JPH11285825A - Welding position detection method and device, and automatic welding device - Google Patents

Abstract

(57) Abstract: Provided is a welding position detection method and device capable of detecting a position with high accuracy, and an automatic welding device using the same. A light projecting means (12) for irradiating a light cutting line to the surface of a workpiece (2, 3) so as to cross a groove (4), and a reflected light of the light cutting line reflected by the workpieces (2, 3). A welding position detecting method in a welding position detecting device having a two-dimensional light receiving means 14 for detecting a light section image and an image processing means 19 for calculating a light section image received by the light receiving means 14 to detect a welding position. Then, a light cutting line is irradiated so as to cross the groove 4 and the welding electrode 1, and from the received light cutting images, both side boundaries of the groove bottom and both sides of the welding electrode are calculated, and The center position of the bottom of the tip 4 and the center position of the welding electrode 1 are calculated, and the amount of deviation of each center position is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a welding position for performing grooved contour welding, and an automatic welding apparatus.

[0002]

2. Description of the Related Art For example, when a thick plate having a thickness of 30 mm or more is welded, a groove is formed in the welded portion, and the groove is joined by performing multi-layer welding. In multi-layer welding, since the number of passes of the weld bead is large, the workpiece is gradually deformed by repeated thermal strain. In multi-layer welding, in order to obtain a high-quality weld bead, the welding electrode (non-consumable electrode, welding wire, etc.) ) Must be positioned accurately.

[0003] As in the prior art, when a skilled welding operator visually judges the boundary position of a weld bead and performs welding manually by experience and intuition, a high quality weld bead can be formed. . However, not only workability is bad,
In a situation where the number of welding workers, especially skilled workers, is decreasing, it is not possible to rely on welding workers.

[0004] In order to automate the welding of a thick plate as described above, and to save labor and unmanned welding work, the groove of the work to be welded is automatically detected, and a welding electrode is formed based on the detection result. For example, Japanese Patent Application Laid-Open No. H5-15-1
No. 38,354 discloses an automatic welding apparatus for welding.

[0005] This automatic welding copying apparatus includes a laser slit light emitting section for obtaining a light cut image in a groove in front of the welding torch in the traveling direction, and a welding slit torch and a laser slit light emitting section located in front of the laser slit light emitting section in the traveling direction. It has an ITV camera for detecting welding information including a light cut image and a weld pool, and means for calculating a groove shape based on welding information of the ITV camera and calculating a welding electrode position.

[0006] Then, the light cut image and the welding electrode image by the laser slit light appear in one image information by the ITV camera, and the inner shape of the groove obtained from the light cut image and the welding electrode obtained from the welding electrode image. The position of the welding torch can be controlled by detecting the displacement of the welding torch from the position. At this time, the position of the lower end of the nozzle of the welding torch is detected as the welding electrode position.

[0007]

However, since the nozzle at the tip of the welding torch is oxidized by heat during welding or has a darkened color like a weld pool due to adhesion of welding fume, the nozzle is not melted on the image. It is not easy to distinguish between the pond and the nozzle, which causes a detection error, and the detection accuracy may be reduced.

In view of the above circumstances, it is an object of the present invention to provide a welding position detecting method and apparatus capable of detecting a position with high accuracy regardless of contamination of a welding electrode, and an automatic welding apparatus using the same. It is in.

[0009]

In order to achieve the above object, the invention according to claim 1 of the present application provides a light projecting means for irradiating a surface of an object to be welded with a light cutting line across a groove. A two-dimensional light receiving means for detecting light reflected by the light cutting line reflected by the workpiece as a light cutting image, and an image processing means for calculating a light cutting image received by the light receiving means and detecting a welding position A welding position detecting method in a welding position detecting device having a method of irradiating a light cutting line so as to cross the groove and the welding electrode, and from a received light cutting image, welding both side boundaries of the groove bottom and welding. Calculate both sides of the electrode and
Calculate the center position of the groove bottom and the center position of the welding electrode,
The shift amount of each center position is detected.

