JPH0134757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an arm for an industrial robot used for painting work, welding work, etc.

A robot arm equipped with a painting spray gun or a welding torch at its tip has at least two degrees of freedom in order to move the spray gun or torch freely in space, but conventional Since the arm has a non-flexible structure, it is difficult to position it in a narrow space, and the object to be worked on is limited to simple structures such as plates or boxes.

In addition, as a bendable arm, JP-A-52-
Although there is an arm disclosed in Japanese Patent No. 111158, it is difficult to obtain the necessary bendability, and the mechanism is complicated, so it is not necessarily satisfactory.

The present invention has been made in view of the above points,
The purpose is to provide a robot arm that can obtain the necessary bending with a simple configuration and can be applied to work objects having various complicated shapes.

According to the present invention, the object is to provide an arm for a robot, which has both ends, one end is connected to a fixing base, and the other end is connected to a working part. The arm has one end connected to the fixed base via a first pivot mechanism so as to be rotatable relative to the fixed base, and a link extending in one direction from the one end. and one end is connected to the fixed base via a second pivot mechanism so as to be rotatable in the same direction as the rotatable direction of the first link with respect to the fixed base, and the one end is connected to the fixed base via a second pivot mechanism. and another link extending in the direction from the first link and juxtaposed with the first link, and the other link being rotatable in the same direction as the first link. , for one link, one end is connected to the other link via a third pivot mechanism so that it can move freely in the extending direction of the one link, while the other end is slidable. and a connecting member connected to one link via a mechanism,
The first pivot mechanism and the second pivot mechanism are achieved by robot arms located apart in the one direction.

Next, a preferred specific example of the present invention will be explained based on the drawings.

In FIGS. 1 to 6, the first link 1 is
It consists of link rods 2 and 3 arranged in parallel, and plates 4 and 5 fixed to the rods 2 and 3, respectively. The rods 2, 3 and the plates 4, 5 form a closed ring. The plate 4 has a semicircular shape, and a bearing part 6 is formed in the center. A link ball 8 extending from a fixed base 7 is fitted into the bearing part 6. The link 1 has a bearing part 6 at one end. It is pivotally supported on a fixed base 7 by a portion 6 and a ball 8. A driving rod 9 is fixed to the plate 4, and a driving mechanism such as a hydraulic cylinder is connected to the rod 9. When the driving mechanism is operated, the plate 4 is moved through the rod 9.
is rotated. The rods 2 and 3 pass through holes 10 and 11 drilled in the fixed base 7, and the rods 2 and 3
can be freely moved within the holes 10 and 11. The second link 12 juxtaposed to link 1 has link rods 13 and 14 arranged in parallel, and rods 13 and 1.
4, and plates 15 and 16, respectively, are fixed to the base plate 4. The rods 13, 14 and the plates 15, 16 also form a closed ring, and the link 12
are arranged so as to intersect with link 1 in a chain. A bearing portion 17 is formed on the plate 15.
A link ball 18 extending from the fixed base 7 is fitted into the bearing portion 17, and one end of the link 12 is pivotally supported by the fixed base 7 via the bearing portion 17 and the ball 18. Links 1 and 12 are connected by a disk-shaped connecting member 19. That is, the connecting member 19 is formed with sliding bearing parts 20, 21 and spherical bearing parts 22, 23, and the rods 2 and 3 are slidably passed through the bearing parts 20 and 21, respectively. The bearing parts 22 and 23 have rods 13 and 1, respectively.
Balls 24 and 25 attached to 4 are fitted. Balls 24 and 25 are attached to bars 13 and 14
a pair of retaining rings 26 to prevent sliding along the
and 27 are fixed to the rods 13 and 14. The bearing part 6 and the link ball 8, the bearing part 17 and the link ball 18, the spherical bearing parts 22, 23, the balls 24, 25, and the retaining rings 26, 27 constitute a pivot mechanism, respectively, and the sliding bearing part 20, 21
constitutes a sliding mechanism. The third link 28 juxtaposed to the link 12 consists of link rods 29 and 30 arranged in parallel and plates 31 and 32 fixed to the rods 29 and 30, respectively.
A closed ring is also formed by the plates 31 and 32, and the link 28 is arranged to intersect with the link 12 in a chain. The plate 31 is
It has a link ball 33 extending integrally from the center, and the ball 33 is fitted into a bearing part 34 formed in the plate 5, and the link 28 has one end pivotally connected to the other end of the link 1. supported. Links 12 and 28 are connected by a connecting member 35 similar to connecting member 19. That is, in the connecting member 35,
Sliding bearings 36, 37 and spherical bearings 38, 39 are formed, and the bearings 36 and 37 are provided with a rod 2.
Balls 40 and 41 attached to the rods 13 and 14 are fitted into the bearing portions 38 and 39, respectively. A pair of retaining rings 42 and 43 are secured to rods 13 and 14, respectively, to prevent balls 40 and 41 from moving along rods 13 and 14, respectively. Hereinafter, the fourth link and the fifth link are formed in the same way, for example, the fourth link 44 is formed by the link rod 45.
and 46, and a plate 47 fixed to bars 45 and 46.
(only one is shown), rods 45, 46,
A closed ring is formed by the plate 47, the links 44 are arranged to intersect with the links 28 in a chain shape, and the plate 47 has a link ball 48 extending integrally from the center. The ball 48 is fitted into a bearing portion 49 formed on the plate 16. That is, link 44 is connected to link 1 at one end.
It is pivoted to the other end of 2. The links 28 and 44 include sliding bearing portions 50 and 51 and spherical bearing portions 52 and 5.
3 and balls 54 and 55 by a connecting member 56. Also, as above, the retaining ring 57
and 58 are fixed to the rods 45 and 46. 5
9 is a link ball of the fifth link. A paint spray gun or a welding torch is attached to one end of the fifth link, or if more links, such as a sixth, seventh, etc., are provided, to one end of the last link. Link stick 2 like this
and 3 and plates 4 and 5.
is connected to the fixed base 7 via a bearing part 6 and a link ball 8, one end of which is a first pivot mechanism, so as to be rotatable with respect to the fixed base 7, and from the one end The second link 12 extends toward the link ball 33, which is one direction, and is made up of link rods 13 and 14 and plates 15 and 16.
One end is connected to the fixed base 7 via a bearing part 17 and a link ball 18, which is a second pivot mechanism, so that the one end can be freely rotated in the same direction as the second pivot mechanism. The connecting member 19 extends in the direction of the link ball 48 which is the same direction as the first direction and is juxtaposed with the first link 1. The second link 12 is movable in the extending direction of the first link 1, that is, in the first direction.
, sliding bearing portions 20 and 21 and a third sliding bearing portion each having a sliding mechanism at one end are provided so as to be rotatable in the same direction as the rotatable direction of the first link 1.
Spherical bearings 22, 23, which are the pivot mechanism of
It is connected to the first link 1 and the second link 12 via the balls 24, 25 and retaining rings 26, 27, and the first pivot mechanism consisting of the bearing part 6 and the link ball 8 and the bearing part 17 and link ball 18
The second pivot mechanism is located apart from the second pivot mechanism in the first direction.

