Exterior paneling for a motor vehicle, method for its production and motor vehicle with such a paneling

Abstract

Exterior paneling (10) for a motor vehicle, characterized by the following features: - the outer cladding (10) has a surface layer of a base material (11), - the outer cladding (10) bears a lettering made of a decorative material (12) and - the outer cladding (10) is designed to illuminate the lettering (12).

Description

[0001] The present invention relates to an exterior panel for a motor vehicle. The present invention also relates to the manufacture thereof and a corresponding motor vehicle. State of the art

[0002] In the manufacture of motor vehicles, especially sports cars, it is common practice to embed the model name or manufacturer's name on plastic exterior components. Such lettering, often in the form of embossing, is often considered an essential element of brand identity and a means of emphasizing the vehicle's sporty character.

[0003] The model designation or manufacturer's name is usually applied to the plastic attachments directly during the manufacturing process. Specifically, the designation is embedded in the injection mold of the plastic component, making it non-die-cut. This means that the designation is molded directly into the plastic of the attachment during the injection molding process.

[0004] The visibility of the embossed lettering depends heavily on various factors, such as its surface texture and depth. The latter, in particular, significantly determines how the lettering stands out from the surface of the component and the strength of the shadow effect along the lettering.

[0005] It is common practice for both the lettering and the surrounding material of the attachment to be in the same color, as the lettering is inserted directly into the plastic of the attachment and is therefore made of the same material.

[0006] WO 2019214994 A1 discloses a translucent exterior component of a motor vehicle, in particular a spoiler, wherein the translucent exterior component has a base body made of a transparent material and a translucent coating applied to the base body.

[0007] DE 102019135491 A1 also discloses a translucent exterior component of a motor vehicle, which has a translucent base body and a translucent coating applied to the base body.

[0008] From EP 3632749 B1, a translucent exterior component of a motor vehicle is also known, which has a translucent base body and a translucent coating applied to the base body, wherein the coating has a perforation.

[0009] DE 102019217659 A1 discloses a trim element for a motor vehicle that is designed to provide a design area for individual customization of the motor vehicle. The design area comprises a translucent plastic layer and a translucent, actively illuminated raised structure. This allows for a three-dimensional appearance.

[0010] US 2023174170 A1 describes a transparent, actively illuminated rear spoiler of a motor vehicle.

[0011] JP10217280A discloses an injection molding process for producing a multicolored toothbrush.

[0012] A cast, two-tone decorative item is known from JP3472403B2.

[0013] From KR19980023964A a method for producing a three-dimensional, multi-colored emblem from epoxy resin is known.

[0014] EP1308259A2 describes a multi-stage injection molding process for producing a vehicle panel. Disclosure of the invention

[0015] One problem is that a significant contrast between the lettering and the surrounding plastic part is often difficult to achieve. The visibility and legibility of the lettering are often suboptimal and depend heavily on the lighting conditions and viewing angle.

[0016] One reason for this is that both the lettering and the surrounding plastic part are typically the same color. This often results in an effect referred to as "black eagle on a black background"—a metaphor that clearly illustrates the problem of a lack of contrast and the resulting poor visibility and legibility.

[0017] Furthermore, the surface texture of the attachment and the lettering itself can impair its visibility. In particular, the depth of the lettering, which is crucial for creating a shadow effect and thus increasing contrast, can be influenced by the surface texture.

[0018] The problem of the lack of visibility and legibility of the lettering is exacerbated by the fact that the lettering is an integral part of the brand identity and the sporty character of the vehicle. Poor visibility and legibility of the lettering can therefore negatively impact the brand image and the perception of the vehicle as a whole.

[0019] The described problem is solved by an outer panel for a motor vehicle, a method for its production and a motor vehicle according to the independent claims.

[0020] The invention offers an elegant solution to this problem by proposing the use of luminous lettering. This approach ensures high contrast that remains constant regardless of external lighting conditions or viewing perspective. While the basic component remains black, the lettering is implemented in a material that is either self-luminous or can be illuminated by an external light source. This concept not only significantly improves the visibility and legibility of the lettering but also offers attractive aesthetic possibilities for customizing and highlighting the vehicle's appearance.

[0021] The invention offers two particularly preferred embodiments. The first variant provides for the use of a self-luminous material for the lettering. Such materials can exhibit fluorescence (daylight glow), phosphorescence (afterglow), or retroreflection (reflection). In the second variant, the lettering consists of a transparent material that acts as a light guide and is illuminated by an external light source. The color of the light can be individually selected, and the light source can, for example, consist of one or more LEDs.

[0022] The invention goes beyond the current state of the art by enabling the implementation of illuminated lettering on exterior add-on components. Previously, such illuminated lettering and symbols were only known in vehicle interiors or as components of headlights and taillights. With the new solution, aerodynamic components such as spoiler lips, airblades, or wing end plates can now also be provided with illuminated lettering.

[0023] The application of the invention significantly increases the visibility of lettering on exterior add-on parts, allowing it to make a much stronger contribution to the identification and characterization of the vehicle. Regardless of lighting conditions and viewing angle, the lettering will always be clearly visible, noticeably improving the vehicle's aesthetics while also contributing to road safety.

