Magnetic flux leakage detection device and method

Abstract

The invention discloses a magnetic flux leakage detection device and method, and the device comprises a wedge-shaped magnet yoke which comprises a cross beam, a first yoke pole and a second yoke pole, the first yoke pole and the second yoke pole are the same, and the included angle between the first yoke pole and the cross beam and the included angle between the second yoke pole and the cross beam are smaller than 90 degrees; the wedge-shaped magnet yoke is used for being in contact with a tested sample in the magnetic flux leakage testing process; the excitation coil is wound on the surface of the wedge-shaped magnet yoke and is used for being electrified in the magnetic flux leakage detection process and generating a magnetic field by depending on the wedge-shaped magnet yoke; the magnetic sensitive element is arranged in an area enclosed by the wedge-shaped magnetic yoke and is used for detecting the magnetic field distribution of the tested sample in the magnetic flux leakage detection process; and the signal processing circuit board is arranged in an area enclosed by the wedge-shaped magnet yoke, is connected with the magnetic sensitive element, and is used for determining whether the tested sample has a magnetic leakage phenomenon or not according to the magnetic field distribution detected by the magnetic sensitive element. The magnetic flux leakage detection device depends on the wedge-shaped magnet yoke, the same magnetic induction intensity can be achieved when small current is used, the heating degree of the excitation coil can be reduced, and the service life of the magnetic flux leakage detection device can be prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of defect detection, and in particular to a magnetic flux leakage detection device and method. Background Art

[0002] Internal defects in thin strip steel are one of the main defects of cold-rolled products and are the main cause of stamping cracking and tank leakage. With the development of the industry, users' quality requirements for cold-rolled products are constantly increasing. The density, type, and size of strip steel defects are crucial quality indicators that are related to user requirements and product market competitiveness.

[0003] Magnetic flux leakage detection technology is an important method for evaluating internal defects of ferromagnetic materials (such as thin strip steel). When performing magnetic flux leakage detection on thin strip steel, a magnetizing device is required to magnetize the sample, and the magnetic conductivity of ferromagnetic materials in a magnetic field is used to determine whether there are defects in the material. If there are defects in the material, a leakage magnetic field will be formed at the defect on the surface of the material, and the size of the defect can be detected by the size of the leakage magnetic field.

[0004] However, the magnetic flux leakage detection device provided in the related art mainly increases the magnetization intensity by increasing the coil current to improve the defect detection intensity, but the increase in the coil current causes the coil to heat up seriously, so the magnetic flux leakage detection device cannot operate for a long time. Therefore, how to alleviate the contradiction between the magnetization intensity and the coil current of the magnetic flux leakage detection device is a problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present application provide a magnetic flux leakage detection device and method, which solves the problem that the magnetic flux leakage detection device provided in the prior art mainly increases the magnetization intensity by increasing the coil current to improve the defect detection intensity, but the increase in the coil current causes serious heating of the coil, and thus there is a technical problem that the magnetic flux leakage detection cannot be performed for a long time. The embodiments of the present application achieve the technical effect of increasing the magnetization intensity under the same current intensity, reducing the severity of the coil heating problem, and achieving long-term operation of the magnetic flux leakage detection.

[0006] In a first aspect, the present application provides a magnetic flux leakage detection device, the device comprising:

[0007] A wedge-shaped magnetic yoke comprises a beam and a first yoke pole and a second yoke pole that are identical, wherein one end of the first yoke pole is connected to one end of the beam, one end of the second yoke pole is connected to the other end of the beam, the first yoke pole and the second yoke pole are symmetrical about the center line of the beam, and the other end of the first yoke pole is spaced a preset distance from the other end of the second yoke pole; the angles between the first yoke pole and the second yoke pole and the beam are respectively less than 90°; the wedge-shaped magnetic yoke is used to contact a test sample during magnetic flux leakage detection;

[0008] an excitation coil, wound on the surface of the wedge-shaped magnetic yoke, for being energized during magnetic flux leakage detection and generating a magnetic field relying on the wedge-shaped magnetic yoke;

[0009] A magnetic sensitive element, arranged in the area enclosed by the wedge-shaped magnetic yoke, for detecting the magnetic field distribution of the tested sample during magnetic flux leakage detection;

[0010] A signal processing circuit board is arranged in the area enclosed by the wedge-shaped magnetic yoke and connected to the magnetic sensitive element, and is used to determine whether there is magnetic leakage in the tested sample according to the magnetic field distribution detected by the magnetic sensitive element.

[0011] Furthermore, the end faces of the other end of the first yoke pole and the other end of the second yoke pole are both on the same plane, and the end face areas of the other end of the first yoke pole and the other end of the second yoke pole are larger than the cross-sectional areas of the first yoke pole and the second yoke pole.

[0012] Furthermore, the crossbeam, the first yoke pole and the second yoke pole are integrally formed to form the wedge-shaped magnetic yoke.