Next, the operation of the robot arm configured as described above will be explained. First, when the plate 4 is set by the drive mechanism via the rod 9 so that the center of the ball 18 is located on the straight line X connecting the center of the ball 8 and the center of the ball 33, other balls 48, 59, etc. The center is also located directly on X. In this way, the arm will extend almost immediately. Therefore, the centers of balls 8, 18, 33, 48 and 59 are respectively
The centers of the balls 24, 40, and 54 are set on the straight line X at positions abdf and h, and when the centers of the balls 24, 40, and 54 are projected onto the straight line X, the positions become ce and g.

Next, when the drive mechanism is activated and the plate 4 is rotated in one direction by an angle θ ₁ via the rod 9, the center of the ball 33 is is moved to position d ₁ . That is, the link 1 is rotated so that the straight line connecting the fixed position a and the position _d1 intersects the straight line X at an angle _θ1 . When the link 1 is rotated, the link 12 is also rotated in the same direction via the connecting member 19. Since the connecting member 19 and the rods 13 and 14 are rotatably connected, and the connecting member 19 and the rods 2 and 3 are slidably connected, the position corresponding to position c is
a circular arc with a radius centered at a fixed position b;
Position c ₁ of the intersection with the straight line connecting position a and position d ₁
will be moved to That is, the link 12 is rotated so that the straight line connecting the position b and the center position f ₁ of the ball 48 has an angle θ ₂ with respect to the straight line X. stick 2,
3 is rotated around position a, while the connecting member 19 is rotated around position b.
Although the respective movement amounts are different, the connecting member 19 and the rod 2,
Since the rods 2 and 3 are connected to each other through the bearings 20 and 21, the difference in movement amount is compensated for by the sliding of the rods 2 and 3 with respect to the connecting member 19. In this way, when the link 12 is rotated so that the straight line connecting positions b and _f1 has an angle θ ₃ with respect to the straight line connecting positions a and _d1 , the link 28 is rotated through the connecting member 35. is also rotated in the same direction. here bar 1
3, 14 and the connecting member 35 are rotatably fixed to each other, while the rods 29, 30 and the connecting member 35 are rotatably fixed to each other.
and are slidably connected, so the position corresponding to position e is the position of the intersection of a circular arc with a radius centered at position b and the straight line connecting position b and _f1 .
Moved to e ₁ . That is, in the link 28, the straight line connecting the position _d1 and the center position _h1 of the ball 59 is the position a.
It is rotated so that it has an angle θ ₄ with respect to the straight line connecting it with d ₁ . Further, since the connecting member 35 is rotated around position b, and the rods 29 and 30 are rotated around position _d1 , the movement of the rods 29 and 30 is connected with the rotation of the link 28. Member 35
However, since the connecting member 35 and the rods 29 and 30 are connected via bearings 36 and 37, the difference in the amount of movement is due to the sliding of the rods 29 and 30 with respect to the connecting member 35. compensated by moving. Below, the link 44 is also rotated in the same way, and the position g
is moved to the position g ₁ corresponding to . A spray gun or torch, for example attached to the other end of the link 44, is then set in place. Furthermore, by rotating the plate 4 so that the center of the ball 33 is located on the straight line X, the centers of the balls 48 and the like are returned to their original positions, that is, on the straight line X.

