EP3450041A1 - Method for producing a tubular hollow body from a blanked metallic sheet, and undercarriage or body components with a hollow body produced according to the method - Google Patents

Abstract

The invention relates to a method for producing a tubular, preferably tubular curved hollow body (5 ') from a cut metal circuit board, wherein the hollow body (5') is produced from the board using a UO-forming, so that the hollow body (5 ' ) after the UO-forming of the board has a slot or edge impact (4.4) along two abutting edges (4.3) of the formed board. In order to economically produce such hollow bodies, in particular tubular-arc-shaped hollow bodies (5 ') for weight-optimized and / or space-optimized chassis and body components (1, 2), the method according to the invention provides for at least one after a work operation (OP10, OP30) is partially U-shaped, at least one reinforcing element (6, 6 ', 6 ") inserted into an at least partially U-shaped portion of the formed board (4) and the inside connected to the same material fit, preferably welded, and that subsequently at least a further operation (OP50) is performed, in which the U-shaped formed board (4) to the tubular hollow body (5, 5 ') is transformed.

Description

The invention relates to a method for producing a tubular, preferably tubular sheet-shaped hollow body from a cut metal circuit board, in which the hollow body is produced from the board using a UO-forming, so that the hollow body after UO-forming the board a slot or edge impact along two abutting edges of the formed board.

Such methods are known (see eg EP 2 616 197 B1 ).

Tubular, in particular tubular-arc-shaped hollow bodies made of metallic material are nowadays frequently used in motor vehicle construction, for example as components of rear-end carriers and front and rear subframes.

A known method for producing complex-shaped tubular body is the so-called hydroforming (hydroforming). In this case, the tubular body to be produced from a tube using a liquid active medium (usually a water-oil emulsion) is formed by applying internal pressure. The pressures required in this process for forming can be up to several thousand bar and are mainly dependent on the material to be formed, the material thickness and the smallest auszubormenden radii. This hydraulic forming process requires technically complex and expensive tools whose use is often not worthwhile for amortization reasons or has a high unit price for the parts to be produced.

From the DE 100 62 836 A1 a method for producing a curved tubular hollow body is known, wherein the hollow body in the course of its length has round and angularly shaped areas and follows its length in the axial direction vertical and / or horizontal bends. For this purpose, a sheet metal blank is first punched, wherein the sheet metal blank is selected so that it has a certain excess in width over the dimensions of the theoretical development of the finished hollow body. Subsequently, the sheet metal blank is pre-bent in a bending device designed as a die by the side areas of the sheet metal blank are raised to a U-shape. In a further bending tool then the upper part of the raised sides of the workpiece is bent in the angularly shaped areas of the hollow body in an inwardly directed inclination, while in the round areas of the hollow body to be formed an inward rounding of the ends of the raised pages. The thus pre-bent workpiece is then pressed in a pressing tool in its final form by the slanted and rounded side portions of the sheet metal blank are joined together at the longitudinal seam of the hollow body under pressure without gaps. Optionally, the hollow body is still welded at the seam.

Components having one or more complex shaped tubular body, such. As rear axle and front or rear subframe of motor vehicles are usually provided with reinforcements and / or cross members, which are welded to the outside of the tubular body. When dimensioning and arranging the reinforcements or cross members, constructive specifications must be taken into account, so that weight specifications are not exceeded and / or required installation space is not lost.

The present invention has for its object to provide a method for producing a tubular hollow body of the type mentioned, with which such hollow body for weight-optimized and / or space-optimized chassis and body parts can be produced economically.

This object is achieved by a method having the features specified in claim 1. Preferred and advantageous embodiments of the method according to the invention are specified in the subclaims.

The invention thus proposes, in a method of the type mentioned above, that after a work process in which the board is at least partially U-shaped, at least one reinforcing element is inserted into an at least partially U-shaped section of the formed blank and internally with the same cohesively connected, preferably welded, and that subsequently at least one further operation is performed, in which the U-shaped reshaped board is formed into the tubular hollow body.

