Diameter and mileage composite detection device applied to bidirectional walking inner detector

Abstract

The invention provides a diameter and mileage composite detection device applied to a bidirectional walking inner detector, and relates to the technical field of pipeline inner detectors. The device comprises a plurality of composite detection units arranged around an inner detector. The composite detection unit comprises a main shell, and a diameter measuring component is arranged in the main shell. The diameter measuring part comprises a connecting rod, and the two ends of the connecting rod extend out of the main shell. A rotor of a conical structure is coaxially arranged on the connecting rod, and a measuring winding coaxial with the connecting rod is arranged in the main shell. The connecting rod is sleeved with a first spring. A mileage measuring part is arranged at one end, back on to the inner detector, of the connecting rod. When recesses and protrusions exist in the pipeline, the rotor and the measuring winding move relatively, the impedance of the measuring winding changes, and the movement distance of the rotor can be obtained by detecting the impedance change. The device can measure the mileage and the pipeline diameter at the same time, is compact in structure and saves space.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline internal detectors, in particular to a diameter-mileage composite detection device applied to a bidirectional traveling internal detector. Background Art

[0002] With the large-scale development of my country's oil and gas pipeline network, the safety of oil and gas pipelines must be considered first, and internal inspections of oil and gas pipelines must be carried out regularly. Limited by the internal space and operating conditions of the pipeline, an internal detector with a compact structure, light weight, simple operation and accurate positioning is required.

[0003] At present, the diameter measuring and mileage measuring units carried on the internal detector are in a split form, that is, the diameter measuring part and the mileage measuring part are two parts. On the one hand, this leads to a complex structure. On the other hand, due to the variable relative distance between the two parts, this structure leads to errors in the axial mileage positioning of the pipe diameter change. Summary of the invention

[0004] In response to the above problems, the present application provides a diameter-mileage composite detection device applied to a bidirectional walking internal detector, which can simultaneously realize the measurement of mileage and pipeline diameter, has a compact structure, saves space, and has no mileage positioning error.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A diameter mileage composite detection device applied to a bidirectional walking inner detector comprises a plurality of composite detection units, and the plurality of composite detection units are arranged around the inner detector;

[0007] The composite detection unit comprises a main housing, and a diameter measuring component for measuring the diameter of the pipeline is arranged in the main housing;

[0008] The diameter measuring component comprises a connecting rod, and both ends of the connecting rod respectively pass through the side wall of the main housing and extend to the outside of the main housing;

[0009] A moving element with a conical structure is coaxially arranged on the connecting rod, and a measuring winding coaxially arranged with the connecting rod is arranged in the main housing;

[0010] A first spring is sleeved on the connecting rod at a side of the mover facing the inner detector;

[0011] An mileage measuring component is provided at one end of the connecting rod facing away from the inner detector;

[0012] When the internal detector is installed in the pipeline to be detected, the mileage wheel abuts against the inner wall of the pipeline, the first spring is compressed, and the measuring winding is located in the middle of the mover;

[0013] When there are depressions and protrusions in the pipeline, the mover and the measuring winding move relative to each other, and the impedance of the measuring winding changes. The movement distance of the mover can be obtained by detecting the impedance change of the measuring winding.

[0014] Furthermore, the mileage measurement component includes a mounting frame arranged on the connecting rod, and the mounting frame is provided with a mileage wheel and a mileage sensor for measuring the number of rotations of the mileage wheel.

[0015] Furthermore, the connecting rod includes a first guide portion and a second guide portion in sequence along a direction approaching the internal detector, and the first guide portion and the second guide portion are fixedly connected in a detachable manner, and the mover is arranged on the second guide portion.

[0016] Furthermore, a second spring is sleeved on the connecting rod at a side of the mover facing away from the inner detector.

[0017] Furthermore, the main shell includes a cylinder and sealing plates for closing openings at both ends of the cylinder, and at least one sealing plate is fixedly connected to the cylinder in a detachable manner.

[0018] Furthermore, the sealing plate fixedly connected to the cylinder in a detachable manner is fixedly connected to the cylinder in a threaded manner, and a boss for cooperating with a tightening tool is provided on the sealing plate fixedly connected to the cylinder in a detachable manner.

[0019] Furthermore, it also includes a mounting unit for tightening the outer side wall of the inner detector, and the composite detection unit is arranged on the mounting unit.

