Flexible scanning device for large size pipes defects

Abstract

The application discloses a large-size pipeline defect flexible scanning device, which comprises a first fixed support, a transmission system, a sensor support and a second fixed support, wherein the three are sequentially and evenly arranged and placed in parallel, and the central axes of the three are coincident with each other, forming a ring-shaped detection mechanism; the sensor support comprises four identical arc-shaped plate bodies and a plurality of sensors; the plurality of sensors are evenly arranged on the ring-shaped plate body in a circumferential direction in a manner that the axial direction of the signal detection end of each sensor is perpendicular to the central axis of the ring-shaped plate body, so that the detection range of all the sensors can cover one round of the pipeline to be detected, and the perpendicular distance between the detection end of each sensor and the central axis of the ring-shaped plate body is consistent; the transmission system comprises four tensioning wheels, four synchronous belts, four synchronous pulleys, a driving device, four trapezoidal lead screws, four trapezoidal nuts and two nut connecting plates; the device adopts a split type detection mechanism, and has the characteristics of high efficiency and accuracy in completing the scanning work on the pipeline.

Description

Technical Field

[0001] This invention relates to the field of non-destructive testing of pipelines, and particularly to a flexible scanning device for defects in large-size pipelines. Background Technology

[0002] In industries such as petroleum, chemical, and power, there are numerous metal pipelines of various specifications. Pipelines laid in the early stages are now entering their aging period and are currently experiencing a high incidence of pipeline accidents. Accurate inspection of in-service pipelines and replacement or reinforcement of those with potential hazards can extend their service life and reduce pipeline accidents. Currently, rapid pipeline inspection technology is not yet mature, and there is a lack of understanding of the health status of most in-service pipelines, often leading to many blind scrappings. This lack of scientific pipeline maintenance results in a significant waste of human and material resources. Pipeline defects can be summarized into three categories: 1. Corrosion: This is the most frequent pipeline defect. Pipeline corrosion is divided into external surface corrosion and internal wall corrosion. External surface corrosion occurs due to damage to the protective layer, causing the pipeline to be directly exposed to the air. Internal wall corrosion is mostly caused by the transport of corrosive media, gradually evolving into pits and thinning of the wall after long-term erosion. 2. Human-caused damage: This is mostly due to improper handling of pipelines, such as incorrect operations during pipeline burial. 3. Man-made defects: For example, porosity created during pipeline welding. Pipeline defects have a variety of causes and can easily lead to catastrophic accidents. Currently, the detection of internal pipeline defects from the outside relies mostly on manual, single-point inspections, which suffers from low efficiency, high workload, and safety hazards. Furthermore, most rapid pipeline external wall inspection devices use a single probe to inspect a localized area of ​​the pipeline, limiting their application range and failing to provide blind-spot-free inspection, making them difficult to meet practical requirements. Therefore, there is a significant demand for pipeline external wall inspection devices capable of performing blind-spot-free scanning of internal pipeline defects.

[0003] Currently, pipeline external wall inspection mechanisms can be broadly categorized as follows: Pneumatic peristaltic type: This type of device moves using a peristaltic motion. Through the coordinated action and sequence of cylinders and clamping mechanisms, the reciprocating motion of the mechanism is achieved, ensuring that at least one pair of grippers clamps the pipeline during the process; Articulated type: This type of device consists of a series of rotating and moving joints, achieving movement on the pipeline by clamping it; Inner frame spiral type: This type of device consists of a cylindrical frame and three evenly distributed identical trolleys. After the wheels grip the pipe wall, the device spirals upwards or downwards by driving the wheels. Among them, patent 108407909A discloses a pipe external flaw detection walking robot, patent CN209946039U discloses a pipe external flaw detection walking robot, and patent CN109668964A discloses a pipe scanning frame. All of the above-mentioned patents disclose a pipe external wall scanning mechanism. However, the mechanisms in the first two patents can only perform linear scanning of the pipe, and the mechanism in the third patent can only perform circumferential scanning of the pipe. They are not suitable for scanning large-sized pipes. None of them can complete the blind spot scanning of the pipe within a certain range, which easily leads to problems of incomplete pipe inspection and low inspection efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a flexible inspection device for defects in large-size pipes that is suitable for large-size pipes and allows for easy replacement and disassembly of sensors.

[0005] Therefore, the technical solution of the present invention is as follows:

[0006] A flexible scanning device for large-size pipe defects includes a first fixed support, a second fixed support, a transmission system, and a sensor support; wherein,

[0007] The first fixed bracket, the sensor bracket, and the second fixed bracket are arranged in sequence at intervals and placed parallel to each other, with their central axes coinciding to form a ring detection mechanism; the first fixed bracket and the second fixed bracket are the same, both being ring structures.

[0008] The sensor support consists of four identical arc-shaped plates and several sensors. The four arc-shaped plates are arranged sequentially along the circumference, with their ends connected, forming a symmetrical annular plate divided into four equal parts: upper left, lower left, upper right, and lower right. The sensors are evenly distributed along the circumference of the annular plate with their signal detection ends perpendicular to the central axis of the annular plate. This ensures that the detection range of all sensors covers the entire circumference of the pipe to be inspected, and the vertical distance between the detection ends of each sensor and the central axis of the annular plate is consistent.

