CN115091498A

CN115091498A - Mechanical grabbing device applied to underwater robot

Info

Publication number: CN115091498A
Application number: CN202211009260.6A
Authority: CN
Inventors: 张作琼; 任申真; 袁明新; 伍红权; 胡刚; 王舜; 张亮
Original assignee: T Sea Marine Technology Co ltd
Current assignee: T Sea Marine Technology Co ltd
Priority date: 2022-08-23
Filing date: 2022-08-23
Publication date: 2022-09-23
Anticipated expiration: 2042-08-23
Also published as: CN115091498B

Abstract

The invention relates to the field of underwater robots, in particular to a mechanical grabbing device applied to an underwater robot. The problems to be solved are that: the existing grabbing device is difficult to grab objects trapped in silt or silt smoothly, the objects slip off easily after being grabbed, friction and collision occur easily, and the objects and the grabs are damaged. The technical implementation scheme of the invention is as follows: the mechanical grabbing device applied to the underwater robot comprises an installation frame, a rotating shaft and the like; the number of the mounting racks is two, and the whole grabbing device is mounted on the underwater robot body through the two mounting racks; the inner sides of the two mounting racks are provided with rotating shafts. According to the invention, the rotating shaft and the loosening plate are arranged, so that when the aquatic weeds are sunk into silt and silt or wound, the whole grabbing part is rotated through the rotating shaft, the objects are gradually loosened, or the aquatic weeds are broken and are easy to pull out, and the convenience is improved.

Description

Mechanical grabbing device applied to underwater robot

Technical Field

The invention relates to the field of underwater robots, in particular to a mechanical grabbing device applied to an underwater robot.

Background

When an underwater object is salvaged and grabbed, an underwater robot is generally adopted to replace manual work, the underwater robot is high in efficiency and can eliminate the threat of underwater conditions to underwater personnel, however, when the underwater robot is adopted to grab the underwater object, the requirements on the grabbing device of the underwater robot are high, if the grabbed object is possibly sunk into silt in water or is wound by underwater waterweeds and the like, or the grabbed object needs to be protected, the grabbing force of the grabbing device is prevented from being large to cause the object to be damaged, meanwhile, in the grabbing process, the existing grabbing device possibly has large weight because the grabbing force of the object to the object is insufficient, so that the object slides down to influence the normal grabbing of the object, and if the object is grabbed, the object is grabbed to the inner side of the grabbing claw of the grabbing device, when the volume of the object is smaller than the space inside the grabbing claw of the grabbing device, even the gripper draws in minimum also can't be fixed with the object completely, because the gripper inboard generally is provided with increase frictional notch etc. and the object constantly takes place friction collision etc. with the inboard notch of gripper under the effect of water buoyancy, leads to grabbing the object surface and harmfully, to some comparatively important grab thing, causes great damage.

Disclosure of Invention

The invention provides a mechanical grabbing device applied to an underwater robot, aiming at overcoming the defects that an object trapped in silt or silt is difficult to grab by the conventional grabbing device, the object is easy to slide off after being grabbed, and the object and a grabbing claw are easy to damage due to friction and collision.

The technical scheme is as follows: the mechanical grabbing device applied to the underwater robot comprises an installation frame, a rotating shaft and a grabbing mechanism; the number of the mounting racks is two, and the whole grabbing device is mounted on the underwater robot body through the two mounting racks; the inner sides of the two mounting frames are connected with a rotating shaft together; a grabbing mechanism for underwater grabbing is arranged on the left side of the rotating shaft; the anti-skid device also comprises an anti-skid mechanism and a secondary locking mechanism; the grabbing mechanism is provided with an anti-skid mechanism; the antiskid mechanism is provided with a secondary locking mechanism; the object grabbed by the grabbing mechanism is subjected to anti-slip and anti-falling treatment through the anti-slip mechanism, and then the grabbed object subjected to sliding is subjected to secondary locking and fixing through the secondary locking mechanism;

