JPS6384889A - Robot hand capable of absorbing axial error - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed description of the invention (a) Industrial application field A robot hand that is attached to the end of the arm of a robot that assembles parts or places parts in a predetermined position, and that plays the role of grasping parts, etc. This invention relates to

(b) Problem to be solved by the invention When a robot hand grasps a part and places it in a predetermined position, the reference point of the part, for example, the axis, may be slightly misaligned with the intended reference point of the other party. This may cause inconvenience in assembly and delivery work by robots. In this case, the axial center error is used to accomplish the desired work by absorbing the axial center error on the robot hand side, without relying on position correction control using a sensor or the like.

(c) Tips for solving the problem Even if the axis of the part placed by the robot is slightly misaligned with the target reference point, there is a small amount of movement within the robot hand mechanism that can be followed. This allows the robot to passively imitate the shape and force of its partner, align its axes, and accomplish the desired task. In particular, it is effective to fix the axis of the part gripped by the robot hand at a predetermined position at the initial stage.

(d) Means for solving the problem The robot hand body (1) is the arm end (14) of the robot.
).

One axis (2) is defined on the robot hand body (1), and two elastic bodies A (8) and elastic body B are placed on the axis (2).
(9) and the mounting part (7), and the elastic body A (8)
), a nip A (3) and a nip B (4) are provided so that the elastic body B (9) can be elastically deformed.

The hand axis (10) is connected to the robot hand body (
1), but the hand shaft (10) is still engaged with the hand shaft (10), which is provided with gaps (k), (ke), and (k) to allow a relatively small amount of movement in each direction. Frame (13
) has two holes A (11) and B (12) located on the axis (2), and elastic body A (8) and elastic body B.
(9), that is, at the insertion points of holes A (11) and B (12)
8), the hand shaft 810) and the robot hand body (1) share the axis (2) via the elastic body B (9).

Normally, the hand shaft (10) is supported on the robot hand body (1) by a catch A (5), and when the robot is working, the axial force is applied by the catch B (6). Also, the gap (
h) is extremely small, and due to the gaps (k) and (k), the robot axis (10) is aligned with the axis (2) relative to the robot hand body (1).
), a suitable amount of lateral movement and tilting movement is possible.

A chuck (15) is attached to the end of the robot shaft (10), by means of which parts, such as pins (16), are gripped or released for handling.

(E) A case will be described in which the present invention is used to perform an assembly operation in which a pin is inserted into a hole by a working robot.

This robot hand body (1) is attached to the arm end (14) of the robot, and a chuck (1) is attached to the end of the hand shaft (10).
If there is an eccentricity in the center of the pin (16) and the pin hole (17) when grasping the pin (16) with the pin (15) and inserting it into the pin hole (17), the end of the robot's arm (14) )
Depending on the insertion force on the side and the shape of the chamfered part of the pin (16) or pin hole (17), the shaft end of the pin (16)
7) will be guided to the center. That is, the hand shaft (10) moves to the center of the pin hole (17) due to the deformation of the elastic bodies (8) and (9), allowing insertion of the pin (16).

Also, if there is an inclination angle (f) between the axial direction of the pin (16) and the axial direction of the pin hole (17), the deformation of elastic body A (8) and elastic body B (9) will cause the pin to (16) is guided to the pin hole (17) and can be inserted.

When the hand shaft (10) is not subjected to external force, the elastic body A (
8), due to the restoring force of the elastic body B (9), the axis (2) is always
is determined to be constant, and the axis of the pin (16) on the robot hand is determined.

(F) Specific example based on the present invention FIG. 8 is an example in which the attachment portions of the rod-shaped elastic body A (8) and elastic body B (9) are respectively an attachment portion (■) and an attachment portion (7).

FIG. 9 shows an elastic body in which a tension spring (19) having an initial tension is combined with a cylinder A (18) and a cylinder B (20), and has a restoring force. Particularly in this case, the elastic body can provide a force (base restoring force) to maintain the position of the axis (2) in the restoring state.

Figure 10 shows springs (22), (23) and balls (21), (24).
) onto the conical slopes (25) and (26) to align the axis (
2), and the restoring force (or base restoring force) is given by the pushing force of the balls (21), (24) and the component force by the slopes (25), (26).

Although not explained in the figure, the elastic body is connected to the hand shaft (10).
A structure in which two holes are provided on the robot hand body (1) side is also possible in the present invention.

(G) Effects of the Invention The effects of this robot hand on welding operations involving axis center errors by robots are as follows.

(1) Axial center errors are absorbed and the machine can immediately follow the other party.

(2) Under the self-standing condition where no external force is applied, the axis of the gripped part is determined.

(3) Simple structure, easy installation, and economical.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the present invention. Figure 2: X-Y cross section of Figure 1. Figure 3: YY cross section in Figure 1. Figure 4: Z-Z cross section in Figure 1. Figure 5 State of eccentricity error of parts to be assembled. Figure 6 Operating state when there is an eccentricity error in the parts to be assembled. Figure 7: Operating state when there is an error in the inclination of the parts to be assembled. 8, 9, 10 Specific different embodiments of the present invention. 1 Robot hand body 14 Arm end 2 axis line 15
Chuck 3 nip A 16 pin 4 nip B 17 pin hole 5 catch A 18 cylinder A 6 catch B 19 tension spring 7. ■Mounting part 20 cylinder B 8 elastic body A 21 ball A 9 elastic body B 22 spring A 10 hand shaft 23 spring B 11 hole A 24 ball B 12 hole B 25 slope A 13 frame 26 slope B

Claims (1)

[Claims] The hand axis (10) is connected to the robot hand body (1).
In a configuration in which the two are engaged with respect to one determined axis (2), the axis (2) is connected to the axis (2) by two holes A (11) and B (12) spaced apart on the axis (2). Elastic body A (8) and elastic body B that have elastic restoring force in the direction perpendicular to
(9). When the hand shaft (10) is not subjected to external force, the elastic body A
(8), one defined axis (2) relative to the robot hand body (1) due to the elastic restoring force of the elastic body B (9)
However, when an external force is applied to the hand axis (10), the axis (2) moves with respect to the robot hand body (1) due to elastic deformation of elastic body A (8) and elastic body B (9).
A robot hand that can absorb axial center errors where it can move horizontally and in the direction of inclination in parallel with the robot hand.