A magnetizing device for magnetic flux leakage detector

Abstract

The present application provides a magnetization device for a magnetic flux leakage detector, which relates to the field of magnetic flux leakage detection and includes several petal magnetization mechanisms, which are evenly distributed on the periphery of a cylindrical skeleton; one end of each petal magnetization mechanism is hinged to one end of the cylindrical skeleton, and the other end of each petal magnetization mechanism is movably connected to the other end of the cylindrical skeleton, and each petal magnetization mechanism is connected to the cylindrical skeleton via a first elastic member, which is arranged close to the other end of the cylindrical skeleton; two adjacent petal magnetization mechanisms are connected via a second elastic member. Under the action of the first elastic member, each petal magnetization mechanism can better fit the weld and the inner wall of the pipe elbow and can achieve independent movement. Under the action of the second elastic member, two adjacent petal magnetization mechanisms can move closer to or farther away from each other, thereby improving the movement flexibility of the petal magnetization mechanism, adapting to various working conditions, and having less operating resistance.

Description

Technical Field

[0001] The present application relates to the field of magnetic flux leakage detection, and in particular to a magnetizing device for a magnetic flux leakage detector. Background Art

[0002] In pipeline inspection, especially when using magnetic flux leakage (MFL) technology to detect pipe wall thickness and defects, the magnetization mechanism is the core component of the detector. Its function is to form a stable and uniform magnetic field inside the pipe. The quality of the magnetization directly determines the accuracy and reliability of the test data.

[0003] At present, commonly used magnetization mechanisms of pipeline detectors include split-petal magnetization mechanisms and steel brush magnetization mechanisms.

[0004] Split-type magnetization mechanisms typically use rigid magnetic materials as their magnetic circuits, resulting in a relatively stable structure. However, this rigidity also makes it difficult to achieve a complete, adaptive fit with the pipe wall when passing through irregular sections such as elbows and welds. This poor fit can significantly affect the magnetization intensity and magnetic field uniformity in a localized area, leading to distorted detection signals or missed detections. Furthermore, rigid structures are susceptible to deformation or damage when subjected to severe vibration or impact (such as when passing through large drop heights, valves, or foreign objects in the pipe), posing challenges to structural stability and reliability.

[0005] Steel brush magnetization mechanisms utilize a large number of steel bristles as a magnetic path. While the brushes offer a degree of flexibility and can partially adapt to pipe wall deformation, they are generally heavy, increasing the detector's load and operating energy consumption. More importantly, when the pipe exhibits significant deformation (such as dents or excessive ovality), the frictional resistance generated by the brush contact with the pipe wall increases dramatically. This can not only cause the detector to become stuck, but also makes it difficult to obtain sufficient traction for effective inspection in low-pressure, low-flow pipeline environments, severely limiting its application scenarios.

[0006] In summary, existing magnetization mechanisms have varying degrees of deficiencies in terms of adaptive fit around pipe elbows and welds, lightweight design, adaptability to large deformations, and structural stability against impact. Especially under complex operating conditions (such as multiple elbows, large deformations, and low pressure and flow rates), it is difficult to simultaneously meet the requirements of efficient magnetization and stable and reliable operation. Summary of the Invention

[0007] The present application provides a magnetization device for a magnetic flux leakage detector, in which each petal magnetization mechanism is independently connected to a cylindrical frame, and the movement flexibility of the petal magnetization mechanism is improved by a first elastic member and a second elastic member to adapt to a variety of complex working conditions, so as to solve the shortcomings of the existing magnetization mechanism in terms of adaptive fit at pipe elbows and welds, lightweight design, large deformation adaptability, and impact-resistant structural stability.

[0008] The present application provides a magnetizing device for a magnetic flux leakage detector, comprising a plurality of split-petal magnetizing mechanisms, wherein the plurality of split-petal magnetizing mechanisms are evenly distributed on the periphery of a cylindrical frame;

[0009] One end of each of the split magnetizing mechanisms is hinged to one end of the cylindrical frame, and the other end of each of the split magnetizing mechanisms is movably connected to the other end of the cylindrical frame, and each of the split magnetizing mechanisms is connected to the cylindrical frame via a first elastic member, and the first elastic member is disposed near the other end of the cylindrical frame;

[0010] Two adjacent petal magnetization mechanisms are connected via a second elastic member.