the grabbing mechanism comprises a fixed block, a support frame, a first connecting shaft, a second connecting shaft, a first linkage plate, a second linkage plate, a third connecting shaft, a third linkage plate, a fourth connecting shaft, a fifth connecting shaft, a telescopic device, a cross connecting frame, a connecting rod, a first elastic element, a mounting plate and a first grabbing claw; a fixed block is fixedly connected to the left side of the rotating part of the rotating shaft; the inner side of the rotating part of the rotating shaft is provided with a telescopic device; four support frames which are distributed in a rectangular shape are fixedly connected to the fixed block; the telescopic end of the telescopic device is fixedly connected with a cross connecting frame; two adjacent support frames are fixedly connected with a second connecting shaft together, and the second connecting shaft is positioned at the left of the first connecting shaft; a second connecting shaft is arranged on the left side of each adjacent four supporting frames; the four first connecting shafts are respectively and rotatably connected with a first linkage plate; a second linkage plate is rotatably connected to each of the four second connecting shafts; a fourth connecting shaft is rotatably connected to each of the four first linkage plates; a fifth connecting shaft is rotatably connected to each of the four second linkage plates; one side of each of the four first linkage plates, which is far away from the fourth connecting shaft, is rotatably connected with a third connecting shaft; the four third connecting shafts are connected with the cross-shaped connecting frame; a third linkage plate is arranged on the adjacent fourth connecting shaft and the fifth connecting shaft together; a connecting rod is fixedly connected to each of the four third linkage plates; the left sides of the four third linkage plates are fixedly connected with a first elastic piece respectively; the four connecting rods are respectively connected with an installation plate in a sliding way; the four mounting plates are fixedly connected with the adjacent first elastic pieces respectively; a first grabbing claw is fixedly connected to each of the four mounting plates; the four connecting rods are all connected with the anti-skid mechanism; four first snatch claws and all connect anti-skidding mechanism.

Preferably, a plurality of grooves are formed in the inner sides of the four first grabbing claws respectively.

Preferably, the anti-skid mechanism comprises a connecting ring, a second elastic piece and a second grabbing claw; the middle parts of the outer surfaces of the four connecting rods are respectively connected with a connecting ring in a sliding way; the left sides of the four connecting rods are fixedly connected with a second elastic piece respectively; the four second elastic pieces are fixedly connected with the adjacent connecting rings respectively; each of the four first grabbing claws is rotatably connected with one second grabbing claw, and a torsion spring is connected between each adjacent second grabbing claw and the corresponding first grabbing claw; the four connecting rings are respectively connected with a secondary locking mechanism.

Preferably, the secondary locking mechanism comprises a first limiting plate, a push plate, an extrusion plate, an arc-shaped rod, a second limiting plate and a bending plate; a push plate is fixedly connected to each of the four connecting rings; two first limiting plates are fixedly connected to the four connecting rods respectively; an extrusion plate is fixedly connected to two adjacent first limiting plates; the four push plates are respectively contacted with the adjacent extrusion plates; a second limiting plate is fixedly connected to each of the four extrusion plates; two arc-shaped rods are fixedly connected to the four extrusion plates respectively; two arc-shaped rods on the same extrusion plate are fixedly connected with a bending plate; each bending plate is matched with the adjacent second grabbing claw.

Preferably, the pressing plate has elasticity.

Preferably, the device also comprises a compression sheet; and a pressing sheet is fixedly connected to each of the four third linkage plates.

Preferably, the four pressing pieces are all arranged in a state of inclining and approaching to the central point of the rotating shaft.

Preferably, the device further comprises a loosening plate, and one loosening plate is fixedly connected to each of the four mounting plates.

Preferably, the end of each of the four loosening plates, which is far away from the adjacent mounting plate, is provided with a reverse grabbing block.

The beneficial effects are that: according to the invention, the rotating shaft and the loosening plate are arranged, so that when the aquatic weeds are sunk into silt and silt or wound, the whole grabbing part is rotated through the rotating shaft, the objects are gradually loosened, or the aquatic weeds are broken and are easy to pull out, and the convenience is improved;

by arranging the four second grabbing claws, when an object slides off, the four second grabbing claws realize secondary grabbing and fixing on the object, and the grabbing strength is in direct proportion according to the sliding degree of the object, so that the object is ensured to be secondarily fixed, and is prevented from sliding off;

through setting up the compact heap, when the object was located four first snatchs between the claw, fix the object, prevent that the object from constantly colliding the friction with four first recesses that snatch the claw inboard because of the buoyancy of water, causing the damage.

