JPH01306085A - Method and device for joining metal foil - Google Patents

Abstract

PURPOSE:To enable joining in a good joint state by restraining body sides of the parts to be welded which are parted from each other and welding the parts to be welded while applying tensile force to the parts to be welded. CONSTITUTION:The welding device has the restraining device for metal foil consisting of a freely liftable backing 3a (lower member) which presses and supports the parts to be seam-welded of the laminar metal foil 2, 2 and metal foil clamps 11a, 11b (upper members) which press and fix the parts near the parts to be seam-welded of the metal foil 2, 2 from above the same. The metal foil 2, 2 are fixed to a base 4 via a plate material 12a by the metal foil clamps 11a by means of bolts, nuts, etc. The other metal foil 2, 2 are fixed between the metal foil clamp 11b and the plate material by the similar means and are pulled from the direction perpendicular to the weld line direction by the plate material 12a and the tension generating bolt 15 penetrating through the plate materials 13, 14 provided in parallel and perpendicular to the joint line 10, by which the metal foil are so mounted as to be movable in parallel. The metal foil are thus so fixed that the tensile strength of the parts to be welded attains 60-90% of the tensile strength of the metal foil itself.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a metal foil bonding method and an apparatus thereof, and more specifically, it is a method for stacking at least two metal foils with a thickness of 100 μm or less and bonding them in a good bonded state using high-density energy. The present invention relates to a metal foil joining method that can be joined and its 1m length.

Conventional technology Until now, in the field of thin plates, the thickness limit was 100μ.
m, but due to recent advances in rolling technology, for example,
For stainless steel, the thickness limit has been lowered to 30 μm. This progress has led to architectural materials that take advantage of the corrosion resistance, heat resistance, and high strength of stainless steel, interior materials using colored stainless steel, shielding materials for magnetic and electromagnetic waves, coating materials for optical fibers, protective materials for ICs, and various tare bags. It has become necessary to weld coil joints in the manufacture of honeycomb structures and the like, as well as in the manufacture of foil itself.

It is well known that dwarf heat is suitable for welding thin materials. From this perspective, attempts are being made to apply
MIG welding, TIG welding, plasma welding, etc.
In either case, due to the size of the heat source, melt drop occurs and sound welding cannot be performed. This problem can be improved to some extent by dispersing the heat input by using a pulsed power source, but the applicable range is at most 0.1 mm, making it difficult to apply to the thin metal foil in question. For example, when the thickness is reduced to 30 μm, a new problem of distortion arises, and the current situation is that it cannot be said to provide sufficient sound weldability.

Recently, microplasma welding has been developed and improved.
It has come to be used in this field. However, even with this method, it is difficult to continuously overlap and weld metal foils, and the problem of distortion remains. Furthermore, there is still room for improvement industrially in terms of low welding efficiency.

Against this background, welding that uses extremely small heat sources such as laser light is attracting attention. For example, with a YAG laser, a heat source with a spot diameter on the order of several 1-1 m can be easily obtained. If such a heat source is used, metal foils can be easily joined by at least spot welding. The reason for this is that the dimensions of the heat source are almost comparable to the thickness of the metal foil, and as a result, the bead width is sufficiently narrow relative to the thickness of the sheet, so there is no melt drop and almost no distortion. . However, since spot welding is discontinuous, it cannot be applied to applications that require airtightness and watertightness as described above.

Moreover, even when using this laser, for example, 100
If you try to continuously join metal foils such as stainless steel with a thickness of less than μm, the weld bead width may not be constant, only one layer may melt, or the molten pool may overheat and the welding may drop. This may result in poor welding.

For example, as shown in Figure 4, a flat copper backing 3
When the laser beam 7 is irradiated onto the metal foil 2.2 from above,
Because there is a gap between the metal foils, most of the heat input from the applied thermal energy is absorbed by the metal foils, resulting in an overheated state.As a result, the weld bead width expands, and if this exceeds a certain level relative to the plate thickness, The welding line is cut due to the fuse effect and the purpose cannot be achieved.

From this point of view, in the octopus shown in Japanese Patent Application Laid-Open No. 58-163587, an attempt is made to press the vicinity of the welding line of the metal foil with the brim of the wheel to eliminate the gap, but
If the thickness is less than that, wrinkles will occur, which will have the opposite effect, and most of the laser light will be absorbed by the metal foil, resulting in overheating and insufficient bonding.

