JPS61276794A - Laser butt welding method for metallic strip - Google Patents

Abstract

PURPOSE:To simplify the removing work of a scrap and to execute it as a continued work in a series of welding works, by removing a scrap by the advance of a metallic strip. CONSTITUTION:Opposed end parts 1a, 2a of a preceding plate 1 and a following plate 2 are superposed on lower clamp bases 8, 9 of the preceding side and the following side, and thereafter, clamps 3, 4 descend and clamp said parts. Subsequently, a rotary wheel cutting body 6 is made to descend, run in a plate width direction and cuts the plate. After cutting, both the preceding and the following clamps 3, 4 are made to ascend, the preceding plate 1 is advanced to a downstream side by a pair of moving clamps 5, and at the same time, the scrap 1b of the following plate placed on is also moved and removed. On the other hand, the following plate 2 is moved backward a little to an upstream side, and thereafter, advanced to the downstream side, and the scrap 2b of the preceding plate 1 is removed. After the scrap has been removed, a cutting plane of the following plate 2 is butted to the cutting plane of the preceding plate 1, a laser welding torch is run along the same passage as the running passage of the rotary wheel cutting body 6, and a laser welding is executed satisfactorily.

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 metal strips, and more specifically, to a method for butt laser welding of metal strips, specifically, a sheet thickness of 0.5 to 0.15 mm.

Both ultra-thin and wide metal strips with a width of 500 to 1,500 u are cut at the same time with their opposing ends overlapped, with good surface quality, and butted together with high precision.
A laser welding method that allows laser welding to be performed by aligning the butt groove line with the traveling line of the welding torch, and in which scrap generated during cutting can be easily removed without any trouble during the forward and backward movement of both metal strips. Pertains to.

Conventional technology generally involves metal strips such as steel plate slips (hereinafter referred to as
It's simply called a strip. ) are joined together and made continuous, and then subjected to a predetermined treatment. This junction is
The rear end of the leading strip (hereinafter referred to as the leading plate) and the tip of the trailing strip (hereinafter referred to as #a, row plate),
That is, after cutting both opposing ends in advance, these cut surfaces are butted together, and welding is performed by running a welding torch along this butt groove. Also,
Usually, TIG welding and MIG welding have been used for this welding, but recently, laser welding has been used as strips have become thinner and wider. Compared to TIG, MIG, etc. welding, this laser welding can generate almost no heat affected zone and the width of the weld bead can be made smaller, so laser welding is suitable for thin and wide strips. be. However, laser welding is TIG
Compared to the precision groove required for welding and MIG welding, a groove with -1l higher precision is required. I can't make the most of it. Furthermore, in addition to high-precision grooves, in order to take advantage of the characteristics of laser welding, it is necessary that the butt lines between the leading and forward plates match.
Furthermore, the surface condition of both cut surfaces forming the butt groove is 5.
Smoothness such as a roughness of about 10 μm is required, and the cutting line is required to be straight in the thickness direction, that is, straightness is required.

That is, the weld between the ends of the strip should preferably be hot-formed.
It is necessary to obtain a welded part with a small weld bead width without generating the J part. Laser welding can fully satisfy this condition because the diameter of the laser beam can be made as small as 0.1 to 0.2 Mφ. The soil, the laser beam itself has excellent straightness, and the diameter is 0.1 to 0.211 II.
Even with a laser beam of about 11, if the groove precision is high and the above conditions are met, the plate thickness is 0.5 to 0.1.
Even if the strip is extremely thin, such as 5 m long, and has a width of 500 to 1,500 m (wide strips), the welding bead width can be made extremely small without any problems.

However, in conventional methods, cutting is usually done with a single cut.
This is done with a shear or double cut shear, and this cutting does not provide a bevel for laser welding of extremely thin and wide strips.

