlet 343 to achieve automatic oil replenishment.

[0035] There are multiple sound guide pads 41 and disc springs 42, and the front end of the force transmission slider 33 is provided with multiple countersunk holes 43.

[0036] See appendix Figure 5There are multiple sound-conducting pads 41 and disc springs 42, and the number of each is one-to-one and they are coaxially matched to form multiple sets of uniformly stressed adaptive thermal compensation and sound transmission units. The front end of the force-transmitting slider 33 is uniformly provided with multiple countersunk holes 43 along its axis. The number of countersunk holes 43 is the same as the number of sound-conducting pads 41 and disc springs 42. The inner diameter and depth of the countersunk holes 43 are adapted to the installation and elastic deformation stroke of the disc springs 42, providing a stable installation and positioning space for the disc springs 42 and sound-conducting pads 41, ensuring that the axial thrust of the force-transmitting slider 33 can be uniformly transmitted to the end face of the piezoelectric ceramic stack 23, ensuring the consistency of sound transmission and the uniformity of thermal compensation.

[0037] One end of each of the multiple disc springs 42 is connected to the inside of each countersunk hole 43, and multiple sound guide pads 41 are installed on the other end of each disc spring 42.

[0038] See appendix Figure 5 One end of each of the multiple disc springs 42 is fixedly connected to the inner bottom surface of each countersunk hole 43 by welding or interference fit, ensuring that the disc springs 42 are installed firmly and without loosening. Multiple sound-conducting pads 41 are installed on the other end of each disc spring 42 by adhesive bonding or snap-fitting. The front end of the sound-conducting pad 41 protrudes from the opening of the countersunk hole 43 to tightly fit against the rear end of the piezoelectric ceramic stack 23. After assembly, the disc springs 42 are in a pre-compressed state, which can press the sound-conducting pads 41 tightly onto the piezoelectric ceramic stack 23. Simultaneously, the springs absorb impact energy through their own elastic deformation, while the sound-conducting pads 41 achieve efficient sound wave transmission. Together, they construct a composite structure of rigid sound transmission and flexible force bearing.

[0039] The disc spring 42 is composed of multiple mating pieces, and the sound guide pad 41 and the countersunk hole 43 form a clearance fit that slides along the axial direction.

[0040] See appendix Figure 5 The disc spring 42 is a multi-layered composite structure made of bimetallic composite material. The high-expansion layer is a manganese-copper-nickel alloy, and the low-expansion layer is an iron-nickel alloy. Utilizing the difference in the thermal expansion coefficients of the bimetallic materials, it can sense temperature changes and generate active restoring tension, achieving automatic compensation for thermal expansion and contraction gaps. The stacked disc spring 42 has nonlinear elastic characteristics, which can efficiently absorb the instantaneous energy during installation pre-tightening or external impacts, preventing damage to the piezoelectric ceramic stack 23 by hard thrust. The sound-conducting pad 41 is made of a high-rigidity, high-sound-conduction-efficiency material. Its outer circumferential surface forms an axial sliding clearance fit with the inner wall of the countersunk hole 43. The clearance is adapted to the axial extension and contraction stroke of the sound-conducting pad 41, ensuring that the sound-conducting pad 41 can slide smoothly along the countersunk hole 43 with the deformation of the disc spring 42, while limiting its radial displacement, ensuring the precise fit with the piezoelectric ceramic stack 23, and achieving dynamic thermal compensation while ensuring sound transmission efficiency.

[0041] Working principle: During testing, the contact 22 at the front end of the waveguide 21 contacts the oil pipe wall, causing the waveguide 21 to move inward under pressure. Simultaneously, this moves the wedge sleeve 31 inward. The inclined surface of the wedge sleeve 31 abuts against the inclined surface of the push block 32, providing the push block 32 with a thrust towards the surface of the piezoelectric ceramic stack 23. The inclined surfaces at the rear ends of the two push blocks 32 abut against the surface of the force transmission slider 33, providing the force transmission slider 33 with a forward thrust. During this process, lubricating oil from the first lubrication channel 344 and the second lubrication channel 345 flows out, reducing the friction between the wedge sleeve 31 and the push block 32, and between the push block 32 and the surface of the force transmission slider 33. Subsequently, the thrust through the countersunk hole 43 and the connecting surface of the disc spring 42 acts on the disc spring 42, causing the disc spring 42 to undergo elastic deformation under pressure. The sound guide pad 41 absorbs the impact energy of the piezoelectric ceramic stack 23 and the force transmission slider 33 at the moment of contact. Under the high pressure thrust of the disc spring 42, the sound guide pad 41 forms an extremely high pressure and tight contact with the end face of the piezoelectric ceramic stack 23. The tail of the thrust waveguide column 21 and the piezoelectric ceramic stack 23 are tightly attached to each other, establishing a zero-gap high-efficiency sound transmission channel. After the test is completed, the wedge sleeve 31, the push block 32 and the force transmission slider 33 are reset. The oil outlet 343, the first lubrication channel 344 and the second lubrication channel 345 are connected. The lubricating oil inside the oil storage chamber 341 flows into the first lubrication channel 344 and the second lubrication channel 345 through the oil outlet 343 to realize automatic oil replenishment. It can also be connected to the oil supply pipe through the oil filling port 342 to add oil into the oil storage chamber 341.

