A four-axis cutting and grinding robot for trenchless pipelines and its usage method

Abstract

This invention discloses a four-axis cutting and grinding robot for trenchless pipelines and its usage method. The robot includes a mobile chassis, a lifting structure, a directional arm, and a grinding device. The lifting structure is mounted on the mobile chassis, the directional arm is positioned at the top of the lifting structure, and the grinding device is located at the outer end of the directional arm. The directional arm includes a rotary directional arm and a pitch directional arm. The rotary directional arm is positioned at the top of the lifting structure, and the pitch directional arm is positioned at the outer end of the rotary directional arm. The rotary directional arm controls the rotation of the pitch directional arm, and the grinding device is located at the outer end of the pitch directional arm. This invention uses a short-arm directional arm and expands its range of motion through the lifting structure, making the robot suitable for pipelines with diameters from DN200mm to DN800mm. This effectively increases the robot's operating radius coverage. Furthermore, the short-arm directional arm avoids instability caused by excessive outward tilt of the center of gravity, resulting in greater stability and safety during operation.

Description

Technical Field

[0001] This invention relates to the field of pipeline robot technology, specifically to a four-axis cutting and grinding robot for trenchless pipelines and its usage method. Background Technology

[0002] With urbanization, existing underground pipe networks often need to be connected to new ones. However, the aging of these older networks severely impacts the efficiency of the new ones, necessitating repairs to improve overall network performance. Traditional open-cut repairs require extensive road disruption, leading to traffic congestion, noise pollution, and earthwork issues, while also being time-consuming and costly. Therefore, trenchless technologies, through in-situ repair or partial upgrades, have become a common solution for pipe network upgrades. Trenchless technologies primarily rely on pipeline robots. Existing pipeline robots often use a coaxial long arm as the cutterhead mounting base. This coaxial design effectively reduces the robot's size, facilitating entry and exit from pipelines, while the long arm provides a wider operating range, enabling the robot to work on larger diameter pipes. However, the long arm itself shifts the center of gravity to one side, making the robot prone to instability. Therefore, the working range cannot be set very large. Either the chassis size needs to be increased and the weight added, but an increased robot size cannot enter pipes with small diameters. Thus, existing robots suffer from a small working radius coverage. This invention provides a four-axis cutting and grinding robot for trenchless pipework and a method of using it to solve the above-mentioned defects. Summary of the Invention

[0003] This invention provides a four-axis cutting and grinding robot for trenchless pipelines and its usage method. By utilizing the combination of a lifting structure and a short arm, it has a large working radius, solving the technical problem of the small working radius coverage of existing robots.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A four-axis cutting and grinding robot for trenchless pipelines includes a mobile chassis, a lifting structure, a directional arm, and a grinding device. The lifting structure is mounted on the mobile chassis, the directional arm is mounted at the top of the lifting structure, and the grinding device is mounted at the outer end of the directional arm. The directional arm includes a rotary directional arm and a pitch directional arm. The rotary directional arm is located at the top of the lifting structure, which controls the rotary directional arm to lift and rotate. The pitch directional arm is located at the outer end of the rotary directional arm, which controls the pitch directional arm to rotate. The grinding device is located at the outer end of the pitch directional arm, which controls the grinding device to pitch.

[0005] Furthermore, the lifting structure includes a turntable, a lifting arm, an actuator arm, and a slide rail mechanism. The turntable is movably mounted on a movable chassis, the actuator arm and the slide rail mechanism are mounted on the turntable, the bottom end of the lifting arm is movably mounted on the slide rail mechanism, and the top ends of the lifting arm and the actuator arm are movably connected to a rotary steering arm.

[0006] Furthermore, the lifting arm includes a first lifting rod, a second lifting rod, and a connecting rod. The bottom ends of the first and second lifting rods are movably connected to the slide rail mechanism, and the top ends of the first and second lifting rods are movably connected to the rotary steering arm. The connecting rod is located between the first and second lifting rods.

[0007] Furthermore, the first lifting rod is provided with a guide groove, one end of the connecting rod is located in the guide groove, and the other end is connected to the top of the second lifting rod.

[0008] Furthermore, the working radius of the lifting structure when it is deployed is four times that when it is retracted.

[0009] Furthermore, the rotary steering arm includes a first power unit, a first transmission unit, and a drive shaft. The first power unit and the drive shaft are arranged side by side. The drive shaft is connected to the first power unit through the first transmission unit. The pitch steering arm is connected to the outer end of the drive shaft.

