A parallelogram linkage type pipeline robot adaptive variable diameter locking mechanism

Abstract

This invention relates to the field of pipeline robot technology, and particularly to an adaptive diameter-changing locking mechanism for a parallelogram-linked pipeline robot, comprising a central body, leg components, a diameter-changing locking ring, a sliding seat, and a linear drive assembly. The leg components include a main swing arm, an upper link, a lower link, a wheel frame, a drive wheel assembly, and an energy storage spring. The diameter-changing locking ring has a combined guide locking groove into which a follower locking pin on the main swing arm passes. This groove includes a release window, an oblique guide section, and an axial locking section. In the release-wall-adhering mode, the follower locking pin is located in the release window, and the energy storage spring causes the drive wheel assembly to adaptively adhere to the pipe wall. In the locking mode, the linear drive assembly pushes the diameter-changing locking ring to move, causing the follower locking pin to enter the axial locking section via the oblique guide section, thus locking the radial swing of the main swing arm. This invention combines adaptive diameter-changing passage capability with walking posture stability, has a compact structure, and high reliability.

Description

Technical Field

[0001] This invention relates to the field of pipeline robot technology, and in particular to an adaptive diameter-changing locking mechanism for a parallelogram-linked pipeline robot. Background Technology

[0002] Pipeline robots are widely used in the inspection, cleaning, and maintenance of pipelines in industries such as oil, natural gas, chemicals, municipal water supply, and sewage. Due to the complex and variable pipeline environment, which often includes obstacles such as diameter changes and bends, extremely high demands are placed on the robot's locomotion mechanism.

[0003] Existing pipeline robot locomotion mechanisms are mainly classified into wheeled, tracked, and peristaltic types, among which wheeled robots are widely used due to their simple structure and high walking speed. However, when facing pipes with varying diameters, traditional wheeled locomotion mechanisms usually rely on complex electronic control systems to adjust the wheel track in real time. This not only results in slow response speed and complex control algorithms, but also makes them prone to failure in deep wells or long-distance pipelines where communication is limited. At the same time, when passing through bends, rigid wheeled mechanisms often slip or get stuck because they cannot adaptively conform to the pipe wall.

[0004] To address the aforementioned issues, although some studies have proposed spring-pressed or swing-arm adaptive mechanisms, these still suffer from technical shortcomings such as limited adaptive capabilities and an inability to balance cornering flexibility with straight-line stability. Summary of the Invention

[0005] The purpose of this invention is to provide a parallelogram linkage-type adaptive diameter-changing locking mechanism for pipeline robots that is compact, responsive, and highly reliable, aiming to solve the problems of poor passability and complex control of existing pipeline robots in variable diameter and curved pipe environments.

[0006] To achieve the above objectives, the present invention provides an adaptive variable diameter locking mechanism for a parallelogram linkage pipe robot, comprising a central body, at least three leg components evenly distributed around the circumference of the central body, a variable diameter locking ring sleeved around the periphery of the central body and moving along the axial direction of the central body, a sliding seat disposed within the central body, and a linear drive assembly for driving the sliding seat. Each of the leg components includes a main swing arm, an upper link, a lower link, a wheel frame, a drive wheel assembly, and an energy storage spring. One end of the main swing arm is hinged to the central body, and the other end of the main swing arm is hinged to the upper link and the lower link. The upper link, lower link, far end of the main swing arm, and wheel frame together form a parallelogram linkage mechanism, and the drive wheel assembly is mounted on the wheel frame.

[0007] Preferably, the upper surface of the variable diameter locking ring is provided with radial guide ear plates corresponding to each leg component, and each radial guide ear plate is provided with a combined guide locking groove. The main swing arm is provided with a follower locking pin that passes through the corresponding combined guide locking groove. The combined guide locking groove includes a release window, an oblique guide section and an axial locking section. The sliding seat is connected to the variable diameter locking ring via a transmission connector, so that the combined guide locking groove moves with the variable diameter locking ring relative to the follower locking pin, and the radial displacement of the follower locking pin is restricted after it enters the axial locking section.

[0008] Preferably, the two ends of the energy storage spring are respectively connected to a first spring seat on the main swing arm and a second spring seat on the upper connecting rod, and the first spring seat and the second spring seat are provided with adjusting nuts for adjusting the initial preload of the spring.

[0009] Preferably, the contour envelope of the release window follows the movement trajectory of the locking pin within the allowable swing angle range of the main swing arm, so that the main swing arm can swing freely when the locking pin is located in the release window.

