Joint device and robot hand apparatus

Abstract

To reproduce rotational motion with two degrees of freedom in a single joint in a wire traction drive type joint device.SOLUTION: A joint device comprises: a base portion; a movable portion that can move relative to the base portion; a spherical bearing that has an inner ring fixed to the base portion side and an outer ring fixed to the movable portion side; a wire traction device that pulls a wire connected to the outer ring side to rotate the outer ring about two rotational axes among a roll axis, a pitch axis and a yaw axis; and a rotation restricting portion that restricts rotation of the outer ring about a remaining one other than the two of the rotational axes.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an articulated device and a robotic hand device. [Background technology]

[0002] Patent Document 1 below discloses a robot hand and a robot including the same. This robot hand includes a base, a plurality of finger structures connected to the base, a drive unit that drives the plurality of finger structures, and wires that transmit drive force from the drive unit to the plurality of finger structures. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-140113 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned wire traction drive system allows for one-degree-of-freedom movements such as bending, stretching, and rotation for a single mechanism, but when pulled from multiple directions, it may not be able to move in the intended direction. For this reason, the wire traction drive system does not reproduce movements with more than one degree of freedom at a single joint. Therefore, conventional robot hand devices have a structure that combines two or more mechanisms that perform one-degree-of-freedom movements, which often results in the device becoming larger.

[0005] An object of the present disclosure is to provide a joint device and a robot hand device that solve the above-mentioned problems. [Means for solving the problem]

[0006] To solve the above problems, this disclosure proposes the following means. The joint device according to the present disclosure includes a base portion, a movable portion movable relative to the base portion, a spherical bearing having an inner ring fixed to the base portion side and an outer ring fixed to the movable portion side, a wire pulling device that pulls a wire connected to the outer ring side and rotates the outer ring around two of the roll axis, pitch axis, and yaw axis, and a rotation restricting portion that restricts rotation of the outer ring around the remaining rotation axis other than the two rotation axes.

[0007] A robot hand device according to the present disclosure includes a hand body, finger parts that are movable relative to the hand body, and the above-described joint device that connects the hand body and the finger parts. [Effects of the Invention]

[0008] According to the present disclosure, in a wire traction drive type joint device, it is possible to reproduce a rotational movement with two degrees of freedom with one joint. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a configuration diagram of a joint device according to an example of a minimum configuration of the present disclosure. [Figure 2] FIG. 1 is a configuration diagram of a joint device according to an embodiment of the present disclosure. [Figure 3] FIG. 1 is an exploded perspective view of a spherical bearing and its surrounding structure according to an embodiment of the present disclosure. [Figure 4] 1 is a perspective view of a joint device according to an embodiment of the present disclosure, viewed from a connection portion side. FIG. [Figure 5] 1 is a perspective view showing a connection state between a first wire attachment portion and a wire pulling device according to an embodiment of the present disclosure. FIG. [Figure 6] FIG. 10 is a perspective view showing a connection between a second wire attachment portion and a wire pulling device according to an embodiment of the present disclosure. [Figure 7] 10A and 10B are diagrams illustrating radial abduction and ulnar adduction of a movable section according to an embodiment of the present disclosure. [Figure 8] 10A and 10B are diagrams illustrating volar abduction and volar adduction of a movable part according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] An example of the minimum configuration of the present disclosure will be described with reference to FIG. FIG. 1 is a configuration diagram of a joint device 1 according to an example of a minimum configuration of the present disclosure. As shown in FIG. 1, the joint device 1 includes a base portion 10, a movable portion 20, a spherical bearing 30, a wire pulling device 40, and a rotation restricting portion 53.

[0011] The base unit 10 is, for example, a hand body of a robot hand device, but is not limited to a hand body. The movable unit 20 is, for example, a finger part of a robot hand device, but is not limited to a finger part. The spherical bearing 30 has an inner ring 31 fixed to the base unit 10 side and an outer ring 32 fixed to the movable unit 20 side.

