Tailor-made semifinished product, and external sidewall reinforcement

Abstract

The invention relates to a tailor-made semifinished product (H) for producing a press hardened external sidewall reinforcement (10, 10') as well as to a press hardened external sidewall reinforcement (10, 10').

Description

[0001] Tailor-made semi-finished product and outer sidewall reinforcement

[0002] The invention relates to a tailor-made semi-finished product for the production of a hot-press hardened outer sidewall reinforcement and a hot-press hardened outer sidewall reinforcement.

[0003] In newly developed vehicles, individual components are increasingly being combined into a single, larger component. Examples include giga-casting aluminum die-cast components and shell construction in the body. The integration of multiple components reduces complexity and costs for logistics and production.

[0004] A highly effective solution is the use of "tailored blank" technology. After manufacturing a tailored blank, only one component needs to be handled, combining the functions of several components. This combination of components leads to different requirements in the individual areas of a tailored blank. Areas with different strength, ductility, surface finish, and material thickness are required.

[0005] Tailor-made semi-finished products are well-known in the art and are referred to in the industry as "tailored blanks" or "tailored welded blanks" for sheet metal. They have the advantage that they can be further processed into components, particularly vehicle components, that, unlike monolithic materials, exhibit properties that can be individually and tailored to specific needs. For example, at least two identical materials with different thicknesses, as well as dissimilar materials, can be joined together.

[0006] Sidewalls of motor vehicles, especially passenger cars (PCAs), today comprise an inner and an outer sidewall reinforcement and an outer skin that seals the sidewall reinforcements to the outside. The outer sidewall reinforcement can be provided from a generic semi-finished product for hot pressing, see, for example, WO 2022 / 064331 A1. Here, additional, so-called patches are applied locally to the semi-finished product in order to optimize the strength and thickness distribution and / or to reinforce weld seams. Based on this, the object of the present invention is to provide a tailor-made semi-finished product with which a hot-press-hardened outer sidewall reinforcement can be produced with comparable or improved properties compared to the prior art while reducing mass.

[0007] The stated object for a generic semi-finished product for producing a hot-press-hardened outer sidewall reinforcement is achieved in that the tailor-made semi-finished product comprises several blanks with different steel compositions, different surface coatings and / or different thicknesses, which are materially bonded to one another, wherein the blanks in the hot-press-hardened state result in an outer sidewall reinforcement with an A-pillar, a B-pillar, a C-pillar, a roof rack and a sill, optionally a front longitudinal member, wherein at least one first blank is made of a steel material which, in the hot-press-hardened state, has a tensile strength of greater than 1700 to 2200 MPa, wherein at least one second blank is made of a steel material which, in the hot-press-hardened state, has a tensile strength of greater than 1400 to a maximum of 1700 MPa,wherein the first plate is arranged in the semi-finished product in such a way that the roof rack and a partial section of the A-pillar are formed therefrom.

[0008] The inventors have discovered that through a targeted selection and combination of different steel compositions, different surface coatings, and / or different thicknesses, high tensile strengths and elongations at break can be combined in a semi-finished product, offering significant potential for weight reduction of the hot-press-hardened outer sidewall reinforcement, thus providing a suitable, tailor-made semi-finished product. The first blank in the semi-finished product, which forms the roof rack and a section of the A-pillar, consists of a steel material that, in the hot-press-hardened state, has a tensile strength of greater than 1700 to 2200 MPa. This allows for improved stabilization of the passenger cell not only in the longitudinal but also in the vertical direction.Especially with the high weight of battery-powered (electric) vehicles, stabilization in the vertical direction represents a major advantage, which is particularly beneficial in load cases such as vehicle rollover and roof crush.

[0009] A-, B- and C-pillars are vertical support structures on a vehicle, which, among other things, stabilize the passenger cell. The A-pillars, left and right, enclose the windshield and the front roof area, so that towards the rear of the vehicle the upper section of the A-pillar merges into the roof rack, and the roof rack is connected to the upper section of the B-pillar and the upper section of the C-pillar as it continues towards the rear of the vehicle. Opposite the roof rack is the sill in the floor area of ​​the vehicle. This extends from the front to the rear wheel house and, starting from the lower section of the A-pillar, is connected to the lower section of the B-pillar and the lower section of the C-pillar as it continues towards the rear of the vehicle.“Connected” can also be understood as “integral (or one-piece) design”, which applies to a semi-finished product according to the invention for producing a hot-press hardened outer sidewall reinforcement.

