Under-actuated finger

Abstract

The invention discloses an underactuated finger and aims to solve the problems that in the underactuated finger, a driving structure for a tail end finger is complex, the structure compactness is poor, and the flexibility of the tail end finger is poor. The robot comprises a first steering engine, a transmission assembly, a first knuckle, a second knuckle and a connecting rod assembly. The output end of the first steering engine is connected with the transmission assembly, the transmission assembly drives the first knuckles to swing around the first ends of the first knuckles, the second ends of the first knuckles are rotationally connected with the second knuckles, the first ends of the connecting rod assemblies are connected with the transmission assembly, and the second ends of the connecting rod assemblies are connected with the second knuckles. The grabbing action of the first knuckles and the second knuckles is completed under the driving of one steering engine, the orderly swinging of the first knuckles and the second knuckles is achieved through the cooperation of the transmission assembly and the connecting rod assembly, the grabbing action is completed, the overall structure is compact, the operation is simple and orderly, the swinging of the second knuckles is more flexible, and the grabbing effect is better.

Description

Technical Field

[0001] The invention belongs to the technical field of robot fingers, and in particular relates to an underactuated finger. Background Art

[0002] Underactuated fingers are an important research direction in robotics in recent years, aiming to simulate the flexibility and adaptability of human fingers. Compared with traditional fully-actuated fingers, underactuated fingers achieve more efficient control and more complex grasping movements by reducing the number of actuators. This design not only reduces cost and complexity, but also improves the flexibility and adaptability of fingers.

[0003] Underactuation refers to a mechanical system in which the number of actuators is less than the system's degrees of freedom. This means that in some cases, the movement of a finger can be controlled by a small number of actuators to control the movement of multiple joints. For example, in a finger with multiple joints, only one motor may be used to drive the movement of the entire finger, while the other joints passively follow through mechanical structures (such as linkages, pulleys, etc.). This design allows the finger to automatically adapt to the shape and size of the object when grasping it, thereby achieving a more natural grasping action.

[0004] In the existing under-actuated fingers, the driving structure of the end fingers is complex, the overall structure is poor in compactness, and the flexibility of the end fingers is poor. Summary of the invention

[0005] The purpose of the present invention is to provide an under-actuated finger, aiming to solve the problems of complex driving structure of the end finger, poor compactness of the structure and poor flexibility of the end finger in the under-actuated finger.

[0006] To solve the above problems, the present invention provides an underactuated finger, comprising a first servo, a transmission assembly, a first finger joint, a second finger joint and a connecting rod assembly;

[0007] The output end of the first servo is connected to the transmission assembly, the transmission assembly drives the first finger joint to swing around the first end of the first finger joint, the second end of the first finger joint is rotatably connected to the second finger joint, the first end of the connecting rod assembly is connected to the transmission assembly, and the second end of the connecting rod assembly is connected to the second finger joint;

[0008] The first knuckle drives the second knuckle to swing, and when the first knuckle swings to an extreme position, the transmission assembly drives the connecting rod assembly to move, and the connecting rod assembly drives the second knuckle to swing around the second end of the first knuckle.

[0009] Through such a setting, a first steering gear is provided, and the transmission assembly drives the first knuckle and the second knuckle to swing together around the first end of the first knuckle. The transmission assembly is connected to the connecting rod assembly, so that when the first knuckle swings to the limit position, the transmission assembly can continue to drive the connecting rod assembly, and then the connecting rod assembly drives the second knuckle to continue to swing, so as to achieve the grasping action. The grasping action of the first knuckle and the second knuckle is completed by driving a steering gear, and the transmission assembly and the connecting rod assembly cooperate to achieve the orderly swing of the first knuckle and the second knuckle to complete the grasping action. The overall structure is compact, the operation is simple and orderly, the swing of the second knuckle is more flexible, and the grasping effect is better.

[0010] Preferably, the transmission assembly includes an active bevel gear, a driven bevel gear and a rotating shaft, the output end of the first servo is connected to the active bevel gear, the active bevel gear is meshed with the driven bevel gear, the driven bevel gear is sleeved on the rotating shaft, and the first end of the first finger joint is connected to the rotating shaft.

