JP2009078341A - Robot hand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a robot hand including a palm, a finger mechanism and a thumb mechanism and capable of stably holding an object with large to small size. <P>SOLUTION: The robot hand includes: the palm 2, the finger mechanism 30 extending from a main palm part 3 located at a leading edge region T of the palm 2 and bending inward of the main palm part 3; a center hand part 4 located at a base end region of the palm; and the thumb mechanism 40 connected with the center hand part 4. The thumb mechanism 40 bends inward of the palm 2 in the direction intersecting with a plane through which the finger mechanism 30 passes when the mechanism 30 is bent. The center hand part 4 rotates in the direction intersecting with a plane through which the thumb mechanism 40 passes when the mechanism 40 is bent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a robot hand configured to include a palm part and a finger mechanism extending from the palm part and grips an object.

As is well known, regarding a robot hand used for a robot to grip an object, in addition to the finger mechanism at the tip of the palm part, the structure is provided with a thumb mechanism on the side of the palm part. A technique related to a robot hand for efficiently grasping an object has been disclosed (see, for example, Patent Document 1).
JP 2007-160448 A

  However, such a robot hand is similar in appearance to a human hand, but the function of gripping an object is greatly different from that of a human hand, so the size of the object that can be gripped is limited, There is a problem that it is difficult to generically grip a large object to a small object.

  The present invention has been made in consideration of such circumstances, and from a large object to a small object by performing an operation similar to a human hand with respect to a robot hand having a palm part, a finger mechanism, and a thumb mechanism. An object of the present invention is to provide a robot hand that can be used for general purpose gripping.

In order to solve the above problems, the present invention proposes the following means.
A robot hand according to the present invention includes a palm part, a finger mechanism extending from a main palm part located in a distal end side region of the palm part and capable of bending toward the inside of the main palm part, and the palm part And a thumb mechanism connected to the middle hand portion, and the thumb mechanism intersects a plane through which the finger mechanism passes when the finger mechanism is bent. It is possible to bend toward the inside of the palm part in the direction, and the middle hand part is rotatable in a direction intersecting with a surface through which the thumb mechanism passes when the thumb mechanism is bent. Features.

According to the robot hand according to the present invention, since the middle hand portion is provided and is rotatable in the direction intersecting the surface through which the thumb mechanism passes when the middle hand portion bends the thumb mechanism, the human hand As with the mother and child spheres, the thumb mechanism can be moved closer to the palm tip end region or the finger mechanism side, and a complex movement close to a human hand can be performed.
Therefore, it is possible to easily grip a large object to a small object by controlling the rotation of the middle hand part, the extension and bending of the finger mechanism and the thumb mechanism.

  Also, a first rotation axis on the base end side where the finger mechanism is connected to the main palm, and a second rotation axis when the middle hand rotates with respect to the main palm May be configured to intersect at a crossing angle of 45 degrees or less in parallel or on the thumb mechanism side of the palm part when viewed from the inside of the palm part.

  According to the robot hand according to the present invention, the rotation direction of the middle hand portion is configured to intersect at a crossing angle of 45 degrees or less with respect to a surface through which the finger mechanism is bent. The space that can be formed by the finger mechanism, the main palm portion, and the middle hand portion can be changed in a large size range while suppressing the generation of force in the width direction of the palm portion when the hand is held.

Further, the middle hand portion may be formed to protrude from the inner surface of the main palm portion.
According to the robot hand according to the present invention, the middle hand portion is formed so as to protrude from the inner surface of the main palm portion, so that the finger mechanism and the middle hand portion can hold the object without using the thumb mechanism. It is said.

In this specification, regarding the palm part, the main palm part, and the finger mechanism, the side facing the object when gripping the object is the inside, and the thumb mechanism is the side corresponding to the inside of the finger mechanism. Regarding the part, when the thumb mechanism is bent, the side facing the inner side of the thumb mechanism is the inner side.
In addition, regarding the thumb mechanism and the middle hand portion, the surface located on the tip side of the palm portion that contacts the object when the robot hand grips the object is referred to as a gripping surface.
Further, when the finger mechanism extended to the palm part is extended, the direction in which the finger mechanism extends is the longitudinal direction of the robot hand and palm part, and the direction perpendicular to the longitudinal direction is the width direction of the robot hand and palm part. .

  According to the robot hand according to the present invention, the middle hand portion provided with the thumb mechanism can be bent in a direction crossing the bending direction of the thumb mechanism, so that it is possible to perform a complicated operation close to a human hand. Thus, it is possible to stably hold a large object to a small object.

