JPH06344167A - Laser beam machine - Google Patents

Abstract

PURPOSE:To improve the quality of a laser beam machine by preventing the focus displacement of CCD camera to photograph a work and precisely travel controlling a laser head. CONSTITUTION:A work 21 to be welded is traveled in the arrow mark direction A with butting a weld zone 22. A welding head 23 is placed so as to weld a weld zone 22. A position detecting sensor 26 is positioned in front of the welding head 23, the work 21 to be welded is irradiated with a belt-like beam by illumination parts 27, 28, photographing its optical cross sectional image by CCD camera 29. A data processing part 31 assumes the weld zone 22 as well as a vertical distance based on the image information, travel controlling the vertical position of CCD camera 29 by a distance correcting monitor 30 so as to set the position in the zone depth to be photographed, accordingly at all times the work to be welded 21 is precisely photographed, confirming the weld zone so as to execute welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus which detects a processed portion of a workpiece without contact and irradiates a laser beam from a laser head.

[0002]

2. Description of the Related Art Conventionally, as this type of device, for example,
There is a laser welding machine as shown in FIG. A work piece 1 as a work piece is set in a state in which linear welding portions 2 are butted, and is moved in the direction of the butted gap portion 1a (direction of arrow A in the figure). The welding head 3 irradiates a laser beam downward to weld the welded portion 2 of the object 1 to be welded, and the irradiation position of the laser beam is set by the vertical position correction motor 4 with respect to the object 1 to be welded. The movement is controlled in the opposite direction (direction of arrow B in the figure) to correct the distance, and the horizontal position correction motor 5 causes the horizontal direction (direction of arrow C in the figure) substantially orthogonal to the line of the butt gap 1a of the workpiece 1 to be welded. The movement is controlled.

A position detecting device 6 for detecting the butt gap portion 1a of the object 1 to be welded is disposed at a position opposite to the arrow A direction with respect to the welding head 3. The position detection device 6 includes two illumination units 7 and 8 that irradiate the workpiece 1 with strip-shaped light through a slit in the same plane, and a CCD camera 9 that captures an illuminated portion of the workpiece 1. Composed.
The optical axis of the CCD camera 9 is set in the direction of arrow B,
The object to be welded 1 is photographed from directly above, and is arranged obliquely upward so that the irradiation position of the band-shaped light from the illumination units 7 and 8 changes according to the unevenness of the surface of the object to be welded 1. ing.

The data processing unit 10 detects the welded portion 2 of the workpiece 1 on the basis of the image signal from the CCD camera 9, and the welded portion 1 of the workpiece 1 is moving in the direction of arrow A and is now detected. The vertical position correction motor 4 and the horizontal position correction motor 5 are arranged via a drive circuit 11 so that the laser beam 2 reaches an appropriate position when the laser beam irradiation position of the welding head 3 is reached.
Drive control.

According to the above configuration, the illumination parts 7 and 8 of the position detecting device 6 are provided with respect to the work piece 1 which is moved in the direction of arrow A.
The welding processing portion 2 is alternately irradiated with the illumination light, the image corresponding to each irradiation timing is photographed by the CCD camera 9, and the relative position between the workpiece 1 and the welding head 3 is based on the image signal. To detect. In this case, the strip-shaped light emitted from the illumination units 7 and 8 is projected on the work piece 1 in a bent state according to the unevenness of the surface of the work piece 1. The strip-shaped light is projected on a predetermined reference line at a portion where the position of the surface of the object to be welded 1 in the height direction (arrow B direction) is at the reference height position, and the light in the height direction from the reference height position is projected. As the size increases, the amount of deviation from the reference line increases.

Therefore, the data processing section 10 can detect the distribution of the surface shape of the workpiece 1 and its distance in the height direction based on the image signal obtained from the CCD camera 9, and the detection result. Based on the above, the position of the welded portion 2 is obtained by comparing with the data of the workpiece 1 stored in advance. Then, the vertical position correction motor 4 and the horizontal position correction motor 5 are drive-controlled via the drive circuit 11 so that the laser beam is irradiated to the welding processed portion 2 when the workpiece 1 reaches the lower portion of the welding head 3. To control.