[0011] Through such an arrangement, the first servo drives the active bevel gear to rotate, and the active bevel gear drives the driven bevel gear and the rotating shaft to rotate along the axial direction of the rotating shaft. The first end of the first finger joint is connected to the rotating shaft, and then the first finger joint swings around the rotating shaft. The two meshing active bevel gears and driven bevel gears can set the first servo below the first finger joint, saving space in the overall structure.

[0012] Preferably, the connecting rod assembly includes a first connecting rod and a second connecting rod, the rotating shaft passes through the first end of the first connecting rod, the driven bevel gear is fixedly connected to the first end of the first connecting rod, the first connecting rod swings around the rotating shaft, the second end of the first connecting rod is rotatably connected to the first end of the second connecting rod, the second connecting rod swings around the second end of the first connecting rod, and the second end of the second connecting rod is connected to the second knuckle.

[0013] Through such an arrangement, when the first knuckle and the second knuckle swing together around the rotating axis, the connecting rod assembly swings around the rotating axis together, and when the first knuckle swings to the extreme position, the transmission assembly continues to drive the first connecting rod to swing around the rotating axis, and the first connecting rod and the second connecting rod are rotationally connected, so that during the swinging of the first connecting rod, the second connecting rod swings around the second end of the first connecting rod, and then the second end of the second connecting rod pushes the second knuckle to continue to complete the swinging work, thereby realizing the swinging of the second knuckle around the second end of the first knuckle to complete the grasping action.

[0014] Preferably, the second finger joint includes a first finger portion and a second finger portion, the first end of the first finger portion is fixedly connected to the first end of the second finger portion, and the second end of the first finger portion is rotatably connected to the second end of the second connecting rod.

[0015] Through such an arrangement, the first finger is arranged on the second finger joint, and the first finger is driven to swing around the second end of the first finger joint by the second connecting rod. The first finger and the second finger are fixedly connected so that the second finger swings around the first end of the first finger joint, thereby improving the integrity of the second finger joint, thereby achieving a better driving effect of the second connecting rod on the first finger joint and a more flexible grasping action.

[0016] Preferably, the under-actuated finger further includes a second servo and a rotating assembly, wherein the output end of the second servo is connected to the rotating assembly, the rotating assembly is connected to the first end of the first finger joint, the second servo drives the rotating assembly to rotate, and the rotating assembly drives the first finger joint to rotate.

[0017] Through such a setting, a second servo and a rotating assembly are set in the under-actuated finger, and the second servo and the rotating assembly enable the first finger joint to complete the rotation movement. During the grasping process, the grasping direction of the first finger joint and the second finger joint is adjusted by the second servo and the rotating assembly, so that the first finger joint and the second finger joint have a better grasping effect and a more flexible grasping movement.

[0018] Preferably, the rotating assembly includes a first gear, a second gear and a rotating bracket, the output end of the second servo is connected to the first gear, the first gear is meshed with the second gear, the second gear is fixedly connected to the rotating bracket, and the rotating bracket is connected to the first finger joint through the rotating shaft.

[0019] Through such an arrangement, the second steering gear drives the first gear to rotate, the first gear and the second gear are meshed, driving the second gear to rotate, the rotating bracket is fixed on the second gear, and the rotating bracket rotates with the second gear, and the rotating shaft is connected to the rotating bracket, and the rotating shaft can rotate with the rotating bracket and the second gear, thereby realizing that the first finger joint and the second finger joint rotate as a whole with the second gear. Gear transmission is used to save space for the rotating component, and the installation space of the rotating bracket is formed on the second gear, making the overall structure more compact.

[0020] Preferably, the second gear is sleeved on the active bevel gear, and a bearing is provided between the active bevel gear and the second gear.

[0021] Through such an arrangement, the second gear is sleeved on the active bevel gear, and the second gear and the active bevel gear are connected through a bearing. The first steering gear drives the active bevel gear to rotate, and the second steering gear drives the second gear to rotate through the first gear, so that the active bevel gear can rotate relative to the second gear, and then the first steering gear and the second steering gear can respectively realize the swinging and rotation of the finger, further saving the space occupied by the transmission assembly and the rotating assembly, making the structure more compact and the transmission effect more stable.