A robot hand according to an embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the robot hand 1 includes a palm part 2, three finger mechanisms 30, and a thumb mechanism 40, and the palm part 2 includes a main palm part 3 positioned in the distal end side region T; It is comprised from the middle hand part 4 located in the base end side area | region F. As shown in FIG.
2 and 3, the finger mechanism 30 is connected to the distal end portion of the palm portion 2 and can be extended and bent in the longitudinal direction of the robot hand 1, and the thumb mechanism 40 is one of the palm portions 2. It is connected to the side via a middle hand part 4 and can be extended and bent in the width direction of the robot hand 1.

In this embodiment, the surface that passes when the thumb mechanism 40 bends (the surface formed along the arrow S1) is the surface that passes when the finger mechanism 30 bends (the surface formed along the arrow S2). Are configured to be orthogonal (intersect).
Further, the surface that passes when the middle hand portion 4 rotates (the surface formed along the arrow S3) and the surface that passes when the thumb mechanism 40 bends are configured to be orthogonal to each other.

  The palm part 2 is a U-shape that is connected to the base end side (the wrist side) of the palm part 2 when viewed from the outside of the palm part 2 (the side opposite to the inside, the back side of the human hand). The frame body 21, the two side wall members 22 disposed on both sides of the palm portion 2 in the width direction of the palm body 21, the three inner wall members 23 disposed inside the palm portion 2, and the middle hand portion 4 And a middle hand drive device 5.

  In the frame body 21 and the side wall member 22, an attachment hole that forms a first hinge portion 34 </ b> A that connects the palm portion 2 and the finger mechanism 30 is formed in the vicinity of the inside on the distal end side of the palm portion 2. By connecting the end side to the mounting hole via a support pin, the finger mechanism 30 is rotatable about the first rotation axis J1 with respect to the palm 2.

Further, a middle hand support member 41 is disposed on the inner surface of the palm part 2, and the middle hand part support member 41 is attached to constitute a middle hand hinge part 4 </ b> A that connects the middle hand part 4 to the palm part 2. A hole is formed.
The middle hand part 4 is formed in a substantially rectangular parallelepiped cylindrical shape, and the distal end side of the palm part 2 of the middle hand part 4 is connected to a mounting hole constituting the middle hand hinge part 4A of the middle hand part support member 41 by a support pin. Thus, the middle hand portion 4 is rotatable around a second rotation axis J2 formed at a position separated from the inner surface of the palm portion 2.

  In the present embodiment, the rotation axis J2 when the middle hand portion 4 rotates is formed in parallel with the rotation axis J1, and as a result, the surface that passes when the middle hand portion 4 rotates is: The finger mechanism 30 is parallel to the plane that passes when the finger mechanism 30 bends.

Further, the middle hand portion 4 is arranged in a state of protruding from the inner side surface of the main palm portion 3 with respect to the palm portion 2, and a thumb mechanism 40 is connected to an attachment hole formed at one end via a support pin. .
The connection between the thumb mechanism 40 and the middle hand portion 4 is the same as that of the first hinge portion 34A, and is shown as the first hinge portion 34A in FIGS.

For example, the middle hand drive unit 5 is connected to the motor arranged in the longitudinal direction of the palm 2, the worm gear attached to the shaft of the motor, the middle hand 4 and the rotation axis J 2, and the worm gear. When the worm gear driven by the motor rotates, the worm gear rotates the wheel, and the middle hand portion 4 is rotated in conjunction with the rotation of the wheel.
In addition, if the middle hand part drive device 5 rotates the middle hand part 4, the structure can be selected freely.

The finger mechanism 30 in the present embodiment is configured to extend forward from the distal end portion of the palm part 2 by extending and bendable so that the inside of the finger mechanism 30 can face the inside of the palm part 2.
The thumb mechanism 40 extends from one end of the palm part 2 to the outside in the width direction of the palm part 2 by stretching, and the inside of the thumb mechanism 40 can be opposed to the inside of the middle hand part 4 by bending. Has been.

4A and 4B are diagrams illustrating an example of a link mechanism of the finger mechanism 30 according to the present embodiment, in which FIG. 4A is a schematic side view of the finger mechanism 30 in an extended state, and FIG. 4B is a finger mechanism. It is a schematic side view in the state where 30 was bent. 4A and 4B, the first structural member 31, the second structural member 32, the third structural member 33, and the one side wall portion of the connecting member 35 of the finger mechanism 30 are removed. The state is shown schematically.
In addition, the link mechanism which comprises the thumb mechanism 40 is the same as the finger mechanism 30 in this embodiment, and attaches | subjects and shows the same code | symbol.

