Molded component, connecting arrangement with a molded component and method for producing a molded component

Abstract

A molded component (2) comprises a metallic component body (5) with an assembly opening (6) and a friction structure (7) surrounding the assembly opening. The component body (5) is made of boron-alloyed steel and is hot-formed and press-hardened. The friction structure (7) is created in the press tool during hot-forming. At the same time, the assembly opening (6) is created in the component body (5).

Description

[0001] The invention relates to a molded component and a connecting arrangement with such a molded component and a method for producing a molded component.

[0002] Molded components with a metallic component body that are connected to another molded component or an assembly element within a connecting arrangement are used in a wide variety of commercial and industrial applications.

[0003] Molded components made of metal or sheet steel are used particularly in automotive engineering, for example in the form of body components or structural components. These molded components are often combined with other molded components and / or add-on components to form an assembly or automotive component.

[0004] The molded parts and components are typically connected using screw connections. Screws are inserted into or through mounting holes and clamped against each other. Depending on the application, this is done by incorporating washers. A washer, placed between the screw head and the component body to be fastened with the screw, serves to distribute and transfer the force emanating from the underside of the screw head over a larger area of the component body. For through-bolts, a washer is also provided under the locking nut, depending on the application.

[0005] Automotive components are subject to severe static and dynamic loads during operation. High-quality automotive components, their assembly, and especially the connection points of or between the molded components, are therefore essential, especially when it comes to chassis or body components. For screw-connected automotive components, a good, slip-proof connection between the components and other connection points is essential.

[0006] Conventional separate washers don't offer the best conditions for this. Their installation is also complex.

[0007] There are also suggestions to dispense with washers and to profile the surface of at least one component in the area of the clamping surface of a press connection.

[0008] DE 10 2012 022 504 A1 discloses a press connection between two components. The components have adjacent connecting surfaces that are joined together under pressure, at least one of which is provided with a surface structure to increase the coefficient of friction. The surface structure is produced and hardened using a laser process or an embossing or cold-pressing process. Hardening can be carried out inductively or by laser or electron beam processes.

[0009] DE 10 2007 016 643 A1 describes a force-locking clamping connection and a method for its production as state-of-the-art. The force-locking clamping connection comprises a first metallic clamping surface, a second metallic clamping surface, and a clamping element for clamping the clamping surfaces against each other. The first clamping surface forms a hardened fine surface structure with micro-elevations and depressions and is preferably surface-treated by sandblasting, shot peening, or embossing before hardening.

[0010] DE 10 2013 004 034 A1 discloses a forming tool for hot forming and / or press hardening with at least one cutting punch for creating a recess in the still warm sheet material.

[0011] DE 101 49 221 C1 discloses a method for producing a hardened sheet metal profile from an optionally preformed blank.

[0012] Further prior art is formed by US 2017 / 0009444 A1, which discloses a connection between a connector, a fastening element and one or more components, wherein the connector can be formed with a fastening and alignment element.

[0013] Known connection point designs with mechanically generated surface structures in the connection or clamping area between joining partners have proven themselves in practice and are well suited for various applications. However, there is also potential for improvement in both the functionality of the connection points and the rationality of the molded components and the connection arrangements with such molded components. There is also a general effort to design the molded components, including their connection points, in an effective lightweight construction.

[0014] Based on the prior art, the invention is based on the object of improving a molded component with a metallic component body and a friction structure in terms of production technology and functionality, of demonstrating a connection arrangement with such a molded component and of creating a rational and advantageous method for producing molded components.

[0015] The solution to the objective part of the problem consists in a shaped component according to claim 1.

[0016] A connecting arrangement with a shaped component according to the invention is the subject of claim 6.

[0017] The process engineering part of the problem is solved by a method for producing a molded component according to claim 7.

[0018] Embodiments and modifications of features of the molded component, as well as of process steps which, individually or in combination, technically advantageously design or further develop the invention, also emerge from the description and the accompanying drawings.

[0019] The molded component according to the invention comprises a metallic component body with a mounting opening and a friction structure surrounding the mounting opening. The friction structure is embossed and hardened.

