Robot hand

Abstract

It is an object of the present disclosure to provide a technique for a robot hand that improves the accuracy with which fluid pressure actuators gather at a second position, as compared with the case where the timings at which the directions of the second ends of the fluid pressure actuators are changed are set individually.SOLUTION: The robot hand 18 includes the plurality of fluid pressure actuators 20 of which the root side is rotatably fixed to the base portion 50 and of which the distal end side opposite to the root side is curved and deformed toward the first position FP, the rotation mechanism 58 that switches the direction of the distal end side of the plurality of fluid pressure actuators 20 to the second position SP, and the synchronization mechanism 80 that synchronizes the timing of switching the direction of the distal end side of the plurality of fluid pressure actuators 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a robotic hand. [Background technology]

[0002] For example, Patent Document 1 discloses a modular robot system including: a first soft actuator having an elastomer bladder configured to receive inflation fluid; a positioning system configured to dynamically adjust the absolute position of the first soft actuator in a Cartesian plane or the position of the first soft actuator relative to a second soft actuator in the Cartesian plane; a quick-change assembly for replacing the first soft actuator with an actuator of a different type or size, the quick-change assembly having two or more mating surfaces that correspond to the shape of the first soft actuator and that fit to form a seal around the first soft actuator; and a shut-off valve for cutting off the flow of inflation fluid to the first soft actuator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6879562 Summary of the Invention [Problem to be solved by the invention]

[0004] In a robot hand in which the position where a first end, which is the base side of a fluid pressure actuator, and a second end, which is the opposite end, meet can be changed from a first position to a second position, it is desirable to improve the accuracy of gathering them at the second position.

[0005] The present disclosure aims to disclose a technology for a robot hand that improves the accuracy with which each fluid pressure actuator gathers at the second position compared to when the timing for changing the direction of the second end of each fluid pressure actuator is individually set. [Means for solving the problem]

[0006] The robot hand of the first aspect includes a plurality of fluid pressure actuators each having a first end rotatably fixed to a base and a second end opposite the first end that bends and deforms toward a first position, a switching mechanism that switches the direction in which the second ends of the plurality of fluid pressure actuators face toward a second position, and a synchronization mechanism that synchronizes the timing at which the directions in which the second ends of the plurality of fluid pressure actuators face are switched.

[0007] The robot hand according to this aspect has a plurality of fluid pressure actuators, and when the plurality of fluid pressure actuators are bent and deformed, the direction of the second end can be switched between a first position and a second position. Furthermore, the robot hand according to this aspect uses a synchronization mechanism to synchronize the timing at which the direction of the second end is switched. Therefore, with the robot hand according to this aspect, it is easier to gather the fluid pressure actuators at the second position compared to a case where the timing at which the direction of the second end is changed is individually set for each fluid pressure actuator.

[0008] A second aspect of the robot hand is the robot hand described in the first aspect, wherein the switching mechanism changes the direction in which the second end faces by rotating each of the plurality of fluid pressure actuators around an axis extending from the first end to the second end.

[0009] In the robot hand according to this aspect, the switching mechanism rotates each of the fluid pressure actuators to switch the direction in which the second ends of the multiple fluid pressure actuators face, which allows the robot hand to be smaller in size than when the switching mechanism is linearly actuated to switch the direction in which the second ends face.

[0010] A robot hand of a third aspect is a robot hand according to the second aspect, wherein the plurality of fluid pressure actuators are each mounted so that the second end is tilted in a direction away from the first position relative to the first end.

[0011] In the robot hand of this aspect, the second ends of the fluid pressure actuators are attached at an angle away from the first position. Therefore, the distance between the second ends of the fluid pressure actuators is greater than the distance between the first ends. As a result, with the robot hand of this aspect, the size of an object to be grasped by the multiple fluid pressure actuators can be made larger than when the fluid pressure actuators are not attached at an angle away from each other in the first direction.

[0012] A fourth aspect of the robot hand is the robot hand described in the third aspect, wherein four or more of the plurality of fluid pressure actuators are attached so that they each extend along an axis inclined in a different direction, and the synchronization mechanism is connected to a connected part provided away from the axis of each of the fluid pressure actuators via a torsional moment absorption mechanism.

