Anti-adsorption mechanism and steel pipe longitudinal defect magnetic flux leakage detection equipment

Abstract

The present invention discloses an anti-adsorption mechanism, comprising a fixed plate, a special-shaped mounting plate, a connecting strip, a roller, and a driving mechanism. The fixed plate has a through hole in its center, the middle of the special-shaped mounting plate is hinged on the fixed plate, and one end of the first special-shaped mounting plate is movably connected to the driving mechanism; the front special-shaped mounting plate is movably connected to the rear special-shaped mounting plate via a connecting strip, and the roller can be mounted on the special-shaped mounting plate in a rolling manner; the rotation axes of all rollers are always on the same circle, the central axis of the circle coincides with the central axis of the steel pipe, and when the roller supports the steel pipe, the roller is tangent to the steel pipe. The present invention also provides a steel pipe longitudinal defect leakage magnetic detection device using the anti-adsorption mechanism. The present invention has the following beneficial effects: simple structure, reliable and rapid operation, ensuring that all longitudinal probe arrays are reliably attached to the outer surface of the steel pipe being tested, overcoming the adsorption effect of the magnetized pole shoes on the two ends of the steel pipe, and improving the reliability and stability of the entire machine.

Description

Technical Field

[0001] The present invention relates to a mechanism used in longitudinal magnetic flux leakage detection of steel pipes, in particular to an anti-adsorption mechanism and equipment for longitudinal defect magnetic flux leakage detection of small-diameter steel pipes. Background Art

[0002] In the rotating device for longitudinal magnetic flux leakage detection of steel pipes, a pair of symmetrical magnetized pole shoes are installed to gather a strong DC magnetic field. While rotating around the steel pipe at high speed, the steel pipe is fully magnetized circumferentially. The strong DC magnetic field excites defect signals on the inner and outer surfaces and inside of the steel pipe to detect whether there are defects inside the steel pipe.

[0003] The powerful DC magnetic field within the rotating device strongly attracts and agitates the passing steel pipes. Therefore, based on the principle that two points define a straight line, at least two clamping and positioning mechanisms are appropriately positioned at each end of the rotating device for longitudinal magnetic flux leakage detection of steel pipes. These clamps, position, and drive the steel pipes as they pass back and forth at high speed, ensuring they pass smoothly and quickly along their axes and preventing them from being attracted by the powerful DC magnetic field. However, due to the flexibility of steel pipes, especially small-diameter steel pipes, and the release and opening of the two clamping and positioning mechanisms at the front end of the rotating device for longitudinal magnetic flux leakage detection of steel pipes, the tail end of the steel pipe is often attracted by or rubs against the magnetized pole piece, causing serious interference, extending the detection blind zone, and damaging the pole piece and the longitudinal array probe.

[0004] At present, the domestic steel pipe longitudinal magnetic leakage detection rotating device adopts Figure 1-1 The magnetizer shown here circumferentially magnetizes steel pipes by symmetrically mounting two coils on the upper and lower inner sides of a circular magnetic circuit and passing a DC current through them. This creates a steady magnetic field, which passes through a pair of symmetrical magnetized pole pieces connected to the ring and passing through the coils, completing the magnetic circuit with the ring. These pole pieces rotate at high speed around the steel pipe, generating a powerful magnetic field that generates signals of defects on the pipe's interior, exterior, and interior, thereby detecting defects within the pipe.

[0005] However, due to the certain flexibility of small-diameter steel pipes, and after the two clamping and positioning mechanisms at the front end of the steel pipe longitudinal magnetic leakage detection rotating device are released and opened, the tail end of the steel pipe is often adsorbed by or rubbed against the magnetized pole shoe, causing serious interference; the detection blind area is lengthened and the magnetized pole shoe is easily damaged; at the same time, a pair of symmetrical longitudinal defect detection array probes distributed in an orthogonal position to a pair of symmetrical magnetized pole shoes are also easily damaged by impact, resulting in a short probe life, high equipment use cost, poor detection reliability and stability, and it is difficult to meet international standard requirements in the long term.

[0006] At present, the American Tubscope company, OEM company and German Forste company also use Figure 1-1In the magnetizer shown, the tail end of the steel tube is always attracted by the magnetized pole shoe, causing serious interference.

[0007] Currently, there is no mechanism for clamping small diameter steel pipes to prevent the tail end of the steel pipe from always being attracted by the magnetized pole shoe.

[0008] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0009] The technical problem to be solved by the present invention is how to solve the problem of the probe being damaged by adsorption at the tail of the steel pipe in the existing magnetic flux leakage detection of longitudinal defects of small-diameter steel pipes.

[0010] The present invention solves the above technical problems through the following technical means:

[0011] The anti-adsorption mechanism includes a fixed plate, at least three special-shaped mounting plates, at least two connecting strips, at least three rollers, and a driving mechanism. The center of the fixed plate has a through hole through which a steel pipe passes. The middle part of the special-shaped mounting plate is hinged on the fixed plate. One end of the first special-shaped mounting plate is movably connected to the output end of the driving mechanism; the front special-shaped mounting plate and the rear special-shaped mounting plate are movably connected through the connecting strip, and the rollers can be rotatably mounted on the special-shaped mounting plates; the rotation axes of all the rollers are always on the same circle, the central axis of the circle coincides with the central axis of the steel pipe, and when the rollers support the steel pipe, the rollers are tangent to the outer surface of the steel pipe.

