JP2006116667A - Articulated mechanism and robot hand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an articulated mechanism and a robot hand, having excellent durability and ease of installation. <P>SOLUTION: This articulated mechanism includes: a plurality of frames 3a to 3c serially arranged; a plurality of joints 4a to 4c connecting the frames 3a to 3c to be tilted; a driving part 5b for generating the power for tilting the suitable frame; and a power transmission part 7 for transmitting the power generated by the driving part 5b to the suitable joint, wherein in the power transmitting part 7, the power transmission element between the joints is composed of gears. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multi-joint mechanism that can bend and stretch, and a robot hand that can grip an object.

  In general, in a robot hand, a large number of joints, that is, degrees of freedom, are required in order to realize various movements similar to human hands and to easily manipulate an object. The finger mechanism of the robot hand has a large number of joints, and transmits power generated by a driving unit such as a motor to each joint by a wire so that it can bend and stretch. The number of the drive units is the same as the number of joints, and many of these drive units are mounted, for example, on a portion corresponding to a palm (see Patent Document 1).

  In this case, since the same number of drive units as the number of joints are used, the robot hand cannot be reduced in size. However, if the number of drive units is simply reduced, the degree of freedom is reduced and various movements cannot be performed.

  On the other hand, in order to reduce the number of drive units and reduce the size and cost, there is one in which two joints are linked and driven (see Patent Document 2). For example, in a finger mechanism, a joint of a fingertip and an intermediate joint adjacent to the finger joint are operated in conjunction with each other. By linking the two joints in this way, the number of drive units can be reduced, but it is difficult to move the finger mechanism in detail. For this reason, since it is impossible to make various gripping states of the robot hand, it becomes difficult to grip an object having a complicated shape and to manipulate the object.

Therefore, it is preferable that the joint operation of the two joints can be released as necessary, so that various gripping states of the robot hand can be created. In Patent Document 2, a friction clutch is inserted between two pulleys in a joint so as to be able to cancel the linkage operation. In this configuration, if there is no load on the finger mechanism, the two joints rotate in association with each other. However, if a load exceeding the frictional force is applied to the finger mechanism, the two joints are not linked.
JP-A-6-8178 JP 2003-89087 A

  In the above conventional example, first, since it is a wire drive system, it is difficult to route the wire at the time of assembly, there is a concern that the wire may loosen with the progress of use, and there is a concern that the durability of the wire is insufficient. The

  In the above conventional example, the linkage operation of the two joints can be canceled using the friction clutch. However, since the linkage operation cannot be canceled arbitrarily, various gripping states of the robot hand are intentionally set. I can't make it. In addition, when a large gripping force is applied, the joint operation of the two joints is released without permission, so that it is impossible to grip an object having a complicated shape, such as the gripping state and conditions of the robot hand being restricted. As described above, the robot hand of the conventional example cannot perform a more advanced gripping operation such as some restrictions when manipulating the gripped object.

  Therefore, the present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a multi-joint mechanism and a robot hand excellent in durability and workability. It is another object of the present invention to provide a multi-joint mechanism and a robot hand that enable various movements while reducing the size and cost.

  The multi-joint mechanism according to the present invention includes a plurality of frames arranged in series, a plurality of joints that connect the respective frames so as to be tiltable, a drive unit that generates power for tilting the appropriate frames, And a power transmission unit that transmits the power generated by the drive unit to the appropriate joint. In the power transmission unit, a power transmission element between the joints is constituted by a gear.

  In short, the multi-joint mechanism of the present invention is applied to all devices having multi-joints.

  In this case, durability is improved, for example, the gear as the power transmission unit is superior in static strength and fatigue strength compared to the conventional wire. And since it becomes easy to assemble compared with the wire of a prior art example, automatic assembly becomes possible.

  The multi-joint mechanism according to the present invention generates a plurality of frames arranged in series, a plurality of joints that connect the respective frames so as to be tiltable, and a power for tilting a proximal end frame of the plurality of frames. A first driving unit that performs power generation, a second driving unit that generates power for driving an intermediate frame of the plurality of frames, and a first driving unit that transmits power generated by the first driving unit to the base frame. A power transmission unit; and a second power transmission unit configured to transmit power generated by the second drive unit to the intermediate frame, and a power transmission element between the joints in the second power transmission unit is configured by a gear. It is characterized by that.

  In this case, since the drive unit that directly drives the front end frame is not provided, the configuration is simplified, which is advantageous for downsizing and downsizing.

  Preferably, among the joints, the proximal joint is a shaft whose both ends are fixed to the base and rotatably supported by one end of the proximal frame, and the both ends of the intermediate joint are the proximal ends. The shaft is fixed to the other end of the frame and rotatably supported by one end of the intermediate frame, and the tip joint is fixed to the other end of the intermediate frame and is connected to one end of the tip frame. The power transmission element between the joints in the second power transmission unit is supported by a shaft as a proximal joint so as to be rotatable relative to the shaft. A gear, an intermediate gear fixed to the intermediate frame and rotatably supported by a shaft serving as an intermediate joint, and one or a plurality of gears disposed between the proximal idle gear and the intermediate gear and meshing with each other Including the relay relay gear It is.

  In this case, the configuration of each joint and the configuration of the power transmission unit are specified, and the durability and workability can be improved as described above.

  Preferably, a linkage state in which the tip frame of the plurality of frames is linked to the tilting operation of the intermediate frame and a linkage release state in which the tip frame is freely tiltable with respect to the intermediate frame are intentionally realized. It is set as the structure provided with the switching part to perform.

  In this case, when the linkage is released, the tip frame can be freely tilted with respect to the intermediate frame. Therefore, when the tip frame is brought into contact with an appropriate object, a wide range of the tip frame is set along the object. It is possible to make it contact in the state.

  Preferably, the switching unit is supported by a shaft serving as an intermediate joint so as to be rotatable adjacent to the intermediate gear, and an intermediate idler gear fixed to the tip frame and rotatably supported by a shaft serving as a tip joint. A front end gear, one or a plurality of intermediate relay gears arranged between the intermediate idle gear and the front end gear and meshing with each other, and the intermediate idle gear is non-rotated to be in the linked state. Or it is set as the structure containing the stopper which accept | permits rotation of an intermediate | middle idling gear, and makes it the said linkage cancellation | release state.

  In this case, since the switching portion is also constituted by a gear, durability and workability can be improved as described above.

  Preferably, the stopper is fitted between the teeth of the intermediate idling gear so as to restrain the intermediate idling gear from non-rotating, and protrudes so as to fit the catching piece between the teeth of the intermediate idling gear. And a moving part that is retracted so as to be pulled out between the teeth of the intermediate idle gear.

  In this case, since the stopper has a simple structure including only the locking piece and the operating portion, it is advantageous for suppressing the equipment cost.