The inventive arrangement of one or more reinforcing elements in the tubular hollow body can be economically produced with such a hollow body weight-optimized and / or space-optimized suspension and body parts. The at least one reinforcing element is preferably arranged inside at a specific point of the at least partially U-shaped portion of the workpiece and integrally connected to the same, so that a peak load on a strength-relevant portion of the finished chassis and body component, for example, at a connecting portion at which the tubular hollow body is connected to a further component of the component is significantly reduced. Due to the internal partial reinforcement of the tubular hollow body of this and / or a component connected thereto can be designed lighter weight. For example, allows the inner partial reinforcement of the tubular hollow body, a reduction in the sheet thickness of the metallic board used for the production of the tubular hollow body (sheet metal blank). Alternatively or additionally, the inner partial reinforcement of the tubular hollow body may sometimes omit external reinforcing or stiffening elements of the chassis or body component, whereby the total weight of the chassis or body component is reduced and space for other vehicle units, such as vehicle drive components, can be obtained.

An advantageous embodiment of the method according to the invention provides that the abutting edges of the tubular hollow body which define the slot or edge joint are joined together by welding, preferably metal-active-gas welding (MAG welding) or laser beam welding. By welding the abutting edges of the tubular hollow body, the dimensional stability of the hollow body is improved. In addition, the interior of the hollow body can be protected by a continuous weld along the abutting edges against ingress of moisture.

The MAG welding, which is preferably used for joining the abutting edges, enables high welding speeds, even in the case of an arcuate abutting edge course. The welding speed may be, for example, at least 10 m / min, preferably at least 15 m / min in MAG welding. The welding wire (additional wire) supplied to the welding point during MAG welding melts there in the arc or in the molten bath. With the melting filler material of the welding wire can be reliably limited by the welded edges to be welded slot.

The laser beam welding, which can alternatively be used to connect the abutting edges, is also distinguished by high welding speeds and the feasibility of complicated seam geometries. Due to the precise, very concentrated energy input results in laser beam welding, a low heat influence and consequently is expected only with a very low thermal distortion of the workpiece. The laser beam welding is preferably carried out with a corresponding embodiment of the method according to the invention also using welding wire (filler wire).

The filler wire may have substantially the same material composition as the board from which the tubular hollow body is formed, both in MAG welding and in laser beam welding. However, according to a further advantageous embodiment of the invention, the filler wire may also contain one or more strength-increasing alloying constituents, e.g. Manganese, nickel and / or carbon included.

When the abutting edges of the tubular hollow body are welded together by MAG welding, as the active gas (shielding gas), for example, argon or carbon dioxide or a mixture of these gases is used. The active gas may also contain oxygen and / or helium as the mixed gas. Argon or an argon-rich mixed gas having up to 25% by volume of carbon dioxide and / or up to about 5% by volume of oxygen and / or about 20-30% by volume of helium is preferably used as the active gas (protective gas). If the abutting edges of the tubular hollow body are welded together by means of laser beam welding, the protective gas used is preferably argon or helium or carbon dioxide or a mixture of at least two of these gas components.

A further preferred embodiment of the invention is characterized in that the hollow body is formed tubular arc-shaped, wherein before and / or during the work process in which the board is at least partially U-shaped, bending of the board takes place, so that the at least partially U Formed-shaped board defines a groove whose elongated groove base line is arcuate. The tubular-arc-shaped hollow body can also be referred to as a curved tubular hollow body. It follows along its length in the axial direction vertical and / or horizontal bends. With a correspondingly designed tubular hollow body weight-optimized and space-optimized chassis and body components can be produced very beneficial.

