JPS6157158B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an articulated robot. Conventionally, in multi-joint robots such as SCARA robots,
As shown in FIG. 1, the first arm 2 is directly connected and driven by an arm drive shaft 5 connected to a first arm drive motor 4 attached to the base 1. The second arm 3 is directly connected and driven by a drive shaft 7 connected to a second arm drive motor 6 attached to the first arm 2. In this case, the second arm drive motor 6 is attached to the joint, so
A motor with a large mass increases the moment of inertia, and in order to drive something with a large inertia, the first arm drive motor 4 needs a motor with a large power, and in order to support a large motor, However, the arm and joint support inevitably become larger, which hinders miniaturization of the robot, and increases the moment of inertia, which impedes high-speed operation. In order to eliminate these drawbacks, the second arm drive motor 6 as shown in FIG. 2 is installed closer to the rotation center of the first arm 2, and the arm drive member 8 is used as a means of power transmission.
A system using a chain or a timing belt has also been devised, but chains and timing belts have large backlash and reduce accuracy, and it is practically impossible to achieve an accuracy of about 2/100 mm like that of an assembly robot. It was impossible. Another method that uses parallel links for the arm drive member 8 has been put into practical use, but due to the mechanism of the parallel links, the range of rotation is limited, and as a result, the operating range of the robot is limited. It had the disadvantage of being narrowed down.

The present invention has been made to eliminate such drawbacks. An embodiment of the present invention will be explained with reference to FIGS. 3, 4, and 5. FIG. 3 is an overall configuration diagram of an embodiment of the present invention, and FIG. 4 is an arm drive member of FIG. 3. FIG. 5 is an enlarged view of the mounting portion of FIG. 4, and FIG. The first arm 9 has one end fixed to a first arm rotation guide 11 and a joint shaft 17 at the other end, and is driven by a first arm drive motor 12 attached to a base 10. The second arm 13 is fixed to the joint shaft 17 and is attached to the first arm 9 so as to be rotatable about the joint shaft 17, and the first arm rotation guide 11 is coaxial with the first arm rotation center 19.
Second arm drive motor 14 disposed above the
The arm drive shaft 15 and the joint shaft 17 connected to the arm drive shaft 15 and the joint shaft 17 are two parallel arm drive members made of a belt-shaped high constant elastic material.
16 and 16' are suspended and rotatably connected. Two parallel belt-shaped arm drive members 16,1
6' is fixed with a set screw 20 so that the fixed position where it is fixed to the arm drive shaft 15 or the joint shaft 17 and the direction in which it is wound are opposite to each other, as shown in FIGS. 5a and 5b. The structure is such that the rotational movement of the arm drive shaft 15 is reliably transmitted to the joint shaft 17, and the second arm 13 is accurately driven.

In the above configuration, the second arm drive motor 1
4 is located coaxially with the first arm rotation center 19, the increase in the moment of inertia caused by the second arm drive motor 14 can be minimized, and the first arm 9 and joint axis 18 can be made smaller accordingly. This made it possible to reduce the weight and enable high-speed operation. In addition, since the aforementioned two parallel arm drive members are screwed so that the fixing position where they are fixed to the arm drive shaft or the joint shaft and the winding direction in which they are wound are opposite relative positions,
The force applied to the fixed part of the arm drive member is also dispersed compared to when there is only one arm drive member, and as the arm drive shaft rotates, tension is always applied to one of the arm drive members, ensuring rotational movement. The information is transmitted to the joint shaft, and the joint shaft can rotate up to approximately 360 degrees, making it possible to operate at high speeds over a large work range.

In terms of accuracy, the arm drive member is made of a highly constant elastic material (product name: Spron, etc.), which is a high tensile strength material that does not change in temperature, and the rotational movement is ensured by screws instead of mechanical transmission like a belt. Since it is possible to transmit data, highly accurate driving and positioning are possible. In the above description, the arm driving member is described as a band-shaped member, but the same applies to a wire rod or the like.

Further, the fixing method is not limited to screwing, but may also be welding, gluing, caulking, etc.

As described above, according to the present invention, two arm drive members made of high-permanence materials such as strips or wires are suspended in parallel on the arm drive shaft and the joint shaft, and the fixed position and the joint shaft are fixed to the arm drive shaft or the joint shaft. By fixing the windings so that the winding directions are opposite to each other, the force applied to the fixed part of the arm drive member by the rotation of the arm drive shaft is also dispersed, so strong stress is not applied to the fixed part. Strength can be maintained without any stress. In addition, tension is always applied to one of the arm drive members, ensuring that the rotational motion is accurately transmitted to the joint shaft.Furthermore, the joint shaft can rotate up to approximately 360 degrees, allowing reliable and high-precision operation over a large work range. An articulated robot capable of rotation transmission and high-speed operation can be provided.

[Brief explanation of the drawing]

Figures 1 and 2 are conceptual diagrams for explaining a conventional multi-jointed robot, Figure 3 is a schematic diagram of an embodiment of the present invention, and Figure 4 shows the installation of the arm drive member in Figure 3. FIG. 5 is a cross-sectional view of the arm drive member shown in FIG.
-B' cross-sectional view. 1, 10... base, 2, 9... first arm,
3, 13... Second arm, 4, 12... First arm drive motor, 5, 15... Arm drive shaft,
6, 14... Second arm drive motor, 7... Drive shaft, 8, 16, 16',... Arm drive member,
11...First arm rotation guide, 17...Joint axis,
18...Joint part, 19...First arm rotation center,
20... Set screw.

Claims (1)

[Claims] 1 a base 10, a first arm drive motor 12 attached to the base 10, a first arm rotation guide 11 that is locked to the shaft of the first arm drive motor 12, and one end of which is attached to the first arm Rotation guide 11
a first arm 9 fixedly attached to the body and having a joint shaft 17 at the other end; and a second arm drive motor 14 disposed above the first arm rotation guide 11 coaxially with the rotation center 19 of the first arm 9. an arm drive shaft 15 that is locked to the shaft of the second arm drive motor 14; and an arm drive shaft 15 that is fixed to the joint shaft 17 and is rotatably attached to the first arm 9 about the joint shaft 17. In a multi-jointed robot comprising two arms 13 and an arm drive member 16 that transmits the rotational movement of the arm drive shaft 15 to the joint shaft 17, the arm drive member 16 is a belt-shaped or linear high-stability robot. The two arm drive members 16 are made of elastic material and are suspended in parallel on the arm drive shaft 15 and the joint shaft 17, and the two arm drive members 16 are fixed to the arm drive shaft 15 or the joint shaft 17 at fixed positions and windings. A multi-jointed robot characterized in that the robot is fixed so that the winding directions thereof are opposite to each other.