WO2021054016A1

WO2021054016A1 - Robot hand

Info

Publication number: WO2021054016A1
Application number: PCT/JP2020/031075
Authority: WO
Inventors: 武志古川; 貴大安部; 保幸小林; 全弘斎藤; 中村　一也
Original assignee: アダマンド並木精密宝石株式会社
Priority date: 2019-09-19
Filing date: 2020-08-18
Publication date: 2021-03-25
Also published as: JPWO2021054016A1; JP7499522B2

Abstract

[Problem] To provide a robot hand capable of having both "miniaturization" and "high durability". [Solution] A first finger part 20 has: segments 21, 22, 23, 24; joints 25, 26, 27, 28; and drive sources 56, 56, 57 which are servo motors included so as to correspond to the respective joints. A base unit 10 is provided with a drive source 51 for rotating the first finger part 20 inward and outward. In order to reduce a burden on a harness connected to each of the drive sources when the finger part is in motion, the harness is wound and disposed in areas indicated by A1, A2, A3, A4 located at positions excluding positions on the circumference of the rotary axis of the joints.

Description

Robot hand

It is related to a robot hand that can grip and operate a work by bending a finger part.

Conventionally, in this type of robot hand, as a general method of arranging a harness for supplying power to a drive source or transmitting a signal, there is a certain amount of slack when the finger is extended so as not to break the wire when the finger is bent. Arrange as follows. Further, particularly in the joint portion, in order to prevent damage to the harness, the harness may be arranged in a form of being wound around the shaft column of the joint shaft with an extra length. Furthermore, in order to reduce the size of the entire robot hand and prevent disconnection by eliminating the exposure of the harness, an elastic body is placed near the joint axis so that the harness can move along the elastic body. The configuration and the like are disclosed (see, for example, Patent Document 1).

In recent years, the development and practical application of a system in which humans and robots work together on the same production line has been progressing (see, for example, Patent Document 2). The collaborative robots used in such systems are small and lightweight from the viewpoints of space saving and ease of installation, and are dexterous so that one robot hand can perform a wide variety of tasks. The movement of the finger is required. In response to such demands, the applicant has already proposed a robot hand that is compact and lightweight, has a wide range of motion, and is dexterous and capable of performing various movements (for example, Japanese Patent Application No. 2018-190909). ).

Japanese Unexamined Patent Publication No. 2008-1789668 Japanese Unexamined Patent Publication No. 2017-039170

In addition to being compact, when applying a robot hand that has a wide range of motion and can perform a variety of dexterous movements to a collaborative robot, it is important to achieve both durability, such as suppressing disconnection of the harness. However, with the conventional arrangement method for the harness, there is a limit in achieving both "miniaturization of the robot hand" and "high durability focusing on the disconnection of the harness". This is because as the size of the finger portion is reduced, the space for arranging the harness is inevitably limited, which leads to the harness becoming "smaller in bending radius" and "more susceptible to stress".

The present invention has been made to solve the above-mentioned problems, and an object thereof is "miniaturization" and "high durability" even in a robot hand having a wide range of motion and capable of performing various movements. The purpose is to achieve both.

One means for solving the above problems is to attach a harness connected to a drive source to a rotation axis of a joint in a robot hand provided with a base unit, a finger portion supported by the base unit, and a drive source for moving the finger portion. It is configured by arranging it in a wound state at a position other than the circumference of.

According to the present invention, it is possible to provide a robot hand that has both "miniaturization" and "high durability".

It is a figure which shows an example of the robot hand which concerns on this invention, (a) the front view of the state in which all the fingers are extended, (b) the right side view of the same. The robot hand is (a) a front view of a state in which a finger portion is bent or the like, and (b) a right side view of the same. It is a schematic diagram which showed the base unit and a part of a finger part about the robot hand. It is an image diagram which shows the state of the winding part of a harness about the robot hand. It is a figure explaining the joint structure of a part of a finger part and the arrangement state of a harness about the robot hand. It is a figure explaining the arrangement state of a guide part and a harness about the robot hand. It is a figure explaining the arrangement state of the harness in the base unit about the robot hand. It is an image figure which shows another example of the state of the winding part of a harness about the robot hand. It is a figure explaining another example of the joint structure of a part of a finger part and the arrangement state of a harness about this robot hand. It is a figure explaining another example of the joint structure of a part of a finger part and the arrangement state of a harness about this robot hand.

