DECORATIVE PART AND METHOD FOR PRODUCING SAME

Abstract

A decorative part and a method for producing a decorative part, wherein the decorative part is in particular a lining part of a motor vehicle. The decorative part has a decorative coat which is provided on the rear side with a reinforcing layer and/or on the visible side with a transparent coating. In order to improve the durability or the optical properties, in particular, of a decorative part provided with a light guide for transilluminating and/or backlighting the decorative coat, the decorative part is post processed by a laser treatment.

Claims

1. Decorative part, in particular lining part for a motor vehicle, having a decorative coat which is provided on a rear side with a reinforcing layer and/or on a visible side with a transparent coating wherein the decorative part is post-processed by laser treatment.

2. Decorative part according to claim 1, wherein an edge of the decorative part is provided with an edge protection wherein the edge protection is formed by laser cutting of the edge of the decorative part.

3. Decorative part according to claim 1, wherein a light guide is provided on the rear side for transilluminating and/or backlighting the decorative coat, wherein a surface of the light guide is laser-processed for applying a shadow pattern.

4. Method for producing a decorative part, in which a decorative coat is provided on a rear side with a reinforcing layer and/or on the visible side with a transparent coating, an intermediate product produced in this way is trimmed to produce a final contour and then laser-processed.

5. Method according to claim 4, wherein an edge of the decorative part is laser-processed.

6. Method according to claim 5, wherein the laser processing carbonizes material of the decorative part to form an edge protection.

7. Method according to claim 4, wherein a light guide provided on the rear side for transilluminating and/or backlighting the decorative coat is laser-processed.

8. A method for producing a decorative part comprising the steps of: forming a decorative layer on a reinforcing layer forming an intermediate product having a circumference; and melting the decorative layer and the reinforcing layer on a part of the circumference with a laser.

9. A method for producing a decorative part as recited in claim 8 wherein: said step of melting further comprises carbonization.

10. A method for producing a decorative part as recited in claim 8 further comprising: prior to said step of forming a decorative layer on a reinforcing layer and said step of melting, forming another decorative layer having through holes on the decorative layer; and molding the reinforcing layer forming projections with the decorative layer extending into the through holes.

11. A method for producing a decorative part as recited in claim 10 wherein: the reinforcing layer comprise a light guide and the projections comprise optical lenses.

12. A method for producing a decorative part as recited in claim 11 further comprising the step of: placing a light source adjacent an edge of the reinforcing layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further details and advantages of the present invention will be apparent from the following description of embodiments in conjunction with the drawing. Therein:

[0020] FIG. 1 shows a perspective sectional view of the embodiment;

[0021] FIG. 2 shows a top view of the rear side of the light-guiding layer of the embodiment;

[0022] FIG. 3 shows a top view of the front side of the light-guiding layer;

[0023] FIG. 4 shows an enlarged detail of the view according to FIG. 3;

[0024] FIG. 5 shows a longitudinal sectional view through a light guide dome of the embodiment with some beam paths,

[0025] FIG. 6 shows a sectional view of a second embodiment, and

[0026] FIG. 7 shows a schematic view of the decorative part during post-treatment by laser.

DETAILED DESCRIPTION OF THE INVENTION

[0027] FIG. 1 shows a decorative part 2 which is provided with a multilayer decorative coat 4. In the present case, the decorative layer consists of a double overmolded decorative layer 6. A transparent coating 8 is applied by overmolding to the front of the decorative layer 6 as a cover to protect the decorative layer 6. On the opposite rear side of the decorative layer 6, a reinforcing layer 10 is provided by injection molding. During injection molding, the reinforcing layer 10 is formed in one piece with pins 12, which will be discussed in more detail later.

[0028] The decorative layer formed in the embodiment has a front surface 14 formed by the coating 8.

[0029] A light-guiding layer 16 is arranged on the opposite rear side of the decorative coat 4. This light-guiding layer is provided for backlighting the decorative coat 4.

[0030] The light-guiding layer 16 is provided on the rear side with a reflector film 18 forming a reflector layer.

[0031] The light-guiding layer 16 is provided between the multilayer decorative coat 4 and a substrate 20, which also serves as a rear side cover and forms fastening pins 22 for fastening the substrate 20 and thus the decorative part 2 to a chassis of a vehicle.

[0032] As can be seen in FIG. 1, a light guide in the form of a light guide dome characterized by reference sign 24 extends through the substrate 20. This light guide dome 24 has a column segment 26 and a funnel section 28 and carries an LED as a light element 30 at its free end. While the column segment 26 is formed of solid material and is formed as a slightly conically widening light guide which emits the light generated by the light element 30 substantially at right angles to the decorative coat 4, the funnel section 28 acts as a light guide which deflects the light from this right-angled alignment along a central longitudinal axis L of the light guide dome 24 so that it is emitted parallel to the plane of the light-guiding layer 16 into this layer 16.