[0011] In a feasible implementation, each of the split magnetization mechanisms includes a magnetic conductive core, a permanent magnet is fixedly mounted on the side of the magnetic conductive core facing away from the cylindrical skeleton, and a magnetic conductive brush head is fixedly mounted on the side of the permanent magnet facing away from the magnetic conductive core.

[0012] In a feasible implementation, one end of each of the split-petal magnetization mechanisms is hinged to one end of a rotating arm, and the other end of the rotating arm is hinged to one end of the cylindrical frame.

[0013] In a feasible implementation, a plurality of limit blocks are fixedly installed on one end of the cylindrical frame, the limit blocks correspond to the rotating arms one by one, and each rotating arm is located between the corresponding limit block and the cylindrical frame.

[0014] In a feasible implementation, both ends of the rotating arm are connected to the petal magnetization mechanism and the cylindrical frame respectively through pins.

[0015] In a feasible implementation, the other end of each of the petal magnetization mechanisms is fixedly connected to one end of the guide shaft, and several guide grooves are opened at the other end of the cylindrical skeleton. The guide grooves correspond one-to-one to the guide shafts, and the other end of each guide shaft is located in the corresponding guide groove. The guide shaft can move radially and circumferentially along the cylindrical skeleton in the guide groove.

[0016] In a feasible implementation, the magnetic brush head includes a bottom plate, and a plurality of bundles of magnetic bristles are embedded on a side of the bottom plate facing away from the permanent magnet.

[0017] In a feasible implementation, both the first elastic member and the second elastic member are springs.

[0018] In a feasible implementation, the magnetic conductive core is a C-shaped structure with an opening facing away from the cylindrical skeleton, and the permanent magnet and the magnetic conductive brush head are provided at both ends of the magnetic conductive core.

[0019] The present application provides a magnetization device for a magnetic flux leakage detector, comprising a plurality of split magnetization mechanisms, the plurality of split magnetization mechanisms being evenly distributed around the outer periphery of a cylindrical frame; one end of each split magnetization mechanism being hinged to one end of the cylindrical frame, the other end of each split magnetization mechanism being movably connected to the other end of the cylindrical frame, and each split magnetization mechanism being connected to the cylindrical frame via a first elastic member, the first elastic member being disposed near the other end of the cylindrical frame; and two adjacent split magnetization mechanisms being connected via a second elastic member. Under the action of the first elastic member, each split magnetization mechanism can better conform to the weld and the inner wall of the pipe elbow, and can achieve independent movement, swinging around the hinge point or moving up and down as a whole, and under the action of the second elastic member, two adjacent split magnetization mechanisms can move closer to or further away from each other, thereby improving the movement flexibility of the split magnetization mechanism and adapting to various working conditions. Compared with existing magnetization mechanisms, the mechanism has lower operating resistance and is suitable not only for conventional pipelines but also for low-pressure, low-flow, and pre-production pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a magnetizing device for a magnetic flux leakage detector provided in one embodiment of the present application;

[0021] Figure 2 is a cross-sectional view of a magnetizing device for a magnetic flux leakage detector provided in one embodiment of the present application;

[0022] Figure 3 It is a structural diagram of the petal magnetization mechanism;

[0023] Figure 4 It is a structural diagram of a magnetic brush head.

