CN111821075A - a prosthetic hand - Google Patents

Abstract

The invention discloses a prosthetic hand which comprises a support frame (1), and a thumb (2), fingers (3) and a driving device (4) which are connected with the support frame (1), wherein the driving device (4) is in gear transmission connection with the thumb (2) and the fingers (3) and is used for driving the thumb (2) and the fingers (3) to be opened and closed, a limiting device (5) is further arranged on the prosthetic hand, and when the driving device (4) drives the thumb (2) and the fingers (3) to be opened to a set included angle, the limiting device (5) and the thumb (2) and the fingers (3) form abutting limiting. According to the invention, the rotation is controlled by adopting the driving device through the electromyographic signal, the opening and closing action between the fingers and the thumb is realized by the driving device through gear transmission, the structure is simple, the complicated structure of adopting a reversing gear is avoided, and the limit device is abutted and limited with the thumb or the fingers, so that the opening and closing angle of the artificial hand is limited, and the opening distance of the artificial hand is effectively controlled.

Description

a prosthetic hand

technical field

The invention relates to the technical field of bionic hands, in particular to a prosthetic hand.

Background technique

The myoelectric prosthetic hand can replace the disabled limb and provide convenience for the daily life of disabled patients with upper limb loss. It is one of the important research directions in the field of rehabilitation engineering at present.

Chinese patent document CN 106821560A discloses a prosthetic hand with bidirectional gear transmission, comprising a fixed part and a movable part, the fixed part includes a connecting end and a palm end, the movable part includes two sets of artificial fingers arranged symmetrically, and arc gears are arranged under the fingers; The components include a drive motor and a main gear. The center of the main gear is formed with a gear shaft extending along the horizontal direction. The gear shaft meshes with the first arc gear, and a reversing gear is arranged between the gear shaft and the second arc gear. The entire prosthetic hand needs to be equipped with multiple gears to realize the opening and closing movements of the thumb and other fingers, and the structure is complex.

The opening and closing methods of the existing prosthetic hands basically adopt the gear-driven opening and closing method under electric control, by directly gearing the thumb, and passively rotating the other fingers, so as to realize the clamping of objects, The gripping force is low, the anti-reverse ability when the prosthetic hand grasps the object is poor, and the opening and closing size between the thumb and the fingers cannot be controlled.

SUMMARY OF THE INVENTION

In view of the above deficiencies in the prior art, the present invention provides a prosthetic hand, which has a simple structure, can effectively control the opening and closing distance between the thumb and the fingers, and improves the ability to grasp, hold and prevent reversal of objects.

To achieve the above object, the present invention adopts the following technical solutions:

A prosthetic hand, comprising a support frame, a thumb, a finger and a driving device connected with the support frame, the driving device and the thumb and the fingers form a gear transmission connection for driving the opening between the thumb and the fingers. In combination, the prosthetic hand is also provided with a limiting device, and when the driving device drives the thumb and the fingers to open to a set angle, the limiting device forms an offset limit with the thumb and the fingers.

The limit device includes a limit switch and a limit switch contact, the limit switch is arranged on the drive device or the support frame; the limit switch contact is arranged on the finger or thumb, and is connected with the limit switch. The fingers or thumbs form a synchronous rotation, and when the limit switch contacts rotate to offset the limit switch, the thumb and the fingers are prevented from continuing to open.

The driving device includes a driving gear, a worm gear shaft, a deceleration mechanism and a linkage mechanism, the driving gear is arranged on the finger, and forms a synchronous rotational connection with the finger; the worm gear shaft is arranged on the support frame and meshes with the drive gear, the reduction mechanism meshes with the worm gear shaft through the worm on it; the linkage mechanism is hinged with the thumb and finger respectively, and the reduction mechanism drives the When the fingers are rotated, the linkage mechanism synchronously controls the opening and closing actions between the thumb and the fingers.

The support frame is provided with a first rotating shaft and a second rotating shaft, the thumb and the support frame are connected in relative rotation through the first rotating shaft; the fingers are tightly connected with the second rotating shaft, and A relative rotational connection is formed between the finger and the support frame, the limit switch contact is fixed on the second rotating shaft, the driving gear is arranged on the second rotating shaft, and is connected with the second rotating shaft A synchronous rotary connection is formed.

