Finger of dexterous hand

Abstract

The invention provides a dexterous hand finger which comprises a first knuckle and a second knuckle which are hinged to each other, a hollow circular truncated cone portion at the end of the second knuckle is rotationally installed at the position, close to the end, in the first knuckle, a notch is formed in the side wall, facing the interior of the first knuckle, of the circular truncated cone portion, and a rotating shaft is coaxially fixed to the circular truncated cone portion. A plurality of fan-shaped plates are annularly arrayed on the end face of one end in the cylindrical cavity, the fan-shaped plates are slidably installed in the radial direction of the cylindrical cavity, plane threads are arranged on the surfaces of the fan-shaped plates, and all the fan-shaped plates are in meshing transmission with the adjusting disc through the plane threads; the outer sides of the fan-shaped plates and the outer sides of the moving wheels are wound with transmission belts, the moving wheels are slidably installed in the horizontal direction, and when all the fan-shaped plates are away from one another, the transmission belts are expanded outwards, so that the moving wheels are close to the circular truncated cone part; and a driving wheel which is in transmission installation with the transmission belt is arranged above the transmission belt, and the driving wheel tensions the transmission belt and drives the transmission belt to move. Fine adjustment of the fingers can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of robotic hand technology, and more specifically, it relates to a dexterous hand finger. Background Technology

[0002] In the design of robotic arms, the transmission structure for finger flexion directly determines its flexibility, load capacity, and operational precision. Currently, the commonly used finger joint flexion transmission mechanisms mainly include the following: I. Gear transmission structure: This type of transmission mainly uses a motor, reducer, and gear set as the core transmission chain. Power is transmitted through the meshing of the driving gear and the driven gear to drive the rotation of the finger joints. A common design involves embedding multiple stages of cylindrical or bevel gears within the proximal and middle phalanges of the fingers. The motor's output torque is amplified by a harmonic reducer and then sequentially drives each joint to bend through gear meshing, thus achieving power transmission. However, this type of transmission requires a large number of gears, demands extremely high gear precision, and has certain limitations in transmission ratio. It is more suitable for gripping applications with extremely high load-bearing capacity.

[0003] II. Wire Rope Drive Structure: Mimicking the tendon transmission mechanism of human fingers, this structure uses high-strength steel wire rope or aramid fiber tendon rope as the transmission element. One end is connected to a winding wheel at the motor output, and the other end is fixed to the distal joint of the finger. The motor rotates forward and backward to wind and unwind the wire rope, causing the joint to bend or extend. A typical design involves creating a groove within the finger bone, with the wire rope arranged along the groove path. Compared to gear drives, this design places fewer demands on structural layout and allows for flexible configuration of the transmission path.

[0004] 3. Linkage transmission structure: This structure uses multiple rigid links, such as aluminum alloy or carbon fiber, to form a hinge mechanism. A motor drives the active link to rotate, which in turn drives the driven link, thus causing the finger joint to bend. It offers stable movement, as the rigid link transmission has no elastic deformation, and the joint movement trajectory can be accurately predicted. It is suitable for scenarios requiring fixed movement paths. However, the structure is complex, and the multi-joint linkage requires precise design of the link lengths and hinge positions; otherwise, movement jamming can easily occur. Furthermore, it has many parts, making assembly difficult.

[0005] The above-mentioned common mechanical hand finger bending transmission structures each have different advantages and disadvantages to suit different occasions. However, the transmission chains of these existing finger transmission structures are relatively long, and the adjustment range of transmission speed is not simple, lightweight, or precise enough. Summary of the Invention

[0006] In view of the current state of the technology mentioned in the background art, and in order to overcome the corresponding defects in the prior art, the present invention specifically discloses a dexterous hand finger that can better solve the problems mentioned in the background art, so that the finger can adjust the precision of bending movements as needed, and achieve grasping more accurately.

