Expansion joint flexible detection support based on magnetic adsorption and multi-degree-of-freedom adjustment

Abstract

The invention belongs to the technical field of industrial pipeline detection and flexible supporting mechanisms, and discloses an expansion joint flexible detection support based on magnetic attraction and multi-degree-of-freedom adjustment, which comprises a main bearing support body, a magnetic attraction positioning assembly and a ball adjustment supporting assembly, wherein the main bearing support body is of a hollow cylindrical structure, the top of the main bearing support body is in a circular layout, five fixed installation positions used for installing the magnetic attraction positioning assemblies are evenly distributed on the outermost side in the circumferential direction, and the number of the fixed installation positions can be increased or decreased according to actual requirements; by arranging the ball adjusting supporting assembly, multi-degree-of-freedom self-adaptive adjustment can be achieved according to curvature changes of complex curved surface structures such as expansion joints, the supporting device can be stably attached to a curved surface, and the universality and stability of the detection device on a special surface are remarkably improved; the problems of slippage and supporting instability caused by the fact that a traditional rigid support is not suitable for curvature changes are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial pipeline detection and flexible support mechanisms, and particularly relates to an expansion joint flexible detection bracket based on magnetic adsorption and multi-degree-of-freedom adjustment. Background Art

[0002] With the increasing demand for structural integrity and service performance evaluation in fields such as high-end equipment manufacturing, nuclear power pipelines, and petrochemical pressure vessels, nanoindentation technology, as a means of microscale mechanical property characterization, is gradually developing from the laboratory towards on-site and engineering applications. Especially in non-planar curved surface structures such as bellows and expansion joints, in order to obtain parameters such as the local hardness, elastic modulus, and yield strength of materials, it is necessary to accurately and stably deploy the nanoindentation probe in the target area. However, traditional nanoindentation instruments rely on rigid platforms, flat samples, and static conditions, and are difficult to adapt to complex curvatures, limited spaces, and non-ideal surfaces in the on-site environment.

[0003] As a typical flexible structural element, the surface of the expansion joint is periodically corrugated, with obvious curvature changes and a certain elastic deformation ability. When conducting local nano-mechanical property tests on it, it is necessary to ensure that the loading direction is perpendicular to the surface normal, and at the same time prevent the device from slipping, deflecting, or attitude drifting during the loading process. In addition, due to the extremely high sensitivity of nanoindentation experiments to displacement and load control, any minor instability factor will lead to measurement errors or experimental failures. Therefore, there is an urgent need for a on-site clamping device with both flexible conformability, attitude stability, and modular installation capabilities to achieve the reliable deployment of nanoindentation instruments on complex surface structures such as expansion joints.

[0004] An existing technology, a permanent magnet portable magnetic multi-purpose sensor bracket (patent application number CN207600504U), discloses a permanent magnet portable magnetic multi-purpose sensor bracket, which uses a single permanent magnet suction seat to achieve adsorption and fixation on a steel surface through a magnetic switch, and cooperates with a slide rail-slide seat mechanism, a rotating base, and a telescopic arm to provide three degrees of freedom for the sensor: lateral sliding, pitching rotation, and axial telescoping; similar magnetic detection brackets also include the magnetic detection device of a vehicle frame (patent application number: CN106312864A) and a magnetic tool bracket (patent application number: US20170232605A1), which also use switchable permanent magnets or electromagnetic chucks to construct adsorption points on the metal surface, and rely on guide rails or slide plate assemblies to achieve probe positioning and local scanning.

[0005] However, the above-mentioned existing technologies are all based on single-point or linear magnetic attraction, and cannot form multi-point circumferential symmetric support on the outer periphery of the bellows expansion joint; there is a lack of a ball-head - ball bearing decoupling structure between its support and the workpiece, which cannot compensate for the normal deviation caused by ovality and micro-inclination, and is prone to lateral movement under micro-load or high-frequency vibration conditions. The slide rail and the telescopic arm only provide planar or axial adjustment, lack support for the rapid reconstruction of the radial center distance and the number of support points, and do not consider the attenuation of the magnetic circuit closing efficiency and the residual magnetic interference in environments such as vacuum, thermal cycling, or coating with an anti-corrosion layer, making it difficult to meet the comprehensive requirements of low stress, self-alignment, and high stability support for the flexible detection of the expansion joint. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides a flexible detection bracket for an expansion joint based on magnetic attraction and multi-degree-of-freedom adjustment.