The contact of the limit switch includes a circular piece fixedly connected with the second rotating shaft and a protrusion arranged on the outer surface of the circular piece, the limit switch is a limit block, and the limit switch is a limit block. The position block is provided with an inclined elastic plate; when the thumb and fingers are in a gradually open state, the protrusion contacts the elastic plate to gradually limit the opening distance between the thumb and the fingers.

The linkage mechanism is a connecting rod, the two ends of the connecting rod are hinged with the thumb and the finger respectively, one end of the connecting rod is set below the first rotating shaft, and the other end is set on the first rotating shaft. Above the second rotating shaft; when the driving device drives the finger to rotate around the second rotating shaft, the connecting rod drives the thumb to rotate in the opposite direction around the first rotating shaft.

The deceleration mechanism is a bearing planetary deceleration mechanism, which includes a deceleration motor, a bearing support plate, a bearing, a rotating plate, a worm and a support seat. A cylindrical cavity is formed in the support seat, and the rotating plate, the bearing and the bearing support plate are formed. One end of the support seat is installed in the cylindrical cavity in turn; at least two bearings are provided, which are arranged between the bearing support plate and the rotating plate, and the lower end surface of the rotating plate is provided with The pin shafts with the same number of bearings are correspondingly penetrated through the shaft holes of the bearings; after the casing of the reduction motor is fixedly connected to the support seat, the extension shaft of the reduction motor penetrates through the shaft. The bearing supports the disk and forms a press fit with each of the bearings; the worm is arranged on the rotating disk and extends out of the cylindrical cavity.

The cylindrical cavity is also provided with a circular ring fitted with its inner surface, the inner surface of the circular ring forms a rolling connection with each of the bearings, and the bearing support plate is pressed against the end surface of the circular ring.

The support seat is also provided with a worm mounting bracket, the lower part of the rotating disk is located in the cylindrical cavity, and the upper part of the rotating plate protrudes out of the cylindrical cavity and is fixedly connected with one end of the worm through a pin. The other end forms a rotational support connection with the worm mounting bracket.

The finger is provided with a finger decoration layer for changing the size of the finger, and the thumb is provided with a thumb decoration layer for changing the size of the thumb.

The technical scheme of the present invention has the following advantages:

A. In the present invention, the driving device is used to control the rotation through myoelectric signals, and the driving device realizes the opening and closing action between the fingers and the thumb through gear transmission, the structure is simple, and the complicated structure of using reversing gears is avoided; the prosthetic hand is provided with a limit device , when the driving device drives the thumb and the finger to open to the set angle, the limit device forms an offset limit with the thumb or finger, thereby limiting the opening and closing angle of the prosthetic hand. According to the set maximum opening, adjust the limit The position of the positioning device can effectively control the opening distance of the prosthetic hand.

B. In the present invention, a planetary bearing deceleration mechanism is set in the drive device. When the deceleration motor starts, the extension shaft of the deceleration motor drives each bearing in a planetary distribution to rotate by means of friction, and the bearing drives the pin shaft to rotate, and the pin shaft and the rotating disk rotate. Connected as a whole through interference fit, the rotation of the pin shaft further drives the rotating disk to rotate, and the rotating disk drives the worm to rotate. The geared motor rotates to drive the bearing to rotate around the extension shaft, and the bearing drives the rotating disk and the worm to rotate, grabbing the item. When the prosthetic hand stops moving, the deceleration motor can keep idling, which will not cause the deceleration motor to get stuck and cause the current to suddenly increase and damage the motor. of keeping.

C. In the present invention, the worm and the worm gear have a large reduction ratio and can realize self-locking, and their clamping force is large. When the deceleration motor stops rotating, it can effectively prevent the prosthetic hand from reversing when grasping items.

Description of drawings

In order to illustrate the specific embodiments of the present invention more clearly, the following will briefly introduce the accompanying drawings used in the specific embodiments. As far as technical personnel are concerned, other drawings can also be obtained based on these drawings without any creative effort.

