CN113211491A

CN113211491A - Flexible tongs device

Info

Publication number: CN113211491A
Application number: CN202110392469.4A
Authority: CN
Inventors: 朱连利; 赫宇; 胡静
Original assignee: Chinese People's Armed Police Force Sea Police Academy
Current assignee: Chinese People's Armed Police Force Sea Police Academy
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-08-06

Abstract

Providing a flexible gripper device, wherein a palm piece (1) is provided with at least 2 finger pieces (2), the outer layer of each finger piece (2) is a corrugated pipe (3), and two opposite sides in each corrugated pipe (3) are provided with strong pull wires (4); the upper end and the lower end of the corrugated pipe (3) are respectively plugged into an upper plug (5) and a lower plug (6) to form a sealing cavity; a support framework is arranged in the corrugated pipe (3); particles (7) are filled in the corrugated pipe (3); the upper plug (5) is externally connected with a vent pipe (9); threading through holes (10) are respectively formed in two corresponding sides of the upper plug (5), an inner side pull wire coiling mechanism and an outer side pull wire coiling mechanism are respectively arranged on the palm component (1), the strong pull wires (4) on two sides respectively penetrate through the upper plug (5) and are respectively led to the inner side pull wire coiling mechanism and the outer side pull wire coiling mechanism, and the tail ends of the strong pull wires (4) on two sides are respectively fixed on the lower plug (6); each finger piece (2) has adjustable rigidity and can be bent in two directions, so that the self-gripping hand can be opened and closed mainly.

Description

Flexible tongs device

Technical Field

The invention belongs to the technical field of robots, and relates to a flexible gripper device, in particular to a flexible gripper device which is adjustable in rigidity and capable of automatically opening and closing.

Background

Robots are the hot spot of current research. The gripper is an actuating mechanism of the robot and naturally a hotspot of current research.

The flexible grip is also easy to transport because the traditional rigid grip is easy to damage the gripped object. The original flexible grip is simply made of a rigid material instead of a flexible material, and the rigidity is not adjustable. Although the flexible gripper has the advantages that the traditional manipulator can protect the easily broken grabbed objects incomparably, the inherent characteristics of the flexible material used by the flexible gripper determine the defects of small gripping force, low rigidity of a non-support structure, poor gripping stability and the like of the flexible gripper, and the application of the flexible gripper is severely limited.

John r, Amend et al propose a flexible gripper with a large amount of granular material wrapped by an elastomer, utilize the principle of particle interference to improve the gripping ability of the flexible gripper, and simultaneously can grip and place a plurality of objects. Cheng et al have invented a continuous manipulator consisting of microparticles and cable driven actuators that can achieve powerful motions and large output forces, and the principle of particle interference is gradually applied to the field of variable stiffness grippers, and the principle of particle interference variable stiffness theory implementation is summarized as follows: particle interference devices typically consist of an outer soft elastic membrane containing solid discrete materials (particles). This results in a very high compliance at atmospheric pressure, since the particles can easily flow and move inside the flexible membrane, but when a vacuum is applied, air is expelled and the membrane collapses over the particles. The friction between the fillers and the density of the overall structure increases due to overcrowding of the material. When the material is densely packed, friction hinders dislocation of the material, so that the whole structure resembles a hard block of material. In this way, the stiffness of the flexible holder can be adjusted by evacuating. However, as an ideal flexible grip, it is far from sufficient that the stiffness is adjustable. In addition, the existing flexible gripper does not have the functions of opening and closing, cannot well perform the gripping function, and is a place to be improved.

