A magnetic leakage internal detection device for large deformation and high temperature pipelines

Abstract

The present invention relates to the field of electromagnetic nondestructive testing, and in particular to a magnetic flux leakage internal detection device for large deformation and high-temperature pipelines; the device comprises a chassis, a middle portion of which is arranged as a regular polygonal frame, a front end cover is arranged at one end of the regular polygonal frame, a rear end cover is arranged at the other end of the regular polygonal frame, a magnetic flux leakage detection structure is arranged on the outside of the regular polygonal frame, variable diameter supporting and walking structures are arranged on both sides of the magnetic flux leakage detection structure, a linkage plate is arranged between the variable diameter supporting and walking structures and the magnetic flux leakage detection structure, an auxiliary diameter-changing mechanism is arranged inside the regular polygonal frame, and the auxiliary diameter-changing structure includes a supporting structure, an extending structure and an unfolding structure; the present invention provides an auxiliary diameter-changing mechanism, the extending mechanism transports the supporting structure into a pipeline with a smaller diameter, the unfolding mechanism unfolds the supporting structure, and the extending mechanism applies a force to the chassis in the direction of the pipeline with a smaller diameter, thereby facilitating the movement of the detection device from a pipeline with a large diameter to a pipeline with a small diameter.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic nondestructive testing, and in particular to a magnetic leakage internal detection device for large deformation and high temperature pipelines. Background Art

[0002] Pipelines of all kinds are used extensively in power generation, metallurgy, petroleum, chemical engineering, natural gas, urban plumbing, construction, and the military. They transport materials necessary for human life, production, construction, and industrial development, and thus play a vital role in the national economy. During use, mechanical damage, corrosion, fatigue failure, and service life issues inevitably lead to obvious or potential defects such as corrosion thinning, holes, and cracks in in-service pipelines. If these defects are not discovered and addressed promptly, they can easily lead to material leaks, resulting in significant losses to property and life.

[0003] Chinese patent CN108426943B discloses a variable-diameter magnetic flux leakage detection device for pipelines. Its working principle is that a screw motor drives the main screw to rotate, and the main screw drives two long connecting rod nuts to move closer or farther away from each other, causing the long connecting rod connecting head to contract inward or expand outward, thereby controlling the distance between the magnetic flux leakage detection detection shoe and the inner wall of the pipeline. In the above scheme, when a large-diameter pipeline enters a small-diameter pipeline, the wheel spring in the universal wheel walking device is compressed, and the wheel spring universal wheel applies a greater force toward the inner wall of the pipeline, which increases the friction between the universal wheel and the inner wall of the pipeline, making it inconvenient for robots or other devices to move the detection device. Summary of the Invention

[0004] In response to the above problems, a magnetic leakage internal detection device for large deformation and high-temperature pipelines is provided. The present invention is provided with an auxiliary diameter-changing mechanism. The extension mechanism transports the supporting structure into a pipeline with a smaller diameter. The expansion mechanism expands the supporting structure, and the supporting structure is pressed against the inside of the pipeline with a smaller diameter. The extension mechanism then works to apply a force to the chassis toward the pipeline with a smaller diameter, thereby facilitating the movement of the detection device from a pipeline with a large diameter to a pipeline with a small diameter.

[0005] In order to solve the problems of the prior art, the technical solution adopted by the present invention is:

[0006] A magnetic leakage internal detection device for large deformation and high-temperature pipelines includes a chassis, the middle part of the chassis is set as a regular polygonal frame, the regular polygonal frame has an even number of side surfaces, one end of the regular polygonal frame is provided with a front end cover, the middle part of the front end cover is provided with a through hole, the other end of the regular polygonal frame is provided with a rear end cover, and a power connection end is provided on the side of the rear end cover facing away from the regular polygonal frame, and the outer annular array of the regular polygonal frame is provided with a plurality of magnetic leakage detection structures, the magnetic leakage detection structure is connected to the middle part of the side surface of the regular polygonal frame, and each of the magnetic leakage detection structures is provided with a variable diameter support walking structure on both sides, and a linkage plate is provided between the variable diameter support walking structure and the magnetic leakage detection structure, and an auxiliary diameter-changing mechanism is provided inside the regular polygonal frame, the auxiliary diameter-changing structure includes a supporting structure, and the supporting structure is provided at the front end cover, and the interior of the regular polygonal frame is provided with an extension structure for transporting the supporting structure out of the interior of the regular polygonal frame and an expansion structure for expanding the supporting structure.

[0007] Preferably, the supporting structure includes a connecting sleeve, one end of the connecting sleeve faces the regular polygon frame and is connected to the extending mechanism, the other end of the connecting sleeve is provided with a connecting block, and a number of support arms are provided in a circular array around the connecting block, the support arm includes a main support rod, one end of the main support rod is connected to the connecting block, the other end of the main support rod faces the interior of the regular polygon frame, and the other end of the main support rod is provided with a tightening block, an oblique support rod is provided in the middle of the main support rod, one end of the oblique support rod is connected to the main support rod, the other end of the oblique support rod is provided with a slider, and the upper end of the slider is connected to the other end of the oblique support rod, a number of sliding grooves are provided on the outer surface of the connecting sleeve along its busbar direction, the slider is slidably arranged in the sliding groove, and the slider faces one side of the regular polygon frame and is connected to the expansion mechanism.

