Dexterous hand with high clamping capacity and robot

Abstract

The invention relates to the technical field of robots, in particular to a high-clamping-capacity dexterous hand which comprises a dexterous hand body, and the dexterous hand body comprises an outer restraining part, an inner restraining part, a clamping part and a driving part; the inner restraining part is arranged in the outer restraining part, the outer restraining part can move front and back in the direction of the inner restraining part, and the inner restraining part is used for restraining the clamping part; the clamping part is restrained by the outer restraining part and the inner restraining part, and the clamping part can clamp an object; the driving part is arranged on the inner restraining part and provides power for the clamping part, the outer restraining part is arranged on the dexterous hand body and can move front and back in the direction of the inner restraining part, the driving part drives the clamping part to move backwards and the outer restraining part to move forwards at the same time, and the overall clamping capacity is improved.

Description

Technical Field

[0001] The invention relates to the technical field of robots, and in particular to a dexterous hand and a robot with high clamping capability. Background Art

[0002] In some robot usage scenarios, the robot will use its working parts to clamp and pick up objects. Most of these working parts are flexible dexterous hands with elastic steel sheets as the main body. They are mostly configured with four elastic steel sheets, of which an inner elastic steel sheet and an outer elastic steel sheet constitute a finger. A rough object (such as a rubber pad) may be installed at the end of each finger to assist the dexterous hand in clamping objects, and the two fingers are symmetrical about the central axis of the dexterous hand.

[0003] For example, a Chinese patent with announcement number CN108214534B discloses an adaptive under-actuated robot gripper, and in a dexterous hand made of a part of elastic steel sheets, when the dexterous hand needs to perform a gripping task, the operator uses a rope or other driving method to pull the two inner elastic steel sheets toward the operator, and a pulling force is generated in the inner elastic steel sheets. At this time, the outer elastic steel sheet is compressed, and a force is also generated on the inner elastic steel sheet. The direction of this force forms an obtuse angle with the direction of the pulling force in the inner elastic steel sheet. After vector addition, a component force called the clamping force is obtained, and this component force just makes the two fingers move toward each other, thereby achieving gripping.

[0004] However, in actual work, when the two fingers are about to close, the angle of the forces in the inner and outer elastic steel sheets will tend to 180°, causing the clamping force to decrease rapidly as the two fingers close together, which is not conducive to the dexterous hand to grasp small and heavy objects. The opening angle of the dexterous hand is limited, and when the length of the dexterous hand is limited, it is not conducive to it to grasp large objects. Summary of the invention

[0005] In view of the above problems, the present invention provides a dexterous hand and a robot with high gripping ability.

[0006] The adopted technical solution is: a dexterous hand with high gripping ability, comprising a dexterous hand body, wherein the dexterous hand body comprises an external constraint part, an internal constraint part, a gripping part and a driving part; The inner restraining part is arranged inside the outer restraining part, and the outer restraining part can move forward and backward along the direction of the inner restraining part, and the inner restraining part is used to restrain the clamping part; The clamping portion is constrained by both the outer constraining portion and the inner constraining portion, and the clamping portion can clamp an article; The driving part is arranged on the inner restraining part, and the driving part provides power to the clamping part.

[0007] Optionally, the clamping portion includes symmetrically arranged dexterous hand mechanisms, and two of the dexterous hand mechanisms are connected by an elastic steel sheet connector.

[0008] Optionally, the dexterous hand mechanism includes an outer elastic steel sheet and an inner elastic steel sheet, and one end of the outer elastic steel sheet is connected to one end of the inner elastic steel sheet, and a finger structure is provided at the connection, and the other ends of the inner elastic steel sheets in the two dexterous hand mechanisms are connected to the elastic steel sheet connecting piece.

[0009] Optionally, the external constraint part includes a sleeve, in which a first through groove is provided, the internal constraint part and the external elastic steel sheet can be inserted into the first through groove, and the external elastic steel sheet can contact the opening of the first through groove and apply pressure outward to the opening of the first through groove.

[0010] Optionally, the inner restraint portion includes a base, in which a second through-groove is provided, and the inner elastic steel sheet and the connector connected to the elastic steel sheet can be inserted into the second through-groove.

[0011] Optionally, the other end of the outer elastic steel sheet is bent into a horizontal section and connected to the outer wall of the base through the horizontal section.

