Low-resistance pipeline magnetic flux leakage internal detection device

Abstract

The application relates to the technical field of pipeline nondestructive testing, in particular to a low-resistance pipeline magnetic flux leakage internal detection device of a roller type, which comprises a driving joint, a universal joint, a magnetization joint and a collision head; the driving joint, the universal joint, the magnetization joint and the collision head are coaxially arranged; the collision head is arranged at the front end of the driving joint; the driving joint and the magnetization joint and a plurality of driving joints are connected through the universal joint; a plurality of skin bowl rollers are uniformly arranged on the outer edge of the sealing skin bowl of the driving joint; the driving joint is in contact with the inner wall of the pipeline through the skin bowl rollers to form rolling friction; the magnetization joint comprises a sealing cabin body and a plurality of single magnetic circuits; the plurality of single magnetic circuits are uniformly arranged on the outer side of the sealing cabin body in the circumferential direction; each single magnetic circuit comprises a magnetic circuit support wheel; the magnetization joint is in contact with the inner wall of the pipeline through the magnetic circuit support wheel to form rolling friction, so that the problem that high-precision magnetic flux leakage internal detection technology cannot be used in pipelines with low pressure and low flow rate is solved.

Description

Technical Field

[0001] This application relates to the field of pipeline non-destructive testing technology, and in particular to a roller-type low-resistance pipeline magnetic flux leakage internal detection device. Background Technology

[0002] Pipelines, especially long-distance oil and gas pipelines, are critical infrastructure for energy transportation. These pipelines are typically buried underground or on the seabed. During long-term operation, they are affected by geological changes, soil corrosion, and material fatigue, leading to defects such as corrosion and cracks in the pipe walls, seriously threatening operational safety. To perform non-destructive testing on pipelines without interrupting transportation, pipeline internal inspection technologies have emerged. Among them, magnetic flux leakage (MFL) testing has become an important technique for pipeline integrity assessment due to its high accuracy, stable signal, and quantifiable defect evaluation. However, the application of MFL testing places high demands on the pipeline's operating conditions (such as internal medium pressure and flow velocity). For example, in natural gas pipelines such as coalbed methane, low operating pressures (e.g., 0.5-0.6 MPa) and low flow velocities (e.g., below 0.2 m / s) are common, posing a significant challenge to conventional MFL testing.

[0003] To adapt to the environment inside pipelines, conventional magnetic flux leakage detectors typically employ a sealed cup structure, utilizing the pressure difference created within the pipe as the driving force. Regarding the magnetic circuit, there are two main technical solutions: one involves using a steel brush to directly contact the pipe wall to close the magnetic circuit and provide support, such as employing a wear-resistant magnetic sheet structure and supporting the magnetic circuit with springs; the other solution is to design a specialized wheeled walking mechanism to support the main body of the detection equipment, thereby reducing movement resistance. Both solutions aim to achieve stable operation of the detector within the pipeline and effective magnetization detection.

[0004] However, the aforementioned technical solutions have significant shortcomings when applied to the aforementioned low-pressure, low-flow-rate pipelines. For detectors using steel brushes or wear-resistant magnetic sheets and relying on cup supports, the magnetic circuit structure and the contact between the cup and the pipe wall involve sliding friction, resulting in significant operating resistance. To overcome this resistance, the detector requires a higher driving pressure differential, which directly translates into strict requirements for the minimum operating pressure of the pipeline (typically greater than 1.6 MPa) and the minimum flow velocity of the medium (typically greater than 1 m / s). This prevents many low-pressure, low-flow-rate pipelines from adopting high-precision magnetic flux leakage internal detection technology due to their inability to meet these operating conditions, forcing them to rely on lower-precision alternatives and creating potential risks for long-term safe pipeline operation. The fundamental reason is that sliding friction (cup friction, steel brush friction, etc.) in the detector structure is the main source of resistance; under high resistance, low pipeline pressure cannot provide sufficient driving force. Therefore, how to design a magnetic flux leakage internal detection device that can significantly reduce operating resistance in pipelines and is suitable for low-pressure, low-flow-rate conditions has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] This application provides a roller-type low-resistance pipeline magnetic flux leakage internal detection device to solve the problem that high-precision magnetic flux leakage internal detection technology cannot be used in pipelines with low pressure and low flow rate.

[0006] This application provides a roller-type low-resistance pipeline magnetic flux leakage detection device, comprising: a drive joint, a universal joint, a magnetized joint, and an anti-collision head; the drive joint, the universal joint, the magnetized joint, and the anti-collision head are coaxially arranged; the anti-collision head is disposed at the front end of the drive joint; the drive joint and the magnetized joint, as well as multiple drive joints, are connected by the universal joint; multiple cup rollers are evenly arranged on the outer edge of the sealing cup of the drive joint; the cup rollers contact the inner wall of the pipeline to form rolling friction; the magnetized joint includes a sealed chamber and multiple single magnetic circuits; the multiple single magnetic circuits are evenly arranged circumferentially on the outer side of the sealed chamber, each single magnetic circuit includes a magnetic circuit support wheel, and the magnetized joint contacts the inner wall of the pipeline through the magnetic circuit support wheel to form rolling friction.

[0007] The roller-type low-resistance pipeline magnetic flux leakage internal detection device provided in this application uses a cup roller in the drive section and a magnetic circuit support wheel in the magnetization section. The drive section and the magnetization section contact the inner wall of the pipeline through rolling friction. Compared with sliding friction, this can reduce the running resistance of the detection device in the pipeline, thereby alleviating the dependence of the detection device on pipeline pressure and flow rate. This allows low-pressure, low-flow-rate pipelines to be detected using magnetic flux leakage internal detection technology. At the same time, it helps to reduce component wear caused by sliding friction and extend the service life of the detection device.

[0008] Optionally, the drive section frame of the drive section is coaxially provided with a front connecting flange and a rear connecting flange; the sealing cup is sleeved on the drive section frame, one side of the sealing cup is supported by the drive section frame, the other side of the sealing cup is pressed and fixed by the cup flange, and the cup flange is connected to the drive section frame by fasteners.