[0008] Preferably, a sliding telescopic rod is provided between the main support rod and the clamping block, one end of the sliding telescopic rod is slidably connected to the main support rod, and the other end of the sliding telescopic rod is connected to the clamping block. A first pressure spring is provided on the outside of the sliding telescopic rod, one end of the first pressure spring is connected to the main support rod, and the other end of the first pressure spring is connected to one end of the sliding telescopic rod and the clamping block.

[0009] Preferably, a limiting rod is provided in each of the several slide grooves on the connecting sleeve, one end of the limiting rod is connected to the bottom of the slide groove, a through hole is opened in the middle of the slider, the limiting rod passes through the through hole in the middle of the slider, and the slider is slidably connected to the limiting rod, and a reset spring is also provided on the limiting rod, one end of the reset spring is connected to the bottom of the slide groove, and the other end of the reset spring is connected to the side wall of the slider facing the bottom of the groove.

[0010] Preferably, the extending mechanism includes a threaded rod arranged inside the regular polygonal frame, the axis of the threaded rod is collinear with the axis of the regular polygonal frame, one end of the threaded rod is connected to one end of the connecting sleeve, and the end of the threaded rod close to the rear end cover is sleeved with a first driving sleeve, the thread on the inner wall of the first driving sleeve cooperates with the thread on the outer surface of the threaded rod, the upper end of the first driving sleeve is provided with a first driving structure, the first driving structure includes a first driven gear, the first driven gear is sleeved on the outside of the first driving sleeve and fixedly connected to the first driving sleeve, a first driving gear is provided on one side of the first driven gear, and the first main gear is sleeved on the outer surface of the first driving sleeve. The driven gear is meshed with the first driven gear for transmission connection, the first driving gear is provided with a first driving motor along its axial direction, the output shaft of the first driving motor is connected to the first driving gear, and a mounting bracket is provided on the side of the first driving motor away from the first driving motor, and one side wall of the mounting bracket is connected to the first driving motor, and both ends of the mounting bracket are connected to the inner wall of the regular polygon frame, and a first auxiliary bracket is also sleeved on the outside of the threaded rod, the inner diameter of the middle part of the first auxiliary bracket is consistent with the maximum outer diameter of the threaded rod, and several connecting ends on the outside of the first auxiliary bracket are connected to the inner wall of the regular polygon frame.

[0011] Preferably, first limiting brackets are provided on both sides of the first driving sleeve, the middle portion of the first limiting bracket is sleeved on the outside of the threaded rod, and several connecting ends outside the first limiting bracket are connected to the inner wall of the regular polygonal frame.

[0012] Preferably, a first limiting groove is provided on the threaded rod, the first limiting groove is in the shape of a long rectangular strip, and the first limiting slide groove passes through the threaded rod along the diameter direction of the threaded rod, and a limiting clamping plate is provided in the first limiting groove, one end of the limiting clamping plate is connected to the inner wall of the regular polygonal frame, and the thickness of the limiting clamping plate is consistent with the width of the first limiting groove.

[0013] Preferably, the outside of the threaded rod is sleeved with an externally threaded sleeve, the inner diameter of the externally threaded sleeve is consistent with the maximum outer diameter of the threaded rod, and the end of the externally threaded sleeve close to the connecting sleeve is sleeved with a second drive sleeve, the thread on the inner wall of the second drive sleeve is matched with the thread on the outer surface of the externally threaded sleeve, and second limiting brackets are provided on both sides of the second drive sleeve, the middle part of the second limiting bracket is sleeved on the externally threaded sleeve, and multiple connecting ends on the outside of the second limiting bracket are connected to the inner wall of the regular polygon frame, and the upper end of the second drive sleeve is provided with a second drive structure, the second drive structure includes a second driven gear sleeved on the outside of the second drive sleeve, a second driving gear is provided on one side of the second driven gear, the second driving gear is meshed with the second driven gear for transmission connection, and the second driving gear is provided with a second drive motor along its axial direction, and the output shaft of the second drive motor is connected to the second driving gear, and a second auxiliary bracket is also sleeved on the end of the externally threaded sleeve close to the connecting sleeve, the inner diameter of the second auxiliary bracket is consistent with the maximum outer diameter of the externally threaded sleeve, and several connecting ends on the outside of the second auxiliary bracket are connected to the inner wall of the regular polygon frame.

[0014] Preferably, a connecting disk is provided at the end of the externally threaded sleeve facing the connecting sleeve, one side of the connecting disk is connected to the end of the externally threaded sleeve, and a plurality of second pressure springs are provided in a circular array on the other side of the connecting disk, one end of the second pressure spring is connected to the connecting disk.

