End effector and robot

Abstract

To provide an end effector that is capable of reducing weight and saving space, and also capable of improving work efficiency of a robot.SOLUTION: An end effector 6 includes a plurality of claws 8 and a drive mechanism 12 that changes the configuration of the plurality of claws 8 from one configuration to another configuration among a plurality of configurations each exhibiting mutually different functions. The plurality of functions includes at least two of: (a) a wheel function for moving the robot 2, (b) a gripper function for gripping an object, (c) a shovel function for digging up the object, and (d) a drill function for excavating the object.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an end effector and a robot equipped with the end effector. [Background technology]

[0002] There is known an end effector that is rotatably attached to the tip of a robot arm (see, for example, Patent Document 1). A conventional end effector includes a main body and a plurality of tools that protrude radially from the main body. Each of the plurality of tools performs a plurality of different functions. When the robot performs a predetermined task on an object, the end effector is rotated relative to the arm, so that a specific tool among the plurality of tools that performs a function corresponding to the predetermined task faces the object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-9379 Summary of the Invention [Problem to be solved by the invention]

[0004] Examples of applications of the above-mentioned end effector include space missions such as lunar exploration, lunar base construction, etc. Conventional end effectors require the robot to be equipped in advance with a number of tools corresponding to the types of tasks to be performed in the space mission.

[0005] However, such a conventional end effector configuration causes problems such as the end effector being heavy and large, making it difficult to transport the robot, and the need to change tools depending on the work performed by the robot, resulting in a decrease in the work efficiency of the robot.

[0006] The present invention seeks to solve the above-mentioned problems, and has an object to provide an end effector that can be made lighter and more space-saving, and that can improve the work efficiency of a robot, and a robot equipped with the end effector. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, an end effector according to a first aspect of the present invention is an end effector mounted on a robot for performing a specified task on an object, and includes a plurality of claw portions and a drive mechanism for changing the shape of the plurality of claw portions from one of a plurality of shapes each performing a plurality of mutually different functions to another, the plurality of functions including at least two of (a) a wheel function for moving the robot, (b) a gripper function for grasping the object, (c) a shovel function for digging up the object, and (d) a drill function for excavating the object.

[0008] According to this aspect, the drive mechanism changes the shape of the multiple claws from one of the multiple shapes that each perform a multiple different functions to another, so that multiple functions can be realized by changing the shape of the multiple claws. This makes it possible to reduce the weight and space of the end effector compared to the conventional end effector described in the Background section, in which multiple tools are pre-installed in the end effector in a number corresponding to the type of work performed by the robot. In addition, since there is no need to change tools depending on the work performed by the robot, as in the conventional end effector described in the Background section, the work efficiency of the robot can be improved.

[0009] For example, in the end effector of the second aspect of the present invention, in the first aspect, the multiple claw portions may be arranged circumferentially around a central axis, and the drive mechanism may be configured to move the multiple claw portions from one to the other of an open position in which they are spaced apart from each other along the circumferential direction, and a closed position in which they are close to each other along the circumferential direction.

[0010] According to this aspect, the shape of the multiple claw portions can be easily changed by moving the multiple claw portions from one of the open position and the closed position to the other.

[0011] For example, in the end effector of the third aspect of the present invention, in the second aspect, the drive mechanism may be configured to rotate the multiple claw portions in a predetermined direction around the central axis while the multiple claw portions are positioned in the open position when the shape of the multiple claw portions is changed to a shape that performs the wheel function.

[0012] According to the present aspect, with the multiple claw portions positioned in the open position, the multiple claw portions can be rotated in a predetermined direction around the central axis, thereby causing the multiple claw portions to perform wheel function.

[0013] For example, in the end effector according to the fourth aspect of the present invention, in the second or third aspect, the drive mechanism may be configured to cause the multiple claw portions to grip the object while moving the multiple claw portions from the open position to the closed position when the shape of the multiple claw portions is changed to a shape that performs the gripper function.

[0014] According to this aspect, the multiple claw portions can be made to grip an object while moving the multiple claw portions from the open position to the closed position, thereby allowing the multiple claw portions to exert a gripper function.

[0015] For example, in the end effector according to the fifth aspect of the present invention, in the fourth aspect, the plurality of claw portions may be configured to pinch and grasp the outer circumferential surface of the object with their respective tip portions.

[0016] According to this aspect, the outer circumferential surface of the object can be pinched and gripped by the multiple claws.

[0017] For example, in the end effector of the sixth aspect of the present invention, in the fourth aspect, the object may be formed in a generally plate-like shape having a first main surface and a second main surface opposite the first main surface, and the driving mechanism may be configured to press some of the multiple claw portions against the first main surface of the object and press the remaining some of the multiple claw portions against the second main surface of the object, thereby causing the multiple claw portions to grasp the object by clamping it from both sides.

[0018] According to this aspect, the object can be grasped by pinching it from both sides with the multiple claw portions.

[0019] For example, in the end effector according to the seventh aspect of the present invention, in any one of the second to sixth aspects, the drive mechanism may be configured to cause the tip of each of the multiple claw portions to dig up the object while moving the multiple claw portions from the open position to the closed position when the shape of the multiple claw portions is changed to a shape that performs the shovel function.

[0020] According to this aspect, while the multiple claw portions are being moved from the open position to the closed position, the tip of each of the multiple claw portions can be used to dig up an object, thereby allowing the multiple claw portions to perform a shovel function.

[0021] For example, in the end effector according to the eighth aspect of the present invention, in any one of the second to seventh aspects, a plurality of cutting blade pieces for excavating the target object are formed on the outer surface of each of the plurality of claw portions, and the drive mechanism may be configured to rotate the plurality of claw portions in a predetermined direction around the central axis while the plurality of claw portions are positioned in the closed position when the shape of the plurality of claw portions is changed to a shape that performs the drill function.

[0022] According to the present aspect, with the multiple claw portions positioned in the closed position, the multiple claw portions can be rotated in a predetermined direction around the central axis, thereby causing the multiple claw portions to perform a drilling function.

