Customized semi-finished product and outer sidewall reinforcement

Abstract

The invention relates to a custom-made semi-finished product (H) for producing a press-hardened outer side wall reinforcement (10, 10 ') and to a press-hardened outer side wall reinforcement (10, 10').

Description

[0001] This invention relates to a customized semi-finished product for producing a thermo-pressed hardened outer wall reinforcement and a thermo-pressed hardened outer wall reinforcement itself. In newly developed vehicles, individual components are increasingly being combined into a single large component. Examples include, in particular, giga-cast aluminum die-cast components and monocoque construction methods in vehicle bodies. The integration of multiple components reduces logistical and production complexity and costs.

[0002] A highly effective solution is to use tailored blank technology. After manufacturing the tailored blank, the number of parts to be processed is reduced to a single component that combines the functions of multiple parts. This combination of parts leads to different requirements for different areas of the tailored blank. Areas with varying strengths, ductility, surface finishes, and material thicknesses are needed.

[0003] Customized semi-finished products are known in the prior art and are technically referred to as "custom slabs" or "custom welded slabs" for sheet metal. Their advantage lies in the fact that they are further processed into components, particularly vehicle components, which, compared to monolithic materials, have the ability to be individually configured according to requirements. For example, at least two materials of the same type or different types with different thicknesses can be joined together.

[0004] The sidewalls of motor vehicles, particularly passenger cars, now include inner sidewall reinforcements and outer sidewall reinforcements, as well as an outer skin that surrounds the sidewall reinforcements. The outer sidewall reinforcements can be produced from generic semi-finished products used for hot pressing, see, for example, WO 2022 / 064331 A1. Additional so-called patches are locally applied to the semi-finished product to optimize strength and thickness distribution and / or reinforce welds.

[0005] Based on this, the object of the present invention is to provide a customized semi-finished product that enables the production of hot-pressed hardened outer wall reinforcements with comparable or improved performance and reduced quality compared to existing technologies. This object is achieved for a general semi-finished product used in the production of hot-pressed hardened outer wall reinforcements by the following method: the customized semi-finished product comprises multiple slabs with different steel compositions, different surface coatings, and / or different thicknesses, these slabs being joined together in a material bonding manner, wherein the slabs form an outer wall reinforcement in a hot-pressed state, the outer wall reinforcement including an A-pillar, a B-pillar, a C-pillar, a roof support, and a sill, optionally including a front longitudinal beam, wherein at least one first slab made of steel having a tensile strength greater than 1700 to 2200 MPa in the hot-pressed state is provided, wherein at least one second slab made of steel having a tensile strength greater than 1400 to at most 1700 MPa in the hot-pressed state is provided, wherein one of the first slabs is arranged in the semi-finished product such that it forms a sub-part of the roof support and the A-pillar.

[0006] The inventors have discovered that specific selections and combinations of different steel compositions, surface coatings, and / or thicknesses enable the integration of high tensile strength and elongation at break in a single semi-finished product. This offers significant potential for weight reduction in hot-pressed hardened outer wall reinforcements, thereby enabling the provision of a custom-designed semi-finished product suitable for this purpose. The first slab forming the roof support and A-pillar portions in the semi-finished product is made of steel with a tensile strength greater than 1700 to 2200 MPa in the hot-pressed hardened state. This allows for improved passenger compartment stability not only in the longitudinal direction of the vehicle but also in the vertical direction. Vertical stability is a significant advantage, particularly in the case of heavier battery-electric vehicles, and is especially useful under load conditions such as vehicle rollover and roof crush.

[0007] The A-pillar, B-pillar, and C-pillar should be understood as referring to vertical support structures on a vehicle, particularly for stabilizing the passenger compartment. The left and right A-pillars surround the windshield and the front roof area, effectively such that, in the rearward direction of the vehicle, the upper sub-section of the A-pillar transitions into the roof support, and the roof support, in its further extension toward the rear of the vehicle, engages with the upper sub-sections of the B-pillar and C-pillar, respectively. Opposite the roof support, a sill is arranged in the floor area of ​​the vehicle, extending from the front wheel arch to the rear wheel arch, and, starting from the lower sub-section of the A-pillar, engages with the lower sub-sections of the B-pillar and C-pillar, respectively, in its further extension toward the rear of the vehicle. The term "engagement" should be understood to include the meaning of "integral formation (or monolithic formation)," as in the case of the semi-finished product of the present invention used for producing hot-pressed hardened outer wall reinforcements.

