Component for a vehicle body outer skin

Abstract

According to the invention, a component for a vehicle body outer skin is made of a fiber-reinforced plastic or a fiber-plastic composite. The fiber-plastic composite comprises multiple fiber layers. A fiber intermediate layer comprises a textile sheet material consisting of natural fibers and a fiber outer layer comprises a textile sheet material consisting of man-made fibers.

Description

[0001] Body outer skin component

[0002] The invention relates to an outer body skin component for a motor vehicle body, for example a passenger car or a commercial vehicle.

[0003] The body of a passenger car is typically constructed using a self-supporting shell construction. The body is usually made of steel or aluminum, or a combination of these materials. Sometimes an outer body shell component is also made of a fiber-plastic composite, such as carbon fiber or glass fiber.

[0004] It's also known to produce a fiber-plastic composite using natural fibers. Natural fibers are usually hygroscopic, meaning they can absorb moisture over time, even in a fiber-plastic composite.

[0005] Natural fibers are made from a renewable raw material and have the advantage that they usually have a better carbon footprint compared to chemical fibers.

[0006] It is the object of the present invention to provide a body outer skin component made of a fiber-plastic composite, wherein the body outer skin component is manufactured more sustainably and has a consistent surface quality over time, for example a consistent optical surface quality.

[0007] This object is achieved by a body outer skin component having the combination of the features of claim 1. Advantageous further developments are mentioned in the dependent claims.

[0008] According to the invention, a body outer skin component is made of fiber-reinforced plastic or a fiber-plastic composite. The fiber-plastic composite has several fiber layers. An intermediate fiber layer comprises a textile fabric consisting of natural fibers, and an outer fiber layer comprises a textile fabric consisting of chemical fibers.

[0009] The outer fiber layer with the textile fabric consisting of chemical fibers, together with a plastic matrix of the fiber-plastic composite, inhibits moisture diffusion, so that less moisture from the outside reaches the intermediate fiber layer. The chemical fibers are not hygroscopic or less hygroscopic than natural fibers. This prevents or at least limits the hygroscopic natural fibers of the intermediate fiber layer from absorbing moisture. Moisture absorption by the natural fibers of the intermediate fiber layer can cause the natural fibers to swell, i.e., increase in volume. The swelling of the natural fibers of the intermediate fiber layer, in turn, affects the surface of the outer body skin component, i.e., the surface of the outer body skin component changes. This makes the surface of the outer body skin component more wavy, i.e., less smooth or even.The change in the surface of the body shell component is visible and can be perceived by the user as aging of the body shell component and thus as a loss of quality. However, a change in the surface can also have other functional disadvantages. For example, it can promote the adhesion of dirt. Likewise, a change in the surface of the body shell component can be disadvantageous with regard to any other function of the body shell component that requires a consistent or as smooth a surface as possible. Thanks to the natural fibers, the body shell component has a better CO2 footprint during production. To further improve the CO2 footprint, the chemical fibers can be made from recycled material.

[0010] The outer body skin component can also be a body attachment. The outer body skin component can be screwed, riveted, clipped, and / or glued to the vehicle body.

[0011] Preferably, the intermediate fiber layer is directly adjacent to the outer fiber layer, i.e., no further fiber layer is arranged between the outer fiber layer and the intermediate fiber layer. The outer fiber layer can be arranged on an outward-facing side of the body outer skin component. The outer fiber layer can also be arranged on an inward-facing side of the body outer skin component. Furthermore, an outer fiber layer with chemical fibers can be formed both on the outward-facing side of the body outer skin component and on the inward-facing side of the body outer skin component.

[0012] Furthermore, several intermediate fiber layers made of natural fibers can be arranged between the outer fiber layers.

[0013] The body outer skin component can be manufactured using the so-called RTM process, i.e. using the resin injection process (Resin Transfer Moulding).

[0014] According to a preferred development, the body outer skin component further has a fiber center layer which has a textile fabric made of chemical fiber.

[0015] The fiber middle layer serves in particular as a flow aid for a resin of the plastic matrix during a manufacturing process of the fiber-plastic composite or the body outer skin component.

[0016] The middle fiber layer is formed in particular by a knitted fabric.

[0017] The resin can flow particularly well through a knitted fabric.

