JPH04361891A - Mirror supporting device for laser robot - Google Patents

Abstract

PURPOSE:To form a mirror supporting device in which the deviation of an optical axis due directly to the influence from the deflection of a robot arm caused by a gravitational effect, is not generated in laser beam pipe lines on mirror units provide at joint parts, in the body of an articulated laser robot. CONSTITUTION:The device is constituted in such a manner that the mirror units 24, 28, which, for changing the course of the laser beam are provided at the joint parts 12, 18 at both end of the robot arm 14 on which the deflection is caused due to the gravitational effect of the laser robot, are supported with rotational bearings 40, 50 and made rotatably displaceable around the same axial center as the rotational shaft of the arm 14, and that a laser beam conductor passage 126 to be arranged between both the mirror units 24, 28 is comprised of the pipe lines 127, 128 which is slidably displaceable via a sliding bearing 129. Since the mirror units are displaced in following up the deflection of the robot arm, and the course of the laser beam is maintained on the course of a prescribed optical axis, the working performance of the laser robot is stabilized.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser robot, and more particularly to an improved structure of a support device for a mirror unit provided at each joint inside the laser robot for changing the course of a laser beam.

0002

[Prior Art] Most laser robots have a robot body, which is formed as an articulated arm type robot, and a laser beam is emitted from an external laser beam oscillator through the top or bottom of a rotating body that can rotate around a vertical axis in the robot body. The laser beam is introduced through a conduit, and passes through a laser beam conduit placed inside the robot body and a mirror unit for changing the beam path placed at each joint, and then a laser beam output device installed at the cutting edge. It has a structure in which a laser beam is guided to a laser beam, and the laser beam is emitted from the emitting device to a target to be irradiated with the laser beam. At this time, the mirror unit relies on the turning motion of the joint of the robot arm in order to change the course of the laser beam that has progressed through one laser beam channel to another laser beam channel by reflection on the mirror surface. It is necessary to configure the laser beam path so that it does not deviate from the normal path, and conventional mirror units have been designed to maintain the reflection point of the mirror located on the pivot axis of each joint. A support device is provided.

FIGS. 4 and 5 are partial cross-sectional views showing the internal structure of a laser robot equipped with such a conventional mirror support device, and a schematic diagram illustrating problems caused by the conventional mirror support device. It is a mechanism diagram.

As shown in FIG. 4, the multi-jointed arm laser robot has a rotating body 10 that can rotate around a vertical axis, and a joint 12 at the top of the rotating body 10 that rotates around the horizontal axis W. A first robot arm 14 supported via a rotary bearing 16 so as to be able to pivot in a plane perpendicular to
, a second robot arm 22 supported via a rotary bearing 20 so as to be rotatable about the horizontal axis U at the joint 18 at the tip of the first robot arm 14; A laser beam emitting unit (not shown) is provided via a joint (not shown) at the tip. The laser beam is introduced from an external laser beam oscillator through an appropriate laser beam conduit, for example, into the rotating trunk 10, and is changed course by the mirror 24a of the mirror unit 24 provided at the joint part 12, and is directed to the first robot. The laser beam enters a conduit 26 inside the arm 14, reaches the joint 18 through this conduit 26, and is exposed to mirrors 28a and 30 in a pair of mirror units 28 and 30 provided in the joint 18.
a to the laser beam conduit 32 of the second robot arm 22
It has a configuration in which the laser beam is guided to the above-mentioned laser beam emitting unit through the.

At this time, the conventional mirror units 24, 2
8, 30, etc., each have a fixed structure that is fixedly positioned to the robot arms 14, 22 at joints 12, 18 with bolts and screws. In other words, during the robot assembly process or repair process, the optical axis of the laser beam is precisely adjusted in a predetermined posture of the laser robot, so that the optical path of the laser beam does not shift even when the robot arm rotates. A method is adopted in which a light receiving point and a reflecting point of the mirror unit 24 etc. are arranged on the rotation axis of the mirror, the optical axis of the mirror is adjusted to coincide with the rotation axis, and the mirror is tightened and fixed with a screw. ing.

