Dexterous mechanical finger and manipulator

Abstract

The invention relates to the technical field of manipulators, and particularly discloses a dexterous mechanical finger and a manipulator, the dexterous mechanical finger comprises a fixed seat, a driving mechanism, a palm finger knuckle, a first knuckle, a second knuckle, a third knuckle, a crank transmission mechanism and a first pull rod; wherein the driving mechanism and the palm finger knuckles are arranged on the fixed seat, the palm finger knuckles, the first knuckles, the second knuckles and the third knuckles are sequentially hinged end to end, the crank transmission mechanism is hinged to the driving mechanism, the palm finger knuckles and the second knuckles at the same time, and the first pull rod is hinged to the crank transmission mechanism and the third knuckles at the same time; through collaborative design of the crank transmission mechanism and the first pull rod, reciprocating linear motion of the driving mechanism is converted into coupling rotation of the first knuckle, the second knuckle and the third knuckle; and a single driving mechanism is adopted for providing power, an independent driving motor does not need to be configured for each knuckle, the fault risk of the dexterous mechanical finger is reduced, the operation stability of the dexterous mechanical finger is improved, and the service life of the dexterous mechanical finger is prolonged.

Description

Technical Field

[0001] This invention relates to the field of robotic hand technology, and in particular to a dexterous mechanical finger and robotic hand. Background Technology

[0002] As robotics technology rapidly advances towards humanoid, precise, and scenario-based applications, dexterous hands, as the core actuators enabling robots to interact with the outside world, are playing an increasingly important role in service robots, medical rehabilitation, industrial precision assembly, and intelligent prosthetics. Existing dexterous hands typically employ three-joint mechanical fingers because they have a larger contact envelope compared to two-joint mechanical fingers, resulting in greater stability in grasping diverse workpieces.

[0003] However, traditional three-joint mechanical fingers usually have multiple drive motors built in to drive the bending movement of each joint. The presence of multiple drive motors makes the internal wiring of the mechanical finger complex. During wiring, the wires are prone to tangling and squeezing. When the finger moves (such as bending and extending the joints), the internal wires will be repeatedly pulled and rubbed with the joint movement. Over time, this can easily lead to wire wear and poor contact, resulting in poor stability of the mechanical finger.

[0004] Therefore, existing technologies still need to be improved and enhanced. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a dexterous mechanical finger and a mechanical hand, which aims to solve the problems of poor stability of the mechanical finger caused by the fact that the three-joint mechanical finger has multiple drive motors built in it and the internal circuits are prone to tangling and squeezing, and the circuits are prone to wear during the movement of the joints.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows: In a first aspect, embodiments of the present invention provide a dexterous mechanical finger, comprising: Fixed base; The drive mechanism is mounted on a fixed base and performs reciprocating linear motion. The first end of the metacarpal joint is fixedly connected to the fixed base; The first phalanx, the first end of which is rotatably connected to the second end of the metacarpophalangeal phalanx; The first end of the second phalanx is rotatably connected to the second end of the first phalanx; The first end of the third phalanx is hinged to the second end of the second phalanx; A crank drive mechanism and a first pull rod are included; the second end of the metacarpophalangeal joint is hinged between the two ends of the crank drive mechanism, and the first end of the crank drive mechanism is hinged to the drive mechanism to convert the reciprocating linear motion of the drive mechanism into its own reciprocating bending motion; the first end of the second metacarpophalangeal joint and the first end of the first pull rod are respectively hinged to the second end of the crank drive mechanism, and the second end of the first pull rod is hinged to the first end of the third metacarpophalangeal joint to work in conjunction with the crank drive mechanism to drive the first, second, and third metacarpophalangeal joints to rotate in a coupled manner.

[0007] As a further improved technical solution, the crank transmission mechanism includes: The second pull rod has a first shaft hole and a second shaft hole at its two ends, and the first shaft hole is hinged to the drive mechanism. A coupling link is provided along the direction from the metacarpophalangeal joint to the third phalanx. The coupling link is provided with a third shaft hole, a fourth shaft hole, a fifth shaft hole and a sixth shaft hole in sequence. The third shaft hole is hinged to the second end of the metacarpophalangeal joint. The fourth shaft hole is hinged to the second pull rod through the second shaft hole. The fifth shaft hole is hinged to the first end of the second phalanx. The sixth shaft hole is hinged to the first end of the first pull rod.

[0008] As a further improved technical solution, the driving mechanism includes: A drive cylinder is mounted on the fixed base and drives the telescopic shaft on it to perform reciprocating linear motion. The nut hinge has a sleeve hole at its first end, through which it is sleeved on the telescopic shaft and fixed to itself. The second end of the nut hinge has a seventh shaft hole, through which it is hinged to the first shaft hole.

[0009] As a further improved technical solution, the metacarpophalangeal joint is L-shaped, with a first pin hole and a first bearing at each end, and an eighth shaft hole at the middle corner. The fixed base is provided with a slot, and a second pin hole is provided in the slot. The first end of the metacarpophalangeal joint is inserted into the slot, and the first pin hole and the second pin hole are arranged opposite to each other to be fixed by a pin. The metacarpophalangeal joint is hinged to the third shaft hole through the eighth shaft hole, and the metacarpophalangeal joint is rotatably connected to the first phalanx through the first bearing.

