Rail rolling contact fatigue crack array detection probe based on alternating electromagnetic field

Abstract

The application provides a rail rolling contact fatigue crack array detection probe based on alternating electromagnetic field, which comprises a rail, a detection probe, a shock absorber, a probe clamp and a fixing device. The detection probe comprises a special-shaped excitation module, an array sensor group and an amplification circuit. The special-shaped excitation module is adaptively designed according to the geometric shape of the rail to generate an induced current perpendicular to the crack, and the induced current has high strength and high uniformity. The array sensor group is designed in an arc shape according to the shape of the rail to completely cover the gauge angle. The shell of the detection probe is designed in a profiled shape for the rail to completely match the surface profile of the rail. The shock absorber is used to ensure that the distance between the detection probe and the surface of the rail is constant to prevent damage to the detection probe. The rail rolling contact fatigue crack array detection probe provided by the application has simple detection method, can completely cover the gauge angle in single detection, has high detection efficiency and detection precision, and can further realize surface profile imaging of rail defects.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing, and more particularly to an array probe for detecting fatigue cracks in rolling contact rails based on alternating electromagnetic fields. Background Technology

[0002] Alternating current field measurement (ACFM) technology induces a uniform alternating current in a workpiece using an excitation coil. This induced current causes disturbances at the locations of defects such as cracks and corrosion. Based on the principle that these electric field disturbances cause distortion of the spatial magnetic field, a detection sensor measures this distortion signal, thereby enabling defect detection and assessment. This technology can detect surface cracks, fractures, and other defects in conductive materials, eliminating the need for extensive pre-cleaning of the inspection area and removing the protective coating from the workpiece surface beforehand.

[0003] Rolling contact fatigue cracks in rails are located at the rail gauge angle, typically propagating at a 45-degree horizontal angle to the direction of travel. Traditional AC electromagnetic field detection technology, when detecting cracks, uses an excitation current on the rail surface perpendicular to the direction of travel, which is not perpendicular to the crack. This results in poor current disturbance and small distortion of the spatial magnetic field at the crack, hindering crack detection and further quantification. Furthermore, due to the complex geometry at the rail gauge angle, a large gap exists between the excitation core and the rail in traditional AC electromagnetic field detection probes, making it difficult for the probe to effectively excite the rail. The induced current on the rail surface is weak and unevenly distributed, making it difficult to perform large-scale crack detection and surface contour imaging. Simultaneously, the sensors in traditional array detection probes are difficult to fit precisely to the rail gauge angle contour, and the inconsistent distances between different sensors and the rail surface cause significant differences in the signals from each sensor. The combined effect of these three factors results in extremely poor crack detection performance, failing to meet the requirements for rail safety inspection.

[0004] This invention proposes a rail rolling contact fatigue crack array detection probe based on AC electromagnetic field detection technology. It adopts a contour-following design based on the rail gauge angle, deeply fitting the rail surface, and employs a multi-sensor design to achieve large-scale effective crack detection and surface contour imaging, thus solving the problem that existing AC electromagnetic field detection technology is difficult to detect rail rolling contact fatigue cracks. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing rail rolling contact fatigue crack detection technologies by designing an array detection probe for rail rolling contact fatigue cracks based on AC electromagnetic fields, enabling the detection of rail gauge angles with complex geometries. The probe employs a customized irregularly shaped excitation module to generate an induced current perpendicular to the crack on the rail surface, exhibiting high intensity and uniformity. An arc-shaped array of sensors, with each sensor equidistant from the rail, covers the entire gauge angle, enabling simultaneous detection of crack-prone areas. The probe housing adopts a contour-following design, deeply fitting the rail surface, and incorporates shock absorbers to reduce vibration during the detection process, thereby achieving large-scale effective detection of rail cracks and imaging of the crack surface contour.