[0022] Preferably, the under-actuated finger further comprises a spring, a first end of the spring is connected to the first finger joint, and a second end of the spring is connected to the second finger joint.

[0023] Through such a setting, the spring cooperates with the connecting rod assembly to fix the initial position of the second knuckle relative to the first knuckle. The connecting rod assembly drives the second knuckle to overcome the spring to complete the grasping action. After the grasping action is completed, the spring drives the second knuckle to swing relative to the first knuckle, so that the second knuckle returns to the starting position. During the reciprocating grasping action, the grasping action is smoother and the grasping efficiency is higher.

[0024] Preferably, a limiting portion is provided on the second finger joint, and the limiting portion abuts against an end portion of the first finger joint.

[0025] Through such a setting, the limit part can limit the swing range of the second knuckle relative to the first knuckle under the action of the spring, so that in the initial state, the spring makes the second knuckle in an open state, that is, a grasping preparation state, and the limit part can prevent the second knuckle from swinging further, thereby reducing the stroke of the second knuckle during the grasping process and further improving the grasping efficiency.

[0026] Preferably, a first connecting portion is provided on the first finger joint, a second connecting portion is provided on the limiting portion, a first end of the spring is connected to the first connecting portion, and a second end of the spring is connected to the second connecting portion.

[0027] Through such an arrangement, a first connecting part is arranged on the first knuckle, and a second connecting part is arranged on the limiting part. The spring is fixed by the first connecting part and the second connecting part, so that the spring runs more stably and the space at the junction of the first knuckle and the second knuckle is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the overall structure of an under-actuated finger according to an embodiment of the present invention;

[0029] Figure 2 is a structural exploded diagram of an underactuated finger according to one embodiment of the present invention;

[0030] Figure 3 It is a schematic diagram of the structure of the first joint and the second joint of an under-actuated finger according to an embodiment of the present invention.

[0031] Reference numerals:

[0032] 1. The first servo;

[0033] 2. Transmission assembly; 21. Active bevel gear; 22. Driven bevel gear; 23. Rotating shaft

[0034] 3. first finger joint; 31. first connecting part;

[0035] 4. second finger joint; 41. first finger portion; 42. second finger portion; 43. limiting portion; 431. second connecting portion;

[0036] 5. connecting rod assembly; 51. first connecting rod; 52. second connecting rod;

[0037] 6. Spring;

[0038] 7. Second servo;

[0039] 8. Rotating assembly; 81. First gear; 82. Second gear; 83. Rotating bracket; 84. Bearing. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0041] The accompanying drawings show schematic diagrams of layer structures according to embodiments of the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clarity. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0042] In the description of the present invention, it should be noted that the terms “first” and “second” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0043] Combination Figure 1 , Figure 1: is a schematic diagram of the overall structure of an underactuated finger in an embodiment of the present invention. The underactuated finger comprises a first servo 1, a transmission assembly 2, a first finger joint 3, a second finger joint 4 and a connecting rod assembly 5; the output end of the first servo 1 is connected to the transmission assembly 2, the transmission assembly 2 drives the first finger joint 3 to swing around the first end of the first finger joint 3, the second end of the first finger joint 3 is rotationally connected to the second finger joint 4, the first end of the connecting rod assembly 5 is connected to the transmission assembly 2, and the second end of the connecting rod assembly 5 is connected to the second finger joint 4; the first finger joint 3 drives the second finger joint 4 to swing, and when the first finger joint 3 swings to the extreme position, the transmission assembly 2 drives the connecting rod assembly 5 to move, and the connecting rod assembly 5 drives the second finger joint 4 to swing around the second end of the first finger joint 3. Through such a setting, the first servo 1 drives the transmission assembly 2 to move, thereby driving the first finger joint 3 and the second finger joint 4 to swing together around the first end of the first finger joint 3, and the transmission assembly 2 and the connecting rod assembly 5 are connected, so that when the first finger joint 3 swings to the extreme position, the transmission assembly 2 can continue to drive the connecting rod assembly 5, and then the connecting rod assembly 5 drives the second finger joint 4 to continue to swing, so as to realize the grasping action. The grabbing action of the first knuckle 3 and the second knuckle 4 is driven by a servo engine. The transmission assembly 2 and the connecting rod assembly 5 cooperate to achieve orderly swinging of the first knuckle 3 and the second knuckle 4 to complete the grabbing action. The overall structure is compact, the operation is simple and orderly, the swing of the second knuckle 4 is more flexible, and the grabbing effect is better.