[0010] As a further improved technical solution, the first finger joint is sleeve-shaped and is sleeved on the outer periphery of the palm and finger joint and the outer periphery of the crank transmission mechanism. The second end of the palm and finger joint is symmetrically provided with the first bearings on both sides. The inner wall of the first end of the first finger joint is connected to the two first bearings on both sides respectively. The first end of the second finger joint is symmetrically provided with the second bearings on both sides respectively. The inner wall of the second end of the first finger joint is rotatably connected to the second finger joint through the second bearings.

[0011] As a further improved technical solution, the first end of the second phalanx is provided with a ninth shaft hole, and is hinged to the fifth shaft hole through the ninth shaft hole; the second end of the second phalanx is provided with a tenth shaft hole, and the back side of the first end of the third phalanx is provided with an eleventh shaft hole, and is hinged to the tenth shaft hole through the eleventh shaft hole.

[0012] As a further improved technical solution, the first end of the first pull rod is provided with a twelfth shaft hole, and is hinged to the sixth shaft hole through the twelfth shaft hole; the second end of the first pull rod is provided with a thirteenth shaft hole, and the fingertip side of the first end of the third phalanx is provided with a fourteenth shaft hole, and is hinged to the thirteenth shaft hole through the fourteenth shaft hole.

[0013] As a further improvement, the aforementioned dexterous mechanical finger also includes: A tactile sensor, wherein the tactile sensor is disposed on the third phalanx; A finger sleeve is provided on the pad side of the second finger joint to cover the middle portion of the first pull rod.

[0014] As a further improvement, the aforementioned dexterous mechanical finger also includes: A tension spring is disposed within the first phalanx, and both ends of the tension spring are respectively connected to the second end of the metacarpophalangeal phalanx and the second end of the first phalanx; A torsion spring is sleeved at the hinge between the third phalanx and the second phalanx, and the two ends of the torsion spring are respectively connected to the first end of the third phalanx and the second end of the second phalanx.

[0015] Secondly, embodiments of the present invention also provide a robotic hand, which includes dexterous mechanical fingers as described in any of the above-described embodiments.

[0016] Compared with the prior art, the embodiments of the present invention have the following advantages: This invention, through the coordinated design of the crank transmission mechanism and the first pull rod, transforms the reciprocating linear motion of the drive mechanism into the coupled rotation of the first, second, and third phalanges. The three phalanges flex and extend in coordination according to a preset pattern, retaining the advantages of the three-phalange structure, such as a large contact envelope and high gripping stability. Furthermore, by using a single drive mechanism to provide power, there is no need to configure an independent drive motor for each phalange, which solves the wiring complexity problem caused by traditional multi-motor designs, reduces the risk of failure in dexterous mechanical fingers, and improves the operational stability and service life of dexterous mechanical fingers. Attached Figure Description

[0017] Figure 1 A side view of a dexterous mechanical finger provided by the present invention; Figure 2 A first three-dimensional structural schematic diagram of a dexterous mechanical finger provided by the present invention; Figure 3 This is a three-dimensional structural diagram of the crank transmission mechanism in this invention; Figure 4 This is an exploded view of the crank transmission mechanism in this invention; Figure 5 This is a three-dimensional structural diagram of the nut hinge component in this invention; Figure 6 This is a schematic diagram of the assembly structure of the fixed base and the drive electric cylinder in this invention; Figure 7 This is a schematic diagram of the first assembly structure of the crank transmission mechanism, the metacarpophalangeal joint, and the nut hinge in this invention. Figure 8 This is a schematic diagram of the second assembly structure of the crank transmission mechanism, the metacarpophalangeal joint, and the nut hinge in this invention. Figure 9 This is a three-dimensional structural diagram of the metacarpophalangeal joints in this invention; Figure 10 This is a schematic diagram of the assembly structure of the first finger joint, the first bearing, and the second bearing in this invention; Figure 11 This is a schematic diagram of the assembly structure of the second finger joint and the second bearing in this invention; Figure 12 This is a three-dimensional structural diagram of the third phalanx in this invention; Figure 13 This is a three-dimensional structural diagram of the first pull rod in this invention; Figure 14 This is a schematic diagram of the first assembly structure of the crank transmission mechanism, the second finger joint, the third finger joint, and the first pull rod in this invention. Figure 15 This is a schematic diagram of the second assembly structure of the crank transmission mechanism, the second finger joint, the third finger joint, and the first tie rod in this invention. Figure 16This is a three-dimensional structural diagram of the finger sleeve in this invention; Figure 17 This invention provides a second three-dimensional structural schematic diagram of a dexterous mechanical finger; Figure 18 A three-dimensional structural diagram of a dexterous mechanical finger in an extended state, provided by the present invention; Figure 19 A first three-dimensional structural diagram of a dexterous mechanical finger in a bent state provided by the present invention; Figure 20 A schematic diagram of a second three-dimensional structure of a dexterous mechanical finger in a bent state, provided by the present invention; Figure 21 A schematic diagram of a third three-dimensional structure of a dexterous mechanical finger in a bent state, provided by the present invention; Figure 22 A schematic diagram of a fourth three-dimensional structure of a dexterous mechanical finger in a bent state, provided by the present invention; Figure 23 This is a schematic diagram of the fifth three-dimensional structure of a dexterous mechanical finger in a bent state, provided by the present invention.

