JPH09131686A - Parallel link manipulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parallel link manipulator which can fix a workpiece on a lower side of a hold section, has high rigidity, and excels in position and attitude accuracy. SOLUTION: A parallel link manipulator consists of a basic section 1, a movable section 2, a first arm 3, and three second arms 4. A hold section 5 which fixes a workpiece is provided on a face opposing to the basic section 1 of the movable section 2, and the second arms are arranged in such a manner that they surround the hold section 5. The second arms can be expanded and shrunk and are connected to the basic section 1 and the movable section 2 through universal joints 8, 9. The first arm 3 is arranged outside a region surrounded by the second arms 4. The first arm 3 has rigidity against torsion, can be expanded and shrunk freely, and one end thereof is connected to the basic section 1 through a free joint 6 having rigidity against torsion and the other end thereof is connected to the movable section 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a parallel link manipulator used for position and attitude control of a work or a tool in an industrial robot or the like.

[0002]

2. Description of the Related Art Various structures have been conventionally developed for a position / orientation control mechanism of a parallel link manipulator. As an example of those, Japanese Patent Publication No. 6-573
The structure of the "arm device" described in Japanese Patent Publication No. 94 is shown in FIG. In the figure, 31 is a base portion, 32 is a first movable portion, 33 is a second movable portion, 34 is a telescopic arm having rigidity against torsion, and 35, 36, 37 are other telescopic arms, 4
Reference numerals 0 and 41 are auxiliary telescopic arms, 38 and 39 are rotatable joints, and 42 is a tool.

Telescopic arm 3 having rigidity against twisting
One end of 4 is connected to the base portion 31 via a universal joint 38, and the other end of the telescopic arm 34 is fixed to the first movable portion 32. In addition to this, the base portion 31 and the first movable portion 32
Are connected by two or more expandable arms 35, 36, 37 having universal joints 38 at both ends. Further, the second movable portion 33 is connected to the first movable portion 32 by a universal joint 39 and auxiliary telescopic arms 40 and 41, and a tool 42 is mounted on the second movable portion 33. In this device, the position of the first movable portion is controlled by the telescopic arms 34, 35, 36, 37, and the auxiliary telescopic arms 40, 41 are used to (connect to the first movable portion. The control of the posture of the second movable part is performed.

As described above, in this device, the first arm 34 is surrounded by the second arms 35, 36 and 37, and the second movable portion 33 is arranged above the first movable portion 32. By doing so, the control of the position and the posture is realized.

[0005]

The apparatus described above is used by mounting a work or tool on the upper surface of the second movable part. Depending on the type of work, the work or tool may be mounted face down. It may be better to use the device in different postures. For example, when machining a workpiece with a cutter or grindstone, in order to avoid soiling the arm due to falling chips and polishing dust, the workpiece or tool can be attached to the lower side of the second movable part. Use it by suspending the whole from the ceiling. When used in such a posture, a frame for fixing the base of the device is required, but this frame requires a rigidity higher than that of the device main body, increasing the overall occupied volume and increasing the manufacturing cost. There was a problem.

An object of the present invention is to develop a new position and attitude control mechanism to provide a parallel link manipulator having high rigidity, excellent positioning accuracy and operability, and which does not increase the manufacturing cost. To provide.

[0007]

In order to solve the above-mentioned problems, in the parallel link manipulator of the present invention, it is possible to mount a work or a tool on the lower side of the movable part with the base part installed on the floor. Adopted a different structure.

That is, the parallel link manipulator of the present invention has a base, a movable part having a work or tool holding part mounted on a surface facing the base, and one end of the movable part via a universal joint at positions separated from each other on the base. And the other end is connected via a universal joint at positions separated from each other on the movable part with the holding part in between, and at least three second arms that can be controlled to expand and contract, and one end The second arm on the base is connected to the outside of a region surrounded by lines connecting the second arm's connection parts via a universal joint having rigidity against torsion, and the other end is on the movable part. A first arm that is connected to the outside of a region surrounded by a line connecting the connecting portions of the arms, has rigidity with respect to the torsion, and is expandable and contractible, and controls the expansion and contraction amount of the second arm. By the base And controlling the relative position and orientation of said holding portion for.

In the above parallel link manipulator, since the first arm and the universal joint connecting the first arm and the base portion have rigidity against torsion, the first arm of the movable portion is centered. Therefore, the three-dimensional position of the holding portion is determined by controlling the amount of expansion and contraction of each of the second arms.

Further, the holding portion is provided on the side of the surface of the movable portion facing the base portion of the movable portion, the holding portion is sandwiched between the second arm and the second arm, and the first arm is attached to the first arm. Since it is placed outside the area surrounded by the second arm, when the base is installed on the floor, the inside of the space surrounded by the second arm, where the work or tool hits the lower surface of the movable part. Can be placed at.

Further, by attaching the holding portion to the movable portion via the turning angle adjusting mechanism and the swinging angle adjusting mechanism,
A parallel link manipulator capable of simultaneously controlling position and orientation can be realized.