In other words, both the single cut shear and the double cut shear consist of a pair of upper and lower blades, and when cutting, the ends of the strip are clamped by the leading and trailing clamping devices, and the ends of the strip are clamped by the upper and lower blades. Cut by shearing. Additionally, the cutting surface of the upper blade is typically sloped with a rake angle, and this slope causes the shear to move from one side edge of the strip to the other. When shearing is initiated at one side edge, a large force is exerted on the strip to ensure good shearing. However, when shearing is performed in this manner, the length of the unsheared portion decreases as the shear progresses, causing the sheared portion to increase and become sagging and clamped by the strip. The bending deformation will become larger as a result of twisting in places where the clamp is not properly clamped or where the clamp is incomplete. Therefore, the bending reaches its maximum at the cutting end point, but since this part is cut in this bent state, when the upper blade retracts, the bending is released and the bending is compensated for by that amount. , the gap when the two strips are butted becomes narrower at the cutting end point.

However, in the middle, this state remains as expected, and the interval becomes maximum, and at the start of cutting, the interval is larger than at the end of cutting.

When shearing with a single-cut shear or double-cut shear, the cutting line in the width direction of the strip is curved, and even if the cut surfaces with this curved cutting line are butted together, the bevel will not fit the small diameter laser beam. I can't get it. Furthermore, if the cut surface is a shear cut, it will be a two-step shear that will cause aggressive fracture, making it impossible to obtain a flat sheet in the thickness direction.

Furthermore, when cutting, instead of cutting the opposite ends of the strip individually, it is preferable in terms of productivity and consistency of the cut surfaces to overlap both opposite ends and cut them at the same time. Conventional shear cutting is fraught with the problems described above, and the cut surfaces cannot always be butted together with good consistency.

Further, simultaneous cutting of the overlapping portions causes the scrap generated after cutting to get between the two scraps, which requires a lot of effort to remove, resulting in a problem that productivity is greatly reduced.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned drawbacks. Specifically, for example, in single or double shear cutting, the cut surface has straightness in the width direction and thickness direction. Therefore, it is not possible to adopt so-called overlap cutting, in which the opposing end surfaces of both strips, that is, the leading plate and the trailing plate, are overlapped and the overlapped portion is cut simultaneously.In the conventional example, the plate thickness is 0.15 mm. Ultra-thin, like 0.5ml, and board width 15
For wide strips such as 00 to 1500 mm, welding
-It is extremely difficult to accurately match the running line of the cutter with the butt line, and furthermore, with overlap cutting, it takes an extremely large number of steps to remove the scrap that is generated, which greatly reduces productivity. The purpose is to solve problems such as being hindered by

<Structure of the Invention> Means for solving the problem and its operation, that is, the method of the present invention provides an overlapping portion in which opposing ends of a leading metal strip and a trailing metal strip are overlapped with each other. While being clamped by the upper and lower clamps on the side and the upper and lower clamps on the trailing side, cutting is performed by abrasive grain cutting while moving the rotary abrasive cutting body in the width direction of the plate. After raising the clamp to release the clamped state, the trailing metal strip I
・With the scrap from the lip still on it, the leading metal strip is advanced downstream to remove this scrap, while the trailing metal strip I ・The scrap from the leading metal strip is removed by advancing the lip downstream and pushing it. After that, the leading metal strip is retreated upstream and the cut surface of the leading metal strip is returned to its original position to position it, and the cut surface of the trailing metal strip is clamped to this cut surface. The invention is characterized in that laser welding is performed along the butt line by running a laser welding I--chi along the travel path of the rotary abrasive cutting body.

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

In addition, Fig. 1 (a), (b), (Q), (d), (e)
, m, (0), (h), (1) and (j) are explanatory diagrams of each step when implementing the method of the present invention, and FIG. 2 shows the cutting step shown in FIG. 1(d). FIG. 3 is an enlarged explanatory diagram showing the cutting process shown in FIG. 1(j).

First, as shown in FIG. 1(a), the rear end 1a of the leading plate 1 is made to straddle the rain clamp stands 8.9 on the leading and trailing sides, and the rear end 1a is placed on top of the rear end 1a. The leading ends 2a of the row plates 2 are overlapped to form an overlapping part. This overlapping part is clamped by the leading-side clamp 'A iff and the trailing-side clamp device, and in the leading-side clamp device, an upper clamp 3- is disposed on the lower clamp table 8 so as to be movable up and down, and In the side clamp device, one clamp 4 is arranged on a lower clamp stand 9 so as to be able to rise and fall freely.

