JP2018167372A - Finger mechanism and humanoid hand incorporating the same - Google Patents

Abstract

【Task】
Provided are a finger mechanism that is close to the shape of a human finger and that is similar to a human, and a humanoid hand incorporating the finger mechanism.
[Solution]
The link mechanism 20 includes a first link member 21 whose base end is pivotally attached to a connection shaft g1 of the first bone member and the second bone member, and a base end of the first link member 21. The second link member 22 is pivotally attached to the shaft g2 of the distal end portion, and the base end portion is pivotally attached to the connecting shaft g3 of the second bone member 22 and the third bone member 23. The third link member 23 is included. The first link member 21 has a plate-like shape that substantially overlaps the second bone member 12 when viewed from the side in the extended position, that is, with the palm open.
[Selection] Figure 2

Description

  The present invention relates to a finger mechanism and a humanoid hand that is attached to the tip of an arm of a robot or used as a prosthetic hand for a handicapped person.

  As disclosed in Patent Document 1, an early humanoid hand that imitates the movement of a human finger is formed with a guide hole in each finger, and a wire is inserted through the guide hole so as to be folded at the tip of the finger. By connecting one end of the wire to a spring and pulling the other end of the wire to the wrist side, each joint of the finger is bent to the palm side.

  Although the humanoid hand disclosed in Patent Document 1 can bend a finger at a joint, it is far from the movement of a human finger, and the present inventors have patented it as a more advanced humanoid hand. Document 2 and Patent Document 3 were proposed.

  In the humanoid hand disclosed in Patent Document 2, three finger plates corresponding to the human proximal phalanx, the middle phalanx and the distal phalanx are respectively connected to the finger plates so that the end portions are rotatable. A link mechanism including a rotating plate and a driving rod is disposed along the rotating plate, and the driving rod and the finger plate are pivotally attached to each other.

  In this patent document 2, by pulling a drive rod by a drive source, a rotation plate having a triangular shape is rotated, and by this rotation, a finger plate corresponding to a proximal phalanx is rotated inwardly. By rotating, the drive rod arranged along the finger plate corresponding to the proximal phalanx is moved forward, and by this movement, the finger plate corresponding to the middle phalanx is rotated inward, and the finger corresponding to the middle phalanx is further moved. The drive rod arranged along the finger plate corresponding to the middle phalanx is pulled to the wrist side by turning the plate to the selling side, and the finger plate corresponding to the distal phalanx is brought into the inner side by the pulling operation of this drive rod. To turn.

  Patent Document 3 discloses the structure of a foot, and a triangular plate constituting a part of a link mechanism is rotatably attached to a proximal end portion of a finger plate corresponding to a proximal phalanx as in Patent Document 2. .

  Patent Document 4 discloses a humanoid hand provided with a force sensor that detects a force acting on a fingertip portion. In this humanoid hand, in order to make the parts corresponding to the human middle phalanx and the distal phalanx to rotate, the driven fluid pressure cylinders are respectively provided at the positions corresponding to the base phalanx and the middle phalanx. It is arranged.

Japanese Utility Model Publication No. 50-28551 Japanese Patent No. 4462742 Japanese Patent No. 6083502 JP 2010-264548 A

  The structure disclosed in Patent Document 1 has a simple mechanism, but cannot require movement similar to that of a human hand.

  The mechanisms disclosed in Patent Documents 2 and 3 are configured by appropriately setting the pivot attachment points of the rotary plate and the drive rod constituting the link mechanism disposed along the finger plate with respect to each finger plate. Can reproduce movements similar to movements. However, as shown in the embodiments of Patent Documents 2 and 3, the triangular rotating plate partially protrudes from the other finger plates in order to generate the necessary moment and rotation angle with respect to the finger plates to be joined. Yes. Since the finger cannot be made smaller than the protruding amount, for example, when used in a structure close to a human hand, a triangular plate end may protrude. Further, when the hand is allowed to enter a narrow gap, the protruding portion of the triangular plate may come into contact with each other, making it impossible to enter the hand.

  Further, in Patent Documents 2 and 3, the pulling operation of the drive rod is converted into the pushing operation of the link member by the triangular rotating plate, and the finger plate is rotated by this pushing operation, and the movement is wasted. is there.

