JPH04315592A - Turning mechanism for robot - Google Patents

Abstract

PURPOSE:To obtain a turning mechanism of a robot capable of smoothly rotating over one rotation, CONSTITUTION:An intermediate ring 8 rotationally movable around the turning axis of a robot trunk base part 2 and the trunk axis is provided in the U-groove 3 on the robot installed base side. First locking parts 10, 11 to stop rotational movement of the intermediate ring 8 against the robot installed base 1, and second locking parts 12, 13 to stop rotational movement of the robot trunk base part 2 against the intermediate ring 8, are provided. A spring conduit 5 of which one end part is fixed to the robot installed base 1 and the other end part is fixed to the robot trunk base part 2 is once folded back between the robot installed base 1 and the intermediate ring 8, and fixed to the intermediate ring 8 and penetrated, and once more folded back between the intermediate ring 8 and the trunk base part 2 and arranged.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a turning mechanism for an industrial robot.

0002

2. Description of the Related Art FIG. 4 is an exploded perspective view schematically showing a turning mechanism of an industrial robot, as disclosed in, for example, Japanese Patent Laid-Open No. 2-100892, and FIG. 5 is a schematic cross-sectional view of the same. 1 is a robot installation base, 2 is a robot trunk base, 3 is a U groove on the installation base side, 4 is a U groove on the trunk base side, 5 is a spring conduit, 6 is a bearing, 7 is a cable group, and 16 is a connector.

Next, the operation of the turning mechanism of this industrial robot will be explained. The robot trunk base 2 is rotatably supported by a bearing 6 with respect to the robot installation base 1. The spring conduit 5 is folded back between the installation base side U-groove 3 formed around the inner edge of the robot installation base 1 and the body base side U-groove 4 formed around the inner edge of the robot body base 2. It is fixed to the robot installation base 1 and the other end to the robot trunk base 2. The spring conduit 5 has a structure that does not bend below a certain curvature, and protects the cable group 7 inserted therein. When the robot trunk base 2 rotates with respect to the robot installation base 1, the spring conduit 5 is dragged or pushed by the rotation of the robot trunk base 2, and the spring conduit 5 is moved between the U groove 3 on the installation base side and the U groove on the trunk base side. 4
It moves along the grooves made by the trees. Therefore, even when the robot trunk base 2 rotates, the cable group 7 is not bent below a certain curvature and does not come into contact with anything other than the inner wall of the spring conduit 5, so it is difficult to break.

[0004] Also, FIG. 6 shows, for example,
7 is a plan view showing a motion area limiting device for an industrial robot disclosed in Publication No. 0, and FIG. 7 is a perspective view showing a robot to which the device is applied. In the figure, 1 is a robot installation base, and 2 is a robot body. 10 is an installation base side contact part, 13 is a trunk base side projection part, and 15 is an arm.

Next, the operation of this industrial robot motion area limiting device will be explained. The installation base side contact part 10 is attached to the robot installation base 1, and the body base side protrusion 1
3 are fixed to the robot trunk base 2, respectively. When the robot torso base 2 rotates with respect to the robot installation base 1, the rotation of the robot torso base 2 is stopped when the torso base side protrusion 13 comes into contact with the installation base side abutment part 10, so that the robot torso base 2 does not move. The area is limited so that the spring conduit (not shown) is not dragged or pushed unnecessarily.

[0006]

Since the rotation mechanism of the conventional industrial robot is constructed as described above, there is a problem in that it is difficult to rotate the robot body base 2 more than one rotation.

The reason for this will be explained with reference to FIG. Figure 8(a)~
(e) is an explanatory diagram schematically depicting the movement of the spring conduit 5 inside the U-groove 3 on the installation base side. Arrow R
represents the direction of rotation. When the robot torso base (not shown) makes exactly one rotation, if the radius of the U-groove 3 on the installation base side is r, then the length l of the spring conduit 5 needs to be at least l=πr. When the spring conduit 5 of this length is folded back at the center, it goes around about 1/4 of the way in the U-groove 3 on the installation base side (
(see Figure 8a). Therefore, when the robot trunk base (not shown) is rotated, the frictional force (generated in the part A in the diagram) between the spring conduit 5 and the inner walls of the U-groove 3 on the installation base side and the U-groove 4 on the trunk base side This prevents the movement of the spring conduit 5 and causes it to sag, making it difficult for the robot body base 2 to rotate (see Figures 8a and 8b).
. The larger the rotation angle of the robot body base 2, the more
This effect will be significant.

Although the U-groove 3 on the installation base side has been described here, the same can be said for the U-groove 4 on the trunk base side.

Furthermore, with the conventional industrial robot motion area limiting device, as is clear from FIG. 6, it is impossible to rotate the robot trunk base 2 more than one rotation.

[0010] This invention was made to solve the above-mentioned problems, and even if the robot body base rotates more than once, the movement of the spring conduit is hindered and the spring conduit sag, and the robot body base may become loose. To provide a turning mechanism for a robot that does not become difficult to rotate and can prevent a robot trunk base from rotating more than a predetermined angle even if it rotates one or more rotations.