[0013] Furthermore, the excitation coils are symmetrically distributed on the first yoke pole and the second yoke pole.

[0014] Furthermore, the preset distance is determined according to the background field distances corresponding to the first yoke pole and the second yoke pole respectively and the installation size of the magnetic sensitive element.

[0015] Furthermore, the preset distance is at least 40 mm.

[0016] Furthermore, the cross-sections of the beam, the first yoke pole and the second yoke pole are square.

[0017] Furthermore, the vertical distance between the other end of the first yoke pole and the other end of the second yoke pole and the crossbeam is determined according to the sizes of the magnetic sensitive element, the signal processing circuit board and the excitation coil.

[0018] Furthermore, the minimum vertical distance between the other end of the first yoke pole, the other end of the second yoke pole and the crossbeam is 50 mm.

[0019] In a second aspect, the present application provides a magnetic flux leakage detection method, the method comprising:

[0020] Attach the other end of the first yoke pole and the other end of the second yoke pole of the magnetic flux leakage detection device provided in the first aspect to the surface of the test sample;

[0021] Supplying power to the excitation coil to form a magnetic field on the test sample;

[0022] The magnetic sensitive element detects the magnetic field distribution of the tested sample;

[0023] The signal processing circuit board obtains the magnetic field distribution from the magnetic sensitive element, and determines whether the tested sample has magnetic leakage according to the magnetic field distribution detected by the magnetic sensitive element.

[0024] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0025] The magnetic flux leakage detection device provided in the embodiment of the present application includes a wedge-shaped magnetic yoke, an excitation coil, a magnetic sensitive element and a signal processing circuit board. Relying on the wedge-shaped magnetic yoke, the effective magnetization area is increased and the minimum distance between the two yoke poles is reduced to optimize the magnetization effect. A smaller current can be used to achieve the same magnetic induction intensity, thereby reducing the heating degree of the excitation coil and extending the service life of the magnetic flux leakage detection device. Relying on the wedge-shaped magnetic yoke, the magnetic induction intensity can be further improved under the same excitation conditions, and the heating degree of the excitation coil can be relatively reduced, thereby extending the service life of the magnetic flux leakage detection device and improving the accuracy of defect detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the structure of a magnetic flux leakage detection device provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram indicating the cross section and end surface of a first yoke pole of a magnetic flux leakage detection device provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram indicating the span D and yoke pole height H of a magnetic flux leakage detection device provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of the positional relationship of a magnetic flux leakage detection device provided in an embodiment of the present application detecting a test sample;

[0031] Figure 5 A schematic diagram of the positional relationship of a U-shaped magnetic flux leakage detection device provided in the prior art detecting a test sample;

[0032] Figure 6 A schematic diagram comparing the effective link lengths of a U-shaped magnetic yoke in the prior art and a wedge-shaped magnetic yoke provided by the present application;

[0033] Figure 7 -(1) is a magnetic flux density distribution diagram corresponding to the magnetic flux leakage detection device provided in this application, Figure 7 -(2) is the magnetic flux density distribution diagram of the intersection line between the wedge-shaped magnetic circuit section and the sample surface, and Figure 4 correspond;

[0034] Figure 8 -(1) is a magnetic flux density distribution diagram corresponding to the magnetic flux leakage detection device provided by the prior art, Figure 8 -(2) is the magnetic flux density distribution diagram of the intersection line between the U-shaped magnetic circuit section and the sample surface, and Figure 5 correspond;

[0035] Fig. 9 -(1) is the magnetic flux density distribution diagram around the defect in the U-shaped magnetic circuit, and Figure 5 and Figure 8 correspond, Fig. 9 -(2) is the magnetic flux density distribution diagram around the defect in the wedge-shaped magnetic circuit, and Figure 4 and Figure 7 correspond;

[0036] Fig.10 A schematic flow chart of a magnetic flux leakage detection method provided in an embodiment of the present application.

[0037] Reference numerals:

[0038] 1-wedge-shaped magnetic yoke, 11-crossbeam, 12-first yoke pole, 13-second yoke pole, 2-excitation coil, 3-test sample, 4-U-shaped magnetic yoke, 41-U-shaped crossbeam, 42-first yoke leg, 43-second yoke leg. DETAILED DESCRIPTION

[0039] The embodiments of the present application provide a magnetic flux leakage detection device and method, thereby solving the technical problem that the magnetic flux leakage detection device provided in the prior art mainly increases the magnetization intensity by increasing the coil current to improve the defect detection intensity, but the increase in the coil current causes the coil to heat up severely, thereby resulting in the inability to perform magnetic flux leakage detection for a long time.