  The finger mechanism 30 includes a first component member (link) 31, a second component member (link) 32, and a third component member (symmetrical when viewed from the inner side and the distal end side of the palm portion 2. Link) 33, first hinge portion 34A, second hinge portion 34B, third hinge portion 34C, connecting member 35, first linear motion device 36, and second linear motion device 37. It is roughly composed.

The first component member 31, the second component member 32, and the third component member 33 are configured by a pair of flat plates constituting the left and right wall portions and a support member that connects and supports the left and right flat plates.
In addition, the second component member 32 is arranged at the outermost portion of the first component member 31 or the third component member 33 at the connection portion of the first component member 31 or the third component member 33. The connecting member 35 and the second component member 32 are arranged in this order on the inner side.

  Support members that connect and support the first component member 31, the second component member 32, and the third component member 33 on the left and right are the first component member 31, the second component member 32, and the third component member. A first hinge portion 34A, a second hinge portion 34B, and a third hinge portion 34C in the component member 33 are configured to form respective rotation axes.

When the finger mechanism 30 is extended, as shown in FIG. 4A, the main palm 3, the first component member 31, the second component member 32, and the third component member 33 are arranged in tandem in this order. The first component member 31 is connected to the main palm portion 3 at the first hinge portion 34A, and the first component member 31 and the second component member 32 are connected to the second component member 32 at the second hinge portion 34B. The third component member 33 is connected to each other at the third hinge portion 34C.
Note that the proximal end side of the thumb mechanism 40 is connected to the first hinge part 34A of the middle hand part 4 so as to be rotatable about the rotation axis J3.

  One end of the connecting member 35 is rotatably connected to the first constituent member 31 via the fourth hinge portion 34D, and the other end is a long hole formed in the third constituent member 33 via the circular convex portion 35A. The circular convex portion 35A is connected to 33A, is movable in the longitudinal direction of the long hole 33A, and the connecting member 35 is rotatable around the fourth hinge portion 34D.

Further, the connecting member 35 is knocked over the line segment connecting the second hinge part 34B and the third hinge part 34C, and the line segment connecting the fourth hinge part 34D and the circular convex part 35A. And the line segment connecting the second hinge portion 34B and the third hinge portion 34C are formed to have substantially the same length, and the first component member 31 and the third component member 33 are the second component. The member 32 is configured to bend at the same angle.
As a result, when the second component member 32 is bent, the third component member 33 is bent with respect to the first component member 31 at an angle twice that of the second component member 32.

  The long hole 33A is formed to extend in the longitudinal direction at the base end side and the inner corner of the third component member 33 formed in a substantially rectangular shape in side view. In addition, a pin 33B is fixed to a position diagonal to the corner, that is, the corner on the distal end side and the outer side of the third component member 33, and the pin 33B and the distal end of the connecting member 35 are connected to each other. A coil spring 39 is hung (pulled) between them.

  When the finger mechanism 30 is not gripping an object, that is, when no load is applied to the third component member 33, the circular convex portion 35A is always located on the distal end side of the long hole 33A. When the finger mechanism 30 grips an object and a load is applied to the third component member 33, the coil spring 39 extends according to the magnitude of the reaction force, and the circular convex portion 35A is on the proximal end side of the elongated hole 33A. Move appropriately (to the second component member 32 side). Thereby, the third component member 33 is stopped in a state in which it is in contact with the object with a predetermined force as shown by a two-dot chain line in FIG.

  With the configuration described above, the force applied to the object from the finger mechanism 30 is always stopped within the elastic region of the coil spring 39, and an excessive force is prevented from being applied to the object to be grasped. In addition, when the finger mechanism 30 is composed only of a link, there is a possibility that the reaction force when an object is gripped is transmitted to the motor that is the driving source and an overload is applied to the motor. However, the coil spring 39 is provided. This suppresses the motor from being overloaded.

  The first linear motion device 36 is a ball screw mechanism that linearly drives the rod 36R in the longitudinal direction of the first linear motion device main body 36A by a motor provided in the first linear motion device main body 36A. The first linear motion device main body 36A, a ball screw mechanism including a rod 36R, and a rod receiving member 36G comprising a bearing, are provided at a substantially central position in the longitudinal direction of the first linear motion device main body 36A. The swing member 36 </ b> C is swingably attached to the frame body 21 and the side wall member 22.

Further, the tip of the rod 36R is connected to the rod receiving member 36G at the connecting portion 31C of the first component member 31, and only forward or backward movement is transmitted to the connecting portion 31C when the rod 36R moves forward or backward while rotating. It has come to be.
The rod receiving member 36G connects and supports the left and right wall portions constituting the first component 31 in the connecting portion 31C.

