Method for producing an interior unit for a motor vehicle, and interior unit for a motor vehicle

Abstract

A method for production of an interior unit for a motor vehicle includes production of a support by injection molding, featuring an enclosed front side, wherein at a backside of the support a screw boss is formed whose drill hole is sealed by a support section in the direction of the front side of the support, which support section features a reduced wall thickness in comparison to the remainder of the support, and production of a foam layer on the enclosed front side of the support. Furthermore, the present disclosure relates to an interior unit for a motor vehicle.

Claims

1. A method for producing an interior unit for a motor vehicle comprising: a first step of producing a support by injection molding, the support having a front side, a back side, a screw boss at the back side, and a support section at the front side, the screw boss having a drill hole sealed by the support section at the front side, the support section including a reduced wall thickness in comparison to a remainder of the support; a second step of producing a foam layer at the front side of the support after the producing of the support by injection molding, the support section forming a continuous surface with the front side of the support and closing the drill hole at the front side of the support preventing the foam layer from entering the drill hole when the foam layer is produced at the front side of the support; and a third step, after the producing of the foam layer at the front side, wherein the support section is pierced or separated for receiving a screw into the drill hole of the screw boss for attachment of a part.

2. The method according to claim 1, wherein the support section is pierced by a punching tool.

3. The method according to claim 1, further comprising producing a decorative layer on a side of the foam layer facing away from the support.

4. The method according to claim 3, wherein the decorative layer is pierced through in a region of the drill hole of the screw boss.

5. The method according to claim 3, wherein the decorative layer is produced by spray application.

6. The method according to claim 3, wherein the decorative layer is produced by powder sintering.

7. The method according to claim 1, wherein the support is produced from a fiber-reinforced thermoplastic material.

8. The method according to claim 1, wherein the foam layer is produced from polyurethane foam.

9. The method according to claim 3, wherein the decorative layer is produced from polyurethane.

Description

DRAWINGS

(1) In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

(2) FIG. 1 is a cut-away, schematic side view of a screw connection which comprises an interior unit to which an attachment part is screwed, wherein the interior unit features a support, a foam layer and a decorative layer according to the present disclosure;

(3) FIG. 2 is a cut-away, schematic side view which depicts exclusively the interior unit, which features the decorative layer, the foam layer and the support, wherein a screw boss is formed at its underside according to the present disclosure; and

(4) FIG. 3 is an enlarged view is depicted of the region of the screw boss which features a drill hole which is enclosed by a support section in the direction of the foam layer according to the present disclosure.

(5) The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

(6) The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

(7) A screw connection 1 is depicted in a cut-away, schematic side view in FIG. 1. The screw connection 1 comprises an interior unit 2 and an attachment part 3, which is fastened to the interior unit by a screw 4. The interior unit 2 features a multiple layer structure. In this regard the interior unit 2 comprises a support 5, a foam layer 6 and a decorative layer 7. In addition, the support 5 features a screw boss 8, which acts as screw-in support and/or as screw cone for the screw 4, by which the attachment 3 is screwed to the interior unit 2. In one form, the support 5 is formed by injection molding.

(8) The interior unit 2 can pertain to an instrument panel support, for instance, wherein the attachment part 3 can pertain to a decorative strip screwed to the instrument panel support. The side of the decorative layer 7 facing away from the foam layer 6 herein forms the visible side which vehicle passengers can see. Due to the provision of the integrated screw boss 8, the attachment part 3 can be particularly easily fastened to the interior unit 2.

(9) FIG. 2 depicts the interior unit 2 solely in a cut-away schematic side view. As was already mentioned, in one form the support 5 is produced by injection molding and in one variation from an elongated-fiber reinforced polypropylene. In this regard the support 5 is produced with an enclosed front side 9, wherein in the course of the injection molding method the screw boss 8 is produced at the back side 10 of the support 5 as an integral constituent of the support 5. In another form, drill hole 11 of the screw boss 8 is produced directly in the course of the injection molding process.

(10) FIG. 3 depicts the region B indicated in FIG. 2 in an enlarged cross-sectional view. During the production of the support 5 by injection molding, the drill hole 11 of the screw boss 8 is sealed in the direction of the front side 9 with a support section 12, which features a significantly reduced wall thickness 13 in comparison to the rest of the support 5. The entire front side 9 of the support 5 produced by injection molding thus does not feature any open passages at all. This is important so that during the subsequent production of the interior unit 2, the foam material from which the foam layer 6 is produced will not be pressed through the support 5.

(11) The decorative layer can be produced, for example, by spray application or by powder sintering. For instance, the decorative layer 7 is placed into a lower tool (not depicted here), wherein subsequently the foam layer 6 is applied onto the decorative layer 7. The support 5 is accommodated in an upper tool (likewise not depicted here), wherein the upper tool and lower tool are then moved together. Thus, an enclosed membrane-foam-support is produced in the form of the interior unit 2.

(12) After production of the interior unit 2 the support section 12 sealing the drill hole 11 of the screw boss 8 can be pierced by a punching tool. But alternatively, it is also possible to leave the support section 12 intact. In one form, the decorative layer 7 is pierced in a region arranged above the drill hole 11 of the screw boss 8. Thus, firstly the screw 4 can subsequently be inserted more easily through the decorative layer 7. And secondly, it is easy to see where the screw 4 is to be inserted through the decorative layer 7.

(13) For instance, the decorative layer can feature a thickness of 1.5 mm, wherein the support section 12, which encloses the drill hole 11, can have a thickness of only 0.2 mm, for example.

(14) In order to produce the screw connection 1 depicted in FIG. 1, the screw 4 is introduced through the pre-pierced decorative layer 7 from above the drill hole 11 of the screw boss 8. In this case the foam layer 6 can be relatively easily penetrated by the screw 4. The same also applies to the support section 12, since it features the very small wall thickness 13 mentioned above. In one form, the screw 4 pertains to a self-tapping screw, so that it forms its own thread in the drill hole 11 of the screw boss 8. A separate production step for cutting the thread of the drill hole 11 of the screw boss 8 can thus be omitted. Due to the provision of the screw boss 8, the attachment part 3 can thus be fastened very easily and quickly to the interior unit 2 by the screw 4.

(15) Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, manufacturing technology, and testing capability.

(16) As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

(17) The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.