Disclosure of Invention

The invention aims to solve the technical problem of providing a flexible gripper device which has adjustable rigidity and can be opened and closed automatically.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a flexible gripper device comprises a palm piece, wherein the palm piece is provided with a connecting structure for connecting a robot mechanical arm or other driving devices; the hand piece is characterized in that at least 2 finger pieces are arranged at intervals on the palm piece, the outer layer of each finger piece is a corrugated pipe, and strong pull wires with high strength are respectively arranged at the positions close to the walls of two opposite sides in the corrugated pipe; when the flexible gripper is installed or used, one side of the flexible gripper is positioned at the inner side facing the center of the flexible gripper, and the other side of the flexible gripper is positioned at the outer side back to the center of the flexible gripper; the upper end and the lower end of the corrugated pipe are respectively plugged into an upper plug and a lower plug to form a sealed cavity; a support framework is arranged in the corrugated pipe, the support framework is an elastic framework which can be bent and deformed under the action of external force and can automatically recover the original shape after the external force disappears; the cavities in the corrugated pipe are filled with particles; the upper plug is provided with a vent hole which is externally connected with a vent pipe; threading through holes are formed in two corresponding sides of the upper plug respectively, an inner side stay wire coiling mechanism and an outer side stay wire coiling mechanism are arranged on the palm piece respectively, strong stay wires on two sides penetrate through the threading through holes of the upper plug respectively in a sealing mode, the head ends of the strong stay wires on the two sides are led to the inner side stay wire coiling mechanism and the outer side stay wire coiling mechanism respectively, and the tail ends of the strong stay wires on the two sides are fixed to the lower plug respectively.

The following are further schemes, respectively:

the palm piece is a forked plate taking the number of fingers as the number of forks, and the forks are uniformly distributed along the circumferential direction; the palm piece is symmetrically bifurcated in a shape of a Chinese character 'yi', and is provided with 2 finger pieces which are symmetrically distributed; or the palm piece is Y-shaped and three-branched and is uniformly distributed along the circumferential direction, and 3 finger pieces are uniformly distributed along the circumferential direction; or the palm piece is in a cross shape and four branches evenly distributed along the circumferential direction, and is provided with 4 finger pieces evenly distributed along the circumferential direction.

The outer ends of the branches of the palm piece are provided with mounting holes, and the upper end parts of the finger pieces, where the plugs are located, are respectively and fixedly mounted in the mounting holes; two rectangular notch grooves are arranged in parallel from the installation holes of each branch to the vacant position of the center; the inner side stay wire coiling mechanism and the outer side stay wire coiling mechanism are steering gears, namely an inner side steering gear for coiling an inner side stay wire and an outer side steering gear for coiling an outer side stay wire, the inner side steering gear and the outer side steering gear are fixedly arranged in the two rectangular notch grooves, and the head ends of the two side strong stay wires are wound on the coiling wheels of the inner side steering gear and the outer side steering gear respectively.

A sealing element made of elastic sealing material is arranged in the threading through hole, the sealing element is provided with a small threading through hole, and strong pull wires on two sides respectively and hermetically penetrate through the small threading through hole of the sealing element; the threading through hole of the upper plug is small in diameter of two end sections and large in diameter of the middle section, two corresponding sides of the upper plug are respectively dug out to form a solid notch, the size of the sealing element is slightly larger than that of the middle section, the sealing element is plugged into the middle section in an interference fit mode to realize sealing between the sealing element and the inner wall of the middle section, the solid notch is covered with the solid block, and the solid block is stuck and sealed by glue.

The connecting structure for connecting the robot mechanical arm or other driving devices is fixedly arranged on a connecting column at the center of the palm component, and a connecting external thread is arranged at the upper end of the connecting column.

The two opposite sides of the inner wall of the corrugated pipe are respectively attached to the wall or are provided with a soft threading pipe close to the wall; the two side strong pull wires respectively penetrate through the two side soft threading pipes.

The support framework is a traditional metal spring.

The upper plug and the lower plug respectively comprise a plugging section with a larger diameter and an inner cavity section with a smaller diameter, the diameter of the plugging section is matched with the inner diameter of the corrugated pipe, and two ends of the metal spring are respectively sleeved on the inner cavity sections of the upper plug and the lower plug; and the threading through hole of the upper plug is arranged between the inner end face and the outer end face of the plug-in section cylinder.

The cylindrical surfaces of the plugging sections of the upper plug and the lower plug are provided with sealing grooves; and the inner sections of the cylindrical surfaces of the upper plug cavity and the lower plug cavity are provided with spiral grooves matched with the metal spring, and two ends of the metal spring are respectively embedded into the spiral grooves of the inner sections of the upper plug cavity and the lower plug cavity.

Sealing grooves of the upper plug and the lower plug and the corrugated bellows by Kevlar fibers; or the sealing grooves of the upper plug and the lower plug are sleeved with O-shaped sealing rings.

