Method for producing a translucent cover, lighting device and vehicle

Abstract

The invention relates to a method for producing a translucent cover (1) by means of multi-component injection molding, wherein the cover (1) comprises at least one transparent section (2) and at least one opaque section (3), wherein the transparent section (2) is designed to allow light emitted by a light source (4) that can be arranged on a rear side (R) of the cover (1) to pass through the cover (1) in the thickness direction (s) to a visible side (S), and the opaque section (3) is designed to block the passage of the light to the visible side (S), and wherein the cover (1) is subjected to a galvanic process after injection molding.The method according to the invention is characterized in that a first thermoplastic material is used to form the transparent section (2) and a second thermoplastic material is used to form the opaque section (3), wherein a transparent and galvanoinert plastic is used as the first thermoplastic material and a galvanizable plastic is used as the second thermoplastic material, and wherein the opaque section (3) is coated with a metal layer (5) in the galvanizing process.

Description

[0001] The invention relates to a method for producing a translucent cover by means of multi-component injection molding according to the type defined in more detail in the preamble of claim 1, a lighting device with such a cover and a vehicle with such a lighting device.

[0002] The electroplating of plastic components is widely known. Electroplating technology allows metallic surfaces to be created on plastic components, which not only protects the plastic itself from environmental influences but also creates a particularly valuable appearance.

[0003] In the automotive sector, backlit components are installed both on the exterior and in the interior. Such components can be used as decorative elements or as display and / or control devices. For example, controls installed on the dashboard can be backlit to make certain numbers, symbols, pictograms, or the like clearly visible even in the dark.

[0004] DE 10 2019 135 152 A1 discloses a decorative part with a partially translucent chrome surface and a corresponding method for its production. The decorative part comprises a carrier element, which is at least partially transparent, and with a chrome layer applied to the visible side. The chrome layer has a recess for transmitting light emitted by a light source arranged on a rear side of the carrier element. The carrier element can be manufactured using a multi-component injection molding process. The carrier element is coated with chrome by electroplating. However, the production of the decorative part is complex. For example, the chrome layer must be partially removed to create the recess.The carrier element must also be covered on the back to prevent chrome plating during the electroplating process, as otherwise the light emitted by the light source would not be able to pass through to the recess.

[0005] The present invention is based on the object of providing an improved method for producing a translucent cover using multi-component injection molding, with the aid of which the cover can be produced more easily and cost-effectively. The present invention is further based on the object of providing a cost-effectively manufactured lighting device.

[0006] According to the invention, these objects are achieved by a method for producing a translucent cover by means of multi-component injection molding having the features of claim 1 and a lighting device having the features of claim 3. Advantageous embodiments and further developments as well as a vehicle with such a lighting device emerge from the dependent claims.

[0007] A generic method for producing a translucent cover by means of multi-component injection molding, wherein the cover comprises at least one transparent and at least one opaque section, wherein the transparent section is configured to allow light emitted by a light source arranged on a rear side of the cover to pass through the cover in the thickness direction to a visible side, and the opaque section is configured to block the passage of light to the visible side, and wherein the cover is subjected to a galvanic process after injection molding, is further developed according to the invention in that a first thermoplastic material is used to form the transparent section and a second thermoplastic material is used to form the opaque section,wherein a transparent and electroplating-inert plastic is used as the first thermoplastic and a electroplatable plastic is used as the second thermoplastic, and wherein the opaque section is coated with a metal layer in the electroplating process.

[0008] Using the method according to the invention, the translucent cover can be produced particularly easily, quickly, reliably, and cost-effectively. The core idea is the use of the first transparent and electroplating-inert plastic and the second electroplatable plastic for multi-component injection molding. This produces a cover that comprises electroplatable and non-electroplatable sections. This is possible due to the respective intrinsic properties of the respective plastics. For example, the electroplatable plastic is capable of enabling the deposition of metal ions on the surface in the electroplating bath, whereas this is not possible with the electroplating-inert plastic. In the electroplating process, the electroplatable sections are coated with the metal layer, whereby the electroplating-inert sections remain free of any metal deposits.This allows for the simple, rapid, reliable, and cost-effective production of at least one transparent and at least one opaque section. In contrast to the prior art, it is not necessary to cover individual surface sections prior to the electroplating process or to at least partially remove the metal layer after electroplating the cover. Thus, fewer manufacturing steps are required.

