JPH06218688A - Positioning error absorbing device - Google Patents

Abstract

PURPOSE:To offset the reaction force between parts due to the positioning error absorbing operation by supporting a body part and a hand holding part in a relatively horizontal shift or turnable manner by the rolling contact between a doughnut shaped ring and steel ball train having a holding ring. CONSTITUTION:When a fluid is supplied inside a cylinder part 3 from a fluid feeding hole 14, a piston 20 is pushed up against an urging body 25, and a steel ball 30 for engagement is engaged with the recessed part 1a of a conical piece 8 by the pressing piece 29 of a pushing member 22, and a body 1 and a hand installation part 2 are fixed in a coaxial form. When the applied fluid pressure is released, the pushing member 22 and the piston 20 are pushed back by the urging force of the urging body 25, and the steel ball 30 for engagement is set free, and the body part 1 and a hand installation part 2 can be shifted in the radial direction. Since at this time, the hand installation part 2 is in a rolling contact state with the steel balls 31 and 32 having holding rings, the shift in the horizontal direction or twist direction in the position deflection absorbing operation can be carried out even by a small force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning error absorbing device, and more particularly, in a robot, an automatic assembling machine or the like, it absorbs an error between a horizontal direction and a twisting direction in a position between parts to be assembled, and smooths it. The present invention relates to a positioning error absorbing device that can perform operations such as simple insertion and extraction.

[0002]

2. Description of the Related Art Conventionally, as a positioning error absorbing device of this type, the elasticity of a rubber member or the like is used to absorb a position / orientation error between assembled parts due to elastic deformation. There is known a configuration in which an elastic state is generated by an urging unit and a positional deviation is absorbed against the urging force. Further, according to this configuration, it is possible to absorb the error between the horizontal direction and the twisting direction in the position between the assembled parts.

[0003]

However, the above-mentioned positioning error absorbing device has the following problems. In other words, the pressure caused by abutting / contacting between parts causes elastic deformation to perform the positional deviation absorption operation, so the reaction force that acts between both parts in proportion to the positional deviation amount to maintain the return state. Increase in productivity, causing tilting of parts, occurrence of defects due to prying or galling, mechanical damage, poor product quality, loss of assembly time, and the like, resulting in reduced productivity. Since the structure absorbs the position due to elastic deformation, a comparatively large part holding force at the hand part such as the gripper is required, and there is a large difference in the allowable load capacity due to elastic deformation in the compression direction and the tension direction. is there.

The present invention has been made in response to the above-mentioned problems, and its purpose is to make a robot, an automatic assembly machine, etc. irrespective of the amount of positional deviation between the assembled parts. It is an object of the present invention to provide a positioning error absorbing device which is capable of absorbing the positional deviations in the horizontal direction and the twisting direction with a small constant reaction force and increasing the allowable withstand load of compression and tension, and which is mechanically simple.

[0005]

A positioning error absorbing device of the present invention as a means for achieving the above object includes a main body portion having a fitting space inside of which a lower portion opens.
A hand gripping portion that fits into the fitting space, and a cylinder portion that includes a piston that vertically moves by fluid pressure and a pressing member are provided inside the hand gripping portion, and a concave portion is formed in a flange portion of the main body portion. An engaging steel ball is inserted between the recess and the pressing member, and donut-shaped rings are respectively provided on the main body and the hand grip in the fitting space, and a holding ring is provided between the donut-shaped rings. A steel ball row with an attached body is provided, and the main body part and the hand gripping portion are relatively horizontally moved or rotated by rolling contact between the donut-shaped ring and the steel ball row with a holding ring, and by supplying / discharging a fluid, The engaging steel ball and the recess are engaged with each other.

[0006]

In the positioning error absorbing apparatus of the present invention, since the hand mounting portion is supported by the steel ring row with the retaining ring, the load resistance becomes large in both the compression direction and the pulling direction operation, and the misalignment absorbing operation is performed. Since the horizontal and twisting movements at this time are performed by rolling contact of the steel ball rows, the reaction force between the components due to the positioning error absorbing operation is almost eliminated.