  Preferably, the operation unit may be configured by a solenoid. Preferably, the operation unit may be composed of a polymer actuator.

  In these cases, the operating portion of the stopper can be made relatively small and inexpensive, which is advantageous in reducing the occupied space and equipment cost.

  Preferably, the tip frame and the intermediate frame coupled thereto may be provided with a spring that urges and urges the tip frame to tilt in one tilting direction with respect to the intermediate frame.

  In this case, in the linkage release state, the tip frame is not easily moved in the direction opposite to the tilting direction of the intermediate frame, and when the tip frame is in contact with the object, it is easy to maintain the state in contact with the object.

  Preferably, the control unit is configured to control the tilting operation of each frame by driving or non-driving the driving unit as necessary.

  Preferably, each joint may be provided with an angle sensor for measuring a relative inclination between frames connected to each other.

  In this case, the tilt angle of each frame can be recognized based on the output of the angle sensor.

  Preferably, when the frames are tilted in the linked state, the control unit recognizes the posture of each frame based on the output of the angle sensor, and executes a process for obtaining the required posture. .

  In this case, the inclination angle of each frame can be adjusted relatively easily and with high accuracy.

  Preferably, a force sensor can be provided on the tip frame. In this case, it is possible to recognize the contact state of the tip frame with the object based on the output of the force sensor.

  Preferably, the control unit retracts the stopper by the driving unit of the switching unit based on the output of the force sensor when the tip frame contacts an object in the process of tilting the frames in the linked state. Thus, a process of bringing the intermediate idle gear into a rotatable disengaged state is executed.

  In this case, the tip frame can be brought into contact with the object in an arbitrary state, and the movement of the multi-joint mechanism can be diversified.

  A robot hand according to the present invention includes a base and a plurality of finger mechanisms each supported by the base in a cantilever shape and having joints in a plurality of locations in the protruding direction, At least one of the features is the multi-joint mechanism described above.

  In this case, the movement of the finger mechanism of the robot hand can be diversified, and a high-level movement similar to the movement of a human finger becomes possible.

  The robot hand here is used as a human hand (a part ahead of the wrist) that holds an appropriate object, but in addition, a human foot (a part ahead of the ankle), a configuration of an arm or a foot It can also be used as a robot having a similar mechanism.

  ADVANTAGE OF THE INVENTION According to this invention, the multi joint mechanism and robot hand excellent in durability and workability can be provided. In addition, the present invention can provide a multi-joint mechanism and a robot hand that enable various movements while reducing the size and cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Description of multi-joint mechanism]
The best embodiment of the multi-joint mechanism 1 will be described with reference to FIGS. This multi-joint mechanism 1 is used as a finger mechanism of a robot hand, for example.

  As shown in FIG. 1 to FIG. 3, the multi-joint mechanism 1 is a piece connected to the base 2 in a state where three frames 3a, 3b, 3c arranged in series are connected to each other by three joints 4a, 4b, 4c so as to be tiltable. It is supported in the form of a cantilever, with two drive parts 5a, 5b, two systems of power transmission parts 6, 7, and a switching part 8, with three frames 3a-3c centered on three joints 4a-4c. It is designed to tilt.

  Hereinafter, each part will be described in detail.

  One end of a base end frame 3a is supported on the base 2 so as to be tiltable via a base end joint 4a, and one end of an intermediate frame 3b is connected to the other end of the base end frame 3a via an intermediate joint 4b. The tip frame 3c is supported by the other end of the intermediate frame 3b through the tip joint 4c so as to be tiltable.

  Each joint 4a-4c is made into the axis | shaft which connects each adjacent frame 3a-3c so that tilting is possible. Specifically, the proximal joint 4a is an axis that is fixed to the base 2 at both ends and is pivotally supported by one end of the proximal frame 3a. The intermediate joint 4b is a shaft whose both ends are fixed to the other end of the base frame 3a and pivotally supported by one end of the intermediate frame 3b. The distal joint 4c is a shaft whose both ends are fixed to the other end of the intermediate frame 3b and rotatably supported by one end of the distal frame 3c.

  Each of the first and second drive units 5 a and 5 b is made of, for example, a motor and mounted on the base 2. The first drive unit 5a generates rotational power for tilting the proximal end frame 3a, and the second drive unit 5b generates rotational power for tilting the intermediate frame 3b.

  The first power transmission unit 6 transmits the rotational power generated by the first drive unit 5a to the proximal joint 4a. As shown in FIGS. 1 and 2, the first power transmission unit 6 includes a first pulley 6a fixed to an output shaft (reference number omitted) of the first drive unit 5a, a base end frame 3a, and a base pulley. It is comprised by the base end pulley 6b penetrated and supported by the one end side of the axis | shaft as the end joint 4a, and the 1st wire 6c wound over the 1st pulley 6a and the base end pulley 6b. .

  The second power transmission unit 7 transmits rotational power generated by the second drive unit 5b to the intermediate joint 4b. As shown in FIGS. 1 to 3, the second power transmission unit 7 includes a second pulley 7a fixed to an output shaft (reference numeral omitted) of the second drive unit 5a, and a shaft as the proximal joint 4a. A proximal idler pulley 7b that is rotatably supported by the proximal side next to the proximal pulley 6b, a second wire 7c wound around the second pulley 7a and the proximal idler pulley 7b, and a proximal end A base idle gear 7d formed integrally with the idle pulley 7b, an intermediate gear 7e fixed to the intermediate frame 3b and rotatably supported on one end side of the shaft as the intermediate joint 4b, and a base idle gear It is comprised by three base end relay gears 7f, 7g, and 7h which are arrange | positioned between 7d and the intermediate | middle gear 7e, and mesh | engage with each other.

  Note that the three proximal relay gears 7f, 7g, and 7h are rotatably supported by the proximal frame 3a via support shafts (reference numerals omitted). The number of the base end relay gears 7f, 7g, and 7h is not particularly limited, but it is necessary to make the intermediate gear 7e an odd number to rotate in the same direction as the base end idle gear 7d. However, since it is only necessary to reverse the motor 5b as the second drive unit, the intermediate gear 7e and the base end idling gear 7d do not need to be rotated in the same direction.

  The switching unit 8 is in a linked state in which the tip frame 3c is tilted by being linked to the tilting operation of the intermediate frame 3b, and a linkage release state in which the tip frame 3c is freely tiltable without being linked to the tilting operation of the intermediate frame 3b. It is to switch.

  As shown in FIGS. 1 and 2, the switching unit 8 includes an intermediate idle gear 8a that is rotatably supported adjacent to the intermediate gear 7e on the other end side of the shaft as the intermediate joint 4b, and a front end frame 3c. A tip gear 8b fixed to the shaft and rotatably supported on one end of the shaft as the tip joint 4c, and two intermediate relay gears arranged between the intermediate idle gear 8a and the tip gear 8b and meshing with each other 8c and 8d, and a stopper 9 that switches between a state in which the intermediate idle gear 8a is restrained from non-rotation and a state in which rotation is allowed.

