JPS61168484A - Multi-freedom-degree joint for manipulator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-degree-of-freedom joint for a manipulator used in a manipulator such as an industrial robot.

[Prior Art] Generally, additional degrees of freedom are added to the manipulator joints of industrial robots in order to improve the movement of the links of the manipulator.
Usually, it is sufficient to be able to express the position of the link in a three-dimensional coordinate system, and for this purpose, at least three degrees of freedom are sufficient.

By the way, as a specific example of a conventional three-degree-of-freedom joint for a manipulator, a joint with a bevel gear as an element is considered, as shown in FIG. is U-shaped, and a first . A second bevel gear 121° (3) is rotatably attached, and a third bevel gear (6) pivotally supported at the tip of the second link (4) is attached to the first bevel gear. The second bevel gear +21i31 is arranged and configured to mesh with the second bevel gear +21i31. Pitching or yawing around the rotational axis of the second bevel gears +21 and +31 and rolling around the rotational axis of the third bevel gear (5) are possible, but the number of degrees of freedom remains at 2 and 1. There is a problem in that the position of the second link (4) in the three-dimensional coordinate system cannot be expressed by the joint.

Therefore, a robot wrist with a rotation axis with three degrees of freedom as described on page 60 of Nikkei Mechanical published on July 19, 1982 has been proposed, and its power transmission mechanism is as shown in Figure 9 (a). , first to third roll shafts (6) to (8) each independently rotationally driven by three motors.
are provided coaxially, and the second. The first and second bevel gears (9) and αO are attached to the third roll shaft (71 and 181, respectively),
A third bevel gear ill whose rotation axis is inclined with respect to the second roll axis (7) and has a larger diameter than the first bevel gear (9) that meshes with the first bevel gear (9) is provided, A $4 bevel gear 1z whose rotating shaft coincides with the rotating shaft of the third bevel gear (+11), meshes with the second bevel gear αO, and rotates separately from the third bevel gear jl11, and Helical gear ++
A fifth bevel gear 1131 is provided opposite the fourth bevel gear +121 on the rotating shaft of No. 2; 121', and the fifth bevel gear (
131, and six bevel gear wheels that mesh with each other in an elongated manner.

The housing of the robot wrist described above is shown in Fig. 9 (
As shown in b), the first to fourth bevel gears (9) to 12
A hemispherical lower blade bar 061 that accommodates the first roll l1tl (6) and rotates by the rotation of the first roll l1tl (6) is attached to the tip of the robot arm via the joint part Q51, and Gear +1: L, 041 is stored and the third
The hemispherical upper cover 〇〇 rotates around the rotation axis of the gear (11) due to the rotation of the bevel gear (old), and the F cover (15
1 is rotatably engaged with the sixth bevel gear! The rotating shaft of I41 is rotatably supported by the upper cover 〇G, and the rotating shaft of the sixth bevel gear ① and the wrist are connected through a joint portion (1a').

[Problem that the invention seeks to solve]

Therefore, the robot wrist described above can obtain three degrees of freedom: rotation by the first roll axis (6), rotation by the third bevel gear (111), and rotation by the sixth bevel gear + 141. The rotation is rolling.

It is a combination of pitching, yawing, and rolling, and because these three rotation axes are not orthogonal, there is a problem that calculations are extremely complicated and time-consuming when calculating the control position and angle of the robot wrist.

Therefore, as shown in Figure 10, the first link (+71
A rectangular frame 181 is rotatably supported at the tip of the frame, and a first vertical shaft is rotatably supported at the center of the frame. A joint in which a second link is connected to a second shaft that is rotatably connected is also considered, and this joint has three degrees of freedom between the support axis of the frame α (to) and the first
．． The 2nd m body (19+, t2111 is a combination of pitching, yawing, and rolling, respectively, as rotation axes, but in this case, the pitching is ±90° or more, and the rolling is ±180°, which is sufficient rotation angle. On the other hand, there is an inconvenience that the second rolling motion range is limited during yawing.

