FI124215B - Method of joining coated metal sheets by welding and joining - Google Patents

Description

METHOD FOR JOINING COATED METAL PLATES BY WELDING AND JOINING

BACKGROUND OF THE INVENTION

The invention relates to a method for joining coated metal plates by welding according to the preamble of claim 1. The invention also relates to a joint according to claim 10.

10

Prior art

Various solutions are known in the art for joining coated metal sheets. Solution 15 is known, for example, in which plates are joined together by means of an auxiliary plate which joins the plates to be joined and in which a glue is used to join the plates together.

EP 0538087A discloses a solution in which 20 coated metal sheets are joined by laser welding in two steps by welding, and either by a direct butt joint or by an overlap. In the method, the first welding step disintegrates the coating with a focused laser beam, which in the second step is corrected by a non-focused laser beam.

25

Prior art solutions are further disclosed in JP 6033278 A and JP 2009039720 A.

(M

° There are some drawbacks to prior art solutions.

X

CC

CL

co The prior art solutions have a problem

\ J

mm. the fact that when gluing is used, it is complicated and han-ς fish, and requires a long drying time and is therefore not a cost-effective way of bonding. Similarly, prior art solutions of welding plates together damage the coatings of the plates 2, resulting in the joint area being prone to corrosion such as crevice corrosion. Furthermore, welded joints according to the prior art do not allow structurally strong joints.

It is an object of the present invention to provide a novel solution for joining coated metal sheets which can avoid the problems encountered in known solutions.

10

Brief Description of the Invention

The method according to the invention is characterized by what is mentioned in the characterizing part of claim 1. The method of Kek-15 is also characterized by what is stated in claims 2-9. The joint according to the invention is characterized by what is mentioned in the characterizing part of claim 10. The joint according to the invention is also characterized by what is stated in claims 11-21. The present solution of the present invention has some significant advantages when compared to known solutions.

The present invention provides a novel solution for joining coated metal sheets and which can effectively prevent crevice corrosion in the joint between the sheets. The solution according to the invention can also be used to make joints 5 which were previously not possible at all or have been

C \ J

^ difficult to do. With the solution of the invention, sheets which are already pre-coated can be used more extensively and in a wider range of applications than in the known solution, and in particular | costly and time consuming work steps (such as painting / coating a seam between sheets co) can be replaced in a more expedient and expeditious manner. The method 5 according to the invention does not break the coating protecting the facade side of the coated metal sheet, whereby the corrosion resistance of the joint is excellent. The solution according to the invention enables the use of hot-dip galvanized sheet metal 3, whereby the corrosion resistance of the joint is achieved efficiently. The joint provided by the method of the invention is also strong and durable. In the solution according to the invention, the joint can be loaded and used immediately after it is made.

5

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail by way of examples with reference to the drawings in which 10

Figure 1a and Ib and Le illustrate the joint according to the invention and the method for providing the joint.

15

DETAILED DESCRIPTION OF THE INVENTION

1a and Ib and le for joining metal sheets coated in a joint and method according to the invention by welding, the sheets to be joined are joined by laser welding, such that a weld 1 is formed by welding between the metal sheets; sections L1 and L2), in which the panels 2 and 4 and 3 and 4 to be joined overlap. In the process, an additive 5 is formed or formed between the coated metal sheets to be joined by welding to protect the joining edges of the metal sheets from corrosion, which is activated to seal the joint. the surface

CVJ

The edges of the cut metal plates usually (when cut) produce points where the coating is not quite at the edge of the sheet and the function of the additional material is to protect the edge of the sheet which has no coating, or where the coating is damaged.

C/O

[£ Activation of the additive can take various forms. The activation can take place, for example, using either UV light, or the additive can be activated by the pressure created when the plates to be joined are laser-bonded, whereby the additive is pressurized (pressed) 4 when the plates are pressed against one another. The additive may also be heat-activated such that, for example, a laser is used to provide heat to the additive. Upon activation, the additive may also swell / swell, which may contribute to protection against crevice corrosion, since the additive, when swollen, covers the edges of the sheet (s) and the areas of the edges where the coating may be damaged. The additive can also strengthen the joint between the boards, increasing the strength and durability of the joint.