[0010] A material connection between the individual blanks is achieved by welding, so that the blanks are preferably butt-jointed. The welding method is known to those skilled in the art, see, for example, CN 112 593 153 A, EP 3 815 837 A1, and WO 2013 / 013676 A1.

[0011] According to one embodiment, the semi-finished product comprises at least a third blank made of a steel material which, in the hot-press hardened state, has a tensile strength of greater than 900 to a maximum of 1400 MPa.

[0012] According to one embodiment, the semi-finished product comprises at least a fourth blank made of a steel material which, in the hot-press hardened state, has a tensile strength of at least 400 to a maximum of 900 MPa.

[0013] The blanks used with the listed tensile strengths in the hot-press hardened state depend essentially on the carbon content of the respective steel composition, so that the increase in tensile strength in the hot-press hardened state is essentially accompanied by an increase in the carbon content in the steel material.

[0014] Manganese steel materials or manganese-boron steel materials are preferred.

[0015] According to one embodiment, a further first blank is arranged in the semi-finished product in such a way that at least a partial section of the B-pillar results. The partial section in which the further first blank is arranged covers at least 70% of the extension of the B-pillar. Preferably, the further first blank is arranged between the blanks forming the roof rack and sills. Preferably, the weld seam for connecting the blanks forming the roof rack and the B-pillar is located below the blank forming the roof rack, and the weld seam for connecting the blanks forming the sills and the B-pillar is located above the blank forming the sill. The course of the weld seams is essentially horizontal.

[0016] According to one embodiment, a further first plate is arranged in the semi-finished product in such a way that at least a partial section of the sill results.

[0017] The first blanks may be made of an identical or similar steel material, but are designed such that they have a tensile strength of greater than 1700 to 2200 MPa in the hot-press hardened state. They preferably differ at least in their thickness. The thickness of the first blank may be between 0.8 and 2.5 mm, in particular between 0.9 and 2.2 mm, preferably between 1.0 and 2.0 mm.

[0018] According to one embodiment, a second blank is arranged in the semi-finished product in such a way that at least a partial section of the A-pillar results. The second blank can thus integrally form the front part of the sill. In particular, the weld seam connecting the blanks forming the A-pillar and the sill is located on the side facing away from the front wheel house and preferably runs essentially vertically. Alternatively, the blank forming the sill can also extend completely between the front and rear wheel houses.

[0019] The second blanks can be made of an identical or similar steel material, but are designed such that they have a tensile strength of greater than 1400 to 1700 MPa in the hot-press hardened state. They preferably differ at least in their thickness. The thickness of the first blank can be between 0.8 and 2.5 mm, in particular between 0.9 and 2.2 mm, preferably between 1.0 and 2.0 mm.

[0020] Terms such as "vertical" and "horizontal" essentially refer to the installed position in / on the vehicle, ensuring a clear and unambiguous assignment. The term "essentially" also allows for a minimal deviation of the weld seam between 0 and + / - 10° from the vertical or horizontal. According to one design, a third blank is arranged in the semi-finished product, resulting in the front longitudinal member.

[0021] The third blanks can be made of an identical or similar steel material, but are designed such that they have a tensile strength of greater than 900 to 1400 MPa in the hot-press hardened state. They preferably differ at least in their thickness. The thickness of the first blank can be between 0.8 and 2.5 mm, in particular between 0.9 and 2.2 mm, preferably between 1.0 and 2.0 mm.

[0022] According to one embodiment, a fourth blank is arranged in the semi-finished product in such a way that at least a partial section of the C-pillar results. The partial section in which the fourth blank is arranged covers at least 70% of the extension of the C-pillar. Preferably, the fourth blank is arranged between the blanks forming the roof rack and sills. Preferably, the weld seam for connecting the blanks forming the roof rack and the C-pillar is located below the blank forming the roof rack, and the weld seam for connecting the blanks forming the sills and the C-pillar is located above the blank forming the sill. The course of the weld seams is essentially horizontal.

[0023] The fourth blanks can be made of an identical or similar steel material, but are designed such that they have a tensile strength of greater than 400 to 900 MPa in the hot-press hardened state. They preferably differ at least in their thickness. The thickness of the first blank can be between 0.8 and 2.5 mm, in particular between 0.9 and 2.2 mm, preferably between 1.0 and 2.0 mm.