[0020] According to the invention, the component body consists of a hardenable steel and is hot-formed and press-hardened, wherein the friction structure is produced during hot-forming of the component body, in particular by embossing.

[0021] The friction structure is stamped in the press tool by material displacement on the steel sheet heated to hot forming temperature, resulting in raised and / or recessed portions of the friction structure. The component body and the friction structure created on the component body are clamped in the cooled press tool and hardened by cooling.

[0022] The molded component, or rather its metallic component body, is made of hardenable steel. The friction structure is created as a single piece on the component body. This is achieved by stamping in the press tool during the forming and stamping process of the component body.

[0023] In particular, the hardenable steel is a boron-alloyed steel, preferably a manganese-boron steel, for example 22MnB5.

[0024] The friction structure has friction elements produced by embossing.

[0025] Particularly advantageous are friction elements in the form of ribs that extend radially outward from a mounting opening. The ribs have an average height of 0.05 to 0.9 mm, in particular 0.1 to 0.4 mm, measured along their length.

[0026] The friction elements can be rib-shaped, wave-shaped, point-shaped, or ball-shaped. The friction elements can surround the mounting opening completely or in sections.

[0027] The friction structure is designed and intended to increase the friction between the joining partners or the clamping surfaces within a connection arrangement. The spatial design and arrangement of the friction elements within the friction structure is tailored to the connection point within a connection arrangement.

[0028] The friction structure can comprise embossed ribs with an annular configuration. The annular friction elements can be arranged concentrically around the mounting opening.

[0029] Particularly advantageously, the friction structure features friction elements produced by stamping in the form of ribs that extend radially outward from the mounting opening. In particular, the ribs run radially, i.e., they have a radial pattern with respect to the center of a mounting opening. The ribs are raised above the areas adjacent to the ribs. The ribs provide the necessary friction and are subject to high loads when the molded component is clamped within a connecting arrangement. In this context, the friction structure produced in the press tool and press-hardened proves advantageous.

[0030] A friction structure that is advantageous in practice has a hardness (Vickers hardness) of 350 HV to 550 HV, in particular 400 HV to 500 HV.

[0031] In a practically advantageous embodiment of the molded component, the component body has a wall thickness of between 1.0 mm and 3.5 mm.

[0032] To produce a molded part according to the invention, a hardenable steel sheet or a semi-finished product made of a hardenable steel sheet, in particular a sheet made of a manganese-boron steel, is hot-formed in a press tool to form a component body and press-hardened. During hot-forming in the press tool, an area of the steel sheet is provided with a friction structure. This is achieved in the press tool by embossing.

[0033] The area with the friction structure is embossed around an assembly opening.

[0034] The assembly opening is particularly preferably produced during hot forming in the press tool.

[0035] The production of the friction structure and the production of the assembly opening preferably takes place in parallel in the press tool.

[0036] The formed component is manufactured by hot stamping from a preformed steel sheet, if necessary. This hot stamping process is referred to in technical terms as press hardening. In press hardening or hot stamping, a sheet of manganese-boron steel is heated to a temperature above the specific austenitizing temperature of the steel material, placed in a press tool, and hot-formed into the formed component, cooling during the forming process. Clamped in the press tool, the formed component is hardened by cooling.

[0037] In particular, the steel sheet or semi-finished product is heated to a temperature above 750°C for hot forming, in particular to a temperature above the Ac3 temperature of the hardenable steel.

[0038] A molded component according to the invention is, in particular, a motor vehicle component. A molded component can be used as a component of an axle, an axle component, or an axle body, for example, a subframe or an assembly carrier.

[0039] A motor vehicle component can be manufactured from steel, preferably from interconnected shell-shaped molded components, at least one of which is designed according to the invention and has connection points with mounting openings. At least one mounting opening has a friction structure surrounding the mounting opening, which is produced during hot forming of the component body and press-hardened with the component body in the press tool.

[0040] The invention advantageously integrates the production and hardening of the friction structure into the forming and hardening process of the component body. This is particularly effective and advantageous. The integration of the friction structure into the component body and the press-hardening process also optimizes the component weight. Additional washers or surface structures created by material deposition are eliminated. This contributes to lightweight construction.