[0012] The present invention drives the special-shaped mounting plate and the connecting strip in linkage through a driving mechanism, so that the roller can move inward and away at the same time, so that it can concentrically clamp and position steel pipes of different specifications. The structure is simple, the action is reliable and rapid, and all longitudinal probe arrays are ensured to be reliably attached to the outer surface of the steel pipe to be inspected, thereby achieving reliable inspection of the steel pipe. The invention can overcome the adsorption effect of the magnetized pole shoes on the two ends of the steel pipe, and ensure that the steel pipe always passes through the longitudinal defect leakage magnetic detection equipment along its axis, thereby creating good inspection conditions for the inspection equipment, thereby greatly improving the reliability and stability of the whole machine in years of operation and inspection.

[0013] Preferably, the fixing plate is a metal circular plate, and the central axis of the through hole in the middle coincides with the central axis of the metal circular plate.

[0014] Preferably, the special-shaped mounting plate has a V-shaped structure, with the V-shaped opening facing away from the center of the fixed plate, the middle part of the V-shape being rotatably connected to the fixed plate via a pin, and both ends being rotatably connected to the driving mechanism or connecting bar via a pin.

[0015] Preferably, the connecting strip is an arc-shaped strip structure, and the arc-shaped opening faces the center of the fixing plate.

[0016] Preferably, there are three special-shaped mounting plates, including a first special-shaped mounting plate, a second special-shaped mounting plate, and a third special-shaped mounting plate, and there are two connecting strips, including a first connecting strip and a second connecting strip. One end of the first special-shaped mounting plate is rotatably connected to the driving mechanism, and the other end is rotatably connected to one end of the first connecting strip. The other end of the first connecting strip is rotatably connected to one end of the second special-shaped mounting plate. The other end of the second special-shaped mounting plate is rotatably connected to one end of the second connecting strip. The other end of the second connecting strip is rotatably connected to one end of the third special-shaped mounting plate.

[0017] Preferably, the special-shaped mounting plate is provided with a U-shaped handle, and the roller is installed in the U-shaped handle via a pin.

[0018] Preferably, the roller is a symmetrical structure with a cylinder in the middle and cones on both sides, and the cylindrical surface of the cylinder is tangent to the outer surface of the steel pipe.

[0019] The roller in the present invention adopts an olive-shaped structure, and the inclined part can automatically guide the eccentric steel pipe end to return to its axial position; the narrow cylindrical surface can reduce the contact area between the middle part of the roller and the passing steel pipe, so the friction is small. The three clamping rollers can not only reliably clamp and position the steel pipe, but also reduce wear, which is particularly suitable for long-term, uninterrupted and continuous operation of the equipment; it reduces the use cost of the leakage magnetic detection equipment and improves the operating efficiency.

[0020] Preferably, the driving mechanism includes a fixing seat, a screw, a spring, a cylinder, a connecting rod, and a nut; one end of the connecting rod extends into the cylinder, the nut is sleeved on the connecting rod and is threadedly connected to one end of the cylinder, the end of the connecting rod entering the cylinder is limited to one end of the nut, and the other end of the nut extends out of the cylinder, the end of the connecting rod away from the cylinder is rotatably connected to one end of the first special-shaped mounting plate, the fixing seat is fixedly arranged, the screw can be rotatably connected to the fixing seat, the end of the screw away from the cylinder is limited to one side of the fixing seat, and the side of the screw extending out of the fixing seat is connected to the other end of the cylinder, the spring and the connecting rod are arranged parallel to each other, the spring is compressed, the two ends of the spring respectively abut the inner end face of the cylinder and one end face of the connecting rod, and the part of the screw extending into the cylinder extends into the inner ring of the spring.

[0021] The present invention can realize the pulling or pushing of the cylinder by rotating the screw under the limit of the fixed seat, thereby pulling the connecting rod, and the connecting rod pulls the special-shaped mounting plate and the connecting plate to realize the simultaneous opening and closing of the roller.

[0022] Preferably, the cylinder is a cylindrical structure with threads at both ends, the inner wall of the cylinder is provided with a slide groove, the nut is a sleeve-type structure, the outer surface of the nut is connected to the thread of the sleeve, the inner surface of the nut is gap-connected with the connecting rod, the other end of the nut is limited outside the cylinder, and the connecting rod has a slider slidably connected to the slide groove.

[0023] In the present invention, the degree to which the spring is compressed can be determined by screwing the nut against one end of the connecting rod, and the magnitude of the three-roller centering clamping force is determined by the elastic force of the spring and the degree of compression of the nut, ensuring that the three-roller centering clamping force is always greater than the adsorption force of the magnetized pole shoe on the end of the steel pipe; the connecting rod is provided with a slider that is slidably connected to the slide groove in the cylinder, which can reduce the friction force of the connecting rod sliding when the nut compresses or loosens the spring.