[0010] Preferably, the inclined guide section connects the release window and the axial locking section with a tangential arc transition; the axial locking section extends axially along the central body, and its groove width is adapted to the diameter and assembly clearance of the follower locking pin, so as to allow the variable diameter locking ring to continue to make a small amount of axial movement and limit the radial displacement of the follower locking pin.

[0011] Preferably, the housing of the central body has an axially penetrating opening, and the transmission connector passes through the opening to connect with the sliding seat and the variable diameter locking ring; The linear drive assembly is a lead screw motor, an electric push rod, or a linear motor.

[0012] Preferably, an axial guide structure is provided between the variable diameter locking ring and the central body, and the axial guide structure restricts the circumferential rotation of the variable diameter locking ring relative to the central body; The two ends of the axial guide structure are provided with limiting members to restrict the axial movement of the variable diameter locking ring.

[0013] Preferably, the number of leg components is three or four, and they are evenly distributed around the central body. Each drive wheel assembly includes a hub motor or a micro geared motor and can be driven independently.

[0014] Preferably, the hinge joints between the main swing arm and the central body, the hinge joints of the parallelogram linkage mechanism, and the sliding fit joint between the variable diameter locking ring and the central body are provided with dustproof or sealing structures.

[0015] Therefore, the parallelogram linkage-type adaptive diameter-changing locking mechanism for pipeline robots provided by this invention has the following beneficial effects: The upper linkage, lower linkage, end of the main swing arm, and wheel structure of this invention form a parallelogram linkage mechanism. Through an energy storage spring, the leg assembly maintains a tendency to open towards the pipe wall in the released state, passively adapting to changes in pipe diameter and the curvature of bends without electrical control intervention, thus solving the problem of jamming or disengagement in variable-diameter pipes and bends. Simultaneously, the linear drive assembly pushes the diameter-changing locking ring, causing the follower locking pin to enter the axial locking section and restricting the radial swing of the main swing arm. This rigidly locks the leg posture during straight pipe movement, avoiding body swaying caused by the continuous elastic action of the spring. The two modes can be switched according to the working conditions, balancing the throughput in complex pipeline environments with posture stability and traction output quality during straight-line movement.

[0016] This invention employs a single linear drive component to propel a variable-diameter locking ring axially. Multiple radial guide lugs and their combined guide locking grooves on the variable-diameter locking ring simultaneously lock or release all circumferentially distributed leg components. The combined guide locking grooves of this invention are equipped with a release window, an oblique guide section, and an axial locking section. These three sections form a continuous guide trajectory, allowing the follower locking pin to sequentially experience three distinct mechanical states during the axial movement of the variable-diameter locking ring: free swing, guided transition, and radial locking. Attached Figure Description

[0017] Figure 1 This is an axial view of an adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to an embodiment of the present invention. Figure 2 This is a top view of an adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to an embodiment of the present invention. Figure 3 This is a front view of an adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to an embodiment of the present invention. Figure 4 This is a cross-sectional view of an adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the radial guide ear plate in an embodiment of the present invention; Figure Labels 1. Central body; 2. Main swing arm; 3. Drive wheel assembly; 4. Variable diameter locking ring; 41. Combined guide locking groove; 411. Release window; 412. Inclined guide section; 413. Axial locking section; 42. Radial guide ear plate; 5. Upper connecting rod; 6. Lower connecting rod; 7. Wheel frame; 8. Transmission connecting component; 9. Energy storage spring; 91. First spring seat; 92. Second spring seat; 10. Follow-up locking pin; 11. Sliding seat; 12. Linear drive assembly; 13. Axial guide structure; 14. Limiting component. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example like Figure 1-5 As shown, the present invention provides an adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot, comprising a central body 1, three leg components, a diameter-changing locking ring 4, a sliding seat 11, and a linear drive component 12.

[0021] The central body 1 is a cylindrical structure with an internal cavity for accommodating the sliding seat 11 and the linear drive assembly 12. Three hinge seats are evenly distributed circumferentially on the upper surface of the central body 1, each used to mount a corresponding leg assembly. The three leg assemblies are evenly arranged at 120° intervals along the circumference of the central body 1. This circumferential distribution ensures that the mechanism receives uniform support force on the pipe cross-section, keeping the axis of the central body 1 essentially coincident with the pipe axis during movement and preventing the body from tilting due to uneven force distribution.