[0012] Optionally, the driving unit includes a steering gear, a rotating shaft, a pull rope and a gear; The steering gear is arranged below the base, and the power output end of the steering gear is connected to the rotating shaft; The rotating shaft passes through the base and is connected to the gear located above the base, and the rotating shaft can drive the gear to rotate; One end of the pull rope is wound around the shaft body of the rotating shaft, and the other end of the pull rope is connected to the elastic steel sheet connecting piece.

[0013] Optionally, a driving rack is also provided on the base, and the driving rack can mesh with the gear. A first fixing hole is provided on the upper part of the sleeve, and the driving rack is connected to the sleeve via a bolt passing through the first fixing hole.

[0014] Optionally, a guide groove and a guide block are further provided on the base, one end of the guide block is inserted into the guide groove, and the other end of the guide block is connected to a second fixing hole provided on the side of the sleeve through a bolt; The guide groove and the guide block are far away from the dexterous hand mechanism, and the guide groove is a straight line and parallel to the long side of the base.

[0015] Optionally, the finger structure includes a finger support and a finger, the finger support is arranged at the connection between the outer elastic steel sheet and the inner elastic steel sheet, and the fingers on the two dexterous hand mechanisms are arranged opposite to each other; The finger support is provided with a mounting groove and a rotating shaft, the protruding end of the finger is inserted into the mounting groove and connected to the rotating shaft, and the finger can rotate 15° to 20° on the rotating shaft.

[0016] The present application also provides a robot that uses the above dexterous hand with high gripping ability.

[0017] The benefits of the present invention include: 1. An external constraint part is set on the dexterous hand body, and the external constraint part can move forward and backward along the direction of the internal constraint part, and the driving part can simultaneously drive the clamping part to move backward and the external constraint part to move forward, thereby improving the overall clamping ability.

[0018] 2. The driving unit uses a pull rope and a gear rack mechanism to drive the dexterous hand mechanism and the sleeve respectively, which can achieve the movement of the two components simultaneously using only one rotating shaft, maintaining the singleness of the driver, making the driving unit structure simple and cost-controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an axonometric view of a high-gripping-capacity dexterous hand in a clamping state; Figure 2 Axonometric view of a dexterous hand with high gripping ability in a relaxed state; Figure 3 De-sleeve isometric view for the relaxed state; Figure 4 Remove the sleeve and base axonometric view for the relaxed state; Figure 5 This is the axonometric view of the drive unit; Figure 6 This is a comparison chart of clamping and relaxation; Figure 7 It is the force analysis diagram; Figure 8 Schematic diagram of finger structure; Fig. 9 for Figure 8 Schematic diagram of the cross section along AA.

[0020] The figure marks are as follows: 1 is an outer elastic steel sheet, 1a is a clamping outer elastic steel sheet, 2 is an inner elastic steel sheet, 2a is a clamping inner elastic steel sheet, 3 is an elastic steel sheet connector, 4 is a pull rope, 5 is a rotating shaft, 6 is a finger support, 7 is a finger, 9 is a driving rack, 10 is a guide block, 11 is a base, 12 is a sleeve, 13 is a first fixing hole, 14 is a second fixing hole, 15 is a gear, 16 is a horizontal section, 17 is a guide groove, 18 is a mounting groove, and 20 is a servo. DETAILED DESCRIPTION

[0021] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0022] It should be noted that the illustrations provided in the following embodiments are only used to schematically illustrate the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0023] like Figure 1 and Figure 2 As shown, a dexterous hand with high gripping ability comprises a dexterous hand body, wherein the dexterous hand body comprises an outer constraint part, an inner constraint part, a gripping part and a driving part; The inner restraining part is arranged inside the outer restraining part, and the outer restraining part can move forward and backward along the direction of the inner restraining part, and the inner restraining part is used to restrain the clamping part; The clamping portion is constrained by both the outer constraining portion and the inner constraining portion, and the clamping portion can clamp an article; The driving part is arranged on the inner restraining part, and the driving part provides power to the clamping part.

[0024] The purpose of this design is to set an external constraint part on the dexterous hand body, which can move forward and backward along the direction of the internal constraint part, and simultaneously drive the clamping part to move backward and the external constraint part to move forward through the driving part, thereby improving the overall clamping ability.