[0013] In the robot hand of this aspect, the multiple fluid pressure actuators extend along axes that are tilted in different directions, which allows the robot hand to grasp a larger object than when the fluid pressure actuators are attached with an inclination toward the same direction. [Effects of the Invention]

[0014] According to the present disclosure, a robot hand technology can be provided that improves the accuracy with which each fluid pressure actuator gathers at the second position, compared to when the timing for changing the direction of the second end of each fluid pressure actuator is set individually. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 illustrates a transport robot according to an embodiment of the present disclosure. [Figure 2] FIG. 1 illustrates a robotic hand according to an embodiment of the present disclosure. [Figure 3] FIG. 1 is an exploded view of a fluid pressure actuator according to the present disclosure. [Figure 4] 1 is a cross-sectional view of a fluid pressure actuator according to the present disclosure. [Figure 5] FIG. 10 is a plan view illustrating a base portion of the robot hand of the present disclosure. [Figure 6] FIG. 10 is a front view illustrating a base portion of the robot hand according to the present disclosure. [Figure 7] FIG. 10 is a plan view illustrating a rotation mechanism of the robot hand of the present disclosure. [Figure 8] FIG. 10 is a front view illustrating a rotation mechanism of the robot hand of the present disclosure. [Figure 9] FIG. 10 is a front view illustrating a synchronization mechanism of the robot hand of the present disclosure. [Figure 10] FIG. 10 is a plan view showing the robot hand of the present disclosure in a first mode with the fluid pressure actuators gathered at a first position. [Figure 11] FIG. 10 is a front view showing the robot hand of the present disclosure in a first mode with the fluid pressure actuators gathered at a first position. [Figure 12] FIG. 10 is a plan view showing the robot hand of the present disclosure in a second mode with the fluid pressure actuators gathered at a second position. [Figure 13] FIG. 10 is a front view showing the robot hand of the present disclosure in a second mode with the fluid pressure actuators gathered at a second position. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments for realizing the technology of the present disclosure will be described in detail with reference to the drawings.

[0017] In addition, components and processes that perform the same actions and functions are given the same reference numerals throughout the drawings, and duplicated explanations may be omitted as appropriate. Furthermore, the present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the purpose of the present disclosure.

[0018] Moreover, the arrow S shown in each drawing indicates the axial direction of the tube in the fluid pressure actuator, and the arrow X indicates a direction perpendicular to the arrow S.

[0019] In addition, the "arrow U+ direction" and "arrow U- direction" in each drawing are horizontal directions in the transport robot and are an example of the left-right direction. Also, the "arrow V+ direction" and "arrow V- direction" in each drawing are horizontal directions in the transport robot and are an example of the front-back direction. Also, the "arrow W+ direction" in each drawing is an example of the upward direction in the transport robot, and the "arrow W- direction" is an example of the downward direction in the transport robot.

[0020] In the following description, "one side" refers to the "+" side of arrows U, V, W, X, and Z, and "the other side" refers to the "-" side of arrows U, V, W, X, and Z.

[0021] (composition) As shown in FIG. 1, the transport robot 10 includes a rotatable base 12, a support 14, an extendable arm 16, and a robot hand 18 serving as a hand (also referred to as a gripper). In this transport robot 10, the arm 16 extends and retracts, causing the robot hand 18 to approach or move away from an object to be grasped. The arm 16 extends and grasps the object with four fluid pressure actuators 20 of the robot hand 18, and then the arm 16 is retracted to lift the object. The base 12 is then rotated, and the object is lowered to another location. In this way, the transport robot 10 can be used to transport an object to be grasped.

[0022] As shown in FIG. 2, the robot hand 18 includes a base 50 attached to the arm 16 and four fluid pressure actuators 20 attached to the base 50.

[0023] (Fluid pressure actuator 20) 3 and 4 show a fluid pressure actuator 20 according to an embodiment of the present disclosure. The fluid pressure actuator 20 includes an actuator body 22, a first sealing member 30A, and a second sealing member 30B.