[0023] For example, in the end effector of the ninth aspect of the present invention, in the eighth aspect, when the driving mechanism positions the multiple claw portions in the closed position, the multiple cutting edge pieces of each of the multiple claw portions may be connected to each other to form at least one spiral cutting edge.

[0024] According to this aspect, the target object can be excavated efficiently with at least one spiral cutting edge.

[0025] For example, in an end effector according to a tenth aspect of the present invention, in any one of the second to ninth aspects, the drive mechanism may be configured to include a movable member, a drive source for reciprocating the movable member along the central axis, and a plurality of four-bar link mechanisms respectively connecting the movable member to each of the plurality of claw portions.

[0026] According to this aspect, the plurality of claw portions can be moved from one of the open position and the closed position to the other with a relatively simple configuration.

[0027] For example, in an end effector according to an eleventh aspect of the present invention, in the first aspect, the multiple claw portions are arranged in a circumferential direction around a central axis, and the drive mechanism includes a worm extending along the central axis, a drive source that rotates the worm in a predetermined direction, and multiple transmission mechanisms that transmit the drive force of the worm to each of the multiple claw portions, and when the drive mechanism changes the configuration of the multiple claw portions from a configuration that performs the drill function to a configuration that performs the wheel function, the multiple claw portions may be configured to (i) be moved by the drive force from the multiple transmission mechanisms from a closed position in which they are arranged close to each other along the circumferential direction to an open position in which they are arranged apart from each other along the circumferential direction, and then (ii) be rotated from a position in which they are arranged radially around the central axis to a position in which they are arranged approximately circularly along the circumferential direction around the central axis.

[0028] According to this aspect, the form of the multiple claws can be easily changed from a form that performs a drill function to a form that performs a wheel function, and the form of the multiple claws can be easily transitioned to a shape and arrangement suitable for achieving the effects of each mode.

[0029] For example, in an end effector according to a twelfth aspect of the present invention, in the eleventh aspect, each of the multiple transmission mechanisms may be configured to include a worm gear that meshes with the worm, a first intermittent gear and a second intermittent gear that rotate integrally with the rotation of the worm gear, a first gear that meshes with the first intermittent gear, a first link portion that connects the claw portion and the first gear and converts the rotational motion of the first gear into a moving motion of the claw portion between the closed position and the open position, a second gear that meshes with the second intermittent gear, and a conversion mechanism that converts the rotational motion of the second gear into a pivoting motion of the claw portion.

[0030] According to this aspect, the driving force of the worm can be transmitted to each of the multiple claw portions with a relatively simple configuration.

[0031] For example, in an end effector according to a 13th aspect of the present invention, in the 12th aspect, the conversion mechanism may be configured to include a first helical gear that rotates integrally with the rotation of the second gear, a second helical gear that meshes with the first helical gear, a rotating member that rotates integrally with the rotation of the second helical gear, and a second link portion that connects the rotating member and the claw portion.

[0032] According to this aspect, the rotational motion of the second gear can be converted into the pivoting motion of the claw portion with a relatively simple configuration.

[0033] A robot according to a fourteenth aspect of the present invention is a robot for performing a predetermined task on an object, and includes an end effector according to any one of the first to thirteenth aspects.

[0034] According to this aspect, as described above, it is possible to reduce the weight and space of the end effector. As a result, for example, when the robot is used in a space mission, the robot can be easily transported. In addition, the work efficiency of the robot can be improved. Effect of the Invention

[0035] According to an end effector and the like according to one aspect of the present invention, it is possible to reduce weight and space, and to improve the work efficiency of a robot. [Brief description of the drawings]

[0036] [Figure 1] FIG. 1 is a perspective view showing a simplified view of a robot according to a first embodiment. [Diagram 2] 1 is a perspective view showing an end effector according to a first embodiment in a state in which a plurality of claws are positioned in an open position. FIG. [Diagram 3] 3 is a perspective view showing the end effector according to embodiment 1 in a state where a plurality of claws are in an open position, as viewed from an angle different from that in FIG. 2. FIG. [Figure 4] 1 is a front view showing the end effector according to embodiment 1 in a state in which a plurality of claw portions are in an open position. FIG. [Diagram 5] 4 is a cross-sectional perspective view of the end effector according to embodiment 1 taken along line VV in FIG. 3. [Figure 6] 1 is a perspective view showing an end effector according to a first embodiment in a state in which a plurality of claw portions are located at intermediate positions between an open position and a closed position. FIG. [Figure 7] 7 is a perspective view showing the end effector according to embodiment 1 in a state where a plurality of claw portions are positioned at intermediate positions between the open position and the closed position, as viewed from an angle different from that in FIG. 6. FIG. [Figure 8] 1 is a front view showing the end effector according to embodiment 1 in a state in which a plurality of claw portions are located at intermediate positions between an open position and a closed position. FIG. [Figure 9]9 is a cross-sectional perspective view of the end effector according to the first embodiment taken along line IX-IX in FIG. 7. [Figure 10] 1 is a perspective view showing an end effector according to a first embodiment in a state in which a plurality of claws are located in a closed position. FIG. [Figure 11] 11 is a perspective view showing the end effector according to the first embodiment in a state where a plurality of claw portions are located in a closed position, as viewed from an angle different from that in FIG. 10. FIG. [Figure 12] 1 is a front view showing the end effector according to embodiment 1 in a state in which a plurality of claw portions are located in a closed position. FIG. [Figure 13] 13 is a cross-sectional perspective view of the end effector according to the first embodiment taken along line XIII-XIII in FIG. 11. [Figure 14] 5A to 5C are diagrams for explaining a wheel function of the end effector according to the first embodiment. [Figure 15] 4A to 4C are diagrams for explaining a gripper function of the end effector according to the first embodiment. [Figure 16] 4A to 4C are diagrams for explaining a gripper function of the end effector according to the first embodiment. [Figure 17] 4A to 4C are diagrams for explaining a shovel function of the end effector according to the first embodiment. [Figure 18] 4A to 4C are diagrams for explaining a drill function of the end effector according to the first embodiment. [Figure 19] FIG. 11 is a perspective view showing an end effector according to a second embodiment in a state in which a plurality of claws are located in a closed position. [Figure 20] FIG. 11 is a perspective view showing an end effector according to a second embodiment in a state in which a plurality of claws are positioned in an open position. [Figure 21] 13 is a perspective view showing an end effector according to a second embodiment in a state in which a plurality of claws have been rotated from an open position. FIG. [Figure 22] FIG. 11 is a perspective view showing a transmission mechanism of an end effector according to a second embodiment. [Diagram 23]23 is a perspective view showing a transmission mechanism of an end effector according to embodiment 2, seen from an angle different from that in FIG. 22. [Figure 24] 10A to 10C are diagrams for explaining the operation of a transmission mechanism of an end effector according to the second embodiment. [Diagram 25] 10A to 10C are diagrams for explaining the operation of a transmission mechanism of an end effector according to the second embodiment. [Figure 26] 10A to 10C are diagrams for explaining the operation of a transmission mechanism of an end effector according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0038] (Embodiment 1) [1-1. Overview of the robot] First, an overview of a robot 2 according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a perspective view showing a simplified view of the robot 2 according to the first embodiment.