[0025] In this embodiment, a specific structure of a clamping portion is provided, such as Figure 3 and Figure 4 As shown, the clamping part includes a symmetrically arranged dexterous hand mechanism, and the two dexterous hand mechanisms are connected by an elastic steel sheet connector 3. The dexterous hand mechanism includes an outer elastic steel sheet 1 and an inner elastic steel sheet 2, and one end of the outer elastic steel sheet 1 is connected to one end of the inner elastic steel sheet 2, and a finger structure is arranged at the connection, and the other ends of the inner elastic steel sheets 2 in the two dexterous hand mechanisms are connected to the elastic steel sheet connector 3.

[0026] At the same time, this embodiment also provides a specific structure of an external constraint part, wherein the external constraint part includes a sleeve 12, and a first through groove is provided in the sleeve 12, the internal constraint part and the external elastic steel sheet 1 can be inserted into the first through groove, and the external elastic steel sheet 1 can contact the opening of the first through groove and apply pressure outward to the opening of the first through groove.

[0027] Furthermore, the present embodiment also provides a specific structure of an internal constraint portion, wherein the internal constraint portion includes a base 11, wherein the base 11 is provided with a second through groove, and the internal elastic steel sheet 2 and the elastic steel sheet connector 3 can be inserted into the second through groove.

[0028] At the same time, the other end of the outer elastic steel sheet 1 is bent into a horizontal section 16 , and is connected to the outer wall of the base 11 through the horizontal section 16 .

[0029] like Figure 5 As shown, this embodiment provides a specific structure of a driving unit, wherein the driving unit includes a steering gear 20, a rotating shaft 5, a pull rope 4 and a gear 15; The steering gear 20 is disposed below the base 11, and the power output end of the steering gear 20 is connected to the rotating shaft 5; The rotating shaft 5 passes through the base 11 and is connected to the gear 15 located above the base 11. The rotating shaft 5 can drive the gear 15 to rotate; One end of the pull rope 4 is wound around the shaft of the rotating shaft 5 , and the other end of the pull rope 4 is connected to the elastic steel sheet connector 3 .

[0030] In addition, a driving rack 9 is also provided on the base 11 , and the driving rack 9 can mesh with the gear 15 . A first fixing hole 13 is provided on the upper portion of the sleeve 12 , and the driving rack 9 is connected to the sleeve 12 via a bolt passing through the first fixing hole 13 .

[0031] The purpose of this design is that the driving part uses a pull rope and a gear rack mechanism to drive the dexterous hand mechanism and the sleeve respectively, which can achieve the movement of two components simultaneously using only one rotating shaft, maintaining the singleness of the driver, making the driving part structure simple and cost-controllable.

[0032] The whole dexterous hand works as follows: Figure 2 In the relaxed state, the servo starts to work, causing the shaft to rotate. On the one hand, the shaft pulls the pull rope, so that the pull rope drives the elastic steel sheet connector to move toward the shaft. At this time, the inner elastic steel sheet bends inward, thereby driving the outer elastic steel sheet to deform and bulge. At the same time, the finger structures at the connection between the inner elastic steel sheet and the outer elastic steel sheet in the two dexterous hand mechanisms move toward each other to complete the clamping. On the other hand, the rotation drives the gear located above the base to rotate, and because the driving rack is meshed with it, the driving rack is connected to the sleeve through bolts, so that the gear drives the sleeve The inner elastic steel sheet moves in a direction opposite to the direction of movement of the inner elastic steel sheet. Without adding additional drive, a force is added to increase the clamping force when clamping small-sized objects. Since the force and the force of the elastic steel sheet are derived from the same drive, the force needs to meet the following conditions: when the two fingers are about to close, the force uses a certain amount of driving torque, and the gain in clamping force is significantly greater than the gain in clamping force of the elastic steel sheet. At the same time, in the design, the outer elastic steel sheet can be pressed to bulge outward, and the sleeve just moves to contact the bulging part of the outer elastic steel sheet. As the sleeve continues to move forward and the outer elastic steel sheet continues to bulge outward, the sleeve begins to apply pressure to the outer elastic steel sheet, and the pressure will produce a significant gain in clamping force, thereby improving the ability of the dexterous hand to clamp small objects or objects that are difficult to clamp.