[0006]

However, as shown schematically in FIG. 5, in particular, the first robot arm 14 of the laser robot has a second robot arm 22, a laser beam emitting unit, etc. on its tip side. Since a mounting structure is provided that is loaded with relatively heavy objects, the load from these heavy objects is applied to the first robot arm 14, causing it to bend. At this time, the laser beam continues to travel along the path passing through the mirror units 24 and 28 in response to the deflection of the robot arm 14, but on the distal end side of the first robot arm 14, the laser beam moves to the position of the mirror unit 28 in accordance with the deflection of the arm. Because of the deviation, the point at which the laser beam is reflected by the mirror unit 28 changes, and the course of the laser beam after reflection deviates from the normal course by δ. As a result, when the laser beam reaches the laser beam output unit via the joint at the tip of the second robot arm 22, the course deviation of the laser beam is further expanded, and as a result, the laser beam is placed at a higher level than the target irradiation target. A problem sometimes arises in that it is not possible to irradiate a laser beam with energy. In other words, the disadvantage is that there is no means provided inside the robot body for following and correcting the course of the laser beam in accordance with the deflection of the robot arm. As a result, there has been a problem in that the performance of laser processing, etc., performed by laser robots cannot be made sufficiently precise.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems in the laser beam path mechanism within the robot body of the conventional laser robot, particularly in the mirror unit support device.

Another object of the present invention is to provide a multi-jointed arm type laser robot body having mirror units at its joints, in which the robot arm, which is deflected by the effect of gravity, is directly affected by the deflection of the laser beam. It is an object of the present invention to provide a mirror support device having a structure that is not comparable to a mirror unit in a conduit.

[0009]

[Means for Solving the Problems] The present invention provides a support device that supports a mirror unit for changing the laser beam course disposed at each joint inside the robot body of a laser robot, which prevents the robot arm from bending due to the gravitational effect. Provided is a support device having a mechanical structure capable of imparting displacement operations of a mirror unit, particularly rotation and expansion/contraction displacement in the axial direction, in accordance with
Therefore, despite the bending of the robot arm, the laser beam always enters and is reflected on the regular optical axis of the mirror unit, and reaches the laser beam output unit via a predetermined course.

That is, according to the present invention, a robot arm having an articulated structure is arranged so as to be rotatable in a plane perpendicular to the ground surface, and is supported by the articulated part at the end of the robot arm. The laser robot is equipped with a mirror unit for changing the course of a laser beam introduced from the outside, and supports the mirror unit in a laser robot that sequentially guides and emits a laser beam introduced from the outside to a state-of-the-art mirror output device through the mirror unit. The mirror support device is coupled to a rotation bearing means for holding the mirror unit at the joint joint so as to be rotatable around an axis coaxial with the rotation axis of the robot arm, and to a beam input end or an output end of the mirror unit. and a beam conduit slidably provided in the longitudinal direction of the robot arm, and a mirror support device for a laser robot, which enables the mirror unit to rotate in a corrective manner according to gravitational deflection of the robot arm. Ru.

[0011] Also, according to the present invention, a robot rotating trunk;
a first robot arm that is rotatable in a plane perpendicular to the ground with a horizontal axis as a pivot axis relative to a first joint provided on the rotating trunk; and a first robot arm provided at the tip of the first robot arm. a second robot arm that is rotatable about a second joint with a horizontal axis as a pivot axis; and a laser coupled to a third joint provided at the tip of the second robot arm. a beam emitting section, a mirror unit for changing the course of the laser beam provided in each of the first, second, and third joints, and a laser provided in the first robot arm and the second robot arm. In the laser robot equipped with beam conduit means, each of the mirror units provided at least at the first and second joints at both ends of the first robot arm
The laser beam is supported by rotary bearing means so as to be rotatable about a rotation axis that is coaxial with the rotation axis of the robot and the rotation axis of the second robot arm, and connects both mirror units. There is provided a laser robot characterized in that the conduit means has a structure capable of expanding and contracting in the axial direction via a sliding bearing.

