JPH0452078A - Welding method - Google Patents

Abstract

PURPOSE:To always accuratelly move a welding torch to the welding target position and also to confirm the welding torch by showing the welding target position and the tip position of the welding torch by spot light of an optical cutting method and a semiconductor laser and enabling to control the positional relation thereof. CONSTITUTION:A CCD camera 3 is set up above the welding target position P and the semiconductor laser 4 is set up at an optional angle on abutment between plates 1 and 2 passing the position P and catches the position P. The position of the torch 5 is then operated so that the electrode tip of the welding torch 5 intersects a plane H formed by a laser beam of the semiconductor laser 4 at a point and the point of intersection is made to Q. The welding torch 5 is moved so that the point P is coincident with the point Q. At this time, the electrode tip of the welding torch 5 moves on the plane H formed by the above-mentioned laser beam and when the point P is coincident with the point Q, the welding torch 5 is pulled up by the arc length and set up. Consequently, an electrode of the welding torch 5 can be correctly set up on the target position P.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a welding positioning method that performs optimal control.

(Conventional technology) In sensing welding using the conventional optical cutting method,
As disclosed in Japanese Patent No. 49114, the groove center position is accurately determined over the entire length of the seam, and welding is performed while correcting the position of the welding torch based on the groove position data. This method classifies the groove shape of a sutured part of a welded pipe etc. into multiple reference shapes in advance, and determines the base of the groove point of each reference shape.
1! In addition to determining the slope value, the groove shape of the seam of the welded pipe to be welded is photographed and converted into coordinates, and the slope of a minute section is determined and compared with the reference slope value to determine the center position of the groove, and the welding position is determined. I was trying to control it.

For this reason, in this method, as shown in FIG. 16, a light source 22 is provided directly above the seam 21 of the welded pipe 20, and the thrift light 23 is irradiated to the seam 21, and the groove revealed by this irradiation is A shape image 24 is photographed by a camera 25, the image is sent to a memory 26, and a calculation device 27 compares it with a pre-classified reference shape.Based on this calculation result, a welding torch 29 is activated via a servo mechanism 28. Welding was done by positioning it in the center of the groove.

(Problems to be Solved by the Invention) However, in the above-described conventional method, welding is performed while correcting the position of the welding torch based on the groove position data, which has the problem that the equipment becomes expensive.

An object of the present invention is to propose a welding method that can perform welding by confirming both the electrode tip position and the welding target position as an unprecedented welding positioning method using a simple device.

(Means for Solving the Problems) In order to achieve the above object, the welding method of the present invention uses an optical cutting method to teach a welding torch to the target welding position of the workpiece, and improves the gloss of the welded joint. The welding start position and end position are determined by measuring the deviation from the position and the shape of the joint groove, and by moving the optical cutting line, and the position of the welding torch is corrected to the target position. It is something.

(Function) The target position of welding and the position of the tip of the welding torch are expressed using the optical cutting method and the spot light of the semiconductor laser, and the positional relationship can be controlled, so that the welding torch always moves accurately to the target welding position. It is also possible to verify the welding torch.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 to 15. This explanation will show examples of typical welded joints, butt joints, cross or T-shaped joints, and corner joints.

FIG. 1 shows an example of a butt joint, and numerals 1 and 2 in the figure are plates. The target position for welding is P on the butt portion of these plate materials 1 and 2. A CCD camera 3 is installed above the target position P of this welding, and a semiconductor laser 4 is installed at an arbitrary angle on the butt of the plates 1 and 2 passing through the position P to capture the position P. Then, the position of the welding torch 5 is manipulated so that the electrode tip of the welding torch 5 and the plane H formed by the laser beam of the semiconductor laser 4 intersect at one point, and the intersection point is designated as Q. As a result, the image captured by the CCD camera 3 is the second one.
It will appear as shown in the figure.

Next, welding torch 5 is moved so that point P and point Q in FIG. 2 coincide. At this time, the electrode tip of the welding torch 5 moves on the plane H created by the laser beam, and points P
Assuming that and point Q match, the welding torch 5 is set to be pulled up by an arc length l as shown in FIG. As a result, ti of the welding torch 5 can be set correctly on the target position P. In addition, since the angle θ between the laser beam and the plate material when the semiconductor laser 4 is irradiating the position P is known, the distance between PQ when the arc length is 2 can also be calculated, so the arc length It is also possible to set the electrode so that the angle is at position 2, find a point Q'' where it intersects with the plane H, and move the electrode tip onto P.

Fig. 4 is an example of a cross or a T scholar.If plate material 1 is set up on plate material 2 and the target position of welding is P, then when position P is irradiated with semiconductor laser 4, there will be a gap between the laser beam and position P. A plane H is formed in .

Place the tip of the welding torch on this plane H to obtain a point Q.

The image captured by the CCD camera 3 of this result is shown in FIG. 5. Next, move the welding torch 5 so that the point Q shown in FIG. When P and P match, the welding torch 5 is pulled up to the arc length 2, and the settings as shown in FIG. 6 can be made.

Furthermore, if the angles formed between the plane H and the plate material 1 or 2 are θ and θ2, since these angles are known, the positional relationship between the plate materials l and 2 and the electrodes of the welding torch 5 can be calculated, and each can be set at a predetermined position. It is also possible to move point Q directly above point P to match them.

FIG. 7 shows an example of a hemlock joint, in which plate materials 1 and 2 are placed with their end surfaces adjacent to each other, and a target position P of welding is irradiated with a semiconductor laser 4. A point Q is obtained by aligning the tip of the welding torch 5 with the plane H created by irradiating the laser beam onto the point IP. When the result is captured by the CCD camera 3, it becomes as shown in FIG. In the following, the welding torch 5 is moved to align the point Q with the point P.

