JP2008238326A - Robot hand and robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To operate a grooved interface by a robot hand holding an object. <P>SOLUTION: This robot hand holding the object is provided with a palm part 10, a pair of grippers 51 and 52 capable of holding the object by projecting from the palm part 10, an opening/closing means for moving the grippers 51 and 42 so that the interval of the grippers 51 and 52 may be changed, and a link means for driving a second fingertip part 56 at a distal end of the second gripper 52 to rotate toward the first gripper 51 by a straight line motion for pressing a first fingertip part 55 at a distal end of the first gripper 51. The link means is provided with a rack connected to the first fingertip part 55, a pinion engaged with the rack and a belt, etc. for transmitting rotation of the pinion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a robot hand and a robot that grip an object.

Robot hands aimed at gripping objects of various positions, sizes, and shapes have been developed (see, for example, Patent Document 1 and Patent Document 2).
JP-A-5-293786 JP-A-8-323678

  For example, in an environment that coexists with humans such as a home, a robot hand is required to handle a door or a drawer by inserting a finger part of the hand into a groove-shaped handle.

  However, a two-finger, one-degree-of-freedom open / closed hand with a pair of parallel-movable fingers has a groove-shaped interface such as a door represented by bran, a drawer, and a storage shelf door. Accessing things is difficult. Furthermore, when the door is locked using a spring or the like, the door cannot be opened or closed unless the lock is released after the hand is inserted into the groove of the interface.

  If you try to open and close the door by making the robot hand perform the same operation as a human, insert the finger of the hand into the groove using a multi-fingered multi-fingered hand, or use a handle that the robot can easily grip as a dedicated interface It is necessary to provide it separately. A multi-finger, multi-degree-of-freedom hand tends to be complicated because it is redundant. When the mechanism becomes complicated, the weight increases, and it is impractical to mount it on a relatively small mobile robot that operates in the home.

  In addition, providing an interface dedicated to a robot hand having a simple mechanism with relatively few degrees of freedom can be an obstacle to both humans and robots in a living environment where protrusions and the like exist.

  SUMMARY OF THE INVENTION An object of the present invention is to enable a groove-like interface to be operated by a robot hand that holds an object.

  In order to achieve the above-mentioned object, the present invention provides a robot hand for gripping an object, comprising a palm part, a projecting part from the palm part, the grip part for the object, and a tip relative to the palm part. A first gripper that can move to the first gripper, a second gripper that protrudes from the palm portion, includes a gripping portion for the object, and has a tip that can be turned toward the first gripper, and the first gripper Link means for driving the tip of the second gripper to rotate toward the first gripper by a movement of bringing the tip of the gripper closer to the palm, a gripping portion of the first gripper, and the second And an opening / closing means for moving at least one of the first and second grippers so that an interval between gripping portions of the grippers is changed.

  According to the present invention, in a robot that grips an object, a palm part and a first part that protrudes from the palm part, includes the grip part for the object, and has a tip that is movable relative to the palm part. A gripper that protrudes from the palm, includes a gripping portion for the object, and has a tip that can be turned toward the first gripper, and a tip of the first gripper. The distance between the link means for driving the tip of the second gripper to rotate toward the first gripper by the movement closer to the first gripper, and the gripping part of the first gripper and the gripping part of the second gripper And an opening / closing means for moving at least one of the first and second grippers so as to change, and an arm portion for moving the palm portion in the protruding direction of the first gripper and in the opposite direction. And

  According to the present invention, the groove-shaped interface can be operated by the robot hand that holds the object.

  An embodiment of a robot hand according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar structure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 6 of the first embodiment of the robot hand according to the present invention. 4 is a cross-sectional view of the robot hand according to the present embodiment taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view of the robot hand according to the present embodiment taken along line VV in FIG. 6 is a cross-sectional view taken along the line VI-VI in FIGS. 3, 4 and 5 of the robot hand according to the present embodiment.

  The robot hand of the present embodiment has a palm portion 10 and first and second grippers 51 and 52. The palm portion 10 is connected to the arm portion 21 via the wrist joint 22.

  The arm portion 21 has a degree of freedom of rotation around its axis and can perform a twisting operation. That is, the rotation of the arm portion 21 allows the first and second grippers 51 and 52 of the robot hand to be directed at an arbitrary angle to access the target. Such a rotatable degree of freedom may be given to the palm 10 or the wrist joint 22.