[0011]

[Means for Solving the Problems] The robot turning mechanism of the present invention provides a mechanism for rotating the robot torso base in a space between an installation base side U groove formed in the robot installation base and a trunk base side U groove formed in the robot torso base. A rotatable intermediate ring coaxial with the shaft is provided, and a first locking portion for stopping rotation of the intermediate ring with respect to the installation base is provided between the intermediate ring and the robot body. a second locking portion is provided at the base to stop rotation of the robot body base relative to the intermediate ring;
A spring conduit with one end fixed to the robot installation base and the other end fixed to the robot body base is folded back once between the robot installation base and the intermediate ring, fixed to the intermediate ring and passed through, and then fixed to the intermediate ring. The ring is folded back again between the ring and the base of the robot body.

0012

[Operation] In this invention, even if the robot trunk base rotates one or more revolutions with respect to the robot installation base, the intermediate ring rotates and the spring conduit follows the rotation while being pushed or pulled, so the spring The movement of the conduit will not be hindered and it will not sag, nor will the robot body base become difficult to rotate. Additionally, when the spring conduit rotates to a predetermined angle, the first locking part and the second locking part prevent it from rotating further, which limits the operating range and prevents the spring conduit from being dragged or pushed more than necessary. I don't do it. A turning mechanism capable of smoothly rotating one rotation or more is obtained.

[0013]

【Example】

Example 1 An example of the present invention will be described below with reference to the drawings. Figure 1
2(a) to 2(c) are explanatory diagrams showing the concept of spring conduit processing in the rotating mechanism of FIG. 1, and FIGS. c.
) is an explanatory diagram showing the concept of the operating area limiting device of the turning mechanism in FIG. 1;

In the figure, 1 is a robot installation base, 2 is a robot trunk base, 3 is a U groove on the installation base side, and 4 is a robot installation base.
is the U groove on the body base side, 5 is the spring conduit, 6 is the bearing, 7 is the cable group, 8 is the intermediate ring, 9 is the bearing for the intermediate ring, 10 is the first locking part provided on the robot installation base, in this case 11 is a first locking portion provided on the intermediate ring 8, in this case a protrusion on the intermediate ring side, and 12 is a second locking portion provided on the intermediate ring 8.
A locking part, in this case, a contact part on the intermediate ring side; 13 is a second locking part provided on the robot trunk base 2; in this case, a projection on the trunk base side; 14a, 14b are drive means; 15 is an arm ,
16 is a connector. Further, in FIG. 1, a is the center of the rotation axis of the turning mechanism.

The robot torso base 2 is rotationally driven around a in FIG. 1 with respect to the robot installation base 1 by a driving means 14a. Further, the arm 15 is rotationally driven with respect to the robot trunk base 2 by a driving means 14b. (The tip of the arm 15 is omitted in the figure).

An installation base side U groove 3 is formed around the inner edge of the robot installation base 1, and a body base side U groove is formed around the inner edge of the robot body base 2.

Power and control signals for the robot are connected to the connector 16 from outside the robot and guided to the cable group 7. The spring conduit 5 does not bend below a certain curvature and protects the cable group 7 inserted therein.

The intermediate ring 8 is attached to the U groove 3 on the installation base side.
It is rotatably supported by an intermediate ring bearing 9 relative to the robot installation base 1 in the space between the U-groove 4 on the body base side, in this case, the U-groove 3 on the installation base side. The spring conduit 5 has one end fixed to the robot installation base 1, then folded back once between the robot installation base 1 and the intermediate ring 8, fixed to the intermediate ring 8, passed through the intermediate ring 8, and then , and is further folded back once more between the intermediate ring 8 and the robot trunk base 2 and fixed to the robot trunk base 2.

The installation base side contact portion 10 contacts the installation base side contact portion 10 outwardly and inwardly of the installation base side U groove 3, and the intermediate ring side projection portion 11 contacts the installation base side contact portion 10 outwardly and outwardly of the intermediate ring 8. In addition, the intermediate ring side abutting portion 12 extends inwardly toward the inside of the intermediate ring 8, and the body base side projection portion 13 extends outwardly toward the inside of the body base side U groove 4. They are attached so that they are in contact with each other.

Next, the operation and function of each part of this embodiment configured as described above will be explained. First, the processing of the spring conduit of the turning mechanism will be explained with reference to FIG. When the robot body base 2 starts rotating clockwise,
The spring conduit 5 (indicated by A in FIG. 2b) between the robot trunk base 2 and the intermediate ring 8 is dragged to the left along the trunk base side U-groove 4. This results in intermediate ring 8
starts rotating clockwise. As a result, the spring conduit 5 (indicated by A in FIG. 2c) between the intermediate ring 8 and the robot installation base 1 is connected to the U groove 3 on the installation base side.
is pushed to the left along the

As explained in the section ``Problems to be Solved by the Invention'', when the robot trunk base 2 is rotated, the space between the spring conduit 5 and the inner walls of the U-groove 3 on the installation base side and the U-groove 4 on the trunk base side is Frictional force prevents the movement of the spring conduit 5 and causes it to sag, making it difficult for the robot body base 2 to rotate. The limit of the relative rotation angle between the two is approximately one rotation. Therefore, in this embodiment, the robot torso base 2 can smoothly rotate up to about two times with respect to the robot installation base 1 without causing the above-mentioned problems.

