DE102012215801A1 - Method for manufacturing composite from molded skin and light conductor for interior parts of automobile, involves spraying or casting molded skin when simultaneously recasting unit from light conductor and protecting layer - Google Patents

Abstract

The method involves providing an integrated light conductor (10). The light conductor is surrounded with a protecting layer (11) i.e. textile layer, or film and protective sheath, along entire outer surface of the light conductor. A unit from the light conductor and the protecting layer is inserted into a cavity of an injection mold (1) for forming molded skin (20) i.e. PVC skin. The molded skin is sprayed or cast when simultaneously recasting the unit from the light conductor and the protecting layer, so that the light conductor is embedded into the molded skin. An independent claim is also included for a composite.

Description

TECHNICAL AREA

The invention relates to a method for producing a composite of a molded skin and a light guide, and such a composite.

BACKGROUND OF THE INVENTION

It is known to make the illumination of vehicle interiors with light guides. The light guide here serves both to generate directly visible lines of light, as well as to produce an indirect illumination, which is also referred to as ambient lighting.

Conventionally, the light guide is clipped in both the direct and in the ambient lighting as in an interior judgment. Alternatively, the optical fiber according to the DE 197 24 486 A1 Sewn or glued over a fastening lug. For this purpose, the light guide is introduced into a fastening device which has an elongate hollow part with fastening lug. The hollow part encloses the light guide. The fastening lug is used for sewing or gluing the hollow part with a Interieurteil.

The gluing or sewing of the light guide according to the DE 197 24 487 A1 is a relatively expensive and expensive process, which is used primarily in luxury vehicles.

DESCRIPTION OF THE INVENTION

It is an object of the invention to simplify the installation of a light guide on an interior, in particular, it is an object of the invention to provide a method by which a light guide can be connected in a simple and stable manner with a Interieurteil equipped with a molded skin is. In addition, it is an object of the invention to provide a composite produced from a molded skin and an integrated light guide.

The object is achieved by a method according to claim 1, a method according to claim 3 and a composite with the features of claim 10.

The composite produced by the method according to the invention is intended in particular for use in vehicle interiors. The molded skin provided with the light guide can be reinforced on the back in order to form an interior judgment. Back reinforcement may be by sticking to a backing, back molding, backfoaming, or otherwise. In particular, a haptic layer, for example of a spacer knitted fabric or a foam, may be provided between the molded skin and any support.

According to the method of the invention, a light guide is first provided. The light guide is then surrounded with a protective layer or protective cover along the entire lateral surface of the light guide. The lateral surface here refers to the peripheral surface of the light guide, without the cross-sectional areas provided perpendicular to its extension. Here, the entire or substantially the entire lateral surface of the light guide is surrounded by the protective layer. That is, if the protective layer is provided, for example in the form of a protective cover, then it may be slotted to facilitate the introduction of the light guide can. However, the light guide should be protected all around. In a further step, the unit of optical waveguide and protective layer is introduced into an injection mold or electroforming mold (hereinafter also to be understood by injection molding) for forming the molded skin. Subsequently, a molded skin, such as a spray skin, a slush skin, a skin made of PVC or other material is sprayed or cast, the unit of optical fiber and protective layer is simultaneously at least partially sprayed or poured, whereby the optical fiber at least partially embedded in the skin becomes. The protective layer serves not only to protect the light guide against external influences, such as touches by the passenger, but also as a spacer to the molded skin, as in the direct contact of the light guide to the molded skin whose lighting behavior is adversely affected.

Incidentally, for the sake of simplicity, the following is often merely the term "light guide", even if it means the unit of light guide and protective layer. Whether it is just the light guide or the unit of light guide and protective layer is clear from the context.

The embedding of the light guide in the molded skin can also be done in an alternative manner, namely by not the unit of optical fiber and protective layer or protective sheath with plastic material sprayed or encapsulated, but by the injection mold has a placeholder, which is sprayed or cast. The placeholder provides a cavity in the molded skin, in which, after removal of the molded skin from the injection mold, the unit of optical fiber and protective layer is introduced. The placeholder may in this case be provided integrally with the injection mold, or this may be subsequently attached thereto and / or attached. The placeholder may be loose or fixed. The injection mold can be retrofitted, for example, with such a placeholder for the light guide.