[0009] The transmission system includes four tensioning pulleys, four synchronous belts, four synchronous pulleys, a drive unit, four trapezoidal lead screws, four trapezoidal nuts, and two nut connecting plates. The drive unit includes at least one drive mechanism mounted on the drive unit housing, a drive synchronous pulley, a drive tensioning pulley, a main support shaft, and an auxiliary support shaft. The four trapezoidal lead screws are respectively mounted in the four trapezoidal nuts with their axes parallel to the axis of the annular detection mechanism. The front and rear ends of each trapezoidal lead screw are rotatably mounted on the first fixed bracket and the second fixed bracket respectively via rotating bearings. Furthermore, the front ends of each trapezoidal lead screw extend to the outside of the first fixed bracket; four trapezoidal nuts are evenly distributed on the annular plate of the sensor bracket and distributed on four arc-shaped plates, with one end of each trapezoidal nut fixed to the arc-shaped plate of the sensor, so that the arc-shaped plate of the sensor and the nut connecting plate can be independently assembled and disassembled on the trapezoidal nuts without affecting each other; two nut connecting plates are distributed on the left and right sides of the annular plate, with the top and bottom ends of each nut connecting plate fixed to two trapezoidal nuts on the same side, to ensure that the two trapezoidal nuts are in the same position on the two sets of trapezoidal lead screws. The device maintains synchronous linear motion under rotary motion; four synchronous pulleys are fixed to the front ends of four trapezoidal lead screws; the drive unit housing is fixed to the bottom of the first fixed bracket; the main support shaft and the auxiliary support shaft are rotatably mounted on the lower and upper sides of the drive unit housing respectively, with their axes parallel to the axis of the annular detection mechanism; the active tensioning wheel is fixed to the front side of the main support shaft, enabling them to rotate synchronously; the active tensioning wheel is rotatably mounted on the front end of the auxiliary support shaft; two synchronous belts are respectively fitted onto two synchronous belts located on the same strip-shaped vertical plate. The first synchronous belt is mounted on the first synchronous pulley, forming a belt drive between the two synchronous pulleys located within the synchronous belt. The second synchronous belt is fitted onto the synchronous pulleys and the driving synchronous pulley located on the lower side of the two strip-shaped vertical plates, and its outer surface contacts the wheel surface of the driving tensioning pulley to form a V-shape, thus forming a belt drive between the two synchronous pulleys and the driving synchronous pulley. The four tensioning pulley pairs are divided into left and right parts, each part containing two tensioning pulleys, and are rotatably fixed on the sides of the two strip-shaped vertical plates, so that the outer surface of the synchronous belt located on the same side contacts the wheel surface of the two tensioning pulleys to form a tension.

[0010] Furthermore, the minimum inner diameter of the sensor bracket is larger than the outer diameter of the pipe to be tested.

[0011] Furthermore, the first and second fixed supports are circular ring structures, rectangular ring structures, or polygonal ring structures.

[0012] Furthermore, the first fixed support consists of two hexagonal shafts, four connecting blocks, two strip-shaped vertical plates, and a pipe clamping device; the two hexagonal shafts are horizontally arranged on the upper and lower sides of the same vertical plane, the two connecting blocks are symmetrically fixed at both ends of the upper hexagonal shaft, and the other two connecting blocks are symmetrically fixed at both ends of the lower hexagonal shaft; the two strip-shaped vertical plates are respectively arranged between the two connecting blocks in the same vertical direction with their long sides vertical, and their ends are respectively fixed to the two connecting blocks; the pipe clamping device consists of an upper pipe clamping mechanism and a lower pipe clamping mechanism, which are symmetrically arranged on the two hexagonal shafts.

[0013] Furthermore, the first fixed support consists of two support horizontal plates, two support side plates, four connectors, and a pipe clamping device; the two support horizontal plates and two support side plates are arranged alternately and connected end to end to form an octagonal ring support with structural symmetry; the connector consists of a shaped plate and a middle partition plate, with the middle partition plate fixed in the center of the shaped plate body with its plate surface perpendicular to two mutually parallel plate surfaces, so that the ends of each adjacent support horizontal plate and support side plate are respectively inserted into two chambers in the connector and connected and fixed to the connector by screws; the pipe clamping device consists of an upper pipe clamping mechanism and a lower pipe clamping mechanism, which are symmetrically arranged on the two support horizontal plates.

[0014] Furthermore, the pipe clamping mechanism is a pad or pipe fixing plate assembly with a concave arc surface facing one side of the pipe; wherein, the pad is fixed on a fixing bracket with adjustable bolt height, and its concave arc surface is adapted to the curvature of the outer wall of the pipe, so that it can be adjusted to fit the concave arc surface with the outer wall of the pipe; the pipe fixing plate assembly consists of two pipe fixing plates arranged symmetrically, each of which has an arc-shaped through groove cut from the bottom corner of its adjacent side, and the concave arc surface of the arc-shaped through groove is adapted to the curvature of the outer wall of the pipe.