[0039] 1, the robot 2 includes a robot main body 4 and an end effector 6. The robot 2 is a space work robot for performing predetermined tasks on objects on the lunar surface in space missions such as lunar exploration or lunar base construction.

[0040] Inside the robot body 4, there are mounted a controller for controlling the end effector 6, a battery for supplying power to the end effector 6, and a communication module for communicating with an external terminal device. For convenience of explanation, the robot body 4 is illustrated in a simplified form in FIG.

[0041] The end effector 6 is disposed, for example, so as to protrude laterally from the side surface of the robot body 4, and is equipped with a plurality (e.g., eight) of claws 8. In the end effector 6, the form of the plurality of claws 8 changes from one form to another form among a plurality (e.g., four) forms each performing a plurality (e.g., four) of mutually different functions. In this specification, the "form" of the plurality of claws 8 means the position and posture of the plurality of claws 8 relative to the robot body 4.

[0042] In this embodiment, the multiple functions include (a) a wheel function for moving (running) the robot 2 on the ground, (b) a gripper function for gripping an object, (c) a shovel function for digging up an object, and (d) a drill function for excavating an object. That is, the form of the multiple claws 8 changes from one form to another form among a form for performing the wheel function, a form for performing the gripper function, a form for performing the shovel function, and a form for performing the drill function.

[0043] [1-2. End effector configuration] Next, the configuration of the end effector 6 according to the first embodiment will be described with reference to FIGS.

[0044] Fig. 2 is a perspective view showing the end effector 6 according to the first embodiment in a state where the multiple claw portions 8 are located in the open position. Fig. 3 is a perspective view showing the end effector 6 according to the first embodiment in a state where the multiple claw portions 8 are located in the open position, as viewed from an angle different from that of Fig. 2. Fig. 4 is a front view showing the end effector 6 according to the first embodiment in a state where the multiple claw portions 8 are located in the open position. Fig. 5 is a perspective cross-sectional view of the end effector 6 according to the first embodiment taken along line VV of Fig. 3.

[0045] Fig. 6 is a perspective view showing the end effector 6 according to the first embodiment in a state where the plurality of claws 8 are located at an intermediate position between the open position and the closed position. Fig. 7 is a perspective view showing the end effector 6 according to the first embodiment in a state where the plurality of claws 8 are located at an intermediate position between the open position and the closed position, as viewed from an angle different from that of Fig. 6. Fig. 8 is a front view showing the end effector 6 according to the first embodiment in a state where the plurality of claws 8 are located at an intermediate position between the open position and the closed position. Fig. 9 is a perspective cross-sectional view of the end effector 6 according to the first embodiment taken along line IX-IX of Fig. 7.

[0046] Fig. 10 is a perspective view of the end effector 6 according to the first embodiment in a state where the multiple claws 8 are located at the closed position. Fig. 11 is a perspective view of the end effector 6 according to the first embodiment in a state where the multiple claws 8 are located at the closed position, as viewed from an angle different from that of Fig. 10. Fig. 12 is a front view of the end effector 6 according to the first embodiment in a state where the multiple claws 8 are located at the closed position. Fig. 13 is a cross-sectional perspective view of the end effector 6 according to the first embodiment taken along line XIII-XIII in Fig. 11.

[0047] As shown in FIGS. 2 to 5, the end effector 6 includes a plurality of claws 8, a base portion 10, and a drive mechanism 12. The claws 8 are arranged in a direction perpendicular to the axis of the actuator 10. As shown in FIG.

[0048] The base portion 10 is for supporting the multiple claw portions 8 and the drive mechanism 12, and is fixed to the side of the robot body 4 (see FIG. 1).

[0049] 5, the drive mechanism 12 is a mechanism for changing the shape of the claws 8 from one of a plurality of shapes each of which exerts a plurality of different functions to another. The drive mechanism 12 has a rotation motor 14, a frame 16, an opening / closing motor 18 (an example of a drive source), a feed screw 20, a moving member 22, and a plurality of (e.g., eight) four-bar link mechanisms 24.

[0050] The rotation motor 14 is a servo motor for rotating the frame 16 relative to the base unit 10 about a central axis 26. Here, the central axis 26 is an imaginary straight line passing through the center of the arrangement of the multiple claws 8. The rotation motor 14 is supported by the base unit 10, and has an output shaft that outputs a driving force. Note that the end effector 6 does not necessarily have to have the rotation motor 14, and the rotation motor 14 may be disposed in the robot body 4, for example.

[0051] The frame 16 is a housing for supporting the opening / closing motor 18, the feed screw 20, and a plurality of four-bar linkage mechanisms 24. The frame 16 is disposed facing the base unit 10, and one end of the frame 16 (i.e., the end closer to the base unit 10) is connected to the output shaft of the rotation motor 14. The frame 16 rotates about a central axis 26 by the driving force from the output shaft of the rotation motor 14 in a first direction (the direction indicated by the arrow P1 in FIG. 2) and a second direction (the direction indicated by the arrow P2 in FIG. 2) that is opposite to the first direction.

