JPH11285880A - Detecting device for copy calibration in welding machine and detecting method for copy deviation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect positional deviation between a laser welding torch and a copying image pickup unit. SOLUTION: This detecting device is provided with a translucent plate 4 like ground glass provided at the same height as the surface of a material to be welded against a welding torch 10, a detecting image pickup unit 5 for photographing the translucent plate 4 through a window opening 3, and index small holes 6a, 6b arranged on a straight line L1 passing the reference point O on the translucent plate 4; the torch 10 and the copying image pickup unit 11 are scanned in the y direction, detecting the collimation light locus L2 of the torch 10 on the translucent plate 4 by the image pickup unit 5, and calculating the positional deviation of the torch. In the meantime, each shortest distance is calculated for the visual field center of the copying image pickup unit 11 to the small holes 6a, 6b, with their average values determined as the positional deviation of the copying image pickup unit 11. Then, deviation is determined between the torch 10 and the image pickup unit 11. The copying deviation of the torch 10 is eliminated by adjusting the deviation and the distance between the torch 10 and the image pickup unit 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding torch for projecting collimating light, a copying imager for photographing a groove of a welding object, and a welding torch and a copying imager for forming a groove. The present invention relates to a scanning position verification apparatus used for calibration of a copying machine and a method of detecting a copying machine using the same, which is provided with a y driver that is driven in an extending y direction. These include, for example, a groove position of a welding target is calculated by image processing from a captured image of a groove imager, and a laser automatic scanning welding for matching a welding target position of a laser welding tor with the groove position. This is used for calibration of the device.

[0002]

2. Description of the Related Art For example, in the laser automatic profile welding apparatus, when welding a groove extending in the y direction, the x position of the center of the visual field of the groove imager and the x position of the welding target line of the laser welding torch are determined. The welding torch cannot accurately follow the groove due to the initial positional deviation of the laser beam, and the positional deviation due to aging, etc., and especially when performing laser welding, the allowable deviation of the laser is small. The deviation needs to be accurately calibrated. In order to solve such a problem, the present inventors have already proposed an automatic calibration apparatus in Japanese Patent Application Laid-Open No. 9-271973.

As shown in FIG. 3A, this automatic calibration apparatus has a configuration in which a laser detector 101 is disposed at a center portion, and simulated groove portions 102a and 102b are disposed at both ends thereof. The calibration amount is measured by moving the groove imager 103 and the laser welding torch 104 along a line L extending in the y direction corresponding to the groove center line. The measurement principle is as shown in FIG. 3B, with respect to the laser trajectory L2 measured by the laser detection unit 101, the distance D1 from the reference point O of the laser detection unit 101, and the reference point of the groove image pickup device 103. The measured value D2a of the position of the simulated groove 102a and the measured value D2b of the position of the simulated groove 102b
And the sum of the average value Dm and the average value Dm is calculated as a calibration value.

[0004]

However, the simulation groove 102a,
102b is a groove imager 103 and a laser welding tool.
3 (c) with respect to the movement trajectory (for example, L3) of the tip 104, for example, when the groove imager 103 measures a region surrounded by the ellipses P1 and P2, and when the ellipse Q1 , Q2, the detection value of the average value Dm fluctuates like Dmp and DmQ, and the calibration accuracy deteriorates. Alternatively, it is difficult to accurately specify the position of the center point O of the laser detection unit 101, and deterioration of the calibration accuracy due to the position shift is inevitable.

SUMMARY OF THE INVENTION It is an object of the present invention to accurately detect the amount of misalignment between a welding torch and a copying imager in a direction orthogonal to the y direction.

[0006]

(1) A verification device for profiling calibration of a welding machine according to the present invention is a welding torch for projecting collimating light.
(10,14 ～ 16) 、 Imager for copying to capture the groove of welding target
(11) and a welding machine having a y-drive for driving the welding torch and the imager for copying in the y-direction in which the groove extends,
Position detecting means (5) for detecting the position of the collimating light on the light receiving plane (4) onto which the collimating light is projected; and the light receiving means for which the position detecting means (5) serves as a reference point (0 ') Reference point on plane (4)
(O) and on the same straight line (L1), the copying imager
(11) includes two indices (6a, 6b) each of which gives a point image. In addition, in order to facilitate understanding,
The reference numerals of the corresponding elements of the embodiment shown in the drawings, which will be described later, or the corresponding items or the reference numerals are added for reference.

[0007]

(2) The welding torch (10,14 to 1)
(6) is a means for emitting a weak laser for laser alignment having an optical axis equal to that of the welding laser during non-welding (14,
A laser welding torch including: 16); said light receiving plane (4).
Is a plane of a translucent plate (4) which is disposed at substantially the same height as the surface of the material to be welded with respect to the laser welding torch; the position detecting means (5) includes a translucent plate (4). An imager for verification placed at a position looking up from the direction opposite to the laser welding torch
(5); the two indices (6a, 6b) are located at the same distance (La = Lb) from the reference point.

