Bionic finger driven by dielectric elastomer

Abstract

The utility model discloses a bionic finger driven by a dielectric elastomer, relates to the technical field of bionic fingers, and solves the problems that a bionic finger in the prior art is complex in structure and cannot meet the requirement for light weight. The finger joint comprises a fixing seat, the fixing seat is sequentially connected with a plurality of middle knuckles and tail end knuckles, hinge structures are fixedly arranged on the middle knuckles and the tail end knuckles, and the fixing seat and the middle knuckles, the adjacent middle knuckles and the middle knuckles and the tail end knuckles are hinged through the hinge structures respectively. The adjacent hinged structures are in transmission fit through a transmission mechanism; a dielectric elastomer driver is arranged on the fixing base, and the movable end of the dielectric elastomer driver is in transmission connection with the hinge structure on the first middle knuckle. According to the utility model, the structure is reliable, the dielectric elastomer driver as a driving power source has a small volume and can maintain a large driving force, the structural complexity is significantly reduced, and the lightweight requirement is met.

Description

TECHNICAL FIELD

[0001] The utility model relates to bionic finger technical field especially is a kind of bionic finger driven by dielectric elastomer. BACKGROUND

[0002] With the continuous progress of robot technology, the design of bionic robot fingers is increasingly concerned. Traditional driving methods such as electric motor, pneumatic and hydraulic drive often have problems such as heavy weight, low efficiency, poor control accuracy and high complexity in practical application. In recent years, dielectric elastomer actuator (DEA) has become a potential alternative driving technology due to its lightweight, high efficiency, flexibility and easy control. Through axial driving mode, dielectric elastomer actuator not only can provide high energy efficient power output, but also can realize more accurate and flexible motion control, so it has important prospect and application value in the application of mechanical fingers.

[0003] Currently, the driving system of mechanical fingers mainly adopts the following technologies: electric drive, pneumatic drive, hydraulic drive and rope drive. Among them, electric drive is widely used due to its high power density and mature control technology. However, the electric drive system usually has the following problems: the volume and weight of the electric drive are relatively large, which limits its use in application scenarios that require lightweight and small design, especially in mechanical finger systems that require high flexibility. The energy conversion efficiency of electric drive is relatively low, especially during long-term use, which will affect the performance due to heating, reducing the stability and endurance of the system.

[0004] The Chinese invention patent with publication number CN109605406A discloses a bionic finger, which includes three U-shaped grooves connected in series from front to back, a rear U-shaped groove rear hinged fixed plate L-shaped corner, a fixed plate L-shaped one side connected with the U-shaped groove in front and rear middle position through inverse parallel four-bar linkage mechanism, the other side of the fixed plate L-shaped is fixed on the palm of the artificial hand, the motor reducer is fixed on the rear U-shaped groove, the output shaft is connected with bevel gear one through double universal connecting shaft joint, bevel gear one is fixedly connected with lower hinged shaft two of front U-shaped groove and middle U-shaped groove, and the lower hinged shaft two is fixedly connected with the front U-shaped groove, cylindrical gear two is fixed on the upper hinged shaft two of the front U-shaped groove and the middle U-shaped groove, cylindrical gear two is engaged with cylindrical gear one on double pulley, belt pulley two on double pulley forms belt drive with belt pulley one, belt pulley one is fixed on the upper hinged shaft one of the middle U-shaped groove and the rear U-shaped groove, and the upper hinged shaft one is fixed on the rear U-shaped groove, to realize bionic motion of finger.

[0005] In the scheme, joint movement is realized through motor driving and through the cooperation of universal connecting shaft joints and bevel gears, on the one hand, motor driving occupies a large volume, and long-term use will cause heating and other problems, affecting stability; in addition, the related mechanical transmission structure is complex, and the flexibility is poor, so there is a lightweight problem. Content of the utility model

[0006] In view of the deficiencies in the foregoing background art, the utility model provides a dielectric elastomer driven bionic finger, which solves the problem of complex structure of the bionic finger in the prior art and does not meet the lightweight requirement.

