Internal and external defect detection sensor structure

Abstract

The utility model provides an internal and external defect detection sensor structure, which comprises an S-pole magnet arranged on one side outside a metal pipeline to be detected; the N-pole magnet is arranged on one side outside the metal pipeline to be detected, and the N-pole magnet and the S-pole magnet are located on the same side and are oppositely arranged; the first Hall element is arranged at a magnetic loop formed by magnetizing the metal pipeline to be detected by the S-pole magnet and the N-pole magnet; the permanent magnet is arranged on one side outside the to-be-detected metal pipeline; the second Hall element is arranged between the permanent magnet and the metal pipeline to be detected; wherein the S-pole magnet, the N-pole magnet and the first Hall element form an external defect detection structure, and the permanent magnet and the second Hall element form an internal defect detection structure. According to the utility model, the problem of internal defect detection of the existing pipeline is effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of defect detection technology, and in particular to a structure for an internal and external defect detection sensor. Background Technology

[0002] In pipeline defect magnetic flux leakage detection technology, the use of Hall effect sensors to detect defect magnetic flux leakage has become the primary technical method. Compared to other pipeline defect detection technologies, magnetic flux leakage defect detection has advantages such as high accuracy and high precision, making it an important technical means for monitoring pipeline health status.

[0003] Magnetic flux leakage defect detection can detect defects on the inner and outer walls of pipes, but this technology cannot distinguish between internal and external defects because small internal defects and large external defects have basically the same magnetic flux leakage pattern, and existing magnetic flux leakage defect detection technology cannot distinguish between internal and external defects.

[0004] Research on pipeline internal and external defect (i.e., inner and outer walls) identification technology based on magnetic flux leakage defect detection has been conducted both domestically and internationally. One solution is to use magnetic flux leakage to detect defects, and then use the eddy current skin effect to detect the inner wall. If both magnetic flux leakage and eddy current detection show defects, it is the inner wall; otherwise, if there are defects in magnetic flux leakage but no defects in eddy current, it is the outer wall. In this solution, eddy current detection requires a coil to generate a high-frequency magnetic field to induce eddy currents on the metal surface. The disadvantages of this structure are: 1. The eddy current coil needs to be coupled with the metal; when the lift-off value is too large, coupling fails, leading to detection failure; 2. The eddy current coil is greatly affected by the lift-off value, and cannot detect small defects; 3. When the external defect is large, the magnetic flux leakage is large, and the moving coil cutting through this magnetic flux leakage will affect the eddy current coil, leading to failure of inner and outer wall detection. Another scheme uses eddy current detection technology to detect inner and outer walls, but this scheme is limited by the eddy current detection depth. When the pipe wall thickness is too large, the eddy current cannot detect external defects, and it still cannot identify internal and external defects.

[0005] For detecting internal defects in pipelines, existing eddy current sensors and eddy current coil detection methods have a series of unavoidable drawbacks, as follows:

[0006] 1. An external high-frequency AC excitation coil is required. In order to achieve a considerable detection effect, a large amount of power is required to drive the coil to generate eddy currents on the surface of the metal to be tested.

[0007] 2. When an eddy current coil couples with the metal under test through a high-frequency alternating magnetic field, it is greatly affected by the lift-off value (the distance between the coil and the surface of the metal under test). A lift-off value that is too small will cause coupling failure, while a lift-off value that is too large will prevent the detection of minute defects.

[0008] 3. Eddy current coils are greatly affected by lift-off values ​​when detecting defects. When the probe cannot achieve a floating fit inside the pipe, the lift-off value fluctuations can be even greater than the defect signal, causing the defect signal to be covered by lift-off noise and making it impossible to identify the defect signal;

[0009] 4. Eddy current testing depth has a significant impact. For pipes with relatively thin walls, when the external defect depth is large and the eddy current coil coupling is strong, the eddy current testing depth may be too deep, causing external wall damage to be misdiagnosed as internal wall damage.