[0012] The outer ring 32 is rotatable around a roll axis (X axis), a pitch axis (Y axis), and a yaw axis (Z axis). The roll axis (X axis), pitch axis (Y axis), and yaw axis (Z axis) are perpendicular to one another, and their intersection is set as the center of rotation of the spherical bearing 30. The wire pulling device 40 rotates the outer ring 32 around two of the three rotation axes, the pitch axis (Y axis) and the yaw axis (Z axis).

[0013] The rotation restricting unit 53 restricts the rotation of the outer wheel 32 around the roll axis (X axis), which is the only remaining rotation axis other than the pitch axis (Y axis) and the yaw axis (Z axis). This allows for independent control of two-degree-of-freedom rotational movements (rotational movements around the two rotational axes, the pitch axis (Y axis) and the yaw axis (Z axis)), and allows the outer wheel 32 to rotate in the intended direction even when pulled in multiple directions by the wire pulling device 40.

[0014] In this way, the joint device 1 described above can reproduce two-degree-of-freedom rotational movement with one joint by combining the spherical bearing 30, the wire-pulling device 40, and the rotation restricting unit 53. Furthermore, a robot hand device including the joint device 1 described above can make the movements of finger parts closer to those of a human hand with a compact configuration.

[0015] Next, an embodiment of the present disclosure will be described with reference to Figures 2 to 7 in addition to Figure 1. In Figures 2 to 7, the same components as those in Figure 1 are denoted by the same reference numerals, and the description will be simplified.

[0016] Fig. 2 is a configuration diagram of the joint device 1 according to one embodiment of the present disclosure. Note that, in Fig. 2, the wire of the wire-pulling device 40 is not shown to improve visibility. The same applies to Figs. 4, 7, and 8, which will be described later. The joint device 1 is provided in a robot hand device, as shown in Fig. 2. The robot hand device includes a hand body and finger parts that are movable relative to the hand body.

[0017] The finger parts include a thumb part (movable part 20) and four finger parts 11 that serve as the index finger, middle finger, ring finger, and little finger. The joint device 1 forms a thumb joint with the hand body as the base part 10 and the thumb part as the movable part 20. The base part 10 is provided with a mount 12 on which a spherical bearing 30 is attached.

[0018] FIG. 3 is an exploded perspective view of the peripheral structure of a spherical bearing 30 according to one embodiment of the present disclosure. 3, the spherical bearing 30 has an inner ring 31 and an outer ring 32. The inner ring 31 is attached to the mounting base 12 via a bolt 60, a first collar 61, and a second collar 62.

[0019] The first collar 61 and the second collar 62 are each formed in a cylindrical shape with a flange at one end, and are inserted from both sides into a through-hole formed in the inner ring 31. The bolt 60 is inserted through the inside of the inner ring 31, the first collar 61, and the second collar 62, and is screwed into the mounting base 12. This fixes the inner ring 31 to the base portion 10 side.

[0020] An annular guide member 50 is attached to the outer periphery of the outer ring 32 with bolts or the like (not shown). The guide member 50 is provided with a first wire attachment portion 51, a second wire attachment portion 52, and a rotation restricting portion 53. The rotation restricting portion 53 protrudes downward from the underside of the guide member 50 (the mounting base 12 side). A pair of rotation restricting portions 53 are provided on either side of the central axis of the guide member 50.

[0021] The rotation restricting portion 53 is provided with an abutment portion 53a that abuts against the base portion 10 (mounting base 12). The abutment portion 53a has a curved surface shape centered on the pitch axis (Y axis) shown in FIG. 1 so as to allow rotation of the outer ring 32 about the pitch axis (Y axis). As shown in FIG. 3, the rotation restricting portion 53 is formed with a first wire mounting portion 51 and a wire guide mounting portion 56. The first wire mounting portion 51 is formed to penetrate the rotation restricting portion 53 in the radial direction.