[0010] Furthermore, the pitch directional arm includes a power box, side arms, and a swing camera. The power box is connected to the outer end of the rotary directional arm. The side arms are arranged in pairs on the power box. The grinding device is movably arranged between the pairs of side arms. The swing camera is movably arranged on one of the side arms.

[0011] Furthermore, the mobile chassis includes a chassis frame, a second power unit, a second transmission unit, and a drive wheel. The drive wheel is movably mounted on the chassis frame, and the second power unit is connected to the drive wheel through the second transmission unit to drive the drive wheel to rotate.

[0012] Furthermore, the grinding device includes a mounting base and a cutting tool, the mounting base being movably mounted on the pitch adjustment arm, and the cutting tool being detachably mounted on the mounting base.

[0013] A method for using a four-axis cutting and grinding robot for trenchless pipework includes the following steps: S1: The lifting structure is in the retracted state, and the grinding device is leveled by controlling the pitch adjustment arm, so that the robot enters the pipe in the retracted state. S2: After the robot moves to the construction position, it determines the unfolding range according to the inner diameter of the pipe, controls the lifting structure to unfold, and then controls the grinding device to move by rotating the directional arm and tilting the directional arm, so that the grinding device contacts the top of the pipe. S3: Start the grinding device to perform cutting and grinding operations. The operation is carried out in the order of circumferential first and then axial. When working in the circumferential direction, the coordinated action of the lifting structure, the rotating directional arm, the pitch directional arm and the moving chassis makes the movement trajectory of the grinding device a circular curve. When working in the axial direction, the robot moves along the pipe axis by moving the chassis. S4: After the operation is completed, the robot is stored in the lifting structure, and then the robot is removed from the pipeline by moving the chassis.

[0014] The beneficial effects of this invention are as follows: By adopting a short-arm directional arm and expanding its range of motion through a lifting structure, the robot is suitable for pipes with diameters from DN200mm to DN800mm, effectively improving the coverage of the robot's working radius. Furthermore, the short-arm directional arm can avoid instability caused by excessive outward tilt of the center of gravity, making the operation more stable and safer. The four-axis motion formed by the lifting structure, rotating directional arm, and pitch directional arm gives the grinding device a higher degree of freedom. During operation, the orientation can be flexibly adjusted as needed, making it easier to cut and grind the object and effectively improving work efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the mobile chassis of the present invention; Figure 3 This is a schematic diagram of the connection state of the lifting mechanism of the present invention; Figure 4 This is a schematic diagram of the lifting structure of the present invention; Figure 5 This is a schematic diagram of the rotary steering arm of the present invention; Figure 6 This is a schematic cross-sectional view of the rotary steering arm of the present invention; Figure 7 This is a top view schematic diagram of the connection state between the pitch adjustment arm and the grinding device of the present invention; Figure 8 This is a side view of the pitch adjustment arm and the grinding device of the present invention in a connected state.

[0016] Reference numerals: 1. Mobile chassis; 11. Chassis frame; 12. Second power unit; 13. Second transmission device; 14. Power wheel; 2. Lifting structure; 21. Turntable; 22. Lifting arm; 221. First lifting rod; 222. Second lifting rod; 223. Connecting rod; 23. Action arm; 24. Slide rail mechanism; 3. Grinding device; 31. Mounting seat; 32. Cutting tool; 4. Rotary steering arm; 41. First power unit; 42. First transmission device; 43. Drive shaft; 5. Pitch steering arm; 51. Power box; 52. Side arm; 53. Swing camera. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] like Figure 1 As shown, a four-axis cutting and grinding robot for trenchless pipelines includes a mobile chassis 1, a lifting structure 2, a directional arm, and a grinding device 3. The lifting structure 2 is mounted on the mobile chassis 1, the directional arm is located at the top of the lifting structure 2, and the grinding device 3 is located at the outer end of the directional arm. The directional arm includes a rotational directional arm 4 and a pitch directional arm 5. The rotational directional arm 4 is located at the top of the lifting structure 2, and the lifting structure 2 is used to control the lifting and rotation of the rotational directional arm 4. The pitch directional arm 5 is located at the outer end of the rotational directional arm 4. The rotary directional arm 4 is used to control the rotation of the pitch directional arm 5. The grinding device 3 is located at the outer end of the pitch directional arm 5. The pitch directional arm 5 is used to control the pitch of the grinding device 3. Through the combined action of the lifting structure 2, the rotary directional arm 4, and the pitch directional arm 5, the four-axis movement of the grinding device 3 is realized, making the orientation adjustment of the grinding device 3 more flexible. In conjunction with the short arm structure of the directional arm, the grinding device 3 can face any direction and achieve cutting and grinding of foreign objects on the inner wall of the pipe from any angle, effectively improving the work capacity and work efficiency.

