JPS609699A - Hand device for industrial 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 Recently, attempts have been made to use industrial robots to insert and assemble bars with a small relative gap into holes drilled in parts using a horizontal force of 1. The relative gap between this hole and the rod is extremely small, ranging from several microns to more than ten microns. On the other hand, the repeatability accuracy of industrial robots is generally about plus or minus 50 microns, which is larger than the relative gap between the hole and the bar. However, making the repeat position accuracy of an industrial robot smaller than the relative gap between the hole and the bar material would significantly increase the manufacturing cost of the industrial robot, making it uneconomical.

This invention was made in view of the above-mentioned circumstances, and is particularly designed to absorb the relative misalignment when inserting and assembling a bar whose center position is shifted from the horizontal direction into a hole provided horizontally on the side of a component. The present invention provides a simple hand device for an industrial robot that enables insertion and assembly of bars into holes with small gaps.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In the figure, (1) is the main body of the industrial robot, (2) is an elevating body that is supported by this main body (1) and moves linearly in the vertical direction, (
3) is a first arm that is supported by the elevating body (2) and rotates in a horizontal plane; (4) is a second arm that is supported on the tip of the first arm (3) and rotates in a horizontal plane; (5) ) is a rotation shaft provided vertically at the tip of the second arm (4), and (6
) is an L-shaped fitting fixed to the rotation shaft (5), and the horizontal surface (6
a), consisting of a vertical surface (6b). (7) is an L-shaped bracket (5
) is a misalignment absorber fixed to the vertical surface (6b) of (
7a) is a shaft installed horizontally on the vertical surface (6b) of the L-shaped fitting (6), G'b) is the core iron fixed to the shaft (7a), and (7b+) C'yb2> is The sliding surface (7c) is the case, and the disk-shaped upper plate (7C1
), a lower plate (7et), and a cylindrical peripheral wall (7cs). (7cn) is a hole provided in the center of the upper plate (7c, ), (7d) is a cylindrical rubber etc. that is compressed and inserted between the shaft (7a) and hole 0CU) and fixed with adhesive etc. The elastic body (8) is the lower plate (7c2) of the case (7C).
) is a gripping device fixed on the other side, comprising a pneumatically or electrically driven gripping pawl (8a). (9) is a bar to be gripped by the gripping claw (8a) of the gripping device (8), (9a) is the IJ part consisting of an inclined surface provided all around the tip of the bar (9); Workbench, I is workbench α [
The part (11a) fixed on the top is a hole drilled horizontally in the part (Ill), and (11b) is a mentory part consisting of an inclined surface provided all around the entrance of the hole (11a).

Here, we will discuss the characteristics of the elastic body (7d) in the second section. 3rd゜5th
Explain using diagrams. The elastic body (7d) is uniformly compressed and inserted between the shaft (7&) and the hole (7cu), but the upper end side (7dl) is connected to the case (7C) and the gripping device (8).
) and the weight of the bar (9).

On the other hand, the lower end side (7d2) is the case QC) and the gripping device (8)
And the compressive force is reduced by the weight of the bar (9). To explain this using the graph of FIG. 5, the horizontal axis represents the displacement dimension (δ) of the elastic body (7d), and the vertical axis represents the force (P) required to displace the elastic body (7d). If point A is the zero point when the elastic body (7d) is set, in this case the elastic body (7d) is compressed from point B to point A over the entire circumference, and the compression of Pl occurs in any direction. It has power.

However, as mentioned above, the case (7C) and the gripping device (8
) and the rod (9), the upper end side (7
In d), the compressive force increases to 22 points, and on the contrary, the lower end side (
, 7dt) has decreased to 28 points. In addition, the 23 points must be equal to or higher than zero, and an elastic body (7d) is used to prevent relative displacement between the core iron (7b) and the case (7C) in the set state.
) The compression dimensions and spring constants of

In other words, when the bar (9) is positioned above the hole (lh), the bar (9) is pushed downward with a force of 21 points or more, and
1a). Conversely, insert the bar (9) into the hole (
11a), the bar (9) is pushed upward by 23 points of force and inserted into the hole (1'la). In addition, in the left and right direction, the case (7c), the gripping device (8) and the bar (
Since it is not affected by the weight of the rod (9), the rod (9) is inserted into the hole (11).
If you shift the position from left to right with respect to a), the bar (9
) is pushed to the right and left by the force of point P and is inserted into the hole (11a).