[0052] When frame 16 rotates in a first direction, the multiple claws 8 accordingly rotate in the first direction (the direction indicated by arrow P1 in FIG. 4) integrally with frame 16 around central axis 26. On the other hand, when frame 16 rotates in a second direction, the multiple claws 8 accordingly rotate in the second direction (the direction indicated by arrow P2 in FIG. 4) integrally with frame 16 around central axis 26.

[0053] The opening / closing motor 18 is a servo motor for moving the moving member 22 back and forth along the central axis 26 to move the multiple claws 8 from one of the open position and the closed position to the other via an intermediate position. The opening / closing motor 18 is supported on one end of the frame 16, and has an output shaft that outputs a driving force.

[0054] Here, the open position is a position where the multiple claws 8 are arranged apart from each other along the circumferential direction centered on the central axis 26, as shown in Figs. 2 to 5. The intermediate position is a position intermediate between the open position and the closed position, as shown in Figs. 6 to 9. The closed position is a position where the multiple claws 8 are arranged close to each other along the circumferential direction centered on the central axis 26, as shown in Figs. 10 to 13. In this specification, the "circumferential direction" means the circumferential direction of a circle centered on the central axis 26.

[0055] The feed screw 20 is disposed inside the frame 16 and extends along a central axis 26. An external thread, for example, a trapezoidal thread, is formed on the outer circumferential surface of the feed screw 20. One end in the longitudinal direction of the feed screw 20 is connected to the output shaft of the opening / closing motor 18. The other end in the longitudinal direction of the feed screw 20 is rotatably supported by a bearing 28 disposed at the other end of the frame 16 (i.e., the end farther from the base 10). The feed screw 20 rotates around the central axis 26 by the driving force from the output shaft of the opening / closing motor 18 in a third direction (the direction indicated by the arrow P3 in FIG. 5) and a fourth direction (the direction indicated by the arrow P4 in FIG. 13) that is opposite to the third direction.

[0056] The moving member 22 is formed, for example, in a plate shape, and is movably disposed inside the frame 16. An insertion hole 30 through which the feed screw 20 is inserted is formed in the center of the moving member 22. A female thread portion that fits with the male thread portion of the feed screw 20 is formed on the inner circumferential surface of the insertion hole 30.

[0057] When the feed screw 20 rotates in the third direction by the driving force from the output shaft of the opening / closing motor 18, the moving member 22 moves along the longitudinal direction of the feed screw 20 from a first position (position shown in FIG. 5) farthest from the opening / closing motor 18 to a second position (position shown in FIG. 13) closest to the opening / closing motor 18. On the other hand, when the feed screw 20 rotates in the fourth direction by the driving force from the output shaft of the opening / closing motor 18, the moving member 22 moves along the longitudinal direction of the feed screw 20 from the second position closest to the opening / closing motor 18 to the first position farthest from the opening / closing motor 18.

[0058] Each of the four-bar link mechanisms 24 is a link mechanism for connecting the movable member 22 to each of the claw portions 8. That is, each of the four-bar link mechanisms 24 is disposed in one-to-one correspondence with each of the claw portions 8. Each of the four-bar link mechanisms 24 has a first link portion 32, a second link portion 34, and a third link portion 36.

[0059] One end of the first link 32 in the longitudinal direction is rotatably connected to the outer periphery of the moving member 22 at a joint 38. The other end of the first link 32 in the longitudinal direction is rotatably connected to one end of the second link 34 at a joint 40. The other end of the second link 34 in the longitudinal direction is rotatably connected to the base end 8a of the claw 8. One end of the third link 36 in the longitudinal direction is rotatably connected to the inner surface 8d of the claw 8 at a joint 42. The other end of the third link 36 in the longitudinal direction is rotatably connected to the outer surface of the frame 16 at a joint 44.

[0060] The claws 8 are arranged around the central axis 26 in the circumferential direction and are made of, for example, metal. Each of the claws 8 has a shape in which the width gradually decreases from the base end 8a to the tip end 8b, and each tip end 8b is formed in a sharp shape. In addition, the outer surface 8c of each of the claws 8 has a convexly curved shape, and the inner surface 8d of each of the claws 8 has a concavely curved shape. In addition, a plurality of cutting edge pieces 46 are formed on the outer surface 8c of each of the claws 8.

[0061] 5, when the movable member 22 is in the first position, the claws 8 are in the open position. In this open position, the second link portion 34 and the third link portion 36 extend substantially perpendicular to the central axis 26, so that the claws 8 are spaced apart from each other along the circumferential direction, and each base end portion 8a projects outward in the radial direction about the central axis 26.

[0062] From this state, when the moving member 22 moves from the first position to the second position as shown in FIG. 13, the multiple claws 8 move from the open position to the closed position via the intermediate position by the action of the multiple four-bar link mechanisms 24. At this closed position, the second link portion 34 and the third link portion 36 extend substantially parallel to the central axis 26, so that the multiple claws 8 are arranged close to each other along the circumferential direction, and the respective tip portions 8b gather together to form a single pointed shape and are in a posture protruding forward (downward in FIG. 13). At this closed position, as shown in FIGS. 10 to 12, the multiple cutting edge pieces 46 of each of the multiple claws 8 are connected to each other to form a single spiral cutting edge 48. At this closed position, almost no gap is formed between a pair of adjacent claws 8. In this embodiment, a single spiral cutting edge 48 is formed, but this is not limited to this, and multiple spiral cutting edges 48, for example, two or three spiral cutting edges, may be formed.

[0063] 13, when the movable member 22 is in the second position, the claws 8 are in the closed position. When the movable member 22 moves from the second position to the first position as shown in FIG. 5, the claws 8 move from the closed position to the intermediate position to the open position by the action of the four-bar linkage mechanisms 24.

[0064] [1-3. Functions of the end effector] [1-3-1. Wheel function] The wheel function of the end effector 6 according to the first embodiment will be described with reference to Fig. 14. Fig. 14 is a diagram for explaining the wheel function of the end effector 6 according to the first embodiment.

