Front or rear end of a vehicle having at least two wheel house elements and at least one cross beam connecting the wheel house elements and method of manufacturing the same

Abstract

The invention relates to a vehicle front or rear end having at least two wheel house elements (14, 16) and at least one cross beam (18, 20) connecting the wheel house elements, which wheel house elements form a main body (22) made of a light metal material, wherein at least one reinforcing element (24) formed from a drawn metal (26) or sheet metal is cast into at least one wheel house element (14, 16) and / or the cross beam (18, 20). The invention also relates to a method for producing such a vehicle front or rear end.

Description

[0001] This invention relates to a front or rear section of a vehicle having at least two wheel arch elements and at least one crossbeam connecting the wheel arch elements, the wheel arch elements and the crossbeam forming a base. In particular, this invention relates to the front or rear section of automobiles having a vehicle weight of up to 2.8 tons, to light commercial vehicles having a weight greater than 2.8 tons, particularly greater than 3.5 tons, or to heavy commercial vehicles having a weight greater than 7.5 tons. The invention also relates to vehicles having a front or rear section designed according to the above structure, particularly automobiles, and especially to commercial vehicles equipped with such a front or rear section. The invention further relates to a method for manufacturing such a front or rear section.

[0002] In the past, vehicle body and chassis structures were typically made from multiple individual components that were glued, welded, or screwed together. More recently, there has been a trend towards simplifying the manufacturing process by producing main body components and structures larger than large castings. One challenge in this context is that the high-load-bearing points of these components must withstand not only the loads incurred during anticipated vehicle operation but also the loads incurred in a collision, so as to maintain the same crash safety as conventionally manufactured bodies and structures. To date, this has been achieved by using suitable materials (such as high-strength steel) in the relevant components. However, this approach is costly, especially for large cast components, which often only require high rigidity in specific areas.

[0003] Alternatively, it is known to partially harden a region by providing a suitable geometry or material accumulation. However, from a casting perspective, this is sometimes difficult or even impossible, or in the case of material accumulation, it is associated with additional weight to the corresponding vehicle and corresponding disadvantages in terms of driving performance and fuel consumption.

[0004] It is also known from FR 2 558 084 A1 that inserts (inserts) are provided for cast components to partially increase stiffness. However, FR 2 558 084 A1 makes no mention of large cast components as described above, nor of base components with crossbeams at the front or rear of a vehicle.

[0005] DE 10 2022 000 631 A1 discloses a cast component for a vehicle body structure, comprising a separately manufactured metal insert connected to a die casting by die casting. The metal insert is partially encapsulated by the die casting. In the method of manufacturing the composite component described in this document, the metal insert is austenitized before being inserted into the die casting mold, and the austenitized heated metal insert is placed in the die casting mold to be fully formed by the die casting melt flowing into the mold and hardened by cooling in the mold. This disclosure also makes no mention of large cast components or base elements with crossbeams for the front or rear of a vehicle as described above.

[0006] DE 10 2018 213 490 A1 discloses a component and a method for manufacturing the component. The component should comprise at least two parts, wherein at least one first part should be at least partially embedded in the second part, and wherein the first part has or forms a boundary layer, and the second part penetrates the first part up to the boundary layer, thereby forming a transition zone. The component is particularly a die-cast component made of aluminum, into which a steel insert is cast. No mention is made of large cast components or base elements with crossbeams for the front or rear of a vehicle as described above in this publication.

[0007] The object of this invention is to provide a front or rear portion of a vehicle according to the preamble of claim 1, and a method for manufacturing such a front or rear portion, which can be manufactured as a large casting and has enhanced crash safety. According to the invention, this object is achieved by the features of the independent claim. Other practical embodiments and advantages of the invention are described in conjunction with the dependent claims.

[0008] The front or rear portion of a vehicle according to the invention has a base formed by at least two wheel arch elements and at least one crossbeam connecting the wheel arch elements. The base is made of a lightweight metal material. Furthermore, at least one reinforcing element formed of stretched metal or sheet metal is embedded in at least one wheel arch element and / or in the crossbeam of the base using a casting technique. Lightweight metal materials in the sense of the invention are particularly understood to be aluminum or magnesium. Metal materials with higher strength than lightweight metal materials are particularly suitable as metallic materials. Here, at least one of the tensile strength, compressive strength, flexural strength, or torsional strength of the reinforcing element is preferably increased relative to the corresponding strength of the lightweight metal material, preferably tensile strength and / or compressive strength, and unrelatedly, at least two or three of the said strengths of the reinforcing element material are preferably increased relative to the lightweight metal material. As will be explained below with the aid of further technical details, such a base can be manufactured as a large casting, wherein collision safety is increased by means of the reinforcing element embedded by casting. In this case, the weight is reduced compared to a base made solely of lightweight metal material, because the material accumulation mentioned at the beginning can be eliminated.