  As a result, when the rod 36R of the linear motion device 36 is advanced, the first component member 31 is rotated around the first hinge portion 34A in the direction in which the finger mechanism 30 is bent, and when the rod 36R is retracted, the first component 31 is rotated. The first component member 31 is rotated about the first hinge portion 34A in the direction in which the finger mechanism 30 extends.

  The first linear motion devices 36 constituting the finger mechanism 30 and the thumb mechanism 40 are respectively disposed inside the robot hand 1, and the first linear motion device 36 that drives the finger mechanism 30 is the frame body 21. The first linear motion device 36 for driving the thumb mechanism 40 is disposed in the middle portion 4 in the longitudinal direction of the thumb mechanism 40 in the space between the inner side and the side wall member 22.

  The second linear motion device 37 has the same configuration as the first linear motion device 36, and includes a second linear motion device main body 37A having a built-in motor, a ball screw mechanism including a rod 37R, and a rod receiver. The first component member 31 is provided by a swing member 37C that is provided in the first component member 31 and provided at a substantially central position in the longitudinal direction of the second linear motion device main body 37A. It is attached so as to be swingable with respect to.

The tip of the rod 37R is connected to the rod receiving member 37G at the connecting portion 32C of the second component member 32, and only forward or backward movement is transmitted to the connecting portion 32C when the rod 37R moves forward or backward while rotating. It is like that.
Note that the rod receiving member 37G connects and supports the left and right wall portions constituting the second component member 32 in the connecting portion 32C.

  As a result, when the rod 37R of the linear motion device 37 is advanced, the second component member 32 is rotated around the second hinge portion 34B in the direction in which the finger mechanism 30 bends, and when the rod 37R is retracted, The second component member 32 is rotated around the second hinge portion 3BA in the direction in which the finger mechanism 30 extends.

  The first linear motion device 36 and the second linear motion device 37 can be driven independently of each other, and the first component member 31 extends and bends with respect to the main palm 3, and the first The extension and bending of the second component member 32 and the third component member 33 relative to the component member 31 can be independently controlled.

Next, the operation of the robot hand 1 according to this embodiment will be described with reference to FIG.
1) When gripping a small object (see FIG. 5A)
Regarding the finger mechanism 30, the first linear motion device 36 is driven to advance the rod 36 </ b> R to bend the first component member 31 with respect to the main palm 3, and the second linear motion device 37 is driven. Then, the rod 37R is advanced to bend the second component member 32 and the third component member 33, and the tip of the third component member 33 is brought into contact with the object.
Regarding the thumb mechanism 40, the distal end of the third component member 33 can easily approach the inner surface of the palm part 2 without interfering with the thumb mechanism 40. It is preferable to be in an extended state.
Further, if necessary, the middle hand part drive device 5 is driven to rotate the middle hand part 4 to the distal end side of the palm part 2 so that the gripping surface 4H of the middle hand part 4 comes into contact with the object.

2) When holding a medium-sized object (see FIG. 5B)
Regarding the finger mechanism 30, the first linear motion device 36 is driven to advance the rod 36 </ b> R so that the first structural member 31 is brought into contact with the object at the inner surface of the first structural member 31. The first component member 31 is bent to the extent that it is orthogonal to the main palm 3, and the second linear motion device 37 is driven to advance the rod 37 </ b> R so that the inner surface of the third component member 33 is moved forward. The second component member 32 and the third component member 33 are bent until they contact the object.
The middle hand part 4 is rotated according to the size of the object until the gripping surface 4H of the middle hand part 4 comes into contact with the object, and does not rotate with respect to the main palm part 3 when it is not necessary to rotate. State.
The thumb mechanism 40 is extended or bent as necessary.

3) When holding a large object (see FIG. 5C)
With respect to the finger mechanism 30, the first component member 31 is driven until the first component member 31 and the third component member 33 abut against the object by driving the first and third linearly moving devices 36 and 37. The second component member 32 and the third component member 33 are bent. At this time, it is preferable that the center of the object is disposed between the inner side surface of the main palm 3 and the tip of the third component member 33, and the upper part of the object is held by the third component member 33. It is.
The middle hand portion 4 is not rotated with respect to the main palm portion 3, and the thumb mechanism 40 drives the first linear motion device 36 and the second linear motion device 37 in accordance with the size of the object, and the thumb. The gripping surface 40H of the palm part 2 of the mechanism 40 is bent so as to contact the object.
Regarding the bending of the thumb mechanism 40, the center of the object is disposed between the inner side surface of the main palm 3 and the tip of the third component member 33, and the object is the first component member 31 or the first member of the thumb mechanism 40. 3 is preferably held by the gripping surface 40H of the constituent member 33, and by extending the thumb mechanism 40, a large object can be easily gripped.
In order to make the first component member 31, the second component member 32, and the third component member 33 wrap around the upper part of the object and make it easier to hold the object, the middle hand part 4 is rotated as necessary. It may be moved.

