JPS62259684A - Laser beam welding method and its device - Google Patents

Abstract

PURPOSE:To make the work efficient by performing a correction so that the butt line coincides with a torch traveling line based on a microscopic measurement after fixing the respective cut face of the rear end part of the preceding strip steel and the tip part of the succeeding strip steel by abutting them on a work table. CONSTITUTION:A tip part 2a is pressed by a cutting clamp 47 and a succeeding strip steel 2 is fed in as well, after cutting the tip part 2a of the succeeding strip steel 2 and the rear end part 1a of the preceding strip steel 1, by descending the upper shear 7, and an opening and closing table 34 is opened, the upper shear 7 is descended to perform the cutting. Each cutting face of both strip steels 1, 2 is abutted as the butt face at a welding position B. In succession, the butt line is measured by using optical enlarging devices 42, 43, the image of a camera 42b is automatically processed, and corrected so that the butt line comes on the torch traveling line by an image sensor. By using this device the welding of high accuracy can be performed.

Description

[Detailed description of the invention] <Object of the invention> Industrial field of application The present invention relates to a laser welding method and an apparatus therefor, and more specifically, the present invention relates to a laser welding method and an apparatus for the same, and more specifically, the present invention relates to a laser welding method and an apparatus for cutting the trailing end of a leading band and the leading end of a returning steel band. However, when laser welding is performed by butting these two cut surfaces as abutting surfaces, the abutting surfaces of both steel strips are accurately butted on the work table of this welding device to form a butt line, and then
A method and apparatus for performing laser welding by enlarging the butt line by optical means and moving or rotating the work table to accurately match the butt line with the travel line of the welding torch, and the apparatus thereof, particularly for a plate having a thickness of 0135 mm. The following (in particular, about 0.2 mm or less) is a laser welding method suitable for laser welding ultra-thin and wide steel strips with a width of about 1.5 mm or more over the entire width with high precision, and It pertains to the device.

Conventional technology Traditionally, in continuous steel strip processing lines, copper strips are joined by butt welding and subjected to rolling or other processing (hereinafter referred to as
This is called a treatment process. ). On the other hand, before supplying the steel strip as a product to customers, etc., it undergoes treatments such as rewinding, winding, welding, slitting, and cutting (hereinafter referred to as edge treatment), and in particular,
They are joined together using butt welding to fit the motorcycle requested by the customer, or they are cut and sent out as a product.

In particular, unlike the welds in the former process, the welds during the latter process are sent out as products with almost no maintenance after welding, so welds with a high quality are required. has been done.

In addition, among steel strips, recent silicon steel strips are required to be thin in order to reduce power loss, and are rolled to a thickness of 0.2w1l'B or less as products, and are extremely difficult to finish with edge treatment. Thin, thin steel strips are to be welded, and even with such ultra-thin steel strips, high-quality welds (h) are required to be formed during welding.

However, since silicon steel strips are processed as products by high-speed, continuous processing lines, etc. at the demand end, welding with one-time edge processing requires (1) ensuring that the side edges of the steel strip are straight and aligned; (2) The thickness of the welded part must be uniform and meet a certain standard, and the surface should be furan [.] (3) Mechanical properties of the welded part (4) There should be no bending or misalignment in at least part of the welded area, and these requirements are becoming stricter year by year.

Furthermore, from the viewpoint of reducing power loss, the grain-oriented silicon steel strip has a thickness ranging from about 0.35 to 0.30 m111 to about 0.23 to 0.00 m.
There is a tendency for the plate thickness to become thinner, such as about 15 mm, and the plate thickness tends to be thinner.

From these points, welding for edge treatment of silicon steel strips is as follows:
If laser butt welding is applied instead of conventional butt welding such as TIG, MIG, etc., the laser diameter will be reduced to 0.
．． Immf'i! Energy density h
(Because it is extremely large, the heat affected zone can be reduced, and
Although the surface of the welded part can be made flat and the heat width can be reduced, laser butt welding can meet the above conditions, especially (1).
In order to satisfy the conditions (2) and (2), it is necessary to have a mouth that achieves highly accurate matching.

In other words, in butt welding of thin materials, melt tends to drop at the welding start and end ends, and to prevent this, so-called "crater treatment" is performed.

In this process, it is necessary that the deviation of both ends of the butt line of the leading and going steel strips to be butted is within a range of 0.05 mm, and the butt line is also perpendicular to the center of both steel strips. However, conventional butting techniques cannot achieve this condition.