[0015] Preferably, a second limiting groove is provided on the externally threaded sleeve, the second limiting groove is in the shape of an elongated rectangle, and the second limiting groove passes through the externally threaded sleeve along the diameter direction of the externally threaded sleeve.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention is provided with an auxiliary diameter-changing mechanism. When the chassis moves to the diameter-changing position of the pipe, the extending mechanism transports the supporting structure into the pipe with a smaller diameter. The unfolding mechanism works to unfold the supporting structure, and the supporting structure is pressed against the inside of the pipe with a smaller diameter. The extending mechanism works again to apply a force to the chassis in the direction of the pipe with a smaller diameter, thereby facilitating the movement of the detection device from the pipe with a large diameter to the pipe with a small diameter.

[0018] 2. The present invention is provided with a connecting sleeve, a connecting block and a support arm. The extending mechanism conveys the connecting sleeve out of the chassis, and the unfolding mechanism applies a force toward the bottom of the slide groove to the slider, so that the slider slides along the slide groove. The movement of the slider causes the oblique support rod to rotate, and the oblique support rod applies an oblique upward thrust to the middle part of the main support rod, so that the main support rod rotates around the connection of the connecting block. The main support rod lifts the clamping block upward, so that the clamping block is pressed against the inner wall of the small-diameter pipe, thereby creating a large friction between the support structure and the inner wall of the small-diameter pipe, thereby facilitating the extending mechanism to pull the chassis toward the small-diameter pipe.

[0019] 3. The present invention is provided with a sliding telescopic rod and a first pressure spring. After the clamping block is pressed against the inner wall of the small-diameter pipe, the expansion mechanism continues to apply thrust to the slider, and the sliding telescopic rod slides toward the main support rod. The first pressure spring is compressed, thereby absorbing the excess thrust applied to the expansion mechanism and preventing the clamping block from damaging the small-diameter pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a front view of a magnetic leakage internal detection device for pipelines with large deformation and high temperature;

[0021] Figure 2 This is a left view of a magnetic leakage internal detection device for pipelines with large deformation and high temperature;

[0022] Figure 3 This is a three-dimensional diagram of a magnetic leakage internal detection device for large deformation and high temperature pipelines in a working state;

[0023] Figure 4 This is a three-dimensional diagram of a magnetic leakage internal detection device for large deformation and high temperature pipelines in another working state;

[0024] Figure 5 This is a three-dimensional diagram of an auxiliary diameter-changing mechanism in a magnetic leakage internal detection device for pipelines with large deformation and high temperature;

[0025] Figure 6 It is a three-dimensional support structure for the magnetic leakage internal detection device of large deformation and high temperature pipelines. Figure 1 ;

[0026] Figure 7 This is an exploded view of the support structure of a magnetic flux leakage internal inspection device for pipelines with large deformation and high temperature;

[0027] Figure 8 It is a three-dimensional support structure for the magnetic leakage internal detection device of large deformation and high temperature pipelines. Figure 2 ;

[0028] Figure 9 This is a three-dimensional diagram of the extension mechanism of a magnetic leakage internal detection device for pipelines with large deformation and high temperature;

[0029] Figure 10 The present invention is a cross-sectional view of a threaded rod, a first drive sleeve, a first drive structure and a first limit bracket in a magnetic leakage internal detection device for large deformation and high temperature pipelines;

[0030] Figure 11 This is a three-dimensional diagram of the threaded rod and deployment mechanism in a magnetic leakage internal detection device for pipelines with large deformation and high temperature;

[0031] Figure 12 yes Figure 11 A partial enlarged view of point A in the middle;

[0032] Figure 13 The invention discloses a cross-sectional view of a threaded rod, an externally threaded sleeve, a second drive sleeve, a second drive structure and a second limit bracket in a magnetic leakage internal detection device for large deformation and high temperature pipelines.

[0033] The numbers in the figure are:

[0034] 1-chassis; 11-regular polygonal frame; 12-front cover; 13-rear cover;

[0035] 2-Magnetic flux leakage detection structure;

[0036] 3-Variable diameter supporting walking structure;

[0037] 4- linkage board;

[0038] 5-Auxiliary reducing mechanism;

[0039] 51-support structure;

[0040] 511-connecting sleeve; 5111-slide;

[0041] 512-connection block;

[0042] 513 - support arm; 5131 - main support rod; 5132 - tightening block; 5133 - oblique support rod; 5134 - slider; 5135 - sliding telescopic rod; 5136 - first pressure spring;

[0043] 514-limiting rod;

[0044] 515-return spring;

[0045] 52- extension mechanism;

[0046] 521-threaded rod; 5211-first limiting groove;

[0047] 522-first drive sleeve;

[0048] 523 - first drive structure; 5231 - first driven gear; 5232 - first driving gear; 5233 - first drive motor; 5234 - mounting bracket;