[0044] It should be noted that the structure of the transmission assembly 2 is not limited here, and it can be gear transmission, belt transmission, or directly drive the first finger joint 3 to swing through the output end of the first steering gear 1. In a preferred case, the transmission assembly 2 adopts the form of gear transmission, which is more conducive to improving the compactness of the structure. Figure 2In one embodiment of the present invention, the transmission assembly 2 includes an active bevel gear 21, a driven bevel gear 22 and a rotating shaft 23. The output end of the first servo 1 is connected to the active bevel gear 21, the active bevel gear 21 is meshed with the driven bevel gear 22, the driven bevel gear 22 is sleeved on the rotating shaft 23, and the first end of the first finger joint 3 is connected to the rotating shaft 23. Through such a configuration, the first servo 1 drives the active bevel gear 21 to rotate, the active bevel gear 21 drives the driven bevel gear 22 and the rotating shaft 23 to rotate along the axis direction of the rotating shaft 23, the first end of the first finger joint 3 is connected to the rotating shaft 23, and then the first finger joint 3 swings around the rotating shaft 23. The two meshing active bevel gears 21 and the driven bevel gear 22 can set the first servo 1 below the first finger joint 3, saving the space of the overall structure. The connection mode between the output end of the first servo 1 and the active bevel gear 21 is not limited here, and can be a clamping connection, a screw connection, etc.; the connection mode between the driven bevel gear 22 and the rotating shaft 23, and the connection mode between the first end of the first finger joint 3 and the rotating shaft 23 are not limited. In an optional situation, the driven bevel gear 22 is sleeved on the rotating shaft 23 and is fixedly connected to the rotating shaft 23, and the first end of the first finger joint 3 is rotatably connected to the rotating shaft 23. Specifically, when the first servo 1 drives the active bevel gear 21 to rotate, the active bevel gear 21 drives the meshed driven bevel gear 22 to rotate, and the driven bevel gear 22 drives the fixedly connected rotating shaft 23 to rotate, so that the first finger joint 3 swings around the rotating shaft 23; when the first finger joint 3 swings to the extreme position, or contacts the grasped object, the first finger joint 3 stops swinging, and the rotating shaft 23 and the first finger joint 3 rotate relative to each other, driving the connecting rod assembly 5 to continue to swing, thereby driving the second finger joint to swing around the second end of the first finger joint 3 through the connecting rod assembly 5, and completing the grasping action. In another optional situation, the driven bevel gear 22 is sleeved on the rotating shaft 23 and is rotatably connected to the rotating shaft 23. The first end of the first knuckle 3 is fixedly connected to the rotating shaft 23. Specifically, when the first knuckle 3 just starts to swing, the driven gear and the rotating shaft 23 rotate together, driving the first knuckle 3 to swing around the rotating shaft 23. When the first knuckle 3 swings to the extreme position or contacts the grasped object, the first knuckle 3 and the rotating shaft 23 stop rotating. At this time, the active bevel gear 21 continues to drive the driven bevel gear 22 to rotate, and the driven bevel gear 22 drives the connecting rod assembly 5 to move, thereby realizing the second knuckle 4 to swing around the second end of the first knuckle 3, and completing the vehicle grasping action. Of course, other transmission combination forms can also be used, as long as it can be realized that after the first knuckle 3 swings to the extreme position or contacts the grasped object, the transmission assembly 2 can continue to drive the connecting rod assembly 5 to realize the grasping action of the first knuckle 3.

