A flexible claw device with adjustable grasping range

Abstract

The present invention discloses a flexible claw device with adjustable grasping range, comprising a shell, a flexible claw unit and a connecting rod; a driving motor is installed on the shell, and a screw transmission mechanism is installed in the shell; the driving motor is connected to the screw transmission mechanism in transmission; the flexible claw unit comprises a claw block; the claw block is installed in the flexible claw unit with a deformable protrusion material and installation method; the flexible claw unit is connected to the outer side surface of the shell in a slidable and translational manner; one end of the connecting rod is rotationally connected to the screw transmission mechanism, and the other end of the connecting rod extends out of the shell and is rotationally connected to the flexible claw unit; the screw transmission mechanism is used to control the contraction or opening of the flexible claw unit; so when it is used, the range of opening and contraction can be controlled by converting the vertical upward movement of the screw nut into the translational movement of the flexible claw unit; the claw block installation method realizes adaptive deformation when grasping objects.

Description

Technical Field

[0001] The invention relates to the field of robots, and in particular to a flexible claw device with adjustable grasping range. Background Art

[0002] As the end effector for the robot to interact with the external environment, the robotic gripper plays an irreplaceable role. The evaluation of a robot's flexibility and practicality depends largely on the performance of its end effector. In recent years, with the development of soft robotics, flexible grippers can adapt well to and complete delicate operations with their soft grasping effect, and have a high degree of freedom of operation space. The overall grasping effect is very flexible, making it a hot research direction in current soft robots. There are many research directions and methods for flexible grippers, among which passive contact flexible grippers have been widely studied since a long time ago.

[0003] Passive contact flexible claws adaptively change their own deformation when contacting an object, thereby forming an enveloping and closing clamping effect on the grasped object. Compared with other active grasping methods, this type of flexible claw has lower power consumption and a wider and more flexible control method.

[0004] There are several key requirements for the design of passive contact flexible claws:

[0005] The design of the flexible claw needs to achieve the effect of easy deformation, and can achieve the effect of adaptive deformation when contacting and grasping objects, so as to face objects with any complex structure. It is necessary to ensure a certain rigidity, and the grasping force is also required to be appropriate, not too large to cause damage to the object. The entire grasping process of the flexible claw should be controllable, which is generally achieved by adding an external driver for control.

[0006] Therefore, there is an urgent need for a technical solution that can improve the flexibility of existing passive contact flexible claws. Summary of the invention

[0007] The object of the present invention is to provide a flexible claw device with an adjustable grasping range to solve the problem of insufficient flexibility of existing passive contact flexible claws.

[0008] In order to solve the above technical problems, the present invention provides a flexible claw device with an adjustable grasping range, comprising a shell, a flexible claw unit and a connecting rod; a driving motor is installed on the shell, and a screw transmission mechanism is installed in the shell; the driving motor is transmission-connected to the screw transmission mechanism; the flexible claw unit comprises a claw block; the claw block is installed in the flexible claw unit with a deformable protrusion material and installation method; the flexible claw unit is connected to the outer side surface of the shell in a slidable and translational manner; one end of the connecting rod is rotationally connected to the screw transmission mechanism, and the other end of the connecting rod extends out of the shell and is rotationally connected to the flexible claw unit; the screw transmission mechanism is used to control the contraction or opening of the flexible claw unit.

[0009] In one of the embodiments, the outer side surface of the shell is provided with a plurality of notches and a plurality of sliding rods; the connecting rod is in the same orientation as the notches and the sliding rods; the sliding rod is arranged at one end adjacent to the notches; the sliding rod is fixedly connected to the outer side surface of the shell, and the sliding rod is slidably connected to the flexible claw unit.

[0010] In one embodiment, the shell is cylindrical; through holes are provided at both ends of the shell; the drive motor is connected and fixed to one end surface of the shell; the rotating shaft of the drive motor passes through the through hole and is transmission-connected to the screw transmission mechanism.

[0011] In one embodiment, the plurality of notches are evenly arranged at 120 degrees from each other along the outer side surface of the shell; and the plurality of sliding bars are evenly arranged at 120 degrees from each other along the outer side surface of the shell.