[0020] Furthermore, the mounting unit includes a plurality of mounting seats corresponding one to one with the composite detection unit, and the composite detection unit is arranged on the corresponding mounting seats, a tightening block is arranged between adjacent mounting seats, a connecting rod is arranged between the connected tightening blocks and the mounting seats, one end of the connecting rod is hinged to the mounting seat, and the other end of the connecting rod is hinged to the tightening block, and the tightening block is provided with a tightening screw for tightening the internal detector.

[0021] Furthermore, a second pressing plate is arranged on the inner side of the pressing block, two guide rods are arranged on the second pressing plate, and a guide hole matching with the guide rod is arranged on the pressing block.

[0022] Furthermore, a hand wheel is provided on the tightening screw, and anti-slip pads are provided on the second tightening plate and the mounting seat.

[0023] The beneficial effects of the present invention are:

[0024] The embodiment of the present application provides a composite diameter and mileage detection device for a two-way walking internal detector, which combines a mileage measurement component and a diameter measuring component into one. When there are depressions and protrusions in the pipeline, the diameter measuring component can drive the mileage measurement component to jump together, and the jumping can cause changes in the impedance parameters of the measuring winding, and the diameter measurement is achieved by measuring the changes in the impedance parameters. In this way, the mileage can be measured while measuring the diameter. Not only is the structure compact and space-saving, but also because the mileage measurement component and the diameter measuring component are in the same axial position, there will be no error in the axial mileage positioning of the pipeline diameter change during measurement. That is, when a change in diameter is measured, the position displayed by the current mileage measurement component is the position where the diameter changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the three-dimensional structure of a diameter-mileage composite detection device applied to a two-way walking internal detector provided in an embodiment of the present application;

[0026] Figure 2 for Figure 1 A schematic diagram of the enlarged structure of part A;

[0027] Figure 3 for Figure 1 A schematic diagram of the enlarged structure of part B;

[0028] Figure 4 A front view of a diameter-mileage composite detection device for a two-way walking internal detector provided in an embodiment of the present application;

[0029] Figure 5 A side view of a diameter-mileage composite detection device for a two-way walking internal detector provided in an embodiment of the present application;

[0030] Figure 6 for Figure 5 AA section view in;

[0031] Figure 7 for Figure 6 A schematic diagram of the enlarged structure of the middle C part;

[0032] Figure 8 for Figure 6 A schematic diagram of the enlarged structure of the D part;

[0033] Fig. 9 is a schematic diagram of the three-dimensional structure of the mounting base;

[0034] Fig.10 It is a three-dimensional structural schematic diagram of the tightening block;

[0035] Fig.11is a schematic diagram of the three-dimensional structure of the composite detection unit;

[0036] Fig.12 The diagram is a structural diagram of a diameter-mileage composite detection device for a bidirectional walking internal detector when it is installed on the internal detector.

[0037] In the figure: 1, composite detection unit; 11, main housing; 111, cylinder; 112, sealing plate; 113, boss; 114, second flange plate; 12, diameter measuring component; 121, connecting rod; 1211, mover; 1212, first guide part; 1213, second guide part; 122, measuring winding; 123, first spring; 124, second spring; 13, mileage measuring component; 131, mounting frame; 132, mileage wheel; 133, mileage sensor; 134, rotating shaft; 14, guide slide;

[0038] 2. Mounting unit; 21. Mounting seat; 211. First top plate; 212. Connecting tube; 213. First flange plate; 214. Connecting plate; 215. First ear plate; 22. Top block; 221. Second ear plate; 222. Threaded through hole; 223. Guide hole; 23. Connecting rod; 24. First hinge axis; 25. Second hinge axis; 26. Top screw; 261. Hand wheel; 27. Second top plate; 271. Guide rod;

[0039] 3. Internal detector. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application, and the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by those skilled in the art without creative work on the basis of the embodiments of the present application shall belong to the protection scope of the present application.

[0041] like Figure 1 and Figure 4 As shown, a diameter mileage composite detection device applied to a bidirectional walking internal detector includes a plurality of composite detection units 1, and the plurality of composite detection units 1 are evenly arranged along the circumferential direction around the internal detector 3 and fixedly connected to the side wall of the internal detector 3 in a detachable manner.

[0042] As a specific implementation, three composite detection units 1 are evenly distributed along the circumferential direction on the inner detector 3 described in this embodiment.