Drawings

Fig. 1 is a schematic perspective view of a mechanical gripping device applied to an underwater robot according to the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is a side view of the present invention;

FIG. 4 is a partial exploded view of the present invention;

FIG. 5 is a schematic view of a first partial body structure according to the present invention;

FIG. 6 is a schematic diagram of a second partial body structure according to the present invention;

fig. 7 is a perspective view of a third embodiment of the present invention.

In the reference symbols: the bending device comprises a mounting frame, a rotating shaft, a fixing block, a supporting frame, a first connecting shaft, a second connecting shaft, a first linkage plate, a second linkage plate, a third connecting shaft, a third linkage plate, a fourth connecting shaft, a fifth connecting shaft, a pressing sheet, a telescopic device, a cross connecting frame, a connecting rod, a first elastic part, a mounting plate, a first grabbing claw, a connecting ring, a second elastic part, a second grabbing claw, a first limiting plate, a second limiting plate, a 25 pushing plate, a squeezing plate, an arc-shaped rod, a second limiting plate, a bending plate and a loosening plate, wherein the mounting frame is 1-mounting frame, the rotating shaft is 2-3-fixing block, the supporting frame is 4-6-first connecting shaft, the pressing sheet, the telescopic device, the cross connecting frame, the first connecting frame, the connecting rod, the first elastic part, the 18-first elastic part, the mounting plate, the first clamping plate, the second clamping claw, the 20-connecting ring, the clamping plate, the connecting plate, the second clamping plate, the connecting plate, the second clamping plate, the clamping plate and the clamping plate, and the clamping plate.

Detailed Description

The invention will be further described with reference to examples of embodiments shown in the drawings to which the invention is attached.

Examples

The mechanical grabbing device applied to the underwater robot is shown in figures 1-7 and comprises a mounting frame 1, a rotating shaft 2 and a grabbing mechanism; the number of the mounting racks 1 is two, and the whole grabbing device is mounted on the underwater robot body through the two mounting racks 1; the inner sides of the two mounting frames 1 are connected with a rotating shaft 2 together; the left side of the rotating shaft 2 is provided with a grabbing mechanism;

the anti-skid device also comprises an anti-skid mechanism and a secondary locking mechanism; the grabbing mechanism is provided with an anti-skid mechanism; and the anti-skid mechanism is provided with a secondary locking mechanism.

The grabbing mechanism comprises a fixed block 3, a support frame 4, a first connecting shaft 6, a second connecting shaft 7, a first linkage plate 8, a second linkage plate 9, a third connecting shaft 10, a third linkage plate 11, a fourth connecting shaft 12, a fifth connecting shaft 13, a telescopic device 15, a cross connecting frame 16, a connecting rod 17, a first elastic element 18, a mounting plate 19 and a first grabbing claw 20; a fixed block 3 is fixedly connected to the left side of the rotating part of the rotating shaft 2; the inner side of the rotating part of the rotating shaft 2 is provided with a telescopic device 15; four support frames 4 which are distributed in a rectangular shape are fixedly connected to the fixed block 3; the telescopic end of the telescopic device 15 is fixedly connected with a cross connecting frame 16; two adjacent support frames 4 are fixedly connected with a second connecting shaft 7 together, and the second connecting shaft 7 is positioned at the left of the first connecting shaft 6; a second connecting shaft 7 is arranged on the left side of each adjacent two of the four supporting frames 4; the four first connecting shafts 6 are respectively and rotatably connected with a first linkage plate 8; a second linkage plate 9 is rotatably connected to each of the four second connecting shafts 7; a fourth connecting shaft 12 is rotatably connected to each of the four first linkage plates 8; a fifth connecting shaft 13 is rotatably connected to each of the four second linkage plates 9; one side of each of the four first linkage plates 8, which is far away from the fourth connecting shaft 12, is rotatably connected with a third connecting shaft 10; the four third connecting shafts 10 are connected with a cross connecting frame 16; a third linkage plate 11 is arranged on the adjacent fourth connecting shaft 12 and the fifth connecting shaft 13; a connecting rod 17 is fixedly connected to each of the four third linkage plates 11; a first elastic member 18 is fixedly connected to each of the left sides of the four third linkage plates 11; the four connecting rods 17 are respectively connected with a mounting plate 19 in a sliding way; the four mounting plates 19 are respectively fixedly connected with the adjacent first elastic pieces 18; each bolt on the four mounting plates 19 is connected with a first grabbing claw 20; the four connecting rods 17 are all connected with an anti-skid mechanism; the four first grabbing claws 20 are connected with an anti-skidding mechanism; the telescopic device 15 is used for controlling the cross connecting frame 16 to move left and right, so that the four first grabbing claws 20 are opened and closed, and grabbing of underwater objects to be grabbed is realized.

