EP0042146B1 - Joining sections using brazing or welding and a method for doing it - Google Patents

Description

The present invention relates to a soldered or welded connection of profiles abutting in one plane according to the preamble of the main claim. It is particularly suitable for thin-walled hollow profiles, such as those used for door and window frames. These profiles often have a complicated cross-sectional shape and are produced in large lengths using an extrusion process. Miter-butting profiles have previously been screwed together, for example, often requiring complicatedly shaped and therefore expensive connectors. If you want to weld or solder these profiles together, especially thin-walled profiles must be carefully aligned with each other and with small tolerances so that there is no unacceptably large gap between them, which cannot be bridged with the usual soldered or welded connections. In addition, there are numerous materials that are very suitable for the production of profiles, but which cannot be joined at all or only with considerable effort in terms of joining technology.

The VDI news from 09/30/77 describes how aluminum windows, doors and garage doors are glued using an epoxy resin using a negative profile. The production of these negative profiles is associated with considerable effort, especially in corner connections. Similar complex processes are described in DE-C-10 95 502 and in DE-A-17 04 026.

From US-A-3 001 497 it is also known to weld two pipe sections with the aid of an eccentrically arranged intermediate ring. For the process described there, however, both pipe ends to be welded must be processed beforehand, and several operations are necessary.

From CH-A-307 388 it is also known that aluminum alloys can be welded better with the aid of an additional material. However, the special problems of intricately shaped hollow profiles are not addressed.

The object of the present invention is a soldered or welded connection of profiles abutting in one plane, in particular with miter, which can be produced quickly and economically in large series and which avoids the problems mentioned above. In particular, complex shaped profiles and thin-walled hollow profiles, such as those used in the construction of window and door frames or the like, are to be connected in one operation.

To solve this problem, a method according to the main claim is proposed. Thereafter, a flat intermediate piece is arranged between the two profiles to be connected, which abut one another with undiminished cross-section, possibly with a touch, the outer contour of which corresponds to the outer contour of the cut surface of the profile to be connected or evenly on all sides by about 1.5 mm survives to the outside. The hollow profiles are made of light metal, in particular extruded material, the intermediate piece serving as a filler material for soldering or welding. In the case of the proposed method, roughly sawn-off profiles can also be moved into the desired position during assembly by the contact surface provided by the intermediate piece. Between the profile and the intermediate piece there is a surface on the full circumference that can be joined better in terms of joining technology than butt-jointed profiles. Inevitable tolerances in the profile cross-section or miter angle or those that can only arise due to the heating during welding or soldering, lead to a shift in the case of directly abutting profiles, so that the profiles can no longer be connected perfectly, while between the profile and the intermediate piece Surface remains geometrically unchanged. Depending on the type of welding process chosen and the materials, it is necessary that the intermediate piece protrudes somewhat, since the protruding Te I is melted off during connection and the connection point sinks somewhat. At the same time, the intermediate piece serves as a filler material, which means that extruded material profiles can also be welded. This material cannot be welded without filler material due to its sensitivity to cracks. Welding with the addition of an additional material in the form of a welding wire would cause considerable effort in the case of complicated profile shapes. Here the intermediate piece supplies the filler material evenly over the entire surface to be welded.

In claim 2, particularly suitable materials for profiles and intermediate piece are proposed, AIMgSi 0.7 being a frequently used extrusion material which can be welded with the aid of AISi 12.

The third claim proposes a welding method which is known per se but is particularly expedient for the present invention. In order to reduce the heat input into the thin-walled profiles, this welding process should be carried out in a pulsating manner, which is also known per se.

Another method for producing such welded connections is described in the fourth claim. It is proposed to establish the connection by a welding process with a magnetically moved arc. This welding process, which is also known per se, requires a large apparatus structure in the vicinity of the connection point, which can be implemented the easier the fewer additional holders for the hollow profiles in the vicinity of the Connection point are necessary. Therefore, this welding process in conjunction with the specially shaped intermediate pieces described below represents an advantageous possibility for producing a welded connection.

In the fifth claim, as an alternative to the welding process, it is proposed to connect the profiles by soldering. For this purpose, a plate clad with solder on both sides is used as an intermediate piece, which can be easily soldered to the profiles.

To facilitate fixing of the profiles and the intermediate piece before the start of the soldering or welding process, a special spatial shape of the intermediate piece is proposed. Thereafter, the intermediate piece corresponds with its outer contour to the outer contour of the cut surfaces of the hollow profiles to be connected with an unimpaired wall thickness or protrudes uniformly on all sides by about 1.5 mm. In addition, the intermediate piece has projections which positively project into the interior of both hollow profiles to be connected and which are arranged such that two adjacent projections each protrude from the intermediate piece on different sides. On the one hand, this configuration ensures that the intermediate piece can no longer slide out after the hollow profiles have been placed against one another, and on the other hand it already ensures that the hollow profiles are in position relative to one another before the connection is made.

