JP2022154784A - arm unit - Google Patents

Abstract

To expand a movable range of an arm 20 without increasing a size of a joint mechanism 30.SOLUTION: An arm unit 100 includes a base part 10 and a joint mechanism 30. The joint mechanism 30 includes: a first link 31 for connecting the base part 10 and an arm 20; a second link 32 that includes a rotation center of the arm 20 on an extension of the base part 10 in a vertical direction while the arm 20 is in an initial position; a third link 33 for connecting the base part 10 and the second link 32; and a fourth link 34 for connecting the base part 10 and the second link 32. When the arm 20 rotates by moving from the initial position to a bending position, the third link 33 and the fourth link 34 connect the base part 10 and the second link 32 in a manner that the rotation center of the arm 20 can move to a position outside the extension of the base part 10 in the vertical direction.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to arm units.

For example, Patent Literature 1 discloses an animal-like robot having joints connected by links. Specifically, a third revolute joint 13 and a second link 15 rotatably supported with respect to the third revolute joint 13 are disclosed.

Japanese Patent No. 5185473

Here, there is a demand for widening the movable range of the arm in order to increase the range of expression of the motion of the robot or the like. In the configuration disclosed in Patent Document 1, the third revolving joint 13 interferes with the second link 15 at a predetermined rotational angle position, and its rotation is restricted. Moreover, when trying to widen the movable range of the arm, the structure of the joint mechanism becomes complicated and large.

An object of the arm unit proposed in the present disclosure is to widen the movable range of the arm without increasing the size of the joint mechanism.

It is a figure which shows an example of the whole structure of the arm unit which concerns on this embodiment. The arm of this embodiment is shown in the initial position. The arm of this embodiment is shown in a bent position. The arm of this embodiment shows a state in the middle of moving from the initial position to the bent position. The arm of this embodiment shows a state in the middle of moving from the initial position to the bent position. The arm of this embodiment shows a state in the middle of moving from the initial position to the bent position. It is a figure which shows the state which has an arm in an initial position in the arm unit which concerns on the modification of this embodiment. It is a figure which shows the state which has an arm in an initial position in the arm unit which concerns on the modification of this embodiment.

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

[Arm unit 100]
FIG. 1 is a diagram showing an example of the overall configuration of an arm unit according to this embodiment. In addition, in FIG. 1 , the internal configuration of the base 10 is indicated by broken lines.

The arm unit 100 may be used, for example, in a bipedal or quadrupedal humanoid or animal robot. In this embodiment, an example in which arm unit 100 has base 10 as an upper arm and arm 20 as a lower arm rotatably provided with respect to base 10 will be described.

In this embodiment, the direction indicated by Z1 in FIG. 1 is defined as upward, and the direction indicated by Z2 in FIG. 1 is defined as downward. Further, the direction indicated by X1 in FIG. 1 is defined as leftward, and the direction indicated by X2 in FIG. 1 is defined as rightward. The definitions of these directions are the same in other drawings.

Further, the arm 20 is provided so as to be rotatable forward and backward with respect to the base portion 10 . In this embodiment, the counterclockwise direction in FIG. 1 is defined as the positive direction, and the clockwise direction is defined as the reverse direction. The same applies to other drawings.

The arm unit 100 has a base 10 , an arm 20 and a joint mechanism 30 .

[Arm unit 100: Base 10]
The base 10 has an exterior cover 11 and a drive mechanism 12 that is housed in the exterior cover 11 and drives the joint mechanism 30 . The base 10 may, for example, be fixed at its upper end to the shoulder of the humanoid robot. The exterior cover 11 accommodates part of the joint mechanism 30 in addition to the drive mechanism 12 .

The drive mechanism 12 includes a motor (not shown) and a gear train that transmits power from the motor to the joint mechanism 30 . In the example shown in FIG. 1, the train wheel includes a first gear G1 and a second gear G2 that meshes with the first gear G1 and rotates as the first gear G1 rotates. The second gear G2 is fan-shaped and provided so as to rotate integrally with a first link 31, which will be described later. The drive mechanism 12 and the arrangement and shape of the gear train included in the drive mechanism 12 are not limited to those shown in FIG.