[0022] The wire guide mounting portion 56 is disposed above the first wire mounting portion 51. The wire guide mounting portion 56 is formed in a concave shape in a portion that protrudes radially outward from the outer circumferential surface of the guide member 50. As shown in FIG. 2, an arc-shaped wire guide 54 is mounted to the wire guide mounting portion 56. In addition, as shown in FIG. 3, a connecting portion 55 for connecting the movable portion 20 is formed on the outer circumferential surface of the guide member 50.

[0023] The second wire mounting portion 52 is provided on the underside (mounting base 12 side) of the guide member 50. The second wire mounting portion 52 is provided as a pair with the rotation restricting portion 53 (first wire mounting portion 51) at an angle of 90° in plan view, sandwiching the central axis of the guide member 50 therebetween. The second wire mounting portion 52 is formed by radially penetrating a protruding piece that protrudes downward from the underside of the guide member 50.

[0024] Fig. 4 is a perspective view of the joint device 1 according to an embodiment of the present disclosure, viewed from the side of the connection portion 55. In Fig. 4, the movable portion 20 has been removed. 4, a pair of arc-shaped openings 12a are formed on the upper surface (guide member 50 side) of the mount 12. The pair of openings 12a are formed inside the rotation path of the rotation restricting portion 53. As a result, the abutting portion 53a of the rotation restricting portion 53 is always in contact with the upper surface of the mount 12. A pair of wire guides 12b are provided on the lower side of the mount 12.

[0025] FIG. 5 is a perspective view showing a connection state between the first wire attachment portion 51 and the wire-pulling device 40 according to the embodiment of the present disclosure. 5, a first wire 41 extending from the wire-pulling device 40 is connected to the first wire attachment portion 51. The first wire 41 is made up of two wires 41a and 41b, which are attached to the pair of first wire attachment portions 51 individually.

[0026] An arc-shaped guide groove that guides the first wire 41 in the circumferential direction is formed in the wire guide 54. A first hole 13 that guides the first wire 41 inside is formed in the base portion 10. The first wire 41 guided inside the base portion 10 extends from a second hole 14 formed on the wrist side of the base portion 10 to the wire pulling device 40 (see FIG. 1).

[0027] 1, the wire-pulling device 40 selectively pulls the wires 41a, 41b to operate a pair of first wire attachment parts 51 provided on both sides of the spherical bearing 30 in the direction in which the pitch axis (Y axis) extends (Y axis direction). In this way, the wire-pulling device 40 can rotate the outer ring 32 around the yaw axis (Z axis) via the guide member 50.

[0028] FIG. 6 is a perspective view showing a connection between the second wire attachment portion 52 and the wire-pulling device 40 according to one embodiment of the present disclosure. 6, the second wire 42 extending from the wire-pulling device 40 is connected to the second wire mounting portion 52. The second wire 42 is made up of two wires 42a and 42b, which are attached to the pair of second wire mounting portions 52 individually.

[0029] A guide hole 12c communicating with the pair of openings 12a (see FIG. 4) is formed in the center of the underside of the mounting base 12. The second wire 42 that passes through the guide hole 12c passes through the pair of wire guides 12b, is led to the base portion 10 side, and extends to the wire pulling device 40 (see FIG. 1).

[0030] 1, the wire-pulling device 40 selectively pulls the wires 42a, 42b to operate a pair of second wire attachment parts 52 provided on both sides of the spherical bearing 30 in the direction (X-axis direction) in which the roll axis (X-axis) extends. In this way, the wire-pulling device 40 can rotate the outer ring 32 around the pitch axis (Y-axis) via the guide member 50.

[0031] FIG. 7 is a diagram showing radial abduction and ulnar adduction of the movable section 20 according to one embodiment of the present disclosure. As shown in Fig. 7, the movable part 20 is capable of radial abduction and ulnar adduction by the spherical bearing 30. Specifically, as shown in Fig. 1, when the wire-pulling device 40 pulls the wire 41a, the movable part 20 undergoes ulnar adduction around the yaw axis (Z-axis). When the wire-pulling device 40 pulls the wire 41b, the movable part 20 undergoes radial abduction around the yaw axis (Z-axis). At this time, the rotation restricting part 53 restricts the rotation of the movable part 20 around the roll axis (X-axis) by abutting against the base part 10 side.