[0024] The present invention also discloses a magnetic flux leakage detection device for longitudinal defects in steel pipes, comprising a rotating ring, a magnetizer, a longitudinal magnetizing pole shoe, an anti-adsorption mechanism, a magnetic sensor clamping mechanism, and a plurality of clamping and positioning mechanisms; the central axis of the steel pipe coincides with the central axis of the rotating ring, the magnetizer is symmetrically installed on the inner surface of the rotating ring along the horizontal orthogonal plane of the steel pipe, the longitudinal magnetizing pole shoe is symmetrically installed on the surface of the magnetizer close to the steel pipe along the horizontal orthogonal plane of the steel pipe, and the magnetizer and the longitudinal magnetizing pole shoe are symmetrical along the vertical orthogonal plane of the steel pipe, one end of the magnetic sensor clamping mechanism is fixed on the rotating ring, and the other end is installed with a magnetic sensor array, and the magnetic sensor array is aligned with the steel pipe. The tube is tangent, and the center line of the magnetic sensor array always coincides with the horizontal orthogonal plane of the steel pipe. It is characterized in that the anti-adsorption mechanism is the above-mentioned anti-adsorption mechanism, and the rotating ring is provided with a flange. The fixed plate of the anti-adsorption mechanism is fixedly installed on the flange. The centerline axial direction of the anti-adsorption mechanism coincides with the central axis of the rotating ring. The steel pipe passes through the anti-adsorption mechanism, and the central axis of the steel pipe coincides with the central axis of the anti-adsorption mechanism. The multiple clamping and positioning mechanisms are spaced apart and located on both sides of the rotating ring. The clamping and positioning mechanism abuts against the surface of the steel pipe. The steel pipe passes through the clamping and positioning mechanism, the longitudinal magnetization pole shoe, the anti-adsorption mechanism, and the clamping and positioning mechanism in sequence.

[0025] In the present invention, when the entry end of a steel pipe passes through a pair of longitudinally magnetized pole shoes within a magnetic flux leakage detection rotating device, the pipe is attracted by the smaller longitudinally magnetized pole shoes, as the spacing between the pipe and the two longitudinally magnetized pole shoes is not completely equal. However, the force arm of this attraction is small, and the pipe end deviates less from the axis. As the pipe passes through the pair of longitudinally magnetized pole shoes, it immediately encounters the inclined surfaces of three rollers and slides along the inclined surfaces into the clamping center of the three rollers. The clamping force of the three rollers overcomes the attractive force of the magnetized pole shoes, ensuring that the pipe continues to advance along its axis. The pipe then continues to advance along its axis, while the three rollers, constantly subject to the rotation of the magnetic flux leakage detection rotating device, rotate along the pipe surface while also being driven by the pipe's forward force, forming three interlaced, densely packed spiral tracks on the pipe's outer surface. This constantly overcomes the attractive force of the magnetized pole shoes, ensuring that the pipe continues to advance along its axis.

[0026] When the tail end of the steel pipe is disengaged from the steel pipe clamping and positioning mechanism at the inlet end of the leakage magnetic detection rotating device, since the distance between the tail end of the steel pipe and the two magnetized pole shoes cannot be completely equal, it is attracted by the magnetized pole shoes with a smaller gap. In particular, the force arm of this attraction (the distance between the magnetized pole shoes and the first set of steel pipe clamping and positioning mechanisms at the outlet end of the rotating detection device) is large, which will cause the end of the steel pipe to deviate seriously from the axis and be adsorbed by the magnetized pole shoes, or the steel pipe will sweep over the magnetized pole shoes. The present invention uses the clamping effect of the three rollers to overcome the attraction of the magnetized pole shoes by the clamping force of the three rollers, thereby ensuring that the steel pipe continues to move along its axis.

[0027] When the steel pipe moves backward and passes through the magnetic flux leakage detection rotating device (the backward process does not belong to the detection process of the equipment), the clamping and anti-adsorption mechanism in the longitudinal defect magnetic flux leakage detection of the present invention can overcome the attraction of the magnetized pole shoe and ensure that the steel pipe passes through the equipment stably along the axis.

[0028] The advantages of the present invention are:

[0029] (1) The present invention drives the special-shaped mounting plate and the connecting strip in linkage through a driving mechanism, so that the roller can move inward and away at the same time, so that it can concentrically clamp and position steel pipes of different specifications. It has a simple structure, reliable and rapid operation, and ensures that all longitudinal probe arrays are reliably attached to the outer surface of the steel pipe to be tested, thereby achieving reliable detection of the steel pipe. It can overcome the adsorption effect of the magnetized pole shoes on the two ends of the steel pipe, and ensure that the steel pipe always passes through the longitudinal defect leakage magnetic detection equipment along its axis, creating good detection conditions for the detection equipment, thereby greatly improving the reliability and stability of the whole machine in years of operation and detection;

[0030] (2) The roller of the present invention adopts an olive-shaped structure, and the inclined surface can automatically guide the eccentric steel pipe end to return to its axial position; the narrow cylindrical surface can make the contact area between the middle part of the roller and the steel pipe passing through small, so the friction is small. The three clamping rollers can not only reliably clamp and position the steel pipe, but also reduce wear, which is particularly suitable for long-term, uninterrupted and continuous operation of the equipment; it reduces the use cost of the leakage magnetic detection equipment and improves the operating efficiency;

[0031] (3) The present invention can achieve the pulling or pushing of the cylinder by rotating the screw under the limit of the fixed seat, thereby pulling the connecting rod, and the connecting rod pulls the special-shaped mounting plate and the connecting plate to achieve the simultaneous opening and closing of the roller;