[0015] Furthermore, the drive mechanism is a manual crank, a motor, a sprocket and chain drive assembly, or a bevel gear drive assembly; wherein, the manual crank or motor is fixed to the front end of the main support shaft; the sprocket and chain drive assembly consists of a sprocket and an annular chain that meshes with the sprocket; the sprocket is fixed to the front end of the main support shaft, one side of the annular chain is mounted on the sprocket, and the other side hangs freely downwards for manual or motor-driven pulling; the bevel gear drive assembly consists of a first bevel gear and a second bevel gear disposed in the inner cavity of the drive device housing; the first bevel gear is fixed to the rear end of the main support shaft, and the second bevel gear is vertically arranged with its axis perpendicular to the axis of the first bevel gear and meshes with the first bevel gear, and a gear shaft is fixed in its central hole, the upper side of the gear shaft is rotatably mounted on the bottom plate of the drive device housing through a bearing, and its bottom end is connected to the output shaft of an external motor.

[0016] Furthermore, a reinforcing rib is fixedly connected between the lower side of the first fixed bracket and the housing of the drive device.

[0017] Furthermore, multiple through slots for installing sensors are formed on the inner arc surface of each arc-shaped plate along the radial direction of the first fixed bracket, and the through slots are evenly distributed on the arc-shaped plate. Correspondingly, ear plates are symmetrically installed on both sides of each sensor, and each ear plate has a strip-shaped through hole along the sensor axis, so that each sensor is set in the through slot in a one-to-one correspondence. By adjusting the position of the screws set in the strip-shaped through hole, the vertical distance from the detection end of each sensor to the central axis of the sensor bracket is adjusted to be consistent.

[0018] Furthermore, the plates and connectors can be made of polyoxymethylene, carbon fiber or polyamide; the lead screw, lead screw nut, wheel body and bearing can be made of aluminum alloy or stainless steel.

[0019] Compared with existing technologies, this large-size flexible pipeline defect scanning device adopts a split-type detection mechanism, which consists of fixed supports on both sides to fix the pipeline to be inspected and a sensor support plate with sufficient sensors arranged along the circumference of the pipe wall. At the same time, a synchronous transmission system is constructed by combining screw and belt drive mechanisms. The synchronous belt drive is driven manually or electrically, which in turn drives the four screws to rotate synchronously. The screws then drive the screw nuts to move the sensor supports along the axis of the pipeline to be inspected, thereby completing the pipeline scanning work. Compared with the current method of manual handheld sensor detection, this scanning mechanism has the characteristics of synchronous efficiency and accurate completion of pipeline scanning work. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the pipeline defect inspection mechanism according to Embodiment 1 of the present invention;

[0021] Figure 2(a) is a partial structural schematic diagram of the pipeline defect inspection mechanism of Embodiment 1 of the present invention;

[0022] Figure 2(b) is a schematic diagram of the drive device of the pipeline defect inspection mechanism according to Embodiment 1 of the present invention;

[0023] Figure 3 This is a schematic diagram of the sensor bracket of the pipeline defect inspection mechanism according to Embodiment 1 of the present invention;

[0024] Figure 4 This is a schematic diagram of the pipeline defect inspection mechanism according to Embodiment 2 of the present invention;

[0025] Figure 5 This is a schematic diagram of the pipeline defect inspection mechanism according to Embodiment 3 of the present invention;

[0026] Figure 6 This is a schematic diagram of the pipeline defect inspection mechanism in use according to Embodiment 1 of the present invention;

[0027] Figure 7 This is a partially enlarged view of the sensor bracket of the pipeline defect scanning mechanism according to Embodiment 1 of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention.

[0029] Example 1

[0030] like Figure 1 As shown, the large-size flexible pipe defect inspection device includes a first fixed support 1, a second fixed support 2, a transmission system 3, and a sensor support 4; wherein,

[0031] The first fixed bracket 1, the sensor bracket 4, and the second fixed bracket 2 are arranged in sequence at intervals and placed parallel to each other, and the central axes of the three are kept coincident to form a ring detection mechanism; as a preferred technical solution of this embodiment, the minimum inner diameter of the sensor bracket is 10mm larger than the outer diameter of the pipe to be detected.

[0032] As shown in Figure 2(a), the first fixed bracket 1 and the second fixed bracket 2 have the same structure and dimensions; therefore, the following description will take the first fixed bracket 1 as an example to illustrate the structure of the two in detail:

[0033] The first fixed bracket 1 consists of two hexagonal shafts 1a, two upper pipe fixing plates 1b, four connecting blocks 1c, two strip vertical plates 1d, a lower pipe fixing plate 1e, and a support base 1f; specifically,

[0034] Two hexagonal shafts 1a are horizontally arranged on the upper and lower sides of the same vertical plane. Correspondingly, each upper pipe fixing plate 1b, each connecting block 1c, and the support base 1f have hexagonal through holes at their centers that match the size of the hexagonal shaft 1a. The two upper pipe fixing plates 1b are inserted through the middle of the upper hexagonal shaft 1a and are symmetrically arranged and fixed to the hexagonal shaft 1a with bolts. The two connecting blocks 1c are inserted through both ends of the upper hexagonal shaft 1a and are symmetrically arranged and fixed to the hexagonal shaft 1a with bolts. The other two connecting blocks 1c are inserted through both ends of the lower hexagonal shaft 1a and are symmetrically arranged and fixed to the hexagonal shaft 1a with bolts. The support base 1f is inserted through the center of the lower hexagonal shaft 1a and is fastened to the hexagonal shaft 1a with bolts respectively arranged on the upper and lower sides of the support base 1f.