For example, in Japanese Patent Publication No. 59-50435, there is a method for cutting the welding line (in the CL position, the opposing ends of both leading and trailing steel strips are simultaneously cut using a double cut shear, and then each cut surface is moved to the welding light head). Therefore, a welding device has been proposed in which each cut surface is butted as a butt surface and then welded along this butt line.The conditions of (1) above are met at the cutting position and welding position of this welding device. In order to align the side edge of the steel strip parallel to the center line of the welding line, install a side guide parallel to the center line of the welding line on the side edge of a guide table or work table, etc., when cutting or welding.
One side edge of the steel strip is brought into contact with these side guides, and a shear or welding machine is run along a line perpendicular to each of these side guides to perform cutting or butt welding of the ends of the steel strip. In addition, the work table is configured to be slidable in the direction of the running line of the steel strip, and is also configured to be pivotable around the intersection of the extension line of the side guide and the running line of laser welding 1. The ends of the leading and trailing steel strips are moved in the direction of the steel strip traveling line of the work table, and by turning, etc., the butt line of both leading and trailing steel strips is aligned with the traveling line of the laser welding torch. .

With this welding device, the butt line can match the welding line relatively well, but there is no SC detection mechanism and there is no gutter groove for fine adjustment such as turning or moving the work table.
For example, when it comes to extremely thin and wide steel strips, such as those with a thickness of 0.35n1m or less and a width of 1.5m or more, the I
It is extremely difficult to match the 1-1000 run line and the butt line exactly. In other words, by visual inspection, the welding 1/-1 travel line must be accurately aligned with the butt line;
In other words, there is a limit to alignment, and it is not possible to form a highly accurate butt groove suitable for laser welding of extremely thin and wide steel strips.

In addition, if the steel strip is a @ product, it is extremely dangerous to handle it manually as it may cause cuts in your fingers, etc. Furthermore, both the leading and trailing strips are cut (cut with a double-cut shear at the Q position). Therefore, when they are butted together, the two cutting lines do not match, resulting in misalignment, etc., and it is difficult to laser weld uniformly across the width.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned problems. Specifically, each end of the leading groove Wf and trailing steel strip is cut, and this cut surface is Match them on the work table,
In order to match this butt line with the welding torch traveling line accurately and with high precision, the work table may be moved parallel to one reference side of the work table, or one side of the work table may be
[laser welding with two reference side surfaces] - When turning at the intersection with the travel line of Welding 1~
- A method and device for laser butt welding by aligning thousands of travel lines with high precision are proposed.

<Structure of the Invention> Means for solving the problem and its operation, that is, the laser welding method according to the present invention is to cut the trailing end of the leading steel strip and the leading end of the trailing steel strip. A butt line is formed by fixing both the leading and trailing copper strips by butting them along one reference side surface of the work daple on the work table with the surface as the butt surface, and then One reference side and laser welding 1
・-〈1〉--Enlarge one end of the butt line with a microscope at a point corresponding to the intersection with the thousand travel line, and set the work table to one end of the work table so that one end of the butt line coincides with the intersection point. While moving parallel to the two reference side surfaces, the other end of the butt line is enlarged using a microscope, and the work table is centered at the intersection point so that the other end of the butt line coincides with the l.-thousand travel line. 1. Turn the laser welding 1.- to the 1.-
C, which performs laser welding by traveling along a thousand travel line.

In addition, a device suitable for carrying out this method cuts the rear end of the leading steel strip and the leading end of the trailing steel strip, and places the cut surfaces on one of the work tables on the work table with these cut surfaces as butt surfaces. In laser welding installation in which a laser welding is performed by butting along a reference side surface and then running a laser welding torch along this butt line, the work table is arranged on a guide track -L parallel to one reference side surface of the work table. The work table is configured to be movable along this guide trajectory parallel to the reference side surface by a numerically controlled motor, and the work table is rotated with the intersection of one reference side surface of the work table and the torch row line as the center of rotation. is configured to be freely rotatable by a numerically controlled motor, and furthermore, at least two optical magnifying devices are provided so as to be reciprocatable in a direction perpendicular or substantially perpendicular to the traveling line of the two-phase zone. is characterized in that it is connected to a numerically controlled motor so as to be movable in a direction perpendicular or substantially perpendicular to the traveling line direction of the steel strip.

