JPH09248687A - Laser beam machining robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the possibility of generating a machining defective article even as keeping the instruction program to a robot caused on the heat strain during welding, for example, in a YAG laser beam welding robot. SOLUTION: A strain measuring sensing unit 3 in order to measure the strain of a work W is arranged in the advancing direction of a laser beam nozzle 1 of a laser beam machining head 2 and the strain is detected with a CCD camera 6 with a semiconductor laser beam source. The position data is calculated with an arithmetic controller 4 from the received image data, it is transmitted to a robot controller 5 and the instruction program is compensated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing robot for automatically processing a work by irradiating a laser beam.

[0002]

2. Description of the Related Art Conventionally, for example, high energy obtained by converging a YAG laser beam is concentrated on a work (work) to automatically and continuously perform processing such as welding, fusing and punching. Laser processing robots have been used in recent years.

In this type of laser welding robot, for example, when the sheet metal works W ₁ and W ₂ as shown in FIG. 4 are automatically welded between P _a and P _b at each (teaching) point P. The operation sequence program of the robot is taught in advance to the robot controller by a predetermined program, and welding is automatically performed according to the input.

[0004]

[Problems to be Solved by the Invention]
The robot faithfully and continuously processes according to the teaching program input to the robot controller.
However, in the actual machining, as the machining process progresses, heat generation causes thermal deformation (strain) of the workpiece as exaggeratedly shown in FIGS. 5A and 5B, and the laser beam of the laser machining head is generated. The regular nozzle gap (height) h between the nozzle portion 1 and the upper surface of the work W changes to h ′ at the teaching point (teaching point) P _b .

As is well known, this type of processing laser beam has a more uniform phase than a normal light beam and has an extremely high light converging property. Therefore, the diameter of the laser beam focused by the laser beam nozzle 1 is The allowable range of the gap g, which is the minimum focal length, is extremely narrow, and the change in the gap has a great influence on the welding performance, which may cause processing defects.

In order to solve these problems, conventionally, the teaching position may be corrected by performing trial welding several times in advance. However, this increases the time required for teaching and the trial. There was a drawback in that the work for welding was also wasted.

The present invention has been made in consideration of the above situation, and a measuring sensor means for detecting these processing strains is provided in the laser processing head portion, and the output is fed back to the robot controller in real time. The purpose of the invention is to provide a means for preventing the occurrence of machining defects and shortening the time required for the initial teaching program by correcting the teaching program input first.

[0008]

Therefore, in the present invention, in a laser processing robot for processing a work by a laser beam, a detection means for detecting thermal deformation of the work on the traveling direction side of the laser processing head. Is provided
By configuring the robot control program of the robot control means to include the arithmetic control means for correcting in real time according to the displacement amount of the output in the three-dimensional direction,
It is intended to achieve the above object.

[0009]

With the configuration of the present invention as described above, the amount of thermal strain of the workpiece generated during the progress of machining is detected, and the measurement program corrects the teaching program initially input to the robot in real time. The occurrence of defects is prevented, and the initial trial machining and initial robot program teaching time are reduced. Furthermore, by carrying out the present invention, the inspection of the distortion state of the product after processing can be performed on the machine.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
This will be described in detail based on one embodiment.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration diagram of a laser welding robot according to an embodiment of the present invention, FIG. 2 shows an example of the internal configuration of a measurement sensing unit, and FIG. 3 shows a measurement sensing procedure diagram thereof.

(Structure) The present embodiment relates to a YAG laser welding robot R, which is adjacent to the machining advancing direction side of a laser machining head 2 having a laser beam nozzle 1 attached to the robot and the manipulator tip of the R. The measurement sensing unit 3 using a semiconductor laser is provided.

FIG. 2 is a view showing an example of the internal configuration of the measurement sensing unit 3, 6 is a CCD camera, and 7 is a semiconductor laser light source for measurement. The semiconductor laser beam from this light source passes through a reflecting mirror, a scan-operable operating mirror 8 and the like, reaches a measurement target work W, for example, a gap g, and is reflected again, and the reflecting mirror and the operating mirror 8, After passing through a lens or the like, it reaches the CCD camera 6 and is received by the image receiving device 9.

(Operation) As described above, for example, the measurement of the gap g between the works W ₁ and W _{2 is performed by} the gap g in the advancing direction of the nozzle 1 as shown in the front view and the side view (a) of the main part of FIG. Line sensing is performed by scanning with a predetermined width centered on the line.

The image data required by the CCD camera 6 obtained by the image receiving device 9 is shown in FIG.
The position data is calculated by the calculation controller 4 via the signal line, and the correction data based on the position data is transmitted to the robot controller 5 through the signal line 11. The robot R uses the program based on the corrected data for welding. Continue processing.

That is, if the reference data is input to the arithmetic controller 4 in advance, it is possible to correct the predetermined processing conditions of the robot R, the moving speed of the nozzle 1 and the like based on the measurement data.

The scan width of the line sensing at the time of the measurement sensing can be arbitrarily selected by operating the operating mirror 8 in FIG. 2, and at the same time, even when it is necessary to measure the height or the like, it can be easily performed by a known existing technique. Can respond.

(Other Embodiments) In the above embodiment, Y
The case where line sensing is performed by using the semiconductor laser beam for the change in the work gap of the AG laser welding robot has been described, but the principle of the present invention is not limited to this, and other processing and deformation modes are also possible. Of course, it can be applied.

[0019]

As described above, according to the present invention, the measuring sensor means for detecting the machining strain of the workpiece is provided on the traveling direction side of the laser machining head, and the machining operation of the robot according to the output thereof. Since the program is configured to be corrected in real time, the occurrence of machining defects due to the machining strain can be prevented, the initial trial machining can be simplified, and the initial robot program display time can be saved. . The program can be corrected even with simple teaching, so it can be processed with high precision.

Furthermore, the practice of the present invention has the advantage that inspection of the distortion state of the processed product can be performed on the machine.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment.

FIG. 2 is a diagram showing an example of the internal configuration of the measurement sensing unit of the embodiment.

FIG. 3 is a diagram of the measurement and sensing procedure of the embodiment.

[Fig. 4] Example of sheet metal work

FIG. 5 is a thermal deformation example of the work shown in FIG.

[Explanation of symbols]

1 Laser Beam Nozzle 2 Processing Head 3 Measurement Sensing Unit 4 Operation Controller 5 Robot Controller 6 CCD Camera 7 Semiconductor Laser Light Source 8 Operating Mirror 9 Image Receiving Device 10, 11 Signal Line g Work Gap h Nozzle Gap P, P _a , P _b Teaching Point R YAG laser welding robot W, W ₁ , W ₂ work

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Claims (2)

[Claims] 1. A laser processing robot for processing a work by means of a laser beam, wherein a detection means for detecting thermal deformation of the work is provided on the traveling direction side of the laser processing head, and the output of the detection means determines the three-dimensional displacement amount. A laser processing robot having arithmetic control means for correcting a robot control program of the robot control means in real time. 2. The laser processing robot according to claim 1, wherein the laser processing robot is a YAG laser welding robot, and the detecting means uses a CCD camera using a semiconductor laser light source.