Vehicle External Surface Component and Method for Producing a Vehicle External Surface Component

Abstract

A vehicle external surface component is disclosed having a layer structure having an SMC layer forming an outer skin layer and having a reinforcing structure connected to the SMC layer and having a core layer, wherein, according to some embodiments, the SMC layer has a reduced thickness of, for example, less than 2 mm, in particular 1.5 mm to 2.0 mm and particularly preferably 1.5 mm to 1.8 mm and/or has a reduced density of less than 1.3 kg/dm.sup.3, in particular between 1.2 kg/dm.sup.3 and 1.0 kg/dm.sup.3. The disclosure further relates to a method for producing such a vehicle external surface component.

Claims

1. A vehicle external surface component having a layered structure with an SMC layer forming an outer skin layer and having a reinforcing structure connected to the SMC layer and comprising: a core layer, wherein the SMC layer has a reduced thickness of less than 2 mm.

2. The vehicle external surface component as claimed in claim 1, wherein the SMC layer is formed by the addition of fillers or hollow glass beads with a reduced density compared to the SMC layer.

3. The vehicle external surface component as claimed in claim 1, wherein the SMC layer has a weight per unit area of less than 4 kg/m.sup.2.

4. The vehicle external surface component as claimed in claim 1, further comprising a paintable in-mold coat layer applied to the SMC layer and together with the SMC layer forms the outer skin layer.

5. The vehicle external surface component as claimed in claim 1, wherein the reinforcing structure comprises an inner cover layer of plastic that is produced from polyurethane applied to the core layer on its inner side that is opposite the outer skin layer.

6. The vehicle external surface component as claimed in claim 1, further comprising the outer skin layer applied to the outer side of the core layer facing the outer skin layer by an outer cover layer of plastic produced from polyurethane.

7. The vehicle external surface component as claimed in claim 5, wherein the inner cover layer of plastic comprises one of a fiber reinforcement or a fiber mat and wherein the outer cover layer of plastic comprises one of a fiber reinforcement or a fiber mat.

8. The vehicle external surface component as claimed in claim 1, wherein the core layer of the reinforcing structure is produced from one of a honeycomb or a foam, wherein the honeycomb is produced from one of paper, aluminum or a phenolic resin.

9. A method for producing a vehicle external surface component as claimed in claim 1, comprising the steps of: a) producing an SMC layer including a thin IMC layer as a semifinished product forming an outer skin layer, b) inserting the coated SMC layer into a mold half of a composite mold, c) pressing a reinforcing structure bearing the outer skin layer and comprising a core layer covered with at least one cover layer of plastic into the SMC layer with an as yet uncrosslinked adhesive or polyurethane so as to shape the vehicle external surface component, and d) demolding the vehicle external surface component.

10. The method as claimed in claim 9, wherein, after the step of demolding of the vehicle external surface component comprises the additional step of trimming to size the edges of the vehicle external surface component.

11. The method as claimed in claim 9, wherein in the step of producing an SMC layer the thin IMC layer is provided with an outer-surface paint finish or the SMC layer is provided with a paintable thin IMC layer; and further comprises the step of painting the vehicle external surface component.

12. A method for producing a vehicle external surface component as claimed in claim 1, comprising the steps of: a) producing an SMC layer as a semifinished product in a standard production method for SMC components, b) inserting the SMC layer into a first mold half of a molding tool and pressing the SMC layer by a second mold half, c) applying an IMC paint layer to the SMC layer facing the first mold half to form an outer skin layer, d) exchanging the second mold half for a second mold half with an enlarged mold cavity, e) inserting a reinforcing structure bearing the outer skin layer and comprising a core layer covered by at least one cover layer of plastic into the enlarged mold cavity, and f) pressing the reinforcing structure into the SMC layer with an as yet uncrosslinked adhesive or polyurethane to shape the vehicle external surface component.

13. The vehicle external surface component as claimed in claim 1, wherein the SMC layer has a reduced thickness of between 1.5 mm to 2.0 mm.

14. The vehicle external surface component as claimed in claim 1, wherein the SMC layer has a reduced thickness of between 1.5 mm to 1.8 mm.

15. The vehicle external surface component as claimed in claim 1, wherein the SMC layer has a reduced thickness of less than 2 mm and has a reduced density of less than 1.3 kg/dm.sup.3.

16. The vehicle external surface component as claimed in claim 1, wherein the SMC layer has a reduced density of less than 1.3 kg/dm.sup.3.

17. The vehicle external surface component as claimed in claim 1, wherein the SMC layer has a reduced density of between 1.2 kg/dm.sup.3 and 1.0 kg/dm.sup.3.

18. The vehicle external surface component as claimed in claim 1, wherein the SMC layer has a reduced thickness of between 1.5 mm to 1.8 mm, and has a reduced density between 1.2 kg/dm.sup.3 and 1.0 kg/dm.sup.3.

19. The vehicle external surface component as claimed in claim 1, wherein the SMC layer (9) has a weight per unit area of between 2.5 kg/m.sup.2 and 1.2 kg/m.sup.2.

Description

[0022] The invention is explained in more detail below on the basis of exemplary embodiments of a vehicle external surface component according to the invention with reference to the drawing, in which;

[0023] FIG. 1 shows a vehicle external surface component according to the invention in a sectional view;

[0024] FIG. 2 shows an outer skin layer of the vehicle external surface component from FIG. 1 in a sectional view;

[0025] FIG. 3 shows a molding tool with two closed mold halves and an SMC semifinished product of the vehicle external surface component arranged therein during a first production step, in a sectional view; and

[0026] FIG. 4 shows the molding tool with a second exchanged mold half and a vehicle external surface component arranged therein during a second production step, in a sectional view.