[0045] It should be noted that the specific structure of the connecting rod assembly 5 is not limited here, and it is sufficient that the transmission assembly 2 drives the second finger joint to continue to swing through the connecting rod assembly 5. Figure 3In a preferred case, the connecting rod assembly 5 includes a first connecting rod 51 and a second connecting rod 52, the rotating shaft 23 passes through the first end of the first connecting rod 51, the driven bevel gear 22 is fixedly connected to the first end of the first connecting rod 51, the first connecting rod 51 swings around the rotating shaft 23, the second end of the first connecting rod 51 is rotatably connected to the first end of the second connecting rod 52, the second connecting rod 52 swings around the second end of the first connecting rod 51, and the second end of the second connecting rod 52 is connected to the second finger joint 4. Through such a setting, when the first knuckle 3 and the second knuckle 4 swing together around the rotating shaft 23, the connecting rod assembly 5 swings together around the rotating shaft 23. When the first knuckle 3 swings to the extreme position, the transmission assembly 2 continues to drive the first connecting rod 51 to swing around the rotating shaft 23, and the first connecting rod 51 and the second connecting rod 52 are rotatably connected, so that during the swinging process of the first connecting rod 51, the second connecting rod 52 swings around the second end of the first connecting rod 51, and then the second end of the second connecting rod 52 pushes the second knuckle 4 to continue to complete the swinging work, thereby realizing the swinging of the second knuckle 4 around the second end of the first knuckle 3 to complete the grasping action. The structure and arrangement of the first connecting rod 51 and the second connecting rod 52 are not limited here, and it can meet the requirements that the driven bevel gear 22 drives the first connecting rod 51 to swing, and the first connecting rod 51 drives the second connecting rod 52 to swing, thereby realizing the pushing of the first knuckle 3 to grasp. In an optional situation, the second connecting rod 52 is arranged on the back side of the first knuckle 3 in the grasping direction, and is rotatably connected to the first end of the second connecting rod 52 through the second end of the first connecting rod 51. During the swinging of the first connecting rod 51 around the rotating shaft 23, the second connecting rod 52 is pushed to move, so that the first knuckle 3 continues to swing. The second connecting rod 52 is arranged on the back side of the first knuckle 3 in the grasping direction. The setting direction of the second connecting rod 52 is consistent with the setting direction of the first knuckle 3, which is more conducive to pushing the first knuckle 3 to swing and saves overall space.

[0046] The connection method and connection position between the second end of the second connecting rod 52 and the second knuckle 4 are not limited here, and can be fixedly connected to the first end or the middle of the second knuckle 4, or can be rotatably connected to the first end or the middle of the second knuckle 4. The specific structural form of the second knuckle is also not limited, and it is sufficient that the second connecting rod 52 can push the second knuckle 4 to complete the grasping action. In a preferred case, the second knuckle 4 includes a first finger portion 41 and a second finger portion 42, the first end of the first finger portion 41 is fixedly connected to the first end of the second finger portion 42, and the second end of the first finger portion 41 is rotatably connected to the second end of the second connecting rod 52. Through such a setting, the first finger portion 41 is provided on the second knuckle 4, and the first finger portion 41 is driven to swing around the second end of the first finger portion 41 by the second connecting rod 52. The first finger portion 41 and the second finger portion 42 are fixedly connected, so that the second finger portion 42 swings around the first end of the first finger portion 41, thereby improving the integrity of the second knuckle 4, and thereby the second connecting rod 52 has a better driving effect on the first knuckle 3, and the grasping action is more flexible. Combined with Figure 2 and Figure 3In one embodiment of the present invention, the second knuckle 4 is configured as an integrated first finger portion 41 and a second finger portion 42, the first finger portion 41 connects the first knuckle 3 and the second connecting rod 52, preferably, both ends of the first finger portion 41 are connected by rotation, further, the first knuckle 3, the first connecting rod 51, the second railing and the first finger portion 41 form a structure similar to a parallelogram, after the first knuckle 3 swings to the extreme position or contacts the grasped object, the position of the first knuckle 3 remains fixed, at this time, the first connecting rod 51 swings around the first end of the first knuckle 3, and the first finger portion 41 swings around the second end of the first knuckle 3, through such a configuration, the swinging arc of the first connecting rod 51, the second connecting rod 52 and the first knuckle 3 is reduced, which is conducive to improving the compactness of the structure.