Therefore, a more specific explanation will be given below with reference to the drawings, focusing on the configuration of these means.

Note that FIG. 1 is a side view of a laser welding device, which is an example of a device for carrying out the method of the present invention, and FIG.
3(a) and 3(fb) are plane views showing the cutting of the end of the steel strip in the laser welding apparatus shown in FIG. 1; FIG. It is a diagram.

First, in Fig. 7A1, reference numeral 1 indicates the preceding steel strip, and 2 indicates the returning steel strip. The trailing steel strip 2 is fed into the line and cut by a pair of chinnels 1.8 at a cutting position A as described later, and then conveyed to a welding position B by a movable clamp 20 on the downstream side. 3.4 to the cutting position A, where it is cut by a pair of shears 7.8, and then conveyed again to the welding position @B by a pair of upper and lower pinch rollers 3.4. That is, the cutting device 5 is provided at the cutting position A, and this cutting device ? ! 75, a pair of square frames A7-frames G (
In FIG. 1, only one side of the frame 6 is shown. ) are arranged at intervals, and a pair of upper and lower shears 7.8 are provided between these V-shear frames 6 so as to be movable up and down. Therefore, the third
As shown in FIG.
After aligning as shown below, attach a pair of upper and lower shears 7.8
The rear end portion 1a is cut along the cutting line 3G to form an abutment surface 1C. Similarly, the leading end 2a of the trailing steel strip 2 is cut along the cutting line 3c by a pair of upper and lower shears 7.8 after one side edge 2b is aligned at the cutting position A as shown in FIG. 3 fb). Then, an abutting surface 2C is formed. That is, at the time of cutting, the opening/closing table 34 is opened by the cylinder 35, and the upper and lower shears 7.8 are lowered into this opening part to cut each end 1a, 2a of the steel strip 1.2, and the rear end of the preceding steel strip 1. Scrap 1a is removed from the opening. Also, when cutting this two-phase band 1.2, the two-phase band 1.
．． In order to fix the ends 1a, 2a of 2, electromagnetic links 9.10 are arranged on the exit side and the entrance side, sandwiching the pair of upper and lower shears 7.8. In addition, a welding torch 11 such as a laser welding torch, for example, is installed in the welding fi7 position B so that it can be raised and lowered and run freely in the width direction of the steel strip 1.2, and is installed in both the leading and trailing phases. Band 1.2 is rear end 8I! The welding torch 11 travels along the butt line formed between 1a and the tip 28, and laser welding is performed. This welding torch 1
A leading side fixing clamp 12 and a trailing side fixing clamp 13 are provided on both sides of C 1 so as to be able to rise and fall freely on a common work table 14, and both abutting surfaces are brought into abutment during welding by the two fixing clamps 12 and 13. The rear end 1a and the tip 2a of the leading steel strip 1 and the trailing steel strip 2 when
to be fixed. Further, the work table 14 has the welding 1 hech 11 sandwiched therebetween, and electromagnetic chucks 15 on the leading side are placed on both sides thereof.
At the same time, an electromagnetic chuck 11G on the trailing side is provided, and at the time of butting, one end 1a of the leading steel strip 1 is fixed and fixed by the electromagnetic chuck 15 on the leading side, and this magnetic chuck 1G is used. When the tip 2a of the trailing chasm 2 approaches the rear end 1a, the magnetized rear end 1a causes a go-around X'
A.? The tips 2a of '+'t 2 are attracted and securely abutted against each other.

As described above, the ends 1a and 2a of the two-phase belt 1.2 are butted together on the workpiece table 14F, and with these ends abutted, the work table 14 is moved on the rotating table 171- to the two-phase band 1.2. The swivel table 17 is located at the intersection of the reference side surface of the work table 140 and the running line of the welding l/-ch, that is, the swiveling part 48 shown in FIG. 2. Constructed so that it can rotate freely around the center.

That is, as shown in FIG. 2, at the welding position B, the rails are vertically moved along the longitudinal direction of the strips 18a of the gate-shaped frame 18 provided across the traveling path of the preceding steel strip 1 and the entertainment steel strip 2. At the same time, the welding torch 11 is provided so as to be freely movable along the moving track +98.19b, and furthermore, a telescopic laser beam optical path 21 is provided on the upper part of the frame 18. A welding torch 11 is connected to the tip of this optical path 21, and a laser 'R and an imaging device 2 are connected to the tip of the optical path 21.
2 are connected, and both steel strips 1.2 are laser welded via a welding torch 11 using a laser beam emitted from a laser oscillator 22.