As a result, the object to be welded 1 is moved in the direction of arrow A, while the laser beam is emitted from the welding head 3 to an appropriate welding position so that the welding process is continuously performed. .

[0008]

However, in the conventional structure as described above, when the work surface of the workpiece 1 has large irregularities or the relative position in the vertical direction is displaced, C
If it is out of the focal length range of the CD camera 9,
The photographed image itself becomes unclear, and when estimating the position of the gap portion 2a based on the image data, the accurate position cannot be detected, resulting in processing defects.

The present invention has been made in view of the above circumstances, and an object thereof is to make an image of a processing target portion of a workpiece by an image pickup means always clear without defocusing, and to perform processing by a laser head. It is an object of the present invention to provide a laser processing apparatus that can always be accurately executed.

[0010]

According to the present invention, a predetermined area of a processed portion of a workpiece is irradiated with band-shaped light by an illuminating means, the light is photographed by an image pickup means, and based on image information from the image pickup means. The present invention is directed to a laser processing device that controls the relative position between a laser head and the object to be processed by irradiating the processed portion with a laser beam, the imaging means and the imaging device. An imaging distance correction means for controlling the relative distance to the workpiece and a relative distance to the workpiece based on image information from the imaging means are within the depth of field of the imaging means. And a control means for controlling the image pickup distance correction means so as to enter.

In addition to the above-mentioned structure, the detecting means for detecting the luminance distribution of the band-shaped light by the illuminating means and the distance distribution in the predetermined direction based on the image information from the image pickup means, and the detection result of the detecting means. Based on the extraction result of the extraction means, the determination means for determining whether or not the imaged region by the image capturing means is the processing target region, and the determination result by the determination means. It is also possible to provide a determining means for determining processing by the laser head based on the above.

[0012]

According to the laser processing apparatus of the present invention, when the laser beam is emitted from the laser head to process the workpiece, the illumination means irradiates a predetermined portion of the workpiece in advance so that the workpiece is processed. The light-section image generated by the band-shaped light at that time due to the unevenness of the image is photographed by the image pickup means to detect the distance between the workpiece and the laser head and the processed portion.
Then, the laser processing is performed by controlling the relative position between the workpiece and the laser head to irradiate the processed portion with the laser light. At this time, the control unit also detects the distance between the workpiece and the image pickup unit based on the image information of the image pickup unit, and when the detected distance is out of the depth of field of the image pickup unit. Outputs a control signal to the imaging distance correction means to correct the relative distance between them so that the distance falls within the depth of field. Therefore, the processed portion of the workpiece imaged by the image pickup means can always be input as an accurate image, and as a result, laser processing based on image information can be performed accurately.

According to the laser processing apparatus of the second aspect,
Based on the image information from the image pickup means by the detection means, the luminance distribution of the strip-shaped light by the illumination means and the distance distribution in a predetermined direction are detected, and the characteristics of the image are extracted by the extraction means based on the detection result. Further, the determination means and the determination means determine whether or not the imaged part by the image pickup part is the part to be processed based on the extraction result, and determine the processing by the laser head. At this time,
Similarly to the above, since the relative distance between the image pickup means and the work piece is controlled so that the work piece is within the depth of field, the processed portion of the work piece based on the image information of the image pickup means. It is possible to perform the laser processing by reliably estimating.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a laser welding machine will be described below with reference to FIGS. FIG. 1 shows the overall configuration. A work piece 21 as a work piece is composed of two members 21 having curved surfaces.
a and 21b are set in a state in which the linear welded portions 22 are butted against each other, and the workpiece 21 is moved in the direction of the butted gap portion 22a (direction of arrow A in the figure) by a drive mechanism (not shown). It has become so.

The welding head 23 irradiates a laser beam downward to weld the welded portion 22 of the workpiece 21, and the laser beam irradiation position is controlled by the vertical position correction motor 24. The distance is corrected by performing movement control in the direction opposite to 21 (the direction of arrow B in the figure), and the horizontal position correction motor 25 makes the horizontal direction orthogonal to the butt gap 22a of the workpiece 21 (direction of the arrow C in the figure). The movement is controlled.