[0018] A knitted fabric can be particularly well realized with a synthetic fiber, especially a thin synthetic fiber, so synthetic fibers, such as PES, are preferable to natural fibers for the knitted fabric. A thinner fiber, in turn, allows for a thinner fiber core, which is advantageous in terms of weight and component thickness. For a knitted fabric made of natural fibers, thicker fibers would have to be used.

[0019] According to a preferred embodiment, the intermediate fiber layer is formed from a non-crimp fabric or a woven fabric. A non-crimp fabric is advantageous in that it can be produced in any fiber orientation. This allows for reduced waste compared to a woven fabric.

[0020] The fiber interlayer can have a fiber alignment (a fiber orientation) of +457 -45°.

[0021] A fiber orientation offset by 90° enables a nearly isotropic behavior of the fiber interlayer or body shell component. If anisotropic material or component behavior is desired, other fiber orientations are also possible.

[0022] The outer fiber layer can have a fiber orientation of 0790°.

[0023] However, a unidirectional alignment of the fibers in the outer fiber layer is also possible.

[0024] The natural fibers can be plant fibers, for example, bast fibers, especially flax, hemp, or bamboo, or seed fibers or leaf fibers. Flax fibers are particularly preferred, as they are readily available. Flax fibers also have a particularly homogeneous structure.

[0025] Furthermore, flax fibers are cost-effective.

[0026] The chemical fibers can be organic or inorganic. Organic chemical fibers include synthetic polymers, for example. Polyester (PES) is particularly preferred. Polyester absorbs very little moisture. Polyester chemical fibers are comparatively inexpensive if of good quality.

[0027] A layer of paint, in particular a clear coat, is preferably applied to the outside of the body outer skin component.

[0028] The paint layer can also reduce the diffusion of moisture into the outer body skin component.

[0029] The layers of the body outer skin component are preferably constructed symmetrically to the fiber center layer. A plastic matrix of the fiber-reinforced plastic is advantageously a thermosetting plastic produced with a liquid resin, in particular an epoxy resin, and a suitable hardener.

[0030] The body outer skin component may be a vehicle roof outer skin or a fender outer skin or a front cover outer skin or a side panel outer skin or a rocker panel or a bumper panel.

[0031] Chemical fibers according to the present invention are synthetically produced organic or inorganic fibers and can therefore be, among other things, so-called plastic fibers. In particular, chemical fibers are non-metallic fibers. Natural fibers, in turn, are non-synthetically produced fibers that occur naturally, for example, in plants, and are obtained, for example, from plants without synthesis. Natural fibers are not plastic fibers. In particular, plastic fibers that are synthesized or produced from hydrocarbons obtained from plants are not natural fibers within the meaning of the present invention.

[0032] The features mentioned above can be combined with each other as far as possible and reasonable.

[0033] A brief description of the figure follows.

[0034] Fig. 1 is a schematic sectional view of a body outer skin component according to an embodiment of the present invention.

[0035] An embodiment of the present invention is explained below with reference to Figure 1.

[0036] Figure 1 shows a schematic section through a body outer skin component 1, in particular a vehicle roof outer skin, made of fiber-reinforced plastic or of a fiber-plastic composite according to the exemplary embodiment of the present invention. The fiber-plastic composite is produced using an RTM process. The section shows the individual layers of the fiber-plastic composite. The layers of the fiber-plastic composite differ in terms of the fiber layers, i.e. the fiber-plastic composite has several fiber layers, which are all embedded in the same plastic matrix. The fiber-plastic composite has an outer fiber layer 3 and an inner fiber outer layer 3. The inner fiber outer layer 3 is thus on an outer side of the body outer skin component 1. The outer fiber outer layer 3 is thus on an inner side of the body outer skin component 1.Adjacent to the outer fiber outer layer 3 and the inner fiber outer layer 3 is a fiber intermediate layer 5. The fiber outer layers 3 are formed by a woven PES fiber fabric. The fiber intermediate layers 5 are formed by a non-woven fabric made of hemp fibers.

[0037] A fiber core layer 7 is arranged in the center of the fiber-reinforced plastic composite. The fiber core layer 7 consists of a knitted fabric made of PES fibers and serves as a flow aid in the RTM manufacturing process. The fiber core layer allows the liquid resin to be better distributed throughout the component during the manufacturing process.