[0027] A vehicle external surface component 1, e.g. a cover of a roof module or an openable roof such as a sliding roof, comprises a reinforcing structure 2 with a core layer 3 which is produced from a honeycomb, e.g. a paper honeycomb, or from a foam. The core layer 3 is provided on each side, i.e. toward the component outer side 4 as well as toward the component inner side 5 of the vehicle external surface component 1, with a cover layer of plastic 6 and 7 respectively. The outer cover layer of plastic 6 as well as the inner cover layer of plastic 7 contain or are formed by a thin adhesive layer consisting in particular of polyurethane, and contain in particular a reinforcing fiber layer or fiber mat consisting e.g. of a fibrous material with basalt fibers, carbon fibers, natural fibers or glass fibers.

[0028] An outer skin layer 8 of the vehicle external surface component 1 is connected to the reinforcing structure 2 and/or the core layer 3 by means of the plastic or polyurethane of the outer cover layer of plastic 6. The outer skin layer 8 is formed from an inner layer and an outer layer. The inner layer is a thin, reduced-density and unpaintable SMC layer 9. The outer layer consists of an in-mold coat (IMC) layer 10.

[0029] In comparison with known SMC components the SMC layer 9 is formed with a reduced thickness of less than 2 mm. It is preferred that the SMC layer 9 has a thickness of 1.5 mm to 2.0 mm and in particular of 1.5 mm to 1.8 mm. Furthermore, the SMC layer 9 has a reduced density of less than 1.3 kg/dm.sup.3 and in particular between 1.2 kg/dm.sup.3 and 1.0 kg/dm.sup.3.

[0030] The reduced density in comparison with known SMC components or SMC semifinished products may be brought about e.g. by the corresponding addition of fillers such as hollow glass beads.

[0031] The outer cover layer of plastic 6 as a fiber-containing layer may also be omitted if the SMC layer 9 concomitantly takes on the structural properties of the outer cover layer of plastic 6. The SMC layer 9 is then adhesively bonded directly to the core layer 3 only by means of plastic, such as e.g. polyurethane.

[0032] A method for producing such a vehicle external surface component 1 provides that first, an SMC layer 9 including a paintable outer thin IMC layer 10 as a semifinished product is produced in a standard production method for SMC components.

[0033] The semifinished product (SMC layer 9 with IMC layer 10) is then inserted into a mold half of a composite mold. If required, the semifinished product is sucked onto the mold half with a vacuum.

[0034] In another downstream method step, the reinforcing structure 2 is pressed into the semifinished product with an as yet uncrosslinked adhesive (e.g. polyurethane). In this method step, the surface of the reinforcing structure 2 facing the SMC layer 9 is shaped.

[0035] After the demolding of the composite component or vehicle external surface component 1, further method steps are optionally performed, such as e.g. trimming or cutting to size the edges of the vehicle external surface component 1. The vehicle external surface component 1 can then be painted in the color of the car or in a contrasting color.

[0036] Another alternative method (see FIGS. 3 and 4) represents the combination of an SMC process with a composite process. A molding tool 11 comprises a first or top mold half 12 and a second or bottom mold half 13. In a mold cavity 14 between the two mold halves 12 and 13, first the SMC layer 9 is pressed and then flooded with an IMC paint layer 10 on the later component outer side by means of the first or top mold half 12 (Class A mold half). As a departure from the first-mentioned method, the semifinished product and/or the outer skin layer 8 (the SMC layer 9 with the IMC paint layer 10) is not removed from the molding tool 11, but rather the counterpunch of the molding tool 11, i.e. the bottom mold half 13, is replaced by an exchanged second mold half 13 to produce the final composite geometry. This can be performed by exchanging the counterpunch and/or by shuttling or moving the mold halves 13 and/or 13, the SMC layer 9 remaining on the top mold half 12. The exchanged bottom mold half 13 comprises an enlarged mold cavity 14 in which the reinforcing structure 2 is arranged. The composite process then takes place, in which the reinforcing structure 2 is pressed against and connected to the SMC layer 9 of the outer skin layer 8.

[0037] As an alternative, the bottom mold half 13 may also be the Class A mold half and both the bottom mold half 13 and the upper mold half 12 may be shuttled. The SMC layer 9 may also optionally remain on the bottom mold half 13 and the process for applying the reinforcing structure 2 may take place in a second pressing tool.

[0038] A great advantage of this method is the omission of additional handling steps for moving the semifinished product, the avoidance of damage to the later surface, and the avoidance of contamination of the composite mold with impurities.

[0039] The individual features of the invention disclosed in the description and on the basis of the exemplary embodiments as well as in the figures may be combined with the subject-matter of the invention in its general form in any technically expedient arrangements and configurations.

TABLE-US-00001 List of reference signs 1 Vehicle external surface component 2 Reinforcing structure 3 Core layer 4 Component outer side 5 Component inner side 6 Outer cover layer of plastic 7 Inner cover layer of plastic 8 Outer skin layer 9 SMC layer 10 In-mold coat layer 11 Molding tool 12 First mold half 13 Second mold half 13 Exchanged second mold half 14 Mold cavity 14 Enlarged mold cavity