Further, an extra load in the radial direction and the slight direction due to the deformation caused by the elastic body which has conventionally been generated is not applied to the hand gripping portion, and the gripping force of the hand gripping portion depends only on the weight and size of parts. Since the device can be selected, the device can be downsized and the cost can be reduced, and the problem that the conventional problems such as the inclination of the component, the prying or the galling can be solved can be eliminated.

Therefore, according to the present invention, in a robot, an automatic assembly machine or the like, the positional deviation in the horizontal direction and the twisting direction is absorbed by a constant small reaction force regardless of the positional deviation between the assembled parts, Moreover, it is possible to provide a positioning error absorbing device which has a large allowable load capacity for compression and tension and which is mechanically simple.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are as follows.
1 shows an embodiment of the present invention, FIG. 1 is an overall vertical sectional view of a positioning error absorbing mechanism, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a sectional view taken along the line BB of FIG.

The positioning error absorbing device of this embodiment is a positioning error absorbing device for an industrial robot, and is roughly mounted between the arm a and the hand b of the industrial robot, The hand grip portion 2, the cylinder portion 3, and the error absorbing portion 4 are provided.

The main body 1 is attached to the arm a of an industrial robot via a mounting screw or the like, and is a main body for transmitting the driving force of the arm a to the hand b. And an inner cylinder member 6, and a fitting space 7 for mounting the hand grip 2 is formed therein. The flange member 5 has conical pieces 8 and 8 having a conical groove 1a in the central peripheral portion thereof, and a donut-shaped ring 9 projecting into the fitting space 7 at the outer portion thereof. It is embedded. Further, the inner tubular member 6 has a tongue portion 10 that is inwardly directed downward.
The tongue portion 10 has a donut-shaped ring 11 protruding into the fitting space 7.

The hand gripping portion 2 is composed of a hand attaching member 12 such as a gripper and a fitting member 13, a cylinder portion 3 is provided at the center, and a space between the inner cylinder member 6 and the fitting member 13. The error absorbing section 4 is provided in the. The hand attachment member 12 is provided with a fluid supply hole 14 that communicates with the cylinder portion 3. Further, the fitting member 13 has an upper member 15 and a lower member 16, and the upper member 15 and the lower member 1
6, a donut-shaped ring 17 is embedded between the ring 9 and the ring 11 so as to project into the error absorbing portion 4. Further, the upper member 15 has a pin member 18, is provided on the flange member 5, and is a circular recess 1 larger than the pin member.
9 is fitted and engaged.

The cylinder portion 3 includes a piston 20 with an O-ring.
The O-ring-equipped piston 20 has a rod 21 and a pressing member 22, and is connected by a biasing body (spring) 25 to a piston support member 24 that is fixed to the hand attachment member 12 via a C-shaped retaining ring 23. ing. Further, the piston 20 is configured to be slidable on the hand attachment member 12 via an O-ring 26, and an oil-free bearing 27 is provided between the rod 21 and the piston support member 24. The pressing member 22 has a pressing piece 29 into which the cylindrical hole 28 provided in the upper member 15 is fitted, and the engaging steel ball 3 is provided between the pressing piece 29 and the conical pieces 8, 8.
0, 30 ... Are inserted. Here, the maximum outer diameter of the engaging steel balls 30, 30, ...
It is inserted so as to be located below the uppermost part of the cylindrical hole 28.

The error absorbing portion 4 includes upper and lower retaining ring steel balls 31, 31, ..., 32, 32.
1, 17 and engaging steel balls 30, 30 ... Steel balls with retaining ring 31, 31, ...
The steel balls 32, 32, ... Provided between the ring 9 and the ring 17 and having the retaining ring are the ring 17 and the ring 11.
It is provided between and.

In the positioning error absorbing device of the present embodiment based on the above structure, after the fluid supply source is connected to the fluid supply hole 14, the fluid (here, air is used).
Is supplied to the inside of the cylinder portion 3 from the fluid supply hole 14, the piston 20 is pushed up against the urging body 25 by the fluid pressure of the fluid, and the engaging steel ball is pushed by the pushing piece 29 of the pushing member 22. By engaging 30, 30, ... With the concave portions 1a of the conical pieces 8, 8 ,.
And the hand attachment part 2 are fixed with the same axis. And
When the applied fluid pressure is released during the operation of absorbing the positional deviation between the parts to be assembled, the pressing member 22 and the piston 20 are pushed back by the urging force of the urging body 25, and the engaging steel balls 30, 30, ... · Indicates a free state, and the main body 1 and the hand mounting portion 2 are movable in the radial direction.