[0018] In the diagram: 1. Fixed base; 101. Slot; 102. Second pin hole; 2. Drive mechanism; 201. Drive cylinder; 2011. Telescopic shaft; 202. Nut hinge; 2021. Sleeve hole; 2022. Seventh shaft hole; 3. Finger joint; 301. First pin hole; 302. Eighth shaft hole; 303. First hook; 4. First finger joint; 401. Second hook; 5. Second finger joint; 501. Ninth shaft hole; 502. Tenth shaft hole; 6. Third finger joint; 601. Eleventh shaft. Hole; 602, Fourteenth shaft hole; 7, Crank drive mechanism; 701, Second pull rod; 7011, First shaft hole; 7012, Second shaft hole; 702, Coupling link; 7021, Third shaft hole; 7022, Fourth shaft hole; 7023, Fifth shaft hole; 7024, Sixth shaft hole; 8, First pull rod; 801, Twelfth shaft hole; 802, Thirteenth shaft hole; 9, First bearing; 10, Second bearing; 11, Tactile sensor; 12, Finger sleeve; 13, Tension spring; 14, Torsion spring. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] Example 1 Please see Figures 1 to 23The dexterous mechanical finger includes: a fixed base 1; a drive mechanism 2, mounted on the fixed base 1 and performing reciprocating linear motion; a metacarpophalangeal joint 3, the first end of which is fixedly connected to the fixed base 1; a first phalanx 4, the first end of which is rotatably connected to the second end of the metacarpophalangeal joint 3; a second phalanx 5, the first end of which is rotatably connected to the second end of the first phalanx 4; a third phalanx 6, the first end of which is hinged to the second end of the second phalanx 5; a crank transmission mechanism 7 and a first pull rod 8; the second end of the metacarpophalangeal joint 3 is hinged between the two ends of the crank transmission mechanism 7, and the first end of the crank transmission mechanism 7 is hinged to the drive mechanism 2 to convert the reciprocating linear motion of the drive mechanism 2 into its own reciprocating bending motion; the first end of the second phalanx 5 and the first end of the first pull rod 8 are respectively hinged to the second end of the crank transmission mechanism 7, and the second end of the first pull rod 8 is hinged to the first end of the third phalanx 6, so as to coordinate with the crank transmission mechanism 7 to drive the first phalanx 4, the second phalanx 5 and the third phalanx 6 to rotate in a coupled manner.

[0021] like Figure 1 and Figure 2As shown, in this embodiment, the dexterous mechanical finger includes a fixed base 1, a drive mechanism 2, a metacarpophalangeal joint 3, a first phalanx 4, a second phalanx 5, a third phalanx 6, a crank transmission mechanism 7, a first pull rod 8, a first bearing 9, and a second bearing 10; wherein, the drive mechanism 2 is disposed inside the fixed base 1 and its left end performs reciprocating linear motion, the right end of the metacarpophalangeal joint 3 is fixed to the fixed base 1, the left end of the metacarpophalangeal joint 3 is provided with the first bearing 9, the right end of the first phalanx 4 is rotatably connected to the left end of the metacarpophalangeal joint 3 through the first bearing 9, and the inner part of the first bearing 9... The ring is fixedly connected to the metacarpophalangeal joint 3, and the outer ring of the first bearing 9 is fixedly connected to the right end of the first phalanx 4; the right end of the second phalanx 5 is provided with a second bearing 10 and is rotatably connected to the left end of the first phalanx 4 through the second bearing 10, the inner ring of the second bearing 10 is fixedly connected to the right end of the second phalanx 5, and the outer ring of the second bearing 10 is fixedly connected to the left end of the first phalanx 4; the right end of the third phalanx 6 is hinged to the left end of the second phalanx 5; the left end of the metacarpophalangeal joint 3 is hinged between the two ends of the crank transmission mechanism 7, and the right end of the crank transmission mechanism 7 is connected to the left end of the drive mechanism 2. The crank transmission mechanism 7, through its hinged engagement with the metacarpophalangeal joint 3, converts the reciprocating linear motion of the drive mechanism 2 into its own reciprocating bending motion. The right end of the second phalanx 5 is hinged to the left end of the crank transmission mechanism 7. Therefore, the crank transmission mechanism 7 is equivalent to the knuckle joint between the first phalanx 4 and the second phalanx 5, used to drive the first phalanx 4 and the second phalanx 5 to rotate in a coupled manner. The right end of the first pull rod 8 is hinged to the left end of the crank transmission mechanism 7, and the left end of the first pull rod 8 is hinged to the right end of the third phalanx 6. The first pull rod 8 is equivalent to the second phalanx 6. When the crank transmission mechanism 7 moves, the finger joint between the 5th and the third phalanx 6 pulls the first pull rod 8 to move simultaneously. At this time, the left end of the drive mechanism 2, the crank transmission mechanism 7, and the first pull rod 8 move together and drive the first phalanx 4, the second phalanx 5, and the third phalanx 6 to rotate in a coupled manner, thereby completing the flexion and extension movement of the dexterous mechanical finger. That is, when the left end of the drive mechanism 2 moves to the right and pulls the right end of the crank transmission mechanism 7, the dexterous mechanical finger performs a flexion movement; when the left end of the drive mechanism 2 pushes the right end of the crank transmission mechanism 7 to the left, the dexterous mechanical finger performs an extension movement.