[0024] Further advantageous embodiments of the invention are specified in the dependent patent claims. Short description of the drawings Fig. 1 shows the rear lower section of a mid-engine sports car covered according to the invention. Fig. 2 shows a variant of the solution with illuminated lettering in detail. Fig. 3 shows schematically the section in plane AA according to Fig. 1 a cladding with ungrained lettering, for example polished with a grain size of 800 µm. Fig. 4 shows the corresponding section of a panel whose lettering has a structural grain. Fig. 5 shows the corresponding section of a panel with embossed and unembossed lettering. Fig. 6 shows the corresponding section of a panel with embossed and grained lettering. Fig. 7 to Fig. 13 show the steps for producing a spoiler lip by skin molding. Fig. 14 to Fig. 20 show the steps for manufacturing a spoiler end plate by assembly injection molding. Embodiments of the invention

[0025] Fig. Figure 1 illustrates the lower rear section of a sports car, featuring an outer panel (10). As can be clearly seen in the illustration, the white lettering made of self-illuminating decorative material (12) stands out clearly against the black background of the lower section and displays the vehicle's model name, "GT4 RS," in high contrast. This effect is achieved by using a self-illuminating decorative material (12) for the lettering, i.e., a material capable of emitting light through fluorescence, phosphorescence, or retroreflection, illuminating the lettering on the outer panel (10) without the need for an external light source (13).

[0026] In the case of a fluorescent design, the decorative material (12) absorbs light of a specific wavelength and emits it as visible light, resulting in luminous lettering. In a phosphorescent design, however, the material (12) stores the absorbed light and emits it over a longer period of time, resulting in a luminescent effect. Finally, with retroreflection, the incident light is reflected back toward its source, resulting in a bright, luminous appearance of the lettering when illuminated by an external light source, such as the headlights of another vehicle.

[0027] Regardless of the exact design of the self-illuminating decorative material (12), this variant of the invention offers the advantage of eliminating the need for additional lighting devices while still allowing for highly visible and high-contrast lettering on the vehicle's exterior panel (10). This can not only improve the vehicle's aesthetics but also contribute to road safety, as the lettering remains clearly visible even in poor lighting conditions.

[0028] In the variant according to Fig. 2, a transparent decorative material (12) is used instead, which serves as a light guide. This means that the decorative material (12) guides light introduced by an external light source (13) along its length and radiates it from its surface. This light ensures a clearly highlighted and easily visible representation of the lettering on the outer panel (10).

[0029] The light source (13) is positioned so that it is not directly visible. It may be mounted at a location on the lettering that is invisible from the side, as in the illustrated example, or it may direct the light into the lettering from behind. One or more light-emitting diodes (LEDs) can be used as the light source (13). The color of the light is freely selectable, allowing the lettering to illuminate in a variety of colors to enhance and individualize the aesthetic appearance of the vehicle.

[0030] The decorative material (12) forming the lettering can be realized in various optical designs. It can be crystal-clear to produce a bright and unadulterated light. Alternatively, the decorative material (12) can also be diffused, similar to frosted glass, to produce a soft and diffused light. Finally, the decorative material (12) can also be colored to emit the light in a specific color, independent of the color of the light source (13).

[0031] The combination of base material (11) and decorative material (12) in the exterior trim (10) makes it possible to create lettering that is not only highly visible but also aesthetically pleasing. Illuminating the lettering creates a high contrast with the base material (11), which significantly improves the legibility of the lettering and enhances the overall appearance of the vehicle.

[0032] Fig. 3 shows a cross section through the outer cladding (10) in plane AA from Fig. 1. In this embodiment, the lettering (12) is ungrained and smooth, for example, polished to a grain size of 800 µm. The surface layer (11) framing the lettering, in contrast, has a fine grain—for example, with a grain depth of 27 µm and a draft angle of at least 2°.

[0033] Fig. 4 presents an alternative embodiment in which the lettering (12) is provided with a hexagonal structural grain that emphasizes the contrast between the layer (11) and the lettering (12) and further improves its visibility.

[0034] Fig. Figure 5 shows another embodiment in which the lettering (12) is unembossed but embossed. The embossing creates an additional shadow effect, thus intensifying the contrast between the lettering (12) and the surrounding layer (11).

[0035] In Fig. Figure 6 shows an embodiment in which the lettering (12) is both embossed and grained. This combination of embossing and graining can contribute to further improving the visibility and legibility of the lettering (12).

[0036] The Fig. Figures 7 to 13 show the production of a spoiler lip visible from one side using the so-called skin molding process with the aid of an injection molding tool having two cavities (1, 2). After closing the injection molding tool ( Fig. 7) the polymeric decorative material (12) is injected into the first cavity (1) on the left as shown in the figure ( Fig. 8), so that a pre-molded part of the carrier component between 0.5 mm and 3.5 mm thick is created, which reproduces the lettering positively. The injection mold is then opened ( Fig. 9) and its matrix and core are shifted against each other ( Fig. 10), while the pre-molded part remains on the latter and is thus transferred from the first cavity (1) to the second cavity (2) on the right as shown in the figure. After closing the injection mold again ( Fig. 11) the polymer base material (12) is now added to the pre-molded part in the second cavity (2) and injected onto the decorative material (12) like a skin between 1 mm and 3 mm thick ( Fig. 12). The spoiler lip produced in this way can be attached to the injection mold after its final opening ( Fig. 13) as a finished component.