In the robot hand of the present embodiment, in a robot hand including a base unit, a finger portion supported by the base unit, and a drive source for moving the finger portion, a harness connected to the drive source is provided around the rotation axis of the joint. One of the basic features is that it is configured by arranging it in a wound state at a position other than the rotation.
According to this configuration, it is possible to process the harness so that it does not wrap around the rotating shaft or to increase the bending radius of the harness, as compared with the case where the harness is wound around the outer circumference of the rotating shaft of the joint for wiring processing. , The harness can be less susceptible to stress. As a result, both "miniaturization" and "high durability" can be achieved.

As another feature, in addition to the above-mentioned features, the specific mode of the number of times the harness is wound is set to be more than one rotation and less than three rotations.
According to this configuration, the stress on the harness due to the movement of the finger portion of the robot hand can be sufficiently reduced while minimizing the space for the place where the harness is wound and arranged.

Another feature is that, in addition to the above-mentioned features, the harness is arranged in a wound state in a space located in the vicinity of the rotation axis and at least partially closed.
According to this configuration, the winding portion of the harness can be efficiently accommodated in the vicinity of the rotation axis and in a small space while preventing the winding portion of the harness from being caught by an external object.

Another feature is that, in addition to the above-mentioned features, the rotating shaft has a hollow cylindrical shape, and the unwound portion of the harness passes through the hollow cylinder of the rotating shaft.
According to this configuration, the winding portion of the harness that reduces stress can be arranged in the vicinity of the rotating shaft where the harness is susceptible to stress while efficiently passing the harness.

As another feature, in addition to the above features, the guide parts of the harness are fixedly arranged in the vicinity of the rotating shaft. The guide component has a cylindrical portion having a diameter larger than the outer diameter size of the rotating shaft, and the harness is wound around the cylindrical portion of the guide component with a margin. It is in what you are doing.
According to this configuration, the harness can be wound with a large bending radius, and the arrangement state of the winding portion can be regulated, so that the winding portion can be prevented from being caught by an external object.

Another feature is that, in addition to the above-mentioned features, the harness is arranged in a wound state in a space formed inside the base unit.
According to this configuration, it is easy to secure a relatively large space in the base unit to which the finger part is connected, so that the harness of the drive source for moving the finger part can be arranged in a wound state with a relatively large radius of curvature. ..

As another feature, in addition to the above-mentioned features, the rotating shaft has a hollow cylindrical shape, and a part of the harness is formed into a pre-wound shape, and the rotating shaft is formed in the hollow cylinder of the rotating shaft. The wound portion of the harness is arranged.
According to this configuration, the winding portion of the harness can be efficiently accommodated in a limited small space.

As another feature, in addition to the above-mentioned features, a specific aspect as a robot hand is that the finger parts have three or more, and each of the three or more finger parts has an adduction / abduction motion and the adduction / abduction motion. It has two or more degrees of freedom including bending and stretching movements in intersecting directions, and the driving source is provided for each of the adduction and abduction movements and the bending and stretching movements in each of the three or more fingers. I made it.
According to this configuration, it is possible to make a robot hand that is dexterous and can perform various movements due to its high athletic ability.

As another feature, in addition to the above-mentioned features, a more specific aspect as a robot hand is that each of the three or more fingers has an adduction / abduction motion with an angle of 90 degrees or more and a bending / stretching motion. It is assumed that at least two fingers having two or more degrees of freedom and capable of pointing in different directions are included.
According to this configuration, it is possible to make a robot hand that can perform more dexterous and various movements by the wide range of movement and the movement form of the finger portion.