[0024] According to one embodiment, at least one of the circuit boards is coated with an aluminum-based coating. Alternatively, at least one of the circuit boards can be coated with a zinc-based coating. Further alternatively, at least one of the circuit boards can be uncoated.

[0025] An outer sidewall reinforcement is hot-press hardened from the tailor-made semi-finished product according to the invention. The method for producing hot-press hardened components, especially from tailor-made semi-finished products, is familiar to those skilled in the art.

[0026] The invention further relates to a hot-press hardened outer sidewall reinforcement with an A-pillar, a B-pillar, a C-pillar, a roof rack and a sill, and optionally a front longitudinal member, wherein the sidewall reinforcement is hot-press hardened from a tailor-made semi-finished product, wherein sections of the sidewall reinforcement are formed with different steel compositions, different surface coatings and / or different thicknesses, wherein the roof rack and a partial section of the A-pillar are formed from a steel material with a tensile strength in the hot-press hardened state of greater than 1700 to 2200 MPa.

[0027] According to one embodiment, a section of the B-pillar is made of a steel material with a tensile strength in the hot-press hardened state of greater than 1700 to 2200 MPa.

[0028] According to one embodiment, a section of the sill is made of a steel material with a tensile strength in the hot-press hardened state of greater than 1700 to 2200 MPa.

[0029] According to one embodiment, a partial section of the A-pillar is made of a steel material with a tensile strength in the hot-press hardened state of greater than 1400 to 1700 MPa.

[0030] According to one embodiment, a partial section of the C-pillar is formed from a steel material with a tensile strength in the hot-press hardened state of greater than 400 to 900 MPa.

[0031] According to one embodiment, the front longitudinal member is made of a steel material with a tensile strength in the hot-press hardened state of greater than 900 to 1400 MPa.

[0032] According to one embodiment, a section of the lower B-pillar and an adjacent area of ​​the sill are designed with a tensile strength in the hot-press hardened state of greater than 900 to 1400 MPa. This section can be adjusted during hot-press hardening using "tailored tempering" technology familiar to those skilled in the art, see, for example, EP 1 888 794 B1 and EP 2 012 948 B1.

[0033] According to one embodiment, the hot press hardened outer sidewall reinforcement is used in a vehicle with a hybrid drive or with an electric drive.

[0034] According to an alternative embodiment, the hot-press hardened outer side wall reinforcement can also be used in a vehicle with an internal combustion engine, wherein the aforementioned section is preferably adjusted by means of “tailored tempering” technology in the lower B-pillar and the adjacent area of ​​the sill.

[0035] With the hot-press hardened outer sidewall reinforcement according to the invention, further weight saving potential is possible.

[0036] The invention is explained in more detail below with reference to a drawing illustrating exemplary embodiments. Identical parts are provided with the same reference numerals. It shows:

[0037] Figure 1: a first tailor-made semi-finished product according to the invention for the

[0038] Production of a hot-press hardened outer sidewall reinforcement and a hot-press hardened outer sidewall reinforcement in front view and

[0039] Figure 2: a second outer side wall reinforcement hot press hardened from a tailor-made semi-finished product according to the invention in front view.

[0040] Figure 1 shows a tailor-made semi-finished product (H) for producing a hot-press-hardened outer sidewall reinforcement (10, 10') comprising several blanks (1, 2, 3, 4) with different steel compositions, different surface coatings, and / or different thicknesses, which are integrally joined by butt-welding. The weld seams between the individual blanks (1, 2, 3, 4) are marked with (S). All blanks (1, 2, 3, 4) can preferably be coated with an aluminum-based coating. Alternatively, it would also be conceivable for them to be coated with a zinc-based coating or to be partially uncoated. Even when using an aluminum-based coating, the composition and / or thickness of the coatings can vary.

[0041] The at least one first blank (1) is made of a steel material which, in the hot-press hardened state, has a tensile strength of greater than 1700 to 2200 MPa. Preferably, the first blanks (1) consist of manganese-boron steel materials, preferably of grade 38MnB5. The at least one second blank (2) is made of a steel material which, in the hot-press hardened state, has a tensile strength of greater than 1400 to a maximum of 1700 MPa. Preferably, the second blank (2) is made of a manganese-boron steel material, preferably of grade 22MnB5. The at least one third blank (3) is made of a steel material which, in the hot-press hardened state, has a tensile strength of greater than 900 to a maximum of 1400 MPa. Preferably, the third blank (3) is made of a manganese-boron steel material, preferably of grade 8MnB7 or 12MnB6.The at least one fourth blank (4) is made of a steel material which, in the hot-press-hardened state, has a tensile strength of at least 400 to a maximum of 900 MPa. Preferably, the fourth blank (4) is made of a manganese steel material, preferably of grade 6Mn3 or 6Mn6.

