A single-degree-of-freedom grasping device

Abstract

This invention proposes a single-degree-of-freedom finger grasping device, belonging to the field of robotic arms. It solves the problem of balancing the simplicity of single-degree-of-freedom finger control with grasping ability. It includes a frame with a drive assembly mounted on it. A first drive shaft and a second drive shaft with parallel axes are rotatably connected to the frame. The first drive shaft has a worm gear and a first incomplete gear, and the second drive shaft has a second incomplete gear. The first and second incomplete gears mesh with each other. The single-degree-of-freedom six-link finger includes a head joint, an intermediate joint, and a distal joint connected in sequence. The distal joint has a length greater than or equal to that of the intermediate joint and has a groove on its grasping surface. The first and second links, driven by the drive assembly, coordinate the intermediate and distal joints to achieve the overall movement of the single-degree-of-freedom six-link finger. It is mainly used for single-finger grasping.

Description

Technical Field

[0001] This invention belongs to the field of robotic arms, and in particular relates to a single-degree-of-freedom grasping device. Background Technology

[0002] In the field of industrial robotics, the design and control of the fingers are crucial. Dexterous hands excel at manipulating complex objects, but they are often bulky and difficult to meet the lightweight requirements of space-based operations.

[0003] In contrast, while single-degree-of-freedom hands are lightweight, their adaptability to objects is limited. For example, some fingers may not be able to grasp large-diameter circular objects, while others require two fingers to grasp even larger circular objects. A good balance cannot be struck between ease of control and grasping ability. Summary of the Invention

[0004] In view of this, the present invention aims to propose a single-degree-of-freedom finger grasping device to solve the problem of the inability to balance the simplicity of single-degree-of-freedom finger control and grasping ability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a single-degree-of-freedom grasping device, comprising:

[0006] A frame is provided with a drive assembly. A first drive shaft and a second drive shaft with parallel axes are rotatably connected to the frame. A worm gear and a first incomplete gear are provided on the first drive shaft, and a second incomplete gear is provided on the second drive shaft. The first incomplete gear and the second incomplete gear mesh with each other.

[0007] A single-degree-of-freedom six-link finger includes a first joint, an intermediate joint, and a last joint connected in sequence. The last joint has a length greater than or equal to that of the intermediate joint and has a groove on its gripping surface. The first link in the first joint is connected at its first end to a second drive shaft and at its last end to the intermediate joint. The second link in the first joint is hinged at its first end to the frame and at its last end to the intermediate joint. The first and second links are used to drive the intermediate and last joints together under the drive of the drive assembly to achieve the overall movement of the single-degree-of-freedom six-link finger.

[0008] Furthermore, the rack includes a lower rack and an upper rack that are detachably connected to each other, and the drive assembly is connected to the lower rack.

[0009] Furthermore, the drive component is a DC geared motor with a worm gear on its output end, the worm gear meshing with a worm wheel.

[0010] Furthermore, the first end joint also includes a sixth link and a seventh link. The first link and the sixth link have the same structure, are arranged opposite each other, and their first ends are both connected to the second drive shaft. The second link and the seventh link have the same cross-section, are arranged opposite each other, and the thickness of the seventh link is twice that of the second link. The first ends of the seventh link and the second link are both hinged to the frame.

[0011] Furthermore, the intermediate joint includes a third link, a fourth link, an eighth link, and a ninth link. The third link and the eighth link have the same structure and are arranged opposite each other. One corner of the first end of the third link, one corner of the first end of the eighth link, the end side of the second link, and the end side of the seventh link are rotatably connected by a pin. The other corner of the first end of the third link, the other corner of the first end of the eighth link, the end of the first link, and the end of the sixth link are rotatably connected by a pin. The fourth link and the ninth link have the same structure and are arranged opposite each other. The end of the second link, the end of the seventh link, the first end of the fourth link, and the first end of the ninth link are rotatably connected by a pin.

