Vehicle body outer skin member

Abstract

The invention relates to an outer skin member for a vehicle body, which is composed of a fiber-reinforced plastic or a fiber-plastic composite material. The invention relates to a fiber-plastic composite material having a plurality of fiber layers, namely at least one intermediate natural fiber layer comprising a woven planar structure made of natural fibers, and an outer natural fiber layer comprising a woven planar structure made of natural fibers. In addition, the fiber-plastic composite material also comprises a non-woven fiber layer or a surface compensation layer which is arranged between the natural fiber intermediate layer and the natural fiber outer layer.

Description

Technical Field

[0001] This invention relates to an outer skin component for a motor vehicle body, such as a passenger car or a commercial vehicle. Background Technology

[0002] Typically, passenger car bodies are constructed using a self-supporting shell structure. This body is usually made of steel or aluminum, or constructed using a hybrid structure. Sometimes, the outer skin components are also made of fiber-plastic composite materials (containing, for example, carbon fiber or glass fiber).

[0003] Fiber-plastic composites are also known to be manufactured using natural fibers. Compared to chemical fibers, natural fibers are generally slightly coarser and less uniform, resulting in fiber-plastic composites containing natural fibers typically having a less smooth surface. Natural fibers are made from renewable raw materials and offer the advantage of generally having a better carbon dioxide balance compared to chemical fibers. Summary of the Invention

[0004] The objective of this invention is to provide a vehicle body skin component made of fiber-plastic composite material that is sustainably manufactured while still meeting quality requirements for surface properties.

[0005] This task is accomplished by a vehicle body outer skin member having the feature combination of claim 1. Advantageous improvements are proposed in the dependent claims.

[0006] According to the present invention, a vehicle body outer skin component is made of fiber-reinforced plastic or fiber-plastic composite material. The fiber-plastic composite material has multiple fiber layers, namely at least one natural fiber intermediate layer and a natural fiber outer layer. The natural fiber intermediate layer comprises a textile planar structure made of natural fibers, and the natural fiber outer layer comprises a textile planar structure made of natural fibers. Furthermore, the fiber-plastic composite material also has a non-woven fiber layer or a surface compensation layer disposed between the natural fiber intermediate layer and the natural fiber outer layer.

[0007] The natural fibers in the middle and outer layers of the natural fiber have a relatively large thickness and are slightly uneven compared to most chemical fibers, which results in a less smooth surface.

[0008] Placing a nonwoven fiber layer or surface compensation layer in the middle can achieve a smoother surface or compensate for unevenness caused by the natural fiber layer.

[0009] The natural fiber interlayer preferably has a unit area weight of 200 g / m² (gsm=g / m²) to 600 g / m², preferably 300 g / m².

[0010] The natural fiber outer layer preferably has a unit area weight of 240 grams per square meter.

[0011] The outer body skin component can also be a body accessory. This outer body skin component can be bolted, riveted, snap-fitted, and / or bonded to the vehicle body.

[0012] Preferably, the nonwoven fiber layer is directly adjacent to the natural fiber outer layer.

[0013] Advantageously, the natural fiber intermediate layer is adjacent to, and especially directly adjacent to, the nonwoven fiber layer.

[0014] Therefore, the nonwoven fiber layer can better compensate for the unevenness of the natural fiber layer.

[0015] According to a preferred improvement, a protective fiber layer is adjacent to the outer side of the natural fiber outer layer.

[0016] This protective fiber layer safeguards the natural fiber outer layer during manufacturing processes (such as the RTM method). Particularly in the RTM method, residual mold release agent on the outer layer is removed through machining (e.g., abrasion). This machining can damage the natural fiber outer layer. By protecting the fiber layer, the natural fiber outer layer is protected from the negative effects of machining.

[0017] Preferably, the protective fiber layer is the outermost fiber layer.

[0018] Advantageously, the protective fiber layer is made of transparent chemical fibers, such as glass fibers or polymer fibers.

[0019] Therefore, the natural fiber outer layer is visible through the protective fiber layer. If the fibers of the protective fiber layer are ground or similarly treated through the aforementioned machining process used to remove the release agent, this becomes invisible due to the transparency of the fibers.

[0020] Preferably, the protective fiber layer is made of fabric.

[0021] The protective fiber layer may have a low unit area weight, for example, from 40 g / m² to 100 g / m², preferably from 50 g / m² to 70 g / m², and particularly preferably 50 g / m².

[0022] According to a preferred improvement, the nonwoven fiber layer is composed of chemical fibers, especially extremely fine fibers.

[0023] Most synthetic fibers can be manufactured in a finer thickness than natural fibers. Therefore, nonwoven fiber layers can better compensate for the less uniformity of natural fiber layers.