[0007] The technical scheme of the utility model is as follows: a dielectric elastomer driven bionic finger, comprising a fixed seat, a plurality of intermediate knuckles and end knuckles are sequentially connected on the fixed seat, hinge structures are fixedly arranged on the intermediate knuckles and the end knuckles, the fixed seat and the intermediate knuckles, adjacent intermediate knuckles and the intermediate knuckles and the end knuckles are hingedly connected through the hinge structures, and the adjacent hinge structures are drivingly matched through a transmission mechanism; a dielectric elastomer driver is arranged on the fixed seat, and the movable end of the dielectric elastomer driver is drivingly connected with the hinge structure on the first intermediate knuckle.

[0008] Preferably, the hinge structure comprises hinge shafts fixedly arranged at one end of the intermediate knuckles and the end knuckles respectively, the hinge shafts are provided with connecting portions, the transmission mechanism is connected with the connecting portions, and the other end of the intermediate knuckles and the end knuckles is provided with a through hole through which the hinge shaft passes.

[0009] Preferably, the transmission mechanism comprises first-stage wheel bodies and second-stage wheel bodies, the first-stage wheel bodies and the second-stage wheel bodies are coaxially fixedly arranged on the connecting portions; in the direction from the intermediate knuckles to the end knuckles, the first-stage wheel bodies and the second-stage wheel bodies on the adjacent hinge shafts are sequentially drivingly matched through a transmission belt. Further, in the direction from the intermediate knuckles to the end knuckles, the rotation speed ratio between the adjacent hinge shafts is less than one.

[0010] Preferably, the transmission belt is a transmission rope, the transmission rope is wound at least once on the first-stage wheel bodies and the second-stage wheel bodies, and the first-stage wheel bodies and the second-stage wheel bodies are provided with grooves for the transmission rope to wind around.

[0011] Preferably, the transmission belt is a synchronous belt, and the first-stage wheel bodies and the second-stage wheel bodies are synchronous pulleys.

[0012] Preferably, the dielectric elastomer drivers on the fixed seat are arranged in pairs, the two movable ends of each pair of dielectric elastomer drivers are connected with two ends of a traction member respectively, the traction member is matched with the first-stage wheel body on the first intermediate knuckle, and the traction member can drive the first-stage wheel body to rotate.

[0013] Preferably, the traction member is a traction rope, a middle part of the traction rope is wound around the first wheel body for at least one turn, and the first wheel body is provided with a groove for winding the traction rope.

[0014] Preferably, the middle phalange and the end phalange each comprise a pair of side plates connected by a connecting plate, and the end phalange is provided with an arc-shaped part.

[0015] The utility model discloses the beneficial effects: through setting up fixed seat, provide installation and connection support base, through setting up a plurality of sequentially connected middle phalange and end phalange on fixed seat, and through the hinged structure articulates, realize bionic structure design purpose, and through transmission mechanism connects adjacent hinged structure, realizes the linkage structure support at joint, and through utilizing dielectric elastomer driver to generate driving force, drive middle phalange and end phalange linkage. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the utility model embodiments, the following will be needed to use the drawings in the embodiment description briefly introduced, obviously, the following description in the drawings only some embodiments of the utility model, for those skilled in the art, under the premise of not paying creative labor, according to these drawings, other drawings can also be obtained.