[0033] To verify this, Figure 7As shown in the figure, the stress analysis of the whole process is carried out. The symbols with "'" in the figure belong to the stress analysis of the pull rope-inner elastic steel sheet structure, and the symbols without "'" belong to the stress analysis of the sleeve-outer elastic steel sheet.

[0034] From the force analysis results of the pull rope-internal elastic steel sheet structure in the figure, it can be seen that when the dexterous hand is about to close, the pull rope-internal elastic steel sheet structure exerts a clamping force F 夹 ''s contribution is very small, less than 0.15 times the tension in the internal elastic steel sheet, that is, less than 0.075 times the tension in the pull rope.

[0035] Then the force analysis of the sleeve-external elastic steel sheet structure was carried out by force decomposition and moment balance. The results showed that the clamping force F 夹 The contribution is about 1.2 times the vertical component of the sleeve on the single-sided external elastic steel sheet, which is 0.6 times the driving force of the gear rack on the sleeve.

[0036] It can be seen that when the dexterous hand is about to close, the contribution of the sleeve to the clamping force can be dozens of times that of the pull rope-internal elastic steel sheet structure. Therefore, the sleeve structure effectively improves the clamping force of the dexterous hand when clamping small objects.

[0037] In addition, by increasing the stiffness of the outer elastic steel sheet and reducing the stroke of the sleeve, that is, increasing the reduction ratio, it is possible to further increase the clamping force when clamping small-sized objects by increasing the driving force of the motor on the sleeve.

[0038] At the same time, the drive unit can realize automatic distribution of the motor torque. When the sleeve contacts the outer spring steel sheet and begins to apply pressure, most of the motor torque will be used to provide power to the sleeve due to the rapid increase in the resistance to sleeve movement. This principle enables the motor torque to automatically flow to the part that is most conducive to increasing the clamping force.

[0039] In this embodiment, the base 11 is further provided with a guide groove 17 and a guide block 10, one end of the guide block 10 is inserted into the guide groove 17, and the other end of the guide block 10 is connected to the second fixing hole 14 provided on the side of the sleeve 12 by a bolt; The guide groove 17 and the guide block 10 are far away from the dexterous hand mechanism, and the guide groove 17 is a straight line and parallel to the long side of the base 11 .

[0040] The purpose of such design is to ensure that the sleeve moves linearly along the axis of the base through the cooperation of the guide groove and the guide block.

[0041] And in Figure 6 In the figure, it can be clearly seen that from the natural relaxation state to the fully clamped state, the difference between the outer elastic steel sheet 1 and the inner elastic steel sheet 2 and the clamped outer elastic steel sheet 1a and the clamped inner elastic steel sheet 2a, the fingertip structure will rotate about 60°.

[0042] like Figures 8 to 9 As shown, the finger structure includes a finger support 6 and a finger 7, wherein the finger support 6 is arranged at the connection between the outer elastic steel sheet 1 and the inner elastic steel sheet 2, and the fingers 7 on the two dexterous hand mechanisms are arranged opposite to each other; The finger support 6 is provided with a mounting groove 18 and a rotation axis. The protruding end of the finger 7 is inserted into the mounting groove 18 and connected to the rotation axis. The finger 7 can rotate 15° to 20° on the rotation axis.

[0043] In actual use, the single-sided rubber pad structure of the fingertip can be changed to two surfaces, with an angle of 45° between the two surfaces. The two clamping contact surfaces at a 45° angle and the small-range free rotation structure together ensure that the fingertips of the dexterous hand can clamp objects with parallel or approximately parallel contact surfaces throughout the entire stroke. Then, a rotating shaft is installed between the rubber pad and the steel sheet, and 15° to 20° of movable space is reserved for the fingertips of the rubber pad to ensure that there is a group of surfaces that remain parallel or approximately parallel throughout the entire stroke of the dexterous hand. At the same time, this design takes into account the stability and clamping ability of the fingertips during clamping. The mobility of the fingertips around the rotation axis will damage the clamping stability, but the influence of the movable space of only 10° on the stability is negligible. The mobility around the rotation axis and the two-sided design at a 30° angle ensure the parallelism of the fingertips, thereby ensuring the clamping ability of the dexterous hand.

[0044] It should be pointed out that the dexterous hand described in this embodiment is actually a clamping claw structure.