At the position opposite to the arrow A direction with respect to the welding head 23, the abutting gap portion 22a of the workpiece 21 is welded.
A position detection device 26 for detecting the position is provided. The position detection device 26 includes two illumination units 27 and 28 that irradiate the workpiece 21 with band-shaped light through a slit in the same plane.
And a CCD camera 29 as an image pickup means for photographing the illuminated portion of the object to be welded 21. CCD camera 2
9, the optical axis is set in the direction of arrow B, and the object to be welded 21
Is designed to be shot from directly above. Illumination unit 27, 2
8 is arranged obliquely above so that the irradiation position of the strip-shaped light changes according to the unevenness of the surface of the workpiece 21. In addition, the position detection device 26 is vertically moved by the distance correction motor 30 as the image pickup distance correction means, that is, the CCD camera 2.
9 is provided so as to be movable in its entirety in the optical axis direction (direction of arrow B in the figure).

The data processing unit 31 as the control means is
Based on the image signal from the CD camera 29, the object to be welded 21
Of the welded portion 22 of the workpiece 2 and the detected workpiece 2
The vertical position correction motor 24 and the horizontal position correction are performed via the drive circuit 32 so that the welding processing portion 22 of No. 1 moves in the direction of the arrow A and reaches an appropriate position when reaching the laser beam irradiation position of the welding head 23. The motor 25 is drive-controlled. Further, the distance correction motor 30 is driven and controlled via the drive circuit 32 so that the photographing distance of the CCD camera 29 with respect to the object to be welded 21 is within the range of the depth of field of the CCD camera 29. There is.

FIG. 2 shows a block configuration of the data processing unit 31, which is configured as follows. An image signal is input from the CCD camera 29 to the detecting unit 33 as a detecting unit, and the luminance distribution detecting unit 33a obtains the luminance distribution in the direction orthogonal to the line of the welded portion 22 in the photographed screen, The distance distribution detection unit 33b detects the amount of deviation of the object 21 to be photographed from the reference position from the information on the photographed screen. The feature extraction unit 34 as an extraction unit sets a predetermined range of interest and extracts the features of the luminance distribution and the distance distribution inside and outside the result of the detection unit 33.

The determination unit 35 as a determination means estimates the accuracy of whether or not the attention range set by the welding line accuracy estimation unit 35a based on the extraction result of the feature extraction unit 34 is a region to be welded. The distance accuracy estimation unit 35b estimates the distance accuracy of the portion to be welded based on the extraction result of the distance distribution between the CCD camera 29 and the workpiece 21. Then, the position determination unit 36 as the determination means
It consists of a horizontal position determination unit 36a and a vertical position determination unit 36b. In the horizontal position determination unit 36a, a region with the highest accuracy estimated for the attention range based on the result of the determination unit 35 is determined as the horizontal welding position. Output as a control signal. Further, in the vertical position determination unit 36b, the determination unit 3
Based on the distance accuracy estimation result of 5, the highest position among these accuracy is determined as the vertical welding position and a control signal is output.

Next, the operation of this embodiment will be described with reference to FIGS. 3 and 4. That is, first, the position detecting device 2 is attached to the object to be welded 21 that is moved in the direction of arrow A.
When the strip-shaped light is alternately emitted from the illumination units 27 and 28 of No. 6, the light-section image SL having a luminance distribution in which the strip-shaped light is cut on the upper surface of the object to be welded 21 in accordance with the uneven state thereof.
Are formed as shown in FIG. The CCD camera 29 photographs the light section image SL within a predetermined range E from the upper surface, and outputs the image information to the data processing unit 31 each time the illumination units 27 and 28 irradiate band-shaped light. At this time, for example, CC
As shown in FIG. 4, the screen E captured by the D camera 29 has the illumination unit 2 according to the uneven shape of the surface of the workpiece 21.
7 and 28, the striped light has a luminance distribution in a cut shape.