In addition, both fixed clamps 12.1 on the leading side and the trailing side
3 so that they can be raised next to each other as described above, the lifting device is installed as follows:
However, in this "A'GJ device, both the fixed clamp pieces 12 and 13 have the same structure, and for convenience of explanation, the elevating device for the fixed clamp piece 13 will be mainly explained.

Usually, a pair of columns 2G are provided inside the gate-shaped frame 18, as shown in FIG. Attach the rod 28 to each cylinder 27. For example, attach the trailing side fixed clamp piece 13 to the upper end of each rod 28 in both cylinders 27. The elevating device for the leading-side fixed clamp 12 is not shown, but it is similarly composed of a pair of supports, a cylinder, and a rod.

Further, a workpiece double 14 is arranged inside the pair of support columns 2G, and the workpiece double 14 is arranged on the turning table 17 via a pair of linear motion bearing rails 29 and a pair of linear motion bearings 30. Therefore, the work table 14 is moved parallel to the reference plane of the steel strip 1.2 by the rotating table 170, and the groove line between both steel strips 1.2 can be made to coincide with the torch line as described later. can. Also,
In order to perform this movement of the work table 14, a numerically controlled motor 31 is installed on the rotary table, a pole screw 32 is connected to the numerically controlled motor 31, and the tip of the pole screw 32 is connected to the work table 14.

The turning table 17 is configured to be able to turn freely at a turning portion 48 at the intersection of one reference side edge of the work table 14, that is, the side edge parallel to the running line center line and the torch row line,
This turning movement is performed by, for example, a cylindrical bearing 49, a pawl screw 50, and a numerically controlled motor 51.

For example, a fixed table 52 is provided below the rotating table 11, and an IJ between the fixed table 52 and the rotating table 17 is
A cylindrical bearing 49 is interposed in i, a pole screw 50 is aligned with this cylindrical bearing 49, and a numerically controlled motor 51 is connected to the pole screw 50.

Next, work table 1 at B at the welding position as shown in F below.
4 and the turning hable 17, while the ends 8 (S1a, 2) of both steel strips 1.2 are placed on the work table 14
At least two optical magnifying devices 42.4 are used to optically magnify and observe the line formed by abutting each abutment surface 10.2C between a, that is, both ends of the abutment line.
3, and the mouth enlargement devices 42 and 43 are equipped with welding torches 11.
It is configured so that it can run in the width direction of the board in the same way.

Of course, each of the optical magnifying devices 42 and 43 has the same structure. ft42a, 43a and camera 42b
, 431), each enlarging device 42.4 of this structure
3 is mounted on movable saddles 42c and 43c. Each of the movable saddles 42c and 430 needs to be configured to be able to run in the width direction of the steel strip 1.2, but normally, as shown in FIG. , 43c, and these movement tracks 1
9a and 19b. In addition,
Each moving saddle 42c, 43c can be driven independently without being associated with welding 1.--11, but as shown in FIG.
The movable saddle 42c is configured so that it can be moved in the board width direction by the pole screw 23a and the numerically controlled motor 24, while the moving saddle 42c is independently moved in the board width direction by the pole screw 44 and the numerically controlled motor 45. It can be configured to move to

Further, as described above, one side edge 1b, 2b of the steel strip 1.2 is cut aligned at the cutting position A, and one side edge 1b of the double-dissipating belt 1.2 is cut on the work table 14 at the welding position B. , 2b
Align and match accurately, but in this case, as shown in Figure 3 (a'
Electromagnets can be used as shown in I and (Ill).

That is, in FIGS. 3(al and (b), 3G indicates the cutting line of the upper and lower shears 7.8, 37 indicates the torch strike line of welding 1 to 11, and cutting 1i3G and i.
- The chill line 37 is perpendicular to the center line of the steel strip running line or welding line, and is fixed without moving during the welding and cutting process. Three alignment devices 38, 39, and 40 are provided across the cutting line 3G and torch row line 37, and between the cutting position A and the welding position B, a hump roll 41 is driven by a numerically controlled motor 41a, and a bevel gear 41b. , a pole screw 11C and a bearing metal fitting 41d so that it can be raised and lowered. Each alignment device 38.39.
40 has the same structure, and at least two reference magnet blocks 38a, 39a, 40a are provided parallel to the welding line center l (or the center line of the traveling line of both steel strips 1 and 2), and these base magnet blocks Blocks 38a, 39a, 4
0a constitutes one reference side of the cutting position formula and welding position B (or work table 14).