[0040] The technical solution of the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0041] A magnetic flux leakage detection device, the device comprising: a wedge-shaped magnetic yoke 1, comprising a beam 11 and a first yoke pole 12 and a second yoke pole 13, one end of the first yoke pole 12 is connected to one end of the beam 11, one end of the second yoke pole 13 is connected to the other end of the beam 11, the first yoke pole 12 and the second yoke pole 13 are symmetrical about the center line of the beam 11, the other end of the first yoke pole 12 and the other end of the second yoke pole 13 are spaced a preset distance apart; the angles between the first yoke pole 12 and the second yoke pole 13 and the beam 11 are less than 90°; the wedge-shaped magnetic yoke 1 is used to contact the test sample 3 during the leakage magnetic field detection process; the excitation coil 2 is wound on the surface of the wedge-shaped magnetic yoke 1, and is used to be energized during the leakage magnetic field detection process, and relies on the wedge-shaped magnetic yoke 1 to generate a magnetic field; the magnetic sensitive element is arranged in the area enclosed by the wedge-shaped magnetic yoke 1, and is used to detect the magnetic field distribution of the test sample 3 during the leakage magnetic field detection process; the signal processing circuit board is arranged in the area enclosed by the wedge-shaped magnetic yoke 1, and is connected to the magnetic sensitive element, and is used to determine whether the test sample 3 has leakage magnetic field according to the magnetic field distribution detected by the magnetic sensitive element.

[0042] The magnetic flux leakage detection device provided in the embodiment of the present application includes a wedge-shaped magnetic yoke 1, an excitation coil 2, a magnetic sensitive element and a signal processing circuit board. Relying on the wedge-shaped magnetic yoke 1, the effective magnetization area is increased and the minimum distance between the two yoke poles is reduced to optimize the magnetization effect. The same magnetic induction intensity can be achieved using a smaller current, thereby reducing the heating degree of the excitation coil 2 and extending the service life of the magnetic flux leakage detection device. Relying on the wedge-shaped magnetic yoke 1, the magnetic induction intensity can be further improved under the same excitation conditions, and the heating degree of the excitation coil 2 can be relatively reduced, thereby extending the service life of the magnetic flux leakage detection device and improving the accuracy of defect detection.

[0043] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0044] First of all, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0045] The present application provides a magnetic flux leakage detection device, the device comprising:

[0046] A wedge-shaped magnetic yoke 1 comprises a beam 11 and identical first yoke poles 12 and second yoke poles 13. One end of the first yoke pole 12 is connected to one end of the beam 11, and one end of the second yoke pole 13 is connected to the other end of the beam 11. The first yoke pole 12 and the second yoke pole 13 are symmetrical about the center line of the beam 11, and the other end of the first yoke pole 12 and the other end of the second yoke pole 13 are spaced by a preset distance; the angle between the first yoke pole 12 and the second yoke pole 13 and the beam 11 is less than 90°; the wedge-shaped magnetic yoke 1 is used to contact with a test sample 3 during magnetic flux leakage detection. The test sample 3 can be a ferromagnetic material such as thin strip steel.

[0047] The excitation coil 2 is wound on the surface of the wedge-shaped magnetic yoke 1 , and is used to be energized during the magnetic flux leakage detection process and to generate a magnetic field relying on the wedge-shaped magnetic yoke 1 .

[0048] The magnetic sensitive element is arranged in the area enclosed by the wedge-shaped magnetic yoke 1 and is used to detect the magnetic field distribution of the test sample 3 during the magnetic flux leakage detection process.

[0049] The signal processing circuit board is arranged in the area enclosed by the wedge-shaped magnetic yoke 1 and connected to the magnetic sensitive element, and is used to determine whether the tested sample 3 has magnetic leakage according to the magnetic field distribution detected by the magnetic sensitive element.

[0050] Regarding the wedge-shaped magnetic yoke 1, as Figure 1 As shown, the upper end of the first yoke pole 12 is connected to the left end of the beam 11, and the upper end of the second yoke pole 13 is connected to the right end of the beam 11. The first yoke pole 12 and the second yoke pole 13 are symmetrical about the center line L of the beam 11.

[0051] The angles between the first yoke pole 12 and the second yoke pole 13 and the crossbeam 11 are respectively less than 90°. For example, the angle between the central axis of the first yoke pole 12 and the central axis of the crossbeam 11 is less than 90°, and the angle between the central axis of the second yoke pole 13 and the central axis of the crossbeam 11 is less than 90°.

[0052] The end surfaces of the other end of the first yoke pole 12 and the other end of the second yoke pole 13 are both on the same plane. Figure 1 The end surfaces of the lower end of the first yoke pole 12 and the lower end of the second yoke pole 13 are both on the same plane.

[0053] The end surface areas of the other end of the first yoke pole 12 and the other end of the second yoke pole 13 are larger than the cross-sectional areas of the first yoke pole 12 and the second yoke pole 13. Figure 2As shown, the end surface area S2 of the lower end of the first yoke pole 12 is larger than the cross-sectional area S1 of the first yoke pole 12. Similarly, the end surface area of ​​the lower end of the second yoke pole 13 is larger than the cross-sectional area of ​​the second yoke pole 13, but not in Figure 2 Shown in.