The additive may already be fixed to one of the sheets, but the additive may only be fixed / applied to the sheet, for example, after laser welding, after which the additive may be activated / cured, for example, with UV light having certain desired wavelengths.

15

If UV light is used for activation, the wavelength of the light may be in the range of 250-450 nm. For example, the power of the UV curing apparatus may be about 50W.

Similarly, the power of the laser used is between 0.5 and 5.0 kW, and the laser can be, for example, a point laser. The power of the laser can be varied or regularly pulsed during connection / activation. The operating parameters of the laser are chosen so that the coating on the first side, that is, the facade side, is not damaged when welding on the other side, that is, on the inside. If necessary, a shielding gas such as Argon is also used. In the method according to the invention, the weld seams between the plates are formed essentially in the longitudinal or transverse direction of the plate, but a solution can also be contemplated. Further, there may be one or more welds in each sheet, always depending on the need, δ δ 35 In the method of the invention, welding is performed on one side of the joint, i.e., on the inside. Thus the actual facade 5 Vu coating a first side of the coating is not damaged welding.

According to one embodiment of the invention, welding is used in combination with gluing, whereby welding provides a fast-workable joint, but the final joint strength is ensured with the adhesive joint. The adhesive is then applied between the overlapping metal plates, preferably before welding.

The joint according to the invention will be described in more detail below with reference to the figures.

Figure 1a-1c shows a joint 1 by which at least two coated metal sheets 2, 3 are joined by welding by laser welding, in such a way that a connection is provided between the metal sheets comprising at least one portion L where the sheets 2 and 4 are to be joined. and 3 and 4 overlap. Between the coated metal sheets 2, 3 is formed an additive 5 to protect the joining edges of the metal sheets from corrosion, which additive is activated to seal the joint 20. The plate serving as auxiliary plate 4 may have a recess or a groove (not shown) for the additive. The additive is a material activated by pressure and / or heat, or a material activated by UV light. The additive is preferably a polymer-based sealing additive such as acrylic. The additive may also be tape-like, or the additive may be attached to a tape such as a shape tape. The additive may also be a polyurethane-based additive, δ

CVJ

^ The edges of the coated metal sheets 2, 3 are not completely closed with one another, with a gap for the additive therebetween. Unlike the defects, the coated plates 2, 3 may also be attached to the auxiliary plate 4 without a gap between them in the figure. Coated metal sheets 2, 3 refer to a metal sheet having a protective coating on its surface, δ 00 35 Preferably, the coated metal sheet is hot-dip galvanized sheet steel. Most preferably, the coated steel sheet is, after hot-dip galvanizing, coated with a plastic paint on at least one side, i.e. the facade side. The other side of the coated metal sheet, i.e., the inside, can furthermore be coated with a backing paint.

An uncoated metal plate can also be used as an auxiliary plate 4, since the joint according to the invention provides a seal, whereby moisture cannot easily pass from the first side to the second side of the plate. According to one embodiment, a hot dip galvanized sheet is used as a backing plate. Preferably, the plated metal sheet and / or the auxiliary sheet has a thickness of 0.4 to 5 mm, most preferably 0.4 to 3 mm.

Preferably, the coated metal plates 2, 3 in the joint are substantially aligned so that there is no level difference between them. In this way, thanks to the joint according to the invention, the first half of the coated plated metal sheets 2, 3, i.e. the facade side, is formed into a seamless assembly. Preferably, the hit seams are parallel to the seam between the coated sheets 2, 3.

Fig. 1c shows an embodiment of the solution according to the invention in which a protective tape 7 is provided on the joint, the function of which is to protect the additive and the joint during connection and storage. The protective tape is removed, for example, when the additive is activated. One may also think of a solution in which the additive is attached to the protective tape itself.

5 Table 1 below describes the various additives which

C \ J

can be used in the joint of the invention.

o 00 30 cc CL ___ co Additive Trade Description | __mi__ g Tape 3M 5958FR Acrylic Wax. . .

___tape_ __Soudaband _Sealing tape- 7 __Acryl__ha_

Lii- Soudal Fix Sealant / Sealant__All__ / Sealant_

Soudal Fix Adhesive __Ali Ultra__

Soudal Fix Gasket- __All High Tack__- / adhesive_ UV-Dymax GA- Gasket cured_ 140__

Table 1. Some additives used in the joint.