[0009] This application improves the stability of the sealing cup on the drive section frame by fitting a sealing cup onto the drive section frame, with one side of the sealing cup supported by the drive section frame and the other side pressed and fixed by the cup flange. Fasteners are used to connect the cup flange and the drive section frame. This reduces the risk of displacement or loosening of the sealing cup during the operation of the detection device. It also helps maintain the contact posture between the outer edge of the sealing cup roller and the inner wall of the pipe, thereby ensuring the reliability of the drive section operating by rolling friction.

[0010] Optionally, a cylindrical protrusion is provided on the front connecting flange of the drive joint, the rear connecting flange of the drive joint, the front cover and the rear cover of the magnetized joint, and a pin hole is provided on the cylindrical protrusion. The center line of the pin hole intersects the axis of the cylindrical protrusion. The universal joint includes a universal joint connecting block, which is sleeved with the cylindrical protrusion through the pin hole, and the universal joint connecting block and the pin hole are fixedly connected by a threaded shaft.

[0011] This application improves the alignment between the drive joint and the magnetized joint, as well as among multiple drive joints, by providing cylindrical protrusions with pin holes on the front connecting flange, the rear connecting flange, the front cover, and the rear cover of the magnetized joint. The universal joint connecting block is then fitted with the cylindrical protrusion through the pin hole, and the universal joint connecting block and the pin hole are fixedly connected by a threaded shaft. This reduces the relative shaking of the connecting components during the operation of the detection device, thereby improving the overall coaxiality and structural stability of the detection device when it travels in the pipeline.

[0012] Optionally, the sealing cup further includes a roller bracket, a roller shaft, and an auxiliary sealing plate; the cup roller is mounted on the roller bracket via the roller shaft; the roller bracket consists of two bracket pieces, which are clamped together and fixed in a groove on the outer edge of the sealing cup; the auxiliary sealing plate is fixed to the side of the cup roller opposite to the direction of travel, and the surface of the auxiliary sealing plate is higher than the surface of the cup roller.

[0013] This application improves the installation stability of the cup roller on the outer edge of the sealing cup by clamping a roller bracket consisting of two support plates within a groove on the outer edge of the sealing cup, and by mounting the cup roller on the roller bracket via a roller shaft. Simultaneously, by fixing an auxiliary sealing plate to the side of the cup roller opposite to the direction of travel, with the surface of the auxiliary sealing plate higher than the surface of the cup roller, a supplementary seal can be formed around the cup roller when it rolls in contact with the inner wall of the pipe. This reduces the degree of leakage of the medium through the installation location of the cup roller, thereby helping to maintain the pressure difference between the front and rear sides of the drive section.

[0014] Optionally, the universal joint further includes a chain pin, a chain, and a polyurethane elastomer; the two ends of the chain are connected to the universal joint connecting block via the chain pin; the polyurethane elastomer is disposed on the inner circumference of the chain to fill the space between the links of the chain; the universal joint connecting block is connected to the drive joint or the magnetized joint via the threaded shaft.

[0015] This application provides a flexible connection between drive joints or between a drive joint and a magnetized joint by incorporating a chain within a universal joint and connecting both ends of the chain to a universal joint connecting block via chain pins. Simultaneously, by placing polyurethane elastomer on the inner circumference of the chain to fill the spaces between the chain links, the uniformity of force distribution under stress is improved, reducing impact and wear between the links. The universal joint connecting block connects to the drive joint or magnetized joint via a threaded shaft, which helps to ensure connection reliability while providing better bending adaptability of the detection device when passing through pipe bends.

[0016] Optionally, the magnetization section further includes a fixed flange, a base fixing ring, and a mileage wheel flange; the front hatch and the fixed flange are coaxially disposed at one end of the sealed chamber, and the rear hatch and the mileage wheel flange are coaxially disposed at the other end of the sealed chamber; the single magnetic circuits are evenly arranged on the fixed flange around the circumference of the sealed chamber, and the base fixing ring is connected to the magnetic circuit base of all the single magnetic circuits.

[0017] This application improves the sealing performance and alignment of the sealed chamber by coaxially mounting a front cover and a fixed flange at one end of the sealed chamber, and coaxially mounting a rear cover and a mileage wheel flange at the other end. Simultaneously, by evenly arranging the single magnetic circuits around the circumference of the sealed chamber on the fixed flange, and connecting the base fixing ring to the magnetic circuit bases of all single magnetic circuits, the overall integrity of the installation of multiple single magnetic circuits on the outside of the sealed chamber is enhanced. This reduces the risk of relative positional shifts in the single magnetic circuits during the operation of the detection device, thereby helping to maintain a uniform magnetization effect of the magnetized joint on the circumference of the pipeline.

[0018] Optionally, the single magnetic circuit is a parallelogram linkage structure, including a magnetic circuit base, a magnetic circuit front support arm, an iron core, a magnetic circuit rear support arm, and a rear support arm base; the magnetic circuit base and the rear support arm base are fixed ends, and the rear support arm base is fixed to the outside of the sealed chamber; the first end of the magnetic circuit front support arm is connected to the magnetic circuit base via a rotating shaft, and the second end of the magnetic circuit front support arm is connected to the magnetic circuit support wheel and the iron core via a rotating shaft; permanent magnets and magnetic conductive sheets are respectively provided at both ends of the iron core, and a detection probe group is provided at the center of the iron core; the first end of the magnetic circuit rear support arm is connected to the rear support arm base via a rotating shaft, and the second end of the magnetic circuit rear support arm is connected to the magnetic circuit support wheel and the iron core via a rotating shaft.