[0008] The joining of materials between the individual slabs is achieved by welding, and the slabs are therefore preferably joined to each other in butt joints. Welding methods are known to those skilled in the art, see, for example, CN 112 593 153 A, EP 3815 837 A1 and WO 2013 / 013676 A1.

[0009] In one embodiment, the semi-finished product includes at least one third slab made of steel material having a tensile strength of greater than 900 to at most 1400 MPa in a hot-pressed hardened state.

[0010] In one embodiment, the semi-finished product includes at least one fourth slab made of steel material having a tensile strength of at least 400 to at most 900 MPa in a hot-pressed hardened state.

[0011] The slab used in the hot-pressed hardening state that has the tensile strength is essentially dependent on the carbon content of the corresponding steel composition, so the increase in tensile strength in the hot-pressed hardening state is essentially related to the increase in carbon content in the steel material.

[0012] Manganese steel or manganese boron steel is preferred.

[0013] In one embodiment, a further first slab is arranged in the semi-finished product such that it forms at least one sub-portion of the B-pillar. The sub-portion with the further first slab covers at least 70% of the B-pillar area. The further first slab is preferably arranged between the slab forming the roof support and the slab forming the sill. Preferably, the weld for joining the slab forming the roof support and the B-pillar is located below the slab forming the roof support, and the weld for joining the slab forming the sill and the B-pillar is located above the slab forming the sill. The weld orientation is substantially horizontal.

[0014] In one embodiment, a first slab is arranged in the semi-finished product such that it forms at least one sub-part of the threshold.

[0015] The first slabs may be made of the same or similar steel material, but have a configuration that gives them a tensile strength greater than 1700 MPa to 2200 MPa in the hot-pressed hardened state. They preferably differ at least in their thickness. The thickness of the first slab may be between 0.8 mm and 2.5 mm, particularly between 0.9 mm and 2.2 mm, and preferably between 1.0 mm and 2.0 mm.

[0016] In one embodiment, a second slab is arranged in the semi-finished product such that it forms at least one sub-part of the A-pillar. The second slab can thus integrally form the front portion of the sill. Specifically, the weld for joining the slab forming the A-pillar and the sill is located on the side away from the front wheel arch, and its orientation is preferably substantially vertical. Alternatively, the slab forming the sill may also extend entirely between the front and rear wheel arches.

[0017] The second slabs can be made of the same or similar steel material, but have a configuration that gives them a tensile strength greater than 1400 MPa to 1700 MPa in the hot-pressed hardened state. They are preferably different, at least in their thickness. The thickness of the first slab can be between 0.8 mm and 2.5 mm, particularly between 0.9 mm and 2.2 mm, and preferably between 1.0 mm and 2.0 mm.

[0018] Indications such as "vertical" and "horizontal" essentially refer to the installation status within / on the vehicle to ensure clear attribution. The term "essentially" also allows for a minimum deviation of 0° to + / - 10° from the vertical or horizontal direction of the weld.

[0019] In one embodiment, a third slab is arranged in the semi-finished product such that it forms the front longitudinal beam.

[0020] The third slabs may be made of the same or similar steel material, but have a configuration that gives them a tensile strength greater than 900 MPa to 1400 MPa in the hot-pressed hardened state. They are preferably different, at least in their thickness. The thickness of the first slab may be between 0.8 mm and 2.5 mm, particularly between 0.9 mm and 2.2 mm, and preferably between 1.0 mm and 2.0 mm.

[0021] In one embodiment, a fourth blank is arranged in the semi-finished product such that it forms at least one sub-portion of the C-pillar. The sub-portion with the fourth blank covers at least 70% of the C-pillar area. The fourth blank is preferably arranged between the blank forming the roof support and the blank forming the sill. Preferably, the weld for joining the blank forming the roof support and the C-pillar is located below the blank forming the roof support, and the weld for joining the blank forming the sill and the C-pillar is located above the blank forming the sill. The weld orientation is substantially horizontal.

[0022] The fourth slab may be made of the same or similar steel material, but has a configuration that gives them a tensile strength greater than 400 MPa to 900 MPa in the hot-pressed hardened state. They are preferably different, at least in their thickness. The thickness of the first slab may be between 0.8 mm and 2.5 mm, particularly between 0.9 mm and 2.2 mm, and preferably between 1.0 mm and 2.0 mm.