Therefore, both opposing ends 1a of the leading plate 1 and the trailing plate 2,
2a are superimposed on the lower clamp bases 8.9 on the leading and trailing sides, and the overlapping portions are covered with the upper clamps 3.4 on the leading and trailing sides as shown in FIG. 1(C). It is lowered and clamped.

Next, as described above, after clamping, the overlapping portion is shown in Figure 1 (
d) As shown in FIG. 2, the rotary abrasive cutting body 6 is lowered and moved in the width direction of the leading plate 1 and the trailing plate 2 to cut them by abrasive cutting. At this time, a travel path (not shown) is installed in advance in the width direction of the board, and a trolley (not shown) is made to run along this travel path, and a drive device such as Tanabata is attached to the trolley. (not shown) and a rotary abrasive cutting body G is mounted thereon. Further, the rotary abrasive cutting body 6 can cut strips of steel plates and other metal plates by abrasive cutting, and may have any configuration as long as it has this configuration. Usually, for example, it is a so-called disk. A disc-shaped cutting whetstone is used, such as a cutter. Therefore, unlike conventional shear cutters and the like, during cutting, almost no cutting reaction force acts on the rotary abrasive cutting body, and the cutting is performed by the abrasive cutting. For this reason, the cut surface is almost flat with a surface roughness of about 5 to 10 microns, and the cutting line also maintains almost perfect straightness.Furthermore, by adjusting the particle size of the abrasive grains used for cutting, the surface becomes It can be made flat and the flatness can be improved, so-called overlap cutting can be performed from these points, and the characteristics of the pin can be fully utilized.

In other words, when performing seam cutting according to the conventional example,
Due to the above-mentioned problem, it is not possible to cut the leading and trailing boards while overlapping them.

On the other hand, when the method of the present invention (i.e., cutting the overlapping portion using a rotating abrasive cutting body), for example, as shown in FIG.
The cutting line 10 formed by one side surface Ga of the rotary abrasive cutting body 6 and the cutting lines of both the leading and trailing plates exactly match. Therefore, as will be described later, even extremely thin and wide items can be successfully laser welded simply by aligning the travel path of the rotary abrasive grain cutting body with the travel path of the welding 1-cheer. In addition to the above-mentioned advantages, the rotary abrasive cutting body has a compact structure, but as it is used frequently, uneven wear occurs on both cutting sides, which causes the cutting line to become slightly wavy. be.

However, because they are cut at the same time with the same rotating abrasive cutting body, the cutting lines of both the leading and trailing plates tend to have the same shape, even if they are slightly wavy, and when they are butted together, the gap is flat. and if the gap is pillow, then
The tolerance for misalignment is also increased, making laser welding possible.

Next, as shown in FIG. 1(e), after cutting, both the leading and trailing upper clamps 3.4 are raised, the leading plate 1 is advanced downstream by the pair of movable clamps 5, and together with this, the leading plate 1 is moved downstream. The scrap 1b of the trailing plate on the board is also moved and removed. On the other hand, the trailing plate 2 is moved slightly backward toward the upstream side, and then the trailing plate 2 is moved back to the upstream side as shown in FIG. 1(g).

As shown in FIG. 2, the leading plate 1 is advanced downstream, and the scrap 2b of the leading plate 1 is removed by this forward movement. Removal of such scraps 1b and 2b can be done without installing a separate automated device.
This can be easily done by simply moving the leading plate and trailing plate forward or backward.

Next, after removing the scrap as described above, the leading plate 1 is moved back upstream as shown in FIG. 6, and align the cut surface of the trailing plate 2 with the cut surface of the leading plate 1 (see FIG. 1(i)). That is, the cutting surface of the leading plate 1 is aligned with the cutting line 10 on one side of the rotary abrasive cutting body 6 at the time of cutting, but it is deviated from the cutting line 10 because it is moved forward for scrap removal. . However, since they match at the time of cutting, if the position of the cutting surface of the leading board 1 at this time is used as a reference, and the subsequent forward movement is determined and retreated by an amount commensurate with this amount, the cutting surface of the leading board 1 will be It can be accurately returned to its original position, and its forward and backward movement can be precisely controlled by digital control.

