DE102012018801B4 - Planking component for a motor vehicle and method for producing a planking component - Google Patents

Abstract

The invention relates to a planking component (10) for a motor vehicle, having a plastic outer planking part (12), wherein the plastic outer planking part (12) comprises a plurality of fiber-reinforced plastic layers (20, 22) each having unidirectionally oriented fibers and a cover layer (18). comprising a thermoplastic and the unidirectionally oriented fibers reinforced plastic layer (20, 22) is made of a fabric (32) containing warp threads (34) of glass fiber strands or hybrid strands and in the manufacture of the plastic layer (20, 22) melted weft threads (36) made of thermoplastic multifilaments. Furthermore, the invention relates to a method for producing a planking component (10).

Description

The invention relates to a Beplankungsbauteil for a motor vehicle specified in the preamble of claim 1. type. Furthermore, the invention relates to a method for producing such a planking component.

The DE 202 20 552 U1 shows a motor vehicle door with such a planking component, which has a plastic Außenbeplankungsteil serving as a door outer skin, which forms an outer design surface of the motor vehicle door, wherein the planking component is connectable to a subframe of the motor vehicle door.

The DE 10 2010 020 308 A1 shows a body component for a motor vehicle, which is formed from a plurality of layers and comprises a cover layer made of a thermoplastic, an inner part and a foam element, which is arranged between the plastic Außenbeplankungsteil and the inner part.

The DE 10 2007 024 163 A1 shows a designed as a trunk lid for a motor vehicle body component. The trunk lid comprises a plastic planking member and an inner support structure formed of a separate precursor in which an antenna unit is fully integrated, wherein the antenna unit, the planking member and the inner support structure are formed as a one-piece assembly.

The WO 2007/054671 A1 shows a plastic plate comprising a laminated plastic material structure having a first plastic cover layer and a second cover layer, each fiber-reinforced, and between which, at least in a part of the plate, a core layer is provided which comprises at least one deformable metal element wherein the introduction of the deformable element is arranged to reduce the elastic behavior of the plastic material structure compared to the plate without the element, so that the plate sustains a permanent deformation during impact, characterized in that the cover layers each comprise at least one fiber-reinforced sub-layer in which fibers are substantially unidirectional.

The DE 198 09 272 A 1 shows a fiber composite sandwich component, in particular a motor vehicle body part, having a spacer core layer disposed between two fiber reinforced cover layers, wherein a foam core preform is disposed between two fiberglass preforms of multiaxially oriented reinforcing fiber bundles formed into a predetermined shape and the preforms are embedded in a reaction plastic matrix.

It is the object of the present invention to provide a cladding component of the aforementioned type and a method for producing such a cladding component, by means of which an improved load-bearing capacity and a high surface quality of the cladding component can be achieved.

This object is achieved by a Plankungsbauteil with the features of claim 1 and by a method for producing a Plankungsbauteils with the features of claim 3.

In order to achieve an improved bearing capacity of the cladding component with a simultaneously high surface quality of the cladding component, it is provided in a cladding component according to the invention for a motor vehicle that the plastic outer cladding part comprises a plurality of fiber-reinforced plastic layers each having unidirectionally oriented fibers and a cover layer made of a thermoplastic. The reinforced with unidirectional fibers oriented plastic layer is characterized by a stretched thread layer. This property of the fabric layer results in a smoother surface compared to conventional fabrics in which the number of bumps due to ondulations resulting from a plurality of crossover points of respective fibers is substantially greater. As a result, a considerable reduction of the usually occurring fiber matrix markings on the cover layer of the cladding component can be achieved. As a result, a particularly good surface quality of the planking component can be achieved. Furthermore, a high load-bearing capacity of the planking component can be achieved by the use of the fiber-reinforced plastic layers, so that the planking component can additionally fulfill a supporting function, in particular in the case of a motor vehicle bodywork, in addition to a purely fairing function.

