Magnetic flux leakage detection experiment device based on TMR magnetic sensor

Abstract

The utility model discloses a magnetic flux leakage detection experiment device based on a TMR magnetic sensor. The magnetic flux leakage detection experiment device comprises a magnetic medium material, a magnetized material, a magnetic field sensor and a data terminal, the magnetizing material is arranged close to the magnetic dielectric material and is used for magnetizing the magnetic dielectric material; a plurality of different magnetic leakage defects are arranged on the magnetic medium material at intervals and are used for triggering a leakage magnetic field with various magnetic field intensities; the magnetic field sensor is close to the magnetic medium material and is movably arranged relative to the magnetic medium material, and the magnetic field sensor is used for keeping a fixed distance from the magnetic medium material and sequentially passing through multiple magnetic leakage defects to carry out magnetic field intensity detection, or is used for measuring the magnetic field intensity of the magnetic leakage defect at different distances by adjusting the distance from the magnetic leakage defect at the position; the data terminal is electrically connected with the magnetic field sensor and used for processing, collecting and displaying magnetic field intensity data detected by the magnetic field sensor. According to the experimental device, the magnetic field and the rule of the factors are obtained by changing the geometrical characteristics of the magnetic leakage defect of the magnetic medium material and the lift-off value of the magnetic field sensor.

Description

Technical Field

[0001] This utility model relates to the field of teaching instruments, and in particular to an experimental device for detecting magnetic leakage based on a TMR magnetic sensor. Background Technology

[0002] In physics teaching, electromagnetism, especially the concept of the magnetic circuit theorem, is one of the more abstract and difficult concepts for students to understand. Textbook instruction alone is insufficient for students to truly grasp the concept of magnetic circuits, and existing physics teaching experiments related to magnetic circuits are very limited. The magnetic circuit theorem is an important teaching concept in courses such as "University Physics" and "Electromagnetism." Its definition is that in a magnetic circuit, the sum of the magnetomotive forces is equal to the sum of the magnetic flux produced in that circuit. Through the magnetic circuit theorem, we can demonstrate how the magnetic field of a magnetic circuit is distributed under the influence of different magnetic reluctances, calculate the magnetic flux and magnetomotive force of each part of the magnetic circuit, and thus analyze the distribution of the entire magnetic field.

[0003] Currently, there are relatively few experimental designs for magnetic circuits. Some experiments involve inserting different magnetic media materials into a notched iron core made of ferromagnetic material, using meters to display changes in "magnetomotive force" and "magnetic flux," and then analyzing the series and parallel relationships of the magnetic reluctance of the magnetic media in the magnetic field. The main drawback of existing experimental schemes is that they only analyze the influence of different magnetic media materials, i.e., different permeabilities, on the magnetic field in the magnetic circuit, lacking analysis of the influence of the structural characteristics of the magnetic media itself on the magnetic field, as well as the influence of the distance (lift-off value) between the testing instrument and the surface of the workpiece on the magnetic field. Utility Model Content

[0004] This utility model discloses a magnetic flux leakage detection experimental device based on a TMR magnetic sensor. By testing the magnitude of magnetic flux leakage caused by magnetic media materials with different magnetic flux leakage defects, the relationship between the magnetic field and the magnetic medium is obtained. By changing the lift-off value during the test, the influence of different lift-off values ​​on the measurement results is analyzed to obtain the influencing factors of the magnetic field testing process.

[0005] This utility model embodiment provides an experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor, including: a magnetic medium material, a magnetizing material, a magnetic field sensor, and a data terminal;

[0006] The magnetizing material is disposed close to the magnetic medium material for magnetizing the magnetic medium material;

[0007] The magnetic medium material has multiple different leakage magnetic defects spaced apart to induce leakage magnetic fields of various magnetic field strengths.

[0008] The magnetic field sensor is positioned close to and relatively movable relative to the magnetic medium material. The magnetic field sensor is used to maintain a fixed distance from the magnetic medium material and sequentially pass through multiple magnetic leakage defects to detect the magnetic field strength, or to measure the magnetic field strength of the magnetic leakage defect at different distances by adjusting the distance to a certain magnetic leakage defect.

[0009] The data terminal is electrically connected to the magnetic field sensor and is used to process, collect, and display the magnetic field strength data detected by the magnetic field sensor.

[0010] Furthermore, the magnetic leakage defect is disposed on the surface of the magnetic medium material.

[0011] Furthermore, the magnetic leakage defect includes a magnetic leakage groove, which is formed on the surface of the magnetic medium material.