According to a second aspect of the present invention, in the first aspect of the present invention, a part of the light cutting line is shielded by a welding electrode from the opposite side of the light receiving means and the welding electrode. Irradiation.

According to a third aspect of the present invention, there is provided a light projecting means for irradiating a light cutting line on a surface of a workpiece so as to cross the groove, and a reflection of the light cutting line reflected by the workpiece. A welding position detecting method for a welding position detecting apparatus, comprising: a two-dimensional light receiving unit that detects light as a light cutting image; and an image processing unit that calculates a light cutting image received by the light receiving unit and detects a welding position. Then, while irradiating a light cutting line across the groove, irradiating the welding electrode with light having a spread from the opposite side across the light receiving means and the welding electrode, the received light cutting image and the welding electrode are illuminated. From the silhouette image, calculate both sides of the groove bottom and both sides of the welding electrode, calculate the center position of the groove bottom and the center position of the welding electrode, and detect the shift amount of each center position. I made it.

According to a fourth aspect of the present invention, there is provided a light projecting means for irradiating a light cutting line on a surface of a work to be traversed across a groove and a welding electrode, and reflected by the welding electrode and the work to be welded. The two-dimensional light receiving means that detects the reflected light of the light-section line as a light-section image, and calculates the both-side boundary of the groove bottom and both-side boundary of the welding electrode from the received image of the welding electrode and the light-section image At the same time, an image processing means for calculating the center position of the groove bottom and the center position of the welding electrode and detecting a shift amount of each center position is provided.

According to a fifth aspect of the present invention, there is provided a light projecting means for irradiating a light cutting line on a surface of a workpiece to traverse the groove, and an external light source for irradiating the inside of the groove including a welding electrode. When,
A two-dimensional light receiving means which is arranged so as to face the external light source with the welding electrode interposed therebetween and which simultaneously detects a silhouette image of the welding electrode and a light cutting image of a light cutting line reflected by the work to be welded; From the image of the received welding electrode and the light-cut image,
Image processing means for calculating both side boundaries of the groove bottom and both sides of the welding electrode, calculating the center position of the groove bottom and the center position of the welding electrode, and detecting a shift amount of each center position. Provided.

According to a sixth aspect of the present invention, there is provided a light projecting means for irradiating a light cutting line on the surface of the workpiece so as to cross the groove, and a light reflected by the light cutting line reflected by the workpiece. A two-dimensional light receiving means for detecting the light cut image as a light cut image, and a welding position detecting device having an image processing means for calculating and processing the light cut image received by the light receiving means to detect the welding position, In an automatic welding apparatus configured to control a movement path of a welding electrode at the time of welding based on an output, a light projecting unit that irradiates a light cutting line so as to cross the groove and the welding electrode is received by the light receiving unit. Calculate the center of the groove bottom and the center of the welding electrode, calculate the center of the groove bottom and the center of the welding electrode, and detect the amount of deviation between the respective centers. And welding position detecting means for And to control the moving path of the pole.

Further, the invention according to claim 7 is a light projecting means for irradiating a light cutting line on the surface of the workpiece so as to cross the groove, and a reflected light of the light cutting line reflected by the workpiece. A two-dimensional light receiving means for detecting the light cut image as a light cut image, and a welding position detecting device having an image processing means for calculating and processing the light cut image received by the light receiving means to detect the welding position, In an automatic welding apparatus configured to control a movement path of a welding electrode at the time of welding based on an output, a light projecting unit that irradiates a light cutting line so as to cross the groove and the welding electrode is received by the light receiving unit. Calculate the center of the groove bottom and the center of the welding electrode, calculate the center of the groove bottom and the center of the welding electrode, and detect the amount of deviation between the respective centers. And both sides of the groove bottom A welding position detecting means for calculating a height provided, and to control the movement path and the height of the welding electrode.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show an automatic welding apparatus according to the present invention. FIG. 1 is a configuration diagram of the automatic welding apparatus according to the present invention, FIG. 2 is a flowchart showing a welding position detecting procedure, and FIG. FIG. 4 is an explanatory diagram showing an example of a light-section image of a portion, FIG. 4 is an explanatory diagram showing another example of a light-section image of a groove portion, FIG. 5 is an explanatory diagram showing a welding position detection method, and FIG. It is a flowchart which shows the welding procedure including welding position detection in an automatic welding apparatus. 3 to 5 show a state in which white and black are inverted.