All of the methods described above are based on a one-line system using one semiconductor laser 4, which allows the welding torch 5 to
The tip of the electrode can be set accurately at the target position for welding.

Next, the two-line system will be explained with reference to FIGS. 9 to 12.

FIG. 9 shows an example of a butt joint, and numerals 1 and 2 in the figure are plates. The target position I of welding on the butt portion of these plates 1 and 2 is set as P. A CCD camera 3 is installed above the target position P of this welding, and a first semiconductor laser 4 is installed at an arbitrary angle on the butt of the plates 1 and 2 passing through the position P. A second semiconductor laser 6 that irradiates parallel laser light to the first semiconductor laser 4 is installed. And the distance between these two parallel laser beams is the arc length! , where θ is the irradiation angle of the laser beam with respect to the plate material, it is set so that L = l cos θ.

In this manner, when the target welding position P is captured by the first semiconductor laser 4, a plane H is formed. On the other hand, the second semiconductor laser 6 forms a plane I parallel to the plane H. By aligning the tip of the welding torch 5 on this plane I, an intersection point Q can be obtained. When this result is photographed by the CCD camera 5, the image appears as shown in FIG.

Next, when the welding torch 5 is moved so that the point P on the plane H coincides with the point Q on the plane I, the two welding torches 5 move at a distance of arc length p as shown in FIG. This means that they were placed with a gap between them.

In this way, by using the semiconductor laser in the 2-line method and the 3-line method, there is no need to correct the welding torch 5 by raising it by 2 as in the case of the 1-line method shown in FIG. 11, and the welding torch can be moved smoothly and It can be placed precisely in a predetermined position.

FIG. 13 shows another embodiment using the spot line method. In this spot line method, semiconductor lasers 7 and 8 are provided on the outer periphery of the welding torch 5 in the diametrical direction. These semiconductor lasers 7 and 8 are irradiated with laser spot lights, and these laser spot lights intersect with each other on the central axis of the li oscillator, and the distance between the intersection point Q and the tip of the electrode is the arc length! Set it to be equal to .

The positioning of the electrode in the butt joint using such a spot line method will be described below. In positioning using this spot line method, as shown in FIG.
When the target position P of welding is determined and the laser spot light from the welding torch 5 is irradiated onto the plate material, the spot light from the semiconductor laser beam is focused on the point Q2, and the spot light 8 is focused on the point Q. As a result, the image captured by CCD camera 3 is
As shown in Figure 4, images of planes H and QQ2 appear.

Here, operate the position of the welding torch 5 in the vertical direction to
Correct the spots of Q2 and Q2 so that they overlap. And Q
, and Q2 match and become Q and a spot light,
Since the tip of the electrode was kept equal to the arc length l, by aligning the point P on the plane H with the point Q, the electrode was correctly placed at the welding target position P, separated by the arc length l. That will happen.

Also, since the laser spot lights of the semiconductor lasers 7 and 8 intersect on the extension of the electrode, if their intersection angle is θ, the distance between the bright spots Q, , Q, which has a predetermined arc length can be calculated. It is also possible to control the arc length by measuring the distance between Q and 92.

FIG. 15 shows another embodiment, in which four semiconductor lasers 9, 10, 11, 12 are arranged around the welding torch 5,
The spot lights of these semiconductor lasers 9, 10, 11.12 intersect at point Q and form Q, , Qz, Q3 . This is to obtain a bright spot of Q. As a result, these bright spots Q
,,Q2. Q3. The welding torch 5 can be positioned directly above a predetermined target position P after the position of Q4 is captured by the CCD camera 3 and the posture and arc length are controlled based on the positional relationship of the bright spots.

It is also possible to measure the deviation from the target position of the weld joint and the shape of the joint groove using the one-line method, two-line method, spot line method, etc. described above. By setting these, it is also possible to determine their positions. In particular, by equipping the robot with a welding torch, it can also be applied to robot teaching.

(Effects of the Invention) As explained above, the welding method of the present invention uses a light cutting method to teach a welding torch to the target welding position of the workpiece, and detects the deviation of the weld joint from the target position and the opening of the joint. In addition to measuring the shape of the tip, the start and end positions of welding are determined by moving the optical cutting line, and the position of the welding torch is corrected to the target position, so a simple device can be used to determine the electrode tip position. There is an advantage that it is possible to weld while confirming both the target position and the welding target position.

[Brief explanation of drawings]

1 to 15 show embodiments of the present invention, and FIG.
A perspective view of a butt joint using the line method, Fig. 2 is the same image, Fig. 3 is a view showing the main parts, Fig. 4 is a perspective view of the T-joint, Fig. 5 is the same image, Fig. 6 Figure 7 shows the same main parts.
Figure 8 is a perspective view of the corner joint, Figure 8 is the same image, Figure 9 is 2
A perspective view of a butt joint using the line method, FIG. 10 is an image of the same, FIG.
Figure 2 is a diagram showing the same essential parts of the 2-line system, Figure 13 is a perspective view of a butt joint using the spot and trine system, and Figure 14:
15 is a perspective view of a four-spot type butt joint, and FIG. 16 is a diagram showing a conventional example. 1.2 ・ ・ ・ ・ ・ ・ 3 ・ ・ ・ ・ ・ 4 ・ ・ ・ ・ ・ 5 ・ ・ ・ −・ ・ 7.8, 9.10, 11.12・

Claims (1)

[Claims] The welding torch is taught to the target welding position of the workpiece using the optical cutting method, the deviation from the target position of the welding joint and the shape of the joint groove are measured, and the welding is performed by moving the optical cutting line. A welding method comprising determining a start position and an end position of the welding torch, and correcting the position of the welding torch to a target position.