The inventive method allow a connection of the molded skin with a light guide in a simple, yet stable and visually very appealing way. Steps of separate gluing or sewing a light guide / sheath combination are not required. In addition, the method provides protection against touching and thus scratching the light guide. On adhesive bonds or compounds which apply a non-uniform pressure on the light guide can be dispensed with, whereby the uniformity of the light emission is ensured. There are thus no structures of light and dark along the light guide, if such uniformity of the light emission is desired.

If the light guide to be sprayed or to be encapsulated is introduced into the injection mold, it is preferably fixed in the mold. This can be done via temporary glue joints, via clip connections, via a vacuum fastening method or otherwise. It is important that the light guide is not damaged when mounted in the injection mold. In some cases, it may be sufficient if the optical fiber is inserted into a correspondingly shaped receptacle in the injection mold. On additional fixatives can then be waived if necessary.

Preferably, the protective layer is a textile layer or a film. Since a three-dimensional installation of the light guide may be desirable, textile protective covers are particularly well suited. It is important to ensure that the textile has a sufficiently small mesh size, so that the material of the molded skin during encapsulation or encapsulation is not in contact with the actual optical fiber material, as this can adversely affect the luminous behavior of the light guide. Similar to a textile cover, a film is also suitable for protection against the surface of the molded skin. As the contour lighting may also be very three-dimensional, d. H. may be intended with fairly small radii of curvature, it may be difficult to lay a flat, flat sheet around the light guide. Therefore, other scenarios are conceivable. In particular, the optical waveguide can be inserted into a prefabricated molded envelope, and this optical waveguide composite is then placed in the injection mold for encapsulation or encapsulation. Alternatively, the light guide can be placed in a prefabricated, optionally longitudinally slotted extrusion envelope. Extrusion sleeves are often available by the meter and should be as flexible as possible in order to be able to follow the three-dimensional contour. Alternatively, a coating by means of dipping or painting the light guide with a clear material is feasible. It should be noted here, as with the other claddings, that the refractive index of the coating is smaller than the refractive index of the optical waveguide in order to fulfill the condition for total reflection.

It follows that it is particularly preferred that the optical fiber material comes into direct contact with the protective layer except for any air layer therebetween, and the protective layer in turn comes into direct contact with the material of the molded skin. The protective layer thus provides a synergistic effect in that it not only protects the optical fiber from damage or other external influences, but also takes over the function of a cladding layer. In this case, no "separate" cladding layer must be provided. It should be noted that rough surfaces are usually more suitable for the fiber optic sheath than smooth ones. Smooth surfaces nestle against the surface of the optical fiber over a large area and degrade the light pipe. Rough surfaces are only punctual. An example of this is an optical fiber / sheath combination in which the optical fiber base body is injection molded from PC, and the sheath or protective layer of PMMA, in which case the refractive index N _{PC of} the PC layer 1.53 and the refractive index N _{PMMA of} the PMMA Layer is 1.49, whereby the condition for total reflection is satisfied.

The protective layer preferably has a fastening lug which extends away from the optical waveguide in the cross section of the optical waveguide and is embedded in the molded skin in the production of the molded skin. If the protective layer is formed, for example, by a textile, then this can be laid around the actual optical fiber, leaving a strip of material extending away from the optical fiber. The mounting lug is in this case formed integrally with the protective cover. However, this is not absolutely necessary. Rather, one or more fastening lugs can be connected to the protective cover. By embedding the or the mounting lugs in the molded skin a more stable integration and accurate positioning of the light guide is enabled in the molded skin.

Due to the outstanding for the present purpose properties is particularly advantageous as a light guide PMMA fiber with a diameter between 0.2 to 3.0 mm. As already mentioned above, it is particularly advantageous if the optical fiber made of PMMA is in direct contact with the protective sleeve and the latter in turn is in direct contact with the molded skin. Additional layers which serve for the reinforcement or the production of the total reflection and the like can thus be dispensed with.