In FIG. 1, reference numeral 1 denotes a non-consumable welding electrode such as a tungsten electrode (hereinafter simply referred to as an electrode). Reference numerals 2 and 3 denote members to be welded, which are arranged at predetermined intervals, and a groove 4 is formed on the opposing surface thereof. B1 to B4 are welding beads,
It is placed in the groove 4. Hereinafter, the groove 4 includes the groove 4 and the weld beads B1 to B4. The surface of the weld bead (B4 in the figure) is called the groove bottom.

Reference numeral 5 denotes an electrode position control mechanism,
3, an X traveling vehicle 7 traveling on the X traveling shaft 6, a Z traveling shaft 8 fixed to the X traveling vehicle 7, A traveling Z traveling vehicle 9 and a Y traveling shaft 10 fixed to the Z traveling vehicle 9
And a Y traveling vehicle 11 traveling on the Y traveling axis 10, and the Y traveling vehicle 11 supports the electrode 1.

Numeral 12 denotes a light projecting means, which is supported by the Y traveling carriage 11 and linearly extends between the workpieces 2 and 3 and the electrode 1 inserted into the groove 4 so as to cross the electrode 1 and the groove 4. A light cutting line Q is formed by irradiating the light beam 13 of FIG. Numeral 14 denotes a light receiving means, which is supported by the Y traveling carriage 11 and which has an interference filter 15
V camera 16 and I
The TV camera 16 images the light cutting line Q.

A control circuit 17 controls the irradiation of the light beam 13 by the light projecting means 12. A control circuit 18 controls the light receiving means 14 and outputs an analog video (image) signal captured by the ITV camera 16 to the outside.

Reference numeral 19 denotes an image processing device, and the control circuit 18
A / A converts the analog image signal input from
An image input unit that accepts D-converted multivalued image data, a multivalued image storage unit that stores the multivalued image data, and binarizes the multivalued image data stored in the multivalued image storage unit with a predetermined threshold value A binarization processing unit that extracts a light section image corresponding to the light section line Q; a binary image storage unit that stores a binary image obtained by the binarization processing unit; and a binary image storage unit. A thinning processing unit for thinning the stored binary image having a certain width by obtaining a center position in each width direction; a thin line image storage unit for storing a thin line image obtained by the thinning processing unit; A line element extraction unit that divides the thin line image stored in the image storage unit into a plurality of line elements (straight lines); a line element storage unit that stores the line elements extracted by the line element extraction unit; From the stored line elements, the width of the electrode 1 and the width of the groove bottom are determined, and the welding position is determined. An arithmetic processing unit for calculating a, and a like main control unit for controlling the overall.

Reference numeral 20 denotes an electrode position control device which drives and controls the electrode position control mechanism 5 to move the electrode 1 to a desired position. A welding power source 21 applies a predetermined welding voltage and current to the electrode 1. Reference numeral 22 denotes an overall control device that controls the image processing device 19, the electrode position control device 20, and the welding power source 21 as a whole.

In the above configuration, the electrode position control device 2
In response to the command of 0, the Y traveling vehicle 11 is operated, and the electrode 1
Is moved to a predetermined position. In accordance with a command from the control circuit 17, a linear light beam 13 is emitted from the light projecting means 12 to the workpieces 2 and 3 across the groove 4. At the same time, the reflected light from the workpieces 2 and 3 is imaged by the light receiving means 14.

The control circuit 18 sends the analog image signal output from the light receiving means 14 to the image input section of the image processing device 19. The image input unit A / D converts the applied analog image signal into a digital signal, receives the digital signal as multi-value image data, and stores the multi-value image data in the multi-value image storage unit. The binarization processing unit calls out the multi-valued image data stored in the multi-valued image storage unit, binarizes the multi-valued image data with a predetermined threshold value, and converts the light section image Ip corresponding to the light section line Q as shown in FIG. ,
IbL and IbR are extracted (step S1 in FIG. 2) and stored in the binary image storage unit.