  The structure disclosed in Patent Document 4 is provided with individual drive sources for bending the human proximal phalanx, middle phalanx, and distal phalanx, thus complicating the mechanism and obstructing freedom of movement. Is done.

  Further, in the structures disclosed in Patent Documents 1 to 4, there is a problem that when a finger receives a strong force in the reverse direction, the joint portion is damaged, and repair takes time and cost.

  In order to solve the above-described problems, a humanoid hand according to the present invention includes a first bone member corresponding to a metacarpal bone whose base end is connected to a palm board via a joint, and a distal end of the first member. A second bone member corresponding to the proximal phalanx to which the proximal end portion is connected, a third bone member corresponding to the middle phalanx to which the proximal end portion is connected to the distal end of the second bone member, and the third member A humanoid hand comprising a fourth bone member corresponding to a distal phalanx having a proximal end connected to a distal end thereof, wherein the second bone member to the fourth bone member are rotated by a link mechanism, The link mechanism includes a first link member having a proximal end pivotally connected to a connecting shaft of the first bone member and the second bone member, and a proximal end pivoting to a distal end of the first link member. A second link member to be worn, and a third link member having a proximal end pivotally attached to a connecting shaft of the second bone member and the third bone member. The first link member has a plate-like shape that substantially overlaps the second bone member in a side view at the extended position, and the tip end portion of the second link member is pivotally attached to the intermediate portion of the third link member. The configuration.

  Further, the shape of the second link member is curved, for example, in a direction perpendicular to the length direction, and the third link member is deformed when a force in the warp direction is applied to the third link member, thereby turning the third link member in the warp direction. Can be made possible.

  According to the present invention, since the movement of all fingers is reproduced with one drive source, the conventional triangular rotation plate is changed to a plate shape, and the protrusion amount in the side view is reduced. The interference with other members can be calculated in the same manner as a human hand.

  Further, since the pulling operation from the drive source is directly transmitted to the link member as the pulling operation, there is no waste in the transmission mechanism.

  In addition, even when an excessive force in the warp direction acts on the fourth and third bone members, the second link member is deformed to allow the bone member to rotate in the warp direction (dislocation). Or there is no possibility of damaging the object held by the hand.

1 is an overall view of a humanoid hand according to the present invention. 1 is a perspective view of one finger mechanism of a humanoid hand according to the present invention. FIG. The disassembled perspective view of the same finger mechanism. The side view of the state which extended the finger member which comprises the same finger mechanism. The side view which shows the one aspect | mode of the holding | grip by the same finger mechanism. The side view which shows the one aspect | mode of the holding | grip by the same finger mechanism. The side view which shows the singular point (thinking point) of the curvature of the same finger mechanism. The side view which shows the state of the curvature of the same finger mechanism. The side view in the state where the fingertip returned to the original after the same finger mechanism warped.

  Examples of use of the finger mechanism of the humanoid hand according to the present invention will be described below. The usage example includes a palm substrate 1, a thumb mechanism 2, an index finger mechanism 3, a middle finger mechanism 4, a ring finger mechanism 5, and a little finger mechanism 6, and each finger mechanism has a structure operated by a motor (stepping motor) 7. Although the operation is performed by the motor 7 here, a driving source other than the motor may be used as long as the driving force can be transmitted from the thumb mechanism 2 to the little finger mechanism 6.

  In particular, with respect to the finger mechanism 3, middle finger mechanism 4, ring finger mechanism 5, and little finger mechanism 6, the pulling operation by the motor 7 is transmitted to each finger mechanism via the reverse tournament-shaped link group 8. Although the reverse tournament-shaped link group 8 is shown as an example of means for transmitting power to each finger mechanism, other means may be used as long as power can be transmitted to each finger mechanism.

  Since the index finger mechanism 3, middle finger mechanism 4, ring finger mechanism 5, and little finger mechanism 6 are the same, the index finger mechanism 3 will be described in FIG.