[0032] (4) In the present invention, the degree of compression of the spring can be determined by screwing the nut against one end of the connecting rod, and the magnitude of the three-roller centering clamping force is determined by the elastic force of the spring and the degree of compression of the nut, ensuring that the three-roller centering clamping force is always greater than the adsorption force of the magnetized pole shoe on the end of the steel pipe; the connecting rod is provided with a slider that is slidably connected to the slide groove in the cylinder, which can reduce the friction force of the connecting rod sliding when the nut compresses or loosens the spring;

[0033] (5) By adopting the anti-adsorption mechanism of the present invention, there will be no interference signal from the two ends of the steel pipe to the probe during the longitudinal defect leakage magnetic flux detection, thereby improving the key technical indicators such as the signal-to-noise ratio and detection sensitivity of the whole machine detection, and meeting and exceeding the technical requirements of the international standard: SN EN ISO 10893-3-2011 "Automated seamless full-circumference magnetic flux leakage detection and longitudinal and / or transverse defect detection of welded (except submerged arc welding) ferromagnetic steel pipes". BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of an anti-adsorption mechanism according to a first embodiment of the present invention;

[0035] Figure 1-1 It is a structural diagram of an existing magnetizer;

[0036] Figure 2 yes Figure 1 A vertical cross-sectional view of

[0037] Figure 3 is a schematic diagram of the fixed plate structure;

[0038] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0039] Figure 5 is a structural schematic diagram of a first special-shaped mounting plate;

[0040] Figure 6 yes Figure 5 Side view of;

[0041] Figure 7 It is a structural diagram of the roller;

[0042] Figure 8 is a cross-sectional view of the anti-adsorption mechanism of Example 2;

[0043] Figure 9 is a cross-sectional view of the drive mechanism;

[0044] Figure 10 This is a schematic diagram of the roller moving away from the steel pipe;

[0045] Figure 11 This is a schematic diagram of the structure of the magnetic flux leakage detection equipment for longitudinal defects in steel pipes;

[0046] Figure 12 This is a schematic diagram of the structure of a magnetic flux leakage detection device for longitudinal defects in steel pipes with a magnetic sensor clamping mechanism;

[0047] Figure 13 It is a schematic diagram of the clamping and positioning mechanism;

[0048] Figure 14 It is a structural diagram of a steel pipe longitudinal defect magnetic flux leakage detection device with a clamping and positioning mechanism.

[0049] Reference numerals in the figure: anti-adsorption mechanism 100, fixing plate 110, through hole 111, mounting hole 112, connecting hole 113, special-shaped mounting plate 120, first connecting hole 121, second connecting hole 122, rotating hole 123, U-shaped handle 124, roller shaft 125, nut 126, first special-shaped mounting plate 120A, second special-shaped mounting plate 120B, third special-shaped mounting plate 120C, connecting bar 130, first special-shaped mounting plate 120A, second special-shaped mounting plate 120B, third special-shaped mounting plate 120C, connecting bar 130, first special-shaped mounting plate 120B, second special-shaped mounting plate 120C, connecting bar 130, first special-shaped mounting plate 120A, second special-shaped mounting plate 120B, third ... A connecting bar 130A, a second connecting bar 130B, a roller 140, a driving mechanism 150, a fixing seat 151, a screw 152, a spring 153, a cylinder 154, a connecting rod 155, a nut 156, a slide 157, a slider 158, a steel pipe 200, a rotating ring 300, a flange 310, a magnetizer 400, a longitudinally magnetized pole shoe 500, a clamping and positioning mechanism 600, and a magnetic sensor clamping mechanism 700. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] Example 1:

[0052] like Figure 1 、 Figure 2As shown, the anti-adsorption mechanism 100 includes a fixed plate 110, at least three special-shaped mounting plates 120, at least two connecting bars 130, at least three rollers 140, and a driving mechanism 150; the fixed plate 110 has a through hole 111 in the center for the steel pipe to pass through, the middle part of the special-shaped mounting plate 120 is hinged to the fixed plate 110 by a pin, and one end of the first special-shaped mounting plate 120A is movably connected to the output end of the driving mechanism 150; the previous special-shaped mounting plate 120 is movably connected to the next special-shaped mounting plate 120 by the connecting bar 130, and the roller 140 can be rotatably installed on the special-shaped mounting plate 120; the rotation axes of all rollers 140 are always on the same circle, the central axis of the circle coincides with the central axis of the steel pipe 200, and when the roller 140 supports the steel pipe 200, the roller 140 is tangent to the steel pipe 200.

[0053] like Figure 3 As shown, the fixing plate 110 is a metal circular plate, the central axis of the through hole 111 in the middle coincides with the central axis of the metal circular plate, and the through hole 111 in the middle is plum blossom-shaped, which is a symmetrical structure; the fixing plate 110 has multiple mounting holes 112 for hinged connection, and connecting holes 113 for fixing the fixing plate 110 on the flange 310, and there are 6 connecting holes 113, which are evenly distributed.

[0054] like Figure 1 、 Figure 5 、 Figure 6 As shown, the special-shaped mounting plate 120 has a V-shaped structure, with the V-shaped opening facing away from the center of the fixed plate 110. The middle of the V is rotatably connected to the fixed plate 110 via a pin, and the two ends are rotatably connected to the drive mechanism 150 or the connecting bar 130 via pins. The connecting bar 130 is an arc-shaped strip structure with the arc-shaped opening facing the center of the fixed plate 110.