[0045] In this embodiment, a robot is also provided, which structurally uses the dexterous hand with high gripping ability in the above embodiments.

[0046] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A dexterous hand with high gripping ability, comprising a dexterous hand body, characterized in that: The dexterous hand body comprises an external constraint part, an internal constraint part, a clamping part and a driving part; The inner restraining part is arranged inside the outer restraining part, and the outer restraining part can move forward and backward along the direction of the inner restraining part, and the inner restraining part is used to restrain the clamping part; The clamping portion is constrained by both the outer constraining portion and the inner constraining portion, and the clamping portion can clamp an article; The driving part is arranged on the inner restraining part, and the driving part provides power to the clamping part.

2. A dexterous hand with high gripping ability according to claim 1, characterized in that: The clamping portion comprises symmetrically arranged dexterous hand mechanisms, and two of the dexterous hand mechanisms are connected via an elastic steel sheet connecting piece (3).

3. A dexterous hand with high gripping ability according to claim 2, characterized in that: The dexterous hand mechanism comprises an outer elastic steel sheet (1) and an inner elastic steel sheet (2), wherein one end of the outer elastic steel sheet (1) is connected to one end of the inner elastic steel sheet (2), and a finger structure is provided at the connection point, and the other ends of the inner elastic steel sheets (2) in the two dexterous hand mechanisms are connected to the elastic steel sheet connecting piece (3).

4. A dexterous hand with high gripping ability according to claim 3, characterized in that: The outer constraint portion comprises a sleeve (12), a first through-groove being provided in the sleeve (12), the inner constraint portion and the outer elastic steel sheet (1) being capable of being inserted into the first through-groove, and the outer elastic steel sheet (1) being capable of being in contact with an opening of the first through-groove and applying pressure outwards to the opening of the first through-groove; The inner restraining portion comprises a base (11), the base (11) being provided with a second through slot, and the inner elastic steel sheet (2) and the connecting piece (3) to the elastic steel sheet can both be inserted into the second through slot.

5. A dexterous hand with high gripping ability according to claim 4, characterized in that: The other end of the outer elastic steel sheet (1) is bent into a horizontal section (16), and is connected to the outer wall of the base (11) via the horizontal section (16).

6. A dexterous hand with high gripping ability according to claim 4, characterized in that: The driving unit comprises a steering gear (20), a rotating shaft (5), a pull rope (4) and a gear (15); The steering gear (20) is arranged below the base (11), and the power output end of the steering gear (20) is connected to the rotating shaft (5); The rotating shaft (5) passes through the base (11) and is connected to a gear (15) located above the base (11), and the rotating shaft (5) can drive the gear (15) to rotate; One end of the pull rope (4) is wound around the shaft of the rotating shaft (5), and the other end of the pull rope (4) is connected to the elastic steel sheet connector (3).

7. A dexterous hand with high gripping ability according to claim 6, characterized in that: A driving rack (9) is also provided on the base (11), and the driving rack (9) can mesh with the gear (15); a first fixing hole (13) is provided on the upper portion of the sleeve (12), and the driving rack (9) is connected to the sleeve (12) via a bolt passing through the first fixing hole (13).

8. The dexterous hand with high gripping ability according to claim 4, characterized in that: The base (11) is also provided with a guide groove (17) and a guide block (10), one end of the guide block (10) is inserted into the guide groove (17), and the other end of the guide block (10) is connected to a second fixing hole (14) provided on the side of the sleeve (12) via a bolt; The guide groove (17) and the guide block (10) are far away from the dexterous hand mechanism, and the guide groove (17) is a straight line and parallel to the long side of the base (11).

9. The dexterous hand with high gripping ability according to claim 3, characterized in that: The finger structure comprises a finger support (6) and a finger (7), wherein the finger support (6) is arranged at the connection between the outer elastic steel sheet (1) and the inner elastic steel sheet (2), and the fingers (7) on the two dexterous hand mechanisms are arranged opposite to each other; The finger support (6) is provided with a mounting groove (18) and a rotating shaft, the protruding end of the finger (7) is inserted into the mounting groove (18) and connected to the rotating shaft, and the finger (7) can rotate on the rotating shaft by 15° to 20°.

10. A robot, characterized in that: A dexterous hand having a high gripping capability as claimed in any one of claims 1 to 9.

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