[0065] As shown in FIG. 14, when the robot 2 is moved forward (in the direction indicated by the arrow D1 in FIG. 14) on the ground 50, such as the surface of the moon, the drive mechanism 12 changes the form of the multiple claws 8 to a form that exhibits a wheel function. That is, the drive mechanism 12 drives the opening / closing motor 18 to move the moving member 22 from the second position to the first position, thereby positioning the multiple claws 8 in the open position and bringing the base end 8a of the claw 8 arranged at the bottom into contact with the ground 50. In this state, the drive mechanism 12 drives the rotation motor 14 to rotate the frame 16 in the first direction, thereby rotating the multiple claws 8 in the first direction (in the direction indicated by the arrow P1 in FIG. 14) about the central axis 26 (see FIG. 2). As a result, the multiple claws 8 roll on the ground 50 like wheels, and the robot 2 can be moved forward on the ground 50.

[0066] Furthermore, when moving the robot 2 on the ground 50 in a backward direction (the direction indicated by the arrow D2 in FIG. 14) opposite to the forward direction, the drive mechanism 12 drives the rotation motor 14 to rotate the frame 16 in the second direction, thereby rotating the multiple claws 8 in the second direction (the direction indicated by the arrow P2 in FIG. 14) about the central axis 26. This causes the multiple claws 8 to roll on the ground 50 like wheels, thereby moving the robot 2 in the backward direction on the ground 50.

[0067] [1-3-2. Gripper function] The gripper function of the end effector 6 according to the first embodiment will be described with reference to Fig. 15 and Fig. 16. Fig. 15 and Fig. 16 are diagrams for explaining the gripper function of the end effector 6 according to the first embodiment.

[0068] As shown in (a) and (b) of FIG. 15, when the plurality of claws 8 grip an object 52 having a substantially annular shape, for example, the drive mechanism 12 changes the shape of the plurality of claws 8 to a shape that performs a gripper function. That is, the drive mechanism 12 drives the opening / closing motor 18 to move the moving member 22 from the first position to the second position, thereby causing the plurality of claws 8 to grip the object 52 while moving the plurality of claws 8 from the open position to the closed position. At this time, the plurality of claws 8 grip the object 52 by pinching the outer peripheral surface of the object 52 with each of the tip portions 8b. In this way, the plurality of claws 8 can grip the object 52 by utilizing the force that moves the plurality of claws 8 from the open position to the closed position.

[0069] Also, as shown in (a) and (b) of FIG. 16, when the plurality of claws 8 grip, for example, a substantially plate-shaped object 54, the drive mechanism 12 changes the shape of the plurality of claws 8 to a shape that performs a gripper function. That is, the drive mechanism 12 drives the opening / closing motor 18 to move the moving member 22 from the first position toward the second position, thereby causing the plurality of claws 8 to grip the object 54 while moving the plurality of claws 8 from the open position to the closed position. At this time, the drive mechanism 12 presses four adjacent claws 8 of the plurality of claws 8 against the first main surface 54a of the object 54, and presses the remaining four adjacent claws 8 of the plurality of claws 8 against the second main surface 54b (the main surface opposite to the first main surface 54a) of the object 54. As a result, the plurality of claws 8 grip the object 54 by sandwiching it from both sides. In this manner, the object 54 can be gripped by the multiple claws 8 by utilizing the force that moves the multiple claws 8 from the open position to the closed position.

[0070] In this embodiment, the shape of the object 52 is formed to be approximately circular and the shape of the object 54 is formed to be approximately plate-like, but this is not limited to this, and the above-mentioned gripper function can be used to cause the multiple claw portions 8 to grip objects of various shapes.

[0071] [1-3-3. Shovel function] The shovel function of the end effector 6 according to the first embodiment will be described with reference to Fig. 17. Fig. 17 is a diagram for explaining the shovel function of the end effector 6 according to the first embodiment.

[0072] As shown in FIG. 17, when the multiple claws 8 are used to dig up an object 56 such as soil and sand, the drive mechanism 12 changes the shape of the multiple claws 8 to a shape that performs a shovel function. That is, the drive mechanism 12 buries the tip 8b of each of the multiple claws 8 in the object 56 while the multiple claws 8 are in the open position. Next, the drive mechanism 12 drives the opening / closing motor 18 to move the moving member 22 from the first position to the second position, thereby causing the multiple claws 8 to dig up the object 56 with each tip 8b while moving the multiple claws 8 from the open position to the closed position. As a result, the excavated object 56 is stored in the space surrounded by the multiple claws 8.

[0073] Next, after moving the robot 2 to a predetermined location, the drive mechanism 12 drives the opening / closing motor 18 to move the moving member 22 from the second position toward the first position, thereby moving the multiple claws 8 from the closed position to the open position. This allows the object 56 contained in the space surrounded by the multiple claws 8 to be lowered into the predetermined location.

[0074] [1-3-4. Drill function] The drill function of the end effector 6 according to the first embodiment will be described with reference to Fig. 18. Fig. 18 is a diagram for explaining the drill function of the end effector 6 according to the first embodiment.

[0075] As shown in FIG. 18, when the multiple claws 8 are used to excavate an object 58, such as an underground wall, the drive mechanism 12 changes the shape of the multiple claws 8 to a shape that performs a drill function. That is, the drive mechanism 12 drives the opening / closing motor 18 to move the moving member 22 from the first position to the second position, thereby positioning the multiple claws 8 in the closed position. In this state, the drive mechanism 12 drives the rotation motor 14 to rotate the frame 16 in the first direction while moving the multiple claws 8 closer to the object 58, thereby rotating the multiple claws 8 in the first direction (the direction indicated by the arrow P1 in FIG. 18) about the central axis 26. As a result, the cutting blades 48 formed on the outer surfaces of the multiple claws 8 can excavate the object 58.

[0076] [1-4. Effects] In this embodiment, as described above, the drive mechanism 12 changes the shape of the plurality of claws 8 from one of the plurality of shapes to another shape. In this manner, by changing the shape of the plurality of claws 8, a plurality of functions can be realized.