Problems to be Solved by the Invention The present invention aims to solve these problems. Specifically, when bonding metal foils using a high-energy heat source such as a laser beam, conventional techniques It is difficult to weld by preventing gaps and controlling thermal energy, and there is no research and development of methods or devices for welding by preventing gaps and controlling thermal energy. The purpose is to

In summary, research and development has been carried out on methods and devices for stacking metal foils with a thickness of 100 μm or more and seam welding them in the width direction using high-density energy. , for example, JP-A-58-
No. 163587 has only proposed a welding method with little practicality.

For this reason, we have not devised any welding methods or welding methods for joining thin metal foils in a good bonding state using high-density energy, such as continuous welding of overlapping metal foils of 100 μm or less.

Means for Solving the Problems and Their Effects The present invention restrains both sides of the welding area when overlapping at least two sheets of metal foil and seam welding them in the width direction using a high-density energy beam. In addition, in the apparatus for seam welding metal foil using a high-density energy beam, the welding is carried out while applying a tensile force to the area to be welded. Gold@foil restraint &
It is characterized by comprising a purchase.

Therefore, a more specific explanation of the combination which is a means of the present invention and its operation will be as follows.

The inventors have discovered that when at least two or more metal foils are overlapped and seam welded in the width direction, the welding conditions are considerably harsher for those with a thickness of 100 μm or less than for those with a thickness of more than 11001i. In particular, find suitable welding conditions for these! It was discovered that the following welding conditions were required.

(1) Eliminate gaps between metal foils to improve the ability of high-density energy such as laser beams to pass through; (2) The tensile strength of the metal foil in the area to be welded is stronger than the tensile strength of the metal foil itself. (3) The backing should have a certain degree of curvature and be thermally conductive. (4) The welding equipment must have low heat input and stable output control.

Historically, welding conditions that satisfy these conditions have been studied, and the present invention was established based on this research.

According to the research conducted by the present inventors, it is extremely difficult to weld metal foil compared to welding ordinary thin steel sheets, but because the metal foil is extremely thin, it is difficult to weld with a low input input when welding. Stable output control under heat is required. In this regard, when welding metal foil using high-density, high-energy laser light, etc., welding S! We can fully handle the installation and there are no problems. Therefore, the problem is the overlapping state of the metal foils in the case of lL';p contact. When welding three metal foils together, if there is a gap of even a few μm between the top and bottom metal foils, the top metal foil will melt and heat energy will not be transferred to the bottom metal foil. Therefore, the energy density is concentrated on the top metal foil, and only the top metal foil is melted. For these reasons, we have learned that the metal foils being welded must always be in close contact with each other in lap welding.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Note that FIG. 1 is an X34 perspective view showing an example of a welding device used in carrying out the present invention, and FIGS.
Each figure is a sectional view of a main part of a welding device used in another embodiment of the present invention, FIG. 4 is a longitudinal sectional view illustrating a conventional welding device, and FIG. FIG. 6A is an enlarged explanatory diagram of a joint, and FIGS. 6A and 6B are explanatory diagrams of heat flow in the joint, respectively.

Code 1a, lb is a holding plate, 2 is metal foil, 3 is backing (copper, flat), 38 is backing (copper, with radius),
3b is a backing (ceramics), 13 is a stand, 5 is a welding point, 6 is a gap, 7 is a laser beam, 8 is a welding bead, 9
10 is a heat flow, 10 is a joining line, 11a, 11b is a metal foil clamp, 12a, 12b, 13.14 is a plate material, 15 is a tension generating bolt, 20 is a winding roller, 21 is a guide roller,
22a and 22b are take-up rollers, and 23 is an elastic member.

First, as shown in FIG. 1, the welding apparatus used in the present invention includes a backing 3a (lower member) that can be raised and lowered to press and support the seam welding area of the layered metal foil 2.2, and a backing 3a (lower member) that presses and supports the seam welding area of the layered metal foil 2.2. It is equipped with a metal foil restraining device consisting of metal foil clamps 11a and 11b (upper members) for pressing and fixing the vicinity of the second seam welding site from its upper surface. The backing 3a is made of a material with excellent thermal conductivity, such as copper, and has a curved surface, for example, about 50 to 100 mm, in contact with the upper metal foil 2.2. Ru.

