JP2006224229A - Robot hand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To mutually interlock a bending motion of each joint of each finger when holding an object from a state where a load is not applied to each finger joint of each finger before holding. <P>SOLUTION: The robot hand is provided with a bush 54 which suppresses displacement of only either one end side or the other end side of a wire 34. When holding the object from the state where the load is not applied to each finger member 10 before holding, the one end side and the other end side of the wire 34 of each finger member are equally displaced when the movable pulley 40 of each finger member is pulled, and the interlocking of the bending motion of a link material 24 of each finger member and a link material 30 of each finger member is assured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a robot hand having a plurality of finger members driven by wires.

  As a robot hand having a high degree of freedom in driving and a function, there is a multi-finger hand in which a driving motor is arranged at each finger joint for the purpose of exhibiting a function close to a human hand. However, the number of parts is large, the control is complicated, and the manufacturing cost is high.

  On the other hand, there is a one-degree-of-freedom gripper as the robot hand having the lowest degree of freedom. This is widely used in industrial robots, and this is sufficient in many cases, but the gripping state cannot be changed depending on the shape of the object, and is not suitable for gripping an irregularly shaped object. In order to grasp an irregular object, the mechanism needs to be flexible so that it can adapt to the irregular shape.

As a method of controlling a highly flexible mechanism with a low-degree-of-freedom drive system, for example, there is a wire drive finger mechanism that controls four fingers with one drive motor (Patent Document 1). In this mechanism, when a moving pulley is suspended on the middle part of two wires each having a tip connected to each finger, and each finger is bent by pulling these moving pulleys, each wire is connected to the moving pulley. The tension is balanced by the action. For this reason, the load of each finger is equally distributed according to the contact state between the object and the finger during the gripping operation.
JP 2003-145474 A

  However, with this technique, when starting the gripping operation of an object from a state in which no load is applied to each finger joint of each finger before gripping, the finger moves inadvertently during the finger bending motion before each finger hits the gripping object. Since the pulley rotates and only a specific finger joint bends, there is a case where an appropriate object cannot be gripped.

  In consideration of the above facts, the present invention is a robot that can interlock the bending operations of each joint of each finger when gripping an object from a state in which no load is applied to each finger joint of each finger before gripping. The purpose is to get a hand.

  According to a first aspect of the present invention, there is provided a robot hand comprising: a first link member having one end rotatably attached to the base; and a second link rotatably attached to the other end of the first link member. A wire having one end connected to the first link material and the other end connected to the second link material and rotating the first link material and the second link material in the same direction by tension; and A moving pulley that is suspended in an intermediate portion of the wire and applies tension of the wire to the first link material and the second link material; and one end side of the wire and the other end side of the wire are moved by the moving force of the moving pulley A plurality of finger members each having a restraining means for uniformly displacing, and displacing the movable pulley of each finger member, and rotating each of the first link material and the second link material via each of the wires. Driving means for providing And butterflies.

  In this configuration, the moving pulley of each finger member is moved by the driving means, and the first link material and the second link material of each finger member are rotated in the same direction via the wire of each finger member. Therefore, the first link material is bent with respect to the base body, and the second link material is bent with respect to the first link material.

  Further, the suppressing means uniformly displaces one end side and the other end side of the wire. For this reason, when gripping an object from a state in which no load is applied to each finger member before gripping, the moving force of the moving pulley of each finger member is applied to one end side and the other end side of the wire of each finger member, The bending operations of the first link material and the second link material of each finger member are interlocked with each other.

  The first suppressing means according to claim 1 of the present invention may be a bush that causes friction to the rotating shaft of the movable pulley as described in claim 2.

  In the robot hand according to a third aspect of the present invention, in the configuration of the first or second aspect, each of the plurality of finger members brakes a displacement of one end side of the wire connected to the first link member. And a second braking device that brakes the displacement of the other end of the wire connected to the second link member.

  In this configuration, if the displacement on the one end side of the wire connected to the first link member is braked by the first braking device, the first link member of each finger member is not bent, and the second link member of each finger member is not bent. Only bending is possible.

  On the other hand, if the second braking device brakes the displacement on the other end side of the wire connected to the second link member, the second link member of each finger member does not bend, and only the first link member of each finger member. Can be bent.

  For this reason, by operating one of the first braking device and the second braking device and bending only one of the first link material and the second link material of each finger member, According to the size, the bending posture of each finger member can be controlled in advance so that it can be easily grasped.

  In the robot hand according to claim 4 of the present invention, in the configuration of claim 3, each of the first braking device and the second braking device includes a pressing member that presses the wire against the braking device body, and the pressing member. An intermediate part connected to the abutting member, and a lever member that displaces the abutting member in a direction in which the wire is pressed against the brake device body by rotating the other end in a predetermined direction with one end serving as a fulcrum; A spring attached to the other end of the lever member and biasing the other end of the lever member in a direction opposite to the predetermined direction; and a spring attached to the other end of the lever member and supplied with current to contract. A contracting member that rotates the other end of the lever member in the predetermined direction against the urging force of the spring, and a power source that supplies current to the contracting member. To do.

  In this configuration, an electric current is supplied to the contracting member, the contracting member is contracted, and the other end of the lever member is rotated in a predetermined direction with the one end of the lever member as a fulcrum against the urging force of the spring. The pressing member to which the part is connected is displaced, and the wire is pressed against the braking device main body. That is, in this configuration, the pressing member is displaced using the lever principle.

  For this reason, even if the force applied to the other end which is the power point of the lever member is small, the braking force for braking the wire can be increased. In addition, since it is possible to determine whether or not to operate the braking device depending on whether or not current is supplied to the contracting member, it is easy to control the braking device.