[0024] As shown in Figures 3 and 4, the actuator main body 22 has a tube 24, a sleeve 26, and a restraining member 28. The tube 24 is cylindrical and can expand and contract due to changes in pressure of the fluid inside. The tube 24 can be made of an elastic material such as butyl rubber. Air can be used as the fluid supplied to the tube 24; in this case, the fluid pressure actuator 20 becomes a pneumatic actuator.

[0025] The sleeve 26 is cylindrical and covers the outer periphery of the tube 24. The sleeve 26 is an elastic structure made by weaving fiber cords oriented in a predetermined direction, and the oriented cords intersect at a predetermined angle θ with respect to the arrow S. Because of this shape, the sleeve 26 undergoes pantograph deformation that changes the angle θ, and follows the contraction and expansion of the tube 24 while regulating this contraction and expansion.

[0026] It is preferable to use fiber cords made of aromatic polyamide (aramid fiber) or polyethylene terephthalate (PET) as the cords constituting the sleeve 26. However, the cords are not limited to these types of fiber cords, and other high-strength fiber cords such as PBO fiber (polyparaphenylene benzobisoxazole) may also be used.

[0027] The restraining member 28 is provided between the tube 24 and the sleeve 26. The restraining member 28 is in the form of a long plate, and is arranged such that its longitudinal direction is along the direction of the arrow S of the tube 24. The restraining member 28 covers part of the outer periphery of the tube 24 and is arranged from one end of the tube 24 to the other end.

[0028] The restraining member 28 is made of a material that does not expand or contract when pressurized, and is capable of bending and deforming in the direction in which its ends approach each other. A so-called leaf spring can be used as the restraining member 28. The dimensions and material of the leaf spring are determined depending on the size of the fluid pressure actuator 20, the required gripping force, and other factors.

[0029] The first sealing member 30A includes a sealing connector 32, a locking ring , and a crimping member .

[0030] The sealing connector 32 has an integrally molded lid portion 32A and an insertion portion 32B. The lid portion 32A is generally cylindrical and has a diameter larger than the outer diameter of the tube 24. The insertion portion 32B extends in the direction of arrow S from the center of one end of the lid portion 32A. The insertion portion 32B has a locking portion 48, is shaped like a bamboo shoot, and is inserted into one end of the tube 24 inside the sleeve 26. The locking portion 48 is a cylindrical portion of the insertion portion 32B on the other end side of the arrow S that is smaller in diameter than the lid portion 32A and the insertion portion 32B. While a metal such as stainless steel can be suitably used for the first sealing member 30A, the first sealing member 30A is not limited to such a metal and may also be made of a hard plastic material.

[0031] 4, a female screw 33A is formed on the end of the cover portion 32A. The axis of this female screw 33A is aligned with the axis of the fluid pressure actuator 20.

[0032] Furthermore, a flow path R is formed in the radial center of the insertion portion 32B, extending in the direction of arrow S, and communicating with a connection hole H on the side surface of the cover portion 32A. An air supply hose (not shown) is connected to the connection hole H, and compressed air is supplied to the flow path R.

[0033] The locking ring 34 is ring-shaped and is disposed on the outside of the sleeve 26 so as to sandwich the sleeve 26 between itself and the locking portion 48, thereby locking the sleeve 26 to the sealing connector 32. The sleeve 26 is folded back onto the outer periphery via the locking ring 34. The locking ring 34 may be made of a material such as metal, hard plastic, fiber, or rubber.

[0034] The crimping member 36 is disposed on the outer periphery of the actuator body 22 so as to cover the portion into which the insertion portion 32B is inserted, and crimps the actuator body 22 to the sealing connector 32. This fixes the actuator body 22 to the sealing connector 32. The crimping member 36 can be made of a metal such as aluminum alloy, brass, or iron.

[0035] The second sealing member 30B has a sealing connector 32, a locking ring 34, and a crimping member 36. The sealing connector 32 is similar to the sealing connector 32 of the first sealing member 30A, except that the connection hole H and the flow path R are not formed and the tip is rounded.

[0036] 4, the fluid pressure actuator 20 is used such that the first sealing member 30A on one end side is fixed to the oscillator 60 and the second sealing member 30B on the other end side is a free end. The first sealing member 30A is attached to the oscillator 60 by screwing it onto a rotating shaft 64 as described below.