[0043] like Figure 7 and Fig.11As shown, the composite detection unit 1 includes a main housing 11, and the main housing 11 is fixedly connected to the side wall of the internal detector 3 in a detachable manner. The main housing 11 includes a barrel 111, and sealing plates 112 for closing the openings at both ends of the barrel 111 are respectively provided at both ends of the barrel 111, and at least one sealing plate 112 is fixedly connected to the barrel 111 in a detachable manner.

[0044] As a specific implementation, the barrel 111 described in this embodiment is a cylindrical barrel structure.

[0045] As a specific implementation, in this embodiment, only one sealing plate 112 is fixedly connected to the cylinder 111 in a detachable manner, and the detachable sealing plate 112 is located on the side close to the internal detector 3.

[0046] As a specific implementation, in this embodiment, the sealing plate 112 that is fixedly connected to the cylinder 111 in a detachable manner is fixedly connected to the cylinder 111 of the main housing 11 by a threaded connection.

[0047] Furthermore, for the convenience of installation, a boss 113 for cooperating with a tightening tool is provided on the outer side (the side facing the outside of the main housing 11 is the outer side) of the sealing plate 112 which is detachably fixedly connected to the cylinder 111. Exemplarily, the boss 113 is a regular hexagonal structure and can be matched with a commonly used tightening tool (wrench).

[0048] like Figure 7 As shown, a diameter measuring component 12 for measuring the diameter of the pipeline is arranged in the main housing 11.

[0049] The diameter measuring component 12 includes a connecting rod 121 extending in the axial direction, and the connecting rod 121 is coaxially arranged with the main housing 11. Both ends of the connecting rod 121 extend to the outside of the main housing 11 through the sealing plate 112, and the sealing plate 112 is provided with an avoidance hole for allowing the connecting rod 121 to pass through.

[0050] The connecting rod 121 is provided with a mover 1211, and the mover 1211 is in a conical structure. As a specific implementation, in this embodiment, the diameter of the mover 1211 gradually increases in the direction toward the inner detector 3.

[0051] A measuring winding 122 coaxially arranged with the connecting rod 121 is disposed in the main housing 11 , and the measuring winding 122 is fixedly connected to the inner side surface of the main housing 11 in a detachable manner.

[0052] A first spring 123 is sleeved on the connecting rod 121 between the mover 1211 and the sealing plate 112 on the side close to the inner detector 3 , and the first spring 123 is used to prevent the mover 1211 from approaching the inner detector 3 .

[0053] like Figure 6 and Fig.11 As shown, an mileage measuring component 13 for measuring mileage is provided at one end of the connecting rod 121 facing away from the inner detector 3 .

[0054] like Figure 8 and Fig.11 As shown, the mileage measurement component 13 includes a mounting frame 131, and the mounting frame 131 is fixedly connected to the connecting rod 121. The mounting frame 131 is provided with a mileage wheel 132 and a mileage sensor 133 for measuring the number of rotations of the mileage wheel 132. As a specific implementation, the mileage sensor 133 in this embodiment is a magnetic mileage sensor 133.

[0055] As a specific implementation, the mounting frame 131 described in this embodiment includes a web, and the two ends of the web are respectively provided with wing plates extending perpendicular to the web toward the side facing away from the main housing 11, and the web and the wing plates together form a U-shaped structure with an opening toward the side facing away from the main housing 11. The web of the mounting frame 131 is fixedly connected to the connecting rod 121. The mileage wheel 132 is located between the two wing plates, and the mileage wheel 132 is rotatably connected to the mounting frame 131 through a rotating shaft 134, and the mileage wheel 132 can rotate synchronously with the rotating shaft 134. The mileage sensor 133 is fixedly arranged on the wing plate on one side of the mounting frame 131 in a detachable manner, and the signal input shaft of the mileage sensor 133 is connected to the rotating shaft 134. When the mileage wheel 132 rotates along the inner side wall of the pipeline, the signal input shaft of the mileage sensor 133 can be driven to rotate synchronously through the rotating shaft 134, so as to measure the number of rotations of the mileage wheel 132, and obtain the straight-line distance traveled by the number of rotations, so as to perform mileage positioning.

[0056] As a specific implementation, the mileage wheel 132 described in this embodiment is connected to the rotating shaft 134 by a key connection, and the two ends of the rotating shaft 134 are rotatably connected to the wing plate through bearing assemblies. The connection flange of the mileage sensor 133 is fixedly arranged on the wing plate on one side of the mounting frame 131 by screws, and a flat mouth is arranged on the signal input shaft of the mileage sensor 133, and a plug hole matching the signal input shaft is arranged at one end of the rotating shaft 134 facing the mileage sensor 133.

