Robot hand end tool

Abstract

To provide end tools of a robot hand to be attached to a robot hand, that are capable of stably scooping up a predetermined amount, when performing an operation of scooping up a desired amount of an object being lightweight, granular and small as a handling object.SOLUTION: An end tool 10 of a robot hand comprises: a mounting part 11 having a cylindrical portion 11a to be removably attached to a finger tip 43a of a robot hand 20 comprising a plurality of curved fluid pressure actuators 40 in which a curved state and a stretched state are controlled by fluid pressure of fluid introduced to the interior; and a claw part 13 which is integrally molded with the mounting part and formed in a fin-shape.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to an end tool that is attached to the tip of a robot hand. [Background technology]

[0002] In a robotic system, a robot uses manipulators such as actuators, grippers, and end effectors to manipulate surrounding objects. In recent years, soft robot actuators have been adopted as manipulators. Unlike conventional manipulators made of metal or hard plastic, soft robot actuators consist of actuators that expand, contract, and bend by changing the pressure inside a tube-shaped body made of an elastomer material such as rubber.

[0003] By using multiple bendable soft robot actuators, it is possible to grip an object while preventing excessive pressure from being applied to the object during the handling process. For example, a robot hand using multiple bendable soft robot actuators is excellent at gripping a soft object without deforming or crushing the object. Summary of the Invention [Problem to be solved by the invention]

[0004] However, when performing an operation such as scooping up a desired amount of small, lightweight granular objects, if the robot hand is used to avoid crushing the objects being handled, it is not easy to perform operations such as scooping up a specified amount stably.

[0005] The present invention aims to provide an end tool for a robot hand that is attached to a robot hand and can stably scoop up a specified amount of small, lightweight objects such as granular objects when handling the object. [Means for solving the problem]

[0006] An end tool of a robot hand according to an embodiment of the present invention comprises an attachment part having a cylindrical portion that is removably attached to the tip of a finger of a robot hand that has a plurality of curved fluid pressure actuators whose curved and expanded states are controlled by the fluid pressure of a fluid introduced therein, and a claw portion that is integrally molded with the attachment part and formed into a fin shape. Effect of the Invention

[0007] According to the above configuration, it is possible to provide an end tool for a robot hand that is attached to the robot hand and can stably scoop up a predetermined amount of small, lightweight objects such as granular objects when handling the object. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 1A is a perspective view showing a robot hand end tool and a robot hand according to a first embodiment, and is a perspective view showing a state before the robot hand starts to operate. [Figure 1B] FIG. 1B is a perspective view showing a robot hand end tool and a robot hand according to the first embodiment, and is a perspective view showing a state in which a storage portion is formed by a plurality of robot hand end tools. [Figure 2A] FIG. 2A is a side view showing a state before the robot hand starts to operate. [Figure 2B] FIG. 2B is a side view showing the state in which the housing portion is formed by multiple robot hand end tools. [Figure 3A] FIG. 3A is a view taken along the line IIIA-IIIA of FIG. 2A. [Figure 3B] FIG. 3B is a view taken along the line IIIB-IIIB of FIG. 2B. [Figure 4A] FIG. 4A is a perspective view of a robot hand and a robot hand end tool according to a second embodiment, showing a state before the robot hand starts to operate. FIG. [Figure 4B]FIG. 4B is a perspective view of a robot hand end tool and a robot hand according to the second embodiment, showing a state in which a storage portion is formed by a plurality of robot hand end tools. [Figure 5A] FIG. 5A is a side view showing the state in which a storage portion is formed by multiple robot hand end tools. [Figure 5B] FIG. 5B is a view taken along the line VB-VB in FIG. 5A, showing a state in which the storage portion has been formed by a plurality of robot hand end tools. [Figure 5C] FIG. 5C is a view taken along the line VC-VC in FIG. 5B, showing a state in which a storage portion has been formed by a plurality of robot hand end tools. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and the description thereof will be omitted as appropriate.

