JPH06270077A - Parallel robot - Google Patents

Abstract

PURPOSE: To provide a parallel robot which is difficult to exert the bending moment on an arm, simple in constitution, and light in weight. CONSTITUTION: Each link 71 is independently rocked in a plane orthogonal to a surface on which six arms are supported, and realizes the control of 6 degrees of freedom of a bracket 2 at the tip of the arms 31. A motor 41 is fitted opposite to a support part. Since the motor 41 is provided concentric with the link 71, a total parallel robot can be miniaturized, and its weight can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel robot having actuators arranged in parallel.

[0002]

2. Description of the Related Art Conventionally, for a 6-degree-of-freedom parallel robot in which actuators are arranged in parallel, the Japan Society of Mechanical Engineers, Volume 56, Volume 523 (1990-3) (P829).
There is a technology as described in. In a parallel robot equipped with this technique, six arms are each configured by three links, and these three links are connected to each other by three rotating pairs that rotate about one axis. The tip of the arm is connected to the bracket by a ball pair, and a drive motor is arranged at each of the tip of the arm to control the position and posture of the bracket.

[0003]

In such a conventional parallel robot, one arm connects three links, and these three links are connected in series so as to be rotatable about axes orthogonal to each other. Since it is composed of three rotating pairs, when a spatial movement with 6 degrees of freedom is realized, a bending moment is likely to act on each link, and the link is likely to be deformed and rattle when used for a long time. there were. Further, since one arm is composed of three links, there is a problem that the entire robot becomes relatively heavy.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a parallel robot in which a bending moment is less likely to act on an arm and which has a simple structure and which can be reduced in weight. .

[0005]

The present invention has been made in order to achieve the above-mentioned object, and is composed of six arms constituted by a link and a rod and arranged on a base at equal intervals. Three support portions that support two ends of each of the six arms, a bracket in which the tips of the six arms are mounted on the same plane, and the six arms are individually rocked 6 A parallel robot having two motors, wherein the supporting part is composed of two side plates perpendicular to the base and parallel to each other, and the motors are attached to face each of the two side plates. Supporting the link coaxially with the rotation axis of the motor so as to be swingable in a plane parallel to the side plate, connecting the link tip and the rod end by a ball pair, and connecting the rod tip to the ball pair. Therefore those linked to the bracket.

[0006]

The parallel robot configured as described above has
By controlling a motor installed on the base and driving each arm, each link swings independently, and the bracket supported on the arm tip can be controlled with 6 degrees of freedom. Further, in the parallel robot of the present invention, the motor is attached to the two side plates of the supporting portion so as to face each other, and the link is supported coaxially with the rotation axis of the motor.
The spacing between the arms can be reduced to reduce the size of the bracket.

[0007]

Embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1 to FIG. 4, the parallel robot of the present embodiment mainly includes a base 1 fixed to the outside and a base 1
It is composed of a protective cover 80 installed around the bracket, a bracket 2 for attaching an end effector such as a hand, and six arms 31 connecting these two members.

The base 1 is a hexagonal member, and the base 1 and the protective cover 80 make the parallel robot of this embodiment a hexagonal box shape. That is, the side surface protection cover 80a is attached to the outer periphery of the base 1, and the bottom surface protection cover 80b is attached to the side surface protection cover 80a in parallel with the plane of the base 1.
The base 1, the side surface protection cover 80a, and the bottom surface protection cover 80b are attached by bolts (not shown), so that the base 1 and the protection cover 80 can be easily removed. Further, the side surface protection cover 80a and the bottom surface protection cover 80b are provided with three notches 80c so that the six arms 31 can swing. Further, stoppers 83 and 84 indicating the swinging end of the arm 31 are attached to the cutout portion 80c at two positions on the bottom surface protective cover 80b side and the side surface protective cover 80a side, respectively.

Inside the box-shaped body formed by the base 1 and the protective cover 80, three support parts 11 are formed at equal intervals, and each of these support parts 11 has six arms 31 with this number. Two are supported in order. Therefore,
The six arms 31 are respectively supported by the support portion 11 3
It can be divided into three groups and these three groups have the same structure.
Only the arm 31 of the book will be described.

The support portion 11 is composed of two side plates 81 that support the motor 41 so as to face each other, and a back plate 82 that connects the two side plates 81. The two side plates 81 are installed parallel to each other, and the side plate 81 and the back plate 82 are fixed vertically to the base 1. Therefore, the parallel robot of the present embodiment has the base 1 and the protective cover 8 described above.
A double box shape is formed by a hexagonal box shape of 0 and a U-shaped box shape of a side plate 81 and a back plate 82 forming the support portion 11.

The arms 31 each include a link 71 and a rod 72. One end of the two links 71 is connected to the motor 41
Is rotatably supported coaxially about the rotation shaft 100. The motor 41 has a side plate 81 of the protective cover 80.
The tubular portion 41b is configured to be driven to rotate with respect to the fixed portion 41a attached to the. The link 71 is attached to the tubular portion 41b.

Further, the tubular portion 4 in the direction opposite to the direction from the mounting portion of the link 71 to the tubular portion 41b toward the tip of the link 71.
A crescent-shaped balancer weight 41c is attached to the side surface of 1b, that is, to the upper surface side of the cylindrical portion 41b when the link 71 is in the vertical direction as shown in FIG.
The tubular portion 4 is provided on the back plate 82 of the support portion 11 described above.
A hole 82a is formed so as not to interfere with the rotation of 1b.