In this context, a further embodiment of the invention that the bending of the board is carried out such that the at least partially U-shaped deformed board defines a groove whose elongated groove base line is formed at least partially convex. If appropriate, a concavely formed channel section can adjoin the convexly formed section of the channel. In particular, it is proposed that the at least one reinforcing element is inserted at least into the convexly formed gutter section and connected on the inside with the same material fit, preferably welded. On the part of the Applicant, it has been found that a bent tubular hollow body produced from a metal plate and whose slot or edge joint runs convexly can thereby be reliably produced by U-O forming.

The at least one reinforcing element can be embodied in various geometric shapes. An advantageous embodiment provides that it is designed as a plate-shaped or disc-shaped reinforcing element. Such a reinforcing element can be produced inexpensively, for example by being punched out of a metal sheet. Due to the plate-shaped or disc-shaped design of the reinforcing element, a considerable increase in stability, in particular increase in flexural strength, can be achieved with a relatively low weight of the reinforcing element. With regard to a weight reduction, it is also advantageous if the plate-shaped or disc-shaped reinforcing element has a plurality of through holes.

A further embodiment of the invention is characterized in that the at least one reinforcing element is an annular or U-shaped reinforcing element. As a result of this embodiment, it is likewise possible to achieve a reduction in weight, while the reinforcing effect nevertheless remains high.

For weight optimization with substantially constant or preferably improved strength properties of the respective chassis or body component, it is also advantageous if, according to a further embodiment the invention, the annular or U-shaped reinforcing element has at least one transverse strut.

A further advantageous embodiment provides that the annular or U-shaped reinforcing element has a collar. As a result, the shape stiffness of the reinforcing element is increased. Accordingly, the sheet thickness (sheet thickness) of the annular or U-shaped reinforcing element can be reduced and thus save material and weight. The formation of a collar at the respective through-hole of the annular or U-shaped reinforcing element is also an option if the reinforcing element according to the above-mentioned embodiment has a plurality of through holes, so that then at least one or more of the through holes have a collar.

According to a further embodiment of the invention, the at least one reinforcing element is designed in such a way that the tubular hollow body, viewed in cross-section, lies completely against the outer peripheral contour of the reinforcing element along its inner contour. This gives the tubular hollow body optimum radial dimensional stability.

Alternatively, according to a further embodiment of the invention, however, the at least one reinforcing element can also be designed such that the tubular hollow body, viewed in cross-section, rests partially against the outer peripheral contour of the reinforcing element along its inner contour. The peripheral contour of the reinforcing element arranged in the tubular hollow body and the adjacent inner contour of the tubular hollow body thus bound at least one passage opening. This embodiment allows more clearance for the at least one or final forming process, in which the previously at least partially U-shaped section of the board is formed into a tubular cross-section of the hollow body. Apart from this, this embodiment favors a weight reduction of the tubular Hollow body, since the reinforcing element arranged therein in this case compared to a reinforcing element, which lies with its peripheral contour substantially completely against the inner contour of the tubular hollow body, significantly smaller and therefore lighter. In this context, a further preferred embodiment is that the at least one reinforcing element defines with the inside of the hollow body a passage opening which lies in the region of the slot or edge impact.

A further advantageous embodiment of the invention provides that at least two reinforcing elements of the type mentioned are inserted into the at least partially U-shaped section of the formed blank and are connected on the inside with the same material fit, preferably welded. This design favors a reliable and weight-optimized design of curved tubular hollow bodies by U-O-forming a metallic board when the slot or edge joint of the formed board along a convexly curved portion of the tubular hollow body (tubular body) extends.

For example, three reinforcing elements of the type mentioned can be inserted into an at least partially U-shaped as well as S-shaped section of the blank as a workpiece and welded on the inside to the deformed section, wherein one of the reinforcing elements in a first substantially straight trough portion of the formed workpiece, a second of the reinforcing elements are arranged in a transition region between a convexly curved and a concave curved trough portion of the formed workpiece and the third of the reinforcing elements in a second substantially straight trough portion of the formed workpiece.

According to a further embodiment of the invention, the at least two reinforcing elements are formed differently; they may in particular have different outer peripheral contours. This embodiment favors the weight-optimized production of a complex-shaped tubular body by UO-forming a metallic circuit board.

