A robot end effector based on adaptive gripping and torque detection

Abstract

The application discloses a robot end effector based on adaptive clamping and torque detection and relates to the technical field of shield machine tool changing robot production, which comprises a shell connected with a robot end; a driving unit arranged in the shell; a driving mechanism arranged in the shell and in transmission connection with the driving unit; a flexible limiting coil spring connected to the driving mechanism; a first port and a second port arranged on the shell; the flexible limiting coil spring is unwound by the driving mechanism, and then the end of the flexible limiting coil spring moves from the first port to the second port and abuts against the driving mechanism. The robot end effector based on adaptive clamping and torque detection is small in size, makes the manipulator more flexible during movement, can adapt to the wear of a tool shaft, can adapt to tool shafts with different degrees of wear during tool changing, does not shake, is safer during tool changing, and greatly improves tool changing efficiency.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine cutter changer manufacturing technology, and more specifically to a robot end effector based on adaptive clamping and torque detection. Background Technology

[0002] As shield tunnel engineering develops towards complex geological environments and small cross-sections, the operation of cutter-changing robots faces the dual challenges of limited space and high torque control precision.

[0003] According to invention patent application CN105855849A, published on August 17, 2016, a single cutterhead changing robot for a tunnel boring machine (TBM) is disclosed. The robot includes a housing, on which are mounted bolt disassembly / assembly modules, trapezoidal wedge disassembly / assembly modules, square wedge disassembly / assembly modules, an axial rotation module, and a cutterhead disassembly / assembly fixing module. The trapezoidal wedge disassembly / assembly module includes a second fixing flange fixed to the housing, and a first electromagnet is fixed to the second fixing flange. The square wedge disassembly / assembly module includes a disassembly / assembly telescopic part and a disassembly / assembly rotation part. The cutterhead disassembly / assembly fixing module includes a third hydraulic cylinder fixed to the housing, and the piston rod of the third hydraulic cylinder is connected to a bolt fixing block. Its main technical advantages are: it can be used in conjunction with a telescopic mechanism to replace manual cutterhead changing operations, thereby improving the efficiency of TBM cutterhead changing, ensuring the safety of construction personnel, and accelerating the progress of tunnel excavation.

[0004] Traditional tool changers are mostly hydraulically or pneumatically driven, relying on multi-stage telescopic structures and external sensors for clamping and torque detection. In existing technologies, hydraulically driven grippers occupy excessive axial space, making them difficult to maneuver flexibly in narrow manholes. While pneumatic grippers offer some flexibility, they lack high-precision torque feedback, which can lead to uncontrolled tool installation stress. Furthermore, because existing grippers are rigid structures, they cannot adapt to subtle dimensional changes in tool wear, requiring frequent positioning adjustments to achieve optimal fixation, significantly reducing tool changing efficiency. Therefore, this paper proposes a robotic end effector based on adaptive clamping and torque detection, aiming to solve the problems of poor flexibility and inability to adapt to tool wear in existing tool changers. Summary of the Invention

[0005] The purpose of this invention is to provide a robot end effector based on adaptive gripping and torque detection, which aims to solve the problems of poor flexibility and inability to adapt to tool wear in the traditional tool changer in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A robot end effector based on adaptive gripping and torque detection includes a housing connected to the robot end effector, and further includes: A drive unit is disposed within a housing, and a drive mechanism is disposed within the housing. The drive unit and the drive mechanism are connected in a transmission connection. A flexible limiting coil spring is connected to the drive mechanism. The outer casing is provided with a first port and a second port; The drive mechanism drives the flexible limiting coil spring to unwind, thereby causing the end of the flexible limiting coil spring to move from the first port to the second port and abut against the drive mechanism.

[0007] Preferably, the drive mechanism includes a take-up pulley, a drive pulley, and a timing belt. The flexible limiting spring is wound onto the take-up pulley. The drive pulley and the take-up pulley are connected inside the housing. The timing belt is connected to the take-up pulley and the take-up pulley.