[0010] (1) Schematic configuration of a robot hand 20 that can be used for the end tool 10 of the first embodiment FIG. 1A is a perspective view showing an end tool 10 of a robot hand and a robot hand 20 according to the first embodiment, and is a perspective view showing a state before the robot hand 20 starts to operate. FIG. 1B is a perspective view showing an end tool 10 of a robot hand and a robot hand 20, and is a perspective view showing a state in which a storage portion 15 is formed by a plurality of end tools 10 of the robot hand. FIG. 2A is a side view showing a state before the robot hand 20 starts to operate. FIG. 2B is a side view showing a state in which a storage portion 15 is formed by a plurality of robot hand end tools 10. FIG. 3A is a view taken along the arrows IIIA-IIIA in FIG. 2A. FIG. 3B is a view taken along the arrows IIIB-IIIB in FIG. 2B.

[0011] 1 shows an example of the configuration of a gripping system that can use a robot hand 20 to which an end tool 10 of the first embodiment is attached.

[0012] The gripping system includes a robot hand 20 having a plurality of curved fluid pressure actuators 40 and a robot hand base 30 supporting the plurality of curved fluid pressure actuators 40 with one end of the plurality of curved fluid pressure actuators 40 fixed to its underside, and a robot arm (not shown) connected to the upper side of the robot hand base 30 and capable of moving the robot hand 20 above an object to be handled by the robot hand 20 and capable of moving the robot hand 20 up and down.

[0013] The multiple curved fluid pressure actuators 40 of the robot hand 20 are suspended from above by the robot arm. In the first embodiment shown in Fig. 1A to Fig. 3B, three curved fluid pressure actuators 40 are suspended from the robot hand base body 30. However, the multiple curved fluid pressure actuators 40 constituting the robot hand 20 are not limited to this, and there may be two curved fluid pressure actuators 40, or four or more curved fluid pressure actuators 40 as described later.

[0014] In this embodiment, the multiple curved fluid pressure actuators 40 are fixed to the robot hand base 30 in a bendable manner so that the tips (other ends), which are the free ends of the multiple curved fluid pressure actuators 40, approach each other so as to function as gripping portions of the robot hand 20.

[0015] In this embodiment, the three curved fluid pressure actuators 40 are disposed at equal intervals from one another so that they are at the vertices of an equilateral triangle in the plane of the lower surface while being fixed to the robot hand base 30. Each of the three curved fluid pressure actuators 40 is fixed to the robot hand base 30 so as to be curved approximately in the direction of the center of gravity of the equilateral triangle.

[0016] For the multiple bending type fluid pressure actuators 40 of the embodiment, bendable McKibben type fluid pressure actuators are used that are configured to be bendable and expandable by the fluid pressure of a fluid introduced inside.

[0017] The bendable McKibben type fluid pressure actuator 40, like a general McKibben type fluid pressure actuator, is composed of a fluid pressure actuator main body 41 including a rubber tube which is a cylindrical tubular body that expands and contracts due to fluid pressure, and a sleeve which is a cylindrical structure having elasticity and is woven with fiber cords oriented in a predetermined direction (predetermined braiding angle) and covers the outer surface of the tube, and sealing members made of a metal such as aluminum or hard plastic which have fittings 43 and seal both ends of the fluid pressure actuator main body 41.

[0018] The bendable McKibben type fluid pressure actuator 40 includes, in addition to the configuration of a typical McKibben type fluid pressure actuator, a restraining member (not shown) provided from one end side to the other end side in the axial direction on a part of the circumferential direction of the tube in the fluid pressure actuator main body 41. The action of this restraining member restrains contraction of a part of the circumferential direction of the tube when the tube contracts or expands, making the bendable fluid pressure actuator 40 bendable.

[0019] The robot hand 20 supported by the robot arm can bend a plurality of curved fluid pressure actuators 40 suspended from the robot hand base 30 to achieve behavior similar to that of human fingers.

[0020] The robot hand 20 using multiple curved fluid pressure actuators 40 can grip even easily deformed and lightweight objects such as chicken eggs without damaging them, or objects such as packaged items filled with inert gas together with the object to be packaged. In addition, by employing an appropriate restraining member, the curved fluid pressure actuator 40 can also grip and lift objects with a certain weight or more, such as a shot put (7.26 kg or more).

[0021] In addition, the multiple curved fluid pressure actuators 40 may be driven by simultaneously increasing the pressure of all of the curved fluid pressure actuators 40, or the multiple curved fluid pressure actuators 40 may be curved by supplying fluid from multiple fluid supply sources or the like to each of the curved fluid pressure actuators 40 in a desired order.

