JPH04141392A - Work tool protecting device for industrial robot - Google Patents

Abstract

PURPOSE:To reset a work tool into an original position with extreme accuracy without generating play by providing a reset means for supplying energizing force in the direction of the recessed part of an external force detecting member coinciding with the protruding part of an original position regulating member. CONSTITUTION:When external shock acts upon a work tool, an external force detecting means 3 moves in relation to an original position regulating member 2 while opposing the energizing force of a reset means (spring) 5 to absorb the external shock. When the factor of the external shock is removed after such shock absorbing action, the recessed part 3c of the external force detecting member 3 and the protruding part 2a of the original position regulating member 2 come to coincide with each other by the energizing force of the reset means 5. At this time, there is no clearance at all between the recessed part 3c of the external force detecting member 3 and the protruding part 2a of the original position regulating member 2, nor is play generated, so that the work tool is reset into the original position with extreme accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for protecting the work of an industrial robot, such as a welding torch in a welding robot or a paint spray gun in a painting robot, from external impact. .

[Prior Art] A work tool (welding torch, paint spray gun, etc.) installed at the tip of an industrial robot's manipulator may accidentally collide with an obstacle such as a workpiece during teaching work or regeneration work. If this occurs, the work tool or even the manipulator body may be damaged.

Therefore, in order to prevent damage to work tools and manipulators in such cases, various shock absorbing protective devices (hereinafter referred to as shock sensors) have been proposed.
In such a shock sensor, after the shock sensor performs a shock absorbing operation, it is necessary to accurately return the work tool to its original position (posture position during teaching work) so that the subsequent regeneration operation can be performed accurately. There must be.

As such a shock sensor, for example, Japanese Patent Laid-Open No. 58
There is one described in No.-171279. This conventional technology includes a return home position regulating member provided on the shock sensor body side and an external force detection member that fits into the return home position regulating member. , the external force detection member moves relative to the return home position regulating member and absorbs the impact, while when the action of the external force is removed, the return home position regulating member returns the work tool to its home position via the external force detection member. It is supposed to be done.

[Problems to be Solved by the Invention] However, in such conventional industrial robot work tool protection devices, when the work tool receives an impact, the external force detection member is activated (moved relative to the return home position regulating member). Therefore, a clearance is required between the external force detecting member and the return home position regulating member, which causes backlash, so that there is a problem that the external force detecting member, that is, the work tool cannot be accurately returned to the home position.

The present invention aims to solve such problems,
It is an object of the present invention to provide a work tool protection device for an industrial robot that allows the work tool to reliably return to its original position after a shock absorbing operation and to perform subsequent regeneration operations with high precision.

[Means for Solving the Problems] In order to achieve the object -1-, the industrial robot work tool protection device of the present invention includes: - a convex part to restrict the industrial robot work tool to its original position; the formed in-situ regulating member;
■ An external force detection member to which a work tool is attached and which is formed with a recess that matches the shape of the convex part of the in-situ regulation member; It is characterized in that it is equipped with a return means for causing the action to take place.

[Function] In the work tool protection device for an industrial robot of the present invention described above, when an external impact is applied to the work tool, the external force detection member moves relative to the original position regulating member while resisting the urging force of the return means. However, the external impact is absorbed. After such a shock absorbing operation, when the cause of the external shock is removed, the concave portion of the external force detection member and the convex portion of the original position regulating member are aligned with each other due to the biasing force of the return means. At this time, there is no clearance between the concave part of the external force detection member and the convex part of the original position regulating member, unlike in the conventional case, and there is no play, so the work tool can return to its original position extremely accurately. become one.

[Embodiments of the invention] Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a work tool protection device for an industrial robot as a first embodiment of the present invention. In FIG. A pedestal 2 is an original position regulating member attached to the mounting pedestal l and formed with a convex portion 2a, and the convex portion 2a is shaped like a truncated cone in this embodiment.