1 is a front view of the overall structure of the prosthetic hand provided by the present invention;

Fig. 2 is the prosthetic hand structure schematic diagram of the other side shown in Fig. 1;

Figure 3 is a schematic diagram of the overall structure of the reduction mechanism;

Fig. 4 is a schematic diagram of a cross-sectional structure of a deceleration mechanism;

Figure 5 is a schematic diagram of the decomposition structure of the deceleration mechanism;

FIG. 6 is a schematic diagram of the distribution of the bearings in the deceleration mechanism in FIG. 5 .

Description of reference numbers:

1-Support frame

11-the first reel, 12-the second reel

2 - Thumb

21 - Thumb Decorative Layer

3-finger

31-finger decoration layer

4-Driver

41-drive gear, 42-turbine gear shaft

43-Reduction mechanism

431-gear motor, 4311-chassis, 4312-protruding shaft

432-bearing support plate, 433-bearing

434 - Turning Disc, 4341 - Pin

435-worm, 436-support base, 437-ring, 438-worm mounting bracket

44 - linkage mechanism

5-Limiting device

51-Limit switch, 511-Elastic plate

52-limit switch contact, 521-round piece, 522-protrusion

6- Rotate wrist

a-cylindrical cavity, b-pin.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figures 1 and 2, the present invention provides a prosthetic hand, comprising a rotating wrist 6, a support frame 1, a thumb 2 connected to the support frame 1, a finger 3 and a driving device 4, where the finger is not limited to one The finger can also be composed of multiple fingers that are driven synchronously, such as the index finger, middle finger, ring finger and little finger of a person. The prosthetic hand is also provided with a limiting device 5. When the driving device 4 drives the thumb 2 and the finger 3 to open to the set angle, the limiting device 5 forms an offset limit with the thumb 2 and the finger 3. According to the set maximum opening, the position of the limit device 5 is adjusted to effectively control the opening distance of the prosthetic hand.

The preferred limit device 5 of the present invention includes a limit switch 51 and a limit switch contact 52 . The limit switch 51 is arranged on the driving device 4 or the support frame 1 ; the limit switch contact 52 is arranged on the finger 3 or the thumb 2 , and rotates synchronously with the finger 3 or the thumb 2 . When the limit switch contact 52 rotates to the limit switch 51 , it prevents the thumb 2 and the finger 3 from continuing to open. The maximum opening distance between the thumb and the fingers can be set according to the size of the grasped object, that is, by setting the position of the limit switch 51, for example, if the limit switch contact 52 is brought into contact with the limit switch 51 in advance, the distance between the thumb and the fingers will be reduced. The maximum opening distance will be reduced; if the opening and closing distance between the thumb and fingers becomes slightly larger, it is necessary to reset the position of the limit switch, that is, the limit switch contact 52 will come into contact with the limit switch later. The setting of the limit device increases the degree of freedom of the prosthetic hand.

The limit switch contacts 52 and the limit switch 51 here are not limited to the structures shown in FIG. 1 , wherein the limit switch preferably includes a circular piece 521 fixedly connected to the first rotating shaft 11 and a circular piece 521 disposed on the outer circumference of the circular piece 521 The protrusion 522 on the surface of the limit switch 51 is a limit block, and a rotating shaft can be set on the limit block, and the position is fixed by a set screw, and an inclined elastic plate 511 is also provided on the limit block. When the thumb 2 and the finger 3 are in the gradually opened state, the protrusion 522 contacts the elastic plate 511 to limit the opening distance between the thumb 2 and the finger 3 . Of course, the contact surface of the limit block in contact with the limit switch contact can also be set as a wedge-shaped surface, so that the contact between the limit switch and the limit switch becomes tighter and tighter to achieve the limit function.