[0007] To overcome the deficiencies of the existing technology, those skilled in the art provide the following technical solutions: A dexterous hand includes a first phalanx and a second phalanx hinged to each other. A frustum of the second phalanx is rotatably mounted near the end of the first phalanx. The frustum has a cylindrical cavity inside and a notch on one side wall facing the first phalanx. A rotating shaft is coaxially fixed on the frustum. Several fan-shaped plates are arranged in a ring on one end face of the cylindrical cavity. One side of the fan-shaped plates is slidably mounted along the radial direction of the cylindrical cavity, and the other side is provided with a planar thread. All the fan-shaped plates are rotatably mounted on the end face of an adjusting disc coaxially in the cylindrical cavity and are driven by the engagement of the planar thread. The outer arc surface of the sector plate is provided with a groove for a transmission belt to be tightly attached. The transmission belt is a closed strip structure, with one end wrapped around all the grooves of the annular array and the other end wrapped around a movable wheel rotatably installed in the first finger joint. The movable wheel is slidably installed in the horizontal direction. When all the sector plates move away from each other, the transmission belt is pushed outward so that the movable wheel moves closer to the frustum. Above the transmission belt between the moving wheel and the sector plates of the annular array, there is a drive wheel that is driven and mounted to the transmission belt. The drive wheel tensions the transmission belt and moves the transmission belt when it rotates, so as to make the frustum rotate through the sector plates of the annular array.

[0008] Furthermore, a slide rail is fixed on the axis of symmetry of the side surface of the sector plate opposite to the planar thread, and the slide rail is slidably installed in a guide groove opened on one end face of the cylindrical cavity.

[0009] Furthermore, a rotating column is coaxially fixed at the end of the adjusting disc away from the sector plate, and the rotating column is rotatably installed in the side wall of the first finger joint.

[0010] Furthermore, a disc is coaxially fixed to the end of the rotating column. The disc is located on the outside of the first finger joint. The center of the disc has a hexagonal groove for inserting a wrench. A radially arranged indicator arrow is fixed on its side. An angle mark is provided around the outside of the indicator arrow on the surface of the first finger joint to show the angle of rotation of the disc.

[0011] Furthermore, an annular groove is provided on the outer side of the disc, and a sliding bolt is installed on the indicator arrow. The nut of the sliding bolt is slidably installed in the annular groove, and its other end protrudes from the surface of the indicator arrow and is fixed by a locking nut to fix the disc.

[0012] Furthermore, the rotating shaft is rotatably installed in the side wall of the first phalanx on the side away from the rotating column, and the rotating shaft is coaxially rotatably sleeved on the opposite end of the rotating column.

[0013] Furthermore, a horizontal groove is provided on the inner wall of one side of the first phalanx, and a rectangular block is slidably installed in the horizontal groove. A bearing is installed in the rectangular block, and the bearing is used to install the rotation shaft of the movable wheel.

[0014] Furthermore, each side of the rectangular block is connected to an elastic telescopic element located in a horizontal groove, so that the rectangular block can be elastically slidably connected, and when the transmission belt is not fitted, the elastic telescopic element limits the rectangular block to the center of the horizontal groove.

[0015] Furthermore, a limiting block is slidably installed in a horizontal groove on the side of the rectangular block near the frustum. One end of the limiting block is located in the horizontal groove to contact the side of the rectangular block, and the other end is threadedly installed on a lead screw. The lead screw is rotatably installed below the horizontal groove, and the end of the lead screw rotates through a bevel gear transmission mechanism so that the limiting block can move to a position where it contacts the rectangular block. The end of the gear shaft of the drive gear of the bevel gear transmission mechanism is provided with a hexagonal groove for inserting a wrench to rotate the gear shaft. The end of the gear shaft is axially pressed by a clamping bolt threadedly installed in the side wall of the first finger joint to fix the gear shaft.

[0016] Furthermore, the inner side of the transmission belt is in close contact with the moving wheel for transmission, while the outer side has teeth that mesh with the drive wheel, which also has teeth.

[0017] Compared with the prior art, the beneficial effects of the present invention are: the present invention designs a special interphalangeal hinge structure with an extremely short transmission chain and a simple and lightweight transmission structure. Under the premise of rated input, the speed of finger bending movement can be continuously and steplessly adjusted by changing the structure of the transmission chain itself, so as to bend to the corresponding position more accurately.