[0017] Figure 1 It is the three-dimensional structure schematic diagram of the utility model;

[0018] Figure 2 It is the upper structure schematic diagram of the utility model;

[0019] Figure 3 It is the lower cross section structure schematic diagram of the utility model;

[0020] In the drawing: 1: fixed seat, 2: middle phalange, 3: end phalange, 4: hinged structure, 5: transmission mechanism, 6: dielectric elastomer driver, 41: hinged shaft, 42: through hole, 51: first wheel body, 52: second wheel body, 53: transmission belt, 61: traction member, 7: side plate, 8: connecting plate, 9: arc-shaped part. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0022] As shown in Figure 1 embodiment 1, a dielectric elastomer driven bionic finger comprises a fixed seat 1, which provides installation and connection support basis for other accessories, a plurality of intermediate knuckles 2 and end knuckles 3 are sequentially connected on the fixed seat 1, hinge structures 4 are fixedly arranged on the intermediate knuckles 2 and the end knuckles 3, the fixed seat 1 and the intermediate knuckles 2, adjacent intermediate knuckles 2 and the intermediate knuckles 2 and the end knuckles 3 are hingedly connected through the hinge structures 4, and adjacent hinge structures 4 are drivingly matched through transmission mechanisms 5; a dielectric elastomer driver 6 is arranged on the fixed seat 1, and the movable end of the dielectric elastomer driver 6 is drivingly connected with the hinge structure 4 on the first intermediate knuckle 2. In this embodiment, the dielectric elastomer driver serving as a driving power source has a small volume and can maintain a large driving force, significantly reducing the structural complexity and meeting the lightweight requirement.

[0023] In use, the fixed seat, the intermediate knuckles and the end knuckles arranged in sequence are hingedly connected through the hinge structures in the embodiment, the bionic structure design purpose is achieved, different numbers of intermediate knuckles can be arranged according to the actual requirement to realize the bionics of fingers of different lengths, in the embodiment, two intermediate knuckles are arranged to simulate the joints of human fingers. The adjacent hinge structures are drivingly connected through the transmission mechanisms, the linkage at the joints is realized, and the dielectric elastomer driver is used to generate driving force to drive the linkage of the intermediate knuckles and the end knuckles, the bending and straightening of the finger are realized. The structure is reliable and flexible to operate, the space occupied by the related components and structures is small, and the number of the intermediate knuckles can be adaptively adjusted according to the actual requirement to meet the requirement of different use scenarios.

[0024] As a further specific embodiment, the intermediate knuckles 2 and the end knuckles 3 both comprise a pair of side plates 7 connected through a connecting plate 8, which can be made by machining or 3D printing. In the embodiment, the connecting plate connects the side plates from the middle of the back, and the connecting plates between the adjacent knuckles are in contact with each other in the straightening state of the finger, thereby limiting the position. The end knuckle 3 is provided with an arc-shaped part 9, which satisfies the profiling design with the end of the human finger, facilitates movement, and facilitates pressing and other actions.

[0025] The hinge structure 4 comprises hinge shafts 41 fixed at one end of the intermediate phalange 2 or the terminal phalange 3 respectively, and the hinge shafts 41 are provided with connecting portions, and the transmission mechanism 5 is connected with the connecting portions, and the other end of the intermediate phalange 2 and the terminal phalange 3 is respectively provided with a through hole 42 for the hinge shaft to pass through, and the adjacent intermediate phalanges or the intermediate phalange and the terminal phalange are hingedly connected through the hinge shafts and the through holes.

[0026] In addition, as shown in the drawings, the transmission mechanism 5 comprises a first-stage wheel body 51 and a second-stage wheel body 52 coaxially fixed on the connecting portions. Figure 2 The first-stage wheel body 51 and the second-stage wheel body 52 on the adjacent hinge shafts 41 are sequentially driven and matched by the transmission belt 53 in the direction from the intermediate phalange 2 to the terminal phalange 3.

[0027] In this embodiment, the speed ratio between the adjacent hinge shafts 41 in the direction from the intermediate phalange 2 to the terminal phalange 3 is less than one, so that the speed increasing transmission is realized, and when the first intermediate phalange rotates, the angular velocity of the subsequent hinge shafts is amplified, and the subsequent intermediate phalanges and terminal phalanges can rotate in sequence at a high speed, so that the purpose of quickly closing the fingers and bending the fingers is achieved.