[0019] This application constructs a single magnetic circuit as a parallelogram linkage structure comprising a magnetic circuit base, a front support arm, an iron core, a rear support arm, and a rear support arm base. The front and rear support arms are each connected to the magnetic circuit base, iron core, and rear support arm base via rotating shafts. This design enables the single magnetic circuit to maintain parallelism with the axis of the detection device when subjected to pressure from the inner wall of the pipe. Permanent magnets and magnetic conductive plates are respectively installed at both ends of the iron core, with a detection probe assembly positioned in the center. This helps maintain a stable magnetization gap while the magnetic circuit support wheel rolls in contact with the inner wall of the pipe, thereby improving the signal consistency of magnetic flux leakage detection.

[0020] Optionally, the single magnetic circuit further includes a spring rod and a magnetic circuit spring; the spring rod is connected between the first end of the front support arm of the magnetic circuit and the magnetic circuit base, the magnetic circuit spring is sleeved on the outside of the spring rod, and the two ends of the spring rod are provided with rod stops for pressing and fixing the magnetic circuit spring.

[0021] This application provides elastic support to the single magnetic circuit by sleeved a magnetic circuit spring on the outside of a spring rod connected to the first end of the magnetic circuit front support arm and the magnetic circuit base, and by setting rod stops at both ends of the spring rod to press and fix the magnetic circuit spring. This allows the single magnetic circuit to have a rebound capability after being compressed by the inner wall of the pipe. At the same time, the cooperation structure between the spring rod and the magnetic circuit spring helps to limit the swing amplitude of the magnetic circuit front support arm, improves the motion stability of the single magnetic circuit under radial compression, and thus ensures continuous rolling contact between the magnetic circuit support wheel and the inner wall of the pipe.

[0022] Optionally, a first pull rod baffle and a second pull rod baffle are respectively provided on both sides of the spring pull rod; in two adjacent single magnetic circuits in the circumferential direction, the first pull rod baffle of one single magnetic circuit and the second pull rod baffle of the adjacent single magnetic circuit are staggered, and the second pull rod baffle is located in the gap of the first pull rod baffle.

[0023] This application, by setting a first pull rod baffle and a second pull rod baffle on both sides of the spring pull rod, and by staggering the first pull rod baffle of one single magnetic circuit with the second pull rod baffle of the adjacent single magnetic circuit in the circumferential direction, with the second pull rod baffle located in the gap of the first pull rod baffle, enables adjacent single magnetic circuits to push against each other through the baffles during compression, achieving coordinated compression between multiple single magnetic circuits. This coordinated structure helps all the magnetic circuit springs of the single magnetic circuits to share the supporting force of the magnetized section, improving the uniformity of the force on each single magnetic circuit, thereby enhancing the overall support stability of the magnetized section.

[0024] Optionally, the magnetized section further includes a junction box assembly, odometer wheels, and a switch cover; the junction box assembly is located on the outer side of the stern of the sealed compartment and fixed to the odometer wheel flange; at least three odometer wheels are evenly arranged circumferentially on the odometer wheel flange; the switch cover is fixed to the rear compartment cover by a threaded connection.

[0025] This application utilizes a junction box assembly installed on the outer side of the rear of the sealed chamber and fixed to the odometer wheel flange. This allows for the centralized convergence of signal lines from each single magnetic circuit detection probe assembly, improving the regularity of the wiring layout. By circumferentially arranging at least three odometer wheels on the odometer wheel flange, the odometer wheels can roll into contact with the inner wall of the pipe, facilitating the acquisition of travel information during the movement of the detection device. Simultaneously, the switch cover is threadedly fixed to the rear cover, enabling operators to easily open or close the sealed chamber, thereby improving the ease of maintenance for the electronic components inside the sealed chamber.

[0026] As can be seen from the above technical solutions, this application provides a roller-type low-resistance pipeline magnetic flux leakage internal detection device, including: a drive joint, a universal joint, a magnetized joint, and an anti-collision head; the drive joint, the universal joint, the magnetized joint, and the anti-collision head are arranged coaxially; the anti-collision head is disposed at the front end of the drive joint; the drive joint and the magnetized joint, as well as multiple drive joints, are connected through the universal joint; multiple cup rollers are evenly arranged on the outer edge of the sealing cup of the drive joint; the cup rollers contact the inner wall of the pipeline to form rolling friction; the magnetized joint includes a sealed chamber and multiple single magnetic circuits; the multiple single magnetic circuits are evenly arranged circumferentially on the outer side of the sealed chamber, each single magnetic circuit includes a magnetic circuit support wheel, and the magnetized joint contacts the inner wall of the pipeline through the magnetic circuit support wheel to form rolling friction, thereby solving the problem that high-precision magnetic flux leakage internal detection technology cannot be used in pipelines with low pressure and low flow rate. Attached Figure Description

[0027] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the roller-type low-resistance pipeline magnetic flux leakage detection device in the embodiments of this application; Figure 2 This is an exploded schematic diagram of the drive section of the roller-type low-resistance pipeline magnetic flux leakage detection device in the embodiments of this application; Figure 3 This is a schematic diagram of the sealing cup roller structure of the roller-type low-resistance pipeline magnetic flux leakage detection device in this application embodiment; Figure 4This is a schematic diagram of the lateral structure of the drive section of the roller-type low-resistance pipeline magnetic flux leakage detection device in this embodiment of the application; Figure 5 This is a schematic diagram of the universal joint structure of the roller-type low-resistance pipeline magnetic flux leakage detection device in this application embodiment; Figure 6 This is a schematic diagram of the single magnetic circuit planar structure of the roller-type low-resistance pipeline magnetic flux leakage detection device in the embodiments of this application; Figure 7 This is a schematic diagram of the single magnetic circuit three-dimensional structure of the roller-type low-resistance pipeline magnetic flux leakage internal detection device in the embodiments of this application; Figure 8 This is a schematic diagram of the single magnetic circuit in the conventional state of the roller-type low-resistance pipeline magnetic flux leakage detection device in the embodiments of this application; Figure 9 This is a schematic diagram of the single magnetic circuit compression state of the roller-type low-resistance pipeline magnetic flux leakage internal detection device in the embodiments of this application; Figure 10 This is a schematic diagram of the magnetization section structure of the roller-type low-resistance pipeline magnetic flux leakage detection device in this application embodiment; Figure 11 This is an enlarged schematic diagram of the magnetized section A of the roller-type low-resistance pipeline magnetic flux leakage detection device in this embodiment of the application; Figure 12 This is a schematic diagram of the spring pull rod structure of the roller-type low-resistance pipeline magnetic flux leakage detection device in this application embodiment.