[0020] The mobile chassis 1 of this invention serves as the moving mechanism and mounting base. The steering arm is connected to the mobile chassis 1 via a lifting structure 2. The lifting structure 2's movement lifts and retracts the steering arm and its grinding device 3. When the lifting structure 2 is fully extended and coordinates with the steering arm's extension, the robot's maximum working pipe diameter is DN800mm. When the lifting structure 2 is fully retracted and coordinates with the steering arm's retraction, the robot's minimum working pipe diameter is DN200mm. This increases the robot's working radius by 200mm compared to existing robots, effectively improving its working range. Furthermore, the short-arm steering arm, which works in conjunction with the lifting structure 2, ensures a large working radius while avoiding the instability defects present in long-arm steering arms.

[0021] like Figure 1 As shown, during operation, the robot is moved by the mobile chassis 1, and the lifting structure 2 lifts the directional arm and the grinding device 3 on it, thereby expanding the working range of the grinding device 3. During operation, the rotation of the directional arm 4 controls the rotation of the pitch directional arm 5 and the grinding device 3 on it around the axis, thereby adjusting the direction of the grinding device 3. The pitch directional arm 5 controls the pitch movement of the grinding device 3 on it, thereby adjusting the pitch of the grinding device 3 and thus adjusting the working radius of the grinding device 3. When a large-scale adjustment of the working radius of the grinding device 3 is required, the forward and backward movement of the mobile chassis 1, the lifting and lowering control of the lifting structure 2, the directional adjustment of the rotation of the directional arm 4, and the pitch adjustment of the pitch of the pitch directional arm 5 are used for comprehensive control, thereby achieving a large-scale adjustment of the working radius of the grinding device 3.

[0022] like Figure 1 , 3 As shown in Figure 4, the lifting structure 2 further includes a turntable 21, a lifting arm 22, an actuator arm 23, and a slide rail mechanism 24. The turntable 21 is movably mounted on the movable chassis 1 and can be rotated in a controlled manner. The actuator arm 23 and the slide rail mechanism 24 are mounted on the turntable 21. The bottom end of the lifting arm 22 is movably mounted on the slide rail mechanism 24. The top ends of both the lifting arm 22 and the actuator arm 23 are movably connected to the rotary directional arm 4. When performing the lifting action, the actuator arm 23 is the active arm, and the lifting action is performed by the extension and retraction of the actuator arm 23. When the actuator arm 23 is in motion, the lifting arm 22 is the passive arm, and works with the slide rail mechanism 24 to perform the passive action of the actuator arm 23. The lifting action is achieved through the cooperation of the lifting arm 22 and the actuator arm 23.

[0023] When applied to large-diameter pipelines, the short-arm directional arm provides sufficient length for operation in the axial direction, but the arm length for lateral movement is insufficient, preventing the grinding device 3 from effectively contacting the pipe walls on both sides. By rotating the turntable 21, the mechanism located above it is turned, allowing the grinding device 3 to effectively contact the pipe walls on both sides, thus enabling normal operation.

[0024] like Figure 3 , 4 As shown, the lifting arms 22 are arranged in pairs, with the two lifting arms 22 symmetrically arranged on both sides of the rotary steering arm 4. Each lifting arm 22 includes a first lifting rod 221, a second lifting rod 222, and a connecting rod 223. The bottom ends of the first lifting rod 221 and the second lifting rod 222 are movably connected to the slide rail mechanism 24, and the top ends of the first lifting rod 221 and the second lifting rod 222 are movably connected to the rotary steering arm 4. The connecting rod 223 is located between the first lifting rod 221 and the second lifting rod 222.

[0025] Furthermore, the first lifting rod 221 is provided with a guide groove, one end of the connecting rod 223 is located in the guide groove, and the other end is connected to the top of the second lifting rod 222. The connecting rod 223 is set as a physical limit, and the range of motion of the connecting rod 223 is the length of the guide groove, which limits the range of motion of the actuator arm 23.

[0026] Furthermore, the working radius of the lifting structure 2 when it is deployed is 4 times that when it is retracted, the minimum working pipe diameter is DN200mm, and the maximum working pipe diameter is DN800mm.