In both cases, the elastic body (7d) is displaced only by the misalignment dimension between the bar (9) and the hole (11a), and the force pushing the bar (8) depending on the displacement dimension is 21 points, 22 points, and From point 28, the upper right side rises along the line drawn by shi.

Next, a state in which the misaligned rod (9) is inserted into the hole (11a) will be explained. Now the elevating body (2) and the first. The second arm (3) (41) is controlled to open the hole (11) as shown in Figure 2.
Even if the center of the bar (9) is shifted by (δ1) relative to &), this misalignment dimension is the main
11b), if the total dimension is less than the total dimension of the first bar (9).
If the second arm (31 (4) and rotating shaft (5) is controlled to enter the hole (11a), the elastic body (7) will be deformed and the bar (9) will be The insertion and assembly operations can be performed by automatically matching the center of the hole (11a).At this time, 22 upward forces are acting on the bar (9).

The mentory dimension of the general processing mentory part (!;'a) (11b) is 0.5 to 1.0 mm, which is much larger than the repeatable positioning accuracy of industrial robots, so it is suitable for industries where the repeatable positioning accuracy is about plus or minus 50 microns. Even robots for
By using the misalignment absorbing device (7), the work of inserting and assembling the rod (9) and the hole (11a) with a small relative gap can be performed reliably.

In the above embodiment, the bar (9) is located below the hole (11B), but the same effect can be obtained no matter where it is located. However, in order to make the insertion work easier and more reliable by reducing the lateral force applied to the bar (9), and to extend the life of each part, the bar (9) is used.
It is desirable to control the elevating body (2) so that the core of the hole (11a) is always located slightly below the core of the hole (11a).

In addition, the compression dimensions and spring constant of the elastic body (7d) were selected to prevent relative displacement between the core iron (7b) and the case (7C) when the bar (9) was set in the gripping claw (8 seconds). Control of the body (2) becomes easier.

Further, although the above example shows the case where the hole and the rod are completely horizontal, the same effect can be obtained even if the hole and the rod are slightly inclined.

Furthermore, if the elastic body (7d) is made of foam rubber or a material with a partially hollow space, the spring constant can be freely selected, and the design of the misalignment absorbing device (7) becomes easy, and the bar material ( 9) and the hole (11a), it is also possible to freely determine the increasing force in the lateral direction that is applied to the bar (9).

As explained above, the present invention aims to facilitate the control of industrial robots by preventing relative displacement between the various parts of the misalignment absorbing device when the bar is set, and to attach the core of the bar to the hole in the center. The rod is positioned slightly below the core of the rod to reduce the lateral force applied to the rod, making insertion work easier and more reliable.In addition, the rod is inserted into the lateral hole to achieve longer service life for each part. The present invention provides a hand device for an industrial robot that inserts and assembles materials.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of a hand device for an industrial robot according to the present invention, and FIG. 2 is an enlarged view of the section ``■'' in FIG. 1, partially showing a cross section. Fig. 6 is a sectional view taken along the line ■-■ in Fig. 2, Fig. 4 is an operation diagram showing the operation status of the misalignment absorbing device when absorbing misalignment between the bar and the hole, and Fig. 5 is a diagram of the operation of the misalignment absorbing device when absorbing misalignment between the bar and the hole. It is a graph showing characteristics. (1)...Industrial robot body, (2)...Elevating body, +31 +4+...1st. Second arm, (5)...
・Rotation axis, (7)... Misalignment absorber, (7B) ・
...Shaft, (7b) ... Core iron, (7e) ... Case, (7d) ... Elastic body, (7d+) ... Upper end, (7d2) ... Lower end, (8 )...gripping device, (
9)...Bar material, (9a)...mentory part, a...
Parts, (11a)...hole, (11b)...mentory part. Agent Masuo Oiwa

Claims (3)

[Claims] (1) A disk-shaped core iron is provided at the other end of the rotating shaft, one end of which is attached approximately horizontally to the tip of the arm, and a ram-shaped case is coaxially surrounded by the core iron. and the rotation shaft, an elastic body for maintaining the relative position of the case and the rotation shaft is installed in a compressed state, and a gripping device is coaxially installed substantially horizontally on the front surface of the case. 7. End device. (2) The hand device for an industrial robot according to claim 1, wherein the elastic body is made of annular rubber. (3) The hand device for an industrial robot according to claim 1, wherein the elastic body has a hollow space inside.