  The palm portion 10 has at least one degree of freedom in a vertical plane including the axis of the arm portion 21 and is attached to the wrist joint 22 so as to be tiltable in the plane. That is, even if the inclination angle of the arm portion 21 with respect to the horizontal direction changes, the posture of the palm portion 10 can be maintained without changing.

  The first gripper 51 has a first finger body 53 extending from the palm portion 10 and a first fingertip portion 55 extending from the first finger body. The second gripper 52 has a second finger main body 54 extending from the palm portion 10 in parallel with the first finger main body 53 and a second fingertip portion 56 extending from the second finger main body.

  A rack 60 that extends in the same direction as the first finger main body 53 is housed inside the first finger main body 53. One end of the rack 60 is fixed to the first fingertip 55, and a spring 62 is attached to the other end. The end of the spring 62 opposite to the rack 60 is fixed to the box 57. The box 57 is fixed to the first finger body 53.

  Inside the palm portion 10, a pinion 61 meshed with the rack 60 and a first pulley 15 coupled to the pinion 61 by an axle 73 are disposed. The second and third pulleys 16 and 64 are attached in the vicinity of the attachment portion of the second finger main body 54. A first belt 63 is stretched between the first pulley 15 and the second pulley 16. The second pulley 16 and the third pulley 64 are connected by a rotating shaft 74. A fourth pulley 66 centered on the coupling shaft 72 is attached to the second fingertip portion 56. A second belt 65 is stretched between the third pulley 64 and the fourth pulley 66.

  A motor 41 is disposed inside the palm 10. The rotation of the motor 41 is transmitted to the motor direct connection gear 82 via the motor shaft 75. The rotation of the motor direct connection gear 82 is transmitted to the first finger main body moving rack 86 via the two gears 84 and 85. The rotation of the motor direct connection gear 82 is also transmitted to the second finger main body moving rack 81 through the gear 83. The first and second finger main body moving racks 86 and 81 are attached to the first and second finger main bodies 53 and 54, respectively.

  An adjustment pulley 17 is disposed substantially in the middle between the first pulley 15 and the second pulley 16. The adjustment pulley 17 is in contact with the first belt 63 on the opposite side of the grippers 51 and 52. An adjustment rack 44 that is attached so as not to interfere with the first belt 63 is attached to the adjustment pulley 17. An adjustment pinion 18 is engaged with the adjustment rack 44. The adjustment pinion 18 is coupled to the motor 41 via the motor shaft 75.

  The movement of the first and second grippers 51 and 52 by such a mechanism will be described.

  First, the movement (arrow 92 in FIG. 1) in which the first and second grippers 51 and 52 approach and move away from each other will be described.

  When the motor 41 rotates, the rotation is transmitted to the first and second finger body moving racks 86 and 81. As a result, the first and second finger main body moving racks 86 and 81 linearly move along the arrow 92. As the first and second finger body moving racks 86 and 81 move linearly, the first and second grippers 51 and 52 move linearly. By this linear motion, the distance between the first and second grippers 51 and 52 changes.

  Thus, by opening and closing the first and second grippers 51 and 52, the first and second grippers 51 and 52 can grip the object. The object may be gripped by the first and second fingertip portions 55 and 56, or may be performed by the first and second finger bodies 53 and 54.

  The opening and closing of the first and second grippers 51 and 52 is performed by moving the first and second grippers 51 and 52 evenly, but they may be moved unevenly or by moving only one of them. Also good.

  Next, the rotation of the tip of the second fingertip, that is, the tip of the second fingertip portion 56 as the tip of the first gripper 51, that is, the tip of the first fingertip portion 55 approaches the palm portion 10 will be described. .

  FIG. 7 is a cross-sectional view of the robot hand in the present embodiment. FIG. 7 shows a state where the distance between the first and second grippers 51 and 52 is narrowed.

  As the distance between the first and second grippers 51 and 52 changes, the distance between the first pulley 15 and the second pulley 16 also changes. The change in the interval is proportional to the angle at which the motor 41 is rotated.

  Adjustment so that the first belt 63 does not bend when the distance between the first and second grippers 51 and 52 changes by the unit length as the distance between the first and second grippers 51 and 52 is narrower. The moving amount of the pulley 17 is large. For this reason, the distance between the teeth carved in the adjustment rack 44 is larger on the side closer to the first and second grippers 51 and 52.

