DE102022125099A1 - Hybrid component for a motor vehicle component and method for producing a hybrid component - Google Patents

Abstract

The present invention relates to a method for producing a hybrid component (100) for a motor vehicle component, in particular for a front apron, for a rear apron, for a front panel, for a bumper or for a housing of a lighting device, at least comprising the following method steps in an unspecified order: - providing a metallic sheet metal component (1), in particular made of an aluminum or steel alloy, - inserting the sheet metal component (1) into an injection molding tool (201, 202), - injection molding a holding structure (2) made of a plastic, in particular a thermoplastic plastic, to form a positive connection with the sheet metal component (1) and/or to form a material connection by means of an adhesion promoter with the sheet metal component (1), - applying a protective varnish (3) to a decorative section (11) of the sheet metal component (1), wherein the sheet metal component (1) is received in the injection molding tool (201, 202) during application, - obtaining the hybrid component (100) and removal from the injection mold (201, 202).

Description

The present invention relates to a hybrid component for a motor vehicle component, in particular for a front apron, for a rear apron, for a front panel, for a bumper, an interior panel or for a housing of a lighting device, as well as a method for producing it.

STATE OF THE ART

In addition to purely technical requirements, visible components of motor vehicles must also meet aesthetic and design requirements. This applies, for example, to front and rear aprons, bumpers, front panels, which are used in electric vehicles in particular instead of a radiator grille, and lighting devices, in particular to sections of their housings that are visible from the outside. The technical functionality of the components relates in particular to their mechanical and thermomechanical properties, such as rigidity and fatigue strength or the distortion behavior during thermal load changes. In terms of aesthetic appearance, a metallic look is often required, i.e. a surface that corresponds to a metal in color and shine or also gives the typical impression of a rough, e.g. brushed, metal surface. In addition, it may be intended to provide the metallic-looking visible component surfaces with colored patterns as applications. In the current state of the art, plastic components, e.g. made of thermoplastics or thermosets, are generally used as construction elements and, in order to achieve the desired aesthetic appearance, the visible surfaces are provided with printed or otherwise appropriately designed films, e.g. by gluing or back-injection. The thermoplastics commonly used, particularly in unreinforced variants with a focus on decorative surface quality, have inappropriately low strengths and high thermal expansion coefficients. The fiber-reinforced thermoplastics known to increase strength, on the other hand, have less decorative suitability (no Class A surfaces) and expand anisotropically under thermal load due to a preferred orientation of the fibers caused by the manufacturing process.

The republished publication EP2021/067636 discloses a hybrid component for visible components of motor vehicles, comprising a metallic sheet metal component and a plastic support structure which is positively connected to the sheet metal component, wherein a decorative section of the sheet metal component has a color coating pattern with a dedicated aesthetic appearance. One problem is protecting the decorative section from wear caused by environmental influences in the practical operation of the associated motor vehicle. In the EP2021/067636 For this purpose, it is proposed to either anodize the decorative section or to apply a transparent plastic protective layer to it by injection molding. However, this solution does not guarantee sufficient scratch and weather resistance under all practical conditions. In addition, protection by overmolding the decorative section with a plastic can lead to undesirable deformation of the hybrid component due to different thermal expansion coefficients of the sheet metal component and the plastic applied to it.

DISCLOSURE OF INVENTION

It is the object of the present invention to propose a development of a hybrid component for a motor vehicle component and an expedient method for its production.

This object is achieved on the basis of a hybrid component according to claim 1 and a method according to claim 6. Advantageous developments of the invention are specified in the dependent claims.

The invention discloses a hybrid component for a motor vehicle component, in particular for a front apron, for a rear apron, for a front panel, for a bumper, an interior panel or for a housing of a lighting device, at least comprising a metallic sheet metal component, in particular made of an aluminum or steel alloy, and a holding structure made of a plastic, in particular a thermoplastic, which is positively connected to the sheet metal component, with a protective lacquer being applied to a decorative section of the sheet metal component.