[0035] Two strip-shaped vertical plates 1d are respectively set between two connecting blocks 1c located in the same vertical direction with their long sides vertical. Their upper and lower ends are respectively fixed to the two connecting blocks 1c by bolts, thus forming a first fixed bracket 1 with a rectangular ring structure. At the same time, each strip-shaped vertical plate 1d has a through hole near its upper and lower ends.

[0036] The adjacent bottom corners of the two upper pipe fixing plates 1b are symmetrically processed into arc-shaped through grooves, and the curvature of the concave arc surface of the arc-shaped through groove and the concave arc surface of the lower pipe fixing plate 1e are adapted to the size of the pipe to be scanned, so that when the two upper pipe fixing plates 1b and the lower pipe fixing plate 1e are sandwiched on the outside of the pipe, each concave arc surface can fit against the outer wall of the pipe to be scanned.

[0037] The lower pipe fixing plate 1e is a plate with one side surface being concave arc surface. It is set on the top surface of the support base 1f with the concave arc surface facing upward. Correspondingly, two screw holes are symmetrically opened on the front side of the support base 1f, penetrating its upper and lower surfaces and not connected to the central hexagonal hole. Two bolts are respectively installed in the two screw holes from bottom to top. The ends of the bolts extending from the upper surface of the support base 1f to the outer side are fixed in the center on the bottom surface of the lower pipe fixing plate 1e. This allows the lower pipe fixing plate 1e to be adjusted in position relative to the support base 1f within the range of 0~10mm, so that the concave arc surface of the plate is completely in contact with the outer wall of the pipe to be tested.

[0038] like Figure 3 As shown, the sensor bracket 4 includes four identical arc-shaped plates 4a, two nut connecting plates 4b, twelve sensors 4c, and four bracket blocks 4d; wherein,

[0039] Four arc-shaped plates 4a are arranged sequentially along the circumference in a way that they are connected end to end. Two nut connecting plates 4b are symmetrically arranged on the left and right sides of one side of the ring-shaped plate. The top and bottom of each nut connecting plate 4b are fixed to the two arc-shaped plates 4a located on the same side, so that the four arc-shaped plates 4a and the two nut connecting plates 4b form a ring-shaped plate that is divided into left and right parts and has structural symmetry.

[0040] Based on the pipe dimensions and the sensor detection range, this embodiment uses twelve sensors 4c evenly distributed along the circumference of the annular plate, with each sensor 4c positioned such that the axis of its signal detection end is perpendicular to the central axis of the annular plate. Figure 7As shown, in order to ensure that the vertical distance between the detection end of each sensor 4c and the central axis of the annular plate is consistent, according to the structural symmetry of the annular plate, three through slots for installing the sensors (4c) are opened on the inner arc surface of each arc plate (4a) along the radial direction of the first fixed bracket. The three through slots are evenly distributed on the arc plate (4a). Correspondingly, ear plates are symmetrically installed on both sides of each sensor (4c). Each ear plate has a strip-shaped through hole along the axis of the sensor (4c), so that the three sensors (4c) are set in the through slots one by one. By adjusting the position of the screws set in the strip-shaped through holes, the vertical distance between the detection end of each sensor (4c) and the central axis of the sensor bracket (4) can be adjusted to be consistent. This layout can ensure that when the pipe to be tested is centered in the detection ring group, the twelve sensors 4c are evenly arranged along the outer wall of the pipe at 360 degrees. At the same time, the detection range of all sensors can cover the pipe to be tested around the circumference without any blind spots.

[0041] As shown in Figures 2(a) and 2(b), the transmission system 3 includes four tensioning pulleys 3a, four synchronous belts 3b, four synchronous pulleys 3c, a drive unit 3e, four fixed blocks 3h, four trapezoidal lead screws 3k, and four trapezoidal nuts 3i; wherein,

[0042] Four trapezoidal nut mounting holes are evenly distributed on the annular ring of the sensor bracket 4. Each trapezoidal nut mounting hole and the through holes located on both sides of it and respectively opened on the first fixed bracket 1 and the second fixed bracket are located on the same central axis, so that the annular detection mechanism forms four sets of screw mounting holes for mounting trapezoidal screws. The four trapezoidal nuts 3i are respectively installed in the four trapezoidal nut mounting holes. Since in actual use, the four trapezoidal nuts 3i will drive the sensor bracket to reciprocate between the first fixed bracket 1 and the second fixed bracket 2, the location of the trapezoidal nut mounting holes is selected at the overlapping part of the arc-shaped plate 4a and the nut connecting plate 4b to ensure structural strength. At the same time, in order to prevent the trapezoidal nuts 3i installed on the annular ring from rotating, the outer circumference of the trapezoidal nuts 3i is connected to the annular plate by multiple bolts arranged circumferentially. In this embodiment, the trapezoidal nut 3i is installed in an open slot on the nut connecting plate 4b. Therefore, the nut connecting plate 4b can also play an auxiliary locking role by the bracket stop 4d set at the opening of the open slot.