[0054] The cross-sections of the crossbeam 11 , the first yoke pole 12 and the second yoke pole 13 may be circular, square (including square, rectangular) or other shapes. The embodiment of the present application is described by taking the cross-section as a square as an example.

[0055] The crossbeam 11, the first yoke pole 12 and the second yoke pole 13 are integrally formed (such as silicon steel sheets), and then laminated to form the wedge-shaped magnetic yoke 1 with a certain thickness. This ensures that the magnetic flux lines inside the wedge-shaped magnetic yoke 1 are minimally affected by the material or structure of the wedge-shaped magnetic yoke 1 itself, thereby ensuring that the accuracy of leakage magnetic detection is high.

[0056] A preset distance is provided between the other end of the first yoke pole 12 and the other end of the second yoke pole 13 .

[0057] like Figure 3 As shown, the lower end of the first yoke pole 12 and the lower end of the second yoke pole 13 are spaced apart by a preset distance D. The preset distance D is determined based on the background field distances corresponding to the first yoke pole 12 and the second yoke pole 13, respectively, and the installation size of the magnetic sensitive element. Usually, the first yoke pole 12 and the second yoke pole 13 have a negative impact on the background field within a range of 10 mm around them, and the installation size of the magnetic sensitive element is usually at least 20 mm, so the preset distance D is at least 10 mm + 10 mm + 20 mm = 40 mm.

[0058] The vertical distance between the other end of the first yoke pole 12 , the other end of the second yoke pole 13 and the crossbeam 11 is determined according to the sizes of the magnetic sensitive element, the signal processing circuit board and the excitation coil 2 .

[0059] like Figure 3 As shown in the figure, the vertical distance H between the lower end of the first yoke pole 12, the lower end of the second yoke pole 13 and the crossbeam 11 is determined according to the size of the magnetic sensitive element (not shown in the figure), the signal processing circuit board (not shown in the figure) and the excitation coil 2. Generally, the vertical distance H between the lower end of the first yoke pole 12, the lower end of the second yoke pole 13 and the crossbeam 11 is at least 50 mm.

[0060] Regarding the excitation coil 2, it is wound on the surface of the wedge-shaped magnetic yoke 1, and is used to be energized during the magnetic flux leakage detection process, and relies on the wedge-shaped magnetic yoke 1 to generate a magnetic field. The excitation coil 2 can be wound on the beam 11, or it can be symmetrically distributed on the first yoke pole 12 and the second yoke pole 13. The excitation coil 2 is wound on the beam 11, and no corresponding illustration is provided. Figure 1-Figure 3 The excitation coils 2 are symmetrically distributed on the first yoke pole 12 and the second yoke pole 13 .

[0061] The excitation coil 2 is wound on the cross beam 11. Although the winding of the excitation coil 2 can be completed only once when manufacturing the leakage magnetic flux detection device, thus saving the winding process, the excitation coil 2 may be wound on the cross beam 11 in 2-3 layers due to the limited length of the cross beam 11. The excitation coil 2 will generate heat after being energized. The 2-3 layers of the excitation coil 2 result in poor heat dissipation performance, which in turn has a negative impact on the working time of the leakage magnetic flux detection device.

[0062] The excitation coil 2 is symmetrically wound on the first yoke pole 12 and the second yoke pole 13. Although the winding process is two times, which increases the complexity of the process, the excitation coil 2 is wound on the first yoke pole 12 and the second yoke pole 13 in two parts, so that the excitation coil 2 on the first yoke pole 12 and the second yoke pole 13 only needs to be wound in one layer, thereby increasing the contact area between the excitation coil 2 and the air, improving the heat dissipation performance of the excitation coil 2, and thus extending the working time of the leakage magnetic detection device. Therefore, the embodiment of the present application preferably chooses to symmetrically wind the excitation coil 2 on the first yoke pole 12 and the second yoke pole 13.

[0063] refer to Figure 4 The wedge-shaped magnetic yoke 1 is used to contact the test sample 3 during the leakage magnetic detection process. After the excitation coil 2 is energized, a magnetic field can be formed between the wedge-shaped magnetic yoke 1 and the test sample 3.

[0064] The magnetic sensitive element (not shown in the figure) is arranged in the area enclosed by the wedge-shaped magnetic yoke 1, that is, in the area enclosed by the crossbeam 11, the first yoke pole 12 and the second yoke pole 13, specifically in a range not affected by the background field of the first yoke pole 12 and the second yoke pole 13. The magnetic sensitive element is used to detect the magnetic field distribution of the test sample 3 during the magnetic flux leakage detection process.