Preferably, the light guide has one or more roughened areas. The roughened areas may in particular be linear and extend along the longitudinal direction of the light guide. If a plurality of roughened lines or areas are provided, the light properties of the light guide can be made invariant or at least less susceptible, in particular, to rotations of the light guide relative to the molded skin. The roughening of the light guide provides regions of the light extraction. The homogeneity of the radiated light and other luminous properties can thus be adjusted with the manner of the roughening.

Methods have been described for making a composite of molded skin and optical fiber. Such a composite can be provided as a semi-finished product that is further processed to an interior judgment elsewhere. Although the present invention has been explained with reference to the application of an automobile, it should be understood that the present invention may be practiced in other fields, such as transportation, particularly aerospace and marine, furniture, home automation, etc. However the present invention particularly suitable for vehicle interiors, as it depends here in a very high degree on a pleasing appearance with high production productivity. In addition, other advantages and features of the present invention will become apparent from the following description of preferred embodiments. The features described therein may be implemented alone or in combination with one or more of the features mentioned above insofar as the features are not contradictory. The following description of the preferred embodiments will be made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

1A to 1C schematically show a cross section through an injection mold, in which a unit of optical fiber and protective layer is inserted.

2 schematically shows a section through an injection mold, which is provided with a placeholder for a light guide.

3A shows a cross section through an injection mold with inserted optical fiber and molded molded skin;

3B shows the taken out of the injection mold composite of optical fiber and molded skin.

4A and 4B show in three dimensions a combination of light guide and molded skin.

5A and 5B show an embodiment in which the light guide is provided for illuminating a joint.

6A and 6B show another variant for joint lighting, which is not part of the invention.

7 shows a light guide with protective layer to which a fastener is attached.

WAYS FOR CARRYING OUT THE INVENTION

1 schematically shows a cross section through a syringe mold 1 , which is designed as Galvanoform. The injection mold 1 has an insert area 2 in which a unit of optical fiber 10 and protective layer 11 is inserted. The loading area 2 may be means for attaching the light guide 10 exhibit. For example, the light guide 10 as it is in 1C is shown by means of vacuum fixation at the insertion area 2 be attached. On the protective cover or protective layer 11 is a fastening flag 12 intended. The fastening flag 12 is also referred to as a fastening nose or fastening strip. Is the protective cover 11 Made of a textile, so can the fastening flag 12 For example, be formed from protruding material strips, which, as it is in the 1A to 1C is shown by the light guide 10 extend away. The light guide 10 becomes partial and the fastening flag 12 completely in a molded skin 20 embedded, which against the spray area 3 the Galvanoform 1 sprayed or sprayed. This becomes a decorative surface 21 the molded skin 20 trained, on the other hand, the light guide 10 partly in the form skin 20 embedded. The fastening flag 12 This is completely in the molded skin 20 embedded, creating an even more intimate integration of the light guide 10 he follows. 1B represents an alternative cross section of the molded skin 20 with integrated light guide 10 represents.

In the 1C is a mold 1 with a vacuum opening 5 for fixing the light guide 10 shown. By creating a vacuum or a negative pressure in the opening 5 and in the adjoining channel is the light guide 10 sucked on the other side of the channel, creating a temporary and gentle attachment of the light guide 10 is accomplished for the time of encapsulation or Umgießens.

Another geometry made of molded skin 20 and light guides 10 , which is particularly suitable for indirect lighting, is in the 3A and 3B shown. The emission direction of the light guide 10 is here for the most part against the skin 20 directed. Furthermore, the light guide 10 so hidden that it is not directly visible to a passenger.

In the embodiments shown above, the light guide 10 into the Galvanoform 1 inserted. Alternatively, the injection mold 1 a placeholder 4 exhibit as it is in 2 is shown. When molding or sprinkling the plastic material to form the molded skin 20 arises in the form skin 20 a recess through the placeholder 4 , in after removing the molded skin 20 from the injection mold 1 the light guide 10 or the unit of optical fiber 10 and protective layer 11 is introduced. In the 2 is the placeholder 4 integral with the injection mold 1 shown. However, the placeholder can 4 Also be provided as a separate part, if necessary in the injection mold 1 is introduced.