[0008] Preferably, the drive mechanism further includes a driven wheel, which is rotatably connected to the inner wall of the housing, and the driven wheel is spaced apart from the drive pulley.

[0009] Preferably, the take-up pulley and the drive pulley are symmetrically arranged inside the housing.

[0010] Preferably, the device also includes a commutator, which is fixedly installed inside the housing. A bearing housing is fixedly installed on the outer wall of the commutator, a bearing is installed on the output end of the commutator, and the drive pulley is fixedly installed on the output end of the commutator.

[0011] Preferably, an arc-shaped guide plate is provided in the second port, with one end of the arc-shaped guide plate located between the driven wheel and the winding wheel.

[0012] Preferably, the flexible limiting coil spring has a positioning hole, and the drive pulley is provided with a connecting rod, which is distributed in an array on the peripheral wall of the drive pulley.

[0013] In the above technical solution, the robot end effector based on adaptive clamping and torque detection provided by the present invention has the following beneficial effects: This invention utilizes a drive unit located inside the housing to drive a drive mechanism that unwinds a flexible limiting spring. This spring then moves from the first port of the housing to the second port, forming a closed structure that limits the tool's shaft, thus fixing the tool to the housing. The use of a flexible limiting spring for tool shaft fixation results in a smaller size, making the robot arm more flexible during movement. Furthermore, the flexible limiting spring's contact with the outer wall of the tool shaft adapts to wear, enabling it to adjust to different wear levels during tool changes. It provides consistent fixation regardless of the wear level, preventing wobbling and enhancing safety during tool changes. Tool changes no longer require repeated adjustments, significantly improving efficiency. The drive unit can directly read the tool's torque, allowing for assessment of wear levels and facilitating maintenance. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a schematic diagram of the overall three-dimensional structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of the outer shell provided in an embodiment of the present invention; Figure 3 A schematic diagram of the internal cross-sectional structure of the outer shell provided in an embodiment of the present invention. Figure 4 A schematic diagram of the internal structure of the outer shell provided in an embodiment of the present invention. Figure 5 A schematic diagram of the internal structure of the outer shell provided in an embodiment of the present invention. Figure 6 This is a schematic diagram of the internal structure of the outer shell provided in an embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures: 1. Housing; 11. First port; 12. Second port; 2. Drive unit; 3. Drive mechanism; 31. Take-up pulley; 32. Drive pulley; 321. Connecting rod; 33. Synchronous belt; 34. Driven pulley; 4. Reversing device; 5. Bearing housing; 6. Bearing; 7. Arc-shaped guide plate; 8. Flexible limiting coil spring; 81. Positioning hole. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0018] Please see Figure 1 — Figure 6 A robot end effector based on adaptive gripping and torque detection includes a housing 1, which is connected to the robot end effector, and further includes: The drive unit 2 is disposed inside the housing 1, and the drive mechanism 3 is disposed inside the housing 1. The drive unit 2 and the drive mechanism 3 are connected in a transmission connection. A flexible limiting coil spring 8 is connected to the drive mechanism 3. The outer casing 1 is provided with a first port 11 and a second port 12; The drive mechanism 3 drives the flexible limiting coil spring 8 to unwind, thereby moving the end of the flexible limiting coil spring 8 from the first port 11 to the second port 12 and abutting against the drive mechanism 3.

[0019] Specifically, the outer shell 1 is fixedly installed on the robot arm, and a drive unit 2 is fixedly installed inside the outer shell 1. As an embodiment provided by the present invention, the drive unit 2 is a servo motor, and a drive mechanism 3 is installed inside the outer shell 1. The drive mechanism 3 is connected to the drive unit 2 in a transmission manner, and the drive unit 2 can drive the drive mechanism 3 to keep rotating.

[0020] A flexible limiting coil spring 8 is connected to the drive mechanism 3. Specifically, the flexible limiting coil spring 8 is an elastic coil spring.

[0021] Furthermore, such as Figure 2 As shown, a first port 11 and a second port 12 are provided on the outer wall of the outer casing 1. As an embodiment provided by the present invention, a groove for accommodating the arc-shaped outer wall of the hob is provided on one side of the outer wall of the outer casing 1. The first port 11 and the second port 12 are respectively located on both sides of the groove.

