JP2018043331A - End effector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase an operation speed of an end effector which grips a gripping object by a plurality of finger bodies.SOLUTION: An end effector 1 grips a gripping object X by a plurality of finger bodies 20. At least one finger body 20 out of the plurality of finger bodies 20 is provided with a conveying part 20c for moving a gripping surface a contacting with the gripping object X. The conveying part 20c is structured so as to drive and rotate around an axis approximately orthogonal to the gripping surface a. With this structure, various operations on the gripping object X such as advancement and retreat, rotation, and a posture change of the gripping object X can be carried out speedily.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an end effector that is provided at a terminal portion of a hand robot or the like and grips an object to be gripped.

Conventionally, in this kind of invention, as described in Patent Document 1, for example, a base (1), five finger mechanisms (2 to 6) attached to the base (1), and these five There is a robot hand provided with a drive unit for driving the finger mechanisms (2 to 6).
In this robot hand, some of the finger mechanisms are rotary finger mechanisms having a plurality of joints and provided with a rotating unit that rotates the entire finger mechanism, and the other finger mechanisms are the rotating finger mechanisms. The auxiliary finger mechanism changes the gripping state of the gripped object.
According to this prior art, it is possible to perform various gripping operations such as a human hand, such as moving the gripping object once gripped while maintaining the gripping state, changing the posture, and the like.

JP 2005-349491 A

However, in the prior art, for example, in order to perform an operation of turning the faucet, an operation of grasping the faucet with a plurality of finger mechanisms, an operation of rotating the entire robot hand, and an operation of opening the plurality of finger mechanisms are sequentially performed. It is necessary to switch to and repeat. Further, in order to move or change the posture of the grasped object, it is necessary to move the grasped object by operating the five finger mechanisms in a predetermined order in a complicated manner.
As described above, in the prior art, since a complicated operation imitating the movement of a human hand finger is performed, the structure and control are complicated, and it is difficult to increase the work speed.

In view of the conventional circumstances, the present invention has the following configuration.
In an end effector configured to grip a gripping object with a plurality of fingers, at least one of the plurality of fingers includes a transport unit that moves a gripping surface that contacts the gripping object. The end effector is characterized in that the transport section is provided so as to be driven to rotate about an axis substantially orthogonal to the gripping surface.

  Since the present invention is configured as described above, the working speed can be improved with a simple structure.

It is a perspective view which shows an example of the end effector which concerns on this invention. It is a principal part perspective view of the same end effector, and is shown through a part of internal structure. It is a principal part perspective view of a conveyance part, and is shown through a part of internal structure. It is a perspective view of the end effector, and shows a state in which each transport unit is rotated 90 degrees. (A) is a perspective view of the state which turned the conveyance part to the vertical direction, (b) is a perspective view which shows the state which turned the conveyance part to the horizontal direction. It is a perspective view which shows the state which rotated only the two conveyance parts which oppose.

  A first feature of the present embodiment is that, in an end effector configured to grip a gripping object by a plurality of fingers, at least one of the plurality of fingers touches the gripping object. A conveyance unit that moves the gripping surface is provided, and the conveyance unit is provided to be driven to rotate about an axis that is substantially orthogonal to the gripping surface.

  The second feature is that the conveyor is a belt conveyor in order to grip the object to be gripped softly (see FIG. 3).

  As a third feature, in order to enable an operation with good workability, the plurality of fingers include two fingers arranged opposite to each other. The conveyance unit is provided.

  According to a fourth feature, in order to enable an operation with better workability, the transport unit is provided on each of the plurality of fingers.

  In the fifth feature, in order to enable more complicated work, a drive source that moves the gripping surface and a drive source that drives and rotates the transport unit are separately provided and controlled ( 2 and 3).

  As a sixth feature, in particular, in order to realize the slimming of the finger body, the drive source that drives and rotates the transport unit is a motor that rotates the output shaft in the reverse direction to the forward direction. It is supported by the finger body along the direction (see FIG. 2).

  As a seventh feature, in order to enable an operation with better workability, the finger body is configured to bend and extend between the front and rear nodes, and the transport unit includes a node on the fingertip side. Is provided.

<Specific Embodiment>
Next, specific embodiments having the above characteristics will be described in detail with reference to the drawings.
The end effector 1 includes a palm portion 10 and a plurality (four in the illustrated example) of finger bodies 20 protruding from the palm portion 10 so that the grasped object X is grasped by the plurality of finger bodies 20. Configured.

The palm portion 10 is a hollow member (for example, a hollow cylindrical member), and has a motor 11 that rotates the proximal end side of each finger 20 inside thereof.
A plurality of support members 13 are provided on one surface (the lower surface in the illustrated example) side of the palm portion 10 so as to correspond to the plurality of fingers 20.