[0023] In one embodiment, at least one slab is coated with an aluminum-based coating. Alternatively, at least one slab may be coated with a zinc-based coating. In another alternative, at least one slab may be uncoated.

[0024] According to the invention, a custom-made semi-finished product is hot-pressed to form an outer wall reinforcement. Methods for producing hot-pressed hardened parts, particularly from custom-made semi-finished products, are known to those skilled in the art.

[0025] The present invention also relates to a thermo-pressurized sidewall reinforcement comprising an A-pillar, a B-pillar, a C-pillar, a roof support and a sill, and an optional front longitudinal beam, wherein the sidewall reinforcement is formed by thermo-pressurization of a custom-made semi-finished product to form portions of the sidewall reinforcement having different steel compositions, different surface coatings and / or different thicknesses, wherein a sub-section of the roof support and the A-pillar is made of steel having a tensile strength greater than 1700 MPa to 2200 MPa in the thermo-pressurized state.

[0026] In one embodiment, a sub-section of the B-pillar is made of steel material having a tensile strength of greater than 1700 MPa to 2200 MPa in a hot-pressed hardened state.

[0027] In one embodiment, a sub-section of the threshold is made of steel material having a tensile strength of greater than 1700 MPa to 2200 MPa in a hot-pressed hardened state.

[0028] In one embodiment, a sub-section of the A-pillar is made of steel material having a tensile strength of greater than 1400 MPa to 1700 MPa in a hot-pressed hardened state.

[0029] In one embodiment, a sub-section of the C-pillar is made of steel material having a tensile strength of greater than 400 MPa to 900 MPa in a hot-pressed hardened state.

[0030] In one embodiment, the front longitudinal beam is made of steel material having a tensile strength of greater than 900 MPa to 1400 MPa in a hot-pressed hardened state.

[0031] In one embodiment, a segment of the lower B-pillar and a region of the adjacent threshold have a tensile strength greater than 900 MPa to 1400 MPa in a thermo-cured state. This segment can be established during thermo-curing using a tailored tempering technique familiar to those skilled in the art, see, for example, EP 1 888 794 B1 and EP 2 012 948 B1.

[0032] In one embodiment, the thermo-pressed hardened outer wall reinforcement is used in a vehicle with hybrid drive or electric drive.

[0033] In an alternative embodiment, the thermo-pressed hardened outer wall reinforcement can also be used in vehicles with internal combustion engines, wherein the aforementioned section is preferably established in the area of ​​the lower B-pillar and the adjacent door sill using a "custom tempering" technique.

[0034] Therefore, the hot-pressed hardened outer wall reinforcement according to the present invention enables further weight reduction potential.

[0035] The invention will now be explained in more detail with reference to the accompanying drawings, which illustrate several exemplary embodiments. The same parts are given the same reference numerals. In the drawings:

[0036] Figure 1 The front view shows a first custom-made semi-finished product for producing a hot-pressed hardened outer wall reinforcement according to the present invention, and the hot-pressed hardened outer wall reinforcement produced therefrom.

[0037] Figure 2 The front view shows a second hot-pressed hardened outer wall reinforcement produced from a custom semi-finished product according to the invention.

[0038] Figure 1 A custom-made semi-finished product (H) for producing hot-pressed hardened outer wall reinforcements (10, 10') is shown, comprising multiple slabs (1, 2, 3, 4) with different steel compositions, different surface coatings, and / or different thicknesses, which are joined together by welding in a butt joint for material bonding. The welds between the individual slabs (1, 2, 3, 4) are marked (S). All slabs (1, 2, 3, 4) are preferably coated with an aluminum-based coating. Alternatively, it is conceivable that the slabs may be coated with a zinc-based coating or may be partially uncoated. Furthermore, when using an aluminum-based coating, the composition and / or thickness of the coating can also be varied.

[0039] The at least one first slab (1) is made of steel having a tensile strength greater than 1700 to 2200 MPa in the hot-pressed hardened state. Preferably, the first slab (1) is made of manganese-boron steel, preferably grade 38MnB5. The at least one second slab (2) is made of steel having a tensile strength greater than 1400 to at most 1700 MPa in the hot-pressed hardened state. Preferably, the second slab (2) is made of manganese-boron steel, preferably grade 22MnB5.

[0040] The at least one third slab (3) is made of steel having a tensile strength greater than 900 to at most 1400 MPa in the hot-pressed hardened state. Preferably, the third slab (3) is made of manganese boron steel, preferably 8MnB7 or 12MnB6. The at least one fourth slab (4) is made of steel having a tensile strength of at least 400 to at most 900 MPa in the hot-pressed hardened state. Preferably, the fourth slab (4) is made of manganese steel, preferably 6Mn3 or 6Mn6.