[0022] The drive unit 2 drives the drive mechanism 3 to rotate, causing the flexible limiting coil spring 8 to unwind and move from the first port 11 to the second port 12. This allows one end of the flexible limiting coil spring 8 to pass around the hob cutter shaft from the first port 11 to the second port 12 and remain connected to the drive mechanism 3. The drive mechanism 3 then winds up one end of the flexible limiting coil spring 8, and finally, the flexible limiting coil spring 8 fixes the hob cutter shaft to the outer shell 1.

[0023] It should be noted that winding up the flexible limiting coil spring 8 does not mean that the flexible limiting coil spring 8 is wound around the drive pulley 32. It is only necessary to drive the flexible limiting coil spring 8 to move so that the flexible limiting coil spring 8 is in close contact with the hob shaft.

[0024] As an embodiment of the present invention, the natural curvature radius of the flexible limiting coil spring 8 is 230mm-250mm, preferably 240mm, and the winding curvature radius of the flexible limiting coil spring 8 is 30mm-50mm.

[0025] It should be noted that the natural curvature radius and the winding curvature radius of the flexible limiting coil spring 8 can be designed according to different types of cutting tools.

[0026] As an embodiment provided by the present invention, such as Figure 3 As shown, the drive mechanism 3 includes a take-up pulley 31, a drive pulley 32, and a synchronous belt 33. The take-up pulley 31 is rotatably connected to the inside of the housing 1 via a shaft. In a preferred embodiment of the present invention, there are two take-up pulleys 31, each located close to the inner wall of opposite sides of the housing 1. The drive unit 2 is fixedly mounted on the inner wall of the housing 1. The drive pulley 32 is tractively connected to the output end of the drive unit 2. In another preferred embodiment, there are two drive pulleys 32, each rotatably connected to the inner wall of opposite sides of the housing 1. Furthermore, both drive pulleys 32 are tractively connected to the drive unit 2. One end of the synchronous belt 33 is connected to the drive pulley 32, and the other end is connected to the take-up pulley 31. Preferably, there are two synchronous belts 33, each connected to one of the two take-up pulleys 31.

[0027] As a further embodiment provided by the present invention, such as Figure 3 As shown, the drive mechanism 3 also includes a driven wheel 34. Furthermore, the driven wheel 34 is rotatably connected to the inside of the housing 1 via a shaft. Preferably, there is a certain gap between the driven wheel 34 and the drive pulley 32 to allow the flexible limiting coil spring 8 to pass through.

[0028] Preferably, the rotational speed of the take-up pulley 32 is greater than that of the drive pulley 31, so as to ensure that when the flexible limiting spring 8 moves to the middle of the drive pulley 32 and the driven pulley 34 and comes into contact with the drive pulley 32, the drive pulley 32 can collect the end of the flexible limiting spring 8 located between the drive pulley 32 and the driven pulley 34. That is, the unwinding speed of the flexible limiting spring 8 at the first port 11 is less than the winding speed at the second port 12, so that the flexible limiting spring 8 can be tightened onto the outer wall of the cutter shaft.

[0029] Preferably, the mounting position of the winding pulley 32 is designed to allow the flexible limiting coil spring 8 wound on it to extend from the first port 11, move around the outside of the cutter shaft, and finally reach the inside of the second port 12. The shape of the flexible limiting coil spring 8 is also designed to ensure that after restoring its deformation, it can bypass the outer wall of the cutter shaft and reach the inside of the second port 12.

[0030] As an embodiment of the present invention, a commutator 4 is also included. Specifically, the commutator 4 is fixedly installed inside the housing 1. The input end of the commutator 4 is connected to the drive unit 2, and the output end of the commutator 4 is connected to the drive pulley 32. A bearing seat 5 is fixedly installed on the outer wall of the commutator 4, and a bearing 6 is installed inside the bearing seat 5. The bearing 6 is connected to the output end of the commutator 4 for lubrication.