[0032] FIG. 8 is a diagram showing the state of palmar abduction and palmar adduction of the movable part 20 according to one embodiment of the present disclosure. As shown in Fig. 8, the movable part 20 is capable of palmar abduction and palmar adduction by the spherical bearing 30. Specifically, as shown in Fig. 1, when the wire-pulling device 40 pulls the wire 42a, the movable part 20 undergoes palmar adduction around the pitch axis (Y-axis). When the wire-pulling device 40 pulls the wire 42b, the movable part 20 undergoes palmar abduction around the pitch axis (Y-axis). At this time, the rotation restricting part 53 comes into contact with the base part 10, thereby restricting the rotation of the movable part 20 around the roll axis (X-axis).

[0033] As described above, the joint device 1 includes the base unit 10, the movable unit 20 movable relative to the base unit 10, the spherical bearing 30 having the inner ring 31 fixed to the base unit 10 and the outer ring 32 fixed to the movable unit 20, the wire-pulling device 40 that pulls the wires (first wire 41, second wire 42) connected to the outer ring 32 side and rotates the outer ring 32 around two rotation axes (pitch axis (Y axis) and yaw axis (Z axis)) out of the roll axis, pitch axis, and yaw axis, and the rotation restricting unit 53 that restricts the rotation of the outer ring 32 around the remaining rotation axis (roll axis (X axis)). With this configuration, the wire-pulling drive type joint device 1 can reproduce a rotational movement with two degrees of freedom with one joint.

[0034] Moreover, in one embodiment of the present disclosure, the rotation restricting portion 53 is provided on the outer ring 32 side and includes an abutting portion 53a that abuts against the base portion 10. According to this configuration, the rotation restricting portion 53 abuts against the base portion 10, thereby restricting the rotation of the outer ring 32 around the roll axis (X axis).

[0035] Furthermore, in one embodiment of the present disclosure, a pair of contact portions 53a are provided on both sides of the spherical bearing 30 in the direction in which one of the two rotation axes (pitch axis (Y axis) and yaw axis (Z axis)) (pitch axis (Y axis)) extends. With this configuration, the rotation restricting portion 53 can restrict rotation of the outer ring 32 around the roll axis (X axis) on both sides of the rotation direction.

[0036] In addition, in one embodiment of the present disclosure, the abutment portion 53a has a curved surface shape centered on one rotation axis (pitch axis (Y axis)). With this configuration, the rotation restricting portion 53 can allow the outer ring 32 to rotate around the pitch axis (Y axis).

[0037] Moreover, in one embodiment of the present disclosure, a guide member 50 is provided that is attached to the outer ring 32 and has wires (first wire 41, second wire 42) connected thereto. This configuration makes it easier to connect the wires to the outer ring 32 side.

[0038] Moreover, in one embodiment of the present disclosure, the guide member 50 has a pair of first wire attachment parts 51 provided in a direction in which one of the two rotation axes (pitch axis (Y axis)) extends, and the wire pulling device 40 has a first wire 41 connected to the first wire attachment parts 51. According to this configuration, by selectively pulling the first wire 41, the outer ring 32 can be rotated around the yaw axis (Z axis).

[0039] Moreover, in one embodiment of the present disclosure, the rotation restricting portion 53 is provided on the guide member 50, and the first wire attaching portion 51 is formed on the rotation restricting portion 53. According to this configuration, the first wire attaching portion 51 and the rotation restricting portion 53 are provided integrally with the guide member 50, thereby reducing the number of parts and making it possible to miniaturize the device.

[0040] Moreover, in one embodiment of the present disclosure, the guide member 50 has a pair of second wire mounting portions 52 provided in the direction in which the remaining rotation axis (roll axis (X axis)) extends, and the wire pulling device 40 has a first wire 41 connected to the second wire mounting portions 52. According to this configuration, by selectively pulling the second wire 42, the outer ring 32 can be rotated around the pitch axis (Y axis).