[0047] Combination Figure 1 and Figure 2 In a preferred case, the underactuated finger further includes a second steering engine 7 and a rotating assembly 8, the output end of the second steering engine 7 is connected to the rotating assembly 8, the rotating assembly 8 is connected to the first end of the first finger joint 3, the second steering engine 7 drives the rotating assembly 8 to rotate, and the rotating assembly 8 drives the first finger joint 3 to rotate. Through such a setting, the second steering engine 7 and the rotating assembly 8 are set in the underactuated finger, and the second steering engine 7 and the rotating assembly 8 enable the first finger joint 3 to complete the rotation action. During the grasping process, the grasping direction of the first finger joint 3 and the second finger joint 4 is adjusted by the second steering engine 7 and the rotating assembly 8, so that the first finger joint 3 and the second finger joint 4 have a better effect during grasping and the grasping action is more flexible. The positional relationship between the second steering engine 7 and the rotating assembly 8 in the overall structure of the underactuated finger is not limited here, and it can be realized that the second steering engine 7 and the rotating assembly 8 drive the first finger joint 3 to rotate, so as to adjust the grasping direction of the underactuated finger during grasping. Further, in the process of multiple underactuated fingers cooperating in grasping, the grasping direction of each first finger joint 3 can be adjusted by the second steering engine 7, so that the grasping is more flexible.

[0048] It should be noted that the positional relationship between the rotating assembly 8 and the transmission assembly 2 is not limited here, and each of them can realize driving the first finger joint 3 to complete the corresponding grasping action. In a preferred case, the rotating assembly 8 includes a first gear 81, a second gear 82 and a rotating bracket 83, the output end of the second steering gear 7 is connected to the first gear 81, the first gear 81 is meshed with the second gear 82, the second gear 82 is fixedly connected to the rotating bracket 83, and the rotating bracket 83 is connected to the first finger joint 3 through the rotating shaft 23. Through such a setting, the second steering gear 7 drives the first gear 81 to rotate, the first gear 81 and the second gear 82 are meshed, and the second gear 82 is driven to rotate, and the rotating bracket 83 is fixed on the second gear 82, so that the rotating bracket 83 rotates with the second gear 82, and the rotating bracket 83 is connected by the rotating shaft 23, and the rotating shaft 23 can rotate with the rotating bracket 83 and the second gear 82, thereby realizing that the first finger joint 3 and the second finger joint 4 rotate as a whole with the second gear 82. Gear transmission is used to save space for the rotating assembly 8, and an installation space for the rotating bracket 83 is formed on the second gear 82, so that the overall structure is more compact. Further, the second gear 82 is sleeved on the active bevel gear 21, and a bearing 84 is provided between the active bevel gear 21 and the second gear 82. Through such a setting, the second gear 82 is sleeved on the active bevel gear 21, and the second gear 82 and the active bevel gear 21 are connected by the bearing 84, the first steering gear 1 drives the active bevel gear 21 to rotate, and the second steering gear 7 drives the second gear 82 to rotate through the first gear 81, so that the active bevel gear 21 can rotate relative to the second gear 82, and then the first steering gear 1 and the second steering gear 7 can respectively realize the swing and rotation of the finger, further saving the space occupied by the transmission component 2 and the rotating component 8, the structure is more compact, and the transmission effect is more stable. The connection mode of the bearing 84 and the active bevel gear 21 and the second gear 82 is not limited here, and the outer ring of the bearing 84 and the second gear 82 can be set as a whole, and the inner ring of the bearing 84 and the active bevel gear 21 are set as a whole, which further saves space. The connection relationship between the rotating bracket 83 and the second gear 82 is also not limited, and it can be a screw connection, a clamping connection or an integral molding method, which can realize that the rotating bracket 83 rotates with the second gear 82. In an optional situation, two opposing fixed plates are set at both ends of the rotating bracket 83, and the fixed plates have through holes. The bearing 84 passes through the through holes and is rotatably connected to the rotating bracket 83. When the rotating bracket 83 rotates with the second gear 82, the bearing 84 can also drive the first finger joint 3 to rotate together. When it rotates to a preset position, the second servo 7 stops running. At this time, the first servo 1 can drive the transmission assembly 2 to drive the first finger joint 3 and the second finger joint 4 to complete the grasping action.

