CN210589368U

CN210589368U - Two-finger mechanical gripper for mounting passive finger

Info

Publication number: CN210589368U
Application number: CN201921470115.1U
Authority: CN
Inventors: 雷亚雄
Original assignee: Chengdu Yizhao Robot Technology Co Ltd
Current assignee: Dongguan Yizhuo Robot Technology Co ltd
Priority date: 2019-09-05
Filing date: 2019-09-05
Publication date: 2020-05-22
Anticipated expiration: 2029-09-05

Abstract

A two-finger mechanical gripper for mounting a passive finger is characterized in that a linear guide rail is mounted on a translation cylinder, and two sliding blocks and the linear guide rail form a sliding pair; the passive finger structure is: the upper ends of the two elastic strips distributed at an acute angle are converged to form a fingertip, the two ends of the plurality of cross beams are connected between the two elastic strips through flexible hinges, and the lower ends of the two elastic strips are fixed on the top plate of the fixed hook. The passive fingers are arranged on the main fixing block and the auxiliary fixing block to form passive finger assemblies, and the two passive finger assemblies are respectively fixed on a sliding block through an adjustable mounting plate. When one pneumatic joint on the cylinder is ventilated, the two passive finger assemblies are separated, and when the other pneumatic joint on the cylinder body is ventilated, the two passive finger assemblies are closed. The utility model has the characteristics of snatch strong adaptability, snatch firm adoption flexible construction and difficult damage object, the assembly is simple and convenient, and the cost of manufacture is low etc.

Description

Two-finger mechanical gripper for mounting passive finger

Technical Field

The utility model relates to a gripper, especially have flexible construction and snatch firm two finger gripper.

Background

The conventional mechanical gripping device mainly comprises a sucker, a single-degree-of-freedom mechanical clamping jaw, an under-actuated mechanical jaw and a rigid mechanical jaw. The sucking disc is difficult for grabbing objects with uneven surfaces and loosening porous objects. The single-degree-of-freedom mechanical clamping jaw is poor in grabbing adaptability, and the clamping jaw profile needs to be specially designed according to objects in different shapes or different sizes. The under-actuated gripper has good gripping adaptability, but has high cost and complex installation and is easy to damage a gripped object; the disadvantages are: the number of parts is large, the assembly is complex, some sensors are needed, and the cost is high; the rigid mechanical claw is easy to generate larger pressure to a grabbed object, so that the object is damaged, the cost is high, a plurality of parts are provided, the assembly is complex, a sensor is required in some cases, and the cost is high.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a rely on the elasticity variability of revolute pair to rotate, self-adaptation object shape, snatch the adaptation and do not harm the object by force, two finger gripper of finger passively with low costs installation.