[0022] This embodiment, through the coordinated design of the crank transmission mechanism 7 and the first pull rod 8, transforms the reciprocating linear motion of the drive mechanism 2 into the coupled rotation of the first phalanx 4, the second phalanx 5, and the third phalanx 6. The three phalanxes flex and extend in coordination according to a preset pattern (it should be noted that the three phalanxes mentioned in this invention refer to the first phalanx 4, the second phalanx 5, and the third phalanx 6), retaining the advantages of the three-phalanx structure, such as a large contact envelope and high gripping stability. Furthermore, the use of a single drive mechanism 2 to provide power eliminates the need for an independent drive motor for each phalanx, solving the wiring complexity problem caused by traditional multi-motor designs. It also avoids poor contact caused by wire entanglement, compression, pulling, and wear, reducing the risk of dexterous mechanical finger failure and improving the operational stability of the dexterous mechanical finger. This invention employs a bearing-driven transmission method, transforming the flexible frictional losses of the wiring in traditional structures into rigid rotation or hinged engagement of mechanical components. This method offers greater reliability and more controllable wear. The core transmission components—crank drive mechanism 7, first tie rod 8, first bearing 9, and second bearing 10—are all rigid mechanical parts, exhibiting significantly superior fatigue and wear resistance compared to wiring. Furthermore, they eliminate the hidden faults associated with poor wiring contact, drastically reducing the frequency of routine maintenance for the mechanical fingers and effectively extending their overall service life. The single drive mechanism 2 simplifies the control system logic, eliminating the need for complex algorithms to coordinate multiple motors, thus reducing control complexity and development costs. Simultaneously, it reduces the number of drive components, wiring, and auxiliary parts, balancing manufacturing and maintenance costs and facilitating large-scale application.

[0023] like Figure 3 and Figure 4 As shown, further, the crank transmission mechanism 7 includes two second pull rods 701 and a coupling link 702. Each end of the second pull rod 701 is provided with a first shaft hole 7011 and a second shaft hole 7012, respectively. The first shaft holes 7011 on the two second pull rods 701 are symmetrically hinged to the left ends of the drive mechanism 2. Along the direction from the metacarpophalangeal joint 3 to the third phalanx 6, the coupling link 702 is provided with a third shaft hole 7021, a fourth shaft hole 7022, a fifth shaft hole 7023 and a sixth shaft hole 7024 in sequence. The third shaft holes 7021 on the two second pull rods 701 are symmetrically hinged to the left ends of the metacarpophalangeal joint 3, the fourth shaft hole 7022 is hinged to the left end of the second pull rod 701 through the second shaft hole 7012, the fifth shaft hole 7023 is hinged to the right end of the second phalanx 5, and the sixth shaft hole 7024 is hinged to the right end of the first pull rod 8. The coupling link 702 is L-shaped with an obtuse angle, and the fifth shaft hole 7023 is located at the corner of the coupling link 702.

[0024] Specifically, along the movement direction from the metacarpophalangeal joint 3 to the third phalanx 6, the second pull rod 701 is provided with a first shaft hole 7011 and a second shaft hole 7012 in sequence, and the coupling link 702 is provided with a third shaft hole 7021 to a sixth shaft hole 7024 in sequence. Each shaft hole corresponds to the hinge engagement with the drive mechanism 2, the metacarpophalangeal joint 3, the second pull rod 701, the second phalanx 5, and the first pull rod 8, respectively. This allows the linear power of a single drive mechanism 2 to be precisely transmitted through the coupling link 702, with one path driving the coupling of the first phalanx 4 and the second phalanx 5. The rotation is assisted by the second pull rod 701 to optimize the transmission torque, and by the first pull rod 8 to pull the third phalanx 6 to move synchronously. This achieves the linkage of the coupling link 702 and the first pull rod 8 to drive the three phalanxes in linkage. The second pull rod 701 is hinged to the fourth shaft hole 7022 through the second shaft hole 7012, forming an auxiliary transmission branch of drive mechanism 2-second pull rod 701-coupling link 702. This effectively avoids mechanical dead points in the reciprocating bending motion of the coupling link 702 and ensures the smoothness of the mechanical finger when switching between bending and stretching movements. The coupling link 702 is designed in an L-shape with an obtuse angle, which conforms to the natural bending angle of human fingers during flexion and extension. This avoids the problems of stiff finger joint movement trajectory and low envelope surface fit when in contact with the workpiece caused by straight rod transmission. It makes the flexion and extension of the mechanical finger closer to biomimetic movement, improves the grasping and envelope effect on diverse workpieces, and further strengthens the inherent advantage of the high grasping stability of the three-joint structure. The fifth shaft hole 7023 is set at the corner of the L-shaped coupling link 702, so that the power receiving point of the second joint 5 is located at the core of the mechanical bending of the transmission mechanism. The torque during power transmission is more balanced, avoiding swaying or jamming when the joint rotates. This ensures the coaxiality and smoothness of the coupling rotation between the second joint 5 and the first joint 4, and makes the movement accuracy of the joint flexion and extension higher.

