DE102008056273B4 - Method for producing a closed hollow profile, closed hollow profile produced by this method and device for producing such a closed hollow profile - Google Patents

Abstract

Method for producing a closed hollow profile (1), characterized by the following method steps to be carried out successively: a) provision of a printed circuit board (2); b) forming the blank (2) in a first forming step, as seen in the longitudinal direction of the hollow profile (1) to be produced, on both sides of the blank (2) each extending in the longitudinal direction of the hollow profile (1) and outwardly facing shutdown (9, 10 ) is formed; c) reshaping the board (2) provided with said shutters (9, 10) in a second forming step by passing the blank (2) through a punch (4a) of a forming tool known per se, in the longitudinal direction of the hollow profile (1) to be produced Deep drawing to a lower portion (2a) of the hollow profile (1) with two on both sides of the board (2) opposite flange (2b), which protrude from said lower portion (2a) of the hollow profile (1) is pulled, the Abstellungen ( 9, 10) according to process step b); d) forming the said (9, 10) provided and drawn board (2) in a third forming step to a closed hollow profile (1) by the flange (2b) according to a known rolling-in to the core geometry of at least one retracted previously Mold core (5) formed around a forming tool known per se and the shutdowns (9, 10) in the form of welding flanges are largely brought together plan, and by the Abstell (9, 10) on a means (15) for supporting the guide and / or fixation the stops (9, 10) in the form of an increase in the mold core (5) extending in the longitudinal direction of the profile (1) to be produced and in a further means (14) corresponding to said elevation for supporting the guidance and / or fixing of the stops ( 9, 10) in the form of a longitudinal groove on the forming pressure stamp (13) initiate; and e) welding the two shutters (9, 10) with each other.

Description

The invention relates to a method for producing a closed hollow profile, a closed hollow profile produced by this method and a device for producing such a closed hollow profile according to the combination of features of claim 1 or 8 or 13.

From practice and the patent literature various methods for the production of closed hollow profiles are known. For some time, however, experts have favored methods which, in turn, include a so-called "rolling-in technique" ( DE 10 2006 017 119 A1 . DE 10 2006 025 522 A1 . DE 10 2007 008 641 A1 ). Essentially, it is provided here in a first forming step, first of all, to partially reshape a blank by deep drawing in such a way that a lower deep-drawn region as well as an upper flange region are formed. In a subsequent forming step, the lower deep-drawn region and said flange regions are then formed around a previously retracted mold core by means of side cheek mold halves of a forming tool known per se until the end edges of the flange regions abut one another. Finally, the flange areas in your contact area are welded together by forming an I-weld. By such a method hollow sections with variable cross-sectional shapes, wall thicknesses and stiffness can be produced, as they are increasingly used in vehicle. Regardless, such a designed manufacturing process requires due to the favored I-weld a precise trimming of the original board, since inaccuracies can not be compensated with hindsight or only with considerable effort. The DE 103 29 424 A1 describes a similar method to that described above. The DE 103 56 137 A1 describes a method for producing a tubular hollow profile, wherein it is provided here by deep drawing form two substantially mirror-like shells, which are integrally connected by a sheet metal tabs together. By buckling the sheet metal flap, the two shells are folded together, whereby the hollow profile is formed. During the molding and a circumcision of the shell mold from a sheet metal, corresponding opposite flange-like sheet-metal tabs are also formed in the region of boundary edges, which are joined together after the collapsing of the two shells of the pipe profile to be formed. The DE 26 09 570 A1 describes a method for producing a gutter drain sheet made of thin sheet, wherein in a first step, a flat sheet metal blank is cut free and deformed in a second step by deep drawing in its central region to form a tube sheet half shell. In a third process step after the second process step on both sides of the pipe bend half-shell left lateral flaps are deformed in a subsequent drawing process to Rohrbogenviertelschalen such that they come with their free ends or in the region of their free ends in an at least linear contact, wherein radially projecting to the pipe bend end portions in be curtailed a further process step. Finally, the free ends of the sheet metal blank which are in line contact are joined together along the contact line, for example welded. The DE 10 2005 057 424 A1 describes a method and an apparatus for coreless molding of hollow sections, wherein first a board by means of two die halves by a closing movement thereof is converted into a slotted hollow profile by preventing the edges of the board is preceded by a projecting into the coreless mold cavity sword. Finally, the slotted hollow profile can be longitudinally welded.