[0057] When the internal detector 3 equipped with the diameter-mileage composite detection device is installed in the pipeline to be detected, the mileage wheel 132 abuts against the inner wall of the pipeline, the first spring 123 is compressed, and the measuring winding 122 is located in the middle of the mover 1211. When there are depressions and protrusions in the pipeline, the mover 1211 will move radially driven by the connecting rod 121. At this time, the distance between the measuring winding 122 and the mover 1211 changes, thereby affecting the impedance change of the measuring winding 122. By detecting the impedance change of the measuring winding 122, the movement distance of the mover 1211 can be obtained, thereby obtaining the change in diameter.

[0058] Furthermore, if Figure 7 As shown, the sealing plate 112 is detachably fixed with a guide slide 14 that matches the connecting rod 121, and the diameter of the avoidance hole on the sealing plate 112 for accommodating the connecting rod 121 is larger than the diameter of the connecting rod 121. As a specific implementation, the guide slide 14 in this embodiment adopts a linear bearing.

[0059] Furthermore, if Figure 7 As shown, the connecting rod 121 includes a first guide portion 1212 and a second guide portion 1213 in sequence along the direction close to the inner detector 3, and the first guide portion 1212 and the second guide portion 1213 are fixedly connected in a detachable manner. The mover 1211 is arranged on the second guide portion 1213.

[0060] As a specific implementation, the mover 1211 described in this embodiment is a frustum structure, and the end surface of the mover 1211 is flush with the end surface of the second guide portion 1213 facing the first guide portion 1212. A stud is provided on the end surface of the second guide column facing the first guide column, and a threaded hole matching the stud is provided on the end surface of the first guide portion 1212 facing the second guide portion 1213.

[0061] The reason for such design is that when the mileage measurement component 13 is damaged, only the first connection portion of the connecting rod 121 needs to be removed, which is convenient and quick for repair and replacement, and can better meet the needs of on-site inspection and ensure the inspection progress.

[0062] Furthermore, a second spring 124 is sleeved on the connecting rod 121 between the mover 1211 and the sealing plate 112 on the side away from the inner detector 3. The second spring 124 can ensure that the mileage wheel 132 can maintain a stable position when no force is applied, thereby avoiding axial movement.

[0063] Furthermore, if Fig.12As shown, a diameter mileage composite detection device applied to a bidirectional walking inner detector also includes an installation unit 2 for clamping the outer wall of the inner detector 3, and the composite detection unit 1 is fixedly arranged on the installation unit 2 in a detachable manner.

[0064] like Figure 1 and Figure 4 As shown, the mounting unit 2 includes a plurality of mounting seats 21, the number of the mounting seats 21 is the same as the number of the composite detection unit 1, and the plurality of mounting seats 21 are evenly arranged in the circumferential direction around the internal detector 3. A tightening block 22 is provided between adjacent mounting seats 21, and the two ends of the tightening block 22 are respectively connected to the adjacent mounting seats 21 through a connecting rod 23. One end of the connecting rod 23 is hinged to the mounting seat 21 through a first hinge shaft 24, and the other end of the connecting rod 23 is hinged to the tightening block 22 through a second hinge shaft 25. The main housing 11 of the composite detection unit 1 is fixedly arranged on the corresponding mounting seat 21 in a detachable manner, and a tightening screw 26 for tightening the internal detector 3 is provided on the tightening block 22, and the tightening screw 26 extends along the radial direction of the internal detector 3, that is, the axis of the tightening screw 26 intersects with the axis of the internal detector 3.

[0065] like Figure 5 and Figure 6 As shown, when the inner end of the tightening screw 26 abuts against the inner detector 3 and the tightening screw 26 is rotated, the tightening screw 26 drives the tightening block 22 to move along the K direction, thereby tightening the connecting rod 23 and applying two forces F to the mounting seat 21 through the connecting rod 23. The two forces F can press the mounting seat 21 against the side wall of the inner detector 3. When several mounting seats 21 press the inner detector 3 inward at the same time, the tightening effect can be achieved, so that the entire mounting unit 2 is tightened on the inner detector 3.