[0009] For example, polycarbonate (PC) can be used as the first plastic and an acrylonitrile butadiene styrene copolymer (ABS) as the second plastic. In general, any thermoplastic can be used as long as the respective properties are present, i.e. transparency and non-electroplating for the first plastic and electroplating for the second plastic. It is completely irrelevant whether the second plastic is inherently transparent or opaque. In this case, the second plastic is made opaque by the electroplating process at the very latest, so that light can pass through the transparent section(s) in the thickness direction from the back to the visible side of the cover and is prevented from doing so in the area of ​​the opaque section(s).

[0010] An advantageous development of the method according to the invention provides for a chrome layer to be applied to the opaque section during the electroplating process, at least as the outermost layer. Chrome protects the underlying plastic particularly reliably from environmental influences. Furthermore, the surface appears particularly valuable. It is irrelevant whether the surface quality of the chrome layer is trimmed to a high gloss or another surface quality or finish is chosen, such as so-called "dark chrome," "silver shadow," or the like.

[0011] Any number of layers of additional metals, such as a copper layer and / or a nickel layer, can be provided between the base substrate made of the second plastic and the final chrome layer. The layer structure can be specifically adapted to the specific intended use of the cover.

[0012] Such a cover produced by means of the method according to the invention is therefore also part of the invention.

[0013] According to the invention, a lighting device comprises a cover manufactured according to a method described above and at least one light source provided on the rear of the cover. With the help of the light source, the cover can be illuminated in the thickness direction towards the visible side. The light source can be attached directly to the cover or spaced from the rear of the cover. All common light sources can be used to form the light source, such as incandescent lamps, gas discharge lamps, LEDs, lasers and the like. The light source or light sources encompassed by the light source can be specifically controlled to emit static light patterns or dynamic light patterns. For example, the brightness of individual light sources can be specifically changed to create the impression of a moving light bar.

[0014] Accordingly, the lighting device includes a connection for supplying the light source with electrical power. Generally, a direct or alternating current supply is possible. Appropriate power electronic components, such as transformers, inverters, and the like, can also be part of the lighting device. Power supply via an internal battery, accumulator, or even an external power supply is conceivable.

[0015] An advantageous development of the lighting device according to the invention provides that the at least one light source is attached to a housing cover, and the cover is connected to the housing cover with the rear side facing the housing cover. This allows the corresponding electronic components of the lighting device to be isolated from the environment and thus protected from environmental influences such as contamination, moisture ingress, or damage caused by mechanical force. The housing cover can be made of any conceivable material; preferably, the housing cover comprises at least a portion of plastic.

[0016] The attachment of the housing cover to the cover can be based on all conceivable detachable or non-detachable connection techniques, such as the use of screws, clips, gluing, soldering, welding and the like

[0017] According to a further advantageous embodiment of the lighting device, the light source comprises at least one illuminant directed directly onto the rear side of the cover, in particular in the form of one or more LEDs arranged on a common circuit board. By directing the illuminants directly onto the rear side of the cover, a particularly large amount of light can be directed towards the visible side of the cover. The lighting device thus appears particularly bright. In particular, the illuminants of the at least one light source and the transparent sections of the cover can be specifically aligned with one another so that, viewed in the thickness direction, corresponding illuminants run beneath a respective transparent section. It would also be conceivable to arrange the illuminants beneath the opaque sections in order to allow only diffusely scattered light from the transparent sections to pass through.This can improve the visual appearance, as the light sources are not directly visible from the outside.