0012

[Operation] According to the above structure, the mirror unit for changing the course of the laser beam provided at each joint in the robot body turns and displaces in the axial direction following the bending of the robot arm.
The course of the laser beam was always changed at the predetermined entrance and reflection points of the reflection mirrors of each mirror unit, and the amount of deflection varied as the gravitational effect changed due to changes in posture due to the rotation of the robot arm. Sometimes, the displacement of the mirror unit follows the amount of deflection, so when it reaches the tip of the robot body, the laser beam that has always traveled the normal course is emitted from the laser beam emitting device to the irradiation target. It is. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a mirror support device for a laser robot according to the present invention and a multi-jointed arm laser robot equipped with the device will be described in more detail with reference to the accompanying drawings.

[0013]

[Example] Fig. 1 is a sectional view of a main part explaining the structure and operation of a mirror support device for a laser robot according to the present invention, and Fig. 2
3 is an external front view of an articulated arm type laser robot in which the mirror support device is incorporated, and FIG. 3 is a schematic mechanical diagram illustrating the displacement of the mirror unit following the deflection of the robot arm. In the embodiment of the present invention, elements and parts that are the same or equivalent to those of the conventional multi-jointed arm laser robot shown in FIG. 4 are designated by the same reference numerals.

The main parts of the laser robot shown in FIG. A rotary bearing 16 that is rotatably supported in a plane perpendicular to the ground around the W axis, which is a horizontal axis; a second joint 18 provided at the tip of the first robot arm 14; Mechanical elements and parts such as the rotary bearing 20 that rotatably supports the second robot arm 22 around the U-axis, which is the horizontal axis, at the joint 18 are the corresponding elements of the conventional laser robot shown in FIG. and a configuration similar to the part,
It can be understood that it has an effect.

Accordingly, the laser beam is introduced through a laser beam conduit (not shown) external to a part of the rotating body 10 of the robot body. This laser beam is transmitted to a reflecting mirror 24a in a first mirror unit 24 provided at the first joint portion 12 on the base end side of the first robot arm 14.
The laser beam is reflected by the laser beam, changes its course approximately at right angles, enters the laser beam conduit 126 provided inside the first robot arm 14, and passes through the laser beam conduit 126 to the second laser beam at the tip of the first robot arm 14. The beam is reflected by the reflection mirror 28a of the second mirror unit 28 provided at the joint 18 of the beam, and its course is again changed to a substantially right angle. The laser beam further enters the reflection mirror 30a of the third mirror unit 30 disposed at a position opposite to the second mirror unit 28 at the same second joint 18, is reflected, and travels approximately at right angles. The laser beam enters the laser beam conduit 132 provided inside the second robot arm 22, passes through this laser beam conduit 132, passes through another mirror unit provided at the joint at the tip of the robot body, and then passes through the laser beam. The output unit (not shown) is reached.

Here, the first robot arm 14 pivots around the W axis under the load of the weight load elements including the second robot arm 22 pivotally attached to its tip.
When the robot arm 14 rotates in a vertical plane, it is subject to different gravitational effects depending on the various rotational posture positions, and even if it has strong mechanical rigidity, the longer it is, the more
Since the moment arm becomes longer, the deflection at the tip of the first robot arm 14 becomes larger. This deflection adversely affects the path of the laser beam traveling through the laser beam conduit 126, and causes the reflection mirror 24 of the first mirror unit 24 to
The laser beam reflected by the second mirror unit 28
The fact that the light does not enter the regular reflection point on the reflection mirror 28a is as already explained based on FIG.

Therefore, according to the invention, the first joint 1
The first mirror unit 24 provided in the first robot arm 14 is rotated around the W axis, which is the pivot axis of the first robot arm 14, and the same axis as the base end side machine frame of the first robot arm 14 by means of a bearing 40. The first mirror unit 24 itself is made pivotable by following the deflection of the first robot arm 14.