[0024] Description of reference numerals:

[0025] 1- petal magnetization mechanism; 2- cylindrical frame; 3- first elastic member; 4- second elastic member;

[0026] 11-magnetic core; 12-magnetic brush head; 13-guide shaft; 14-rotating arm; 15-permanent magnet;

[0027] 121- bottom plate; 122- magnetic bristles;

[0028] 21-pin; 22-limiting block; 23-guide groove. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0030] Figure 1 : is a structural diagram of a magnetizing device for a magnetic flux leakage detector provided in one embodiment of the present application. Figure 2 is a cross-sectional view of a magnetizing device for a magnetic flux leakage detector provided in one embodiment of the present application. Figure 3 It is a structural diagram of the split-petal magnetization mechanism. Figure 4 This is a schematic diagram of the structure of the magnetic brush head. Figures 1 to 4 As shown, an embodiment of the present application provides a magnetizing device for a magnetic flux leakage detector, comprising a plurality of petal magnetizing mechanisms 1, wherein the plurality of petal magnetizing mechanisms 1 are evenly distributed on the periphery of a cylindrical frame 2;

[0031] One end of each of the split magnetizing mechanisms 1 is hinged to one end of the cylindrical frame 2, and the other end of each of the split magnetizing mechanisms 1 is movably connected to the other end of the cylindrical frame 2. Each of the split magnetizing mechanisms 1 is connected to the cylindrical frame 2 via a first elastic member 3, and the first elastic member 3 is disposed near the other end of the cylindrical frame 2.

[0032] Two adjacent petal magnetization mechanisms 1 are connected via a second elastic member 4 .

[0033] It should be noted that several petal magnetization mechanisms 1 are evenly distributed on the periphery of the cylindrical skeleton 2, that is, several petal magnetization mechanisms 1 are distributed in a circular array on the periphery of the cylindrical skeleton 2. The number of petal magnetization mechanisms 1 is 6-12, and this application does not impose any restrictions on this.

[0034] It is easy to understand that the two ends of the first elastic member 3 are respectively fixedly connected to the cylindrical frame 2 and the corresponding petal magnetization mechanism 1, such as welding, clamping and bonding. The number of the first elastic member 3 can be one or two, and this application does not impose any restrictions on this.

[0035] The two ends of the second elastic member 4 are fixedly connected to the corresponding petal magnetizing mechanism 1, and the connection method can be the same as or different from the connection method of the first elastic member 3. The number of the second elastic members 4 is 2-4.

[0036] Furthermore, the pre-tightening force of the second elastic member 4 is lower than the deformation resistance of the tube wall, so that adjacent petal magnetizing mechanisms 1 can be displaced independently without the need for the magnetizing device as a whole to overcome friction.

[0037] In some examples, the first elastic member 3 and the second elastic member 4 are both springs. In other examples, they can also be elastic rubber bodies or butterfly-shaped springs.

[0038] In the above embodiment, the cylindrical skeleton 2 serves as the supporting body and installation base of the magnetization device, and its shape is designed to be a cylindrical structure that adapts to the inner diameter of the pipe. In actual use, each petal magnetization mechanism 1 can fit the pipe wall under the action of the first elastic member 3, contacting the pipe wall to form a magnetic circuit, thereby establishing the required detection magnetic field in the pipe. Since one end of the petal magnetization mechanism 1 is hinged to the cylindrical skeleton 2 and the other end is movably connected to the cylindrical skeleton 2, the petal magnetization mechanism 1 can swing around the hinge point. When the magnetization device encounters a protrusion on the pipe wall or is impacted, it can absorb energy through the elastic deformation of the first elastic member 3, playing a buffering and protective role. The first elastic member 3 can continuously apply radial elastic force to the petal magnetization mechanism 1, so that the petal magnetization mechanism 1 can always fit the pipe wall. When passing through an elbow or weld, the magnetization device adaptively adjusts its posture and contact pressure to maintain a good fit with the pipe wall. The second elastic member 4 between two adjacent petal magnetizing mechanisms 1 can constrain the relative positions of the adjacent petal magnetizing mechanisms 1 in the circumferential direction of the cylindrical skeleton 2, prevent excessive twisting or dislocation during movement, and maintain the uniform distribution of the array of petal magnetizing mechanisms 1. When the magnetizing device passes through a deformed section of the pipeline (such as depression or elliptical), the petal magnetizing mechanism 1 can also be displaced slightly in the circumferential direction, and restored by the elastic force after passing through, which can significantly improve the adaptability of the magnetizing device to large deformation of the pipeline.