[0049] 524-first auxiliary bracket;

[0050] 525-first limiting bracket;

[0051] 53-Deployment mechanism;

[0052] 531-externally threaded sleeve; 5311-second limiting groove;

[0053] 532-second drive sleeve;

[0054] 533-second limiting bracket;

[0055] 534 - second drive structure; 5341 - second driven gear; 5342 - second driving gear; 5343 - second drive motor;

[0056] 535-second auxiliary bracket;

[0057] 536-connection plate;

[0058] 537-second pressure spring;

[0059] 54-Limiting card. DETAILED DESCRIPTION

[0060] In order to further understand the features, technical means, specific objectives and functions achieved by the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] Reference Figures 1 to 13 As shown: A magnetic flux leakage internal detection device for large deformation and high temperature pipelines, including a chassis 1, a regular polygonal frame 11 is set in the middle of the chassis 1, the regular polygonal frame 11 has an even number of side surfaces, a front end cover 12 is set at one end of the regular polygonal frame 11, a through hole is opened in the middle of the front end cover 12, a rear end cover 13 is set at the other end of the regular polygonal frame 11, and a power connection end is set on the side of the rear end cover 13 facing away from the regular polygonal frame 11, and a plurality of magnetic flux leakage detection structures 2 are set in the outer annular array of the regular polygonal frame 11. The magnetic flux leakage detection structure 2 is connected to the regular polygonal frame 11. The middle part of the side surface of the polygonal frame 11 is connected, and variable diameter supporting walking structures 3 are provided on both sides of each leakage magnetic detection structure 2. A linkage plate 4 is provided between the variable diameter supporting walking structure 3 and the leakage magnetic detection structure 2. An auxiliary variable diameter mechanism 5 is provided inside the regular polygonal frame 11. The auxiliary variable diameter structure includes a supporting structure 51, and the supporting structure 51 is provided at the front end cover 12. The interior of the regular polygonal frame 11 is provided with an extending mechanism 52 for conveying the supporting structure 51 out of the interior of the regular polygonal frame 11 and an unfolding mechanism 53 for expanding the support structure 51.

[0062] The connection end of the rear end cover 13 is connected to a robot or other driving and traction equipment. The variable diameter support walking structure 3 automatically adjusts its own diameter according to the inner diameter of the pipe, and then drives the leakage magnetic detection structure 2 to change through the linkage plate 4, so that the leakage magnetic detection structure 2 can automatically adapt to pipes of different diameters and get closer to the inner wall of the pipe, thereby improving the accuracy of the detection results. When the detection device moves from a large diameter pipe to a small diameter pipe, the variable diameter support walking structure 3 contracts toward the center of the chassis 1, so that the force applied by the variable diameter support walking structure 3 on the inner wall of the pipe increases, and the resistance encountered by the chassis 1 in the forward direction increases. Therefore, an auxiliary variable diameter mechanism 5 is provided. When the chassis 1 moves to the diameter change point of the pipe, the extension mechanism 52 transports the support structure 51 out of the chassis 1 so that the support structure 51 is in the pipe with a smaller diameter. Then, the deployment mechanism 53 works to deploy the support structure 51, and the support structure 51 is pressed against the inside of the pipe with a smaller diameter. The extension mechanism 52 works again to apply a force to the chassis 1 in the direction of the pipe with a smaller diameter, thereby facilitating the movement of the detection device from the large diameter pipe to the small diameter pipe.

[0063] Reference Figure 5 、 Figure 6 、 Figure 7 and Figure 8 As shown: the support structure 51 includes a connecting sleeve 511, one end of the connecting sleeve 511 faces the regular polygon frame 11 and is connected to the extension mechanism 52, the other end of the connecting sleeve 511 is provided with a connecting block 512, and a plurality of supporting arms 513 are provided in a circular array around the connecting block 512. The supporting arm 513 includes a main support rod 5131, one end of the main support rod 5131 is connected to the connecting block 512, the other end of the main support rod 5131 faces the interior of the regular polygon frame 11, and the other end of the main support rod 5131 is provided with a tight block 5132, an oblique support rod 5133 is provided in the middle of the main support rod 5131, one end of the oblique support rod 5133 is connected to the main support rod 5131, and a slider 5134 is provided at the other end of the oblique support rod 5133, and the upper end of the slider 5134 is connected to the other end of the oblique support rod 5133, and a plurality of sliding grooves 5111 are provided on the outer surface of the connecting sleeve 511 along its busbar direction, and the slider 5134 is slidably set in the sliding groove 5111, and the slider 5134 is connected to the unfolding mechanism 53 toward one side of the regular polygonal frame 11.