(3) The translucent plate (4) is supported by a window frame having a light-transmitting aperture (3), and the reference point (O) on the light-receiving plane (4) is at the center of the light-transmitting aperture (3). This is the position of the axis and the reference point of the imager for verification (5).
(0 ') is the position of the center of gravity of the translucent aperture image (3') on the screen in which the entire translucent aperture is contained within one screen.

(4) The two indices (6a, 6b) are small holes (6a, 6b)
The apparatus further comprises light sources (7a, 7b) for emitting illumination light to the eyelets in a direction opposite to the laser welding torch.

(5) The apparatus further includes an air supply passage (9) for blowing out gas from the small holes (6a, 6b) in a direction opposite to the laser welding torch.

(6) The welding torch (10, 14 to 16) and the tracing imager (11) are driven in the y direction to move the trajectory (L2) of the collimating light on the light receiving plane (4). Are detected by the position detecting means (5), and the two indices (6) are detected by the copying image pickup device (11).
a, 6b), and the distance (Lc) between the movement trajectory (L2) and the reference point (O) on the light receiving plane (4), that is, the torch position shift amount (L
c) was calculated, and the above-mentioned 2 was taken by the copying image pickup device (11).
The average value (Ls) of the shortest distances (Lsma, Lsmb) of the reference point (Os) on the field of view of the copying imager (11) for each image of the index (6a, 6b).
m) That is, the scanning detection position deviation amount (Lsm) is calculated, and the sum (Lc + Lsm) of the calculated torch position deviation amount (Lc) and the scanning detection position deviation amount (Lsm) is calculated by using the welding torch and the imaging for scanning. An imitation test method using the test device of the above (2), which is calculated as an amount of relative positional deviation between instruments.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG.
1 is an overall view of an assay device. 1 is a main body of the testing device,
It is a solid product that is manufactured by integral molding by cutting out. A window (opening) 3 is cut in the center at a square, and the outside of the window 3 is shielded from light. The window frame 2 is provided with a ground glass 4 having a size larger than that of the window 3. In the lower part, C as position detection means (imager for verification)
A CD camera 5 is provided. Small holes 6 at both ends of window frame 2
a, 6b are opened, and the light sources 7a, 7
b is installed in each. Further, these are installed in the storage box 8, and by introducing air for purging from the pipe 9, air is blown out from the small holes 6a and 6b, thereby preventing the small holes from being clogged by dust or the like. I have. The midpoint between the small holes 6a and 6b and the center of gravity O of the window 3 are on a straight line L1 connecting the small holes 6a and 6b, and the center of gravity O
And the small holes 6a, 6b are precisely machined so that the distances La, Lb are equal.

In this embodiment, a laser welding torch 10
In the welding, the laser welding torch 10 moves along a straight line L2 extending in the y direction, and detects a groove position (x) detected using the copying imager 11 during welding. The position x is controlled in the direction perpendicular to L2 according to the position), and the groove 12 to be welded is welded while following.

The main body of the inspection apparatus is installed such that the straight line L1 connecting the small holes 6a and 6b is substantially parallel to the moving direction y (L2) of the laser welding torch 10 and the copying image pickup device 11. The small holes 6a and 6b are
Are not necessarily parallel if they are within the field of view of the copying image pickup device 11 during the movement in the y direction.

The field of view 13 of the image of the CCD camera (image sensor for verification) 5 used as the position detecting means is installed so that the entire image 3 ′ of the window 3 is within the field of view. As long as the position of the window frame portion is within the field of view, the position may be changed.

The laser welding torch 10 can irradiate a high-power laser generated by a laser light source 15 at the time of welding and a weak laser for collimation generated by the laser light source 16 at the time of calibration by switching the reflecting mirror 14. It has become.

Referring to FIG. 2, a method for testing imitation using the above-described test apparatus will be described. A straight line L2 indicates the locus of the weak laser on the ground glass 4 when the laser welding torch 10 and the copying image pickup device 11 are driven in the y direction. Points a to j are laser irradiation points on the ground glass 4 detected by the CCD camera 4. The reference point O on the window glass 4 is the center of gravity of the window opening 3, and the center of gravity O ′ of the window opening image 3 ′ captured by the CCD camera 5 corresponds to the reference point O on the window glass 4. Distance Lc between reference point O and straight line L2
Is detected as the distance Lc between the straight line L2 ′ (≒ L2) obtained by the least squares approximation using the position coordinates of the points a to j and the point O, that is, the amount Lc of the torch imitation.