  A robot hand according to a fifth aspect of the present invention is the robot hand according to any one of the first to fourth aspects, wherein the driving force from the driving means is transmitted to the movable pulley of each finger member and passed through the outer tube. An inner wire, and a speed reducer that is disposed between the inner wire and the moving pulley of each finger member, decelerates the driving force transmitted from the inner wire, and transmits it to the moving pulley of each finger member. It is characterized by that.

  In this configuration, the driving force from the driving means is transmitted to the movable pulley of each finger member by the inner wire passed through the outer tube. The driving force transmitted from the inner wire is decelerated (converted into low-speed, high-torque rotational energy) by a speed reducer disposed between the inner wire and the moving pulley of each finger member. It is transmitted to the moving pulley of the finger member.

  For this reason, the tension of the wire on the side of each finger member from the speed reducer increases, the tension of the inner wire does not increase, and the gripping force of each finger member is increased. Accordingly, friction between the outer tube through which the inner wire is passed and the inner wire is reduced, hysteresis friction characteristics due to friction between the outer tube and the inner wire are reduced, and smooth control becomes possible. .

  In addition, since the tension of the inner wire can be kept small and an outer tube with low rigidity can be used, the outer tube can be deformed according to the installation location, so the degree of freedom of arrangement of the outer tube and the inner wire Increase.

  A robot hand according to a sixth aspect of the present invention is the robot hand according to any one of the first to fifth aspects, wherein the driving means is connected at one end to the moving pulley of one finger member, and moves the other finger member. A drive wire that connects the other end to the pulley and displaces the moving pulley of each finger member by tension, and a drive wire that is suspended in an intermediate portion of the driving wire and applies tension of the driving wire to the moving pulley of each finger member A moving pulley, a driving wire suppressing means for uniformly displacing one end side of the driving wire and the other end side of the driving wire by the moving force of the driving pulley for the driving wire, displacing the driving pulley for the driving wire, And a driving device for displacing the movable pulley of each finger member via the driving wire.

  In this configuration, the driving wire moving pulley is moved by the driving device, and the moving pulley of each finger member is displaced via the driving wire. For this reason, the 1st link material and the 2nd link material of each finger member rotate, and each finger member bends, respectively.

  Further, the drive wire suppressing means uniformly displaces one end side and the other end side of the drive wire. Therefore, when gripping an object from a state in which no load is applied to each finger member before gripping, the moving force of the drive wire pulley is applied to one end side and the other end side of the drive wire, The bending motions are linked to each other.

  Since the present invention is configured as described above, the bending operation of each joint of each finger can be interlocked with each other when an object is gripped from a state in which no load is applied to each finger joint of each finger before gripping.

  An embodiment according to a robot hand of the present invention will be described with reference to FIGS.

  The robot hand 100 according to the present embodiment has three finger members 10 having the same mechanism (only one finger member 10 is shown in FIGS. 1 and 2). First, the finger member 10 will be described.

  As shown in FIGS. 1A and 1B, the finger member 10 includes two parallel bases 14 erected from a robot hand body (part corresponding to a palm) 12. A first shaft 16 is spanned between the distal ends of these bases 14, and both ends of the first shaft 16 are fixed to the base 14. The rear end portions of the two link members 18 are rotatably attached to both end portions of the first shaft 16.

  First fixed pulleys 20 </ b> A and 20 </ b> B are coaxially fixed to the rear end portion of the link member 18. For this reason, the first fixed pulleys 20A and 20B and the link member 18 rotate integrally. When the first fixed pulleys 20A and 20B are rotated in one direction (X direction in FIG. 1B), the link member 18 is tilted with respect to the base 14, and the finger straight state (the phantom line state in FIG. 1B) ) To bend. When the first fixed pulleys 20A and 20B rotate in the other direction (Y direction in FIG. 1B), the link member 18 extends with respect to the base 14 and approaches a finger straight state.

  Further, a second shaft 22 is stretched around the tip of the link material 18, and both ends of the second shaft 22 are fixed to the link material 18, respectively. The rear end portions of the two link members 24 are rotatably attached to both end portions of the second shaft 22. The link member 24 according to the present embodiment corresponds to the first link member described in claim 1.

  Second fixed pulleys 26 </ b> A and 26 </ b> B are coaxially fixed to the rear end portion of the link member 24. For this reason, 2nd fixed pulley 26A, 26B and the link material 24 rotate integrally. When the second fixed pulleys 26A and 26B are rotated in one direction (X direction in FIG. 1B), the link member 24 is tilted with respect to the link member 18, and the finger straight state (the phantom line state in FIG. 1B) ) To bend. When the second fixed pulleys 26A and 26B are rotated in the other direction (Y direction in FIG. 1B), the link member 24 extends with respect to the link member 18 and approaches the finger straight state.

  Further, a third shaft 28 is stretched around the distal end portion of the link member 24, and both ends of the third shaft 28 are fixed to the link member 24, respectively. A rear end portion of the link member 30 is rotatably attached to the third shaft 28. The link member 30 according to the present embodiment corresponds to the second link member described in claim 1.

  Third fixed pulleys 32 </ b> A and 32 </ b> B are coaxially fixed to the rear end portion of the link member 30. For this reason, the third fixed pulleys 32A and 32B and the link member 30 rotate integrally. When the third fixed pulleys 32A and 32B rotate in one direction (X direction in FIG. 1B), the link member 30 is inclined with respect to the link member 24, and the finger straight state (the phantom line state in FIG. 1B) ) To bend. When the third fixed pulleys 32A and 32B rotate in the other direction (Y direction in FIG. 1B), the link member 30 extends with respect to the link member 24 and approaches the finger straight state.