[0006] This application provides a rail rolling contact fatigue crack array detection probe based on AC electromagnetic field. The rail rolling contact fatigue crack array detection probe includes a rail, a detection probe, a shock absorber, a probe clamp, and a fixing device. The detection probe is designed with an irregular excitation module and an array sensor group. The irregular excitation module consists of an irregular magnetic core and an excitation coil wound on the magnetic core. The irregular magnetic core is placed parallel to the crack at a horizontal angle of 45 degrees to the direction of travel. Its two legs have different lengths, and the bottom of each leg is designed with inclined surfaces with different inclination angles. The inclined surfaces are tangent to the rail surface and have a small gap with the rail surface. The array sensor group consists of several magnetic sensors, which are distributed in an arc shape according to the contour of the rail surface. Each magnetic sensor is equidistant from the rail surface.

[0007] Furthermore, the detection probe also includes a probe housing, a probe top cover, a Remo connector, an amplification circuit, and fixing screws. The amplification circuit performs preliminary amplification and filtering on the signal output from the array sensor group; the Remo connector connects the excitation signal from the chassis to the detection probe; the probe housing adopts a contour-following design, with a curved bottom surface that matches the track gauge angle depth; the probe housing has a boss inside to fix an irregularly shaped magnetic core; the bottom of the probe housing has a groove to fix the array sensor group; and threaded holes are designed on both sides of the probe housing to cooperate with the probe clamp to fix the detection probe; the probe top cover is fixed to the probe housing using fixing screws.

[0008] Furthermore, the probe clamp includes a clamp body, probe fixing screws, and a clamp connecting device. The clamp body is designed with four fixing claws to fix the detection probe by the probe fixing screws; the top of the clamp body is designed with a bracket, which, in cooperation with the clamp connecting device consisting of bolts and nuts, hinges and fixes the probe clamp to the shock absorber.

[0009] Furthermore, the shock absorber includes a shock absorber housing, a slider, a spring, and a fixing bolt. The top of the slider is designed with a boss for mounting the spring; the installed spring and slider are fixed together in a groove inside the shock absorber housing. The fixing bolt engages with threaded holes on the slider through rectangular holes on both sides of the shock absorber housing. The top of the shock absorber housing is designed with a boss to further engage with a fixing device to form a hinged structure.

[0010] Furthermore, the fixing device includes a fixing device body and a connecting device. The connecting device consists of bolts and nuts, which cooperate with the bracket on the fixing device body and the top boss on the shock absorber to form a hinge structure. The fixing device further cooperates with the testing vehicle through a fixing threaded hole on the fixing device body.

[0011] Compared with the prior art, the beneficial technical effects of the technical solution proposed in the embodiments of this application include:

[0012] (1) High detection sensitivity, with contour design tailored to the rail, closely matching the rail profile.

[0013] (2) It has a large detection range and adopts a multi-sensor design to completely cover the track gauge angle.

[0014] (3) Good detection stability, ensuring that the distance between the probe and the rail remains constant, reducing interference signals.

[0015] (4) Simple operation and easy to learn Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall detection probe for rail rolling contact fatigue cracks in the embodiments of this application.

[0018] Figure 2 This is an exploded structural diagram of the rail rolling contact fatigue crack array detection probe in the embodiments of this application.

[0019] Figure 3 This is a schematic diagram of the exploded structure of the detection probe in an embodiment of this application.

[0020] Figure 4 This is a schematic diagram illustrating the function of the irregular excitation module in the embodiments of this application.

[0021] Figure 5 This is a schematic diagram of current disturbance in an embodiment of this application.

[0022] Figure 6 This is a schematic diagram of the internal structure of the probe housing in an embodiment of this application.

[0023] Figure 7 This is an exploded view of the probe clamp in the embodiments of this application.

[0024] Figure 8 This is an exploded structural diagram of the shock absorber in the embodiments of this application.

[0025] Figure 9 This is an exploded view of the fixing device in the embodiments of this application.

[0026] Figure 10 The detection signal diagram in the embodiment of this application

[0027] Figure 11 This is an image of the crack surface contour in an embodiment of this application.

[0028] Figure 12 This is a photograph of the detection probe in an embodiment of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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, 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.

