METHOD AND SEMIFINISHED PRODUCT FOR PRODUCING AN AT LEAST PARTIALLY HARDENED PROFILED COMPONENT

Abstract

The invention relates to a method for producing an at least partially hardened profiled component and to a corresponding semi-finished product (1) which simplifies the development process and reduces the investment costs in production machines. At first, a first profiled segment (19), which has a uniform cross-sectional shape (9, 10) along its extent (22), and a second profiled segment (20), which has a non-uniform cross-sectional shape (9, 10) along its extent (22), are joined together at a joining point (6) in order to form at least part of a semi-finished product (1). At the joining point (6), the first and the second profiled segments (19, 20) have cross-sectional shapes (9, 10) which substantially correspond with one another. After heating (25) to a hardening temperature, the semi-finished product (1) is formed in a forming tool (11) by means of internal high-pressure forming (26) or pressing to produce the profiled component (2) which, after the forming (26) within the forming tool (11), is hardened by quenching (27).

Claims

1. A method (34) for producing an at least partially hardened profiled component (2), with a first profiled segment (19), which has a uniform cross-sectional shape (9, 10) along its extension or length (22), and a second profiled segment (20), which has a non-uniform cross-sectional shape (9, 10) along its extension or length (22), comprising: joining the first profiled segment (19) to the second profiled segment (20) at a joint (6) in order to form at least part of a semi-finished product (1), wherein the first and the second profiled segments (19, 20) have cross-sectional shapes (9, 10) that substantially match at the joint (6), heating the semi-finished product (1) to a hardening temperature, shaping the semi-finished product (1) in a forming tool (11) by hydroforming (26) or by means of pressing so as to produce the profiled component (2), and hardening the profiled component (2) in the forming tool (11) by quenching (27).

2. The method (34) according to claim 1, wherein the second profiled segment (20) has a connecting end (32) with a cross-sectional shape (9, 10) substantially matching the cross-sectional shape (9, 10) of the first profiled component (19).

3. The method (34) according to claim 1, wherein the profiled segments (19, 20) are joined together by welding their connecting ends (31, 32, 33) at the joint (6).

4. The method (34) according to claim 1, wherein at least a third profiled segment (21) is joined to the first profiled segment (19) or to the second profiled segment (20), said third profiled segment having either a uniform or a non-uniform cross-sectional shape (9, 10) along its extension or length (22).

5. The method (34) according to claim 4, wherein at least one of the first profiled segment (19), second profiled segment (20) and third profiled segment (21) is made of an alloy that can be hardened when heated up (25) to a hardening temperature and subsequently quenched (27).

6. The method (34) according to claim 1, wherein the hydroforming (26) is carried out by a pressurized gas that serves as the forming medium, at a pressure between 300 bar and 600 bar, and the quenching (27) is carried out with a separate cooling medium which is conveyed into the forming tool (11) after the hydroforming process (26).

7. The method (34) according to claim 1, wherein the first profiled segment (19) is produced by roller/roll profiling, while the second profiled segment (20) is produced by a U/O bending method.

8. A semi-finished product (1) for producing an at least partially hardened profiled component (2), comprising: at least two profiled segments (19, 20) whose extensions or lengths (22) are arranged one after the other and which are joined together at a joint (6), wherein the first profiled segment (19) has a uniform cross-sectional shape (9, 10) along its length while the second profiled segment (20) has a non-uniform cross-sectional shape (9, 10) along its length, and the profiled segments (19, 20) have substantially matching cross-sectional shapes (9, 10) at the joint (6), and wherein the semi-finished product (1) of the joined together profiled segments (19, 20) is shaped by hydroforming or by pressing, along the extensions or lengths (22) of the joined together profiled segments (19, 20).

9. The semi-finished product (1) according to claim 8, wherein the second profiled segment (20) has a connecting end (32) whose cross-sectional shape (9, 10) substantially matches the cross-sectional shape (9, 10) of the first profiled component (19).

10. The semi-finished product (1) according to claim 8, wherein the profiled segments (19, 20) are joined by an integral welded bond at the joint (6).

11. The semi-finished product (1) according to claim 8, further comprising: at least a third profiled segment (21) that has either a uniform or else a non-uniform cross-sectional shape (9, 10) along its extension or length (22) that is joined to one of the first profiled segment (19) or second profiled segment (20) as part of the semi-finished product (1).

12. The semi-finished product (1) according to claim 11, wherein the at least one profiled segment (19, 20, 21) comprises an alloy that can be hardened by being heated up (25) to a hardening temperature and subsequently quenched (27).

13. A semi-finished product (1) according to claim 8, wherein the extension or length (22) of the semi-finished product (1), at least in certain sections, follows at least a straight line (29) and/or a two-dimensional and/or three-dimensional curve (30).

14. The method according to claim 5, wherein the alloy comprises steel or a boron alloyed steel.

15. The method according to claim 3, wherein the first profiled segment and second profiled segment are joined together by laser welding or orbital laser welding.