In order to avoid springing back of the raised limbs of the U-shaped portion of the workpiece during cohesive bonding (eg welding) of the reinforcing member with the U-shaped section, provides a further embodiment of the invention, that after insertion of the at least one reinforcing element and before the cohesive bonding, preferably welding, the reinforcing element is performed with the at least partially U-shaped section of the board a calibration of the deformed portion. As a result, the reliability of the subsequent deformation of the at least partially U-shaped preformed workpiece is further improved to a tubular cross-section.

Furthermore, the invention relates to a chassis or body component with a tubular, preferably tubular-arc-shaped hollow body produced by the process according to the invention.

Fig. 1

einen Abschnitt einer Verbundlenker-Hinterachse für ein Kraftfahrzeug in einer perspektivischen Darstellung;

Fig. 2

einen Hinterachshilfsrahmen für ein Kraftfahrzeug in einer perspektivischen Darstellung;

Fig. 3

vier Arbeitsschritte eines herkömmlichen Prozesses zur Herstellung eines bogenförmigen Rohres mittels U-O-Umformung, wobei die Arbeitsschritte durch perspektivische Darstellungen und zugehörige Querschnittansichten des umgeformten, nach Durchführung des jeweiligen Arbeitsschrittes vorliegenden Werkstücks schematisch gezeigt sind;

Fig. 4

mehrere Arbeitsschritte des erfindungsgemäßen Verfahrens zur Herstellung eines bogenförmigen Rohres mittels U-O-Umformung, wobei die Arbeitsschritte durch Querschnittansichten des umgeformten, nach Durchführung des jeweiligen Arbeitsschrittes vorliegenden Werkstücks schematisch gezeigt sind;

Fig. 5a und 5b

Arbeitsschritte einer Variante des erfindungsgemäßen Verfahrens zur Herstellung eines bogenförmigen Rohres mittels U-O-Umformung, wobei die Arbeitsschritte wiederum durch Querschnittansichten des umgeformten, nach Durchführung des jeweiligen Arbeitsschrittes vorliegenden Werkstücks schematisch gezeigt sind;

Fig. 6

ein mittels U-O-Umformung hergestellter rohrbogenförmiger Hohlkörper, ein ringscheibenförmiges Verstärkungselement und ein erfindungsgemäß mittels U-O-Umformung hergestellter rohrbogenförmiger Hohlkörper mit einem darin angeordneten ringscheibenförmigen Verstärkungselement, in einer perspektivischen Darstellung;

Fig. 7a bis 7h

verschiedene Verstärkungselemente zur Anordnung in einem rohrförmigen, vorzugsweise rohrbogenförmigen Hohlkörper während dessen Herstellung mittels U-O-Umformung, jeweils in einer perspektivischen Darstellung; und

Fig. 8

ein erfindungsgemäß hergestellter rohrbogenförmiger Hohlkörper mit drei darin angeordneten ringscheibenförmigen Verstärkungselementen, in einer perspektivischen Darstellung.

The invention will be explained in more detail with reference to a drawing illustrating several embodiments. Show it:

Fig. 1

a section of a torsion beam rear axle for a motor vehicle in a perspective view;

Fig. 2

a Hinterachshilfsrahmen for a motor vehicle in a perspective view;

Fig. 3

four steps of a conventional process for the production of an arcuate tube by means of UO-forming, the steps by perspective views and associated cross-sectional views of the formed, after performing the respective work step present workpiece are shown schematically;

Fig. 4

several steps of the inventive method for producing an arcuate tube by means of UO-forming, wherein the steps are shown schematically by cross-sectional views of the formed, present after performing the respective step workpiece;

Fig. 5a and 5b

Steps of a variant of the inventive method for producing an arcuate tube by means of UO-forming, wherein the steps in turn are shown schematically by cross-sectional views of the formed, present after performing the respective work step workpiece;