According to a further advantageous embodiment of the invention, it is provided that the plastic outer planking part has a plastic layer reinforced with random fibers, optionally based on hybrid rovings. By integrating extremely fine, quasi-isotropic tangled glass fiber webs into the layer structure, a marking of the fibers used on the surface, ie on the cover layer, can be additionally reduced, which thus has a positive effect on the surface quality. Furthermore, the use of the random fibers or the tangled glass fiber webs, prevents the glass fibers during melting of the Move matrix. The reinforced with random fibers plastic layer thus acts as a kind of barrier layer.

An advantageous embodiment of the invention provides that the fibers and random fibers of the plastic Außenbeplankungsteils are embedded in a formed of a thermoplastic matrix. Thereby, a particularly stable structure of the entire plastic Außenbeplankungsteils ensured, whereby the carrying capacity of the entire Plankungsbauteils is improved.

In a further advantageous embodiment of the invention, it is provided that the unidirectionally oriented fibers reinforced plastic layer is made of a fabric which has warp threads of glass fiber strands or hybrid strands and melted in the manufacture of the plastic layer weft threads of thermoplastic multifilaments. In other words, when wringing the plastic outer planking part, the weft thread melts and the previous fabric structure becomes a unidirectional structure. This structure is characterized by a stretched thread layer. As a result, a correspondingly high surface quality of the plastic Außenbeplankungsteils is ensured.

• - Umformen eines ersten aus einem faserverstärkten Kunststoff ausgebildeten Halbzeugs und Umspritzen mit Kunststoff zu einem Innenteil;
• - Umformen eines zweiten aus einem faserverstärkten Kunststoff ausgebildeten Halbzeugs zu einem Kunststoff-Außenbeplankungsteil;
• - induktives Erwärmen einer aus einem Thermoplast ausgebildeten Deckschicht des Kunststoff-Außenbeplankungsteils;
• - Aneinanderfügen des Innenteils und des Kunststoff-Außenbeplankungsteils;
• - Einbringen eines Schaumstoffs in ein zwischen dem Innenteil und dem Kunststoff-Außenbeplankungsteil ausgebildeten Hohlraum, wobei das Innenteil und das Kunststoff-Außenbeplankungsteil anschließend im Bereich des Hohlraums um einen vorgegebenen Weg voneinander wegbewegt werden.

A method according to the invention for producing a paneling component for a motor vehicle comprises the following steps:

• - Forming a first formed from a fiber-reinforced plastic semi-finished product and encapsulation with plastic to an inner part;
• - Forming a second formed of a fiber-reinforced plastic semi-finished product to a plastic Außenbeplankungsteil;
• - Inductive heating of a formed from a thermoplastic cover layer of the plastic Außenbeplankungsteils;
• - Joining the inner part and the plastic Außenbeplankungsteils;
• - Introducing a foam in a formed between the inner part and the plastic Außenbeplankungsteil cavity, wherein the inner part and the Kunststoff-Außenbeplankungsteil are then moved away in the region of the cavity by a predetermined distance from each other.

By the inductive heating of the cover layer, it is melted, after which an outer skin with a particularly high surface quality is formed. As a result, post-processing of the surface after the production process is no longer necessary. This usually eliminates the need for repeated grinding and application of matrix material, thereby considerably reducing the cycle time for a paneling component. By introducing the foam into the cavity and the subsequent movement away from each other of the inner part and the plastic Außenbeplankungsteils in the region of the cavity, a particularly strong density reduction of the introduced foam can be achieved. In contrast to the classical low-pressure method, the cavity is filled first volumetrically completely and then there is a Kavitätsvergrößerung, which leads to pressure drop and expansion of the gas-loaded foam. This foam casting with preferably "breathing tool" shorter cycle times can be achieved with reduced component weights. This results in the following advantages: Material savings, increased specific rigidity, improved dimensional stability, less distortion, reduction of sink marks, lower stresses and longer flow paths.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing.