  The rotation of the motor 41 is transmitted to the adjustment pinion 18 via the motor shaft 75. The adjustment pulley 17 is moved so that the first belt 63 is not loosened by being transmitted to the adjustment rack 44 by the rotation of the adjustment pinion 18.

  When a force is applied to the first fingertip portion 55 in the direction in which the first fingertip portion 55 is pushed (the direction of the arrow 90 in FIG. 1), the first fingertip portion 55 is pushed into the first finger main body 53. . As the first fingertip portion 55 moves, the rack 60 is pushed into the palm portion 10, and the pinion 61 rotates accordingly. The rotation of the pinion 61 is transmitted to the first pulley 15 by the axle 73.

  The rotation of the first pulley 15 is transmitted to the second pulley 16 via the first belt 63 that does not loosen even if the distance between the first and second grippers 51 and 52 changes as described above. . The rotation of the second pulley 16 is transmitted to the third pulley 64 by the rotation shaft 74. The rotation of the third pulley 64 is transmitted to the fourth pulley 66 by the second belt 65. The rotation of the fourth pulley 66 is transmitted to the second fingertip portion 56 via the coupling shaft 72.

  In this manner, the movement of the first fingertip portion 55 in the direction of the arrow 90 causes the second fingertip portion 56 to rotate in the direction toward the first gripper 51 (the direction of the arrow 91 in FIG. 1).

  FIG. 1 is a side view showing the robot hand of this embodiment together with an access target. FIG. 2 is a perspective view showing the robot hand according to the present embodiment together with an access target.

  It is assumed that a shelf with drawers to be accessed includes a shelf 34, a drawer portion 30, and a lock portion 32, and a groove-like interface 31 is formed between the shelf 34 and the drawer portion 30. The drawer portion 30 is normally not pulled out of the shelf 34 by the lock portion 32 and can be pulled out in the direction of the arrow 90 when the lock is released. The lock portion 32 is configured to release the lock when the claw 33 disposed on the groove-like interface 31 of the drawer-equipped shelf is pushed in the direction of the arrow 91.

  The first and second grippers 51 and 52 move along the arrow 92, and the distance between the first and second grippers 51 and 52 can be changed. Accordingly, the object can be gripped using the first and second grippers 51 and 52.

  When using the robot hand to pull out the drawer portion 30, first, the arm portion 21 is moved to move the palm portion 10 in the direction opposite to the arrow 90, and the first fingertip portion 55 is pressed against the drawer portion 30. As a result, the first fingertip portion 55 moves in the direction of the arrow 90 and is pushed into the first finger main body 53. As the first fingertip portion 55 moves, the second fingertip rotates in the direction of the arrow 91 about the coupling shaft 72. At this time, since the palm part 10 is moving toward the drawer part 30, the second fingertip part 56 enters the interface 31 while rotating.

  In this way, the second fingertip portion 56 enters the interface 31 and the nail 33 is pushed, so that the lock by the lock portion 32 is released. When the arm portion is moved and the palm portion 10 is moved in the direction of the arrow 90 in the unlocked state as described above, the drawer portion 30 is removed from the shelf 34 while the second fingertip portion 56 is caught by the nail 33. Can be pulled out in the direction of arrow 90.

  Thereafter, the second fingertip portion 56 is separated from the nail 33 by, for example, moving the arm portion 21. With the second fingertip portion 56 away from the nail 33, the robot hand is moved away from the drawer portion 30 by moving the entire robot hand in the direction of the arrow 90.

  As described above, as the tip of the first gripper 51, that is, the tip of the first fingertip portion 55 approaches the palm portion 10, the tip of the second fingertip, that is, the tip of the second fingertip portion 56 rotates. When the robot hand is used, the groove-shaped interface 31 can be easily operated. Further, it is not necessary to provide a new drive source such as a motor for such an operation.

  Further, since the first and second grippers 51 and 52 can be moved so as to approach each other, it is also possible to grip an object.

  In addition, although access to the shelf with a drawer was demonstrated here, it can access similarly to the other object which has a groove-shaped interface.

[Second Embodiment]
FIG. 8 is a cross-sectional view of the robot hand according to the second embodiment of the present invention. FIG. 8 shows a state where the distance between the first and second grippers 51 and 52 is narrowed.