[0012] Furthermore, the end joint includes a fifth link, a tenth link, and an eleventh link with identical structures and arranged opposite each other. The ends of the third link, the eighth link, one corner of the first end of the fifth link, one corner of the first end of the tenth link, and one corner of the first end of the eleventh link are rotatably connected by a pin. The other corner of the first end of the fifth link, the other corner of the first end of the tenth link, the other corner of the first end of the eleventh link, the end of the fourth link, and the end of the ninth link are rotatably connected by a pin. The ends of the fifth link, the tenth link, and the eleventh link are fixedly connected.

[0013] Furthermore, the fifth, tenth, and eleventh links all have grooves at the same position on the gripping surfaces.

[0014] Furthermore, the groove is arc-shaped.

[0015] Furthermore, the line connecting one corner of the first end, the other corner of the first end, and the end of the fifth link forms a triangle.

[0016] Furthermore, the single-degree-of-freedom six-link finger is a carbon fiber finger.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. This gripping device adopts a single-degree-of-freedom finger structure with no degree-of-freedom redundancy, which makes the system more stable and easier to control.

[0019] 2. This gripping device uses a DC motor as the actuating element and can be controlled in conjunction with sensor information, making control simple;

[0020] 3. Each joint of this gripping device uses a repeating arrangement of connecting rods, which can improve stability and gripping ability and reduce the impact of the backlash of the rotating joints;

[0021] 4. This gripping device uses an extended end joint and groove design to achieve a larger coverage area. Combined with the repeated arrangement of rods, it can improve gripping ability and still ensure good gripping ability even with a single finger. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 This is a three-dimensional structural diagram of a single-degree-of-freedom finger grasping device according to the present invention;

[0024] Figure 2 This is a schematic diagram of the single-degree-of-freedom six-link finger structure described in this invention;

[0025] Figure 3 This is a cross-sectional view of the single-degree-of-freedom six-link finger described in this invention;

[0026] Figure 4 This is a schematic diagram of the connection structure of the single-degree-of-freedom six-link finger described in this invention;

[0027] Figure 5 This is a diagram illustrating the state of a single-degree-of-freedom grasping device grasping an object, as described in this invention.

[0028] 1. DC geared motor; 2. Lower frame; 3. Upper frame; 4. Single-degree-of-freedom six-bar linkage; 4-1. First link; 4-2. Second link; 4-3. Third link; 4-4. Fourth link; 4-5. Fifth link; 4-6. Sixth link; 4-7. Seventh link; 4-7. Eighth link; 4-8. Ninth link; 4-9. Tenth link; 4-10. Eleventh link; 4-11. Worm gear; 5. First drive shaft; 6. Worm wheel; 7. First incomplete gear; 8. Second incomplete gear; 9. Second drive shaft; 10. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0030] Referring to the accompanying drawings, this embodiment describes a single-degree-of-freedom grasping device, comprising:

[0031] A frame is provided with a drive assembly. A first drive shaft 6 and a second drive shaft 10 with parallel axes are rotatably connected to the frame. A worm gear 7 and a first incomplete gear 8 are provided on the first drive shaft 6. A second incomplete gear 9 is provided on the second drive shaft 10. The first incomplete gear 8 and the second incomplete gear 9 mesh with each other.

[0032] The single-degree-of-freedom six-link finger 4 includes a head joint, an intermediate joint, and an end joint connected in sequence. The end joint has a length greater than or equal to that of the intermediate joint and has a groove on its gripping surface. The head joint's first link 4-1 is connected to the second drive shaft 10 at its head and to the intermediate joint at its end. The head joint's second link 4-2 is hinged to the frame at its head and to the intermediate joint at its end. The first link 4-1 and the second link 4-2 are used to drive the intermediate joint and the end joint in a linkage manner under the drive of the drive assembly to realize the overall movement of the single-degree-of-freedom six-link finger 4.

[0033] In this embodiment, the frame includes a lower frame 2 and an upper frame 3 that are detachably connected to each other, and the drive assembly is connected to the lower frame 2. This detachable, modular design improves disassembly convenience and maintenance economy.