Similarly, a second mirror unit 28 provided at the second joint 18 at the tip of the first robot arm 14
The rotary bearing 50 also constitutes a support device that rotatably supports the first robot arm 14 on the distal end side machine frame. The laser beam conduit 126 provided inside the first robot arm 14 is made of a mechanically rigid and relatively lightweight pipe material, such as an aluminum pipe material or a thin stainless steel pipe material, which is coupled to the first mirror unit 24. A conduit section 127 made of a pipe material, a hard synthetic resin pipe material, etc. and a conduit section 128 made of a similar mechanically rigid pipe material coupled to the second mirror unit 28 are fitted in a telescopic nesting structure. A sliding bearing 129, 1 made of a tetrafluoroethylene material, which is a well-known lubricating resin material, or a copper alloy material, is attached to the tip side of both pipe materials while bringing them together.
29 or equivalent linear motion bearings using, for example, balls are provided respectively, so that both conduit sections 127 and 128 are formed in a structure in which they can be slidably and linearly displaced relative to each other.

As a result, as shown in FIG. 3, even when the first robot arm 14 is deflected (indicated by a dotted line), the first mirror unit 24 rotates and is prevented from being displaced in the axial direction due to the deflection. Since the laser beam is followed by the displacement of the laser beam conduit 126 in the form of expansion and contraction, the laser beam is reflected by the mirror 24a of the first mirror unit 24 and then reflected by the second mirror unit 28 on the arm tip side. When the light reaches a predetermined regular input point, it is reflected without causing any deviation δ.

For this reason, even after being reflected by the second mirror unit 28, the laser beam can travel along a path whose optical axis is aligned in advance. The light can be incident on a predetermined incident point of the reflecting mirror 30a in the mirror unit 30 of No. 3.

Preferably, the third mirror unit 30 is also similar to the first and second mirror units 24 and 2.
8, it is provided so as to be rotatable about the pivot axis U of the joint part 18 by a rotary bearing 60, and the laser beam conduit 1
32 is also composed of a conduit 133 made of the same pipe material as the above-mentioned pipe material (fitted in a nested structure with the conduit of the mirror unit provided on the distal end side of the second robot arm 22), and Since it has a sliding bearing 135 and is configured to be slidable, even if the second robot arm 22 is deflected due to the gravitational effect, the third mirror unit will follow the displacement and the course of the laser beam will be shifted. will never occur.

FIG. 2 is a front view showing the overall appearance of the multi-jointed arm type laser robot equipped with the above-mentioned mirror support device. A rotating trunk 10 is provided on the robot base 8 so as to be able to rotate (θ) around the vertical axis, and a joint 12 is provided at the top of the tip of the rotating trunk 10. the first robot arm 14
is pivotably mounted around the W axis. This turning movement of the first robot arm 14 is driven by a drive motor (not shown) built into the joint 12. Also,
At the joint 18 provided at the tip of the first robot arm 14, the second robot arm 22 is aligned with the U axis parallel to the W axis.
It is provided so as to be able to turn around the axis, and its turning drive is built into the joint portion 12 at the top of the turning trunk 10 described above. A wrist drive motor M is provided at the rear end of the second robot arm 22.
The robot wrist 25 is mounted on the robot wrist 25 and is driven by the drive motor M. The robot wrist 25 is connected to a joint 27 at the tip of the second robot arm 22 and rotates around the long axis of the second robot arm 22 and an axis perpendicular thereto. It is configured to allow α rotation and β rotation around the center. The robot wrist 25 is equipped with a laser beam emitting unit 25a consisting of a focusing optical system.
A laser beam is irradiated toward a desired laser beam irradiation target in accordance with posture control operations of the second robot arms 14, 22, etc. A laser beam is introduced into the joint 12 from a laser oscillator (not shown) installed outside the robot body through a suitable laser beam conduit means, and is supported by the support device according to the present invention provided in the joint 12. a mirror unit provided in the first robot arm 14, a similar mirror unit built in the joint portion 18, a laser beam conduit means provided in the second robot arm 22, and a laser beam conduit means provided in the joint portion 27. After condensing the light through a similar mirror unit etc., the laser beam output unit 2
The light is emitted from 5a.

