A vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer

Abstract

A vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer includes: a shell, an inner liner, vibration isolation components, and a piezoelectric ceramic stack. The inner liner includes at least one chamber and is disposed inside the shell. The vibration isolation components are at least partially distributed around the circumference and ends of the inner liner, respectively abutting against the inner liner and the shell, and are used to absorb mechanical vibrations transmitted by the shell. The piezoelectric ceramic stack is disposed within the chamber and assembled with the inner liner, forming an ultrasonic transceiver unit. This invention effectively isolates the mechanical vibrations transmitted by the metal shell by setting an inner liner inside the shell and setting vibration isolation components around the circumference and ends of the inner liner, avoiding the resonance amplification effect with the tested mounting shaft and reducing the blind zone. Simultaneously, placing the piezoelectric ceramic stack within the inner liner chamber to form a transceiver unit allows for stable operation under high pressure and vibration interference conditions, thereby improving testing accuracy and adaptability.

Description

Technical Field

[0001] This utility model relates to the field of defect detection, and in particular to a transducer for testing vibration-isolated and pressure-resistant ultrasonic pile foundations. Background Technology

[0002] With the rapid development of large-scale infrastructure construction such as bridges, ports, and offshore wind power, the demand for pile foundation construction and quality inspection has increased significantly. Pile foundation inspection typically needs to be carried out underwater, under high pressure, and in environments filled with mud. Ultrasonic testing, as a commonly used non-destructive testing method, relies on transducers to stably transmit and receive acoustic signals in harsh media to determine internal defects and borehole wall conditions. However, in existing technologies, pressure-resistant ultrasonic transducers have significant shortcomings in pile foundation inspection applications.

[0003] Traditional pressure-resistant transducers typically require a rigid connection to mounting components such as a metal rotating shaft to ensure sealing and positioning in high-pressure underwater environments. However, this rigid connection can easily cause mechanical resonance between the transducer and the mounting structure, resulting in a large detection blind zone at the transducer's sound beam emission initiation position, thus reducing detection accuracy. This is especially problematic when bentonite slurry with a specific gravity of 1.1–1.5 is injected into the pile hole. The high density and large attenuation coefficient of the medium significantly shorten the propagation distance of high-frequency ultrasonic waves in the slurry; for example, a 1MHz signal may travel at 1.5 g / cm³. 3 The attenuation in mud can reach 5.7 dB / cm, which severely limits the detection depth and signal quality. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer to solve the problem of easy resonance interference.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A transducer for testing vibration-isolated and pressure-resistant ultrasonic pile foundations includes: a shell, an inner liner, a vibration isolation component, and a piezoelectric ceramic stack;

[0007] The inner liner includes at least one chamber and is disposed inside the housing; the vibration isolation components are at least partially distributed in the circumference and ends of the inner liner, and the vibration isolation components abut against the inner liner and the housing respectively, and are used to absorb the mechanical vibration transmitted by the housing;

[0008] The piezoelectric ceramic is stacked in the cavity and assembled with the inner lining layer to form an ultrasonic transceiver unit.

[0009] In some embodiments, the vibration isolation assembly includes a sealing vibration isolation O-ring disposed along the outer periphery of the inner liner and a rubber gasket located at the end of the inner liner.

[0010] In some embodiments, at least two of the sealing and vibration-damping O-rings are provided on the outer periphery of the inner liner.

[0011] In some embodiments, the piezoelectric ceramic stack adopts a type 1-3 composite ceramic sheet structure, and is a multi-sheet structure stacked in parallel along the axial direction.

[0012] In some embodiments, the operating frequency of the piezoelectric ceramic stack includes at least 88 kHz.

[0013] In some embodiments, the inner liner is an aluminum alloy liner, and an acoustic matching layer is provided on the side near the piezoelectric ceramic stack, the acoustic matching layer being connected to the piezoelectric ceramic stack.

[0014] In some embodiments, a shielded cable is also included, which passes through the inner liner and is communicatively connected to the piezoelectric ceramic stack.