[0038] The outer fiber layers 3 made of PES fibers inhibit moisture diffusion, so that less moisture from the outside reaches the intermediate fiber layers 5. This prevents, or at least limits, the hygroscopic flax fibers of the intermediate fiber layers 5 from absorbing moisture during operation of the motor vehicle with the outer body skin component 1. If the flax fibers absorbed moisture, the intermediate fiber layers 5 would swell, which would also be visible to a user of the motor vehicle on the surface of the outer body skin component 1. A change in the surface of the outer body skin component 1 would be visible, which a user could perceive as aging of the outer body skin component 1 and thus as a loss of quality. Furthermore, dirt could then accumulate more easily.

[0039] There is no additional fiber layer between the outer fiber layers 3 and the intermediate fiber layers 5, and between the intermediate fiber layers 5 and the center fiber layer 7. However, the outer fiber layers 3 can consist of several superimposed woven layers of PES fibers. Likewise, the intermediate fiber layers 5 can comprise several superimposed layers of flax fibers. The intermediate fiber layers 5 have a fiber orientation of +457° to -45°. The outer fiber layers 3 have a fiber orientation of 0790°. Overall, the body outer skin component 1 thus has the most isotropic behavior possible.

[0040] The flax fibers of the intermediate fiber layers 5 could be replaced by other suitable natural fibers. Likewise, the PES fibers of the outer fiber layers 3 could be replaced by other suitable chemical fibers that impede moisture diffusion from the outside to the intermediate fiber layers 5.

[0041] A paint layer 9, in particular a clear coat, is also applied to the outside of the body outer skin component 1. In the case of a clear coat, the fabric structure of the fiber outer layer 3 is visible on the body outer skin component 1.

[0042] The layers of the body outer skin component 1 are essentially - apart from the paint layer 9 - constructed symmetrically to the center of the body outer skin component 1, so that the component does not warp during the manufacturing process and has the same mechanical properties in both bending directions of the component.

[0043] The plastic matrix of the fiber-reinforced plastic is made of epoxy resin and a corresponding hardener.

[0044] The intermediate fiber layers 5 advantageously have a basis weight of 200 gsm to 600 gsm, particularly preferably 300 gsm. The outer fiber layers 3 advantageously have a basis weight of 100 gsm to 130 gsm, particularly preferably 130 gsm. The middle fiber layer advantageously has a basis weight of 100 gsm to 400 gsm, particularly preferably 130 gsm. The unit gsm corresponds to the unit g / m 2 .

Claims

Patent claims 1. Body outer skin component made of fiber-reinforced plastic or of a fiber-plastic composite, which has a plurality of fiber layers with at least one fiber intermediate layer (5) comprising a textile fabric consisting of natural fibers and a fiber outer layer (3) comprising a textile fabric consisting of chemical fibers.

2. Body outer skin component according to claim 1, wherein the intermediate fiber layer (5) is in particular directly adjacent to the outer fiber layer (3).

3. Body outer skin component according to claim 1 or 2, further comprising a fiber center layer (7) comprising a textile fabric made of chemical fiber, wherein the fiber center layer (7) is formed in particular by a knitted fabric.

4. Body outer skin component according to one of claims 1 to 3, wherein the fiber intermediate layer (5) is formed from a scrim or woven fabric, and wherein the fiber orientation is in particular +457-45°.

5. Body outer skin component according to one of claims 1 to 4, wherein the fiber outer layer (5) is formed from a woven or non-woven fabric, and wherein the fiber orientation is in particular 0 90°.

6. Body outer skin component according to one of claims 1 to 5, wherein the natural fibers are plant fibers, for example bast fibers, in particular flax fibers, or seed fibers or leaf fibers.

7. Body outer skin component according to one of claims 1 to 6, wherein the body outer skin component (1) further comprises a lacquer layer (9), in particular a clear lacquer layer, on its outer side.

8. Body outer skin component according to one of claims 1 to 7, wherein a plastic matrix of the fiber-reinforced plastic consists of a thermosetting plastic, in particular based on epoxy resin.

9. Body outer skin component according to one of claims 1 to 8, wherein the body outer skin component (1) is a vehicle roof outer skin or a fender outer skin or a front cover outer skin or a side wall outer skin or a sill panel or a bumper panel.

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