A plurality of grooves are formed on the inner sides of the four first grabbing claws 20.

The first elastic member 18 is a spring.

The anti-skid mechanism comprises a connecting ring 21, a second elastic piece 22 and a second grabbing claw 23; the middle parts of the outer surfaces of the four connecting rods 17 are respectively connected with a connecting ring 21 in a sliding way; the left sides of the four connecting rods 17 are fixedly connected with a second elastic part 22 respectively; the four second elastic pieces 22 are respectively fixedly connected with the adjacent connecting rings 21; each of the four first grabbing claws 20 is rotatably connected with one second grabbing claw 23, and a torsion spring is connected between each adjacent second grabbing claw 23 and the first grabbing claw 20; the four connecting rings 21 are respectively connected with a secondary locking mechanism; the second grabbing claw 23 is used for grabbing the grabbed object for the second time, so that the grabbed object is prevented from sliding off.

The secondary locking mechanism comprises a first limit plate 24, a push plate 25, an extrusion plate 26, an arc-shaped rod 27, a second limit plate 28 and a bending plate 29; a push plate 25 is fixedly connected to each of the four connecting rings 21; two first limiting plates 24 are fixedly connected to the four connecting rods 17 respectively; an extrusion plate 26 is fixedly connected to two adjacent first limiting plates 24; the four push plates 25 are respectively in contact with the adjacent extrusion plates 26; a second limiting plate 28 is fixedly connected to each of the four extrusion plates 26; two arc-shaped rods 27 are fixedly connected to the four extrusion plates 26 respectively; two arc-shaped rods 27 on the same extrusion plate 26 are jointly fixedly connected with a bending plate 29; each bending plate 29 cooperates with an adjacent second gripping claw 23; the second gripper jaw 23 is limited by the first stopper plate 24, and is prevented from loosening.

The pressing plate 26 has elasticity.

The second elastic member 22 is a spring.

Also comprises a compression sheet 14; a pressing piece 14 is fixedly connected to each of the four third linkage plates 11, and the four pressing pieces 14 are elastic.

The four pressing pieces 14 are all arranged in a state of inclining and approaching to the central point of the rotating shaft 2.

The four mounting plates 19 are fixedly connected with one loosening plate 30, and the four mounting plates 19 are all inwards concave towards the central point of the rotating shaft 2.

The end of each of the four trip plates 30 remote from the adjacent mounting plate 19 is provided with a back grab block.

The following rotating visual angle directions are from top to bottom, from left to right and from front to back. When salvaging and grabbing underwater objects, the underwater robot is generally adopted to replace manpower, the underwater robot is adopted to be not only high in efficiency, but also capable of eliminating threats of underwater conditions to underwater personnel, however, when the underwater robot is adopted to grab the underwater objects, the requirements on the grabbing device of the underwater robot are also high, if the grabbed objects are possibly sunk into silt in water, or are wound by underwater waterweeds and the like, or the grabbed objects need to be protected, the grabbing force of the grabbing device is prevented from being large, so that the grabbing device is damaged, meanwhile, in order to adapt to grabbing of different objects, different grabbing parts can be required to be replaced, the existing grabbing parts of the grabbing robot are difficult to replace and are not convenient to detach.