The 4A and 4B show a finished semi-finished product made of molded skin 20 and light guides 10 , The light guide 10 is from a protective cover 11 surrounded, in turn, with a fastening flag 12 Is provided. From the 4A and 4B In particular, the flexibility of the composite that can be achieved with the described methods is apparent. This allows almost any illumination contours in the vehicle interior to be generated.

When spraying or encapsulating the optical fiber 10 with the plastic material of the molded skin 20 which is, for example, a spray skin, a slush skin, a PVC skin, etc., becomes the light guide 10 already in the production of the molded skin 20 in the molded skin 20 integrated. This allows a later installation of the light guide 10 remain under.

Alternatively, as described above, in the injection mold 1 a placeholder 4 or dummy light guide be installed, whereby after removal from the mold a recess in the molded skin 20 for the light guide 10 remains. The light guide 10 can then later in the skin 20 or be built only after the completion of the Interie judgment. In particular, the light guide 10 after any foaming of the molded skin 20 be built, which may bring a procedural advantage.

The protective layer 11 of the light guide 10 must be provided so that the liquid surface material for the molded skin 20 does not get onto the optical fiber surface. In addition, since the contour lighting should also be provided in three dimensions under certain circumstances, it may be difficult, a flat, flat film around the light guide 10 to lay. Therefore, in addition to the textile already mentioned following scenarios are conceivable: the light guide 10 can be placed in a prefabricated protective cover, and this optical fiber / sheath composite can in the injection mold 1 be inserted. The light guide 10 could be placed in a prefabricated, optionally longitudinally slotted extrusion sleeve. The extrusion cover should be very flexible in order to follow the three-dimensional contour. A coating by dipping or painting the light guide 10 is also conceivable, for example, with a clear material, wherein the relative refractive indices between the light guide 10 and the protective cover 11 must be met for total reflection. Rough surfaces are for the light guide shell 11 better suited as smooth. Smooth surfaces nestle over a large area of the light guide surface and usually deteriorate the light pipe. Rough surfaces, however, are only punctual.

The 5A and 5B show the application of the fiber optic / molded skin composite for joint staging. The 5B here is an enlarged section of the 5A by the reference numeral 31 should be designated here an area in the cockpit, in a joint 30 passes. On the other side is the door area 32 partially, namely in the field 33 in the shade. The light guide 10 produces indirect lighting, here an indirect joint lighting. By the edge 34 In the door area, an indirectly illuminated line with a defined width B is generated. The geometry of the visible joint area is designed to give the impression of a direct line of light. Regardless of the gap width, the observer always sees an equally wide light band. If possible, this illuminated area should have a lighter color, different from black, so that the area stands out clearly from the surroundings when illuminated. The lighting element is an injection molded optical fiber as set forth above 10 which is integrated into a molded skin of the decorative part.

The light guide 10 may for example have a diameter of 1 mm, with optical fibers with a diameter of up to 5 mm are conceivable. The composite of optical fiber 10 and protective layer 11 was overmolded or poured. The maximum visible width of the line illumination is then determined by the protective layer diameter, typically less than 2 mm, in the above case.

An alternative embodiment of the joint staging, which is not part of the invention but is used to understand the invention is in the 6A and 6B shown. Here is the 6B again an enlarged section of the 6A In this arrangement, the optical fiber is located 10 visible directly in the gap, for example between the door 32 and cockpit 31 , One can imagine that the flexible light guide 10 on a rubber-like element 40 is fixed and thereby creates an illuminated Nullfuge.