Next, after forming such butt grooves, the laser welding +-- chia is run along the same path as the traveling path of the rotary abrasive cutting body G, as shown in FIGS. 1(j) and 3. , the beam focus is the groove line formed by both cutting surfaces, that is,
Accurately matches the cutting line 10 on one side of the rotary abrasive cutting body 6,
Can be laser welded well.

That is, in the method of the present invention, cutting is not performed by shearing, as in conventional single and double cut shears, but cutting is performed by abrasive cutting by a rotating abrasive cutting body such as a disc-shaped grindstone.

Therefore, the properties of the obtained cut surface are flat and excellent, and the linearity in the width direction of the plate can also be sufficiently maintained. For this reason,
Just by accurately returning the leading plate 1 to its original position after scrap removal, the cutting IFita of the leading plate 1 can be completely welded 1.
- Coincides with the travel line of the chia, and using this as a reference, welding can be performed satisfactorily with a small diameter laser beam along the groove where the cut surfaces of the trailing plate 2 are brought together.

<Effects of the Invention> As explained in detail above, the method of the present invention is a slip laser welding method, in which a thin strip with a wide width is cut in advance by overlapping each opposing end and cutting simultaneously. Then, by butting the strips together, a highly accurate groove suitable for laser welding can be formed, and moreover, scrap generated during cutting can be removed without any problem by simply moving the strip forward or backward.

That is, in the method of the present invention, first, the opposing ends of the leading strip and the trailing strip, each having a wide plate width, are overlapped in advance, and this overlapping portion is then subjected to abrasive cutting using a rotating abrasive cutting body in a clamped state. disconnect.

Therefore, the opposite ends of both strips can be cut at the same time by the same rotating abrasive cutting body, and since this cutting is done with abrasive grains, each cut surface has an extremely good surface quality, and each cutting line By maintaining straightness, using the cut surface of the preceding strip as a reference, and butting the cut surface of the succeeding strip against this, a very highly accurate bevel can be formed. Further, if the radar welding j.

In addition, workability is good because the overlapping parts of each opposing end are cut at the same time, and even when this cutting is performed, scrap generated from the following strip can be removed by the advancement of the preceding strip to the downstream side. , scrap generated from the preceding strip can be pushed and removed by the downstream advancement of the trailing strip. Therefore, the scrap removal operation is extremely simple and can be carried out continuously in a series of welding operations.

[Brief explanation of the drawing]

Figure 1 (a), (b), (C), (d), (e), (f
), (g), (h), (i) and (j) are explanatory diagrams of each step when carrying out the method of the present invention, and FIG.
) is an explanatory diagram showing an enlarged view of the cutting process shown in Fig. 1.
FIG. 3 is an explanatory diagram showing an enlarged view of the cutting process shown in FIG. Code 1... Leading board 2... Trailing board 1a, 2a... Each opposing end 1b, 2b... Scrap 3... Leading side 1 clamp 4... Trailing side upper clamp 5... Moving clamp 6... Rotating abrasive cutting body

Claims (1)

[Claims] With the overlapping parts of the opposing ends of the leading metal strip and the trailing metal strip being clamped by the upper and lower clamps on the leading side and the upper and lower clamps on the trailing side, the rotary abrasive cutting body is cut across the plate width. The upper clamps on both the leading and trailing sides are lifted to release the clamped state, and the scraps from the trailing metal strip are still placed on top of the leading metal strip. The metal strip is advanced downstream to remove this scrap, while the trailing metal strip is advanced downstream and pushed to remove scrap from the leading metal strip, and then the leading metal strip is retreated upstream. The cut surface of the leading metal strip is returned to its original position and positioned, and after clamping, the cut surface of the trailing metal strip is butted against this cut surface, and the cut surface of the trailing metal strip is moved along the traveling path of the rotary abrasive cutting body. A method for butt laser welding metal strips, characterized in that laser welding is carried out along this butt line by running a laser welding torch.