[0031] This invention utilizes a drive unit 2 located inside the housing 1 to drive a drive mechanism 3, which in turn unwinds a flexible limiting coil spring 8. This causes the flexible limiting coil spring 28 to move from the first port 11 of the housing 1 to the second port 12, forming a closed structure that limits the movement of the tool shaft and fixes the tool to the housing 1. The use of the flexible limiting coil spring 8 to limit and fix the tool shaft results in a smaller size, making the robot arm more flexible during movement. Furthermore, the flexible limiting coil spring 8, by fitting against the outer wall of the tool shaft, can adapt to wear on the tool shaft. During tool changing, it can adapt to tool shafts with different wear levels, providing the same fixing effect regardless of the wear level, preventing wobbling and enhancing safety during tool changing. Tool changing eliminates the need for repeated adjustments, significantly improving efficiency. The drive unit 2 can directly read the tool torque, thereby determining the degree of tool wear and facilitating maintenance.

[0032] Since the embodiments provided by this invention use a servo motor as the drive, the torque of the servo motor can be read during actual use to obtain the torque of the cutter shaft rotation and determine the degree of hob wear. Compared with an external torque sensor, the structure is simpler, the manufacturing cost is lower, no wiring or sealing is required, and the failure rate is lower.

[0033] In the embodiments provided by the present invention, only one drive unit 2, namely a servo motor, is used for driving. The structure is relatively simple and easy to operate. During operation, it can provide a larger operating space for the gripper.

[0034] As another embodiment of the drive unit 2 provided by the present invention, it specifically includes a drive motor and a torque sensor. The drive motor drives the drive pulley 32 to keep rotating, and the torque sensor reads the torque of the drive motor, which can also determine the wear degree of the tool.

[0035] As a further embodiment provided by the present invention, such as Figure 5 and Figure 6As shown, a positioning hole 81 is provided on the flexible limiting coil spring 8, and an insertion rod 321 is provided on the outer wall of the drive pulley 32. The insertion rods 321 are arranged in a circumferential array on the outer wall of the drive pulley 32. The diameter of the insertion rods 321 is adapted to the diameter of the positioning hole 81, so that the insertion rods 321 can be inserted into the positioning hole 81. When the insertion rods 321 are inserted into the positioning hole 81, the drive pulley 32 and the flexible limiting coil spring 8 are locked together, so that the rotation of the drive pulley 32 can drive the flexible limiting coil spring 8 to move, thereby tightening the flexible limiting coil spring 8 onto the outer wall of the cutter shaft. At the same time, through the cooperation of the insertion rods 321 and the positioning hole 81, the flexible limiting coil spring 8 can be prevented from coming out, and the flexible limiting coil spring 8 can be prevented from loosening when the cutter shaft is moved.

[0036] Working principle: When it is necessary to grasp the hob, the robotic arm drives the housing 1 to move, so that the groove on the housing 1 can accommodate the outer wall of the hob. Subsequently, the commutator 4 is driven by the drive unit 2 to keep rotating, and the two drive pulleys 32 are driven by the commutator 4 to keep rotating. When the drive pulleys 32 keep rotating, the winding pulley 31 is driven to rotate by the synchronous belt 33, thereby unwinding the flexible limiting coil spring 8 wound on the winding pulley 31. The flexible limiting spring 8 extends from the first port 11. When the flexible limiting spring 8 is unwound and moves out of the first port 11, the flexible limiting spring 8 restores its deformation and gradually moves towards the second port 12 under the synchronous unwinding action of the winding pulley 31, so as to be able to bypass the hob cutter shaft. When the flexible limiting coil spring 8 moves to the second port 12, the arc-shaped guide plate 7 set on the second port 12 guides one end of the flexible limiting coil spring 8 to the driven wheel 34 and the drive pulley 32. Under the rotation of the drive pulley 32, the winding pulley 31 rotates and unwinds the flexible limiting coil spring 8, so that the flexible limiting coil spring 8 moves within the second port 12. When the flexible limiting coil spring 8 moves within the second port 12, as the drive pulley 32 rotates, the flexible limiting coil spring 8 will move toward the gap between the drive pulley 32 and the driven pulley 34. When the insertion rod 321 on the drive pulley 32 is inserted into the positioning hole 81 on the flexible limiting coil spring 8, the rotation of the drive pulley 32 can drive one end of the flexible limiting coil spring 8 to unwind, while the other end tightens, tightening the flexible limiting coil spring 8 onto the outer wall of the cutter shaft, thus fixing the cutter shaft to the outer shell. After tightening, the flexible limit spring 8 drives the cutter shaft to rotate at a certain angle. At this time, the torque signal of the cutter shaft can be read by the servo motor and fed back to the robot.