The sheet metal component is the central element of the hybrid component, as it has extremely useful mechanical and thermomechanical properties on the one hand and on the other hand creates the desired metallic appearance per se. The decorative section is the area of the sheet metal component that is visible to an outside observer in the intended installation position of the hybrid component on the motor vehicle. The support structure is intended to connect the hybrid component to a motor vehicle and/or to provide additional stiffening of the hybrid component. The support structure can have several sections that are not connected to one another. In terms of thermomechanical properties, the hybrid component is characterized by the low, isotropic and fully reversible thermal expansion of the sheet metal component, whereby the comparatively small-sized plastic support structure contributes only slightly to thermal distortion in absolute terms. The protective varnish protects the decorative section from wear caused by abrasion, erosion, weathering and/or UV radiation during operation of the associated motor vehicle. The protective varnish is based, for example, on polyurethane, polyurea or is designed as an inorganic-organic hybrid varnish. The protective varnish is in particular optically transparent, so that the underlying surface of the decorative section is visible. Alternatively, the protective varnish can be translucent or opaque and/or contain dye pigments and/or functional fillers (e.g. electrically conductive fillers as powder or in the form of nanoparticles, nanotubes, nanowires) in order to make an additional or separate design contribution to the appearance or to the further functionalization of the hybrid component (e.g. heating or darkening). In addition to the primary protective function, the protective varnish can optionally have other technical functionalities, for example be designed to be dedicatedly hydrophilic, lipophobic or hydrophobic, or have an anti-dirt or anti-ice effect. The thickness of the applied layer of protective varnish is preferably 20 micrometers to 3 millimeters.

In an exemplary embodiment of the hybrid component according to the invention, the decorative section has at least in sections a decorative pattern that is applied under the protective varnish. The decorative pattern is designed as a color coating pattern of any design or a sticker, whereby such a pattern can also form, for example, a monochrome, in particular translucent coloring of the entire surface of the decorative section.

In a further embodiment, the sheet metal component has at least one opening, in particular in the decorative section, the opening being provided in particular as a sensor window or for backlighting the hybrid component. For example, the opening can be designed to accommodate a radome.

In particular, a cover plate can be inserted into the opening, the cover plate preferably being integrally connected to the support structure. In a further embodiment, a metal grid is arranged on or in the cover plate, in particular an expanded metal sheet or a metal wire grid. The metal grid is, for example, overmolded by the cover plate or connected by means of gluing or welding. The cover plate, in particular made of a plastic, and with certain restrictions also an open-pore metal grid, is permeable to radio waves or light and can thus function, for example, as a radar window for a vehicle radar device to be arranged behind it or as a camera window. The use of a metal grid covering the opening expands the design freedom of the hybrid component. The cover plate is, for example, heated on the surface during injection molding of the support structure, forming an integral connection with the support structure.

• - Bereitstellen des metallischen Blechbauteils, insbesondere aus einer Aluminium- oder Stahllegierung,
• - Einlegen des Blechbauteils in ein Spritzgusswerkzeug,
• - Spritzgießen der Haltestruktur aus einem Kunststoff, insbesondere einem thermoplastischen Kunststoff, unter Bildung einer formschlüssigen Verbindung mit dem Blechbauteil und/oder unter Bildung einer stoffschlüssigen Verbindung mittels eines Haftvermittlers mit dem Blechbauteil,
• - Applizieren eines Schutzlacks auf den Dekorabschnitt des Blechbauteils, wobei das Blechbauteil während des Applizierens in dem Spritzgusswerkzeug aufgenommen ist,
• - Erhalt des Hybridbauteils und Entnahme aus dem Spritzgusswerkzeug.

The invention also relates to a method for producing the hybrid component, at least comprising the following method steps in an unspecified order:

• - Providing the metallic sheet metal component, in particular made of an aluminum or steel alloy,
• - inserting the sheet metal component into an injection molding tool,
• - Injection molding of the holding structure from a plastic, in particular a thermoplastic, to form a positive connection with the sheet metal component and / or to form a material connection by means of an adhesion promoter with the sheet metal component,
• - applying a protective varnish to the decorative section of the sheet metal component, the sheet metal component being received in the injection molding tool during application,
• - Receipt of the hybrid component and removal from the injection molding tool.

According to the invention, the injection molding of the holding structure and the application of the protective lacquer are carried out in a single injection molding tool. The order of these two process steps is in principle arbitrary. Compared to a traditional approach, which would involve applying the protective lacquer in a separate process step outside the injection molding tool in a separate painting device, the process according to the invention can significantly shorten the production time.

In a first embodiment of the method according to the invention, the injection molding tool is designed in such a way that when the sheet metal component is inserted, a cavity is formed between the decorative section and the injection molding tool, the cavity being flooded with the protective lacquer when the protective lacquer is applied. For this purpose, the injection molding tool has a suitable channel system for passing the protective lacquer from a lacquer injection device into the cavity. When the cavity is flooded, the decorative section is completely wetted with the protective lacquer and hardening occurs through heating in the injection molding tool. of the protective varnish to form the desired protective layer on the decorative section.