[0065] The signal processing circuit board (not shown in the figure) is arranged in the area enclosed by the wedge-shaped magnetic yoke 1, that is, in the area enclosed by the crossbeam 11, the first yoke pole 12 and the second yoke pole 13, specifically in a range not affected by the background field of the first yoke pole 12 and the second yoke pole 13. The signal processing circuit board is connected to the magnetic sensitive element, and is used to determine whether the test sample 3 has leakage magnetic field according to the magnetic field distribution detected by the magnetic sensitive element.

[0066] The detection principle of the magnetic flux leakage detection device provided by the present application is explained. During the test of the test sample 3, if the test sample 3 has no defects, the magnetic flux lines pass through the inside of the test sample 3 and will not leak into the air. If the inside of the test sample 3 is discontinuous, that is, there are defects, the magnetic field will be distorted around it, and part of it will leak into the air. This is the magnetic flux leakage phenomenon. The magnetic field leaked into the air will be detected by the magnetic sensitive element.

[0067] The structural aspects of the magnetic flux leakage detection device provided in the embodiment of the present application have been introduced and described above. Now, in combination with the U-shaped magnetic flux leakage detection device in the prior art, the magnetic flux leakage detection performance advantages of the magnetic flux leakage detection device provided in the embodiment of the present application (referred to as the wedge-shaped magnetic flux leakage detection device for short) are compared and described as follows.

[0068] First, the U-shaped magnetic flux leakage detection device in the prior art is described. Figure 5 As shown, it is a structural schematic diagram of a U-shaped magnetic leakage detection device, including a U-shaped magnetic yoke 4 and an excitation coil 2. The U-shaped magnetic yoke 4 includes a U-shaped beam 11, a first yoke leg 42, and a second yoke leg 43. The first yoke leg 42 and the second yoke leg 43 are connected to both ends of the U-shaped beam 41, and the first yoke leg 42 and the second yoke leg 43 are respectively perpendicular to the U-shaped beam 41.

[0069] exist Figure 4 and Figure 5 When the materials, dimensions (including yoke, coil, etc.) and other parameters used in the same Figure 4 and Figure 5 It can be seen that the differences between the wedge-shaped magnetic flux leakage detection device provided in the embodiment of the present application and the U-shaped magnetic flux leakage detection device in the related art are mainly as follows:

[0070] (1) The shapes of the yokes are different. The embodiment of the present application is a wedge-shaped yoke 1 , while the related art is a U-shaped yoke 4 .

[0071] (2) The end surface areas of the lower ends of the yoke poles are different. The end surface of the yoke leg of the U-shaped magnetic flux leakage detection device is the cross section of the yoke leg, while the end surface of the yoke pole of the wedge-shaped magnetic flux leakage detection device of the embodiment of the present application is not the cross section of the yoke pole. The end surface area of ​​the yoke pole is larger than the cross section area of ​​the yoke pole (refer to Figure 2 S1 and S2 shown).

[0072] (3) The distance between the lower ends of the yoke poles of the wedge-shaped magnetic flux leakage detection device (referred to as the span, see Figure 3 The two yoke legs of the U-shaped magnetic flux leakage detection device are parallel, while the two yoke poles of the wedge-shaped magnetic flux leakage detection device in the present application are close to each other.

[0073] It should be noted that the end surface area of ​​the lower end of the yoke pole of the wedge-shaped magnetic flux leakage detection device in the present application is larger. The main reason is that the magnetic yoke of the wedge-shaped magnetic flux leakage detection device in the embodiment of the present application is a wedge-shaped magnetic yoke 1, and the angle between the yoke pole and the beam 11 is less than 90°, resulting in a larger end surface area of ​​the yoke pole.

[0074] For example, refer to Figure 2 , when the cross section S1 of the yoke pole is a square with a side length of 20mm, the cross section S1 of the yoke pole is 400mm 2 , and the end surface area S2 will be larger than 400mm 2 The end surface area S2 will increase as the angle between the yoke pole and the beam 11 decreases. For example, at a certain angle, the end surface area S2 will be 430 mm 2 .

[0075] Since the yoke pole of the wedge-shaped magnetic leakage detection device in the embodiment of the present application is not perpendicular to the test sample 3, the contact area between the yoke pole end face and the test sample 3 will be larger. Comparing the present application with the related art, when the same current is passed through the excitation coil 2, combined with the magnetic flux calculation formula φ=BS, it can be seen that the yoke pole end face area of ​​the magnetic yoke in the present application is larger, so under the same magnetic density, the magnetic flux of the magnetic circuit is also larger.

[0076] From the previous paragraph, it can be seen that under the condition of the same current, since the end face area of ​​the device of the present application is larger, the magnetic flux is larger. It can be seen that the leakage magnetic detection device provided in the embodiment of the present application can increase the magnetic flux under the premise of using the same current size, that is, increase the magnetic induction intensity, thereby improving the defect detection intensity of the leakage magnetic detection device and improving the defect detection accuracy.