[0012] In one of the embodiments, the screw transmission mechanism includes a transmission screw, a transmission nut and a fixed plate; the transmission screw is transmission-connected to the drive motor, and the transmission nut is threadedly connected to the transmission screw; a flange is provided at one end of the transmission nut; a sleeve hole is provided on the fixed plate; the sleeve hole is sleeved on the outer side of the transmission nut, and one side of the fixed plate is connected and fixed to one side of the flange; a connecting cross bar is provided on the other side of the fixed plate; the connecting cross bar is rotationally connected to the connecting rod; guide holes are provided on both the flange and the fixed plate; a limit column is provided in the shell along the axial direction of the transmission screw, and the guide hole is slidably connected to the limit column.

[0013] In one embodiment, the flexible claw unit includes a claw sleeve; a sleeve is provided on one side of the claw sleeve, the sleeve is connected and fixed to the claw sleeve, and the axial direction of the sleeve is perpendicular to the length direction of the claw sleeve; the sleeve is slidably sleeved on the sliding rod; a connecting rod is provided on the outer side of the sleeve, the connecting rod is perpendicular to the axis of the sleeve, and the connecting rod is rotatably connected to the connecting rod; two oppositely arranged splints are provided on the other side of the claw sleeve, the claw block is embedded in the two splints, and the claw block is connected and fixed to the two splints.

[0014] In one embodiment, the flexible claw unit also includes a connecting shaft; two claw through holes are provided at one end of the clamping plate, and the two claw through holes are arranged side by side, and the line connecting the two claw through holes is perpendicular to the length direction of the clamping plate; a claw through hole is provided at the other end of the clamping plate; three claw through holes are also provided on the claw block in the same manner as the clamping plate; the connecting shaft is inserted into the claw through holes of the clamping plate and the claw block, the connecting shaft is rotatably connected to the claw through holes, and the claw block is movably mounted on the clamping plate on opposite sides of the clamping plate; the material of the claw block is thermoplastic polyurethane elastic rubber.

[0015] In one of the embodiments, the clamping surface of the claw block is provided with a continuous wedge, and the large end of the wedge is connected and fixed to the clamping surface.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. The uniqueness of the flexible claw unit lies in that the clamping plate and the claw block are connected by three clamping holes, so that one end of the claw block is kept fixed and the other end can rotate around the clamping hole; the material of the claw block makes the claw block bend outward from between the two clamping plates when subjected to force, instead of moving outward at an angle; the design of the clamping plate makes it possible for the flexible claw unit to adapt to the outer contour of the object being grasped through the bending of the claw block when grasping the object, and to maintain its rigidity when grasping the object through the clamping plate.

[0018] 2. The range of opening and contraction can be controlled by converting the vertical upward movement of the transmission screw and the transmission nut into a translational movement of the flexible claw unit.

[0019] 3. The clamping surface of the claw block is provided with a continuous wedge. This design enables the claw block to bend the continuous wedge as a whole by applying a very small load at the tip of the wedge when grasping an object, thereby realizing passive bending of the flexible clamping claw unit, better adapting to the contour of the grasped object, and realizing more flexible passive grasping.

[0020] 4. The characteristic of the entire flexible claw device is to use a rigid claw sleeve to drive the movement of the flexible claw block and limit the freedom of the claw block to achieve a smoother and ideal bending, ultimately achieving an effect of promoting flexibility with rigidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of a partially cutaway shell of the present invention;

[0024] Figure 3 It is an exploded view of the assembly of the transmission nut and the fixing plate of the present invention;

[0025] Figure 4 It is a schematic assembly diagram of the screw transmission mechanism of the present invention;

[0026] Figure 5 It is an exploded view of the assembly of the flexible claw unit of the present invention.

[0027] The reference numerals are as follows:

[0028] 1. Housing; 11. Driving motor; 12. Notch; 13. Sliding rod; 14. Through hole; 15. Limiting column;

[0029] 2. Flexible claw unit; 21. Claw sleeve; 211. Sleeve; 212. Connecting rod; 22. Claw block; 221. Wedge; 23. Clamping plate; 24. Claw through hole; 25. Connecting shaft;

[0030] 3. Connecting rod;

[0031] 4. Screw drive mechanism; 41. Drive screw; 42. Drive nut; 421. Flange; 43. Fixing plate; 431. Bushing hole; 432. Connecting cross bar; 44. Guide hole. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0033] An embodiment of the flexible claw device is as follows Figure 1 , Figure 4 and Figure 5As shown, it includes a shell 1, a flexible claw unit 2 and a connecting rod 3; a driving motor 11 is installed on the shell 1, and a screw transmission mechanism 4 is installed in the shell 1; the driving motor 11 is transmission-connected with the screw transmission mechanism 4; the flexible claw unit 2 includes a claw block 22; the claw block 22 is installed in the flexible claw unit 2 with a deformable protrusion material and installation method; the flexible claw unit 2 is connected to the outer side surface of the shell 1 in a slidable and translational manner; one end of the connecting rod 3 is rotationally connected to the screw transmission mechanism 4, and the other end of the connecting rod 3 extends out of the shell and is rotationally connected to the flexible claw unit 2; the screw transmission mechanism 4 is used to control the contraction or opening of the flexible claw unit 2.