Fig. 6

a tube-shaped hollow body produced by means of UO deformation, an annular disk-shaped reinforcing element and a tube-shaped hollow body produced according to the invention by means of UO deformation with an annular disk-shaped reinforcing element arranged therein, in a perspective representation;

Fig. 7a to 7h

Various reinforcing elements for arrangement in a tubular, preferably tubular arc-shaped hollow body during its production by means of UO-forming, each in a perspective view; and

Fig. 8

an inventively produced tubular tubular hollow body with three annular disk-shaped reinforcing elements arranged therein, in a perspective view.

Fig. 1 shows a portion of a torsion beam rear axle 1 as an example of a chassis component of a motor vehicle. The torsion beam rear axle 1 has a left arm 1.1 and a right arm (not shown), which are fixedly connected to each other by a load on torsion cross member 1.2. Both the cross member 1.2 and the link arms 1.1 are formed as tubular hollow body. At the link arms 1.1 and the cross member 1.2 cup-shaped console plates 1.3 and cross struts 1.4 are welded. The bracket plate 1.3 serves to support and support a suspension spring and a shock absorber (not shown). The respective link arm 1.1 has at one of its ends a hinge bush (bearing bush) 1.5 and at the other end a connecting flange 1.6 for attaching a rear wheel bearing. The link arm 1.1 is designed as a tubular sheet-shaped hollow body. It is made of a sheet metal blank, preferably sheet steel, by UO-forming.

In Fig. 2 An auxiliary frame 2 is shown as a further example of a chassis component of a motor vehicle. The subframe 2 serves in particular for the articulated mounting of wishbones to be connected to the rear wheel carriers (not shown). It has two lateral, substantially longitudinally to the vehicle longitudinal central axis extending side support (side member) 2.1, which are fixedly connected to a front cross member 2.2 and a rear cross member 2.3. The front cross member 2.2 and the side support 2.1 of the rear axle subframe 2 are formed as tubular hollow body, in particular, the cross member has 2.2 arcuate portions. The side members 2.1 and / or the cross member 2.2 are made of sheet metal blanks, preferably sheet steel blanks, produced by UO-forming.

A conventional process for producing a bent tubular body using UO forming is in Fig. 3 outlined. The conventional manufacturing process comprises at least four work steps (OP10, OP30, OP50, OP70). First, a substantially flat, suitably cut to achieve the finished tubular body 5 sheet metal blank is partially formed U-shaped (OP10). Before or preferably during this deformation, the sheet metal blank so transformed that after this forming step (OP10), as in Fig. 3 left upper and lower left, a groove 3 defined, the elongated or axial groove base line is arcuate. In Fig. 3 the gutter baseline is concave. The thus formed workpiece (sheet metal blank) 4 has two mutually parallel side sections (legs) 4.1, which laterally connect to the channel-shaped section 4.2 and are bent according to the groove base line. Viewed in cross-section, the side sections (legs) 4.1 initially protrude in opposite directions from the channel-shaped section 4.2 of the workpiece 4.

In a subsequent forming step (operation) OP30, the side sections 4.1 are upshifted, i. bent upwards, so that the workpiece 4 then viewed in cross section has a total of a U-shaped profile.

In a further working step (OP50), the raised side sections 4.1 of the workpiece 4 are then reshaped such that their longitudinal edges 4.3 are moved toward one another and define a slot or edge joint 4.4. This step can also be referred to as O-forming. The workpiece 4 now has a tubular cross-section. The two longitudinal edges (abutting edges) 4.3 are then welded together (OP70), so that the slot or edge joint 4.4 is preferably completely closed. In Fig. 3 , right above 4.5 is the weld at the edge joint 4.4.