  In the robot hand according to the present embodiment, the adjustment rack of the first embodiment is changed to another adjustment rack 77 and two rollers 76 are provided.

  The two rollers 76 are in contact with the outer surface of the first belt 63 on both sides of the adjustment pulley 17. The two rollers 76 are parallel to the first pulley 15 and the second pulley 16 and the roller 76 in a direction in which the first belt 63 is directed from the first pulley 15 toward the second pulley 16. Are arranged as follows.

  The adjustment rack 77 has teeth cut at equal intervals.

  In such a robot hand, the first belt 63 can be prevented from being loosened by moving the adjustment pulley 17 in proportion to the change in the distance between the first and second pulleys 15 and 16. it can.

  The robot hand of this embodiment has an adjustment rack 77 that is simpler than that of the first embodiment, and can be easily manufactured.

[Third Embodiment]
FIG. 9 is a cross-sectional view of a robot hand according to a third embodiment of the present invention. FIG. 9 shows a state in which the first fingertip portion 55 is pushed into the first finger main body 53.

  The robot hand according to the present embodiment is obtained by adding locking means that can be fixed in a state where the first fingertip portion 55 is pushed into the robot hand according to the first embodiment. The locking means is disposed inside a box 57 fixed to the first finger main body 53.

  The locking means has a lock claw 1 and a lock release claw 4 attached to the rack 60. Further, the locking means includes an unlocking switch 3 attached to the box 57 via a spring, and a hook portion 2 attached to the unlocking switch 3.

  The lock claw 1 and the lock release claw 4 are urged away from the rack 60 and are formed so as to be able to be pushed into the rack 60. Further, a force is applied to the first fingertip portion 55 in a direction in which the first fingertip portion 55 is pushed out of the first finger main body 53 by the spring 62. For this reason, when the first fingertip portion 55 is pushed into the first finger main body 53 for a predetermined length, the lock claw 1 is caught by the catch portion 2 and fixed.

  The lock release switch 3 is arranged at a position where the first fingertip portion 55 is pushed by the lock release claw 4 in a state where the first fingertip portion 55 is pushed deepest into the first finger body 53. When the lock release switch 3 is pressed, the catch portion 2 moves so as not to be caught by the lock claw 1 until the first fingertip portion 55 returns to the state where it protrudes most from the first finger body.

  Thus, by providing the first gripper 51 with a locking means, the second fingertip portion 56 can be fixed in a rotated state. If such a robot hand is used, more various interfaces 31 can be accessed.

[Fourth Embodiment]
FIG. 10 is a cross-sectional view of the robot hand according to the fourth embodiment of the present invention.

  The robot hand according to the present embodiment is different from the robot hand according to the first embodiment in the mechanism for transmitting the movements of the first gripper 51 and the first gripper to the first pulley 15.

  In the first gripper 51 of this robot hand, an intermediate portion 58 is provided between the first finger body 53 and the first fingertip portion 55. A spring 59 is attached between the first finger main body 53 and the intermediate portion 58 and between the first fingertip portion 55 and the intermediate portion 58 so as to extend the first gripper 51. It is energized.

  Further, the first finger main body 53 and the intermediate portion 58 are coupled by a finger joint shaft 48, and a finger joint pulley 47 is coupled to the finger joint shaft 48. A pulley 49 is also coupled to a coupling shaft between the first finger body 53 and the intermediate portion 58. The rotation of the finger joint pulley 47 is transmitted to the rotating shaft 74 via the belts 45 and 46 and is transmitted to the first pulley 15.

  When the first fingertip portion 55 is pushed toward the palm portion 10, the angle between the first fingertip portion 55 and the intermediate portion 58 becomes small, and the distance between the first fingertip portion 55 and the palm portion 10 is Shorter. When the first fingertip portion 55 is rotated toward the palm portion 10 in this manner, the first pulley 15 is rotated by the finger joint pulley 47 and the belts 45 and 46 along with the rotation.

  The rotation of the first pulley 15 is transmitted to the second gripper 52 as in the first embodiment, and the second fingertip portion 56 rotates. Accordingly, when the first fingertip portion 55 approaches the palm portion 10, the second fingertip portion 56 rotates.