Description

DESCRIPTION OF THE DRAWINGS

[0042] Additional objectives, advantages, features and application possibilities of the present invention ensue from the description below of an embodiment making reference to the drawing. In this context, all of the described and/or depicted features, either on their own or in any meaningful combination, constitute the subject matter of the present invention, also irrespective of their compilation in the claims or the claims to which they refer back.

[0043] In this context, the following is shown, at times schematically:

[0044] FIG. 1 a view of the first profiled segment according to the invention, of the second profiled segment and of a profiled segment before being joined;

[0045] FIG. 2 a side view of a semi-finished product according to the invention;

[0046] FIG. 3 a side view from the left onto a profiled component according to the invention;

[0047] FIG. 4 a side view from the right onto a profiled component according to the invention;

[0048] FIG. 5 a schematic view from below of a semi-finished product consisting of a first profiled segment and of a second profiled segment;

[0049] FIG. 6 a schematic view from below of a semi-finished product with a first profiled segment and a second profiled segment;

[0050] FIG. 7 a schematic view of a production system according to the invention; and

[0051] FIG. 8 a schematic view of the production method according to the invention, in individual steps.

DETAILED DESCRIPTION OF EMBODIMENTS

[0052] For the sake of clarity, identical components or those having the same effect are provided with the same reference numerals in the figures shown below.

[0053] FIG. 1 schematically shows the constituents with which the semi-finished product 1 according to the invention can be produced, said product being shown in the joined state in FIG. 2. A profiled component 2 is shown in side views from the left in FIG. 3 and in side views from the right in FIG. 4.

[0054] In the present example, the profiled component 2 forms an A-pillar 8 of a convertible that has to be configured so as to be very stable in case the convertible rolls over. Here, especially the area between an upper tube 3 and a lower tube 4 has to be configured so as to be very stable, and in the present case, this area is formed by an intermediate piece 5.

[0055] On the upper right, FIG. 1 shows the upper tube 3 that forms the first profiled segment 19 as set forth in the invention. The profiled segment 19 has a uniform cross-sectional shape along its extension 22. This means that, in the present case, the cross-sectional shape 9, which is shown here as being circular by way of an example, is the same at every place along the extension 22. In the present case, the extension 22 itself follows a straight line 29 in the first profiled segment 19. At its ends, the first profiled segment 19 is provided with at least one connecting end 31. Owing to the uniform cross-sectional shape 9, which can be seen, for example, in FIG. 5, the connecting ends 31 of the first profiled segment 19 are likewise configured so as to be the same. Instead of two connecting ends 31, there can also be a conical expansion (not shown here) at one end so that a connection piece for feeding in a forming medium or a cooling medium can be attached so as to create a seal. Such a conical expansion is located in a part of the appertaining profiled segment that does not have to be included in the concept of extension.

[0056] The second profiled segment 20 has a non-uniform cross-sectional shape 9, 10 along its extension 22, whereby in the present case, said shape expands starting at a connecting end 31 towards a connecting end 32 of the second profiled segment 20. Moreover, the extension 22 of the second profiled segment 20 follows an at least two-dimensional curve 30. By the same token, the two-dimensional curve 30 can also be a three-dimensional curve 30 which, in the views of FIGS. 1 and 2, additionally extends into the plane of the page.

[0057] The second profiled segment, as an intermediate piece 5, has the two differently configured connecting ends 35, 36, whereby the connecting end 35 is shaped during the production of the profiled segment 20 in such a way that it essentially matches the first profiled segment 19. This means that the two connecting ends 31 and 35 can be, for instance, positioned so as to abut each other and can then be joined together by means of a simple welding operation.

[0058] The second connecting end 36which lies on the second profiled segment 20 along the extension 22 opposite from the first connecting end 35in turn, is shaped so as essentially match another connecting end 32 of a third profiled segment 21. The third profiled segment 21 is shown at the bottom of FIG. 1. It forms the lower tube 4 of the A-pillar 8 shown in FIG. 2 and it fundamentally has the same properties as the first profiled segment 19. Diverging from this, however, the cross-sectional shape of the third profiled segment 21 according to the view of FIG. 6 does not have a circular shape but rather, for example, can have an oval cross-sectional shape. It is also possible to select a box-like shape or a shape that is different but that is uniform over the course of the extension 22. These cross-sectional shapes 9, 10 would also be possible for the first profiled segment 19. Other, different profiled segments can adjoin the first profiled segment 19 or else the other profiled segments 20, 21 so as to form the semi-finished product 1 according to the invention.

[0059] FIG. 2 shows the semi-finished product 1 with the joined upper tube 3, the lower tube 4 and the intermediate piece 5 joined between them, and they are welded at the joints 6, 7. A well-suited welding method here is especially one in which the individual profiled segments 19,20, 21 are positioned so as to abut each other. Here, it is easy to use laser welding or orbital laser welding. The addition of welding filler is likewise possible.

[0060] It can be seen in FIG. 2 that the semi-finished product 1 likewise has an extension 22, whereby the result is that it has a non-uniform cross-sectional shape along its extension 22. Moreover, the extension 22 of the semi-finished product 1 here follows a curve 30 that can be configured so as to be two-dimensional or else three-dimensional.