[0037] The Fig. Figures 14 to 20 illustrate the production of a spoiler end plate visible on both sides using the so-called assembly injection molding process. In this variant, after closing the mold ( Fig. 14) the base material (11) is first injected into both cavities (1, 2) ( Fig. 15), so that two half-shells, each between 1 mm and 3 mm thick, are created, whereby the pre-molded part in the first cavity (1) negatively reproduces the lettering by so-called spotting. After opening the tool ( Fig. 16) the die together with the pre-moulded part is positioned relative to the core according to Fig. 17 is shifted to the right, while the pre-molded part formed in the second cavity remains on the core and is thus transferred into the first cavity. When the mold is closed again ( Fig. 18) the two shells form a cavity into which the decorative material (12) can now be injected ( Fig. 19). This also creates the lettering - also between 1 mm and 3 mm thick - so that the end plate can be attached to the tool after its final opening ( Fig. 20) can be removed as a finished component.

[0038] The technology described may also be used in other areas of the front or rear of a vehicle, or on its sides. Examples include front spoilers, sill panels, air intakes, and door panels. List of reference symbols 1 first cavity 2 second cavity 10 Exterior cladding 11 Base material 12 Decorative material 13 Light source QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] WO 2019214994 A1

[0006] DE 102019135491 A1

[0007] EP 3632749 B1

[0008] DE 102019217659 A1

[0009] US 2023174170 A1

[0010] JP 10217280A

[0011] JP 3472403B2

[0012] KR 19980023964A

[0013] EP 1308259A2

[0014]

Claims

[1] Exterior panel (10) for a motor vehicle, characterized by following features: - the outer cladding (10) has a surface layer of a base material (11), - the outer cladding (10) bears a lettering made of a decorative material (12) and - the outer cladding (10) is designed to illuminate the lettering (12). [2] Outer cladding (10) according to claim 1, characterized by at least one of the following characteristics: - the decorative material (12) is fluorescent, - the decorative material (12) is phosphorescent or - the decorative material (12) is transparent. [3] Outer cladding (10) according to claim 1 or 2, characterized by at least one of the following characteristics: - the outer cladding (10) has a reflector integrated into the lettering (12) or - the outer cladding (10) has a light source (13) arranged next to or below the lettering (12). [4] Exterior cladding (10) according to one of the preceding claims, characterized by at least one of the following characteristics: - the surface layer (11) has a fine grain, in particular with a grain depth of 27 µm and a draft angle of at least 2°, and - the lettering (12) has a surface structure or embossing that differs from the layer. [5] Exterior cladding (10) according to one of the preceding claims, characterized by at least one of the following characteristics: - the lettering (12) is smooth, in particular polished, or - the lettering (12) has a particularly hexagonal structural grain. [6] Exterior cladding (10) according to one of the preceding claims, characterized by at least one of the following characteristics: - the superficial layer (11) is between 1 mm and 3 mm thick and - the lettering (12) is between 0.5 mm and 3.5 mm thick. [7] Production of an outer panel (10) according to one of the preceding claims in an injection molding tool with a die, a core, a first cavity (1) and a second cavity (2), characterized by following features: - the injection mold is closed, - a first component is injected into the injection moulding tool so that at least one pre-moulded part is produced which depicts the lettering (12), - the injection mold is opened, - the die and the core are moved against each other, while the pre-moulded part remains in the injection moulding tool, - the injection mould with the pre-moulded part is closed again, - a second component is added to the pre-moulded part to create the outer panel (10), - the injection mold is opened again and - the outer cover (10) is removed from the tool. [8] Production according to claim 7, characterized by following features: - the first component is the decorative material (12), - the second component is the base material (11), - the decorative material (12) is injected into the first cavity (1), whereby the lettering is positively reproduced, - when moving, the pre-molded part is transferred from the first cavity (1) on the core into the second cavity (2) and - the base material (11) is added into the second cavity (2), whereby the lettering (12) on the pre-molded part is overmolded. [9] Production according to claim 7, characterized by following features: - the first component is the base material (11), - the second component is the decorative material (12), - the injection of the base material (11) takes place in both cavities (1 and 2), whereby the pre-molded part in the first cavity (1) negatively reproduces the lettering (12), - during displacement, the said pre-molded part remains in the die, while the pre-molded part is transferred from the second cavity (2) on the core into the first cavity (1), and - the decorative material (12) is added into the second cavity (2), whereby the pre-molded part is back-injected with the lettering (12). [10] Motor vehicle, characterized by following features: - the motor vehicle has an attachment and - the attachment part carries an outer cladding (10) according to one of claims 1 to 6.

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