The inventive method differs from that in Fig. 3 sketched conventional process in that after the operation (OP10 and OP30), in which the board (workpiece 4) is at least partially U-shaped, at least one reinforcing element 6 inserted into the at least partially U-shaped section 4.2 of the workpiece 4 and inside with the same cohesively connected, preferably welded. Subsequently, at least one further operation (OP50) is carried out, in which the in When viewed in cross-section, U-shaped workpiece 4 is shaped into a tubular hollow body 5.

As in Fig. 4 shown, the at least one reinforcing element 6, for example, annular, in particular annular disk-shaped. Further embodiments of the at least one reinforcing element 6 are in the FIGS. 5 to 8 outlined. The reinforcing element 6 is formed with respect to the inner contour of the tubular hollow body 5 such that it in the finished state of the tubular hollow body 5, for example along at least 30%, preferably at least 40%, more preferably at least 50% of its outer contour with the inner contour of the hollow body 5 cohesively is connected or at least touching touches it.

The at least one reinforcing element 6 is preferably inserted into the U-shaped and thus channel-shaped section 4.2 of the workpiece 4 and the inside materially connected to the same, after the adjoining the channel-shaped portion 4.2, laterally projecting side sections 4.1 up, that is. were bent upwards.

However, it is also within the scope of the present invention to use the at least one reinforcing element 6 already in the channel-shaped section 4.2 of the workpiece 4 and to connect the inside materially with the same, before the laterally projecting side sections 4.1 are bent upwards.

After the reinforcing element 6 has been materially bonded to the inside of the trough-shaped or U-shaped workpiece 4, the workpiece 4 is further formed into a tubular hollow body (tubular body) 5. Subsequently, the two longitudinal edges (abutting edges) 4.3 of the workpiece 4 are welded together, so that the slot or edge joint 4.4 is preferably completely closed by the weld 4.5.

At the in Fig. 4 sketched embodiment, the reinforcing element 6 is designed or dimensioned such that it after the O-forming of the cross-sectionally U-shaped workpiece 4, in which the workpiece 4 is formed into a tubular cross-section, with the inside of the hollow body (tubular body). 5 defines a passage opening 7, which is located in the region of the slot or edge impact 4.4.

After inserting the at least one reinforcing element 6 and before welding it to the inside of the U-shaped formed workpiece 4, the formed workpiece 4 is preferably subjected to an additional calibration process.

In the FIGS. 5a and 5b Steps of a variant of the method according to the invention are outlined, in which the at least one reinforcing element 6 'or at least one of the reinforcing elements 6' designed or dimensioned such that after the O-forming of the cross-sectionally U-shaped workpiece 4 of the tubular hollow body. 5 along its inner contour completely against the outer peripheral contour 6.1 of the reinforcing element 6 '. Before the O-forming, the reinforcing element 6 'is integrally connected, preferably welded, to the inside of the channel-shaped workpiece 4. The cohesive connection or weld, for example, extends along approximately 50 to 60% of the outer peripheral contour of the reinforcing element 6 '. The cohesive connection of the reinforcing element 6 'to the inside of the workpiece 4 may be executed as a single continuous joining or welding seam 8 or comprise a plurality of connecting or welding seams. In addition, the outer contour of the reinforcing element 6 'is welded to the mutually facing abutting edges 4.3 of the tubular workpiece 4 with the abutting edges 4.3.

Fig. 6 shows a tubular arc-shaped hollow body 5, which has a reinforcing element 6 'welded on the inside and according to the in the FIGS. 5a and 5b sketched variant of the method according to the invention can be produced.

In the FIGS. 7a to 7h 5, various exemplary embodiments of the at least one reinforcing element 6, 6 ', 6 "to be welded on the inside to the U-shaped workpiece 4 are shown, for example, in the form of a closed sheet-metal disc (US Pat. Fig. 7a ) or annular disc 6 '( Fig. 7b ), wherein the annular sheet-metal disc 6 'can also have a peripheral collar 6.3 at its passage opening 6.2 ( Fig. 7c ). The passage opening 6.2 is in the in the FIGS. 7b and 7c and 5 and 6 embodiments shown circular.