The first motor 11 may be an electric motor that can control the bi-directional rotation angle. For example, a DC stepping motor is used, and the rotation angle (or rotation amount) is controlled by a control unit (not shown).
A worm gear 12 is fixed to the output shaft of the first motor 11.

  Each support member 13 is a member that pivotally supports the proximal end side of the finger 20, and is formed in the shape of two protruding pieces according to the illustrated example, and includes a gear 21 and a shaft portion 22 on the finger 20 side. Is supported rotatably.

  The finger 20 is supported by the first node 20a on the palm 10 side, the second node 20b connected to the fingertip side of the first node 20a, and the outer surface of the finger 20 on the fingertip side. And a transport unit 20c.

A plurality of fingers 20 are arranged at intervals in the circumferential direction of the palm 10 so that the transport unit 20c faces the central axis of the palm 10.
According to the illustrated example, of the four fingers 20, the two fingers 20 are arranged to face each other so as to be positioned on both sides in the radial direction of the cylindrical gripping object X. The other two fingers 20 are arranged to face each other so as to be located on both sides in the radial direction orthogonal to the radial direction (see FIG. 1). According to this arrangement, the four fingers 20 come into contact with the outer peripheral surface of the cylindrical gripping object X at equal intervals in the circumferential direction.

  Each of the first node 20a and the second node 20b is formed in a substantially cylindrical shape (in the illustrated example, a rectangular tube shape).

A gear 21 and a shaft portion 22 are fixed to the proximal end side of the first node portion 20a (see FIG. 2).
The gear 21 is a spur gear meshed with the worm gear 12.
The shaft portion 22 is inserted through the center portion of the gear 21 and is fixed so as not to rotate. The shaft portion 22 is fixed so as not to rotate with respect to the first node portion 20a, and is supported rotatably with respect to the support member 13.
Therefore, when the worm gear 12 is rotated by the first motor 11, the finger body 20 bends toward the center of the palm portion 10 around the shaft portion 22 or extends in the opposite direction.

Further, a second motor 23 (for example, a DC stepping motor) is supported on the fingertip side in the first node 20a (see FIG. 2).
The second motor 23 has a bevel gear 23a fixed to an output shaft directed toward the fingertip side. The bevel gear 23a meshes with a bevel gear 24 in a second node 20b described later.

A bevel gear 24 and a shaft portion 25 are fixed to the proximal end side of the second node portion 20b.
The bevel gear 24 meshes perpendicularly to the bevel gear 23a on the first node 20a side.
A shaft portion 25 is inserted into the central portion of the bevel gear 24 and is fixed so as not to rotate. The bevel gear 24 is fixed so as not to rotate with respect to the second node 20b, and is supported rotatably with respect to the first node 20a.
Therefore, when the bevel gears 23a and 24 are rotated by the second motor 23, the second node 20b is bent or extended.

A third motor 26 (for example, a DC stepping motor) is supported on the fingertip side in the second node 20b along the extending direction of the second node 20b.
The third motor 26 has a bevel gear 26a fixed to an output shaft directed toward the fingertip side. The third motor 26 meshes with an orthogonal bevel gear 27.

The bevel gear 27 is rotatably supported on the distal end side of the second node portion 20b via a shaft portion 28 fixed to the center portion thereof.
The end portion of the shaft portion 28 on the palm portion 10 side is exposed to the outside through the second node portion 20b, and the end portion supports the transport portion 20c.

  The third motor 26, the bevel gears 26a and 27, and the shaft portion 28 configured as described above function as a rotation mechanism that drives and rotates the transport portion 20c about an axis that is substantially orthogonal to the gripping surface a.

As shown in FIG. 3, the transport unit 20 c includes a pair of rollers 20 c 1 that are provided substantially parallel to each other at intervals, a belt 20 c 2 wound around the outer peripheral surface of the rollers 20 c 1, and a gear mechanism 20 c 3 that rotates the rollers 20 c 1. And a fourth motor 20c4 that transmits the rotational force to the gear mechanism 20c3, and a support bracket 20c5 that supports them.
This conveyance part 20c is a belt conveyor which moves the holding surface a which contacts the holding | grip target object X along a linear conveyance direction.

Both ends of the pair of rollers 20c1 are rotatably supported by support brackets 20c5.
The belt 20c2 is formed in an endless ring shape with an elastic material such as rubber.
The gear mechanism 20c3 is configured by a plurality of spur gears combined so as to decelerate and transmit the rotation of the fourth motor 20c4 to the roller 20c1. Each spur gear is supported rotatably with respect to the support bracket 20c5.