The driving device 4 preferably includes a driving gear 41, a worm gear shaft 42, a deceleration mechanism 43 and a linkage mechanism 44. The driving gear 41 is arranged on the finger 3 and forms a synchronous rotational connection with the finger 3; the turbine gear shaft 42 is arranged on the support frame 1, and meshes with the drive gear 41, the speed reduction mechanism 43 meshes with the turbine gear shaft 42 through the worm 435 on it; the linkage mechanism 44 is hinged with the thumb 2 and the finger 3 respectively, and the linkage mechanism 44 here is preferably a connecting rod When the deceleration mechanism 43 drives the finger 3 to rotate, the linkage mechanism 44 synchronously controls the opening and closing action between the thumb 2 and the finger 3 .

The support frame 1 in the structure shown in FIG. 1 and FIG. 2 is provided with a first rotating shaft 11 and a second rotating shaft 12, and the thumb 2 and the support frame 1 are connected in relative rotation through the first rotating shaft 11; the finger 3 and the second rotating shaft 12 A tight-fitting connection is formed, and a relative rotational connection is formed between the finger 3 and the support frame 1 , the limit switch contact 52 is fixed on the second rotating shaft 12 , and the driving gear 41 is arranged on the second rotating shaft 12 and forms with the second rotating shaft 12 Synchronized rotary connection. The driving gear 41 is sleeved and fixed on the second rotating shaft 12, and meshes with the worm gear shaft 42. The rotation of the driving gear 41 drives the fingers to rotate synchronously. One end of the connecting rod is set below the first rotating shaft 11 , and the other end is set above the second rotating shaft 12 ; when the driving device 4 drives the finger 3 to rotate around the second rotating shaft 12 , the connecting rod drives the thumb 2 to rotate around the first rotating shaft 11 Rotate in the opposite direction to achieve the opening and closing action. The fingers here can also be flexible fingers that are bent inwards, and at the same time the thumb can rotate around the first rotation axis, which increases the degree of freedom of the prosthetic hand. Of course, the fingers in the present invention can also be made non-bendable, and the thumb can be made non-rotatable, which are all within the protection scope of the present invention.

Specifically, the worm 435 on the speed reduction mechanism 43 rotates and drives the worm gear shaft 42 to rotate, as shown in FIG. Rotate to open and close your fingers. A connecting rod is connected between the finger 3 and the thumb 2, so that the fingers and the thumb can be opened and closed at the same time. Due to the large reduction ratio of the worm and the worm gear and can realize self-locking, it can prevent the prosthetic hand from reversing when grasping the object.

The deceleration mechanism 43 here adopts a bearing planetary deceleration mechanism, which includes a deceleration motor 431, a bearing support plate 432, a bearing 433, a rotating plate 434, a worm 435 and a support seat 436. A cylindrical cavity a is formed in the support seat 436, and the rotating plate 434 , the bearing 433 and the bearing support plate 432 are sequentially installed in the cylindrical cavity a by one end of the support seat 436; the bearing 433 is provided with at least two, as shown in FIG. There are several bearings, and the included angle between the bearings is 120°; as shown in FIG. 4 and FIG. 5 , a plurality of bearings are arranged between the bearing support plate 432 and the rotating plate 434 , and the lower end surface of the rotating plate 434 is provided with the same number of bearings 433 . The pin 4341 of the gear motor 431 penetrates through the shaft hole of the bearing 433 correspondingly, and forms a fixed connection with the rotating plate 434; It penetrates through the bearing support plate 432 and forms a press fit with each bearing 433; the worm 435 is arranged on the rotating plate 434 and extends out of the cylindrical cavity a, that is to say, the worm 435 is not connected with the extension shaft of the reduction motor 431, Instead, the drive connection between the worm 435 and the deceleration motor 431 is realized by rotating the disk 434 . Of course, the present invention is further provided with a circular ring 437 in the cylindrical cavity a that fits with its inner surface, the inner surface of the circular ring 437 forms a rolling connection with each bearing 433, and the bearing support plate 432 is pressed against the end surface of the circular ring 437. superior.

When the deceleration motor starts, the extension shaft 4312 of the deceleration motor 431 drives the three bearings 433 to rotate by means of friction, and the bearings 433 then drive the pin shaft 4341 to rotate. The rotation of 4341 drives the rotating disk 434 to rotate, which in turn drives the worm 435 connected to the rotating disk 434 to rotate.