[Arm unit 100: arm 20]
The arm 20 has an exterior cover 21 connected to the joint mechanism 30 and an end effector 22 attached to the tip of the exterior cover 21 . The outer cover 21 accommodates a part of the joint mechanism 30 inside. Although the spherical end effector 22 is shown in FIG. 1, it is not limited to this. The end effector 22 may be, for example, hand-shaped or foot-shaped.

[Arm Unit 100: Joint Mechanism 30]
A joint mechanism 30 of the present embodiment will be described with reference to FIGS. 1 to 3. FIG. FIG. 2 shows the arm of this embodiment in its initial position. FIG. 3 shows the arm of this embodiment in a bent position. 2, 3, and FIGS. 4 to 6, which will be described later, the exterior cover 11 of the base 10 and the exterior cover 21 of the arm 20 are omitted from the front side of the paper surface in order to show the configuration of the joint mechanism 30. FIG.

2, 3, and FIGS. 4 to 6, which will be described later, differ from the shape of each configuration shown in FIG. 1, but the functions of each configuration are common. Therefore, FIG. 1 and FIGS. 2 to 6 are regarded as the same embodiment, and the same reference numerals are assigned to the common configurations.

In this embodiment, the position of the arm 20 shown in FIGS. 1 and 2 is defined as "initial position". The initial position is a position where the arm 20 is adjacent to the base 10 in the vertical direction (first direction). Also, the position of the arm 20 shown in FIG. 3 is defined as a "bent position". The bent position is a position where the arm 20 is rotated 180 degrees in the positive direction from the initial position, and is a position where the arm 20 is adjacent to the base 10 in the left-right direction (second direction).

The joint mechanism 30 connects the base 10 and the arm 20 and rotates the arm 20 from an initial position vertically adjacent to the base 10 to a bent position horizontally adjacent to the base 10 . As shown in FIG. 2, the joint mechanism 30 includes a first link 31, a second link 32, a third link 33, and a fourth link .

The first link 31 has a shape including a 1-1 end portion 311 and a 1-2 end portion 312 . The second link 32 has a shape including a 2-1 end portion 321 , a 2-2 end portion 322 and a 2-3 end portion 323 . The third link 33 has a shape including a 3-1 end portion 331 and a 3-2 end portion 332 . The fourth link 34 has a shape including a 4-1 end portion 341 and a 4-2 end portion 342 .

The joint mechanism 30 further includes a first rotation support portion A1 to a seventh rotation support portion A7.

The first rotation support portion A1 rotatably supports the 1-1 end portion 311 of the first link 31 with respect to the base portion 10. As shown in FIG. The second rotation support portion A2 rotatably supports the arm 20 with respect to the first-second end portion 312 of the first link 31. As shown in FIG. The third rotation support portion A3 rotatably supports the 3-1 end portion 331 of the third link 33 with respect to the base portion 10. As shown in FIG. The fourth rotation support portion A4 rotatably supports the 4-1 end portion 341 of the fourth link 34 with respect to the base portion 10. As shown in FIG. The fifth rotation support portion A5 rotatably supports the 2nd-1st end portion 321 of the second link 32 with respect to the 3rd-2nd end portion 332 of the third link 33 . The sixth rotation support portion A6 rotatably supports the 2nd-2nd end portion 322 of the second link 32 with respect to the 4th-2nd end portion 342 of the fourth link .

The seventh rotation support portion A7 rotatably supports the arm 20 with respect to the second-third end portion 323 of the second link 32. As shown in FIG. The seventh rotation support portion A7 is the rotation center of the arm 20 included in the second link 32. As shown in FIG. The center of rotation of the arm 20 is on the extension of the base 10 in the vertical direction when the arm 20 is in the initial position. In FIGS. 2 and 3, O1 indicates an extended area of the base portion 10 in the vertical direction.

As described above, the base 10 includes the 1-1 end 311 of the first link 31, the 3-1 end 331 of the third link 33, and the 4-1 end 341 of the fourth link 34. rotatably supported. Also, the arm 20 rotatably supports the first-second end 312 of the first link 31 and the second-third end 323 of the second link 32 . The second link 32 rotatably supports the 3rd-2nd end 332 of the third link 33 and the 4th-2nd end 342 of the fourth link 34 .

In addition, each of the above-mentioned rotation support parts is a part called a joint in a general link mechanism. The specific structure of each rotation support is not particularly limited. and a bearing formed at 11. Alternatively, for example, the first rotation support portion A1 includes a shaft hole formed in the 1-1 end portion 311 of the first link 31, a rotating shaft inserted through the shaft hole, and an outer cover 11 of the base portion 10. and a bearing to be formed.