[0041] Moreover, a robot hand device according to an embodiment of the present disclosure includes a hand body (base unit 10), finger parts (movable unit 20) that are movable relative to the hand body, and the above-described joint device 1 that connects the hand body and the finger parts. With this configuration, the movement of the finger parts can be made to approximate the movement of a human hand, despite the compact configuration.

[0042] Moreover, in one embodiment of the present disclosure, the finger part is a thumb part, and the thumb part is capable of palmar abduction, palmar adduction, radial abduction, and ulnar adduction by the joint device 1. With this configuration, the movement of the thumb part can be reproduced with a compact configuration.

[0043] The above-described embodiment of the present disclosure may employ the following modifications.

[0044] For example, the joint device 1 combines a spherical bearing 30 with a wire traction drive system to enable a wide range of rotational motion. By tightly tensioning the wires connected to each of the two degrees of freedom in the guide member 50, it can be constantly pulled from multiple directions. Pulling the first wire 41 fixed to the side of the guide member 50 performs "radial abduction and ulnar adduction," while pulling the second wire 42 fixed to the bottom of the guide member 50 performs "volar abduction and volar adduction." During each rotational motion, the rotation restriction unit 53 of the guide member 50 restricts the direction of movement, allowing rotation in the intended direction for each degree of freedom without being affected by the rotation of the other. Simultaneous pulling can also be used to rotate the thumb diagonally.

[0045] Joint device 1 can reproduce the high degree of freedom of movement of the joint at the base of the thumb (CM joint), which is considered extremely difficult to reproduce in a humanoid five-fingered robot hand device. By making the movement of the robot hand device as close as possible to that of a human hand, it becomes possible to perform delicate movements such as holding and pinching small objects, and it is possible to manufacture a highly accurate five-fingered robot hand device.

[0046] The joint device 1 can be applied to locations requiring two or more degrees of freedom at one location. For example, the joint device 1 is an example of application to a robot hand device that imitates the "base joint of the thumb" of a hand, but the shoulder, elbow, wrist, etc. of the human body also have high degrees of freedom and can be similarly replaced. By applying the joint device 1 to parts that have high degrees of freedom and are difficult to reproduce, it is also possible to create an entire human body, such as arms and legs, as another body (avatar).

[0047] Furthermore, it is not only robotic hand devices that require the delicate movements of a human hand; the same is true for medical devices such as prosthetic hands and legs. Prosthetic hands and legs are medical devices that substitute for the joint movements of humans, so applying them to joints can make them closer to actual joint movements.

[0048] Furthermore, applying this joint device to the manipulator hands of industrial robots used on production lines can expand the range of media that can be handled. Manipulator hands used in assembly, picking, and placing on production lines often have two or three fingers, and the types of parts they can grasp are often limited. For irregularly shaped or difficult-to-grasp media, methods include replacing the manipulator hand with a tool changer or using a camera-based media identification function to determine the orientation of the media. However, these methods increase the tasks of preparing the replacement hand and switching hands during operation, as well as the costs of preparing control software and equipment. Therefore, applying the joint device 1 to the manipulator hand allows the fingers to move flexibly, enabling the gripping style to be switched according to the shape and orientation of the media, thereby continuously grasping the media, thereby minimizing the tasks and costs involved.

[0049] Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like are also included within the scope of the present disclosure. Furthermore, each embodiment can be appropriately combined with other embodiments.

[0050] Furthermore, some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0051] (Appendix 1) A base portion and a movable portion movable relative to the base portion; a spherical bearing having an inner ring fixed to the base portion side and an outer ring fixed to the movable portion side; a wire pulling device that pulls a wire connected to the outer wheel side to rotate the outer wheel around two rotation axes selected from a roll axis, a pitch axis, and a yaw axis; a rotation restricting portion that restricts rotation of the outer ring around the remaining rotation shaft other than the two rotation shafts, Articulation device.

[0052] (Appendix 2) the rotation restricting portion is provided on the outer ring side and includes an abutting portion that abuts against the base portion; 10. The articulation device of claim 1.

