JP2001179471A - Method of feeding filler wire for laser beam welding equipment and device of feeding filler wire for laser beam welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of feeding a filer wire for a laser beam welding machine and a device of feeding the filler wire for the laser beam welding machine with which a weld defect is easily suppressed by feeding the filler wire automatically and to an optimum position. SOLUTION: In a welding work where a laser beam LB is used, the tip part of a filler wire 13 which is fed to a welding spot from a filler feeding device 17 via a filler nozzle 11 is picked up by an image pick-up means 27 provided at a laser beam machine 1 at the area and its vicinity irradiated by a laser beam LB, the feeding amount of and the deviation of feeding direction of the filler wire 13 are detected by processing the image of the picked-up data by an image processing means 33, and the filler feeding device 17 is automatically controlled by a filler wire controller 25 so that the tip of the filler wire 13 is located in an allowable range from the position irradiated by the laser beam LB.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler wire supply for a laser welding machine for performing welding by laser light emitted from a laser processing head using a filler wire fed from a filler nozzle to a processing position by a filler feeding device. The present invention relates to a method and a filler wire supply device for a laser welding machine.

[0002]

2. Description of the Related Art Referring to FIG.
In the filler wire supply device 109 of the laser welding machine 107 in which the laser processing head 105 is attached to the tip of one arm 103, the filler wire 111 is connected to the filler feeding device 115 installed on the shoulder 113 of the articulated robot 101. Is guided to the tip of the arm 103 of the articulated robot 101 through the guide pipe 117,
It is sent out from the filler nozzle 119 toward the processing point at the tip of the laser processing head 105.

[0005] A CCD camera 121 is attached to the laser processing head 105, and a filler wire 111 sent from a filler nozzle 119 is projected on a monitor 125 via a CCD camera signal cable 123.

Although not shown, the filler feeder 115 feeds the filler wire 111 by, for example, a motor and a pressure roller. The motor can perform inching (forward rotation) / retract (reverse rotation), and can feed or retract the filler wire 111.

[0005] The above-mentioned filler delivery device 115 includes:
A filler wire controller 127 for controlling the filler feeding device 115 is connected, and is capable of controlling inching / retract / constant speed operation / stop by command speed.

As a command to the filler wire controller 127, a speed command / run / stop command is issued by a program during playback from the robot controller 129. Also, an inching / retract command at a fixed speed can be issued from the programming pendant 131 via the robot controller 129 by direct button operation.

[0007] If the processing is performed without reaching the processing point due to the shortage of the filler wire 111, the insufficient wire build-up occurs. On the other hand, if the feeding amount is too large, the surplus portion does not melt and becomes unmelted, resulting in poor welding.

Further, if the delivery of the filler wire 111 is shifted in a direction perpendicular to the delivery direction of the filler wire 111 or in a vertical direction, the filler wire 111
Is not irradiated with the laser beam, so that undissolved residue is generated.

Therefore, the operator pulls out the filler wire 111 using the inching / retract button of the programming pendant 131, and adjusts while checking the position of the tip of the filler wire 111 on the monitor 125.

[0010]

However, in such a conventional technique, since the adjustment is performed at a constant speed, the adjustment must be performed while being excessively extended or returned, which requires a long time. There is.

In order to eliminate welding defects, the filler wire 111 must be adjusted before processing.
It is troublesome.

Although there is a teaching point correction system for assisting teaching by image processing, there is a problem that if a filler wire 111 is present in an image for correcting a teaching point, a welding line cannot be detected.

An object of the present invention is to pay attention to the above-mentioned problems of the prior art, and the occurrence of defective welding can be easily suppressed by automatically feeding out a filler wire to an optimum position. It is an object of the present invention to provide a filler wire supplying method for a laser welding machine and a filler wire supplying apparatus for a laser welding machine.

[0014]

According to a first aspect of the present invention, there is provided a filler wire supplying method for a laser welding machine, comprising the steps of: In a filler wire supply method of a laser welding machine for performing welding by laser light emitted from a laser processing head, an end of the fed filler wire is imaged by an imaging unit provided in the laser processing head. The imaging signal is image-processed by image processing means to detect the amount of the filler wire to be sent out and the deviation in the sending direction, so that the tip of the filler wire is located within an allowable range from the irradiation position of the laser beam. Automatically controlling the filler delivery device.

Therefore, the tip of the filler wire sent from the filler feeder to the welding location via the filler nozzle is imaged by the imaging means provided in the laser processing machine, and the image data is imaged by the image processing means. The processing is performed to detect the amount of feed of the filler wire and the deviation in the feed direction, and automatically control the filler feeder so that the tip of the filler wire is located within an allowable range from the irradiation position of the laser beam.