[0018] In addition, surface structures can be incorporated into the rear-facing side and / or the visible side of the transparent section to specifically scatter or redirect the light. These surface structures can be manufactured integrally during multi-component injection molding.

[0019] Additionally or alternatively, a further advantageous embodiment of the lighting device according to the invention further provides that the light source comprises at least one light guide running along the housing cover, wherein light emitted by at least one illuminant can be coupled into the light guide via a light coupling point and coupled out of the light guide via at least one light coupling point. With the help of the light guide, light can be distributed in a targeted manner in the space between the cover and the housing cover. This allows specific light patterns to be generated in an even more targeted manner. The light preferably emerges evenly via the light guide. This further improves the visual appearance of a switched-on lighting device.

[0020] Preferably, the at least one light output point faces the cover. In particular, the corresponding light output points overlap with the transparent sections of the cover. This allows a particularly large amount of light to be directed toward the visible side of the cover.

[0021] A further advantageous embodiment of the lighting device according to the invention further provides for at least one light source configured to emit light of a different color. For this purpose, the light source can comprise, for example, differently colored LEDs, such as at least one red, green, and blue LED, or one or more color filters. The brightness of the differently colored light sources can be specifically varied so that colors can be mixed by color addition. Dynamic light patterns can be generated by means of the lighting device according to the invention. By providing different colors, dynamic light patterns characterized by a color gradient can also be generated.

[0022] A vehicle according to the invention comprises at least one lighting device as described above. Corresponding lighting devices can be provided both in the vehicle interior and on the exterior of the vehicle. For example, such a lighting device can be integrated into the dashboard of the vehicle or even form it. Further lighting devices can, for example, be arranged above the transmission tunnel, integrated into the A-pillar or the roof lining, or the like. Corresponding lighting devices can also be used to implement external vehicle lights, such as the brake lights, the turn signal, or the like. The lighting device according to the invention can, for example, also be used to form a bumper or radiator grille. In this way, a bumper or radiator grille that emits light from within can be provided.This opens up a completely new scope for a vehicle manufacturer to design the appearance of the vehicle.

[0023] In general, it can be any road vehicle such as a car, truck, van, bus, or the like. It could also be a rail vehicle, watercraft, or aircraft.

[0024] Further advantageous embodiments of the method according to the invention for producing the translucent cover and the lighting device according to the invention also result from the exemplary embodiment which is described in more detail below with reference to the figure.

[0025] This shows Fig. 1 a schematic representation of a process sequence for producing a lighting device according to the invention.

[0026] In a method step 101, an assembly 11 is produced from a first thermoplastic and a second thermoplastic by means of multi-component injection molding. According to the invention, a transparent and electroplating-resistant plastic is used as the first thermoplastic, and a electroplating-resistant plastic is used as the second thermoplastic. The first thermoplastic serves to form one or more transparent sections 2, and the second thermoplastic serves to form one or more opaque sections 3.

[0027] The assembly 11 produced in step 101 is subsequently subjected to a galvanization process. Because only the second thermoplastic material is galvanizable, but not the first thermoplastic material, a corresponding metal layer 5 is deposited exclusively on the second thermoplastic material in process step 102. Thus, a cover 1 according to the invention is produced. Thus, no further post-treatment steps are required to enable the partial transmission of light through the cover 1, such as, for example, a subsequent surface treatment of the cover 1. Thus, the cover 1 according to the invention can be manufactured particularly cost-effectively, quickly, easily, and reliably.

[0028] In method step 103, the cover 1 according to the invention is connected to a housing cover 7. At least one light source 4 is attached to the housing cover 7. Thus, a lighting device 6 according to the invention is produced.

[0029] The at least one light source 4 in turn comprises at least one illuminant 8, whose light can be guided in the thickness direction s from a rear side R of the cover 1 to a visible side S. The cover 1 according to the invention is accordingly configured to transmit light in the thickness direction s by a suitable geometric arrangement of the transparent and opaque sections 2, 3. The light travels through the transparent sections 2 and is reflected back or at least partially absorbed in the respective opaque sections 3.