[0025] like Figure 5 and Figure 6As shown, further, the driving mechanism 2 includes a driving electric cylinder 201 and a nut hinge 202. The driving electric cylinder 201 is mounted on the fixed base 1 and drives the telescopic shaft 2011 at its left end to perform reciprocating linear motion. The nut hinge 202 has a sleeve hole 2021 at its right end, and is sleeved on the telescopic shaft 2011 through the sleeve hole 2021 and fixed to each other. The nut hinge 202 has a seventh shaft hole 2022 at its left end, and is hinged to the first shaft hole 7011 through the seventh shaft hole 2022. Specifically, the methods by which the sleeve 2021 and the telescopic shaft 2011 are fixed to each other include, but are not limited to, threaded connection and fixed by a pin. For example, the sleeve 2021 has an internal thread and the telescopic shaft 2011 has an external thread. The sleeve 2021 is fitted onto the telescopic shaft 2011 and is connected by the mating of the internal and external threads. Alternatively, the sleeve 2021 and the telescopic shaft 2011 have corresponding through holes. A pin is inserted into the through hole to lock the two together and fix them to each other, so as to facilitate disassembly or reassembly later. In this embodiment, the sleeve hole 2021 and the telescopic shaft 2011 are connected by a thread. Through the rigid connection of surface contact, the fit gap between the telescopic shaft 2011 and the connecting part is eliminated, ensuring that the linear power of the drive cylinder 201 can be transmitted to the nut hinge 202 without loss or delay, avoiding slippage and loosening during power transmission, and improving the reliability of power transmission. Because the crank transmission mechanism 7 will produce a change in bending angle when it moves, there is a posture difference with the pure linear motion of the telescopic shaft 2011. Therefore, the left end of the nut hinge 202 is hinged to the first shaft hole 7011 of the coupling rod 702 through the seventh shaft hole 2022. This flexibly connects the linear translation of the drive cylinder 201 with the reciprocating bending motion of the crank transmission mechanism 7, adapting to the change in the motion posture between the two, avoiding component jamming and stress concentration caused by hard connection, ensuring the smoothness of the transmission link, and dispersing the force at the connection point to reduce component wear.

[0026] Meanwhile, the nut hinge 202 serves as a force-bearing buffer between the drive cylinder 201 and the crank transmission mechanism 7. Through hinged engagement, it disperses the radial stress on the telescopic shaft 2011 during power transmission. For example, when the crank transmission mechanism 7 bends, it will generate radial tension or thrust on the telescopic shaft 2011. The nut hinge 202 prevents the radial stress from acting directly on the core components such as the piston rod and guide rail inside the drive cylinder 201, preventing the drive cylinder 201 from jamming or being damaged due to stress concentration. It also reduces the load on the first shaft hole 7011 and extends the service life of the crank transmission mechanism 7.

[0027] like Figure 7 , Figure 8 and Figure 9As shown, in this embodiment, the metacarpophalangeal joint 3 is L-shaped, with a first pin hole 301 and a first bearing 9 at each end, and an eighth shaft hole 302 at the middle corner. The fixed base 1 is provided with a slot 101, and a second pin hole 102 is provided in the slot 101. One end of the metacarpophalangeal joint 3 is inserted into the slot 101, and the first pin hole 301 and the second pin hole 102 are arranged opposite to each other to be fixed by a pin (not shown). The metacarpophalangeal joint 3 is hinged to the third shaft hole 7021 through the eighth shaft hole 302. Specifically, the left end of the metacarpophalangeal joint 3 is provided with symmetrical first bearings 9 and symmetrically distributed eighth shaft holes 302 on both sides. The left end of the metacarpophalangeal joint 3 is rotatably connected to the two sides of the first phalanx 4 through two symmetrical first bearings 9. There is a gap between the two eighth shaft holes 302 on the left end of the metacarpophalangeal joint 3. The right end of the coupling rod 702 is located in the gap and the third shaft hole 7021 corresponds synchronously with the two eighth shaft holes 302 to achieve hinge connection, forming a structure in which the left end of the metacarpophalangeal joint 3 clamps the right end of the coupling rod 702, which makes the motion balance between the two better and more stable.

[0028] Furthermore, the eighth shaft hole 302, which is hinged to the third shaft hole 7021 of the coupling rod 702, is located at the corner of the metacarpophalangeal joint 3, making the metacarpophalangeal joint 3 a fixed fulcrum for the reciprocating bending motion of the crank transmission mechanism 7. The rigid structure at the fulcrum can effectively withstand the radial and axial combined forces transmitted by the crank transmission mechanism 7, preventing deformation and loosening at the fulcrum due to excessive force, thus ensuring the stability of power transmission from the basic support level. The first bearing 9 at the end of the metacarpophalangeal joint 3 is used to realize the relative rotation with the first finger joint 4, and the eighth shaft hole 302 at the corner is used to realize the hinge fulcrum with the crank transmission mechanism 7. The two core motion stations are set separately along the L-shaped structure, so that the rotational motion of the first finger joint 4 is related to the crank transmission mechanism 7. The reciprocating bending motion has no spatial overlap, avoiding mutual interference between the two moving parts, ensuring the independent movement and coordinated cooperation between the first finger joint 4 and the crank transmission mechanism 7, and eliminating the hidden dangers of motion jamming and stagnation; the L-shaped metacarpophalangeal joint 3 conforms to the natural bending structure of the human finger's metacarpophalangeal joint, forming a biomimetic synergy with the L-shaped obtuse angle coupling link 702 and the structure of the three-segment finger joint, making the overall flexion and extension trajectory of the mechanical finger closer to the natural movement trajectory of the human finger. When grasping a workpiece, the L-shaped structure of the metacarpophalangeal joint 3 can drive the subsequent three-segment finger joints to form an envelope angle that is more in line with the workpiece surface, further improving the utilization rate of the contact envelope surface of the three-segment finger joint structure, enhancing grasping stability, and adapting to the grasping needs of diverse and irregularly shaped workpieces.