The lower plug is characterized in that side notches are respectively formed in two corresponding sides of the lower plug, two threading holes are formed between the inner end face of the plugging section cylinder of the lower plug and the side notches in parallel, and the strong pull wire penetrates through one threading hole, passes through the side notch and then penetrates out of the other threading hole and is fixed by knotting.

The finger piece of the flexible gripper device can be bent forwards and backwards according to the requirement, and the bending angle range can reach +/-70 degrees. The change in stiffness of the finger can be more than 10 times the change in amplitude in 2 seconds. In a specific implementation process, the positive and negative rotation and the rotating speed of the steering engine on the inner side and the outer side of each finger piece are adjusted to force the take-up wheel to take up and release the stay wire, each finger piece is instructed to bend reversely, and each finger piece of the flexible gripper device is opened to increase the gripping space; and then, each finger piece is instructed to bend forwards, so that each finger piece of the flexible gripping device is closed to grip the article. The rigidity of the finger piece can be adjusted by the negative pressure of an external vacuum pump, and the rigidity is changed by changing the negative pressure value so as to adapt to the object to be grabbed, so that the grabbing force is improved and the stability in the grabbing process is realized.

The invention has the beneficial effects that:

1. the flexible gripper device can be suitable for different gripping environments, and negative pressure rigidity changing is carried out in the air by using the vacuum pump, so that the gripping force is increased; the rigidity is changed by using the water pump in water, and the water pump has good environment adaptability.

2. According to the flexible gripper device, each finger piece can be bent in two directions, so that the gripping range is enlarged, and the gripping stability is improved.

3. The finger piece of the flexible gripper device is different from the traditional variable rigidity, the strong pull wire and the negative pressure drive are independently controlled, the rigidity change can be flexibly realized by adjusting the negative pressure vacuum degree, and the rigidity can be effectively adjusted according to the material of the gripped object.

4. The flexible gripper device can realize rigidity change of more than 10 times within 2 seconds, and can realize bending and rigidity change of each finger piece.

Drawings

FIG. 1 is an overall perspective view of the flexible grip of the present invention;

FIG. 2 is a perspective view of a single finger member;

FIG. 3 is a schematic cross-sectional view of a single finger member;

FIG. 4 is a perspective view of the upper plug;

FIG. 5 is a schematic cross-sectional view of the upper plug; the left side of FIG. 5 is the state that the sealing element and the solid block are not installed, and the right side of FIG. 5 is the state that the sealing element and the solid block are installed;

FIG. 6 is a perspective view of a solid block;

FIG. 7 is a perspective view of the seal;

FIG. 8 is a perspective view of the lower plug;

FIG. 9 is a perspective view of the palm member;

fig. 10 is a perspective view of an inner steering engine.

Reference numbers in the figures: 1. a palm member; 2. a finger member; 3. a corrugated pipe; 4. a strong pull line; 5. an upper plug; 6. a lower plug; 7. (ii) particulate matter; 8. a vent hole; 9. a breather pipe; 10. a threading through hole; 11. mounting holes; 12. a rectangular notch groove; 13. an inner steering engine; 14. an outer steering engine; 15. a take-up reel; 16. connecting columns; 17. an external thread; 18. a soft threading tube; 19. a metal spring; 20. sealing the groove; 21. a spiral groove; 22. a side notch; 23. threading holes; 24. a wiring port; 25. solid blocks; 26. a seal member; 27. threading a small through hole; 28. an end segment; 29. a middle section.

Detailed Description

The following description will explain embodiments of the present invention by taking preferred embodiments shown in fig. 1 to 10 as examples.

A flexible gripping device with adjustable rigidity and capable of being opened and closed automatically comprises a palm piece 1, wherein the palm piece 1 is provided with a connecting structure for connecting a robot mechanical arm or other driving devices. The connection structure may take a variety of forms. For example, as shown in fig. 1 or fig. 9, a connecting column 16 fixedly arranged at the center of the palm member 1 is adopted, and the upper end of the connecting column 16 is provided with a connecting external thread 17.