[0034] Regarding the structure of the housing 1, this embodiment Figure 1 and Figure 2 As shown, the outer side surface of the shell 1 is provided with multiple notches 12 and multiple sliding rods 13; the connecting rod 3 is in the same direction as the notches 12 and the sliding rod 13; the sliding rod 13 is arranged at one end adjacent to the notch 12; the sliding rod 13 is fixedly connected to the outer side surface of the shell 1, and the sliding rod 13 is slidably connected to the flexible claw unit 2.

[0035] It should be noted that the slide bar 13 is arranged perpendicular to the outer side of the housing 1 , and the slide bar 13 and the notch 12 are oriented in the same direction.

[0036] Among them, Figure 1 and Figure 2 As shown, the housing 1 is cylindrical; both ends of the housing 1 are provided with through holes 14; the drive motor 11 is connected and fixed to one end surface of the housing 1; the rotating shaft of the drive motor 11 passes through the through hole 14 and is transmission-connected to the screw transmission mechanism 4.

[0037] It should be noted that the through holes 14 at both ends of the shell 1 are of different sizes. The through hole 14 at the end of the shell 1 connected to the drive motor 11 is smaller than the through hole 14 at the other end; the through hole 14 at the end of the shell 1 connected to the drive motor 11 is used for the driving motor 11 to pass through the shaft, while the through hole 14 at the end of the shell 1 opposite to the drive motor 11 is larger and is used to install the screw transmission mechanism 4.

[0038] Particularly, the plurality of notches 12 are evenly arranged at 120 degrees to each other along the outer side surface of the housing 1 ; and the plurality of slide bars 13 are evenly arranged at 120 degrees to each other along the outer side surface of the housing 1 .

[0039] When in use, there are three slots 12 and three slide bars 13, so that three flexible claw units 2 and connecting rods 3 can be installed; making the flexible claw device a three-finger structure; and being evenly arranged at 120 degrees apart, the three fingers can be better stressed when grasping objects; practice has proved that the symmetrical three-finger design has excellent robustness and reliability when grasping objects, and the three fingers can be translated by the transmission mechanism, and with the setting of the flexible claw unit 2, the effect of adaptive bending can be achieved, and objects of different sizes can be adaptively grasped.

[0040] Regarding the structure of the screw transmission mechanism 4, this embodiment Figures 1 to 4 As shown, the screw transmission mechanism 4 includes a transmission screw 41, a transmission nut 42 and a fixing plate 43; the transmission screw 41 is transmission-connected to the driving motor 11, and the transmission nut 42 is threadedly connected to the transmission screw 41; a flange 421 is provided at one end of the transmission nut 42; a sleeve hole 431 is provided on the fixing plate 43; the sleeve hole 431 is sleeved on the outer side of the transmission nut 42, and one side of the fixing plate 43 is connected and fixed to one side of the flange 421; a connecting cross bar 432 is provided on the other side of the fixing plate 43; the connecting cross bar 432 is rotationally connected to the connecting rod 3; guide holes 44 are provided on the flange 421 and the fixing plate 43; a limiting column 15 is provided in the housing 1 along the axial direction of the transmission screw 41, and the guide hole 44 is slidably connected to the limiting column 15.

[0041] During application, 1. the rotating shaft of the driving motor 11 is connected to the transmission screw 41 through a coupling.

[0042] 2. The limit column 15 is slidably connected with the guide hole 44 on the driving nut 42 and the fixing plate 43. The limit column 15 can limit the freedom of the driving nut 42, so that the driving nut 42 and the fixing plate 43 can only move along the axis of the screw. In addition to the guide hole 44, the driving nut 42 and the fixing plate 43 are also provided with screw holes for locking the driving nut 42 and the fixing plate 43. Figure 3 and Figure 4 As shown, the fixing plate 43 is installed on the flange 421 by the cooperation of the screws and the screw holes.