[0042] When the tubing pump generates low-frequency mechanical vibration, the bidirectional rigid shell 11 reflects most of the vibration noise, and the residual noise undergoes multiple diffuse reflections through the porous structure of the sound-absorbing layer 12, converting sound energy into heat energy for dissipation. The wall enclosed by the sound insulation layer 13 is filled with inert gas or evacuated. The sealing ring 14 at the penetration point of the waveguide column 21 constitutes acoustic damping, cutting off the propagation path of noise through the side wall of the bidirectional rigid shell 11 to the core component, ensuring that the core cavity only receives the tubing leakage signal transmitted by the waveguide column 21. The Ω-shaped corrugated diaphragm 15 inside the cavity undergoes elastic deformation, absorbing the displacement of the piezoelectric ceramic stack 23 relative to the shell mechanism 1. When the high-pressure oil pipe transports a high-temperature medium, the housing mechanism 1 expands due to heat. This originally caused a micron-level gap in the force transmission chain. The disc spring 42, located deep in the countersunk hole 43, senses the temperature rise and, by utilizing the difference in the thermal expansion coefficients of the bimetallic materials, generates active restoring tension, pushing the sound guide pad 41 to extend further outward, automatically filling the thermal expansion gap and ensuring that the pressure at the acoustic coupling interface does not decrease.

Claims

1. A high-precision acoustic receiver structure for oil pipe leak detection, characterized in that, include: The housing structure (1) includes a bidirectional rigid shell (11), a sound-absorbing layer (12), a sound-insulating layer (13), a sealing ring (14), and an Ω-shaped corrugated diaphragm (15) for constructing an acoustically isolated environment and filtering out background noise and absorbing displacement; The acoustic receiving mechanism (2) includes a waveguide column (21) and a piezoelectric ceramic stack (23) for capturing oil pipe leakage signals; The pre-tightening mechanism (3) includes a wedge sleeve (31), a push block (32) and a force transmission slider (33), which is used to convert the radial displacement of the waveguide column (21) after being compressed into the axial thrust of the piezoelectric ceramic stack (23) and make it fit tightly against the waveguide column (21); The lubrication assembly (34) includes a first lubrication channel (344) and a second lubrication channel (345), which are used to lubricate the inclined mating parts between the wedge sleeve (31) and the push block (32) and between the push block (32) and the force transmission slider (33), and to store, replenish and distribute the lubricating oil; The auxiliary mechanism (4) includes a sound-conducting pad (41) and a disc spring (42) for constructing an adaptive thermal compensation for rigid sound transmission and flexible force.

2. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 1, characterized in that, The sound-absorbing layer (12) is attached to the inner wall of the bidirectional rigid shell (11), and the sound insulation layer (13) is fixedly connected to the inner side of the sound-absorbing layer (12) and forms a core cavity.

3. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 2, characterized in that, The sealing ring (14) is fitted at the position where the waveguide post (21) penetrates the bidirectional rigid shell (11). The outer edge of the Ω-shaped corrugated diaphragm (15) is connected to the inner wall of the shell mechanism (1), and the inner edge is connected to the outer circumferential surface of the waveguide post (21).

4. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 1, characterized in that, The rear end of the waveguide post (21) is tapered, and the front end of the waveguide post (21) is equipped with a contact (22). The contact (22) is a hemispherical shape and penetrates the side wall of the bidirectional rigid shell (11) and extends to the outside. The piezoelectric ceramic stack (23) is located at the other end of the waveguide post (21).

5. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 1, characterized in that, The wedge sleeve (31) is fixedly sleeved on the waveguide post (21) and located behind the Ω-shaped corrugated diaphragm (15). The inner surface of the rear end of the wedge sleeve (31) is provided with an inclined surface, and the push block (32) is distributed in two rings on the top and bottom.

6. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 5, characterized in that, The front inclined surface of the push block (32) abuts against the inclined surface of the wedge sleeve (31), the force transmission slider (33) is conical, the inner surfaces of the rear ends of the two push blocks (32) are provided with inclined surfaces, the rear inclined surface of the push block (32) abuts against the surface of the force transmission slider (33), and the force transmission slider (33) is movably connected to the rear end of the piezoelectric ceramic stack (23).

7. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 1, characterized in that, An oil storage chamber (341) is installed on the outer surface of the bidirectional rigid shell (11). One end of the oil storage chamber (341) is connected to an oil filling port (342). An oil outlet (343) is provided at the connection between the oil storage chamber (341) and the bidirectional rigid shell (11). The first lubrication channel (344) is opened inside the wedge sleeve (31), and the second lubrication channel (345) is opened inside the push block (32).

8. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 1, characterized in that, The number of the sound guiding pads (41) and disc springs (42) are both multiple, and the front end of the force transmission slider (33) is provided with multiple countersunk holes (43).

9. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 8, characterized in that, The number of disc springs (42) is multiple, and one end of each disc spring (42) is connected to the interior of the corresponding countersunk hole (43). The sound guiding pad (41) is connected to the rear end of the piezoelectric ceramic stack (23), and the multiple sound guiding pads (41) are respectively installed at the other end of the corresponding disc spring (42).

10. The high-precision acoustic receiver structure for oil pipe leak detection according to claim 9, characterized in that, The disc spring (42) is composed of multiple mating pieces, and the sound guide pad (41) and the countersunk hole (43) form a clearance fit that slides along the axial direction.

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