[0018] Specifically, this invention utilizes the constant displacement of the transmission belt and the constant rotational speed of the drive wheel, meaning there is no requirement for flexible adjustment of the input. Starting from the transmission element itself, the larger the radius of the wound transmission wheel, the lower the rotational speed. In this invention, the densely arranged fan-shaped plates in a ring array form the aforementioned transmission wheel. Although the resulting structure is not a complete and continuous circle, it still conforms to the principle that the larger the radius, the lower the rotational speed. That is, the slower the rotational speed of the second knuckle relative to the first knuckle, the more conducive it is to fine-tuning and improving the adjustment accuracy. For dexterous hand fingers, this is more in line with the characteristic of simulating the limited bending angle of human fingers. Within this limited angle range, by utilizing the characteristic of the transmission wheel radius increasing due to the fan-shaped plates moving further apart, the operability of fine-tuning the rotational speed of the frustum is greater, and the adjustment accuracy is easier to control.

[0019] Other functions and features of the present invention will be described in detail in the following embodiments to provide a full understanding of the concept of the present invention and to enable its practical application in production. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the appearance of the present invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 This is a sectional view of the internal structure of the frustum section; Figure 4 This is a diagram of a two-knuckle hinge structure; Figure 5 A schematic diagram showing all the sector plates moving away from each other; Figure 6 This is a sectional view of the frustum section; Figure 7 This is a structural diagram of the fan-shaped plate and slide rail installation. Figure 8 This is one of the cross-sectional structural diagrams of the present invention; Figure 9 When all sector plates are far apart, Figure 8 A schematic diagram of the structure shown; Figure 10 This is a side view of the moving wheel; Figure 11 A schematic diagram of the sliding installation structure of the rectangular base of the movable wheel; Figure 12 This is a schematic diagram of the end face of the disc on the side of the first phalanx; Figure 13 This is a partial structural diagram of the transmission belt.

[0021] As shown in the figure, the components are: first finger joint 1, horizontal slide groove 101, second finger joint 2, frustum 201, guide groove 20101, notch 20102, annular slide groove 20103, sector plate 3, adjusting disc 4, rotating column 5, transmission belt 6, moving wheel 7, drive wheel 8, rotating shaft 9, rotating shaft 10, disc 11, indicator arrow 12, sliding bolt 13, angle mark 14, rectangular block 15, bearing 16, limit block 17, lead screw 18, bevel gear transmission mechanism 19, clamping bolt 20, gear shaft 21, and slide rail 22. Detailed Implementation

[0022] Based on the accompanying drawings and the following description, the technical solutions in the embodiments of the present invention can be clearly and completely described. However, it should be understood that the embodiments mentioned herein are merely one or more specific methods of the present invention, and not all implementation structures or method steps. As shown in the figures, This invention proposes a dexterous hand finger, such as Figures 1-2As shown, the main structure includes a first finger joint 1 and a second finger joint 2 that are hinged to each other. The number of finger joints is determined according to the actual situation, for example, a common three-joint finger joint. Adjacent finger joints are manufactured according to the following hinge structure. Specifically, a frustum 201 of the end of the second finger joint 2 is rotatably mounted inside the first finger joint 1 near its end. The frustum 201 has a cylindrical cavity inside, and a notch 20102 is provided on the side wall of the frustum 201 facing the inside of the first finger joint 1. The notch 20102 is mainly for the transmission belt 6 mentioned later to pass through freely. In addition, see also Figure 3 , Figure 6 A rotating shaft 10 is coaxially fixed on the frustum portion 201 for rotatable installation within the port of the first finger joint 1. On one end face of the cylindrical cavity, a plurality of sector plates 3 are arranged in a ring array; the more sector plates 3, the better, provided they meet dimensional requirements. One side of these sector plates 3 is slidably mounted radially along the cylindrical cavity, while the other side has a planar thread. All sector plates 3 are rotatably mounted coaxially with the end face of an adjusting disc 4 within the cylindrical cavity, and are driven by the planar thread engagement. Thus, when the adjusting disc 4 rotates, all sector plates 3 move away from or closer to each other. The transmission belt 6 is a closed-loop belt structure, similar to a leather belt, which causes the arc shape at one end of the transmission belt 6 wrapped around its outer side to be expanded or contracted.