[0029] Illustration: Among them, 1-Drive joint; 11-Drive joint front connecting flange; 12-Drive joint rear connecting flange; 13-Drive joint frame; 14-Sealing cup; 141-Roller bracket; 142-Roller shaft; 143-Cup roller; 144-Auxiliary sealing plate; 15-Cup flange; 2-Universal joint; 21-Universal joint connecting block; 22-Threaded shaft; 23-Chain pin; 24-Chain; 25-Polyurethane elastomer; 3-Magnetized joint; 31-Front hatch cover; 32-Fixed flange; 33-Sealed compartment; 34-Base fixing ring; 35- Single magnetic circuit; 351-Magnetic circuit base; 352-Magnetic circuit front support arm; 353-Magnetic circuit support wheel; 354-Iron core; 355-Permanent magnet; 356-Magnetic conductive sheet; 357-Detection probe group; 358-Magnetic circuit rear support arm; 359-Rear support arm base; 350-Spring pull rod; 350a-First pull rod baffle; 350b-Second pull rod baffle; 35a-Magnetic circuit spring; 35b-Pull rod stop block; 36-Cable junction box group; 37-Odometer wheel; 38-Rear compartment cover; 38a-Switch cover; 39-Odometer wheel flange; 4-Anti-collision head. Detailed Implementation

[0030] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application.

[0031] To address the issue of the inability to employ high-precision magnetic flux leakage detection technology in low-pressure, low-flow-rate pipelines, see [reference needed]. Figures 1-12 This application provides a roller-type low-resistance pipeline magnetic flux leakage detection device, including: a drive joint 1, a universal joint 2, a magnetized joint 3, and an anti-collision head 4; the drive joint 1, universal joint 2, magnetized joint 3, and anti-collision head 4 are arranged coaxially; the anti-collision head 4 is disposed at the front end of the drive joint 1; the drive joint 1 and the magnetized joint 3, as well as multiple drive joints 1, are connected by universal joints 2; multiple cup rollers 143 are evenly arranged on the outer edge of the sealing cup 14 of the drive joint 1; the cup rollers 143 contact the inner wall of the pipeline to form rolling friction; the magnetized joint 3 includes a sealed chamber 33 and multiple single magnetic circuits 35; the multiple single magnetic circuits 35 are evenly arranged circumferentially on the outer side of the sealed chamber 33, each single magnetic circuit 35 includes a magnetic circuit support wheel 353, and the magnetized joint 3 contacts the inner wall of the pipeline through the magnetic circuit support wheel 353 to form rolling friction.

[0032] It should be understood that the core of this application lies in modifying all contact components of the detection device that may experience sliding friction with the inner wall of the pipe—namely, the sealing cup of the drive section and the magnetic circuit support structure of the magnetized section—to contact via rolling friction. Specifically, such as... Figure 2 and Figure 3 As shown, a rubber cup roller 143 is installed on the outer edge of the sealing cup 14 of the drive section 1, and the magnetized section 3 contacts the pipe wall through the magnetic circuit support wheel 353. This design transforms the high resistance generated by the direct sliding contact between the sealing cup and the magnetic circuit steel brush (or wear-resistant magnetic sheet) and the pipe wall into low resistance generated by the rolling of the roller. Actual measurements have verified that this reduces the operating resistance of the detection device in the pipeline by more than 80%, thus ensuring that even under low pressure (e.g., 0.5-0.6 MPa) and low flow velocity (e.g., below 0.2 m / s), the pressure difference generated by the sealing cups 14 on both sides of the drive section 1 is sufficient to propel the device forward stably, solving the problem that high-precision magnetic flux leakage detection technology cannot be applied to low-pressure, low-flow-velocity pipelines.

[0033] like Figure 1As shown, the anti-collision head 4 is made of non-metallic elastic materials such as polyurethane and rubber. Its function is to buffer the impact force through its own elastic deformation when the device encounters protrusions, weld beads, or bends in the pipeline, thus avoiding damage to the inner wall of the pipeline or the precision components inside the device. Depending on the actual pipeline inspection conditions, the number of drive joints 1 is usually no less than two, and the drive joints 1 are connected by universal joints 2. The length of the universal joint 2 determines the spacing between adjacent sealing cups 14, which is generally 1.1-1.3 times the inner diameter of the pipeline to achieve optimal driving effect and passage.

[0034] In some embodiments, the drive joint frame 13 is coaxially provided with a drive joint front connecting flange 11 and a drive joint rear connecting flange 12; a sealing cup 14 is sleeved on the drive joint frame 13, one side of the sealing cup 14 is supported by the drive joint frame 13, and the other side of the sealing cup 14 is pressed and fixed by the cup flange 15, and the cup flange 15 is connected to the drive joint frame 13 by fasteners.

[0035] It should be understood that, such as Figure 2 As shown, the drive section frame 13 of the drive section 1 is coaxially equipped with a front connecting flange 11 and a rear connecting flange 12. A sealing cup 14 is fitted onto the drive section frame 13, with one side supported by a corresponding structure (such as a boss) on the drive section frame 13, and the other side pressed against the edge of the sealing cup 14 by the cup flange 15. The cup flange 15 is connected to the drive section frame 13 using bolts or other fasteners, ensuring a stable fixation of the sealing cup 14. This structural design effectively improves the stability of the sealing cup 14 on the drive section frame 13, reducing the risk of displacement or loosening when the detection device operates at high speed or passes through complex pipe sections. This ensures that the cup roller 143 on the outer edge of the sealing cup 14 always maintains the correct contact posture with the inner wall of the pipe, guaranteeing that the drive section 1 operates in a stable rolling friction manner.