[0037] When compressed air is introduced through the connection hole H, the pressure inside the fluid pressure actuator 20 increases. Due to the increase in internal pressure, the tube 24 elastically deforms and expands, the sleeve 26 undergoes pantograph deformation so that the angle θ increases, and a force acts in a direction that shortens the length of the actuator main body 22. At this time, because the shortening of the outer peripheral side wall on which the restraining member 28 of the actuator main body 22 is arranged is restricted, the outer peripheral wall of the actuator main body 22 on one side in the direction of arrow X, i.e., the side on which the restraining member 28 is not arranged (the left side in FIG. 4), shortens. This causes the restraining member 28 to flex and deform, and the entire actuator main body 22 bends as shown by the two-dot chain line in FIG. 4.

[0038] In the present disclosure, because restraint member 28 has a length in the width direction, it is difficult to bend in any direction other than the thickness direction, i.e., the direction intersecting with arrow S in first sealing member 30A and second sealing member 30B. In other words, as shown in FIG. 4, restraint member 28 bends in a direction toward the axis of tube 24.

[0039] 1, in the following description, the "tip side" of the fluid pressure actuator 20 refers to the direction in which the second sealing member 30B in FIG. 3 is located, and the "root side" refers to the opposite side. The "root side" is an example of the "first end" in this embodiment, and the "tip side" is an example of the "second end" in this embodiment.

[0040] 2, as will be described later, the four fluid pressure actuators 20 function as a robot hand 18 by having their root sides attached to protruding portions that protrude from the base 50. Next, specific examples of other configurations of the base 50 and the robot hand 18 will be described with reference to FIGS.

[0041] (Base 50 and Rotation Mechanism 58) 5 and 6 show one of the four protrusions 54 formed on the base 50. The protrusion 54 is a portion of the base 50 that protrudes in a radial direction (the directions of arrows U and V in FIG. 2 and the like, and the direction of arrow U- in FIG. 5) from the mounting portion 52 that is attached to the arm portion 16.

[0042] The protruding portion 54 is formed with an inclined portion 56 that inclines in the radial direction. More specifically, the inclined portion 56 has an upper surface 56T side (arrow W+ side) and a lower surface 56B side (arrow W- side) that are parallel to each other, and the upper surface 56T side is inclined toward the base portion 50 side (center side). The protruding portion 54 is also formed with a guide hole 62 and an attachment hole 66.

[0043] 6, the mounting hole 66 is a through-hole that is inclined in a direction perpendicular to the upper surface 56T and the lower surface 56B of the inclined portion 56. Therefore, as will be described later, when the fluid pressure actuator 20 is mounted in the mounting hole 66, the extension direction of the fluid pressure actuator 20 is along a direction perpendicular to the upper surface 56T and the lower surface 56B.

[0044] As shown in FIG. 6, the guide hole 62 is a through-hole that is inclined in a direction perpendicular to the upper surface 56T and the lower surface 56B of the inclined portion 56. As shown in FIG. 5, the guide hole 62 is an elongated hole that is formed in an arc shape and is located radially outward of the mounting hole 66. As shown in FIG. 5, the center of the arc of the guide hole 62 in this embodiment coincides with the central axis AL of the mounting hole 66. As shown in FIG. 6, the length of the arc in this embodiment corresponds to the length of the arc of an octant that is centered on the central axis AL of the mounting hole 66. In other words, the angle that both ends of the guide hole 62 in this embodiment form with the center of the arc is 45°.

[0045] The angle that the inclined portion 56 forms with respect to the horizontal direction (the directions of arrows U and V) can be set as appropriate, but is set to 10° in this embodiment. Although not shown in FIGS. 5 and 6, four protrusions 54 are formed at equal intervals on the mounting portion 52. That is, the base 50 in this embodiment has similar protrusions 54 in both the directions of arrows U and V. Furthermore, the protrusions 54 are inclined in different directions from each other, as shown in FIG. 2 and other figures.

[0046] 7 and 8 show the configuration of the rotation mechanism 58 in this embodiment. As shown in Fig. 7 and Fig. 8, the rotation mechanism 58 includes a rotation shaft body 64, a guide shaft body 72, and a swing body 60.