[0055] In this embodiment, there are three special-shaped mounting plates 120, including a first special-shaped mounting plate 120A, a second special-shaped mounting plate 120B, and a third special-shaped mounting plate 120C. There are two connecting bars 130, including a first connecting bar 130A and a second connecting bar 130B. One end of the first special-shaped mounting plate 120A is rotatably connected to the driving mechanism 150, and the other end is rotatably connected to one end of the first connecting bar 130A. The other end of the first connecting bar 130A is rotatably connected to one end of the second special-shaped mounting plate 120B. The other end of the second special-shaped mounting plate 120B is rotatably connected to one end of the second connecting bar 130B. The other end of the second connecting bar 130B is rotatably connected to one end of the third special-shaped mounting plate 120C.

[0056] like Figure 3 , combined Figure 6As shown, the first special-shaped mounting plate 120A has a first connecting hole 121, a second connecting hole 122, and a rotating hole 123. The first connecting hole 121 away from the roller 140 is rotatably connected to the driving mechanism 150 through a pin shaft. The first connecting hole 121 is a sheet-like single-hole structure, and the corresponding output end of the driving mechanism 150 is a concave groove, and the concave groove has a through hole; the other end of the first special-shaped mounting plate 120A has a second connecting hole 122, and the second connecting hole 122 is rotatably connected to the first connecting bar 130A through a pin shaft. The second connecting hole 122 is a sheet-like single-hole structure, and correspondingly, the two ends of the first connecting bar 130A are concave grooves, and the concave groove has a through hole; the middle part of the first special-shaped mounting plate 120A, that is, the V-shaped inflection point, has a larger rotating hole 123, and the rotating hole 123 is rotatably connected to the fixed plate 110 through a pin shaft.

[0057] The first and second special-shaped mounting plates 120A and 120B have identical structures. The third special-shaped mounting plate 120C is not connected to the end of the second connecting bar 130B, so the corresponding part of the material is cut off for adaptive design.

[0058] Combine Figure 6 As shown, a U-shaped handle 124 is provided on the special-shaped mounting plate 120 between the second connecting hole 122 and the rotating hole 123, and the roller 140 is installed in the U-shaped handle 124 through a pin. Figure 7 Specifically, the left end of the U-shaped handle 124 is processed into a coaxial circular hole, and the roller shaft 125 is passed through the coaxial circular hole and then extended out. The two ends are tightened by nuts 126, and the roller 140 is installed through the roller bearing 27. The roller 140 can rotate arbitrarily around the roller shaft 125.

[0059] like Figure 6 As shown, the roller 140 is a symmetrical structure with a cylindrical center and conical sides. The cylindrical surface of the cylinder is tangent to the outer surface of the steel pipe 200. The roller 140 is designed to be olive-shaped, and the inclined surface can automatically guide the eccentric steel pipe end to return to its axial position and prevent the steel pipe end from damaging the roller 140, U-shaped handle 124, roller shaft 125, and nut 126. The narrow cylindrical surface can reduce the contact area between the center of the roller 140 and the passing steel pipe 200, thereby reducing friction. The three clamping rollers 140 can not only reliably clamp and position the steel pipe 200, but also reduce wear, making it particularly suitable for long-term, uninterrupted continuous operation of the equipment. This reduces the operating cost of the magnetic flux leakage detection equipment and improves operating efficiency.

[0060] In this embodiment, the rollers 140 are made of a highly wear-resistant alloy to ensure that they can hold the steel pipe passing through at high speed for a long time during the rotation process without being easily worn.

[0061] The present invention drives the special-shaped mounting plate 120 and the connecting strip 130 in linkage through the driving mechanism 150, so that the roller 140 can simultaneously move inwardly toward and away from the inside, so that it can concentrically clamp and position steel pipes of different specifications. It has a simple structure and reliable and rapid operation, ensuring that all longitudinal probe arrays are reliably attached to the outer surface of the steel pipe to be inspected, thereby achieving reliable inspection of the steel pipe 200. It can overcome the adsorption effect of the magnetized pole shoes on the two ends of the steel pipe, ensuring that the steel pipe always passes through the longitudinal defect leakage magnetic detection equipment along its axis, creating good inspection conditions for the inspection equipment, thereby greatly improving the reliability and stability of the entire machine in years of operation and inspection.

[0062] Example 2:

[0063] like Figure 8 As shown, based on the above embodiment 1, this embodiment specifically discloses the structure of the driving mechanism 150;