[0027] like Figure 5 , 6 As shown, the rotary steering arm 4 further includes a first power unit 41, a first transmission unit 42, and a drive shaft 43. The first power unit 41 is located below the drive shaft 43 and is arranged parallel to the drive shaft 43 to reduce the arm length of the rotary steering arm 4. The drive shaft 43 is connected to the first power unit 41 through the first transmission unit 42, and the pitch steering arm 5 is connected to the outer end of the drive shaft 43.

[0028] Preferably, the first power device 41 is an electric motor, and most of the first transmission devices 42 are gear sets.

[0029] like Figure 7 , 8As shown, the pitch adjustment arm 5 further includes a power box 51, side arms 52 and a swing camera 53. The power box 51 is connected to the outer end of the rotary adjustment arm 4. The side arms 52 are arranged in pairs on the power box 51 to form a U-shaped double arm structure. The grinding device 3 is movably arranged between the pairs of side arms 52 and located inside the U-shaped structure. The swing camera 53 is movably arranged on one of the side arms 52.

[0030] Furthermore, a third power device is provided inside the power box 51. A first rotating shaft is provided on one side arm 52, and a second rotating shaft is provided on the other side arm 52. Both the first and second rotating shafts are connected to the third power device. The rotation of the first and second rotating shafts is controlled by the third power device. The grinding device 3 is provided on the first rotating shaft, and the swing camera 53 is provided on the second rotating shaft.

[0031] like Figure 2 As shown, the mobile chassis 1 further includes a chassis frame 11, a second power unit 12, a second transmission device 13, and a power wheel 14. The power wheel 14 is movably mounted on the chassis frame 11. The second power unit 12 is connected to the power wheel 14 through the second transmission device 13, driving the power wheel 14 to rotate.

[0032] Furthermore, the drive wheels 14 are arranged in groups, with the drive wheels 14 located on the same side of the chassis frame 11 forming a group. The second power device 12 and the second transmission device 13 are connected to form a power mechanism, and two power mechanisms are provided. The two power mechanisms control the two groups of drive wheels 14 respectively, and steering is achieved through the differential speed of the two power mechanisms.

[0033] Preferably, the second power device 12 is an electric motor, and the second transmission device 13 is a multi-gear gear set.

[0034] Furthermore, the grinding device 3 includes a mounting base 31 and a cutting tool 32. The mounting base 31 is movably mounted on the pitch adjustment arm 5, and the cutting tool 32 is detachably mounted on the mounting base 31.

[0035] Preferably, the mounting base 31 is provided with a fourth power device, which is a pneumatic motor.

[0036] A method for using a four-axis cutting and grinding robot for trenchless pipework includes the following steps: S1: The lifting structure 2 is in the retracted state, and the grinding device 3 is leveled by the pitch adjustment arm 5, reducing the size of the robot so that the robot can enter the pipe in the retracted state. S2: After the robot moves to the construction position, the robot's deployment range is determined according to the inner diameter of the pipe. Then, the lifting structure 2 is controlled to deploy, and the grinding device 3 is controlled to move by rotating the directional arm 4 and tilting the directional arm 5, so that the grinding device 3 contacts the top of the pipe. S3: Start the grinding device 3 to perform cutting and grinding operations. The operation is carried out in the order of first circumferential and then axial. When working in the circumferential direction, the coordinated action of the lifting structure 2, the rotary directional arm 4, the pitch directional arm 5 and the moving chassis 1 makes the movement trajectory of the grinding device 3 a circular curve. After completing one cycle of operation, it moves forward in the axial direction. When working in the axial direction, the robot moves along the pipe axis by moving chassis 1. S4: After the operation is completed, the robot is stored in the lifting structure 2, and then the robot is removed from the pipeline by moving the chassis 1.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A four-axis cutting and grinding robot for trenchless pipework, characterized in that, It includes a mobile chassis (1), a lifting structure (2), a steering arm, and a grinding device (3). The lifting structure (2) is mounted on the mobile chassis (1), the steering arm is mounted at the top of the lifting structure (2), and the grinding device (3) is mounted at the outer end of the steering arm. The directional arm includes a rotary directional arm (4) and a pitch directional arm (5). The rotary directional arm (4) is located at the top of the lifting structure (2). The lifting structure (2) is used to control the rotary directional arm (4) to lift and rotate. The pitch directional arm (5) is located at the outer end of the rotary directional arm (4). The rotary directional arm (4) is used to control the pitch directional arm (5) to rotate. The grinding device (3) is located at the outer end of the pitch directional arm (5). The pitch directional arm (5) is used to control the grinding device (3) to pitch. The working radius of the lifting structure (2) when it is deployed is 4 times that when it is retracted; The lifting structure (2) includes a turntable (21), a lifting arm (22), an action arm (23), and a slide rail mechanism (24). The turntable (21) is movably mounted on the movable chassis (1). The action arm (23) and the slide rail mechanism (24) are mounted on the turntable (21). The bottom end of the lifting arm (22) is movably mounted on the slide rail mechanism (24). The top ends of the lifting arm (22) and the action arm (23) are movably connected to the rotary steering arm (4). The pitch adjustment arm (5) includes a power box (51), side arms (52) and a swing camera (53). The power box (51) is connected to the outer end of the rotary adjustment arm (4). The side arms (52) are arranged in pairs on the power box (51). The grinding device (3) is movably arranged between the pairs of side arms (52). The swing camera (53) is movably arranged on one of the side arms (52). The power box (51) is equipped with a third power device. A first rotating shaft is provided on one side arm (52), and a second rotating shaft is provided on the other side arm (52). Both the first and second rotating shafts are connected to the third power device. The rotation of the first and second rotating shafts is controlled by the third power device. The grinding device (3) is provided on the first rotating shaft, and the swing camera (53) is provided on the second rotating shaft.