[0064] When the detection device moves to the point where the diameter of the pipe changes from large to small, the extending mechanism 52 transports the connecting sleeve 511 out of the chassis 1, and then the unfolding mechanism 53 applies a force toward the bottom of the slide groove 5111 on the slider 5134, so that the slider 5134 slides along the slide groove 5111. The movement of the slider 5134 causes the oblique support rod 5133 to rotate, and the oblique support rod 5133 applies an oblique upward thrust to the middle part of the main support rod 5131, so that the main support rod 5131 rotates around the connection with the connecting block 512, and the main support rod 5131 lifts the clamping block 5132 upward, so that the clamping block 5132 is pressed against the inner wall of the small-diameter pipe, thereby creating a greater friction between the support structure 51 and the inner wall of the small-diameter pipe, thereby facilitating the extending mechanism 52 to pull the chassis 1 toward the small-diameter pipe.

[0065] Reference Figure 6 and Figure 7 As shown: a sliding telescopic rod 5135 is arranged between the main support rod 5131 and the tightening block 5132, one end of the sliding telescopic rod 5135 is slidingly connected to the main support rod 5131, and the other end of the sliding telescopic rod 5135 is connected to the tightening block 5132, and a first pressure spring 5136 is provided on the outside of the sliding telescopic rod 5135, one end of the first pressure spring 5136 is connected to the main support rod 5131, and the other end of the first pressure spring 5136 is connected to one end of the sliding telescopic rod 5135 and the tightening block 5132.

[0066] The inner diameters of small-diameter pipes are of different sizes. When the deployment mechanism 53 deploys several support arms 513 and the clamping block 5132 is pressed against the inner wall of the small-diameter pipe, the deployment mechanism 53 continues to apply a thrust to the slider 5134, so that the main support rod 5131 has a tendency to continue to expand outward. If the main support rod 5131 continues to expand outward, it will cause damage to the inner wall of the small-diameter pipe. Therefore, after the clamping block 5132 is pressed against the inner wall of the small-diameter pipe, the deployment mechanism 53 continues to apply a thrust to the slider 5134, and the telescopic rod 5135 slides toward the inside of the main support rod 5131. The first pressure spring 5136 is compressed, thereby absorbing the excess thrust applied by the deployment mechanism 53 and preventing the clamping block 5132 from damaging the small-diameter pipe.

[0067] Reference Figure 7 As shown: a limiting rod 514 is provided in each of the several sliding grooves 5111 on the connecting sleeve 511, one end of the limiting rod 514 is connected to the bottom of the sliding groove 5111, a through hole is opened in the middle of the slider 5134, the limiting rod 514 passes through the through hole in the middle of the slider 5134, and the slider 5134 is slidably connected to the limiting rod 514, and a return spring 515 is also sleeved on the limiting rod 514, one end of the return spring 515 is connected to the bottom of the sliding groove 5111, and the other end of the return spring 515 is connected to the side wall of the slider 5134 facing the bottom of the groove.

[0068] The unfolding mechanism 53 applies a thrust to the slider 5134, pushing the slider 5134 to slide on the limit rod 514, and the return spring 515 is compressed. When the auxiliary variable-diameter mechanism 5 transfers the detection device from the large-diameter pipe to the small-diameter pipe, the extending mechanism 52 needs to retract the support structure 51 into the chassis 1. The unfolding mechanism 53 removes the thrust applied to the slider 5134, and the return spring 515 is reset, pushing the slider 5134 to move along the limit rod 514 toward the chassis 1. The slider 5134 then drives the main support rod 5131 to rotate toward the connecting sleeve 511 through the oblique support rod 5133, thereby reducing the volume occupied by the support structure 51, making it easier to be retracted into the interior of the chassis 1.

[0069] Reference Figure 5 、 Figure 9 and Figure 10 As shown: the extending mechanism 52 includes a threaded rod 521 arranged inside the regular polygon frame 11, the axis of the threaded rod 521 is collinear with the axis of the regular polygon frame 11, one end of the threaded rod 521 is connected to one end of the connecting sleeve 511, and the end of the threaded rod 521 close to the rear end cover 13 is sleeved with a first driving sleeve 522, the thread on the inner wall of the first driving sleeve 522 cooperates with the thread on the outer surface of the threaded rod 521, and the upper end of the first driving sleeve 522 is provided with a first driving structure 523, the first driving structure 523 includes a first driven gear 5231, the first driven gear 5231 is sleeved on the outside of the first driving sleeve 522 and fixedly connected to the first driving sleeve 522, and a first driving gear 5232 is provided on one side of the first driven gear 5231. The wheel 5232 is meshed with the first driven gear 5231 for transmission connection. The first driving gear 5232 is provided with a first driving motor 5233 along its axial direction. The output shaft of the first driving motor 5233 is connected to the first driving gear 5232. A mounting bracket 5234 is provided on the side of the first driving motor 5233 away from the first driving motor 5233. One side wall of the mounting bracket 5234 is connected to the first driving motor 5233. Both ends of the mounting bracket 5234 are connected to the inner wall of the regular polygon frame 11. A first auxiliary bracket 524 is also sleeved on the outside of the threaded rod 521. The inner diameter of the middle part of the first auxiliary bracket 524 is consistent with the maximum outer diameter of the threaded rod 521. Several connecting ends on the outside of the first auxiliary bracket 524 are connected to the inner wall of the regular polygon frame 11.