The utility model discloses the purpose realizes like this: a two-finger gripper for mounting a passive finger comprises a linear guide rail mounted on a cylinder body of a translation cylinder, two sliding blocks positioned on the linear guide rail and forming a sliding fit with the linear guide rail, wherein when one pneumatic joint on the cylinder body is ventilated, the two sliding blocks are separated, and when the other pneumatic joint on the cylinder body is ventilated, the two sliding blocks are closed; the finger is characterized in that the structure of the passive finger is as follows: the two plate-type elastic strips are distributed in an acute angle and are gathered together at the upper ends to form fingertips, two ends of a plurality of cross beams are respectively connected between the two elastic strips through flexible hinges, the fixed hook is a bent plate with symmetrical left and right parts, the section shape of the left part of the fixed hook is formed by connecting a right horizontal segment, a vertical lower segment and a left horizontal segment end to end, the left horizontal segment is smaller than the right horizontal segment, the vertical lower segment and the left horizontal segment form a hook, the lower ends of the two elastic strips are fixed on a top plate of the fixed hook, and the lower edges of the outer side surfaces of the two elastic strips are respectively positioned on two outer vertical surfaces of the fixed hook; the passive finger component is formed by installing a passive finger on the main fixing block and the auxiliary fixing block, and has the following structure: the main fixing block is a rectangular frame with a rear opening and a top opening, which is formed by enclosing a front main board, a left vertical board and a bottom board, fixing bulges with fixing clamping blocks on the left side and the right side are fixed on the upper surface of the bottom board of the main fixing block, a driven finger is inserted from the rear opening of the main fixing block and enables a fixing hook of the driven finger to be clamped and sleeved on the two fixing clamping blocks to form a sliding block matching relationship, the left outer vertical surface, the right outer vertical surface and the outer bottom surface of the fixing hook are respectively attached to the left inner vertical surface, the right inner vertical surface and the upper surface of the bottom board of the left vertical board and the right vertical board of the fixing block, the auxiliary fixing block is formed by fixing auxiliary fixing bulges on the front side surface of the auxiliary; two fixing bolts penetrate through auxiliary fixing holes in the auxiliary fixing blocks and then are screwed in threaded holes of the fixing protrusions, so that auxiliary fixing vertical plates of the auxiliary fixing blocks are fixed on rear openings of the main fixing blocks, fixing hooks of the driven fingers are clamped and sleeved on the two auxiliary fixing blocks of the auxiliary fixing blocks to form a sliding fit relation, and mounting lugs and auxiliary mounting lugs which are symmetrical in shape and flush with the bottom surface of a bottom plate of the main fixing block are fixedly connected to the lower portion of the outer surface of the front vertical plate of the main fixing block and the lower portion of the rear side of the auxiliary fixing vertical plate of the auxiliary fixing block respectively;

the two passive finger assemblies are inserted into the mounting holes of the mounting lug and the auxiliary mounting lug through mounting bolts and then are screwed and fixed on the mounting screw hole of one adjustable mounting plate, and the two adjustable mounting plates are fixed on one sliding block through four connecting bolts.

The passive finger is provided with a composite sleeve; the composite sleeve is an outer layer coated on the outer surfaces of the two elastic strips, and patterns for increasing friction are arranged on the outer layer; or the composite sleeve is formed by integrating an outer layer coated on the outer surfaces of the two elastic strips and an inner layer positioned between the two adjacent cross beams and attached to the inner surfaces of the two elastic strips.

The composite sleeve is a silicon rubber composite sleeve; the elastic strip is made of thermoplastic polyurethane.

The two elastic strips are provided with hollows.

The two elastic strips are two waists of an isosceles triangle; an inclined angle is formed between the inner surfaces of the bottom plates of the two main fixing blocks in the two passive finger assemblies and the outer surface of the bottom plate positioned horizontally, so that two adjacent elastic strips of the two passive fingers are parallel and in a vertical direction.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the driven finger 1 is geometrically characterized by a plurality of trapezoidal structures and is made of a high-elasticity material, so that the driven finger 1 is bent towards the object to be grabbed, the inner elastic strip 12 can be attached to the surface of the grabbed object in a self-adaptive manner, the driven finger can adapt to objects with various radians and shapes, and the grabbing adaptability is high.

2. The adopted material is an elastic material II which is not a rigid material, and is not easy to damage objects.

3. The adoption of the flexible structure ensures that the integration degree of the passive finger is high, the manufacture and the assembly are simple and convenient, and a sensor is not needed, so the price is lower.

4. The fixing hook 11 coincides with all the abutment surfaces of the fixing assembly, making the fixing by the passive finger very stable.

The utility model is made of flexible material, can adapt to the shape of the object, and has strong grabbing adaptability; the pressure on the grabbed object is small, and the object is not easy to damage; the flexible hinge with a flexible structure is adopted, so that the production cost and the installation cost are greatly reduced.

Drawings

Fig. 1 is a front view of a passive finger.

Fig. 2 is a left view of the passive finger.

Fig. 3 is a perspective view of a passive finger.

Fig. 4 is a cross-sectional view of a passive finger.

Fig. 5 is a perspective view of a passive finger integrated with two fingers.