The whole grabbing device is installed on an underwater robot through two installation frames 1, after the installation is completed, the underwater robot is launched into water and moves to the position close to an object to be grabbed, the four first grabbing claws 20 are ensured to smoothly grab the object to be grabbed when being close to and furled, then the object to be grabbed starts to be grabbed, the expansion piece 15 is controlled to start working, the cross connecting frame 16 is pulled to move rightwards through the expansion piece 15, the third connecting shaft 10 is driven to move rightwards synchronously through the cross connecting frame 16, then the first linkage plate 8 is pulled to move through the third connecting shaft 10, so that the first linkage plate 8 rotates anticlockwise around the central point of the first connecting shaft 6, the fourth linkage plate 12 is driven to move through the first linkage plate 8, then the third linkage plate 11 is linked through the fourth connecting shaft 12, and when the third linkage plate 11 moves, the third linkage plate 11 moves towards the lower left, the third linkage plate 11 is simultaneously linked with the fifth connection shaft 13, and further synchronously linked with the second linkage plate 9 through the fifth connection shaft 13, so that the second linkage plate 9 rotates anticlockwise around the central point of the second connection shaft 7, and further when the first linkage plate 8, the second linkage plate 9 and the third linkage plate 11 are linked, the third linkage plate 11 simultaneously drives the first elastic element 18, the mounting plate 19 and the first grabbing claw 20 to move towards the central point of the rotating shaft 2, namely the first grabbing claw 20 gradually draws towards the central point of the rotating shaft 2, so as to realize the grabbing action, during the grabbing process, according to the underwater photography equipment carried by the underwater robot, the whole image data of the object to be grabbed is transmitted back to the terminal, and an operator determines how to grab the object according to the shape, the size, the appearance characteristics of the object to be grabbed and the environment where the object is located, when the four first grabbing claws 20 are gradually folded towards the central point of the rotating shaft 2, an object to be grabbed can be effectively grabbed, for example, when the four first grabbing claws 20 are in the state shown in the figure, due to the shape of the object to be grabbed, the four first grabbing claws 20 cannot grab the object to be grabbed, that is, the grabbing force of the object to be grabbed is insufficient, or the object to be grabbed has irregular bulges and the like, and the bulges obstruct one or more of the four first grabbing claws 20, so that the object cannot be smoothly folded towards the central point of the rotating shaft 2, and further the grabbing of the object to be grabbed is influenced, therefore, the relative positions of the four first grabbing claws 20 and the object need to be adjusted, that is, the rotating shaft 2 is controlled to drive the fixed block 3 to rotate, and then the supporting frame 4 is driven to rotate by the fixed block 3, and when the supporting frame 4 rotates, the first grabbing claws 20 also rotate, the relative position of the first grabbing claws 20 and the object to be grabbed is changed until the first grabbing claws 20 rotate to the state that the first grabbing claws 20 are not blocked to be furled by the irregular bulges and the like of the object to be grabbed in the furling process, after the object to be grabbed is tightly grabbed by the four first grabbing claws 20, if the object to be grabbed is buried in underwater silt or is wound by waterweeds, after the object to be grabbed is tightly grabbed, because the whole grabbing device forms a certain angle with the object to be grabbed, the object to be grabbed is taken as a base point, the grabbing device is generally positioned in a hemispheroid space above the object to be grabbed, for the existing equipment, after the object to be grabbed which is sunk into the silt or the silt and has a low stroke, the object to be grabbed can be directly grabbed, but for the object to be grabbed which is sunk into the silt or the silt and has a high stroke, the mode is adopted, the object cannot be smoothly grabbed, and for the four first grabbing claws 20, in the grabbing process, because a greater force is required to be applied to pull the object out of the silt or the silt, at this time, the reaction force exerted on the four first grabbing claws 20 is greatly increased, so that the possibility of damage of the object is greatly increased, and at the same time, the acting force on the object to be grabbed is also synchronously increased, so that the object to be grabbed is damaged, and the purpose of lossless grabbing cannot be achieved, therefore, for the object trapped in the silt or the silt, in the grabbing process, in order to smoothly grab the object, the object needs to be loosened first and then grabbed, that is, after the object to be grabbed is grabbed tightly, the four first grabbing claws 20 rotate back and forth through small angles to gradually loosen the object to be grabbed, and when the third connecting plate 11 rotates back and forth, synchronously driving the loosening plate 30 to rotate in a small-angle reciprocating manner, applying thrust to an object to be grabbed through the loosening plate 30, increasing the loosening degree of the object, and ensuring that the object is grabbed smoothly in the follow-up process.