[0009] In a suitable embodiment of the front or rear of a vehicle according to the invention, the at least one reinforcing element is made of a material that experiences a strength-enhancing effect when the substrate is manufactured using a casting process, when heated by contact with a liquid light metal, and subsequently cooled. The casting process is particularly understood to be an aluminum casting process or a magnesium casting process. If the above technical conditions are met, a material can be selected for the reinforcing element that is relatively soft in its basic state (i.e., before being embedded in the substrate), thereby ensuring good deformability. This is particularly useful for shaping the reinforcing element into a suitable, especially specific, curved shape. The embedding by the casting technique, along with the associated heating and subsequent cooling, and then the strength-enhancing effect, ensures that the reinforcing element possesses the desired increased strength only during or after the manufacture of the substrate. In this respect, the aforementioned strength refers to the strength of the reinforcing element present after the manufacture of the substrate with the embedded reinforcing element. In the last case described above, this strength is also enhanced compared to the inherent strength of the reinforcing element before it is embedded in the substrate. The cooling of the substrate specifically refers to cooling the substrate to ambient temperature after casting, particularly a temperature between about 15°C and 25°C, for example, 20°C.

[0010] In another practical embodiment of the front or rear of the vehicle according to the invention, at least one reinforcing element is made of air-hardened steel and / or medium-manganese steel, also known as medium-manganese steel (Medium-Manganese-Stahl). This is steel with a manganese content of about 4% to 12%.

[0011] For information on air-hardening steel, please refer to the Salzgitter flat steel grades LH®900 and RobuSal®800. The material composition and parameters for these materials are clearly described and can be found at https: / / www.saltgitter-flat steel.de / fileadmin / medialdb / szfg / information / material / product information / kaitrolled f single sheet / deu / lh 900 szfq material sheet3 15 3.pdf and https: / / www.saltgitter-flat steel.de / fileadmin / medialdb / szfg / information / material / product information / warmqerolled products / deu / robal r800.pdf.

[0012] In another practical embodiment, it is advantageous that the reinforcing element is made of a material that undergoes a strength-enhancing effect upon contact with a liquid light metal material at a temperature of approximately 600°C to 1,000°C and subsequent cooling. This strength-enhancing effect is even more advantageous if it occurs within a temperature range of 600°C to 800°C, particularly between 700°C and 750°C. At such temperatures, the liquefied light metal material has been used in the casting process, particularly aluminum processed in aluminum casting. For this embodiment, medium manganese steel is particularly suitable for bonding with a matrix made of aluminum material.

[0013] If at least one reinforcing element is formed by stretching metal through cutting and alternately bending and / or stretching strips of material produced by the cutting on a metal sheet, the resulting matrix has very high weight-specific stiffness, which is advantageous for impact requirements. Therefore, it is particularly preferred to introduce reinforcing elements formed of stretching metal.

[0014] Alternatively or additionally, in the case of the front or rear portion of the vehicle according to the invention, at least one reinforcing element may also be a planar element extending over a large portion of the width of at least one crossbeam and / or an arcuate element extending at least over an arcuate sub-segment of the wheel arch element.

[0015] If the reinforcing element extends over most of the width of the crossbeam, particularly over 60%, preferably 70%, 80%, or 90% of the width between the inner sides of the wheel arch elements, high lateral stiffness of the matrix is ​​generated. This high lateral stiffness provides increased stiffness to the passenger compartment in this area, especially in the event of a side impact. If the wheel arch elements are provided with appropriate reinforcing elements, lateral stiffness can be improved, as can the shape stability of the wheel arch load-bearing components. This increases the likelihood of maintaining the shape of the wheel arch when forces are applied directly to it, resulting in no contact between the wheel arch and the wheel, allowing the vehicle to remain drivable even after a collision.

[0016] Preferably, at least one reinforcing element is embedded across its entire surface at least on one side, thereby creating a large-area connection with the substrate and making detachment or shearing of the reinforcing element unlikely during a collision. At least one reinforcing element is preferably fully embedded in the substrate, such that the reinforcing element is secured in the best possible manner to resist external influences and separation during a collision. In this regard, a generally centered arrangement of the substrate thickness within the substrate is preferred. If an eccentric arrangement of the reinforcing element is provided, the reinforcing element can be arranged more towards the vehicle's outer side and more towards the vehicle's inner side. The arrangement closer to the vehicle's interior has the advantage of optimally protecting the reinforcing element from external forces arising from intrusion forces from a collision partner. The arrangement towards the vehicle's outer side has the advantage that intrusion forces act first on the reinforcing element, which has higher strength, so that the force is transferred from this stiffer element to the body that is substantially further away on the vehicle's inner side. If there is no risk of the reinforcing element loosening from the body due to a sufficiently load-bearing connection and the geometry of the reinforcing element (e.g., substantially covering the entire surface on the exterior), then from a collision perspective, it is preferable to arrange the reinforcing element on the vehicle's outer side of the body.