[0007] The present invention is implemented as follows. A flexible detection bracket for an expansion joint based on magnetic attraction and multi-degree-of-freedom adjustment includes:

[0008] A main load-bearing bracket body, a magnetic attraction positioning component, and a ball bearing adjustment support component; wherein, the main load-bearing bracket body is a hollow cylindrical structure, its top is circularly arranged, and five fixed installation positions for installing the magnetic attraction positioning component are evenly distributed circumferentially on the outermost side; the number of the fixed installation positions can be increased or decreased according to actual needs; an instrument installation hole is provided in the middle of the top structure, and five guide grooves evenly distributed in the circumferential direction along the radial direction are also provided on the top; the number of the guide grooves can also be adjusted according to specific needs; the magnetic attraction positioning component is arranged on the periphery of the main load-bearing bracket body and includes a magnetic attraction block and a connecting arm, and the magnetic attraction block is connected to the fixed installation position through the connecting arm; the ball bearing adjustment support component is located at the lower part of the main load-bearing bracket body and includes a support connecting rod, a pin shaft, a U-shaped connecting seat, a cylindrical sleeve, and a ball bearing. One end of the support connecting rod is hinged to the U-shaped connecting seat through the pin shaft, the U-shaped connecting seat is fixedly connected to the cylindrical sleeve, and a ball bearing is provided at the lower end of the cylindrical sleeve. The ball bearing is a ball-head structure and can realize multi-directional self-adaptive adjustment and fitting.

[0009] Furthermore, the magnetic attraction positioning components are symmetrically distributed around the main load-bearing bracket body, and can realize the preliminary adsorption and clamping of the device on the surface of the expansion joint, and are applicable to ferromagnetic bellows structures.

[0010] Furthermore, each magnetic attraction block is connected to the connecting arm through a pin shaft, so that the magnetic attraction block can swing in the vertical direction to adapt to the local curvature change of the surface of the expansion joint.

[0011] Furthermore, one end of the support connecting rod in the ball bearing adjustment support component is hinged to the U-shaped connecting seat through a pin shaft, and can realize angular swing within a certain range to adapt to different attitude adjustment requirements.

[0012] Furthermore, a positioning pin is provided on the top structure of the main bearing bracket body, which is used to assist in the assembly and positioning of the ball screw adjustment support assembly.

[0013] Furthermore, the instrument mounting hole is used to connect and fix a nano-indentation instrument or other non-destructive testing equipment.

[0014] Furthermore, the guide groove is used to install the ball screw adjustment support assembly, and each ball screw adjustment support assembly can radially adjust its position along the guide groove to meet the requirements of different detection areas.

[0015] Furthermore, the connection between the ball and the cylindrical sleeve is a ball-head structure, which can automatically adjust the support angle when contacting the surface of a curved surface structure such as an expansion joint, realizing multi-directional adaptive adjustment and stable fitting.

[0016] Furthermore, the main bearing bracket body, the magnetic adsorption positioning assembly, and the ball screw adjustment support assembly are all modularly designed, which is convenient for quick assembly, disassembly, and expansion, improving the on-site installation efficiency and the versatility of the device.

[0017] Furthermore, the number and distribution mode of the fixed mounting positions and the guide grooves can be adjusted according to the actual detection object and engineering requirements, realizing flexible expansion and multi-scenario adaptation.

[0018] Combined with the above technical solutions and the solved technical problems, the advantages and positive effects of the technical solution to be protected by the present invention are as follows:

[0019] By setting the ball screw adjustment support assembly, the present invention can realize multi-degree-of-freedom adaptive adjustment according to the curvature change of complex curved surface structures such as expansion joints, enabling the support device to stably fit the curved surface, significantly improving the versatility and stability of the detection device on special surfaces, and effectively avoiding the problems of slippage and support instability caused by the inadaptability of traditional rigid brackets to curvature changes.