[0012] Furthermore, the magnetic leakage grooves are arranged sequentially in a single direction, and the interval between two adjacent magnetic leakage defects is greater than the detection range of the magnetic field sensor.

[0013] Furthermore, the magnetic leakage groove is a rectangular groove, including three geometric structural features that affect the strength of the magnetic leakage field: length, width, and depth. The width of the magnetic leakage groove is the distance between the two sides of the magnetic leakage groove in the single direction. The depth of the magnetic leakage groove is the distance from the bottom of the magnetic leakage groove to the surface of the magnetic medium material. The length of the magnetic leakage groove is the distance between the two sides of the magnetic leakage groove perpendicular to the single direction.

[0014] The depth of the magnetic flux leakage grooves varies in several places, but the length and depth are the same;

[0015] The width of the magnetic flux leakage slots and / or the length and depth of the slots are different, and the width of the magnetic flux leakage slots is smaller than the scanning width of the magnetic field sensor along the single direction.

[0016] The length of the magnetic flux leakage slots and / or the width and depth of the slots are different, and the length of the magnetic flux leakage slots is less than the scanning width of the magnetic field sensor perpendicular to the single direction.

[0017] Furthermore, the magnetizing material is symmetrically disposed on opposite sides of the magnetic medium material, and the sides are perpendicular to the surface of the magnetic medium material.

[0018] Furthermore, the length of the magnetic flux leakage groove is greater than its width, and the magnetizing material is symmetrically arranged on the side perpendicular to the length direction of the magnetic flux leakage groove.

[0019] Furthermore, it includes a horizontal sliding structure, which includes a guide and a sliding member that cooperates with the guide, as well as a first support for supporting the magnetic field sensor or the magnetic medium material or magnetizing material; the guide is used to fix it on the operating table plane, and the guiding direction of the guide is parallel to the arrangement direction of the magnetic leakage defect; the sliding member is connected to the first support.

[0020] Furthermore, the first support member is provided with a lifting and sliding structure, which includes a first rotating member and a second rotating member, as well as a second support member for supporting the magnetic field sensor or the magnetic medium material or magnetizing material. The first rotating member and the second rotating member are threaded together, the first rotating member is rotatably connected to the first support member, and the second rotating member is connected to the second support member.

[0021] Furthermore, the data terminal includes a processing unit, a data acquisition unit, and a display terminal connected in sequence. The input terminal of the processing unit is connected to the data output terminal of the magnetic field sensor. The processing unit is used to denoise and amplify the magnetic field strength data to obtain processed data. The data acquisition unit is used to acquire the processed data according to a preset sampling rate to obtain acquired data. The display terminal is used to store and display the acquired data.

[0022] As can be seen from the technical solution, the embodiments provided by this utility model have the following advantages:

[0023] On the one hand, by sequentially passing a magnetic field sensor over different leakage magnetic defects that can induce leakage magnetic fields of varying strengths, the magnetic field strength is detected, and the magnitude of leakage magnetic field caused by different leakage magnetic defects is measured. After processing and displaying the magnetic field strength data detected by the magnetic field sensor through a data terminal, the relationship between the magnetic field and the structural characteristics of the magnetic medium itself on the magnetic field in the magnetic circuit of the magnetic medium is obtained. On the other hand, by adjusting the distance between the magnetic field sensor and a certain leakage magnetic defect, the magnetic field strength of the leakage magnetic defect at different distances can be detected. After processing and displaying the magnetic field strength data detected by the magnetic field sensor through a data terminal, the results are obtained. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a magnetic flux leakage detection experimental device based on a TMR magnetic sensor provided in an embodiment of this utility model;

[0026] Figure 2 This is a schematic diagram of the geometric dimensions of a magnetic flux leakage defect in a magnetic flux leakage detection experimental device based on a TMR magnetic sensor provided in an embodiment of this utility model.

[0027] Figure 3 This is a three-dimensional schematic diagram of a magnetic flux leakage detection experimental device based on a TMR magnetic sensor provided in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the magnetic field distribution at different magnetic leakage defects in a magnetic medium material under the same lift-off value, obtained by using an experimental device for detecting magnetic leakage magnetic field based on a TMR magnetic sensor provided in this embodiment of the present invention.

[0029] Figure 5 This diagram illustrates the relationship between the magnetic field and the lift-off value obtained from an experiment using a leakage magnetic field detection experimental device based on a TMR magnetic sensor, as provided in this embodiment of the present invention.

[0030] Explanation of reference numerals in the attached drawings: 1. Magnetic medium material; 2. Magnetized material; 3. Magnetic field sensor; 4. Magnetic leakage defect; 5. Guide component; 6. Sliding component; 7. First support component; 8. First rotating component; 9. Second support component. Detailed Implementation

[0031] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0033] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0035] This utility model discloses an experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor.