[0041] To reduce weight, especially in battery-electric vehicles, parts of the body shell are increasingly being manufactured as hot-formed parts. Their higher strength allows for material and thus weight savings. According to the invention, the friction structure is embossed into the component body during the hot-forming process and hardened simultaneously with the component body through cooling in the press tool.

[0042] When the molded component is used within a connection arrangement, it is assembled or mounted with other molded components and / or add-on components. This is done via screw connections. When assembling a molded component according to the invention with a counterpart or joining partner, particularly a softer one, such as an axle carrier, the friction structure can dig into the counterpart or the second joining partner.

[0043] Within the scope of the invention, the process steps of hot forming and embossing a friction structure, as well as its hardening, are combined in a single process step and in a single press tool. Subsequent hardening of the friction structure is not necessary. The process achieves hardnesses in the range of 350 to 550 HV, in particular 400 to 500 HV. The friction structure preferably has a homogeneous hardness distribution, which also transitions evenly into the area surrounding the friction structure. This avoids critical mechanical notches and, while ensuring high wear protection, prevents the risk of cracks or component breakage. Within the scope of the invention, a homogeneous hardness distribution within the friction structure is to be understood as meaning that the hardness therein preferably does not fluctuate by more than 100 HV, in particular by less than 50 HV.Likewise, the hardness of the friction structure preferably does not differ by more than 100 HV from the hardness of surrounding areas.

[0044] The invention is further described below using an exemplary embodiment. In the drawings: Fig. 1 a motor vehicle component in the form of a subframe in a perspective view; Fig. 2 a section of the motor vehicle component with the representation of a connection point in the motor vehicle component and Fig. 3 technical schematically shows a section of a friction structure on the motor vehicle component.

[0045] Fig. 1 shows a perspective view of a motor vehicle component 1 in the form of a subframe.

[0046] The motor vehicle component 1 is designed as a sheet metal shell construction and has a first shell-shaped molded component 2 and a second shell-shaped molded component 3. Furthermore, the motor vehicle component 1 has lateral dome elements 4. The molded components 2 and 3 as well as the dome elements 4 are designed as sheet metal molded parts and joined to the motor vehicle component 1.

[0047] The first molded component 2 has a component body 5 with mounting openings 6, which are provided as connection points.

[0048] The assembly openings 6 in the component body 5 of the first molded component 2 are surrounded by a friction structure 7. The friction structure 7 has elevations and depressions. The friction structure 7 is produced by stamping as a single piece on or in the component body 5 using a uniform material. This takes place during the hot-forming production of the component body 5 in a press tool. During the hot-forming process, the friction structure 7 is stamped into an area of the component body 5 that surrounds an assembly opening 6. Clamped in the press tool, the component body 5 with the friction structure 7 is press-hardened in the press tool.

[0049] A section through the motor vehicle component 1 in the area of a connection point with a mounting opening 6 and a friction structure 7 is shown in the illustration of the Fig. 2.

[0050] The assembly opening 6 is provided in the component body 5 of the first shell-shaped molded component 2 and is radially surrounded by the friction structure 7. The lower second molded component 3 has an assembly opening 8. A sleeve body 9 is arranged below the upper assembly opening 6 in the first molded component 2. The through-opening 10 of the sleeve body 9 communicates with the upper assembly opening 6. The sleeve body 9 penetrates the lower assembly opening 8 and is integrally joined to both the first molded component 2 and the second molded component 3.

[0051] The friction structure 7 completely surrounds the assembly opening 6 in the component body 5 of the first molded component 2 in a ring or wreath shape.

[0052] An enlarged section of a friction structure 7 is shown in the Fig. 3 shown.

[0053] The friction structure 7 has friction elements in the form of ribs 11 produced by embossing in the press tool during the formation of the component body 5. The ribs 11 extend outwards from the mounting opening 6. The friction structure 7 has a plurality of radially arranged, straight ribs 11 which run from radially inward to radially outward with respect to the mounting opening 6. A rib 11 is triangular in cross-section and widens towards its base. The straight flanks 12 of a rib 11 are at an angle to one another and open into a rib crest 13. The ribs 11 have an average height H, measured over their length, of 0.1 to 0.4 mm, in particular of approximately 0.3 mm.