Alternatively, the injection molding tool can be provided with a displaceable mold core, for example, wherein the mold core is displaced before the application of the protective lacquer in such a way that a cavity is formed between the decorative section of the sheet metal component and the mold core, wherein the cavity is flooded with the protective lacquer when the protective lacquer is applied. The cavity can be created in the injection molding tool alternatively by transferring the component into a second cavity or rotating or turning it to a second cavity. These embodiments are useful, for example, to protect the surface of the sheet metal component from undesirable deformation during injection molding of the holding structure. The holding structure is typically molded onto the side of the sheet metal component opposite the decorative section, so that the mold core stabilizes the sheet metal component against the injection pressure.

In a further embodiment, a transfer film coated with the protective lacquer is placed in the injection molding tool before the sheet metal component is inserted, whereby when the protective lacquer is applied, the protective lacquer is transferred from the transfer film to the decorative section of the sheet metal component. The protective lacquer is in a partially hardened state on the transfer film and by pressing the sheet metal component when the injection molding tool is closed, the protective lacquer is transferred to the decorative section, where it hardens when the sheet metal component is heated in the injection molding tool, forming the desired protective layer. The transfer film can be removed without leaving any residue after the hybrid component has been removed from the injection molding tool.

Furthermore, it can be provided that before the sheet metal component is placed in the injection mold, a decorative pattern is applied at least in sections to the decorative section of the sheet metal component, in particular by means of anodizing, inkjet printing, piezo inkjet printing, pad printing, screen printing, painting, applying a paint film, masking-free, selective application methods or by applying a film or a sticker. The decorative pattern is then covered by the applied protective paint. Furthermore, the decorative section of the sheet metal component can be subjected to a surface finishing beforehand.

In a further embodiment, the sheet metal component is provided with at least one opening, in particular in the decorative section, and with a cover plate inserted therein, wherein during injection molding of the holding structure, a material-locking connection of the holding structure to the cover plate and the metal grid is preferably formed. For example, the cover plate can be provided with a metal grid arranged on it or in it, in particular an expanded metal sheet or a metal wire grid.

Furthermore, it can be provided within the scope of the method according to the invention that the sheet metal component is deformed at least in sections when the injection molding tool is closed and/or when the holding structure is injection molded. In this embodiment, the injection molding tool acts like a press or the injected plastic acts as an active medium for forming the sheet metal component. The final contour of the sheet metal component is therefore only obtained after injection molding, and the sheet metal component can be provided as a flat or only partially formed semi-finished product. For example, the injection molding tool can be provided with exchangeable inserts, the inserts being designed to deform the semi-finished product into different geometries.

PREFERRED EMBODIMENTS OF THE INVENTION

• 1a - 1 d eine Illustration des erfindungsgemäßen Verfahrens in einer ersten Ausführungsform,
• 2a - 2d eine Illustration des erfindungsgemäßen Verfahrens in einer zweiten Ausführungsform,
• 3, 4 Frontansichten eines Blechbauteils für ein erfindungsgemäßes Hybridbauteil,
• 5a, 5b Front- und Rückansicht eines erfindungsgemäßen Hybridbauteils in einer ersten Ausführungsform,
• 6 eine Frontansicht eines weiteren Blechbauteils für ein erfindungsgemäßes Hybridbauteil, und
• 7 eine Frontansicht eines erfindungsgemäßen Hybridbauteils in einer zweiten Ausführungsform.

Further measures improving the invention are shown in more detail below together with the description of preferred exemplary embodiments of the invention with reference to the figures. It shows:

• 1a - 1d an illustration of the method according to the invention in a first embodiment,
• 2a - 2d an illustration of the method according to the invention in a second embodiment,
• 3 , 4 Front views of a sheet metal component for a hybrid component according to the invention,
• 5a , 5b Front and rear view of a hybrid component according to the invention in a first embodiment,
• 6 a front view of another sheet metal component for a hybrid component according to the invention, and
• 7 a front view of a hybrid component according to the invention in a second embodiment.