• 1 ein Perspektivansicht auf ein Beplankungsbauteil für einen Kraftwagen, welches als Beplankungsträger für eine Kraftfahrzeugtür dient, wobei das Beplankungsbauteil ein Kunststoff-Außenbeplankungsteil und ein Innenteil umfasst, zwischen welchen ein Schaumstoffelement angeordnet ist;
• 2 eine Schnittansicht eines mehrere Schichten aufweisenden Schichtaufbaus, aus welchem durch anschließendes Verpressen und Umformen das Kunststoff-Außenbeplankungsteil hergestellt wird;
• 3 eine Schnittansicht eines alternativen Schichtaufbaus;
• 4 eine Schnittansicht eines weiteren alternativen Schichtaufbaus;
• 5 eine Perspektivansicht auf einen Teil eines Gewebes, mittels welchem eine oder mehrere Schichten des Schichtaufbaus realisiert werden können;
• 6 eine schematische Schnittansicht eines Hybridstrangs, welcher Glasfasern und thermoplastische Multifilamente aufweist;
• 7 eine schematische Darstellung einer Wirrfaserschicht, welche Bestandteil des Kunststoff-Außenbeplankungsteils ist;
• 8 zwei nebeneinander angeordnete Produktionsstationen, mittels welchen das in 1 gezeigte Beplankungsbauteil hergestellt wird.

The drawing show in:

• 1 a perspective view of a planking component for a motor vehicle, which serves as a planking support for a motor vehicle door, wherein the planking component comprises a plastic Außenbeplankungsteil and an inner part, between which a foam element is arranged;
• 2 a sectional view of a multi-layered layer structure, from which by subsequent pressing and forming the plastic Außenbeplankungsteil is prepared;
• 3 a sectional view of an alternative layer structure;
• 4 a sectional view of another alternative layer structure;
• 5 a perspective view of a part of a fabric, by means of which one or more layers of the layer structure can be realized;
• 6 a schematic sectional view of a hybrid strand comprising glass fibers and thermoplastic multifilaments;
• 7 a schematic representation of a random fiber layer, which is part of the plastic Außenbeplankungsteils;
• 8th two juxtaposed production stations, by means of which the in 1 Planking component shown is produced.

A planking component 10 with a plastic Außenbeplankungsteil 12 and an inner part 14 between which a foam part 16 is arranged in a perspective view in 1 shown. In the present case is the planking component 10 shown in an exploded view, so that between the plastic Außenbeplankungsteil 12 and the inner part 14 absorbed foam element 16 can be represented.

The planking component 10 is presently designed as a planking carrier for a vehicle door, by means of which a door carrier (not shown here) can be clad. In other words, it is in the planking component 10 to a supporting outer skin component for motor vehicles. As outer skin, all exterior surfaces of motor vehicles are referred to. Exemplary applications are tailgates, car doors, car roofs and the like. Consequently, the planking component is 10 not limited only to planking for vehicle doors.

The planking component 10 shows a bivalve sandwich construction of the outer shell forming Außenbeplankungsteil 12 , the inner shell forming an inner shell 14 and the foam member received therebetween 16 on. In the plastic Außenbeplankungsteil 12 and the inner part 14 These are fiber-reinforced plastic components using thermoplastic materials. This is necessary, on the one hand, the carrying capacity of the planking component 10 on the other hand to achieve a class-A surface always required in the automotive sector. Matrix materials such as polyamide, polypropylene or polyphthalamide are used. As reinforcing fibers, for example, glass fibers are used, and so-called hybrid rovings can be used. The Class-A surface is achieved by a non-descript designated here of a thermoplastic cover layer of a low thermal expansion, low distortion matrix material, which is prepared in a pressing process by means of an inductively heated tool by melting the surface.

The plastic Außenbeplankungsteil 12 is formed of a plurality of layers not shown here and has the already mentioned cover layer 18 made of a thermoplastic. Based on 2 to 4 Below are different possible layer structures of plastic Außenbeplankungsteils 12 explained, wherein in the 2 to 4 the different layers before pressing these layers and subsequent forming to the plastic Außenbeplankungsteil 12 are shown.

In 2 is a first embodiment of a layer structure 17 for the production of the plastic Außenbeplankungsteils 12 shown. The layer structure 17 includes the already mentioned cover layer 18 , a plastic layer reinforced with unidirectional fibers 20 another plastic layer reinforced with unidirectional fibers 22 , wherein the fibers of this plastic layer 22 90 ° across the fibers of the plastic layer 20 are arranged, a slide 24 made of thermoplastic material and a nonwoven fabric made of random fibers 26 after which the layers in turn follow or repeat themselves in mirror image sequence.