[0029] like Figure 10 and Figure 11As shown, further, the first finger joint 4 is sleeve-shaped, with its two sides symmetrically spliced ​​together by screws to form a sleeve shape. The first finger joint 4 is sleeved on the outer periphery of the metacarpophalangeal joint 3 and the outer periphery of the crank transmission mechanism 7. The left end of the metacarpophalangeal joint 3 is symmetrically provided with the first bearing 9 on both sides. The right end of the inner wall of the first finger joint 4 is respectively connected to the two first bearings 9. The right end of the second finger joint 5 is symmetrically provided with the second bearings 10 on both sides. The left end of the inner wall of the first finger joint 4 is rotatably connected to the second finger joint 5 through the second bearings 10. Moreover, the first finger joint 4 covers the hinge joint between the second pull rod 701 and the coupling rod 702 and the hinge joint between the coupling rod 702 and the metacarpophalangeal joint 3.

[0030] Specifically, the metacarpophalangeal joint 3 and the first phalanx 4, as well as the first phalanx 4 and the second phalanx 5, both employ a double-sided symmetrical bearing connection. This ensures that the rotational force is evenly distributed along both sides of the phalanx axis, guaranteeing the coaxiality accuracy of the first phalanx 4 and the second phalanx 5 during rotation. It eliminates phalanx wobble and jamming issues caused by single-sided connections, resulting in smoother coupling rotation of the three phalanx segments. The surface contact rotational fit of the double-sided bearings significantly increases the contact area of ​​the rotational support, disperses local pressure during phalanx rotation, reduces bearing wear per unit area, extends bearing life, and simultaneously reduces friction during rotation, minimizing mechanical losses in the transmission chain and improving the transmission efficiency of single-drive power. The sleeve-shaped first phalanx 4 provides independent and ample internal movement space for the reciprocating bending motion of the internal crank transmission mechanism 7 and the second pull rod 701. The first phalanx 4, the palm and finger phalanx 3, and the crank transmission mechanism 7 form a coaxial nested layout, allowing the transmission components inside the dexterous mechanical finger to highly overlap with the first phalanx 4 in space, further compressing the radial dimension of the mechanical finger, making the overall structure more compact and lightweight, which is in line with the design trend of dexterous hand precision and humanoid shape. At the same time, the first phalanx 4 can also protect the internal coupling link 702 and the second pull rod 701.

[0031] like Figures 12 to 15 As shown, further, the right end of the second phalanx 5 is provided with a ninth shaft hole 501, and is hinged to the fifth shaft hole 7023 through the ninth shaft hole 501; the left end of the second phalanx 5 is provided with a tenth shaft hole 502, and the right end of the third phalanx 6 has an eleventh shaft hole 601 on the back side of the finger, and is hinged to the tenth shaft hole 502 through the eleventh shaft hole 601. Specifically, setting the eleventh shaft hole 601 of the third phalanx 6 on the back side of the finger, rather than the fingertip side, better conforms to the biomimetic motion law of human fingers bending and extending, where the back side of the finger is the bending fulcrum and the fingertip side naturally conforms to the workpiece. When the third phalanx 6 rotates around the hinge point eleventh shaft hole 601, the fingertip side can naturally form an arc-shaped bending trajectory. When grasping the workpiece, the fingertip of the third phalanx 6 can more closely conform to the surface of the workpiece, greatly improving the contact envelope effect of the distal phalanx.

[0032] In this embodiment, the right end of the first pull rod 8 is provided with a twelfth shaft hole 801, and is hinged to the sixth shaft hole 7024 through the twelfth shaft hole 801; the left end of the first pull rod 8 is provided with a thirteenth shaft hole 802, and the right end of the third finger joint 6 is provided with a fourteenth shaft hole 602 on the fingertip side, and is hinged to the thirteenth shaft hole 802 through the fourteenth shaft hole 602. Specifically, the eleventh shaft hole 601 on the back side of the third phalanx 6 serves as the hinge rotation fulcrum, and the fourteenth shaft hole 602 on the fingertip side serves as the traction fulcrum. These fulcrums are radially aligned along the phalanx, forming a symmetrical mechanical support structure. This allows the force on the third phalanx 6 during bending to be evenly distributed along the phalanx body, preventing stress concentration at a single fulcrum and thus avoiding shaft hole wear and deformation. The design of the traction fulcrum on the fingertip side allows the traction force of the first pull rod 8 to directly act on the gripping force surface of the third phalanx 6. When gripping a workpiece, the traction force can be directly converted into an enveloping clamping force on the workpiece, eliminating the need for additional force transmission links, reducing power loss, improving the clamping force and reliability of the distal phalanx gripping, and preventing workpiece slippage. The third phalanx 6 is simultaneously driven by the hinge rotation of the tenth shaft hole 502 of the second phalanx 5 and the traction force of the first pull rod 8 on the fingertip side, forming a composite motion mode of hinge rotation and fingertip traction, which better conforms to the mechanical laws of flexion and extension of the human fingertip. When the distal phalanx of a human finger bends, the back of the finger acts as the hinge fulcrum, while the fingertip is pulled by the tendon. This embodiment replicates the biomimetic movement of a human finger through a composite motion mode of hinge rotation and fingertip traction, making the bending trajectory of the third phalanx 6 more natural and smoother, forming a continuous arc-shaped envelope surface, which greatly improves the fit with the workpiece surface, and is especially suitable for grasping irregular workpieces such as arc-shaped, spherical, and irregular shapes.