[0020] By providing multiple groups of fixing holes and guide grooves on the top of the main bearing bracket body, the present invention facilitates the quick assembly and position adjustment of the magnetic adsorption positioning assembly and the ball screw adjustment support assembly, realizing the flexible layout and efficient assembly of each functional module, and improving the on-site installation efficiency and the modular expansion ability of the device.

[0021] By adopting the magnetic adsorption positioning assembly, the present invention realizes the quick adsorption and preliminary positioning on the surface of ferromagnetic bellows or expansion joints, simplifies the on-site operation process, improves the clamping reliability and repeated positioning accuracy, and reduces the human operation error.

[0022] The flexible detection bracket for expansion joints based on magnetic adsorption and multi-degree-of-freedom adjustment proposed by the present invention can achieve efficient and non-destructive detection of complex curved surface structures, greatly improving the adaptability and detection efficiency of high-precision instruments such as on-site nanoindenters. The industrialization and popularization of this technology are expected to promote the improvement of intelligent detection and quality assurance levels in industrial fields such as high-end equipment manufacturing, nuclear power, petrochemical, aerospace, etc. Relevant enterprises can reduce the customization cost and commissioning cycle of detection equipment, improve the consistency and reliability of detection data, and have significant economic benefits and broad market prospects. At the same time, as a modular and universal support platform, it can also be extended to more emerging fields such as detection and flexible clamping of robots, and has continuous commercial development and application value.

[0023] At present, there is no special clamping and supporting device for nano-mechanical testing of complex curved surface structures such as expansion joints and bellows at home and abroad. Existing detection methods mostly rely on rigid brackets and manual alignment, and it is difficult to meet the requirements of multi-curvature, limited space, and high repeatability in actual engineering environments. The present invention combines magnetic adsorption positioning, multi-degree-of-freedom adjustment of ball bearings, and modular design for the first time, innovatively solves the problem of stable installation of complex surface detection instruments, fills the technical gap in related fields, and has important theoretical significance and promotion value.

[0024] For a long time, how to achieve high-precision nano-mechanical property testing on non-flat curved surfaces, in limited spaces, and even under special working conditions has been a technical bottleneck hindering the development of related engineering fields. Traditional solutions have problems such as unstable brackets, difficult attitude adjustment, and low detection accuracy, which greatly limit the improvement of on-site detection capabilities. Through the innovative integration of magnetic adsorption and multi-degree-of-freedom adaptive adjustment structures, the present invention truly realizes reliable fitting and stable support for complex curved surface, effectively solves the problem of "unable to be stably deployed" of high-precision instruments in actual engineering sites, and provides a new technical idea for the industry development.

[0025] Existing technologies generally believe that high-precision tests such as nanoindentation can only be carried out in flat and ideal laboratory environments, and are not applicable to complex curved surfaces and limited spaces in engineering sites. The present invention breaks through this traditional understanding, and through the coordinated design of magnetic adsorption and ball bearing adjustment mechanisms, realizes precise detection and support under complex working conditions, breaks the technical prejudice in the industry that high-precision detection "can only be achieved under ideal conditions", and provides strong support for the on-site mechanical property characterization of complex structures. Description of the Drawings

[0026] Figure 1 It is a structural diagram of the flexible detection bracket for expansion joints based on magnetic adsorption and multi-degree-of-freedom adjustment provided by an embodiment of the present invention.

[0027] Figure 2It is a schematic structural diagram of the ball screw adjustment support assembly provided by an embodiment of the present invention.

[0028] Figure 3 It is a top view structural schematic diagram of the main bearing bracket body provided by an embodiment of the present invention.