[0043] 3. The connecting cross bar 432 is suspended at the bottom of the fixed plate 43, and the two ends of the connecting rod 3 are rotatably connected with the connecting cross bar 432 and the connecting rod 212 described below, so that the linear motion of the transmission nut 42 and the fixed plate 43 can be converted into the swing of the connecting rod 3; because the sleeve 211 described below is slidably connected to the sliding rod 13, and the axis of the connecting rod 212 on the sleeve 211 is perpendicular to the length direction of the connecting rod 3, through the dual constraints of the sliding rod 13 and the connecting rod 3 on the flexible claw unit 2, the swing of the connecting rod 3 is converted into the translational motion of the flexible claw unit 2 on the sliding rod 13.

[0044] Regarding the structure of the flexible claw unit 2, this embodiment Figure 1 and Figure 5As shown, the flexible claw unit 2 includes a claw sleeve 21; a sleeve 211 is provided on one side of the claw sleeve 21, the sleeve 211 is connected and fixed to the claw sleeve 21, and the axial direction of the sleeve 211 is perpendicular to the length direction of the claw sleeve 21; the sleeve 211 is slidably sleeved on the sliding rod 13; a connecting rod 212 is provided on the outer side of the sleeve 211, the connecting rod 212 is perpendicular to the axis of the sleeve 211, and the connecting rod 212 is rotatably connected to the connecting rod 3; two oppositely arranged splints 23 are provided on the other side of the claw sleeve 21, the claw block 22 is embedded in the two splints 23, and the claw block 22 is connected and fixed to the two splints 23.

[0045] It should be noted that the axis of the connecting rod 212 is perpendicular to the axis of the sleeve 211 , and the axis of the connecting rod 212 is perpendicular to the length direction of the connecting rod 3 .

[0046] In particular, this embodiment Figure 5 As shown, the flexible claw unit 2 also includes a connecting shaft 25; two claw through holes 24 are provided at one end of the clamping plate 23, and the two claw through holes 24 are arranged side by side, and the line connecting the two claw through holes 24 is perpendicular to the length direction of the clamping plate 23; a claw through hole 24 is provided at the other end of the clamping plate 23; three claw through holes 24 are also provided on the claw block 22 in the same manner as the clamping plate 23; the connecting shaft 25 is inserted into the claw through holes 24 of the clamping plate 23 and the claw block 22, and the connecting shaft 25 is rotatably connected to the claw through holes 24, and the claw block 22 is movably mounted on the clamping plate 23 on both sides opposite to the clamping plate 23; the material of the claw block 22 is thermoplastic polyurethane elastic rubber.

[0047] When applying, Figure 5 As shown, the top of the claw block 22 and the top of the splint 23 are connected to two connecting shafts 25 through two clamping claw through holes 24, so that the top of the claw block 22 can be fixedly connected to the splint 23 and cannot rotate; and the bottom of the claw block 22 and the bottom of the splint 23 are connected to a connecting shaft 25 through a clamping claw through hole 24, so that the bottom of the claw block 22 can be rotatably connected to the connecting shaft 25, and the bottom of the claw block 22 is fixed to the bottom of the splint 23; when the claw block 22 is subjected to force, the bottom of the claw block 22 will rotate around the connecting shaft 25, so that the two ends of the claw block 22 bend outward from between the two splints 23 instead of moving outward obliquely; fully imitating the bending state of human fingers grasping objects, so that the flexible claw device is more flexible when grasping objects; combined with the design of the splint 23, when grasping an object, the flexible claw unit 2 can not only adapt to the outer contour of the grasped object through the bending of the claw block 22, but also maintain the rigidity when grasping the object through the splint 23.

[0048] Furthermore, in order to make the claw block 22 bear better force when it is passively deformed, this embodiment Figure 1 and Figure 5 As shown, the clamping surface of the claw block 22 is provided with a continuous wedge 221, and the large end of the wedge 221 is connected and fixed to the clamping surface.

[0049] During application, only a small load needs to be applied to the tip of the continuous wedge 221 to bend the continuous wedge 221, thereby bending the claw block 22, achieving passive bending of the flexible clamping claw unit and better adapting to the contour of the grasped object; bending can be achieved by only slightly contacting the object with the tip of the continuous wedge 221 on the claw block 22, thereby improving the flexibility of the flexible claw device and adaptively grasping some more delicate and fragile objects.

[0050] Analysis and comparison with the prior art: The prior art, for example, directly sets the clamping jaws to soft materials or elastic materials, or embeds elastic materials such as torsion springs in soft materials to increase the rigidity of the clamping jaws; while the prior art uses the above-mentioned setting method, the bending of the clamping jaws is fixed at one end and the other end moves outward, and the rigidity is relatively insufficient when grasping objects.

