JPH0468109B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an industrial robot used for painting, sealing, welding, etc., curved workpieces such as car doors and bodies, and particularly relates to industrial robots used for painting, sealing, welding, etc. Regarding the shaft configuration.

[Conventional technology]

Industrial robots can be classified based on their operating modes into polar coordinate systems, cylindrical coordinate systems, articulated coordinate systems, and orthogonal coordinate systems. Among these, the joint shape is
The ratio of the operating range to the occupied area is large;
It has advantages such as being easy to reduce weight and easy to take dust-proof measures. For this reason, articulated robots are widely used for tasks such as welding, assembly, handling, and deburring.

FIG. 4a shows the axis configuration of a typical conventional articulated robot, which includes three basic axes: a lower arm tilting axis 2 and an upper arm tilting axis 3 provided on the rotation axis 1, and the upper arm tilting axis 3. The wrist 4 has a biaxial or triaxial configuration and operates at the tip of the wrist. A processing tool 5 such as a paint spray nozzle or a welding torch is attached to the wrist 4.

[Problem that the invention seeks to solve]

By the way, in a robot having a conventional shaft configuration as shown in FIG. 4a, when an attempt is made to perform work with the arm extended, even if the rotation axis 1 is rotated as shown in FIG. 4b, There was a problem in that the processing tool 5 at the tip could only move within the range indicated by arrow A, resulting in a narrow operating range.

Furthermore, when using the robot shown in Figure 4a to perform work by approaching an area with a curved surface, such as a car door or body, the one-dash line shown in Figure 4a A case is assumed in which it is necessary to swing the processing tool 5 in the posture shown in FIG. When swinging the machining tool 5 in this posture, the turning motion of the turning shaft 1 is used. At this time, since the central axis of the turning movement coincides with the axis of the turning shaft 1, as shown in part B of FIG. 4c, the rear end of the lower arm tilting shaft 2 is There was a problem in that the machine collided with a part of the workpiece or a fixed structure such as the wall surface 6, which prevented the machining operation from being performed as instructed and also caused damage to the workpiece or the wall surface 6.

In this way, in the robot having the shaft configuration shown in FIG. 4, the lower arm tilting axis 2 and the upper arm tilting axis 3
Since the center of rotation of the rotation axis 1 is fixed regardless of the angle of This inevitably creates problems of interference.

The present invention has been made in view of such conventional problems, and provides a robot axis configuration that can expand the working range and also eliminate the problem of interference with workpieces or problem structures. The purpose is to

[Means for solving problems]

In order to achieve this object, the shaft structure of the robot of the present invention includes a fixed base and a lower arm tilting shaft that is tiltably connected to the fixed base, and the upper arm is tilted and rotated about the lower arm tilting shaft. A tilting axis is provided, and the pivot axis of the upper arm tilting axis and the longitudinal direction of the upper arm tilting axis 27 are perpendicular, and the tilting center of the upper arm tilting axis is arranged around the pivot axis of the upper arm tilting axis. The lower arm tilting axis is located closer to the lower arm tilting axis than the disc-shaped locus area formed by the turning movement of the lower arm.

[Effect]

In the present invention, instead of providing a lower arm drive shaft on a rotation axis as in the past, a rotation means is provided on an upper arm fixed shaft that is tiltably provided on a lower arm tilting axis that is tiltably connected to a fixed base. I am trying to set it up. When the processing tool attached to the wrist at the tip of the upper arm tilting shaft is to be swung, the turning means is driven. As a result, the processing tool at the tip of the upper arm swings about the pivot axis perpendicular to the longitudinal direction of the upper arm drive shaft. The operating range of the processing tool due to this swinging can be maintained within a certain range regardless of the magnitude of the inclination angle of the lower arm tilting axis. Moreover, since the turning means for performing this swinging is provided between the lower arm tilting axis and the upper arm tilting axis, the lower arm tilting axis itself has no relation to the turning operation. This also solves the problem of interference in which the rear end of the upper arm tilting shaft collides with a fixed structure. In addition, since the center of tilt of the upper arm tilt axis is always at a position away from the disk-shaped locus area created by the rotation movement of the upper arm tilt axis,
The upper arm tilting axis does not interfere with the tilting center, making it possible to widen the range of motion. Furthermore, since the longitudinal direction of the upper arm tilting axis and the rotation axis are perpendicular and constant, the upper arm tilting axis can be rotated (swinging) with a constant radius of rotation regardless of the angle between the upper arm tilting axis and the lower arm tilting axis.
can be done.

〔Example〕

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings.

FIG. 1 is a side view showing a first embodiment of the present invention. In the figure, a fixed base 21 is fixed to a fixed seat 20, and a lower arm tilting shaft 22 is connected to the fixed base 21 so as to be tiltable. This lower arm tilting shaft 22 is driven by a lower arm tilting motor 23. An upper arm fixing shaft 24 is connected to the tip of the lower arm tilting shaft 22 so as to be tiltable by an upper arm tilting motor 25 . Further, the upper arm fixed shaft 24 is provided with an upper arm tilting shaft 27 that is driven to rotate by an upper arm rotation motor 26 . The upper arm tilt axis 27 and the pivot axis are perpendicular to each other. A wrist portion 28 is provided at the tip of this upper arm tilting shaft 27;
A processing tool 29 is attached to 8. In the figure, 30 is a wrist rotation motor for rotating the entire wrist 28, 31 is a wrist tilting motor for tilting the wrist, and 32 is a wrist for rotating only the tip of the wrist that holds the processing tool 29. This is a motor for rotating the tip.

