ITBG20100006A1 - WELDING PROCESS FOR THIN SHEETS - Google Patents

Description

DESCRIPTION

Invention having as TITLE:

"Welding process for thin sheets"

To make the system that acts as a container or tub, some household appliances use an iron sheet with a thickness of less than 1.5 mm. This system is obtained by welding together 2 or more components, ie with an assembly weld. The assembly welding must have some characteristics: a) be continuous, without interruptions or holes, in order to guarantee impermeability; b) be uniform in size and color, for aesthetic reasons; c) not be porous, in order to guarantee hygiene, since the porosity consists of cavities which can also be collection points for organic material and bacteria. Under these 3 aspects, the thin thickness of the sheet metal makes welding more difficult. The subject of this patent relates to a welding "with cast or fused seam <"> (such as for example that of plasma welding), which has all the required characteristics listed above. Currently in household appliances these welds are carried out by carrying out the "butt" operation, fig. 1, i.e. the 2 flat shims to be welded rest and a fused bead is created, fig. 2, in an area (2.1) of very limited width. This system can easily present discontinuities or holes in the sections where the 2 thicknesses do not match perfectly. Another system used is the one called "transparency and overlapping edges" fig. 3. For obvious aesthetic reasons, the internal part of the container must be the fate A, the external part the side 3 of fig.3. In addition to aesthetic reasons, also in order not to have receptacles of organic materials, the weld bead must be positioned along the edge (3.4) of the flat component (3.1) in contact with the bottom of the concave marginal impression (3.2) of the component (3.3). The heat source needed to create the molten weld bead, for example a "plasma torch", for reasons of space, can only be on the outside, side B, of the container to be welded. it may present aesthetic non-uniformities and even discontinuities if the edge (3.4) of the component (3.1) does not correctly touch the bottom of the concave marginal impression (3.2) of the component (3.3). These defects mainly depend on the scarcity of the material that it enters the fusion making the weld bead. In the present patent a method is described which allows to have more fusion material available without resorting to filler material as instead occurs in the known art with the term IVflG ". The purpose is achieved by obtaining by bending or by molding or with an equivalent technique a flap (5.1) along the entire line (5.3) on which the welding (6.2) is foreseen. This flap can be either on 1 only or on all 2 components (5.4) and (5.5) to be welded. These flaps (5.1) will be on the side (5.2) which will be external with respect to the container to be made and will have an adequate height (5.6), for example from 0.5 to 4 mm, to melt almost completely and fill the voids. between the components to be joined and by welding, the flaps (5.1) in question also have the task of keeping the edge to be welded more rigid and more precise in order to make the positioning of the parts to be joined easier and more uniform them weld bead, Figure 5 represents the positional and ready-to-weld components; figure 6 shows the components of fig: 5 already welded; with (5.1) the edges before welding are represented; with (6,1) the flaps after welding. The melting temperature of the edges, necessary to make the weld bead (6.2), is reached using either a "torch" like the one used in the technique called 'plasma welding "or with an equivalent system, for example a LASER beam of adequate power. . The welded seam is protected either on one side only, A, or on both sides. A and B Fig. 5, using inert gases as in MIG processes.

Claims (1)

CLAIMS 1. Flap fusion welding process to be applied for example to 2 components in thin sheet metal, i.e. with a thickness of less than 1.5mm, where the process is characterized by the fact that at least one of the 2 parts, or components, to be welded is provided of a fold or flap (5.1) of adequate height (5.6), as a flap in the process of welding molten glass in order to form filler material equivalent to that used in the process known by the abbreviation "MIG", 2. Welding process as that described in claim 1), characterized in that the edge can be present on the 2 sides of the line (5.3) along which the welding is foreseen. 3. Welding process as described in claims 1) and 2), characterized by the fact that the edges also have the function of keeping the position of the components to be welded rigid and of maintaining their position precisely along the entire line (5.3 ) on which welding is planned. 4. Welding process such as that described in claims 1), 2) and 3), characterized in that said process is applied in the manufacture of household appliances such as dishwashers, ovens or washing machines. 5. Welding process as that described in claims 1), 2), 3) and 4), characterized in that the sheets to be welded are made of stainless steel or iron. 6. Welding process such as that described in claim 1), 2), 3), 4) and 5), characterized in that the molten weld bead is protected against oxidation using the same inert gas systems already known with the process indicated with the abbreviation "MIG". 7 Welding process as described in claim 1), 2), 3), 4), 5) and 6), characterized in that the melting temperature of the edges (5.1) is reached □ by means of the known art such as "'plasma welding" or by means of the technique known as "LASER welding". 8 ,. Welding process such as that described in claim 1), 2), 3), 4), 5). 6) and 7), characterized by the fact that the edges (5.1) are walls that are approximately at right angles to the surface of the components, for example (5.4) and (5.5), from which they were obtained. 9. Welding process as described in claim 1), 2), 3), 4), 5), 6), 7) and 8), characterized by the fact that after welding all the edges (5.1) can practically also be completely fused.