[0036] In some embodiments, a cylindrical protrusion is provided on the front connecting flange 11 of the drive joint, the rear connecting flange 12 of the drive joint, the front cover 31 and the rear cover 38 of the magnetized joint 3. A pin hole is provided on the cylindrical protrusion, and the center line of the pin hole intersects with the axis of the cylindrical protrusion. The universal joint 2 includes a universal joint connecting block 21, which is sleeved with the cylindrical protrusion through the pin hole, and the universal joint connecting block 21 and the pin hole are fixedly connected by a threaded shaft 22.

[0037] It should be noted that, as Figure 2 As shown, a cylindrical protrusion with a pin hole is provided on the front connecting flange 11 of the drive section, the rear connecting flange 12 of the drive section, and the front hatch 31 and rear hatch 38 of the magnetized section 3. Figure 1 and Figure 6As shown in the connection details, the centerline of this pin hole intersects with the axis of the cylindrical protrusion, thus forming a structure similar to a "hinged hole". The universal joint 2 includes a universal joint connecting block 21, which engages with the cylindrical protrusion through this pin hole to form a rotating pair. A threaded shaft 22 then passes through the universal joint connecting block 21 and the pin hole for fixation. This connection method effectively improves the alignment between the drive joint 1 and the magnetized joint 3, as well as between multiple drive joints 1. When the device passes through bends or encounters changes in pipe diameter, each connecting component can rotate relative to the pin hole axis at a certain angle, thereby reducing the hard impact and relative shaking of the connecting components during the operation of the detection device, and improving the overall coaxiality and structural stability of the detection device when traveling through complex pipelines.

[0038] In some embodiments, the sealing cup 14 further includes a roller bracket 141, a roller shaft 142, and an auxiliary sealing plate 144; the cup roller 143 is mounted on the roller bracket 141 via the roller shaft 142; the roller bracket 141 consists of two bracket pieces, which are fixed in the outer groove of the sealing cup 14 by clamping; the auxiliary sealing plate 144 is fixed on the side of the cup roller 143 away from the direction of travel, and the surface of the auxiliary sealing plate 144 is higher than the surface of the cup roller 143.

[0039] It should be understood that, such as Figure 3 and Figure 4As shown, the structure of the sealing cup 14 also includes a roller bracket 141, a roller shaft 142, and an auxiliary sealing plate 144. The cup roller 143 is rotatably mounted on the roller bracket 141 via the roller shaft 142. The roller bracket 141 preferably consists of two bracket pieces, which are fixed in a pre-designed groove on the outer edge of the sealing cup 14 by clamping (e.g., by bolt clamping). This installation method is simple and reliable. Furthermore, the auxiliary sealing plate 144 is fixed on the side of the cup roller 143 away from the direction of travel of the detection device (i.e., rearwards), and its surface must be higher than the surface of the cup roller 143, with a height difference H1 preferably of 1-3 mm. The purpose of this design is twofold: firstly, the two-piece clamping roller bracket 141 significantly improves the stability of the cup roller 143 on the outer edge of the sealing cup 14, preventing the roller from falling off; secondly, the auxiliary sealing plate 144 provides supplementary sealing. When the cup roller 143 contacts and rolls against the inner wall of the pipe, the installation gap between the roller bracket 141 and the cup roller 143 may cause leakage of the medium (such as natural gas) in the pipe, thereby reducing the pressure difference before and after the drive section 1 and affecting the driving force. The auxiliary sealing plate 144, due to its higher surface area, can contact the pipe wall and undergo slight deformation before the cup roller 143, thus effectively blocking the installation gap around the cup roller 143, mitigating medium leakage, and helping to maintain the required driving pressure difference before and after the drive section 1. The cup roller 143 can be designed as an arc (spindle shape), with its surface curvature radius being less than or equal to the inner diameter of the pipe, allowing it to better adapt to the curvature of the pipe wall. Simultaneously, for wear resistance, the outer surface of the cup roller 143 can be wrapped with a high-hardness polyurethane material, such as a material with a Shore hardness A ≥ 90. The diameter of the drive section 1 is typically slightly larger than the inner diameter of the pipe, for example, 1.01-1.05 times the inner diameter, to ensure effective contact between the seal and the roller.

[0040] In some embodiments, the universal joint 2 further includes a chain pin 23, a chain 24, and a polyurethane elastomer 25; the two ends of the chain 24 are connected to the universal joint connecting block 21 by the chain pin 23; the polyurethane elastomer 25 is disposed on the inner circumference of the chain 24 to fill the space between the links of the chain 24; the universal joint connecting block 21 is connected to the drive joint 1 or the magnetized joint 3 by a threaded shaft 22.

[0041] It should be understood that, such as Figure 5As shown, the universal joint 2 includes not only a universal joint connecting block 21 and a threaded shaft 22, but also a chain pin 23, a chain 24, and a polyurethane elastomer 25. The two ends of the chain 24 are connected to the universal joint connecting block 21 via the chain pin 23, which can be secured with a cotter pin or similar structure. The universal joint connecting block 21 is then connected to the drive joint 1 or the magnetized joint 3 via the threaded shaft 22. The length of the chain 24 determines the spacing between adjacent drive joints 1, which can be selected according to the pipe diameter. The polyurethane elastomer 25 is disposed on the inner circumference of the chain 24, formed by mold casting, and is used to fill the space between the links of the chain 24. This structure, through the flexible connection of the chain 24, provides excellent bending adaptability between adjacent drive joints 1 or between drive joint 1 and magnetized joint 3, enabling the device to smoothly pass through bends in the pipe. On the other hand, the filling of polyurethane elastomer 25 improves the uniformity of force distribution of the ring chain 24 under stress (especially under tension and bending), reduces hard impact, friction and wear between chain links, thereby extending the service life of the universal joint and improving the smoothness of device operation.

