Exterior cladding for a motor vehicle, method for its manufacture and motor vehicle with such cladding

Abstract

Exterior trim (10) for a motor vehicle, characterized by the following features: - the exterior trim (10) has a surface layer made of a base material (11), - the exterior trim (10) bears lettering made of a decorative material (12) and - the base material (11) and the decorative material (12) are in color contrast.

Description

The present invention relates to an exterior trim for a motor vehicle. The present invention also relates to the production thereof and to a corresponding motor vehicle.Prior ArtIn the production of motor vehicles, in particular sports cars, it is known and customary to introduce the model designation or the manufacturer name onto exterior add-on parts made of plastic. Such writing, often in the form of embossing, is often considered an essential element of the brand identity and as a means of underlineing the sporting character of the vehicle.The model name or the manufacturer name is generally applied to the plastics add-on parts directly in the production process of these parts. In particular, the designation is anchored in the injection mold of the plastic component and is thus tool-falling. This means that the designation is formed directly into the plastic of the add-on part in the injection molding process.The visibility of the writing displayed in this way depends strongly on various factors such as its surface nature and depth. The latter in particular determines significantly how the writing lifts from the surface of the add-on part and how strongly the shadow effect is produced along the writing.It is customary here for both the writing and the surrounding material of the add-on part to be implemented in the same color, since the writing is inserted directly into the plastic of the add-on part and therefore consists of the same material.JP10217280 A discloses an injection molding process for manufacturing a multi-color toothbrush.JP3472403B2 discloses a cast two-colour decorative article.KR19980023964A discloses a method for producing a three-dimensional, multi-coloured emblem from epoxy resin.EP1308259A2 describes a multistage injection molding process for producing a vehicle trim.Disclosure of the InventionOne problem is that significant contrast between the writing and the surrounding plastic part is often difficult to achieve. The visibility and readability of the writing is suboptimal in many cases and strongly depends on the lighting conditions and the viewing angle.One reason for this is that both the writing and the surrounding plastic part are usually carried out in the same color. This often results in an effect referred to as a "black adler on black ground"-a metapher that clearly illustrates the problem of lack of contrasting and associated poor visibility and readability.Furthermore, the surface nature of the add-on part and of the writing itself can impair its visibility. In particular, the depth of the writing, which is decisive for producing a shadow effect and thus for increasing the contrast, can be influenced by the surface condition.The problem of the lack of visibility and readability of the writing is exacerbated by the fact that the writing is an essential component of the brand identity and the sporting character of the vehicle. Poor visibility and readability of the writing may therefore negatively affect the mark image and the perception of the vehicle as a whole.The described problem is solved by an outer cladding for a motor vehicle, a method for the production thereof and a motor vehicle according to the independent claims.This approach has the advantage of increasing the contrast between the writing and the surrounding plastic part by using two different colors. In contrast to the prior art, in which writing and plastic part are embodied in the same color, the writing with the proposed approach can be realized in a different color than the surrounding plastic part. This in turn leads to a significant improvement in the visibility and readability of the writing, regardless of lighting conditions and viewing angles.In particular, the surrounding plastic part can be executed in a dark color, preferably black, and the writing can be executed in a bright, high-contrast color. This combination produces high contrast which further improves the visibility and readability of the writing.In addition, the writing can be performed by the proposed approach not only in a different color, but also with a different surface structure than the surrounding plastic part. This offers additional possibilities for increasing the contrast and for improving the visibility and readability of the writing.The application of the proposed approach can moreover be extended to different parts of the vehicle. This allows the model or manufacturer names to be applied to different locations of the vehicle in a high contrast and readily visible manner. This contributes to strengthening the tag identity and to improving the general perception of the vehicle.In addition, the proposed approach enables precise and reproducible production of the writings by injection molding. This enables a high quality and consistency of the writings and contributes to the professionality and high-valueness of the overall appearance of the vehicle.Further advantageous embodiments of the invention are specified in the dependent patent claims.Brief Description of the DrawingsFIG. 1 shows the bow bottom part of a middle-engine sport car covered according to the invention. FIG. 2 schematically shows the section in the plane A-A according to FIG. 1 of a cladding with unabbed writing polished, for example with a grain size of 800 μm. FIG. 3 shows the corresponding section of a cladding, the writing of which has a structure grain. FIG. 4 shows the corresponding section of a covering with a stamped and unembed writing. FIG. 5 shows the corresponding section of a covering with a stamped and grained writing. FIGS. 6 to 12 show the steps for producing a spoiler lip by skin molding. FIGS. 13 to 19 show the steps for producing a spoiler end plate by assembly injection molding.Embodiments of the InventionFIG. 1 illustrates the bow bottom part of a sport car provided with an outer cladding (10). As the illustration can easily be seen, the colored writing made of yellow decorative material ( 12) is clearly distinguished from the black base material ( 11) and displays the model name "GT4 RS" of the vehicle with high contrast.FIG. 2 shows a cross section through the outer cladding ( 10) in the plane A-A from FIG. 1 ; in this embodiment, the writing ( 12) is unabbed and polished smooth, for example with a grain size of 800 μm. The superficial layer (11) framing the writing, on the other hand, has a fine grain-for example with a grain depth of 27 μm and a draft of at least 2°.FIG. 3 presents an alternative embodiment in which the writing (12) is provided with a hexagonal structure grain that undersamples the contrast between the layer (11) and the writing (12) and further improves its visibility.FIG. 4 shows another embodiment in which the font (12) is disambiguous but is displayed. The embossing produces an additional shadow effect and thus enhances the contrast between the writing (12) and the surrounding layer (11).In Figure 5, an embodiment is shown in which the font (12) is both stamped and inherited. This combination of embossing and scarring can help to further improve the visibility and readability of the writing (12).FIGS. 6 to 12 show the production of a spoiler lip visible on one side in the so-called skin-molding process with the aid of an injection-molding tool which has two cavities ( 1, 2). After the injection molding tool (FIG. 6 ) has been closed, the polymeric decorative material ( 12) is injected (FIG. 7 ) into the first cavity ( 1), which is on the left as viewed in the drawing, so that a pre-injection molding of the carrier component that is between 0.5 mm and 3.5 mm thick is produced, which pre-injection molding positively reproduces the writing. The injection mold is then opened (FIG. 8 ) and its die and core are displaced with respect to one another (FIG. 9 ), while the pre-injection molding remains on the latter and is thus transferred from the first (1) into the second cavity (2) on the right as shown. After the injection molding tool (FIG. 10 ) has been closed again, the polymeric base material ( 11) is now added to the pre-molded part located in the second cavity ( 2) and is injected onto the decorative material ( 12) equal to a skin between 1 mm and 3 mm thick (FIG. 11 ). The spoiler lip produced in this way can be removed from the injection molding tool as a finished component after it has been finally opened (FIG. 12 ).FIGS. 13 to 19 illustrate the production of a spoiler end plate visible on both sides in the so-called assembly injection molding process. In this variant, after the tool (FIG. 13 ) has been closed, the base material (11) is initially injected (FIG. 14 ) into both cavities (1, 2), so that two half shells each having a thickness of between 1 mm and 3 mm are produced, wherein the pre-injection molding in the first cavity (1) negatively reproduces the writing by means of so-called tufting. After opening the tool (FIG. 15 ), the die together with the pre-injection molding is displaced to the right with respect to the core according to FIG. 16, while the pre-injection molding formed in the second cavity remains on the core and is thus transferred into the first cavity. When the tool (FIG. 17 ) is closed again, the two shells form a cavity in this way, into which the decorative material ( 12) can now be injected (FIG. 18 ). The writing, which is likewise between 1 mm and 3 mm thick, thus also arises, so that the end plate can be removed from the tool as a finished component after its final opening (FIG. 19 ).The technique explained may also be applied in other areas on the front or rear part of a vehicle or its sides. For example only, bow spoilers, sill panels, air inlets or door panels may be mentioned.List of reference characters1 first cavity 2 second cavity 10 outer cladding 11 base material 12 decorative materialReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 10217280

