Search

EP-4034351-B1 - GRASPING MECHANISM, ROBOT AND GRASPING DEVICE

EP4034351B1EP 4034351 B1EP4034351 B1EP 4034351B1EP-4034351-B1

Inventors

  • AN, Ran
  • WANG, SHIQUAN

Dates

Publication Date
20260513
Application Date
20191120

Claims (10)

  1. A grasping mechanism (50), comprising: a base (10); and at least two linkage grasping assemblies (20) configured to cooperate with each other to grasp an object (02), each of the at least two linkage grasping assemblies (20) comprising: a grasping member (210) comprising a grasping portion (212) and a connecting portion (214) connected to each other; a first rod (220) having a first end rotatably connected to the connecting portion (214) and a second end rotatably connected to the base (10), a connecting line between a rotation center of the first end of the first rod (220) and a rotation center of the second end of the first rod (220) defining a first connecting line (L1); and a second rod (240) having a first end rotatably connected to the connecting portion (214) and a second end rotatably connected to the base (10), a connecting line between a rotation center of the first end of the second rod (240) and a rotation center of the second end of the second rod (240) defining a second connecting line (L2), wherein a first end of the connecting portion (214) is rotatably connected to the first end of the first rod (220); wherein a second end of the connecting portion (214) is rotatably connected to the first end of the second rod (240) and is fixed to the grasping portion (212); and wherein the second rod (240) is switchable between a first state in which a length of the second rod (240) is kept constant and a second state in which the second rod (240) is bent and deformed in such a way that the length of the first connecting line (L1) is greater than the length of the second connecting line (L2); wherein the second rod (240) comprises a first finger root portion (242), an elastic portion (246), and a second finger root portion (244) successively connected; and the first finger root portion (242) is rotatably connected to the connection portion (214), the second finger root portion (244) is rotatably connected to the base (10), and the elastic portion (246) is bent and deformed in the second state.
  2. The grasping mechanism (50) of claim 1, wherein the elastic portion (246) is an elastic metal sheet.
  3. The grasping mechanism (50) of claim 1, further comprising a driving assembly (40), wherein: each of the linkage grasping assemblies (20) further comprises a connecting shaft (310) and a first bearing (320); the base (10) defines a first mounting hole, the first bearing (320) is mounted in the first mounting hole; the connecting shaft (310) is mounted on the first bearing (320) and sealingly fits with the first bearing (320); an end of the connecting shaft (310) extends out of the first mounting hole, the second end of the first rod (220) is fixed to the end of the connecting shaft (310); and the connecting shaft (310) is connected to the driving assembly (40), and the driving assembly (40) is configured to drive the connecting shaft (310) to rotate so as to drive the first rod (220) to rotate.
  4. The grasping mechanism (50) of claim 3, wherein: the first mounting hole comprises two sub-holes, the first bearing (320) comprises two sub-bearings mounted in the two sub-holes, respectively; and the connecting shaft (310) is mounted on the two sub-bearings, two ends of the connecting shaft (310) extend out of the two sub-holes, respectively, and the second end of the first rod (220) comprises two first mounting portions (222) fixed to the two ends of the connecting shaft (310), respectively.
  5. The grasping mechanism (50) of claim 3 wherein the connecting shaft (310) is connected to an inner ring of the first bearing (320) by interference fit, and an outer ring of the first bearing (320) is received in the first mounting hole by interference fit.
  6. The grasping mechanism (50) of claim 3, wherein: the driving assembly (40) comprises a power source (410), a screw rod (420), a nut (430), at least two first transmission rods (440), and at least two second transmission rods (450); the power source (410) is connected to the screw rod (420); the nut (430) is sleeved on the screw rod (420) and movable along the screw rod (420); the first transmission rod (440) has one end rotatably connected to the nut (430) and the other end rotatably connected to the second transmission rod (450); and the second transmission rod (450) is fixed to the connecting shaft (310).
  7. The grasping mechanism (50) of claim 3, wherein each of the linkage grasping assemblies (20) further comprises a rotary shaft (330) disposed on an outer wall of the base (10), the second end of the second rod (230) is rotatably connected to the rotary shaft (330).
  8. The grasping mechanism (50) of claim 1, wherein the grasping member (210) further comprises a contacting portion (216) connected to the grasping portion (212) and located on a side corresponding to a grasping surface of the grasping portion (212).
  9. The grasping mechanism (50) of claim 1, comprising two of the linkage grasping assemblies (20), wherein the two linkage grasping assemblies (20) are opposingly arranged, and the two second rods (230) are located on an inner side of the two linkage grasping assemblies (20).
  10. A robot comprising a body (60) and the grasping mechanism (50) according to any of preceding claims.