[0066] As a specific implementation method, Figure 2 and Fig. 9As shown, the mounting seat 21 includes a first top plate 211 with an arc-shaped structure, a connecting tube 212 is arranged on the outer cylindrical surface of the first top plate 211, one end of the connecting tube 212 is fixedly connected to the first top plate 211 by welding, and the other end of the connecting tube 212 is provided with a first flange plate 213. The end of the main housing 11 facing the inner detector 3 is provided with a second flange plate 114, and the first flange plate 213 and the second flange plate 114 are connected and fixed by a bolt assembly. The two ends of the first top plate 211 are respectively provided with connecting plates 214 extending along the radial direction of the first top plate 211, and the outer side surface of the connecting plate 214 (the side facing the connecting tube 212 is the inner side) is provided with a first ear plate 215, and the end of the connecting rod 23 facing the mounting seat 21 is hinged to the first ear plate 215 through a first hinge shaft 24. The two ends of the tightening block 22 are respectively provided with second ear plates 221 , and one end of the connecting rod 23 facing the tightening block 22 is hinged to the second ear plate 221 via a second hinge shaft 25 .

[0067] Furthermore, in order to prevent the tightening screw 26 from causing damage to the outer side of the inner detector 3, as shown in FIG. Figure 3 and Fig.10 As shown, a second clamping plate 27 with an arc-shaped structure is provided on the inner side of the clamping block 22 (the side facing the inner detector 3 is the inner side), and two guide rods 271 are provided on the second clamping plate 27. Guide holes 223 matching with the guide rods 271 are respectively provided on both sides of the threaded through hole 222 on the clamping block 22 matching with the clamping screw 26.

[0068] Furthermore, in order to facilitate operation, a hand wheel 261 is provided at one end of the tightening screw 26 facing away from the inner detector 3 .

[0069] Furthermore, anti-slip pads (not shown in the figure) made of rubber material are disposed on the inner side surfaces of the first pressing plate 211 and the second pressing plate 27 .

[0070] Embodiment 2

[0071] The flange plate is located at the closed end of the main housing 11. The remaining structures are the same as those in the first embodiment.

[0072] Embodiment 3

[0073] The diameter of the mover 1211 gradually decreases in the direction toward the opening end of the main housing 11. The rest of the structure is the same as that of the first embodiment.

[0074] Embodiment 4

[0075] The mileage sensor 133 is located between the two wing plates, and the signal input shaft of the mileage sensor 133 passes through one wing plate and extends to the outside of the wing plate (the side opposite to the two wing plates is the inside). The signal input shaft of the mileage sensor 133 is connected to the rotating shaft 134 through a transmission mechanism.

[0076] As a specific implementation, the transmission mechanism described in this embodiment adopts synchronous belt transmission.

[0077] The remaining structures are the same as those in the first embodiment.

[0078] Embodiment 5

[0079] Remove the installation unit 2, and a third flange plate with an arc-shaped structure is provided at one end of the main housing 11 facing the inner detector 3, and the third flange plate is consistent with the outer side surface of the inner detector 3. The third flange plate is fixedly connected to the outer side wall of the inner detector 3 by screws. There is a distance between the sealing plate 112 fixedly connected to the cylinder 111 in a detachable manner and the end surface of the cylinder 111 facing the inner detector 3, and the distance can provide space for the extension and retraction of the connecting rod 121. The rest of the structure is the same as that of the first embodiment.

[0080] Embodiment 6

[0081] The installation unit 2 includes two hoops with a semicircular structure, and a third ear plate is respectively provided at both ends of the hoops. The two opposite second ear plates 221 are connected and fixed by a bolt assembly. The two hoops form a circular structure and are clamped on the internal detector 3. The hoops are provided with mounting tubes extending in the radial direction. The number of the mounting tubes is the same as the number of the composite detection units 1, and they correspond one to one. The mounting tubes are evenly arranged along the circumferential direction on the circular structure formed by the two hoops. An internal thread is provided at the open end of the mounting tube, and an external thread matching the internal thread is provided on the outer side surface of the end of the main shell 11 facing the internal detector 3, that is, the main shell 11 is connected and fixed to the mounting tube by a threaded connection. The remaining structure is the same as that of Example 1.

[0082] Other embodiments obtained by those skilled in the art by combining, splitting, reorganizing, etc. the embodiments of the present application on the basis of the embodiments provided in the present application do not exceed the protection scope of the present application.