[0006] JP 3472403B2

[0007] KR 19980023964A

[0008] EP 1308259A2

[0009]

Claims

Exterior cladding (10) for a motor vehicle, characterized bythe following features: - the exterior cladding (10) has a surface layer made of a base material (11), - the exterior cladding (10) carries a writing made of a decorative material (12), and - the base material (11) and the decorative material (12) stand in color contrast.Exterior cladding (10) according to claim 1, characterised byat least one of the following features: - the base material (11) is achromatic and preferably dark, in particular black, and - the decorative material (12) is chromatic and preferably light, in particular yellow.Exterior cladding (10) according to claim 1 or 2, characterised byat least one of the following features: - the letter (12) denotes the model of the motor vehicle or - the letter (12) denotes the manufacturer of the motor vehicle.Outer cladding (10) according to one of the preceding claims, characterized byat least one of the following features: - the surface layer (11) has a fine grain, in particular with a grain depth of 27 μm and a draft of at least 2°, and - the writing (12) has a surface structure or embossing which differs from the layer.Exterior cladding (10) according to one of the preceding claims, characterized byat least one of the following features: - the writing (12) is smooth-faced, in particular polished, or - the writing (12) has an in particular hexagonal structure grain.Exterior covering (10) according to one of the preceding claims, characterized byat least one of the following features: - the surface layer (11) is between 1 mm and 3 mm thick, and - the writing (12) is between 0.5 mm and 3.5 mm thick.Production of an outer cladding (10) according to one of the preceding claims in an injection mould having a die, a core, a first cavity (1) and a second cavity (2), characterized bythe following features: - the injection mould is closed, - a first component is injected into the injection mould, so that at least one pre-injection moulding is produced, which images the writing (12), - the injection mould is opened, - the die and the core are displaced with respect to one another while the pre-injection moulding remains in the injection mould, - the injection mould with the pre-injection moulding is closed again, - a second component is added to the pre-injection moulding, so that the outer cladding (10) is produced, - the injection mould is opened again and - the outer cladding (10) is removed from the mould.Production according to claim 7, characterised bythe following features: - the first component is the decorative material (12), - the second component is the base material (11), - the injection of the decorative material (12) takes place into the first cavity (1), wherein the writing is positively mapped, - during the displacement the pre-injection moulded part is transferred from the first cavity (1) on the core into the second cavity (2) and - the addition of the base material (11) takes place into the second cavity (2), wherein the writing (12) is injection moulded onto the pre-injection moulded part.Production according to claim 7, characterised bythe 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 into both cavities (1 and 2), wherein the pre-injection moulded part in the first cavity (1) images the writing (12) in a negative manner, - during displacement the said pre-injection moulded part remains in the die, while the pre-injection moulded part is transferred from the second cavity (2) on the core into the first cavity (1), and - the addition of the decorative material (12) takes place into the second cavity (2), wherein the pre-injection moulded part is back-injected with the writing (12).Motor vehicle, characterized bythe following features: - the motor vehicle has an attachment part and - the attachment part carries an outer cladding (10) according to one of Claims 1 to 6.

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