  Thus, even when the first fingertip portion 55 rotates, the second fingertip portion 56 can be rotated while the first fingertip portion 55 approaches the palm portion 10. That is, even in the robot hand according to the present embodiment, the groove-shaped interface 31 (see FIG. 1) can be easily operated as in the first embodiment. Further, it is not necessary to provide a new drive source such as a motor for such an operation. Since the first and second grippers 51 and 52 can be moved so as to approach each other, it is possible to grip an object.

  In addition, once the angle between the first fingertip portion 55 and the intermediate portion 58 is reduced, the lock is released, and further, the lock is released by rotating the first fingertip portion 55 toward the palm portion 10. You may be made to do.

[Other embodiments]
The first to fourth embodiments are merely examples, and the present invention is not limited to these.

  For example, each of the above-described embodiments is a two-finger robot hand having two grippers, but can also be applied to a robot hand having three or more fingers. The robot hand in which the palm portion 10 is connected to the arm portion 21 via the wrist joint 22 has been described. However, depending on the shape of the interface 31, the freedom of movement of the palm portion 10 is small. There are cases where it is good. In such a case, an appropriate wrist joint 22 or arm portion 21 may be used as appropriate.

  In each of the above-described embodiments, the pulley and the belt are used when the rotational motion is transmitted to the rotational motion, but other transmission means may be used. For example, a timing belt or a chain can be used. Further, an adjustment pulley or the like is used to suppress the looseness of the belt, but a belt that expands and contracts according to the distance between rotating bodies such as a pulley can also be used.

  Furthermore, the features of the embodiments may be combined.

It is a side view which shows 1st Embodiment of the robot hand which concerns on this invention with the access object. It is a perspective view which shows 1st Embodiment of the robot hand which concerns on this invention with the access object. FIG. 7 is a cross-sectional view taken along the line III-III in FIG. 6 of the first embodiment of the robot hand according to the present invention. It is IV-IV arrow sectional drawing in FIG. 6 of 1st Embodiment of the robot hand which concerns on this invention. It is a VV arrow sectional view in Drawing 6 of a 1st embodiment of a robot hand concerning the present invention. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIGS. 3, 4, and 5 of the first embodiment of the robot hand according to the present invention. It is sectional drawing in 1st Embodiment of the robot hand which concerns on this invention. It is sectional drawing in 2nd Embodiment of the robot hand which concerns on this invention. It is sectional drawing in 3rd Embodiment of the robot hand based on this invention. It is sectional drawing in 4th Embodiment of the robot hand based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lock claw, 2 ... Hook part, 3 ... Lock release switch, 10 ... Palm part, 15 ... 1st pulley, 16 ... 2nd pulley, 17 ... Adjustment pulley, 18 ... Adjustment pinion, 21 ... Arm Part, 22 ... wrist joint, 30 ... drawer part, 31 ... interface, 32 ... lock part, 33 ... claw, 34 ... shelf, 41 ... motor, 44 ... rack for adjustment, 45 ... belt, 46 ... belt, 47 ... finger Joint pulley, 48 ... finger joint axis, 49 ... pulley, 51 ... first gripper, 52 ... second gripper, 53 ... first finger body, 54 ... second finger body, 55 ... first fingertip part 56 ... second fingertip portion, 58 ... intermediate portion, 59 ... spring, 60 ... rack, 61 ... pinion, 63 ... first belt, 64 ... third pulley, 65 ... second belt, 66 ... first 4 pulleys, 72 ... coupling shaft, 73 ... axle 74 ... Rotating shaft, 75 ... Motor shaft, 76 ... Roller, 77 ... Adjustment rack, 81 ... Second finger main body moving rack, 82 ... Motor direct connection gear, 83 ... Gear, 84 ... Gear, 85 ... Gear, 86 ... First finger body moving rack

Claims (11)