Next, a specific embodiment having the above characteristics will be described in detail based on the drawings.

First, the overall configuration of the robot hand H of this embodiment will be described with reference to FIGS. 1 and 2.
1 and 2 show the robot hand H of this embodiment. FIG. 1 shows a state in which all the fingers of the robot hand H are extended, and FIG. 1B shows a right side view with respect to the front view of (a). FIG. 2 shows a state in which the finger portion of the robot hand H is bent or the like, and FIG. 2B shows a right side view with respect to the front view of (a).

This robot hand H is composed of a base unit 10 and first to

third finger portions

20, 30, 40 supported by the base unit 10. Further, the base unit 10 or the

finger portions

20, 30, 40 are provided with a plurality of servomotors for bending / stretching motion and adduction / abduction motion of each finger portion as a drive source.

Here, the flexion / extension exercise is an exercise in which the joint portion of each finger is flexed or extended. Further, the adduction / abduction motion is a motion in a direction substantially orthogonal to the bending / stretching motion, and each finger portion is rotated with the finger base side as a fulcrum so as to approach an adjacent finger portion. It is an exercise that rotates the finger away from the adjacent finger.

The first finger portion 20 bends and stretches a plurality of joints by the power of an internal drive source so as to correspond to each joint. Further, the power of the drive source 51 supported by the base unit 10 can cause an adduction / abduction motion in a range of an angle of 180 degrees or more.

The second finger portion 30 flexes and stretches a plurality of nodes sequentially from the finger base side by the link mechanism with the power of a single drive source 53. Further, the power of the drive source 52 supported by the base unit 10 can cause an adduction / abduction motion in a range of an angle of 90 degrees or more and 120 degrees or less.

The third finger portion 40 flexes and stretches a plurality of nodes sequentially from the finger base side by the link mechanism with the power of a single drive source 55. Further, the power of the drive source 54 supported by the base unit 10 can cause an adduction / abduction motion in a range of an angle of 90 degrees or more and 120 degrees or less.

Each drive source is an electric servomotor whose rotation angle, rotation speed, etc. are appropriately controlled, and the rotational force of the built-in motor is transmitted to the output shaft via gears, a clutch mechanism, and the like. It is composed. A harness for supplying power and transmitting signals is connected to the servomotor, which is the drive source.

By arranging the robot hand H in a state where the harness is wound around a position other than the circumference of the rotation axis of each joint, the first to

third fingers

20, 30, and 40 perform bending and stretching movements and adduction and abduction movements. The stress on the harness is reduced when repeating.

In the following, the arrangement form of the harness in the robot hand H will be specifically described with reference to FIGS. 3 to 7.

First, an area or the like in which the harness is arranged in a wound state will be described with reference to FIG.
FIG. 3 is a diagram schematically showing the base unit 10 and the first finger portion 20 for explaining the arrangement of the harness. (A) shows a state in which the first finger portion 20 is extended, and (b) shows a state in which the first finger portion 20 is bent.

The first finger portion 20 includes

joints

21, 22, 23, 24, joints 25, 26, 27, 28, and drive

sources

56, 57, 58, which are servomotors built in so as to correspond to each joint. Further, the base unit 10 is provided with a drive source 51 that causes the first finger portion 20 to make an adduction / abduction motion.

The drive source 51 makes the node 21 abduct and abduct with the rotation shaft 25a of the joint 25 as a support shaft. The drive sources 56, 57, and 58 correspond to the

joints

26, 27, and 28, respectively, and the

joints

22, 23, and 24 are rotated around the

rotation shafts

26a, 27a, and 28a as support axes. The finger portion 20 is bent and stretched.

Harnesses for power supply and signal communication are connected to each drive source.

Harnesses

58h, 57h, 56h, 51h are connected to the

drive sources

58, 57, 56, 51, respectively, when viewed from the fingertip side where the node 24 is located. The harness 58h connected to the drive source 58 is electrically connected to the harness 57h connected to the drive source 57 via a branch board (not shown), and is organized as a set of harnesses in terms of wiring. Similarly, the harnesses of each drive source are wired by a set of harnesses from the fingertip side toward the base unit side.