The in the FIGS. 7a to 7c shown reinforcing elements 6 ', 6 "are dimensioned so that after the O-forming of the cross-sectionally U-shaped workpiece 4, the tubular hollow body 5 along its inner contour completely against the outer peripheral contour 6.1 of the reinforcing element 6', 6". The in the FIGS. 7d to 7h shown reinforcing elements 6, however, are dimensioned so that after the O-forming of the viewed in cross section U-shaped workpiece 4, the tubular hollow body 5 along its inner contour only partially abuts the outer peripheral contour 6.1 of the reinforcing member 6, wherein the reinforcing member 6 with the inside of the hollow body 5 defines a passage opening 7, which lies in the region of the slot or edge impact 4.4 (see. Fig. 4 ).

This in Fig. 7f shown reinforcing element 6 has two through holes 7, which are separated by a transverse strut 6.4. The in the Fig. 7g and 7h shown reinforcing elements 6 are designed as U-shaped or bow-shaped sheet-metal discs, wherein the reinforcing element 6 according to Fig. 7h has a collar 6.3 on the inner circumference.

The tube body 5 produced by the method according to the invention using a UO molding can in particular also be produced in the manner that in the cut sheet metal plate, a channel 3 is formed, the elongated or axial groove base line convex or convex and concave. In Fig. 8 is exemplified such an arcuate tubular body 5 'shown.

For the production of such a tubular hollow body 5 ', the laterally projecting side sections 4.1 of the workpiece 4 are raised after the formation of the channel 3 (cf. Fig. 4 such as Fig. 5a ). Subsequently, for example, three reinforcing elements 6 'inserted into the viewed in cross-section U-shaped workpiece 4 and inside welded to the same. The reinforcing elements 6 'are in this case positioned so that a first reinforcing element 6' is arranged in a first, essentially straight section of the formed workpiece 4, a second reinforcing element 6 'is arranged in a transition region between the convexly curved and the concavely curved channel section, and the third reinforcing member 6 'is disposed in a second, substantially straight trough portion of the formed workpiece 4. The first and the third reinforcing element 6 'are preferably arranged at a very small distance from the convexly or concavely curved channel section.

The reinforcing elements 6, 6 'used in the trough-shaped or U-shaped workpiece 4 can be designed differently, preferably have different outer peripheral contours. In particular, it is within the scope of the present invention, at least two different reinforcing elements 6, 6 'in the Fig. 7a to 7h Insert shown reinforcing elements 6, 6 'in the trough or U-shaped workpiece 4 and to weld before the O-forming of the workpiece 4 on the inside with the trough-shaped or U-shaped workpiece 4.

In a chassis component according to Fig. 1 or Fig. 2 the at least one reinforcing element 6 is preferably arranged in the curved tubular link arm 1.1 in the region of the connected cross member 1.2 or in the curved tubular cross member 2.2 in the region of the connected side member 2.1.

The embodiment of the invention is not limited to the embodiments shown in the drawing. On the contrary, numerous variants are conceivable which make use of the invention specified in the claims even if the design deviates from the examples shown.

LIST OF REFERENCE NUMBERS

1

Chassis component, e.g. Torsion beam rear axle

1.1

control arm

1.2

crossbeam

1.3

Konsolblech

1.4

crossmember

1.5

joint bush

1.6

connecting flange

2

Subframe, e.g. Rear axle subframe

2.1

side beams

2.2

front cross member

2.3

rear cross member

3

gutter

4

formed sheet metal plate / workpiece

4.1

Side sections (thighs)

4.2

trough-shaped section

4.3

Abutting edges (longitudinal edges)

4.4

Slot / edge impact

4.5

Weld

5, 5 '

tubular hollow body (tubular body)

6, 6 ', 6 "

reinforcing element

6.1

Outer circumferential contour

6.2

Through opening

6.3

collar

6.4

crossmember

7

Through opening

8th

Weld

OP10

Work step "Form channel"