After the object is grabbed, for the existing grabbing equipment, because only the part of the grabbed object above the sediment can be touched, the phenomenon that the contact surface is not large enough and the grabbing is not stable enough may occur, and because of the interference of the object self gravity or water flow and the like, the object may slide off, therefore, the object needs to be prevented from falling off, as the object is gradually grabbed, the object gravity enables the first grabbing claw 20 to synchronously slide on the connecting rod 17, and further synchronously stretches the four first elastic members 18 through the first grabbing claw 20, and simultaneously pushes the connecting ring 21 to slide on the connecting rod 17, and further drives the push plate 25 to move towards the extrusion plate 26 through the connecting ring 21, and further extrudes the extrusion plate 26 through the push plate 25, and because the extrusion plate 26 is made of an elastic material, further the extrusion plate 26 deforms, and synchronously extrudes the adjacent arc-shaped rods 27, then, the arc-shaped rod 27 is used for extruding the adjacent second grabbing claws 23, so that the second grabbing claws 23 rotate counterclockwise, the pressure between the second grabbing claws 23 and the object to be grabbed is increased, and further, when the object slides down from the first grabbing claws 20, the second grabbing claws 23 further fix the object, and the degree of secondary fixing is in direct proportion to the gravity of the object, that is, when the object is heavier and the sliding degree is higher, the extrusion force of the bending plate 29 on the second grabbing claws 23 is synchronously increased, so that the secondary extrusion force of the second grabbing claws 23 on the object is increased, so as to prevent the object from sliding down, and meanwhile, the second limiting plate 28 is used for preventing the push plate 25 and the extrusion plate 26 from completely separating from each other, so that the extrusion force of the extrusion plate 26 on the second grabbing claws 23 is lost, and the object which slides down cannot be secondarily fixed.

When the object is limited between the four first grabbing claws 20, the object is in water, water generates corresponding buoyancy to the object, when the volume of the object is smaller than the space formed by the four first grabbing claws 20 after being folded, the grabbed object floats and shakes among the four first grabbing claws 20, so that the object continuously generates friction collision with the inner sides of the four first grabbing claws 20, because the inner sides of the four first grabbing claws 20 are provided with notches, the friction between the object and the object is increased, when the grabbing strength is improved, the surface of the grabbed object needs to be protected due to the floating of the object, so as to prevent the object from generating large-scale scratch, the object on the inner sides of the four first grabbing claws 20 needs to be further fixed, so that the object cannot continuously generate friction collision with the notches on the inner sides of the four first grabbing claws 20 under the action of the buoyancy of water, when the four third linkage plates 11 are continuously folded to be close to the central point of the rotating shaft 2, make four compressing blades 14 be close to 2 central points of pivot, because four compressing blades 14 adopt the elastic material, and four compressing blades 14 set up to the state that 2 central points of pivot squint is close to, and then make four first snatching when claw 20 snatchs the object, four compressing blades 14 are synchronous to snatching the object and move and contact with the object, and then extrude the object through four compressing blades 14, make it fixed completely between four first snatching claw 20, prevent that it from constantly taking place the friction collision with the inboard notch of four first snatching claw 20 because of the buoyancy of water, cause four first snatching claw 20 impaired, perhaps snatch the object surface and take place the damage.

Although embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. The mechanical grabbing device applied to the underwater robot comprises a mounting rack (1), a rotating shaft (2) and a grabbing mechanism; the number of the mounting racks (1) is two, and the whole grabbing device is mounted on the underwater robot body through the two mounting racks (1); the inner sides of the two mounting frames (1) are connected with a rotating shaft (2) together; a grabbing mechanism for underwater grabbing is arranged on the left side of the rotating shaft (2); it is characterized by also comprising an anti-skid mechanism and a secondary locking mechanism; the grabbing mechanism is provided with an anti-skid mechanism; the antiskid mechanism is provided with a secondary locking mechanism; the object grabbed by the grabbing mechanism is subjected to anti-slip and anti-falling treatment through the anti-slip mechanism, and then the grabbed object subjected to sliding is subjected to secondary locking and fixing through the secondary locking mechanism;