The palm member 1 is provided with at least 2 finger members 2 at intervals. The palm piece 1 is a forked plate taking the number of the finger pieces 2 as the number of forks, and the forks are uniformly distributed along the circumferential direction; the palm piece 1 is symmetrically bifurcated in a shape of a Chinese character 'yi', and is provided with 2 finger pieces 2 which are symmetrically distributed; or, as shown in fig. 1 or fig. 9, the palm component 1 is three forks of a "y" shape uniformly distributed along the circumferential direction, and is provided with 3 finger components 2 uniformly distributed along the circumferential direction; or, the palm piece 1 is in a cross shape and four branches evenly distributed along the circumferential direction, and is provided with 4 finger pieces 2 evenly distributed along the circumferential direction.

As shown in fig. 2 and 3, the outer layer of each finger 2 is corrugated bellows 3, and near walls of opposite sides in the corrugated bellows 3 are respectively provided with strong pull wires 4 with high strength. The strong pull wires 4 arranged on both sides are symmetrically arranged at 180 degrees on the circumference of the inner wall of the corrugated pipe 3. One side of the flexible gripper is positioned towards the inner side of the center of the flexible gripper and the other side of the flexible gripper is positioned away from the outer side of the center of the flexible gripper when the flexible gripper is installed or used.

The strong tensile wire has the properties of flexibility, free bending deformation, no elongation deformation or small elongation deformation amount when being stretched, and the tensile wire is as thin as possible and has strong tensile strength in order to ensure the flexibility of driving. The invention can select the strong pull wire made of nylon material. The specific size and the bearing capacity of the pull wire are determined according to the actual grabbing object, the diameter is generally not more than 3mm, and the pulling force is not less than 15 kg. Preferably 0.6mm in diameter and 23kg or more in vertical tensile strength.

The arrangement of the strong pull wires 4 in the corrugated pipe 3 is not limited to two opposite sides, and the strong pull wires can also be uniformly distributed along the 3 sides or 4 sides of the circumference of the inner wall of the corrugated pipe 3 as required to realize multidirectional bending. The number of the power cords 4 per side is not limited to 1, and may be 2 or more.

In order to make the bending resistance and the restoring force suitable, the wire diameter of the spring is not less than 1.8mm and not more than 4 mm.

The upper end and the lower end of the corrugated bellows 3 are respectively plugged into the upper plug 5 and the lower plug 6 to form a sealed cavity. The upper plug 5 and the lower plug 6 can be made of PLA materials and formed by 3D printing. The corrugated pipe 3 is internally provided with a support framework which is an elastic framework capable of bending and deforming under the action of external force and automatically recovering the original shape after the external force disappears. The elastic framework can be designed and manufactured according to the functional requirements. More conveniently, the traditional metal spring 19 can be directly used as a supporting framework, so that the required function that the spring can be bent and deformed under the action of external force and can automatically recover the original shape after the external force disappears can be achieved. And the traditional metal spring 19 is used as a supporting framework, so that the implementation is more convenient, and the cost is lower.

As shown in fig. 3, the cavities in corrugated bellows 3 are filled with particulate matter 7. The granules 7 can be hard plastic pellets, and the diameter of the pellets is generally not less than 1mm and not more than 10mm, and is usually preferably 5 mm. Alternatively, balls of different sizes may be used depending on the size of the gripper module being designed. The vent pipe 9 is a flexible silicone tube, and the outer diameter of the vent pipe 9 is slightly smaller than the vent hole 8 of the upper plug 5. The mounting and sealing method comprises the following steps: firstly, winding a plurality of circles of raw adhesive tapes on the vent pipe 9, then connecting the raw adhesive tapes with the vent hole 8 of the upper plug 5, and finally sealing the interface by using hot melt adhesive. The joints of the upper and lower plugs and the corrugated pipe are bound and connected by using flexible thin wires with the diameter of 0.5mm in the sealing grooves 20 of the upper and lower plugs. Three sealing grooves 20 are uniformly arranged in the circumferential axial direction of the upper plug and the lower plug, and each further sealing groove 20 is bound and sealed by a thin line.

As shown in fig. 1, the palm member 1 is provided with an inner thread take-up mechanism and an outer thread take-up mechanism, respectively. The stay wire coiling mechanism can be designed and manufactured according to the functional requirements. More convenient, can directly select for use the steering wheel, can order steering wheel supply producer, by its customization as required. Thus, the method is more convenient to implement and has lower cost. The steering engines are respectively an inner side steering engine 13 for reeling an inner side stay wire and an outer side steering engine 14 for reeling an outer side stay wire according to the positions of the stay wires to be reeled.