[0030] As a light source 4, the lighting device 6 can, for example, comprise a plurality of illuminants 8, for example LEDs, arranged on a common circuit board 9. The illuminants 8 can be directed directly onto the rear side R of the cover 1.

[0031] Additionally or alternatively, light emitted by corresponding illuminants 8 can also be introduced via a coupling structure 12 into a light guide 10 for targeted distribution of the light in the space between the cover 1 and the housing lid 7. The light can emerge over a large area or only at specific points on the light guide 10. The respective light output points of the light guide 10 can be adapted to the respective application conditions. Either only illuminants 8 directed directly onto the rear side R, only light guides 10, or combinations of both variants can be provided.

[0032] The cover 1 and the housing lid 7 are preferably supported by a circumferential flange 13, via which the cover 1 and the housing lid 7 are also fastened to one another. For this purpose, the cover 1 and the housing lid 7 can be connected, for example, by means of screws, clips, adhesives, soldering, welding, or the like. This connection is preferably non-destructively removable, allowing for easy replacement of individual electronic components during maintenance.

[0033] According to the invention, at least one such lighting device 6 is particularly preferably integrated into the interior and / or exterior of a vehicle.

[0034] With the aid of the lighting device according to the invention, components galvanized in the conventional manner can now also be backlit, in particular using an animated light pattern. This is preferably a colored, animated light pattern. By implementing the method according to the invention for producing the translucent cover 1, the lighting device 6 according to the invention can also be manufactured particularly easily, quickly, reliably, and cost-effectively. This also allows for simple and cost-effective production of the corresponding vehicle. 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] DE 10 2019 135 152 A1

[0004]

Claims

[1] Method for producing a translucent cover (1) by means of multi-component injection molding, wherein the cover (1) comprises at least one transparent section (2) and at least one opaque section (3), wherein the transparent section (2) is designed to allow light emitted by a light source (4) arranged on a rear side (R) of the cover (1) to pass through the cover (1) in the thickness direction (s) to a visible side (S), and the opaque section (3) is designed to block the passage of the light to the visible side (S), and wherein the cover (1) is subjected to a galvanic process after injection molding, characterized bythat a first thermoplastic is used to form the transparent section (2) and a second thermoplastic is used to form the opaque section (3), wherein a transparent and galvanoinert plastic is used as the first thermoplastic and a galvanizable plastic is used as the second thermoplastic, and wherein the opaque section (3) is coated with a metal layer (5) in the galvanizing process. [2] Method according to claim 1, characterized by that a chromium layer is applied to the opaque section (3) in the electroplating process, at least as the outermost layer. [3] Lighting device (6), characterized by a cover (1) produced by a method according to claim 1 or 2 and at least one light source (4) provided on the rear side (R). [4] Lighting device (6) according to claim 3, characterized bythat the at least one light source (4) is fastened to a housing cover (7) and the cover (1) is connected to the housing cover (7) with the rear side (R) facing the housing cover (7). [5] Lighting device (6) according to claim 3 or 4, characterized by that the light source (4) comprises at least one illuminant (8) directed directly onto the rear side (R) of the cover (1), in particular in the form of one or more LEDs arranged on a common circuit board (9). [6] Lighting device (6) according to one of claims 3 to 4, characterized by that the light source (4) comprises at least one light guide (10) running along the housing cover (7), wherein light emitted by at least one illuminant (8) can be coupled into the light guide via a light coupling point and can be coupled out of the light guide (10) via at least one light coupling point. [7] Lighting device (6) according to claim 6, characterized bythat the at least one light output point faces the cover (1). [8] Lighting device (6) according to one of claims 3 to 7, characterized by at least one light source (4) arranged to emit light of different colours. [9] Vehicle, characterized by at least one lighting device (6) according to one of claims 3 to 8.

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