The point (reference point O ') on the photographing screen of the CCD camera 5 at the reference point O of the window opening 3 is previously irradiated with illumination light from the direction opposite to the CCD camera 5 to the ground glass 4. The window opening 3 is photographed by the CCD camera 5. On the photographing screen, a window opening image 3 ′, in which the window frame 2 is dark and the window opening 3 is bright, appears. In the image processing, the window opening image 3 ′ is clarified by binarizing the image brightness to make the window opening image 3 ′ bright and the window frame dark,
Then, the center of gravity O 'of the window opening image 3' is obtained, and
A reference point O ′ on the photographing screen of the CCD camera 5 corresponding to the reference point O on the ground glass 4 is set.

The straight line L3 is the locus of the center line (reference point) of the visual field of the copying image pickup device 11. From the photographing screen of the copying image pickup device 11, each distance of the visual field center line (reference point) Os to each small hole when the copying image pickup device 11 passes directly above each of the small holes 6a and 6b, that is, the shortest distances Lsma and Lsmb
Is measured five times by image processing of the photographing screen of the copying image pickup device 11, and the average value is calculated as the shortest distances Lsma and Lsm.
b. And the average value Lsm = (Lsma +
Lsmb) / 2 is calculated. This average value Lsm corresponds to the distance from the reference point O to the straight line L3, that is, the amount of copying Lsm of the copying image pickup device 11.

Next, the scanning locus L of the laser welding torch 10
The distance between 2 ′ (≒ L2) and the scanning trajectory L3 of the copying image pickup device 11, that is, the copying amount (offset amount) is represented by Lc +
Lsm is calculated.

In the above embodiment, the reference point O is
Although the intermediate point between a and 6b is (La = Lb; La / Lb = 1), LaＬLb may be satisfied. In that case, the weighted average corresponding to the values of La and Lb (interpolation method)
Then, the distance Lsm of the scanning locus L2 ′ (≒ L2) from the reference point O is calculated.

[0022]

According to the present invention, it is possible to accurately calculate the relative displacement between the copying imager and the welding torch, and the displacement due to aging.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of an embodiment of the present invention.

FIG. 2 shows a photographing screen of the CCD camera 5 shown in FIG.
It is a top view which shows the image 3 'of the window opening 3.

3A is a perspective view showing a conventional testing device, and FIG. 3B is a perspective view showing the appearance of the testing device. FIGS. 3B and 3C are plan views showing images taken by the laser detector 101 shown in FIG. .

[Explanation of symbols]

1: Inspection device body 2: Window frame 3: Window opening 4: Ground glass 5: CCD camera 6a, 6b: Small hole 7a: Light source 7b: Light source 8: Storage box 9: Air piping 10: Welding torch 11: Imaging device 12 for copying : Groove 13: Image screen of CCD camera 5 14: Reflector 15: High power laser light source 16: Weak laser light source 101: Laser detector 102 a, 102 b: Simulated groove 103: Imaging device 104 for copying 104: Laser

Claims (6)

[Claims] 1. A welding torch for projecting collimating light, a tracing imager for photographing a groove of a welding target, and a welding torch and a tracing imager are driven in the y direction in which the groove extends. y
Position detecting means for detecting the position of the collimating light on the light receiving plane onto which the collimating light is projected, of a welding machine having a driver; and a reference point on the light receiving plane to be used as a reference point by the position detecting means. And two indices which are on the same straight line and respectively give a point image to the copying image pickup device. 2. The welding torch is a laser welding torch including means for projecting a weak laser for laser alignment having an optical axis equal to that of the welding laser when the welding is not performed; A plane of a translucent plate disposed at substantially the same height as the surface of the material to be welded with respect to the welding torch; the position detecting means looks up at the translucent plate from a direction facing the laser welding torch; The inspection device for profiling calibration of a welding machine according to claim 1, wherein the inspection device is a verification imager arranged at a position; and the two indices are located at the same distance from the reference point. 3. The translucent plate is supported by a window frame having a light-transmitting opening, the reference point on the light-receiving plane is the position of the center axis of the light-transmitting opening, and the reference point of the imaging device for verification is light-transmitting. The inspection apparatus according to claim 2, wherein the center of gravity of the image of the transparent aperture on the screen in which the entire optical aperture is contained in one screen. 4. The two indicators are eyelets and the device further comprises:
4. A light source which emits illumination light to a small hole in a direction opposite to a laser welding torch.
The verification device for profiling calibration of a welding machine as described in the above. 5. An apparatus according to claim 4, wherein the apparatus further comprises an air supply passage for blowing gas from a small hole in a direction opposite to the laser welding torch. 6. The welding torch and the tracing imager are designated by y.
Driven in the direction, the movement trajectory of the collimating light on the light-receiving plane is detected by the position detecting means, and the two indices are photographed by a copying imager. , That is, the torch position shift amount, and calculates the shortest distance of each reference point on the visual field of the copying image pickup device with respect to each image of the two indices taken by the copying image pickup device. Calculating an average value, that is, a scanning detection position deviation amount, and calculating a sum of the calculated torch position deviation amount and the scanning detection position deviation amount as a relative position deviation amount between the welding torch and the scanning imaging device; An imitation test method using the test device according to claim 2.