[0023] In practice, a groove is provided on the outer arc surface of the sector plate 3 for a transmission belt 6 to fit snugly against. One end of the transmission belt 6 is wrapped around all the grooves in the annular array, and the other end is wrapped around a movable wheel 7 rotatably mounted in the first finger joint 1. This means that the movable wheel 7 and the annular array of sector plates 3 serve as two transmission wheels for the transmission belt 6. As one specific implementation structure, the movable wheel 7 is slidably mounted along the horizontal direction, such as... Figures 4-5 When all the sector plates 3 are far apart from each other, the drive belt 6 is spread outward so that the moving wheel 7 moves along the horizontal groove 101 to approach the frustum 201, ensuring that the drive belt 6 is in close contact with the moving wheel 7 and the side of the corresponding sector plate 3 of the annular array.

[0024] In addition, such as Figure 2 , Figure 8 , Figure 9In this embodiment, a drive wheel 8 is also provided above the transmission belt 6 between the moving wheel 7 and the fan-shaped plates 3 in the annular array. This drive wheel 8 can be driven by a fixed-speed micro motor, without requiring high speed regulation performance or relying on the speed regulation accuracy of the motor. The micro motor can be installed inside the first knuckle 1. One of the functions of this drive wheel 8 in this embodiment is to tension the transmission belt 6 to ensure reliable transmission. In addition, another key function is that when the fan-shaped plates 3 are adjusted to the correct position, the drive wheel 8 rotates to move the transmission belt 6, thereby rotating the frustum 201 where the fan-shaped plates 3 in the annular array are located by an angle, such as 45 degrees, so that the frustum 201 rotates to the corresponding position, so that the two knuckles form the corresponding included angle.

[0025] As a specific implementation structure, such as Figure 7 On the symmetrical axis of the side surface of the sector plate 3 facing away from the planar thread, a slide rail 22 is fixed. The slide rail 22 is slidably installed in a guide groove 20101 opened on one end face of the cylindrical cavity, guiding it to move within the frustum 201, and when driven by the transmission belt 6, it can rotate the frustum 201 by a certain angle. In specific manufacturing, as follows... Figures 2-4 , Figures 8-9 At one end of the adjusting disc 4 away from the sector plate 3, a rotating column 5 is coaxially fixed. This rotating column 5 is rotatably installed in the side wall of the first finger joint 1 so that when the rotating column 5 is rotated, the adjusting disc 4 can rotate, thereby driving all the sector plates 3 to move.

[0026] In this embodiment, as Figure 1 and Figure 12 A disc 11 is coaxially fixed to the end of the rotating column 5. The disc 11 is located on the outside of the first finger joint 1. The center of the disc 11 has a hexagonal groove for inserting a wrench. A radially arranged indicator arrow 12 is fixed on its side. An angle mark 14 is provided around the outside of the indicator arrow 12 on the surface of the first finger joint 1 to visually show the rotation angle of the disc 11, so as to grasp the rotation angle of the adjusting disc 4 and thus clarify the synchronous sliding displacement of each sector plate 3. In order to fix all the sector plates 3 after adjustment, such as... Figure 12 An annular groove 20103 is provided on the outer side of the disc 11. A sliding bolt 13 is installed on the indicator arrow 12. The nut of the sliding bolt 13 is slidably installed in the annular groove 20103. After its other end protrudes from the surface of the indicator arrow 12, it is fixed by the locking nut to fix the disc 11, thereby achieving the purpose of fixing the adjusting disc 4 and the sector plate 3 relative to each other.

[0027] To facilitate installation and improve stability, the rotating shaft 10 is rotatably mounted in the side wall of the first finger joint 1 on the side opposite to the rotating column 5, and as shown... Figure 6As shown, a blind hole is provided at the end of the rotating shaft 10, which allows the rotating column 5 to be installed coaxially, so as to realize the rotational installation of the two.