In this case, the two members 21 of the object to be welded 21 are
The light section image SL is formed in a state where arc-shaped projection portions are abutted corresponding to the shapes of a and 21b, and the abutted portion D is a portion to be welded by the laser head 23. . In FIG. 4, the welding point D is deviated by ΔQ with respect to the center line Q along the arrow A which is the moving direction of the workpiece 21.

Due to the geometrical relationship, when the photographing surface of the object to be welded 21 is at the reference position in the height direction with respect to the CCD camera 29, the light section image SL on the screen E corresponds to the reference position. Appears on the reference line P that
The further the image plane 1 is away from the reference position in the vertical direction, the more the light section image SL appears at a position further away from the reference line P. Therefore, since the welding point D in the figure is shifted to the left by ΔP, it indicates that the welding point D is located below the reference position by a distance corresponding to ΔP.

In the data processing unit 31, CC
Based on the image signal given from the D camera 29, first,
The luminance distribution detecting unit 33a of the detecting unit 33 obtains the luminance distribution in the direction orthogonal to the line of the welded part 22 in the photographed screen E, and the distance distribution detecting unit 33b uses the image signal in the photographed screen E to obtain the luminance distribution. Workpiece 2 for reference position
The amount of deviation from the photographing surface of No. 1 is detected. Next, the feature extraction unit 3
Reference numeral 4 sets a predetermined attention range, extracts the features of the luminance distribution and the distance distribution inside and outside thereof from the result of the detection unit 33, and the determination unit 35 sets the attention range set based on the extraction result of the feature extraction unit 34. The accuracy of whether or not the range is the part to be welded is estimated, and the distance accuracy of the part to be welded is estimated based on the extraction result of the distance distribution between the CCD camera 29 and the workpiece 21. Like

Next, the position determining unit 36 determines, in the horizontal position determining unit 36a, the portion having the highest accuracy estimated from the result of the determining unit 35 with respect to the attention range as the horizontal welding position and outputs it as a control signal. Then, in the vertical position determination unit 36b, the position of the highest accuracy is determined as the vertical welding position from the estimation result of the distance accuracy by the determination unit 35, and the control signal is output.

At this time, in the data processing section 31,
First, based on the above result, the distance correction motor 30 is drive-controlled via the drive circuit 32, the position detection device 26 including the CCD camera 29 is moved, and the welding object 21 is set to the depth of field of the CCD camera 29. Control to stay within the range. As a result, the CCD camera 29 can always take a clear image of the object to be welded 21 within the depth of field, that is, in the state where defocusing does not occur.

Then, the data processing unit 31 drives and controls the vertical position correction motor 24 and the horizontal position correction motor 25 via the drive circuit 32 based on the control signal thus obtained, and the workpiece 21 is welded to the welding head. Control is performed so that the laser beam is applied to the welded portion 22 when reaching the lower portion of 23. As a result, the object to be welded 21 is constantly moved in the direction of the arrow A while being irradiated with the laser beam from the welding head 23 at an appropriate welding position and continuously subjected to the welding process.

According to the present embodiment as described above, the position detecting device 26 estimates the distance between the CCD camera 29 and the object to be welded 21, and the distance correction motor 3 is based on the detection result.
Since 0 is driven and the CCD camera 29 is moved so that the object to be welded 21 is within the range of the depth of field of the CCD camera 29, the CCD camera 29 always moves the object to be welded 21. It becomes possible to shoot a clear image within the depth of field, that is, in a state where defocusing does not occur.

Further, the position detecting device 26 is provided with a detecting section 33,
A light-section image SL obtained by the CCD camera 29, which includes a feature extraction unit 34, a determination unit 35, and a position determination unit 36.
The data processing is performed on the basis of the image signal of (1) to estimate the portion to be welded, and the vertical position correction motor 24 and the horizontal position correction motor 25 are drive-controlled via the drive circuit 32. In addition to this, it is possible to accurately recognize the welding processing portion and perform the welding processing by the laser head 23.

In the above embodiments, the case where the present invention is applied to the laser welding machine has been described, but the present invention is not limited to this, and a workpiece is processed by using laser light, for example, a laser cutting machine. It is applicable to all laser processing devices.