[0043] Four trapezoidal lead screws 3k are respectively inserted into four sets of lead screw mounting holes, with the axis of each trapezoidal lead screw 3k parallel to the axis of the pipe to be scanned, to ensure that the sensor bracket 4 always moves relative to the axis of the pipe to be scanned. Specifically, each trapezoidal lead screw 3k is assembled in a trapezoidal nut 3i, and its front and rear ends are rotatably inserted into the through holes of the first fixed bracket 1 and the second fixed bracket 2 through rotary bearings, with the front end of each trapezoidal lead screw 3k extending to the outside of the first fixed bracket 1; the four trapezoidal nuts 3i are mounted on the sensor bracket. The four arc-shaped plates 4a are evenly distributed on the annular plate of the frame 4, and one end of each trapezoidal nut 3i is fixed to the arc-shaped plate 4a of the sensor, so that the arc-shaped plate 4a of the sensor and the nut connecting plate 3j can be independently assembled and disassembled on the trapezoidal nut 3i without affecting each other; the two nut connecting plates 3j are distributed on the left and right sides of the annular plate, and the top and bottom ends of each nut connecting plate 3j are respectively fixed to the two trapezoidal nuts 3i located on the same side, so as to ensure that the two trapezoidal nuts 3i maintain synchronous linear motion under the synchronous rotation of the two sets of trapezoidal lead screws 3k;

[0044] The drive unit 3e includes a first drive mechanism, a second drive mechanism, a drive synchronous pulley 3r, a drive tensioning pulley 3l, a main support shaft 3t, and an auxiliary support shaft 3m, all mounted on the drive unit housing; specifically,

[0045] The drive unit housing consists of two fixed panels 3n, two fixed side plates 3o, and a fixed base plate 3s. The two fixed side plates 3o are fixed to the left and right sides of the support base 1f by bolts, and the two fixed plates 3n are fixed to the front and rear sides of the support base 1f by bolts and connected to the two fixed side plates 3o by screws. The fixed base plate 3s is fixed to the bottom of the two handwheel fixed plates 3n and the two handwheel fixed side plates 3o by bolts, so that the above five plates form a gear mounting chamber under the support base 1f.

[0046] Four synchronous pulleys 3c are fixed to the front ends of four trapezoidal lead screws 3k; the main support shaft 3t and the auxiliary support shaft 3m are rotatably mounted on the lower and upper sides of the drive unit housing respectively, with their axes parallel to the axis of the annular detection mechanism; the active tensioning wheel 3l is fixed to the front side of the main support shaft 3t, enabling the two to rotate synchronously; the active tensioning wheel 3l is rotatably mounted on the front end of the auxiliary support shaft 3m; two synchronous belts 3b are respectively fitted onto two synchronous pulleys 3c located on the same strip-shaped vertical plate 1d, forming a belt drive between the two synchronous pulleys 3c located within the synchronous belt 3b; the third synchronous belt 3b... The step belt 3b is mounted on the synchronous pulleys 3c and the driving synchronous pulley 3r located under the two strip-shaped vertical plates 1d, and its outer surface contacts the wheel surface of the driving tensioning wheel 3l and is tensioned in a V shape, so that the two synchronous pulleys 3c and the driving synchronous pulley 3r form a belt drive; then, turning the manual crank handle 3d can synchronously rotate the driving synchronous pulley 3r. Under the action of the synchronous belt 3b, the four synchronous pulleys 3c rotate synchronously with the driving synchronous pulley 3r, driving the four trapezoidal screws 3k to translate relative to the four trapezoidal nuts 3i that cooperate with them, that is, the sensor bracket 4 translates between the first fixed frame 1 and the second fixed frame 2.

[0047] The first drive mechanism is a hand crank, which is fixed to the front end of the main support shaft 3t; the second drive mechanism is a bevel gear drive group, which consists of a first bevel gear and a second bevel gear 3p set in the inner cavity of the drive device housing; the first bevel gear is fixed to the rear end of the main support shaft 3t, and the second bevel gear 3p is vertically set with its axis perpendicular to the axis of the first bevel gear and meshes with the first bevel gear. A gear shaft 3u is fixed in its central hole, and the upper side of the gear shaft 3u is rotatably set on the bottom plate of the drive device housing through a bearing. Its bottom end is connected to the output shaft of an external motor. The two drive mechanisms improve the versatility of the scanning device. When the pipeline is at a low position, the operator can complete the scanning work of the pipeline to be inspected by operating the hand crank. When the pipeline is at a high position, the second bevel gear 3p can be directly driven to rotate by the gear shaft 3u extending to the ground, thereby realizing the synchronous rotation of the first bevel gear and the main support shaft 3t to complete the same working state as driving the hand crank.

[0048] As a preferred technical solution in this embodiment, the timing pulley 3c is a tensioning type timing pulley;

[0049] The four tensioning pulleys 3a are divided into left and right parts. Each part contains two tensioning pulleys, one above the other. Each tensioning pulley has its own bearing and is rotatably mounted on the tensioning pulley fixing plate 3h. The tensioning pulley fixing plate 3h then fixes each tensioning pulley to a suitable position on the side of the two strip vertical plates 1d, so that the outer side of the synchronous belt 3b on the same side contacts the wheel surface of the two tensioning pulleys 3a and is tensioned.