In a special embodiment of the invention, it is proposed to use an embossed intermediate piece. In this case, projections should be embossed in both the one and in the other direction in the intermediate piece, in such a way that the projections also secure the hollow profiles. This embossed intermediate piece is particularly useful when no hole is to be provided in the middle of the intermediate piece. The arrangement of the embossed projections on each side should be chosen so that both hollow profiles can be fixed in their position. If the protrusions are not too large, a joining connection can be made at any angle between the hollow profiles, without causing difficulties in the accuracy of the fit.

In claim 8 it is proposed in an alternative embodiment of this inventive concept to use a sheet as an intermediate piece, which is flanged so that projections project positively into the interior of both hollow profiles. The outer shape of the sheet corresponds to the outer cross section of the profile, while it has an opening on the inside, the edges of which are flanged in sections in one direction or the other. Such an intermediate piece is easy to produce in one operation and yet offers all the desired advantages. With a suitable flanging, both hollow profiles can be fixed with the aid of this intermediate piece, without the need for expensive holding devices in the vicinity of the connecting plane.

In claim 9, a welded connection produced according to the method described in claims 1-4 is described, the hollow profiles being made of extruded material, in particular AIMgSi 0.7. The weld contains an easily weldable filler material, in particular AISi 12, which was added during the welding process in the form of a flat intermediate piece arranged in the cutting plane of the hollow profiles. Such a welded connection is particularly suitable for complexly shaped light metal profiles for door and window frames, in which the profiles abut with a miter. With this connection, the considerable requirements regarding the dimensional accuracy of the finished frame can be met. Also in motor vehicle construction, where light metal window frames would have considerable advantages in terms of weight savings and corrosion resistance, window frames could be produced with this welded joint from the inexpensive extruded profiles.

• Figur 1 zeigt schematisch eine fügetechnisch Verbindung mit einem geprägten Zwischenstück,
• Figur 2 zeigt einen Querschnitt entsprechend der Linie II-II durch die in der Fig. 1 dargestellten Profile,
• Figur 3 zeigt eine Ansicht des Zwischenstücks aus Fig. 1 aus der Richtung 111,
• Figur 4 zeigt die Ansicht des Zwischenstücks aus der Richtung IV.
• Figur 5 zeigt schematisch ein geprägtes Zwischenstück, wobei hier zur Veranschaulichung des Erfindungsgedankens auf die speziellen Querschnitte der Hohlprofile keine Rücksicht genommen wurde,
• Figur 6 zeigt ebenfalls schematisiert ein Zwischenstück mit umgebördelten Innenrändern und
• Figur 7 veranschaulicht, wie die Umbördelung auszuführen ist, wenn Hohlprofile unter einem Winkel von beispielsweise 90° aneinandergefügt werden sollen.

Exemplary embodiments of the invention are shown in the drawing:

• FIG. 1 schematically shows a joining connection with an embossed intermediate piece,
• FIG. 2 shows a cross section along the line II-II through the profiles shown in FIG. 1,
• FIG. 3 shows a view of the intermediate piece from FIG. 1 from the direction 111,
• Figure 4 shows the view of the intermediate piece from the direction IV.
• FIG. 5 schematically shows an embossed intermediate piece, with no consideration being given to the special cross sections of the hollow profiles in order to illustrate the inventive concept,
• Figure 6 also schematically shows an intermediate piece with flanged inner edges and
• FIG. 7 illustrates how the flanging is to be carried out when hollow profiles are to be joined together at an angle of, for example, 90 °.

In Fig. 1, the profiles 1 and 2 are each cut at 45 ° to their longitudinal axis and pressed against an intermediate plate 3, the outline of which is greater by about 1.5 mm over the entire circumference than the outline of the profiles in the miter plane. With a profile cross-section of 40 mm and a profile wall thickness of 1.5-5 mm, the 1.5 mm mentioned are sufficient to compensate for all tolerances and are almost melted down to the profile cross-section in the usual tungsten inert gas / AC welding processes that after welding no or little reworking of the weld is required.

Fig. 2 shows a cross section through the profiles shown in Fig. 1, namely perpendicular to the longitudinal axis of the profile. The profile shown is just a schematic example; for the often very complicated profiles, however, joining technology connections with correspondingly shaped intermediate pieces can be made quite analogously.

3 and 4 show a schematic embodiment of the intermediate piece for the joining connection shown in FIG. 1, FIG. 3 showing the view from one side and FIG. 4 showing the view from the other side.

To illustrate this, an embossed intermediate piece is shown in perspective in FIG. 5. To better illustrate the principle of the embossing on both sides of the intermediate piece, no consideration was given to the special shapes of the hollow profiles, but an intermediate piece for hollow profiles with a square cross-section was drawn. A sheet 10 is provided with protrusions by stamping. The embossments 11 are raised on one side of the sheet, while the embossments 12 are raised on the other side. The shape and the location of the embossments are chosen so that each of the two hollow profiles to be connected can no longer be moved after being pressed onto the intermediate piece.