[0022] The variable diameter locking ring 4 is sleeved on the periphery of the central body 1, and an axial guide structure 13 is provided between the ring body and the outer wall of the central body 1. The axial guide structure 13 can be in the form of a guide rail and slide groove, which is used to restrict the circumferential rotation of the variable diameter locking ring 4 relative to the central body 1, while ensuring that it can slide freely along the axial direction of the central body 1.

[0023] Viewed from the end face, the three leg components are evenly distributed circumferentially. The root of each main swing arm 2 is hinged to the central body 1. The three radial guide plates 42 on the variable diameter locking ring 4 correspond to the positions of the three main swing arms 2 respectively. The follower locking pin 10 on each main swing arm 2 passes into the combined guide locking groove 41 on the corresponding radial guide plate 42.

[0024] Each leg assembly includes a main swing arm 2, an upper connecting rod 5, a lower connecting rod 6, a wheel frame 7, a drive wheel assembly 3, and an energy storage spring 9. The root of the main swing arm 2 is connected to a hinge seat on the central body 1 via a hinge shaft, and the end of the main swing arm 2 is hinged to one end of the upper connecting rod 5 and the lower connecting rod 6 via two hinge shafts, respectively. The other ends of the upper connecting rod 5 and the lower connecting rod 6 are respectively hinged to the wheel frame 7 via two hinge shafts. The upper connecting rod 5, the lower connecting rod 6, the end section of the main swing arm 2, and the corresponding section on the wheel frame 7 together constitute a parallelogram linkage mechanism.

[0025] The upper link 5 and the lower link 6 are of equal length. The distance between the two hinge axes at the end of the main swing arm 2 is equal to the distance between the two corresponding hinge axes on the wheel frame 7, and the axes of the four hinge axes are parallel to each other. When the above geometric conditions are met, no matter what angle the main swing arm 2 rotates around its root hinge axis, the attitude of the wheel frame 7 remains unchanged relative to absolute space.

[0026] The drive wheel assembly 3 is mounted on the wheel frame 7. The rolling plane of the drive wheel assembly 3 is parallel to the axis of the central body 1, and the rotation axis of the drive wheel assembly 3 is set tangentially along the local circumference of the pipe. This arrangement ensures that the direction of movement of the drive wheel on the inner wall of the pipe is consistent with the direction of the pipe axis, and the drive wheel can drive the body to move axially along the pipe when it rolls.

[0027] In this embodiment, the energy storage spring 9 is a tension spring. One end of the tension spring is connected to a first spring seat 91 disposed on the main swing arm 2, and the other end is connected to a second spring seat 92 disposed on the upper connecting rod 5. The function of the spring is to provide a continuous outward expansion torque for the leg assembly, that is, the energy storage spring 9 always has a tendency to push the main swing arm 2 outward away from the central body 1, thereby keeping the drive wheel assembly 3 pressed against the tube wall.

[0028] An adjusting nut is provided on the first spring seat 91. By rotating the adjusting nut, the installation position of the first spring seat 91 relative to the main swing arm 2 can be changed, thereby changing the initial preload of the energy storage spring 9. In practical applications, operators can adjust the preload of each spring uniformly by adjusting the adjusting nut according to the diameter of the target pipe and the required wall pressure, so that the mechanism can adapt to different pipe specifications without replacing springs or other parts.

[0029] The variable diameter locking ring 4 includes an annular body sleeved on the outside of the central body 1, and a plurality of radial guide plates 42 extending radially outward from the annular body. The number of radial guide plates 42 is the same as the number of leg components, and in this embodiment there are three, with each radial guide plate 42 located in the swing plane of the corresponding main swing arm 2.

[0030] Each radial guide ear plate 42 has a combined guide locking groove 41. The follower locking pin 10 on the main swing arm 2 passes into the corresponding combined guide locking groove 41 and can slide relative to it within the groove.

[0031] The combined guide locking groove 41 includes a release window 411, an inclined guide section 412, and an axial locking section 413. The release window 411 is located at the starting end of the combined guide locking groove 41. The groove shape of this section is a large-sized open window, and its contour is designed to enclose the entire movement trajectory of the follower locking pin 10 within the allowable swing angle range of the main swing arm 2. When the follower locking pin 10 is located within the release window 411, the radial displacement generated by the follower locking pin 10 swinging with the main swing arm 2 is completely within the contour range of the window, and the edge of the window will not interfere with or limit the follower locking pin 10. Therefore, in this state, the main swing arm 2 can swing freely within its entire designed swing angle range without any constraint from the variable diameter locking ring 4.

