EP3590617B1 - Method for manufacturing a support profile comprising a sheet and support profile manufactured using this process - Google Patents

Description

The invention relates to a method for producing a support profile from sheet metal, the sheet metal having a first longitudinal edge and a second longitudinal edge, the first longitudinal edge and the second longitudinal edge being parallel to one another. The present invention also provides a carrier profile which is produced by the method according to the invention, in particular according to one of the embodiments described above.

The method comprises a step of bending, the sheet metal being bent into the shape of the carrier profile. The first longitudinal edge is bent into a first envelope with a first envelope edge and the second longitudinal edge is bent into a second envelope with a second envelope edge, the first envelope edge and the second envelope edge being in direct contact, with sheet metal being bent to form the carrier profile in such a way that the first and the second longitudinal edge lie within the carrier profile.

The method further comprises a step of welding the first folded edge and the second folded edge to one another, the welding being formed by a step of high-frequency welding or by a step of fusion welding.

A method for producing a support profile is from among others FR 2 865 667 A1 known. Processes of this type are used for the production of support profiles with integrated rails. However, the outwardly bent envelopes lead to an inhomogeneous outer surface with additional joints or edges, which make it difficult to use for carrier profiles with a precise surface fit. The welding consumables used for this process can also contribute to the unevenness of the outer surface, but reworking them can weaken the connection point and thus the strength of the support profile.

Further processes for the production of support profiles are from DE102008051894A1 , US5163225A , JP2002168576A , GB2486788A and the DE4442434C1 known.

A method according to the preamble of independent claim 1 is for example from DE69002760T2 known.

The object of the present invention is to provide a method for producing a support profile from a sheet metal which has both high strength and high surface quality.

The object is achieved by the features of independent claims 1 and 14. Accordingly, in a method according to the preamble of independent claim 1, there is an inventive solution to the object when the longitudinal edges are bent over by 180 ° so that the envelopes each on the later On the inside of the support profile, the longitudinal edges being bent in such a way that, after the sheet metal has been formed into the support profile and before the two cover edges have been welded, the end face facing the other edge, which runs orthogonally to the respective envelope and has a first radius into an outer side of the support profile, and with a second radius merges into the respective envelope, at least the first radius being smaller than the sheet thickness D of the sheet metal ..

The folded edges are welded to one another either by means of inductive high-frequency welding or fusion welding. By using a high-frequency (HF) welding process, a particularly good connection between the two envelopes can be achieved, with the use of welding consumables being dispensed with. This process gives the weld seam a particularly high level of strength and enables its high stability without supporting the seam from the inside on the profile. The eddy currents generated by the induction coils also make it possible to limit the heat input to the edges to be welded.

As an alternative to an HF welding process, a fusion welding process such as a metal-active gas welding process or a carbon dioxide laser welding process can also be used.

The inwardly bent envelopes also reinforce the stability of the support profile in the area around the weld, since the support profile is double-walled in this area. As a result, the moment of resistance and the geometrical moment of inertia of the support profile can be increased in this area without additional reinforcement elements having to be welded on in this area. The edge of the envelope forms the folded edge of the envelope. After the bend has taken place, and before the two folded edges are welded together, it forms the new outer edge of the respective longitudinal edge, so to speak.

Together with the HF welding process, by bending the envelopes inward, a particularly high surface quality can be achieved, so that carrier profiles which have been produced by a process according to the invention can be used as precision profiles.

The sheet metal is preferably formed in a process for cold roll forming.

The sheet metal is preferably a pure metal sheet without a plastic coating or the like. In any case, the base material of the sheet metal is worn away. More preferably, the sheet is a steel sheet.

Advantageous embodiments of the present invention are the subject of the subclaims.

According to a particularly preferred embodiment of the present invention, the carrier profile has a longitudinal side, the longitudinal side having an inner width, the weld running along the longitudinal side. By bending the folds inwards, the rigidity of the long side can be increased, whereby in particular one-sided loaded carrier profiles can be reinforced without increasing their external dimensions.