[0039] Reference Figure 2 and Figure 3 As shown, in some examples, each of the split magnetization mechanisms 1 includes a magnetic core 11, a permanent magnet 15 is fixedly mounted on the side of the magnetic core 11 facing away from the cylindrical skeleton 2, and a magnetic brush head 12 is fixedly mounted on the side of the permanent magnet 15 facing away from the magnetic core 11.

[0040] It should be noted that the permeable core 11 forms the basic support structure of the split-petal magnetization mechanism 1 and is made of a soft magnetic material with high magnetic permeability and low coercivity, such as electrical pure iron, silicon steel sheet, or a soft magnetic alloy. The inner side of the permeable core 11, i.e., the side facing the cylindrical frame 2, is used for connection to the cylindrical frame 2; the outer side of the permeable core 11, i.e., the side facing away from the cylindrical frame 2, faces the inner wall of the pipe.

[0041] Reference Figure 4 As shown, in some examples, the magnetic brush head 12 includes a bottom plate 121 , and a plurality of bundles of magnetic bristles 122 are embedded on a side of the bottom plate 121 facing away from the permanent magnet 15 .

[0042] It is easy to understand that the permanent magnet 15 is fixedly mounted on the outer working surface of the magnetic core 11, and the fixing installation method may include but is not limited to: bonding (using high-strength magnetic adhesive), welding, bolting or embedded clamping, etc., to ensure that a stable and low magnetic resistance interface connection is formed between the permanent magnet 15 and the magnetic core 11. The magnetization direction is usually along the radial direction of the pipe, that is, perpendicular to the pipe wall, so that the magnetic lines of force can penetrate the pipe wall vertically. The magnetic brush head 12 is a flexible structure, and the base plate 121 can be fixedly connected to the permanent magnet 15 by screws, or the above-mentioned fixed installation method can be adopted. This application does not impose any restrictions on this. The magnetic bristles 122 are made of flexible metal wire with high magnetic permeability, such as magnetic wear-resistant steel wire.

[0043] In the above embodiment, the magnetic bristles 122 can bend and deform to form a flexible magnetic contact surface. When passing through pipe elbows, welds, local depressions or protrusions, each bundle of magnetic bristles 122 can be adaptively adjusted to achieve maximum contact with the pipe wall, improve magnetization uniformity, and efficiently magnetize the pipe wall. The flexible structure can also effectively absorb vibrations and transient impacts encountered during detection operation, protecting the inner permanent magnet 15 and the magnetic core 11 from damage, thereby improving the reliability and durability of the device. In addition, the contact method with the pipe wall is multi-point elastic contact, which can significantly reduce sliding friction resistance when there is a large deformation in the pipe, making it more suitable for the traction conditions of low-pressure and low-flow pipes.

[0044] Continue to refer to Figure 2 and Figure 3 As shown, in some examples, one end of each of the split-petal magnetization mechanisms 1 is hinged to one end of a rotating arm 14 , and the other end of the rotating arm 14 is hinged to one end of the cylindrical frame 2 .

[0045] It is easy to understand that the two ends of the rotating arm 14 are connected to the cylindrical frame 2 and the corresponding petal magnetization mechanism 1 via hinged shafts. The rotating arm 14 can rotate about either hinged shaft or simultaneously relative to both hinged shafts. The rotating arm 14 can be made of aluminum alloy or high-strength composite materials to reduce its own weight, which contributes to the overall lightweighting of the magnetization device. In other examples, the rotating arm 14 can also adopt a hollow or hollow structure.

[0046] In some examples, both ends of the rotating arm 14 are connected to the petal magnetization mechanism 1 and the cylindrical frame 2 respectively through a pin shaft 21.

[0047] In the above embodiment, when the pipe's inner diameter changes or encounters a localized protrusion or depression, the rotating arm 14 can swing about the pin 21, driving the split-petal magnetization mechanism 1 to produce a relatively large radial displacement, significantly enhancing its ability to adapt to changes in the pipe's radial dimensions. When passing through a pipe elbow or weld, the rotating arm 14 can rotate slightly about the pins 21 at its ends, achieving overall vertical movement of the split-petal magnetization mechanism 1, or swinging the split-petal magnetization mechanism 1 around the first elastic member 3, thereby improving its adaptability to complex curved surfaces.