Fig. 6 is a partial exploded view of a passive finger integrated with two fingers.

Fig. 7 is an exploded view of a passive finger fixation structure.

Fig. 8 is a cross-sectional view of a passive finger fixation arrangement.

Fig. 9 is a front view of the passive finger integrated two-finger object.

Fig. 10 is a perspective view of another embodiment of the present invention.

Fig. 11 is an exploded view of fig. 10.

Fig. 12 is an exploded view of the passive finger and securing assembly of fig. 11.

Fig. 13 is a cross-sectional view of the passive finger of fig. 12 with the securing assembly assembled.

Detailed Description

Fig. 1-4 show a two-finger gripper for mounting a passive finger, comprising a translational cylinder having a linear guide mounted on a cylinder body, two sliding blocks disposed on the linear guide in sliding engagement therewith, the two sliding blocks being separated when one pneumatic connector on the cylinder body is vented and closed when the other pneumatic connector on the cylinder body is vented; the finger is characterized in that the structure of the passive finger is as follows: the two plate-type elastic strips are distributed in an acute angle and are gathered together at the upper ends to form fingertips, two ends of a plurality of cross beams are respectively connected between the two elastic strips through flexible hinges, the fixed hook is a bent plate with symmetrical left and right parts, the section shape of the left part of the fixed hook is formed by connecting a right horizontal segment, a vertical lower segment and a left horizontal segment end to end, the left horizontal segment is smaller than the right horizontal segment, the vertical lower segment and the left horizontal segment form a hook, the lower ends of the two elastic strips are fixed on a top plate of the fixed hook, and the lower edges of the outer side surfaces of the two elastic strips are respectively positioned on two outer vertical surfaces of the fixed hook;

the passive finger component is formed by installing a passive finger on the main fixing block and the auxiliary fixing block, and has the following structure: the main fixing block is a rectangular frame with a rear opening and a top opening, which is formed by enclosing a front main board, a left vertical board and a bottom board, fixing bulges with fixing clamping blocks on the left side and the right side are fixed on the upper surface of the bottom board of the main fixing block, a driven finger is inserted from the rear opening of the main fixing block and enables a fixing hook of the driven finger to be clamped and sleeved on the two fixing clamping blocks to form a sliding block matching relationship, the left outer vertical surface, the right outer vertical surface and the outer bottom surface of the fixing hook are respectively attached to the left inner vertical surface, the right inner vertical surface and the upper surface of the bottom board of the left vertical board and the right vertical board of the fixing block, the auxiliary fixing block is formed by fixing auxiliary fixing bulges on the front side surface of the auxiliary; two fixing bolts penetrate through auxiliary fixing holes in the auxiliary fixing blocks and then are screwed in the threaded holes of the fixing protrusions, so that auxiliary fixing vertical plates of the auxiliary fixing blocks are fixed on the rear openings of the main fixing blocks, fixing hooks of the passive fingers are clamped and sleeved on the two auxiliary fixing clamping blocks of the auxiliary fixing blocks to form a sliding fit relation, and the outer surface lower portion of the front side vertical plate of the main fixing block and the rear side lower portion of the auxiliary fixing vertical plate of the auxiliary fixing block are respectively fixedly connected with mounting lugs and auxiliary mounting lugs which are symmetrical in shape and flush with the bottom surface of a bottom plate of the main fixing block.

As shown in fig. 1 and 2: the passive finger mainly comprises a fixed hook 11, two elastic strips 12, a plurality of cross beams 13 and a fingertip 14. The two elastic strips 12 are distributed in an acute angle, one ends of the two elastic strips are gathered together and rounded to form a fingertip 14, a plurality of cross beams 13 are connected between the two elastic strips 12, each cross beam 13 mainly comprises a cross beam main body 131 and two cross beam end parts 132, the cross beam end parts 132 and the elastic strips 12 form a flexible hinge 133 at the connection position, the other ends of the two elastic strips 12 are connected with the fixed hook 11, and the fixed hook 11 comprises an inner hook surface 111, an outer bottom surface 112, an outer vertical surface 113 and a side vertical surface 114.