[0028] like Figure 2 , Figure 8 , Figure 9 as well as Figure 11 As shown, a horizontal groove 101 is provided on the inner wall of one side of the first phalanx 1. A rectangular block 15 is slidably installed in the horizontal groove 101, and a bearing 16 is installed in the rectangular block 15. The bearing 16 is used to mount the rotation shaft 9 of the movable wheel 7, so that the movable wheel 7 can both translate and rotate. In addition, to improve reliability, such as Figure 11 On both sides of the rectangular block 15, it is connected to an elastic telescopic element located in the horizontal slide groove 101. The elastic telescopic element can be a spring, so that the rectangular block 15 is elastically slidably connected. Moreover, when the transmission belt 6 is not attached, the elastic telescopic element limits the rectangular block 15 to the center of the horizontal slide groove 101 so that the rectangular block 15 can move left and right.

[0029] Continue reading Figure 11 A limiting block 17 is slidably installed in the horizontal groove 101 on the side of the rectangular block 15 near the frustum 201. One end of the limiting block 17 is located in the horizontal groove 101 to contact the side of the rectangular block 15, preventing the moving wheel 7 from wobbling towards the frustum 201. The other end of the limiting block 17 is threadedly installed on a lead screw 18. The lead screw 18 is rotatably installed below the horizontal groove 101. The end of the lead screw 18 rotates through a bevel gear transmission mechanism 19, allowing the limiting block 17 to move to a position where it contacts the rectangular block 15, preventing the rectangular block 15 from wobbling to the right and affecting the smoothness and reliability of the transmission belt 6. In addition, the axle of this embodiment, such as Figure 11 At the end of the gear shaft 21 of the drive gear of the bevel gear transmission mechanism 19, a hexagonal groove is specially provided for inserting a wrench to rotate the gear shaft 21 and move the limiting block 17 to the position where it connects with the rectangular block 15. After adjustment, the end of the gear shaft 21 is axially pressed by the clamping bolt 20, which is threaded into the side wall of the first finger joint 1, so as to fix the gear shaft 21, that is, to fix the position of the limiting block 17.

[0030] In the above embodiments, it is preferable to use a transmission belt 6 with its inner side in close contact with the movable wheel 7 for transmission, similar to a common belt drive. Figure 13 As shown, it has teeth on its outer side, which mesh with the drive wheel 8, which also has teeth, to improve the smoothness and reliability of the transmission.

[0031] When using the dexterous hand fingers in the above embodiments, if it is necessary to finely adjust the rotation angle of the two knuckles, the rotating column 5 is rotated to make the adjusting disk 4 rotate, causing all the sector plates 3 to move away from each other, so that the moving wheel 7 moves closer to the frustum 201. Because the rotation speed of the drive wheel 8 is constant, the moving speed of the transmission belt 6 is constant, and the angular velocity of the circular disk-shaped structure formed by the annular array of sector plates 3 will decrease, thereby finely adjusting the rotation angle of the two knuckles and improving the adjustment accuracy.

[0032] This invention is not limited to the field covered by this embodiment. Some well-known structures or principles have not been further described. However, those skilled in the art can theoretically know all the well-known technologies in this field prior to the application date or priority date, and can fully master all the prior art in this field. They also have the means and ability to apply these prior art in practical design. Under the technical guidance provided in this application, those skilled in the art can more comprehensively improve and implement this invention by combining their own capabilities. Furthermore, it should be noted that although the text and graphics of the above embodiments have shown specific implementation scenarios of the invention, those skilled in the art can make various obvious extensions and expansions to these embodiments without departing from the design concept of the invention, forming different embodiments. However, this does not affect the fact that the scope of protection of the invention is covered and embodied by the technical features of this claim and equivalent technical features.

Claims

1. A dexterous hand finger comprising a first phalanx (1) and a second phalanx (2) hinged together, characterized in that, A frustum (201) of the end of the second phalanx (2) is rotatably mounted inside the first phalanx (1) near its end. The frustum (201) has a cylindrical cavity inside and a notch (20102) is provided on one side wall facing the first phalanx (1). A rotating shaft (10) is coaxially fixed on the frustum (201). Several fan-shaped plates (3) are arranged in a ring on one end face inside the cylindrical cavity. One side of the fan-shaped plate (3) is slidably mounted along the radial direction of the cylindrical cavity, and the other side is provided with a planar thread. All the fan-shaped plates (3) are rotatably mounted on the end face of an adjusting disc (4) coaxially inside the cylindrical cavity and are driven by meshing with the planar thread. The outer arc surface of the sector plate (3) is provided with a groove for a transmission belt (6) to be tightly attached. The transmission belt (6) is a closed strip structure, with one end wrapped around all the grooves of the annular array and the other end wrapped around the movable wheel (7) rotatably installed in the first finger joint (1). The movable wheel (7) is slidably installed in the horizontal direction. When all the sector plates (3) are far apart from each other, the transmission belt (6) is pushed outward so that the movable wheel (7) approaches the frustum (201). Above the transmission belt (6) between the moving wheel (7) and the sector plate (3) of the annular array, there is a drive wheel (8) that is driven and mounted to the transmission belt (6). The drive wheel (8) tensions the transmission belt (6) and moves the transmission belt (6) when rotating, so that the frustum portion (201) rotates through the sector plate (3) of the annular array.