[0028] As a further specific embodiment, the transmission belt 53 is a transmission rope, and the transmission rope is wound at least one turn on the first-stage wheel body 51 and the second-stage wheel body 52 respectively, and the first-stage wheel body 51 and the second-stage wheel body 52 are both provided with grooves for the transmission rope to wind around. In this embodiment, the transmission rope is a ring rope, which can be made of nylon wire and has strong durability. The transmission rope is wound multiple turns on the first-stage wheel body and the second-stage wheel body at both ends, so as to improve the friction between the transmission rope and the grooves of the first-stage wheel body and the second-stage wheel body. In order to meet the winding and rotation of the transmission rope, the grooves are arc grooves in this embodiment, so that the rope body of the wound transmission rope is more centered, and the transmission is more stable.

[0029] Embodiment 3: A dielectric elastomer driven bionic finger, based on embodiment 2, different from embodiment 2 is that, in this embodiment, the transmission belt 53 is a synchronous belt, and the first-stage wheel body 51 and the second-stage wheel body 52 are both synchronous pulleys. The synchronous belt is used to realize the transmission between the first-stage wheel body and the second-stage wheel body, and the transmission force is stronger, but the width of the synchronous belt is larger, which will increase the size of the bionic finger, so it only meets the needs of the scenes with large activity space and large required force.

[0030] Embodiment 4: A dielectric elastomer driven bionic finger, based on embodiment 2 or 3, as shown in the drawings, Figure 3As shown, the dielectric elastomer driver 6 on the fixing seat 1 is arranged in pairs, and the two movable ends of each pair of dielectric elastomer drivers 6 are connected with the two ends of the traction member 61 respectively. The traction member 61 cooperates with the first-stage wheel body 51 on the middle phalanx 2 of the first segment, and can drive the first-stage wheel body 51 to rotate. In the embodiment, the dielectric elastomer driver can be driven by a novel driver based on dielectric elastomer disclosed in the Chinese Utility Model Patent with the publication number CN202160126U, and can also be driven by a driver driven by a PDMS dielectric elastomer film. Under the energized state, the dielectric elastomer driver will be elongated under the action of Maxwell force. Under the non-energized state, the dielectric elastomer driver will be contracted under the action of the internal spring.

[0031] Specifically in the embodiment, the traction member 61 is a traction rope, and the middle part of the traction rope is wound at least one turn on the first-stage wheel body 51. The first-stage wheel body 51 is provided with a groove satisfying the winding of the traction rope. The groove in the embodiment is an arc-shaped groove, which can limit the winding range of the traction rope on the first-stage wheel body during rotation. The more turns of the middle part of the traction rope wound on the arc-shaped groove, the greater the friction between the traction rope and the first-stage wheel body, and the more stable the transmission.

[0032] In use, each bionic finger is provided with a pair of dielectric elastomer drivers, and the two dielectric elastomer drivers are arranged on the inner side and the outer side of the bionic finger respectively. The fixed ends of the dielectric elastomer drivers are fixedly connected with the fixing seat, the movable ends of the dielectric elastomer drivers are connected with the traction rope respectively, and the dielectric elastomer drivers are pre-stretched. When the finger needs to be bent, the dielectric elastomer driver on the outer side is stretched under the energized state, the dielectric elastomer driver on the inner side is not energized, the movable end of the dielectric elastomer driver on the inner side pulls the traction rope to move under the self-contracting action of the internal spring, and the traction rope pulls the first-stage wheel body to rotate. When the first-stage wheel body is pulled to rotate, the first segment middle phalanx is driven to rotate relative to the fixing seat through the hinge shaft synchronously. With the rotation of the hinge shaft, the hinge shaft on the second segment middle phalanx is driven to rotate at a higher speed under the action of the synchronous belt, and in turn, the second segment middle phalanx is driven to rotate at a higher speed while rotating with the first segment middle phalanx. Similarly, the terminal phalanx rotates relative to the second segment middle phalanx under the accelerated transmission, and finally the finger is bent and folded. When the finger needs to be straightened, the dielectric elastomer driver on the inner side is elongated under the energized state, and the dielectric elastomer driver on the outer side is automatically contracted, while pulling the traction rope to move, thereby reversely driving the hinge shaft to rotate, and synchronously transmitting to other hinge shafts, driving the middle phalanx and the terminal phalanx to return to the straightened state.