As shown in fig. 2, the thickness at the fingertip 14 is smaller than the thickness of the fixing hook 11.

As shown in fig. 3, the middle of the elastic strip 12 may be provided with a hollow 121. So that the arc-shaped object can be better grabbed.

As shown in fig. 4, a composite sleeve 15 with a larger material friction coefficient can be added outside the elastic strip 12 and the finger tip 14 to increase the friction force during grabbing and improve the grabbing load and the grabbing reliability. The composite sleeve 15 basically includes an outer layer 151 and an inner layer 152, the inner layer 152 being spaced apart due to the presence of the beam 13, but both being connected to the outer layer 151. There may be only an outer layer 151. patterns or the like may be added to the outer layer 151 to further increase the grip friction coefficient.

The proposed passive finger integration may be designed to translate a two finger gripper as shown in fig. 5 to 9.

The translational two-finger mechanical claw mainly comprises two passive fingers 1, two fixed components 2, an adjustable mounting plate 4 and a translational air cylinder 5.

As shown in fig. 7, the fixing assembly 2 includes a main fixing block 21 and an auxiliary fixing block 22. The main fixing block 21 is provided with a fixing groove 211, a fixing bulge 212 and a mounting lug 213; the fixing groove 211 is provided with a groove bottom surface 2111, a groove vertical surface 2112 and a groove side vertical surface 2113; the fixing protrusion 212 is provided with a fixing block 2121 and a fixing threaded hole 2122; the mounting lug 213 is provided with a mounting hole 2131, and the auxiliary fixing block 22 is provided with an auxiliary fixing vertical plate 221, an auxiliary fixing protrusion 222 and an auxiliary mounting lug 223; the auxiliary fixing protrusion 222 is provided with an auxiliary fixing latch 2221 and an auxiliary fixing hole 2222, and the auxiliary fixing lug 223 is provided with an auxiliary mounting hole 2231.

When the passive finger 1 and the fixing component 2 are installed, the passive finger 1 and the main fixing block 21 are installed first. The outer bottom surface 112 of the fixing hook 11 is overlapped with the groove bottom surface 2111, the inner hook surface 111 is overlapped with the fixing block 2121, the outer vertical surface 113 is overlapped with the groove vertical surface 2113, and the passive finger 1 is pushed in towards the groove vertical surface 2113 until one side vertical surface 114 of the fixing hook 11 is overlapped with the groove vertical surface 2113. Then, the auxiliary fixing block 22 is installed so that the auxiliary fixing block 2221 coincides with the inner hook surface 111, and is pushed in toward the passive finger 1. The fixing bolt 31 is coupled with the fixing thread 2122 through the auxiliary fixing hole 2222. The fixing bolt 31 is tightened so that the auxiliary fixing riser 221 coincides with the other side elevation 114 of the fixing hook 11. The passive finger 1 is mounted with the fixed component 2.

An adjustable mounting plate 4 is used to adjustably connect the fixed assembly 2 to the translation cylinder 5. The adjustable fixing plate 4 is provided with a connecting hole 41 connected with the translation cylinder 5, and a plurality of mounting screw holes 42 for adjustably mounting the fixing component 2. The translation cylinder 5 in the prior art mainly comprises a cylinder body 51, a linear guide rail 52 and two sliding blocks 53. The slide blocks 53 are provided with connecting threaded holes 531, and the pneumatic connector 6 is ventilated, so that the two slide blocks 53 can simultaneously move oppositely or oppositely along the linear guide rail 52 at the same speed. The adjustable mounting plate 4 is coupled with the translation cylinder 5 by using the coupling bolt 33 to pass through the coupling hole 41 and couple with the coupling screw hole 531. The fixing assembly 2 is coupled to the adjustable mounting plate 4 by tightening the mounting bolts 32 through the mounting holes 2131 of the mounting ears 213 and the auxiliary mounting holes 2231 of the auxiliary mounting ears 223 onto the mounting threads 42.