[0050] It should be noted that, in this embodiment, considering the large number of sensors required for large pipelines, which would result in a large weight of the sensor ring, the transmission system 3 is designed with two trapezoidal lead screws on each side of the ring detection mechanism to ensure the stability and reliability of the movement after the lead screws are assembled. In this way, the sensor ring is actually divided into four equal parts by the four lead screws, so that each lead screw bears one-quarter of the weight of the sensor ring, which greatly reduces the load on the lead screws. In addition, each sensor ring can be installed and disassembled independently, which facilitates the maintenance of the sensor. Moreover, the installation and disassembly of the sensor ring will not affect the synchronous movement of the lead screw on one side, realizing the flexible installation and disassembly of the sensor arc plate, which is more convenient and efficient.

[0051] As a preferred technical solution in this embodiment, a reinforcing rib plate 3f is fixedly connected between the two connecting blocks 1c on the lower hexagonal shaft 1a of the first fixed bracket 1 and the handwheel fixing plate 3n to increase the stability of the driving device.

[0052] In addition, as a preferred technical solution of this embodiment, in order to eliminate anti-signal interference, the upper pipe fixing plate 1b, the lower pipe fixing plate 1e, the sensor arc plate 4a, the nut connecting plate 4b, the bracket block 4d and the bolts used for connection and fixation in this large-size pipe defect flexible scanning device are all made of polyoxymethylene (POM); the remaining parts are made of aluminum alloy.

[0053] Example 2

[0054] like Figure 4 As shown, the large-size pipe defect flexible scanning device has a basically the same structural composition as the large-size pipe defect flexible scanning device in Embodiment 1. The difference is that in this embodiment, the manual crank 3d in the drive device 3 is replaced with an explosion-proof motor 3x. At the same time, a flange bracket 3y is bolted to the bottom end of the handwheel fixing plate 3n on the side where the explosion-proof motor 3x is installed. The explosion-proof motor 3k is fixed on the flange bracket 3y with its output shaft center axis coinciding with the center axis of the support shaft 3m. The output shaft of the explosion-proof motor 3k is also fixed in the center hole of the active synchronous pulley 3r, so that the active synchronous pulley 3r is driven to rotate by the explosion-proof motor 3x. Compared with the manual drive in Embodiment 1, the use of the explosion-proof motor 3x in this embodiment can further improve the stability of the sensor bracket ring 3's operation.

[0055] In addition, in this embodiment, the nut connecting plate 4b in the sensor bracket 4 is replaced with a plate connecting plate 4e with a U-shaped structure. The plate connecting plate 4e has through holes at both ends, allowing two arc-shaped plates 4a located on the same side to be connected as a whole by bolts. Compared with the nut connecting plate 4b in Embodiment 1, the plate connecting plate 4e in this embodiment can further reduce the weight of the mechanism.

[0056] Example 3

[0057] like Figure 5 As shown, the large-size pipe defect flexible scanning device has a basically the same structural composition as the large-size pipe defect flexible scanning device in Embodiment 1. The difference is that in this embodiment, the structure of the first fixed support 1 and the second fixed support 2 is improved. Specifically, since the first fixed support 1 and the second fixed support 2 have the same structure and size, the improvement method is described using the first fixed support 1 as an example: the two hexagonal shafts 1a on the first fixed support 1 in Embodiment 1 are replaced with two support horizontal plates 1g, the upper pipe fixing plate 1b is replaced with the upper pipe pad 1h, and the strip vertical plate 1d is replaced with the support side plate 1j; the connecting block 1c is replaced with the connecting piece 1r; specifically,

[0058] Two horizontal support plates 1g and two side support plates 1j are arranged alternately and connected end to end to form an octagonal ring support with structural symmetry. The connector 1r is composed of a U-shaped plate and a partition plate. The partition plate is fixed in the center of the U-shaped plate with its plate surface perpendicular to the two parallel plate surfaces in the U-shaped plate, so that the interior of the U-shaped plate is divided into two chambers by the partition plate. Then, by inserting the ends of each adjacent horizontal support plate 1g and side support plate 1j into the two chambers in the connector 1r and connecting and fixing them to the connector 1r with screws, the two horizontal support plates 1g and the two side support plates 1j are connected and fixed in sequence to form an integral support.

[0059] The upper pipe pad 1h is inserted and fixed in the middle of the support plate 1g located on the upper side through the through groove opened on its top. Its bottom surface is processed into an inward arc surface, which matches the inward arc surface on the lower pipe fixing plate 1e. When the upper pipe pad 1h and the lower pipe fixing plate 1e are sandwiched on the outside of the pipe to be scanned, both inward arc surfaces can fit against the outer wall of the pipe to be scanned.

[0060] As a preferred technical solution of this embodiment, in order to facilitate the adjustment of the upper and lower positions of the upper pipe pad 1h, symmetrical fixing through holes are provided on the top through groove wall of the upper pipe pad 1h. Correspondingly, when the upper pipe pad 1h is installed on the support horizontal plate 1g, by adjusting the installation position of the upper pipe pad 1h on the support horizontal plate 1g and fixing it with bolts set in the through holes on both sides of the groove wall, the upper and lower positions of the upper pipe pad 1h can be adjusted within the range of 0~10mm.

[0061] Compared to the rectangular ring support in Example 1, the octagonal ring support used in this example occupies less space when used for pipes of the same size to be tested. It can be spliced ​​with components of different materials, resulting in a lighter weight. At the same time, the octagonal ring support is also relatively more stable from a structural point of view.