According to a further particularly preferred embodiment of the present invention, the carrier profile has a first width of the first envelope perpendicular to the longitudinal extension of the carrier profile and a second width of the second envelope perpendicular to the longitudinal extension of the carrier profile, the first envelope over the first length and the second envelope over the second length rest against an inside of the support profile. As a result, the rigidity and the geometrical moment of inertia of the carrier profile can be increased further. In particular, the effect of the eddy currents and thus of the heat input on the edges to be welded can be improved by the high-frequency welding step through the electrical contact between the envelopes and the inside of the carrier profile.

According to a further embodiment of the present invention, the first width and the second width are each at least twice the thickness of the sheet metal. As a result, in particular the region of the carrier profile directly adjacent to the weld seam can be reinforced.

According to an alternative embodiment of the present invention, the sum of the first width and the second width covers at least 50% of the inner width of the long side.

According to a further preferred embodiment of the present invention, the sum of the first width and the second width essentially completely covers the inner width of the longitudinal side. As a result, a particularly stressed side wall of the carrier profile can be additionally reinforced mechanically.

According to a further embodiment of the present invention, the first longitudinal edge and the second longitudinal edge abut one another. As a result, at least a part of the carrier profile can be made double-walled, so that its cross-sectional values can be improved without the use of a greater thickness of the sheet metal used for production. In particular in the case of carrier profiles that are loaded on one side, at least a first cavity of the carrier profile can be doubled in its wall thickness. Furthermore, eddy currents flowing back on the inside of the support profile can cause the first longitudinal edge to be welded to the second longitudinal edge in addition to welding the edge of the first envelope to the edge of the second envelope.

According to a further particularly preferred embodiment of the present invention, the first radius is less than half the sheet metal thickness D, more preferably less than 10% of the sheet thickness D, particularly preferably less than 2% of the sheet thickness, and very particularly preferably the first radius is so small that there is a sharp edge at this point. The second radius is preferably larger than the first radius and is preferably more than 30% of the sheet metal thickness D. In order to achieve such a geometry with a particularly small first radius and to be able to bend the longitudinal edges by 180 ° with the least possible damage, in the sheet metal before or during the bending of the longitudinal edges a groove is rolled in the area of the later folded edge, in particular in the area of the first radius, the groove being made in the side of the sheet metal opposite the later first radius, and / or the longitudinal edge is made up to later cover edge thinned to a smaller thickness. The smaller thickness of the thinned longitudinal edge is preferably between 50% and 80% of the sheet metal thickness D. The end face between the first radius and the second radius is also preferably straight, so that the end faces of the two folded edges can be at least partially brought into flat contact during welding .

As already mentioned above, this embodiment has the advantage that the longitudinal edges can be bent over by 180 ° with as little damage as possible. In addition, it is thereby possible to upset the edges of the fold with sharp edges before welding on the outer circumference and then to weld the edges of the fold without breaking.

According to a further embodiment of the present invention, the production of the support profile includes an additional step of finishing the weld, for example by grinding or planing. As a result, the quality of the surface of the weld seam can be further improved, so that particularly high surface tolerances can be achieved. During welding, the folded edges are preferably pressed against one another in such a way that a weld seam is raised on the outside of the carrier profile, which is planed off immediately after welding while it is still hot in order to achieve a high surface quality. The elevation of the weld seam is preferably planed in the line at a distance of 500 mm to 700 mm from the weld point. A particularly economical production is thereby achieved. This embodiment also contributes to rapid production of the support profile. Due to the above-described upsetting of the edges of the fold before the welding process, the edges of the fold do not have to be so strongly compressed or upset during welding in order to achieve a clean weld seam, especially on the outside of the carrier profile, and a high surface quality after planing the weld seam. This also reduces the risk of cracking.

According to a further preferred embodiment of the present invention, the width of a weld seam formed by the welding is at least a single thickness of the sheet metal, but is at most three times the thickness of the sheet metal.