Also, these groups 21! Magnet blocks 38a, 39a, 4
At least one moving magnet chuck 38b between 0a
, 39b, 40b are provided, and during cutting or butting, the lower surface of the leading steel strip 1 or the trailing steel strip 2 is attracted by a moving magnetic chuck, and each reference magnet block 38a, 39a, 4 is
0a side, one side edge 1b of each steel strip 1.2,
2b are brought into contact with each other. In addition, each moving magnet chuck 38b,
391), 40b and each reference magnet block 38a,
39a, 40a are cylinders 38c, 39c, 40
c, it is configured to be movable in the board width direction.

Therefore, a method of welding after cutting the ends 1a and 2a of both the leading and trailing steel strips 1.2 according to the present invention in the welding apparatus having the above configuration will be described as follows.

First, when cutting the rear end portion 1a of the preceding steel strip 1, at the welding position B, the movable clamp 20 is opened and moved to the most upstream side, while at the cutting position type, the opening/closing table 34
Close the steel strip 1 preceded by a pair of pinch rollers 3.4
is sent to stop the yi1 portion 1a on the opening table 34 as shown in FIG. At this time, the movable magnet chuck 39b of the alignment device 39 is magnetized, the reference magnet block 39a is magnetized, and the cylinder 39c is cut (pressed against the reference side surface of the table at position A) by the cylinder 39c.

Next, move! l] The preceding steel strip 1 is moved in the strip width direction using the Ia stone chuck 3'lb, and one side edge 1b is placed against the reference magnet block 39a for automatic alignment (the state of +: is shown in Fig. 3 (a+). (The leading steel strip 1 is shown by a dotted line.), the electromagnetic chuck 9 on the shear exit side is energized, the leading steel strip 1 is held by the movable clamp 20, and in some cases, the movable clamp 20 is driven while the electromagnetic chuck 9 is kept energized. 10m
The cutting clamp 47 is lowered by the hydraulic cylinder 46 to hold the rear end 1a of the preceding steel strip 1 from above.

Subsequently, the opening/closing table 34 is opened, the upper shear 1 is lowered, the east end 1a is cut, the upper shear 7 is raised, the opening/closing table 34 is closed, and the cutting clamp 47 is moved by the hydraulic cylinder 4G.
is opened, the reference magnet block 39a is demagnetized, and the cylinder 39c is moved back.

After cutting, the preceding steel strip 1 is moved downstream by the movable clamp 20, and the electromagnetic chuck 15 is excited at the position B of welding 1q.

In this state, the movable clamp 20 is driven by, for example, a numerically controlled motor, and the leading steel strip 1 is moved approximately 10 mm toward the flow side [
Move this.

Next, the tip 4 part 2a of the trailing steel strip 2 is cut.
-8, that is, stop LL after passing the cutting line 3C
(The trailing steel strip 2 in this state is shown by a dashed line in FIG. 3 (1) 1.) The movable magnetic chuck 38b of the aligning device 38
At the same time, the base Q magnet block 38a is energized and pressed against the reference side surface of the table to the cutting position, and as in the case of the preceding steel strip 1, as shown in FIG. The trailing steel strip 2 is attracted and one side edge 2b thereof is brought into contact with the reference magnet block 38a (the trailing steel strip 2 in this state is shown in FIG. 3 rb) by a dotted line. ). Next, the electromagnetic chuck 10 is energized, the tip 2a is held down by the cutting clamp 47, and in this state, the pinch roller 3.
4, feed the trailing steel strip 2 by approximately 3011I11 (this suspension is the suspension by which the trailing steel strip 2 is pulled in by the upper shear 7 during cutting), open the opening/closing table 34, and lower the upper shear 17-7. disconnect.

Next, at welding position 8, each cut surface 1C of both steel strips 1.2
Abut against each other using 52C as the abutting surface. At this time, the pinch roller 3.4 feeds the leading end 2a of the trailing steel strip 2 onto the hump roller 41, and at this time, the hump roller 41 is raised to loop the leading end 2a.