  As shown in FIG. 1A, one end of the wire 34 is wound around the third fixed pulley 32A from one direction (the front side in FIG. 1A), and one end of the wire 34 is connected to the third fixed pulley 32A. The connection is fixed.

  The other end of the wire 34 extends downward and is wound around a part of the outer periphery of an idle roller 36 that is rotatably attached to the second shaft 22 and is then rotatably attached to the first shaft 16. It is wound around a part of the outer periphery of the idle roller 38, and is then wound around the moving pulley 40 over a half circumference, and the moving pulley 40 is suspended (supported by suspension). Further, the other end side of the wire 34 is wound around a part of the outer periphery of the idle roller 42 rotatably attached to the first shaft 16, and is then wound around the second fixed pulley 26 </ b> B. The end is connected and fixed to the second fixed pulley 26B.

  The wire 34 according to the present embodiment corresponds to the wire described in claim 1. The moving pulley 40 according to the present embodiment corresponds to the moving pulley according to claim 1. The winding direction of the wire 34 is the same direction (the front side in FIG. 1A) for the idle roller 36, the idle roller 38, the idle roller 42, and the second fixed pulley 26B.

  Accordingly, when the movable pulley 40 moves downward in FIG. 1, tension is applied to both ends of the wire 34, and the link member 30 and the link member 24 are bent in the bending direction (FIG. 1) via the third fixed pulley 32A and the second fixed pulley 26B. It will be turned counterclockwise.

  Further, one end of the wire 44 is wound around the first fixed pulley 20A from one direction (front side in FIG. 1A), and one end of the wire 44 is connected and fixed to the first fixed pulley 20A.

  The other end side of the wire 44 extends downward and is wound around the moving pulley 46 over a half circumference, and the moving pulley 46 is suspended (supported by suspension). The other end of the wire 44 is rotated by the rotating pulley 40. It is fixed to the shaft.

  Accordingly, when the movable pulley 46 moves downward in FIG. 1, tension is applied to both ends of the wire 44, and the link member 18 is rotated in the bending direction (counterclockwise in FIG. 1) via the first fixed pulley 20A. At the same time, tension is applied to both ends of the wire 34 via the movable pulley 40, and the link member 30 and the link member 24 are similarly rotated in the bending direction (counterclockwise in FIG. 1).

  Further, one end of the wire 34 fixed to the third fixed pulley 32A can be directly fixed to the link member 30 if it is a position that rotates the link member 30 in the bending direction when tension is applied to the wire 34. Good. Similarly, the other end of the wire 34 fixed to the second fixed pulley 26B may be directly fixed to the link member 24. Similarly, one end of the wire 44 fixed to the first fixed pulley 20A is connected to the link member 18. It may be fixed directly.

  A moving pulley 48 is connected to the moving pulley 46 via a frame 50, and the moving pulley 46 and the moving pulley 48 are displaced up and down integrally. Note that a first drive wire 91 (described later) is wound around the movable pulley 48.

  The moving pulley 46 and the moving pulley 40 are rotated when moving downward, so that the tension acting on one end side and the other end side of the wire 44 is balanced.

  Further, the moving pulley 40 fixed to the other end of the wire 44 and the wire 34 wound around the moving pulley 40 are displaced downward, and the link member 24 and the link member 30 are bent. At this time, the moving pulley 40 rotates to balance the tension acting on one end side and the other end side of the wire 34.

  That is, the reaction force received by each link member 18, 24, 30 varies depending on the contact pressure between the gripping object and each link member 18, 24, 30 that varies depending on the shape and size of the grasped object. For this reason, when gripping an object, the downward displacement of the wire connected to the link material having a large load is reduced, and the downward displacement of the wire connected to the link material having a small load is increased. As a result, the load is not concentrated on the specific link material of the finger member.

  In addition, when each link material 18, 24, 30 bends, the moving pulley 49, the moving pulley 47, the reverse winding wire 45, the dynamic pulley 41, and the reverse winding wire 35 mentioned later raise.

  Here, a description will be given of a configuration that suppresses displacement of only one of the one end side and the other end side of the wire 34 and the wire 44 (a configuration that uniformly displaces one end side and the other end side of the wire 34 and the wire 44). To do.

The rotating shaft of the movable pulley 40 is supported not by a ball bearing having a small rotational resistance but by a bush (first suppressing means) 54 having a large rotational resistance. The bush 54 is, for example, a cylindrical bearing made of synthetic resin, and one end of the wire 44 is fixed to the shaft center portion.
For this reason, the friction with the rotating shaft is slightly larger than in the case of the ball bearing, and when the reaction force is not received from the object gripped by the link member 30 and the link member 24, one end side and the other end side of the wire 34 It is suppressed that only any one of these is displaced greatly.

  Similarly, the rotating shaft of the movable pulley 46 is also supported by the bush (second suppressing means) 56, and the displacement of only one of the one end side and the other end side of the wire 44 is suppressed, and the same operation is performed. With this configuration, in a process of gripping an object from a state in which no load is applied to each link member 18, 24, 30 before gripping the object (hereinafter referred to as an approach process), the moving pulley 48 is pulled to When displaced downward, one end side and the other end side of the wire 44 are displaced substantially uniformly downward, and further, one end side and the other end side of the wire 34 are displaced substantially uniformly downward. For this reason, each link material 18, 24, 30 is interlocked with each other and bent by substantially the same amount.