[0061] FIGS. 3 and 4 show the finished profiled components 2 in the form of the A-pillars 8, whereby it can be seen here that the joints 6, 7 shown in FIG. 2 are hardly or not at all present on the finished profiled components 2.

[0062] FIGS. 5 and 6 show the various cross-sectional shapes 9, 10 of the profiled segments 19, 20, 21, whereby the cross-sectional shape 9 should depict an approximately circular form and the cross-sectional shape 10 an approximately oval form. Instead of a circle or an oval, there can also be an irregularly shaped contour or a box-like shape. This depends on the desired final shape of the profiled component 2 as well as on the production parameters of the hydroforming method with which the semi-finished product 1 is formed into its final shape.

[0063] FIG. 7 schematically shows a production system 33 in which the profiled component 2 according to the invention can be produced. This production system 33 has an installation 16 for producing the semi-finished product 16 in which there is a tube feed mechanism 14 for producing the first profiled segment 19, that is to say, the upper tube 3, as well as for producing and feeding in the third profiled segment, i.e. the lower tube 4. Moreover, the production installation 16 for the semi-finished product has a U/O processing station where the second profiled segment 20, that is to say, the intermediate piece 5, is produced. The upper tube 3, the lower tube 4 as well as the intermediate piece 5 are then fed inside the production installation 16 for the semi-finished product to a joining station 13 where the semi-finished product 1 is created by joining the upper tube 3, the lower tube 4 and the intermediate piece 5. The semi-finished product 1 is then fed to a heating device 17 where it is heated up to a hardening temperature, for example, above 950 C., in order to subsequently be fed in its heated state to the forming tool 11 for the subsequent shaping. The shaping takes place inside the forming tool 11. The semi-finished product 1 is shaped into the profiled component 2 either by means of pressing or hydroforming 26. The hydroforming 26 is carried out in that a pressurized and optionally preheated gas that serves as the forming medium is fed into the interior of the semi-finished product 1 so that the material of the semi-finished product 1, under the influence of the gas pressure, comes to rest against the contour of the forming tool 11 and in this process, the profiled component 2 acquires its final shape. The profiled component 2 thus produced then remains in the forming tool 11 for the time being.

[0064] The gas that serves as the forming medium is subsequently vented from the forming tool 11 and replaced by a cooling medium that then performs the quenching 27 of the profiled component 2 and thus the hardening. The forming tool 11 and the heating device 17 can each be part of a physically interrelated hydroforming installation 18.

[0065] The formed and hardened profiled component 2 in its final shape can still be fed to an aftertreatment station 12 where, for instance, by means of laser cutting, any protruding edges or burrs or else conical expansions that might have been provided at the ends for the hydroforming 26 can then be removed.

[0066] The production method 34 schematically shown in FIG. 8, is as follows:

[0067] First of all, the profile production 23 is carried out for the first and second and optionally additional profiled segments 19, 20 21 which are subsequently put together to create the semi-finished product 1 by means of joining 24. Then the semi-finished product 1 is brought to a hardening temperature, for instance, above 950 C., in order to subsequently impart the profiled component 2 with its final shape by means of hydroforming 26. The profiled component 2 is hardened by means of quenching 27 and by the structural transformation that takes place in this process. Subsequently, an aftertreatment 28 can be carried out in order to remove any protruding edges and burrs.

[0068] The method 34 according to the invention or the semi-finished product 1 according to the invention make it possible to produce partially as well as completely hardened profiled components. Putting together the semi-finished product 1 out of various profiled components 19, 20, 21 allows the use of profiled segments made of different materials having, for example, different hardening characteristics, so that in a single work step, differing degrees of hardening occur in the same profiled component 2 during the quenching 27 down from the hardening temperature.

[0069] The present invention is not restricted in terms of its configuration to the embodiments presented here. Rather, several variants are conceivable which make use of the solution presented here, even in the case of other types of configurations. It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this disclosure is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present disclosure as defined by the appended claims.

LIST OF REFERENCE NUMERALS

[0070] 1 semi-finished product [0071] 2 profiled component [0072] 3 upper tube [0073] 4 lower tube [0074] 5 intermediate piece [0075] 6 joint [0076] 7 joint [0077] 8 A-pillar [0078] 9 cross-sectional shape (circular) [0079] 10 cross-sectional shape (oval) [0080] 11 forming tool [0081] 12 aftertreatment station [0082] 13 joining station [0083] 14 pipe feed mechanism [0084] 15 U/O processing station [0085] 16 production installation for the semi-finished product [0086] 17 heating device [0087] 18 hydroforming installation [0088] 19 profiled segment [0089] 20 profiled segment [0090] 21 profiled segment [0091] 22 extension [0092] 23 profile production [0093] 24 joining [0094] 25 heating [0095] 26 hydroforming [0096] 27 quenching [0097] 28 aftertreatment [0098] 29 straight line [0099] 30 curve [0100] 31 connecting end [0101] 32 connecting end [0102] 33 production system [0103] 34 production method [0104] 35 connecting end [0105] 36 connecting end