This height is set higher depending on the thickness of the plate, and the thinner the plate is. Further, at the rear end portion 1a of the preceding steel strip 1, its abutting surface 1C (that is, the cutting line IC+ coincides with the torch travel line 37 as described above, and while the electromagnetic chuck 15 is energized in this state, The trailing steel strip 2 is fed by the pinch rollers 3.4 to the point where the leading end 2a, especially the abutting surface 1C, contacts the abutting surface 1C of the leading steel strip 1.

Since the electromagnetic chuck 15 is energized at this time, a magnetic force is generated on the abutting surface 1C of the preceding steel strip 1, and the abutting surfaces IC12C are attracted to each other, allowing even thin materials to be butted over the entire length, and the subsequent Since the row steel strip 2 has a certain degree of freedom, the trailing steel strip 2 is butted along the preceding steel strip 1, and the butt angle becomes zero. In addition, when both the abutting surfaces 1C12C are attracted to each other in this way, when the reference magnet block 40a of alignment gi@10 is excited and pressed by the cylinder 40c, both the abutting surfaces IC52C are at the welding position 8. move in the width direction of the plate while keeping them drawn together, and can bring both side edges 1b and 2b together, and then,
The leading end portion 2a of the trailing steel strip 2 is attracted by the electromagnetic chuck 1G on the work table 14, and a butt line with substantially zero gap is formed between the two butt surfaces 1C120.

Next, as shown below, on the work table 14, place 1.
After butting each of the butt lines 1C and 12C of 2, optically magnify to confirm whether or not this butt line accurately matches the torch row line of weld 1 heech 11, and check the distance between the butt line and the torch row line. If there is even a slight error, correct it.

First, to check and make corrections, use work table 14.
- Lower the fixed clamp 12.13 to the intermediate position. That is, it is necessary to bring the microscopes 42a, 43a of the two optical magnifying devices 42, 43 closer to the two steel strips 1.2 of the target object, and for this purpose both fixing clamps 12, 13 must be lowered. In order to move the work table 14 etc. for fine adjustment, both fixed clamps 12 are used.
,] 3 are kept floating from the work table 14.

Next, the numerical control motor 45 is driven to move one of the movable saddles 42c to the microscope tn42a via the pole screw 44.
i'f-Move the rotating table 17 to the center of the rotating section 48. Also, while opening the moving clamp 20, the upper roller 3 of the pinch rollers 3.4 is opened,
Reference magnet blocks 39a, 40 with alignment device 39.40
a, and retreat it from the work table 14 using the cylinders 39c and 40c.

Next, the electromagnetic chuck 15.1G is energized, and with both the leading and trailing steel strips 1.2 attracted onto the work table 14, the numerical control motor 31 is driven, and the workpiece is moved through the pole screw 32. The table 14 is moved parallel to the reference side surface of the steel strip so that one end of the butt line magnified by the microscope 42a is located at the center of the field of view. In other words, camera 42b
The image is automatically processed and corrected by the image sensor so that it is on the -+a lf l -chill row line 37 of the butt line, and the vision mirror 42a8 is retracted.

Next, the two-woman value control motor 24 is driven to move the other movable saddle 43c via the pole screw 23a, and the microscope 43a and camera 43b are aligned at the butt line, that is, each butt of the two steel strips 1.2. 1C12C should be at one end of the line formed by butting.

In this case as well, the microscope tfl 43a is used as in the above case.
The image is automatically processed by the image sensor so that one end of the enlarged butt line comes to the center of the field of view, and at this time, the numerically controlled motor 51 is driven to move the rotating table 17 to the rotating section 48 via the pole screw 50. , and weld the other end of the butt line [・-Torch travel l1 of torch 11]
Match 137.

Note that the microscope 43a is evacuated by the numerically controlled motor 24. In addition, welding is carried out by holding the leading and trailing steel strips 1.2 against the back bar with the fixed clamp 12.13 across the butt line, and under the welding conditions set based on the plate thickness, steel type, plate width, etc. Laser welding is performed by moving the welding torch 11 in the width direction of the plate.