[0047] The rotating shaft 64 is a member having a rectangular column portion 64S at one end (the side of the arrow W+ in FIG. 8) that is thicker than the mounting hole 66, and a cylindrical portion 64C at the other end (the side of the arrow W-) that is thinner than the mounting hole 66. A male screw is formed on the other end of the cylindrical portion 64C of the rotating shaft 64.

[0048] The guide shaft body 72 is a cylindrical member that is thinner than the groove width (radial width) of the guide hole 62. Furthermore, the guide shaft body 72 has male threads formed on both ends.

[0049] The oscillator 60 is a member that connects the rotating shaft 64 and the guide shaft 72 on the lower surface 56B side of the inclined portion 56. The oscillator 60 may have any shape, but has a rotating shaft hole 68 into which the rotating shaft 64 is inserted and a guide shaft hole 67 into which the guide shaft 72 is inserted.

[0050] The fluid pressure actuator 20 is attached to the underside of the oscillator 60. More specifically, the male thread of the rotating shaft 64 inserted through the rotating shaft hole 68 of the oscillator 60 is threadedly engaged with the female thread 33A of the fluid pressure actuator 20, thereby fixing the first sealing member 30A to the oscillator 60. As a result, the fluid pressure actuator 20 and the rotating shaft 64 are constrained relative to the oscillator 60 in a direction perpendicular to the central axis AL of the rotating shaft 64. Furthermore, the guide shaft 72 inserted into the guide shaft hole 67 is, for example, combined with the female thread F on the underside of the oscillator 60, thereby constraining the guide shaft 72 relative to the oscillator 60 in a direction perpendicular to the central axis AL.

[0051] As shown in Fig. 8, the rectangular column portion 64S and the upper surface 56T of the inclined portion 56 are in contact with each other via the axial bearing 70. Similarly, the oscillating body 60 and the lower surface 56B of the inclined portion 56 are in contact with each other via the axial bearing 70. Therefore, the rotating shaft 64 and the oscillating body 60 are rotatable about the central axis AL of the rotating shaft 64 relative to the inclined portion 56. The range of angles through which the oscillating body 60 rotates is the range within which the guide shaft 72 is guided by the guide hole 62, as shown in Fig. 7. That is, in this embodiment, the oscillating body 60 rotates within a range of 45° when viewed from the upper surface 56T of the inclined portion 56.

[0052] 7 and 8, the female screw 33A of the fluid pressure actuator 20 is connected to the rotating shaft 64, and the center of the female screw 33A of the fluid pressure actuator 20 is aligned with the central axis AL of the fluid pressure actuator 20. Therefore, in this embodiment, the fluid pressure actuator 20 rotates around the central axis AL within a range of 45°. That is, in this embodiment, the guide shaft 72 moves along the guide hole 62 to rotate the oscillator 60 around the central axis AL of the rotating shaft 64, which is an example of "rotating around an axis extending from the first end to the second end" in this embodiment. Although not shown in FIGS. 7 and 8, the same applies to the rotation mechanisms 58 in the other protrusions 54.

[0053] 7 and 8, when the fluid pressure actuator 20 is attached to the oscillator 60 by the rotary shaft 64, the direction in which the fluid pressure actuator 20 extends is a direction away from the center of the base 50.

[0054] (Synchronization mechanism 80) 9 shows a synchronization mechanism 80 in this embodiment. The synchronization mechanism 80 in this embodiment has a pair of rod ends, a first rod end 82A and a second rod end 82B, and a turnbuckle 86. In the following description, terminology related to rod ends will be in accordance with JIS B 0161:1999.

[0055] As shown in Fig. 9, the first rod end 82A is connected to the guide shaft body 72 arranged on the arrow U- side. More specifically, as shown in Fig. 9, the guide shaft body 72 protruding from the upper surface 56T side of the inclined portion 56 is inserted as a stud into the inner ring of the first rod end 82A. In addition, the rod end shank 84A of the first rod end 82A is a right-handed thread.