The material of the passive finger 1 is a thermoplastic elastomer material, in particular thermoplastic polyurethane. So that the arc-shaped object can be better grabbed.

The composite sleeve 15 is made of silicone rubber.

In fig. 10 to 13, 1 passive finger, 2 fixing component, 21 main fixing block, 211 side vertical plate, 2111 notch, 2112 side vertical plate inner wall surface, 212 'clamping plate, 2122 threaded hole, 22' auxiliary fixing plate, 31 bolt, 32 bolt, 33 bolt, 4 adjustable mounting plate, 41 holes, 42 threaded hole, 5 translation cylinder, 51 cylinder body, 52 linear guide rail, 53 slide block and 6 pneumatic joint.

Fig. 9-12 show a two finger gripper for mounting a passive finger, comprising a linear guide 52 mounted on a cylinder 51 of a translatory cylinder 5, two sliders 53 positioned on the linear guide 52 in sliding engagement therewith, the two sliders being spaced apart when one pneumatic connector 6 on the cylinder 51 is vented and closed when the other pneumatic connector on the cylinder 51 is vented; the structure of the passive finger 1 is characterized in that: the two plate-type elastic strips 12 are distributed in an acute angle and are gathered together at the upper ends to form a fingertip 14, two ends of a plurality of crossbeams 13 are respectively connected between the two elastic strips through flexible hinges 133, the fixed hook 11 is a bent plate with symmetrical left and right parts, the cross section shape of the left part of the fixed hook is formed by connecting a right-to-left horizontal section, a vertical lower section and a left-to-right horizontal section end to end, the left-to-right horizontal section is smaller than the right-to-left horizontal section, the vertical lower section and the left-to-right horizontal section form a hook, the lower ends of the two elastic strips are fixed on a top plate of the fixed hook 11, and the lower edges of the outer side surfaces of the two elastic strips; the passive finger component is formed by installing and fixing a passive finger 1 on a main fixing block 21 and two auxiliary fixing pieces 22', and has the following structure: the cross section of main fixed block 21 is right trapezoid, there is a horizontal recess its bottom, top both sides upwards extend and form left and right side riser 211, the middle part upwards extends for towards left and right convex cardboard 212 to form left and right longitudinal notch 2111, the fixed hook 11 of passive finger embolias two cardboard 212 along longitudinal notch 2111, and the fixed hook all forms sliding fit relation with all the buttcock faces of main fixed block (21), two are assisted stationary blade 22 and connect soon respectively through bolt 31 and fix on the screw hole 2122 of main fixed block 21 front and rear side facade.

The transverse grooves of the two passive finger assemblies are respectively clamped and sleeved on the convex edge of one adjustable mounting plate 4 and are fixed by four bolts 32, and the two adjustable mounting plates 4 are respectively fixed on the sliding block 53 by the other four connecting bolts 33. The longitudinal section of the main fixed block is rectangular. The top plate where the middle clamping plates 212 of the two main fixing blocks 21 in the two passive finger assemblies are located and the bottom surface of the main fixing block which is located horizontally form an inclined angle, so that two adjacent elastic strips of the two passive fingers 1 are parallel and vertical. Referring to fig. 3, the fixing hooks are attached to all the adjacent surfaces of the main fixing block. Compared with the first embodiment, the second embodiment changes the original 1 main fixed block and 1 auxiliary fixed block into one main fixed block and 2 auxiliary fixed plates, changes the previous adjustable mounting flat plate 4 into an adjustable mounting plate with convex edges, changes the mounting direction, reduces the thickness of the whole part, and is convenient to process.