[0077] This allows the end effector 6 to be lighter and more space-saving than the conventional end effector described in the Background section, which is equipped with a number of tools corresponding to the type of work to be performed by the robot. As a result, for example, when the robot 2 is used in a space mission, the robot 2 can be easily transported. Also, since there is no need to change tools depending on the work to be performed by the robot, as in the conventional end effector described in the Background section, the work efficiency of the robot 2 can be improved.

[0078] (Embodiment 2) [2-1. Overall configuration of the end effector] The overall configuration of an end effector 6A according to the second embodiment will be described with reference to FIGS.

[0079] Fig. 19 is a perspective view of the end effector 6A according to the second embodiment in a state where the plurality of claws 8 are located at the closed position. Fig. 20 is a perspective view of the end effector 6A according to the second embodiment in a state where the plurality of claws 8 are located at the open position. Fig. 21 is a perspective view of the end effector 6A according to the second embodiment in a state where the plurality of claws 8 are rotated from the open position.

[0080] In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0081] An end effector 6A according to the second embodiment includes a plurality of claws 8 and a drive mechanism 12A. In this embodiment, the number of the plurality of claws 8 and the configuration of the drive mechanism 12A are different from those in the first embodiment.

[0082] Similar to the first embodiment, the plurality of claws 8 are arranged in the circumferential direction around the central axis 26. In the present embodiment, the number of the plurality of claws 8 is six.

[0083] The drive mechanism 12A includes a motor 60 (an example of a drive source), a worm 62, and a plurality of transmission mechanisms 64.

[0084] The motor 60 is a servo motor for rotating the worm 62 about the central axis 26. The motor 60 is supported, for example, on a base (not shown), and has an output shaft that outputs a driving force. For convenience of explanation, the motor 60 is not shown in FIG.

[0085] The worm 62 extends along the central axis 26. One end in the longitudinal direction of the worm 62 is connected to the output shaft of the motor 60. The worm 62 rotates by the driving force from the output shaft of the motor 60 around the central axis 26 in a fifth direction (the direction indicated by the arrow P5 in FIG. 21) and a sixth direction (the direction indicated by the arrow P6 in FIG. 21) that is opposite to the fifth direction.

[0086] Each of the multiple transmission mechanisms 64 is a mechanism for transmitting (distributing) the driving force of the worm 62 to the multiple claw portions 8. That is, each of the multiple transmission mechanisms 64 is disposed in one-to-one correspondence with the multiple claw portions 8. In order to avoid complicating the drawings, only one transmission mechanism 64 is illustrated in Figs. 19 to 21, and the remaining five transmission mechanisms 64 are partially omitted from illustration.

[0087] The drive mechanism 12A changes the form of the multiple claws 8 from one form to another form among multiple (e.g., three) forms each performing multiple (e.g., three) functions different from one another. In this embodiment, the multiple functions include (a) a wheel function for moving (running) the robot (not shown) on the ground, (b) a gripper function for gripping an object, (c) a shovel function for digging up an object, and (d) a drill function for excavating an object.

[0088] When the driving mechanism 12A changes the shape of the multiple claw portions 8 from a shape that performs a drill function to a shape that performs a wheel function, each of the multiple claw portions 8 is moved by the driving force from the multiple transmission mechanisms 64, (i) from a closed position (position shown in FIG. 19) in which they are arranged close to each other along the circumferential direction to an open position (position shown in FIG. 20) in which they are arranged apart from each other along the circumferential direction, and then (ii) rotated approximately 90° from a position in which they are arranged radially around the central axis 26 (position shown in FIG. 20) to a position in which they are arranged approximately in a circle around the central axis 26 along the circumferential direction (position shown in FIG. 21).

[0089] In addition, when the drive mechanism 12A changes the shape of the multiple claw portions 8 to a shape that performs a gripper function or a shovel function, each of the multiple claw portions 8 is moved from the open position to the closed position by the drive force from the multiple transmission mechanisms 64.

[0090] [2-2. Transmission mechanism configuration] 22 and 23, the configuration of the transmission mechanism 64 of the end effector 6A according to embodiment 2 will be described. Note that since each of the multiple transmission mechanisms 64 has the same configuration, only the configuration of one of the transmission mechanisms 64 will be described below.

[0091] Fig. 22 is a perspective view showing the transmission mechanism 64 of the end effector 6A according to embodiment 2. Fig. 23 is a perspective view showing the transmission mechanism 64 of the end effector 6A according to embodiment 2 when viewed from an angle different from that of Fig. 22. Figs. 24 to 26 are views for explaining the operation of the transmission mechanism 64 of the end effector 6A according to embodiment 2.

[0092] As shown in Figures 22 and 23, the transmission mechanism 64 has a worm gear 66, a first intermittent gear 68, a second intermittent gear 70, a first gear 72, a first link portion 74, a second gear 76, and a conversion mechanism 78.

[0093] The worm gear 66 meshes with the worm 62 and rotates as the worm 62 rotates.

[0094] The first intermittent gear 68 is fixed relative to the worm gear 66 and rotates together with the rotation of the worm gear 66 .

[0095] The second intermittent gear 70 is fixed to the worm gear 66 and rotates integrally with the rotation of the worm gear 66. The second intermittent gear 70 is interposed between the worm gear 66 and the first intermittent gear 68. When viewed from the direction of the rotation axis of the second intermittent gear 70, the multiple teeth of the first intermittent gear 68 and the multiple teeth of the second intermittent gear 70 are arranged so as not to overlap with each other.

[0096] The first gear 72 is capable of meshing with the first intermittent gear 68 and rotates in conjunction with the rotation of the first intermittent gear 68 .

[0097] The first link portion 74 connects the first gear 72 and the claw portion 8. One end of the first link portion 74 in the longitudinal direction is fixedly (non-rotatably) connected to a side surface of the first gear 72. The other end of the first link portion 74 in the longitudinal direction is rotatably connected to a base end portion 8a of the claw portion 8. The first link portion 74 converts the rotational movement of the first gear 72 into the movement of the claw portion 8 between the closed position and the open position.