[0033] like Figure 16 and Figure 17 As shown, the dexterous mechanical finger also includes a tactile sensor 11 and a finger sleeve 12. The tactile sensor 11 is disposed on the third phalanx 6; the finger sleeve 12 is disposed on the fingertip side of the second phalanx 5 to cover the middle part of the first pull rod 8. Based on the feedback of the weight of the workpiece grasped by the tactile sensor 11, the control system can adjust the stroke and thrust of the drive cylinder 201 in real time to achieve adaptive adjustment of the grasping force. The finger sleeve 12 covers the middle part of the first pull rod 8 along the grasping force area, forming a closed protective layer for the first pull rod 8. On the one hand, it can effectively prevent the workpiece from scraping and bumping during the grasping process, avoid the surface wear and deformation of the first pull rod 8 caused by direct contact with the workpiece, and prevent the rigidity of the first pull rod 8 from affecting the transmission of pulling power. On the other hand, it can isolate external dust, iron filings, liquids and other impurities, avoid the movement jamming caused by impurities adhering to the surface of the first pull rod 8, and ensure the smoothness of the pulling movement of the first pull rod 8.

[0034] Furthermore, the dexterous mechanical finger also includes a tension spring 13 and a torsion spring 14. The tension spring 13 is disposed within the first phalanx 4. The left end of the metacarpophalangeal phalanx 3 is provided with a first hook 303, and the left end of the first phalanx 4 is provided with a second hook 401. The two ends of the tension spring 13 are respectively connected to the first hook 303 and the second hook 401. The torsion spring 14 is sleeved at the hinge between the third phalanx 6 and the second phalanx 5, that is, the torsion spring 14 is sleeved on the outside of the eleventh shaft hole 601. The two ends of the torsion spring 14 are respectively connected to the left end of the third phalanx 6 and the right end of the second phalanx 5. Specifically, since the phalanxes are hinged through shaft holes, there will be a certain gap between the phalanxes after processing and assembly. The tension spring 13 is used to compensate for the play between the first phalanx 4 and the metacarpophalangeal phalanx 3, and the torsion spring 14 is used to compensate for the play between the third phalanx 6 and the second phalanx 5, making the overall structure of the dexterous mechanical finger more compact and stable.

[0035] like Figures 18 to 23 As shown, the nut hinge 202, the second pull rod 701, and the coupling link 702 in this invention constitute a first-stage crank-slider mechanism; the palm and finger joints 3, the coupling link 702, the first finger joint 4, and the second finger joint 5 constitute a second-stage four-bar linkage; and the coupling link 702, the first pull rod 8, the second finger joint 5, and the third finger joint 6 constitute a third-stage four-bar linkage. The second finger joint 5 serves as both the link in the second-stage four-bar linkage and the main crank in the third-stage four-bar linkage, while the coupling link 702 serves as both the main crank in the second-stage four-bar linkage and the frame in the third-stage four-bar linkage.

[0036] When the drive cylinder 201 drives the nut hinge 202 to move linearly along the axial direction, the second pull rod 701 is hinged to the nut hinge 202, and the second pull rod 701 is also hinged to the coupling link 702. Thus, the nut hinge 202 pulls the coupling link 702 to swing around the fixed metacarpophalangeal knuckle 3 via the second pull rod 701. In the second-stage four-bar linkage, the coupling link 702 acts as the main rocker arm. Its swinging motion drives the first knuckle 4 of the driven rocker arm to rotate around the metacarpophalangeal knuckle 3, achieving flexion and extension of the first joint of the dexterous mechanical finger. Simultaneously, its swinging motion drives the second knuckle 5 to rotate relative to the first knuckle 4, achieving flexion and extension of the second joint of the dexterous mechanical finger. In the third-stage four-bar linkage, the coupling link 702 acts as the frame, and the second knuckle 5 acts as the main rocker arm. Their relative movement causes the third knuckle 6 to rotate relative to the second knuckle 5, achieving flexion and extension of the third joint of the dexterous mechanical finger. It should be noted that the present invention can also change the flexion and extension range of the dexterous mechanical finger and the rotation ratio of the three joints by changing the rod length ratio and coupling angle of the first pull rod 8, the second pull rod 701 and the coupling link 702.