In a robot hand that holds an object,
The palm,
A first gripper that protrudes from the palm, includes a gripping portion for the object, and has a tip that is movable relative to the palm;
A second gripper that protrudes from the palm, includes a gripping portion for the object, and has a tip that is pivotable toward the first gripper;
Link means for driving the tip of the second gripper to rotate toward the first gripper by a movement of bringing the tip of the first gripper closer to the palm portion;
An opening / closing means for moving at least one of the first and second grippers so that an interval between the grip portion of the first gripper and the grip portion of the second gripper is changed;
A robot hand characterized by comprising:   The link means drives the tip of the second gripper to rotate toward the first finger by a linear motion of at least a part of the first gripper. The robot hand described. The first gripper includes a first finger main body extending in a direction away from the palm portion, and a first fingertip extending in a direction away from the first finger main body and capable of being pushed toward the first finger main body. Part
The second gripper is rotatable about a second finger main body extending in a direction away from the palm and a coupling shaft located at an end of the second finger main body opposite to the palm. An attached second fingertip,
The link means includes: a rack that moves along a straight line along with the linear motion in which the first fingertip portion is pushed toward the first finger body; and the first finger body that is meshed with the rack. A pinion whose relative position does not change, and a rotation means for rotating the second fingertip portion around the coupling shaft by the rotation of the pinion.
The robot hand according to claim 2, wherein: The opening / closing means moves at least one of the first and second finger bodies relative to the palm,
The rotating means includes a first pulley coupled coaxially with the pinion, a second pulley whose relative position with the second finger body does not change, and a coaxial coupling with the second pulley. A third pulley, a fourth pulley attached to the coupling shaft, a first belt spanned between the first pulley and the second pulley, the third pulley, and the A second belt stretched over a fourth pulley, and the first belt in contact with the first belt in response to a change in a distance between the first pulley and the second pulley. An adjustment pulley that moves so as not to loosen,
The robot hand according to claim 3. A spring for biasing the first fingertip portion in a direction away from the first finger body;
When the first fingertip portion is pushed down to the first length, the first fingertip portion is fixed so as not to move in a direction away from the finger main body, and the first fingertip portion is further moved from the first length. Locking means for releasing the fixation at the first length when pushed into the second long length;
The robot hand according to claim 3 or 4, characterized by comprising:   The link means drives the tip of the second gripper to rotate toward the first finger by a rotational movement of at least a part of the first gripper. The robot hand described in 1. The first gripper is rotatably coupled to an intermediate portion extending in a direction away from the palm portion and a finger joint shaft at an end portion far from the palm portion of the intermediate portion, and the palm portion from the finger joint axis. A first fingertip portion extending in a direction away from
The second gripper is rotatable about a second finger main body extending in a direction away from the palm and a coupling shaft located at an end of the second finger main body opposite to the palm. An attached second fingertip,
The link means includes a finger joint pulley coupled to the finger joint shaft and a rotation shaft that does not change a relative position between the finger body pulley and the first finger body that rotates as the finger joint pulley rotates. A rotating means for rotating the second fingertip portion around the coupling shaft by a rotating motion of the rotating shaft;
The robot hand according to claim 6. The opening / closing means moves at least one of an end portion of the intermediate portion close to the palm portion and a second finger main body relative to the palm portion,
The rotating means is coaxially coupled to the first pulley coupled to the rotating shaft, the second pulley whose relative position with respect to the second finger body does not change, and the second pulley. A third pulley, a fourth pulley attached to the coupling shaft, a first belt spanned between the first pulley and the second pulley, the third pulley and the second pulley The first belt is loosened in response to a change in the distance between the first belt and the second pulley that is in contact with the first belt and the second belt that is stretched over four pulleys. An adjustment pulley that moves so as not to move,
The robot hand according to claim 7. A spring that biases the relative angle between the first fingertip part and the intermediate part to be large;
When the relative angle between the first fingertip portion and the intermediate portion is equal to or less than the first angle, the relative angle between the first fingertip portion and the intermediate portion is fixed so as not to increase, and further, Lock means for releasing the fixation at the first angle when a relative angle between the first fingertip portion and the intermediate portion is equal to or smaller than a second angle smaller than the first angle;
The robot hand according to claim 7 or 8, characterized by comprising: In a robot that holds an object,
The palm,
A first gripper that protrudes from the palm, includes a gripping portion for the object, and has a tip that is movable relative to the palm;
A second gripper that protrudes from the palm, includes a gripping portion for the object, and has a tip that is pivotable toward the first gripper;
Link means for driving the tip of the second gripper to rotate toward the first gripper by a movement of bringing the tip of the first gripper closer to the palm portion;
An opening / closing means for moving at least one of the first and second grippers so that an interval between the grip portion of the first gripper and the grip portion of the second gripper is changed;
An arm for moving the palm in the protruding direction of the first gripper and in the opposite direction;
A robot characterized by comprising:   The robot according to claim 10, further comprising a wrist joint provided between the palm and the arm that changes a relative angle between the palm and the arm.

Images