The step of high-frequency welding further preferably comprises the use of an impedance core. In particular, a rod made of ferritic material is held in the area of the induction coil in the interior of the support profile, with the heat input being able to be concentrated further on the edges to be welded.

Embodiments of the present invention are explained in more detail below with reference to drawings.

Figur 1:

einen Querschnitt eines durch ein erfindungsgemäßes Verfahren hergestellten Trägerprofils 10,

Figur 2:

eine Detailansicht eines der beiden Längsränder im Querschnitt vor dem Umbiegen mit einer eingewalzten Rille,

Figur 3:

die Detailansicht aus Figur 2 mit einem ausgedünnten Randbereich anstatt einer eingewalzten Rille,

Figur 4:

die Detailansicht aus Figur 3 nach dem Umbiegen des Längsrands,

Figur 5:

die Detailansicht aus Figur 4 nach dem Verscheißen der Umschlagkanten, und

Figur 6:

die Detailansicht aus Figur 5 nach dem Abhobeln der Schweißnahtüberhöhung.

Show it:

Figure 1:

a cross section of a carrier profile 10 produced by a method according to the invention,

Figure 2:

a detailed view of one of the two longitudinal edges in cross section before bending with a rolled-in groove,

Figure 3:

the detailed view Figure 2 with a thinned edge area instead of a rolled-in groove,

Figure 4:

the detailed view Figure 3 after bending the long edge,

Figure 5:

the detailed view Figure 4 after the cover edges have been scoured, and

Figure 6:

the detailed view Figure 5 after planing off the weld seam elevation.

The carrier profile 10 is formed from a sheet metal 12, in particular a sheet metal strip, the sheet metal 12 having a first envelope 4 bent by 180 ° with a first envelope edge 6 and a second envelope 5 bent by 180 ° with a second envelope edge 7. By bending parallel to the longitudinal extension of the sheet metal 12, and thus parallel to the first longitudinal edge 2 and the second longitudinal edge 3, the sheet metal 12 is brought into the shape of the carrier profile 10, with the first folded edge 6 and the second folded edge 7 of the formed sheet metal 12 lying against one another . The area of the sheet metal 12 lying between the first folded edge 6 and the second folded edge 7 thus forms a cladding sheet 13 of the carrier profile 10. The envelopes 4 and 5 are bent inward in such a way that the first longitudinal edge 2 and the second longitudinal edge 3 within the carrier profile 10 lie. The bending and the means for its implementation are known and are not described in detail here. The forming preferably takes place in a process for cold roll forming.

The carrier profile 10 encloses a first cavity 11 and a second cavity 17.

The envelopes 4 and 5 are pressed firmly against the cladding sheet 13 of the carrier profile 10 by the 180 ° bending, so that the envelopes 4 and 5 form a double-walled area of the carrier profile 10 with the enveloping sheet 13. The first envelope 4 has a first width 14 and the second envelope 5 has a second width 15.

The shape of the envelopes 4 and 5 is selected such that the contact point of the first envelope edge 6 and the second envelope edge 7 is in the middle of the longitudinal side 16. The sum of the first width 14 and the second width 15 essentially completely covers the inner width 9 of the longitudinal side 16.

In the welding step, the carrier profile 10 is continuously guided through at least one induction coil through which alternating current flows, with a gap between the first folded edge 6 and the second folded edge 7 which, after passing through the induction coil, is caused by pressing the first folded edge 6 and the second folded edge 7 together is closed. The side surfaces 8 are each by a profile roller pressed together, so that the material of the folded edges 6 and 7 heated to a welding temperature is welded together to form a weld seam 1. The width of the weld 1 is approximately twice the thickness of the sheet metal 12, so that the envelope edges 6 and 7 are welded to one another over their entire thickness, but the envelopes 4 and 5 themselves are essentially not welded to the cladding sheet 13. The means for performing high-frequency welding are already known and will not be described in detail.