[Arm Unit 100: Details of Each Link of Joint Mechanism 30]
The third link 33 has a curved shape so as not to interfere with the seventh rotation support portion A7 when the arm 20 rotates forward and backward. The fourth link 34 has a curved shape so as not to interfere with the first link 31 when the arm 20 rotates forward and backward.

The fourth link 34 is provided upstream of the third link 33 in the direction in which the arm 20 rotates from the initial position to the bent position. That is, in the illustrated example, the fourth link 34 is provided on the left side of the third link 33 .

Also, the length of the fourth link 34 is longer than the length of the third link 33 . In other words, the diameter of rotation of the fourth link 34 is longer than the diameter of rotation of the third link 33 . That is, the distance between the fourth rotation support portion A4 and the sixth rotation support portion A6 is longer than the distance between the third rotation support portion A3 and the fifth rotation support portion A5.

Further, the third link 33 and the fourth link 34 move the rotation center (seventh rotation support portion A7) of the arm 20 to the vertical extension of the base portion 10 when the arm 20 rotates from the initial position to the bent position. The base 10 and the second link 32 are connected so as to be movable to upper and lower positions. That is, the center of rotation of arm 20 moves to the right as arm 20 moves from the initial position to the bent position.

Further, the third link 33 and the fourth link 34 move the rotation center (seventh rotation support portion A7) of the arm 20 to the extension of the base portion 10 in the left-right direction when the arm 20 rotates from the initial position to the bent position. The base 10 and the second link 32 are connected so as to be movable to the upper position. In FIG. 3, O2 indicates an extended area of the base portion 10 in the left-right direction. That is, the center of rotation of arm 20 moves upward as arm 20 moves from the initial position to the bent position.

The first link 31 also has a curved shape. Specifically, the first link 31 has a shape including a curved first interference avoidance portion 31e so as not to interfere with the third link 33 when the arm 20 rotates forward and backward. Further, the first interference avoiding portion 31e has a curved shape so as not to interfere with the third rotation support portion A3 when the arm 20 rotates forward and backward.

With such a shape, the first link 31 forms a first interference avoidance area E1 surrounded by the first link 31 and the imaginary line L1 connecting the first rotation support portion A1 and the second rotation support portion A2. is doing. As shown in FIG. 3, the third rotation support portion A3 is provided such that at least a part thereof is positioned within the interference avoidance area E1 when the arm 20 is in the bent position.

The second link 32 also has a curved shape. Specifically, the second link 32 has a shape including a curved second interference avoidance portion 32e so as not to interfere with the first link 31 when the arm 20 rotates forward and backward. Further, the second interference avoiding portion 32e has a curved shape so as not to interfere with the second rotation support portion A2 when the arm 20 rotates forward and backward.

With such a shape, the second link 32 forms a second interference avoidance area E2 surrounded by the second link 32 and the imaginary line L2 connecting the sixth rotation support portion A6 and the seventh rotation support portion A7. is doing. As shown in FIG. 3, the second rotation support portion A2 is provided such that at least a part thereof is positioned within the second interference avoidance area E2 when the arm 20 is in the bent position.

[Operation of arm unit 100]
Next, operations of the arm unit 100 according to the present embodiment will be described with reference to FIGS. 2 to 6. FIG. 3 to 5 show states in which the arm of this embodiment is in the process of moving from the initial position to the bent position. That is, when the arm 20 rotates in the positive direction, it moves from the initial position shown in FIG. 2 to the bent position shown in FIG. 3 via the states shown in FIGS. On the other hand, when the arm 20 rotates in the opposite direction, it moves from the bent position shown in FIG. 3 to the initial position shown in FIG. 2 via the states shown in FIGS.

In the following description, the operation when the arm 20 rotates in the positive direction from the initial position and moves to the bent position will be described.

First, the train wheel shown in FIG. 1 rotates with power from a motor (not shown) included in the drive mechanism 12, thereby rotating the first rotation support portion A1. As a result, the first link 31 rotates forward about the first rotation support portion A1. The positive rotation of the first link 31 causes the arm 20 to be pushed by the 1-2 end 312 of the first link 31, moving the arm 20 to rotate in the positive direction.