  The finger mechanism includes a first bone member 11 corresponding to a metacarpal bone whose base end portion is connected to the palm board 1 via a universal joint, and a base end portion rotatably connected to the distal end of the first member 11. A second bone member 12 corresponding to the proximal phalanx, a third bone member 13 corresponding to the middle phalanx whose proximal end portion is rotatably connected to the distal end of the second bone member, and a proximal end portion Includes a fourth bone member 14 corresponding to the distal phalanx rotatably connected to the tip of the third member.

  The second bone member 12, the third bone member 13, and the fourth bone member 14 are rotated by a link mechanism 20 that is connected to a drive member 15 that can be pulled or pushed by driving the motor 7. .

  The link mechanism 20 includes a first link member 21 whose base end is pivotally attached to a connection shaft g1 of the first bone member and the second bone member, and a base end of the first link member 21. A second link member 22 pivotally attached to the shaft g2 of the distal end portion, and a base end portion pivotally attached to the connecting shaft g3 of the second bone member 12 and the third bone member 13 are pivotally attached. The third link member 23 is included.

  The first link member 21 has a plate-like shape that substantially overlaps the second bone member 12 when viewed from the side in the extended position, that is, with the palm open. Conventionally, a triangular plate is used as a member corresponding to the first link member 21, and a portion close to one of the three apexes of the triangular plate is pivotally attached to the connecting shaft of the first bone member and the second bone member, Corresponding to the third link member 23 because the drive rod is pivotally attached to one of the other portions close to the apex, and the proximal end portion of the second link member 22 is pivotally attached to the remaining one. In order to give a moment or amount of rotation necessary to rotate the portion to be rotated to the target rotation angle, a part of the triangular plate protrudes greatly. However, the second link member 22 is formed on the same axis at the tip of the first link member 21. Since the drive member 15 is pivotally attached, the first link member 21 can be formed into a plate shape and can be overlapped with the second bone member 12 in a side view in a side view.

  The distal end of the second link member 22 is pivotally attached to the shaft g4 of the intermediate portion of the third link member 23, and the shape of the second link member 22 is such that the overall shape extends when a strong force in the extending direction is applied. In the figure, the shape is curved upward).

  The third link member 23 is pivotally attached to an axis g6 at a position offset from a connection axis g5 between the third bone member 13 and the fourth bone member 14. The positional relationship between the shafts 5 and 6 is such that when the third link member 23 rotates counterclockwise, it rotates in the direction of closing the finger.

  In the above, with reference to the state shown in FIG. 4 (the state in which the finger is extended), the motor 7 is driven in this state, and the driving member 15 is pulled (rightward in FIG. 4).

  Then, a counterclockwise force is applied to the first link member 21 about the axis g1, and the second link member 22 is pulled. Then, since the distal end of the second link member 22 is connected to the intermediate portion of the third link member 23, the second bone member 12 to which the proximal end portion of the third ring member 23 is pivoted is centered on the axis g1. It rotates counterclockwise.

  When the second bone member 12 rotates and contacts the gripping object 50, the second bone member 12 can no longer rotate, and when the drive member 15 is further pulled in this state, the third link member 23 pivots. It rotates counterclockwise around g3.

  When the third link member 23 is rotated counterclockwise, the third bone member 13 is also rotated in the same direction, and the fourth bone member 14 is also rotated counterclockwise from the positional relationship between the shafts g5 and g6. As a result, as shown in FIG. 5, the object 50 to be grasped is grasped so as to be wrapped by the second bone member 12, the third bone member and the fourth bone member 14.

  In the example shown in FIG. 6, the first bone member 14 is first touched with the grasped object 50. In this case, the second bone member 12, the third bone member 13, and the fourth bone member 14 are touched. Is rotated integrally around the axis g1, and the object to be grasped 50 is formed with the fourth bone member 14 of the other finger.

  In the above description, when the driving member 15 is pulled, the second bone member 12 is first rotated, and then the third bone member and the fourth bone member are rotated. By adjusting the position of the pivot point of the front end portion and the rear end portion, the generated moment also changes, so the rotation of the second bone member 12 and the rotation of the third bone member and the fourth bone member are the same. It can also be set to progress at the timing.

  FIG. 7 shows a singular point when a force in the warping direction is applied to the fourth bone member 14. That is, when a warping force is applied to the fourth bone member 14, the fourth bone member 14 rotates clockwise, and at the same time, the third bone is connected to the fourth bone member 14 via the third link member 23. The member 13 also rotates clockwise.