[0030] This application provides a rail rolling contact fatigue crack array detection probe based on an alternating electromagnetic field. For example... Figure 1-5 As shown, the rail rolling contact fatigue crack array detection probe includes a rail 10, a detection probe 20, a probe clamp 30, a shock absorber 40, and a fixing device 50. The detection probe 20 is designed with an irregularly shaped excitation module 203 and an array sensor group 204, wherein the irregularly shaped excitation module 203 is as follows: Figure 4 As shown, it consists of an irregularly shaped magnetic core 2031 and an excitation coil 2032 wound on the magnetic core 2031. The irregularly shaped magnetic core 2031 is placed parallel to the crack at a horizontal angle of 45 degrees to the direction of travel. Its two legs are of different lengths. The bottom is designed with inclined surfaces 2033 and 2034 with different inclination angles. The inclined surfaces 2033 and 2034 are tangent to the surface of the rail 10 and maintain a small gap with the surface of the rail 10, so that the surface current of the rail 10 has the greatest possible intensity and uniformity. Figure 5Figure 1 shows a schematic diagram of the induced current generated on the surface of rail 10 by a conventional probe, and Figure 2 shows a schematic diagram of the induced current generated on the surface of rail 10 by the irregular excitation module 203. It can be seen that the induced current disturbance range generated by the irregular excitation module 203 is larger and more uniformly distributed, which enhances the crack detection rate and the signal-to-noise ratio. The array sensor group 204 consists of 5 TMR2505 sensors, which are arranged in an arc shape according to the contour of the rail 10 surface to ensure that each sensor is at the same distance from the surface of rail 10. The spacing between the sensors is 5mm. While ensuring detection sensitivity and imaging accuracy, it has a large detection range and can completely cover the crack-prone area at the track gauge angle.

[0031] Furthermore, such as Figure 3 and Figure 6 As shown, the detection probe 20 also includes a probe housing 201, a probe top cover 202, an amplifier circuit 205, a Remo connector 206, and a fixing screw 207. The amplifier circuit 205 is used to perform preliminary amplification and filtering of the signal output from the array sensor group 204; the Remo connector 206 connects the excitation signal from the chassis to the detection probe 20; the probe housing 201 adopts a contour-following design, the bottom surface 2013 of the probe housing 201 is designed as a curved surface, which can match the track gauge angle depth, the probe housing 201 has a boss 2011 inside to fix the irregular magnetic core 2031, the bottom of the probe housing 201 has a groove 2012 to fix the array sensor group 204, and the probe housing 201 has threaded holes 2014 on both sides to fix the detection probe 20 to the probe clamp 30; the probe top cover 202 is fixed by the fixing screw 207 engaging with the threaded hole 2016 of the probe housing 201, and the detection probe 20 is sealed by the protrusions 2017 around the top of the probe housing 201.

[0032] Furthermore, such as Figure 7 As shown, the probe clamp 30 includes a clamp body 301, a clamp connecting device 302, and a probe fixing screw 303. The clamp body 301 is designed with four fixing claws 3012, which are fixed to the detection probe 20 by the probe fixing screw 303. The top of the clamp body 301 is designed with a bracket 3011, which, in cooperation with the clamp connecting device 302 composed of nuts 3021 and bolts 3022, enables the probe clamp 30 to be hinged and fixed to the shock absorber 40, and the angle of the probe clamp 30 can be adjusted according to different working conditions.

[0033] Furthermore, such as Figure 8As shown, the shock absorber 40 includes a shock absorber housing 401, a slider 402, a spring 403, and a fixing bolt 404. The slider 402 has a boss 4021 on its top for mounting the spring 403. The installed spring 403 and slider 402 are fixed together in a groove 4013 inside the shock absorber housing 401, enabling sliding guidance. The fixing bolt 404 engages with the threaded hole 4022 on the slider 402 through rectangular holes 4012 on both sides of the shock absorber housing 401, limiting the stroke of the slider 402. The top of the shock absorber housing 401 has a boss 4011 for further engagement with the fixing device 50 to form a hinged structure.