[0064] like Figure 9 As shown, the driving mechanism 150 includes a fixing seat 151, a screw 152, a spring 153, a cylinder 154, a connecting rod 155, and a nut 156; the left end of the connecting rod 155 extends into the cylinder 154, and the nut 156 is sleeved on the connecting rod 155 and is threadedly connected to the left end of the cylinder 154. The diameter of the leftmost end of the connecting rod 155 is larger than that of the right end. Therefore, its left end is limited to the left end of the nut 156, and the horizontal movement of the two banks 55 is achieved by screwing the nut 156. The cross-section of the nut 156 is T-shaped, and the right end of the nut 156 extends out of the cylinder 154. As shown in Figure 8, the right end of the connecting rod 155 is rotatably connected to the upper end of the first special-shaped mounting plate 120A; fixed The seat 151 is fixedly mounted on the fixed plate 110, and the screw 152 is gap-connected with the fixed seat 151, so the screw 152 can be rotatably connected to the fixed seat 151, and the left end of the screw 152 is limited to the left side of the fixed seat 151, and the right end of the screw 152 is connected to the left end of the cylinder 154. Therefore, by rotating the screw 152, the screw 152 and the cylinder 154 can realize the change of the length of the screw 152 extending into the cylinder 154 through threaded rotation; the spring 153 is arranged parallel to the connecting rod 155, and the spring 153 is compressed. The two ends of the spring 153 respectively abut the inner end surface of the cylinder 154 and the left end surface of the connecting rod 155, and the part of the screw 152 extending into the cylinder 154 extends into the inner circle of the spring 153.

[0065] Specifically, the cylinder 154 is a cylindrical structure with threads at both ends, and a slide groove 157 is provided on the inner wall of the cylinder 154. The nut 156 is a sleeve-type structure. The outer surface of the nut 156 is connected to the thread of the sleeve, and the inner surface of the nut 156 is gap-connected with the connecting rod 155. The connecting rod 155 has a slider 158 that is slidably connected to the slide groove 157; the slider 158 is slidably connected to the slide groove 157, which can reduce the friction of the connecting rod 155 when the nut 156 compresses or loosens the spring 153.

[0066] In this embodiment, by rotating the screw 152, under the limit of the fixing seat 151, the cylinder 154 can be pulled closer or pushed away, thereby pulling the connecting rod 155, and the connecting rod 155 pulls the special-shaped mounting plate 120 and the connecting bar 130 to realize the simultaneous opening and closing of the roller 140.

[0067] In this embodiment, the degree to which the spring 153 is compressed can be determined by screwing the nut 156 and then moving the left end of the connecting rod 155. The magnitude of the three-roller centering clamping force is determined by the elastic force of the spring 153 and the degree of compression of the nut 156, ensuring that the three-roller centering clamping force is always greater than the adsorption force of the magnetized pole shoe on the end of the steel pipe.

[0068] like Figure 10 As shown, when the screw 152 is rotated to make the cylinder 154 close to the fixing seat 151, the connecting rod 155 can simultaneously pull the roller 140 apart.

[0069] like Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 As shown, this embodiment also provides a steel pipe longitudinal defect magnetic flux leakage detection device, including a rotating ring 300, a magnetizer 400, a longitudinal magnetization pole shoe 500, four clamping and positioning mechanisms 600, two magnetic sensor clamping mechanisms 700, and an anti-adsorption mechanism 100;

[0070] The central axis of the steel pipe 200 coincides with the central axis of the rotating ring 300. The magnetizer 400 is symmetrically installed on the inner surface of the rotating ring 300 along the horizontal perpendicular plane of the steel pipe 200. The longitudinal magnetization pole shoe 500 is symmetrically installed on the surface of the magnetizer 400 close to the steel pipe 200 along the horizontal perpendicular plane of the steel pipe 200. The magnetizer 40 and the longitudinal magnetization pole shoe 500 are symmetrical along the vertical perpendicular plane of the steel pipe 200. The fixing plate 110 of the anti-adsorption mechanism 100 is fixedly installed on the flange 310. , and ensure that the anti-adsorption mechanism 100 is concentric with the flange 310 in the longitudinal magnetic flux leakage detection rotating device, the steel pipe 200 passes through the center of the anti-adsorption mechanism 100, and the central axis of the steel pipe 200 coincides with the central axis of the anti-adsorption mechanism 100; one end of the magnetic sensor clamping mechanism 700 is fixed to the rotating ring 300 and the other end is installed with the magnetic sensor array, the magnetic sensor array is tangent to the steel pipe 200, and the center line of the magnetic sensor array always coincides with the horizontal orthogonal plane of the steel pipe 200;

[0071] like Figure 14 As shown, the four clamping and positioning mechanisms 600 are spaced apart and located on both sides of the rotating ring 300. There is space in the middle of the four clamping and positioning mechanisms 600 for the steel pipe to pass through, ensuring that the steel pipe moves along the axis as much as possible. Among them, the first clamping and positioning mechanism 600A and the second clamping and positioning mechanism 600B are respectively located on the front side of the rotating ring 300, and the second clamping and positioning mechanism 600B is as close to the steel pipe as possible. The third clamping and positioning mechanism 600C and the fourth clamping and positioning mechanism 600D are located on the rear side of the rotating ring 300, and the third clamping and positioning mechanism 600C is closer to the steel pipe 200; therefore, the steel pipe 200 passes through the first clamping and positioning mechanism 600A, the second clamping and positioning mechanism 600B, the longitudinal magnetized pole shoe 500, the anti-adsorption mechanism 100, the third clamping and positioning mechanism 600C, and the fourth clamping and positioning mechanism 600D in sequence.

[0072] The clamping and positioning mechanism 600 only needs to be able to realize the clamping and positioning function of the steel pipe 200, and any existing one in the prior art may be selected.