  In this case, the friction generated between the movable pulley 40 and the bush 54 and the force acting on one end side and the other end side of the wire 34 are imbalanced, and one end side of the wire 34 and The force acting on the other end side is not completely evenly distributed but is approximately distributed. Also, the friction generated between the movable pulley 46 and the bush 56, one end side of the wire 44. The force acting on the other end side is unbalanced, and the force acting on the one end side and the other end side of the wire 44 is not distributed completely uniformly but is approximately distributed. .

  In addition, when the friction is not applied by the bush, the force acting on one end side and the other end side of the wire 34 is always uniform, and the force acting on the one end side and the other end side of the wire 44 is uniform. There is a possibility that the change in the posture of each link member 18, 24, 30 when shifting to the gripping state from before gripping becomes large, but in this embodiment, between the rotating shaft of the movable pulley 40 and the bush 54, Since intentional friction is caused between the rotating shaft of the movable pulley 46 and the bush 56, only one of the one end side of the wire 34 and the other end side of the wire 34 is suppressed from being displaced, Only one of the one end side and the other end side of the wire 44 is restrained from being displaced, and the change when shifting from the pre-gripping state to the gripping state can be kept small.

  In this embodiment, the rotating shafts of the moving pulley 40 and the moving pulley 46 are supported by the bush 54 and the bush 56, respectively. However, as a support portion that supports the rotating shafts of the moving pulley 40 and the moving pulley 46, Other support portions may be used as long as the rotational resistance is intentionally increased without being limited to the bush.

  Further, as a configuration for suppressing displacement of only one of the one end side and the other end side of the wires 34 and 44, the rotation of the movable pulleys 40 and 46 is stopped in a state where there is no reaction force from the object, and It is configured like a disc that moves only. As a result, the peripheral surfaces of the disc are caused by sliding friction between the wires 34 and 44 in the same manner as in the above-described embodiment, and one end side of the wires 34 and 44 and the wires 34 and 44. Only one of the other end sides may be suppressed from being displaced. In addition, the case where the moving pulley 40 is configured like a disk that only moves up and down is also included in the moving pulley according to claim 1.

  A first brake 62 is provided between the first fixed pulley 20 </ b> A and the movable pulley 46 so as to brake the downward displacement of one end side of the wire 44. In addition, a second brake 64 is provided between the moving pulley 40 and the moving pulley 46 so that the downward displacement of the other end side of the wire 44 can be braked.

  Next, the configuration of the brake (the first brake 62 and the second brake 64) will be described with reference to FIG. Note that the third and fourth brakes 63 and 65 when the third and fourth brakes 63 and 65 are used in place of the second brake 64 are also configured as follows.

  As shown in FIG. 2, the brakes 62 and 64 include a disk-like block (pressing member) 66, and a through groove 68 having an inner diameter slightly larger than the diameter of the wires 34 and 44 is formed in the block 66. Then, the wires 34 and 44 are passed through the through groove 68. A rod (pressing member) 70 extends laterally from the block 66 and is loosely inserted into an insertion hole 74 formed in a plate-like brake body (braking device body) 72. A pole (lever member) 76 extending in the vertical direction is attached to the tip of the rod 70 so as to be rotatable. A contact member 78 that contacts the brake main body 72 is provided at the upper end of the pole 76. A bias spring 80 extending from the brake body 72 side is connected to the lower end portion of the pole 76, and the lower end portion of the pole 76 is urged toward the brake body 72 side.

  Further, a shape memory alloy (for example, biometal fiber “registered trademark”) 82 as a contracting member is attached to the lower end portion of the pole 76 in the direction opposite to the brake main body 72 side. The electrode of the power source 84 is connected to one end and the other end so that current can be supplied.

  With this configuration, when the brake is turned on (the wire is braked), a current is supplied to the shape memory alloy 82 to cause the shape memory alloy 82 to contract, and against the biasing force of the bias spring 80, the pole The lower end of 76 is displaced rightward. Then, the lower end portion of the pole 76 rotates with the contact member 78 at the upper end portion of the pole 76 as a fulcrum, and the rod 70 and the block 66 move rightward, and the wire is moved between the block 66 and the brake body 72. , And the movement of the wires 34 and 44 is suppressed.

  When the brake is turned off (the wire is not braked), the current supply to the shape memory alloy 82 is stopped and the contraction of the shape memory alloy 82 is released. Due to the elastic force of the bias spring 80, the pole 76 returns to its original position, the pressing of the block 66 is released, and the wires 34 and 44 can be displaced without resistance. Although this method may not provide a large braking force, it works well if the use of the brakes 62 and 64 is limited to the approach process.

  Accordingly, when the first brake 62 is applied, the wire 44 between the first fixed pulley 20A and the movable pulley 46 is not displaced, so the link material 18 is not bent, and only the link material 24 and the link material 30 are present. If the second brake 64 is bent, the wire 44 between the moving pulley 40 and the moving pulley 46 is not displaced. Therefore, the link member 24 and the link member 30 are not bent, and only the link member 18 is bent. . By configuring in this way, in the approach process, it is possible to select a link material that bends in advance according to the shape and size of the object to be grasped, and before the object is grasped, the outline of the link material The posture can be determined.

  In place of the second brake 64, a third brake (first braking device) 63 is provided between the idle roller 38 and the moving pulley 40, and a fourth brake (first brake) is provided between the idle roller 42 and the moving pulley 40. (2 braking device) 65 may be provided, and one end side and the other end side of the wire 34 may be braked by separate brakes. In this way, the link member 30 and the link member 24 can be bent separately, and the range of selection of the link member to be bent is further expanded.