  The two intermediate relay gears 8c and 8d are rotatably supported by the intermediate frame 3b via a support shaft (reference numeral omitted). The number of intermediate relay gears 8c, 8d is not particularly limited, but it is necessary to make the tip gear 8b an even number to rotate in the same direction as the intermediate gear 7e.

  By the way, the stopper 9 is comprised with the solenoid. As shown in FIG. 2, the stopper 9 made of a solenoid includes a cylindrical electromagnet 9a, a movable iron core 9b inserted in a state where one end protrudes from the center of the electromagnet 9a and is in a non-contact state, and a movable iron core The coil 9c is wound around the outer periphery of the projecting end of 9b, and the engaging piece 9d is connected in a straight line to the projecting end of the movable iron core 9b.

  As an operation of the stopper 9, when the locking piece 9d is fitted between the teeth of the intermediate idling gear 8a by projecting the movable iron core 9b, the intermediate idling gear 8a is set in a non-rotating state. In addition, when the locking piece 9d is extracted from between the teeth of the intermediate idle gear 8a by retreating the movable iron core 9b, the intermediate idle gear 8a can be allowed to rotate.

  The stopper 9 made of a solenoid has a configuration in which the movable iron core 9b protrudes when the electromagnet 9a is energized, and the movable iron core 9b is retracted when the electromagnet 9a is not energized. However, the stopper 9 may be configured to be held in a state in which the movable iron core 9b protrudes when power is not supplied.

  Further, since the electromagnet 9a only needs to move the engaging piece 9d forward and backward and has a small power, it is sufficient to store and dispose the solenoid stopper 9 in the base end frame 3a, and the entire size can be reduced. Become. However, the stopper 9 may be disposed on the base 2 side.

  Next, the operation will be described.

  First, when the first drive unit 5a is driven, the base pulley 6b is rotated in the direction indicated by the arrow X (counterclockwise) in FIG. 4 via, for example, the first wire 6c. Therefore, as shown in FIG. The base frame 3a integral with the end pulley 6b is tilted in the same direction (downward) as the base pulley 6b. As a result, the base end frame 3a is inclined with respect to the base 2 by a predetermined angle θ1.

  Further, when the second drive unit 5b is driven in the same manner as the first drive unit 5a, for example, the base idle rotation pulley 7b is rotated via the second wire 7c, and the base end idle rotation that rotates integrally with the base end idle pulley 7b is performed. Since the intermediate gear 7e is rotated by the gear 7d in the same direction as the base idle gear 7d via the three base end relay gears 7f, 7g, and 7h, the intermediate frame 3b integrated with the intermediate gear 7e is connected to the intermediate gear 7e. Tilt in the same direction (downward). As a result, as shown in FIG. 5, the intermediate frame 3b is inclined at a predetermined angle θ2 with respect to the base end frame 3a.

  At this time, when the locking piece 9d of the stopper 9 is fitted between the teeth of the intermediate idle gear 8a and the intermediate idle gear 8a is restrained from non-rotating, the intermediate frame 3b is tilted as shown in FIG. Thus, the two base end relay gears 8c, 8d meshing with the non-rotating intermediate idle gear 8a revolve around the outer periphery of the intermediate idle gear 8a in the same direction as the tilt direction of the intermediate frame 3b while rotating. The tip frame 3c integrated with the tip gear 8b is tilted in the same direction (downward) as the tilt direction of the intermediate frame 3b. As a result, the leading end frame 3c is inclined at a predetermined angle θ3 with respect to the intermediate frame 3b.

  That is, if the intermediate idle gear 8a is constrained to be non-rotating, the power generated by the second drive unit 5b can be transmitted to the distal joint 4c via the intermediate joint 4b, so that the distal frame 3c is tilted by the intermediate frame 3b. It can be linked to be tilted in conjunction with.

  On the other hand, when the locking piece 9d of the stopper 9 is extracted from between the teeth of the intermediate idle gear 8a and the intermediate idle gear 8a can be freely rotated, as shown in FIG. Since the base end relay gears 8c and 8d meshing with the idle gear 8a are not rotated, the front end frame 3c integrated with the front end gear 8b is not tilted. However, the tip gear 8b is not constrained by any of them, so that the tip frame 3c integrated with the tip gear 8b can tilt in any direction up and down with the tip joint 4c as a fulcrum. In the state of FIG. 6, the leading end frame 3c is inclined by a predetermined angle θ4 downward with respect to the intermediate frame 3b due to its own weight.

  That is, when the intermediate idle gear 8a is freely rotatable, the power generated by the second drive unit 5b is transmitted from the base frame 3a to the intermediate frame 3b, but the transmission from the intermediate frame 3b to the front frame 3c is cut off. Therefore, the distal end frame 3c can be brought into a linkage release state capable of free tilting without being linked to the tilting motion of the intermediate frame 3b.

  In such a multi-joint mechanism 1, the contact state of the distal end frame 3c with respect to the rod-like object 10 will be described.

  First, when the switching unit 8 is in the linked state, if the tip frame 3c is brought into contact with the rod-like object 10, the intermediate frame 3b and the tip frame 3c are linked and tilted, for example, as shown in FIG. For this purpose, the tip edge of the tip frame 3 c comes into contact with the outer peripheral surface of the rod-like object 10.

  However, when the switching unit 8 is in the linked state and the intermediate frame 3b is tilted with respect to the base frame 3a by a predetermined angle and then the switching unit 8 is in the linked release state, the distal frame 3c is moved relative to the intermediate frame 3b. Since it can be freely tilted, even if the tip angle of the tip frame 3c contacts the outer peripheral surface of the rod-like object 10, the tip frame 3c moves in the direction opposite to the tilt direction of the intermediate frame 3b (upward in the figure). Thus, as shown in FIG. 8, the side surface of the tip frame 3 c comes into contact with the outer peripheral surface of the rod-like object 10. In this way, the wide range of the side surface portion of the tip frame 3 c comes into contact with the outer peripheral surface of the rod-shaped object 10. At this time, the contact state can be maintained by bringing the switching unit 8 into the linked state again.

  According to the multi-joint mechanism 1 described above, the following effects can be obtained.

  First, in the second power transmission unit 7, the power transmission element from the proximal joint 4a to the intermediate joint 4b is performed by the gear mechanism (7b to 7h), and the power transmission from the intermediate joint 4b to the distal joint 4c is performed. Since the elements are operated by the gear mechanism (8a to 8d), the durability is improved, such as excellent static strength and fatigue strength compared to the case of using the conventional wire, and the conventional wire. Since it becomes easier to assemble compared with the case of using, the workability is improved such that automatic assembly becomes possible.