The link 71 and the rod 72 are connected to each other by a ball joint 61 (a ball pair), and the rod 72 can swing in three dimensions with respect to the link 71 with the ball joint 61 as a fulcrum.
The tips of the rods 72 are connected to the bracket 2 via ball joints 51. With this configuration, the link 71 can swing in a three-dimensional direction with the ball joint 51 (sphere pair) as a fulcrum with respect to the bracket 2.

With the above-mentioned structure, each link 71 is connected to the rotary shaft 100 by giving an operation command value from a controller (not shown) for each of the six motors 41 arranged on the base 1.
By swinging around and combining the swings of these six links 71, the rod 72 at the tip of each link 71 can be swung three-dimensionally, and as a result, each support portion 11
The bracket 2 can be positioned by one arm 31 supported by each of the three arms 31, that is, a total of three arms 31, and the attitude of the bracket 2 can be determined by the other three arms 31. Therefore, the parallel robot of this embodiment has each arm 3
By swinging 1, the bracket 2 can be controlled in 6 degrees of freedom, that is, the position and attitude can be controlled.

As described above, in the parallel robot of the present embodiment, one arm 31 is composed of two elements of the link 71 and the rod 72, and these two elements are connected by the ball joint 61, Since it is possible to operate with 6 degrees of freedom with a small number of elements, it is possible to realize lightweight and high-speed operation. Further, since the joints at both ends of the rod 72 are connected by the two ball pairs of the ball joint 61, it is possible that bending moment acts on the rod 72 itself to deform the rod 72 and cause the arm 31 to be loose. It can be prevented.

The parallel robot of the present embodiment has a structure in which the motor 41 is attached to the two side plates 81 of the supporting portion 11 so as to face each other, and the link 71 is supported coaxially with the rotation shaft 100 of the motor 41. Therefore, it is very compact and lightweight, and when the protective cover 80 is removed, the motor 41 is exposed,
The motor 41 can be easily maintained. Moreover, since the motors 41 are attached to face each other, the arm 31 in FIG.
Since it is possible to reduce the distance d between, the bracket 2 can be reduced, the parallel robot as a whole can be downsized, and the motion performance can be improved.

Further, the balancer weight 4 is attached to the motor 41.
By mounting 1c, the load acting on the motor 41 by the bracket 2 and the arm 31 can be efficiently canceled in a small space.
It is possible to widen the swing angle of, and to realize smooth arm movement. Although the ball joint is used as the ball pair in the above-described embodiments, a universal joint may be used.

[0018]

As described above, in the parallel robot of the present invention, one arm is composed of a link and a rod, and these two elements are connected by a ball pair. Since it is possible to perform the above-mentioned operation, it is possible to realize a lightweight and high-speed operation. Further, since both ends of the rod are connected in a spherical pair, the rod can freely swing even when a force acts from each direction of the rod. Therefore, a bending moment is less likely to act on the rod, and as a result, rattling of the entire arm can be reduced.

Further, in the parallel robot of the present invention, the motor is attached to the two side plates of the supporting portion so as to face each other, and the link is supported coaxially with the rotation axis of the motor. The bracket can be made smaller by making it smaller. Therefore, the parallel robot of the present invention can be reduced in weight with a compact structure, so that it is possible to improve the motion performance and facilitate maintenance work of the motor and the like.

Further, the balancer weight is attached to at least one of the portion on the side opposite to the longitudinal direction of the arm with respect to the rotation center of the link or the motor, so that the load acting on the motor by the bracket and the arm is efficiently canceled in a small space. Therefore, the swinging angle of the arm can be widened, and the smooth movement of the arm can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view of a parallel robot of this embodiment.

FIG. 2 is a cross-sectional view of a parallel robot of this embodiment.

FIG. 3A for the parallel robot of this embodiment, which corresponds to FIG.
FIG.

[FIG. 4] B of FIG. 2 of the parallel robot of the present embodiment.
FIG.

[Explanation of symbols]

 1 Base 2 Bracket 11 Support 31 Arm 41 Motor 41c Balancer Weight 51, 61 Ball Joint 71 Link 72 Rod 81 Side Plate 82 Rear Plate

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor François Pierrot France, 34070 Montpellier 1 En 5 Luangpeer 261 (72) Inventor Osamu Toyama 1-1 Asahi-cho, Kariya city, Aichi Toyota Koki Co., Ltd.

Claims (2)

[Claims] 1. An arm comprising six arms composed of a link and a rod, three arm portions arranged on a base at equal intervals and supporting two ends of the arm arms, respectively. A parallel robot having a bracket in which the tips of four arms are mounted on the same plane, and six motors for individually swinging the six arms, wherein the supporting parts are perpendicular to the base and are mutually Two parallel
It is composed of one side plate, and the motor is attached to each of the two side plates so that the link can swing in a plane parallel to the side plate coaxially with the rotation axis of the motor. A parallel robot characterized in that the link tip and the rod end are connected by a ball pair and the rod tip is connected to the bracket by a ball pair. 2. The parallel robot according to claim 1, wherein a balancer weight is attached to at least one of a portion of the arm opposite to the longitudinal direction of the link or the rotation center of the motor.