[0015] In some embodiments, the vibration isolation assembly is provided on the outer periphery of the housing.

[0016] The beneficial effects of this utility model are as follows: It provides a vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer. By setting an inner lining layer inside the shell and setting vibration isolation components around the circumference and ends of the inner lining layer, the mechanical vibration transmitted by the metal shell is effectively isolated, avoiding the resonance amplification effect with the installation shaft being tested and reducing the blind zone. At the same time, placing the piezoelectric ceramic stack in the inner lining cavity to form a transceiver unit can still work stably under high pressure and vibration interference conditions, thereby improving the detection accuracy and adaptability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer in one embodiment;

[0018] Figure 2 This is a cross-sectional view of a vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer in one embodiment;

[0019] Figure 3 This is a schematic diagram of the piezoelectric ceramic stack in the embodiment;

[0020] Figure 4 This is a schematic diagram of the assembly of a vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer and a metal rotating shaft in one embodiment.

[0021] Label Explanation:

[0022] 10. Transducer; 11. Housing; 12. Liner; 13. Vibration isolation assembly; 131. Sealing vibration isolation O-ring; 132. Rubber gasket; 14. Piezoelectric ceramic stack; 15. Acoustic matching layer; 16. Shielded cable; 20. Metal rotating shaft. Detailed Implementation

[0023] To explain in detail the technical content, objectives, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0024] Please refer to Figures 1 to 3 A vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer 10 includes: a shell 11, an inner liner 12, a vibration isolation component 13, and a piezoelectric ceramic stack 14.

[0025] The inner liner 12 includes at least one chamber and is disposed inside the housing 11; the vibration isolation component 13 is at least partially distributed in the circumferential and end directions of the inner liner 12, the vibration isolation component 13 abuts against the inner liner 12 and the housing 11 respectively, and is used to absorb the mechanical vibration transmitted by the housing 11.

[0026] The piezoelectric ceramic stack 14 is disposed in the cavity and assembled and connected with the inner liner 12, and is used to form an ultrasonic transceiver unit.

[0027] Understandably, the existing pressure-resistant ultrasonic transducer 10 has problems in pile foundation testing, such as a large blind zone and easy resonance when tightly installed with the metal rotating shaft 20, leading to a decrease in testing accuracy. Especially when bentonite slurry with a specific gravity of 1.1–1.5 is injected into the pile hole, the high-frequency signal attenuation is severe (e.g., 1MHz at 1.5g / cm³). 3 The attenuation coefficient in mud can reach 5.7 dB / cm, limiting the detection distance. This invention addresses this by installing an inner liner 12 made of aluminum alloy or other materials inside the housing 11, and by installing vibration isolation components 13 around the circumference and ends of the inner liner 12. This effectively isolates the mechanical vibration transmitted by the metal housing 11, avoids the resonance amplification effect with the mounting shaft, and reduces the blind zone. Simultaneously, placing a piezoelectric ceramic stack 14 within the inner liner 12 cavity forms a transceiver unit, which can still operate stably under high pressure and vibration interference conditions, thereby improving detection accuracy and adaptability.

[0028] In some embodiments, the vibration isolation assembly 13 includes a sealing vibration isolation O-ring 131 disposed along the outer periphery of the inner liner 12 and a rubber gasket 132 located at the end of the inner liner 12.

[0029] As described above, the vibration isolation assembly 13 is composed of a sealing vibration isolation O-ring 131 and a rubber gasket 132. The O-ring forms a circumferential elastic buffer along the outer periphery of the inner liner 12, while the rubber gasket 132, located at the end, provides axial buffering and sealing. Together, they form a double vibration isolation and protection. Compared with the prior art, this structure not only effectively absorbs the vibration transmitted from the metal shell 11 to the inner liner 12, but also prevents liquid infiltration in high-pressure mud environments, improving sealing durability and the reliability of the transducer 10 during long-term underwater operation.

[0030] In some embodiments, at least two of the sealing and vibration-damping O-rings 131 are provided on the outer periphery of the inner liner 12.