  In addition, since the number of drive units is smaller than the number of joints, it is possible to reduce the size and cost. Thus, even if the number of driving units is smaller than the number of joints, all the frames 3a to 3c can be tilted independently, and thus various movements can be made possible.

  Hereinafter, other embodiments of the multi-joint mechanism 1 of the present invention will be described.

  (1) The stopper 9 can be composed of a polymer actuator 9e whose length can be electrically variably controlled. In this case, for example, as shown in FIG. 9, a locking piece 9d is connected to the tip of a polymer actuator 9e as a stopper 9. In the polymer actuator 9e, when the length thereof is increased and the locking piece 9d is fitted between the teeth of the intermediate idle gear 8a, the intermediate frame 3b and the front end frame 3c can be linked and moved. On the other hand, when the length of the polymer actuator 9e is shortened and the locking piece 9d is extracted from between the teeth of the intermediate idle gear 8a, the link operation between the intermediate frame 3b and the tip frame 3c can be released. The force required to retract the locking piece 9d may be small, and the displacement stroke of the locking piece 9d may be as short as the height of the teeth of the intermediate idle gear 8a, so the specifications required for the polymer actuator 9e are You don't have to be strict. In addition, since the polymer actuator 9e is lighter and smaller than the solenoid described above, it is preferable that the polymer actuator 9e is housed and arranged inside the proximal end frame 3a.

  (2) In the above embodiment, in the state in which the linkage between the intermediate frame 3b and the tip frame 3c is released, the tip frame 3c can freely rotate. For example, as shown in FIG. A spring 11 for elastically tilting the front end frame 3c downward with respect to the intermediate frame 3b may be incorporated. In FIG. 10, the spring 11 is indicated by a one-dot chain line.

  In this case, in the disconnected state, the distal end frame 3c does not rotate freely but tilts in one direction due to the elastic restoring force of the spring 11, so that the distal end frame 3c is brought into contact with the object 10 to be contacted. In the state, the tip frame 3c is prevented from being separated from the object 10.

  Such an elastic restoring force of the spring 11 may be set as appropriate according to the usage target of the multi-joint mechanism 1. If the elastic restoring force of the spring 11 is increased, the contact pressure against the object 10 becomes too strong in the disengaged state, which may be undesirable. Therefore, if the elastic restoring force of the spring 11 is set to be equal to or less than the joint loss torque, for example, the distal end frame 3c does not tilt in one direction without a large external force. What spring constant is to be set may be appropriately determined according to the usage target of the multi-joint mechanism 1. However, although not shown, it is possible to completely stop the front end gear 8b of the front end frame 3c with a stopper or the like, but it is preferable that the front end frame 3c can be freely rotated to some extent in the disengagement state. .

  (3) In the said embodiment, although the wire mechanism (6a-6c) of the 1st power transmission part 6 and the wire mechanism (7a-7c) of the 2nd power transmission part 7 are not shown in figure, it is set as a gear mechanism. Can do.

  (4) In the above embodiment, the multi-joint mechanism 1 having a configuration in which three frames are connected to be tiltable by three joints is taken as an example, but three or more frames can be tilted by three or more joints. The present invention can be applied even to a connected configuration. In that case, as the two frames to be switched to the linked state and the linked release state, a front end frame and an intermediate frame coupled thereto are desirable. However, the present invention is not limited to this, and two frames in the middle part of the multi-joint mechanism may be switched to the linked state or the linked release state. This may be determined according to the use of the multi-joint mechanism.

[Explanation of robot hand]
An embodiment of a robot hand according to the present invention will be described with reference to FIGS. In this example, the robot hand has a shape corresponding to a human hand.

  The robot hand has a configuration in which, for example, five finger mechanisms 20, 30, 40, 50, and 60 are supported in a cantilever shape on a base 15 corresponding to a palm.

  As will be described in detail below, the first to fifth finger mechanisms 20 to 60 can appropriately perform various movements via a drive unit (a motor in the present embodiment) and a power transmission unit, respectively. Yes.

  In the robot hand of this embodiment, the same configuration as that of the multi-joint mechanism 1 is applied to the second finger mechanism 30 and the third finger mechanism 40.

  First, the first finger mechanism 20, the fourth finger mechanism 50, and the fifth finger mechanism 60 will be described, and then the second finger mechanism 30 and the third finger mechanism 40 will be described.

[First finger mechanism 20]
As shown in FIGS. 11 to 13, the first finger mechanism 20 corresponds to a thumb and can tilt three frames 21a, 21b, and 21c arranged in series by three joints 22a, 22b, and 22c, respectively. It is the structure connected to.

  Of the three frames 21a, 21b, and 21c, the base end frame 21a is supported by the first angle 23 via the base end joint 22a so as to be tiltable. The first angle 23 is supported by the base 15 via a rotation shaft 24 as a root joint. The central axis of the rotating shaft 24 is substantially orthogonal to the central axes of the joints 22a to 22c.

  In the first finger mechanism 20, the three frames 21a, 21b, and 21c are individually tilted by the first, second, and third driving units 25a, 25b, and 25c, and the entire first finger mechanism 20 is the fourth driving unit 25d. Is rotated around the rotation axis 24 and has a total of four degrees of freedom.

  Although the 1st-3rd drive parts 25a-25c are mounted in the 1st angle 23 and are not illustrated in detail, three frames 21a-21c are connected to three joints 22a via three power transmission parts. Each of them is tilted individually with ˜22c as fulcrums.

  The fourth drive unit 25d is mounted on the base 15 and rotates the first angle 23 about the rotation shaft 24 via a linear motion-rotation conversion unit 26. The linear motion-rotation conversion unit 26 is a screw 28 a that is rotatably supported on the base 15, a nut 28 b that is screwed to the screw 28 a, and a swing that is integrated with the nut 28 b and fixed to the rotary shaft 24. The arm 28c has a drive gear 27a fixed to the output shaft (reference number omitted) of the fourth drive unit 25d, and a driven gear 27a fixed to one end of the screw 28a and meshed with the drive gear 27a. The screw 28a and the nut 28b constitute a feed screw mechanism.

  The operation of the first finger mechanism 20 will be described.

  (A) When the first drive unit 25a is driven, the proximal end frame 21a, the intermediate frame 21b, and the distal end frame 21c are tilted integrally with the proximal end joint 22a as a fulcrum.

  (B) When the second drive unit 25b is driven, the intermediate frame 21b and the distal end frame 21c are integrally tilted with the intermediate joint 22b as a fulcrum.

  (C) When the third drive unit 25c is driven, only the fingertip frame 21c tilts with the center of the distal joint 22c as a fulcrum.