In 3 is an alternative embodiment of a layer structure 28 shown. To the top layer 18 close in turn reinforced with the unidirectionally oriented fibers plastic layers 20 and 22 according to which, in the present case, the nonwoven consisting of random fibers 26 and follow the slide 24 made of thermoplastic connects, which in the present case, the axis of symmetry of the layer structure 28 represents, which in turn, in turn, the other layers 26 . 22 . 20 . 18 connect. Again, the thermoplastic film is used 24 as a matrix material, but in this variant is only a single film 24 necessary, because the plastic layers 20 . 22 so-called hybrid rovings having a certain thermoplastic content and thus sufficient matrix material is provided.

In 4 is another alternative embodiment of a layer structure 30 shown. The layer structure 30 consists successively of the top layer 18 , the plastic layer comprising the unidirectionally oriented fibers 20 , the random fibers having fleece 26 and the plastic layer having the unidirectionally oriented fibers 22 according to which the respective layers repeat in reverse order or in a mirrored manner.

The following are the functional properties of the respective layers 18 to 26 explained. The outer layer, which consists of the thermoplastic cover layer 18 is formed, causes a significant reduction in shrinkage compared to thermoset materials, thereby reducing the fiber matrix marking on the plastic Außenbeplankungsteil 12 is achieved. This is especially through the use of amorphous, KTL-compatible high-temperature thermoplastics, which can be additionally refined with mineral, nano and microfillers to achieve even better properties with respect to the shrinkage.

The thermoplastic cover layer 18 is processed in the form of thin films. Due to the positive influence of the amorphous cover layer 18 on the surface quality, own all layer variants 17 . 28 . 30 a cover layer 18 from this material.

In addition, the cover layer 18 consist of two different matrices not shown here. The cover layer 18 has in this case an outer layer, not shown here, which is UV-resistant, KTL-suitable, water-repellent and / or paintable, in particular ESTA-compatible. This thus serves as a moisture barrier and for improved paintability or adhesion of corresponding paints on the plastic Außenbeplankungsteil 12 while providing UV protection. Furthermore, the cover layer 18 an inner layer also not shown, which with the below the cover layer 18 arranged plastic layer 20 connected is. This inner layer may be formed, for example, as a (co) extrusion film which, in addition to the connection with the matrix material, serves as a barrier layer for further fibers and for reducing the shrinkage behavior.

Another decisive influence on the Class-A surface from a textile-technical point of view is the use of unidirectional tapes or ribbons. The unidirectional tapes are the respective plastic layers reinforced with the unidirectionally oriented fibers 20 . 22 ,

The special feature lies in the production of fiber-reinforced plastic layers 20 . 22 , which from a like in 5 shown tissue 32 getting produced. The tissue 32 comprises a plurality of warp threads 34 and weft threads 36 , Here are the weft threads 36 of the tissue 32 made of a thermoplastic multifilament and the warp threads 34 formed from a hybrid or Glasfaserroving. When pressing the layer structure 17 . 28 . 30 the weft yarn melts 34 on and off the previous fabric structure becomes a unidirectional structure. This structure is characterized by a stretched fiber layer. This property of the textile layer results in a more flat surface compared to conventional fabrics, since the number of unevenness, and the number of undulations is much lower, and there are no longer any crossing points as with conventional fabrics. Furthermore, the unidirectional tapes reduce matrix accumulations, which can lead to discontinuities on the surface.

Another advantage of using hybrid rovings in the unidirectional position 20 . 22 Compared to glass fiber rovings is that the weaving speed for producing the fiber reinforced plastic layers 20 . 22 can be significantly increased. The reason is that the thermoplastic content in hybrid roving reduces the brittleness of the roving, so that yarn breaks occur only at higher weaving speeds.