[0010] Eddy current coils are affected by leakage flux and equipment operating speed, causing external wall damage to be mistakenly detected as internal wall damage. When the leakage flux of the external wall damage is large, the eddy current coil cuts the leakage flux lines during equipment operation, causing changes in coil impedance, which affects the detection of internal walls and leads to false detections. When the speed is too fast, the faster the coil cuts the leakage flux lines, the greater the impact on the eddy current coil detection. Utility Model Content

[0011] This invention provides a sensor structure for detecting internal and external defects to solve one or more of the problems mentioned above.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] An internal and external defect detection sensor structure, comprising:

[0014] The S-pole magnet is located on the outside of the metal pipe to be tested.

[0015] The N-pole magnet is located on the outside of the metal pipe to be tested, and is on the same side as the S-pole magnet and is positioned opposite to it.

[0016] The first Hall element is placed at the magnetic circuit formed by the S-pole magnet and the N-pole magnet in the metal pipe to be tested;

[0017] A permanent magnet is placed on the outside of the metal pipe to be tested.

[0018] A second Hall element is disposed between the permanent magnet and the metal pipe to be tested;

[0019] The S-pole magnet, N-pole magnet, and first Hall element constitute the external defect detection structure, while the permanent magnet and second Hall element constitute the internal defect detection structure.

[0020] In this specification, a circuit board is provided between the permanent magnet and the second Hall element. The permanent magnet is fixedly disposed on one side of the circuit board, and the second Hall element is fixedly disposed on the other side of the circuit board.

[0021] In this specification, the permanent magnet is a bar magnet.

[0022] In this specification, there are at least three second Hall elements arranged in a straight line.

[0023] In this specification, the permanent magnet is located directly opposite the second Hall element, and the length direction of the permanent magnet is consistent with the direction of the straight line in which the second Hall elements are arranged.

[0024] In this specification, the first Hall element and / or the second Hall element are triaxial Hall elements.

[0025] In this specification, the circuit board is provided with a limiting structure to facilitate fixing the circuit board during production and installation.

[0026] In this specification, the circuit board is provided with a square through hole.

[0027] In this specification, there are four second Hall elements.

[0028] In summary, this utility model has at least the following beneficial effects:

[0029] This invention effectively solves the problem of detecting internal defects in existing pipelines. First, it eliminates the traditional coil design, employing weak magnetic magnetization to detect defects. This eliminates the need for coupling between the excitation coil and the metal, significantly reducing sensor power consumption. Second, the permanent magnet helps to stably adhere to the ferromagnetic metal pipeline, aligning perfectly with the floating, contact probe design concept and reducing lift-off interference compared to traditional designs. Furthermore, eliminating the coil design ensures that the internal defect detection structure is unaffected by the equipment's operating speed. Finally, due to the skin effect of weak magnetic magnetization and ferromagnetic material magnetization, the magnetized magnetic field lines only act on the metal surface, preventing deep external wall damage from being misdetected as internal wall damage.

[0030] The internal defect detection structure boasts extremely high accuracy. When using weakly magnetized metal, the skin effect of ferromagnetic materials provides a significant advantage in identifying minute defects on the metal surface. This design improves the accuracy of distinguishing between the inner and outer walls of pipes while exhibiting ultra-low power consumption, optimizing the design that addresses the failures of traditional pipe inner and outer wall detection, thus enhancing its practical value. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments 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.

[0032] Figure 1 This is a schematic diagram of the external defect detection structure involved in some embodiments of the present invention.

[0033] Figure 2 This is a schematic diagram of the internal defect detection structure involved in some embodiments of the present invention.

[0034] Figure 3 This is a schematic diagram of an internal defect detection structure consisting of a permanent magnet, a second Hall element, and a circuit board, as described in some embodiments of this utility model.