  (D) When the fourth drive unit 25d is driven, the screw 28a is rotated via the drive gear 27a and the driven gear 27b. As the screw 28a rotates, the nut 28b linearly reciprocates along the screw 28a, and the swing arm 28c integrated with the nut 28b rotates by a predetermined angle in one direction, so that the entire first finger mechanism 20 rotates. It turns around the axis 24. The turning direction of the first finger mechanism 20 can be controlled by changing the rotation direction of the screw 28a.

[Fourth finger mechanism 50 and fifth finger mechanism 60]
As shown in FIGS. 11 to 13, the fourth finger mechanism 50 corresponds to a ring finger, and three frames 51 a, 51 b, 51 c arranged in series can be tilted by three joints 52 a, 52 b, 52 c, respectively. It is the structure connected to. The fifth finger mechanism 60 corresponds to a little finger, and has a configuration in which three frames 61a, 61b, 61c arranged in series are connected to each other by three joints 62a, 62b, 62c so as to be tiltable.

  As shown in FIGS. 11 and 13, the fourth finger mechanism 50 and the fifth finger mechanism 60 are connected by a rotating shaft 63. By rotating the rotating shaft 63 with the power of the tenth drive unit 64, the fourth finger mechanism 50 and the fifth finger mechanism 60 are linked and stretched. The tenth drive unit 64 is mounted on the angle 65. The tenth drive unit 64 and the rotary shaft 63 are connected by, for example, a gear mechanism (not shown), but the detailed configuration of this gear mechanism is omitted.

  The operation of the fourth finger mechanism 50 and the fifth finger mechanism 60 will be described. When the tenth drive unit 64 is driven, the fifth finger mechanism 60 tilts the entire base end frame 61a, intermediate frame 61b, and front end frame 61c with the base end joint 62a as a fulcrum. At this time, the intermediate frame 61b tilts in conjunction with the tilting operation of the proximal end frame 61a, and the distal end frame 61c tilts in conjunction with the tilting operation of the intermediate frame 61b. Since the fourth finger mechanism 50 is connected to the fifth finger mechanism 60, the fourth finger mechanism 50 moves in the same manner as the fifth finger mechanism 60. As described above, the fourth and fifth finger mechanisms 50 and 60 have one degree of freedom in total.

[Second finger mechanism 30]
As shown in FIGS. 11 and 14, the second finger mechanism 30 corresponds to an index finger, and three frames 31 a, 31 b, 31 c arranged in series can be tilted by three joints 32 a, 32 b, 32 c, respectively. It is the structure connected to.

  Of the three frames 31a to 31c, the proximal end frame 31a is supported by the second angle 33 via the proximal end joint 32a so as to be tiltable. The second angle 33 is supported by the base 15 via a rotation shaft 34 as a root joint. The central axis of the rotating shaft 34 is substantially orthogonal to the central axes of the joints 32a to 32c.

  In the second finger mechanism 30, the three frames 31 a to 31 c are tilted by the fifth and sixth drive portions 35 a and 35 b, and the entire second mechanism 30 is rotated around the rotation shaft 34 as a root joint by the seventh drive portion 35 c. It is designed to turn.

  The fifth and sixth drive portions 35a and 35b are mounted on the second angle 33, and as shown in FIGS. 16 to 18, the base end frame is interposed via the first and second power transmission portions 6 and 7. 31a and the intermediate frame 31b are individually tilted with the proximal joint 32a and the intermediate joint 32b as fulcrums. As shown in FIG. 17, the leading end frame 31 c is switched by the switching unit 8 between a linked state that is driven in linkage with the intermediate frame 31 b and a linked release state that is not linked.

  As shown in FIG. 11, the seventh drive unit 35 c is mounted on the base 15, and rotates around the rotation shaft 34 as a root joint with the second angle 33 via the linear motion-rotation conversion unit 36.

  The linear motion-rotation conversion unit 36 is integrated with the screw 37a fixed to the output shaft (not shown) of the seventh drive unit 35c, a nut 37b screwed to the screw 37a, the nut 37b, and the rotation shaft 34. And a swing arm 37c fixed to the head.

  The screw 37a and the nut 37b constitute a feed screw mechanism. The screw 37a is rotatably supported on the base 15.

  As an operation of the linear motion-rotation conversion unit 36, when the seventh drive unit 35c is driven, the screw 37a of the linear motion-rotation conversion unit 36 is rotated. As the screw 37a rotates, the nut 37b linearly reciprocates along the screw 37a, and the swing arm 37c integrated with the nut 37b rotates by a predetermined angle in one direction, so that the entire second finger mechanism 30 rotates. It turns around the axis 34. The turning direction of the second finger mechanism 30 can be controlled by changing the rotation direction of the screw 37a.

[Third finger mechanism 40]
As shown in FIGS. 11 and 20, the third finger mechanism 40 corresponds to the middle finger, and can tilt the three frames 41a, 41b, 41c arranged in series by the three joints 42a, 42b, 42c, respectively. It is the structure connected to.

  Of the three frames 41a to 41c, the base end frame 41a is supported by the third angle 43 via the base end joint 42a so as to be tiltable. The third angle 43 is fixed to the base 15, and eighth and ninth drive portions 44 a and 44 b for tilting the three frames 41 a to 41 c are mounted on the third angle 43.

  In the third finger mechanism 40, the three frames 41a to 41c are tilted by the eighth and ninth drive portions 44a and 44b.

  The second finger mechanism 30 and the third finger mechanism 40 are the same as the first and second power transmission units 6 and 7 and the switching unit 8 in the multi-joint mechanism 1 shown in FIGS. Since it has a mechanism, it will be briefly described below.

  The first power transmission unit 6 transmits rotational power generated by the fifth drive unit 35a (eighth drive unit 44a) to the proximal joint 32a (42a). As shown in FIGS. 16 and 17, the first power transmission unit 6 includes a first pulley 6a fixed to an output shaft (reference numeral omitted) of the fifth drive unit 35a (eighth drive unit 44a), and a proximal end. A base end pulley 6b that is fixed to the frame 31a (41a) and rotatably supported by one end of a shaft serving as a base end joint 32a (42a), straddling the first pulley 6a and the base end pulley 6b. It is comprised with the 1st wire 6c wound.