[0056] As shown in Fig. 9, the second rod end 82B is connected to the guide shaft body 72 located on the side of arrow V+. More specifically, as shown in Fig. 9, the guide shaft body 72 protruding from the upper surface 56T side of the inclined portion 56 is inserted as a stud into the inner ring of the second rod end 82B. In addition, the rod end shank 84B of the second rod end 82B is a left-handed thread.

[0057] 9, the first rod end 82A and the second rod end 82B are each screwed together by a turnbuckle 86. Therefore, rotation of the turnbuckle 86 causes the guide shaft body 72 to which the first rod end 82A is connected to expand and contract between the guide shaft body 72 to which the second rod end 82B is connected. Then, as the pair of guide shaft bodies 72 connected to the synchronization mechanism 80 rotate along the guide hole 62, the pair of fluid pressure actuators 20 rotate about their respective central axes AL.

[0058] Here, because the guide shaft body 72 moves along the guide holes 62 formed in the inclined portions 56 that are inclined in different directions relative to the horizontal, a torsional moment is generated between the guide shaft body 72 and the turnbuckle 86. However, because the guide shaft body 72 is inserted into the first rod end 82A and the second rod end 82B as a stud, the torsional moment is absorbed by the first rod end 82A and the second rod end 82B. That is, in this embodiment, the first rod end 82A and the second rod end 82B are an example of a "torsional moment absorption mechanism." Also, in this embodiment, the guide shaft body 72 is an example of a "connected portion."

[0059] In this embodiment, the rotation of the turnbuckle 86 is controlled by a motor (not shown). Although not shown in Fig. 9, the rotation mechanism 58 in the protrusions 54 on the arrow U+ side and the arrow V- side is also provided with a synchronization mechanism 80.

[0060] In this embodiment, the direction in which the tip of the robot hand 18 faces is changed by the rotation mechanism 58 as described above. In this embodiment, the states before and after the change in the direction in which the tip of the robot hand faces are referred to as the "first mode" and the "second mode," respectively. The state in which the direction in which the tip of the robot hand 18 faces is changed by the rotation mechanism 58 will be described with reference to FIGS. 10 to 13.

[0061] (First mode) 10 and 11 are diagrams showing the direction in which the fluid pressure actuator 20 bends when the robot hand 18 in this embodiment is in the first mode.

[0062] 10 , the first mode is a state in which, when the synchronization mechanism 80 is retracted, the guide shafts 72 connected by the synchronization mechanism 80 move along the guide holes 62 so as to come closest to each other. In this embodiment, the first mode is a mode in which, when the fluid pressure actuator 20 is bent and deformed, the tip side bends toward the center of the base 50.

[0063] 10 and 11, in the first mode, all four fluid pressure actuators 20 can bend and deform toward the first position FP. Therefore, in the first mode, an object to be grasped placed below the robot hand 18 can be grasped by wrapping it with the fluid pressure actuators 20. In other words, in the first mode, it is easy to grasp an object to be grasped that has a small aspect ratio in the horizontal direction (the ratio of the length of one side to the other side), such as a spherical or cylindrical object.

[0064] (Second mode) Next, FIGS. 12 and 13 are diagrams showing the direction in which the fluid pressure actuator 20 bends when the robot hand 18 in this embodiment is in the second mode.

[0065] As shown in FIG. 12 , in the second mode, when the synchronization mechanism 80 is extended, the guide shafts 72 connected by the synchronization mechanism 80 move along the guide holes 62 so that they are furthest apart. In this state, the pair of fluid pressure actuators 20 rotated by the pair of guide shafts 72 connected by the synchronization mechanism 80 rotate by 45° in opposite directions relative to each other as viewed from the direction of arrow W. Therefore, the pair of fluid pressure actuators 20 rotated in opposite directions by 45° each other bend and deform toward each other. In other words, the second mode in this embodiment is a mode in which, when the fluid pressure actuators 20 bend and deform, the distal ends thereof bend toward each other of the fluid pressure actuators 20 connected by the synchronization mechanism 80. Note that in the second mode, the position where the distal ends of the pair of fluid pressure actuators 20 meet is an example of a “second position SP” in this embodiment. Furthermore, in this embodiment, the rotation mechanism 58 switches the direction in which the pair of fluid pressure actuators 20 bend and deform, and is therefore an example of a “switching mechanism.”