In particular, when bending the fingers, in order to reduce the burden on each harness, the harness is basically wound in a form that is more than one rotation and less than three rotations in the areas indicated by A1, A2, A3, and A4. I'm turning. The amount of winding of the harness has a certain effect even if it is one rotation or less or three or more rotations, but by winding more than one rotation, the effect of reducing stress on the harness becomes remarkably high. On the other hand, even if the number of windings is greatly increased, the effect of stress reduction is small and the space for arrangement is large. Therefore, by setting the number of turns to be more than one turn and less than three turns, the stress on the harness due to the movement of the fingers of the robot hand is minimized while minimizing the space for winding and arranging the harness. Can be sufficiently reduced.

Next, the basic action and effect of the winding portion of the harness during the bending and stretching movement of the finger part will be described with reference to FIG.

FIG. 4 is an image diagram showing a state of the winding portion of the harness.
FIG. 4A shows the state of the finger portion 20 at the time of extension.
FIG. 4B shows the state of the finger portion 20 at the time of bending.

In FIG. 4A, Ds indicates the diameter dimension of the portion wound in a substantially circular shape. Further, Ls indicates the distance between adjacent winding portions.

In FIG. 4B, Dk indicates the diameter dimension of the portion wound in a substantially circular shape. Further, Lk indicates the distance between adjacent winding portions.

The diameter dimension Dk when the finger is bent is smaller than the diameter dimension Ds when the finger is extended (Dk <Ds).
Further, the distance Lk at the time of bending becomes equal to or more than the distance Ls at the time of extension (Ls ≦ Lk).

That is, the stress applied to the harness is reduced by fluctuating the diameter dimension of the winding portion of the harness and fluctuating the axial distance of the winding portion as necessary in the bending and stretching movement of the finger portion.

Next, the mode of winding the harness in the areas A1 and A2 will be described mainly with reference to FIG. 5, which shows the structure of the joint portion.

In area A1, the harness 58h connected to the drive source 58 is wound around. [Fig. 5 (a)]
In area A2, the harness 57h connected to the drive source 57 is wound around.

FIG. 5A shows the internal structure of the joint 27. The rotation shaft 27a of the joint 27 has a hollow cylindrical shape. The knot portion 23 and the knot portion 22 are in a state of being rotatable with each other via a bearing 23b located on the outer peripheral portion of the rotating shaft 27a.

Spaces

23s and 22s connected to the hollow portion of the rotating shaft 27a are formed in each of the knots 23 and the knots 22. The harness 58h is routed from the space 23s to the joint 26 side through the hollow portion of the rotating shaft 27a and the space 22s.

The harness 58h is wound about two turns in total at a position close to the hollow portion of the rotating shaft 27a in the space 23s and a position close to the hollow portion of the rotating shaft 27a in the space 22s.

When the finger portion 20 bends at the joint 27, the diameter dimension of the winding portion of the harness 58h in the

spaces

23s and 22s becomes small, and the stress applied to the harness 58h is reduced.

In the joint 26 having the area A2, the harness 57h is arranged in the same manner as the harness 58h is passed through the joint 27 in the area A1, and the stress applied to the harness 57h is reduced when the finger portion 20 bends at the joint 26. ..

As described above, since the harness 58h is organized in the harness 57h as an electrical path, normally, only the harness 57h may be arranged in the area A2 and routed to the base unit side. However, as shown in FIG. 5B, for example, it is possible to arrange both the harness 57h and the harness 58h without putting them together.

At this time, the harness 57h and the harness 58h are wound at a position close to the hollow portion of the rotating shaft 26a in the space 22s and a position close to the hollow portion of the rotating shaft 26a in the space 21s. When the finger portion bends at the joint 26, the diameter dimension of the winding portion of the harness 57h and the harness 58h in the

spaces

22s and 21s becomes small, and the stress applied to the harness 57h and the harness 58h is reduced. Then, the harness 57h, together with the harness 58h, passes through the space 21s and is routed to the base unit side.