  The second power transmission unit 7 transmits the rotational power generated by the sixth drive unit 35b (the ninth drive unit 44b) to the intermediate joint 32b (42b). As shown in FIGS. 16 to 18, the second power transmission unit 7 includes a second pulley 7a fixed to an output shaft (reference number omitted) of the sixth drive unit 35b (the ninth drive unit 44b), and a proximal end. Winding over the base idler pulley 7b that is rotatably supported by the other end of the shaft as the joint 32a (42a) so as to be rotatable adjacent to the base pulley 6b, the second pulley 7a, and the base idler pulley 7b A second wire 7c to be hung, a proximal idler gear 7d formed integrally with the proximal idler pulley 7b, and fixed to the intermediate frame 31b (41b) and rotated to one end of the shaft as the intermediate joint 32b (42b). The intermediate gear 7e is movably supported by the through-holes, and the three base end relay gears 7f, 7g, and 7h are disposed between the base end idle gear 7d and the intermediate gear 7e and mesh with each other. The three base end relay gears 7f, 7g, and 7h are rotatably supported by the base end frame 31a (41a) via a support shaft (reference numeral omitted).

  The switching unit 8 links the leading end frame 31c (41c) to the tilting operation of the intermediate frame 31b (41b) and links the leading end frame 31c (41c) to the tilting operation of the intermediate frame 31b (41b). Without switching to the linkage release state that allows free tilting.

  As shown in FIGS. 16 and 17, the switching unit 8 includes an intermediate idle gear 8 a that is rotatably supported by the other end side of the shaft as the intermediate joint 32 b (42 b) so as to be rotatable adjacent to the intermediate gear 7 e. A tip gear 8b fixed to the tip frame 31c (41c) and rotatably supported by one end of a shaft as the tip joint 32c (42c) is disposed between the intermediate idle gear 8a and the tip gear 8b. The intermediate relay gears 8c, 8d meshing with each other, and a stopper 9 for switching the intermediate idle gear 8a to a non-rotating state and a rotating-permitting state. The two intermediate relay gears 8c and 8d are rotatably supported by the intermediate frame 31b (41b) via a support shaft (reference numeral omitted).

  The stopper 9 is composed of a solenoid. The solenoid stopper 9 includes a cylindrical electromagnet 9a, a movable iron core 9b inserted in a non-contact state with one end projecting from the center of the electromagnet 9a, and a projecting end side outer periphery of the movable iron core 9b. The coil 9c is wound and a locking piece 9d connected in a straight line to the protruding end of the movable iron core 9b.

  Next, operations of the second finger mechanism 30 and the third finger mechanism 40 will be described.

  First, when the fifth drive unit 35a (eighth drive unit 44a) is driven, the base end frame 31a (base end frame 41a) and the intermediate frame 31b (intermediate frame 41b) with the base end joint 32a (base end joint 42a) as a fulcrum. ) And the tip frame 31c (tip frame 41c) as a whole are tilted integrally.

  Further, when the sixth drive unit 35b (the ninth drive unit 44b) is driven, the intermediate frame 31b (the intermediate frame 41b) and the distal end frame 31c (the distal end frame 41c) are integrated with the intermediate joint 32b (the intermediate joint 42b) as a fulcrum. Tilt to.

  At this time, in the case where the locking piece 9d of the stopper 9 is fitted between the teeth of the intermediate idle gear 8a by the switching portion 8 and the intermediate idle gear 8a is restrained to non-rotation, as shown in FIG. When the frame 31b (intermediate frame 41b) is tilted by a predetermined angle θ2, the two base end relay gears 8c, 8d meshing with the non-rotating intermediate idle gear 8a by the tilting operation rotate around the outer periphery of the intermediate idle gear 8a while rotating. Since 31b (intermediate frame 41b) is revolved in the same direction as the tilt direction, the tip gear 8b is rotated in the same direction as the tilt direction of the intermediate frame 31b (intermediate frame 41b), and the tip frame 31c integral with the tip gear 8b. The (front end frame 41c) is tilted in the same direction (downward) as the tilt direction of the intermediate frame 31b (intermediate frame 41b). Thereby, the front end frame 31c (front end frame 41c) is inclined at a predetermined angle θ3 with respect to the intermediate frame 31b (intermediate frame 41b).

  That is, if the intermediate idle gear 8a is constrained to be non-rotating, the power generated by the second drive unit 5b can be transmitted to the distal joint 4c via the intermediate joint 4b, so that the distal frame 31c (the distal frame 41c) is intermediate. It is possible to be in a linked state in which the frame 31b (intermediate frame 41b) is linked and tilted.

  On the other hand, when the locking piece 9d of the stopper 9 is extracted from between the teeth of the intermediate idle gear 8a and the intermediate idle gear 8a is freely rotatable, the intermediate frame 31b (intermediate frame 41b) is shown in FIG. Even if the predetermined angle θ2 is inclined, the proximal relay gears 8c and 8d meshing with the intermediate idle gear 8a are not rotated, so that the distal end frame 31c (the distal end frame 41c) integral with the distal end gear 8b is not tilted. However, since the tip gear 8b is not restrained in any way, the tip frame 31c (tip frame 41c) integral with the tip gear 8b can tilt in any direction up and down with the tip joint 4c as a fulcrum. In the state of FIG. 20, the front end frame 31c (front end frame 41c) is inclined downward by a predetermined angle θ4 with respect to the intermediate frame 31b (intermediate frame 41b) due to its own weight.

  That is, if the intermediate idle gear 8a is freely rotatable, the power generated by the second drive unit 5b is transmitted from the base frame 31a (base frame 41a) to the intermediate frame 31b (intermediate frame 41b), but the intermediate frame 31b. Since transmission from the (intermediate frame 41b) to the tip frame 31c (tip frame 41c) can be blocked, the tip frame 31c (tip frame 41c) is free to be tilted in conjunction with the intermediate frame 31b (intermediate frame 41b). Tiltable linkage release state.

  Next, the operation in the case of gripping a rod-like object 70 such as a chalk with the robot hand described above will be described.

  First, as shown in FIG. 21, when the object 70 is gripped while the tip frames 31c and 41c and the intermediate frames 31b and 41b of the second and third finger mechanisms 30 and 40 are linked to each other, the object 70 is gripped. The tip edges of the tip frames 31c and 41c come into contact with the outer periphery of the object 70, and are gripped by the tip edges of the tip frames 31c and 41c of the second and third finger mechanisms 30 and 40. Become stable.

  However, if the distal end frames 31c and 41c of the second and third finger mechanisms 30 and 40 and the intermediate frames 31b and 41b are in a disengaged state and the object 70 is gripped, the distal end frames 31c and 31c, Since 41c can tilt freely, as shown in FIG. 22, the finger rotates slightly in the opening direction, and the side surfaces of the end frames 31c and 41c are in a preferred gripping state along the object 70. In this state, the linkage is executed again, and a gripping force is generated from the fingertip portion, so that the object 70 can be gripped firmly.

  However, in the second and third finger mechanisms 30 and 40, when the linkage is released, the end frames 31c and 41c can freely rotate without being constrained by any of them, for example, as shown in FIG. In some cases, an appropriate gripping state cannot be created. Considering this point, it is preferable to incorporate the spring 11 shown in FIG. 10 in the second and third finger mechanisms 30 and 40. If this spring 11 is incorporated, the end frames 31c and 41c of the second and third finger mechanisms 30 and 40 are always elastically biased so as to tilt toward the palm side. It can be shaped like a grasp. In particular, when the distal end frames 31c and 41c come into contact with the object 70 in the disengagement state, they can be kept in contact with each other.