[0022] (2) Configuration of the end tool 10 of the first embodiment The end tool 10 of the robot hand according to the first embodiment is applicable to the robot hand 20 included in the gripping system configured as described above. The end tool 10 of the robot hand includes an attachment part 11 having a cylindrical part 11a detachably attached to a finger tip part 43a, which is the tip part of a joint 43 of the robot hand 20 including a plurality of fluid pressure actuators (curved fluid pressure actuators) 40 whose curved and expanded states are controlled by the fluid pressure of a fluid introduced therein, and a claw part 13 formed in a fin shape and integrally molded with the attachment part 11.

[0023] The tubular portion 11a of the mounting portion 11 in the first embodiment is a bottomed tubular portion formed in a cylindrical shape. The claw portion 13 integrally formed with the mounting portion 11 is formed in a fin (plate) shape protruding from the side and bottom surfaces of the outer circumferential surface of the mounting portion 11, and one surface has a curved surface that is curved concavely.

[0024] The material of the end tool 10 may be appropriately selected depending on the object to be handled by the end tool 10. For example, it may be a hard plastic such as ABS resin, which is a copolymer of acrylonitrile butadiene styrene, or polylactic acid resin (PLA), or a soft resin material such as silicone resin.

[0025] When the multiple curved fluid pressure actuators 40 are operated with the mounting portion 11 attached to each of the finger tips 43a of the multiple curved fluid pressure actuators 40, the multiple claws 13 are combined to form a concave storage portion 15. Specifically, the concave storage portion 15 is formed by combining the concave curved surfaces formed on the claws 13 with the edges of the claws 13 protruding from the mounting portion 11 abutting against each other. Note that in the first embodiment, the configuration in which the multiple end tools 10 form a set of end tools to form the storage portion 15 is not limited to the one in which the edges of the claws 13 abut against each other. For example, the storage portion 15 may be formed by slightly overlapping the edges of the claws 13.

[0026] In the first embodiment, the attachment portion 11 formed in a bottomed cylindrical shape in the end tool 10 is attached so that the finger tip 43a fits into the bottom of the attachment portion 11 when the end tool 10 is attached to the finger tip 43a of the robot hand 20, thereby ensuring that the end tool 10 is stably attached to the finger tip 43a.

[0027] (3) Behavior of the robot hand 20 to which the end tool 10 of the first embodiment is attached 1A, 2A, and 3A are respectively a perspective view and a side view of the curved fluid pressure actuator 40 provided in the robot hand 20 before bending, and a view of the curved fluid pressure actuator 40 and the end tool 10 seen from above. Figures 1B, 2B, and 3B show a curved state from the state shown in Figures 1A, 2A, and 3A by increasing the fluid pressure inside the tubes of the multiple curved fluid pressure actuators 40 provided in the robot hand 20 of the first embodiment.

[0028] In the state shown in Figures 1B, 2B, and 3B, the edges of the fin-shaped claw portions 13 of the end tool 10 attached to the finger tips 43a of the joints 43 of each curved fluid pressure actuator 40 abut against each other to form a concave accommodating portion 15.

[0029] In the first embodiment, the concave storage portion 15 is formed in a container shape (bowl shape) with a concave curved bottom surface and an open top surface. However, the bottom shape of the concave storage portion 15 is not limited to the bowl-shaped curved surface as shown in Fig. 1B etc., as long as the storage portion 15 forms a recess that is recessed into the outer edge of the upper surface side of the combined multiple claw portions.

[0030] In the first embodiment, the claws 13 of the three end tools 10 that form the concave storage portion 15 are all formed in the same shape. However, when the claws 13 of a plurality of end tools 10 are combined to form the concave storage portion 15, it is sufficient that the fin-shaped portions of the claws 13 come into contact with each other or the fin-shaped edges overlap each other when the claws 13 of the plurality of end tools 10 are combined to form the concave storage portion 15, and all of the claws 13 do not necessarily have to be formed in the same shape.