[0066] 12 and 13, in this embodiment, of the four fluid pressure actuators 20, two pairs of fluid pressure actuators 20 rotate in directions facing the corresponding pairs of fluid pressure actuators 20. Therefore, in this embodiment, there are two second positions SP, as shown in FIG.

[0067] 12 and 13, in the second mode, the two sets of fluid pressure actuators 20 can bend and deform toward two second positions SP. Therefore, in the first mode, an object to be grasped placed below the robot hand 18 can be grasped by sandwiching it between the two fluid pressure actuators 20. In other words, in the second mode, it is easy to grasp an object to be grasped that has a large aspect ratio in the horizontal direction, such as a rod-like object.

[0068] (Action and effect) The robot hand 18 according to this embodiment has a plurality of fluid pressure actuators 20, and when the plurality of fluid pressure actuators 20 are bent and deformed, the direction of the tip side can be switched between a first position FP and a second position SP. Furthermore, in the robot hand 18 according to this embodiment, the timing of switching the direction of the tip side is synchronized by a synchronization mechanism 80. More specifically, as shown in FIGS. 10 to 13 , a pair of fluid pressure actuators 20 connected by the synchronization mechanism 80 rotate in synchronization with the extension and contraction of the synchronization mechanism 80. That is, in the robot hand 18 according to this embodiment, when one of the pair of fluid pressure actuators 20 rotates, the other fluid pressure actuator 20 also rotates.

[0069] Therefore, with the robot hand 18 according to this embodiment, it is easier to gather the fluid pressure actuators 20 together at the second position SP compared to when the timing for changing the direction in which the tip side of each fluid pressure actuator 20 is to be set individually for each fluid pressure actuator 20. In other words, with the robot hand 18 according to this embodiment, the fluid pressure actuators 20 can be integrally curved and deformed with the tip side set to be directed toward the second position SP.

[0070] Incidentally, if a linear motion mechanism is used to switch the direction in which the tip of the fluid pressure actuator 20 faces from the first position FP to the second position SP, it is necessary to move the fluid pressure actuator 20 by a distance corresponding to the distance from the first position FP to the second position SP. For example, as shown in Figures 10 and 12, if the second position SP is located outside the center of the first position FP, it is necessary to move the pair of fluid pressure actuators 20 outward. In such a structure, the protrusion 54 to which the fluid pressure actuators 20 are attached necessarily has a structure that allows it to move in the movement direction of the fluid pressure actuators 20, which tends to make the robot hand 18 larger.

[0071] On the other hand, in the robot hand 18 according to this embodiment, the switching mechanism rotates each of the fluid pressure actuators 20, thereby switching the direction in which the tip ends of the multiple fluid pressure actuators 20 face. In other words, according to the robot hand 18 according to this embodiment, the robot hand 18 can be made smaller than when the switching mechanism is linearly actuated to switch the direction in which the tip ends face.

[0072] Furthermore, in the robot hand 18 of this embodiment, the tip sides of the fluid pressure actuators 20 are attached with an inclination in a direction away from the first position FP. More specifically, the direction in which the fluid pressure actuators 20 extend is a direction away from the center of the base 50. As shown in FIGS. 10 and 11 , in the first mode, the fluid pressure actuators 20 are attached with an inclination in a direction in which the tip sides move away from the first position FP. Therefore, in the robot hand 18 of this embodiment, the distance between the tip sides of the fluid pressure actuators 20 is wider than the distance between the base sides. As a result, with the robot hand 18 of this embodiment, the size of an object that can be grasped by the multiple fluid pressure actuators 20 can be made larger than when the fluid pressure actuators 20 are not attached with an inclination in a direction away from the first direction.

[0073] Furthermore, in the robot hand 18 of this embodiment, the multiple fluid pressure actuators 20 extend along central axes AL that are tilted in different directions. As a result, the robot hand 18 of this embodiment can grip a larger object with the multiple fluid pressure actuators 20 than when the fluid pressure actuators 20 are attached with an inclination toward the same direction.