[0029] In the figure: 1. Main bearing bracket body; 2. Ball screw adjustment support assembly; 3. Magnetic adsorption positioning assembly; 11. Base 1; 12. Base 2; 21. Short shaft pin 1; 22. Connecting block; 23. Connecting arm; 24. Magnetic adsorption block; 31. Support connecting rod; 32. Pin shaft 2; 33. U-shaped connecting seat; 34. Cylindrical sleeve; 35. Ball; 121. Fixed installation position; 122. Positioning pin; 123. Instrument installation hole; 124. Guide groove. Specific embodiments

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] During the traditional expansion joint detection process, the bracket often relies on mechanical clamps or welding points for fixation. When encountering multi-layer curvature or coated protective layers, additional stresses are likely to be generated and local plastic deformation is induced. The device of the present invention replaces rigid clamping with pure magnetic adsorption, and uses the principle of magnetic circuit closure to generate a stable normal adsorption force without damaging the coating layer. The magnetic flux density adapts to the curvature of the pipe wall, significantly reducing the surface residual stress and the probability of microcrack initiation.

[0032] The radial guide groove at the top of the bracket and the lower-placed ball form a spatial-spherical composite kinematic pair, allowing the support connecting rod to achieve instantaneous centripetal adjustment in the pitch, yaw and roll directions. The ball is made of high-nitrogen stainless steel and undergoes PVD diamond-like coating treatment after vacuum quenching. The surface hardness reaches above HV2600, and with a mirror surface roughness of Ra≤0.04μm, it can maintain a stable static friction coefficient under point contact conditions, ensuring that the attitude is locked without drift during micro-displacement.

[0033] The pin shaft between the magnetic adsorption block and the connecting arm constitutes a single-degree-of-freedom swinging hinge, which can compensate for the normal deviation caused by the local ellipticity of the pipe wall; at the same time, a fluoropolyether-based high-vacuum grease is embedded in the hinge cavity to reduce the swinging damping, and it can still maintain low volatility in an environment of 10-4Pa level, ensuring non-destructive testing operations compatible with vacuum.

[0034] The instrument mounting holes adopt an internal countersunk double - guiding positioning structure. During installation, the indentation instrument (or other acoustic / optical non - destructive probes) is quickly coupled through double taper pins, and the axis reproduction error is controlled within ±8μm. The overall center of gravity design of the device is coaxially aligned with the center line of the expansion joint. Combined with the equipotential surface distribution of the ball - supported points, the external vibration excitation forms a closed moment loop after being shunted by each support link, effectively suppressing the micro - vibration coupling between the probe and the specimen.

[0035] To avoid magnetic circuit interference, a coaxial double - magnetic - pole structure is set inside the magnetic - attraction block. The middle alloy shielding ring leads the magnetic leakage to a detour circuit, and the influence of the magnetic field gradient on adjacent sensors is theoretically reduced to <1μT. Through finite - element transient electromagnetic - structure coupling analysis, it can be seen that when the wall thickness is 6mm and the outer diameter is 450mm, the maximum displacement of each magnetic - attraction block under a 200N external load impact is only 1.3μm, verifying the stability under high - order modes.

[0036] All modular interfaces of the device adopt an interference - positioning hybrid mating strategy of H7 / g6. No heat treatment or special fixtures are required for on - site disassembly and assembly. The unified quick - release buckle ensures that the operator can complete the layout within a single - side space of 200mm. After the whole machine passes the IEC60068 - 2 - 6 vibration tolerance test (5 - 500Hz, 5g, 30min), the magnetic - attraction attenuation rate <0.5%, and the change rate of the rolling resistance moment of the ball <1%, meeting the reliability requirements for long - cycle repeated measurements in high - frequency dynamic loading scenarios.

[0037] See Figures 1 to 3 , the embodiment of the present invention provides a flexible detection bracket for expansion joints based on magnetic - attraction adsorption and multi - degree - of - freedom adjustment, which can meet the on - site non - destructive detection needs of complex curved - surface structures such as expansion joints, and is particularly suitable for the installation and support of nano - indentation instruments.

[0038] Specifically, the detection bracket includes a main load - bearing bracket body 1, a magnetic - attraction positioning component 2, and a ball - adjusting support component 3.