As shown in fig. 1 and 9, the outer end of each branch of the palm member 1 is provided with a mounting hole 11, and the upper end of each finger member 2 where the plug 5 is located is fixedly mounted in the mounting hole 11; two rectangular notch grooves 12 are arranged in parallel from the mounting holes 11 to the vacant positions at the centers. The inner steering engine 13 and the outer steering engine 14 are fixedly installed in the two rectangular notched grooves 12, the head ends of the two strong pull wires 4 are respectively wound on the take-up wheels 15 of the inner steering engine 13 and the outer steering engine 14, and as shown in fig. 1 and 10, the wiring port 24 of each steering engine is connected with a controller of a robot mechanical arm or other driving devices. As shown in fig. 1, the inner side pull wire is closer to the inner side steering engine 13, the outer side pull wire is farther from the outer side steering engine 14, the inner side steering engine 13 is a short-axis steering engine, and the outer side steering engine 14 is a long-axis steering engine.

As shown in fig. 3 and 4, the upper plug 5 is provided with a vent hole 8, which is externally connected with a vent pipe 9, and the vent pipe 9 is used for connecting a vacuum pump. Threading through holes 10 are respectively formed in the two corresponding sides of the upper plug 5. The two strong pull wires 4 respectively pass through the threading through holes 10 of the upper plug 5 in a sealing way, the head ends of the two strong pull wires 4 respectively lead to the inner pull wire coiling mechanism and the outer pull wire coiling mechanism, and the tail ends of the two strong pull wires 4 are respectively fixed on the lower plug 6. The through hole is provided with the following seals: as shown in fig. 5, 6 and 7, a sealing member 26 made of an elastic sealing material is installed in the threading through hole 10, the sealing member 26 is provided with a small threading through hole 27, and the two side strong pulling wires 4 respectively pass through the small threading through holes 27 of the sealing member 26 in a sealing manner. As shown in fig. 5, the threading through hole 10 of the upper plug 5 has two end sections 28 with a small diameter and a middle section 29 with a large diameter. The two corresponding sides of the upper plug 5 are respectively dug out with a solid block 25 as shown in fig. 6, and as shown in the left side of fig. 5, a solid notch is formed. The sealing element 26 is slightly larger than the middle section 29, and is inserted into the middle section 29 in an interference fit manner, as shown in the right side of fig. 5, so that the sealing element 26 is sealed with the inner wall of the middle section 29, the solid block 25 is covered on the solid notch, and the solid notch is sealed by gluing.

As shown in fig. 8, two corresponding sides of the lower plug 6 are respectively provided with a side gap 22, two threading holes 23 are arranged in parallel between the inner end surface of the plugged section cylinder of the lower plug 6 and the side gaps 22, and the strong pulling wire 4 penetrates through one threading hole 23, passes through the side gap 22, penetrates out of the other threading hole 23 and is fixed by knotting.

In order to protect the strong pull wire 4 and facilitate threading, as shown in fig. 3, soft threading pipes 18 are respectively attached to the wall or close to the wall at two opposite sides of the inner wall of the corrugated bellows 3; the two side strong pull wires 4 respectively pass through the two side soft threading pipes 18.

As shown in fig. 3, 4 and 8, each of the upper plug 5 and the lower plug 6 includes a plugging section with a larger diameter and an inner cavity section with a smaller diameter, the diameter of the plugging section is matched with the inner diameter of the corrugated pipe 3, and two ends of the metal spring 19 are respectively sleeved on the inner cavity sections of the upper plug 5 and the lower plug 6; the threading through hole 10 of the upper plug 5 is arranged between the inner end face and the outer end face of the plug-in section cylinder. The cylindrical surfaces of the plugging sections of the upper plug 5 and the lower plug 6 are provided with sealing grooves 20; the inner cylindrical surfaces of the upper plug 5 and the lower plug 6 are provided with spiral grooves 21 matched with the metal spring 19, and two ends of the metal spring 19 are respectively embedded into the spiral grooves 21 of the inner sections of the upper plug 5 and the lower plug 6. In order to ensure the sealing effect of the inner cavity of the corrugated pipe 3 of each finger 2, Kevlar fibers are adopted for sealing between the sealing grooves 20 of the upper plug 5 and the lower plug 6 and the corrugated pipe 3; or the sealing grooves 20 of the upper plug 5 and the lower plug 6 are sleeved with O-shaped sealing rings.