Reference numeral 3 denotes an external force detection member, and this external force detection member 3 includes a cylindrical work tool attachment part 3a to which a work tool of an industrial robot (not shown) can be attached, and an outer peripheral shape of the convex part 2a of the original position regulating member 2. It has an enlarged diameter portion 3b having a concave portion 3C that matches. Further, the edge of the enlarged diameter portion 3b is adapted to engage with the groove portion 2b on the outer periphery of the original position regulating member 2, and furthermore, a notch 3d is formed at the edge of the enlarged diameter portion 3b. When the tip of the toggle-end bolt 4 provided on the original position regulating member 2 side engages with the notch 3d, the external force detecting member 3
Rotation around the axis can be restricted in the original position restriction state (state shown by the solid line in FIG. 1).

Reference numeral 5 denotes a tension spring (returning means) that applies a biasing force in the direction of aligning the concave portion 3C of the external force detection member 3 with the convex portion 2a of the original position regulating member 2; It is housed in a hole 3e drilled along. One end of the tension spring 5 is attached to the urging force adjusting member 6, and the other end is connected to the contact piece 8 via a spherical joint 7. Here, the biasing force adjustment member 6 is screwed into the inner periphery of the hole 3e of the external force detection member 3, and by adjusting the screwing position, the biasing force by the tension spring 5 can be adjusted. . The spherical joint 7 is held within the original position regulating member 2, and when the external force detecting member 3 receives an external force and moves as shown by the two-dot chain line in FIG. It rotates around its center point while keeping its position fixed, thereby rotating the contact piece 8.

The contact piece 8 has a spherical part 8a, and a four part 8b is formed in the center of the contact piece 8, which engages with the tip of the actuating piece 9a of the tactile switch 9 in the original position regulation state. Tactile switch 9
is in the on state in the original position regulation state, and the contact piece 8 rotates with the movement of the external force detection member 3, and the four parts 8b
When the tip of the actuating piece 9a comes off, it becomes an OFF state and outputs a stop signal for the industrial robot.

” Due to the dual configuration, when an external impact is applied to the work tool,
While resisting the biasing force of the tension spring 5, the external force detection member 3 detects the contact point between the edge of the enlarged diameter portion 3b and the groove portion 2b of the original position regulating member 2, as shown by the two-dot chain line in FIG. As a fulcrum, it moves relative to the original position regulating member 2, and external shocks are absorbed.

At this time, on the original position regulating member 2 side of the tension spring 5, while the end position of the tension spring 5 is regulated by the spherical joint 7,
According to the movement of the external force detection member 3, the contact piece 8 rotates together with the spherical joint 7. Accordingly, the operating piece 9a of the tactile switch 9 comes off the four parts 8b of the contact piece 8 and comes into contact with the spherical part 8a, the tactile switch 9 is activated, and the industrial robot is stopped.

After such a shock absorbing operation, when the cause of the external shock is removed, the external horn detection member 3 moves from the state shown by the two-dot chain line to the state shown by the solid line in FIG. 1 due to the urging force of the tension spring 5. , the concave portion 3C of the external force detection member 3 and the convex portion 2a of the original position regulating member 2 match and return to the predetermined original position. At this time, there is no clearance between the concave portion 3C of the external force detection member 3 and the convex portion 2a of the original position regulating member 2, and no play occurs, so the work tool returns to the original position extremely accurately. , subsequent playback operations can be performed with high precision.

In addition, when the external force detection member 3 receives a rotating external force with respect to the original position regulating member 2, the cutout portion 3d of the enlarged diameter portion 3b
Then, the torsion end bolt 4 disengages and rides up, causing the external force detection member 3 to be in a tilted state. At this time as well, the tactile switch 9 is activated and outputs a stop signal to the robot.

Next, a working tool protection device as a second embodiment of the present invention will be explained. FIG. 2 is a sectional view thereof.
This embodiment is also constructed almost the same as the first embodiment, but in the first embodiment, the tension spring 5 is used as a return means.
is arranged in the hole 3e of the external force detection member 3, whereas in this second embodiment, the compression spring 5A as the return means is
As shown in FIG. 2, it is arranged outside the external force detection member 3.

In order to arrange the compression spring 5A outside the external force detection member 3 in this way, in this embodiment, a mounting base] is used.