According to a second aspect of the present invention, there is provided a filler wire supplying method for a laser welding machine according to the first aspect, wherein the deviation of the filler wire feeding direction detected by the image processing means is suppressed. If an allowable value is exceeded, an alarm is issued.

Therefore, when the position of the filler wire is shifted from the direction of feeding the filler wire by an allowable value or more, an alarm process is performed and the operator is notified.

According to a third aspect of the present invention, there is provided a filler wire supply method for a laser welding machine according to the first or second aspect, wherein the filler wire is positioned at an optimum position by the imaging means. Is characterized in that after the filler wire is once drawn in, imaging is performed while gradually sending out the filler wire.

Therefore, when starting the welding process, the filler wire is once drawn in and then sent out, and the leading end is imaged by the imaging means to perform image processing.

According to a fourth aspect of the present invention, there is provided a filler wire supply device for a laser welding machine, wherein a filler wire fed from a filler nozzle to a processing position by a filler delivery device is used to perform welding by laser light emitted from a laser processing head. A filler wire supply device of a laser welding machine for performing an image processing provided on the laser processing head and imaging the laser light irradiation position as a center, and performing image processing by a signal from the imaging means. Image processing means for detecting the amount of feed of the filler wire and a deviation in the feed direction; and the filler feeding means such that the tip of the filler wire detected by the image processing means is located within an allowable range from the irradiation position of the laser light. A filler wire control device for automatically controlling the device,
It is characterized by comprising.

Therefore, in the welding process using the laser beam, the tip of the filler wire sent out from the filler feeder to the welding location via the filler nozzle through the filler nozzle is scanned by the imaging means provided in the laser processing machine. An image is taken with the light irradiation position as the center, the image data is subjected to image processing by image processing means to detect the amount of feed of the filler wire and the deviation of the direction of feed, and the tip of the filler wire is within an allowable range from the irradiation position of the laser light. The filler delivery device is automatically controlled by the filler wire control device so as to be positioned inside.

According to a fifth aspect of the present invention, there is provided a filler wire supplying apparatus for a laser welding machine according to the fourth aspect, wherein the filler wire feeding direction of the laser welding machine is detected by the image processing means. Is provided with an alarm which issues an alarm when the value exceeds the allowable value.

Therefore, when the position of the filler wire is deviated from the feed direction of the filler wire by more than an allowable value, an alarm or the like is issued by an alarm to notify the worker.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a laser welding machine 1 according to the present invention.
Is shown. In this laser welding machine 1, a laser processing head 9 is attached to the tip of an arm 7 of an articulated robot 5, and irradiates a laser beam to a work to perform welding.

In the filler wire supply device 3, a filler nozzle 11 is provided at the tip of the arm 7 of the articulated robot 5, and a filler delivery device 17 for delivering the filler wire 13 through the guide pipe 15.
Is installed on the shoulder 19 of the articulated robot 5. Although not shown, the filler feeder 17 feeds or draws the filler wire 13 by a pressure roller rotated by a motor, for example.

Therefore, the filler wire 13 is guided by the filler delivery device 17 through the guide pipe 15 to the tip of the arm 7 of the articulated robot 5, and is sent out from the filler nozzle 11 toward the processing point at the tip of the laser processing head 9, or The filler wire 13 is pulled in.

A robot controller 21 is connected to the articulated robot 5.
1 is connected to a programming pendant 23 which is a man-machine interface. Further, the above-described filler feeding device 17 is connected to the robot controller 21 via a filler wire controller 25 which is a filler wire control device.

Therefore, the robot controller 21 issues a speed command / run / stop command to the articulated robot 5 in accordance with the program to control it. Alternatively, a teaching program can be created by the programming pendant 23, the articulated robot 5 can be manually operated, or the constant-speed inching / retract can be operated on the filler feeding device 17.

The laser processing head 9 is provided with a CCD camera 27 as an image pickup means, so that an image can be picked up coaxially with the laser beam. The CCD camera 27 is connected to an image processing system personal computer 33 as image processing means via a CCD camera signal cable 29 and an image processing board 31. The robot controller 21 is also connected to the image processing system personal computer 33.

The image processing system personal computer 33 can detect the nozzle gap / weld line using the laser slit light, and can calculate the position correction amount of the teaching point. Further, as shown below,
The protrusion amount / shift amount of the filler wire 13 can be detected. The image processing system personal computer 33 is provided with an alarm 35 that issues an alarm by an alarm process.

Next, a method of supplying a filler wire in a laser welding machine will be described with reference to FIG.

When entering the teaching point correction process,
For example, as shown in FIG.
OB is instructed by communication, and the filler wire 13 drawing step (retract) is first performed (step S).
1).