In FIG. 3, the light-section image Ip is based on light reflected by the light-section line Q reflected by the electrode 1, and the light-section images IbL and IbR are light-section images Qb reflected by the groove bottom. This is due to the reflected light.

The thinning processing unit calls a binary image having a certain width stored in the binary image storage unit, finds the center position in each width direction, thins it, and stores it in the thin line image storage unit. The line element extraction unit calls out the thin line image stored in the thin line image storage unit, and determines the line elements (straight lines) L1, L2, L2, and L3 as shown in FIGS.
It is divided into L3, L4, L5, and L6 and stored in the line element storage unit.

At this time, when the opening angle of the groove 4 formed on the members 2 and 3 to be welded is large, the line elements LSL and LSR corresponding to the side surfaces of the groove 4 appear as shown in FIG. . However, when the opening angle of the groove 4 is small, as shown in FIG.
SR does not appear.

Even if the opening angle of the groove 4 is large, the machined groove 4 has a substantially flat processing surface, so that the above processing is performed and the side surface of the groove 4 The remaining line elements LSL and LSR remain as relatively long straight lines. Therefore, by selecting the lengths of the line elements on a predetermined basis, as shown in FIG. 5, only the line elements L1, L2, L3, L4, L5, and L6 of the light section image at the groove bottom are extracted. Can be.

The line elements L1, L thus extracted
2, L3, L4, L5, and L6 are grouped according to the size of the interval between adjacent line elements. In the example of FIG. 5, a first group IbL is configured by the line elements L1, L2, L3,
The line elements L4, L5, and L6 form a second group IbR. In other words, between the first group IbL and the second group IbR, the light cut images IbL, IbL
This indicates that bR has become discontinuous.

The image processing apparatus 19, the left end of the coordinates of the first group IbL shown in FIG. 5 (the line element L1) left boundary coordinates _BL (X BL, Y BL) and a second group IbR
(Line element L6) The coordinates of the right end are represented by the right boundary position coordinates BR (X
_BR , Y _BR ) (step S2 in FIG. 2) and stored.

The detected left boundary position coordinates BL (X
_BL , _YBL ) and the right boundary position coordinates BR ( _XBR , _YBR ).
, The middle point (center of groove 4) Cb (X _Cb , Y _Cb ) of the middle point of the left boundary position coordinate BL and the right boundary position coordinate BR is represented by X _Cb = (X _BL + X _BR ) / 2 Y _Cb = (Y _(BL + _YBR ) / 2 (step S3 in FIG. 2) and stored.

The image processing apparatus 19 sets the coordinates of the right end of the first group IbL (line element L3) shown in FIG. 5 as the left boundary position coordinates PL (X _PL , Y _PL ) of the electrode shadow part, and The coordinates of the left end of the group IbR (line element L6) are detected as the right boundary position coordinates PR (X _PR , Y _PR ) of the electrode shadow part (step S4 in FIG. 2) and stored.

From the detected left boundary position coordinates PL (X _PL , Y _PL ) of the electrode shadow part and the right boundary position coordinates PR (X _PR , Y _PR ) of the electrode shadow part, the left boundary position coordinate PL is obtained.
And the middle point (center of electrode 1) Cp (X _Cp , Y _Cp ) of the middle point of the right boundary position PR are calculated by X _Cp = (X _PL + X _PR ) / 2 Y _Cp = (Y _PL + Y _PR ) / 2 (Step S5 in FIG. 2).

The midpoint (center of groove 4) position coordinates Cb (X _Cb , Y _Cb ) and midpoint (center of electrode 1) position coordinates Cp (X _Cp , Y _Cp ) calculated in steps 3 and 5 From
Deviation Δ of the center position of electrode 1 from the center position of groove 4
S is calculated from ΔS = X _Cp −X _Cb (step 6S in FIG. 2) and stored.