[0077] From the foregoing, it can be seen that under the condition of the same current, since the end face area of ​​the device of the present application is larger, the magnetic flux is larger. Then conversely, when the present application and the related technology obtain the same magnetic flux φ, since S in the present application is larger, based on the magnetic flux calculation formula φ=BS, it can be seen that S is larger and φ is the same, then B can be smaller, and the size of B is controlled by the size of the current in the excitation coil 2. Therefore, the current of the excitation coil 2 used in the present application will be smaller, and the Joule heat corresponding to the smaller current will be smaller.

[0078] For example, when the current of the excitation coil 2 in the present application is 0.5A, the magnetic flux of φ can be achieved, while the current of the excitation coil 2 in the related art needs to reach 2A to achieve the magnetic flux of φ. Based on the Joule heat formula I 2It can be seen from R that the resistance R of the excitation coil 2 corresponding to the two is the same. Due to the difference in I, the Joule heat of the two is 16 times. In other words, the excitation coil 2 in the magnetic yoke of the wedge-shaped magnetic flux leakage detection device provided by the present application can generate the same magnetic flux under the premise of using 1 / 16 of the heating value. It can be seen that the wedge-shaped magnetic flux leakage detection device provided by the present application can greatly reduce the heating value in the process of magnetic flux leakage detection, extend the working time, and improve the accuracy of defect detection. Excessive heating of the coil will mainly affect the stable working process of the magnetic sensitive element. Therefore, the heating value of the wedge-shaped magnetic flux leakage detection device provided by the present application is relatively lower, and thus the impact on the magnetic sensitive element is lower, which can also extend the working time of the magnetic flux leakage detection device.

[0079] For the difference between the span in this application and the prior art, refer to Figure 6 , where a, b, c, d, and e are the lengths of the corresponding line segments. For ease of description, each line segment is also named with its corresponding length and its orientation (up, down, left, right, etc.). For example, the a of the upper line segment can be recorded as upper a. Figure 5 The first yoke leg 42, the U-shaped cross beam 41, the second yoke leg 43, the left e-upper a-right e respectively correspond to Figure 4 The first yoke pole 12, the cross beam 11, the second yoke pole 13, the lower a and Figure 4 and Figure 5 Corresponding to the test sample 3 in .

[0080] from Figure 6 It can be seen that the first yoke leg 42 left b in the U-shaped magnetic flux leakage detection device takes the upper end as a fixed point, and then the lower end is a moving point and shifts to the right to form the first yoke pole 12 left e of the wedge-shaped magnetic flux leakage detection device in this application. Similarly, the second yoke leg 43 right b of the U-shaped magnetic flux leakage detection device takes the upper end as a fixed point, and then the lower end is a moving point and shifts to the left to form the second yoke pole 13 right e of the wedge-shaped magnetic flux leakage detection device in this application. Finally, the span between the left e and the right e is c, and the span of the U-shaped magnetic flux leakage detection device is a (that is, d+c+d). It can be seen that the span of the U-shaped magnetic flux leakage detection device is larger than that of the wedge-shaped magnetic flux leakage detection device.

[0081] When the magnetic yoke method is used for magnetic flux leakage detection, the magnetic induction intensity B of the test sample 3 increases as the span between the two yoke poles decreases. Therefore, when the same excitation effect is obtained, the smaller the span, the lower the required excitation current intensity. However, when the span decreases, the background field (hereinafter referred to as the background field) emitted from the magnetic poles to the air will affect the detection. Therefore, the span cannot be too large or too small. The span of the wedge-shaped magnetic flux leakage detection device is smaller than that of the U-shaped magnetic flux leakage detection device, which means that under the same current intensity, the magnetic induction intensity of the wedge-shaped magnetic flux leakage detection device is greater, which is more conducive to improving the accuracy and efficiency of defect detection.

[0082] Continue comparing from the effective link length.

[0083] The effective link length corresponding to the U-shaped magnetic flux leakage detection device of the prior art is a+b+a+b, and the effective link length of the wedge-shaped magnetic flux leakage detection device provided in the present application is a+e+c+e. Comparing the size relationship between a+b+a+b and a+e+c+e, the specific process is as follows:

[0084] Substituting a=d+c+d into this, we get d+c+d+b+d+c+d+b, and d+c+d+e+c+e;

[0085] By canceling the two with the same factors, we can get b+d+b+d, and e+e;

[0086] According to the relationship between the lengths of the three sides of a right triangle, b+d>e, so b+d+b+d>e+e.

[0087] Therefore, the effective link length of the device in the present application is shorter.