  It is also possible to perform control so that the linkage is released after the tip edges of the tip frames 31c and 41c are brought into contact with the object 70 in the linked state. Thus, in order to perform control of releasing the linkage in the middle of the gripping operation and then switching to the linkage state again, the switching timing between the linkage release state and the linkage state becomes important.

  For this purpose, for example, a force sensor (not shown) may be attached from the tip angle to the side of the tip frames 31c and 41c, and the release and execution of the linkage may be controlled by the output of the force sensor. In this case, if an unreasonable force is applied to the end frames 31c and 41c by measuring the shearing force or vertical force applied to the end frames 31c and 41c with a force sensor in the state shown in FIG. What is necessary is just to cancel linkage. If the linkage is canceled in advance, it is possible to apply a gripping force to the object 70 by detecting contact with the object 70 and executing the linkage at that timing.

  By the way, the tilting operation of each finger mechanism 20 to 60 and the turning operation of the first and second finger mechanisms 20 and 30 in the robot hand described above are implemented by mounting an angle sensor (not shown) such as a potentiometer at each joint. The rotation angle of each rotating portion can be detected by the angle sensor, and can be controlled by a control unit (not shown) based on the detected value.

  As another method, there is a method of judging from the value of the angle sensor mounted on each joint. If a gripping operation is determined, the linkage operation is canceled at a rotation angle set in advance by a control unit (not shown), and the linkage operation is performed again at the next rotation angle set. Further, when the link release operation and the link operation are repeated and the finger mechanism is finally returned to the original straight state, the rotation angles of the two joints in the link state must be matched. At that time, the timing for executing the linkage operation may be determined while checking the value of the angle sensor mounted on each joint.

  If the control unit (not shown) selectively performs the linkage operation and the linkage release operation of the front end frames 31c and 41c and the adjacent intermediate frames 31b and 41b as described above, a variety of robot hands can be gripped. Can make a state. Therefore, it is important to appropriately control the execution of the linkage operation and the execution of the linkage release operation in order to create various gripping states of the robot hand.

  In the robot hand described above, the distal end frames 31c and 41c in the second finger mechanism 30 and the third finger mechanism 40 are configured to tilt in conjunction with the tilting operation of the intermediate frames 31b and 41b, so that the number of joints is increased. The number of motors as drive units is reduced. Therefore, the robot hand can be reduced in size and cost.

  Moreover, even if the number of motors used as the drive unit is reduced in this way, by switching between the linkage state in which the end frames 31c and 41c are linked to the intermediate frames 31b and 41b and the linkage release state in which the tip frames 31c and 41c are not linked, The gripping posture of the object 70 can be relatively diversified.

  Moreover, in the 2nd power transmission part 7 with which the 2nd, 3rd finger mechanisms 30 and 40 are equipped, the power transmission element from the 2nd drive part 5b to the proximal end joint 4a is made into a wire mechanism (7a-7c), and a proximal end The power transmission element from the joint 4a to the intermediate joint 4b is a gear mechanism (7d to 7h). As described above, when the wire mechanism is arranged outside the second and third finger mechanisms 30 and 40 in the second power transmission unit 7, the second drive unit 5b can be arranged freely. In addition, when the gear mechanism is arranged inside the second and third finger mechanisms 30 and 40 in the second power transmission unit 7, the workability, maintainability and reliability of the gear mechanism can be improved. Of course, although not shown, the power transmission element from the second drive unit 5b to the proximal joint 4a in the second power transmission unit 7 may be a gear mechanism.

  Moreover, since the power transmission element from the intermediate joint 4b to the tip joint 4c is also the gear mechanism (8a to 8d) for the switching unit 8 provided in the second and third finger mechanisms 30 and 40, the construction of the gear mechanism is performed. , Maintenance and reliability can be improved.

  Hereinafter, other embodiments of the robot hand will be described.

  (1) In the said embodiment, although it does not demonstrate in detail about the power transmission part in the 1st finger mechanism 20, the 4th finger mechanism 50, and the 5th finger mechanism 60, the same wire mechanism as a prior art example is used. Moreover, the same gear mechanism as the power transmission part in the said 2nd finger mechanism 30 or the 3rd finger mechanism 40 can be used.

  (2) In the robot hand of the above embodiment, the second finger mechanism 30 and the third finger mechanism 40 are intended to be in a linked state in which the end frames 31c and 41c are linked to the intermediate frames 31b and 41b and in a linked release state in which the tip frames 31c and 41c are linked. However, the first finger mechanism 20, the fourth finger mechanism 50, and the fifth finger mechanism 60 can be configured in the same manner. Decide according to the purpose of the hand. However, as in the above-described embodiment, the first finger mechanism 20 corresponding to the thumb is configured to use the same number of drive units as the number of joints, and can be moved in substantially the same manner as the thumb of a human hand. This is advantageous for moving the robot hand in various ways.

  (3) In the above embodiment, in the finger mechanism having three frames, the tip frame and the intermediate frame are switched between the linked state and the linked release state, but the three or more frames are switched to the three or more joints. Even if it is the structure connected so that tilting is possible, this invention can be applied. In that case, the two frames to be switched to the linked state and the linked release state are the leading end frame and the intermediate frame coupled thereto.

It is a top view which shows one Embodiment of the multi joint mechanism which concerns on this invention. It is the figure which looked at the multi-joint mechanism of FIG. 1 from one side (the right side in the figure). It is the figure which looked at the multi joint mechanism of FIG. 1 from the other side (left side in a figure). It is a figure which shows the motion of the base end frame of FIG. It is a figure which shows the motion at the time of cooperation of the intermediate | middle frame of FIG. 2, and a front-end | tip frame. It is a figure which shows the motion at the time of cancellation | release of linkage with the intermediate | middle frame of FIG. 2, and a front-end | tip frame. It is explanatory drawing which shows the contact state with respect to the object of a front-end | tip frame in the state of FIG. It is explanatory drawing which shows the contact state with respect to the object of a front-end | tip frame in the state of FIG. It is a figure corresponding to FIG. 2 in the other example of the stopper of FIG. It is a figure corresponding to Drawing 2 in other embodiments of the articulated mechanism concerning the present invention. It is the top view which looked at one embodiment of the robot hand concerning the present invention from the former side. It is the figure which looked at the robot hand of FIG. 11 from the 1st finger mechanism side. It is the figure which looked at the robot hand of FIG. 11 from the 5th finger mechanism side. It is a side view which shows the 2nd finger mechanism single-piece | unit of FIG. It is a side view which shows the 3rd finger mechanism single-piece | unit of FIG. It is a top view which shows the 2nd finger mechanism of FIG. 14, and the 3rd finger mechanism of FIG. It is the figure which looked at the 2nd, 3rd finger mechanism of Drawing 16 from one side (the figure right side). It is the figure which looked at the 2nd, 3rd finger mechanism of Drawing 16 from the other side (left side in a figure). It is a figure which shows the motion at the time of the cooperation of the intermediate | middle frame and front-end | tip frame in the 2nd, 3rd finger mechanism of FIG. It is a figure which shows the motion at the time of cancellation | release of linkage with the intermediate | middle frame and front-end | tip frame in the 2nd, 3rd finger mechanism of FIG. It is explanatory drawing which shows the unpreferable example of the holding state of the object by the robot hand of FIG. It is explanatory drawing which shows the preferable example of the holding | grip state of the object by the robot hand of FIG. It is explanatory drawing which shows the other example of the unpreferable holding | grip state of the object by the robot hand of FIG.