[0033] The funnel section 28 surrounds a shading element 32, which is provided between the column segment 26 and the decorative coat 4 and is rotationally symmetrical in the present case.

[0034] Details of the light guide dome 24 can be seen in FIGS. 2 and 3. FIG. 2 shows a shadow pattern 34 formed at the free end of the column segment 26 by means of laser treatment, against which the LED 30 is placed with its light-emitting surface. This shadow pattern 34 is illuminated by the LED 30. This results in a corresponding shadow pattern on the front surface 14. By laser treatment, for example, a lettering or a logo can be applied, which appears as a corresponding shadow pattern on the front surface 14. This makes it possible to customize the decorative part 2.

[0035] FIG. 2 further shows a structural grid 36 provided on the rear side of the light-guiding layer 16 and comprising a plurality of spherical caps with a radius of 1 mm and a height of 0.34 mm. This structural grid 36 serves to emit light in the direction of the decorative coat 4. FIG. 2 further shows longitudinal slits 38, to which corresponding longitudinal slits 40 are cut out on the substrate 20. As FIG. 1 illustrates, the pin 12 protrudes through the longitudinal slits 38, 40, which are to be regarded as pin openings in the sense of the present invention. FIG. 1 shows the pin 12 before hot caulking. After hot caulking, the free end of the pin 12 is plastically deformed and abuts against a locking surface 42 formed on the rear side of the longitudinal slit 40. On the opposite side, the substrate 20 forms a supporting surface 44 against which the flat light-guiding layer 16 abuts over a relatively full area, so that the tensile force caused by the caulked pin 12 does not result in any deformation of the light-guiding layer 16 that could impair the light-guiding properties of the layer 16.

[0036] The free end region of the light guide dome 24, formed primarily by the pillar or column segment 26, is hexagonal to optimize color mixing when using an RGB LED as a lighting element.

[0037] As FIG. 3 illustrates, the shading element 32 is in the form of an injection-molded funnel which has a plurality of bores 46 distributed around its circumference, each of which tapers off towards the decorative coat 4 in the form of a funnel. The bores 46 serve as apertures that partially absorb and partially transmit and thereby scatter the light emitted from the light guide dome 24 toward the decorative coat 4, so that it emerges scattered from the shading element 32 on the front surface thereof facing the decorative coat 4. The shading element 32 has a cone-shaped projection 48 positively coupled to the tapered end portion of the funnel section 28 and positioned centrally with respect to the central longitudinal axis L.

[0038] As FIG. 4 illustrates, the shading element 32 extends radially to above a reflector identified by reference sign 50, which has a crescent-shaped course in top view and is thus provided partly below the shading element 32 and partly radially outside it, and the reflector surface 52 of which extends substantially parallel to the longitudinal center axis L.

[0039] The production of the embodiment shown in the Figures is as follows: First, the decorative layer 6 is back injection molded with the reinforcing layer 10 and then overmolded with the coating 8 on the visible side to obtain the decorative coat 4 together with the pins 12. In parallel, for example, injection molding is used to form the light-guiding layer 16 as a unitary component together with the light guide dome 24. It is understood that multiple light guide domes 24 may be provided depending on the size of the light-guiding layer 16. Then, with recessing of a substantial part of the light guide domes 24, the reflector film 18 is applied against the rear side of the light guide layer 16 and joined thereto, in particular glued. These components are joined to the substrate 20, which is produced separately by means of injection molding, by aligning the two longitudinal slits 38, 40 with respect to one another and passing them through with the pin 12. This is melted to its end projecting beyond the substrate 20, resulting in a thickened region that abuts against the locking surface 42. Typically, only then is the LED glued on and wired for power. This wiring can be done via a printed circuit board that electrically connects a plurality of LEDs 30, and can be provided on the rear side of the substrate 20 and/or abut on the rear side of the substrate 20.

[0040] FIG. 5 shows a sectional view of a light guide dome 24 with beam paths. For example, light rays directed via the column segment 26 reach the reflector 50 and are reflected at its surface. The ray path, identified by reference sign I, strikes the reflector 50 at a relatively acute angle and is reflected by a segment of the structural grid 36 immediately adjacent the funnel section and is emitted through the front surface of the light-guiding layer 16.

[0041] The light beam, identified by reference sign II, strikes the surface of reflector 50 at a relatively obtuse angle and is passed through the light-guiding layer 16 substantially parallel thereto.