[0083] The above specific implementation methods have detailed the purpose, technical solutions and beneficial effects of the embodiments of the present application. The above are only specific implementation methods of the embodiments of the present application and are not used to limit the protection scope of the embodiments of the present application. That is, any modifications, equivalent substitutions, improvements, etc. made on the basis of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A diameter-mileage composite detection device for a two-way walking internal detector, characterized in that: It comprises a plurality of composite detection units (1), wherein the plurality of composite detection units (1) are arranged around an inner detector (3); The composite detection unit (1) comprises a main housing (11), wherein a diameter measuring component (12) for measuring the diameter of a pipeline is arranged in the main housing (11); The diameter measuring component (12) comprises a connecting rod (121), and two ends of the connecting rod (121) respectively pass through the side wall of the main housing (11) and extend to the outside of the main housing (11); A mover (1211) with a conical structure is coaxially arranged on the connecting rod (121), and a measuring winding (122) coaxially arranged with the connecting rod (121) is arranged in the main housing (11); A first spring (123) is sleeved on the connecting rod (121) on the side of the mover (1211) facing the inner detector (3); An mileage measuring component (13) is provided at one end of the connecting rod (121) facing away from the inner detector (3); When the internal detector (3) is installed in a pipeline to be detected, the mileage wheel (132) abuts against the inner wall of the pipeline, the first spring (123) is compressed, and the measuring winding (122) is located in the middle of the mover (1211); When depressions and protrusions exist in the pipeline, the mover (1211) and the measuring winding (122) move relative to each other, the impedance of the measuring winding (122) changes, and the movement distance of the mover (1211) can be obtained by detecting the impedance change of the measuring winding (122).

2. According to claim 1, a diameter-mileage composite detection device for a two-way walking internal detector is characterized in that: The mileage measurement component (13) comprises a mounting frame (131) arranged on the connecting rod (121), and the mounting frame (131) is provided with a mileage wheel (132) and a mileage sensor (133) for measuring the number of rotations of the mileage wheel (132).

3. According to claim 1, a diameter-mileage composite detection device for a two-way walking internal detector is characterized in that: The connecting rod (121) includes a first guide portion (1212) and a second guide portion (1213) in sequence along a direction approaching the internal detector (3), and the first guide portion (1212) and the second guide portion (1213) are fixedly connected in a detachable manner, and the mover (1211) is arranged on the second guide portion (1213).

4. According to claim 1, a diameter-mileage composite detection device for a two-way walking internal detector is characterized in that: A second spring (124) is sleeved on the connecting rod (121) on the side of the mover (1211) facing away from the inner detector (3).

5. The diameter-mileage composite detection device for a two-way walking internal detector according to claim 1 is characterized in that: The main shell (11) comprises a cylinder (111) and sealing plates (112) for closing openings at both ends of the cylinder (111), and at least one sealing plate (112) is fixedly connected to the cylinder (111) in a detachable manner.

6. The diameter-mileage composite detection device for a two-way walking internal detector according to claim 5 is characterized in that: The sealing plate (112) fixedly connected to the cylinder (111) in a detachable manner is fixedly connected to the cylinder (111) in a threaded manner, and a boss (113) for cooperating with a tightening tool is provided on the sealing plate (112) fixedly connected to the cylinder (111) in a detachable manner.

7. The diameter-mileage composite detection device for a two-way walking internal detector according to claim 1 is characterized in that: It also includes a mounting unit (2) for tightening the outer side wall of the inner detector (3), and the composite detection unit (1) is arranged on the mounting unit (2).

8. The diameter-mileage composite detection device for a two-way walking internal detector according to claim 7 is characterized in that: The mounting unit (2) comprises a plurality of mounting seats (21) corresponding one to the composite detection unit (1), and the composite detection unit (1) is arranged on the corresponding mounting seat (21), a tightening block (22) is arranged between adjacent mounting seats (21), a connecting rod (23) is arranged between the connected tightening blocks (22) and the mounting seats (21), one end of the connecting rod (23) is hinged to the mounting seat (21), and the other end of the connecting rod (23) is hinged to the tightening block (22), and the tightening block (22) is provided with a tightening screw (26) for tightening the internal detector (3).

9. The diameter-mileage composite detection device for a two-way walking internal detector according to claim 8 is characterized in that: A second pressing plate (27) is arranged on the inner side of the pressing block (22), two guide rods (271) are arranged on the second pressing plate (27), and a guide hole (223) matching with the guide rod (271) is arranged on the pressing block (22).

10. The diameter-mileage composite detection device for a two-way walking internal detector according to claim 9, characterized in that: The tightening screw rod (26) is provided with a hand wheel (261), and the second tightening plate (27) and the mounting seat (21) are both provided with anti-slip pads.

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