Description

TECHNICAL FIELD The present disclosure relates to a grasping mechanism, and a robot. BACKGROUND Generally, when a gripper is used to catch an object, a grasping portion is moved by a finger linkage of the gripper to come into contact with or separate from the object to be grasped. The finger linkage of the gripper is disposed in a parallelogram shape which is suitable for grasping the object that has a flat external surface. However, the conventional gripper cannot be ensured to firmly grasp the object that has a ball shape or other complex shape. US 2014/265401 A1 discloses a mechanical gripper adapted to automatically perform a stable pinch grasp and an encompassing grasp. The gripper comprising at least one mechanical finger comprising a first phalanx and a second phalanx that are pivotally connected. When a load is applied on a stable pinch grasp region, an actuation mechanism is adapted to allow the second phalanx to translate and allow its contact surface to maintain a constant orientation in order to automatically perform a pinch grasp. When a load is applied on the first phalanx or below the stable pinch grasp region, the actuation mechanism is adapted to allow the second phalanx to pivot and automatically perform an encompassing grasp. CN 110 216 703 A discloses a multi-mode robot dexterous hand comprising a palm, a first finger, a second finger and a third finger, wherein a main body structure of the palm comprises a pair of shared drive double-slider mechanisms, and the fingers comprise a parallel five-bar RR-RRR finger, a parallel five-bar RR-RPR finger and a parallel five-bar RR-PRR finger. WO 2019/140931 A discloses a self-adaptive underactuated robot clamping claw comprising a clamping claw shell, a drive module, and finger modules. The finger modules comprise a first finger module and a second finger module, the first finger module and the second finger module each being provided with a first finger section and a second finger section. The first finger section and the second finger section are hinged to a drive rod via a self-adaptive linkage and a parallel linkage, and are driven to move by the drive rod. The document CN 107 214 721 B discloses a parallel self-adaptive grasping robot dexterous hand. SUMMARY The invention is defined in claim 1 and dependent claims, and in claim 10. One or more embodiments are described further below by way of the drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a grasping mechanism not according to the invention that is useful for understanding the invention;FIG. 2 is a schematic view of a grasping mechanism not according to the invention with grasping portions being in a first position;FIG. 3 is a schematic view of the grasping mechanism shown in FIG. 2 with the grasping portions being in a second position;FIG. 4 is a schematic view of a grasping mechanism in a second state according to another or more embodiments;FIG. 5 is a schematic view of a grasping mechanism in a first state according to another or more embodiments;FIG. 6 is a schematic plan view of a grasping mechanism according to one or more embodiments;FIG. 7 is a schematic cross-sectional view taken along line E-E in FIG. 6;FIG. 8 is a schematic view of a driving assembly of a grasping mechanism according to one or more embodiments;FIG. 9 is a schematic view of a grasping mechanism not according to the invention;FIG. 10 is a schematic view of a grasping mechanism not according to the invention;FIG. 11 is a schematic view of a robot according to one or more embodiments;FIG. 12 is a schematic view of a grasping device according to one or more embodiments. Reference numerals: 02, object; 04, object;10, base;20, linkage grasping assembly; 210, grasping member; 212, grasping portion; 214, connecting portion; 216, contacting portion; 220, first rod; 222, first mounting portion; 224, third mounting portion; 230, second rod; 232, second mounting portion; 234, fourth mounting portion; 236, positioning projection; 238, positioning groove; 240, second rod; 242, first finger root portion; 244, second finger root portion; 246, elastic portion; 310, connecting shaft; 320, first bearing; 330, rotary shaft;40, driving assembly; 410, power source; 420, screw rod; 430, nut; 440, first transmission rod; 450, second transmission rod;50, grasping mechanism; 60, body; 70, mounting base. For a better description and illustration of the embodiments and/or examples of the inventions disclosed herein, reference may be made to one or more of the accompanying drawings. Additional details or examples used to describe the accompanying drawings should not be considered as limiting the scope of any of the disclosed inventions, the presently described embodiments and/or examples, and the optimal patterns of these inventions that are presently understood. DETAILED DESCRIPTION OF THE EMBODIMENTS Embodiments of the invention are described more fully hereinafter with refe