The object of the invention is first to provide a simpler and cost-effective method to be performed of the generic type, which takes into account the disadvantageous circumstance described above, that in particular costly Beschnittmaßnahmen the original board before forming to ensure the creation of a conventional I-weld can be avoided , It is also an object to provide a closed hollow profile, in particular produced by this process, as well as a device for producing such a closed hollow profile.

The invention is based on the finding that by creating a parked welding flange instead of an I-shock dimensional inaccuracies or tolerances of the original or output board in the production of a closed hollow profile by forming, the board can be met easily and inexpensively.

• a) Bereitstellung einer Platine;
• b) Umformung der Platine in einem ersten Umformschritt, indem in Längsrichtung des herzustellenden Hohlprofils gesehen, beidseitig der Platine je eine sich in Längsrichtung des Hohlprofils erstreckende und nach außen weisende Abstellung ausgebildet wird;
• c) Umformung der mit besagten Abstellungen versehenen Platine in einem zweiten Umformschritt, indem die Platine vermittels eines sich in Längsrichtung des herzustellenden Hohlprofils erstreckenden Stempels eines an sich bekannten Umformwerkzeuges durch Tiefziehen zu einem unteren Bereich des Hohlprofils mit zwei beidseitig der Platine gegenüberstehenden Flanschbereichen, die von dem besagten unteren Bereich des Hohlprofils abstehen, gezogen wird, wobei die Abstellungen gemäß Verfahrensschritt b) erhalten bleiben;
• d) Umformung der mit besagten Abstellungen versehenen sowie gezogenen Platine in einem dritten Umformschritt zu einem geschlossenen Hohlprofil, indem die Flanschbereiche nach einem an sich bekannten Einrollverfahren um die Kerngeometrie zumindest eines vorab eingefahrenen Formkerns eines an sich bekannten Umformwerkzeuges herumgeformt und die Abstellungen in Form von Schweißflanschen weitestgehend plan zusammengeführt werden, und indem die Abstellungen auf ein Mittel zur Unterstützung der Führung und/oder Fixierung der Abstellungen in Form einer sich in Längsrichtung des herzustellenden Profils erstreckenden Erhöhung des Formkerns aufgleiten und in ein zur besagten Erhöhung korrespondierendes weiteres Mittel zur Unterstützung der Führung und/oder Fixierung der Abstellungen in Form einer Längsnut am Formdruckstempel eingleiten; und
• e) Verschweißen der beiden Abstellungen untereinander.

On this basis, the object is accordingly achieved by a method for producing a closed hollow profile, which comprises the following steps to be carried out successively:

• a) providing a circuit board;
• b) forming the board in a first forming step, as seen in the longitudinal direction of the hollow profile to be produced, is formed on both sides of the board each one extending in the longitudinal direction of the hollow profile and facing outward Abstellung;
• c) forming the board provided with said shutters in a second forming step by the board by means of extending in the longitudinal direction of the hollow profile to be produced stamp of a known forming tool by deep drawing to a lower portion of the hollow profile with two sides of the board facing flange portions of protrude the said lower portion of the hollow profile, is pulled, wherein the shutdowns remain in accordance with method step b);
• d) transformation of the provided with said shutdowns and drawn board in a third forming step to form a closed hollow profile by the flange after a known curl around the core geometry of at least one pre-retracted mandrel of a known forming tool and the shutdowns in the form of welding flanges largely merged plan, and by the shutters slide on a means for supporting the guidance and / or fixation of the shutters in the form of extending in the longitudinal direction of the profile to be produced increasing the mold core and in a corresponding to said increase further means for supporting the guide and / or fix the shutdowns in the form of a longitudinal groove on the forming pressure stamp initiate; and
• e) welding the two stops together.