According to the flexible gripping device, in the air, the finger piece 2 is connected with the vacuum pump, and the gripping force is increased by changing the rigidity through negative pressure; when in water, the steering engine adopts a waterproof steering engine, the finger piece 2 is connected with the water pump, and the water pump can also realize rigidity adjustment, so that the steering engine has good environment adaptability.

The specific implementation manner of grabbing the articles is as follows: in the grabbing operation process, the grab quickly approaches to a target, when the grab is only about 10cm away from the target, the grab slowly approaches to the target, an external controller simultaneously starts a reverse starting command to the outer side steering engine 14 and the inner side steering engine 13, the rotating shaft of the outer side steering engine 14 rapidly rotates clockwise to drive the outer side coiling wheel 15 to rotate, and the outer side strong pull wire is rapidly wound; the rotating shaft of the inner side steering engine 13 rapidly rotates anticlockwise to drive the short shaft winding turntable 41 to rotate, the inner side strong pull wire is rapidly released, and the pull wire is always kept in a tight state by coordinating the rotating speed of the long shaft steering engine and the rotating speed of the short shaft steering engine, so that high precision is ensured. During this process the finger members 2 are bent back against the gripped article until-70 is reached, where the angle of the reverse bend is adjusted to increase the gripping range to match the size of the gripped article, depending on the size of the gripped article, and the controller then sends a stop command. The gripper slowly approaches to the gripped object, the controller sends a forward starting command, the rotating shaft of the outer side steering engine 14 rapidly rotates anticlockwise to drive the outer side winding wheel 15 to rotate, so that the outer side strong pull wire 4 is rapidly released, the rotating shaft of the inner side steering engine 13 rapidly rotates clockwise to drive the winding wheel 15 of the inner side steering engine 13 to rotate, and the inner side strong pull wire 17 is rapidly wound. By coordinating the rotating speeds of the inner steering engine 13 and the inner steering engine, the finger piece 2 is bent forwards and slowly approaches to the grabbed object until the finger piece contacts with the grabbed object to grab. At the moment, the external controller sends a command to start the vacuum pump, negative pressure regulation is carried out through the pressure regulating valve according to the actual weight of the grabbed object so as to adapt to the grabbed object, the change of rigidity smoothness is realized, the grabbing force and the grabbing stability are improved, and the grabbing of the target object is realized.

Claims

1. A flexible gripper device comprises a palm piece (1), wherein the palm piece (1) is provided with a connecting structure for connecting a robot mechanical arm or other driving devices; the folding palm piece is characterized in that at least 2 finger pieces (2) are arranged on the palm piece (1) at intervals, the outer layer of each finger piece (2) is a folding corrugated pipe (3), and strong pull wires (4) with high strength are respectively arranged at the positions close to the walls of two opposite sides in the folding corrugated pipe (3); when the flexible gripper is installed or used, one side of the flexible gripper is positioned at the inner side facing the center of the flexible gripper, and the other side of the flexible gripper is positioned at the outer side back to the center of the flexible gripper; the upper end and the lower end of the corrugated pipe (3) are respectively plugged into an upper plug (5) and a lower plug (6) to form a sealed cavity; a support framework is arranged in the corrugated pipe (3), the support framework is an elastic framework which can be bent and deformed under the action of external force and can automatically recover the original shape after the external force disappears; the cavities in the corrugated bellows (3) are filled with particles (7); the upper plug (5) is provided with a vent hole (8) which is externally connected with a vent pipe (9); threading through holes (10) are respectively formed in two corresponding sides of the upper plug (5), an inner side stay wire coiling mechanism and an outer side stay wire coiling mechanism are respectively arranged on the palm piece (1), strong stay wires (4) on two sides respectively penetrate through the threading through holes (10) of the upper plug (5) in a sealing mode, the head ends of the strong stay wires (4) on two sides are respectively led to the inner side stay wire coiling mechanism and the outer side stay wire coiling mechanism, and the tail ends of the strong stay wires (4) on two sides are respectively fixedly tied to the lower plug (6).