[0074] (Variation) In the above description, the rotation mechanism 58 rotates each of the fluid pressure actuators 20, thereby switching the direction in which the tip ends of the multiple fluid pressure actuators 20 face. In this embodiment, the method for changing the positions in which the fluid pressure actuators 20 face is not limited to this. For example, the switching mechanism may employ a method in which the pair of fluid pressure actuators 20 are moved in a horizontal direction while being synchronized to change the position in which the tip ends meet. In other words, the "switching mechanism" may employ a mechanism that switches the position in which the tip ends of the pair of fluid pressure actuators 20 meet by a method other than rotation.

[0075] In the above description, the second position SP is a position where the pair of fluid pressure actuators 20 are rotated by 45° from the first mode. The second position SP according to this embodiment is not limited to this, and may be any position where the pair of fluid pressure actuators 20 are gathered. For example, the second position SP may be a position where the pair of fluid pressure actuators 20 are gathered when rotated by 30° or 60° from each other.

[0076] Furthermore, in the above description, the rotation times of a pair of fluid pressure actuators 20, i.e., two fluid pressure actuators 20, are synchronized by the synchronization mechanism 80. In this embodiment, the number of fluid pressure actuators 20 synchronized by the synchronization mechanism 80 is not limited to this, and the rotation times of three or more fluid pressure actuators 20 may be synchronized.

[0077] In the above description, the inclined portions 56 are inclined in different directions, but the shape of the robot hand 18 according to this embodiment is not limited to this. For example, the inclined portions 56 may be inclined in the same direction. Furthermore, the inclined portions 56 may not be inclined in the vertical direction.

[0078] Furthermore, although the above description has shown that the robot hand 18 has four fluid pressure actuators 20, the shape of the robot hand 18 according to this embodiment is not limited to this. That is, the technology of the robot hand 18 according to this embodiment can be applied to a greater number of fluid pressure actuators 20 than described above, such as six or more. Furthermore, the number of fluid pressure actuators 20 included in the robot hand 18 is not limited to an even number.

[0079] The above describes an embodiment of the present disclosure with reference to the accompanying drawings. However, it is clear that a person with ordinary knowledge in the field of technology to which the present disclosure pertains can conceive of various modifications or applications within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. [Explanation of symbols]

[0080] 10 conveying robot, 12 base portion, 14 support portion, 16 arm portion, 18 robot hand, 20 fluid pressure actuator, 22 actuator main body portion, 24 tube, 26 sleeve, 28 restraining member, 30A first sealing member, 30B second sealing member, 32 sealing connector, 32A lid portion, 32B insertion portion, 34 locking ring, 36 crimping member, 48 locking portion, 50 base portion, 52 mounting portion, 54 protrusion portion, 56 inclined portion, 56B lower surface, 56T upper surface, 58 rotation mechanism (an example of a switching mechanism), 60 oscillator, 62 guide hole, 64 rotating shaft body, 64C cylindrical portion, 64S square column portion, 66 mounting hole, 67 guide shaft hole, 68 rotating shaft hole, 70 axial bearing, 72 guide shaft body, 80 Synchronizing mechanism, 82A first rod end (an example of a screw moment absorption mechanism), 82B second rod end (an example of a screw moment absorption mechanism), 84A rod end shank, 84B rod end shank, 86 turnbuckle, AL central axis, FP first position, SP second position

Claims

1. a plurality of fluid pressure actuators, each having a first end rotatably fixed to a base and a second end opposite to the first end that bends and deforms toward a first position; a switching mechanism for switching the direction in which the second ends of the plurality of fluid pressure actuators face to a second position; a synchronization mechanism that synchronizes timings at which the directions of the second ends of the plurality of fluid pressure actuators are switched; A robotic hand comprising:

2. the switching mechanism changes the direction in which the second end faces by rotating each of the plurality of fluid pressure actuators about an axis extending from the first end to the second end. The robot hand according to claim 1 .

3. the plurality of fluid pressure actuators are each attached so that the second end is inclined more in a direction away from the first position than the first end; The robot hand according to claim 2 .

4. the four or more fluid pressure actuators are attached so as to extend along axes inclined in different directions, the synchronization mechanism is connected to a connected portion provided away from the axis of each of the fluid pressure actuators via a torsional moment absorption mechanism. The robot hand according to claim 3 .

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