The subclaims describe preferred developments or refinements of the invention.

Thereafter, it can be provided, with regard to the method step a), to provide a blank made of a cold- or hot-formable steel. Furthermore, with regard to method step a), it may be advantageous to provide a cold-formable steel circuit board which has one or more areas reinforced by "patchwork blanks", "tail blanks" and / or "tail-edge strips". With regard to method step b), it may further be provided to produce the shutdowns by means of deep drawing, swaging, roll forming or the like known per se. With regard to method step e), it is advantageous to weld the two stops together, while the formed blank is still in the forming tool. Further advantageously, the two shutdowns can be welded together by laser welding, spot welding and / or according to another suitable welding method known per se. Finally, if necessary, a dimensionally accurate trimming of the two welded-together abutments, respectively of the welding flange created, can follow process step e).

The closed hollow profile made of metal, prepared according to the method described in more detail above, is characterized essentially by the fact that the closed hollow profile has a deep-drawn region extending over the entire length of the hollow profile with flange regions formed on both sides of the deep-drawn region, viewed in the longitudinal direction of the hollow profile at the respective free end of the said flange portions each created by forming Abstell is formed, and wherein the Abstell are formed so that these following a known rolling-in, in which the deep-drawn region and the flange around the core geometry of a mandrel on Known forming tool are guided around, facing outward and largely brought together plan and welded, forming the axially extending weld. The axially extending weld can here be produced by laser welding, spot welding and / or according to another suitable welding method known per se. Advantageously, the hollow profile can be formed from a blank made of a cold- or hot-formable steel, wherein a hollow profile, which is formed from a blank made of a cold-workable steel, also one or more by "patchwork blanks", "Tailord blanks" and / or " Tailord Strips "may have reinforced areas. Particularly advantageously, the hollow profile can be designed as a body pillar for vehicle construction, in particular as an A-pillar.

The invention also relates to a device for producing a closed hollow profile from a board, comprising at least one forming tool in the form of a Formdruckgesenkes wherein the Formdruckgesenk has at least one forming pressure die and a die, and wherein the Formdruckgesenk at least one retractable in the same mold core can be assigned to the core geometry after a known rolling process, the board is formed around. In particular, it is proposed that the mold pressure stamp and the at least one retractable mold core each have a means for supporting the guidance and / or fixation of pre-formed and outwardly parked and extending in the longitudinal direction of the hollow profile to be produced shutdown of the board in the form of welding flanges to be welded together during the implementation of said rolling-in process, wherein one means is formed by a longitudinal groove in the forming pressure stamp and the other means by a longitudinal groove corresponding to the longitudinal groove and extending in the longitudinal direction of the hollow profile to be produced local increase, on which increase the shutdowns during the implementation of said Forced roll on forced and then slide into the longitudinal groove. The invention will be explained in more detail with reference to an embodiment schematically illustrated in the drawings. Show it:

1a , b very schematically the representation of a known forming method for producing a closed hollow profile according to the so-called Einrolltechnik (prior art),

2 the representation of a suitable forming tool for forming a prepared board by deep-drawing known per se,

3 the representation of a suitable forming tool with a retracted mold core at the beginning of a process step subsequent to the deep-drawing step for further shaping of the blank according to a rolling-in method known per se,

4 the representation of the forming tool after 3 with finally converted board, and

5 exemplifying a produced by the inventive method and the inventive device closed hollow profile in the form of an A-pillar of a motor vehicle.

As already described above, it is already known closed hollow sections 1 to produce according to the so-called "rolling-in technique". Essentially, this is according to 1a a circuit board 2 in a first forming step by means of a known forming tool in the form of a mold pressure die with a lower die 3 and a superstar 4 which in turn has a stamp 4a has, in the present case at the same time the mold core 5 for a subsequent forming step, first the board 2 partially formed by deep drawing such that a lower deep-drawn area 2a as well as two raised flange areas 2 B be formed.