[0031] In the first embodiment, the robot hand 20 is moved downward by the robot arm from the state where it is moved to the top of the object to be handled, and at least the tip of the end tool 10 is lowered to a position below the top surface of the object to be handled. Next, the curved fluid pressure actuator 40 is curved, and a concave storage portion 15 is formed by the claws 13 of the multiple end tools 10, thereby storing the object to be handled in the storage portion 15. Here, the top surface of the object to be handled does not only refer to the top surface of a single object such as a lightweight granular object to be handled, but also includes the top surface of the object to be handled when a group of small, lightweight granular objects is defined as the object to be handled, such as a state in which a large number of small, lightweight granular objects to be handled are stored inside a container, etc.

[0032] (4) Schematic configuration of a robot hand 120 that can be used in the end tool 110 of the second embodiment FIG. 4A is a perspective view of the robot hand end tool 110 and the robot hand 120 according to the second embodiment, and is a perspective view showing a state before the robot hand 120 starts to operate. FIG. 4B is a perspective view of the robot hand end tool 110 and the robot hand 120 according to the second embodiment, and is a perspective view showing a state in which the storage portion 115 is formed by a plurality of robot hand end tools 110. FIG. 5A is a side view showing a state in which the storage portion 115 is formed by a plurality of robot hand end tools 110. FIG. 5B is a VB-VB arrow view of FIG. 5A showing a state in which the storage portion 115 is formed by a plurality of robot hand end tools 110. FIG. 5C is a VC-VC arrow view of FIG. 5B showing a state in which the storage portion 115 is formed by a plurality of robot hand end tools 110.

[0033] 1 shows an example of the configuration of a gripping system that can use a robot hand 120 to which an end tool 110 of the second embodiment is attached.

[0034] The gripping system includes a robot hand 120 having a plurality of curved fluid pressure actuators 140, a robot hand base 130 having one end of the plurality of curved fluid pressure actuators 140 fixed to its underside and supporting the plurality of curved fluid pressure actuators 140, and a robot arm (not shown) connected to the upper side of the robot hand base 130, capable of moving to above an object to be handled by the robot hand 120, and capable of moving the robot hand 120 up and down.

[0035] The multiple curved fluid pressure actuators 140 of the robot hand 120 are suspended from above by the robot arm. The second embodiment shown in Fig. 4A to Fig. 5C differs from the robot hand 120 of the first embodiment in that four curved fluid pressure actuators 140 are suspended from the robot hand base body 130.

[0036] The multiple curved fluid pressure actuators 140 used in this embodiment are bendable McKibben type fluid pressure actuators including an actuator body 141, joints 143, and finger tip portions 143a similar to the multiple curved fluid pressure actuators 40 used in the first embodiment. The multiple curved fluid pressure actuators 140 are fixed to the robot hand base 130 so that the tips (other ends) on the free end side of the multiple curved fluid pressure actuators 140 can be bent so as to approach each other, so as to function as gripping portions of the robot hand 120.

[0037] The four curved fluid pressure actuators 140 are arranged so that they are at the vertices of a diamond (including a square) in the plane of the lower surface while fixed to the robot hand base 130. Each of the four curved fluid pressure actuators 140 is fixed to the robot hand base 130 so as to be curved in the direction of approximately the center of gravity of the diamond.

[0038] The robot hand 120 supported by the robot arm can achieve behavior similar to that of human fingers by bending a plurality of curved fluid pressure actuators 140 suspended from the robot hand base 130.

[0039] The multiple curved fluid pressure actuators 140 may all be boosted at the same time, or fluid may be supplied to each curved fluid pressure actuator 140 in a desired order, so that, for example, a pair of curved fluid pressure actuators 140 arranged on the same diagonal of a diamond (square) are first curved, and then another pair of curved fluid pressure actuators 140 arranged on the other diagonal are bent.

[0040] (5) Configuration of the end tool 110 of the second embodiment The end tool 110 of the robot hand according to the second embodiment is applicable to the robot hand 120 included in the gripping system configured as described above. The end tool 110 of the robot hand includes an attachment part 111 having a cylindrical part 111a detachably attached to a finger tip part 143a, which is the tip part of a joint 143 of the robot hand 120 including a plurality of fluid pressure actuators (curved fluid pressure actuators) 140 whose curved and expanded states are controlled by the fluid pressure of a fluid introduced therein, and a claw part 113 formed in a fin shape integrally with the attachment part 111.