The fourth motor 20c4 is, for example, a DC stepping motor, and transmits the rotational force of the gear fixed to the output shaft thereof to the gear mechanism 20c3. The casing of the fourth motor 20c4 is supported by the support bracket 20c5.
The support bracket 20c5 is integrally connected to the shaft portion 28 on the distal end side of the second node portion 20b.

Next, the characteristic effect of the end effector 1 having the above configuration will be described in detail.
First, when a plurality of finger bodies 20 are arranged around the object to be grasped X and each finger body 20 is bent by driving the first motor 11 and the second motor 23, as shown in FIG. The gripping object X is gripped by the plurality of fingers 20.

  In this gripping state, if the fourth motors 20c4 (see FIG. 3) of all the finger bodies 20 are simultaneously driven in the same direction, the gripping object X moves in the direction approaching the palm 10 (according to FIG. 1). (Upward) or away from the palm 10.

  In addition, before gripping the gripping target object X, the transport unit 20c of each finger 20 is rotated by driving the third motor 26 so that the transport direction of each transport unit 20c is orthogonal to the extending direction of the finger 20. (See FIG. 5 (b).) After that, if the outer periphery of the cylindrical gripping object X is gripped and the fourth motors 20c4 of all the finger bodies 20 are simultaneously driven in the same direction, it is shown in FIG. As described above, the gripping object X can be rotated.

  In addition, among the plurality of fingers 20, the gripping object X is gripped by the conveying unit 20 c of the two opposing fingers 20, and the fourth motor 20 c 4 (see FIG. 3) of these two fingers 20 is simultaneously used. When driven in the direction, the posture of the grasped object X can be rotated by a predetermined angle (90 degrees according to FIG. 6).

  Therefore, according to the end effector 1 having the above-described configuration, various operations on the grasped object X such as advance / retreat, rotation, and posture change of the grasped object X can be quickly performed with a simple structure and operation.

  The mechanism for bending and extending each finger 20 is not limited to the above-described embodiment. For example, a mechanism using a mechanism other than the illustrated example such as a plurality of link mechanisms and feed screw mechanisms may be used.

  Moreover, as a structure added to the said embodiment, you may comprise the mechanism in which each finger 20 is rotated to the adjacent other finger 20 side (inner rotation and outer rotation), for example.

  Moreover, in the said embodiment, although the conveyance part 20c was provided in each of all the finger bodies 20 as a particularly preferable aspect, it is set as the aspect which provided the conveyance part 20c only in some fingers 20. Is also possible. For example, in a mode in which the transport unit 20c is provided only on one finger 20, the finger 20 that does not have the transport unit 20c functions to simply support or slide the grasped object X.

  Moreover, in the said embodiment, although the conveyance part 20c was comprised by the belt conveyor, this conveyance part 20c should just be a mechanism to which a holding surface is moved, and the roller conveyor was used as another example of this conveyance part. It is also possible to adopt a mode, a mode in which the gripping surface is linearly moved by an electromagnetic solenoid, a mode in which the gripping surface is linearly moved by a feed screw mechanism, or the like.

  Moreover, this invention is not limited to the embodiment mentioned above, In the range which does not change the summary of this invention, it can change suitably.

1: End effector 10: Palm part 20: Finger body 20a: First node part 20b: Second node part 20c: Transport part 11, 23, 26, 20c4: First to fourth motors (drive sources)
a: gripping surface X: gripping object

Claims (7)

In an end effector that is configured to grip a target object with a plurality of fingers,
Among the plurality of fingers, at least one finger is provided with a transport unit that moves a gripping surface that is in contact with the gripping object,
The end effector according to claim 1, wherein the transport unit is provided so as to drive and rotate about an axis substantially orthogonal to the gripping surface.   The end effector according to claim 1, wherein the transport unit is a belt conveyor.   3. The plurality of fingers include two fingers arranged to face each other, and each of the two fingers is provided with the transport unit. 4. End effector.   The end effector according to any one of claims 1 to 3, wherein the transport unit is provided on each of the plurality of fingers.   The end effector according to any one of claims 1 to 4, wherein a drive source that moves the gripping surface and a drive source that drives and rotates the transport unit are separately provided and controlled. .   The drive source that drives and rotates the transport unit is a motor that rotates an output shaft in a direction opposite to a forward direction, and is supported by the finger along the extending direction of the finger. Item 6. The end effector according to Item 5.   The said finger body is comprised so that it may bend and extend between the front and back node parts, The said conveyance part is provided in the node part by the side of a fingertip, The any one of Claims 1-6 characterized by the above-mentioned. End effector.

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