  The above is a series of bending mechanisms for bending the link material.

  On the other hand, in the mechanism for extending the link material, one end side of the reverse winding wire 35 is wound around the third fixed pulley 32B from the opposite direction to the wire 34 (the back side in FIG. 1), and one end of the reverse winding wire 35 is third fixed. It is connected and fixed to the pulley 32B.

  The other end side of the reverse winding wire 35 extends downward and is wound around a part of the outer periphery of an idle roller 37 that is rotatably attached to the second shaft 22, and is then rotatably attached to the first shaft 16. The idle roller 39 is wound around a part of the outer periphery, and is then wound around the movable pulley 41 supported by a ball bearing over a half circumference, and the movable pulley 41 is suspended (supported by suspension). . Further, the other end side of the reverse winding wire 35 is wound around a part of the outer periphery of the idle roller 43 rotatably attached to the first shaft 16, and is then wound around the second fixed pulley 26 </ b> A. The other end is connected and fixed to the second fixed pulley 26A.

  In FIG. 1A, the intermediate portion of the reverse winding wire 35 is cut and illustrated, but the A portion of the reverse winding wire 35 wound around the movable pulley 41 and the A of the reverse winding wire 35 wound around the idle roller 43 are illustrated. The portion B is connected to each other, and the portion B of the reverse winding wire 35 wound around the movable pulley 41 and the portion B of the reverse winding wire 35 wound around the idle roller 39 are connected to each other. Further, the winding direction of the reverse winding wire 35 is the same direction (the back side in FIG. 1) for the idle roller 37, the idle roller 39, the idle roller 43, and the second fixed pulley 26A. Further, one end side of the reverse winding wire 45 is wound around the first fixed pulley 20B from a direction opposite to the wire 44 (the back side in FIG. 1), and one end of the reverse winding wire 45 is connected and fixed to the first fixed pulley 20B. Yes.

  The other end side of the reverse winding wire 45 extends downward and is wound around a moving pulley 47 supported by a ball bearing over a half circumference. The moving pulley 47 is suspended, and the other end of the reverse winding wire 45 is moved. The rotation shaft of the pulley 41 is fixed.

  In FIG. 1A, the C portion of the reverse winding wire 45 wound around the first fixed pulley 20B and the C portion of the reverse winding wire 45 fixed to the rotating shaft of the movable pulley 41 are connected. .

  A moving pulley 49 that freely rotates is connected to the moving pulley 47 via a frame 51, and the moving pulley 47 and the moving pulley 49 are moved up and down integrally. A second drive wire 89, which will be described later, is wound around the movable pulley 49.

  Further, the moving pulley 41, the moving pulley 47, and the moving pulley 49 are movable in the vertical direction. When the moving pulley 49 is pulled downward, the moving pulley 47, the reverse winding wire 45, and the moving pulley 41 are interlocked therewith. Then, the reverse winding wire 35 moves downward, and the link members 18, 24, 30 extend. In addition, when each link material 18, 24, 30 extends, the moving pulley 48, the moving pulley 46, the wire 44, the moving pulley 40, and the wire 34 rise.

  Next, a drive mechanism in the robot hand having the above-described three finger members (finger members 1, 2, 3) will be described with reference to FIGS.

  As shown in FIG. 3, the robot hand 100 includes a drive motor (drive device) 86, and a drive pulley 88 is fixed to the drive shaft of the drive motor 86. An inner wire 90 is wound around the drive pulley 88, and one end side and the other end side of the inner wire 90 are respectively passed through a coiled bellows tube (outer tube) 92, and then a reduction gear (for example, a harmonic) The belt is wound around an input shaft pulley 96 attached to the input shaft of a drive "Harmonic Drive Systems Co., Ltd.") 98 and is looped.

  One end and the other end of the bellows tube 92 are respectively fixed to the robot body 12, and the inner wire 90 and the bellows tube 92 that are passed through the bellows tube 92 are in close contact with each other. For this reason, since the inner wire 90 is guided along the path of the bellows tube 92, even if the bellows tube 92 is bent, the rotational force from the drive pulley 88 is reliably transmitted to the input shaft pulley 96.

  An output shaft pulley (drive pulley) 97 is attached to the output shaft of the speed reducer 98. As shown in FIG. 4, a second drive wire 89 is wound around the output shaft pulley 97 in one direction a plurality of times, and the first drive wire 91 is wound around the other direction a plurality of times and then fixed. Yes.

  The first drive wire 91 includes a bending pulley 48 for bending the finger member 1, a base pulley (body pulley) 93 </ b> A provided in the robot hand body 12, a moving pulley 48 for bending the finger member 2, and the robot hand body 12. The base pulley (main body pulley) 93 </ b> C and the bending pulley 48 for bending the finger member 3 are wound around in order, and the tip of the first drive wire 91 is fixed to the hand main body 12.

  On the other hand, the second drive wire 89 includes a moving pulley 49 for extending the finger member 1, a base pulley (main body pulley) 93B provided in the robot hand body 12, a moving pulley 49 for extending the finger member 2, and a robot hand body. 12 is wound around a base pulley (main body pulley) 93 </ b> D and a movable pulley 49 for extending the finger member 3 in order, and the tip of the first drive wire 91 is fixed to the hand main body 12. The moving pulley 48, the base pulleys 93A to 93D, and the moving pulley 49 are pivotally supported by ball bearings (not shown). Further, the second drive wire 89 and the first drive wire 91 may be configured by a single drive wire.