[0036] Please see Figure 1 One embodiment of the magnetic flux leakage detection experimental device based on a TMR magnetic sensor provided in this utility model includes:

[0037] Includes: magnetic medium material 1, magnetizing material 2, magnetic field sensor 3, and data terminal;

[0038] Magnetizing material 2 is placed close to magnetic medium material 1 for magnetizing magnetic medium material 1;

[0039] Multiple leakage magnetic defects 4 are spaced apart on the surface of the magnetic medium material 1 to induce leakage magnetic fields of various magnetic field strengths.

[0040] Understandably, magnetizing material 2 possesses high remanence and coercivity, maintaining strong magnetism without an external magnetic field. In contrast, magnetic medium material 1 requires an external magnetic field to magnetize, and its remanence is low after the external magnetic field is removed. Therefore, magnetizing material 2 can generate a magnetic field to magnetize magnetic medium material 1, placing it in a magnetized state and enhancing defect response. A leakage magnetic defect 4 is placed on magnetic medium material 1. This defect causes a sudden change in the permeability of magnetic medium material 1, significantly disturbing its magnetic circuit and forming a local leakage magnetic field, which is easily captured by the magnetic field sensor 3, making the leakage magnetic field signal clearly measurable.

[0041] The magnetic field sensor 3 is positioned close to and relatively sliding with respect to the surface of the magnetic medium material 1. The magnetic field sensor 3 is used to maintain a fixed distance from the surface of the magnetic medium material 1 and sequentially pass through multiple magnetic leakage defects 4 to detect the magnetic field strength, or to measure the magnetic field strength of the magnetic leakage defect 4 at different distances by adjusting the distance from a certain magnetic leakage defect 4.

[0042] The data terminal is electrically connected to the magnetic field sensor 3 and is used to process and display the magnetic field strength data detected by the magnetic field sensor 3.

[0043] Understandably, in practical implementation, on the one hand, the magnetic field sensor 3 sequentially passes through different magnetic leakage defects 4 that can induce various magnetic leakage magnetic fields of varying strengths to detect the magnetic field strength. The magnitude of magnetic leakage caused by different magnetic leakage defects 4 is measured. The data terminal processes and displays the magnetic field strength data detected by the magnetic field sensor 3 to determine the influence of the magnetic field and the structural characteristics of the magnetic medium itself on the magnetic field in the magnetic circuit. On the other hand, by adjusting the distance between the magnetic field sensor 3 and a certain magnetic leakage defect 4, the magnetic field strength of that defect 4 at different distances is detected. The data terminal processes and displays the magnetic field strength data detected by the magnetic field sensor 3 to determine the influence of the distance (lift-off value) between the testing instrument and the surface of the workpiece on the magnetic field, thus assisting in the analysis of the influencing factors in the magnetic field testing process. Therefore, conducting experiments based on the magnetic leakage detection experimental device of this embodiment allows for a more intuitive and in-depth understanding of the magnetic circuit theorem, facilitating student operation and explanation, and making abstract theories concrete.

[0044] In a more specific embodiment, the magnetic leakage defect 4 is disposed on the surface of the magnetic medium material 1.

[0045] Understandably, in practice, when the magnetic leakage defect 4 is placed on the surface of the magnetic medium material 1, the magnetic leakage field is more likely to escape, the magnetic leakage signal is stronger, the magnetic leakage defect 4 is closer to the magnetic field sensor 3, the magnetic field sensor 3 is more likely to detect the magnetic leakage signal, and it is more conducive to the generation of experimental results.

[0046] In a more specific embodiment, the magnetic leakage defect 4 includes a magnetic leakage groove formed on the surface of the magnetic medium material 1.

[0047] Understandably, in practice, on the one hand, the large changes in permeability and magnetic reluctance at the magnetic flux leakage groove cause magnetic flux distortion, resulting in more magnetic flux leaking to the surface and forming a leakage magnetic field. This artificially created leakage magnetic field is more pronounced, making it easier for detection equipment to capture and improving the sensitivity of magnetic flux leakage tests for defects. Even tiny grooves can generate detectable leakage magnetic signals, helping to discover potential minute defects in magnetic media. On the other hand, by controlling the size (width, depth, etc.) and shape of the groove, the influence of different defect characteristics on the leakage magnetic signal can be studied. For example, within a certain range, the leakage magnetic field strength increases approximately linearly with increasing groove depth. This allows for more accurate assessment of parameters such as defect size and depth based on the leakage magnetic signal, enabling quantitative analysis of defects and providing more precise data support for the quality assessment and safety testing of magnetic media.