As the arm 20 moves, the fifth rotation support portion A5 and the sixth rotation support portion A6 connected to the arm 20 move. As a result, the third link 33 rotates forward about the third rotation support portion A3. Similarly, the fourth link 34 rotates forward about the fourth rotation support portion A4.

Also, the second link 32 connected to the fifth rotation support portion A5 and the sixth rotation support portion A6 moves along with the movement of the fifth rotation support portion A5 and the sixth rotation support portion A6.

As shown in FIGS. 4 to 6, the movement of the second link 32 moves the seventh rotation support portion A7 to a position where it does not overlap the base portion 10 in the vertical direction. In other words, the seventh rotation support portion A7 moves rightward from the right end of the base portion 10 .

By moving to a position where it does not overlap with the base portion 10 in the vertical direction, the seventh rotation support portion A7 can move upward in the vertical direction. That is, the seventh rotation support portion A7 is movable above the lower end of the base portion 10 .

The arm 20 interferes with the base 10 by moving the seventh rotation support A7, which is the center of rotation of the arm 20, to the right of the right end of the base 10 and above the lower end of the base 10. It is possible to move to a position rotated by 180° from the initial position, that is, the bent position shown in FIG.

In addition, since the first link 31 has a shape including the first interference avoidance portion 31e, it does not interfere with the third link 33 and the third rotation support portion A3 when the arm 20 moves from the initial position to the bent position. no. In addition, since the second link 32 has a shape including the second interference avoidance portion 32e, it does not interfere with the first link 31 and the second rotation support portion A2 when the arm 20 moves from the initial position to the bent position. no.

[summary]
In the arm unit 100 of this embodiment described above, the movable range of the arm 20 can be widened. Specifically, the arm 20 can be moved to a bent position rotated 180° from the initial position. As a result, the range of expression of the motion of the arm unit 100 can be increased. In addition, in this embodiment, by adopting a configuration in which the center of rotation of the arm 20 can be moved left and right, the joint mechanism 30 does not become large in the left and right direction. Therefore, the joint connecting the base 10 and the arm 20 can be made inconspicuous. In addition, in this embodiment, by adopting the joint mechanism 30 including a plurality of links, the weight of the mechanism that constitutes the joint can be reduced.

[Modification]
Next, an arm unit 200 according to a modification of the present embodiment will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 is a diagram showing a state in which the arm is in the initial position in the arm unit according to the modified example of the present embodiment. FIG. 8 is a diagram showing a state in which an arm is in a bent position in an arm unit according to a modification of this embodiment.

The modified example has the same configuration as the present embodiment shown in FIG. 1 and the like, except that the configuration of the drive mechanism for operating the joint mechanism 30 is different. Therefore, configurations having the same functions are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

1 and the like show an example in which the arm 20 is driven by transmitting rotational motion from the drive mechanism 12 including a motor (not shown) to the first link 31. A configuration is adopted in which the arm 20 is driven by transmitting linear motion to the first link 31 .

The base 10 of the arm unit 200 includes a drive mechanism 212. As shown in FIG. The drive mechanism 212 includes a drive source 51 , a tubular member 52 and a vertically moving member 53 . The cylindrical member 52 rotates around the vertical direction by a rotational force from a driving source 51 such as a motor. A spiral groove 52 a is formed in the cylindrical member 52 . The vertically movable member 53 has its upper end fitted in the groove 52 a of the cylindrical member 52 and its lower end connected to the first link 31 .

As the cylindrical member 52 rotates, the upper end of the vertically moving member 53 moves along the groove 52a. As a result, the vertically movable member 53 moves vertically. 7, the upper end of the vertical movement member 53 is at the upper end of the groove 52a of the cylindrical member 52, and in FIG. 8, the upper end of the vertical movement member 53 is at the lower end of the groove 52a of the cylindrical member 52 is shown.

As described above, in the modified example, the vertically moving member 53 moves vertically as the cylindrical member 52 rotates. As the vertically movable member 53 moves vertically, the first link 31 rotates around the first rotation support portion A1. The movements of the other links and arm 20 at this time are the same as those in the configuration of this embodiment shown in FIGS.

As described above, in the arm units of the present embodiment and its modifications, not only rotational motion but also linear motion can be used, so a drive mechanism suitable for the shape and size of the base 10 is applied. becomes possible.