[0041] Customized semi-finished products comprising slabs (1, 2, 3, 4) in different arrangements are subjected to known hot-pressing hardening to produce outer wall reinforcements (10, 10'), which include A-pillars (11), B-pillars (12), C-pillars (13), a roof support (14), and a sill (15), optionally including a front longitudinal beam (16). Crucially, the first slab (1) is arranged in the semi-finished product (H) such that it forms a sub-part of the roof support (14) and the A-pillars (11). The first slab (1) providing the roof support (14) and the A-pillars (14) sub-parts has a thickness of 1.5 mm after hot-pressing hardening. Therefore, this first slab (1) should preferably have a thickness between 1.3 mm and 1.7 mm.

[0042] The sub-section of column B (12) is further made of steel material having a tensile strength greater than 1700 MPa to 2200 MPa in the hot-pressed hardened state, and this section is then provided by another first slab (1) having a thickness of 1.1 mm. Therefore, this other first slab (1) should preferably have a thickness between 0.9 mm and 1.3 mm.

[0043] The sub-section of the threshold (15) is further made of steel material having a tensile strength greater than 1700 MPa to 2200 MPa in the hot-pressed hardened state, and this part is subsequently provided by another first slab (1) having a thickness of 1.0 mm. Therefore, this other first slab (1) should preferably have a thickness between 0.8 mm and 1.2 mm.

[0044] The sub-section of column A (11) is further made of steel material having a tensile strength greater than 1400 MPa to 1700 MPa in the hot-pressed hardened state, and this part has been provided by a second slab (2) having a thickness of 1.8 mm. Therefore, this second slab (2) should preferably have a thickness between 1.6 mm and 2.0 mm.

[0045] The sub-section of the C-pillar (13) is further made of steel material having a tensile strength greater than 400 MPa to 900 MPa in the hot-pressed hardened state, and this part has been provided by a fourth slab (4) having a thickness of 1.1 mm. Therefore, this fourth slab (4) should preferably have a thickness between 0.9 mm and 1.3 mm.

[0046] The front longitudinal beam (16) is further made of steel with a tensile strength greater than 900 MPa to 1400 MPa in the hot-pressed hardened state, and this part has been provided by a third slab (3) with a thickness of 1.3 mm. Therefore, this third slab (3) should preferably have a thickness between 1.1 mm and 1.5 mm.

[0047] Figure 1 The hot-pressed hardened outer wall reinforcement (10) is designed for vehicles with hybrid drive or electric drive (not shown) and, among other things, provides continuous and uniform tensile strength in the sill (15) so that only minor intrusion (if any) occurs in the event of a side collision to protect the battery (not shown) arranged in the floor area between the sills (15).

[0048] Figure 2 A thermo-pressed hardened outer wall reinforcement (10') is shown, which has been modified by... Figure 1 The same custom-made semi-finished product (H) is produced by hot-pressing hardening, but with the difference that the well-known “custom tempering” technique is used locally to form a section (17) in the area of ​​the lower B-pillar (12) and the adjacent sill (15) with a tensile strength greater than 900 MPa to 1400 MPa in the hot-pressed hardened state. Compared with the surrounding areas of the B-pillar (12) and sill (15), the section (17) is intentionally made “softer” to allow intrusion and therefore deformation, thereby reducing incident energy in the event of a side impact. Therefore, the hot-pressed hardened outer wall reinforcement (10') is intended for use in vehicles with internal combustion engines (not shown).

[0049] It is also conceivable that at least one slab (1, 2, 3, 4) can be in a flexible rolling form, wherein the production and processing of flexible rolled flat products are also familiar to those skilled in the art.

Claims

1. A customized semi-finished product (H) for producing hot-pressed hardened outer wall reinforcements (10, 10'), said semi-finished product (H) comprising a plurality of slabs (1, 2, 3, 4) having different steel compositions, different surface coatings, and / or different thicknesses, said slabs being joined together in a material bonding manner, wherein, The slabs (1, 2, 3, 4) form outer wall reinforcements (10, 10') in a hot-pressed hardened state, the outer wall reinforcements including an A-pillar (11), a B-pillar (12), a C-pillar (13), a top cover support (14), and a sill (15), optionally including a front longitudinal beam (16), wherein at least one first slab (1) is provided, the first slab (1) being made of steel material having a tensile strength greater than 1700 MPa to 2200 MPa in a hot-pressed hardened state, wherein at least one second slab (2) is provided, the second slab (2) being made of steel material having a tensile strength greater than 1400 MPa to a maximum of 1700 MPa in a hot-pressed hardened state, characterized in that the first slab (1) is arranged in the semi-finished product (H) such that it forms a sub-part of the A-pillar (11) and the top cover support (14).