In-situ regulation member 2. A cylindrical spring holding member 10 is provided on the outer periphery of the external force detection member 3.
A compression spring 5A is provided between the expanded diameter portion 3b of the external force detection member 3 and
is retained. In addition, the spring holding member 10 is screwed into the mounting pedestal l via its threaded portion Oa, and by adjusting the threaded position, the compression spring 5
The biasing force caused by A can be adjusted. Furthermore, an opening lOb is formed in the spring holding member 10 so as to allow the external force detection member 3 to tilt when receiving an external force.

Further, in this embodiment, the rod member 14 is fixed to the spherical joint 7 at one end, and the other end is attached to the hole 3e of the external force detection member 3.
The rod member 14 transmits the tilting motion of the external force detection member 3 when receiving an external force to the spherical joint 7, and the contact is made via the spherical joint 7. Piece 8 is adapted to rotate.

With the above-described configuration, the second embodiment of the present invention also provides the same effects as the first embodiment.

A working tool protection device as a third embodiment of the present invention will be explained with reference to FIG. 3. FIG. 3 is a sectional view thereof,
In this third embodiment, a compression spring 5B serving as a return means is arranged within the original position regulating member 2. In other words, the third
As shown in the figure, the compression spring 5B is held between the end surface 2c in the original position regulating member 2 and the spring receiver 11, and is screwed into the spring receiver 11 and the hole 3e of the external lock detection member 3. A biasing force adjustment screw 13 provided at the same time is connected via a wire rope 12. Thereby, by adjusting the screwing position of the screw 13, the urging force by the compression spring 5B can be adjusted.

In addition, the spring receiver 11 side is arranged so as to contact and press the actuating piece 9a of the microswitch 9A in the original position regulation state, so that when the external force detection member 3 is tilted due to external force, the tilting Accordingly, the spring receiver 11 moves to the right in FIG. 3 against the biasing force of the compression spring 5B via the wire rope 12, and the microswitch 9A is activated.

With the above-described configuration, the third embodiment of the present invention can obtain the same effects as the first embodiment, and also eliminates the need for the spherical joint 7, resulting in a simpler configuration.

In the above embodiment, the shape of the convex portion 2a of the original position regulating member 2 is a truncated cone, but the present invention is not limited to this, and the shape of the convex portion 2a of the in-situ regulating member 2 is a truncated cone.
The recess 3c on the external force detection member 3 side is naturally formed to match the shape of the recess 3c.

In addition, by forming the truncated pyramid shape in this way, the external force detection member 3 can be rotated around its axis in the original position regulation state without providing the notch 3d or l/gully end bolt 4 as shown in FIG. It is possible to restrict rotation.

[Effects of the Invention] As described in detail below, according to the industrial robot work tool protection device of the present invention, after the shock absorbing operation, when the cause of the external shock is removed, the external force is detected by the urging force of the return means. The concave part of the member can be matched with the convex part of the original position regulating member, and there is no need to provide a clearance like in the past, so there is no play and the tool can be returned to its original position extremely accurately. This has the effect of allowing subsequent playback operations to be performed with high precision.

[Brief explanation of drawings]

1 to 3 are sectional views showing working tool protection devices for industrial robots as first to third embodiments of the present invention, respectively. In the figure, 1 - mounting pedestal, 2 - original position regulating member, 2a
-Convex portion, 2b-Groove portion, 2C one end surface, 3 External force detection member, 3
a-Working tool attachment part, 3b-Enlarged diameter part, 3c-Concave part, 3d-
Notch part, 3C-hole part, 4-)-gully tip bolt, 5-tension spring (returning means), 5A, 5B-m-compression spring (returning means), 6-biasing force adjustment member, 7-spherical joint , 8-contact piece, 8a-spherical part, 8b-recessed part, 9-tactile switch, 9
A-micro switch, 9a-actuating piece, 10-spring holding member, 10a-screwing part, 10b-opening, 11-spring receiver, 12-wire rope, 13-old force adjustment screw,
14-rod member. Patent applicant: Kobe Steel, Ltd.

Claims (1)

[Claims] an in-place regulating member formed with a convex portion for regulating a working tool of an industrial robot to its in-place position; and an external force sensor having a concave portion to which the working tool is attached and which matches the shape of the convex portion of the in-place regulating member. 1. A work implement protection device for an industrial robot, comprising: a member; and a return means for applying a biasing force in a direction to cause the concave portion of the external force detection member to match the convex portion of the original position regulating member.