[0048] In a more specific embodiment, the magnetic leakage slots are arranged sequentially in a single direction, and the interval between two adjacent magnetic leakage defects 4 is greater than the detection range of the magnetic field sensor 3.

[0049] Understandably, in practical implementation, on the one hand, the magnetic leakage defects 4 are arranged sequentially along a single direction, allowing the magnetic field sensor 3 to detect multiple different magnetic leakage defects 4 one by one along a single direction. Moving the sensor along a fixed direction ensures that the lift-off height remains consistent for each detection, reducing variable interference and improving data comparability. This facilitates uniform movement of the sensor along a single direction, enabling a systematic scan of the entire detection area and avoiding path overlap or omissions that may occur in two-dimensional scanning. At the same time, unidirectional scanning simplifies the temporal-spatial correspondence of signals, with the temporal data of unidirectional scanning strictly corresponding to the spatial position, facilitating the establishment of a unified defect feature database. On the other hand, the interval between two adjacent magnetic leakage defects 4 is greater than the detection range of the magnetic field sensor 3, enabling the magnetic field sensor 3 to capture the magnetic leakage magnetic field signal of only one defect in a single scan when scanning the magnetic leakage defects 4 sequentially, avoiding signal overlap and difficulty in differentiation.

[0050] In a more specific embodiment, the magnetic leakage groove is a rectangular groove, including three geometric structural features that affect the strength of the magnetic leakage field: length, width, and depth. The width of the magnetic leakage groove is the distance between the two sides of the magnetic leakage groove in a single direction, the depth of the magnetic leakage groove is the distance from the bottom of the magnetic leakage groove to the surface of the magnetic medium material 1, and the length of the magnetic leakage groove is the distance between the two sides of the magnetic leakage groove perpendicular to a single direction.

[0051] The depth of the magnetic flux leakage grooves varies, but the length and depth are the same.

[0052] The width of the magnetic flux leakage slots and / or the length and depth are different, and the width of the magnetic flux leakage slots is smaller than the scanning width of the magnetic field sensor 3 along the sliding direction.

[0053] The length of the magnetic flux leakage slots is different, but the width and depth are the same. The length of the magnetic flux leakage slots is less than the scanning width of the magnetic field sensor 3 perpendicular to the sliding direction.

[0054] Understandably, in practical implementation, on the one hand, when any of the three geometric features affecting the leakage magnetic field strength—length, width, and depth—of the leakage magnetic groove is used as a dependent variable, it must be ensured that the structural range determined by that geometric feature is within the detection range of the magnetic field sensor 3, so as to avoid affecting the comparability of the results due to detection errors. On the other hand, the rectangular groove is easy to process on the magnetic medium material 1, and the length, width, and depth of the rectangular groove can be precisely controlled by machining methods such as milling and wire cutting, which provides convenience for quantitatively studying the relationship between the leakage magnetic field and the defect size.

[0055] In a more specific embodiment, the magnetizing material 2 is symmetrically disposed on opposite sides of the magnetic medium material 1, and the sides are perpendicular to the surface of the magnetic medium material 1.

[0056] It is understandable that, in specific implementation, magnetizing materials 2 can be symmetrically arranged on the front and rear sides of the magnetic medium material 1 and / or symmetrically arranged on the left and right sides of the magnetic medium material 1. When the magnetizing materials 2 are placed opposite each other on the sides of the magnetic medium material 1, the magnetic field between them will form a relatively uniform magnetic field region. The magnetic medium material 1 placed in this region can be more uniformly affected by the magnetic field, thereby achieving more uniform and stronger magnetization. By adjusting the direction and spacing of the magnetic poles of the magnetic medium materials 1 on both sides, the strength and distribution of the magnetic field can be controlled to meet the magnetization requirements of different magnetic medium materials 1. The uniform magnetic field reduces random noise caused by uneven magnetic field distribution, making the leakage magnetic field signal caused by the leakage magnetic field defect 4 more prominent. At the same time, the uniform magnetic field helps the material as a whole to achieve a more uniform magnetic saturation state, ensuring the consistency of detection conditions. This embodiment limits the magnetizing materials 2 to be placed on the side perpendicular to the surface of the magnetic medium material 1 where the leakage magnetic field defect 4 is located, rather than on the surface, to avoid affecting the leakage magnetic field detection.

[0057] In a more specific embodiment, the length of the magnetic flux leakage groove is greater than its width, and the magnetizing material 2 is symmetrically arranged on the side perpendicular to the length direction.