[0041] 4A and 4B, the tubular portion 111a of the mounting portion 111 in the second embodiment is a bottomed tubular shape similar to that in the first embodiment, and is formed in a cylindrical shape. The claw portion 13 integrally molded with the mounting portion 11 is formed in a fin shape (plate shape) protruding from the side and bottom surfaces of the outer circumferential surface of the mounting portion 11, and has an L-shaped plate shape.

[0042] In the first embodiment, as shown in Fig. 1B, 3B, etc., the three claws 13 to be combined have the same shape. In contrast, in the second embodiment, as shown in Fig. 4A, 5A, 5B, etc., the claws 113 of one pair of end tools 110 attached to the finger tips 143a of a pair of curved fluid pressure actuators 140 arranged on the short diagonal of the diamond are formed in an L-shaped plate shape extending from the mounting part 111 in a direction parallel to the long diagonal of the diamond, and the claws 113 of the other pair of end tools 110 attached to the finger tips 143a of the other pair of curved fluid pressure actuators 140 arranged on the long diagonal of the diamond are formed in an L-shaped plate shape extending from the mounting part 111 in a direction parallel to the short diagonal of the diamond.

[0043] As in the first embodiment, the material of the end tool 110 may be appropriately selected depending on the object to be handled by the end tool 110. For example, the material may be a hard plastic such as ABS resin made by copolymerizing acrylonitrile-butadiene-styrene or polylactic acid resin (PLA), or a soft resin material such as silicone resin.

[0044] As shown in FIG. 4B, when the multiple curved fluid pressure actuators 140 are operated with the mounting portion 111 attached to each of the finger tips 143a of the multiple curved fluid pressure actuators 140, the fin-like portions of the multiple claw portions 113 combine to form a box-shaped storage portion 115 with an open top.

[0045] Specifically, as shown in FIG. 4B and FIG. 5A to 5C, the box-shaped (concave) storage portion 115 formed by using a plurality of end tools 110 as a set of end tools is formed by first bending a pair of curved fluid pressure actuators 140 arranged on a short diagonal line of a rhombus (square) to abut the edges of the claws 113 attached to the finger tips 143a of the pair of curved fluid pressure actuators 140 arranged on a long diagonal line, and then bending the other pair of curved fluid pressure actuators 140 arranged on a long diagonal line to abut the claws 113 attached to the finger tips 143a of the pair of end tools 110 against the side edges and bottom surface of the claws 113 of one pair of end tools 110. The angle of the L-shaped plate-shaped claws 113 with respect to the mounting portion 111 may be designed to an angle that allows the box-shaped storage portion 115 to be formed when the curved fluid pressure actuator 140 is curved. Also, similar to the first embodiment, the configuration in which the claws 113 abut at the edges may be configured so that the edge portions of the claws 113 overlap each other.

[0046] The attachment portion 111 of the end tool 10 of the second embodiment, which is formed in a bottomed cylindrical shape, is such that when the end tool 110 is attached to the finger tip 143a of the robot hand 120, as in the first embodiment, the finger tip 143a is fitted to the bottom of the attachment portion 111, thereby allowing the end tool 110 to be stably attached to the finger tip 143a.

[0047] (6) Behavior of the robot hand 120 to which the end tool 110 of the second embodiment is attached Fig. 4A is a perspective view of the curved fluid pressure actuator 140 provided in the robot hand 120 in a state before bending. Figs. 4B, 5A to 5C show a curved state from the state shown in Fig. 4A by increasing the fluid pressure inside the tubes of the multiple curved fluid pressure actuators 140 provided in the robot hand 120 of the second embodiment.

[0048] In the state shown in Figures 4B, 5A to 5C, the fin-shaped claw portions 13 of the end tools 10 attached to the finger tips 43a of the joints 43 of each curved fluid pressure actuator 40 abut against each other to form a box-shaped (concave) storage portion 15.