In addition, the hybrid rovings can be processed as so-called spread-tows. In 6 is a schematic cross-sectional view of the formed as a hybrid roving warp 34 shown. The individual fiberglass strands 38 and thermoplastic strands 40 trained filaments are thereby spread as far as possible to obtain a flatter roving. The advantage here is that the thickness of the unidirectional layer 20 . 22 is significantly reduced and at the same time the bumps are reduced due to the flattening of the rovings and thus even more level surfaces arise. As a result, textile technology already provides an ideal basis for a later Class A surface. The Glasfaserrovings and thermoplastic Mulitfilamentgarne be swirled together, for example by means of the so-called commingling process. As a result, as homogeneously mixed yarn as possible is achieved.

Alternatively, a textile layer can also be realized by a leno fabric, not shown here. Here, the high slip resistance is an advantage that arise due to the structure of a leno fabric (with multiple warp threads). For this reason, this fabric also has a low structural strain. When the leno weave is woven with nearly stretched ground threads, the weave has similar properties as a unidirectional layer. Thus, unidirectional layers can also be substituted by leno tissue.

In 7 is one of random fibers or hybrid rovings 42 trained fleece 26 shown in a schematic view. The reason for the integration of extremely fine, quasi-isotropic fiberglass fiber webs in the respective layer structure 17 . 28 . 30 lies in the fact that a marking of the fibers on the surface is additionally reduced and thus has a positive effect on the surface quality. In addition, by the fleece 26 or by this nonwoven layer prevents the glass fibers from shifting when the matrix melts. So it acts as a kind of barrier. An additional positive effect on the processability and the surface brings an education of the fleeces 26 also from hybrid rovings with him.

Hereinafter, a method for producing the planking component 10 based on 8th explained. First, the layer structure 17 or 28 or 30 by hot pressing of the individual layers 18 . 20 . 22 . 24 . 26 to a semi-finished product 44 pressed and, where appropriate, before or after confectioning.

A previously heated and ready-made semifinished product designed as an organic sheet 46 gets into a tool in a first station 50 inserted and not shown here by vacuum suction in the tool 48 held. In other words, it is the semi-finished product 46 around an organo-sheet made of a fiber-reinforced plastic. After the semifinished product 46 in the tool 48 has been inserted, this is closed and the semi-finished product 46 reshaped. Then the formed semi-finished product 46 molded with plastic and thereby the inner part 14 educated. Parallel to this will be in a second station 52 the semi-finished product 44 with the help of a vacuum gripper 54 inserted, reshaped and tempered, making the plastic Außenbeplankungsteil 12 is trained.

Inside the tool 54 there is a mold tempering module 56 which is the thermoplastic topcoat 18 heated inductively and thus generates a Class-A surface. The benefit of variothermal inductive mold temperature control represents a huge leap forward in the production of a fiber composite with Class-A surfaces. By briefly melting the thermoplastic topcoat 18 on a inductively heated tool surface creates a smooth cover layer 18 ,

By means of a turning plate 58 this is made from the plastic-coated semi-finished product 46 trained inner part 14 the station 52 facing, after which the inner part 14 and the plastic Außenbeplankungsteil 12 be joined together to form a cavity, not shown. Subsequently, a foam unspecified here, from which the foam element 16 is formed in the between the inner part 14 and the plastic outer planking part 12 formed cavity formed, wherein the inner part 14 and the plastic outer planking part 12 then be moved away in the region of the cavity by a predetermined distance from each other.

In other words, the plastic outer planking part becomes 12 and the inner part 14 grown after filling with the foam, which is referred to as so-called "breathing". By the so-called foam spraying with "breathing" tool, a significant reduction in density of the foam element 16 be achieved. The foaming takes place by tool breathing about three seconds after the volumetric filling of the cavity or the cavity.

In contrast to the classical low-pressure method, the cavity or the cavity is first filled volumetrically completely and there is a cavity enlargement, which leads to the pressure drop and to the expansion of the gas-laden melt or of the foam. The cavity enlargement can be realized by a precise opening movement of a closing unit of an injection molding machine or by correspondingly movable cores. As a rule, dipping edge tools are used for this purpose in order to avoid melt escape from a parting plane.