[0012]

FIG. 1 shows an example with the minimum components of a parallel link manipulator according to the invention.
In the figure, 1 is a base part, 2 is a movable part, 3 is a first arm that has rigidity against torsion and is expandable and contractible, 4 is a second arm that can be expanded and contracted, and 5 is a chuck (holding part). 6 is a universal joint having rigidity against torsion, 8 and 9 are universal joints,
Reference numeral 11 is a turning angle adjusting mechanism, 12 is a swinging angle adjusting mechanism, and 13 is a work.

The movable part 2 is connected to the base part 1 via a first arm 3 and three second arms 4, and the chuck 5 is movable via a turning angle adjusting mechanism 11 and a swinging angle adjusting mechanism 12. 2 is attached to the surface side facing the base portion 1 on the work 1
3 is attached to the chuck 5. Three second arms 4
Are arranged so as to surround the chuck 5, one end of which is connected to the base 1 at a position separated from each other via a universal joint 8 and the other end of which is connected to the movable unit 2 at a position separated from each other. Connected through. Although FIG. 1 is drawn in a simplified manner, in reality, the universal joints 8 and 9 are two-dimensionally arranged on the base portion 1 and the movable portion 2, respectively. The first arm 3 is arranged outside the region surrounded by the three second arms 4, and one end of the first arm 3 is connected to the base 1 via a universal joint 6 having rigidity against torsion. , The other end is rigidly connected to the movable part 2.
The turning angle adjustment mechanism 11 adjusts a rotation angle in a plane parallel to the lower surface of the movable portion 2, and the swing angle adjustment mechanism 12 adjusts a rotation angle about an axis parallel to the lower surface of the movable portion 2.

In the above parallel link manipulator, by controlling the amount of expansion and contraction of each of the second arms 4, the universal joint 6 connecting the base 1 and the first arm 3 is used as the center of the first arm 3. The three-dimensional position of the chuck 5 is determined on the spherical surface depending on the length. Further, by controlling the turning angle adjusting mechanism 11 and the swinging angle adjusting mechanism 12, the posture of the chuck 5 is determined, and as a whole, the position and the posture of the work 13 can be controlled with 6 degrees of freedom.

An example of the operation of this parallel link manipulator is shown in FIG. In FIG. 2, first, the second arm 4
After positioning the chuck 5 by adjusting the expansion and contraction amount of
An example is shown in which the turning angle adjusting mechanism 10 and the swinging angle adjusting mechanism 11 are adjusted to control the posture so that the lower surface of the chuck 5 is parallel to the base 1.

[0016]

According to the parallel link manipulator of the present invention, when the base is installed on the floor surface, it becomes possible to mount the tool or the work downward in the area surrounded by the second arm. Alternatively, a space can be secured below the work. Further, the parallel link manipulator of the present invention has high rigidity, a small occupied area, and a low manufacturing cost, as compared with a case where the parallel link manipulator having a conventional structure is hung from the ceiling. Further, although the position and posture of the holding portion are adjusted with the base portion as a reference, the base portion can be installed and used on the floor surface, so that the position and posture control can be highly accurate.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a structure of a parallel link manipulator according to the present invention.

FIG. 2 is a diagram illustrating an example of the operation of a parallel link manipulator based on the present invention.

FIG. 3 is a sketch drawing showing an example of the structure of a conventional “arm device”.

[Explanation of symbols]

1 ... Base part, 2 ... Movable part, 3 ... First arm, 4 ... Second arm, 5 ... Chuck (holding part), 6 ... Rigidity against torsion A universal joint having
8, 9 ... Universal joint, 11 ... Turning angle adjustment mechanism, 1
2 ... rocking angle adjusting mechanism, 13 ... work, 31 ...
-Base, 32 ... First movable part, 33 ... Second movable part, 34, 35, 36, 37 ... Telescopic arm, 3
8, 39 ... Universal joint, 40, 41 ... Auxiliary telescopic arm, 42 ... Tool.

Claims (2)

[Claims] 1. A base part, a movable part having a work or tool holding part attached to a surface facing the base part, one end connected to a position separated from each other on the base part through a universal joint, and the other end. Is connected via a universal joint to positions separated from each other on the movable part with the holding part interposed therebetween,
At least three second arms that are controllable for expansion and contraction, and a universal joint that has rigidity against torsion is provided outside a region surrounded by a line whose one end connects the connecting portions of the second arm on the base portion to each other. And the other end is connected to the outside of a region surrounded by a line connecting the connection parts of the second arm on the movable part, and has rigidity against torsion.
A parallel link manipulator, comprising: a retractable first arm; and controlling a relative amount and extension of each of the second arms to control a relative position and posture of the holding portion with respect to a base portion. . 2. The parallel link manipulator according to claim 1, wherein the holding portion is attached to the movable portion via a turning angle adjusting mechanism and a swinging angle adjusting mechanism.