2. The semi-finished product according to claim 1, wherein, The assembly includes at least one third slab (3), which is made of steel material having a tensile strength of greater than 900 MPa to a maximum of 1400 MPa in a hot-pressed hardened state.

3. The semi-finished product according to claim 1 or 2, wherein, The facility is provided with at least one fourth slab (4), which is made of steel material having a tensile strength of at least 400 MPa to a maximum of 900 MPa in a hot-pressed hardened state.

4. The semi-finished product according to any one of the preceding claims, wherein, Another first slab (1) is arranged in the semi-finished product (H) such that it forms at least one sub-part of the B column (12).

5. The semi-finished product according to any one of the preceding claims, wherein, Another first slab (1) is arranged in the semi-finished product (H) such that it forms at least one sub-part of the threshold (15).

6. The semi-finished product according to any one of the preceding claims, wherein, The second slab (1) is arranged in the semi-finished product (H) such that it forms at least one sub-part of the A-pillar (11).

7. The semi-finished product according to claim 2, wherein, The third slab (3) is arranged in the semi-finished product (H) such that it forms the front longitudinal beam (16).

8. The semi-finished product according to claim 3, wherein, The fourth slab (3) is arranged in the semi-finished product (H) such that it forms at least one sub-part of the C-pillar (13).

9. The semi-finished product according to any one of the preceding claims, wherein, At least one slab (1, 2, 3, 4) is coated with an aluminum-based coating.

10. A thermo-pressurized outer wall reinforcement (10, 10'), said outer wall reinforcement (10, 10') comprising an A-pillar (11), a B-pillar (12), a C-pillar (13), a roof support (14), and a door sill (15), and optionally a front longitudinal beam (16), wherein, The sidewall reinforcements (10, 10') are formed by hot-pressing hardening of a customized semi-finished product (H) to form portions of sidewall reinforcements (10, 10') having different steel compositions, different surface coatings and / or different thicknesses, particularly the semi-finished product (H) according to any one of the preceding claims, characterized in that the sub-parts of the top cover support (14) and the A-pillar (11) are made of steel material having a tensile strength greater than 1700 MPa to 2200 MPa in the hot-pressed hardened state.

11. The hot-pressed hardened outer wall reinforcement according to claim 10, wherein, The sub-parts of the B column (12) are made of steel with a tensile strength of greater than 1700 MPa to 2200 MPa in the hot-pressed hardened state.

12. The hot-pressed hardened outer wall reinforcement according to claim 10 or 11, wherein, The sub-section of the threshold (15) is made of steel material having a tensile strength of greater than 1700 MPa to 2200 MPa in the hot-pressed hardened state.

13. The hot-pressed hardened outer wall reinforcement according to any one of claims 10 to 12, wherein, The sub-parts of the A-pillar (11) are made of steel material having a tensile strength of greater than 1400 MPa to 1700 MPa in the hot-pressed hardened state.

14. The hot-pressed hardened outer wall reinforcement according to any one of claims 10 to 13, wherein, The sub-parts of the C-pillar (13) are made of steel material having a tensile strength of greater than 400 MPa to 900 MPa in the hot-pressed hardened state.

15. The hot-pressed hardened outer wall reinforcement according to any one of claims 10 to 14, wherein, The front longitudinal beam (16) is made of steel material having a tensile strength of greater than 900 MPa to 1400 MPa in the hot-pressed hardened state.

16. The hot-pressed hardened outer wall reinforcement according to any one of claims 10 to 14, wherein, The lower section (17) of the B-pillar (12) and the adjacent area of ​​the threshold (15) have a tensile strength greater than 900 MPa to 1400 MPa in the hot-pressed hardened state.

17. The thermo-pressed hardened outer wall reinforcement according to any one of claims 10 to 15, for use in vehicles having hybrid drive or electric drive.

18. The thermo-pressed hardened outer wall reinforcement according to claim 16, for use in a vehicle having an internal combustion engine.

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