  With this configuration, when the drive motor 86 is rotated forward, the output shaft pulley 97 is rotated forward via the drive pulley 88, the inner wire 90, the input shaft pulley 96, and the speed reducer 98, and the first drive wire 91 is output to the output shaft. When the portion wound around the pulley 97 and unwound from the output shaft pulley 97 is shortened, each of the movable pulleys 48 of the finger members 1, 2, and 3 moves downward. At this time, the second drive wire 89 is unwound, the moving pulley 49 is displaced upward by the downward displacement of the moving pulley 48, and the link members 18, 24, 30 of the finger members 1, 2, 3 are bent. To do.

  In addition, as the finger member having a higher load on each link material, the downward displacement of the movable pulley 48 becomes smaller, the bending change of each link material is suppressed, and as the finger member having a lower load on each link material, the finger member moves less. The downward displacement of the pulley 48 is greatly reduced, and the bending change of each link member is also increased.

  Further, as described above, since the movable pulley 48 and the base pulleys 93A to 93D are supported by ball bearings, the friction is small, the tension of the first drive wire 91 is balanced, and the driving torque to each finger member is Will be equal. That is, the load on each finger member is equally distributed. For this reason, it is possible to perform flexible gripping that is familiar with the gripping object and that shares the load.

  When the drive motor 86 is reversed, the output shaft pulley 97 is reversed via the drive pulley 88, the inner wire 90, the input shaft pulley 96, and the speed reducer 98, and the second drive wire 89 is wound around the output shaft pulley 97. As a result, the portion that is unwound from the output shaft pulley 97 is shortened, so that the movable pulleys 49 of the finger members 1, 2, and 3 move downward. At this time, the first drive wire 91 is unwound, and the moving pulley 48 is displaced upward by the downward displacement of the moving pulley 49, and the link members 18, 24, 30 of the finger members 1, 2, 3 are extended. To do.

  In the present embodiment, the first drive wire 91 and the second drive wire 89 are wound around the output shaft pulley 97 a plurality of times, but in addition to or instead of this configuration, the input shaft pulley 96. Similarly, the inner wire 90 wound around the drive pulley 88 may be wound around the drive pulley 88 a plurality of times. That is, as shown in FIG. 4, one end of the inner wire 90 is wound around the drive pulley 88 a plurality of times in one direction and then fixed to the drive pulley 88, and the other end of the inner wire 90 is connected to the drive pulley 88. After being wound several times in the other direction, it may be fixed to the drive pulley 88. According to this configuration, there is an advantage that the range of forward rotation and reverse rotation can be regulated at a low torque (upstream side of the speed reducer).

  In addition, there is a conventional mechanism for performing the extending operation of each finger member by using the biasing force of the bias spring. In this mechanism, when the bending angle of each link member 18, 24, 30 is increased, the bias spring becomes resistant to resistance. The gripping force is reduced. Further, since the speed of the extension operation is determined only by the characteristics of the bias spring, the speed cannot be controlled. In this embodiment, since each link member 18, 24, 30 is extended by reversing the drive motor 86, the gripping force does not decrease when each link member 18, 24, 30 is bent. In addition, it becomes easy to control the speed of the extending operation of each link member 18, 24, 30.

  Further, the speed reducer 98 is provided on the downstream side of the inner wire 90 driven by the drive motor 86, and the rotational power transmitted through the inner wire 90 is converted into rotational energy of low speed and high torque, This is transmitted to the moving pulley 48 and the moving pulley 49.

  For this reason, even if the tension of the first drive wire 91 and the second drive wire 89 on the finger members 1, 2, 3 side is increased by the speed reducer 98, the tension of the inner wire 90 does not increase, and each link material The gripping force of 18, 24, 30 is increased. Therefore, the friction between the bellows tube 92 and the inner wire 90 is reduced, the hysteresis friction characteristic caused by the friction between the bellows tube 92 and the inner wire 90 is reduced, and smooth control is possible.

  Moreover, since the tension | tensile_strength of the inner wire 90 can be kept small and the bellows tube 92 with low rigidity can be used, since the bellows tube 92 can be deform | transformed according to an installation place, arrangement | positioning of the bellows tube 92 and the inner wire 90 is possible. The degree of freedom increases.

  Next, another example of the above-described drive mechanism in a robot hand having three finger members (finger members 1, 2, 3) will be described with reference to FIGS. The same parts as those of the above-described drive mechanism are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in FIG. 5, the other end of the first drive wire 91, one end of which is wound around the output shaft pulley 97 in one direction, is fixed to a frame 83 on which the movable pulley 85 is pivotally supported. A third drive wire 81 is wound around the moving pulley 85 over a half circumference, and the moving pulley 85 is suspended (supported under suspension). One end side of the third drive wire 81 is fixed to the frame 50 that pivotally supports the moving pulley 46 for bending the finger member 3 (see FIG. 6), and the other end side of the third drive wire 81 is connected to the moving pulley 77. It is fixed to a frame 79 that supports the shaft. A fourth drive wire 57 is wound around the moving pulley 77 over a half circumference, and the moving pulley 77 is suspended (supported under suspension). As shown in FIG. 6, one end side of the fourth drive wire 57 is fixed to the frame 50 that pivotally supports the movable pulley 46 for bending the finger member 2, and the other end side of the fourth drive wire 57 is the finger member. 1 is fixed to a frame 50 that pivotally supports a bending pulley 46 for bending.