[0032] The inclined guide section 412 connects the release window 411 and the axial locking section 413. Its channel extends obliquely, meaning that the channel direction is neither parallel to the axial direction nor the radial direction, but rather at an inclined angle. The connection between the inclined guide section 412 and the release window 411, as well as the connection between the inclined guide section 412 and the axial locking section 413, uses a smooth arc transition to ensure that the follower locking pin 10 moves smoothly during the section switching process and avoids impact or jamming.

[0033] The axial locking section 413 is located at the end of the combined guide locking groove 41, and the groove direction of this section is parallel to the axial direction of the central body 1. The groove width of the axial locking section 413 is set to match the diameter of the follower locking pin 10 and the preset assembly gap. When the follower locking pin 10 enters the axial locking section 413, due to the limiting effect of the groove wall in the radial direction, the follower locking pin 10 cannot produce any effective displacement in the radial direction. Since the follower locking pin 10 is fixed on the main swing arm 2, the radial swing of the main swing arm 2 is completely restricted.

[0034] A limiting element 14 is also provided between the annular body of the variable diameter locking ring 4 and the central body 1. This limiting element 14 is used to limit the two extreme positions of the variable diameter locking ring 4 along the axial direction. When the variable diameter locking ring 4 moves to the release limit position, the limiting element 14 prevents it from moving further in the release direction. At this time, the follower locking pin 10 is exactly located in the release window 411. When the variable diameter locking ring 4 moves to the locking limit position, the limiting element 14 prevents it from moving further in the locking direction. At this time, the follower locking pin 10 is exactly fully inserted into the axial locking section 413.

[0035] The sliding seat 11 is disposed within the internal cavity of the central body 1, and a sliding mating surface is provided between its outer wall and the inner wall of the central body 1, allowing the sliding seat 11 to freely reciprocate along the axial direction of the central body 1. A linear drive assembly 12 is disposed inside the central body 1, and its output end is connected to the sliding seat 11 to drive the sliding seat 11 to move axially. The linear drive assembly 12 can be any one of a lead screw motor, an electric actuator, or a linear motor. In this embodiment, an electric actuator is preferred.

[0036] The transmission connector 8 is a rod-shaped component, one end of which is fixedly connected to the sliding seat 11, and the other end passes through an axial opening in the housing of the central body 1 and is fixedly connected to the annular body of the variable diameter locking ring 4. The axial opening extends axially along the central body 1, and its length is not less than the maximum axial stroke of the variable diameter locking ring 4, so as to ensure that the transmission connector 8 is not interfered with by the housing when it moves with the sliding seat 11. The axial movement of the sliding seat 11 is synchronously transmitted to the variable diameter locking ring 4 via the transmission connector 8, so that the variable diameter locking ring 4 produces the same axial displacement relative to the central body 1.

[0037] The working principle of the adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to the present invention: In the release-wall-attached mode, the linear drive assembly 12 remains in the release position, the variable diameter locking ring 4 is at the limit position of the release end, and the follower lock pin 10 is located within the release window 411 of the combined guide locking groove 41. At this time, the follower lock pin 10 has sufficient radial movement space within the release window 411, and the variable diameter locking ring 4 does not impose any radial constraint on the main swing arm 2.

[0038] The energy storage spring 9 continuously pulls the main swing arm 2, causing each leg assembly to open outwards. The drive wheel assembly 3, under the spring force, presses against the inner wall of the pipe. When the pipe diameter changes or the robot enters a bend, the balance between the pipe wall reaction force and the spring force is broken. The main swing arm 2 can then swing freely outwards or inwards around its root hinge axis. Simultaneously, the upper connecting rod 5 and the lower connecting rod 6 rotate around the hinge axis to compensate for local geometric changes, ensuring that the drive wheel assembly 3 always remains in contact with the pipe wall. In this mode, each leg assembly adapts independently and does not interfere with the others.

[0039] When it is necessary to lock the leg assembly at the current angle, the linear drive assembly 12 is activated, which pushes the sliding seat 11 to move axially. The sliding seat 11 drives the variable diameter locking ring 4 to move in the same direction through the transmission connector 8. At this time, the combined guide locking groove 41 moves together with the variable diameter locking ring 4, while the follower locking pin 10 remains relatively stationary.