1a - 1d show schematic cross-sectional views to illustrate the method according to the invention for producing a hybrid component 100 in a first embodiment. The injection molding tool 201 is provided with the paint injection device 300, and when the sheet metal component 100 is inserted into the injection molding tool 201, a cavity 30 is created between the decorative part section 11 and the injection molding tool (200) ( 1a) , wherein the cavity 30 is connected to the paint injection device 300 via a suitable channel system. Following the closing of the injection molding tool 201, 1 b the application of the protective lacquer 3 to the decorative section 11 of the sheet metal component 1, for which purpose the cavity 30 is flooded with the protective lacquer 3 while the sheet metal component 1 is accommodated in the injection molding tool 201. 1c shows the injection molding of the holding structure 2 from a plastic by means of the plastic injection devices 400. The holding structure 2 here comprises, for example, two sections that are not connected to one another, each of which forms a positive connection with the sheet metal component 1. The previously applied protective lacquer 3 advantageously already has a protective effect for the decorative section 11 against the tool surface during the injection molding of the holding structure 2.

The procedural steps of the 1 b and 1c In principle, they can also be carried out in reverse order. Care must be taken to ensure that the sheet metal component is not deformed during injection molding of the holding structure, unless such a deformation is specifically intended. In particular, the injection molding tool can have a displaceable mold core, which is displaced before the protective lacquer is applied in such a way that a cavity is formed between the decorative section of the sheet metal component and the mold core. The cavity can alternatively be created in the injection molding tool by moving the component into a second cavity or rotating or turning it into a second cavity.

After the protective lacquer 3 and the support structure 2 have hardened, the manufactured hybrid component 100 ( 1d ) from the injection molding tool 201.

2a - 2d show schematic cross-sectional views to illustrate the method according to the invention for producing a hybrid component 100 in a second embodiment. 2a shows the insertion of the transfer film 7 coated with the protective lacquer 3 into the injection molding tool 202, the protective lacquer 3 being in a partially hardened, transferable state. 2 B shows the insertion of the sheet metal component 1 into the injection molding tool 202, with the decorative section 11 of the sheet metal component 1 being applied flatly to the protective lacquer 3 adhering to the transfer film 7. Following the closing of the injection molding tool 202 shows 2c the injection molding of the holding structure 2 made of a plastic by means of the plastic injection devices 400. Under the heating and pressure of the closed injection molding tool 202, the protective lacquer 3 is transferred to the decorative section 11. After the protective lacquer 3 and the holding structure 2 have hardened, this is manufactured hybrid component 100 ( 2d ) is removed from the injection molding tool 202 and the transfer film 7 is removed.

3 shows a front view of a sheet metal component 1 for use for a hybrid component according to the invention. The front side of the sheet metal component 1 forms the decorative section 11, which is visible to a viewer from the outside in a proper installation position as part of a front apron of a motor vehicle. The sheet metal component 1 preferably consists of an aluminum or steel alloy and has a thickness of, for example, 1-2 mm. The sheet metal component 1 can have been formed by a conventional forming process, for example a punching-bending process, or also when closing the injection molding tool as part of the manufacturing process according to the invention. The sheet metal component 1 has the opening 5 in the decorative section 11, which is provided, for example, as a sensor window for a radar sensor to be arranged behind it.

4 shows the sheet metal component 1 of the 3 , wherein a cover plate 6 that is transparent to radio waves, for example made of polycarbonate, is inserted into the opening 5. For further handling, the cover disk 6 can be attached to the sheet metal component 1 by means of temporary pre-fixation.

5a and 5b show a front and rear view of a first embodiment of the hybrid component 100 according to the invention, in which the various sections of the plastic holding structure 2 were positively connected to the sheet metal component 1 by means of injection molding. The protective varnish 3, which in particular represents a wear protection layer, is applied to the decorative section 11 on the front side of the sheet metal component 1. The holding structure 2 comprises the rib-shaped stiffening structures 21 and the connecting means 22 in the form of screw domes at the rear. The stiffening structures 21 counteract a bending of the sheet metal component 1 and the connecting means 22 serve to connect the hybrid component 100 to a motor vehicle component. The cover plate 6 is positively connected to the holding structure 2 and is integrated into the hybrid component 100 via this.

6 shows the sheet metal component 1 of the 4 , whereby the decorative pattern 4 was applied to the decorative section 11, which is exemplified here as a printed lettering “TURBO”. 7 shows a second embodiment of the hybrid component 100 according to the invention based thereon, in which the protective lacquer 3 was applied to the decorative section 1 following the decorative pattern 4, so that the protective effect of the protective lacquer 3 also extends to the decorative pattern 4.