Claims

1. A two-finger mechanical gripper for mounting a passive finger comprises a linear guide rail (52) mounted on a cylinder body (51) of a translation cylinder (5), two sliding blocks (53) positioned on the linear guide rail (52) and forming a sliding fit relation with the linear guide rail, wherein when one pneumatic connector (6) on the cylinder body (51) is ventilated, the two sliding blocks are separated, and when the other pneumatic connector on the cylinder body (51) is ventilated, the two sliding blocks are closed; the passive finger (1) is characterized in that: the two plate-type elastic strips (12) are distributed in an acute angle and are gathered together at the upper ends to form a fingertip (14), two ends of a plurality of crossbeams (13) are respectively connected between the two elastic strips through flexible hinges (133), the fixed hook (11) is a bent plate with symmetrical left and right parts, the left section of the fixed hook (11) is formed by connecting a right-to-left horizontal section, a vertical lower section and a left-to-right horizontal section end to end, the left-to-right horizontal section is smaller than the right-to-left horizontal section, the vertical lower section and the left-to-right horizontal section form a bent hook, the lower ends of the two elastic strips are fixed on a top plate of the fixed hook (11), and the lower edges of the outer side surfaces of the two elastic strips are respectively positioned on two outer vertical;

the passive finger component is formed by installing a passive finger (1) on a main fixing block (21) and an auxiliary fixing block (22), and has the following structure: the main fixing block (21) is a cuboid frame which is enclosed by a front main board, a left vertical board, a right vertical board and a bottom board and has an opening at the rear part and an opening at the top, fixing bulges (212) with fixing blocks (2121) at the left side and the right side are fixed on the upper surface of the bottom board of the main fixing block (21), a passive finger (1) is inserted from the opening at the rear part of the main fixing block (21) and a fixing hook (11) of the passive finger (1) is clamped and sleeved on the two fixing blocks (2121) to form a slide block matching relationship, the left outer vertical surface (113) and the right outer vertical surface (112) of the fixing hook (11) are respectively attached to the left inner vertical surface and the right inner vertical surface of the left vertical plate and the right vertical plate of the fixing block (21) and the upper surface of the bottom plate, the auxiliary fixing block (22) is formed by fixing an auxiliary fixing bulge (222) on the front side surface of the auxiliary fixing vertical plate (221), and the shape of the auxiliary fixing bulge (222) is symmetrical to that of a fixing bulge (212) of the main fixing block; two fixing bolts (31) penetrate through auxiliary fixing holes (2222) on the auxiliary fixing blocks (22) and then are screwed on threaded holes (2122) of the fixing bulges (212), so that auxiliary fixing vertical plates (221) of the auxiliary fixing blocks (22) are fixed on rear openings of the main fixing blocks (21), fixing hooks (11) of passive fingers (1) are clamped and sleeved on the two auxiliary fixing blocks (2221) of the auxiliary fixing blocks (22) to form a sliding fit relation, and mounting lugs (213) and auxiliary mounting lugs (223) which are symmetrical in shape and flush with the bottom surface of a bottom plate of the main fixing block (21) are fixedly connected to the lower parts of the outer surfaces of front vertical plates of the main fixing block (21) and the lower parts of the rear side surfaces of the auxiliary fixing vertical plates (221) of the auxiliary fixing blocks (22) respectively;

the two passive finger assemblies are inserted into mounting holes of the mounting lug (213) and the auxiliary mounting lug (223) through mounting bolts (32) and then are screwed and fixed on a mounting screw hole (42) of one adjustable mounting plate (4), and the two adjustable mounting plates (4) are fixed on one sliding block (53) through four connecting bolts (33).

2. The double finger gripper according to claim 1, characterised in that the passive finger (1) is provided with a composite sleeve (15); the composite sleeve (15) is an outer layer (151) coated on the outer surfaces of the two elastic strips (12), and patterns for increasing friction are arranged on the outer layer (151); or the composite sleeve (15) is formed by integrating an outer layer (151) covering the outer surfaces of the two elastic strips and an inner layer (152) positioned between the two adjacent cross beams (13) and attached to the inner surfaces of the two elastic strips.

3. The double finger gripper according to claim 2, characterised in that the composite sleeve (15) is a silicone rubber composite sleeve; the elastic strip (12) is made of thermoplastic polyurethane.