2. A dexterous hand finger according to claim 1, characterized in that, On the axis of symmetry of the side surface of the fan-shaped plate (3) away from the planar thread, a slide rail (22) is fixed, and the slide rail (22) is slidably installed in the guide groove (20101) opened on one end face of the cylindrical cavity.

3. A dexterous hand finger according to claim 1, characterized in that, The adjusting disc (4) is coaxially fixed with a rotating column (5) at one end away from the fan-shaped plate (3), and the rotating column (5) is rotatably installed in the side wall of the first finger joint (1).

4. A dexterous hand finger according to claim 3, characterized in that, The end of the rotating column (5) is coaxially fixed with a disc (11). The disc (11) is located on the outside of the first finger joint (1). The center of the disc (11) has a hexagonal groove for inserting a wrench. A radially arranged indicator arrow (12) is fixed on its side. An angle mark (14) is provided on the outside of the indicator arrow (12) on the surface of the first finger joint (1) to show the angle of rotation of the disc (11).

5. A dexterous hand finger according to claim 4, characterized in that, An annular groove (20103) is provided on the outer side of the disc (11). A sliding bolt (13) is installed on the indicator arrow (12). The nut of the sliding bolt (13) is slidably installed in the annular groove (20103). Its other end protrudes from the surface of the indicator arrow (12) and is fixed by a locking nut to fix the disc (11).

6. A dexterous hand finger according to claim 3, characterized in that, The rotating shaft (10) is rotatably installed in the side wall of the first finger joint (1) on the side away from the rotating column (5), and the rotating shaft (10) is coaxially rotatably sleeved on the opposite end of the rotating column (5).

7. A dexterous hand finger according to claim 1, characterized in that, On one side of the inner wall of the first phalanx (1), there is a horizontal sliding groove (101), a rectangular block (15) is slidably installed in the horizontal sliding groove (101), a bearing (16) is installed in the rectangular block (15), and the bearing (16) is used for the rotation shaft (9) of the moving wheel (7).

8. A dexterous hand finger according to claim 7, characterized in that, The two sides of the rectangular block (15) are each connected to an elastic telescopic element located in the horizontal slide groove (101) so that the rectangular block (15) is elastically slidably connected, and when the transmission belt (6) is not fitted, the elastic telescopic element limits the rectangular block (15) to the center of the horizontal slide groove (101).

9. A dexterous hand finger according to claim 8, characterized in that, A limiting block (17) is slidably installed in the horizontal slide groove (101) on the side of the rectangular block (15) near the frustum (201). One end of the limiting block (17) is located in the horizontal slide groove (101) to contact the side of the rectangular block (15), and the other end is threadedly installed on a lead screw (18). The lead screw (18) is rotatably installed below the horizontal slide groove (101). The end of the lead screw (18) rotates through a bevel gear transmission mechanism (19) so that the limiting block (17) can move to a position where it connects with the rectangular block (15). The drive gear of the bevel gear transmission mechanism (19) has a hexagonal groove at the end of the gear shaft (21) for inserting a wrench to rotate the gear shaft (21); the end of the gear shaft (21) is axially pressed by a clamping bolt (20) threadedly installed in the side wall of the first finger joint (1) to fix the gear shaft (21).

10. A dexterous hand finger according to claim 1, characterized in that, The inner side of the transmission belt (6) is in close contact with the moving wheel (7) for transmission, and the outer side has teeth that mesh with the drive wheel (8) which also has teeth for transmission.

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