[0040] The follower lock pin 10 enters the inclined guide section 412 from the release window 411, and then enters the axial locking section 413. The axial locking section 413 extends axially, and its groove width restricts the radial displacement of the follower lock pin 10. Since the follower lock pin 10 is fixed to the main swing arm 2, the radial swing of the main swing arm 2 is completely locked. At this time, the main swing arm 2 can no longer open outward or retract inward, and the leg posture is rigidly maintained.

[0041] After the linear drive assembly 12 reaches the locking limit position, it stops driving. The variable diameter locking ring 4 is limited by the limit member 14, and the locking operation is completed. At this time, the main swing arms 2 of each leg assembly are locked at a fixed angle, and the drive wheel assembly 3 adheres to the pipe wall with a stable positive pressure. The robot walks in a stable posture without shaking when walking on the straight pipe section.

[0042] When the adaptive wall-hugging capability needs to be restored to cope with subsequent diameter change sections or bends, the linear drive assembly 12 reverses its action, pulling the sliding seat 11 and the diameter change locking ring 4 to move in the opposite direction. The follower locking pin 10 returns from the axial locking section 413 through the oblique guide section 412 to the release window 411, regaining radial freedom. The main swing arm 2 regains its free swing capability, and the mechanism returns to the release wall-hugging mode.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A parallelogram-linked adaptive diameter-changing locking mechanism for a pipe robot, characterized in that: It includes a central body, at least three leg assemblies evenly distributed around the circumference of the central body, a variable diameter locking ring sleeved around the periphery of the central body and moving along the axial direction of the central body, a sliding seat disposed inside the central body, and a linear drive assembly for driving the sliding seat. Each of the leg components includes a main swing arm, an upper link, a lower link, a wheel frame, a drive wheel assembly, and an energy storage spring. One end of the main swing arm is hinged to the central body, and the other end of the main swing arm is hinged to the upper link and the lower link. The upper link, lower link, far end of the main swing arm, and wheel frame together form a parallelogram linkage mechanism, and the drive wheel assembly is mounted on the wheel frame.

2. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 1, characterized in that: The upper surface of the variable diameter locking ring is provided with radial guide ear plates corresponding to each leg component. Each radial guide ear plate is provided with a combined guide locking groove. The main swing arm is provided with a follower locking pin that passes through the corresponding combined guide locking groove. The combined guide locking groove includes a release window, an oblique guide section and an axial locking section. The sliding seat is connected to the variable diameter locking ring via a transmission connector, so that the combined guide locking groove moves with the variable diameter locking ring relative to the follower locking pin, and the radial displacement of the follower locking pin is restricted after it enters the axial locking section.

3. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 2, characterized in that: The two ends of the energy storage spring are respectively connected to a first spring seat on the main swing arm and a second spring seat on the upper connecting rod. The first spring seat and the second spring seat are provided with adjusting nuts for adjusting the initial preload of the spring.

4. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 2, characterized in that: The contour envelope of the release window follows the movement trajectory of the follower lock pin within the allowable swing angle range of the main swing arm, allowing the main swing arm to swing freely when the follower lock pin is located in the release window.

5. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 4, characterized in that: The inclined guide section connects the release window and the axial locking section with a tangential arc transition; the axial locking section extends axially along the central body, and its groove width is adapted to the diameter and assembly clearance of the follower locking pin, so as to allow the variable diameter locking ring to continue to make a small amount of axial movement and limit the radial displacement of the follower locking pin.

6. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 5, characterized in that: The housing of the central body has an axially penetrating opening, through which the transmission connector passes to connect with the sliding seat and the variable diameter locking ring. The linear drive assembly is a lead screw motor, an electric push rod, or a linear motor.

7. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 6, characterized in that: An axial guide structure is provided between the variable diameter locking ring and the central body, and the axial guide structure restricts the circumferential rotation of the variable diameter locking ring relative to the central body. The two ends of the axial guide structure are provided with limiting members to restrict the axial movement of the variable diameter locking ring.

8. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 1, characterized in that: The number of leg components is three or four, and they are evenly distributed around the central body. Each drive wheel assembly includes a hub motor or a micro geared motor and can be driven independently.

9. The adaptive diameter-changing locking mechanism for a parallelogram-linked pipe robot according to claim 1, characterized in that: The hinge joints between the main swing arm and the central body, the hinge joints of the parallelogram linkage mechanism, and the sliding fit between the variable diameter locking ring and the central body are provided with dustproof or sealing structures.

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