[0042] In some embodiments, the magnetized section 3 further includes a fixed flange 32, a base fixing ring 34, and a mileage wheel flange 39; the front hatch 31 and the fixed flange 32 are coaxially disposed at one end of the sealed chamber 33, and the rear hatch 38 and the mileage wheel flange 39 are coaxially disposed at the other end of the sealed chamber 33; the single magnetic circuits 35 are evenly arranged around the sealed chamber 33 on the fixed flange 32, and the base fixing ring 34 is connected to the magnetic circuit base 351 of all the single magnetic circuits 35.

[0043] It should be understood that, such as Figure 7 As shown, the magnetizing section 3 also includes a fixed flange 32, a base fixing ring 34, and a mileage wheel flange 39. The front cover 31 and the fixed flange 32 are coaxially arranged at one end of the sealed chamber 33, and the rear cover 38 and the mileage wheel flange 39 are coaxially arranged at the other end of the sealed chamber 33. This flange connection structure helps improve the sealing performance and centering of both ends of the sealed chamber 33. Multiple single magnetic circuits 35 are evenly arranged on the fixed flange 32 around the circumference of the sealed chamber 33 through magnetic circuit bases 351 at their bottom. The base fixing ring 34 acts as a circumferential fastener, connecting to the magnetic circuit bases 351 of all the single magnetic circuits 35. This design greatly enhances the integrity and coaxiality of the multiple single magnetic circuits 35 installed on the outside of the sealed chamber 33, reducing the risk of relative positional shift or loosening of the single magnetic circuits 35 when the detection device travels at high speed, vibrates, or passes through deformed pipes, thereby helping the magnetizing section 3 achieve a uniform and stable magnetization effect on the circumference of the pipe.

[0044] In some embodiments, the single magnetic circuit 35 is a parallelogram linkage structure, including a magnetic circuit base 351, a magnetic circuit front support arm 352, an iron core 354, a magnetic circuit rear support arm 358, and a rear support arm base 359; the magnetic circuit base 351 and the rear support arm base 359 are fixed ends, and the rear support arm base 359 is fixed to the outside of the sealed chamber 33; the first end of the magnetic circuit front support arm 352 is connected to the magnetic circuit base 351 through a rotating shaft, and the second end of the magnetic circuit front support arm 352 is connected to the magnetic circuit support wheel 353 and the iron core 354 through a rotating shaft; permanent magnets 355 and magnetic conductive sheets 356 are respectively provided at both ends of the iron core 354, and a detection probe group 357 is provided at the center of the iron core 354; the first end of the magnetic circuit rear support arm 358 is connected to the rear support arm base 359 through a rotating shaft, and the second end of the magnetic circuit rear support arm 358 is connected to the magnetic circuit support wheel 353 and the iron core 354 through a rotating shaft.

[0045] It should be noted that, as Figures 6-9 As shown, one of the core structures of this application is that the single magnetic circuit 35 adopts a parallelogram linkage structure. This structure includes a magnetic circuit base 351, a front magnetic circuit support arm 352, an iron core 354, a rear magnetic circuit support arm 358, and a rear support arm base 359. The magnetic circuit base 351 and the rear support arm base 359 are fixed ends, with the rear support arm base 359 fixed to the outside of the sealed chamber 33. The first end (rear end) of the front magnetic circuit support arm 352 is connected to the magnetic circuit base 351 via a rotating shaft, and its second end (front end) is connected to the magnetic circuit support wheel 353 and one end of the iron core 354 via the same rotating shaft. The other end of the iron core 354 is connected to the second end (front end) of the rear magnetic circuit support arm 358 via a rotating shaft, and the first end (rear end) of the rear magnetic circuit support arm 358 is then connected to the rear support arm base 359 via a rotating shaft. Figure 8 and Figure 9As shown, the lines connecting the front support arm 352 and the rear support arm 358 of the magnetic circuit, the iron core 354, and the magnetic circuit base 351 and the rear support arm base 359 form a parallelogram (for example, the line connecting points C1 and C2 is parallel to and of equal length to the line connecting points D1 and D2). When the magnetic circuit support wheel 353 is radially compressed by the inner wall of the pipe, the entire parallelogram structure can deform, but the iron core 354 (i.e., the magnetic circuit core) always remains parallel to the axis of the detection device. Permanent magnets 355 and magnetic guide plates 356 are respectively provided at both ends of the iron core 354. The magnetic guide plates 356 face the pipe wall, their purpose being to form a magnetic circuit with the pipe wall. A stable magnetization gap is maintained between the magnetic guide plates 356 and the inner wall of the pipe. This gap is smaller than the protrusion height H2 of the magnetic circuit support wheel 353 (for example, approximately 1-2 mm), so as to maintain effective magnetization while providing rolling support. A detection probe assembly 357 is located at the center of the iron core 354 to detect magnetic leakage signals caused by pipe wall defects. This parallelogram structure ensures that the magnetic circuit can adaptively compress or rebound when the pipe diameter changes or when there are weld protrusions, while maintaining the optimal detection posture between the detection probe assembly 357 and the pipe wall defects, thereby greatly improving the consistency and stability of the magnetic leakage detection signal.

[0046] In some embodiments, the single magnetic circuit 35 further includes a spring rod 350 and a magnetic circuit spring 35a; the first end of the magnetic circuit front support arm 352 is connected to the magnetic circuit base 351 by a spring rod 350, the magnetic circuit spring 35a is sleeved on the outside of the spring rod 350, and the two ends of the spring rod 350 are provided with rod stops 35b for pressing and fixing the magnetic circuit spring 35a.