[0051] However, the claw block 22 of the flexible claw device is cleverly arranged when installed with the claw sleeve 21, so that the claw block 22 can be bent like an animal's finger. While adapting to the shape of the object, the bottom end of the claw block 22 can bend upward when the claw block 22 is bent, and can hold the bottom of the object, thereby improving the grasping stability; in combination with the splint 23, the arrangement can maintain sufficient rigidity during clamping; at the same time, the unique continuous wedge-shaped 221 design of the clamping surface of the claw block 22 further enhances the bending sensitivity of the claw block 22, thereby greatly improving the grasping flexibility of the flexible claw device.

[0052] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A flexible claw device with adjustable gripping range, characterized in that: It includes a housing, a flexible claw unit and a connecting rod; A driving motor is installed on the housing, and a screw transmission mechanism is installed in the housing; the driving motor is in transmission connection with the screw transmission mechanism; The flexible claw unit includes a claw block; the claw block is installed in the flexible claw unit with a deformable protrusion material and installation method; the flexible claw unit is connected to the outer side surface of the shell in a slidable and translational manner; One end of the connecting rod is rotatably connected to the screw transmission mechanism, and the other end of the connecting rod extends out of the housing and is rotatably connected to the flexible claw unit; The screw transmission mechanism is used to control the contraction or opening of the flexible claw unit; The outer side surface of the shell is provided with a plurality of notches and a plurality of slide bars; The connecting rod is in the same orientation as the notch and the sliding rod; The sliding rod is arranged at one end adjacent to the notch; the sliding rod is fixedly connected to the outer side surface of the shell, and the sliding rod is slidably connected to the flexible claw unit; The flexible claw unit includes a claw sleeve; A sleeve is provided on one side of the claw sleeve, the sleeve is connected and fixed to the claw sleeve, and the axial direction of the sleeve is perpendicular to the length direction of the claw sleeve; the sleeve is slidably sleeved on the sliding rod; A connecting rod is provided on the outer side of the sleeve, the connecting rod is perpendicular to the axis of the sleeve, and the connecting rod is rotatably connected to the connecting rod; The other side of the claw sleeve is provided with two clamping plates arranged opposite to each other, the claw block is embedded in the two clamping plates, and the claw block is connected and fixed to the two clamping plates; The flexible claw unit also includes a connecting shaft; One end of the clamping plate is provided with two clamping claw through holes, the two clamping claw through holes are arranged side by side, and the connecting line of the two clamping claw through holes is perpendicular to the length direction of the clamping plate; The other end of the clamping plate is provided with a clamping claw through hole; The claw block is also provided with three claw through holes in the same manner as the clamping plate; The connecting shaft is inserted into the clamping plate and the clamping jaw through hole of the claw block, the connecting shaft is rotatably connected to the clamping jaw through hole, and the two sides of the claw block opposite to the clamping plate are movably mounted to the clamping plate; The material of the claw block is thermoplastic polyurethane elastomer rubber; The clamping surface of the claw block is provided with a continuous wedge, and the large end of the wedge is connected and fixed to the clamping surface.

2. The flexible claw device according to claim 1, characterized in that: The housing is cylindrical; Both ends of the shell are provided with through holes; The driving motor is connected and fixed to one end surface of the housing; The rotating shaft of the driving motor passes through the through hole and is transmission-connected to the screw transmission mechanism.

3. The flexible claw device according to claim 2, characterized in that: The plurality of notches are evenly arranged at 120 degrees from each other along the outer side surface of the shell; The plurality of sliding bars are evenly arranged at 120 degrees from each other along the outer side surface of the shell.

4. The flexible claw device according to claim 3, characterized in that: The screw transmission mechanism comprises a transmission screw, a transmission nut and a fixing plate; The transmission screw is in transmission connection with the driving motor, and the transmission nut is in threaded connection with the transmission screw; One end of the transmission nut is provided with a flange; The fixing plate is provided with a sleeve hole; the sleeve hole is sleeved on the outer side of the transmission nut, and one side of the fixing plate is connected and fixed to one side of the flange; A connecting cross bar is provided on the other side of the fixing plate; the connecting cross bar is rotatably connected to the connecting rod; The flange and the fixing plate are both provided with guide holes; A limiting column is arranged in the housing along the axial direction of the transmission screw rod, and the guide hole is slidably connected to the limiting column.

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