[0062] As another alternative to this embodiment, the first fixed bracket 1 and the second fixed bracket 2 can also be formed into a ring-shaped structure by using arc-shaped plates that are evenly divided into multiple pieces.

[0063] like Figure 6 As shown, the usage method of this large-size pipe defect flexible scanning device is as follows:

[0064] S1. Fix the pipe to be tested using the first and second fixing brackets; since the pipe temperature is relatively high, a heat insulation layer is first wrapped on the outer wall of the pipe before the above steps.

[0065] S2. Adjust the position of the pipe fixing block below the first fixed bracket and the second fixed bracket according to the outer diameter of the pipe to be tested, so that the first fixed bracket and the second fixed bracket can be clamped and fixed on the outer wall of the pipe to be tested.

[0066] S3. Install the arc-shaped plate of the sensor bracket onto the corresponding trapezoidal nut and connect the sensor's signal transmission line to the external signal acquisition device.

[0067] S4. Drive the sensor bracket smoothly from one end of the device to the other end of the device along the axial direction of the pipe to be tested by a crank or motor. The sensor collects the corresponding signal. The scanning speed range is 1mm / s to 30mm / s.

[0068] Specifically, the sensor can be an eddy current sensor or an ultrasonic sensor. It continuously emits voltage, current, or sound signals to the pipeline being inspected to obtain feedback voltage, current, or sound signals induced along the scanning path. By analyzing the changing trends of the feedback voltage, current, or sound signals, the internal characteristics of the pipeline can be identified. During use, the sensor support ring 4 collects the induced signals as it moves, thereby evaluating the defects in the inner wall of the pipeline.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flexible scanning device for large-size pipe defects, characterized in that, It includes a first fixed bracket (1), a second fixed bracket (2), a transmission system (3), and a sensor bracket (4); wherein, The first fixed bracket (1), the sensor bracket (4), and the second fixed bracket (2) are arranged in sequence at intervals and placed parallel to each other, and their central axes are kept coincident to form a ring detection mechanism; the first fixed bracket (1) and the second fixed bracket (2) are the same, both of which are ring structures; The sensor bracket (4) includes four identical arc-shaped plates (4a) and several sensors (4c); the four arc-shaped plates (4a) are arranged sequentially along the circumference in a way that they are connected end to end, so that the four arc-shaped plates (4a) form a ring plate that is evenly divided into four parts: upper left, lower left, upper right, and lower right and has structural symmetry; the several sensors (4c) are evenly distributed along the circumference of the ring plate with the axis of their signal detection end perpendicular to the central axis of the ring plate, so that the detection range of all sensors can cover the circumference of the pipe to be detected, and the vertical distance between the detection end of each sensor (4c) and the central axis of the sensor bracket (4) is consistent; The transmission system (3) includes four tensioning pulleys (3a), four synchronous belts (3b), four synchronous pulleys (3c), a drive unit (3e), four trapezoidal lead screws (3k), four trapezoidal nuts (3i), and two nut connecting plates (3j); the drive unit (3e) includes at least one drive mechanism mounted on the drive unit housing, an active synchronous pulley (3r), an active tensioning pulley (3l), a main support shaft (3t), and an auxiliary support shaft (3m); the four trapezoidal lead screws (3k) are respectively mounted in the four trapezoidal nuts (3i) with their axes parallel to the axis of the annular detection mechanism, and the front and rear ends of each trapezoidal lead screw (3k) are respectively Rotatably mounted on the first fixed bracket (1) and the second fixed bracket (2) via rotating bearings, with the front ends of each trapezoidal screw (3k) extending to the outside of the first fixed bracket (1); four trapezoidal nuts (3i) are evenly distributed on the annular plate of the sensor bracket (4) and distributed on four arc-shaped plates (4a), with one end of each trapezoidal nut (3i) fixed to the arc-shaped sensor plate (4a); two nut connecting plates (3j) are distributed on the left and right sides of the annular plate, with the top and bottom ends of each nut connecting plate (3j) respectively fixed to the two trapezoidal nuts (3i) located on the same side; four synchronous pulleys (3c) are respectively fixed At the front end of the four trapezoidal lead screws (3k); the drive unit housing is fixed to the bottom of the first fixed bracket (1), the main support shaft (3t) and the auxiliary support shaft (3m) are rotatably mounted on the lower and upper sides of the drive unit housing respectively with their axes parallel to the axis of the annular detection mechanism via rotating bearings; the active tension wheel (3l) is fixed to the front side of the main support shaft (3t) so that the two can rotate synchronously; the active tension wheel (3l) is rotatably mounted on the front end of the auxiliary support shaft (3m); two synchronous belts (3b) are respectively fitted onto two synchronous pulleys (3c) located on the same strip-shaped vertical plate (1d) so that the pulleys within the synchronous belts (3b) can rotate synchronously. A belt drive is formed between the two synchronous pulleys (3c); a third synchronous belt (3b) is fitted onto the synchronous pulleys (3c) and the driving synchronous pulley (3r) located under the two strip-shaped vertical plates (1d), and its outer surface contacts the wheel surface of the driving tensioning pulley (3l) to be tensioned in a V shape, so that a belt drive is formed between the two synchronous pulleys (3c) and the driving synchronous pulley (3r); the four tensioning pulleys (3a) are divided into left and right parts, each part containing two tensioning pulleys, and are rotatably fixed on the sides of the two strip-shaped vertical plates (1d), so that the outer surface of the synchronous belt (3b) located on the same side contacts the wheel surface of the two tensioning pulleys (3a) to be tensioned.