[0031] As described above, at least two sealing and vibration-damping O-rings 131 are provided around the outer periphery of the inner liner 12. Compared to a single O-ring design, this forms a multi-level sealing and vibration isolation barrier, significantly reducing the intensity of vibration and impact transmission. Even under high-frequency vibration or pressure fluctuation environments, the piezoelectric unit can maintain stable operation. Furthermore, the multiple O-rings increase sealing redundancy; even if one O-ring wears or fails, the others can still ensure overall sealing, extending the equipment's service life.

[0032] In some embodiments, the piezoelectric ceramic stack 14 adopts a type 1-3 composite ceramic sheet structure, and is a multi-sheet structure stacked in parallel along the axial direction.

[0033] As described above, the piezoelectric ceramic stack 14 adopts a 1-3 composite ceramic sheet structure, with multiple sheets stacked in parallel along the axial direction. The 1-3 composite material structure maintains mechanical strength while reducing transverse wave interference and improving longitudinal acoustic wave energy transmission efficiency, significantly reducing the blind zone and improving signal transmission and reception sensitivity. In mud environments, this structure better maintains the penetration performance of low-frequency signals (such as 88kHz), resulting in a wider defect detection range and clearer echo signals for deep holes or large-diameter pile foundations.

[0034] In some embodiments, the operating frequency of the piezoelectric ceramic stack 14 includes at least 88 kHz.

[0035] As described above, setting the operating frequency of the piezoelectric ceramic stack 14 to 88kHz, compared to the common 200kHz or higher frequencies, results in less attenuation of low-frequency signals in high-density mud media, effectively extending the detection distance. For example, at 1.5g / cm³... 3 In mud, the attenuation of the 88kHz signal is significantly lower than that of 200kHz and 500kHz, making it suitable for construction sites in deep water or with high mud density. This frequency configuration, combined with the piezoelectric material structure, ensures both penetration and detection resolution.

[0036] In some embodiments, the inner liner 12 is an aluminum alloy inner liner 12, and an acoustic matching layer 15 is provided on the side near the piezoelectric ceramic stack 14, the acoustic matching layer 15 being connected to the piezoelectric ceramic stack 14.

[0037] As described above, the inner liner 12 is made of aluminum alloy, which is lightweight, high-strength, corrosion-resistant, and has good sound conductivity. An acoustic matching layer 15 is provided near the piezoelectric ceramic stack 14, allowing the acoustic impedance to transition gradually between the piezoelectric ceramic and the external medium, reducing sound energy reflection and improving sound energy transmission efficiency and echo signal strength. Compared with traditional designs without a matching layer, this scheme significantly improves the echo signal-to-noise ratio in the slurry medium.

[0038] In some embodiments, a shielded cable 16 is also included, which passes through the inner liner 12 and is communicatively connected to the piezoelectric ceramic stack 14.

[0039] As can be seen from the above description, the shielded cable 16 is run inside the inner liner 12 and communicates with the piezoelectric ceramic stack 14. This not only reduces the risk of damage to the sealing structure caused by wiring, but also effectively shields complex electromagnetic interference on site (such as electromagnetic noise generated by construction equipment), ensuring the stability and accuracy of ultrasonic signal transmission and reducing false echoes or signal distortion.

[0040] In some embodiments, the vibration isolation assembly 13 is provided on the outer periphery of the housing 11.

[0041] As described above, the vibration isolation assembly 13 installed around the outer periphery of the housing 11 forms an additional mechanical vibration buffer layer between the external structure and the transducer 10, achieving bidirectional vibration isolation: on the one hand, it prevents external vibration sources from entering the piezoelectric unit, and on the other hand, it reduces the impact of the transducer 10's own vibration on the mounting components. This bidirectional vibration isolation helps maintain detection accuracy under conditions of intense vibration from construction machinery.