[0017] Not only in terms of lightweight structure but also in terms of reliable connection between the reinforcing element and the substrate, it is preferable that the reinforcing element has a through-hole in the front or rear end according to the invention, the through-hole being designed such that it is completely filled with a lightweight metal material after being embedded by casting technology. In this case, the reinforcing element has a reduced weight due to the through-hole. Furthermore, a very good and load-bearing connection is created between the reinforcing element and the substrate because the substrate penetrates the connecting element in the region of the through-hole in each case, resulting in a large contact surface and good "engagement" between the reinforcing element and the substrate overall.

[0018] The present invention also relates to a method for manufacturing a front or rear section of a vehicle as described above, according to which a reinforcing element is held by a support structure made of a light metal material, and a matrix is ​​then manufactured from the light metal material by casting at least partially around the reinforcing element, wherein the support structure only delays melting during the casting process while the reinforcing element is fixed in its relative position within the front or rear section of the vehicle by the hardened light metal. This can be achieved, for example, by providing the support structure on the lower side, while casting is primarily performed from the upper side, particularly in such a manner that the casting mold is initially filled on the upper side and only filled on the lower side at the end of the casting process. This is because once the mold is largely filled, the flow rate decreases significantly, and therefore, if the choice of mold and casting location results in the molten light metal only reaching the area with the support structure at the end of mold filling, there may be a time delay in the flow around the support structure.

[0019] In another embodiment of the method according to the invention for manufacturing the front or rear of a vehicle as described above, the reinforcing element is held by a casting core, which is lost or ejected after the casting process. In the case of demolding, the casting process can be designed to a great extent as needed. If a lost-foil core is used, boundary conditions similar to those in the method described above must be observed, where the support structure is melted. In this case, after manufacturing, through-holes remain in the area of ​​the lost core, allowing visual contact with the reinforcing element. This can be advantageous if it is desired to maintain the ability to inspect the material condition of the reinforcing element through visual inspection and / or material inspection techniques requiring direct access to the reinforcing element.

[0020] Further practical embodiments of the present invention are described below with reference to the accompanying drawings. As shown below:

[0021] Figure 1 A partial view of a vehicle having a rear section according to the invention is shown, wherein the embedded reinforcing element is shown in dashed lines.

[0022] Figure 2 Details of the reinforcing element designed for stretching metal are shown.

[0023] Figure 3 Details of the reinforcing element designed as a perforated plate are shown, and

[0024] Figure 4 A schematic diagram of a casting mold according to the invention is shown, which has a support structure that supports reinforcing elements during the manufacturing of the front or rear of a vehicle according to the invention by casting technology.

[0025] Figure 1A portion of a vehicle 10 with a rear section 12 is shown, and the rear section 12 is formed by a first wheel arch element 14 and a second wheel arch element 16, which extend arcuately on the outer side of the vehicle 10 and cover the wheel arch opening area, respectively. In the illustrated embodiment, wheel arch elements 14 and 16 are connected to each other to form a base 22 by a first crossbeam 18 and a second crossbeam 20.

[0026] The substrate 22 has already been made of aluminum in an aluminum casting process. In the illustrated embodiment, the reinforcing element 24 is fully embedded in the first crossbeam 18 by casting. The reinforcing element 24 extends over the entire width between the wheel arch elements 10 and 16.

[0027] exist Figure 2 and Figure 3 The image shows two different embodiments of different reinforcing elements 24.

[0028] exist Figure 2 In the illustrated embodiment, the reinforcing element 24 is formed of stretched metal 26. The stretched metal 26 is formed of a plurality of material strips 28, which are alternately separated from each other by bending and stretching the material strips 28 in different directions (upward and downward in this case). To manufacture the stretched metal 26, slits of approximately equal length are provided, thereby forming the material strips 28. The areas between the material strips 28 where no grooves are provided are so-called nodes 30.

[0029] Figure 3 A reinforcing element 24 in the form of a perforated plate 32 is shown. The perforated plate 32 has a plurality of through holes 34, which, in the illustrated embodiment, have a square configuration. However, other shapes of through holes 34 can also be provided, particularly circular, elliptical, rectangular, polygonal, or otherwise shaped.