The expansion of the foam is due to the unidirectional cavity enlargement in one direction only. In the case of foam spraying with a "breathing" tool, compact cover layers form immediately after the tool filling due to the solidification of the polymer on the cold mold wall. Due to a delay between the injection and the "breathing", the thickness of the compact cover layers of the integral foam can be adjusted, with a longer delay time leading to thicker compact cover layers. During this delay time, the injected melt or the injected foam is prevented from foaming by a brief pressurization (holding pressure phase). Overall, foam spraying offers shorter cycle times, reduced component weights and lower cavity pressures.

In summary, the planking component allows 10 or the plastic Außenbeplankungsteil 12 a reduction in weight and cost compared to skins made of aluminum or sheet molding compound. In addition, the foamed sandwich structure results in a visually considerably higher appearance of the paneling components 10 with simultaneous cost and weight reduction.

Added to this is the creation of a Class-A surface of the outer skin of the planking component 10 , The decisive advantage with regard to the creation of this surface is that no reworking of the surface after the production process is necessary and a very good paintability in the painting lines for metal bodies is given. Among other things, the use of inductive, variothermic mold temperature control technology is responsible for this. In addition, the manufacturing process is energetically very effective and through the use of inductively heated plates in the tool 53 also very fast. The usual repeated grinding of matrix material is eliminated. Thus, the cycle time for producing the planking component is shortened 10 considerably.

Compared to metallic materials, there are enormous advantages with regard to the corrosion behavior and the resulting longer durability, especially in that no additional corrosion protection is necessary. Furthermore, a greater freedom of design of the components is made possible.

Another positive aspect of fiber reinforced plastics is the lower weight compared to metals, with the same to higher rigidity and comparable installation space. The result is among other things an increased energy efficiency and a resulting greater range of vehicles, in which the weight-reduced planking components 10 be used.

Furthermore, such planking components 10 made of fiber-reinforced plastic a vibration-reduced construction with a higher rigidity and thus also very good crash properties. In addition, the planking component 10 an improved acoustic and thermal insulation property in contrast to metal structures. In the course of electrification of motor vehicles, this is a particularly important factor, since so the energy consumption for example, an interior air conditioning can be significantly reduced.

Added to this is the reduction in manufacturing costs. This is due to the use of thermoplastics and a close-to-net shaping, whereby appropriate tooling costs can be minimized. It should be noted that the increasing cost-effectiveness of fiber composites due to the future decline in the number of individual vehicle variants due to the steadily growing variety of models.

Advantages compared to thermosetting planking (eg from Sheet Modeling Compound) are virtually unlimited shelf life of the thermoplastic matrix at room temperature, no need for solvent in component manufacturing, with thermoplastics available as granules and cycle times can be reduced by significantly shorter curing times. Furthermore, thermoplastics have a lower shrinkage, which has a positive effect on the surface to be achieved. Finally, thermoplastics have increased media resistance and higher impact strength.

Claims (3)

A planking component (10) for a motor vehicle, having a plastic Außenbeplankungsteil (12), wherein the plastic Außenbeplankungsteil (12) comprises a plurality of fiber reinforced plastic layers (20, 22) each having unidirectionally oriented fibers and a cover layer (18) made of a thermoplastic characterized in that the unidirectionally oriented fibers reinforced plastic layer (20, 22) is made of a fabric (32), which warp threads (34) of glass fiber strands or hybrid strands and in the manufacture of the plastic layer (20, 22) melted weft threads (36) having thermoplastic multifilaments. Planking component (10) according to Claim 1 characterized in that the plastic Außenbeplankungsteil (12) with a random fibers (42) reinforced plastic layer (26). Method for producing a paneling component (10) for a motor vehicle, comprising the steps of: - Forming a first formed from a fiber-reinforced plastic semi-finished product (46) and encapsulating with plastic to an inner part (14); - Forming a second made of a fiber-reinforced plastic semi-finished product (44) to a plastic Außenbeplankungsteil (12); - Inductive heating of a formed from a thermoplastic covering layer (18) of the plastic Außenbeplankungsteils (12); - Joining the inner part (14) and the plastic Außenbeplankungsteils (12); - Introducing a foam in between the inner part (14) and the Kunststoff-Außenbeplankungsteil (12) formed cavity, wherein the inner part (14) and the Kunststoff-Außenbeplankungsteil (12) are then moved away in the region of the cavity by a predetermined distance from each other ,

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