[0047] It should be understood that, such as Figures 9-12 As shown, the single magnetic circuit 35 also includes a spring rod 350 and a magnetic circuit spring 35a. A spring rod 350 connects the first end (rear end) of the magnetic circuit front support arm 352 to the magnetic circuit base 351. The magnetic circuit spring 35a is sleeved on the outside of the spring rod 350, and both ends of the spring rod 350 are provided with rod stops 35b for pressing and fixing the magnetic circuit spring 35a. This structure has a dual function: firstly, the magnetic circuit spring 35a provides a continuous outward elastic support force, allowing the single magnetic circuit 35 to automatically rebound after being compressed by the inner wall of the pipe, thereby always maintaining effective contact and appropriate clamping force between the magnetic circuit support wheel 353 and the magnetic guide plate 356 and the inner wall of the pipe. Secondly, the spring rod 350 itself constitutes a physical limiting structure for the swing amplitude of the front support arm 352 of the magnetic circuit. Combined with the damping effect of the magnetic circuit spring 35a, it helps to improve the motion stability of the single magnetic circuit 35 when subjected to severe radial compression or vibration, and prevents it from generating excessive and harmful swing, thereby ensuring continuous and stable rolling contact between the magnetic circuit support wheel 353 and the inner wall of the pipe.

[0048] In some embodiments, a first pull rod baffle 350a and a second pull rod baffle 350b are respectively provided on both sides of the spring pull rod 350; in two adjacent single magnetic circuits 35 in the circumferential direction, the first pull rod baffle 350a of one single magnetic circuit 35 and the second pull rod baffle 350b of the adjacent single magnetic circuit 35 are staggered, and the second pull rod baffle 350b is located in the gap of the first pull rod baffle 350a.

[0049] It should be noted that a significant improvement in this application lies in the linkage mechanism between magnetic circuits. For example... Figure 11 and Figure 12 As shown, a first pull rod baffle 350a and a second pull rod baffle 350b are respectively provided on both sides of the spring pull rod 350. In two adjacent single magnetic circuits 35 in the circumferential direction, the first pull rod baffle 350a of one single magnetic circuit 35 and the second pull rod baffle 350b of the adjacent single magnetic circuit 35 are staggered. Specifically, the second pull rod baffle 350b is located in the gap of the first pull rod baffle 350a. When a single magnetic circuit 35 is squeezed by the inner wall of the pipe, its spring pull rod 350 moves forward (towards the central axis of the sealed chamber 33), and the baffle on its side pushes the baffle of the adjacent single magnetic circuit 35, thereby driving the adjacent single magnetic circuit 35 to compress together. This "linked compression" structure allows the magnetic circuit springs 35a of all single magnetic circuits 35 to jointly bear the supporting force of the magnetized section 3 (whose weight is mainly made of metal and is relatively heavy), effectively avoiding the support failure problem caused by insufficient stiffness of a single spring or uneven force. Simultaneously, it improves the uniformity of force distribution in each individual magnetic circuit 35, enhancing the overall support stability of the magnetized section 3 and its adaptability to the tube wall. This structure can also be deformed, such as... Figure 10 and Figure 11 As shown, by removing the second pull rod baffle 350b on the spring pull rod 350 of a portion of the single magnetic circuit 35, all single magnetic circuits 35 can be divided into several groups (such as 3, 4, or 5 linked magnetic circuit groups). After grouping, when the detector passes through a pipe with local deformation (such as weld bulge), only the magnetic circuit group in contact with the deformation undergoes linked compression, while the other magnetic circuit groups maintain their normal support posture. This "grouped linkage" structure significantly improves the detector's ability to pass through locally deformed pipes without sacrificing overall support force.

[0050] In some embodiments, the magnetized section 3 further includes a junction box assembly 36, a mileage wheel 37, and a switch cover 38a; the junction box assembly 36 is disposed on the outer side of the tail of the sealed compartment 33 and fixed to the mileage wheel flange 39; at least three mileage wheels 37 are evenly arranged circumferentially on the mileage wheel flange 39; the switch cover 38a is fixed to the rear compartment cover 38 by a threaded connection.

[0051] It should be understood that the magnetized section 3 also includes a junction box assembly 36, a mileage wheel 37, and a switch cover 38a. The junction box assembly 36 is located on the outer side of the rear of the sealed chamber 33 and is fixed to the mileage wheel flange 39. Its function is to centrally collect, organize, and protect the signal lines led out from the detection probe groups 357 of each single magnetic circuit 35, improving the regularity and reliability of the wiring layout. At least three mileage wheels 37 are evenly arranged circumferentially on the mileage wheel flange 39. The mileage wheels 37 also contact the inner wall of the pipe in a rolling manner. During the movement of the detection device, the travel and position information of the device can be accurately obtained by recording the number of rotations, which is crucial for defect location. The switch cover 38a is fixed to the rear cover 38 by a threaded connection. This design allows operators to open or close the sealed chamber 33 without damaging the main structure, thereby facilitating the installation, replacement, or maintenance of electronic components such as batteries, data storage units, and control circuits inside the sealed chamber 33.

[0052] As can be seen from the above technical solutions, the embodiments of this application provide a roller-type low-resistance pipeline magnetic flux leakage internal detection device, including: a drive joint 1, a universal joint 2, a magnetized joint 3, and an anti-collision head 4; the drive joint 1, universal joint 2, magnetized joint 3, and anti-collision head 4 are arranged coaxially; the anti-collision head 4 is disposed at the front end of the drive joint 1; the drive joint 1 and the magnetized joint 3, as well as multiple drive joints 1, are connected by a universal joint 2; multiple cup rollers 143 are evenly arranged on the outer edge of the sealing cup 14 of the drive joint 1; the cup rollers 143 contact the inner wall of the pipeline to form rolling friction; the magnetized joint 3 includes a sealed chamber 33 and multiple single magnetic circuits 35; the multiple single magnetic circuits 35 are evenly arranged circumferentially on the outer side of the sealed chamber 33, each single magnetic circuit 35 includes a magnetic circuit support wheel 353, and the magnetized joint 3 contacts the inner wall of the pipeline through the magnetic circuit support wheel 353 to form rolling friction, so as to solve the problem that high-precision magnetic flux leakage internal detection technology cannot be used in low-pressure, low-flow-rate pipelines.