The implementation of the invention is not limited to the preferred exemplary embodiment given above. Rather, a number of variants are conceivable, which make use of the solution presented even in fundamentally different designs. All features and/or advantages arising from the claims, the description or the drawings, including constructive details, spatial arrangements and method steps, can be essential to the invention both individually and in a wide variety of combinations.

List of reference symbols

100

Hybrid component

1

Sheet metal component

2

Support structure

21

Stiffening structure

22

lanyard

3

Protective varnish

4

Decorative patterns

5

opening

6

Cover disc

7

Carrier film

201, 202

Injection molding tool

300

Paint injector

400

Plastic injection device

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2021/067636 PCT [0003]

Claims (12)

Hybrid component (100) for a motor vehicle component, in particular for a front apron, for a rear apron, for a front panel, for a bumper, for an interior panel or for a housing of a lighting device, comprising at least one metallic sheet metal component (1), in particular made of aluminum or Steel alloy, and a holding structure (2) made of a plastic, in particular a thermoplastic, which is positively connected to the sheet metal component (1), wherein a protective lacquer (3) is applied to a decorative section (11) of the sheet metal component (1). Hybrid component (100) according to Claim 1 , characterized in that the decorative section (11) has at least in sections a decorative pattern (4) which is applied under the protective varnish (3). Hybrid component (100). Claim 1 or 2 , characterized in that the sheet metal component (1) has at least one opening (5), in particular in the decorative section (11), the opening being provided in particular as a sensor window or for backlighting the hybrid component (100). Hybrid component (100) according to Claim 3 , characterized in that a cover plate (6) is inserted into the opening (5), wherein the cover plate (6) is preferably materially connected to the holding structure (2). Hybrid component (100). Claim 4 , characterized in that a metal grid is arranged on or in the cover plate (6), in particular an expanded metal sheet or a metal wire grid. Method for producing a hybrid component (100) for a motor vehicle component, in particular for a front apron, for a rear apron, for a front panel, for a bumper or for a housing of a lighting device, at least comprising the following method steps in an unspecified order: - providing a metallic sheet metal component (1), in particular made of an aluminum or steel alloy, - inserting the sheet metal component (1) into an injection molding tool (201, 202), - injection molding a holding structure (2) made of a plastic, in particular a thermoplastic plastic, to form a positive connection with the sheet metal component (1) and/or to form a material connection with the sheet metal component (1) by means of an adhesion promoter, - applying a protective varnish (3) to a decorative section (11) of the sheet metal component (1), wherein the sheet metal component (1) is received in the injection molding tool (201, 202) during application, - obtaining the hybrid component (100) and removal from the injection mold (201, 202). Procedure according to Claim 6 , characterized in that when the sheet metal component (1) is inserted into the injection molding tool (201), a cavity (30) is formed between the decorative section (11) and the injection molding tool (201), wherein the cavity (30) is flooded with the protective lacquer (3) when the protective lacquer (3) is applied. Procedure according to Claim 6 , characterized in that the injection molding tool is provided with a displaceable mold core, wherein the mold core is displaced before the application of the protective lacquer (3) such that a cavity is formed between the decorative section (11) of the sheet metal component (1) and the mold core, wherein the cavity is flooded with the protective lacquer (3) when the protective lacquer (3) is applied. Procedure according to Claim 6 , characterized in that before inserting the sheet metal component (1), a transfer film (7) coated with the protective lacquer (3) is inserted into the injection molding tool (202), wherein during application of the protective lacquer (3) the protective lacquer (3) is transferred from the transfer film (7) to the decorative section (11) of the sheet metal component (1). Method according to one of the Claims 6 until 9 , characterized in that before the sheet metal component (1) is inserted into the injection molding tool (201, 202), a decorative pattern (4) is applied at least in sections to the decorative section (11) of the sheet metal component (1), in particular by means of anodizing gravure printing, inkjet printing, piezo inkjet printing, pad printing, screen printing, painting, application of a paint film, masking-free, selective application methods or by applying a film or a sticker. Procedure according to one of the Claims 6 until 10 , characterized in that the sheet metal component (1) is provided with at least one opening (5), in particular in the decorative section (11), and with a cover disk (6) inserted therein, with the holding structure (2) preferably being injection molded with a cohesive connection Holding structure (2) is formed with the cover disk (6). Method according to one of the Claims 6 until 11 , characterized in that the sheet metal component (1) during closing of the injection molding tool (201, 202) and/or during injection molding of the holding structure (2) is deformed at least in sections.

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