In an in 1b shown subsequent forming step then the lower deep-drawn area 2a and the said flange portions 2 B around the core geometry of the mold core 5 by means of appropriately trained Seitenwangengesenkhälften 6 . 7 formed around the forming tool until the end edges of the flange 2 B lie on each other in push. Finally, the flange areas 2 B in your contact area by means of a known welding device 8th , For example, a laser welding device welded together by an I-weld is formed.

By such a method are when using appropriately prepared boards 2 closed hollow profiles 1 With variable cross-sectional shapes, wall thicknesses and stiffness produced, as they are increasingly used in vehicle. However, such a fabricated manufacturing process requires a precise trimming of the source or output board due to the favored I-weld 2 because inaccuracies can not be compensated in hindsight or only with considerable effort.

To cope with this fact, an improved method for producing a closed hollow profile 1 according to the 2 to 5 proposed as follows.

First, it is provided that a provided board 2 , which is preferably trimmed, but no longer required to have the required degree of accuracy to produce a conventional I-weld, during a first Umformschrittes is transformed such that in the longitudinal direction of the hollow profile to be produced 1 seen, for example, according to 5 seen in the longitudinal direction of an A-pillar of a motor vehicle, both sides of the board 2 one each in the longitudinal direction of the hollow profile 1 extending and outward facing shutdown 9 . 10 is trained.

The board 2 can consist of a cold formable, optionally higher strength or of a thermosetting or thermoformable steel, wherein a circuit board 2 , which is formed from a cold-workable steel, further comprising one or more patchwork blanks, "Tailord blanks" and / or "Tailord Strips" reinforced areas, whereby different wall thicknesses and / or stiffnesses of the finished hollow profile 1 are feasible.

Said shutdowns 9 . 10 like her 2 can be seen, can be prepared by known per se deep drawing, swaging, roll forming or the like. (Not shown in detail).

Based on 1a and with particular reference to 2 then the one with said shutdowns 9 . 10 provided board 2 by means of an upper Gesenkes 4 with itself in the longitudinal direction of the hollow profile to be produced 1 extending stamp 4a a known forming tool or drawing tool by deep drawing to a lower die 3 or in a die forming lower area 2a with two flange areas 2 B from the lower area 2a of the hollow profile 1 stand, pulled, with the pre-trained shutdowns 9 . 10 remain.

According to 3 In the present case, there is a so-called U-stamp 4a Use, whereby with the help of the U-stamp 4a associated vertically formed side walls 11 . 12 of the forming tool, the two flange areas 2 B a vertical orientation to the lower, in the present plan trained area 2a taking.

In a third forming step, according to the 3 and 4 those with said shutdowns 9 . 10 provided and drawn board 2 to a closed hollow profile 1 deformed by the flange areas 2 B by means of a mold pressure stamp 13 a Formdruckgesenkes, which a not-shown in detail, but known per se die for receiving the pre-formed by deep drawing board 2 is assigned, according to the known rolling-in to the core geometry of at least one pre-retracted mold core 5 shaped around and the shutdowns 9 . 10 be brought together in the form of welding flanges plan. Said die can by the above-described lower die 3 , which is used during the second forming step, be formed.

Like that 3 and 4 can be further seen, both have the form pressure stamp 13 as well as the mold core 5 a means 14 . 15 to support the management and / or fixation of the shutdowns 9 . 10 the board 1 during the implementation of the curling process.

That's the way it is 14 to support the management and / or fixation of the shutdowns 9 . 10 through a longitudinal groove in the mold pressure stamp 13 formed, in which the shutdowns 9 . 10 penetrate to the end of said rolling process and thus fixed.

To this longitudinal groove corresponds another means 15 to support the management and / or fixation of the shutdowns 9 . 10 on the mold core 5 which is essentially arranged by a radially to the longitudinal groove and in the longitudinal direction of the hollow profile to be produced 1 extending local elevation is formed, on which the shutdowns 9 . 10 during the implementation of the rolling-in advantageous up in the manner of a forced operation and subsequently introduce into the longitudinal groove. Said local increase can be generated or modified, for example, by milling the core geometry or subsequently by means of build-up welding.