[0053] (Appendix 3) The abutment portions are provided as a pair on both sides of the spherical bearing in a direction in which one of the two rotation shafts extends. 10. The articulation device of claim 2.

[0054] (Appendix 4) The contact portion has a curved surface shape centered on the one rotation axis. 4. The articulation device of claim 2 or 3.

[0055] (Appendix 5) a guide member attached to the outer ring and connected to the wire; 5. The articulation device of any one of claims 1 to 4.

[0056] (Appendix 6) the guide member has a pair of first wire attachment portions provided in a direction in which one of the two rotation shafts extends, The wire pulling device includes a first wire connected to the first wire attachment portion. 10. The articulation device of claim 5.

[0057] (Appendix 7) the rotation restricting portion is provided on the guide member, The first wire attachment portion is formed on the rotation restriction portion. 10. The articulation device of claim 6.

[0058] (Appendix 8) the guide member has a pair of second wire attachment portions provided in a direction in which the remaining rotation shaft extends, The wire pulling device includes a second wire connected to the second wire attachment portion. 8. The articulation device of any one of clauses 5 to 7.

[0059] (Appendix 9) A hand body, finger parts that are movable relative to the hand body; and a joint device according to any one of Supplementary Notes 1 to 8, which connects the hand body and the finger parts. Robotic hand device.

[0060] (Appendix 10) the finger part is a thumb part, The thumb part is capable of palmar abduction and palmar adduction, radial abduction and ulnar adduction by the articulation device. 10. The robot hand device according to claim 9. [Explanation of symbols]

[0061] 1 Articulation device 10 Base 11 Finger parts 12 Mounting base 12a opening 12b Wire Guide 12c Guide hole 13 First hole 14 2nd hole 20 Moving parts 30 spherical bearing 31 Inner circle 32 outer ring 40 Wire pulling device 41 First Wire 41a wire 41b Wire 42 Second Wire 42a wire 42b wire 50 Guide member 51 First wire attachment part 52 Second wire attachment part 53 Rotation restriction part 53a Contact part 54 Wire guide 55 Connection 56 Wire guide attachment part 60 volts 61 First Color 62 Second Color

Claims

1. A base portion; a movable portion movable relative to the base portion; a spherical bearing having an inner ring fixed to the base portion side and an outer ring fixed to the movable portion side; a wire pulling device that pulls a wire connected to the outer wheel side to rotate the outer wheel around two rotation axes selected from a roll axis, a pitch axis, and a yaw axis; a rotation restricting portion that restricts rotation of the outer ring around one remaining rotation shaft other than the two rotation shafts, Articulation device.

2. the rotation restricting portion is provided on the outer ring side and includes an abutting portion that abuts against the base portion; The articulation device according to claim 1 .

3. The abutment portions are provided as a pair on both sides of the spherical bearing in a direction in which one of the two rotation shafts extends. The articulation device according to claim 2.

4. the abutment portion has a curved surface shape centered on one of the two rotation axes, 4. The articulation device according to claim 2 or 3.

5. a guide member attached to the outer ring and connected to the wire; An articulation device according to any one of claims 1 to 3.

6. the guide member has a pair of first wire attachment portions provided in a direction in which one of the two rotation shafts extends, The wire pulling device includes a first wire connected to the first wire attachment portion. The articulation device according to claim 5.

7. the rotation restricting portion is provided on the guide member, The first wire attachment portion is formed on the rotation restriction portion. The articulation device according to claim 6.

8. the guide member has a pair of second wire attachment portions provided in a direction in which the remaining one rotation shaft extends, The wire pulling device includes a second wire connected to the second wire attachment portion. The articulation device according to claim 5.

9. A hand body, finger parts that are movable relative to the hand body; the joint device according to claim 1 , which connects the hand body and the finger parts. Robotic hand device.

10. the finger part is a thumb part, The thumb part is capable of palmar abduction and palmar adduction, radial abduction and ulnar adduction by the articulation device. The robot hand device according to claim 9.

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