[0088] According to the excitation magnetic field strength formula H=N×I / Le, it can be known that the excitation magnetic field strength H increases with the increase of the number of turns N of the excitation coil 2, the increase of the current I of the excitation coil 2, and the decrease of the effective magnetic path length Le. It can be seen that the wedge-shaped magnetic flux leakage detection device of the present application is compared with the U-shaped magnetic flux leakage detection device provided by the prior art. When N and I are the same, the effective magnetic path length Le is shorter, and the corresponding excitation magnetic field strength is greater, which can improve the accuracy of defect detection.

[0089] Use this application (reference Figure 4 ) and related technologies (reference Figure 5 ) performs defect detection on the test sample 3, and collects the magnetic flux density distribution during the detection process, and obtains the following Figure 7 and Figure 8 The magnetic flux density distribution diagram is shown in Figure 1. Figure 7 -(1) is a magnetic flux density distribution diagram corresponding to the wedge-shaped magnetic flux leakage detection device provided in this application, Figure 7 -(2) is the magnetic flux density distribution diagram of the intersection line between the wedge-shaped magnetic circuit section and the sample surface, and Figure 4 correspond; Figure 8 -(1) is a magnetic flux density distribution diagram corresponding to the U-shaped magnetic flux leakage detection device provided by the prior art, Figure 8 -(2) is the magnetic flux density distribution diagram of the intersection line between the U-shaped magnetic circuit section and the sample surface, and Figure 5 correspond.

[0090] according to Figure 7 -(1) and Figure 8-(1) By comparison, it can be seen that the magnetic flux density in the U-shaped magnetic yoke 4 is significantly greater than that in the wedge-shaped magnetic yoke 1, indicating that the magnetic resistance of the U-shaped magnetic circuit is relatively large, which consumes the energy generated by the excitation coil 2. The magnetic resistance of the wedge-shaped magnetic yoke 1 of the present application is relatively small, which reduces the consumption of the energy generated by the excitation coil 2. Figure 7 -(1) Characterization: The device in the present application was used to test the test sample 3. The magnetic flux density modulus B at the center of the test sample 3 was 1.09T>1T, which met the design requirements.

[0091] according to Figure 7 -(2) and Figure 8 -(2) It can be determined that the magnetic flux density distortion rate of the device corresponding to the present application and the prior art is the same, indicating that the range of the uniform magnetization area is not affected by the reduction of the minimum distance between the yoke poles, and does not affect the detection. Compared with the U-shaped magnetic circuit, the wedge-shaped magnetic circuit has a smaller minimum distance between the two yoke poles, a smaller magnetized area of ​​the sample, and more concentrated energy, which is more conducive to defect detection.

[0092] Further, use this application (reference Figure 4 ) and related technologies (reference Figure 5 ) performs defect detection on the test sample 3, and collects the magnetic flux density distribution around the defect of the test sample 3 during the two detection processes, and obtains the following Fig. 9 The magnetic flux density distribution diagram is shown in Figure 1. Fig. 9 -(1) is the magnetic flux density distribution diagram around the defect in the U-shaped magnetic circuit, and Figure 5 and Figure 8 correspond, Fig. 9 -(2) is the magnetic flux density distribution diagram around the defect in the wedge-shaped magnetic circuit, and Figure 4 and Figure 7 correspond.

[0093] Compare Fig. 9 -(1) and Fig. 9 -(2) Analyzing the leakage magnetic field distribution around defects in the two magnetic circuits, the magnetic flux density around defects in the wedge-shaped magnetic circuit is greater than that around defects in the U-shaped magnetic circuit, which improves the detection efficiency. In other words, a greater magnetic flux density makes it easier to identify defects.

[0094] In summary, the magnetic flux leakage detection device provided in the embodiment of the present application includes a wedge-shaped magnetic yoke 1, an excitation coil 2, a magnetic sensitive element and a signal processing circuit board. Relying on the wedge-shaped magnetic yoke 1, the effective magnetization area is increased and the minimum distance between the two yoke poles is reduced to optimize the magnetization effect. The same magnetic induction intensity can be achieved using a smaller current, thereby reducing the heating degree of the excitation coil 2 and extending the service life of the magnetic flux leakage detection device. Relying on the wedge-shaped magnetic yoke 1, the magnetic induction intensity can be further improved under the same excitation conditions, first reducing the heating degree of the excitation coil 2, extending the service life of the magnetic flux leakage detection device, and improving the accuracy of defect detection.

[0095] Based on the same inventive concept, the present application embodiment provides the following Fig.10 A magnetic flux leakage detection method is shown, and the method includes steps S101 to S104.

[0096] Step S101, attach the other end of the first yoke pole 12 and the other end of the second yoke pole 13 of the magnetic flux leakage detection device provided above to the surface of the test sample 3; for details, please refer to Figure 4 Status shown.

[0097] Step S102 , energizing the excitation coil 2 to form a magnetic field on the test sample 3 .

[0098] Step S103 : the magnetic sensor detects the magnetic field distribution of the test sample 3 .