In the end, the two largely coordinated mergers 9 . 10 in the form of welding flanges with each other by means of a known per se and thus not shown here welding device 8th (cf however 1b ) are welded reliably, including offered to known welding methods, such as laser welding, spot welding and / or other suitable welding methods known per se.

Like that 3 and 4 can still be seen, is the form pressure stamp 13 formed closed upwards and must therefore be removed before welding. However, the invention is not limited to such a mold pressure stamp 13 , but also includes a longitudinally divided form pressure stamp not shown in detail 13 whose punch halves are arranged spaced from each other in such a way that said longitudinal groove is equivalent and accordingly realized the same effect by the spacing of the two punch halves. In this case, advantageously, the welding of an axially extending longitudinal seam can take place when the deformed circuit board 2 still located in the forming tool or even from the longitudinally divided mold pressure stamp 13 is fixed, whereby any suspensions of the flange 2 B are effectively avoided.

If said longitudinal seam is welded, if necessary or desired, the produced welded flange can finally be trimmed to a desired size. The trimming can advantageously be carried out by laser cutting and during the creation of the weld by laser welding (not shown in detail).

As already indicated above, the method described above and the apparatus for carrying out the method for producing a body pillar for vehicle construction, in particular for producing an A pillar, primarily for producing an A pillar for a convertible vehicle ( 5 ). Due to the particular stiffness requirements for an A-pillar of a convertible vehicle, especially during a rollover crash event, it is using appropriately designed and / or pre-treated originating or outgoing boards 2 allowed to produce the body pillar or A-pillar according to the method described above easily and inexpensively.

LIST OF REFERENCE NUMBERS

1

hollow profile

2

circuit board

2a

deep-drawn area (board 2 )

2 B

Flange areas (board 2 )

3

lower die

4

upper die

4a

stamp

5

mold core

6

Seitenwangengesenkhälfte

7

Seitenwangengesenkhälfte

8th

welder

9

secondment

10

secondment

11

Side wall

12

Side wall

13

Form plunger

14

Means for supporting the management and / or fixing of the shutdowns 9 . 10 (Longitudinal groove in the mold pressure stamp 13 )

15

Means for supporting the management and / or fixing of the shutdowns 9 . 10 (local boost on the mandrel 5 )

Claims (13)