[0058] Understandably, in practical implementation, on the one hand, the magnetic flux leakage groove adopts a rectangular groove design, with its width less than its length, which can effectively simulate crack defects in magnetic media. Both the rectangular groove and real cracks such as open-type cracks induce magnetic flux leakage through abrupt changes in permeability, and their peak values, gradients, and other signal characteristics are comparable. On the other hand, a magnetic field is formed between magnetized materials 2 symmetrically arranged on both sides of the magnetic medium material 1. The direction of the magnetic field is parallel to the connection direction of the magnetic medium materials 1 on both sides. By symmetrically arranging the magnetized materials 2 on the sides perpendicular to the length direction, the direction of the magnetic field is made perpendicular to the length direction of the magnetic flux leakage groove, i.e., the direction of the magnetic field is perpendicular to the crack. It should be noted that the perpendicular relationship between the magnetic field direction and the crack is the optimal condition for generating a significant magnetic flux leakage. When the magnetic field direction is perpendicular to the crack length direction, the magnetic field lines are severely hindered when passing through the crack due to the abrupt change in permeability, causing a large amount of magnetic flux to overflow from both sides of the crack, forming a strong magnetic flux leakage. Compared with other magnetic field layout directions, the magnetic flux leakage signal is strongest at this time, and the detection sensitivity is highest.

[0059] In some other, more specific implementations, students can use modeling to design different leakage magnetic groove structures on the magnetic medium material 1 to provide different defect characteristics, use simulation software to simulate the magnetic field, and use experimental acquisition programs. This allows students to learn more modern experimental methods and thinking, which is conducive to stimulating students' learning interest.

[0060] In a more specific embodiment, the magnetizing material 2 is neodymium iron boron material, which has an extremely high magnetic energy product, meaning that it can generate a strong magnetic field in a small volume and weight. By attaching a piece of neodymium iron boron magnetizing material 2 to each end of the magnetic medium, it can be ensured that the magnetic medium material 1 under test produces a strong magnetization effect.

[0061] In a more specific embodiment, the magnetic medium material 1 is a ferromagnetic material such as 65 manganese steel. 65 manganese steel has high magnetic permeability, meaning it can effectively conduct and concentrate magnetic fields. In magnetic flux leakage tests, when an external magnetic field acts on this material, it can be well magnetized, allowing the magnetic flux to distribute smoothly within the material. If defects exist on the material's surface or inside, such as cracks or pores, the magnetic flux will leak to the material surface due to changes in magnetic resistance at the defect, forming a detectable magnetic leakage field. The high magnetic permeability makes this magnetic leakage phenomenon more pronounced, which is beneficial for improving the sensitivity of magnetic flux leakage detection and enabling the detection of even smaller defects.

[0062] In a more specific embodiment, the magnetic field sensor 3 adopts a TMR magnetic sensor, which has the advantages of high sensitivity, wide linear range and high temperature stability. It can measure the magnetic field magnitude with high precision, the measurement result is more accurate, and the measurement range is wider. It can measure the magnetic field magnitude over a larger range and the adjustment range of test conditions is wider.

[0063] In a more specific embodiment, such as Figure 3 As shown, it includes a horizontal sliding structure, which includes a guide 5 and a sliding member 6 that cooperates with the guide 5, as well as a first support member 7 for supporting the magnetic field sensor 3 or the magnetic medium material 1; the guide 5 is used to fix it on the operating table plane, and the guiding direction of the guide 5 is parallel to the arrangement direction of the leakage magnetic defects 4; the sliding member 6 is connected to the carrier.

[0064] Understandably, in practical implementation, the horizontal sliding structure, achieved through the cooperation of guide 5 and slider 6, ensures that the magnetic field sensor 3 maintains a fixed distance from the magnetic medium material 1 and sequentially passes through multiple magnetic leakage defects 4 to detect the magnetic field strength. The rigid guiding effect of guide 5 ensures that the sensor maintains a constant distance from the surface of the magnetic medium material 1 being measured, avoiding the impact of lift-off value fluctuations and sudden jamming during movement on the accuracy of the test results. This facilitates control, enabling the magnetic field sensor 3 to stably and controllably scan multiple magnetic leakage defects 4 on the surface of the magnetic medium material 1. Simultaneously, the relative sliding between the magnetic field sensor 3 and the magnetic medium material 1, achieved through the cooperation of guide 5 and slider 6, allows for efficient control of the magnetic field sensor 3 to move to a specific magnetic leakage defect 4 for detection, facilitating experiments analyzing the relationship between lift-off value and magnetic field.