[others]
Although the example in which the arm 20 is driven by the power from the drive source has been described in the present embodiment and its modification, the present invention is not limited to this, and the drive source may not be provided. That is, the arm 20 may be manually moved by the user.

Moreover, in the present embodiment and its modification, an example in which the power from the drive source is transmitted to the first link 31 has been described, but the present invention is not limited to this. Since each link of the joint mechanism 30 interlocks with each other, it is preferable that one of the links connected to the base 10 side receives power. For example, the arm 20 may be driven by transmitting power to the third link 33 or the fourth link 34 .

In addition, in the present embodiment and its modification example, the example in which the arm 20 moves from the initial position to the bent position by rotating 180° has been described, but the present invention is not limited to this. For example, the bent position may be a position in which the arm 20 is rotated in the forward direction by an angle larger than 90° and smaller than 180° from the initial position. That is, the bent position is not limited to the position where the arm 20 is adjacent to the base 10 in the horizontal direction orthogonal to the vertical direction, but may be the position where the arm 20 is adjacent to the base 10 in at least the direction intersecting the vertical direction.

Also, in the present embodiment and its modification, an example in which each rotation support portion is provided at the end of each link has been shown, but the present invention is not limited to this.

Reference Signs List 10 Base 11 Exterior Cover 12,212 Drive Mechanism 20 Arm 21 Exterior Cover 22 End Effector 30 Joint Mechanism 31 First Link 32 Second Link 33 Third Link 34 Fourth Link 51 Drive source, 52 cylindrical member, 53 vertically moving member, 100, 200 arm unit.

Claims (13)

a base;
an arm;
a joint mechanism that connects the base and the arm and rotates the arm from an initial position adjacent to the base in a first direction to a bent position;
has
The joint mechanism is
a first link connecting the base and the arm;
a second link including a center of rotation of the arm on the extension of the base in the first direction when the arm is in the initial position;
a third link connecting the base and the second link;
a fourth link connecting the base and the second link;
including
The third link and the fourth link are
When the arm rotates from the initial position to the bent position, the base and the second link are connected so that the center of rotation of the arm can be moved to a position outside the extension of the base in the first direction. connected,
arm unit. The bending position is a position adjacent to the base in a second direction intersecting the first direction,
The arm unit according to claim 1. The second direction is a direction orthogonal to the first direction,
The arm unit according to claim 2. The third link and the fourth link are
When the arm rotates from the initial position to the bent position, the base and the second link are connected so that the center of rotation of the arm can be moved to a position on the extension of the base in the second direction. connected,
The arm unit according to claim 2 or 3. The fourth link is provided upstream of the third link in a direction in which the arm rotates from the initial position to the bent position,
The diameter of rotation of the fourth link is longer than the diameter of rotation of the third link,
The arm unit according to any one of claims 2-4. The joint mechanism is
a first rotation support that rotatably supports the first link with respect to the base;
a second rotation support that rotatably supports the arm with respect to the first link;
a third rotation support that rotatably supports the third link with respect to the base;
a fourth rotation support that rotatably supports the fourth link with respect to the base;
a fifth rotation support that rotatably supports the second link with respect to the third link;
a sixth rotation support that rotatably supports the second link with respect to the fourth link;
including,
The arm unit according to claim 5. The first link has a shape including a first interference avoidance portion that bends so as not to interfere with the third link,
The arm unit according to claim 6. The first interference avoidance part has a shape that bends so as not to interfere with the third rotation support part.
The arm unit according to claim 7. When the arm is in the bent position, at least part of the third rotation support portion is surrounded by the first link and an imaginary line connecting the first rotation support portion and the second rotation support portion. is placed in the first interference avoidance area,
The arm unit according to claim 8. The second link has a shape including a second interference avoidance portion that bends so as not to interfere with the first link.
The arm unit according to any one of claims 6-9. The second interference avoidance part has a shape that bends so as not to interfere with the second rotation support part.
The arm unit according to claim 10. When the arm is in the bent position, at least part of the second rotation support portion is a second interference avoidance area surrounded by a virtual line connecting the rotation center of the arm and the sixth rotation support portion. placed within the
The arm unit according to claim 11. at least one of the first link, the third link, and the fourth link is rotatably connected to the base by power from a drive source;
The arm unit according to any one of claims 1-12.

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