[0037] When the hob needs to be removed from the housing 1, the drive unit 2 controls the drive pulley 32 to rotate in the opposite direction, and the synchronous belt 33 drives the take-up pulley 31 to rotate in the opposite direction. At this time, the take-up pulley 31 winds up the flexible limiting coil spring 8, and the drive pulley 32 unwinds the flexible limiting coil spring 8, so that the flexible limiting coil spring 8 moves back from the second port 12 to the first port 11. The installation position of the flexible limiting coil spring 8 is designed to ensure that when it extends, it can bypass the cutter shaft to reach the second port 12, and when it retracts, it can return from the second port 12 to the first port 11 of the housing 1.

[0038] The flexible limiting coil spring 8 mentioned in this article has an elastic coefficient that meets the technical requirements of the technical solution of this invention.

[0039] Those skilled in the art will understand that other similar connection methods can also achieve the present invention. For example, welding, bonding, or screwing.

[0040] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A robot end effector based on adaptive gripping and torque detection, comprising a housing (1) connected to the robot end effector, characterized in that, Also includes: The drive unit (2) is located inside the housing (1), and the drive mechanism (3) is located inside the housing (1). The drive unit (2) and the drive mechanism (3) are connected in a transmission connection. A flexible limiting coil spring (8) is connected to the drive mechanism (3). The outer casing (1) is provided with a first port (11) and a second port (12); The flexible limiting coil spring (8) is unwound by the drive mechanism (3), thereby causing the end of the flexible limiting coil spring (8) to move from the first port (11) to the second port (12) and abut against the drive mechanism (3).

2. The robot end effector based on adaptive clamping and torque detection according to claim 1, characterized in that, The drive mechanism (3) includes a take-up pulley (31), a drive pulley (32), and a timing belt (33). The flexible limiting spring (8) is wound onto the take-up pulley (31). The drive pulley (32) and the take-up pulley (31) are connected inside the housing (1). The timing belt (33) is connected to the take-up pulley (31) and the take-up pulley (31).

3. The robot end effector based on adaptive gripping and torque detection according to claim 1, characterized in that, The drive mechanism (3) also includes a driven wheel (34), which is rotatably connected to the inner wall of the housing (1) and is spaced apart from the drive pulley (32).

4. A robot end effector based on adaptive clamping and torque detection according to claim 2, characterized in that, The winding pulley (31) and the drive pulley (32) are symmetrically arranged inside the outer shell (1).

5. A robot end effector based on adaptive gripping and torque detection according to claim 4, characterized in that, It also includes a commutator (4), which is fixedly installed inside the housing (1). A bearing seat (5) is fixedly installed on the outer wall of the commutator (4). A bearing (6) is installed on the output end of the commutator (4). The drive pulley (32) is fixedly installed on the output end of the commutator (4).

6. A robot end effector based on adaptive gripping and torque detection according to claim 3, characterized in that, An arc-shaped guide plate (7) is provided inside the second port (12), with one end of the arc-shaped guide plate (7) located between the driven wheel (34) and the winding pulley (31).

7. The robot end effector based on adaptive clamping and torque detection according to claim 1, wherein the flexible limiting coil spring (8) is provided with a positioning hole (81), the drive pulley (32) is provided with a plug rod (321), and the plug rod (321) is arrayed on the peripheral wall of the drive pulley (32).

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