According to the usual procedure, each teaching point is corrected by image processing by the image processing system personal computer 33 (step S2). Then, before the start of the welding process, the automatic adjustment of the filler wire 13 is started as follows (step S3).

First, an inching job as shown in FIG. 4 is selected and a start command is issued to the articulated robot 5 by communication (step S4). The amount of protrusion of the filler wire 13 is confirmed by image processing by the image processing system personal computer 33 (step S5).

That is, referring to FIGS. 5A and 5B, in the image processing, the input image shown in FIG. 5A is filtered by a maximum value operation as shown in FIG. Processing to obtain a filtered image as shown in FIG. When this filtered image is projected in the vertical direction, a graph as shown in FIG. 7 is obtained. From this graph, the tip position of the filler wire 13 is detected.

Next, as shown in FIGS. 8A to 8D, the filler wire 1 obtained as described above is obtained.
Until the tip position of No. 3 becomes the center position of the laser beam which is the optimum position (step S6), the filler wire 13 is gradually sent out by the inching JOB command to the articulated robot 5, and the protrusion amount of the filler wire 13 is confirmed. Is repeated to perform automatic adjustment. The pixel position on the image of the center position of the laser beam is previously confirmed by calibration.

During the automatic adjustment, the filler wire 13
When the tip of the robot has passed the center position of the laser beam (step S7), a retract JOB is commanded to the articulated robot 5 to pull in the filler wire 13 (step S7).
8).

When a job is performed in each step, the motor is turned on for 0.1 second to feed or retract the filler wire 13, for example.
The timer may be turned on for a second, and when approaching the optimum position, may be turned on for 0.1 second by a timer for fine movement.

Further, the accuracy of the protrusion amount may be, for example, about ± 0.2 mm with respect to the center of the calibration data.

After the automatic adjustment of the protrusion amount of the filler wire 13 has been completed as described above, the processing direction of the filter in the image processing is changed to a direction orthogonal to the above-described detection of the protrusion amount (step). S9) The projection process is also performed in the orthogonal direction (step S10), and the position of the filler wire 13 (the vertical position of the screen in FIG. 5B)
Is confirmed (step S11).

If the position of the filler wire 13 deviates from the center position of the calibration data by, for example, ± 0.2 mm or more (step S12), it is determined that there is a possibility that unmelted residue may occur, and an alarm process is performed. The worker is warned (step S13).

When the automatic adjustment of the filler wire 13 is completed normally, the job with the teaching point corrected is downloaded to the articulated robot 5 as usual, and a start command is executed to perform laser welding (step S14). .

From the above results, the amount of protrusion of the tip end of the filler wire 13 is detected by image processing and is automatically adjusted so as to be at the optimum position. And work efficiency can be improved.

In addition, since not only the amount of protrusion of the filler wire 13 but also the protrusion position can be detected, it is possible to prevent welding defects such as residual melting of the filler wire 13 due to displacement of the filler wire 13 and the like.

Further, when the teaching point correction system or the like automates the correction of the teaching point, it is possible to automate a portion that must be manually adjusted, so that the work efficiency can be improved.

It should be noted that the present invention is not limited to the above-described embodiment of the present invention, but by making appropriate changes,
It can be implemented in other aspects. That is, in the above-described embodiment, the alarm processing is performed when the position of the filler wire 13 is not appropriate. However, even when a molten ball is attached to the tip of the filler wire 13, normal welding processing is performed. You can handle the alarm as not.

Further, a cutter for cutting the filler wire 13 may be provided, and the filler wire 13 may be automatically cut by a dedicated job.

When the position of the filler wire 13 is displaced, it is possible to adjust the position by moving the filler nozzle 11 by a driving means such as a motor or an air cylinder, instead of performing an alarm process. .

In the above-described embodiment of the present invention, the command to the filler feeding device 17 is issued via the job. However, the image processing system personal computer 33 may directly command the robot controller 21 via the I / O. It is possible. In this case, the image processing system personal computer 33
, It is necessary to control the time of turning on by a timer. Alternatively, the image processing system personal computer 33 can directly instruct the filler feeding device 17 by I / O.

[0051]

As described above, in the filler wire supply method for a laser welding machine according to the first aspect of the present invention, the tip portion of the filler wire delivered from the filler delivery device to the welding location via the filler nozzle is formed by the laser. An image is taken by imaging means provided in the processing machine, the image data is subjected to image processing by image processing means to detect the amount of feed of the filler wire and the deviation in the direction of feed, and the tip of the filler wire is irradiated with the laser light. Since the filler feeding device is automatically controlled so as to be located within an allowable range from the position, there is no need for an operator to make adjustments while checking on a monitor as in the related art, thereby improving work efficiency. Further, since not only the protrusion amount of the filler wire but also the protrusion position can be detected, it is possible to prevent welding defects such as undissolved filler wire caused by displacement of the filler wire.