Explanation of symbols

1 Articulated mechanism
2 base
3a Base frame
3b Intermediate frame
3c Tip frame
4a proximal joint
4b Intermediate joint
4c Tip joint
5a 1st drive part
5b Second drive unit
6 1st power transmission part
6a First pulley
6b Base end pulley
6c 1st wire
7 Second power transmission unit
7a Second pulley
7b Base idle pulley
7c Second wire
7d Base idler gear
7e Intermediate gear 7f-7h Proximal relay gear
8 Switching part
8a Intermediate idle gear
8b Tip gear 8c, 8d Intermediate relay gear
9 stopper 10 object 15 base 20 first finger mechanism 30 second finger mechanism 31a proximal frame 31b intermediate frame 31c distal frame 32a proximal joint 32b intermediate joint 32c distal joint 35a fifth drive unit 35b second finger mechanism 6th drive part for finger mechanism 40 3rd finger mechanism 41a Base end frame 41b Intermediate frame 41c End frame 42a Base end joint 42b Intermediate joint 42c End joint 44a 8th drive part for 3rd finger mechanism 44b For 3rd finger mechanism 9th drive part 50 4th finger mechanism 60 5th finger mechanism 70 Object

Claims (15)

A plurality of frames arranged in series, a plurality of joints that connect each frame so as to be tiltable, a drive unit that generates power for tilting the appropriate frame, and a power generated by the drive unit A power transmission unit that transmits to the joints of
In the power transmission unit, a power transmission element between the joints is constituted by a gear. A plurality of frames arranged in series;
A plurality of joints that connect each frame in a tiltable manner;
A first drive unit that generates power for tilting a proximal frame of the plurality of frames;
A second drive unit that generates power for driving an intermediate frame of the plurality of frames;
A first power transmission unit configured to transmit power generated by the first drive unit to the base frame;
A second power transmission unit that transmits power generated by the second drive unit to the intermediate frame;
In the second power transmission unit, a power transmission element between the joints is constituted by a gear. The multi-joint mechanism according to claim 2,
Among the joints, the base joint is a shaft whose both ends are fixed to the base and is rotatably supported by one end of the base frame, and the intermediate joint has both ends other than the base frame. The shaft is fixed to the end and is pivotally supported by one end of the intermediate frame, and the tip joint is fixed to the other end of the intermediate frame and rotatable to one end of the tip frame. It is assumed that the shaft is penetrated and supported by
The power transmission element between the joints in the second power transmission unit includes a base idle gear that is supported by a shaft serving as a base end joint so as to be relatively rotatable, a base end idling gear fixed to the intermediate frame, and An intermediate gear rotatably supported on the shaft, and one or a plurality of proximal relay gears arranged between the proximal idle gear and the intermediate gear and meshing with each other. Features a multi-joint mechanism. The multi-joint mechanism according to claim 2 or 3,
A switching unit that intentionally realizes a linkage state in which the tip frame of the plurality of frames is linked to the tilting operation of the intermediate frame and a linkage release state in which the tip frame is freely tiltable with respect to the intermediate frame. An articulated mechanism characterized by comprising: The multi-joint mechanism according to claim 4,
The switching unit includes an intermediate idler gear that is rotatably supported adjacent to the intermediate gear by an axis as an intermediate joint, and a distal end that is fixed to the distal end frame and is rotatably supported by an axis as a distal joint. A gear, one or a plurality of intermediate relay gears arranged between the intermediate idle gear and the tip gear and meshing with each other, and the intermediate idle gear is restricted to non-rotation to be in the linked state or the intermediate idle gear. A multi-joint mechanism characterized by including a stopper that allows the rotation of the gear to be in the disengaged state. The multi-joint mechanism according to claim 5,
The stopper is inserted between the teeth of the intermediate idle gear and is locked to prevent the intermediate idle gear from rotating, and the stopper is protruded to be inserted between the teeth of the intermediate idle gear. A multi-joint mechanism characterized by including a moving part that moves backward so as to be pulled out between the teeth of the intermediate idle gear. In the multi-joint mechanism according to claim 6,
The multi-joint mechanism characterized in that the operating part is constituted by a solenoid. In the multi-joint mechanism according to claim 6,
The multi-joint mechanism characterized in that the operating part is composed of a polymer actuator. The multi-joint mechanism according to any one of claims 4 to 8,
A multi-joint mechanism characterized in that a spring for resiliently biasing the tip frame in a tilting direction with respect to the intermediate frame is provided on the tip frame and an intermediate frame connected thereto. The multi-joint mechanism according to any one of claims 1 to 9,
A multi-joint mechanism comprising a control unit that controls the tilting operation of each frame by driving or non-driving the driving unit as required. The multi-joint mechanism according to any one of claims 1 to 10,
Each articulated mechanism is provided with an angle sensor for measuring a relative inclination between frames connected to each other. The multi-joint mechanism according to claim 11,
The controller is configured to recognize a posture of each frame based on an output of the angle sensor and to perform a required posture when tilting each frame in the linkage state. mechanism. The multi-joint mechanism according to any one of claims 1 to 12,
A multi-joint mechanism characterized in that a force sensor is provided on the distal end frame. The multi-joint mechanism according to claim 13,
The controller is configured to retract the stopper by the driving unit of the switching unit based on the output of the force sensor when the tip frame contacts an object in the process of tilting the frames in the linked state. A multi-joint mechanism characterized by executing a process for releasing an intermediate idler gear in a disengageable linkage state. In a robot hand including a base and a plurality of finger mechanisms each supported by the base in a cantilever shape and having joints in a plurality of positions in the protruding direction,
A robot hand, wherein at least one of the plurality of finger mechanisms is the multi-joint mechanism according to any one of claims 1 to 14.

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