[0049] Combination Figure 1 and Figure 3In a preferred case, the underactuated finger further includes a spring 6, the first end of the spring 6 is connected to the first knuckle 3, and the second end of the spring 6 is connected to the second knuckle 4. Through such a configuration, the spring 6 cooperates with the connecting rod assembly 5, so that the initial position of the second knuckle 4 relative to the first knuckle 3 is fixed, and the connecting rod assembly 5 drives the second knuckle to overcome the spring 6 to complete the grasping action. After the grasping action is completed, the spring 6 drives the second knuckle 4 to swing relative to the first knuckle 3, so that the second knuckle 4 returns to the starting position. In the reciprocating grasping action, the grasping action is smoother and the grasping efficiency is higher. Specifically, before grasping, the spring 6 is used to keep the second knuckle 4 in an open state. When the first knuckle 3 is in the extreme position or contacts the grasped object, the connecting rod assembly 5 starts to push the second knuckle 4 to swing around the end of the first knuckle 3, overcoming the elastic force of the spring 6 to complete the grasping action; when the grasping action is completed, the transmission assembly 2 drives the first knuckle 3 to swing back, and the first knuckle 3 and the second knuckle 4 leave the grasped object. At this time, the transmission assembly 2 no longer has the support force for the connecting rod assembly 5, and the spring 6 is reset to drive the second knuckle 4 back to the starting position, completing the reset of the under-actuated finger and facilitating the next grasping operation. The specific installation position of the spring 6 is not limited here. It can be installed on the back of the first knuckle 3 and the second knuckle 4 in the grasping direction. During the grasping process, the spring 6 is stretched; or it can be installed on the inner side of the first knuckle 3 and the second knuckle 4 in the grasping direction. Without affecting the grasping stroke, the spring 6 is compressed to complete the grasping of the second knuckle 4. The number of springs 6 is also not limited. It can be one or more. Figure 3 In one embodiment, two springs 6 are provided on the back of the first and second knuckles 3 and 4 in the grasping direction, so that the position of the second knuckle 4 is more stable and accurately reset after the grasping is completed.

[0050] It should be noted that the fixing position and fixing method of the spring 6 on the first knuckle 3 and the second knuckle 4 are not limited here. In a preferred case, a limiting portion 43 is provided on the second knuckle 4, and the limiting portion 43 abuts against the end of the first knuckle 3. Through such a setting, the limiting portion 43 can limit the swing range of the second knuckle 4 relative to the first knuckle 3 under the action of the spring 6, so that in the initial state, the spring 6 makes the second knuckle 4 in an open state, that is, a grasping preparation state, and the limiting portion 43 can prevent the second knuckle 4 from further swinging, thereby reducing the stroke of the second knuckle 4 during the grasping process, and further improving the grasping efficiency. Further, a first connecting portion 31 is provided on the first knuckle 3, and a second connecting portion 431 is provided on the limiting portion 43. The first end of the spring 6 is connected to the first connecting portion 31, and the second end of the spring 6 is connected to the second connecting portion 431. By such a configuration, the first connection part 31 is provided on the first knuckle 3, and the second connection part 431 is provided on the limiting part 43. The spring 6 is fixed by the first connection part 31 and the second connection part 431, so that the spring 6 runs more stably and saves space at the junction of the first knuckle 3 and the second knuckle 4. Preferably, the limiting part 43 and the second knuckle 4 are integrally formed, and the second connection part 431 is arranged on the side of the limiting part 43 away from the grasping direction. The first connection part 31 and the first knuckle 3 are integrally formed and arranged on the side of the first knuckle 3 away from the grasping direction. By such a configuration, the fixing of the spring 6 is facilitated and the grasping effect is not affected. The specific structure of the first connection part 31 and the second connection part 431 is not limited here, and it is sufficient to fix the spring 6 and ensure the relative position of the first knuckle 3 and the second knuckle 4. The fixing method of the spring 6 to the first connecting part 31 and the second connecting part 431 is not limited. Optionally, a spring 6 limiting hole is set on the first connecting part 31 and the second connecting part 431, and a hook structure is set at both ends of the spring 6. The hook structure is connected to the limiting hole to achieve the fixation of the spring 6; the two ends of the spring 6 can also be directly clamped with the first connecting part 31 and the second connecting part 431 respectively, and a clamping card is set to fix the two ends of the spring 6. The clamping card can be adjusted and fixed by bolts.