[0042] Please refer to Figures 1 to 3 The comprehensive embodiment of this utility model is as follows: A vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer 10 includes a housing 11, an inner liner 12, a vibration isolation component 13, and a piezoelectric ceramic stack 14. The inner liner 12 includes at least one chamber and is disposed inside the housing 11 for mounting the piezoelectric ceramic stack 14. The vibration isolation component 13 is at least partially distributed in the circumferential and end positions of the inner liner 12, respectively abutting against the inner liner 12 and the housing 11, for absorbing the mechanical vibration transmitted by the housing 11, reducing the resonance phenomenon caused by the fixed installation of the metal rotating shaft 20, thereby reducing the blind zone and improving the detection accuracy.

[0043] The vibration isolation assembly 13 consists of a sealing and vibration isolation O-ring 131 arranged along the outer periphery of the inner liner 12 and a rubber gasket 132 located at the end of the inner liner 12. The O-ring forms a circumferential elastic buffer layer, and the rubber gasket 132 forms an axial buffer layer and a sealing barrier. Together, they achieve dual vibration isolation and sealing protection, effectively preventing mud or water from seeping into the piezoelectric unit and extending the service life of the transducer 10 under long-term underwater, high-pressure, and high-vibration conditions. To further improve the sealing and vibration isolation effect, at least two O-rings are arranged on the outer periphery of the inner liner 12, thereby forming a multi-level sealing and vibration isolation barrier. Even if one O-ring wears out, other O-rings still provide sealing and vibration reduction functions.

[0044] The piezoelectric ceramic stack 14 employs a 1-3 composite ceramic sheet structure, with multiple sheets stacked in parallel along the axial direction. This structure reduces transverse wave interference while maintaining mechanical strength and enhances longitudinal acoustic wave energy transmission efficiency, thereby significantly reducing the dead zone and improving signal sensitivity. Specifically, the piezoelectric ceramic stack 14 uses a 1-3 composite ceramic sheet structure to enhance the signal of the transducer 10 while reducing the dead zone, and is bonded to the acoustic matching layer 15 with adhesive to form an ultrasonic transceiver unit. The transceiver unit is separated from the stainless steel housing 11 by an aluminum alloy inner liner 12, a sealing vibration-damping O-ring 131, and a rubber gasket 132, thereby effectively reducing resonance.

[0045] To adapt to the characteristics of ultrasonic signal attenuation in high-density bentonite slurry environment, the working frequency of the piezoelectric ceramic stack 14 includes at least 88kHz. Compared with conventional transducers 10 with frequencies of 200kHz or higher, the low-frequency signal has less attenuation in slurry, which can effectively extend the detection distance and improve the detection capability of deep holes and large-diameter pile foundation defects.

[0046] Please refer to Figure 4 During installation and use, the transducer 10 is sealed to the metal rotating shaft 20 via an O-ring and secured with M4 bolts. This ensures a reliable seal in underwater operating environments while facilitating quick on-site installation, replacement, and maintenance. This installation method guarantees a secure and reliable connection between the transducer 10 and the metal rotating shaft 20, while avoiding the resonance effect caused by hard metal contact, thus improving the stability and accuracy of the detection.

[0047] The inner liner 12 is made of lightweight, high-strength, corrosion-resistant aluminum alloy with excellent sound conduction performance. An acoustic matching layer 15 is provided on the side close to the piezoelectric ceramic stack 14, so that the sound waves emitted by the piezoelectric ceramic stack 14 achieve a gradual transition of acoustic impedance before entering the water or mud medium, reducing reflection loss and improving the signal-to-noise ratio of the echo signal.

[0048] The signal transmission section uses a shielded cable 16 that runs through the inner lining layer 12 and is directly connected to the piezoelectric ceramic stack 14. This effectively suppresses electromagnetic interference at the construction site, avoids signal distortion and false echoes, and ensures the stability and accuracy of the detection data. Furthermore, vibration isolation components 13 can also be installed on the outer periphery of the housing 11 to form an additional vibration buffer between the transducer 10 and the external mounting structure, achieving bidirectional vibration isolation. This prevents external vibration sources from entering the piezoelectric unit and reduces the reverse effect of the transducer 10's own vibration on the mounting structure, thereby maintaining detection accuracy and stability in complex construction environments.

