JPS61276793A - Laser butt welding method for thin metallic strip having wide plate width - Google Patents

Abstract

PURPOSE:To form a butting bevel edge having high accuracy by superposing both opposed end parts of a preceding metallic strip and a following metallic strip, whose plate widths are wide, and clamping them, cutting them by a rotary wheel cutting body in said state, and butting the cutting planes. CONSTITUTION:Each opposed end part 1a, 1a' of a preceding plate 1 and a following plate 1' is superposed at a cutting position, and the preceding plate 1 is clamped between an upper clamp 3 and a lower clamp base 2. On the other hand, only the tip of the superposed part is clamped between a preceding auxiliary clamp 6 and the lower clamp base 2. Other part of the superposed part is clamped between a following upper clamp 3' and an auxiliary clamp 6', and a lower clamp base 2'. Next, a strip is cut by running a rotary wheel cutting body 4 in a plate width direction. Subsequently, after having removed a scrap, the cutting plane of the following plate is butted to the cutting plane of the preceding plate 1. In this state, welding is executed by running a laser welding torch along a cutting plane line 7.

Description

DETAILED DESCRIPTION OF THE INVENTION <Object of the invention> Industrial field of application The present invention relates to a method for butt laser welding of wide and thin metal strips.
．． 15111II! , a method in which opposite ends of a thin and wide metal strip with a width of 500 to 1000 mm are cut, and the cut surfaces are butted together and laser welded, and a high-precision butt opening suitable for this laser welding is performed. The present invention relates to a butt laser welding method in which a tip can be formed and the butt line can be reliably aligned with the travel line of the laser torch to perform laser welding without any trouble.

BACKGROUND OF THE INVENTION In general, metal strips such as steel plate strips are made continuous by joining their ends together, and then subjected to a certain treatment. This joining is usually done by cutting the rear end of the leading metal strip (hereinafter referred to as the leading plate) using a so-called shear welder, and cutting the leading end of the trailing metal strip (hereinafter referred to as the trailing plate). This is done by cutting, abutting the cut surfaces of the leading plate and the trailing plate against each other, and welding along the butt grooves. In addition, this welding is usually done by TIG welding or MIG welding, but compared to these weldings, laser welding creates almost no heat affected zone and the width of the weld bead can be made extremely small. Laser welding is very often used for thin metal strips. However, in laser welding, in order to take full advantage of the fact that the hot wire diameter can be made extremely thin, a bevel precision that is -1 higher than that required for TIG welding and MIG welding is required, and furthermore, the welding I - It is necessary for the chain to run exactly in line with the butt line between the preceding plates.

That is, in welding to join the ends of metal strips, it is preferable to make the diameter as small as possible.On this point, in laser welding, the diameter of the laser beam can be as small as 0.1 to 0.2 mmφ, and in addition, the laser beam diameter can be as small as 0.1 to 0.2 mmφ. Since the weld itself has excellent straightness, the weld bead width can be made extremely small. For example, even with extremely thin metal strips with a plate thickness of 0.5 to 0.15 (2), welds can be kept to a minimum. It will be done. Furthermore, due to the ultra-thin diameter of the laser beam, the permissible value of the butt gap between the leading and trailing plates is extremely small, and the requirements for groove precision are also very strict, and a groove that meets these requirements is required. However, the conventional cutting method is a single cut.
This is done mainly by shearing action using a shear, double cut shear, etc., and it is difficult to obtain a bevel that meets this requirement.

To explain in more detail, when using a single-cut shear or a double-cut shear, the ends of the metal strip inevitably bend in the width direction of the board and cannot be cut with straightness.
The plate is cut in a so-called two-stage cut in the thickness direction as well. Therefore, even if cut surfaces having such a tendency are butted together, the laser beam may partially penetrate through them, and a good bond cannot be obtained.

Next, in order to perform good butt welding with a laser beam, in addition to ensuring sufficient cutting accuracy for each cut surface using a cutting device such as a double cut shear or single cut shear as described above, it is also necessary to ensure that the butt line It is necessary for the welding to take place while the welding moves in exact alignment.

In this regard, in conventional methods, the leading plate and trailing plate are manually butted together each time we weld, and welding is carried out along this butt line!・
- The welding torch is run to confirm whether the running line matches the butt line, and then the welding torch is run to perform welding.