[0098] The second gear 76 is disposed opposite to the first gear 72. The second gear 76 is capable of meshing with the second intermittent gear 70, and rotates in conjunction with the rotation of the second intermittent gear 70.

[0099] The conversion mechanism 78 is a mechanism for converting the rotational motion of the second gear 76 into the pivoting motion of the claw portion 8. The conversion mechanism 78 has a first helical gear 80, a second helical gear 82, a pivot member 84, and a second link portion 86.

[0100] The first helical gear 80 is fixed relative to the second gear 76 and rotates together with the rotation of the second gear 76 .

[0101] The second helical gear 82 meshes with the first helical gear 80 and rotates with the rotation of the first helical gear 80. The rotation axis of the second helical gear 82 and the rotation axis of the first helical gear 80 are approximately perpendicular to each other.

[0102] The rotating member 84 is fixed to the second helical gear 82 and rotates together with the rotation of the second helical gear 82. The rotating member 84 is also fixed to one end of the first link portion 74 in the longitudinal direction.

[0103] The second link portion 86 connects the pivot member 84 and the claw portion 8. One end portion in the longitudinal direction of the second link portion 86 is pivotally connected to the pivot member 84. The other end portion in the longitudinal direction of the second link portion 86 is pivotally connected to an inner surface 8d of the claw portion 8.

[0104] Next, the operation of the transmission mechanism 64 when changing the form of the multiple claws 8 from a form exhibiting a drill function to a form exhibiting a wheel function will be described with reference to Figs. 24 to 26. Figs. 24 to 26 are diagrams for explaining the operation of the transmission mechanism 64 of the end effector 6A according to the second embodiment. For convenience of explanation, the worm gear 66 is omitted from Figs. 24 and 26.

[0105] As in the first embodiment, the claws 8 are in the closed position (the position shown in Fig. 19 and Fig. 25(a)) in the mode in which the drill function is exercised. In this state, as shown in Fig. 24, the first intermittent gear 68 and the first gear 72 are engaged with each other, and the second intermittent gear 70 and the second gear 76 are disengaged from each other.

[0106] From this state, the worm 62 rotates in the fifth direction, and the worm gear 66 rotates with the rotation of the worm 62. As a result, as shown in Fig. 25(a), the first intermittent gear 68 and the second intermittent gear 70 rotate integrally with the rotation of the worm gear 66, and the first gear 72 rotates with the rotation of the first intermittent gear 68. At this time, since the meshing between the second intermittent gear 70 and the second gear 76 is released, the second gear 76 does not rotate with the rotation of the second intermittent gear 70.

[0107] As a result, as shown in (b) of Figure 25, the first link portion 74 tilts together with the rotation of the first gear 72, and accordingly, the multiple claw portions 8 move from the closed position to the open position (the positions shown in Figures 20, (b) of Figure 25, and (a) of Figure 26).

[0108] As shown in (a) of Figure 26, when the multiple claw portions 8 are positioned in the open position, the first intermittent gear 68 and the first gear 72 are disengaged, and the second intermittent gear 70 and the second gear 76 are engaged with each other.

[0109] From this state, the worm 62 rotates in the fifth direction, and the worm gear 66 rotates with the rotation of the worm 62. As a result, the first intermittent gear 68 and the second intermittent gear 70 rotate integrally with the rotation of the worm gear 66, and the second gear 76 rotates with the rotation of the second intermittent gear 70.

[0110] Then, the first helical gear 80 rotates integrally with the second gear 76, and the second helical gear 82 rotates with the rotation of the first helical gear 80. As a result, as shown in Fig. 26(b), the rotating member 84 rotates integrally with the rotation of the second helical gear 82, and the rotating motion of the rotating member 84 is transmitted to the claw portion 8 via the second link portion 86. At this time, since the meshing between the first intermittent gear 68 and the first gear 72 is released, the first gear 72 does not rotate with the rotation of the first intermittent gear 68, but rotates integrally with the rotating member 84.

[0111] As a result, the multiple claws 8 rotate by approximately 90° from a position in which they are radially arranged about the central axis 26 (the position shown in Fig. 20 and Fig. 26(a)) to a position in which they are arranged in a substantially circular shape circumferentially about the central axis 26 (the position shown in Fig. 21 and Fig. 26(b)). In this manner, the shape of the multiple claws 8 changes from a shape that performs the drill function to a shape that performs the wheel function.

[0112] In addition, when changing the shape of the multiple claw portions 8 from a shape that performs a wheel function to a shape that performs a drill function, the worm 62 is rotated in the sixth direction to perform the operation of the transmission mechanism 64 in the opposite manner to that described above.

[0113] In this embodiment, the transmission mechanism 64 has two intermittent gears (the first intermittent gear 68 and the second intermittent gear 70), but may have three or more intermittent gears. As a result, when the shape of the multiple claws 8 is changed to a shape that performs a gripper function, instead of a shape that performs a gripper function similar to that of the first embodiment, the shape may be changed to a shape that performs a gripper function of a different type from that of the first embodiment. When the shape of the multiple claws 8 is changed to a shape that performs a gripper function of a different type, for example, while the multiple claws 8 are moved from the open position to the closed position, three adjacent claws 8 among the multiple claws 8 are brought close to each other, and the remaining three adjacent claws 8 among the multiple claws 8 are brought close to each other. Next, by bringing these three pairs of claws 8 close to each other, the object can be gripped so as to be sandwiched from both sides.

[0114] [2-3. Effects] In this embodiment, when the form of the plurality of claws 8 is changed to a form that exhibits wheel functions, the overall shape of the plurality of claws 8 can be made closer to a circle, which allows the robot to move more stably.

[0115] (Other variations, etc.) Although the end effector according to the first and second embodiments of the present invention has been described above, the present invention is not limited to these first and second embodiments. For example, the above-described embodiments may be combined with each other.