2. The four-axis cutting and grinding robot for trenchless pipelines according to claim 1, characterized in that, The lifting arm (22) includes a first lifting rod (221), a second lifting rod (222), and a connecting rod (223). The bottom ends of the first lifting rod (221) and the second lifting rod (222) are movably connected to the slide rail mechanism (24), and the top ends of the first lifting rod (221) and the second lifting rod (222) are movably connected to the rotary steering arm (4). The connecting rod (223) is located between the first lifting rod (221) and the second lifting rod (222).

3. A four-axis cutting and grinding robot for trenchless pipelines according to claim 2, characterized in that, The first lifting rod (221) is provided with a guide groove, one end of the connecting rod (223) is located in the guide groove, and the other end is connected to the top of the second lifting rod (222).

4. A four-axis cutting and grinding robot for trenchless pipelines according to claim 1, characterized in that, The rotary steering arm (4) includes a first power unit (41), a first transmission unit (42) and a drive shaft (43). The first power unit (41) and the drive shaft (43) are arranged side by side. The drive shaft (43) is connected to the first power unit (41) through the first transmission unit (42). The pitch steering arm (5) is connected to the outer end of the drive shaft (43).

5. A four-axis cutting and grinding robot for trenchless pipelines according to claim 1, characterized in that, The mobile chassis (1) includes a chassis frame (11), a second power unit (12), a second transmission device (13), and a power wheel (14). The power wheel (14) is movably mounted on the chassis frame (11). The second power unit (12) is connected to the power wheel (14) through the second transmission device (13) to drive the power wheel (14) to rotate.

6. A four-axis cutting and grinding robot for trenchless pipelines according to claim 1, characterized in that: The grinding device (3) includes a mounting base (31) and a cutting tool (32). The mounting base (31) is movably mounted on the pitch adjustment arm (5), and the cutting tool (32) is detachably mounted on the mounting base (31).

7. The method of using a four-axis cutting and grinding robot for trenchless pipelines as described in claim 1, characterized in that, Includes the following steps, S1: The lifting structure (2) is in the storage state, and the grinding device (3) is leveled by the pitch adjustment arm (5), so that the robot enters the pipe in the storage state; S2: After the robot travels to the construction position, it determines the unfolding range according to the inner diameter of the pipe, controls the lifting structure (2) to unfold, and then controls the grinding device (3) to move by rotating the directional arm (4) and tilting the directional arm (5) so that the grinding device (3) contacts the top of the pipe. S3: Start the grinding device (3) to carry out cutting and grinding operations. The operation is carried out in the order of first circumferential and then axial. When the operation is carried out in the circumferential direction, the movement trajectory of the grinding device (3) is a circular curve through the coordinated action of the lifting structure (2), the rotating adjustment arm (4), the pitch adjustment arm (5) and the moving chassis (1). When the operation is carried out in the axial direction, the robot moves along the pipeline axis through the moving chassis (1). S4: After the operation is completed, the robot is stored in the lifting structure (2), and then the robot is removed from the pipeline by moving the chassis (1).

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