[0065] In a more specific embodiment, the guide member 5 includes a guide rail, the sliding member 6 includes a pulley, and a pulley is provided on each side of the guide rail. The pulleys on both sides cooperate with the guide rail to achieve sliding, thereby driving the first support member 7 to move along the direction of the guide rail.

[0066] In a more specific embodiment, both the magnetic medium material 1 and the magnetizing material 2 are disposed on the operating platform, and the first support 7 is connected to the magnetic field sensor 3.

[0067] In a more specific embodiment, the first support member 7 is provided with a lifting and sliding structure, which includes a first rotating member and a second rotating member, as well as a second support member 9 for supporting the magnetic field sensor 3 or the magnetic medium material 1. The first rotating member 8 and the second rotating member are threaded together, the first rotating member 8 is rotatably connected to the first support member 7, and the second rotating member is connected to the second support member 9.

[0068] Understandably, in specific implementation, the distance between the magnetic field sensor 3 and the magnetic medium material 1 is controlled by the threaded transmission of the first rotating part 8 and the second rotating part. Based on the high-precision transmission and self-locking properties of the threaded transmission, the distance position between the magnetic field sensor 3 and the magnetic medium material 1 can be accurately positioned.

[0069] In a more specific embodiment, the second support 9 is connected to the magnetic field sensor 3, and the second support 9 is located outside the first support 7 so that the magnetic field sensor 3 is located above the surface of the magnetic medium material 1.

[0070] In a more specific embodiment, the first rotating component 8 is a screw, and the second rotating component is a nut. One end of the screw is rotatably disposed within the first support component 7, and the other end of the screw protrudes from the surface of the first support component 7 and is connected to a knob. A scale hole is provided on the side of the first support component 7, and a scale rod is provided in the scale groove. The scale rod is connected to one side of the nut and can slide vertically within the scale hole. The other side of the nut is connected to one end of the second support component 9. A movable hole is provided on the side of the first support component 7 facing the magnetic medium material 1, and the other end of the second support component 9 extends out of the movable hole and is connected to the magnetic field sensor 3. The second support component 9 can slide vertically within the movable hole.

[0071] Understandably, in practice, rotating the control knob drives the screw to rotate, and the screw thread drives the nut to move along the axial direction of the screw. This, in turn, moves the scale rod and the second support member 9 along the axial direction of the screw, allowing the second support rod to move the magnetic field sensor 3 up and down on the surface of the magnetic medium material 1. Simultaneously, during operation, the distance between the magnetic field sensor 3 and the surface of the magnetic medium material 1 can be precisely controlled by observing the specific scale position of the scale rod in the scale groove, thereby achieving precise control of the lift-off value.

[0072] In a more specific embodiment, the data terminal includes a processing unit, a data acquisition unit, and a display terminal connected in sequence, with the input terminal of the processing unit connected to the data output terminal of the magnetic field sensor 3;

[0073] The processing unit is used to denoise and amplify the magnetic field strength data to obtain processed data, the acquisition unit is used to acquire the processed data according to the preset sampling rate to obtain acquired data, and the display terminal is used to store and display the acquired data.

[0074] It should be understood that the data processing methods used in this invention for denoising and amplifying magnetic field strength data, as well as for obtaining collected data through sampling, are all existing technologies, and the methods for storing and displaying the collected data on the display terminal are also existing technologies.

[0075] Understandably, in practice, after the data from the magnetic field sensor 3 is processed by the processing unit for noise reduction and amplification, the processed data is sampled by the acquisition unit and sent to the display terminal. The magnetic field test results can then be observed on the display terminal, making it convenient for students to observe experimental phenomena and improve test conditions.

[0076] In a more specific embodiment, the processing unit includes a low-pass filter and an amplifier. The input of the low-pass filter is connected to the data output of the magnetic field sensor 3, the output of the low-pass filter is connected to the input of the amplifier, and the output of the amplifier is connected to the data acquisition unit.

[0077] Understandably, in practical implementation, during magnetic flux leakage detection, the magnetic field sensor 3 will capture both useful signals and high-frequency noise. The low-pass filter allows low-frequency signals to pass through, filtering out noise, improving the signal-to-noise ratio, and making signal analysis more accurate. Minor signal fluctuations are smoothed by the low-pass filter, clearly reflecting the magnetic field distribution and aiding in defect identification. Furthermore, since the signal detected by the sensor is weak, the amplifier can amplify the signal amplitude, enhancing anti-interference capabilities and detectability, ensuring matching with the input of the acquisition unit, guaranteeing the normal operation of the detection system, and accurately acquiring and analyzing signals.