  Further, the other end side of the second drive wire 89 having one end side wound around the output shaft pulley 97 in one direction is fixed to a frame 73 on which the movable pulley 75 is pivotally supported. The moving pulley 75 is supported by a ball bearing, and the fifth driving wire 71 is wound around the moving pulley 75 over a half circumference, and the moving pulley 75 is suspended (suspended). One end side of the fifth drive wire 71 is fixed to the frame 51 that pivotally supports the moving pulley 47 for extending the finger member 3 (see FIG. 6), and the other end side of the fifth drive wire 71 is connected to the moving pulley 67. It is fixed to a frame 69 that supports the shaft. The moving pulley 67 is supported by a ball bearing, and the sixth driving wire 55 is wound around the moving pulley 67 over a half circumference, and the moving pulley 67 is suspended (supported by suspension). As shown in FIG. 6, one end side of the sixth drive wire 55 is fixed to the frame 51 that pivotally supports the moving pulley 47 for extending the finger member 2, and the other end side of the sixth drive wire 55 is the finger member. 1 is fixed to a frame 51 that pivotally supports a moving pulley 47 for extension.

  Further, the rotating shafts of the moving pulley 85 and the moving pulley 77 are supported by the bush 61 and the bush 59, respectively, like the above-described moving pulley 40.

  With this configuration, in the process of gripping an object from a state in which no load is applied to each finger member 1, 2, 3 before gripping the object, the first drive wire 91 is wound up by the output shaft pulley 97, and the frame 83 is When the movable pulley 85 is pulled and displaced downward, the one end side and the other end side of the third drive wire 81 are displaced substantially uniformly downward, and the one end side and the other end side of the fourth drive wire 57 are substantially Displaces uniformly downward. For this reason, the finger members 1, 2, and 3 are interlocked with each other and bent by substantially the same amount.

  In this case, the friction generated between the movable pulley 85 and the bush 61 and the force acting on one end side and the other end side of the third drive wire 81 are imbalanced, and the third drive The force acting on the one end side and the other end side of the wire 81 is not completely evenly distributed but is approximately distributed, and a frictional component generated between the moving pulley 77 and the bush 59. The force acting on the one end side and the other end side of the fourth drive wire 57 is imbalanced, and the force acting on the one end side and the other end side of the fourth drive wire 57 is completely evenly distributed. Instead, it is approximately distributed.

  Further, when friction is not applied by the bush, the force acting on one end side and the other end side of the third drive wire 81 is always uniform, and the force acting on the one end side and the other end side of the fourth drive wire 57 is always obtained. However, in this embodiment, the rotational shaft and bush of the movable pulley 85 may change. 61, intentional friction is generated between the rotating shaft of the movable pulley 77 and the bush 59, so that only one of the one end side and the other end side of the third drive wire 81 is displaced. This suppresses the displacement of only one of the one end side and the other end side of the fourth drive wire 57, and the change when shifting from the pre-gripping state to the grasping state can be kept small.

  In this embodiment, the rotating shafts of the moving pulley 85 and the moving pulley 77 are supported by the bush 61 bush 59, respectively. However, as a support portion for supporting the rotating shaft of the moving pulley 85 and the moving pulley 77, the bush is used. Other support portions may be used as long as the rotational resistance is intentionally increased.

  Further, the fourth drive wire 57 according to this embodiment corresponds to the drive wire of claim 6, and the moving pulley 77 according to this embodiment corresponds to the driving wire moving pulley of claim 6. The bush 59 according to the embodiment corresponds to the drive wire suppressing means of the sixth aspect. When the third drive wire 81 according to this embodiment is viewed as the drive wire of claim 6, the moving pulley 85 according to this embodiment corresponds to the driving wire moving pulley of claim 6, and The bush 61 corresponds to the drive wire suppressing means of the sixth aspect.

  Next, the operation of the above embodiment will be described.

  When the drive motor 86 is rotated forward, the output shaft pulley 97 is rotated forward via the drive pulley 88, the inner wire 90, the input shaft pulley 96, and the speed reducer 98, and the first drive wire 91 is wound up, so that the output shaft When the portion unwound from the pulley 97 is shortened, the movable pulleys 48 of the finger members 1, 2, and 3 move downward (see FIG. 3). When the moving pulley 48 moves downward, the moving pulley 46 connected to the moving pulley 48 is displaced downward, the one end side and the other end side of the wire 44 are displaced substantially uniformly downward, and the one end side of the wire 34 is further moved. And the other end side is displaced almost uniformly downward. For this reason, the link members 18, 24, 30 of each finger member are interlocked with each other and bent by substantially the same amount (see FIG. 1).

  Further, when the object is gripped, the downward displacement of the wire connected to the link material having a large load becomes small, and the downward displacement of the wire connected to the link material having a small load becomes large. That is, the force acting on each finger member is approximately distributed, and flexible gripping corresponding to the shape and size of the gripping object is possible.

  At this time, the second drive wire 89 is rewound, and the moving pulley 49 is displaced upward by the downward displacement of the moving pulley 48, and in conjunction therewith, the moving pulley 49, the moving pulley 47, the reverse winding wire 45, The movable pulley 41 and the reverse winding wire 35 rise.

  When the drive motor 86 is reversed, the output shaft pulley 97 is reversed via the drive pulley 88, the inner wire 90, the input shaft pulley 96, and the speed reducer 98, and the second drive wire 89 is wound around the output shaft pulley 97. When the portion unwound from the output shaft pulley 97 is shortened, the movable pulleys 49 of the finger members 1, 2, and 3 move downward (see FIG. 3). When the moving pulley 49 moves downward, the moving pulley 47, the reverse winding wire 45, the moving pulley 41, and the reverse winding wire 35 move downward in conjunction therewith, and the link members 18, 24, 30 of each finger member extend ( (See FIG. 1).