Method for producing a closed hollow profile ( 1 ), characterized by the following process steps to be carried out successively: a) provision of a printed circuit board ( 2 ); b) forming the board ( 2 ) in a first forming step, by in the longitudinal direction of the hollow profile to be produced ( 1 ), both sides of the board ( 2 ) one each in the longitudinal direction of the hollow profile ( 1 ) extending and outward facing Abstell ( 9 . 10 ) is formed; c) transformation of said shutdowns ( 9 . 10 ) board ( 2 ) in a second forming step by the board ( 2 ) by means of a in the longitudinal direction of the hollow profile to be produced ( 1 ) extending punch ( 4a ) of a known forming tool by deep drawing to a lower area ( 2a ) of the hollow profile ( 1 ) with two sides of the board ( 2 ) opposite flange areas ( 2 B ) coming from the said lower area ( 2a ) of the hollow profile ( 1 ), is withdrawn, the shelters ( 9 . 10 ) are retained according to process step b); (d) transformation of said shutdowns ( 9 . 10 ) and pulled board ( 2 ) in a third forming step to a closed hollow profile ( 1 ), the flange areas ( 2 B ) according to a rolling-in method known per se about the core geometry of at least one previously retracted mandrel (US Pat. 5 ) formed around a forming tool known per se and the shutdowns ( 9 . 10 ) are brought together in the form of welding flanges as far as possible, and by 9 . 10 ) to an agent ( 15 ) to support the management and / or fixation of the redundancies ( 9 . 10 ) in the form of a longitudinal direction of the profile to be produced ( 1 ) extending the mandrel ( 5 ) and into a further means corresponding to said increase ( 14 ) to support the management and / or fixation of the redundancies ( 9 . 10 ) in the form of a longitudinal groove on the forming pressure stamp ( 13 ) initiate; and e) welding the two shutters ( 9 . 10 ) among themselves. A method according to claim 1, characterized in that with regard to the method step a) a circuit board ( 2 ) is provided from a cold or hot forming steel. Method according to one of claims 1 or 2, characterized in that with regard to the method step a) a circuit board ( 2 ) is provided from a cold formable steel having one or more patchwork blanks, tailor blanks, and / or tailord strips. A method according to claim 1, characterized in that with regard to the method step b) the shutdowns ( 9 . 10 ) are produced by deep-drawing, stamping, roll forming or the like known per se. A method according to claim 1, characterized in that with regard to the method step e) the two shutdowns ( 9 . 10 ) are welded together while the deformed board ( 2 ) is still in the forming tool. A method according to claim 1, characterized in that with regard to the method step e) the two shutdowns ( 9 . 10 ) are welded together by laser welding, spot welding and / or by another suitable welding method known per se. Method according to one of claims 1 to 6, characterized in that at the process step e) a dimensionally accurate trimming of the two mutually welded shutdowns ( 9 . 10 ). Closed hollow profile ( 1 ) made of metal, with an axially extending weld, produced by a process according to one or more of claims 1 to 7, wherein the closed hollow profile ( 1 ) one over the entire length of the hollow profile ( 1 ) extending deep-drawn area ( 2a ) in the longitudinal direction of the hollow profile ( 1 ) seen on both sides of the deep-drawn area ( 2a ) formed flange areas ( 2 B ), wherein at the respective free end of said flange portions ( 2 B ) each one created by deformation Abstell ( 9 . 10 ), and the shutdowns ( 9 . 10 ) are designed so that these follow a known rolling-in method, in which the deep-drawn region ( 2a ) and the flange areas ( 2 B ) around the core geometry of a mold core ( 5 ) are guided around a per se known forming tool, facing outward and largely brought together plan and welded, forming the axially extending weld. Closed hollow profile ( 1 ) according to claim 8, characterized in that the axially extending weld by laser welding, Spot welding and / or produced according to another suitable welding method known per se. Closed hollow profile ( 1 ) according to one of claims 8 to 9, characterized in that the hollow profile ( 1 ) from a board ( 2 ) is formed from a cold- or hot-formable steel. Closed hollow profile ( 1 ) according to one of claims 8 to 10, characterized in that the hollow profile ( 1 ) from a board ( 2 ) is formed from a cold formable steel having one or more areas reinforced by "patchwork blanks", "tail blanks" and / or "tailor strips". Closed hollow profile ( 1 ) according to one of claims 8 to 11, characterized in that the hollow profile ( 1 ) is designed as a body pillar for vehicle construction in particular as an A-pillar. Device for producing a closed hollow profile ( 1 ) according to one of claims 8 to 12 from a circuit board ( 2 ), with at least one forming tool in the form of a mold pressure die, wherein the mold pressure die at least one mold pressure stamp ( 13 ) and a die, and wherein the molding die at least one retractable in the same mold core ( 5 ) can be assigned to its core geometry according to a rolling process known per se, the board ( 2 ), characterized in that the forming pressure stamp ( 13 ) and the at least one retractable mold core ( 5 ) one agent each ( 14 . 15 ) to support the guidance and / or fixation of pre-formed and outwardly parked and in the longitudinal direction of the hollow profile to be produced ( 1 ) extending redundancies ( 9 . 10 ) of the board ( 2 ) in the form of welding flanges to be welded together during the performance of said rolling-in process, the one means ( 14 ) by a longitudinal groove in the mold pressure stamp ( 13 ) and the other means ( 15 ) by a corresponding to the longitudinal groove and in the longitudinal direction of the hollow profile to be produced ( 1 ) is formed, on which increase the shutdowns ( 9 . 10 ) slip forcibly guided during the implementation of said rolling-in process and then introduce it into the longitudinal groove.

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