[0049] In the second embodiment, the robot hand 120 is moved downward by the robot arm from the state where it is moved to the upper part of the object to be handled, and the end tool 110 is lowered to a position below the upper surface of the object to be handled. Then, among the four curved fluid pressure actuators 140 arranged on the lower surface of the robot hand base body 130 so as to be the vertices of a diamond, a pair of curved fluid pressure actuators 140 arranged on a short diagonal line are curved, and the edges of the claws 113 of one pair of end tools 110 attached to the finger tips 143a of the curved fluid pressure actuators 140 come into contact with each other. Next, the other pair of curved fluid pressure actuators 140 arranged on a long diagonal line are curved, and the claws 113 of the other pair of end tools 110 attached to the finger tips 143a come into contact with the side edges and bottom surface of the claws 113 of one pair of end tools 110. In this manner, a concave storage portion 115 is formed by the claws 113 of the multiple end tools 110, and the object to be handled is stored in the storage portion 115.

[0050] (7) Actions and Effects The end tool 10, 110 of the robot hand 20, 120 configured as described above is attached to the finger tip portion 43a, 143a of the robot hand 20, 120, so that even when performing an operation to scoop up a desired amount of small, lightweight granular objects that are difficult to handle with the robot hand 20, 120, the claw portion 13, 113 formed on the end tool 10, 110 can stably scoop up a predetermined amount.

[0051] Furthermore, when the end tool 10, 110 is attached to the finger tips 43a, 143a of multiple curved fluid pressure actuators 40, 140 of the robot hand 20, 120 and the concave storage portion 15, 115 formed by combining the claw portions 13, 113 of the multiple end tools 10, 110 is used to scoop up a desired amount of small, lightweight granular objects or other objects, it becomes possible to scoop up a specified amount more stably.

[0052] (8) Other embodiments The present invention has been described above in accordance with the embodiments, but the present invention is not limited to these descriptions, and it will be obvious to those skilled in the art that various modifications and improvements are possible.

[0053] For example, in the first and second embodiments, the cylindrical portions 11a, 111a of the mounting portions 11, 111 of the end tools 10, 110 are formed cylindrically, but the shape of the cylindrical portions 11a, 111a is not limited to this. The shape of the cylindrical portions may be a non-cylindrical shape such as an elliptical cylinder or a polygonal cylinder.

[0054] When the cylindrical portion of the mounting portion of the end tool is a non-cylindrical shape such as an elliptical cylinder or a polygonal cylinder, the cylindrical portion has a rotation-preventing effect on the finger tip. Specifically, when an end tool having a non-cylindrical cylindrical portion is attached to the finger tip of a curved fluid pressure actuator, the rotation of the claw of the end tool around the axis during actual operation of the robot hand is prevented. This allows the shape of the housing portion to be stably formed for a long period of time when the curved fluid pressure actuator is in operation.

[0055] In the first and second embodiments, McKibben type curved fluid pressure actuators are used as the multiple curved fluid pressure actuators 40, 140 provided in the robot hand 20, 120, but the curved fluid pressure actuators are not limited to this. The curved fluid pressure actuator may be any bendable actuator that can be gripped without applying excessive pressure to an object to be handled. For example, a soft actuator using a soft material such as elastomer may be used as the curved fluid pressure actuator.

[0056] In the first and second embodiments, the finger tip 43a, 143a is configured with a hard joint 43 made of metal or the like, but the finger tip is not limited to this. The finger tip may be a tip of an actuator to which the end tool 10, 110 of the robot hand can be attached or detached, and may be configured with a soft material such as elastomer.

[0057] As described above, the embodiment of the present invention has been described, but the description and drawings forming a part of this disclosure should not be understood as limiting this invention. From this disclosure, various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art. [Explanation of symbols]

[0058] 10,110 End Tools 11,111 Mounting part 11a, 111a Cylindrical part 13,113 Claw 15,115 Storage area 20,120 Robot Hand 30,130 Robot hand base 40,140 Curved fluid pressure actuator 41,141 Fluid pressure actuator body 43,143 Joints 43a, 143a Finger tip

Claims

1. a mounting part having a cylindrical part detachably attached to a tip of a finger of a robot hand including three or more bending type fluid pressure actuators whose bending and stretching states are controlled by the fluid pressure of a fluid introduced therein; A claw portion formed integrally with the mounting portion and shaped like a fin; Equipped with An end tool for a robot hand, in which when the mounting portion is attached to the finger tips of three or more of the curved fluid pressure actuators and the three or more curved fluid pressure actuators are operated, the end edges of the three or more claw portions abut or overlap to form a concave storage portion.

2. The end tool of a robot hand according to claim 1 , wherein the cylindrical portion is a bottomed cylindrical portion.

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