According to the filler wire supply method of the laser welding machine according to the second aspect of the present invention, if the position of the filler wire is shifted from the feed direction of the filler wire by an allowable value or more, an alarm process is performed and the operator is notified. It is possible to prevent poor welding such as undissolved filler wire caused by displacement of the filler wire.

In the method for supplying a filler wire for a laser welding machine according to the third aspect of the present invention, when starting welding,
Once the filler wire is drawn in and then sent out, the tip is imaged by the imaging means and image processing is performed, so that the tip position of the filler wire can be reliably obtained by image processing.

In the filler wire supply device for a laser welding machine according to the present invention, the tip portion of the filler wire fed from the filler delivery device to the welding location via the filler nozzle during the welding process using the laser beam. Is imaged around the irradiation position of the laser beam by the imaging means provided in the laser processing machine, and image processing of this imaged data is performed by the image processing means to detect the amount of feed of the filler wire and the deviation in the direction of feed, Since the filler feeder is automatically controlled by the filler wire controller so that the tip of the filler wire is located within an allowable range from the laser beam irradiation position, it is necessary for the operator to adjust the filler wire while checking the monitor as in the conventional case. And work efficiency can be improved. Further, since not only the protrusion amount of the filler wire but also the protrusion position can be detected, it is possible to prevent welding defects such as undissolved filler wire caused by displacement of the filler wire.

In the filler wire supply device for a laser welding machine according to the fifth aspect of the present invention, when the position of the filler wire deviates from the feed direction of the filler wire by more than an allowable value, an alarm is issued by an alarm and an operator is issued. , It is possible to prevent welding defects such as undissolved filler wires caused by displacement of the filler wires and the like.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a filler wire supply device of a laser welding machine according to the present invention.

FIG. 2 is a flowchart showing a filler wire supply method for a laser welding machine according to the present invention.

FIG. 3 is a drawing control program.

FIG. 4 is a program of a delivery control.

FIG. 5 (A) is an input original image of a captured filler wire, and FIG. 5 (B) is an image after filtering.

FIG. 6 is a mathematical expression showing a maximum value calculation by filter processing.

FIG. 7 is a graph showing a result of projecting a filtered image in a direction orthogonal to a filler sending direction.

FIGS. 8A to 8D are images taken at each stage in the filler wire supply method of the laser welding machine according to the present invention.

FIG. 9 is a configuration diagram showing a filler wire supply device of a conventional laser welding machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Laser welding machine 3 Filler wire supply device 9 Laser processing head 11 Filler nozzle 13 Filler wire 17 Filler sending device 25 Filler wire controller (Filler wire control device) 27 CCD camera (Imaging means) 33 Image processing system personal computer (Image processing means) 35 alarm

Claims (5)

[Claims] 1. A filler wire feeding method for a laser welding machine for performing welding by laser light emitted from a laser processing head using a filler wire fed from a filler nozzle to a processing position by a filler feeding device. The leading end of the filler wire that has been taken is imaged by an imaging means provided in the laser processing head, and the imaging signal is image-processed by an image processing means to detect the amount of the filler wire to be sent and a deviation in the sending direction, A filler wire supply method for a laser welding machine, characterized by automatically controlling the filler feeder so that the tip of the filler wire is located within an allowable range from the irradiation position of the laser beam. 2. The method according to claim 1, wherein an alarm is issued when the deviation in the feeding direction of the filler wire detected by the image processing means exceeds an allowable value.
A method for supplying a filler wire for a laser welding machine as described in the above. 3. The image pickup device according to claim 1, wherein when the filler wire is positioned at an optimum position by the image pickup means, an image is taken while the filler wire is pulled out and then gradually fed out. Filler wire supply method for laser welding machine. 4. A filler wire supply device of a laser welding machine for performing welding by laser light emitted from a laser processing head using a filler wire sent from a filler nozzle to a processing position by a filler delivery device. An imaging unit provided on the laser processing head for imaging the irradiation position of the laser beam as a center, and performing image processing based on a signal from the imaging unit to detect a feed amount and a shift of the feed direction of the filler wire. Image processing means, and a filler wire control device for automatically controlling the filler delivery device so that the tip of the filler wire detected by the image processing means is located within an allowable range from the irradiation position of the laser light, A filler wire supply device for a laser welding machine. 5. The laser welding apparatus according to claim 4, further comprising an alarm which issues an alarm when a deviation of the feed direction of the filler wire detected by the image processing means exceeds an allowable value. Machine filler wire feeder.