At this time, if they do not match, the positions of the leading board and trailing board are shifted so that they match the running line, and the butt line matches the running line. In this way, they are matched manually. This is not a problem when the board width is narrow, but when the board thickness is extremely thin and the board width is wide, such as 500 to 1500 mm, it takes a lot of effort to match accurately. The work itself is dangerous, and having to perform this check after each welding requires an extremely large amount of time.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned drawbacks. Specifically, for example, a single or double shear cut cannot obtain a cut surface with straightness, and furthermore, the conventional example For example, it is extremely thin with a board thickness of about 0.15 to 0.5, and the board width is s.
With a wide metal strip such as 1,500mm, it is extremely difficult to accurately match the running line of welding 1--1 and the butt line, and even if it were possible to do so, it would be a busy and time-consuming process. The purpose is to solve the problem that productivity is greatly hindered due to

<Structure of the Invention> Means for solving the problem and its operation, that is, the method of the present invention provides at least the leading and After cutting by abrasive cutting with a rotating abrasive cutting body while clamped with each trailing auxiliary clamp, the leading metal lip is held in a clamped state between the leading upper clamp and the lower clamp stand. Only the leading auxiliary clamp is released to remove scrap from the leading metal strip, while the trailing metal strip is released from the clamped state of the trailing upper clamp, auxiliary clamp, and lower clamp base to remove the scrap from the leading metal strip. Remove the scrap from the row metal strip, then butt the cut surface of the trailing metal strip against the cut surface of the leading metal strip, and then match the cutting surface of the trailing metal strip against the cutting surface of the leading metal strip, and then It is characterized in that laser welding is carried out by running laser welding I--chi along a track.

Therefore, the configuration of this means and its operation] will be specifically explained with reference to the drawings as follows.

In addition, FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are explanatory diagrams of each step when carrying out the method of the present invention.

First, the opposing ends 1a, 1 of the leading plate 1 and the trailing plate 1'
overlap a' at the cutting position. At this cutting position, a leading upper clamp 3 and a lower clamp 2 are arranged on the downstream side, and an auxiliary clamp 6 is slidably provided at one end of the leading upper clamp 3. Furthermore, a trailing upper clamp 3' and a lower clamp 2' are arranged at intervals on the upstream side, and similarly, an auxiliary clamp 6' is slidably provided at one end of the trailing upper clamp 3'. Therefore, both opposing ends 1a, 1
As shown in FIG.
Clamping is performed between the following upper clamp 3' and the auxiliary clamp 6' and the trailing lower clamp stand 2'.

That is, the leading plate 1 is reliably clamped between the leading upper clamp 3 and the lower clamp stand 2, while only the tip of the overlapping portion is clamped between the leading auxiliary clamp 6 and the lower clamp stand 2. The other portion of the overlapping portion is clamped between the trailing upper clamp 3' and auxiliary clamp 6' and the trailing lower clamp table 2'.

Next, in the clamped state as described above, the overlapping portion is cut by abrasive cutting by moving the rotary abrasive cutting body 4 in the width direction of the plate as shown in FIG.

This rotary abrasive cutting body may have any configuration as long as it can cut steel plates or other metal plates by abrasive cutting, and for example, a disc-shaped cutting whetstone such as a so-called disc cutter can be used. .

Next, after cutting as shown in FIG. 2, as shown in FIG. 3, the leading auxiliary clamp 6 is raised to remove the scrap 1b at the tip of the trailing plate 1'. At the same time, the trailing upper clamp 3' is raised, and together with the trailing auxiliary clamp 6', the leading plate 1 and the scrap 1b' at the rear end are removed. Each of these scraps 1
b, 1b' can be removed by separately providing an automated device (not shown) and pulling them out from the side, but it is not necessarily necessary to provide an automated device and they can also be removed manually from the side.

Next, as described above, after removing the scraps, the cut surface of the trailing plate 1' is butted against the cut surface of the leading plate 1.

In addition, at this time, since the leading plate 1 is clamped between the leading upper clamp 3 and the lower clamp stand 2 as described above, its cut surface is formed by the leading side cutting surface 4a of the rotary abrasive cutting body 4. It coincides with the cutting line 7. For this reason, when the cut surface of the trailing plate 1' is butted against the cut surface of the leading plate 1 as a reference, the groove line thereof exactly coincides with the cutting line 1. Therefore, as shown in FIG. 4, when the laser welding 1 and 5 are run along the cutting line 7, the beam focus exactly matches the groove line formed by both cutting surfaces, and the laser welding is performed well. can.