Since the calculated shift amount ΔS of the center position of the electrode 1 with respect to the center position of the groove 4 is a detection result on the screen of the ITV camera 16, it is determined by various constants such as the imaging magnification of the ITV camera 16. The coordinates are converted into the actual displacement amount between the groove 4 and the electrode 1 (step S7 in FIG. 2).

From the above detection results, for example, the width between the left boundary position coordinates BL and the right boundary position coordinates BR (| X _BL −
X _BR |), or the width (| X _PL −X _PR |) between the left boundary position coordinate PL and the right boundary position coordinate PR, or the deviation ΔS of the center position of the electrode 1 with respect to the center position of the groove 4.
Is within a preset range, and the detection result is evaluated (step S8 in FIG. 2). If the detection result is evaluated as abnormal, error processing is performed and the subsequent work is stopped.

The operation of the automatic welding apparatus using the above welding position detecting method will be described with reference to the flowchart shown in FIG.

After the operation starts, the overall control device 22 inquires of the electrode position control device 20 about the current position of the electrode 1, and obtains information on the current position of the electrode 1 from the report from the electrode position control device 20 (step F18). (Step F
1).

The overall control device 22 includes the electrode position control device 2
A movement command for raising the electrode 1 to 0 is issued (step F2). The electrode position control device 20 operates the electrode position control mechanism 5 based on the movement command from the overall control device 22 to pull up the electrode 1 to a predetermined position (step F1).
9).

When the electrode 1 is raised, the overall control device 22 issues a movement command to the electrode position control device 20 to move the electrode 1 to a position above the reference position at which welding position detection is started (step F3). The electrode position control device 20 operates the electrode position control mechanism 5 based on the movement command from the overall control device 22 to move the electrode 1 above the reference position (step F20).

When the electrode 1 is positioned above the reference position, the overall control device 22 issues a movement command to the electrode position control device 20 to lower the electrode 1 to a position where the welding position can be detected (step F4). ). Electrode position control device 2
0, the electrode position control mechanism 5 is operated based on the movement command from the overall control device 22 to lower the electrode 1 to a predetermined position in the groove 4 where the welding position can be detected (step F).
21).

When the electrode 1 is lowered to a predetermined position, the overall control device 22 issues a movement command to move the electrode 1 in the X direction to the electrode position control device 20 (step F5).
The electrode position control device 20 operates the X traveling vehicle 7 by the electrode position control mechanism 5 to move the electrode 1 in the X direction based on the movement command from the overall control device 22 (step F).
22). The movement of the electrode 1 in the X direction is continued until the detection operation up to the welding end point ends.

After the movement of the electrode 1 in the X direction is started, the overall control device 22 issues a welding position detection command to the image processing device 19 (step F6). The image processing device 19
Based on the welding position detection command from the overall control device 22,
The welding position is detected by the above-described procedure (step F2).
7).

During the movement of the electrode 1 in the X direction, the overall control device 22 inquires of the electrode position control device 20 about the current position of the electrode 1 and, based on the report from the electrode position control device 20 (step F23), the control of the electrode 1 is performed. The information of the current position is obtained (step F7).

The general control device 22 inquires of the image processing device 19 about the detection result in parallel with the acquisition of the current position information of the electrode 1, and receives the detection result report (step F28) from the image processing device 19 (step F28). F8), and stores the detected data in the internal storage device (step F9).

The overall control unit 22 repeats the detection of the welding position at a predetermined interval from the welding start position to the welding end position (step 10).

When the electrode 1 reaches the welding end position, the overall control device 22 issues a stop command to the electrode position control device 20 to stop the movement of the electrode 1 in the X direction (step F1).
1). The electrode position control device 20 causes the electrode position control mechanism 5 to stop traveling of the X traveling vehicle 7 based on the stop command from the overall control device 22 (step F24).

The overall control device 22 includes the electrode position control device 2
A movement command for raising the electrode 1 to 0 is issued (step F12). The electrode position control device 20 includes an overall control device 22
The electrode position control mechanism 5 is actuated to raise the electrode 1 to a predetermined position on the basis of the movement command (step F2).
5) Move the electrode 1 to the welding start position (Step F)
26).