[0034] In this embodiment, the driving component is a DC geared motor 1 with a worm gear 5 at its output end, which meshes with a worm wheel 7. The rotation of the DC geared motor 1 drives the worm gear 5 to rotate, which in turn drives the worm wheel 7 to rotate. The rotation of the worm wheel 7 drives the first incomplete gear 8 to rotate via the first transmission shaft 6. The first incomplete gear 8 then drives the second transmission shaft 10 to rotate via the second incomplete gear 9, thereby driving the single-degree-of-freedom six-link finger 4 to perform actions.

[0035] In this embodiment, the first-end joint further includes a sixth link 4-6 and a seventh link 4-7. The first link 4-1 and the sixth link 4-6 have the same structure, are arranged opposite each other, and their first ends are both connected to the second drive shaft 10. The second link 4-2 and the seventh link 4-7 have the same cross-section, are arranged opposite each other, and the thickness of the seventh link 4-7 is twice that of the second link 4-2. The first ends of both the seventh link 4-7 and the second link 4-2 are hinged to the frame. The arrangement of the first link 4-1 and the sixth link 4-6 having the same structure and being arranged opposite each other can improve structural strength and gripping stability, and increase the contact area during gripping. The principle behind the arrangement of the seventh link 4-7 having a thickness equal to that of the second link 4-2 is the same, also to improve structural strength and gripping stability.

[0036] In this embodiment, the intermediate joint includes a third link 4-3, a fourth link 4-4, an eighth link 4-8, and a ninth link 4-9. The third link 4-3 and the eighth link 4-8 ​​have the same structure and are arranged opposite each other. One corner of the first end of the third link 4-3, one corner of the first end of the eighth link 4-8, the end side of the second link 4-2, and the end side of the seventh link 4-7 are rotatably connected by a pin. The other corner of the first end of the third link 4-3, the other corner of the first end of the eighth link 4-8, the end of the first link 4-1, and the end of the sixth link 4-6 are rotatably connected by a pin. The fourth link 4-4 and the ninth link 4-9 have the same structure and are arranged opposite each other. The end of the second link 4-2, the end of the seventh link 4-7, the first end of the fourth link 4-4, and the first end of the ninth link 4-9 are rotatably connected by a pin. The arrangement of the third link 4-3 and the eighth link 4-8 ​​having the same structure and being arranged opposite each other can improve structural strength and gripping area. The number can be increased or decreased according to actual needs.

[0037] In this embodiment, the end joint includes a fifth link 4-5, a tenth link 4-10, and an eleventh link 4-11 with identical structures and arranged opposite each other. The ends of the third link 4-3, the eighth link 4-8, one corner of the first end of the fifth link 4-5, one corner of the first end of the tenth link 4-10, and one corner of the first end of the eleventh link 4-11 are rotatably connected by a pin. The other corner of the first end of the fifth link 4-5, the other corner of the first end of the tenth link 4-10, the other corner of the first end of the eleventh link 4-11, the end of the fourth link 4-4, and the end of the ninth link 4-9 are rotatably connected by a pin. The ends of the fifth link 4-5, the tenth link 4-10, and the eleventh link 4-11 are fixedly connected. The fifth link 4-5, the tenth link 4-10, and the eleventh link 4-11 are arranged in an equal array to improve structural stability and gripping ability. The number can be appropriately increased or decreased according to actual needs to meet usage requirements.

[0038] In this embodiment, the fifth link 4-5, the tenth link 4-10, and the eleventh link 4-11 all have grooves at the same position on the gripping side.

[0039] In this embodiment, the groove is arc-shaped. The arc shape increases the gripping area, thereby improving gripping ability. Depending on actual usage needs, anti-slip pads or other friction-enhancing components can be placed within the groove to further improve gripping ability. The groove can also be chosen in other shapes to improve gripping ability, such as a wavy shape.

[0040] In this embodiment, the line connecting one corner of the first end, the other corner of the first end, and the end of the fifth link 4-5 forms a triangle. This ensures the stability of the structure while allowing for normal gripping and rotation.

[0041] In this embodiment, the single-degree-of-freedom six-link finger 4 is a carbon fiber finger. This ensures high strength while reducing the overall weight of the gripping device, thus guaranteeing the reliability of the finger's gripping action.