[0042] Using known hot press hardening, an outer side wall reinforcement (10, 10') with an A-pillar (11), a B-pillar (12), a C-pillar (13), a roof rack (14), and a sill (15), optionally a front longitudinal member (16), is produced from the tailor-made semi-finished product with the differently arranged blanks (1, 2, 3, 4). It is essential that a first blank (1) in the semi-finished product (H) is arranged in such a way as to produce the roof rack (14) and a partial section of the A-pillar (11). The thickness of the first blank (1), from which the roof rack (14) and the partial section of the A-pillar (14) are provided after hot press hardening, is 1.5 mm. Thus, thicknesses between 1.3 and 1.7 mm are preferably provided for this first blank (1).

[0043] Furthermore, a partial section of the B-pillar (12) is formed from a steel material with a tensile strength in the hot-press-hardened state of greater than 1700 to 2200 MPa, which in turn is provided by a further first plate (1) with a thickness of 1.1 mm. Thus, thicknesses between 0.9 and 1.3 mm are preferably provided for this further first plate (1).

[0044] Furthermore, a partial section of the sill (15) is formed from a steel material with a tensile strength in the hot-press-hardened state of greater than 1700 to 2200 MPa, which in turn is provided by a further first blank (1) with a thickness of 1.0 mm. Thus, thicknesses between 0.8 and 1.2 mm are preferably provided for this further first blank (1).

[0045] Furthermore, a partial section of the A-pillar (11) is formed from a steel material with a tensile strength in the hot-press-hardened state of greater than 1400 to 1700 MPa, which has been provided by a second blank (2) with a thickness of 1.8 mm. Thus, thicknesses between 1.6 and 2.0 mm are preferably provided for this second blank (2). Furthermore, a partial section of the C-pillar (13) is formed from a steel material with a tensile strength in the hot-press-hardened state of greater than 400 to 900 MPa, which has been provided by a fourth blank (4) with a thickness of 1.1 mm. Thus, thicknesses between 0.9 and 1.3 mm are preferably provided for this fourth blank (4).

[0046] Furthermore, the front longitudinal member (16) is made of a steel material with a tensile strength in the hot-press hardened state of greater than 900 to 1400 MPa, which is provided by a third plate (3) with a thickness of 1.3 mm. Thus, thicknesses between 1.1 and 1.5 mm are preferably provided for this third plate (3).

[0047] The hot press hardened outer side wall reinforcement (10) in Figure 1 is designed for use in a vehicle not shown with a hybrid drive or with an electric drive, which, among other things, provides a continuous uniform tensile strength in the sill (15) so that in the event of a side crash there is no or only slight intrusion in order to protect the batteries not shown arranged in the floor area between the sills (15).

[0048] Figure 2 shows a hot-press-hardened outer sidewall reinforcement (10') which has been hot-press-hardened from a tailor-made semi-finished product (H) identical to that in Figure 1, but with the difference that the well-known "tailored tempering" technology was used locally to form a section (17) in the lower B-pillar (12) and an adjacent area of ​​the sill (15) with a tensile strength in the hot-press-hardened state of greater than 900 to 1400 MPa. The section (17) is deliberately made "softer" than the surrounding areas of the B-pillar (12) and the sill (15) in order to allow intrusion and thus deformation and thus dissipation of the introduced energy in the event of a side crash. The hot-press-hardened outer sidewall reinforcement (10') is thus designed for use in a vehicle (not shown) with an internal combustion engine.

[0049] It is also conceivable that at least one of the blanks (1, 2, 3, 4) can be flexibly rolled, whereby the manufacture and processing of flexible rolled flat products is also familiar to the person skilled in the art.