On the other hand, the overall control device 22 calculates the position correction amount of the electrode 1 in the direction of the Y traveling axis 10 based on the detection result of the welding position, and calculates the movement path of the electrode 1 during welding (step F13). .

The overall control device 22 instructs the calculated position of the electrode 1 to the electrode position control device 20 and also instructs the welding power source 21 to start welding. Electrode position control device 2
0 activates the electrode position control mechanism 5 and the overall control device 2
The electrode 1 is moved in accordance with the movement path instructed from 2. At the same time, the welding power source 21 applies a welding current and voltage to the electrode 1 and the members 2 and 3 to generate an arc between the electrode 1 and the members 2 and 3 and the welding bead. Then, a welding wire is fed from a welding wire feeding device (not shown) to the arc to perform welding (step F14).

After the start of welding, the overall control device 22 inquires of the electrode position control device 20 about the current position of the electrode 1, and based on the current position information of the electrode 1 reported from the electrode position control device 20, determines whether the current position is the welding end position. It is determined whether or not it is (step F14). If the electrode 1 has not reached the welding end position, welding is continued.

When the electrode 1 has reached the welding end position, the overall control device 22 issues a welding stop command to the electrode position control device 20 and the welding power source 21. Further, the overall control device 22 determines whether or not all of the preset welding passes have been completed for the completed welding passes (step F1).
6). If all planned welding passes have been reached,
Finish the work.

If the total welding pass has not been reached, when the next welding is performed, the moving path of the electrode 1 used in the immediately preceding welding may be used as it is, or a new electrode 1 may be used. It is determined whether to set a moving route (step F17).

When the moving path of the electrode 1 used in the immediately preceding welding is to be used as it is, the flow returns to the step F12 to perform the welding. When a new movement path of the electrode 1 is set, the process returns to the step F1 and the above-described operation is repeated.

In the above embodiment, the case where the light projecting means 12 and the light receiving means 14 are provided on the same side with respect to the electrode 1 has been described.
4 may be arranged on opposite sides of the electrode 1.

The case where the light projecting means 12 irradiates the linear light beam 13 has been described. However, the light projecting means 12 is scanned across the groove 4 by spot light such as a laser beam, and the reflected light is received by a line sensor. Then, the shape of the groove 4 may be detected from the principle of triangulation.

The positions (Y axis and Z axis) of the Y traveling axis 8 and the Z traveling axis 10 in the electrode position control mechanism 5 may be reversed. 3 may be moved in the X-axis direction, and the electrodes may be moved in the Y-axis direction and the Z-axis direction. That is, as long as the electrode 1 is configured to be able to move in three-dimensional directions with respect to the workpieces 2 and 3, an articulated robot, a self-feeding welding robot, or the like can be used.

FIGS. 7 to 9 show another embodiment of the welding position detecting device in the automatic welding device according to the present invention. FIG. 7 is a block diagram of the welding position detecting device, and FIG.
FIG. 9 is an explanatory diagram showing a light cut image, and FIG. 9 is a characteristic diagram showing an intensity distribution of light near the electrodes in FIG.

In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals. Reference numeral 23 denotes an external light source, which is disposed on the Y traveling carriage 11 in the above embodiment so as to face the light receiving means 14 with the electrode 1 interposed therebetween. Reference numeral 24 denotes a control circuit that controls ON / OFF of the external light source 23 and its brightness based on a command from the image processing device 19.

In the above-described configuration, the light beam 12 irradiates the linear light beam 13 to the groove 4, and the external light source 23 irradiates the light to the groove 4 with spreading light. At the same time, the light receiving unit 14 captures an image of the groove 4. At this time, by adjusting the brightness of the light projecting means 12 and the external light source 23, the brightness of the light cut image Ib, the reflection image Ik in the groove 4 by the external light source 23 and the silhouette image Id of the electrode 1 shown in FIG. The relationship of the heights can be set to IB>Ik> Id, and the distribution of brightness on the horizontal line AA crossing the silhouette image Id of the electrode 1 can be as shown in FIG.