[0035] Figure 4 This is a schematic diagram illustrating the surface micro-defect testing effect in some embodiments of this utility model.

[0036] Figure 5 This is a schematic diagram illustrating the test effect of a 4mm diameter hole-like defect in some embodiments of this utility model.

[0037] Figure 6 This is a schematic diagram of a metal with minute surface defects involved in some embodiments of the present invention.

[0038] Figure 7 This is a schematic diagram of a metal with a hole-like defect with a diameter of 4 mm, as described in some embodiments of this utility model.

[0039] Figure label:

[0040] 1. Metal pipe under test; 2. S-pole magnet; 3. N-pole magnet; 4. Magnetic circuit; 5. External defect; 6. First Hall element; 22. Permanent magnet; 23. Second Hall element; 24. Internal defect; 25. Magnetic lines of force when there is no defect; 26. Magnetic lines of force when there is a defect; 33. Circuit board; 34. Limiting structure. Detailed Implementation

[0041] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0042] In the description of the embodiments of this utility model, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of 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 the embodiments of this utility model.

[0043] Furthermore, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] In this embodiment of the invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention according to the specific circumstances.

[0045] In this embodiment of the invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] The following disclosure provides many different implementations or examples for different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of the present invention; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0047] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0048] like Figure 1 and Figure 2 As shown, this embodiment provides an internal and external defect detection sensor structure, including:

[0049] S-pole magnet 2 is located on the outside side of the metal pipe 1 to be tested;

[0050] The N-pole magnet 3 is located on the outside of the metal pipe 1 to be tested, and is located on the same side as the S-pole magnet 2 and is positioned opposite to it.

[0051] The first Hall element 6 is placed at the magnetic circuit 4 formed by the S pole magnet 2 and N pole magnet 3 of the metal pipe 1 to be tested;

[0052] Permanent magnet 22 is located on the outside of the metal pipe 1 to be tested;

[0053] The second Hall element 23 is disposed between the permanent magnet 22 and the metal pipe 1 to be tested;

[0054] The S-pole magnet 2, N-pole magnet 3, and first Hall element 6 constitute an external defect detection structure, while the permanent magnet 22 and second Hall element 23 constitute an internal defect detection structure.

[0055] In some embodiments, such as Figure 3 As shown, a circuit board 33 is provided between the permanent magnet 22 and the second Hall element 23. The permanent magnet 22 is fixedly disposed on one side of the circuit board 33, and the second Hall element 23 is fixedly disposed on the other side of the circuit board 33.

[0056] In some embodiments, such as Figure 3 As shown, the permanent magnet 22 is a bar magnet.

[0057] In some embodiments, such as Figure 3 As shown, there are at least three second Hall elements 23 arranged in a straight line.

[0058] In some embodiments, such as Figure 3 As shown, the permanent magnet 22 is located directly opposite the second Hall element 23, and the length direction of the permanent magnet 22 is consistent with the direction of the straight line in which the second Hall element 23 is arranged.

[0059] In some embodiments, the first Hall element 6 and / or the second Hall element 23 are triaxial Hall elements.

[0060] In some embodiments, such as Figure 3 As shown, the circuit board 33 is provided with a limiting structure 34 to facilitate fixing the circuit board 33 during production and installation.

[0061] In some embodiments, the circuit board 33 is provided with a square through hole.

[0062] In some embodiments, such as Figure 3 As shown, there are four second Hall elements 23.

[0063] The technical concept of this utility model is as follows:

[0064] The process for distinguishing between inner and outer walls is as follows:

[0065] 1. Inspect the metal pipe under test using external and internal defect detection structures;

[0066] 2. Observe whether any defects are detected;

[0067] 3. If the external defect detection structure detects a defect, check if the internal defect detection structure detects internal defect 24. If the internal defect detection structure detects internal defect 24, it is an internal wall damage; if the internal defect detection structure does not detect a defect, it is an external wall damage.