Claims

Claims 1. Tailor-made semi-finished product (H) for producing a hot-press-hardened outer side wall reinforcement (10, 10') comprising a plurality of blanks (1, 2, 3, 4) with different steel compositions, different surface coatings and / or different thicknesses, which are materially bonded to one another, wherein the blanks (1, 2, 3, 4) in the hot-press-hardened state form an outer side wall reinforcement (10, 10') with an A-pillar (11), a B-pillar (12), a C-pillar (13), a roof rack (14) and a sill (15), optionally a front longitudinal member (16), wherein at least one first blank (1) is made of a steel material, which in the hot-press-hardened state has a tensile strength of greater than 1700 to 2200 MPa, wherein at least one second blank (2) is made of a steel material, which in the hot-press-hardened state has a tensile strength of greater than 1400 to a maximum of 1700 MPa, characterized in thatthat the first plate (1) is arranged in the semi-finished product (H) in such a way as to form the roof support (14) and a partial section of the A-pillar (11).

2. Semi-finished product according to claim 1, wherein at least one third blank (3) made of a steel material is provided which, in the hot-press hardened state, has a tensile strength of greater than 900 to a maximum of 1400 MPa.

3. Semi-finished product according to claim 1 or 2, wherein at least one fourth blank (4) made of a steel material is provided which, in the hot-press hardened state, has a tensile strength of at least 400 to a maximum of 900 MPa.

4. Semi-finished product according to one of the preceding claims, wherein a further first plate (1) is arranged in the semi-finished product (H) in such a way that at least a partial section of the B-pillar (12) results.

5. Semi-finished product according to one of the preceding claims, wherein a further first plate (1) is arranged in the semi-finished product (H) in such a way that at least a partial section of the sill (15) results.

6. Semi-finished product according to one of the preceding claims, wherein a second plate (1) is arranged in the semi-finished product (H) in such a way that at least a partial section of the A-pillar (11) results.

7. Semi-finished product according to claim 2, wherein a third plate (3) is arranged in the semi-finished product (H) in such a way as to form the front longitudinal member (16).

8. Semi-finished product according to claim 3, wherein a fourth plate (3) is arranged in the semi-finished product (H) in such a way that at least a partial section of the C-pillar (13) results.

9. Semi-finished product according to one of the preceding claims, wherein at least one of the blanks (1, 2, 3, 4) is coated with an aluminum-based coating.

10. Hot-press-hardened outer side wall reinforcement (10, 10') with an A-pillar (11), a B-pillar (12), a C-pillar (13), a roof rack (14) and a sill (15), and optionally a front longitudinal member (16), wherein the side wall reinforcement (10, 10') is hot-press-hardened from a tailor-made semi-finished product (H), wherein sections of the side wall reinforcement (10, 10') are formed with different steel compositions, different surface coatings and / or different thicknesses, in particular by a semi-finished product (H) according to one of the preceding claims, characterized in that the roof rack (14) and a partial section of the A-pillar (11) are formed from a steel material with a tensile strength in the hot-press-hardened state of greater than 1700 to 2200 MPa.

11. Hot-press hardened outer sidewall reinforcement according to claim 10, wherein a portion of the B-pillar (12) is formed from a steel material having a tensile strength in the hot-press hardened state of greater than 1700 to 2200 MPa.

12. Hot-press hardened outer side wall reinforcement according to claim 10 or 11, wherein a portion of the sill (15) is formed from a steel material having a tensile strength in the hot-press hardened state of greater than 1700 to 2200 MPa.

13. Hot press hardened outer side wall reinforcement according to one of claims 10 to 12, wherein a section of the A-pillar (11) is made of a steel material with a Tensile strength in the hot press hardened state of greater than 1400 to 1700 MPa.

14. Hot press hardened outer sidewall reinforcement according to one of claims 10 to 13, wherein a partial section of the C-pillar (13) is formed from a steel material having a tensile strength in the hot-press hardened state of greater than 400 to 900 MPa.

15. Hot press hardened outer sidewall reinforcement according to one of claims 10 to 14, wherein the front longitudinal member (16) is formed from a steel material having a tensile strength in the hot-press hardened state of greater than 900 to 1400 MPa.

16. Hot-press hardened outer side wall reinforcement according to one of claims 10 to 14, wherein a portion (17) of the lower B-pillar (12) and an adjacent region of the sill (15) is formed with a tensile strength in the hot-press hardened state of greater than 900 to 1400 MPa.

17. A hot press hardened outer sidewall reinforcement according to any one of claims 10 to 15 for use in a hybrid or electric vehicle.

18. A hot press hardened outer sidewall reinforcement according to claim 16 for use in an internal combustion engine vehicle.

Images