[0037] Example 2 This invention also provides a robotic hand, which includes dexterous mechanical fingers as described in any one of the above embodiments.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0043] Of course, the above description of the embodiments of the present invention is quite detailed, but it should not be construed as a limitation on the scope of protection of the present invention. The present invention may have many other implementations. Based on this implementation, other implementations obtained by those skilled in the art without any creative effort are all within the scope of protection of the present invention. The scope of protection of the present invention is determined by the appended claims.

Claims

1. A dexterous mechanical finger, characterized in that, include: Fixed base; The drive mechanism is mounted on a fixed base and performs reciprocating linear motion. The first end of the metacarpal joint is fixedly connected to the fixed base; The first phalanx, the first end of which is rotatably connected to the second end of the metacarpophalangeal phalanx; The first end of the second phalanx is rotatably connected to the second end of the first phalanx; The first end of the third phalanx is hinged to the second end of the second phalanx; A crank drive mechanism and a first pull rod are included; the second end of the metacarpophalangeal joint is hinged between the two ends of the crank drive mechanism, and the first end of the crank drive mechanism is hinged to the drive mechanism to convert the reciprocating linear motion of the drive mechanism into its own reciprocating bending motion; the first end of the second metacarpophalangeal joint and the first end of the first pull rod are respectively hinged to the second end of the crank drive mechanism, and the second end of the first pull rod is hinged to the first end of the third metacarpophalangeal joint to work in conjunction with the crank drive mechanism to drive the first, second, and third metacarpophalangeal joints to rotate in a coupled manner.

2. The dexterous mechanical finger according to claim 1, characterized in that, The crank transmission mechanism includes: The second pull rod has a first shaft hole and a second shaft hole at its two ends, and the first shaft hole is hinged to the drive mechanism. A coupling link is provided along the direction from the metacarpophalangeal joint to the third phalanx. The coupling link is provided with a third shaft hole, a fourth shaft hole, a fifth shaft hole and a sixth shaft hole in sequence. The third shaft hole is hinged to the second end of the metacarpophalangeal joint. The fourth shaft hole is hinged to the second pull rod through the second shaft hole. The fifth shaft hole is hinged to the first end of the second phalanx. The sixth shaft hole is hinged to the first end of the first pull rod.

3. The dexterous mechanical finger according to claim 2, characterized in that, The drive mechanism includes: A drive cylinder is mounted on the fixed base and drives the telescopic shaft on it to perform reciprocating linear motion. The nut hinge has a sleeve hole at its first end, through which it is sleeved on the telescopic shaft and fixed to itself. The second end of the nut hinge has a seventh shaft hole, through which it is hinged to the first shaft hole.

4. The dexterous mechanical finger according to claim 2, characterized in that, The metacarpophalangeal joint is L-shaped, with a first pin hole and a first bearing at each end. An eighth shaft hole is provided at the middle corner. The fixed base is provided with a slot, and a second pin hole is provided in the slot. The first end of the metacarpophalangeal joint is inserted into the slot, and the first pin hole and the second pin hole are arranged opposite to each other to be fixed by a pin. The metacarpophalangeal joint is hinged to the third shaft hole through the eighth shaft hole. The metacarpophalangeal joint is rotatably connected to the first phalanx through the first bearing.

5. The dexterous mechanical finger according to claim 4, characterized in that, The first finger joint is sleeve-shaped and is sleeved on the outer periphery of the palm and finger joint and the outer periphery of the crank transmission mechanism. The second end of the palm and finger joint is symmetrically provided with the first bearing on both sides. The inner wall of the first end of the first finger joint is connected to the two first bearings on both sides respectively. The first end of the second finger joint is symmetrically provided with the second bearing on both sides respectively. The inner wall of the second end of the first finger joint is rotatably connected to the second finger joint through the second bearing.

6. The dexterous mechanical finger according to claim 5, characterized in that, The first end of the second phalanx is provided with a ninth shaft hole, and is hinged to the fifth shaft hole through the ninth shaft hole; the second end of the second phalanx is provided with a tenth shaft hole, and the back side of the first end of the third phalanx is provided with an eleventh shaft hole, and is hinged to the tenth shaft hole through the eleventh shaft hole.

7. The dexterous mechanical finger according to claim 6, characterized in that, The first end of the first pull rod is provided with a twelfth shaft hole, and is hinged to the sixth shaft hole through the twelfth shaft hole; the second end of the first pull rod is provided with a thirteenth shaft hole, and the fingertip side of the first end of the third phalanx is provided with a fourteenth shaft hole, and is hinged to the thirteenth shaft hole through the fourteenth shaft hole.

8. The dexterous mechanical finger according to claim 1, characterized in that, Also includes: A tactile sensor, wherein the tactile sensor is disposed on the third phalanx; A finger sleeve is provided on the pad side of the second finger joint to cover the middle portion of the first pull rod.

9. The dexterous mechanical finger according to claim 1, characterized in that, Also includes: A tension spring is disposed within the first phalanx, and both ends of the tension spring are respectively connected to the second end of the metacarpophalangeal phalanx and the second end of the first phalanx; A torsion spring is sleeved at the hinge between the third phalanx and the second phalanx, and the two ends of the torsion spring are respectively connected to the first end of the third phalanx and the second end of the second phalanx.

10. A robotic arm, characterized in that, Including the dexterous mechanical finger as described in any one of claims 1-9.

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