[0039] The main load - bearing bracket body 1 is a hollow cylindrical structure as a whole, and its top is circularly arranged. Five fixed mounting positions 121 for installing the magnetic - attraction positioning component 2 are evenly distributed in the outermost circumferential direction. Each fixed mounting position 121 can be adjusted according to actual needs. The fixed mounting position 121 is connected to the magnetic - attraction block 24 through bolts or pin shafts to achieve preliminary adsorption and clamping of the expansion - joint surface. An instrument mounting hole 123 is provided in the middle of the top structure of the main load - bearing bracket body 1 for the installation and positioning of equipment such as nano - indentation instruments. Five guiding grooves 124 evenly distributed in the radial and circumferential directions are also provided at the top for installing the ball - adjusting support component 3. The number of each guiding groove 124 can also be adjusted according to specific needs. Each ball - adjusting support component 3 can adjust its position in the radial direction along the guiding groove 124 to adapt to different curvatures and support requirements. A positioning pin 122 can also be provided at the top for auxiliary assembly and positioning.

[0040] The magnetic positioning components 2 are symmetrically distributed on the outside of the main bearing bracket body 1, and include magnetic blocks 24 and connecting arms 23. Each magnetic block 24 is connected to the fixed installation position 121 of the main bearing bracket body 1 through the connecting arm 23, and the magnetic block 24 can adapt to the local curvature of the surface of the expansion joint, realizing efficient adsorption and auxiliary positioning of the ferromagnetic corrugated pipe structure.

[0041] The ball screw adjustment support assembly 3 is located at the lower part of the main bearing bracket body 1, and includes a support connecting rod 31, a pin shaft 32, a U-shaped connecting seat 33, a cylindrical sleeve 34 and a ball 35. One end of the support connecting rod 31 is hinged to the U-shaped connecting seat 33 through the pin shaft 32, and can swing at a certain angle to meet the adjustment requirements of different postures. The U-shaped connecting seat 33 is fixedly connected to the cylindrical sleeve 34, and the lower end of the cylindrical sleeve 34 is provided with a ball 35. The ball 35 adopts a ball head structure, which can realize multi-directional self-adaptive adjustment and fitting when contacting the surface of a curved surface structure such as an expansion joint, improving the stability and flexibility of the support.

[0042] During actual application, the detection bracket can be adsorbed on the surface of the expansion joint through the magnetic block 24 first. According to the actual curvature and detection area, the positions and support angles of the ball screw adjustment support assemblies 3 are adjusted through the guide grooves 124, and finally the precise installation of the nano-indentation instrument is completed through the instrument installation holes 123. The above structural design can effectively adapt to irregular curved surfaces such as expansion joints, realizing the stable support and precise positioning of the detection device.

[0043] It should be noted that the self-adaptive structure of the ball screw adjustment support assembly 3 and the modular design of the main bearing bracket body 1 endow the detection bracket of the present invention with good versatility and expandability, and can be applied to the on-site detection requirements of various complex curved surfaces and limited spaces in the industrial field.

[0044] Through the innovative structural design, the embodiment of the present invention realizes the stable, flexible and convenient installation of high-precision non-destructive testing devices such as nano-indentation instruments under complex curved surface structures such as expansion joints, and has wide engineering application value.

[0045] Specific application fields, related products and technical effects of the present invention:

[0046] 1. High-end equipment manufacturing field: applicable to on-site non-destructive testing and mechanical property characterization of complex curved surface structures such as large pipelines, expansion joints, and corrugated pipes in the fields of nuclear power, petrochemical, shipbuilding, aerospace, etc.

[0047] 2. Structural health monitoring and maintenance: can be used for regular inspection and maintenance of key parts such as industrial pipelines, pressure vessels, and chemical storage tanks, improving operation safety and reliability.

[0048] 3. Supporting components for micro-nano mechanical testing instruments: As standardized support components for high-precision characterization equipment such as nanoindenters and micro-indenters, they enhance the on-site adaptability of the instruments.

[0049] 4. Quality control of complex curved surface components: Widely applicable to the mechanical testing and quality assessment of curved surface shells and special-shaped workpieces in industries such as electronics, medical, and precision manufacturing.

[0050] 5. Installation efficiency and operation convenience: Through the coordinated action of the magnetic adsorption positioning component and the ball screw adjustment support component, rapid adsorption, flexible adjustment, and modular assembly of the bracket are achieved, greatly improving the on-site installation efficiency. A single person can efficiently complete various operations, reducing human errors.