<Effects of the Invention> As explained in detail above, the present invention is capable of cutting the rear end of the leading steel strip and the leading end of the trailing steel strip, and then abutting these cut surfaces on a work table as abutting surfaces to close the gap. A butt line is formed in a substantially zero state, and then this butt line is moved to the welding torch's [・-chill row line while finely adjusting the welding]・-chi to the torch travel line. Laser welding is performed by traveling along the

Therefore, a butt line with substantially zero gap can be formed, and this butt line and the l~-chill row line exactly match, so that highly accurate laser welding can be performed simply by running the welding torch.

In addition, in making this fine adjustment, one end of the butt line is magnified using a microscope at a point corresponding to the intersection of one reference side surface of the work table on which the butt line is formed and the torch traveling line of the laser welding torch. While moving the work table in the direction of the running line of both copper strips so that one end of the butt line coincides with the intersection, the other end of the butt line is magnified by a microscope, and the other end of the butt line is aligned with the intersection point. Rotate the worktable around the intersection to match the line. The matching line is magnified using a microscope and a camera, and finely adjusted through image processing to match the matching line, so that the matching line reliably matches the torch row line.

In addition, movement of the work table and rotation of the turning table are performed by numerically controlled motors and pole screws, so adjustments can be made in microns. In particular, the deviation between the butt line and the torch row line is 40 microns or less, and the difference between the two steel strips can be adjusted in microns. The vertical misalignment is less than 10 microns, the gap at the butt line is less than 40 microns over the entire white area, and it is 0.1
Laser welding of ultra-thin and wide steel strips of less than 5 cm is possible.

[Brief explanation of drawings]

Fig. 1 is a side view of a laser welding device which is an example of a device for carrying out the method of the present invention, Fig. 2 is a front view partially shown in cross section along the arrow II-II force direction in Fig. 1, and Fig. 3 fa ) and fb) are plan views showing when the end of a steel strip is cut in the laser welding apparatus shown in FIG. 1; Code 1... Leading steel strip 1a... Rear end 1b... Side edge 10...
Butt surface 2... Trailing steel strip 2a...
・Tip 2b...Side edge 2C...
...Abutting surface 3.4...Pinch roller 5...Cutting device 6...Skeyasha frame 7.8...Sill 9...・Electromagnetic chuck 10... Electromagnetic chuck 11...
・Welding torch 12.13... Fixed clamp 1 4... Work table 1 5.1C... Electromagnetic chuck 1 7... Swivel table 18... ... Frame 1
9a, 19b...Moving trajectory 2 0...Moving clamp 21...Laser beam optical path 22...Laser oscillator 23a...Pole screw 24・・・・・・Numerical control motor 25・・・Base 2G・・・Strut 27・・・Cylinder 28・・・Rod 29・・・Bearing rail 30... Bearing 31... Numerical control motor 32... Pole screw 34... Opening/closing table 35... Cylinder 3G... - Cutting line 37...Tortil row line 3 8.39.40...Aligning device 42.43...
...Optical magnification G position 44...Pole screw 4 5...Numerical control motor 4 G...Hydraulic cylinder 47...Cutting clamp 48...・・・・・・Swivel part

Claims (1)

[Claims] 1) After cutting the rear end of the leading steel strip and the tip of the trailing steel strip,
These cut surfaces are used as butt surfaces to butt on a work table to form a butt line with both the leading and trailing steel strips fixed, and then one reference side surface of this work table and the torch travel of the laser welding torch. magnifying one end of the butt line with a microscope at a point corresponding to the intersection with the line, and moving the work table parallel to one reference side surface of the work table so that one end of the butt line coincides with the intersection point; The other end of the butt line is magnified using a microscope, and the work table is rotated about the intersection point so that the other end of the butt line coincides with the torch travel line, and then the laser welding torch is A laser welding method characterized by performing laser welding by running a torch along a running line. 2) Cut the rear end of the leading steel strip and the tip of the trailing steel strip,
In a laser welding device that butts these cut surfaces on a work table as butting surfaces, and then runs a laser welding torch along this butt line to perform laser welding, the work table is aligned parallel to one reference side surface of the work table. Arranged on a guide track and configured to be movable along this guide track parallel to one reference side surface of the work table by a numerically controlled motor, and at the intersection of one reference side surface of the work table and the torch travel line. The work table is configured to be rotatable by a numerically controlled motor with the center of rotation being the center of rotation, and at least two optical magnifying devices are provided so as to be movable back and forth along the torch travel line, and the optical magnifying devices are provided with numerically controlled A laser welding device characterized by being configured to connect a motor and be movable along a torch travel line.