That is, the blade surface of the conventional cutter 11- is single;
Both doubles are formed to be inclined at a predetermined rake angle, and shearing is performed by a cutter having this shape.

The reason for this is that in order to reduce the elastic deformation of the device due to shear reaction force, the upper blade of the cud jar has a rake angle of θ with respect to the lower blade.
For this reason, when shearing in the conventional example, the cut surface of the preceding plate, especially the cutting line in the thickness direction, is curved, and straightness cannot be obtained. To explain in more detail,
In the groove where the two cut surfaces butt together, the gap between the leading and trailing plates is somewhat narrow at the cutting start point, but widens as the cutting progresses, and the gap reaches its maximum midway.

After that, the spacing gradually becomes narrower, sharply narrowing near the end, and reaching its minimum at the end of the cut. For this reason, if the groove has such a shape, even if the groove is formed by butting the cut surface of the trailing plate with the cut surface of the leading plate as a reference as described above, there will be a gap at least in the middle. There are also areas where the gap is approximately 0.2- or more, and in these areas the laser beam passes through and welding is impossible.
It will also hail.

In this regard, in the method of the present invention, the overlapping portions of the leading plate and the trailing plate are cut by abrasive cutting using a rotating abrasive cutting body such as a disc-shaped grindstone, so that almost no reaction force is applied to the device itself. Since the cut surface is cut while being ground by abrasive grains, the cut surface is not only flat and excellent, but also maintains straightness in the thickness direction. For this reason, if the leading plate 1 is kept in a clamped state between the leading upper clamp 3 and the lower clamp stand 2, the cutting line of the leading plate 1 will be perfectly linear. By butting the cut surfaces of the trailing plate 1' using this as a reference, a highly accurate groove can be formed.

<Effects of the Invention> As explained in detail above, the method of the present invention is a laser welding method for metal strips, and is characterized by butt laser welding of wide and thin metal strips.

Therefore, in the method of the present invention, the overlapping portion of the leading and trailing metal strips, each having a wide width, is clamped by at least each of the leading and trailing auxiliary clamps. One of the characteristics is that the cutting is performed by abrasive cutting with a grain cutting body, and because of this cutting, the cutting surface of the four preceding metal strips, which remain in the clamped state after cutting, is used as a reference, and the trailing metal strip is cut with respect to this. Laser welding can be performed by simply butting the cut surfaces of the metal strips together and then running a laser welding torch along a travel trajectory that coincides with the cutting line on the leading side of the rotary abrasive cutting body.

In addition, since the overlapping part where the opposing ends of both metal strips are overlapped is abrasively cut by a rotating abrasive cutting body, workability is excellent. The trailing metal strip is held in a clamped state between the clamping pedestals and only the leading auxiliary clamp is released to remove scrap from the leading metal strip, while the trailing metal strip is held between the trailing upper clamp, auxiliary clamp, and lower clamping pedestal. The scrap removal can be carried out very effectively by releasing the clamp from the trailing metal strip and removing the scrap from the trailing metal strip.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are explanatory diagrams of each step when carrying out the method of the present invention. Code 1... Advance board "1'...
Trailing plates 1a, 1a'... Each opposing end lb, lb'... Scrap 2...
Leading lower clamp base 2'... Trailing lower clamp base 3... Leading upper clamp 3'... Trailing upper clamp 4... Rotating abrasive cutting body 5... Laser welding torch 6... Leading auxiliary clamp 6'... Trailing auxiliary clamp 7... Leading side cutting line

Claims (1)

[Claims] The overlapping portion where the opposing ends of the leading and trailing metal strips of wide plate width are overlapped is cut by abrasive cutting using a rotating abrasive cutting body while clamped by at least the leading and trailing auxiliary clamps. After that,
The leading metal strip is held in a clamped state between the leading upper clamp and the lower clamp base, and only the leading auxiliary clamp is released to remove scrap from the leading metal strip. Release the upper clamp, auxiliary clamp, and lower clamp stand from the clamped state, remove scrap from the trailing metal strip, and then butt the cut surface of the trailing metal strip against the cut surface of the leading metal strip. butt laser welding of wide and thin metal strips, characterized in that the laser welding is performed by running a laser welding torch along a leading trajectory that coincides with the cutting line on the leading side of the rotary abrasive cutting body. Method.