[0051] 6. Enhanced versatility and adaptability: Through the design of guide grooves and modular structures, the bracket can be flexibly adapted to different specifications of expansion joints and various complex curved surface structures, supporting multi-scenario and multi-target detection requirements.

[0052] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention by those skilled in the art within the technical scope disclosed by the present invention shall be covered by the protection scope of the present invention.

Claims

1. A flexible detection bracket for expansion joints based on magnetic adsorption and multi-degree-of-freedom adjustment, comprising a main bearing bracket body, a magnetic adsorption positioning component, and a ball adjustment support component; The main bearing bracket body is a hollow cylindrical structure, its top is circular, and a plurality of fixed mounting positions are circumferentially distributed on the outermost side. An instrument mounting hole is provided in the middle of the top, and several guide grooves are arranged radially on the top; The magnetic adsorption positioning component is installed at the fixed mounting position. The magnetic adsorption positioning component includes a magnetic adsorption block and a connecting arm. The magnetic adsorption block is connected to the fixed mounting position through the connecting arm; The ball adjustment support component is installed below the guide groove. The ball adjustment support component includes a support connecting rod, a pin shaft, a U-shaped connecting seat, a cylindrical sleeve, and a ball. One end of the support connecting rod is hinged to the U-shaped connecting seat through the pin shaft. The U-shaped connecting seat is fixedly connected to the cylindrical sleeve, and the lower end of the cylindrical sleeve is connected to the ball by a ball head connection method; The ball adjustment support component can move radially along the guide groove to adjust the support position.

2. A magnetic positioning component, which is suitable for being installed at a fixed installation position of a bracket, is characterized in that, It includes a magnetic adsorption block and a connecting arm. The magnetic adsorption block is provided with a magnetic adsorption surface. One end of the connecting arm is connected to the magnetic adsorption block, and the other end is provided with a detachable mounting end. The connecting arm is hinged to the magnetic adsorption block through a pin shaft, so that the magnetic adsorption block can swing in the vertical plane.

3. A ball screw adjustment support assembly, applicable to a flexible inspection bracket, characterized in that, It includes a support connecting rod, a pin shaft, a U-shaped connecting seat, a cylindrical sleeve, and a ball. One end of the support connecting rod is hinged to the U-shaped connecting seat through the pin shaft. The U-shaped connecting seat is fixedly connected to the cylindrical sleeve, and the lower end of the cylindrical sleeve is connected to the ball by a ball head method. The ball is used to contact the surface of the workpiece to be detected and can rotate with multiple degrees of freedom.

4. An expansion joint flexible detection system, comprising the expansion joint flexible detection bracket described in claim 1 and a non-destructive testing instrument installed in the instrument mounting hole. The non-destructive testing instrument is fixed on the outer surface of the expansion joint to be detected through the main bearing bracket body, and the position fixing and attitude adjustment are realized through the magnetic adsorption positioning component and the ball adjustment support component.

5. The flexible detection bracket for expansion joints according to claim 1, wherein, The magnetic adsorption positioning components are distributed axially symmetrically along the outer periphery of the main bearing bracket body.

6. The flexible detection bracket for expansion joints according to claim 1, characterized in that, The number and distribution mode of the fixed mounting positions and the guide grooves are variably configured according to the size of the expansion joint to be detected.

7. The flexible detection bracket for expansion joints according to claim 1, characterized in that, A positioning pin is provided at the top of the main bearing bracket body, and the positioning pin is used to provide a positioning reference when installing the ball adjustment support component.

8. The magnetic attraction positioning component according to claim 2, wherein, The mounting end is connected to the fixed mounting position of the bracket by a threaded connection method for quick disassembly and assembly.

9. The ball screw adjustment support assembly according to claim 3, wherein The other end of the support connecting rod is provided with a chute connection structure for cooperating with the guide groove of the bracket to realize radial position adjustment.

10. The flexible detection system for expansion joints according to claim 4, characterized in that, The non-destructive testing instrument is a nano-indentation instrument.

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