JPH0244678B2 - 3JIGENYODOKIKO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a three-dimensional swing mechanism that is effective for use in, for example, a wrist device for arbitrarily changing the posture of an end effector in an industrial robot.

For example, in a wrist device for an industrial robot, in order to control the posture of the end effector of the robot, it is necessary to give the wrist three degrees of freedom.
An example of this type of robot is the one shown in Figure 1. That is, a rotating base 2 is supported on the base 1 so as to be rotatable around a vertical axis (α ₁ direction), and the rotating base 2
At the top, there is a _first
A rotating arm 3 is supported, and a second rotating arm 4 is supported at the tip of the arm 3 so as to be rotatable in the α ₃ direction (same direction as the α ₂ direction), and furthermore, a second rotating arm 4 is supported at the tip of the arm 4 so as to be rotatable in the α ₄ direction. The first rotating member 5 is supported so as to be rotatable in the α ₂ direction (same direction as the α 2 direction), and furthermore, the first rotating member 5 is supported so as to be rotatable in the α ₅ direction (around an axis perpendicular to the α ₄ axis). Second rotating member 6
is supported in the α ₆ direction (α ₅
There is an articulated arc welding robot in which a holding member 7 of an end effector (for example, welding torch T, etc.) is supported rotatably around an axis perpendicular to the axis, and the α ₄ to _{α 6} axes are It corresponds to a wrist device.

In this case, in order to reduce the inertia of the robot and improve positioning accuracy, or to avoid providing protrusions on the wrist, all drive sources for the α ₄ to _{α 6} axes are generally attached to the arm 4. , is configured to drive the α ₄ to _{α 6} axes via appropriate power transmission mechanisms. However, the power transmission mechanism has a complicated structure and is heavy.

This invention was made in view of the above-mentioned circumstances, and aims to provide a three-dimensional rocking mechanism with a simplified power transmission mechanism.

Examples will be described in detail below. Although this embodiment will be described as a three-dimensional swing mechanism M utilized in a wrist device of an arc welding robot, the present invention is not limited to this embodiment.

11, 12, and 13 are a first pivot support 11a, a second pivot support 12a, These are the first arm, the second arm, and the third arm supported by the third pivot 13a. Each drive source for each arm 11 to 13 is
Although not shown, it is attached to the support member 4.

14 is a rotatable fourth pivot support 14 at the tip of the arm 11;
It is the fourth arm with a shape.

15, a fifth pivot support 15 is rotatably provided at the tip of the arm 12;
It is the fifth arm with a shape.

16, a sixth pivot support 16 is rotatably provided at the tip of the arm 13;
It is the 6th arm with a shape.

17, a seventh pivot 17a at the tip of the arms 14 to 16;
It is an annular rocking body having an eighth shaft supported 17b and a ninth shaft supported 17c.

Note that each axis 11a, 12a, 13a, 14a, 1
5a, 16a, 17a, 17b, and 17c are set so that their respective axial center lines intersect at one point _O1 .

The three-dimensional swing mechanism M of this embodiment is constituted by the above items 11 to 17.

The holding member 7 of the torch T is attached to the swinging body 17.

Furthermore, the operation of this embodiment will be described.

The α ₁ to _{α 3} axes and the axes 11a to 13a are driven through a control device (not shown) to control the position and attitude of the torch T with respect to the welding line of the workpiece, especially when controlling the attitude of the torch T. I will explain about it.

Assume now that the mechanism M is in the state shown in FIG. 2, that is, the arms 11 to 13 are in positions spaced apart from each other by 120 degrees.

Therefore, in the state shown in Fig. 2, if arm 12 is rotated counterclockwise by a certain angle while arms 11 and 13 are fixed, the oscillator 17 will oscillate around point _O1 , as shown in Fig. 3. is displaced into a posture.

In addition, in the state shown in FIG. 2, if arm 11 is rotated counterclockwise by a certain angle while arms 12 and 13 are fixed, oscillator 17 will oscillate about point _O1 ,
It is displaced into the posture shown in Figure 4.

Fix any two arms like this and move the other one.
You can rotate arms 11, 12, or 13, or fix any one of arms 11 to 13 and rotate the other two at the same time, or even rotate arm 1.
By rotating all 1 to 13,
It will be obvious that the oscillator 17 oscillates around the _O1 point and can change the torch T to any desired position.

Note that if all the arms 11 to 13 are simultaneously rotated in the same direction at the same angular velocity, the oscillating body 17 will not oscillate and the torch T will rotate around the shafts 11a to 13a.

The above description is an example of a wrist device in which the shafts 11a to 13a are configured on the input side and the swinging body 17 is configured on the output side. If configured as a side, three axes can be controlled with one lever, and it can also be used as an operating lever device. It goes without saying that the technical scope of the present invention also includes the replacement of each component with equivalents.

Since the swinging mechanism M of the present invention is configured as described above, if it is used in a wrist device of an industrial robot with its shafts 11a to 13a on the input side and the swinging body 17 on the output side, the wrist device can be used as a conventional wrist device. It is smaller, has a simpler structure, and is lighter in weight than the previous model, and is highly effective. On the other hand, the oscillator 17 is placed on the input side, and the shaft 1 is placed on the input side.
If this mechanism M is used as an operating lever device with 1a to 13a on the output side, three axes can be controlled with one lever, making it extremely effective as an operating lever device.

[Brief explanation of the drawing]

Fig. 1 is a schematic illustration of a conventional industrial robot (articulated arc welding robot), Figs. 2 to 4 each show an embodiment of the present invention, and Fig. 2 shows a wrist of the arc welding robot. FIGS. 3 and 4 are partially cutaway perspective views when used in an apparatus, and FIGS. 3 and 4 are perspective views for explaining the operation. In the figure, M... three-dimensional swing mechanism, 4... support member, 11... first arm, 11a... first shaft, 12... second
Arm, 12a...second axis, 13...third arm, 13a...third axis, 14...fourth arm, 14a...fourth axis, 15...fifth arm, 15a...fifth axis, 16...sixth arm, 16a...
6th axis, 17... Rocking body, 17a... 7th axis, 17b
...8th axis, 17c...9th axis, O ₁ ...point.

Claims (1)

[Claims] 1 first, second, and third shafts coaxially supported separately and rotatably relative to the support member;
a third arm, a fourth arm rotatably supported on a fourth axis at the tip of the first arm, and a fifth arm rotatably supported at the tip of the second arm.
a sixth arm rotatably supported at the tip of the third arm; and a seventh, eighth, and ninth arm supported at the tips of the fourth, fifth, and sixth arms. a three-dimensional rocking mechanism, wherein the first to ninth axes are set such that their axial center lines intersect at one point.