[0054] The mounting opening 6 in the component body 5 of the molded component 2 is created during hot forming of the component body 5 in the press tool. To produce the molded component 2, a sheet made of a boron-alloyed steel, in particular a manganese-boron steel, or a semi-finished product pre-formed from the sheet is heated to a temperature above the specific austenitizing temperature of the boron-alloyed steel material. The steel sheet or the semi-finished product is then placed in a press tool and hot-formed between an upper tool and a lower tool of the press tool to form the molded component. In this process, the mounting opening 6 is created in the component body 5, and the friction structure 7 is embossed in the area surrounding the mounting opening 6 in the component body 5. During forming, the component body 5 is clamped in the press tool, and the molded component is hardened by cooling.

[0055] It is understood that the second shell-shaped molded component 3 can also be produced by mold or press hardening. Here, too, the mounting opening 8 in the press tool and, if appropriate, a friction structure 7 surrounding the mounting opening 8 can be produced and hardened by stamping in the press tool.

[0056] The friction structure 7 has a hardness, determined by the Vickers hardness test, of 350 HV to 550 HV, in particular 400 HV to 500 HV. Since the component body 5 and the friction structure 7 on the component body 5 are produced by form hardening or press hardening during the manufacture of the molded component, the component body 5 of the molded component 2 also has a corresponding hardness in the range between 350 HV and 550 HV, in particular 400 HV to 500 HV.

[0057] The friction structure 7 increases the friction in the surface area surrounding a mounting opening 6, thereby ensuring better and more lasting retention of the screw elements used for assembly and the resulting screw connection, even under heavy static and dynamic loads during operational use in a motor vehicle. Reference symbols: 1 motor vehicle component 2 first mold component 3 second mold component 4 dome element 5 component bodies 6 Mounting opening 7 Friction structure 8 Mounting opening 9 sleeve body 10 passage opening 11 rib 12 flank 13 Costal crest H average height of 11

Claims

[1] A molded component comprising a metallic component body (5) with a mounting opening (6) and a friction structure (7) surrounding the mounting opening (6), wherein the friction structure is designed and intended to increase the friction between the joining partners or the clamping surfaces within a connection arrangement, wherein the friction structure (7) is embossed and hardened, characterized by that the component body (5) consists of a hardenable steel and is hot-formed, wherein the friction structure (7) is produced and the component body (5) is press-hardened, wherein the friction structure (7) has friction elements produced by embossing. [2] Shaped component according to claim 1, characterized by that the friction elements are configured in a rib-shaped, wave-shaped, point-shaped or ball-shaped manner. [3] Shaped component according to one of claims 1 or 2, characterized bythat the friction structure (7) has a hardness of 350 HV to 550 HV, in particular 400 HV to 500 HV. [4] Shaped component according to one of claims 1 to 3, characterized by that the component body (5) has a wall thickness of between 1.0 mm and 3.5 mm inclusive. [5] Shaped component according to one of claims 1 to 4, characterized by that the component body (5) consists of a boron-alloyed steel. [6] Connecting arrangement with a shaped component according to one of claims 1 to 5. [7] Method for producing a shaped component, wherein a hardenable steel sheet or a semi-finished product made of a hardenable steel sheet is hot-formed and press-hardened in a press tool to form a component body (5), characterized bythat during hot forming in the press tool, an area of the steel sheet is provided with a friction structure (7) having friction elements by embossing, wherein the friction structure (7) is designed and intended to increase the friction between the joining partners or the clamping surfaces within a connection arrangement [8] Method according to claim 7, characterized by that the area with the friction structure (7) is created around a mounting opening (6). [9] Method according to claim 8, characterized by that the mounting opening (6) is created during hot forming. [10] Method according to claim 8 or 9, characterized by that the production of the friction structure (7) and the production of the assembly opening (6) in the press tool are carried out in parallel. [11] Method according to one of claims 7 to 10, characterized bythat the steel sheet or semi-finished product is heated for hot forming to a temperature T above 750 °C, in particular to a temperature above the Ac3 temperature of the hardenable steel.

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