OP30

Work step "Elevate page sections"

OP40

Step "Insert reinforcing element and weld inside"

OP50

Work step "O-forms"

OP70

Step "Welding of 4.4"

Claims (15)

Method for producing a tubular, preferably tubular-arc-shaped hollow body (5, 5 ') from a cut-to-size metallic blank, in which the hollow body (5, 5') is produced from the blank using UO forming, such that the hollow body (5, 5) 5 ') after the UO deformation of the board has a slot or edge impact (4.4) along two abutting edges (4.3) of the formed board, characterized in that after a working operation (OP10, OP30), in which the board at least partially U-shaped is formed, at least one reinforcing element (6, 6 ', 6 ") inserted into an at least partially U-shaped portion of the formed blank (4) and on the inside with the same materially connected, preferably welded, and that subsequently at least one further operation ( OP50) is performed, in which the U-shaped formed plate (4) to the tubular hollow body (5, 5 ') is transformed. A method according to claim 1, characterized in that the slot or edge joint (4.4) defining abutting edges (4.3) of the tubular hollow body (5, 5 ') by welding, preferably metal-active gas welding or laser beam welding are interconnected. A method according to claim 1 or 2, characterized in that the hollow body (5, 5 ') is formed tubular arc, wherein before and / or during the operation (OP10), in which the board is at least partially U-shaped, bending the Board takes place, so that the at least partially U-shaped formed board defines a groove (3) whose elongated groove base line is arcuate. A method according to claim 3, characterized in that the bending of the board is performed such that the at least partially U-shaped formed board defines a channel (3) whose elongated groove base line is at least partially convex. Method according to Claim 4, characterized in that the at least one reinforcing element (6, 6 ', 6 ") is inserted at least into the convexly formed gutter section and is materially connected, preferably welded, to the inside thereof. Method according to one of claims 1 to 5, characterized in that the at least one reinforcing element (6, 6 ', 6 ") is a plate-shaped or disk-shaped reinforcing element (6, 6', 6"). A method according to claim 6, characterized in that the plate or disc-shaped reinforcing element (6) has a plurality of through holes (6.2). Method according to one of claims 1 to 6, characterized in that the at least one reinforcing element (6, 6 ') is an annular or U-shaped reinforcing element (6, 6'). A method according to claim 8, characterized in that the annular or U-shaped reinforcing element (6, 6 ') has at least one transverse strut (6.4) and / or a collar (6.3). Method according to one of claims 1 to 9, characterized in that the at least one reinforcing element (6 ', 6 ") is designed such that the tubular hollow body (5, 5') viewed in cross-section along its inner contour completely on the outer peripheral contour of the reinforcing element (6 ') is present. Method according to one of claims 1 to 9, characterized in that the at least one reinforcing element (6) is designed such that the tubular hollow body (5, 5 ') viewed in cross-section along its inner contour partially against the outer peripheral contour of the reinforcing element (6) , A method according to claim 11, characterized in that the at least one reinforcing element (6) with the inside of the hollow body (5, 5 ') defines a passage opening (7) which lies in the region of the slot or edge impact (4.4). Method according to one of claims 1 to 12, characterized in that at least two such reinforcing elements (6, 6 ', 6 ") inserted into the at least partially U-shaped portion of the deformed blank (4) and the inside materially connected to the same, preferably be welded, wherein the at least two reinforcing elements (6, 6 ', 6 ") are preferably designed differently, preferably have different outer peripheral contours (6.1). Method according to one of claims 1 to 13, characterized in that after the insertion of the at least one reinforcing element (6, 6 ') and before the cohesive bonding, preferably welding, the reinforcing element (6, 6') with the at least partially U-shaped deformed portion of the board (4) a calibration of the deformed portion is performed. Chassis or body component (1, 2) with a tubular, preferably tubular arc-shaped hollow body (5, 5 ') produced according to the method according to one of claims 1 to 14.

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