[0053] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A roller-type low-resistance pipeline magnetic flux leakage detection device, characterized in that, include: Drive joint (1), universal joint (2), magnetized joint (3) and anti-collision head (4); The drive joint (1), the universal joint (2), the magnetized joint (3) and the anti-collision head (4) are arranged coaxially; the anti-collision head (4) is located at the front end of the drive joint (1); the drive joint (1) and the magnetized joint (3), as well as multiple drive joints (1), are connected by the universal joint (2); The sealing cup (14) of the drive section (1) is provided with a plurality of cup rollers (143) evenly arranged on the outer edge; the cup rollers (143) contact the inner wall of the pipe to form rolling friction; The magnetized section (3) includes a sealed chamber (33) and multiple single magnetic circuits (35); the multiple single magnetic circuits (35) are evenly arranged circumferentially on the outside of the sealed chamber (33), and each single magnetic circuit (35) includes a magnetic circuit support wheel (353). The magnetized section (3) contacts the inner wall of the pipe through the magnetic circuit support wheel (353) to form rolling friction.

2. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 1, characterized in that, The drive section (1) has a drive section frame (13) coaxially provided with a drive section front connecting flange (11) and a drive section rear connecting flange (12). The sealing cup (14) is sleeved on the drive joint frame (13). One side of the sealing cup (14) is supported by the drive joint frame (13), and the other side of the sealing cup (14) is pressed and fixed by the cup flange (15). The cup flange (15) and the drive joint frame (13) are connected by fasteners.

3. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 2, characterized in that, A cylindrical protrusion is provided on the front connecting flange (11) of the drive section, the rear connecting flange (12) of the drive section, the front cover (31) and the rear cover (38) of the magnetized section (3). A pin hole is provided on the cylindrical protrusion, and the center line of the pin hole intersects with the axis of the cylindrical protrusion. The universal joint (2) includes a universal joint connecting block (21), which is sleeved with the cylindrical protrusion through the pin hole, and is fixedly connected to the universal joint connecting block (21) and the pin hole through a threaded shaft (22).

4. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 1, characterized in that, The sealing cup (14) also includes a roller bracket (141), a roller shaft (142), and an auxiliary sealing plate (144). The leather cup roller (143) is mounted on the roller bracket (141) via the roller shaft (142); The roller bracket (141) consists of two bracket pieces, which are fixed in the groove on the outer edge of the sealing cup (14) by clamping. The auxiliary sealing plate (144) is fixed to the side of the cup roller (143) away from the direction of travel, and the surface of the auxiliary sealing plate (144) is higher than the surface of the cup roller (143).

5. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 3, characterized in that, The universal joint (2) also includes a chain pin (23), a chain (24) and a polyurethane elastomer (25); The two ends of the ring chain (24) are connected to the universal joint connecting block (21) through the ring chain pin (23); the polyurethane elastomer (25) is disposed on the inner circumference of the ring chain (24) to fill the space between the links of the ring chain (24); the universal joint connecting block (21) is connected to the drive joint (1) or the magnetized joint (3) through the threaded shaft (22).

6. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 3, characterized in that, The magnetization section (3) also includes a fixed flange (32), a base fixing ring (34), and a mileage wheel flange (39). The front hatch (31) and the fixed flange (32) are coaxially arranged at one end of the sealed chamber (33), and the rear hatch (38) and the odometer wheel flange (39) are coaxially arranged at the other end of the sealed chamber (33). The single magnetic circuits (35) are evenly arranged around the sealed chamber (33) on the fixed flange (32), and the base fixing ring (34) is connected to the magnetic circuit base (351) of all the single magnetic circuits (35).

7. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 1, characterized in that, The single magnetic circuit (35) is a parallelogram linkage structure, including a magnetic circuit base (351), a magnetic circuit front support arm (352), an iron core (354), a magnetic circuit rear support arm (358), and a rear support arm base (359). The magnetic circuit base (351) and the rear support arm base (359) are fixed ends, and the rear support arm base (359) is fixed to the outside of the sealed chamber (33); The first end of the front support arm (352) of the magnetic circuit is connected to the magnetic circuit base (351) via a rotating shaft, and the second end of the front support arm (352) of the magnetic circuit is connected to the magnetic circuit support wheel (353) and the iron core (354) via a rotating shaft. The iron core (354) is provided with a permanent magnet (355) and a magnetic sheet (356) at both ends, and a detection probe group (357) is provided at the center of the iron core (354). The first end of the magnetic circuit rear support arm (358) is connected to the rear support arm base (359) via a rotating shaft, and the second end of the magnetic circuit rear support arm (358) is connected to the magnetic circuit support wheel (353) and the iron core (354) via a rotating shaft.

8. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 7, characterized in that, The single magnetic circuit (35) also includes a spring rod (350) and a magnetic circuit spring (35a). The first end of the magnetic circuit front support arm (352) is connected to the magnetic circuit base (351) by the spring rod (350), the magnetic circuit spring (35a) is sleeved on the outside of the spring rod (350), and the two ends of the spring rod (350) are provided with rod stops (35b) for pressing and fixing the magnetic circuit spring (35a).

9. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 8, characterized in that, The spring rod (350) is provided with a first rod baffle (350a) and a second rod baffle (350b) on both sides respectively. In two adjacent single magnetic circuits (35) in the circumferential direction, the first pull rod baffle (350a) of one single magnetic circuit (35) and the second pull rod baffle (350b) of the adjacent single magnetic circuit (35) are staggered, and the second pull rod baffle (350b) is located in the gap of the first pull rod baffle (350a).

10. The roller-type low-resistance pipeline magnetic flux leakage internal detection device according to claim 6, characterized in that, The magnetization section (3) also includes a junction box assembly (36), a mileage wheel (37), and a switch cover (38a). The junction box assembly (36) is located on the outer side of the rear of the sealed chamber (33) and fixed to the mileage wheel flange (39); At least three of the odometer wheels (37) are circumferentially evenly arranged on the odometer wheel flange (39); The switch cover (38a) is fixed to the rear hatch cover (38) by a threaded connection.

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