[0116] In the above-mentioned first and second embodiments, the robot 2 is applied as a space work robot for performing work in outer space, but the present invention is not limited to this and may be applied as an industrial robot for performing various tasks such as construction work or product assembly work on the ground.

[0117] In addition, in the above-mentioned embodiments 1 and 2, four functions (wheel function, gripper function, shovel function, and drill function) are realized by modifying the shape of the multiple claw portions 8, but this is not limited to this, and at least two of these four functions may be realized.

[0118] In addition, in the above embodiment 1, the drive mechanism 12 has multiple four-bar link mechanisms 24, but this is not limited to this and may have various other mechanisms, such as a mechanism composed of a belt and a pulley. [Industrial Applicability]

[0119] The present invention can be applied, for example, as an end effector mounted on a robot for working in outer space. [Explanation of symbols]

[0120] 2. Robot 4 Robot body 6,6A End effector 8 Claws 8a Proximal end 8b Tip 8c External surface 8d inner surface 10 Base 12,12A Drive mechanism 14 Rotation motor 16 Frames 18 Opening and closing motor 20 Lead screw 22 Moving parts 24 Four-bar link mechanism 26 Center axis 28 Bearing section 30 Insertion hole 32,74 First link 34,86 Second link 36 Third Link 38,40,42,44 nodes 46 Cutting blade piece 48 Cutting edge 50 ground 52, 54, 56, 58 Object 54a First main surface 54b Second main surface 60 Motor 62 Warm 64 Transmission Mechanism 66 Worm Gear 68 First Intermittent Gear 70 Second Intermittent Gear 72 First Gear 76 Second Gear 78 Conversion Mechanism 80 First helical gear 82 Second helical gear 84 Swivel member

Claims

1. An end effector mounted on a robot for performing a predetermined task on an object, A plurality of claws; a drive mechanism for changing the shape of the plurality of claws from one shape to another shape among a plurality of shapes each of which exerts a plurality of functions different from each other, The plurality of functions includes at least two of: (a) a wheel function for moving the robot; (b) a gripper function for gripping the object; (c) a shovel function for digging up the object; and (d) a drill function for excavating the object. End effector.

2. The plurality of claws are arranged in a circumferential direction around a central axis, The drive mechanism moves the plurality of claw portions from one of an open position in which the claw portions are spaced apart from each other along the circumferential direction and a closed position in which the claw portions are close to each other along the circumferential direction to the other. The end effector of claim 1 .

3. When the drive mechanism changes the shape of the plurality of claw portions to a shape that performs the wheel function, the drive mechanism rotates the plurality of claw portions in a predetermined direction around the central axis while the plurality of claw portions are positioned at the open position. The end effector of claim 2 .

4. When the drive mechanism changes the shape of the plurality of claw portions to a shape that performs the gripper function, the drive mechanism causes the plurality of claw portions to grip the object while moving the plurality of claw portions from the open position to the closed position. The end effector of claim 2 .

5. The plurality of claws grip the outer circumferential surface of the object by pinching it with their respective tip portions. The end effector of claim 4 .

6. The object is formed in a generally plate-like shape having a first main surface and a second main surface opposite to the first main surface, The drive mechanism presses some of the plurality of claw portions against the first main surface of the object and presses the remaining some of the plurality of claw portions against the second main surface of the object, so that the plurality of claw portions grip the object so as to sandwich the object from both sides. The end effector of claim 4 .

7. When the drive mechanism changes the shape of the plurality of claws to a shape that performs the shovel function, the drive mechanism causes the plurality of claws to dig up the object with the tip end of each of the plurality of claws while moving the plurality of claws from the open position to the closed position. The end effector of claim 2 .

8. A plurality of cutting blade pieces for excavating the target object are formed on an outer surface of each of the plurality of claw portions, When the drive mechanism changes the configuration of the plurality of claw portions to a configuration that performs the drill function, the drive mechanism rotates the plurality of claw portions in a predetermined direction around the central axis while the plurality of claw portions are positioned at the closed position. The end effector of claim 2 .

9. When the drive mechanism positions the plurality of claw portions at the closed position, the plurality of cutting edge pieces of each of the plurality of claw portions are connected to each other, thereby forming at least one helical cutting edge. The end effector of claim 8 .

10. The drive mechanism includes: A moving member; a drive source for reciprocating the moving member along the central axis; a plurality of four-joint link mechanisms each connecting the moving member to each of the plurality of claw portions, The end effector according to any one of claims 2 to 9.

11. The plurality of claws are arranged in a circumferential direction around a central axis, The drive mechanism includes: A worm extending along the central axis; A drive source that rotates the worm in a predetermined direction; a plurality of transmission mechanisms for transmitting the driving force of the worm to the plurality of claw portions, respectively; When the drive mechanism changes the configuration of the plurality of claw portions from the configuration for performing the drill function to the configuration for performing the wheel function, the drive mechanism (i) moves each of the plurality of claw portions from a closed position in which the claw portions are disposed close to each other along the circumferential direction to an open position in which the claw portions are disposed apart from each other along the circumferential direction by the drive force from the plurality of transmission mechanisms, and then (ii) rotates the claw portions from a position in which the claw portions are disposed radially about the central axis to a position in which the claw portions are disposed substantially circularly about the central axis along the circumferential direction. The end effector of claim 1 .

12. Each of the plurality of transmission mechanisms is a worm gear that meshes with the worm; a first intermittent gear and a second intermittent gear which rotate integrally with the rotation of the worm gear; a first gear that meshes with the first intermittent gear; a first link portion that connects the claw portion and the first gear and converts a rotational motion of the first gear into a moving motion of the claw portion between the closed position and the open position; a second gear that meshes with the second intermittent gear; a conversion mechanism for converting the rotational motion of the second gear into a pivoting motion of the claw portion. The end effector of claim 11.

13. The conversion mechanism is a first helical gear that rotates together with the second gear; a second helical gear meshing with the first helical gear; a rotating member that rotates together with the second helical gear; a second link portion connecting the pivot member and the claw portion. The end effector of claim 12.

14. A robot for performing a predetermined task on an object, The end effector according to claim 1 is provided. robot.

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