The procedure for detecting the welding position from the output of the light receiving means 14 is almost the same as that shown in FIG. The difference from the above-described procedure is that the light cut image Ib is included in one group. Therefore, when detecting the positions of the shadow part boundaries CL and CR of the electrode 1, the silhouette image Id of the electrode 1 is used instead of the light cut image Ib. The point is to use the change in the brightness of the horizontal line AA that crosses (the position where the value changes from 1 to 0 or 0 to 1 in the binarized data is defined as the boundary position CL or CR of the shadow portion).

The left boundary position coordinates CL (X _CL , Y _CL ) and right boundary position coordinates CR (X _CR ,
Y _CR ), the middle point (center of electrode 1) position coordinate Cp (X _Cp ,
Y _Cp ) is calculated by X _Cp = (X _CL + X _CR ) / 2 Y _Cp = (Y _CL + Y _CR ) / 2. Others are the same as in FIG.

FIG. 10 is an explanatory view showing another example of the light-section image in the welding position detecting device of the automatic welding device according to the present invention.

As shown in the drawing, in this example, the height of the left boundary position BL and the right boundary position BR of the groove bottom are different from those in the example shown in FIG. In such a case, the left boundary position coordinates BL ( _XBL , _YBL ) and the right boundary position coordinates B
R (X _BR, Y _BR) the height difference [Delta] H of the left and right boundary position from the calculated by _{ΔH = (Y BL -Y BR)} .

On the basis of the calculation result, the aim of welding can be corrected on the lower side (BR side in the figure) of the groove bottom so that the height of the groove bottom can be made uniform. Therefore, in the case of multi-layer welding, even if a deviation occurs in the weld bead in the middle layer for some reason, the deviation of the weld bead can be repaired by welding after detecting the welding position, and a high-quality weld bead can be obtained. be able to.

[0066]

As described above, according to the present invention, an electrode and a groove are irradiated with a light-section line, and a light-section image is taken.
Alternatively, irradiating the groove with a light cutting line and irradiating the electrode with an external light source to capture a light cutting line and a silhouette image of the electrode so as to detect a shift between the center position of the groove and the center position of the electrode. Therefore, highly accurate detection can be performed.
Further, by performing high-precision detection, high-precision correction can be performed, and high-quality welding can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an automatic welding device according to the present invention.

FIG. 2 is a flowchart showing a welding position detection procedure.

FIG. 3 is an explanatory view showing an example of a light section image of a groove portion.

FIG. 4 is an explanatory view showing another example of a light section image of a groove portion.

FIG. 5 is an explanatory diagram showing a welding position detection method.

FIG. 6 is a flowchart showing a welding procedure including welding position detection in the automatic welding device.

FIG. 7 is a configuration diagram of a welding position detection device.

FIG. 8 is an explanatory view showing a light-section image.

FIG. 9 is a characteristic diagram showing an intensity distribution of light near an electrode in FIG. 8;

FIG. 10 is an explanatory view showing another example of the light-section image in the welding position detection device of the automatic welding device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electrode 2, 3 ... Welded member, 4 ... Groove, 5 ... Electrode position control mechanism, 12 ... Light emitting means, 13 ... Light beam, 14 ... Light receiving means, 17 ... Control circuit, 18 ... Control circuit, 19 ... image processing device, 20 ... electrode position control device, 21 ... welding power source, 2
2 ... Overall control device, 23 ... External power supply, 24 ... Control circuit.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Junichiro Morisawa 3-1-1, Sakaimachi, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant

Claims (7)