[0030] Figure 4 A schematic diagram of a mold 36 with a support structure 38 is shown, which supports the reinforcing element 24 during manufacturing by casting technology. The mold 36 has a gating section 40 arranged on the upper side. Liquid metal, particularly liquid aluminum, flows into the mold 36 via the gating section 40 and flows around the reinforcing element 24.

[0031] During this process, the liquid metal flows to the support structure 38 only when the casting process is nearing completion and the mold 36 is essentially filled with liquid metal. The support structure 38 can be made of cast metal material, so that after the support structure 24 has been firmly supported from above, the sides and partly below by solidified material, the support structure 38 will be melted and fused together with the same liquid metal.

[0032] Alternatively, the support structure 38 can also be designed as a lost-wax core or a removable mold core, which can be removed after the casting process is complete. In the latter case, after demolding and removing the mold core, a through hole will remain in the area where the support structure 38 is located; even after the front or rear of the vehicle is manufactured, the support structure 38 can still be directly observed and touched through this through hole.

[0033] The technical features of the present invention disclosed in this specification, drawings, and claims can be used individually or in any combination to achieve various embodiments of the present invention. The present invention can be modified within the scope of the claims and in conjunction with common knowledge known to those skilled in the art.

[0034] Reference Symbol List

[0035] 10 vehicles

[0036] Rear of 12 vehicles

[0037] 14 First round cover element

[0038] 16 Second Round Cover Components

[0039] 18 First crossbeam

[0040] 20 Second crossbeam

[0041] 22 matrix

[0042] 24 reinforcing elements

[0043] 26 stretch metal

[0044] 28 materials

[0045] 30 nodes

[0046] 32 Perforated Plate

[0047] 34-channel opening

[0048] 36 casting molds

[0049] 38 Support Structure

[0050] 40 casting sections

Claims

1. A front or rear section of a vehicle having at least two wheel arch elements (14, 16) and at least one crossbeam (18, 20) connecting the wheel arch elements (14, 16), the wheel arch elements and the crossbeam forming a substrate (22) made of a lightweight metal material, characterized in that, At least one reinforcing element (24) made of stretched metal (26) or metal plate is embedded in at least one wheel cover element (14, 16) and / or crossbeam (18, 20) of the matrix by casting technology.

2. The front or rear portion of a vehicle according to the preceding claim, characterized in that, The at least one reinforcing element (24) is made of a material that is heated by contact with a liquid light metal when the matrix is ​​manufactured using a casting process, and undergoes a strength-enhancing effect during the subsequent cooling process.

3. The front or rear portion of a vehicle according to any one of the preceding claims, characterized in that, The at least one reinforcing element (24) is made of air-hardened steel and / or medium manganese steel.

4. The front or rear portion of a vehicle according to any one of the preceding claims, characterized in that, The reinforcing element (24) is made of a material that undergoes a strength-enhancing effect when in contact with a liquid light metal material at a temperature of about 600°C to 1000°C and subsequently cooled.

5. The front end portion or the rear end portion according to any one of the preceding claims, characterized in that, The at least one reinforcing element (24) is a stretched metal (26) formed by cutting a metal sheet and alternately bending and / or stretching strips of material (28) in opposite directions.

6. The front or rear portion of a vehicle according to any one of the preceding claims, characterized in that, The at least one reinforcing element (24) is a planar element extending over a large portion of the width of the at least one crossbeam (18, 20) and / or an arcuate element extending at least over an arcuate subsection of the wheel cover element (14, 16).

7. The front or rear portion of a vehicle according to any one of the preceding claims, characterized in that, The at least one reinforcing element (24) is embedded on at least one side of the entire surface (preferably fully embedded, so as to be completely arranged within the substrate (22)).

8. The front or rear portion of a vehicle according to any one of the preceding claims, characterized in that, The reinforcing element (24) has a through hole (34) which is designed to be completely filled by the light metal material after being embedded by the casting technique.

9. A method for manufacturing a front or rear part (12) of a vehicle according to any one of claims 1 to 8, characterized in that, The reinforcing element (24) is held by a support structure (38) made of a light metal material, and the base (22) is subsequently made of a light metal material by casting at least partially around the reinforcing element (24), wherein the support structure (38) is delayed in melting during casting only when the reinforcing element (24) is fixed in its relative position within the front or rear (12) of the vehicle by the hardened light metal.

10. A method for manufacturing a front or rear part (12) of a vehicle according to any one of claims 1 to 8, characterized in that, The reinforcing element (24) is held by a casting core, which is lost or removed after the casting process.

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