the grabbing mechanism comprises a fixed block (3), a support frame (4), a first connecting shaft (6), a second connecting shaft (7), a first linkage plate (8), a second linkage plate (9), a third connecting shaft (10), a third linkage plate (11), a fourth connecting shaft (12), a fifth connecting shaft (13), a telescopic device (15), a cross connecting frame (16), a connecting rod (17), a first elastic piece (18), a mounting plate (19) and a first grabbing claw (20); a fixed block (3) is fixedly connected to the left side of the rotating part of the rotating shaft (2); the inner side of the rotating part of the rotating shaft (2) is provided with a telescopic device (15); four support frames (4) which are distributed in a rectangular shape are fixedly connected to the fixed block (3); the telescopic end of the telescopic device (15) is fixedly connected with a cross connecting frame (16); two adjacent support frames (4) are fixedly connected with a second connecting shaft (7) together, and the second connecting shaft (7) is positioned on the left of the first connecting shaft (6); a second connecting shaft (7) is arranged on the left side of each adjacent four supporting frames (4); the four first connecting shafts (6) are respectively connected with a first linkage plate (8) in a rotating way; a second linkage plate (9) is rotatably connected to each of the four second connecting shafts (7); a fourth connecting shaft (12) is rotatably connected to each of the four first linkage plates (8); a fifth connecting shaft (13) is rotatably connected to each of the four second linkage plates (9); one sides of the four first linkage plates (8) far away from the fourth connecting shaft (12) are respectively and rotatably connected with a third connecting shaft (10); the four third connecting shafts (10) are connected with a cross connecting frame (16); a third linkage plate (11) is arranged on the adjacent fourth connecting shaft (12) and the fifth connecting shaft (13) together; a connecting rod (17) is fixedly connected to each of the four third linkage plates (11); the left sides of the four third linkage plates (11) are respectively fixedly connected with a first elastic piece (18); the four connecting rods (17) are respectively connected with a mounting plate (19) in a sliding way; the four mounting plates (19) are respectively fixedly connected with the adjacent first elastic pieces (18); a first grabbing claw (20) is fixedly connected to each of the four mounting plates (19); the four connecting rods (17) are all connected with the antiskid mechanism; the four first grabbing claws (20) are all connected with an anti-skidding mechanism.

2. The mechanical grabbing device for an underwater robot as claimed in claim 1, wherein a plurality of grooves are formed on the inner sides of the four first grabbing claws (20).

3. The mechanical gripping device applied to underwater robots according to claim 1, characterized in that the anti-slip means comprises a connection ring (21), a second elastic member (22) and a second gripping claw (23); the middle parts of the outer surfaces of the four connecting rods (17) are respectively connected with a connecting ring (21) in a sliding way; the left sides of the four connecting rods (17) are fixedly connected with a second elastic piece (22) respectively; the four second elastic pieces (22) are respectively and fixedly connected with the adjacent connecting rings (21); each of the four first grabbing claws (20) is rotatably connected with one second grabbing claw (23), and a torsion spring is connected between each adjacent second grabbing claw (23) and the corresponding first grabbing claw (20); the four connecting rings (21) are respectively connected with a secondary locking mechanism.

4. The mechanical grabbing device applied to the underwater robot of claim 3, wherein the secondary locking mechanism comprises a first limiting plate (24), a push plate (25), an extrusion plate (26), an arc-shaped rod (27), a second limiting plate (28) and a bending plate (29); a push plate (25) is fixedly connected to each of the four connecting rings (21); two first limiting plates (24) are fixedly connected to the four connecting rods (17) respectively; two adjacent first limiting plates (24) are fixedly connected with an extrusion plate (26) together; the four push plates (25) are respectively contacted with the adjacent extrusion plates (26); a second limiting plate (28) is fixedly connected to each of the four extrusion plates (26); two arc-shaped rods (27) are fixedly connected to the four extrusion plates (26) respectively; two arc-shaped rods (27) positioned on the same extrusion plate (26) are fixedly connected with a bending plate (29) together; each bending plate (29) is matched with the adjacent second grabbing claw (23).

5. The mechanical gripping device applied to an underwater robot as claimed in claim 4, wherein the pressing plate (26) has elasticity.

6. The mechanical grabbing device for underwater robots according to claim 4, further comprising a pressing sheet (14); and a pressing sheet (14) is fixedly connected to each of the four third linkage plates (11).

7. The mechanical grabbing device applied to an underwater robot as claimed in claim 4, wherein the four pressing pieces (14) are arranged in a state of being inclined close to the central point of the rotating shaft (2).

8. The mechanical grabbing device for underwater robots of claim 7, further comprising a releasing plate (30), wherein one releasing plate (30) is fixed to each of the four mounting plates (19).

9. Mechanical gripping device applied to underwater robots according to claim 8, characterised in that the ends of the four loosening plates (30) remote from the adjacent mounting plate (19) are each provided with an inverted gripping block.