[0024] Preferably, the chemical fibers in the nonwoven fiber layer are PES fibers.

[0025] The nonwoven fiber layer preferably has a unit area weight of 50 g / m² to 200 g / m², for example 60 g / m² to 100 g / m², and particularly preferably 60 g / m².

[0026] In addition, multiple adjacent natural fiber intermediate layers can also be arranged.

[0027] The body skin components can be manufactured using the so-called RTM method (i.e., using resin injection molding).

[0028] According to a preferred improvement, the vehicle body skin component also has a fiber interlayer (Fasermittellage), which includes a textile planar structure made of chemical fibers.

[0029] This fiber interlayer is used in particular as a flow aid for the resin in the plastic matrix during the manufacturing process of fiber-plastic composites or body skin components.

[0030] The fiber's intermediate layer is made of knitted fabric.

[0031] The resin can flow particularly well through knitted fabrics.

[0032] Knitted fabrics can be made particularly well using chemical fibers (especially fine chemical fibers), making chemical fibers (such as PES) preferred over natural fibers for knitted fabrics. Finer fibers allow for thinner interlayers, which is advantageous in terms of weight and structural thickness. When knitted fabrics are made from natural fibers, coarser fibers must be used.

[0033] The fiber interlayer preferably has a unit area weight of 100 g / m² to 400 g / m², and particularly preferably 130 g / m².

[0034] According to a preferred improvement, the natural fiber interlayer is composed of a lay-up or a fabric. The advantage of a lay-up is that it can be manufactured with arbitrary fiber orientation. This reduces cutting waste compared to a fabric.

[0035] The natural fiber interlayer can have a fiber orientation (fiber orientation) of +45° / -45°.

[0036] By using 90° staggered fiber orientation, near-isotropic behavior of fiber intermediate layers or vehicle body outer skin components can be achieved. If anisotropic material or component behavior is desired, other fiber orientations can be used.

[0037] The outer layer of natural fibers can have a fiber orientation of 0° / 90°.

[0038] However, unidirectional orientation of fibers in the outer layer of the fiber is also possible.

[0039] Natural fibers can be plant fibers, such as bast fibers, especially flax, hemp, or bamboo, or seed or leaf fibers. Flax fiber is particularly preferred due to its high availability. Flax fiber also has a particularly uniform structure. In addition, flax fiber is inexpensive.

[0040] Chemical fibers can be organic or inorganic. Organic chemical fibers are, for example, synthetic polymers. Particularly preferred are chemical fibers made of polyester (PES). Polyester is virtually non-hygroscopic. Chemical fibers made of polyester are relatively inexpensive when of good quality.

[0041] Preferably, a paint layer, especially a clear coat layer, is applied to one or both outer sides of the vehicle body skin component.

[0042] The natural fiber outer layer is visible through the varnish layer.

[0043] The layers of the vehicle body outer skin components are preferably symmetrically constructed with respect to the intermediate layer. In particular, the natural fiber intermediate layer, the natural fiber outer layer, and, if possible, the protective fiber layer (if present) are all arranged and constructed symmetrically with respect to the intermediate layer.

[0044] The plastic matrix of fiber-reinforced plastics is preferably a thermosetting plastic, which is manufactured using liquid resin (especially epoxy resin) and a corresponding curing agent.

[0045] The vehicle body exterior skin component can be the roof exterior skin, fender exterior skin, front fascia exterior skin, side wall exterior skin, door sill trim, or bumper trim.

[0046] The chemical fibers according to the invention are synthetically manufactured organic or inorganic fibers, and therefore can be, in particular, so-called plastic fibers. In particular, chemical fibers are non-metallic fibers. Natural fibers are also non-synthetically manufactured fibers that exist in nature (e.g., in plants) and are obtained, for example, from plants without synthesis. Natural fibers are not plastic fibers. In particular, plastic fibers synthesized or manufactured from hydrocarbons obtained from plants are not natural fibers in the sense of this invention.

[0047] The above features can be combined in any way as long as they are possible and meaningful. Attached Figure Description

[0048] The following is a brief description of the accompanying drawings.

[0049] Figure 1 A schematic cross-sectional view of a vehicle body outer skin component according to an embodiment of the present invention is shown. Detailed Implementation

[0050] The following is for reference Figure 1An embodiment of the present invention will be described.