[0034] Furthermore, such as Figure 9 As shown, the fixing device 50 includes a fixing device body 501 and a connecting device 502. The connecting device 502 consists of a nut 5021 and a bolt 5022. It achieves hinged fixing of the shock absorber 40 by cooperating with the bracket 5012 on the fixing device body 501 and the top boss on the shock absorber 40. The angle of the shock absorber 40 can be adjusted according to different working conditions. The fixing device 50 further cooperates with the inspection vehicle through the fixing threaded hole 5011 on the fixing device body 501 to achieve overall fixing of the rail contour array inspection probe.

[0035] Furthermore, Figure 10 and Figure 11 These are the detection signal image and surface contour image of the rail rolling contact fatigue crack array detection probe, respectively. Figure 10 and Figure 11 It can be seen that the rail rolling contact fatigue crack array detection probe can effectively detect rail rolling contact fatigue cracks of different depths and image their surface contours. Figure 12 This is a physical image of the detection probe 20.

Claims

1. A rail rolling contact fatigue crack array detection probe based on alternating electromagnetic field, characterized in that, Includes rails, inspection probes, shock absorbers, probe clamps, and fixing devices; The detection probe is designed with an irregular excitation module and an array sensor group. The irregular excitation module consists of an irregular magnetic core and an excitation coil wound on the magnetic core. The irregular magnetic core is placed parallel to the crack at a horizontal angle of 45 degrees to the direction of travel. Its two legs are of different lengths and the bottom is designed with inclined surfaces of different inclination angles. The inclined surfaces are tangent to the surface of the rail and the gap between them and the surface of the rail is small. The array sensor group consists of several magnetic sensors, which are arranged in an arc shape according to the contour of the rail surface, and each magnetic sensor is at the same distance from the rail surface.

2. The rail rolling contact fatigue crack array detection probe based on AC electromagnetic field as described in claim 1, characterized in that, The detection probe also includes a probe housing, a probe top cover, an amplifier circuit, and fixing screws; The amplifier circuit performs preliminary amplification and filtering on the signal output by the array sensor group. The Remo connector connects the excitation signal from the chassis to the detection probe; The probe housing adopts a contour-following design, with its bottom surface designed as a curved surface to match the track gauge angle depth. The probe housing has a boss inside to fix the irregularly shaped magnetic core. The bottom of the probe housing has a groove to fix the array sensor group. The probe housing has threaded holes on both sides to cooperate with the probe clamp to fix the detection probe. The probe top cover is fixed to the probe housing using the fixing screws.

3. The rail rolling contact fatigue crack array detection probe based on AC electromagnetic field as described in claim 1, characterized in that, The probe clamp includes a clamp body, probe fixing screws, and a clamp connecting device; The fixture body is designed with four fixing claws, and the detection probe is fixed by the probe fixing screws; The top of the clamp body is designed with a bracket, which, in conjunction with the clamp connection device consisting of bolts and nuts, hinges and fixes the probe clamp to the shock absorber.

4. The rail rolling contact fatigue crack array detection probe based on AC electromagnetic field as described in claim 1, characterized in that, The shock absorber includes a shock absorber housing, a slider, a spring, and fixing bolts; The top of the slider is designed with a boss to install the spring. After installation, the spring and the slider are fixed together in the internal groove of the shock absorber housing. The fixing bolts engage with the threaded holes on the slider through rectangular holes on both sides of the shock absorber housing; The top of the shock absorber housing is designed with a boss to further cooperate with the fixing device to form a hinge structure.

5. The rail rolling contact fatigue crack array detection probe based on AC electromagnetic field as described in claim 1, characterized in that, The fixing device includes a fixing device body and a connecting device; The connecting device consists of bolts and nuts, and together with the bracket on the main body of the fixing device and the top boss on the shock absorber, it forms a hinged structure. The fixing device further engages with the testing vehicle through a fixing threaded hole on the main body of the fixing device.

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