By using an impedance core, which is held in the first cavity 11 enclosed by the carrier profile 10, a backflow of the eddy currents in the envelopes 4 and 5 is reduced, the heat input in the envelope edges 6 and 7 being improved and particularly good welding achieved .

The surface quality of the carrier profile is further improved by a subsequent step of mechanical reworking of the weld seam 1, in particular by a step of scraping or planing.

Those skilled in the art will recognize that the invention is not limited to the above embodiment, but rather to the scope of the claims. In addition to the inner width 9 of the longitudinal side 16, the sum of the first width 14 and the second width 15 can cover the entire inner circumference of the first cavity 11 so that the first longitudinal edge 2 and the second longitudinal edge 3 lie directly against one another.

As Figure 2 shows, before or during the bending of the longitudinal edges in the sheet metal, a groove 18 is preferably rolled in the area of the later folded edge in order to facilitate further deformation and to reduce the risk of cracking. As an alternative or in addition, the longitudinal edge is thinned to a smaller thickness until the later edge of the envelope, as is the case Figure 3 shows. The smaller thickness is preferably between 50% and 80% of the original sheet metal thickness D of the sheet metal 12. The thinned edge area is then reshaped as shown in FIG Figure 4 is shown. After the sheet metal has been formed into the carrier profile and before the two edges are welded, the resulting edge 6 has an end face facing the other edge 7, which runs orthogonally to the respective envelope 4 and with a first radius R1 into an outside of the carrier profile , and with a second radius R2 merges into the envelope 4, the first radius R1 being significantly smaller than the sheet thickness D of the sheet metal and the second radius R2. In the ideal case, the edge of the envelope is compressed in such a way that the first Radius R1 is particularly small and essentially forms a sharp edge. The end face facing the other folded edge runs essentially straight between the first radius R1 and the second radius R2, so that the two folded edges can be at least partially brought into flat contact during welding, which makes the welding process much easier and a relatively low contact pressure during welding requires. This can reduce the risk of cracks.

As Figure 5 shows, when welding on the outer circumference, a certain weld seam elevation 19 arises, which is also desired, since this weld seam elevation 19, like Figure 6 shows, in a planing step immediately following the welding process, planing can be carried out while still hot in order to achieve particularly high dimensional accuracy and surface quality. A certain elevation 20 also arises on the inner circumference, but due to the relatively large second radius R2, it does not protrude beyond the surface of the two envelopes 4 and 5 directed into the interior of the carrier profile.

Claims (14)

1. A method for manufacturing a beam profile (10) from a metal sheet (12), the metal sheet (12) having a first longitudinal edge (2) and a second longitudinal edge (3), wherein the first longitudinal edge (2) and the second longitudinal edge (3) are parallel to each other, the method comprising:

   a. bending the metal sheet (12) to the beam profile (10), wherein the first longitudinal edge (2) is bent to a first seam (4) with a first seam edge (6) and the second longitudinal edge (3) is bent to a second seam (5) with a second seam edge (7), wherein the first seam edge (6) and the second seam edge (7) are in direct contact with each other;