[0099] In step S104, the signal processing circuit board obtains the magnetic field distribution from the magnetic sensor element, and determines whether the test sample 3 has magnetic leakage according to the magnetic field distribution detected by the magnetic sensor element.

[0100] When it is detected that the test sample 3 has magnetic leakage, it indicates that there is a defect at the position of the test sample 3. When it is detected that the test sample 3 does not have magnetic leakage, it indicates that there is no defect at the position of the test sample 3.

[0101] In summary, the magnetic flux leakage detection device provided in the embodiment of the present application includes a wedge-shaped magnetic yoke 1, an excitation coil 2, a magnetic sensitive element and a signal processing circuit board. Relying on the wedge-shaped magnetic yoke 1, the effective magnetization area is increased and the minimum distance between the two yoke poles is reduced to optimize the magnetization effect. The same magnetic induction intensity can be achieved using a smaller current, thereby reducing the heating degree of the excitation coil 2 and extending the service life of the magnetic flux leakage detection device. Relying on the wedge-shaped magnetic yoke 1, the magnetic induction intensity can be further improved under the same excitation conditions, and the heating degree of the excitation coil 2 can be relatively reduced, thereby extending the service life of the magnetic flux leakage detection device and improving the accuracy of defect detection.

[0102] Since the electronic device introduced in this embodiment is an electronic device used to implement the information processing method in the embodiment of the present application, based on the information processing method introduced in the embodiment of the present application, a person skilled in the art can understand the specific implementation of the electronic device of the present embodiment and its various variations, so how the electronic device implements the method in the embodiment of the present application is not described in detail here. As long as a person skilled in the art implements the electronic device used by the information processing method in the embodiment of the present application, it belongs to the scope of protection of this application.

[0103] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0104] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0105] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0106] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1A step that specifies a function in one or more boxes.

[0107] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0108] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A magnetic flux leakage detection device, characterized in that: The device comprises: A wedge-shaped magnetic yoke comprises a beam and a first yoke pole and a second yoke pole that are identical, wherein one end of the first yoke pole is connected to one end of the beam, one end of the second yoke pole is connected to the other end of the beam, the first yoke pole and the second yoke pole are symmetrical about the center line of the beam, and the other end of the first yoke pole is spaced a preset distance from the other end of the second yoke pole; the angles between the first yoke pole and the second yoke pole and the beam are respectively less than 90°; the wedge-shaped magnetic yoke is used to contact a test sample during magnetic flux leakage detection; an excitation coil, wound on the surface of the wedge-shaped magnetic yoke, for being energized during magnetic flux leakage detection and generating a magnetic field relying on the wedge-shaped magnetic yoke; A magnetic sensitive element, arranged in the area enclosed by the wedge-shaped magnetic yoke, for detecting the magnetic field distribution of the tested sample during magnetic flux leakage detection; A signal processing circuit board is arranged in the area enclosed by the wedge-shaped magnetic yoke and connected to the magnetic sensitive element, and is used to determine whether there is magnetic leakage in the tested sample according to the magnetic field distribution detected by the magnetic sensitive element.

2. The device according to claim 1, characterized in that The end surfaces of the other end of the first yoke pole and the other end of the second yoke pole are both on the same plane, and the end surface areas of the other end of the first yoke pole and the other end of the second yoke pole are larger than the cross-sectional areas of the first yoke pole and the second yoke pole.

3. The device according to claim 1, characterized in that The crossbeam, the first yoke pole and the second yoke pole are integrally formed to form the wedge-shaped magnetic yoke.

4. The device according to claim 1, characterized in that The excitation coils are symmetrically distributed on the first yoke pole and the second yoke pole.

5. The device according to claim 1, characterized in that The preset distance is determined according to the background field distances respectively corresponding to the first yoke pole and the second yoke pole and the installation size of the magnetic sensitive element.

6. The device according to claim 1, characterized in that The preset distance is at least 40 mm.

7. The device according to claim 1, characterized in that The cross-sections of the beam, the first yoke pole and the second yoke pole are square.

8. The device according to claim 1, characterized in that The vertical distance between the other end of the first yoke pole, the other end of the second yoke pole and the crossbeam is determined according to the sizes of the magnetic sensitive element, the signal processing circuit board and the excitation coil.

9. The device according to claim 1, characterized in that The minimum vertical distance between the other end of the first yoke pole, the other end of the second yoke pole and the crossbeam is 50 mm.

10. A magnetic flux leakage detection method, characterized in that: The method comprises: Attach the other end of the first yoke pole and the other end of the second yoke pole of the magnetic flux leakage detection device according to any one of claims 1 to 9 to the surface of the test sample; Supplying power to the excitation coil to form a magnetic field on the test sample; The magnetic sensitive element detects the magnetic field distribution of the tested sample; The signal processing circuit board obtains the magnetic field distribution from the magnetic sensor element, and determines whether the tested sample has magnetic leakage according to the magnetic field distribution detected by the magnetic sensor element.

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