Next, the mode of routing the harness in the area A3 will be described mainly using FIG.

In the area A3 located near the joint 25, the harness 56h connected to the drive source 56 is wound around the guide component 61 and arranged. The guide component 61 is integrally fixed with the knot portion 21. The distance between the joint 25 and the guide component 61, which are in a close positional relationship, basically does not exceed the distance between the joint 25 and the adjacent joint 26 on the assumption that they are arranged as close as possible. To do.

As shown in FIG. 6, the guide component 61 is formed with a cylindrical portion 61a and support portions 61b located on both sides of the cylindrical portion 61a in the axial direction.

The cylindrical portion 61a is formed with a diameter larger than that of the rotating shaft 25a. The harness 56h is wound around the cylindrical portion 61a with a margin. Further, the support portion 61b can prevent the harness 56h from being displaced in the axial direction of the cylindrical portion 61a. It is effective to reduce friction with the harness 56h by attaching a tape material having excellent slidability to the surface of the cylindrical portion 61a.

When the finger portion performs an adduction / abduction operation at the joint 25, the diameter dimension of the winding portion of the harness 56h in the guide part 61 fluctuates, and the stress applied to the harness 56h is reduced.

One side of the harness 56h with respect to the drive source 56 side is wound around the guide component 61 and then routed into the base unit 10.

The mode in which the guide component 61 is used in the area A3 around the joint 25 for the adduction / abduction movement in the finger portion 20 has been described above, but the same applies to the joint circumference for the adduction / abduction movement in the

finger portions

30 and 40. It can be configured. Alternatively, the harness can be arranged by arranging the guide component in the vicinity of other joints involved in the abduction motion. If there is no risk that the winding portion of the harness may come into contact with other parts during operation and cause a problem, the harness may be arranged in a wound state without using the guide parts.

Next, the mode of routing the harness in the area A4 will be described mainly using FIG. 7.

In the area A4 inside the base unit 10, the harness 56h from the finger portion 20 is pulled into a relatively wide space, and is arranged in a wound state as shown in FIG. 7. A tape material having excellent slidability for reducing friction with the harness may be attached to a part of the inner wall of the space.

The harnesses from the second finger portion 30 and the third finger portion 40 are also pulled into the base unit 10 with a margin. The harness from the second finger portion 30 and the third finger portion 40 may also be wound and arranged.

When the

fingers

20, 30, 40 perform bending / stretching motion or adduction / abduction motion, the diameter dimension also fluctuates in the winding portion of the harness inside the base unit 10, and the stress applied to each harness is reduced as a whole.

The inventor of the present application has confirmed that the durability according to the present embodiment is improved by at least 3 times or more to prevent disconnection.

It is assumed that cover parts (not shown) that do not interfere with the operation are attached to the first to

third fingers

20, 30, and 40 of the robot hands H of FIGS. 1 and 2 in which the mechanical portion can be seen. With this cover component, it is possible to protect a part where the harness is exposed so as not to come into contact with the outside.

Next, another example of winding the harness in the area A1 will be described mainly with reference to FIGS. 8 to 10.

In this embodiment, the harness 58w shown in FIG. 8 is used as the harness connected to the drive source 58 (see FIG. 3). The harness 58w is a set of three cables arranged side by side. In addition, the harness 58w has a part that is wound about twice, and is formed so that this wound state is maintained even when no external force is applied. There is. In the form of a set of three cables of the harness 58w arranged side by side, the cables may not be joined to each other and may be separable. For example, the coatings of the cables may be joined to each other. It may be an integral strip.