Next, the operating area limiting device for the turning mechanism will be explained with reference to FIG. When the robot trunk base 2 starts rotating clockwise, the trunk base protrusion 13 comes into contact with the intermediate ring contact part 12 (see FIG. 3b). Therefore, the intermediate ring 8 also begins to rotate clockwise together with the robot trunk base 2. The robot trunk base 2 and the intermediate ring 8
rotates (see Figure 3c). Therefore, the robot trunk base 2
The operating range is approximately 2 rotations at most. Since the operating area is thus limited, the spring conduit is not dragged or pushed unnecessarily.

By increasing the circumferential width of the installation base side contact portion 10, the intermediate ring side projection 11, the intermediate ring side contact portion 12, and the trunk base side projection 13, the operating area of the robot trunk base 2 can be increased. becomes smaller. By appropriately setting the above width, the operating area can be set according to the specifications of the robot.

[0024] In the above embodiment, the case where there is one intermediate ring is shown, but the number of intermediate rings may be two or more. When there are n intermediate rings, the maximum operating range of the robot torso base is approximately n rotations.

[0025]Although the above embodiment shows the case where the present invention is applied to the pivot axis of the torso base of the robot, it may also be applied to the pivot axis of the robot's wrist.

Further, although the case where the present invention is applied to the rotation axis of a vertically articulated robot is shown, it may be applied to other types of robots such as a horizontally articulated robot.

[0027]

As described above, according to the present invention, the rotation axis of the robot torso base is located in the space between the installation base side U groove formed in the robot installation base and the torso base side U groove formed in the robot torso base. A first locking portion is provided between the intermediate ring and the robot body base to stop rotation of the intermediate ring with respect to the installation base. A spring conduit is provided with a second locking portion for stopping the rotation of the robot torso base relative to the intermediate ring, and has one end fixed to the robot installation base and the other end fixed to the robot torso base. The structure is folded back once between the robot installation base and the intermediate ring, fixed to and passed through the intermediate ring, and then folded back again between the intermediate ring and the robot body base, so that the robot body base is Even if it rotates more than one rotation relative to the installation base, the intermediate ring rotates and the spring conduit follows the rotation while being pushed or pulled, which may hinder the movement of the spring conduit and cause it to sag, or cause the robot body to become The base does not become difficult to rotate, and when it has rotated to a predetermined angle, the first and second locking parts prevent rotation and prevent further rotation, so the spring conduit will not be dragged unnecessarily. This has the effect of providing a robot turning mechanism that does not get pushed and can smoothly rotate one or more revolutions.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a turning mechanism of a robot according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the concept of spring conduit processing according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing the concept of an operating area limiting device according to an embodiment of the present invention.

FIG. 4 is an exploded perspective view schematically showing a rotation mechanism of a conventional industrial robot.

5 is a schematic cross-sectional view showing a turning mechanism of the conventional industrial robot shown in FIG. 4. FIG.

FIG. 6 is a plan view showing a conventional motion area limiting device for an industrial robot.

FIG. 7 is a perspective view showing a robot to which the motion area limiting device shown in FIG. 7 is applied.

FIG. 8 is a schematic explanatory diagram showing the movement of a spring conduit in a rotation mechanism of a conventional industrial robot.

[Explanation of symbols]

1 Robot installation base 2 Robot trunk base 3 Installation base side U groove 4 Trunk base side U groove 5 Spring conduit 7 Cable group 8 Intermediate ring 10 Installation base side contact part 11 of the first locking part
Intermediate ring side protrusion 12 of the first locking portion Intermediate ring side contact portion 13 of the second locking portion Trunk base side protrusion of the second locking portion

Claims (1)

[Claims] 1. An installation base side U-groove is formed around the inner edge of the robot installation base, a body base side U-groove is formed around the inner edge of the robot body base that is rotatable with respect to the robot installation base, and the robot One end of the spring conduit through which the robot drive cable group led from the installation base is inserted and protected is fixed to the robot installation base, the other end is fixed to the robot body base, and the spring conduit is inserted into the U groove on the installation base side. In the rotating mechanism of the robot, which is folded back and arranged in upper and lower layers across the U-groove on the body base side and the U-groove on the body base side, the robot rotates coaxially with the rotation axis of the robot body base in the space between the U-groove on the installation base side and the U-groove on the body base side. A movable intermediate ring is provided, and a first locking portion for stopping rotation of the intermediate ring with respect to the installation base is provided on the robot installation base and the intermediate ring, and a first locking portion is provided on the intermediate ring and the robot body base to stop the rotation of the intermediate ring with respect to the installation base. On the other hand, a second locking portion is provided to stop the rotation of the robot body base,
The spring conduit is once folded back between the robot installation base and the intermediate ring, fixed to and passed through the intermediate ring, and further folded back and disposed between the intermediate ring and the robot trunk base. The rotation mechanism of the robot.