[0070] The first auxiliary bracket 524 makes the axis of the threaded rod 521 collinear with the axis of the regular polygon frame 11, and the first driving motor 5233 works to drive the first driving gear 5232 to rotate, and the first driving gear 5232 then drives the first driven gear 5231 to rotate, and the first driven gear 5231 drives the first driving sleeve 522 to rotate forward. The forward rotating first driving sleeve 522 drives the end of the threaded rod 521 connected to the connecting sleeve 511 to move toward the outside of the regular polygon, and the detection device enters the small-diameter pipe from the large-diameter pipe. The first driving motor 5233 then drives the first driving sleeve 522 to rotate in the opposite direction through the first driving gear 5232 and the first driven gear 5231, so that the end of the threaded rod 521 connected to the connecting sleeve 511 is retracted into the regular polygon frame 11, thereby realizing the retraction and extension of the support structure 51 by the extending mechanism 52.

[0071] Reference Figure 9 and Figure 10 As shown: a first limiting bracket 525 is provided on both sides of the first driving sleeve 522, the middle part of the first limiting bracket 525 is sleeved on the outside of the threaded rod 521, and several connecting ends outside the first limiting bracket 525 are connected to the inner wall of the regular polygonal frame 11.

[0072] The two first limiting brackets 525 fix the position of the first driving sleeve 522 so that the first driving sleeve 522 will not move with the threaded rod 521 under the drive of the first driving structure 523, thereby preventing the first driven gear 5231 from disengaging from the first driving gear 5232, thereby avoiding the problem that the first driving sleeve 522 cannot be retracted after driving the threaded rod 521 to extend.

[0073] Reference Figure 3 and Figure 9 As shown: a first limiting groove 5211 is opened on the threaded rod 521, the first limiting groove 5211 is in the shape of a long rectangle, and the first limiting slide groove 5111 passes through the threaded rod 521 along the diameter direction of the threaded rod 521, and a limiting clamping plate 54 is set in the first limiting groove 5211. One end of the limiting clamping plate 54 is connected to the inner wall of the regular polygonal frame 11, and the thickness of the limiting clamping plate 54 is consistent with the width of the first limiting groove 5211.

[0074] When the first driving sleeve 522 drives the threaded rod 521 to move, one end of the limiting clamping plate 54 is stuck in the first limiting groove 5211, limiting the threaded rod 521 from rotating. When the threaded rod 521 is subjected to the torsional force applied by the first driving sleeve 522, the threaded rod 521 cannot rotate, causing the threaded rod 521 to move in a straight line, thereby realizing the first driving sleeve 522 driving the threaded rod 521 to move in a straight line.

[0075] Reference Figure 3 、 Figure 11 and Figure 13 As shown: the outer part of the threaded rod 521 is sleeved with an externally threaded sleeve 531, the inner diameter of the externally threaded sleeve 531 is consistent with the maximum outer diameter of the threaded rod 521, and the end of the externally threaded sleeve 531 close to the connecting sleeve 511 is sleeved with a second driving sleeve 532, and the thread on the inner wall of the second driving sleeve 532 cooperates with the thread on the outer surface of the externally threaded sleeve 531, and second limiting brackets 533 are provided on both sides of the second driving sleeve 532. The middle part of the second limiting bracket 533 is sleeved on the externally threaded sleeve 531, and multiple connecting ends on the outside of the second limiting bracket 533 are connected to the inner wall of the regular polygonal frame 11, and the upper end of the second driving sleeve 532 is provided with a second driving structure 534, which includes The second driven gear 5341 is sleeved on the outside of the second driving sleeve 532, and a second driving gear 5342 is provided on one side of the second driven gear 5341. The second driving gear 5342 is meshed and transmission-connected with the second driven gear 5341. The second driving gear 5342 is provided with a second driving motor 5343 along its axial direction. The output shaft of the second driving motor 5343 is connected to the second driving gear 5342. A second auxiliary bracket 535 is also sleeved on one end of the externally threaded sleeve 531 close to the connecting sleeve 511. The inner diameter of the second auxiliary bracket 535 is consistent with the maximum outer diameter of the externally threaded sleeve 531. Several connecting ends on the outside of the second auxiliary bracket 535 are connected to the inner wall of the regular polygonal frame 11.