[0033] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A dielectric elastomer actuated bionic finger, characterized in that: The utility model provides a kind of finger mechanism, including fixed seat (1), the fixed seat (1) is sequentially connected with several intermediate knuckles (2) and terminal knuckles (3), and hinge structure (4) is fixedly arranged on intermediate knuckle (2) and terminal knuckle (3), and fixed seat (1) and intermediate knuckle (2) between, adjacent intermediate knuckles (2) between, intermediate knuckle (2) and terminal knuckle (3) between are respectively hinged by hinge structure (4), and adjacent hinge structure (4) between is driven by transmission mechanism (5) transmission cooperation;Dielectric elastomer driver (6) is equipped on the fixed seat (1), and the movable end of dielectric elastomer driver (6) is transmission connection with the hinge structure (4) on the first section intermediate knuckle (2).

2. The dielectric elastomer driven bionic finger according to claim 1, characterized in that: The hinge structure (4) includes hinge shaft (41) fixedly arranged at one end of intermediate knuckle (2) and terminal knuckle (3) respectively, the hinge shaft (41) is equipped with connecting portion, and the transmission mechanism (5) is connected with the connecting portion, and the other end of the intermediate knuckle (2) and the terminal knuckle (3) is equipped with through hole (42) for the hinge shaft (41) to pass through.

3. The dielectric elastomer driven bionic finger according to claim 2, characterized in that: The transmission mechanism (5) includes first stage wheel body (51) and second stage wheel body (52), and the first stage wheel body (51) and the second stage wheel body (52) are coaxially fixedly arranged on the connecting portion;In the direction of intermediate knuckle (2) to terminal knuckle (3), the first stage wheel body (51) and the second stage wheel body (52) between adjacent hinge shaft (41) are sequentially transmission cooperation by transmission belt (53).

4. The dielectric elastomer driven bionic finger according to claim 3, characterized in that: In the direction of intermediate knuckle (2) to terminal knuckle (3), the rotation speed ratio between adjacent hinge shaft (41) is less than one.

5. The dielectric elastomer driven bionic finger according to claim 4, characterized by: The transmission belt (53) is transmission rope, and the transmission rope is wound at least one circle on the first stage wheel body (51) and the second stage wheel body (52), and the first stage wheel body (51) and the second stage wheel body (52) are all equipped with recess for the transmission rope to wind.

6. The dielectric elastomer actuated bionic finger according to claim 4, characterized in that: The transmission belt (53) is synchronous belt, and the first stage wheel body (51) and the second stage wheel body (52) are all synchronous pulleys.

7. The dielectric elastomer driven bionic finger according to claim 5 or 6, characterized in that: The dielectric elastomer driver (6) on the fixed seat (1) is arranged in pairs, and the two movable ends of each pair of dielectric elastomer driver (6) are connected with the two ends of traction member (61) respectively, the traction member (61) is matched with the first stage wheel body (51) on the first section intermediate knuckle (2), and the traction member (61) can drive the first stage wheel body (51) to rotate.

8. The dielectric elastomer driven bionic finger according to claim 7, characterized by: The traction member (61) is traction rope, and the traction rope is wound at least one circle on the first stage wheel body (51) in the middle, and the first stage wheel body (51) is equipped with recess for the traction rope to wind.

9. The dielectric elastomer actuated bionic finger according to claim 8, characterized in that: The recess is all arc-shaped recess.

10. The dielectric elastomer actuated bionic finger according to claim 1 or 8, characterized in that: The intermediate knuckle (2) and the terminal knuckle (3) all include a pair of side plates (7), and the two side plates (7) are connected by connecting plate (8), and the terminal knuckle (3) is equipped with arc-shaped part (9).

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