When the prosthetic hand grabs the item, the fingers of the prosthetic hand stop moving, and then the pin shaft stops moving. At this time, the extension shaft 4312 of the deceleration motor 431 will idly rotate, which will not cause the deceleration motor 431 to get stuck and cause the current to suddenly increase and damage the motor. Therefore, the deceleration motor 431 is well protected. At the same time, by changing the size of the inner diameter of the ring 437, the pressing force between the bearing 433 and the extension shaft of the reduction motor can be changed, thereby adjusting the overall grip strength of the prosthetic hand.

As shown in Figures 3 and 4, the two sides of the rotating disk are respectively provided with pins and connecting pieces connected to the worm. In the present invention, a worm mounting bracket 438 is provided on the support base 436, and the rotating disk 434 is located in the cylindrical cavity a. , the connecting piece on the upper side extends out of the cylindrical cavity a and is fixedly connected with one end of the worm 435 through a pin b, the worm 435 is detachably connected with the rotating disk 434, and the other end of the worm 435 is connected with the worm mounting bracket 438 to form a rotational support connection. In the present invention, the support base 436 and the worm mounting bracket 438 are preferably formed into an integral structure. After the worm is installed on the worm mounting bracket 438, one side of the worm can be exposed from the worm mounting bracket, so as to form a meshing transmission with the worm gear shaft.

In the present invention, the outside of the prosthetic hand is also covered with finger outer decoration, that is, the finger 3 is provided with a finger decoration layer 31 for changing the size of the finger, and the thumb 2 is provided with a thumb decoration layer 21 for changing the size of the thumb. The outer decoration of the middle finger is divided into two halves, which are installed on the fingers of the prosthetic hand by tightening the bolts. The outer decoration of the prosthetic hand can also be made into one body, and the rubber material is directly applied to the fingers of the prosthetic hand. Change the size of the entire prosthetic hand by changing the size of the outer decoration of the fingers, so that the prosthetic hand can be adapted to different groups of people (men, women, children).

The deceleration motor 431 here is controlled by the electromyographic signal to rotate, and sequentially drives the bearing 433, the rotating disk 434, the worm 435, and the worm gear shaft 42 to rotate. The worm gear shaft 42 rotates and then drives the driving gear 41 to rotate. The driving gear 41 is connected with the fingers of the prosthetic hand. , the driving gear 41 rotates and then drives the fingers of the prosthetic hand to rotate, and is driven by the connecting rod between the finger 3 and the thumb 2 to realize the rotation of the thumb 2, thereby realizing the opening and closing of the prosthetic hand. The structure is simple and avoids the complicated structure of the reversing gear. .

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. However, the obvious changes or changes derived therefrom still fall within the protection scope of the present invention.

Claims (10)