  At this time, the first drive wire 91 is rewound, and the moving pulley 48 is displaced upward by the downward displacement of the moving pulley 49, and in conjunction therewith, the moving pulley 46, the wire 44, the moving pulley 40, the wire 34 rises.

  In the above embodiment, the link material 24 is described as equivalent to the first link material of claim 1. However, when the link material 18 is regarded as the first link material of claim 1, the base 14, the link material 24, the wire 44, the moving pulley 46, and the bush 56 correspond to the base body, the second link member, the wire, the moving pulley, and the restraining means of claim 1, respectively, and the first brake 62 and the second brake 64 respectively. This corresponds to the first braking device and the second braking device.

  Moreover, in the said embodiment, although the structure where three link materials were connected was demonstrated, as a concept of this invention, it is not restricted to the structure where three link materials were connected like said embodiment. Two or four or more link members may be connected.

  For example, only the link material 18 and the link material 24 are provided, and one end side of the wire 44 is wound around and fixed to the first fixed pulley 20A, and the other end side of the wire 44 is wound around and fixed to the second fixed pulley 26B. A configuration in which one end side of 45 is wound and fixed on the first fixed pulley 20B and the other end side of the reverse winding wire 45 is wound and fixed on the second fixed pulley 26A is possible.

  In this case, the base 14, the link material 18, the link material 24, the wire 44, the movable pulley 46, and the bush 56 are respectively the base body, the first link material, the second link material, the wire, the motion, and the like. Corresponds to pulley and suppression means. The first brake 62 and the second brake 64 correspond to the first braking device and the second braking device according to claim 4, respectively.

1A is a front view showing one finger member, and FIG. 1B is a side view showing one finger member. 2A is a left side view showing the brake, FIG. 2B is a front view showing the brake, and FIG. 2C is a bottom view showing the brake. FIG. 3 is a diagram illustrating a drive mechanism of the robot hand according to the present embodiment. FIG. 4 is a diagram showing a method of winding a wire around the output shaft pulley of the speed reducer according to the present embodiment. FIG. 5 is a view showing another example of the driving mechanism of the robot hand according to the present embodiment. FIG. 6 is a view showing another example of the driving mechanism of the robot hand according to the present embodiment.

Explanation of symbols

10 Finger member 18 Link material (base)
24 Link material (first link material)
30 Link material (second link material)
34 Wire 40 Moving pulley 54 Bush (suppressing means)
57 Fourth drive wire (drive wire)
59 Bush (drive wire suppression means)
63 Third brake (first braking device)
65 Fourth brake (second braking device)
66 blocks (pressing members)
70 Rod (Pushing member)
76 Pole (Lever member)
77 Moving pulley (Driving pulley for drive wire)
80 Bias spring (spring)
82 Shape memory alloy (shrinkable member)
84 Power supply 86 Drive motor (drive device)
92 Bellows tube (outer tube)
98 Reducer 100 Robot Hand

Claims (6)

A first link member having one end rotatably attached to the base;
A second link member rotatably attached to the other end of the first link member;
One end is connected to the first link member, the other end is connected to the second link member, and the wire rotates the first link member and the second link member in the same direction by tension,
A movable pulley that is suspended in an intermediate portion of the wire and applies tension of the wire to the first link member and the second link member;
Suppressing means for uniformly displacing one end side of the wire and the other end side of the wire by the moving force of the movable pulley;
A plurality of finger members having
Driving means for displacing the movable pulley of each finger member and rotating each of the first link material and the second link material via the wires;
A robot hand characterized by comprising:   The robot hand according to claim 1, wherein the suppressing means is a bush that causes friction to a rotation shaft of the movable pulley. Each of the plurality of finger members is
A first braking device that brakes displacement on one end side of the wire connected to the first link member;
A second braking device that brakes the displacement of the other end of the wire connected to the second link member;
The robot hand according to claim 1, further comprising: Each of the first braking device and the second braking device is:
A pressing member that presses the wire against the braking device body;
An intermediate portion is connected to the pressing member, and the other end portion rotates in a predetermined direction with one end portion serving as a fulcrum, thereby displacing the pressing member in a direction in which the wire is pressed against the braking device body. Members,
A spring attached to the other end of the lever member and biasing the other end of the lever member in a direction opposite to the predetermined direction;
A contracting member that is attached to the other end of the lever member and contracts when supplied with an electric current to rotate the other end of the lever member in the predetermined direction against the biasing force of the spring;
A power source for supplying current to the contraction member;
The robot hand according to claim 3, further comprising: Transmitting the driving force from the driving means to the movable pulley of each finger member, and an inner wire passed through an outer tube;
A speed reducer that is disposed between the inner wire and the moving pulley of each finger member, decelerates the driving force transmitted from the inner wire, and transmits it to the moving pulley of each finger member;
The robot hand according to any one of claims 1 to 4, further comprising: The driving means includes
One end of the finger member is connected to the moving pulley, the other end of the other finger member is connected to the moving pulley, and the driving wire displaces the moving pulley of each finger member by tension.
A driving wire moving pulley that is suspended in an intermediate portion of the driving wire and applies tension of the driving wire to the moving pulley of each finger member;
Drive wire suppression means for uniformly displacing one end side of the drive wire and the other end side of the drive wire by the moving force of the drive wire pulley;
A driving device for displacing the driving pulley for the driving wire and displacing the driving pulley of each finger member via the driving wire;
The robot hand according to claim 1, further comprising:

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