[0051] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. An underactuated finger, characterized in that: The underactuated finger comprises a first steering gear (1), a transmission assembly (2), a first finger joint (3), a second finger joint (4) and a connecting rod assembly (5); The output end of the first steering engine (1) is connected to the transmission assembly (2), the transmission assembly (2) drives the first finger joint (3) to swing around the first end of the first finger joint (3), the second end of the first finger joint (3) is rotationally connected to the second finger joint (4), the first end of the connecting rod assembly (5) is connected to the transmission assembly (2), and the second end of the connecting rod assembly (5) is connected to the second finger joint (4); The first finger joint (3) drives the second finger joint (4) to swing, and when the first finger joint (3) swings to an extreme position, the transmission assembly (2) drives the connecting rod assembly (5) to move, and the connecting rod assembly (5) drives the second finger joint (4) to swing around the second end of the first finger joint (3).

2. The underactuated finger according to claim 1, characterized in that: The transmission assembly (2) comprises an active bevel gear (21), a driven bevel gear (22) and a rotating shaft (23); the output end of the first steering gear (1) is connected to the active bevel gear (21); the active bevel gear (21) is meshed with the driven bevel gear (22); the driven bevel gear (22) is sleeved on the rotating shaft (23); and the first end of the first finger joint (3) is connected to the rotating shaft (23).

3. The underactuated finger according to claim 2, characterized in that: The connecting rod assembly (5) comprises a first connecting rod (51) and a second connecting rod (52); the rotating shaft (23) passes through the first end of the first connecting rod (51); the driven bevel gear (22) is fixedly connected to the first end of the first connecting rod (51); the first connecting rod (51) swings around the rotating shaft (23); the second end of the first connecting rod (51) is rotationally connected to the first end of the second connecting rod (52); the second connecting rod (52) swings around the second end of the first connecting rod (51); and the second end of the second connecting rod (52) is connected to the second finger joint (4).

4. The underactuated finger according to claim 3, characterized in that: The second finger joint (4) comprises a first finger portion (41) and a second finger portion (42), wherein the first end of the first finger portion (41) is fixedly connected to the first end of the second finger portion (42), and the second end of the first finger portion (41) is rotatably connected to the second end of the second connecting rod (52).

5. The underactuated finger according to claim 4, characterized in that: The underactuated finger further comprises a second steering gear (7) and a rotating assembly (8), wherein an output end of the second steering gear (7) is connected to the rotating assembly (8), and the rotating assembly (8) is connected to a first end of the first finger joint (3); the second steering gear (7) drives the rotating assembly (8) to rotate, and the rotating assembly (8) drives the first finger joint (3) to rotate.

6. The underactuated finger according to claim 5, characterized in that: The rotating assembly (8) comprises a first gear (81), a second gear (82) and a rotating bracket (83); the output end of the second steering gear (7) is connected to the first gear (81); the first gear (81) is meshed with the second gear (82); the second gear (82) is fixedly connected to the rotating bracket (83); and the rotating bracket (83) is connected to the first finger joint (3) via the rotating shaft (23).

7. The underactuated finger according to claim 6, characterized in that: The second gear (82) is sleeved on the active bevel gear (21), and a bearing (84) is provided between the active bevel gear (21) and the second gear (82).

8. The underactuated finger according to claim 1, wherein: The underactuated finger further comprises a spring (6), a first end of the spring (6) being connected to the first finger joint (3), and a second end of the spring (6) being connected to the second finger joint (4).

9. The underactuated finger according to claim 8, characterized in that: The second finger joint (4) is provided with a limiting portion (43), and the limiting portion (43) abuts against the end of the first finger joint (3).

10. The underactuated finger according to claim 9, characterized in that: The first finger joint (3) is provided with a first connecting portion (31), the limiting portion (43) is provided with a second connecting portion (431), the first end of the spring (6) is connected to the first connecting portion (31), and the second end of the spring (6) is connected to the second connecting portion (431).

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