[Claims] 1. A light projecting means for irradiating a light cutting line on a surface of a workpiece to traverse a groove, and detecting light reflected by the welding object as a light cutting image. Dimensional light receiving means, a welding position detection method in a welding position detection device having image processing means for calculating and processing a light section image received by the light receiving means and detecting a welding position, wherein the groove and the welding electrode are By irradiating the light cutting line so as to traverse, from the received light cutting image, calculate both side boundaries of the groove bottom and both sides of the welding electrode, and calculate the center position of the groove bottom and the center position of the welding electrode. And detecting the deviation amount of each center position. 2. The welding position detecting device according to claim 1, wherein said light cutting line is irradiated from the opposite side of said light receiving means and the welding electrode so that a part thereof is blocked by the welding electrode. Method. 3. A light projecting means for irradiating a light cutting line on a surface of a workpiece so as to cross a groove, and detecting a light beam of the light cutting line reflected by the workpiece as a light cutting image. A welding position detecting method in a welding position detecting device having a two-dimensional light receiving means and an image processing means for calculating and processing a light cut image received by the light receiving means to detect a welding position, so as to cross the groove. While irradiating the light cutting line and irradiating the welding electrode with light having a spread from the opposite side with the light receiving means and the welding electrode interposed therebetween, from the received light cutting image and the silhouette image of the welding electrode, both sides of the groove bottom are obtained. A welding position detection method comprising: calculating a boundary portion on both sides between a boundary portion and a welding electrode; calculating a center position of a groove bottom and a center position of the welding electrode; and detecting a shift amount of each center position. 4. A light projecting means for irradiating a light cutting line on a surface of a workpiece to traverse a groove and a welding electrode, and light reflecting light of the light cutting line reflected by the welding electrode and the workpiece. From the two-dimensional light receiving means to be detected as a cut image, the received welding electrode image and the light cut image, the two-sided boundary of the groove bottom and the two-sided boundary of the welding electrode are calculated, and the center position of the groove bottom is calculated. And a center position of the welding electrode, and image processing means for detecting a shift amount of each center position. 5. A light projecting means for irradiating a light cutting line on a surface of an object to be welded so as to cross a groove, an external light source for irradiating a groove including a welding electrode, and an external light source sandwiching the welding electrode. A two-dimensional light receiving unit that is arranged to face the light source and simultaneously detects a silhouette image of the welding electrode and a light cutting image of a light cutting line reflected by the work to be welded, and a welding electrode of the received welding electrode. From the image and the light-section image, calculate both sides of the groove bottom and both sides of the welding electrode, calculate the center position of the groove bottom and the center position of the welding electrode, and calculate the amount of deviation between the respective center positions. A welding position detecting device, comprising: an image processing means for detecting. 6. A light projecting means for irradiating a light cutting line on a surface of a workpiece so as to cross a groove, and two-dimensionally detecting a light of the light cutting line reflected by the workpiece as a light cutting image. A welding position detecting device having a light receiving means and an image processing means for calculating a light cutting image received by the light receiving means to detect a welding position, and based on an output of the welding position detecting means, a welding electrode at the time of welding. In an automatic welding apparatus configured to control the moving path of the light, a light projecting means for irradiating a light cutting line across the groove and the welding electrode, and a light cutting image received by the light receiving means, a groove bottom portion Along with calculating both side boundaries of the welding electrode and both side boundaries of the welding electrode, calculating the center position of the groove bottom and the center position of the welding electrode, and providing a welding position detecting means for detecting the amount of deviation of each center position, To control the movement path of the welding electrode Automatic welding apparatus, characterized in that the. 7. A light projecting means for irradiating a light cutting line on a surface of a workpiece so as to cross a groove, and a two-dimensional detecting means for detecting, as a light cutting image, light reflected by the light cutting line reflected by the workpiece. A welding position detecting device having a light receiving means and an image processing means for calculating a light cutting image received by the light receiving means to detect a welding position, and based on an output of the welding position detecting means, a welding electrode at the time of welding. In an automatic welding apparatus configured to control the moving path of the light, a light projecting means for irradiating a light cutting line across the groove and the welding electrode, and a light cutting image received by the light receiving means, a groove bottom portion Calculate the center position of the groove bottom and the center position of the welding electrode, calculate the center position of the groove bottom and the center position of the welding electrode, and detect the amount of deviation of each center position. Welding position detection hand that calculates the height of the part Preparative provided, automatic welding apparatus is characterized in that so as to control the movement path and the height of the welding electrode.