[0076] One end of the second driving motor 5343 is connected to the mounting bracket 5234. When the extending mechanism 52 extends the supporting structure 51 out of the regular polygonal frame 11, the unfolding mechanism 53 is also working at the same time. The second driving motor 5343 works to drive the second driving gear 5342 to rotate. The second driving gear 5342 drives the second driven gear 5341 to rotate. The second driven gear 5341 drives the second driving sleeve 532 to rotate. The second limiting brackets 533 on both sides of the second driving sleeve 532 fix the position of the second driving sleeve 532 so that the second driving sleeve 532 drives the externally threaded sleeve 531 to move, and the movement speed of the externally threaded sleeve 531 is the same as that of the threaded rod 521, keeping the relative position of the externally threaded sleeve 531 and the threaded rod 521 unchanged, and the support structure 51 moves into the small-diameter pipe, and the second drive motor 5343 continues to drive the second drive sleeve 532 to rotate through the second driving gear 5342 and the second driven gear 5341, and the second drive sleeve 532 continues to push the externally threaded sleeve 531 toward the support structure 51, thereby pushing the support structure 51 to expand and press against the inner wall of the small-diameter pipe.

[0077] Reference Figure 11As shown: a connecting disk 536 is provided at the end of the externally threaded sleeve 531 facing the connecting sleeve 511, one side of the connecting disk 536 is connected to the end of the externally threaded sleeve 531, and a plurality of second pressure springs 537 are provided in a ring array on the other side of the connecting disk 536, and one end of the second pressure spring 537 is connected to the connecting disk 536.

[0078] The unfolding mechanism 53 applies a thrust to the slider 5134, and the second pressure spring 537 is pressed against the slider 5134. When the support structure 51 is unfolded to a certain extent and cannot continue to unfold outward, if the unfolding mechanism 53 continues to apply a thrust to the slider 5134, the second pressure spring 537 contracts at this time and absorbs the excess thrust applied by the unfolding mechanism 53, thereby protecting the support structure 51.

[0079] Reference Figure 11 and Figure 12 As shown, a second limiting groove 5311 is opened on the externally threaded sleeve 531 . The second limiting groove 5311 is in a long rectangular shape and penetrates the externally threaded sleeve 531 along the diameter direction of the externally threaded sleeve 531 .

[0080] The first limiting groove 5211 is connected to the second limiting groove 5311, and the limiting clamping plate 54 is clamped in the second limiting groove 5311 to limit the external threaded sleeve 531 from rotating. When the external threaded sleeve 531 receives the torsional force applied by the second driving sleeve 532, the external threaded sleeve 531 performs linear motion, thereby realizing that the second driving sleeve 532 drives the external threaded sleeve 531 to perform linear motion.

[0081] The above embodiments merely represent one or several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A magnetic leakage internal detection device for large deformation and high temperature pipelines, characterized in that: The invention comprises a chassis, wherein the middle part of the chassis is set as a regular polygonal frame, the regular polygonal frame has an even number of side surfaces, a front end cover is set at one end of the regular polygonal frame, a through hole is opened in the middle part of the front end cover, a rear end cover is set at the other end of the regular polygonal frame, a power connection end is set at the side of the rear end cover facing away from the regular polygonal frame, a plurality of leakage magnetic detection structures are set in an annular array outside the regular polygonal frame, the leakage magnetic detection structure is connected to the middle part of the side surface of the regular polygonal frame, variable diameter supporting walking structures are set on both sides of each leakage magnetic detection structure, a linkage plate is set between the variable diameter supporting walking structure and the leakage magnetic detection structure, an auxiliary diameter-changing mechanism is set inside the regular polygonal frame, the auxiliary diameter-changing structure includes a supporting structure, the supporting structure is set at the front end cover, and an extension mechanism for conveying the supporting structure out of the interior of the regular polygonal frame and an expansion mechanism for expanding the supporting structure are set inside the regular polygonal frame; The supporting structure includes a connecting sleeve, one end of the connecting sleeve is connected to the extension mechanism toward the regular polygonal frame, the other end of the connecting sleeve is provided with a connecting block, a plurality of supporting arms are provided in a circular array around the connecting block, the supporting arm includes a main supporting rod, one end of the main supporting rod is connected to the connecting block, the other end of the main supporting rod faces the interior of the regular polygonal frame, the other end of the main supporting rod is provided with a tightening block, an oblique supporting rod is provided in the middle of the main supporting rod, one end of the oblique supporting rod is connected to the main supporting rod, the other end of the oblique supporting rod is provided with a slider, the upper end of the slider is connected to the other end of the oblique supporting rod, and the connecting A plurality of slide grooves are provided on the outer surface of the sleeve along the direction of its busbar, and the slider is slidably arranged in the slide groove. The slider is connected to the expansion mechanism on one side of the regular polygonal frame, and the expansion mechanism applies a force toward the bottom of the slide groove to the slider, and the slider slides along the slide groove. The movement of the slider causes the oblique support rod to rotate, and the oblique support rod applies an oblique upward thrust to the middle part of the main support rod, so that the main support rod rotates around the connection with the connecting block, and the main support rod lifts the tightening block upward, so that the tightening block is pressed against the inner wall of the small-diameter pipe, so that there is a greater friction between the support structure and the inner wall of the small-diameter pipe.

2. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 1 is characterized in that: A sliding telescopic rod is arranged between the main support rod and the clamping block, one end of the sliding telescopic rod is slidably connected to the main support rod, and the other end of the sliding telescopic rod is connected to the clamping block. A first pressure spring is provided on the outside of the sliding telescopic rod, one end of the first pressure spring is connected to the main support rod, and the other end of the first pressure spring is connected to one end of the sliding telescopic rod connected to the clamping block.

3. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 2, characterized in that: A limiting rod is provided in each of the several slide grooves on the connecting sleeve, one end of the limiting rod is connected to the bottom of the slide groove, a through hole is opened in the middle of the slider, the limiting rod passes through the through hole in the middle of the slider, the slider is slidably connected to the limiting rod, and a return spring is also provided on the limiting rod, one end of the return spring is connected to the bottom of the slide groove, and the other end of the return spring is connected to the wall of the slider facing the bottom of the groove.

4. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 3 is characterized in that: The extending mechanism includes a threaded rod arranged inside the regular polygonal frame, the axis of the threaded rod is collinear with the axis of the regular polygonal frame, one end of the threaded rod is connected to one end of the connecting sleeve, and the end of the threaded rod close to the rear end cover is sleeved with a first driving sleeve, the thread on the inner wall of the first driving sleeve cooperates with the thread on the outer surface of the threaded rod, the upper end of the first driving sleeve is provided with a first driving structure, the first driving structure includes a first driven gear, the first driven gear is sleeved on the outside of the first driving sleeve and is fixedly connected to the first driving sleeve, a first driving gear is provided on one side of the first driven gear, and the first driving gear The wheel is meshed with the first driven gear for transmission connection, the first driving gear is provided with a first driving motor along its axial direction, the output shaft of the first driving motor is connected to the first driving gear, and a mounting bracket is provided on the side of the first driving motor away from the first driving motor, and one side wall of the mounting bracket is connected to the first driving motor, and both ends of the mounting bracket are connected to the inner wall of the regular polygon frame, and a first auxiliary bracket is also sleeved on the outside of the threaded rod, the inner diameter of the middle part of the first auxiliary bracket is consistent with the maximum outer diameter of the threaded rod, and several connecting ends on the outside of the first auxiliary bracket are connected to the inner wall of the regular polygon frame.

5. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 4, characterized in that: A first limiting bracket is provided on both sides of the first driving sleeve. The middle portion of the first limiting bracket is sleeved on the outside of the threaded rod. Several connecting ends outside the first limiting bracket are connected to the inner wall of the regular polygonal frame.

6. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 5, characterized in that: A first limiting groove is provided on the threaded rod, and the first limiting groove is in the shape of a long rectangular strip. The first limiting slide groove passes through the threaded rod along the diameter direction of the threaded rod. A limiting clamping plate is provided in the first limiting groove, and one end of the limiting clamping plate is connected to the inner wall of the regular polygonal frame. The thickness of the limiting clamping plate is consistent with the width of the first limiting groove.

7. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 6, characterized in that: The outside of the threaded rod is sleeved with an externally threaded sleeve, the inner diameter of the externally threaded sleeve is consistent with the maximum outer diameter of the threaded rod, and the end of the externally threaded sleeve close to the connecting sleeve is sleeved with a second drive sleeve, the thread on the inner wall of the second drive sleeve is matched with the thread on the outer surface of the externally threaded sleeve, and second limiting brackets are provided on both sides of the second drive sleeve. The middle part of the second limiting bracket is sleeved on the externally threaded sleeve, and multiple connecting ends on the outside of the second limiting bracket are connected to the inner wall of the regular polygon frame. The upper end of the second drive sleeve is provided with a second drive structure, and the second drive structure includes a second driven gear sleeved on the outside of the second drive sleeve, and a second driving gear is provided on one side of the second driven gear. The second driving gear is meshed with the second driven gear for transmission connection, and the second driving gear is provided with a second drive motor along its axial direction. The output shaft of the second drive motor is connected to the second driving gear. A second auxiliary bracket is also sleeved on the end of the externally threaded sleeve close to the connecting sleeve, and the inner diameter of the second auxiliary bracket is consistent with the maximum outer diameter of the externally threaded sleeve. Several connecting ends on the outside of the second auxiliary bracket are connected to the inner wall of the regular polygon frame.

8. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 7, characterized in that: A connecting disk is provided at the end of the externally threaded sleeve facing the connecting sleeve, one side of the connecting disk is connected to the end of the externally threaded sleeve, and a plurality of second pressure springs are provided in a circular array on the other side of the connecting disk, one end of the second pressure spring is connected to the connecting disk.

9. The magnetic flux leakage internal detection device for large deformation and high temperature pipelines according to claim 8, characterized in that: A second limiting groove is provided on the externally threaded sleeve. The second limiting groove is in the shape of an elongated rectangle and penetrates the externally threaded sleeve along the diameter direction of the externally threaded sleeve.

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