4. The gripper according to claim 3, characterized in that the two elastic strips (12) are provided with a cutout (121).

5. The finger gripper according to any of claims 1 to 4, characterised in that said two elastic strips (12) are the two waists of an isosceles triangle; an inclined angle is formed between the inner surfaces of the bottom plates of the two main fixing blocks (21) in the two passive finger assemblies and the outer surface of the bottom plate positioned horizontally, so that two adjacent elastic strips (12) of the two passive fingers (1) are parallel and vertical.

6. A two-finger mechanical gripper for mounting a passive finger comprises a linear guide rail (52) mounted on a cylinder body (51) of a translation cylinder (5), two sliding blocks (53) positioned on the linear guide rail (52) and forming a sliding fit relation with the linear guide rail, wherein when one pneumatic connector (6) on the cylinder body (51) is ventilated, the two sliding blocks are separated, and when the other pneumatic connector on the cylinder body (51) is ventilated, the two sliding blocks are closed; the passive finger (1) is characterized in that: the two plate-type elastic strips (12) are distributed in an acute angle and are gathered together at the upper ends to form a fingertip (14), two ends of a plurality of crossbeams (13) are respectively connected between the two elastic strips through flexible hinges (133), the fixed hook (11) is a bent plate with symmetrical left and right parts, the left section of the fixed hook (11) is formed by connecting a right-to-left horizontal section, a vertical lower section and a left-to-right horizontal section end to end, the left-to-right horizontal section is smaller than the right-to-left horizontal section, the vertical lower section and the left-to-right horizontal section form a bent hook, the lower ends of the two elastic strips are fixed on a top plate of the fixed hook (11), and the lower edges of the outer side surfaces of the two elastic strips are respectively positioned on two outer vertical;

the passive finger component is formed by installing and fixing a passive finger (1) on a main fixing block (21) and two auxiliary fixing pieces (22'), and has the following structure: the cross section of the main fixed block (21) is in a right trapezoid shape, the bottom of the main fixed block is provided with a transverse groove, two sides of the top of the main fixed block extend upwards to form a left vertical plate (211) and a right vertical plate (211), the middle of the main fixed block extends upwards to form a clamping plate (212 ') protruding towards the left and the right, and a left longitudinal notch (2111) and a right longitudinal notch (2111) are formed, a fixed hook (11) of a passive finger is sleeved into the two clamping plates (212 ') along the longitudinal notches (2111), the fixed hook and all adjacent surfaces of the main fixed block (21) form a sliding fit relation, and two auxiliary fixed plates (22 ') are screwed and fixed on threaded holes (2122) of front vertical surfaces; the transverse grooves of the two passive finger assemblies are respectively clamped and sleeved on the convex edges of one adjustable mounting plate (4) and are fixed by four bolts (32), and the two adjustable mounting plates (4) are respectively fixed on the sliding block (53) through the other four connecting bolts (33).

7. The double finger gripper according to claim 6, characterised in that the passive finger (1) is provided with a composite sleeve (15); the composite sleeve (15) is an outer layer (151) coated on the outer surfaces of the two elastic strips (12), and patterns for increasing friction are arranged on the outer layer (151); or the composite sleeve (15) is formed by integrating an outer layer (151) covering the outer surfaces of the two elastic strips and an inner layer (152) positioned between the two adjacent cross beams (13) and attached to the inner surfaces of the two elastic strips.

8. The double finger gripper according to claim 7, characterised in that the composite sleeve (15) is a silicone rubber composite sleeve; the elastic strip (12) is made of thermoplastic polyurethane.

9. The gripper according to claim 8, characterized in that the two elastic strips (12) are provided with a cutout (121).

10. The gripper according to claim 9, characterized in that the top plate of the middle clamping plate (212') of the two main fixing blocks (21) of the two passive finger assemblies has an angle with the horizontal bottom surface of the main fixing block, so that the two adjacent elastic strips of the two passive fingers (1) are parallel and vertical.