[0023]

Effects of the Invention As can be understood through the explanation of the structure and operation of the embodiments above, the present invention provides a method for changing the course of a laser beam disposed at the joints of a laser robot, particularly a multi-jointed arm type laser robot. Unlike the conventional fixed support system using simple bolts and screws, the support device for supporting the mirror unit is provided with a structure that includes a rotation bearing and can rotate around the same axis as the rotation axis of the robot arm at the joint part, and The laser beam conduit means disposed between the mirror units at both ends of the arm supports both mirror units by having a conduit made of mechanically highly rigid and lightweight pipe material slidably arranged on sliding bearings. Because of this configuration, when the robot arm turns around the pivot axis of the joint in a plane perpendicular to the ground,
Due to the gravitational effect due to the weight load of other arms connected to the tip of the arm, the arm flexes according to the turning posture.
The deflection does not adversely affect the incidence and reflection of the laser beam by the mirror unit; in other words, the mirror unit is displaced to follow the deflection of the arm, so the laser beam always follows the predetermined optical axis path. Therefore, even when the laser robot takes various postures, it is possible to always stably emit a laser beam having a desired energy level to a desired laser irradiation target. As a result, the processing performance of the laser robot can be further stabilized compared to the conventional method.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part explaining the configuration and operation of a mirror support device for a laser robot according to the present invention.

FIG. 2 is an external front view of a multi-jointed arm laser robot in which the mirror support device is incorporated.

FIG. 3 is a schematic mechanical diagram illustrating the displacement of the mirror unit following the deflection of the robot arm.

FIG. 4 is a sectional view showing a conventional mirror support method in a laser robot.

FIG. 5 is a schematic mechanical diagram illustrating a deviation δ in the course of a laser beam that occurs in a conventional mirror unit in accordance with the deflection of a robot arm.

[Explanation of sign]

10...Swivel trunk 12...First joint part 14...First robot arm 18...Second joint part 22...Second robot arm 24...First mirror unit 24a...Mirror 25...Robot wrist 25a...Laser beam emission unit 28...Second mirror unit 28a...Mirror 40...Rotating bearing 50...Rotating bearing 126...Laser beam conduit 127... Pipe section 128... Pipe section 129...Sliding bearing

Claims (3)

[Claims] 1. A robot arm having an articulated structure is disposed so as to be rotatable in a plane perpendicular to the ground surface, and a path of a laser beam supported by the articulated portion at the end of the robot arm. In a laser robot that is equipped with a changing mirror unit and sequentially guides and emits a laser beam introduced from the outside to a state-of-the-art mirror output device via the mirror unit, a mirror support device that supports the mirror unit includes: a rotary bearing means that holds the mirror unit in the joint joint section so as to be able to rotate around an axis coaxial with the rotation axis of the robot arm; 1. A mirror support device for a laser robot, comprising a beam conduit slidably provided in a longitudinal direction, and capable of correcting and rotating the mirror unit in response to gravitational deflection of the robot arm. 2. A robot rotating body; a first robot arm that is capable of rotating within a plane perpendicular to the ground with a horizontal axis as the pivot axis relative to a first joint provided on the rotating body; a second robot arm that is rotatable about a horizontal axis as a pivot axis relative to a second joint provided at the tip of the first robot arm; and a second robot arm that is provided at the tip of the second robot arm. a laser beam emitting section coupled to a third joint;
, a laser robot comprising a mirror unit for changing the course of a laser beam provided in each joint of a third joint, and laser beam conduit means provided in the first robot arm and the second robot arm. , each of the mirror units provided at least at the first and second joints at both ends of the first robot arm is aligned with the pivot axis of the first robot and the second joint of the second robot arm. The laser beam conduit means is supported by rotary bearing means so as to be rotatable about the respective rotation axes coaxial with the rotation axis, and the laser beam conduit means connecting both mirror units is movable in the axial direction via a sliding bearing. A laser robot characterized by having a structure. 3. The laser robot according to claim 2, wherein the laser beam conduit means is formed of a hollow tube with high mechanical rigidity.