[0042] In operation, the rotation of the DC geared motor 1 drives the worm gear 5 to rotate, which in turn drives the worm wheel 7. The worm wheel 7, in turn, drives the first incomplete gear 8 via the first transmission shaft 6. The first incomplete gear 8, in turn, drives the second transmission shaft 10 via the second incomplete gear 9. The forward and reverse rotation of the DC geared motor 1 causes the rotation direction of the second transmission shaft 10 to change accordingly. When the second transmission shaft 10 rotates, it drives the first connecting rod 4-1 to rotate around the second transmission shaft 10. The first connecting rod 4-1, in conjunction with the second connecting rod 4-2, causes the third connecting rod 4-3 to rotate in the direction of grasping the object, which in turn drives the fifth connecting rod 4-5 to perform a covering motion, thus completing the grasping and covering of the object. This single-degree-of-freedom grasping method ensures the stability of the grasp while simplifying the overall structure. Furthermore, thanks to the length, arrangement, and groove of the connecting rods, the grasping ability is improved. It can still grasp objects with a single finger, and can hold cylindrical objects without the need for multi-finger coordination. Despite its simple overall structure, it can perform actions that cannot be done with a single finger.

[0043] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A single degree of freedom finger grasp device, characterized by, The utility model relates to a single degree of freedom six connecting rod finger (4) and a driving assembly, and the single degree of freedom six connecting rod finger (4) is driven by the driving assembly. The utility model relates to a single degree of freedom six connecting rod finger (4) and a driving assembly, and the single degree of freedom six connecting rod finger (4) is driven by the driving assembly. The utility model relates to a single degree of freedom six connecting rod finger (4) and a driving assembly, and the single degree of freedom six connecting rod finger (4) is driven by the driving assembly. The utility model relates to a single degree of freedom six connecting rod finger (4) and a driving assembly, and the single degree of freedom six connecting rod finger (4) is driven by the driving assembly. The utility model relates to a single degree of freedom six connecting rod finger (4) and a driving assembly, and the single degree of freedom six connecting rod finger (4) is driven by the driving assembly. The end joint comprises a fifth connecting rod (4-5), a tenth connecting rod (4-10) and an eleventh connecting rod (4-11) which are arranged in the same structure and face each other, the third connecting rod (4-3) end, the eighth connecting rod (4-8) end, one corner of the first end of the fifth connecting rod (4-5), one corner of the first end of the tenth connecting rod (4-10) and one corner of the first end of the eleventh connecting rod (4-11) are connected through a pin shaft, the other corner of the first end of the fifth connecting rod (4-5), the other corner of the first end of the tenth connecting rod (4-10), the other corner of the first end of the eleventh connecting rod (4-11), the fourth connecting rod (4-4) end and the ninth connecting rod (4-9) end are connected through a pin shaft, and the ends of the fifth connecting rod (4-5), the tenth connecting rod (4-10) and the eleventh connecting rod (4-11) are fixedly connected. The fifth connecting rod (4-5), the tenth connecting rod (4-10) and the eleventh connecting rod (4-11) are provided with grooves at the same position of the surface for gripping.

2. A single degree of freedom finger grasp device according to claim 1, wherein: The rack comprises a lower rack (2) and an upper rack (3) which are detachably connected with each other, and the driving assembly is connected with the lower rack (2).

3. The single degree of freedom finger grasp device of claim 1, wherein: The driving assembly is a direct-current speed reducer motor (1) and a worm (5) is arranged on the output end of the direct-current speed reducer motor (1), and the worm (5) is engaged with a worm wheel (7).

4. The single degree of freedom finger grasp device of claim 1, wherein: The groove is arc-shaped.

5. The single degree of freedom finger grasp device of claim 1, wherein: The line connecting the first end corner, the other first end corner and the end of the fifth connecting rod (4-5) is triangular.

6. The single degree of freedom finger grasp device of claim 1, wherein: The single-degree-of-freedom six-connecting-rod finger (4) is a carbon fiber finger.

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