[0078] In a more specific embodiment, the low-pass filter is an RC passive filter, the amplifier is an AD620 amplifier, and the acquisition unit is an STM32H7 (with a built-in 16-bit ADC). This combination scheme is cost-effective and meets the experimental requirements.

[0079] In a more specific embodiment, the display terminal is a computer.

[0080] It should be noted that in this utility model, the processing unit, acquisition unit, and display terminal all provide the hardware foundation for visualizing the magnetic field strength data measured by the magnetic field sensor 3. The specific programming involved in further realizing intelligent functions is a method that can be implemented by those skilled in the art based on common knowledge. These methods are not within the scope of this solution. The above description is only to illustrate the beneficial effects that can be achieved by this hardware structure improvement in conjunction with common knowledge. The effect of this embodiment does not depend on the implementation of these methods used as examples.

[0081] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The experimental process involved in this technical solution and the results obtained through experiments are as follows: Figure 4 and Figure 5 The methods for simulating the magnetic field diagrams shown are all existing technologies. They are used to further explain and demonstrate the beneficial effects of the leakage magnetic field detection experimental device based on the TMR magnetic sensor provided by this utility model in the process of use, in conjunction with any of the above embodiments, so that those skilled in the art can understand the contribution of the solution. The following embodiments are not limitations on this utility model, and those skilled in the art can make adjustments according to the experimental purpose in practical applications.

[0082] In a more specific embodiment, such as Figure 2 As shown, a rectangular prism-shaped 65# manganese steel material is selected as the magnetic medium material 1. Multiple cracks are sequentially engraved along the length of the magnetic medium material 1 as leakage magnetic defects 4. The length of the cracks is the same as the width of the cuboid. The width and depth of each crack are as follows: the first crack is 0.2mm wide and 25mm deep, the second crack is 0.5mm wide and 25mm deep, the third crack is 1.0mm wide and 25mm deep, the fourth crack is 1.0mm wide and 10mm deep, the fifth crack is 0.5mm wide and 10mm deep, and the sixth crack is 0.2mm wide and 10mm deep.

[0083] The magnetic medium material 1 is placed on the operating table, and two magnetized materials 2 are symmetrically arranged on the two sides of the two magnetic medium materials 1 perpendicular to the crack length direction. The magnetized materials 2 are magnet blocks made of neodymium iron boron material.

[0084] The measuring probe of the magnetic field sensor 3 is located directly above the surface of the magnetic medium material 1 where the magnetic leakage defect 4 is engraved, and at the middle position in the crack length direction.

[0085] The specific experimental procedure is as follows:

[0086] The height of the fixed magnetic field sensor 3 is the distance between the measuring probe of the fixed magnetic field sensor 3 and the surface of the ferromagnetic material with leakage magnetic defects 4. The magnetic field sensor 3 slides left and right along the guide rail of the horizontal sliding structure, passing through each crack in turn, and measures the magnetic field magnitude at different leakage magnetic defects 4 on the magnetic medium material 1, thereby analyzing the influence of different geometric features of leakage magnetic defects 4 on the magnetic medium material 1 on the magnetic field.

[0087] When the distance between the measuring probe of the fixed magnetic field sensor 3 and the surface of the magnetic medium material 1 with the magnetic leakage defect 4 remains constant (i.e., the lift-off value), the simulation result of the magnetic field of the sliding magnetic field sensor 3 measuring the magnetic leakage defect 4 on the surface of the magnetic medium material 1 is as follows: Figure 4 As shown, it can be seen that the magnitude of the magnetic field is positively correlated with the width and depth of the magnetic leakage defect 4;

[0088] The second method is to fix the position of the magnetic field sensor 3 on the horizontal sliding structure guide rail, fix the magnetic field sensor 3 directly above any magnetic leakage defect 4, adjust the distance between the measuring probe of the magnetic field sensor 3 and the surface of the magnetic medium material 1, measure the magnitude of the magnetic field at different lift-off values, and thus analyze the influence of the lift-off value on the magnetic field measurement.

[0089] When the position of the fixed magnetic field sensor 3 is fixed, the magnitude of the magnetic field measured at different lift-off values ​​is as follows: Figure 5 As shown, it can be seen that the magnitude of the measured magnetic field is negatively correlated with the magnitude of the lift-off value;

[0090] Therefore, this embodiment designs a magnetic flux leakage detection experimental device based on a TMR magnetic sensor, based on the principle of magnetic flux leakage detection. This experimental device uses a magnetic field sensor 3 to test the magnetic field of a magnetic medium material 1 with known characteristic defects. The measurement data is processed and displayed by a data terminal to achieve real-time observation of the experimental phenomena. By changing different geometric characteristics of the magnetic flux leakage defect 4 in the magnetic medium material 1 and the lift-off value of the magnetic field sensor 3, the relationship between the magnetic field and these factors is obtained, thereby verifying the magnetic circuit theorem theory. This helps students intuitively understand the abstract concept of the magnetic circuit theorem, making the abstract theory concrete.