   b. welding the first seam edge (6) and the second seam edge (7) together,

   wherein the metal sheet (12) is bent to the beam profile (10) in such a way that the first (2) and second (3) longitudinal edges are located within the beam profile (10), the welding being performed by means of a step of high-frequency welding or by a step of fusion welding,
   characterised in that the longitudinal edges (2, 3) are folded by 180° so that the seams (4, 5) each abut against a side which is to become the inner side of the beam profile (10), the longitudinal edges (2, 3) being folded in such a way that the seam edge (6, 7), after forming the metal sheet (12) to the beam profile and before welding the two seam edges (6, 7) together, has an end face opposite the respective other seam edge (6, 7) which extends orthogonally to the respective seam (4, 5) and merges into an outer surface of the beam profile with a first radius R1 and into the respective seam (4, 5) with a second radius R2, wherein at least the first radius R1 is smaller than the sheet thickness D of the metal sheet (12).
2. The method according to claim 1, characterized in that the beam profile (10) has a longitudinal side (16), wherein the longitudinal side (16) has an inner width (9), and wherein the weld (1) extends along the longitudinal side (16).
3. The method according to claim 1 or 2, characterised in that the beam profile (10) has a first width (14) of the first seam (4) perpendicular to the longitudinal extension of the beam profile and a second width (15) of the second seam (5) perpendicular to the longitudinal extension of the beam profile (10), wherein the first seam (4) and the second seam (5) abut against an inner side of the beam profile (10) over the first length (14) and over the second length (15), respectively.
4. The method according to claim 3, characterized in that the first width (14) and the second width (15) are each at least twice the thickness of the metal sheet (10).
5. The method according to claims 2 and 3, characterized in that the sum of the first width (14) and the second width (15) covers at least 50 % of the inner width (9) of the longitudinal side (16).
6. The method according to claims 2 and 3, characterized in that the sum of the first width (14) and the second width (15) covers substantially the entire inner width (9) of the longitudinal side (16).
7. The method according to claim 7, characterized in that the first radius R1 is smaller than half the sheet thickness D, particularly preferably smaller than 10 % of the sheet thickness D.
8. The method according to claim 7 or 8, characterized in that the second radius R2 is larger than the first radius R1 and is preferably more than 30 % of the sheet thickness D.
9. The method according to one of claims 7 to 9, characterised in that a groove (18) is rolled into the metal sheet (12) before or during the folding of the longitudinal edges (2, 3) in the region of the seam edge (6, 7) to be formed, in particular in the region of the first radius R1, and/or the longitudinal edge (2, 3) is thinned to a smaller thickness up to the seam edge (5, 6) to be formed.
10. The method according to claim 10, characterized in that the reduced thickness of the thinned longitudinal edge is between 50 % and 80 % of the sheet thickness D.
11. The method according to one of claims 7 to 11, characterised in that the end face extends linearly between the first radius R1 and the second radius R2, so that the end faces of the two seam edges (6, 7) can be brought at least partially in surface contact during welding.
12. The method according to one of claims 1 to 12, characterised in that the seam edges (6, 7) are pressed together during welding so that a weld reinforcement (19) is produced on the outside of the beam profile (10) that is planed off immediately after welding while still warm.
13. The method according to claim 13, characterised in that planing off the weld reinforcement (19) is carried out in the line at a distance of 500 mm to 700 mm from the welding point.
14. A beam profile (10) made from a metal sheet (12), the metal sheet (12) having a first longitudinal edge (2) and a second longitudinal edge (3), wherein the first longitudinal edge (2) and the second longitudinal edge (3) are parallel to each other, the metal sheet (12) being bent to the beam profile (10), wherein the first longitudinal edge (2) is bent to a first seam (4) with a first seam edge (6) and the second longitudinal edge (3) is bent to a second seam (5) with a second seam edge (7), wherein the first seam edge (6) and the second seam edge (7) are in direct contact with each other and the first seam edge (6) and the second seam edge (7) are welded together,
    wherein the first seam (4) and the second seam (5) are bent in such a way that the first (2) and second (3) longitudinal edges are located within the beam profile (10), wherein the first (6) and the second (7) seam edge are high-frequency welded,
    characterised in that the longitudinal edges (2, 3) are folded by 180° so that the seams (4, 5) each abut against a side which is to become the inner side of the beam profile (10), the longitudinal edges (2, 3) being folded in such a way that the seam edge (6, 7), after forming the sheet (12) to the beam profile and before welding the two seam edges (6, 7) together, has an end face opposite the respective other seam edge (6, 7) which extends orthogonally to the respective seam (4, 5) and merges into an outer surface of the beam profile with a first radius R1, and into the respective seam (4, 5) with a second radius R2, at least the first radius R1 being smaller than the sheet thickness D of the metal sheet (12), wherein the beam profile (10) is in particular produced by means of a method according to any of claims 1 to 14.

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