Further, the metal foil 2.2 is fixed to the base 4 via the plate 12a by the metal foil clamp 11a using conventional fixing means such as bolts and nuts. In addition, the other gold flexor 2.2 is placed between the metal foil clamp 111] and the plate 12t) with the same hand as above [9, plate 1m) and on the table 4 parallel to the joining line 10 and It is attached so that it can be pulled in a direction perpendicular to the welding line direction by a tension generating bolt 15 passing through a vertically provided plate material 13, 14, and can be moved in parallel, within a range that does not exceed the elastic limit of the metal foil, e.g. The tensile strength of the area to be welded is always 60 to 9 of the tensile strength of the metal foil itself.
Fixed it to be 0%.

It is recommended to set the tensile strength of the part to be welded to 60 to 90% of the metal foil itself.
If it is higher than 60%, solidification cracks will occur in the molten (-2) part, making it impossible to obtain a bead with excellent weldability, and if it is lower than 60%, cracks will occur parallel to the weld line. Since the solidification shrinkage stress is larger than the tensile stress for tensioning the metal foil, the welding heat becomes very irregular in shape, causing cracks and wrinkles in many places, and it is difficult to maintain a good welded joint. be.

With the above configuration, it is possible to apply tension to the metal foil 2.2 within a range that does not exceed the elastic limit, reduce the thrust force in the gap between the metal foils 2.2, and provide protection against high-density energy such as laser light. deformation (thermal distortion) of the metal foil can be prevented.

It was completely unknown in the prior art to apply tension to the metal foil 2.2 within a range that does not exceed its elastic limit. For example, as shown in FIG. 4 of the conventional example, a method using a backing 3 made of a flat plate made of an upper body by simply pressing the metal foil 2.2 with presser feet 1a and 1b from both sides can also be used to maintain the tension within a range that does not exceed the elastic limit. metal foil 2.2, but the gaps cannot be sufficiently eliminated.

In the method of the present invention, the most important point in eliminating this gap is to make use of the flexibility of the metal foil to make it fit into the backing, and the characteristics of the metal foil can be utilized to the maximum.

Naturally, the backing used here needs to be provided in the opposite direction to the laser beam irradiation direction, but this is also necessary over the entire weld line. This is because, once a cut occurs due to a gap created during welding, it continues until the weir is dredged.

The adaptation of the metal foil to the backing by this tension is also effective in preventing gaps in long weld lines.

In general, this backing needs to have the above-mentioned curvature. The reason for this is that as shown in FIG. 5 of the conventional example, a gap 6 is created between the welding site and the backing 3 as well as between the metal foil 2.2, and no matter how much the plane + JO machining accuracy is improved, the gap is several μm. Some degree of unevenness is unavoidable in the case of long welding, and the occurrence of the gap 6 cannot be completely prevented.

Further, by having the curvature, the surface contact accuracy of the backing surface can be significantly relaxed. Furthermore, as mentioned above, the backing must be a good thermal conductor, which is essential to prevent overheating, which is the cause of the cutting phenomenon.

For example, Fig. 6(a) is an explanatory diagram of the flow of heat flow when a Hiramix flat plate backing 31) is used as the backing material. This is an explanatory diagram of the flow of heat flow when 3a is used.As is clear from the diagram, when ceramics are used as the backing material, the heat flow from the laser beam is reflected by the ceramics, causing overheating and widening the weld bead width, resulting in welding. Parts may fall off, resulting in a poor bonding condition, but if a material with thermal conductivity, such as copper, is used, the heat flow will flow in the direction of the copper packing 3a, suppressing the weld bead width from widening. A good bonding condition can be obtained.

Also, if there is a groove directly under the welding point, the welding heat energy will be dissipated. This may cause the bonding to deteriorate due to overheating.

Next, another embodiment of the present invention will be described.