Another exemplary embodiment of an intermediate piece 20 is shown in FIG. 6. This intermediate piece is particularly suitable in the event that the cavity of the hollow profiles should not be interrupted at the connection point. The intermediate piece is a sheet which has an opening in the middle. The edges of the opening are crimped in sections and alternately in one direction or the other. This results in projections 21 which protrude into the interior of one hollow profile and projections 22 which are in the interior of the other hollow profile. As can be seen from the drawing, these flanged edges can also be designed so that a good fixation of the intermediate plate and hollow profiles is ensured. Such an intermediate piece can be produced without great effort.

Fig. 7 also shows only schematically for square cross sections of hollow profiles, an intermediate piece 30, which illustrates the type of flanging to be selected when hollow profiles are to be connected at an angle of, for example, 90 °. There are in turn transports 31 and 33 on one side of the intermediate piece and transports 32 and 34 on the other side. The arrangement of the flanges is now chosen so that the hollow profiles can be connected at an angle of 90 °. For this purpose, the projections 31 and 32 must each form an angle of 45 ° to the connection plane. The projections 33 and 34 continue to form an angle of 90 ° to the connecting plane, but care must be taken that their corners do not abut the inner sides of the hollow profiles before they are in the correct position to one another. For this reason, a somewhat different arrangement of the flanges compared to FIG. 6 was chosen, which meets the task.

The exemplary embodiments are of course to be modified for different hollow profile cross sections, but the essential factors that have to be taken into account were illustrated in the schematic drawings. At least the embodiment of an embossed intermediate piece is also suitable for hollow profiles with a non-rectilinear cross-section and when connecting at any angle. The embossing can always be shaped and carried out in such a way that the intermediate piece and hollow profiles remain fixed in the connecting plane.

Claims (9)

1. A process for the production of a brazed or welded joint between two sections (1, 2), in particular hollow sections, which may abut against one another in a plane by means of a mitre-joint, in which an intermediate piece (3) is arranged in the cutting plane of the two hollow sections (1, 2) and incorporated into the brazed and welded joint, and in which the intermediate piece has projections which protrude into the ; interiors of the two hollow sections to be joined and hold the sections during joining, characterised by the following features :

a) before the joining process, a flat intermediate piece (3) is arranged between the two hollow sections (1, 2) which abut against one another and have an undiminished cross-section, the outer contour of which intermediate piece (3) corresponds to the outer contour of the cutting planes of the hollow sections (1, 2), which are to be joined, or uniformly protrudes outwardly by about 1.5 mm on all sides ;

b) hollow sections made of light metal, in particular of extruded material, are used, the intermediate piece (3) serving as an additional material during brazing or welding.

2. A process according to Claim 1, characterised by the following features :

a) sections (1, 2) made of AIMgSi 0.7 are used ;

b) an easily weldable light metal, in particular AISi 12 is used for the intermediate piece (3).

3. A process according to Claim 1 or Claim 2, characterised by the following feature :

the hollow sections (1, 2) and the intermediate piece (3) are welded by the tungsten inert-gas method without additional welding material.

4. A process according to one of Claims 1-3, characterised by the following feature :

a welding process with a magnetically moved arc is used to join the hollow sections.

5. A process according to Claim 1, characterised by the following features :

a) a sheet metal. clad with solder on both sides is used as the intermediate piece (3) ;

b) hollow sections (1, 2) and intermediate piece (3) are soldered.

6. Intermediate piece (10 ; 20 and 30) for the production of a brazed or welded joint using the process according to one of Claims 1 to 4, characterised by the following features :

a) the outer contour of the intermediate piece corresponds to the outer contour of the cutting planes of the hollow sections (1, 2) which are to be joined, with undiminished wall thickness or uniformly protrudes outwardly by about 1.5 mm on all sides ;

b) the intermediate piece (3) has projections (11, 12 ; 21, 22 or 31, 32), which protrude into the interiors of the two hollow sections to be joined in shape-locking manner, and said projections being arranged in such a way that each two adjacent projections protrude from the intermediate piece towards different sides.

7. An intermediate piece (10) according to Claim 6, characterised by the following feature :

the projections (11, 12) of the intermediate piece (10) are produced by stamping.

8. An intermediate piece (20 or 30) according to Claim 6, characterised by the following features :

a) the projection (21, 22 or 31, 32) of the intermediate piece (20 or 30) are produced by turning over all round ;

b) the angle of the turned-over projections corresponds to the angle, at which the profiles abut against one another.

9. A welded joint between two sections (1, 2) produced by means of the process according to one of Claims 1-4, characterised by the following features :

a) the section (1, 2) consist of extruded material, in particular, AIMgSi 0,7 ;

b) the weld contains an easily weldable additional material, in particular AISi 12, which has been added during the welding process in the form of a flat intermediate piece (3) arranged in the cutting plane of the sections (1, 2), the sections (1, 2) and the intermediate piece (3) corresponding to the statement of Claim 1 as regards their shape.

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