1. A prosthetic hand, comprising a support frame (1) and a thumb (2), a finger (3) and a drive device (4) connected with the support frame (1), the drive device (4) and the The thumb (2) and the fingers (3) of the device form a gear transmission connection for driving the opening and closing between the thumb (2) and the fingers (3), and it is characterized in that the prosthetic hand is also provided with a limiting device (5 ), when the driving device (4) drives the thumb (2) and the finger (3) to open to the set angle, the limiting device (5) and the thumb (2) and the finger ( 3) Form the offset limit. 2. The prosthetic hand according to claim 1, wherein the limit device (5) comprises a limit switch (51) and a limit switch contact (52), and the limit switch (51) is provided with on the drive device (4) or the support frame (1); the limit switch contact (52) is arranged on the finger (3) or the thumb (2), and is connected with the finger (3) or the thumb (2). The thumb (2) forms a synchronous rotation, and when the limit switch contact (52) rotates to abut against the limit switch (51), the thumb (2) and the finger (3) are prevented from continuing to open. 3. The prosthetic hand according to claim 2, wherein the driving device (4) comprises a driving gear (41), a worm gear shaft (42), a deceleration mechanism (43) and a linkage mechanism (44), so The driving gear (41) is arranged on the finger (3), and forms a synchronous rotational connection with the finger (3); the worm gear shaft (42) is arranged on the support frame (1), and is connected with the finger (3). The drive gear (41) is meshed with the deceleration mechanism (43) through the worm (435) thereon and the worm gear shaft (42) is meshed; the linkage mechanism (44) is respectively connected with the thumb (2) is hinged with the finger (3), and when the deceleration mechanism (43) drives the finger (3) to rotate, the linkage mechanism (44) synchronously controls the opening between the thumb (2) and the finger (3). combined action. 4. The prosthetic hand according to claim 3, characterized in that, the support frame (1) is provided with a first rotating shaft (11) and a second rotating shaft (12), the thumb (2) and the support A relative rotational connection is formed between the racks (1) through the first rotating shaft (11); the finger (3) forms a tight fitting connection with the second rotating shaft (12), and the finger (3) is connected to the support A relative rotational connection is formed between the frames (1), the limit switch contact (52) is fixed on the second rotating shaft (12), and the driving gear (41) is arranged on the second rotating shaft (12) , and form a synchronous rotational connection with the second rotating shaft (12). 5 . The prosthetic hand according to claim 4 , wherein the limit switch contact ( 52 ) comprises a circular piece ( 521 ) fixedly connected with the second rotating shaft ( 12 ) and a circular plate ( 521 ) arranged on the A protrusion (522) on the outer surface of the circular sheet (521), the limit switch (51) is a limit block, and an inclined elastic plate (511) is arranged on the limit block; the thumb (2) When the finger (3) and the thumb (3) are in a gradually opened state, the protrusion (522) contacts the elastic plate (511) to gradually limit the opening distance between the thumb (2) and the finger (3). 6 . The prosthetic hand according to claim 5 , wherein the linkage mechanism ( 44 ) is a connecting rod, and the two ends of the connecting rod are respectively hinged with the thumb ( 2 ) and the finger ( 3 ). 7 . One end of the connecting rod is arranged below the first rotating shaft (11), and the other end is arranged above the second rotating shaft (12); the driving device (4) drives the finger (3) When rotating around the second rotating shaft (12), the connecting rod drives the thumb (2) to rotate around the first rotating shaft (11) in the opposite direction. 7. The prosthetic hand according to any one of claims 3-6, wherein the deceleration mechanism (43) is a bearing planetary deceleration mechanism, which comprises a deceleration motor (431), a bearing support plate (432), a bearing ( 433), a rotating plate (434), a worm (435) and a support seat (436), a cylindrical cavity (a) is formed in the support seat (436), the rotating plate (434), the bearing (433) and the The bearing support plate (432) is sequentially installed in the cylindrical cavity (a) by one end of the support seat (436); at least two bearings (433) are provided, which are arranged on the bearing support plate (436). 432) and the rotating plate (434), the lower end surface of the rotating plate (434) is provided with the same number of pins (4341) as the bearings (433). into the shaft hole of the bearing (433); after the casing (4311) of the geared motor (431) is fixedly connected to the support seat (436), the protruding shaft (4312) of the geared motor (431) passes through The bearing supports the disc (432) and forms a press fit with each of the bearings (433); the worm (435) is arranged on the rotating disc (434) and protrudes out of the cylindrical cavity (a ). 8. The prosthetic hand according to claim 7, wherein the cylindrical cavity (a) is further provided with a circular ring (437) fitted with its inner side surface, and the inner side surface of the circular ring (437) is further provided with a circular ring (437). A rolling connection is formed with each of the bearings (433), and the bearing support plate (432) is pressed against the end face of the annular ring (437). 9 . The prosthetic hand according to claim 8 , wherein a worm mounting bracket ( 438 ) is further provided on the support base ( 436 ), and the lower part of the rotating disk ( 434 ) is located in the cylindrical cavity ( 9 . In a), its upper part protrudes from the cylindrical cavity (a) and is fixedly connected to one end of the worm (435) through a pin (b), and the other end of the worm (435) is connected to the worm mounting bracket (438) ) to form a swivel support connection. 10. The prosthetic hand according to claim 1, wherein a finger decoration layer (31) for changing the size of the finger is provided on the finger (3), and a finger decoration layer (31) for changing the size of the thumb is provided on the thumb (2) the thumb decoration (21).

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