[0030]

As described above, according to the laser processing apparatus of the present invention, the following effects can be obtained.
That is, according to the laser processing apparatus of the first aspect, the control means controls the image processing means based on the image information obtained by capturing the light-section image generated by the band-shaped light from the illumination means due to the unevenness of the workpiece. The control means detects the distance between the workpiece and the image pickup means, and when the detected distance is out of the range of the depth of field of the image pickup means, a control signal is sent to the image pickup distance correction means. Since the output is made so as to correct the relative distance between them so as to be within the depth of field, the processed portion of the workpiece imaged by the imaging means can be always input as an accurate image, As a result, there is an excellent effect that the laser processing based on the image information can be accurately performed.

According to the laser processing apparatus of the second aspect,
Providing detection means, extraction means, determination means and determination means,
Based on the image information from the image pickup means, the detection means detects the luminance distribution of the band-shaped light emitted from the illumination means to the workpiece and the distance distribution in a predetermined direction, and the extraction means detects the luminance distribution based on the detection result of the detection means. The feature of the image is extracted, and the determination unit determines whether or not the imaged region by the image capturing unit is the processing target region based on the extraction result by the extraction unit,
After that, the processing portion is determined by the laser head based on the determination result of the determination means by the determination means. Therefore, the processing portion of the workpiece is reliably estimated based on the image information of the image capturing means, and the laser beam is reliably estimated. It has an excellent effect that processing can be performed.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of the overall configuration showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a data processing unit.

FIG. 3 is a top view of the work piece.

FIG. 4 is a diagram showing a shooting screen of a CCD camera.

FIG. 5 is a view corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

21 is a workpiece (workpiece), 21a and 21b are members,
22 is a welded portion, 22a is a butt gap portion,
23 is a welding head (laser head), 24 is a vertical position correction motor, 25 is a horizontal position correction motor, 26 is a position detection device, 27 and 28 are illumination units (illumination means), and 29 is a CCD.
A camera (imaging unit), 30 is a distance correction motor (imaging distance correcting unit), 31 is a data processing unit (control unit), 32 is a drive circuit, 33 is a detection unit (detection unit), 33a is a luminance distribution detection unit, and 33b. Is a distance distribution detecting unit, 34 is a feature extracting unit (extracting unit), 35 is a determining unit (determining unit), 36 is a position determining unit (determining unit), 36a is a horizontal position determining unit, and 36b.
Is a vertical position determining unit.

Claims (2)

[Claims] 1. A predetermined area of a processed portion of a workpiece is irradiated with band-shaped light by an illuminating means and is photographed by an image pickup means. Based on image information from the image pickup means, a laser head and the workpiece. In the laser processing apparatus that performs processing by irradiating the processed portion with a laser beam by controlling the relative position between, for controlling the relative distance between the imaging unit and the workpiece. Control means for controlling the imaging distance correction means so that the relative distance between the imaging distance correction means and the workpiece based on the image information from the imaging means falls within the depth of field of the imaging means. A laser processing apparatus comprising: 2. A predetermined area of a processed portion of a workpiece is irradiated with band-shaped light by an illuminating means and is photographed by an image pickup means. Based on image information from the image pickup means, a laser head and the workpiece. In the laser processing apparatus that performs processing by irradiating the processed portion with laser light by controlling the relative position between the two, the brightness of the band-shaped light by the illumination unit based on the image information from the imaging unit. The detection means for detecting the distribution and the distance distribution with respect to the predetermined direction; the extraction means for extracting the characteristics of the image based on the detection result of the detection means; and the imaging region by the imaging means based on the extraction result by the extraction means. Determination means for determining whether or not it is a processing target portion, determination means for determining processing by the laser head based on a determination result by the determination means, and the imaging means Imaging distance correction means for controlling the relative distance to the workpiece, and the relative distance to the workpiece based on the distance distribution result obtained by the detection means, the relative distance And a control means for controlling the image pickup distance correction means so that the image pickup distance is within the depth of field of the image pickup means.