Incidentally, in the specific example described above, the arm is constructed by forming the link into an annular shape, but for example, as shown in FIGS. The link 1A is made up of a plate 15A, a link rod 13A and a plate 16A, the second semi-annular link 12A is made up of a plate 31A, a link rod 30A and a plate 32A, and the third semi-annular link 28A is made up of a plate 47A and a link rod 46A. It is also possible to form the fourth semi-annular links 44A in the same manner as above, and to form the arms by connecting the links 1A, 12A, 28A and 44A in the same manner as described above with the fan-shaped connecting members 19A, 35A and 56A. good. In this case, links 1A and 28A and also link 12A
and 44A are alternately placed in opposite positions,
This is preferable because it allows the arm to be balanced. Further, if the link rod is formed of a tubular member or the like, the arm can be made lightweight.

In addition, in the two specific examples, the second link 1 is slidable with respect to the first links 1 and 1A.
Connecting members 19, 1 rotatably relative to 2, 12A
9A, and connecting members 35, 35A were attached rotatably to the second links 12, 12A and slidably to the third links 28, 28A, and the arms were constructed in the same manner. , instead of this, as shown in FIGS. 10 and 11, the bearing part 22A and the ball 24 are connected to the first link 1B.
The connecting member 19A is rotatably connected to the second link 12B through the A and retaining ring 26A, and the connecting member 19 is slidably connected to the second link 12B through the sliding bearings 20A and 27A.
A, 35A is rotatably connected to the connecting member 3 via the bearings 38A, 52A, balls 40A, 55A, and retaining rings 42A, 57A with respect to the third link 28B.
5A and 56A may be slidably attached to the fourth link 44A via a sliding bearing 51A to form an arm.
As shown in FIGS. 12 and 13, the connecting member 19A is slidably connected to the first link 1c and rotatably connected to the second link 12c.
The connecting member 35A is slidably connected to the third link 2c and rotatably connected to the third link 28c.
The connecting member 56A may be slidably attached to the fourth link 8c and rotatably attached to the fourth link 44c, and as shown in FIGS. The connecting member 19A is rotatably and slidably attached to the second link 12D.
The connecting member 35A is rotatably connected to the link 12D, and slidably connected to the third link 28D.
The connecting member 56A may be rotatably attached to the fourth link 44D and slidably attached to the fourth link 44D, respectively. By varying the connection modes in this way, the degree of bending of the arms can be varied. For example, in the case of the connection modes shown in Figures 1 and 2 and 7 and 8, the bending is greater than the others. is obtained.

In the present invention, each link may be formed integrally, or five or more links may be provided, or conversely, two links may be provided.

As described above, according to the present invention, the arm can be made sufficiently bendable, making it easy to position it in a narrow space.In addition, since it can be constructed more easily than conventional bendable arms, it is less expensive. We can provide robots that are

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a preferred example of the present invention, FIG. 2 is a plan sectional view of the example shown in FIG. 1, FIG. 3 is a sectional view taken along the - line shown in FIG.
The figure is a sectional view taken along the - line shown in Figure 1, and Figure 5 is a cross-sectional view taken along the line 1.
- line sectional view shown in the figure, Figure 6 is an operation explanatory diagram,
7 to 9 show other preferred embodiments of the present invention, in which FIG. 7 is a cross-sectional view taken along the line shown in FIG. 8, FIG. 8 is a cross-sectional view taken along the line shown in FIG. 7, and FIG. is a - line cross-sectional explanatory diagram shown in Fig. 7, No. 10
15 through 15 are explanatory diagrams of various connection modes in preferred embodiments of the present invention. 1, 12, 28, 44... link, 7... fixed base, 19, 35... connecting member.

Claims (1)

[Scope of Claims] 1. A robot arm having both ends, one end of which is connected to a fixing base, and the other end to which a working part is connected, the robot arm comprising:
one link whose one end is connected to the fixed base via a first pivot mechanism so as to be rotatable with respect to the fixed base, and which extends from the one end in one direction; One end is connected to the fixed base via a second pivot mechanism so as to be rotatable in the same direction as the rotational direction of the first link with respect to the fixed base, and from the one end another link extending in the one direction and juxtaposed with the one link; and the other link is rotatable in the same direction as the one link;
For one link, one end is connected to the other link via a third pivot mechanism so as to be movable in the extending direction of the one link,
a connecting member whose other end is connected to the one link via a sliding mechanism, and the first pivot mechanism and the second pivot mechanism are located apart with respect to the one direction. An arm for a robot. 2. The robot arm according to claim 1, wherein one link and the other link are formed in an annular shape, and both links are arranged in a chain. 3. The robot arm according to claim 1, wherein one link and the other link are formed in a semi-annular shape.