JPS5973283A - Multi-joint type robot - 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 more versatile articulated robot. Multi-jointed mouth bots have a wide range of motion compared to the installation location and are fast in operation, so they are widely used in industry.

Conventional configuration and its problems Traditionally, the range of motion of an articulated robot/nod was determined by the configuration and arrangement of degrees of freedom, the motion angle of each degree of freedom, and the center of that motion angle, and it was not easy to change these. Ta. In order to increase the range of motion or change the position with the same degree of freedom configuration, it is necessary to increase the distance between the joints or increase or change the motion angle of the joints, which makes the robot throat large. However, there were disadvantages that it was not easy to deal with, such as the fact that it was complicated and the mechanism was complicated. As a way to avoid this, by curving the robot's arm within the rotation plane,
Although there are robots that have an uncurved arm that has a range of motion that is larger than that of robot throats, there remains a large range of motion that is meaningless from a practical standpoint. This will be explained with reference to FIGS. 2 and 4. First, in FIGS. 1 and 2, the first joint 2. Each of the second joints 3 is rotatable around a vertical axis, and has a built-in motor and encoder (none of which are shown).
It is a joint that is driven independently. The first joint 2 has a fixed base 1. The 8° support post is fixed by bracket 7,
The second joint 3 is connected to the first joint 2 by a first arm 5, and a second arm 6 is attached to the end thereof. A vertical unit 4 is installed at the tip of the second arm 6.

In this conventional example, if the first. If the operating angles of the second joints are respectively ±9o degrees, the operating range of the tip of the second arm will be the area surrounded by the curved line shown in FIG. In this figure, the father point 9 of the cross indicates the rotation center position of the first joint. However, the robot whose operating area is shown in FIG. 3 is not the same as the robot shown in FIGS. This is a case where the distance between the joint 3 and the upper and lower units 4 is the same.

Next, in FIG. 4, the first arm 106 and the second arm 10
6 is a curved curve, and when the first joint 2 and the second joint 3 are at the center of the movement angle, the straight line 107 connecting the first joint and the second joint and the straight line 1α connecting the second joint and the upper and lower units 4 The angle formed is θ.

The other configurations are the same as those of the conventional example described above. Similar to the robot used when describing FIG. 3, the distance between the first joint and the second joint and the distance between the second joint and the upper and lower units are the same, and hereinafter this length will be 2. k 1st. The tip of the second arm of a robot whose first and second arms are curved so that the operating angles of the second joints are ±90 degrees and θ-30 degrees, 46 degrees, 60 degrees, and 90 degrees. The operating ranges are shown in FIGS. 5 to 8, respectively. As is clear from the figure, as θ approaches the maximum angular displacement of 90 degrees from the center of the second joint's motion angle, the practically meaningless motion range displayed on the left side of the figure becomes smaller, and The range of motion used for the task shown in is increased.

As mentioned above, if the arm is not curved at all, or even if the arm is curved, as shown in Figure 4, the practical range of motion is small and it is difficult to actually make the robot do the work. In some cases, it is extremely difficult to arrange objects and parts to be assembled, and as a result, the tasks that robots can perform are quite limited.

OBJECT OF THE INVENTION The present invention solves the above-mentioned drawbacks.It is an object of the present invention to solve the above-mentioned drawbacks. The purpose of this invention is to provide an articulated robot that makes it possible to increase the practical range of motion by facilitating the arrangement of robots, etc., and increasing the tasks that the robot can perform.

Structure of the Invention The present invention provides a plurality of joints whose rotational axes are arranged in parallel, a plurality of arms that connect the plurality of joints so as to be substantially perpendicular to the rotational axis, and one end of the arm. the plurality of joints connected to each other and a strut supporting the arm, and with the plurality of joints at the center of the operating angle, the center of rotation of one joint and the joints on both sides connecting it and the arm is set. This multi-joint robot has a structure in which the angle formed by the two straight lines that connect it almost corresponds to the maximum angular displacement from the center of the operating angle of the joint, and it has the largest practical range of motion, and it is easy to assemble objects and parts. Due to the layout, it is extremely advantageous for introducing Robo Soto.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on FIG. 9. In the figure, 1.2, 3.4, and 7.8 are the same as the conventional examples in FIGS. 1, 2, and 4.

The operating angles of the first and second joints 2 and 3 are ±90 degrees, respectively, and the first arm 206 and the second arm 206 have the first and second joints at the center of the operating angle, respectively. The straight line 207 connecting the first joint and the second joint and the straight line 208 connecting the second joint and the upper and lower units are each tilted within the plane of rotation by 9o degrees, which corresponds to the maximum angular displacement from the center of the operating angle of the second joint. It's curved. The range of motion of the tip of the second arm in this case has the most practical meaning, as shown in FIG. 8 above.

The table below shows the area of the movement range, the longest distance in the radial direction around the rotation center 9 of the first joint, and the longest straight line distance possible within the movement range for the value of θ.

Margin Below In this embodiment, for convenience of explanation, the operating angle of the first and second joints is set to 190 degrees, but the same applies to cases other than ±9Q degrees. Further, although the explanation has been given using an example in which the distance between the first joint and the second joint and the distance between the second joint and the upper and lower units are the same, the same applies to a case where these lengths are different. The range of motion when the distance between the first joint and the second joint is longer is 10.
FIG. 11 shows the range of motion when the distance between the second joint and the upper and lower units is longer. As is clear from these figures, the radius is the absolute value of the difference between the two distances above, and the circle centered on the rotation center of the first joint is excluded from the motion area, so the size of the first joint is taken into consideration. It is more effective to determine the above two distances by

Furthermore, the way the arms are curved is not unique, and can be determined by taking into account interference between the arms and the support, or by rotating only the joints, it is possible to prevent the arms from curving. be.

It goes without saying that the same applies to robots with three or more joints or robots whose joint rotation axes are in a direction other than the vertical direction.

As explained in detail, according to the present invention, in an articulated robot, the practical range of motion is maximized without changing the distance between joints or the motion angle of the joints with the same configuration of degrees of freedom. Therefore, it is possible to provide an articulated robot that is inherently versatile but has improved versatility in a work area.

[Brief explanation of drawings]

Fig. 1 is a front view of the conventional example, Fig. 2 is a plan view thereof, Fig. 3 is a diagram showing the operating range of the conventional example, Fig. 4 is a plan view of another conventional example, and Figs. 5 to 7 are FIG. 8 is a diagram showing the operating range of the conventional example, FIG. 9 is a diagram showing the operating range of the embodiment of the present invention, and FIG.
The figure is a plan view of the articulated robot of the same example, No. 10.11
The figure is a diagram showing the operating range in another embodiment. 2...First joint, 3...Second joint, 8
...... Pillar, 105, 205...1st
Arm, 206...Second arm, 207.208...
...Two straight lines connecting the rotation centers of the joints. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] A plurality of joints whose rotational axes are arranged parallel to each other, a plurality of arms that connect the plurality of joints so as to be approximately perpendicular to the rotational axis, and one end of the arms are connected, and the A structure of two straight lines that has a plurality of joints and a strut that supports the arm, and connects one joint and the rotation centers of the joints on both sides connecting the jointed arm with the plurality of joints at the center of the operating angle. An articulated robot configured such that the angle approximately corresponds to the maximum angular displacement from the center of the operating angle of the joint.