JPS62106168A - Rectilinear motion mechanism of robot - Google Patents

Abstract

PURPOSE:To enable rectilinear motion of a hand without a rectilinear sliding shaft and without changing the posture of the hand by using a space closing link mechanism having oblique rotary shafts. CONSTITUTION:A two-stage pivot joint portion 1 has pivot joints for rotatably retaining oblique two shafts, and a link 2 and a link 4 are connected to the respective pivot joints. The other end of the link 2 is coupled to a two-stage pivot joint of a block 8 of a hand portion through a pivot joint 6 and a link 3, and the other end of the link 4 is similarly coupled to the block 8 of the hand portion through a pivot joint 7 and a link 5. Thus, a space closing link mechanism comprising flat link mechanisms 10, 11 is formed to easily enable rectilinear motion of the hand without changing its posture.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a mechanism that allows a robot to perform linear motion, and in particular eliminates linear sliding parts by using space-closed links with oblique rotation axes. This paper relates to a new robot linear motion mechanism.

[Conventional technology]

Conventionally, in this type of linear motion mechanism for robots, software has been developed for linear sliding axes using a mechanism for converting rotational motion into linear motion, such as a ball screw or rack and pinion, or for a planar link with two degrees of freedom. Linear motion was achieved by generating a synchronous movement command to the drive motor so that it would move linearly. Furthermore, in order to maintain the posture of the hand attached to the tip of the driven part without changing even with this movement of degrees of freedom, the belt is hung in multiple stages, and the hand part has a freedom to change the posture. Attitude control was performed by setting a degree and calculating the correction amount on software.

[Problem that the invention seeks to solve]

Among the linear motion mechanisms of conventional robots mentioned above, linear sliding axes using linear guides and ball screws can cause problems due to sliding when used in environments that require ultra-clean air, such as clean rooms. 1. In order to prevent dust from flowing out, it is necessary to seal it with a wiper, etc., so if a perfect seal cannot be obtained and the air cleanliness that can be handled is lower than that of the rotating shaft, there will be disadvantages. be.

On the other hand, in the method of driving a planar link with two degrees of freedom in a straight line by giving synchronous movement commands on software, the load on the CPU on the controller side increases because the synchronous movement commands are generated by calculation. A drawback is that it is difficult to obtain a perfect linear trajectory due to various disturbances acting on the planar link. In the latter case, the posture of the hand attached to the tip of the drive unit generally changes due to the movement of this degree of freedom, so in order to maintain the posture, a belt is hung in multiple stages, or the hand is It was necessary to provide a degree of freedom for changes.

[Means for solving problems]

The linear motion mechanism of the robot of the present invention includes a planar link mechanism a consisting of a link a and a link b pivotally connected to the link a, and a pivot joint having a pivot axis that is not parallel to the pivot axis of the planar link mechanism a. A planar link mechanism consisting of a link C and a link d, which are joined together, includes a two-stage pivot joint that rotates and holds the oblique rotational axes of the link a and link C, and an obliquely intersecting axis of the link b and link d. It has a block part that rotates and holds the rotation axis and automatically controls the posture.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. In the figure, the two-stage pivot joint 1 has a pivot joint that rotates and holds two oblique axes, and each pivot joint has a link (
a) 2 $ and link (C) 4 are respectively combined. The other end of said link (a) 2 is connected to link (b) 3 via a pivot joint (a) 6, and link (a) 2. E
The pivot joint (a) 6 and the link (b) 3 constitute a planar link mechanism (a) 10.

On the other hand, the other end of the link (C) 4 is a pivot joint (b)
7 to link (d) 5 and link (C) 4
．． 2, the pivot joint (b) 7, and the link (d) 5 constitute a planar link mechanism (b) 11. The end opposite to the two-stage pivot joint part 1 of the planar link mechanism (a) 10 and the planar link mechanism [b) 1x is a hand part having a two-stage pivot joint that rotates and holds two obliquely intersecting axes. It is connected by block 8. As a result, the planar link mechanism 1a) 10 and the planar link mechanism (ball) constitute one space-closing link fR structure.

Next, the operation of the present invention will be explained. Said link ta)
2, Bipoft A1mj(a)6, IJ/ri(
b) 3K Yacht-built planar link machine (a
) 10 is the pivot joint 7'! :, it is possible to perform a motion in a plane with the normal line to one rotation axis of the two bivoft connecting parts 1. On the other hand, a planar link mechanism (ball is a two-stage pivot link connected by a pivot +: J1 joint 1 It is possible to perform a motion in a plane with the other axis of rotation as the normal.However, as mentioned above, 29.These two planar links 1 m long have two stages at both ends waiting for oblique pivot joints. Since the space-closing link machine is constrained by the pivot joint part 1.2 and the hand part block 8, for example, when the two-stage pivot part 3Lrn part 1 is fixed in the space, the hand part block 8 , OT function is achieved only on a straight line, which is the common part of the plane stretched by the two planar link mechanisms.In other words, the single groove structure realizes the degree of freedom of linear movement without using a linear sliding axis.

At any moment of this linear movement, the rotation axes of the planar link mechanism (a) 108 and planar link mechanism (b) 11, which are rotated and held by the arm block 8, are aligned with the plane spanned by the respective planar link mechanisms. Since the normal direction to the rotation axis is maintained, the direction of the common normal to these two rotation axes is always constant. This indicates that the posture of the hand block 8 is maintained.

S, the above explanation assumes that there are two pivot joints that maintain rotation.
S was done on the assumption that they are incorporated in the stage pivot joint 1 and the hand block 8, but
It goes without saying that the same result will be obtained even if this pivot joint is incorporated in the link (a) 2, link (C) 4, link (b) 3, and link (d) 5, respectively.

〔Effect of the invention〕

As explained above, the present invention uses a space-closed link mechanism with oblique rotation axes to achieve a degree of freedom in linear movement without using a linear sliding axis. This has the effect that such postures are automatically maintained. Furthermore, since the rotary shaft provides a degree of freedom in linear motion, it can easily be used in environments that require ultra-high air cleanliness, and has the effect of easily achieving high air cleanliness.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention. In the figure, 1...2-stage pivot joint, 2...
...Link a, 3...Link b, 4...
・Link C15...Link d, 6...
Pivot joint a, 7... Pivot joint S, B.
...Hand part block, 10 Kawaichi plane link mechanism a, 11... Planar link mechanism b0 Agent Patent attorney Uchihara Otomo / Tl! J

Claims (1)

[Claims] The degree of freedom of linear motion is achieved by using a space-closed link in which the rotational axes of the joints intersect obliquely, without using a linear sliding axis. A robot linear motion mechanism characterized by being held unchanged by.