[0051] Figure 1 A schematic cross-sectional view of a vehicle body outer skin component 1 (particularly a roof outer skin) made of fiber-reinforced plastic or fiber-plastic composite material according to an embodiment of the present invention is shown. The fiber-plastic composite material is manufactured by an RTM method. The various layers of the fiber-plastic composite material are shown in this cross-sectional view. These layers of the fiber-plastic composite material differ in terms of fiber layers. The fiber-plastic composite material has multiple fiber layers, all embedded in the same plastic matrix. The fiber-plastic composite material has an outer natural fiber outer layer 3 and an inner natural fiber outer layer 3. The outer natural fiber outer layer 3 is therefore located on the outer side of the vehicle body outer skin component 1. The inner natural fiber outer layer 3 is therefore located on the inner side of the vehicle body outer skin component 1. Both natural fiber outer layers 3 are constructed of fabric made of flax fibers.

[0052] A nonwoven fiber layer 11 is arranged adjacent to the outer natural fiber outer layer 3. This nonwoven fiber layer 11 may also be referred to as a surface compensation layer. The nonwoven fiber layer 11 has the lowest possible weight per unit area, for example, about 60 grams per square meter (gsm), and is composed of PES fibers.

[0053] Furthermore, an outer natural fiber intermediate layer 5 is arranged adjacent to the nonwoven fiber layer 11. In other words, the nonwoven fiber layer 11 is arranged between the outer natural fiber outer layer 3 and the outer natural fiber intermediate layer 5. The natural fiber intermediate layer 5 is constructed of a flax fiber lining.

[0054] A fiber interlayer 7 is arranged in the middle of the fiber-plastic composite. The fiber interlayer 7 is composed of PES fiber knitted fabric and serves as a flow aid in the RTM manufacturing process. Through the fiber interlayer 7, the liquid resin can be better distributed in the component during the manufacturing process.

[0055] A fiber interlayer 7 is arranged between the outer natural fiber interlayer 5 and the inner natural fiber interlayer 5. Like the outer natural fiber interlayer 5, the inner natural fiber interlayer 5 is also composed of a lining made of flax fibers.

[0056] The nonwoven fiber layer 11 between the outer natural fiber intermediate layer 5 and the outer natural fiber outer layer 3 serves as a surface compensation because most natural fibers (especially flax used in this embodiment) are less uniform than chemical fibers and generally have a larger fiber diameter. Due to this non-uniformity and relatively large fiber diameter, the surface of the vehicle body outer skin component 1 is relatively uneven or not very smooth. These unevennesses are reduced by the nonwoven fiber layer 11 arranged in the middle.

[0057] There are no other fiber layers between the outer fiber layer 3 and the middle fiber layer 5, or between the middle fiber layer 5 and the middle fiber layer 7. However, the outer fiber layer 3 may be composed of multiple overlapping fabric layers made of PES fibers. Similarly, the middle fiber layer 5 may also have multiple overlapping layers made of flax fibers.

[0058] The natural fiber intermediate layer 5 has a fiber orientation of +45° / -45°. The natural fiber outer layer 3 has a fiber orientation of 0° / 90°.

[0059] The flax fibers in the middle layer 5 and the outer layer of natural fibers can be replaced by other suitable natural fibers.

[0060] Furthermore, a paint layer 9, particularly a clear coat layer, is applied to the outer side of the vehicle body outer skin component 1. In the case of the clear coat layer, the fabric structure of the fiber outer layer 3 is visible on the vehicle body outer skin component 1.

[0061] When the outer body skin component 1 is manufactured using the RTM method, mold release agent residue remains on it. This mold release agent must be removed before applying paint or paint layer 9, otherwise the adhesion of paint layer 9 to the outer body skin component 1 will be poor. These mold release agent residues are removed by sanding. During sanding, the fibers of the outermost fiber layer (i.e., the outer natural fiber outer layer) may be partially sanded. If the paint layer 9 is transparent (i.e., the clear coat), the sanded fibers are visible, resulting in a different surface appearance of the outer body skin component 1 compared to when the fibers are not sanded.

[0062] To prevent such changes in surface appearance, a protective fiber layer 13 can optionally be arranged outside the outer natural fiber outer layer 3. If a protective fiber layer 13 is provided, then the protective fiber layer 13, rather than the natural fiber outer layer 3, is the outermost fiber layer. The protective fiber layer 13 has transparent fibers (e.g., glass fiber) in the form of a fabric. If these transparent fibers are abraded during the aforementioned abrasion process for removing the release agent, they are not visible. Due to the presence of the protective fiber layer 13, the natural fiber outer layer is not negatively affected or abraded during the abrasion process. Therefore, through the substantially transparent protective fiber layer 13, the natural fiber outer layer 3 is visible and determines the appearance of the vehicle body outer skin component 1. The protective fiber layer 13 has a low unit area weight of approximately 50 grams per square meter, thus the protective fiber layer 13 has a relatively small impact on the mechanical properties of the vehicle body outer skin component 1. Nevertheless, it is preferable to also arrange an inner protective fiber layer 13 on the inner side of the vehicle body outer skin component 1 to have a layer structure that is as symmetrical as possible and to keep the impact on mechanical properties and component distortion as small as possible.