FIG. 9 shows the internal structure of the joint 27 (see FIG. 3). The rotation shaft 27a of the joint 27 has a hollow cylindrical shape. The knot portion 23 and the knot portion 22 are in a state of being rotatable with each other via a bearing 23b located on the outer peripheral portion of the rotating shaft 27a. Most of the woundly formed portion of the harness 58w is housed in the hollow portion of the rotating shaft 27a. The outer diameter do of the wound portion of the harness 58w when no force is applied from the outside is smaller than the inner diameter Di of the hollow portion of the rotating shaft 27a. When the finger portion 20 bends at the joint 27, the winding portion of the harness 58w extends in the axial direction of the joint 27 and the overall diameter dimension becomes smaller, thereby reducing the stress applied to the harness 58w.

In FIG. 9, the wiring in the

nodes

23 and 22 of the harness 58w is arranged vertically with the three cables (58w1, 58w2, 58w3) constituting the harness 58w in the same manner as the winding portion (in the illustration of FIG. 9). 58w1, 58w2, 58w3) are wired from the top to the

spaces

23s and 22s, but as shown in FIG. 10, they may be arranged side by side in the

spaces

23s and 22s. In this case, since the

distance dimensions

23d and 22d of the

spaces

23s and 22s with respect to the width direction of the finger portion can be made smaller, the width of the finger portion can be suppressed. As the harness 58w used at this time, a harness in which the cables are not joined to each other is applied so as not to apply an excessive load to each cable constituting the harness 58w in the vicinity of changing from vertical arrangement to horizontal arrangement. ..

Although not shown, the harness 58w wired toward the drive source 57 (see FIG. 3) through the space 22s includes each harness connected to each drive source on the same finger and a plurality of branch boards. It is electrically connected toward the base unit side via. Further, in this embodiment, the state of the harness in the area A1 has been described, but also in the area A2, the same embodiment as in the present embodiment is applied by using a harness in which three cables arranged side by side are set. Can be done.

The present invention is not limited to the above-described embodiment, and can be appropriately modified without changing the gist of the present invention.

H: Robot hand 10: Base unit 20:

First finger

21, 22, 23, 24:

Nodal

25, 26, 27, 28: Joint 30: Second finger 40:

Third finger

51, 52, 53, 54, 55, 56, 57, 58: Drive

source

51h, 56h, 57h, 58h: Harness 58w: Harness

Claims

In a robot hand provided with a finger portion supported by a base unit and a drive source for moving the finger portion.
A robot hand characterized in that a harness connected to the drive source is arranged in a wound state at a position other than the circumference of the rotation axis of the joint.
The robot hand according to claim 1, wherein the wound state is more than one rotation and less than three rotations.
The robot hand according to claim 1 or 2, wherein the harness is arranged in a wound state in a space located in the vicinity of the rotation axis and at least partially closed.
The robot hand according to claim 3, wherein the rotating shaft has a hollow cylindrical shape, and a portion of the harness that is not wound is passed through the hollow cylinder of the rotating shaft.
The guide parts are fixedly arranged in the vicinity of the rotating shaft, and the guide parts are fixedly arranged.
The guide component has a cylindrical portion having a diameter size larger than the outer diameter size of the rotating shaft.
The robot hand according to claim 1 or 2, wherein the harness is wound around the cylindrical portion of the guide component with a margin.
The robot hand according to claim 1 or 2, wherein the harness is arranged in a wound state in a space formed inside the base unit.
The rotating shaft has a hollow cylindrical shape, a part of the harness is formed in a pre-wound shape, and the wound portion of the harness is arranged in the hollow cylinder of the rotating shaft. The robot hand according to claim 1 or 2, wherein the robot hand is characterized by the above.
There are three or more fingers,
Each of the three or more fingers has two or more degrees of freedom, including an adduction / abduction motion and a flexion / extension motion in a direction intersecting the adduction / abduction motion.
The robot hand according to any one of claims 1 to 7, wherein the drive source is provided for each of the adduction / abduction motion and the flexion / extension motion in each of the three or more finger portions.
Each of the three or more fingers has two or more degrees of freedom including the adduction / abduction motion and the flexion / extension motion at an angle of 90 degrees or more.
The robot hand according to claim 8, wherein the robot hand includes at least two fingers capable of pointing in different directions from each other.