[0048] In some examples, a plurality of limit blocks 22 are fixedly mounted on one end of the cylindrical frame 2 , the limit blocks 22 correspond one-to-one to the rotating arms 14 , and each rotating arm 14 is located between the corresponding limit block 22 and the cylindrical frame 2 .

[0049] It should be noted that, referring to Figure 2 As shown, an annular protrusion is provided on the outer periphery of one end of the cylindrical frame 2. The annular protrusion can be integral with the cylindrical frame 2 or connected by welding or other fixing methods. A screw hole is provided on the annular protrusion, and at least two through holes are provided on the stop block 22. Bolts are passed through the through holes and then screwed into corresponding screw holes to secure the stop block 22. The rotating arm 14 has an inverted L-shaped structure, and the stop block 22 has an L-shaped structure. The bottom of the stop block 22 can contact the top of the rotating arm 14.

[0050] In the above embodiment, the maximum outward swing angle of the rotating arm 14 is limited by the limit block 22, thereby constraining the maximum radial displacement of the petal magnetization structure and preventing the magnetization device from being damaged or failing due to excessive opening. It effectively avoids the rotating arm 14 and the petal magnetization mechanism 1 connected thereto from undergoing structural plastic deformation, articulated shaft breakage or elastic part failure due to excessive displacement under conditions of extreme deformation or strong impact of the pipeline. It ensures that the petal magnetization mechanism 1 operates within a safe travel range, which is conducive to maintaining the overall stability of the magnetization mechanism array. It can also prevent the magnetic bristles 122 from excessively contacting the pipe wall, reducing the wear of the magnetic bristles 122 while reducing the contact friction resistance with the pipe wall.

[0051] In some examples, the other end of each of the petal magnetization mechanisms 1 is fixedly connected to one end of the guide shaft 13, and several guide grooves 23 are opened at the other end of the cylindrical skeleton 2. The guide grooves 23 correspond one-to-one to the guide shafts 13, and the other end of each of the guide shafts 13 is located in the corresponding guide groove 23. The guide shaft 13 can move radially and circumferentially along the cylindrical skeleton 2 in the guide groove 23.

[0052] It should be noted that the rotating arm 14 and the guide shaft 13 are both arranged at the bottom of the magnetic conductive core 11 close to the axial end of the cylindrical frame 2 .

[0053] It is easy to understand that the width of the guide groove 23 is greater than the diameter of the guide shaft 13 to meet the movement of the guide shaft 13 along its width direction, that is, circumferential movement. In some specific examples, the guide groove 23 can be a waist-shaped hole or a curved through groove.

[0054] In the above embodiment, the free end of the guide shaft 13 passes through the guide slot 23 to form a sliding pair. The guide shaft 13 can slide along the length of the guide slot 23 to accommodate the radial expansion and contraction or radial swing of the petal magnetizing mechanism 1 as a whole. It can also be laterally offset within the guide slot 23 to accommodate small circumferential movements of the petal magnetizing mechanism 1. This can constrain the motion trajectory of the other end of the petal magnetizing mechanism 1, avoid disordered deflection, improve the stability of the magnetizing mechanism array, and also help the petal magnetizing mechanism 1 maintain an optimal fit posture in complex paths.

[0055] In other examples, the movable connection between the petal magnetization mechanism 1 and the cylindrical skeleton 2 can also be achieved through a slider and a curved slide rail, or through a universal joint, which is not limited in this application.

[0056] In some examples, the magnetic core 11 is a C-shaped structure with an opening facing away from the cylindrical frame 2 , and the permanent magnets 15 and the magnetic brush heads 12 are disposed at both ends of the magnetic core 11 .

[0057] It should be noted that the two free ends of the C-shaped iron core, i.e. the two ends of the opening side, are symmetrically fixed with permanent magnets 15 and magnetic brush heads 12. The permanent magnets 15 at both ends are radially magnetized with opposite polarities to form axially parallel dual excitation units.