[0068] By following the above approach, the inner and outer walls of the pipe can be distinguished.

[0069] like Figure 1 As shown, when the S-pole magnet 2 and N-pole magnet 3 are used to magnetize the metal pipe 1 under test, a closed magnetic circuit 4 is formed in the metal at both ends of the magnets. When the metal pipe 1 under test has an external defect 5, the magnetic circuit 4 inside the metal will leak at the first Hall element 6. Based on the data change of the first Hall element 6, it can be determined whether the metal pipe 1 under test has a defect.

[0070] like Figure 2 As shown, an internal defect detection structure is used to inspect the inner wall of the metal pipe 1 under test. A permanent magnet 22 is used to magnetize the inner wall of the pipe, and a second Hall element 23 detects this magnetization magnetic field. When there is no internal defect 24, the magnetic field lines 25 of the permanent magnet 22 when there is no defect can be detected by the second Hall element 23. When the inner wall of the pipe has an internal defect 24, the magnetic field lines 25 of the permanent magnet 22 when there is no defect will be changed, such as... Figure 2 The magnetic field lines 26 are shown when there is a defect. The changes in the magnetic field lines at this time can be detected by the second Hall element 23. When there is an external defect 5, the shape of the magnetic field lines cannot be changed due to the influence of the magnet strength and the magnetization skin effect, thereby realizing the detection of the inner wall of the defect.

[0071] In one experimental embodiment, the structure of this invention is used to... Figure 6 and Figure 7 The metal shown was subjected to defect detection, and the detection results are as follows: Figure 4 and Figure 5 As shown. The surface micro-defect test results are as follows. Figure 4 As shown (corresponding) Figure 6 The test results for a 4mm diameter pore-like defect are as follows: Figure 5 As shown (corresponding) Figure 7 ).

[0072] The above embodiments describe several specific implementations of this utility model. However, those skilled in the art should understand that various changes or modifications can be made to these implementations without departing from the principles and essence of this utility model, but all such changes and modifications fall within the protection scope of this utility model.

Claims

1. An internal and external defect detection sensor structure, characterized by, The utility model relates to a metal pipeline internal and external defect detection device, including: S pole magnet, be located in the metal pipeline outside one side of to be measured; N pole magnet, be located in the metal pipeline outside one side of to be measured, with the S pole magnet is located in the same side and opposite arrangement; First hall element, place in the magnetic loop that the metal pipeline to be measured is magnetized under the S pole magnet and N pole magnet; Permanent magnet, be located in the metal pipeline outside one side of to be measured; Second hall element, be located between the permanent magnet and the metal pipeline to be measured; Wherein, the S pole magnet, N pole magnet and first hall element constitute external defect detection structure, the permanent magnet and second hall element constitute internal defect detection structure.

2. The internal and external defect detection sensor structure according to claim 1, characterized by, The circuit board is arranged between the permanent magnet and the second hall element, one side of the circuit board is fixedly provided with the permanent magnet, and the other side of the circuit board is fixedly provided with the second hall element.

3. The internal and external defect detection sensor structure according to claim 2, wherein The permanent magnet is a bar magnet.

4. The internal and external defect detection sensor structure according to claim 3, wherein The second hall element is at least three and arranged on the same straight line.

5. The internal and external defect detection sensor structure according to claim 4, wherein The permanent magnet is located opposite the second hall element, and the length direction of the permanent magnet is consistent with the direction of the straight line arranged by the second hall element.

6. The internal and external defect detection sensor structure according to claim 5, wherein The first hall element and / or the second hall element are three-axis hall elements.

7. The internal and external defect detection sensor structure according to claim 6, wherein The circuit board is provided with a limiting structure to facilitate the production and installation of the circuit board.

8. The internal and external defect detection sensor structure according to claim 7, wherein The circuit board is provided with a square through hole.

9. The internal and external defect detection sensor structure according to claim 8, wherein, The second hall element has four.

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