  The second link member 22 is also rotated clockwise by the clockwise rotation of the fourth bone member 14 and the third bone member 13, and the axes g1, g2 and g4 are on the same line. The singular points shown in FIG. 7 are obtained.

  In order for the fourth bone member 14 and the third link member 23 to further rotate in the warping direction (clockwise) from this singular point, the third link member 23 must rotate clockwise about the axis g3. Don't be. Since the tip end of the second link member 22 is coupled to the third link member 23, the second link member 22 must simultaneously rotate about the axis g1. However, at this time, as described above, the axis g1, the axis g2, and the axis g4 are located on the same line and have the maximum length.

  Therefore, in order for the third link member 23 to rotate in the warp direction about the shaft 3 from the above state, the second link member 22 must extend. In this embodiment, the shape of the second link member 22 is partially curved in the width direction, and as shown in FIG. 8, the second link member 22 is deformed when a force in the tensile direction is applied, and a singular point (a thought point). ) To be able to turn in the warping direction.

  In the state shown in FIG. 8, when an inward force is applied to the fourth bone member 14, the axis g <b> 1, the axis g <b> 2, and the axis g <b> 4 do not pass through the singular point on the same line. The fourth bone member 14 and the third bone member 13 shown in Fig. 9 return to their original positions.

  When the drive member 15 is pulled from the state shown in FIG. 9, the first link member 21 rotates counterclockwise, and the second link member 22 can also return to the original position through a singular point.

In FIGS. 1 to 9, the drive member 15 is shown to be pivotally attached to the second link member 22 on the same axis at the tip of the first link member 21, but this pivotally attached portion is given traction force. For example, any part other than the rotating shaft of the first link member may be used, or any part other than the rotating shaft of the second link member 22 may be used.

  The humanoid hand according to the present invention can be used as an industrial hand or a prosthetic hand. In the illustrated example, a humanoid hand having five fingers has been described as a specific example incorporating a finger mechanism. It can also be used for 2-4 finger manipulators attached to the tip of the robot arm.

  DESCRIPTION OF SYMBOLS 1 ... Palm board, 2 ... Thumb mechanism, 3 ... Indicating finger mechanism, 4 ... Middle finger mechanism, 5 ... Ring finger mechanism, 6 ... Little finger mechanism, 7 ... Motor (stepping motor), 8 ... Reverse tournament-like link group, 11 ... First 1 bone member, 12 ... 2nd bone member, 13 ... 3rd bone member, 14 ... 4th bone member, 15 ... drive member, 20 ... link mechanism, 21 ... 1st link member, 22 ... 2nd link member, 23 ... 3rd link member, 50 ... Holding object, g1, g2, g3, g4, g5, g6 ... axis.

Claims (3)

In a finger mechanism in which a plurality of bone members to be connected are rotated about the connecting portion by a link mechanism,
The plurality of bone members include a first bone member corresponding to a metacarpal bone, a second bone member corresponding to a proximal phalanx, a third bone member corresponding to a middle phalanx, and a fourth bone corresponding to a distal phalanx. The link mechanism includes a first link member having a base end portion pivotally connected to a connecting shaft of the first bone member and the second bone member, and a base end portion at a distal end portion of the first link member. The second link member is pivotally attached and the third link member is pivotally attached to the connecting shaft of the second bone member and the third bone member. The first link member extends forward. The second link member has a plate shape that substantially overlaps with the second bone member in a side view, and the second link member is pivotally attached to an intermediate portion of the third link member, so that the second link member is attached to the first bone member. The second bone member and the first link member can be rotated separately, and further, the rotation of the first link member causes the third bone member and the fourth bone member to rotate. Finger mechanism, characterized the structure of the rolling possible.   2. The finger mechanism according to claim 1, wherein the second link member is deformed when a force in a warping direction acts on the third link member, thereby enabling the third link member to rotate in the warping direction. A finger mechanism characterized by that. A humanoid hand in which the finger mechanism according to claim 1 or 2 is incorporated as at least one of a finger mechanism, a middle finger mechanism, a ring finger mechanism, and a little finger mechanism.

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