[Means for solving problems]

This invention has been made to address the above points.
In a multi-degree-of-freedom joint for a manipulator consisting of a plurality of elements connecting a first link and a second link of a manipulator, one of the elements has an arc shape slidably attached to the tip of the first link. This is a multi-degree-of-freedom joint for a manipulator, characterized by a sliding body.

[Effect]

Next, to explain the operation of the present invention, the sliding body provides one degree of freedom, and in combination with other well-known components, rotation and rotation provide at least three mutually orthogonal degrees of freedom: pitching, yawing, and rolling.
A joint with an axis is constructed.

[Embodiment] Next, FIGS. 1 to 7 showing embodiments of the present invention will be described.

First, FIGS. 1 to 4 showing one embodiment will be explained.

@ In Figure 1, the circle is a support guide with a U-shaped cross section as shown in Figure 3, which is provided at the tip of the first link of the manipulator, and □□□ is a guide? Guide Q
A slide body as an arc-shaped pitching element is slidably attached to 11, (241 is a fixed shaft with both ends fixed to the inside of the slide body, or a well-known fixed shaft provided at the center of the fixed shaft). The yawing and rolling element with the configuration shown in FIG. The second link (to) slides, the second link (to) pitches, and the second link (to) yaws and rolls depending on the element side, thereby providing a joint with three degrees of freedom.

At this time, by fixing the fixed shaft (24I off to the opening side from the center of the slide body),
Due to this slide, the pitching range of the second link crane becomes ±90° or more, the yawing range also becomes ±90° or more, and the rolling range becomes ±180°.

In addition, as shown in FIG. 4(a), the curved joints are connected to the pitch axis [F
] When used in the wrist part of a robot manipulator, the joint part has a rotation axis with three degrees of freedom that is perpendicular to each other, so the roll axis ■ is When considering the origin of the coordinates, the second link (to) between the pitch axis [F] and the XY plane
can be easily set parallel to the X axis by simply setting the pitch angle of the joint part to -(θ, +03) and the yaw angle to 10. can be calculated very easily.

Alternatively, as shown in FIGS. 5 and 6, an arcuate slide body slope having a U-shaped cross section may be engaged with the large diameter portion of the tip of the first link so that it can slide freely. .

Furthermore, as shown in Fig. 7, two pairs of drive rollers 4 are attached to the tip of the first link, and an arc-shaped slide body □□□ is held between each pair of roller surveyors and slid. Good too.

〔Effect of the invention〕

Therefore, according to the multi-degree-of-freedom joint for a manipulator of the present invention, since one degree of freedom for pitching is given by the sliding bodies E, el'Q, and 13 Pitching even when jointed.

The rotational range of yawing can be set to ±90' or more, and the rotational range of rolling can be set to ±180°, and the effect is remarkable.

Furthermore, since it is possible to construct a joint with a rotation axis of pitching, yawing, and rolling having three degrees of freedom that are orthogonal to each other, the calculation of the control, I[1 position, and angle of the second link (to) is shown in Figure 9. , can be carried out much more easily than in the case of FIG.

[Brief explanation of drawings]

Figures 1 to 7 show an embodiment of the multi-degree-of-freedom joint for a manipulator according to the present invention, and Figures 1 to 4 show one embodiment. Figure 1 is a perspective view, and Figure 2 is a partial Perspective view of 3rd
The figure is a cutaway plan view of FIG. 2, FIGS. 4(a) and 4(b) are operation explanatory views, FIGS. 5 and 6 are perspective views and cutaway plan views of a part of other embodiments, and FIGS. The figure is a front view of still another embodiment, and FIGS. 8 to 10 respectively show conventional multi-degree-of-freedom joints for manipulators.
Figure (a) is a configuration diagram, Figure (b) is a front view, and Figure 10 is a perspective view. 21)... Support guide, Zeng... First link, within
@. (Support)...Slide body, inscription...Second link. J slide

Claims (1)

[Claims] (1) In a multi-degree-of-freedom joint for a manipulator consisting of a plurality of elements connecting a first link and a second link of a manipulator, one of the elements is slidably attached to the tip of the first link. A multi-degree-of-freedom joint for a manipulator, which is characterized by a sliding body with a curved arc shape.