As shown in Fig. 2, the metal foil 2.2 is held by the plates 1a, 11]
The process of overlapping two metal foils with a backing 3a having a curvature at the tip and welding them with a laser beam is the same as in the previous embodiment, but one end of the metal foils 2, 2 is placed on a winding roller 20. The sheet is scraped off, and the other side is wound up by lifting rollers 22a and 22b via a guide roller 21, and the parts to be welded are joined.

With this configuration, since the take-up roller applies tension to the metal foil that does not exceed its elastic limit, the tension can be applied uniformly and there is an advantage that no distortion occurs.

Further, in the present invention, as shown in FIG.
a, ll) and the stand 4.4, the metal foil 2.2 is fixed via an elastic member 23 such as 81 rubber or hard rubber, and the tip of the metal foil to be welded 3 has a curvature. The metal foil 2 is pushed up by the backing 3b made of material.
．． The metal foil 2.2 has a stress of 60 to 90% of the strength of the metal foil 2.2, and is welded to the planned welding area.

With this configuration, since the metal foil is fixed via the elastic member, damage such as linear scratches on the surface of the metal foil can be prevented, and since the elastic member is used, slipping is prevented and the stacking density is high. It can be fixed and the desired tension can be applied.
The metal foil joins well after welding.

Example The present invention will be explained below with reference to Examples.

Table 1 shows the conditions and f8 prefecture of the example. As a heat source, a YAG laser with an output of 100 W was used and
Welded at a speed of in. The sample material is 100 μm to 30
AM stainless steel foil (elastic limit: 35 kq/mm2) was used. No shielding gas was used. Incidentally, the apparatus used in the Examples had a tool 〉h as shown in Fig. ``N41''. That is, both ends of the foil are pulled over the length of the weld and a copper curvature (approximately 5
0mm) It is held in close contact with a backing.

According to the present invention, the cutting phenomenon does not occur and the effect of the melting invention is good> As explained above, the present invention is capable of seam welding in the width direction of at least two or more metal foils by overlapping them with a high-density energy beam. An apparatus for welding metal reinforcement seams using a high-density energy beam, the welding being carried out while restraining both sides of the part to be welded and applying a tensile force to the part to be welded. In this method, a metal foil is restrained by a lower member that presses and supports a part of the metal foil that is to be seam welded in a flexible manner, and an upper member that presses and fixes the vicinity of the part of the metal foil that is to be seam welded from its upper surface. It is characterized by comprising a device.

Therefore, it is now possible to join metal foils such as stainless steel with a thickness of 100 μm or less, which was previously extremely difficult.
However, it can be bonded in a good bonding state, and is expected to be widely applied to various pre-construction fields.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a welding device used in carrying out the present invention, and FIGS. 2 and 3 are sectional views of essential parts of welding devices used in other embodiments of the present invention, respectively. , FIG. 4 is a longitudinal sectional view illustrating a conventional welding device, and FIG.
The figure is an enlarged explanatory diagram of the joint portion in FIG. 4, and FIGS. 6(a) and (b) are explanatory diagrams of the flow of heat flow in the joint portion, respectively. Code 18.1b... Pressing plate 2...
Metal foil 3...Backing (copper, flat) 3a...
...Backing (copper, with radius) 3b...
Backing (ceramics) 4 units
5...Welding point 6...Gap
7...Laser beam 8...Welding bead 9...Heat flow 10...Joining line 11a, 11b...Metal foil clamp 12a,
12b, 13.14... Plate material 15...
...Tension generating bolt 20...Take-up roller 21...Guide rollers 22a, 22b...Take-up roller 23...
...Elastic member

Claims (1)

[Claims] 1) When at least two or more metal foils are overlapped and seam welded in the width direction using a high-density energy beam, both sides of the welding area are restrained, and the welding area is A metal foil joining method characterized by welding while applying a tensile force to. 2) Claim 1 wherein the tensile force is 60 to 90% of the strength of the metal foil.
Metal foil bonding method described. 3) In an apparatus for seam welding metal foils using a high-density energy beam, a lower member that can be raised and lowered presses and supports the seam welding area of the layered metal foil, and the vicinity of the seam welding area of the metal foil is pressed from its upper surface. 1. A metal foil bonding device comprising a metal foil restraining device comprising a fixing upper member. 4) The metal foil bonding device according to claim 3, wherein the lower member is made of a material having a curvature at its tip.