2. The large-size pipeline defect flexible scanning device according to claim 1, characterized in that, The minimum inner diameter of the sensor bracket is 10mm larger than the outer diameter of the pipe to be tested.

3. The large-size pipeline defect flexible scanning device according to claim 1, characterized in that, The first fixed support (1) and the second fixed support (2) are circular ring structures, rectangular ring structures or polygonal ring structures.

4. The flexible inspection device for large-size pipe defects according to claim 3, characterized in that, The first fixed support (1) consists of two hexagonal shafts (1a), four connecting blocks (1c), two strip vertical plates (1d), and a pipe clamping device. The two hexagonal shafts (1a) are horizontally arranged on the upper and lower sides of the same vertical plane. The two connecting blocks (1c) are symmetrically fixed at both ends of the upper hexagonal shaft (1a), and the other two connecting blocks (1c) are symmetrically fixed at both ends of the lower hexagonal shaft (1a). The two strip vertical plates (1d) are respectively arranged between the two connecting blocks (1c) in the same vertical direction with their long sides vertical, and their two ends are respectively fixed on the two connecting blocks (1c). The pipe clamping device consists of an upper pipe clamping mechanism and a lower pipe clamping mechanism, which are symmetrically arranged on the two hexagonal shafts (1a).

5. The large-size pipeline defect flexible scanning device according to claim 3, characterized in that, The first fixed support (1) consists of two support horizontal plates (1g), two support side plates (1j), four connectors (1r), and a pipe clamping device. The two support horizontal plates (1g) and two support side plates (1j) are arranged alternately and connected end to end to form an octagonal ring support with structural symmetry. The connector (1r) consists of a U-shaped plate and a partition plate. The partition plate is fixed in the center of the U-shaped plate with its plate surface perpendicular to the two parallel plate surfaces in the U-shaped plate. The ends of each adjacent support horizontal plate (1g) and support side plate (1j) are inserted into the two chambers in the connector (1r) and connected and fixed to the connector (1r) with screws. The pipe clamping device consists of an upper pipe clamping mechanism and a lower pipe clamping mechanism, which are symmetrically arranged on the two support horizontal plates (1g).

6. The large-size pipeline defect flexible scanning device according to claim 4, characterized in that, The pipe clamping mechanism consists of a pad or a pipe fixing plate assembly with a concave arc surface facing one side of the pipe. The pad is mounted on a fixing bracket with adjustable bolt height, and its concave arc surface adapts to the curvature of the outer wall of the pipe, allowing it to be adjusted to fit snugly against the outer wall of the pipe. The pipe fixing plate assembly consists of two symmetrically arranged pipe fixing plates, each with an arc-shaped through groove cut from the bottom corner of its adjacent side, and the concave arc surface of the arc-shaped through groove adapts to the curvature of the outer wall of the pipe.

7. The large-size pipeline defect flexible scanning device according to claim 1, characterized in that, The drive mechanism can be a manual crank, a motor, a sprocket and chain drive assembly, or a bevel gear drive assembly; among which, The manual crank or motor is fixed to the front end of the main support shaft (3t); The sprocket and chain drive assembly consists of a sprocket and a ring chain that cooperates with the sprocket; the sprocket is fixed to the front end of the main support shaft (3t), and the ring chain is mounted on the sprocket on one side and hangs freely to the bottom on the other side for manual or motor-driven operation. The bevel gear drive assembly consists of a first bevel gear and a second bevel gear (3p) disposed in the inner cavity of the drive unit housing. The first bevel gear is fixed to the rear end of the main support shaft (3t), and the second bevel gear (3p) is vertically arranged with its axis perpendicular to the axis of the first bevel gear and meshes with the first bevel gear. A gear shaft (3u) is fixed in its central hole. The upper side of the gear shaft (3u) is rotatably mounted on the bottom plate of the drive unit housing through a bearing, and its bottom end is connected to the output shaft of an external motor.

8. The large-size pipeline defect flexible scanning device according to claim 1, characterized in that, A reinforcing rib (3f) is fixedly connected between the lower side of the first fixed bracket (1) and the housing of the drive device.

9. The large-size pipeline defect flexible scanning device according to claim 1, characterized in that, Multiple through slots for mounting sensors (4c) are provided on the inner arc surface of each arc plate (4a) along the radial direction of the first fixed bracket. The through slots are evenly distributed on the arc plate (4a). Correspondingly, ear plates are symmetrically installed on both sides of each sensor (4c). Each ear plate has a strip-shaped through hole along the axis of the sensor (4c), so that each sensor (4c) is set in the through slot one by one. By adjusting the position of the screws set in the strip-shaped through hole, the vertical distance from the detection end of each sensor (4c) to the central axis of the sensor bracket (4) is adjusted to be consistent.

10. The large-size pipeline defect flexible scanning device according to claim 1, characterized in that, Each plate and connector can be made of polyoxymethylene, carbon fiber or polyamide; the lead screw, lead screw nut, each wheel and each bearing can be made of aluminum alloy or stainless steel.

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