The 7 shows a light guide 10 with protective layer 11 on which a fastening flag 12 is provided. To the integration between optical fibers 10 and molded skin 20 To further improve, may be at the mounting flag 12 a fastener 13 be provided. With this fastener 13 becomes the light guide 10 kept safe. In particular, when the optical fiber 10 a very filigree element, for example, 1 mm in diameter, is an additional fastener 13 advantageous, for example, then may have a diameter of 2 mm. The fastener 13 may have a suitable cross section, for example in the form of a barbed Christmas tree structure. The protective layer 11 this can advantageously as a protective cover 11 be designed, which is optionally present as an extrusion sheath and with a cavity for receiving the optical fiber 10 Is provided. The subsequent insertion of the light guide 10 in this cavity also has the advantage that the light pipe is less affected, as an air layer between the cladding and light guide 10 located.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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

• DE 19724486 A1 [0003]
• DE 19724487 A1 [0004]

Claims (15)

Process for producing a composite from a molded skin ( 20 ) and a light guide ( 10 ), in particular for use for interior parts in vehicle interiors, the method comprising the following steps: a) providing a light guide ( 10 ); b) surrounding the light guide ( 10 ) with a protective layer ( 11 ) along substantially the entire lateral surface of the light guide ( 10 ); c) inserting the unit of optical fiber ( 10 ) and protective layer ( 11 ) in an injection mold ( 1 ) for the formation of the molded skin ( 20 ); d) spraying or casting the molded skin ( 20 ), with simultaneous at least partial spraying or pouring the unit of optical fiber ( 10 ) and protective layer ( 11 ), whereby the light guide ( 10 ) in the molded skin ( 20 ) is embedded. A method according to claim 1, characterized in that the unit of optical fiber ( 10 ) and protective layer ( 11 ) before and / or during the spraying or casting in the injection mold ( 1 ) is fixed. Process for producing a composite from a molded skin ( 20 ) and a light guide ( 10 ), in particular for use for interior parts in vehicle interiors, the method comprising the following steps: a) providing an injection mold ( 1 ) for forming a molded skin ( 20 ) for an interior judgment, wherein the injection mold ( 1 ) a placeholder for a light guide ( 10 ) having; b) spraying or casting the molded skin ( 20 ), with simultaneous at least partial spraying or pouring over the placeholder; c) providing a light guide ( 10 ); d) surrounding the light guide ( 10 ) with a protective layer ( 11 ) along substantially the entire lateral surface of the light guide ( 10 ); e) inserting the unit of optical fiber ( 10 ) and protective layer ( 11 ) in the resulting by the placeholder cavity of the molded skin ( 20 ). Method according to one of the preceding claims, characterized in that the protective layer ( 11 ) is a textile layer or a film. Method according to one of the preceding claims, characterized in that the protective layer ( 11 ) a fastening flag ( 12 ), which in cross-section of the light guide ( 10 ) seen from the light guide ( 10 ) and when forming the molded skin ( 20 ) in the molded skin ( 20 ) is embedded. Method according to one of the preceding claims, characterized in that in the molded skin ( 20 ) embedded part of the protective layer ( 11 ) both directly with the light guide ( 10 ) as well as directly with the material of the molded skin ( 20 ) is in contact. Method according to one of the preceding claims, characterized in that the light guide ( 10 ) has no separate cladding layer. Method according to one of the preceding claims, characterized in that the light guide ( 10 ) consists of PMMA. Method according to one of the preceding claims, characterized in that the light guide ( 10 ) is roughened along one or more lines along its extent. Composite of a molded skin ( 20 ) and an integrated light guide ( 10 ), wherein the light guide ( 10 ) along the lateral surface substantially completely with a protective layer ( 11 ) is surrounded and the unit of optical fiber ( 10 ) and protective layer ( 11 ) at least partially from the molded skin ( 20 ) is poured or sprayed over. Composite according to claim 10, characterized in that the protective layer ( 11 ) is a textile layer or a film. Composite according to claim 10 or 11, characterized in that the protective layer ( 11 ) a fastening flag ( 12 ), which in cross-section of the light guide ( 10 ) seen from the light guide ( 10 ) and extends into the skin ( 20 ) is embedded. Composite according to one of claims 10 to 12, characterized in that in the molded skin ( 20 ) embedded part of the protective layer ( 11 ) both directly with the light guide ( 10 ) as well as directly with the material of the molded skin ( 20 ) is in contact. Composite according to one of claims 10 to 13, characterized in that the light guide ( 10 ) consists of PMMA and has no separate cladding layer. Composite according to one of claims 10 to 14, characterized in that the light guide ( 10 ) is roughened along one or more lines along its extent.

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