According to the robot hand 1 according to this embodiment, the middle hand part 4 can be rotated with respect to the palm part 2, and the surface that passes when the thumb mechanism 40 bends and the middle hand part 4 rotate. Since the planes passing through are orthogonal to each other, it is possible to give a complicated motion to the thumb mechanism 40 like a mother-child ball part in a human hand. It is possible to easily approach the 30 side.
As a result, it is possible to easily grip a large object to a small object by controlling the bending of the finger mechanism 30 and the thumb mechanism 40 and the rotation of the middle hand portion 4.

  Further, the rotation axis J1 of the finger mechanism 30 with respect to the palm 2 and the rotation axis J2 of the middle hand 4 are made parallel, and the finger mechanism 30 and the middle hand 4 move in directions facing each other. Generation of force in the width direction of the palm portion 2 is suppressed, and the object can be gripped stably.

  Further, since the middle hand portion 4 is formed so as to protrude from the inner side surface of the main palm portion 3 of the palm portion 2, an object can be gripped by the finger mechanism 30 and the middle hand portion 4.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.
For example, in the above embodiment, the case where the middle hand portion 4 is formed so as to protrude from the inner surface of the main palm portion 3 has been described. 3 may be arranged on the same plane as the inner surface of 3 or at a position recessed from the inner surface of the main palm 3.

  In the above embodiment, the case where the rotation axis J2 extends in parallel to the rotation axis J1 when viewed from the palm 2 is described. However, the rotation axis J2 and the rotation axis J1 are described. It is good also as a structure which cross | intersects with the crossing angle of 45 degrees or less in the thumb mechanism 40 side of the palm part 2. FIG.

  Further, in the above embodiment, the three finger mechanisms 30 are extended in the robot hand 1, and the finger mechanism 30 and the thumb mechanism 40 include the first component member 31, the second component member 32, and the third component. Although the case where it is configured by three links of the component member 33 has been described, the number of finger mechanisms 30 provided in the robot hand 1, the number of links constituting the finger mechanism 30 and the thumb mechanism 40, the structure of the finger mechanism 30, etc. Can be arbitrarily set, and the structure of the finger mechanism 30 and the thumb mechanism 40 may be a structure that does not use a link mechanism. Also, the finger mechanism 30 and the thumb mechanism 40 may have different structures.

  Furthermore, although the link mechanism is used as the finger mechanism 30 in the robot hand described above, the present invention is not limited to this, and any structure can be applied as long as it can be bent and functions as a finger.

It is a figure showing the outline of the robot hand concerning one embodiment of the present invention. It is a perspective view explaining schematic structure of the robot hand concerning one embodiment of the present invention. It is a perspective view explaining schematic structure of the robot hand concerning one embodiment of the present invention. It is a schematic side view explaining the finger mechanism of the robot hand concerning this embodiment, (A) shows the state where the finger mechanism was extended, and (B) shows the state where the finger mechanism was bent. It is a figure explaining the effect | action of the robot hand which concerns on this embodiment, (A) is a case where a small object is gripped, (B) is a case where a medium-sized object is gripped, (C) is large The state in the case of gripping an object is shown.

Explanation of symbols

T distal end side region F proximal end side region J1 first rotation axis J2 second rotation axis 1 robot hand 2 palm part 3 main palm part 4 middle hand part 30 finger mechanism 40 thumb mechanism

Claims (3)

Palms,
A finger mechanism that extends from the main palm portion located in the distal side region of the palm portion and is bendable toward the inside of the main palm portion;
A middle hand portion located in a proximal side region of the palm portion;
A thumb mechanism connected to the middle hand part,
The thumb mechanism is
When the finger mechanism is bent, it can be bent toward the inside of the palm in a direction intersecting with a plane through which the finger mechanism passes,
The robot hand according to claim 1, wherein the middle hand portion is rotatable in a direction intersecting a plane through which the thumb mechanism passes when the thumb mechanism is bent. A first rotation axis on the base end side where the finger mechanism is connected to the main palm;
The second rotation axis when the middle hand part rotates with respect to the main palm part is
2. The robot hand according to claim 1, wherein when viewed from the inside of the palm part, the robot hand intersects at a crossing angle of 45 degrees or less in parallel or on the thumb mechanism side of the palm part. The robot hand according to claim 1, wherein the middle hand portion is formed so as to protrude from an inner surface of the main palm portion.

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