5 The additive may be dyed to the color of the coated sheet, whereby the joint, for example, is uniform in color. Alternatively, the additive may be formed substantially different from the color of the plated sheet if the seams are to be emphasized.

10 The additive may be pre-attached to either the edge of one or both of the plated metal plates, or to the auxiliary plate used for the joint.

The metal sheets used in the joint may also be, for example, painted or galvanized / zinc plated, for example, hot-dip galvanized sheet metal.

It will be apparent to one skilled in the art that the various embodiments of the invention are not limited solely to the foregoing Examples and may therefore vary within the scope of the following claims.

C/O

X

The additive used in the solution of the invention may also be gel, liquid, or solid which, when activated, will seal the gap between the plates to be joined.

δ

C \ J

8 't δ c \ j δ δ

X

X

CL

C/O

ln m o δ c \ j

Claims (21)

A method of joining coated metal sheets by welding, in which method the sheets (2, 3) are joined by laser welding such that a joint (1) is provided between said metal sheets, which joint comprises at least one such section L in which the sheets (2, 3) to be joined overlap with an auxiliary plate (4), characterized in that in the process, between the hot-dip galvanized steel sheets to be joined by welding, an additive (5) is formed to protect the edges of the metal sheets to be joined. against corrosion, which additive is activated to seal the joint. 15 Method according to Claim 1 for joining of coated metal sheets, characterized in that the steel sheets are furthermore painted with plastic paint on at least a first, ie. frontage side. 20 Method according to claim 1 for joining of coated metal sheets, characterized in that the additive is activated by laser. 25 Method according to claim 1 for joining coated metal sheets, characterized in that the additive o is activated with UV-lius. C \ J ° 5. A method according to claim 1 for joining of coated metal sheets, characterized in that the additive £ is activated by pressure. CO Method according to claim 4 for joining of coated metal sheets, characterized in that UV light is used in the activation ™ 35, whose wavelength is between 250-450 nm. Method according to claim 1 for joining coated metal sheets, characterized in that the power of the laser used is between 0.5 kW-4.0 kW. 5 Method according to claim 1 for joining of coated metal ice sheets, characterized in that the weld seams (6) are formed substantially parallel to the seam between the coated sheets 2,3. 10 Method according to Claim 1 for joining of coated metal ice sheets, characterized in that the weld seams are formed one or more in the respective sheet. A joint (2), with which the joint at least two coated metal discs are joined by welding with laser welding in such a way that between the metal discs there is a joint, which joint comprises at least one such section L, where the discs (2, 3) to be joined overlap with an auxiliary disc, characterized in that between the hot-dip galvanized plates, an additive (5) has been formed to protect the edges of the metal discs to be joined against corrosion, which additive is activated for sealing the joint A joint according to claim 10, characterized in that the additive is of a material which is activated by pressure and / or humidity and / or heat. ° 12. Joint according to claim 10, characterized in that the additive is made of a material which is activated by UV light. In 1 CO A joint according to claim 12, characterized in that the additive is a polymer-based additive suitable for St sealing, such as acrylic. m o ^ 35 Seam according to claim 12, characterized in that the additive is tape-like, or the additive is attached to a tape, such as molding tape. Seam according to claim 12, characterized in that the additive is colored with the color of the coated sheet. The joint according to claim 12, characterized in that the additive is attached to a disc (4) to be used as auxiliary disc in the joint. 17. A joint according to claim 12, characterized in that the additive is attached to the joint at least on the edge of a second coated metal sheet. Seam according to claim 10, characterized in that the metal discs are coated with paint. 15 A joint according to claim 18, characterized in that the hot-dip galvanized metal Iskis are coated with plastic paint at least on a first surface. A joint according to claim 10 or 11, characterized in that the coated metal sheets 2,3 are located in the joint substantially in the same pane, with no level difference between them. A joint according to Claim 10 or 11, characterized in that the edges of the metal sheets 2, 3 are not completely fixed to one another, with a gap for the addition substance C between them. δ δ X IX Q. CO m m o δ C \ J