[0058] In the above embodiment, the C-shaped core converges and conducts the magnetic flux from the two poles, significantly increasing the magnetic induction intensity compared to a single-pole structure. Given the same magnetization intensity, the length of the permeable core 11 can be significantly shortened, thereby facilitating miniaturization and lightweighting of the magnetizing device, adapting to short-distance elbow pipes and improving throughput capacity.

[0059] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application based on the several embodiments provided in the present application to obtain other embodiments, and these embodiments do not exceed the scope of protection of the present application.

[0060] The above specific implementation methods further explain in detail the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above are only specific implementation methods of the embodiments of the present application and are not intended to limit the scope of protection of the embodiments of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the scope of protection of the embodiments of the present application.

Claims

1. A magnetizing device for a magnetic flux leakage detector, characterized in that: It comprises a plurality of split-petal magnetizing mechanisms (1), wherein the plurality of split-petal magnetizing mechanisms (1) are evenly distributed on the periphery of the cylindrical frame (2); One end of each of the split-petal magnetizing mechanisms (1) is hinged to one end of the cylindrical frame (2), and the other end of each of the split-petal magnetizing mechanisms (1) is movably connected to the other end of the cylindrical frame (2), and each of the split-petal magnetizing mechanisms (1) is connected to the cylindrical frame (2) via a first elastic member (3), and the first elastic member (3) is arranged near the other end of the cylindrical frame (2); Two adjacent petal magnetization mechanisms (1) are connected via a second elastic member (4).

2. The magnetizing device for a magnetic flux leakage detector according to claim 1, wherein: Each of the split-petal magnetization mechanisms (1) comprises a magnetic core (11), a permanent magnet (15) is fixedly mounted on the side of the magnetic core (11) facing away from the cylindrical frame (2), and a magnetic brush head (12) is fixedly mounted on the side of the permanent magnet (15) facing away from the magnetic core (11).

3. The magnetizing device for a magnetic flux leakage detector according to claim 1 or 2, wherein: One end of each of the split-petal magnetization mechanisms (1) is hinged to one end of a rotating arm (14), and the other end of the rotating arm (14) is hinged to one end of the cylindrical frame (2).

4. The magnetizing device for a magnetic flux leakage detector according to claim 3, wherein: A plurality of limit blocks (22) are fixedly mounted on one end of the cylindrical frame (2), the limit blocks (22) corresponding to the rotating arms (14) one by one, and each rotating arm (14) is located between the corresponding limit block (22) and the cylindrical frame (2).

5. The magnetizing device for a magnetic flux leakage detector according to claim 3, wherein: Both ends of the rotating arm (14) are connected to the petal magnetization mechanism (1) and the cylindrical frame (2) via pins (21) respectively.

6. The magnetizing device for a magnetic flux leakage detector according to claim 1 or 2, wherein: The other end of each of the split-petal magnetization mechanisms (1) is fixedly connected to one end of the guide shaft (13), and the other end of the cylindrical skeleton (2) is provided with a plurality of guide grooves (23), and the guide grooves (23) correspond one-to-one to the guide shafts (13). The other end of each of the guide shafts (13) is located in the corresponding guide groove (23), and the guide shaft (13) can move radially and circumferentially along the cylindrical skeleton (2) in the guide groove (23).

7. The magnetizing device for a magnetic flux leakage detector according to claim 2, wherein: The magnetic conductive brush head (12) comprises a bottom plate (121), and a plurality of bundles of magnetic conductive bristles (122) are embedded on a side of the bottom plate (121) facing away from the permanent magnet (15).

8. The magnetizing device for a magnetic flux leakage detector according to claim 1 or 2, wherein: The first elastic member (3) and the second elastic member (4) are both springs.

9. The magnetizing device for a magnetic flux leakage detector according to claim 2, wherein: The magnetic conductive core (11) is a C-shaped structure with an opening facing away from the cylindrical frame (2), and the permanent magnets (15) and the magnetic conductive brush heads (12) are provided at both ends of the magnetic conductive core (11).

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