2. The flexible grip device as claimed in claim 1, wherein the palm member (1) is a bifurcated plate having a number of bifurcations corresponding to the number of finger members (2), the bifurcations being uniformly distributed in the circumferential direction; the palm piece (1) is symmetrically bifurcated in a straight shape and is provided with 2 finger pieces (2) which are symmetrically distributed; or the palm piece (1) is Y-shaped and three-branched and is uniformly distributed along the circumferential direction, and 3 finger pieces (2) are uniformly distributed along the circumferential direction; or the palm piece (1) is in a cross shape and four branches evenly distributed along the circumferential direction, and is provided with 4 finger pieces (2) evenly distributed along the circumferential direction.

3. The flexible hand grab according to claim 2, wherein the outer ends of the branches of the palm member (1) are provided with mounting holes (11), and the upper ends of the finger members (2) where the plugs (5) are located are respectively fixedly mounted in the mounting holes (11); two rectangular notch grooves (12) are arranged in parallel from the installation holes (11) to the vacant positions at the center; the inner side stay wire coiling mechanism and the outer side stay wire coiling mechanism are steering gears, namely an inner side steering gear (13) used for coiling an inner side stay wire and an outer side steering gear (14) used for coiling an outer side stay wire, the inner side steering gear (13) and the outer side steering gear (14) are fixedly installed in the two rectangular notch grooves (12), and the head ends of the two side strong stay wires (4) are wound on coiling wheels (15) of the inner side steering gear (13) and the outer side steering gear (14) respectively.

4. The flexible hand grip device as claimed in claim 1, wherein a sealing member (26) made of elastic sealing material is installed in the threading through hole (10), the sealing member (26) is provided with a threading small through hole (27), and the two side strong pulling wires (4) respectively and hermetically penetrate through the threading small through holes (27) of the sealing member (26); go up threading through-hole (10) of end cap (5) and be that both ends section (28) diameter is little and interlude (29) diameter is big, go up corresponding both sides of end cap (5) and dig out a solid block (25) respectively and form the entity breach, the size of sealing member (26) slightly is greater than interlude (29), fills in interlude (29) with interference fit's mode, realizes sealing member (26) with between interlude (29) inner wall is sealed to cover solid block (25) on the entity breach, and paste sealedly with glue.

5. The flexible gripper as claimed in claim 1, wherein the corrugated bellows (3) is provided with a soft threading tube (18) attached to or near the wall on opposite sides of the inner wall; the two side strong pull wires (4) respectively pass through the two side soft threading pipes (18).

6. Flexible grip device as claimed in claim 1, characterized in that said supporting skeleton is a conventional metal spring (19).

7. The flexible gripper device as claimed in claim 6, wherein the upper plug (5) and the lower plug (6) each comprise a plugging section with a larger diameter and an inner cavity section with a smaller diameter, the diameter of the plugging section is matched with the inner diameter of the corrugated pipe (3), and two ends of the metal spring (19) are respectively sleeved on the inner cavity sections of the upper plug (5) and the lower plug (6); and a threading through hole (10) of the upper plug (5) is formed between the inner end face and the outer end face of the plug-in section cylinder.

8. The flexible hand grab device as claimed in claim 7, wherein the cylindrical surfaces of the plugging sections of the upper plug (5) and the lower plug (6) are provided with sealing grooves (20); and spiral grooves (21) matched with the metal springs (19) are formed in the cylindrical surfaces of the inner sections of the upper plug (5) and the lower plug (6), and two ends of each metal spring (19) are respectively embedded into the spiral grooves (21) of the inner sections of the upper plug (5) and the lower plug (6).

9. The flexible gripper as claimed in claim 8, characterized in that Kevlar fiber sealing is adopted between the sealing grooves (20) of the upper plug (5) and the lower plug (6) and the corrugated bellows (3); or the sealing grooves (20) of the upper plug (5) and the lower plug (6) are sleeved with O-shaped sealing rings.

10. The flexible gripper device as claimed in claim 7, wherein the lower plug (6) is provided with side notches (22) on two corresponding sides, two threading holes (23) are arranged between the inner cylindrical end surface of the stuffing section of the lower plug (6) and the side notches (22) in parallel, and the strong pulling wire (4) penetrates through one threading hole (23), passes through the side notch (22), penetrates out of the other threading hole (23) and is fixed by knotting.