[0049] The transducer 10 comprehensively adopts multi-level vibration isolation design, piezoelectric unit of type 1-3 composite material, acoustic matching layer 15 optimization, low-frequency working mode, bidirectional vibration isolation installation method and shielded signal transmission, etc. It not only solves the problems of large blind zone, severe signal attenuation and susceptibility to resonance interference of existing pressure-resistant transducers 10 in high mud density environment, but also significantly improves detection sensitivity, effective detection distance and signal stability. It is particularly suitable for pile foundation defect detection operations in underwater, high mud density and strong vibration conditions.

[0050] In summary, the vibration-isolated and pressure-resistant ultrasonic pile foundation testing transducer of this invention effectively reduces the interference of external mechanical vibration and installation component resonance on the piezoelectric unit by arranging multi-stage vibration isolation components between the shell and the inner liner, significantly reducing the detection blind zone. The multiple sealing vibration-isolated O-rings and end rubber gaskets arranged on the outer periphery of the inner liner not only provide dual circumferential and axial buffering but also form a reliable sealing barrier, ensuring long-term stable operation in high-density mud and high-pressure underwater environments.

[0051] The piezoelectric ceramic stack employs a multi-layer stacked structure of Class 1-3 composite materials, combined with an acoustic matching layer design. This enhances the penetration ability of low-frequency signals in mud while maintaining high sensitivity. Coupled with an 88kHz operating frequency, it significantly reduces signal attenuation and improves the detection distance and accuracy for deep holes and large-diameter pile foundations. The aluminum alloy inner liner is lightweight, high-strength, and has excellent sound conductivity, further optimizing acoustic energy transmission efficiency.

[0052] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An isolation pressure-resistant ultrasonic pile foundation detection transducer, characterized in that: include: Shell, inner liner, vibration isolation components and piezoelectric ceramic stack; The inner liner includes at least one chamber and is disposed inside the housing; the vibration isolation components are at least partially distributed in the circumference and ends of the inner liner, and the vibration isolation components abut against the inner liner and the housing respectively, and are used to absorb the mechanical vibration transmitted by the housing; The piezoelectric ceramic is stacked in the cavity and assembled with the inner lining layer to form an ultrasonic transceiver unit.

2. The isolation pressure-resistant ultrasonic pile foundation detection transducer according to claim 1, characterized in that: The vibration isolation assembly includes a sealing vibration isolation O-ring disposed along the outer periphery of the inner liner and a rubber gasket located at the end of the inner liner.

3. The transducer for testing vibration-isolated and pressure-resistant ultrasonic pile foundations according to claim 2, characterized in that: At least two sealing and vibration-damping O-rings are provided on the outer periphery of the inner lining layer.

4. The isolated pressure-resistant ultrasonic pile foundation detection transducer according to claim 1, characterized in that: The piezoelectric ceramic stack adopts a type 1-3 composite material ceramic sheet structure, and is a multi-sheet structure stacked in parallel along the axial direction.

5. The isolated pressure-resistant ultrasonic pile foundation detection transducer according to claim 4, characterized in that: The operating frequency of the piezoelectric ceramic stack includes at least 88 kHz.

6. The isolated pressure-resistant ultrasonic pile foundation detection transducer according to claim 1, characterized in that: The inner liner is an aluminum alloy liner, and an acoustic matching layer is provided on the side near the piezoelectric ceramic stack, the acoustic matching layer being connected to the piezoelectric ceramic stack.

7. The isolated pressure-resistant ultrasonic pile foundation detection transducer according to claim 1, characterized in that: It also includes a shielded cable, which passes through the inner liner and is communicatively connected to the piezoelectric ceramic stack.

8. The isolated pressure-resistant ultrasonic pile foundation detection transducer according to claim 1, characterized in that: The vibration isolation assembly is provided on the outer periphery of the housing.

Images