[0073] Specifically, the clamping and positioning process is as follows:

[0074] S01: According to the outer diameter of the steel pipe being tested, the nut 156 on the screw rod 152 is adjusted to pull the cylinder 154 to the left or right. The connecting rod 155 drives the first, second, and third special-shaped mounting plates 120A, 120B, 120C to rotate around their respective central rotation axes, thereby driving the three rollers 140 to open and close along the center of the fixed plate 110, so that the three rollers can just clamp the outer wall of the steel pipe 200 of this specification.

[0075] S02: At the inlet end of the steel pipe longitudinal defect magnetic leakage detection equipment, a first clamping and positioning mechanism 600A and a second clamping and positioning mechanism 600B are set, wherein the second clamping and positioning mechanism 600B is as close to the inlet of the longitudinal magnetic leakage detection rotating device as possible. According to the principle that two points determine a straight line, they can clamp the steel pipe 200 and enter the inlet end of the rotating steel pipe longitudinal defect magnetic leakage detection equipment along the axis of the steel pipe 200, and coincide with the rotation center of the detection device. When the entry end of the steel pipe 200 passes through a pair of longitudinal magnetized pole shoes 500, since the distance between the steel pipe 200 and the two longitudinal magnetized pole shoes 500 cannot be completely equal, it is attracted by the longitudinal magnetized pole shoes 500 with a smaller gap. However, the force arm of this attraction (the force arm is the vertical distance between the longitudinal magnetized pole shoes 500 and the second set of steel pipe clamping and positioning mechanisms) is small, and the end of the steel pipe deviates less from the axis. After the entry end of the steel pipe passes through the pair of longitudinal pole shoes 500, it immediately hits the inclined surface of the three rollers 140 and slides along the inclined surface into the clamping center of the three rollers 140. The clamping force of the three rollers 140 overcomes the attraction of the longitudinal magnetized pole shoes 500, ensuring that the steel pipe 200 continues to move along its axis.

[0076] S03: Thereafter, the steel pipe 200 continues to move forward along its axis. The three rollers 140 are constantly subjected to the rotation of the longitudinal magnetic leakage detection rotating device. While rotating along the surface of the steel pipe 200, they are also driven by the forward force of the steel pipe 200, forming three densely interlaced spiral tracks on the outer surface of the steel pipe, and constantly overcoming the attraction of the longitudinal magnetized pole shoe 500, ensuring that the steel pipe 200 continues to move forward along its axis.

[0077] S04: A third clamping and positioning mechanism 600C and a fourth clamping and positioning mechanism 600D are installed at the exit of the steel pipe longitudinal defect magnetic flux leakage detection equipment. The third clamping and positioning mechanism 600C is positioned as close as possible to the exit of the steel pipe longitudinal defect magnetic flux leakage detection equipment. When the steel pipe's inlet reaches and passes through the third and fourth clamping and positioning mechanisms 600C and 600D at the exit of the detection rotary device, the steel pipe 200 is further clamped by the third and fourth clamping and positioning mechanisms and the three rollers 140, ensuring that the steel pipe 200 continues to advance along its axis.

[0078] S05: When the tail end of the steel pipe 200 is disengaged from the second clamping and positioning mechanism 600B at the inlet end of the leakage magnetic detection rotating device, since the distance between the tail end of the steel pipe 200 and the two longitudinal magnetized pole shoes 500 cannot be completely equal, it is attracted by the longitudinal magnetized pole shoes 500 with a smaller gap. In particular, the force arm of this attraction (the distance between the longitudinal magnetized pole shoe 500 and the first clamping and positioning mechanism 600A at the outlet end) is large, and the end of the steel pipe will seriously deviate from the axis, which may cause the longitudinal magnetized pole shoe 500 to be adsorbed or the steel pipe 200 to sweep over the longitudinal magnetized pole shoe 500. However, due to the clamping effect of the three rollers 140 of this embodiment, the clamping force of the three rollers 140 overcomes the attraction of the longitudinal magnetized pole shoe 500, ensuring that the steel pipe 200 continues to move along its axis.