[0091] In a more specific embodiment, by inserting media with different permeabilities into the leakage groove of the magnetic medium material 1, it is possible to analyze the influence of different permeabilities of the magnetic medium on the magnetic field.

[0092] It should be noted that the terms used to describe positional relationships in the above examples and accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. The various embodiments of this utility model described above are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. An experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor, characterized in that, include: Magnetic media materials, magnetized materials, magnetic field sensors, and data terminals; The magnetizing material is disposed close to the magnetic medium material for magnetizing the magnetic medium material; The magnetic medium material has multiple different leakage magnetic defects spaced apart to induce leakage magnetic fields of various magnetic field strengths. The magnetic field sensor is positioned close to and relatively movable relative to the magnetic medium material. The magnetic field sensor is used to maintain a fixed distance from the magnetic medium material and sequentially pass through multiple magnetic leakage defects to detect the magnetic field strength, or to measure the magnetic field strength of the magnetic leakage defect at different distances by adjusting the distance to a certain magnetic leakage defect. The data terminal is electrically connected to the magnetic field sensor and is used to process, collect, and display the magnetic field strength data detected by the magnetic field sensor.

2. The experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 1, characterized in that, The magnetic leakage defect is located on the surface of the magnetic medium material.

3. The experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 2, characterized in that, The magnetic flux leakage defect includes magnetic flux leakage grooves, which are formed on the surface of the magnetic medium material.

4. The experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 3, characterized in that, The magnetic flux leakage slots are arranged sequentially in a single direction, and the interval between two adjacent magnetic flux leakage defects is greater than the detection range of the magnetic field sensor.

5. The experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 4, characterized in that, The magnetic flux leakage groove is a rectangular groove, including three geometric structural features that affect the strength of the magnetic flux leakage field: length, width, and depth. The width of the magnetic flux leakage groove is the distance between the two sides of the magnetic flux leakage groove in the single direction. The depth of the magnetic flux leakage groove is the distance from the bottom of the magnetic flux leakage groove to the surface of the magnetic medium material. The length of the magnetic flux leakage groove is the distance between the two sides of the magnetic flux leakage groove perpendicular to the single direction. The depth of the magnetic flux leakage grooves varies in several places, but the length and depth are the same; The width of the magnetic flux leakage slots and / or the length and depth of the slots are different, and the width of the magnetic flux leakage slots is smaller than the scanning width of the magnetic field sensor along the single direction. The length of the magnetic flux leakage slots and / or the width and depth of the slots are different, and the length of the magnetic flux leakage slots is less than the scanning width of the magnetic field sensor perpendicular to the single direction.

6. The experimental apparatus for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 5, characterized in that, The magnetizing material is symmetrically disposed on opposite sides of the magnetic medium material, and the sides are perpendicular to the surface of the magnetic medium material.

7. The experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 6, characterized in that, The length of the magnetic flux leakage groove is greater than its width, and the magnetizing material is symmetrically arranged on the side perpendicular to the length direction of the magnetic flux leakage groove.

8. The experimental apparatus for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 7, characterized in that, The system includes a horizontal sliding structure, which comprises a guide member, a sliding member that cooperates with the guide member, and a first support member for supporting the magnetic field sensor or the magnetic medium material or magnetizing material; the guide member is used to fix the system on the operating table plane, and the guiding direction of the guide member is parallel to the arrangement direction of the magnetic leakage defects; the sliding member is connected to the first support member.

9. The experimental apparatus for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 8, characterized in that, The first support member is provided with a lifting and sliding structure, which includes a first rotating member and a second rotating member, as well as a second support member for supporting the magnetic field sensor or the magnetic medium material or magnetizing material. The first rotating member and the second rotating member are threaded together, the first rotating member is rotatably connected to the first support member, and the second rotating member is connected to the second support member.

10. The experimental device for detecting magnetic flux leakage based on a TMR magnetic sensor according to claim 1, characterized in that, The data terminal includes a processing unit, a data acquisition unit, and a display terminal connected in sequence. The input terminal of the processing unit is connected to the data output terminal of the magnetic field sensor. The processing unit is used to denoise and amplify the magnetic field strength data to obtain processed data. The data acquisition unit is used to acquire the processed data according to a preset sampling rate to obtain acquired data. The display terminal is used to store and display the acquired data.

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