[0063] The layers of the outer skin component 1 are substantially (except for the nonwoven fiber layer 11) centrally symmetrical with respect to the outer skin component 1, thus preventing twisting during manufacturing and ensuring that the component has the same mechanical properties in both bending directions. The nonwoven fiber layer 11 has a low weight per unit area, thus its influence on component twisting and on the mechanical properties of the finished outer skin component 1 is negligible. Furthermore, the paint layer 9 can also be applied to the inner side of the outer skin component. If a smoother surface is desired on the inner side of the outer skin component 1, the nonwoven fiber layer 11 can also be arranged between the inner natural fiber outer layer 3 and the inner natural fiber intermediate layer 5.

[0064] The plastic matrix of fiber-reinforced plastics consists of epoxy resin and a corresponding curing agent.

Claims

1. A vehicle body outer skin component (1), the vehicle body outer skin component being made of fiber reinforced plastic or fiber-plastic composite material having a plurality of fiber layers, the plurality of fiber layers including at least one natural fiber intermediate layer (5) and a natural fiber outer layer (3), the natural fiber intermediate layer comprising a textile planar structure composed of natural fibers, the natural fiber outer layer comprising a textile planar structure composed of natural fibers, and further comprising a nonwoven fiber layer (11) disposed between the natural fiber intermediate layer (5) and the natural fiber outer layer (3).

2. The vehicle body outer skin component according to claim 1, wherein, The nonwoven fiber layer (11) is adjacent to, and especially directly adjacent to, the natural fiber outer layer (3).

3. The vehicle body outer skin component according to claim 1 or 2, wherein, The natural fiber intermediate layer (5) is adjacent to, and especially directly adjacent to, the nonwoven fiber layer (11).

4. The vehicle body outer skin component according to any one of claims 1 to 3, wherein, A protective fiber layer (13) is adjacent to the outside of the natural fiber outer layer (3), wherein the protective fiber layer (13) is particularly the outermost fiber layer, and the protective fiber layer (13) is made of, for example, transparent chemical fibers, such as glass fibers or polymer fibers, and the protective fiber layer (13) is preferably made of fabric, and the protective fiber layer (13) advantageously has a low unit area weight of, for example, 40 g / m² to 100 g / m², preferably 50 g / m² to 70 g / m², particularly preferably 50 g / m².

5. The vehicle body outer skin component according to any one of claims 1 to 4, wherein, The nonwoven fiber layer (11) is composed of chemical fibers, especially very fine fibers, such as PES fibers, and the nonwoven fiber layer (11) has a unit area weight of 50 g / m² to 200 g / m², for example 60 g / m² to 100 g / m², particularly preferably 60 g / m².

6. The vehicle body outer skin component according to any one of claims 1 to 5, further comprising a fiber interlayer (7), said fiber interlayer comprising a textile planar structure made of chemical fibers, such as PES fibers, wherein, The fiber interlayer (7) is made of knitted fabric in particular, and the fiber interlayer (7) has, for example, a unit area weight of 100 g / m² to 400 g / m², especially about 130 g / m².

7. The vehicle body outer skin component according to any one of claims 1 to 6, wherein, The natural fiber interlayer (5) is composed of a fabric or woven material, and the fiber orientation is especially +45° / -45°, and the natural fiber interlayer has, for example, a unit area weight of 200 g / m² to 600 g / m², especially about 300 g / m².

8. The vehicle body outer skin component according to any one of claims 1 to 7, wherein, The natural fiber outer layer (5) is made of fabric or drape, and the fiber orientation is particularly 0° / 90°, and the natural fiber outer layer has, for example, a unit area weight of 150 g / m² to 400 g / m², preferably 240 g / m².

9. The vehicle body outer skin component according to any one of claims 1 to 8, wherein, Natural fibers are plant fibers, such as bast fibers, especially flax fibers, or seed or leaf fibers.

10. The vehicle body outer skin component according to any one of claims 1 to 9, wherein, The outer skin component (1) of the vehicle body also has a paint layer (9) on its outer side, especially a clear coat layer.

11. The vehicle body outer skin component according to any one of claims 1 to 10, wherein, The plastic matrix of fiber-reinforced plastics is composed of thermosetting plastics, especially epoxy resin-based thermosetting plastics.

12. The vehicle body outer skin component according to any one of claims 1 to 11, wherein, The vehicle body outer skin component (1) is the roof outer skin, fender outer skin, front cover outer skin, side wall outer skin, door sill trim, or bumper trim.

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