[0079] S06: When the steel pipe 200 moves backward and passes through the steel pipe longitudinal defect leakage magnetic detection equipment (not part of the equipment's detection process), the clamping anti-adsorption mechanism can still ensure that the steel pipe passes along its axis to overcome the attraction of the longitudinal magnetized pole shoe 500.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. Steel pipe longitudinal defect magnetic flux leakage detection equipment, characterized by: The device comprises a rotating ring, a magnetizer, a longitudinal magnetizing pole shoe, an anti-adsorption mechanism, a magnetic sensor clamping mechanism, and multiple clamping and positioning mechanisms. The central axis of the steel pipe and the rotating ring coincide with each other. The magnetizer is symmetrically mounted on the inner surface of the rotating ring along the horizontal orthogonal plane of the steel pipe. The longitudinal magnetizing pole shoe is symmetrically mounted on the surface of the magnetizer close to the steel pipe along the horizontal orthogonal plane of the steel pipe. The magnetizer and the longitudinal magnetizing pole shoe are symmetrical along the vertical orthogonal plane of the steel pipe. One end of the magnetic sensor clamping mechanism is fixed to the rotating ring, and the other end is mounted with a magnetic sensor array. The magnetic sensor array is tangent to the steel pipe, and the centerline of the magnetic sensor array always coincides with the horizontal orthogonal plane of the steel pipe. The anti-adsorption mechanism includes a fixed plate, at least three special-shaped mounting plates, at least two connecting bars, at least three rollers, and a drive mechanism. The fixed plate has a through hole in the center through which the steel pipe passes. The middle of the special-shaped mounting plate is hinged to the fixed plate. One end of the first special-shaped mounting plate is movably connected to the output end of the drive mechanism. The front special-shaped mounting plate is movably connected to the rear special-shaped mounting plate by the connecting bar. The rollers are rotatably mounted on the special-shaped mounting plates. The rotation axes of all the rollers are always on the same circle. The central axis of the same circle coincides with the central axis of the steel pipe. When the rollers support the steel pipe, the rollers are tangent to the outer surface of the steel pipe. The roller is a symmetrical structure with a cylinder in the middle and cones on both sides. The cylindrical surface of the cylinder is tangent to the outer surface of the steel pipe. The center axis of each roller is parallel to the center axis of the steel pipe. The inclined surface of the roller automatically guides the eccentric steel pipe end to return to its axial position. A flange is provided inside the rotating ring, and a fixing plate of the anti-adsorption mechanism is fixedly installed on the flange. The central axis of the anti-adsorption mechanism coincides with the central axis of the rotating ring. The steel pipe passes through the anti-adsorption mechanism, and the central axis of the steel pipe coincides with the central axis of the anti-adsorption mechanism. A plurality of clamping and positioning mechanisms are spaced apart and located on both sides of the rotating ring. The clamping and positioning mechanisms abut against the surface of the steel pipe. The steel pipe passes through the clamping and positioning mechanism, the longitudinal magnetized pole shoe, the anti-adsorption mechanism, and the clamping and positioning mechanism in sequence. At the entrance end of the steel pipe longitudinal defect magnetic leakage detection equipment, a first clamping and positioning mechanism and a second clamping and positioning mechanism are set. When the entrance end of the steel pipe passes through a pair of longitudinally magnetized pole shoes, it immediately hits the inclined surface of the three rollers and slides along the inclined surface into the clamping center of the three rollers. The clamping force of the three rollers overcomes the attraction of the longitudinally magnetized pole shoes.

2. The steel pipe longitudinal defect magnetic flux leakage detection equipment according to claim 1, characterized in that: The fixing plate is a metal circular plate, and the central axis of the through hole in the middle coincides with the central axis of the metal circular plate.

3. The steel pipe longitudinal defect magnetic flux leakage detection equipment according to claim 1, characterized in that: The special-shaped mounting plate has a V-shaped structure, with the V-shaped opening facing away from the center of the fixed plate. The middle part of the V is connected to the fixed plate through a pin, and the two ends are connected to the driving mechanism or connecting bar through a pin.

4. The steel pipe longitudinal defect magnetic flux leakage detection equipment according to claim 1, characterized in that: The connecting strip is an arc-shaped strip structure, and the arc-shaped opening faces the center of the fixing plate.

5. The steel pipe longitudinal defect magnetic flux leakage detection equipment according to claim 1, characterized in that: There are three special-shaped mounting plates, including a first special-shaped mounting plate, a second special-shaped mounting plate, and a third special-shaped mounting plate. There are two connecting strips, including a first connecting strip and a second connecting strip. One end of the first special-shaped mounting plate is rotatably connected to the driving mechanism, and the other end is rotatably connected to one end of the first connecting strip. The other end of the first connecting strip is rotatably connected to one end of the second special-shaped mounting plate. The other end of the second special-shaped mounting plate is rotatably connected to one end of the second connecting strip. The other end of the second connecting strip is rotatably connected to one end of the third special-shaped mounting plate.

6. The steel pipe longitudinal defect magnetic flux leakage detection equipment according to claim 1, characterized in that: The special-shaped mounting plate is provided with a U-shaped handle, and the roller is mounted in the U-shaped handle through a pin shaft.

7. The magnetic flux leakage detection equipment for longitudinal defects of steel pipes according to claim 1, characterized in that: The driving mechanism includes a fixed seat, a screw, a spring, a cylinder, a connecting rod, and a nut; one end of the connecting rod extends into the cylinder, the nut is sleeved on the connecting rod and threadedly connected to one end of the cylinder, the end of the connecting rod entering the cylinder is limited to one end of the nut, and the other end of the nut extends out of the cylinder, the end of the connecting rod away from the cylinder is rotatably connected to one end of the first special-shaped mounting plate, the fixed seat is fixedly set, the screw can be rotatably connected to the fixed seat, the end of the screw away from the cylinder is limited to one side of the fixed seat, and the side of the screw extending out of the fixed seat is connected to the other end of the cylinder, the spring and the connecting rod are arranged parallel to each other, the spring is compressed, and the two ends of the spring respectively abut the inner end face of the cylinder and one end face of the connecting rod, and the part of the screw extending into the cylinder extends into the inner ring of the spring.

8. The magnetic flux leakage detection equipment for longitudinal defects of steel pipes according to claim 7, characterized in that: The cylinder is a cylindrical structure with threads at both ends. The inner wall of the cylinder is provided with a slide groove. The nut is a sleeve structure. The outer surface of the nut is connected to the thread of the sleeve, and the inner surface of the nut is gap-connected with the connecting rod. The other end of the nut is limited outside the cylinder, and the connecting rod has a slider that is slidably connected to the slide groove.

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