At this time, the hand attaching portion 2 has the rings 9, 1
Steel ball row 31 with two retaining rings sandwiched between 1 and 17
··································································. In addition, during the process of inserting or pulling out a part by a robot or an assembly machine, when the part held by this device and the other part to be assembled come into contact with each other or gripper gripping is started, the fluid is supplied to the inside of the cylinder part 3. By stopping and releasing, misalignment and twist existing between both parts are absorbed and corrected by parallel movement or twist movement in the direction of 360 °,
You can perform smooth insertion and extraction work.

The present invention is not limited to the above-described embodiments, but includes configurations that can be modified and implemented within the scope of the present invention.

[0018]

As is apparent from the above description, according to the positioning error absorbing apparatus of the present invention, since the hand attaching portion is supported by the steel ring row with the retaining ring, the hand attaching portion is supported in both the compression direction and the tension direction. Since the withstand load increases during operation, and the horizontal and twist movements during the displacement absorption operation are performed by the rolling contact of the steel ball row,
This has the effect of almost eliminating the generation of reaction force between the components due to the positioning error absorbing operation.

Further, according to the positioning error absorbing device of the present invention, an excessive load in the radial direction and the slight direction due to the deformation caused by the elastic body which has been conventionally generated is not applied to the hand gripping portion, and the hand gripping portion is prevented. Since the gripping force can be selected only by the weight and size of the parts, downsizing of the device and cost reduction can be realized, and the problems of the conventional problems such as tilt of parts, prying or galling can be eliminated. Has the effect.

Therefore, according to the present invention, in a robot, an automatic assembly machine or the like, the positional deviation in the horizontal direction and the twisting direction is absorbed by a constant small reaction force regardless of the positional deviation between the assembled parts, Moreover, it is possible to provide a positioning error absorbing device which has a large allowable load capacity for compression and tension and which is mechanically simple.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view showing a positioning error absorbing mechanism according to the present invention.

FIG. 2 is a cross-sectional view showing a positioning error absorption range restriction portion according to the present invention.

FIG. 3 is a sectional view showing a state in which the positioning error absorbing mechanism according to the present invention is locked.

[Explanation of symbols]

a: industrial robot arm, b: hand, 1
... Main body, 1a ... Concave groove (recess), 2 ... Hand gripping section, 3 ... Cylinder section, 4 ... Error absorbing section,
5 ... Flange member, 6 ... Inner cylinder member, 7 ... Fitting space, 8 ... Cone piece, 9 ... Donut-shaped ring, 10 ... Inward tongue portion , 11 ... Donut-shaped ring, 12 ... Hand mounting member, 13 ... Fitting member, 14 ... Fluid supply hole, 15 ... Upper member, 1
6 ... Lower member, 17 ... Donut-shaped ring, 1
8 ... Pin member, 19 ... Circular recess, 20 ...
Piston with O-ring, 21 ... Rod, 22 ... Pressing member, 23 ... C-shaped retaining ring, 24 ... Piston support member, 25 ... Biasing body (spring), 26 ...
..O-ring, 27 ... Oil-free bearing, 28 ... Cylindrical hole, 29 ... Pressing piece, 30 ... Engaging steel ball, 3
1 ... Steel ball with retaining ring, 32 ... Steel ball with retaining ring

Claims (1)

[Claims] 1. A body part having a fitting space with an opening at the bottom, a hand gripping part fitting into the fitting space, and a piston that moves up and down by fluid pressure inside the hand gripping part. And a pressing member having a cylinder portion, the flange member of the main body portion is provided with a concave portion, an engaging steel ball is inserted between the concave portion and the pressing member, and in the fitting space, A donut-shaped ring is provided on the main body and the hand grip, and a steel ring row with a retaining ring is provided between the donut-shaped rings. The main body and the hand grip are connected to each other with the donut-shaped ring and the steel ball row with a retaining ring. The positioning error absorbing device is characterized in that it can be horizontally moved or rotated relatively by rolling contact of the above, and that the engaging steel ball and the recess are engaged with each other by supplying and discharging the fluid.