In such a configuration, the upper arm rotation motor 2
6 is reciprocated, the upper arm tilting shaft 27 swings about the upper arm rotation axis, and the processing tool 29 can swing. At this time, since the upper arm rotation axis and the upper arm tilting axis 27 are perpendicular, the upper arm tilting axis 27 can be swung at a constant radius of rotation regardless of the angle between the upper arm tilting axis 27 and the lower arm tilting axis 22. can.

FIG. 2 shows the left and right swinging state of the upper arm tilting shaft 27. Since the center of swing of the upper arm tilting shaft 27 is the axis of the upper arm fixed shaft 24, the rear end of the upper arm tilting shaft 27 swings. is small and the workpiece or fixed structure 18
There will be no more collisions.

At this time, the upper arm tilting axis 27 is adjusted so that the axis of the upper arm tilting axis 27 is approximately parallel to the axis of the lower arm tilting axis 22.
Even if the upper arm tilting shaft 27 is extended, the upper arm tilting shaft 27 can be rotated around the upper arm pivoting axis by the drive of the upper arm rotating motor 26, so that a sufficient operating range of the processing tool 29 attached to the tip of the upper arm tilting shaft 27 is ensured. be able to. Conversely, even when working with the upper arm tilting shaft 27 retracted in a dogleg shape relative to the lower arm tilting shaft 22, interference can be prevented due to the small swing of the rear end of the upper arm tilting shaft 27. You can expect good results.

FIG. 3 shows a second embodiment of the present invention, in which the lower arm tilting shaft 22 in the embodiment of FIG. 1 can be rotated by a lower arm tilting shaft rotation motor 33. Thereby, the lower arm tilting shaft 22 and the upper arm tilting shaft 27 can be driven to rotate independently, and the operating range of the processing tool 29 can be expanded.

〔Effect of the invention〕

As explained above, in the present invention, the shaft of the robot is provided with a fixed base and a lower arm tilting shaft that is tiltably connected to the fixed base, and is tiltable and rotatable about the lower arm tilting shaft. Provides an upper arm tilting axis,
and the rotation axis of the upper arm tilting axis is perpendicular to the longitudinal direction of the upper arm tilting axis, and the tilting center of the upper arm tilting axis is rotated by the rotational movement of the upper arm tilting axis about the rotation axis. It is configured to be located closer to the lower arm tilting axis than the disc-shaped locus area that is formed.

As a result, when swinging the upper arm tilt axis,
It becomes possible to rotate the upper arm tilting axis with respect to the lower arm tilting axis. Since this turning movement is performed around the base end of the upper arm tilting shaft, it is possible to operate the processing tool at the tip of the upper arm tilting shaft over a wide range even when the upper arm tilting shaft is extended.

Furthermore, even when the upper arm tilting axis is retracted and swung, the base end of the upper arm tilting axis does not swing significantly due to the rotational movement, eliminating the problem of interference with the workpiece or fixed structure. Ru. Therefore, according to the present invention, the operating range can be expanded compared to the conventional basic shaft configuration, and the problem of interference with a workpiece or a fixed structure can be solved. Furthermore, the tilting center of the upper arm tilting axis is always located at a position that is outside the disc-shaped locus area created by the upper arm tilting axis through its rotational movement, so the upper arm tilting axis does not interfere with the tilting center and the range of motion is limited. Can be made wider. Furthermore, since the longitudinal direction of the upper arm tilting axis and the rotation axis are perpendicular and constant, the upper arm tilting axis can be rotated (swinging) with a constant radius of rotation, regardless of the angle between the upper arm tilting axis and the lower arm tilting axis. ), making control easier.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of the first embodiment of the present invention, FIG. 2 is an explanatory view showing its operating range, FIG. 3 is a side view showing the configuration of the second embodiment of the present invention, and FIG.
The figure is an explanatory diagram of a conventional articulated robot. 18: Work or fixed structure, 20: Fixed seat,
21: Fixed base, 22: Lower arm tilting axis, 23: Lower arm tilting motor, 24: Upper arm fixed axis, 25: Upper arm tilting motor, 26: Upper arm rotation motor, 27:
Upper arm tilting axis, 28: Wrist part, 29: Processing tool,
30: Wrist rotation motor, 31: Wrist tilting motor, 32: Wrist tip rotation motor, 33: Lower arm tilting axis rotation motor.

Claims (1)

[Claims] 1 comprises a fixed base 21 and a lower arm tilting shaft 22 that is tiltably connected to the fixed base 21, and an upper arm tilting shaft 2 that is tiltable and rotatable on the lower arm tilting shaft 22.
7, and the pivot axis of the upper arm tilting shaft 27 is perpendicular to the longitudinal direction of the upper arm tilting shaft 27, and the tilting center of the upper arm tilting shaft 27 is aligned with the pivot axis of the upper arm tilting shaft 27. The lower arm tilting axis 2
A shaft configuration of an industrial robot characterized by having a configuration located on two sides.