[0042] The light beam, identified by reference sign III, passes through the bore 46 and is reflected within the bore and emitted in the direction of the decorative layer 6.

[0043] These and other reflection effects result in uniform backlighting of the decorative layer 6.

[0044] In FIG. 6, reference sign 62 identifies a second decorative coat that forms a visible surface 62a that can be provided with a transparent layer as a coating, which is not shown. Opposite the visible side surface 62a is a lamination 64, which is joined to a rear side surface of the second decorative coat 62 in a first lamination step. In a top view of the embodiment or the visible side 62a, a first decorative layer 66 is provided behind the first lamination 64. This first decorative layer 66 is formed as a continuous decorative layer. In the viewing direction behind it, there is a second lamination 68 which connects the first decorative layer 66 to a reinforcing layer 70.

[0045] The second decorative coat 62 is provided with a plurality of through-holes 72. These through-holes are formed before the reinforcing layer 70 is formed. Before forming the reinforcing layer 70, the first decorative layer 66 and the second decorative coat 62 each lie on top of one another as a flat decorative layer. The injection molding of the reinforcing layer 70 forces surface portions 74 of the first decorative layer 66 into the through-holes 72, so that these surface portions 74 lie in the plane of the second decorative coat 62. This situation is shown in FIG. 6. As a result of the receding of the first decorative layer 66 in the direction of the through-holes 72, projections are formed by the material of the reinforcing layer 70 which act as optical lenses and are characterized in the drawing by reference sign 76. In the embodiment shown, the through-holes 72 have an edge geometry that extends orthogonally from the visible surface. Thus, the through-holes 72 are formed as cylindrical through-holes.

[0046] Reference sign 78 indicates a light source that introduces light laterally into the reinforcing layer 70, which in the embodiment acts as a light guide.

[0047] This results in a specific emission of the incident light in the region of the projections 76. The projections 76 emit a higher proportion of light from the reinforcing layer 70 than flat segments 80, which are arranged between the projections 76 and extend parallel to the rear side of the second decorative coat 62. In these regions, this decorative molding has a strictly plane-parallel layered structure in which the layers of the first and second decorative coats 62, 66 and bonding agent layers 64, 68 provided therebetween and the flat segments 80 of the reinforcing layer 70 extend parallel to each other.

[0048] The projections 76 project from the flat segments 80 with their flank surfaces directed obliquely towards each other.

[0049] In FIG. 6, reference sign 82 identifies an edge protection applied to a circumferential edge 81, which almost completely surrounds the decorative part 2′. The laser treatment causes carbonization of at least the plastic reinforcing layer 70. The edge protection 82 covers the entire edge from the visible side of the second decorative coat 62 to the lower side of the reinforcing layer 70 and accordingly seals all decorative coats 62, 66 circumferentially. Only in the region of the light source 78 is the edge protection 82 removed by post-treatment, so that the light source 78 can inject light into the reinforcing layer 70.

[0050] FIG. 7 shows an example of production of the edge protection. A robot 84 handles the decorative part 2′ and positions it relative to a fixed laser source 86, which applies the edge protection 82 by laser post-processing.

[0051] As a result of this laser post-processing, light is not emitted from the light-guiding layer. The decorative part 2 is shaded at the edge and does not emit any light at the edge.

LIST OF REFERENCE SIGNS

[0052] 2 decorative part

[0053] 4 decorative coat

[0054] 6 decorative layer

[0055] 8 coating

[0056] 10 reinforcing layer

[0057] 12 pin

[0058] 14 front surface

[0059] 16 light-guiding layer

[0060] 18 reflector film

[0061] 20 substrate

[0062] 22 fastening pin

[0063] 24 light guide dome

[0064] 26 column segment

[0065] 28 funnel section

[0066] 30 light element/LED

[0067] 32 shading element

[0068] 34 shadow pattern

[0069] 36 structural grid

[0070] 38 longitudinal slit

[0071] 40 longitudinal slit

[0072] 42 locking surface

[0073] 44 supporting surface

[0074] 46 bore

[0075] 48 cone-shaped projection

[0076] 50 reflector

[0077] 52 reflector surface

[0078] L center longitudinal axis of the light guide dome

[0079] 2′ decorative part

[0080] 62 second decorative coat

[0081] 62a visible side surface

[0082] 64 bonding agent layer/first lamination

[0083] 66 first decorative coat

[0084] 68 second lamination/bonding agent layer

[0085] 70 reinforcing layer

[0086] 72 through-hole

[0087] 74 surface portion

[0088] 76 projection

[0089] 78 light source

[0090] 80 flat segment of the reinforcing layer 10

[0091] 81 edge

[0092] 82 edge protection

[0093] 84 robot

[0094] 86 laser source