DE102021110877A1 - METHOD FOR MANUFACTURING A COMPONENT AND VEHICLE DOOR FOR A MOTOR CAR - Google Patents

Abstract

The invention relates to a method for producing a component (10), in particular a motor vehicle component, with the steps: providing a fiber mat (V1), weakening the fiber mat at at least one predetermined point (V2), heating the fiber mat; and forming the fiber mat by means of a forming tool to form the component (10), whereby the forming process causes the fiber mat to fail at the at least one weakened point (V3).

Description

technical field

The invention relates to a method for producing a component, in particular a motor vehicle component, and a vehicle door for a motor vehicle.

State of the art

Shaping a motor vehicle component with natural fibers can be limited by a yield point and formability of the respective natural fiber. Certain constructive proportions and thus restrictions that limit the use of natural fiber materials in contrast to plastic materials may have to be observed.

Description of the invention

The object of the present invention is to enable a particularly extensive use of components comprising fibers, in particular in motor vehicles.

This object is solved by the subject matter of the independent patent claims. Further possible configurations of the invention are disclosed in the dependent claims, the description and the figures.

The invention relates to a method for producing a component, in particular a motor vehicle component, in which a fiber mat is provided. In a further step of the method, provision is made for the fiber mat to be provided with a weakening at at least one predetermined point. This means that a targeted weakening of the fiber mat is provided at the at least one predetermined point. The weakening is to be understood in particular as meaning that the stability of the fiber mat is reduced at the at least one predetermined point. In the method, it is further provided that the fiber mat is heated and the fiber mat is shaped by means of a shaping tool to form the component, in particular the motor vehicle component. The fiber mat is caused to fail at the at least one weakened point by the forming process. In addition to the forming, the fiber mat can be heated and/or weakened by means of the forming tool. Provision can furthermore be made for the fiber mat to be weakened by means of the shaping tool before the heating and subsequent shaping of the fiber mat. Alternatively, the batt can be first heated, then weakened, and then reshaped. Furthermore, it is possible that the fiber mat is first formed and then heated. Here, the weakening can take place before or after the forming. The steps of weakening, heating and forming can thus be adjusted in their order. Of these steps, at least the forming step can take place in the forming tool. In addition, the fiber mat can be heated and/or weakened by means of the forming tool. Due to the heating of the fiber mat, at least some of the fibers of the fiber mat melt at least partially. As a result, several of the fibers of the fiber mat can be fused together. After forming, the fiber mat can cool down, causing the partially melted or melted fibers to harden.

The failure of the fiber mat at the at least one weakened point is to be understood in particular as a material failure in which the stability of the fiber mat at the at least one weakened point falls within the scope of the failure. In particular, a failure can be understood to mean a tearing open of the fiber mat or a widening of openings in the fiber mat provided as part of the weakening. In the method, it is therefore provided that the fiber mat fails due to the targeted weakening at the predetermined weakened points during forming, as a result of which failure at points on the fiber mat that are different from the weakened points can be avoided. As a result, a particularly high complexity of a geometry of the component comprising the fibers, in particular of the motor vehicle component, can be implemented. The component provided from the fiber mat, in particular a motor vehicle component, can thus have areas with particularly small radii and/or edged transitions and/or sharp contour jumps. For use of the motor vehicle component in a motor vehicle, the motor vehicle component provided by the reshaping of the fiber mat can be subjected to at least one further processing step.

In a further embodiment of the invention, it is provided that the fiber mat is slit and/or perforated and/or cut at the at least one point in order to provide the weakening. Slitting the fiber mat means that a slit completely penetrating the fiber mat is made in the fiber mat. Perforating the fiber mat means that at least one at least essentially round through-opening is made in the fiber mat, which completely penetrates the fiber mat. Cutting the fiber mat means that individual fiber layers of the fiber mat are severed, however, the batt is not fully penetrated by the cut. The fiber mat can thus be scratched. By selecting the type of weakening in each case, the failure of the fiber mat resulting from the forming can be influenced in a targeted manner at the respective points. In particular, the selection of the respective weakening can trigger a tearing or tearing open of the fiber mat as a result of the forming as a failure, or the respective selection of the weakening can be used to influence how far or how severely the fiber mat tears or widens as a result of the forming process in the event of failure . By selecting the respective type of weakening, by influencing the failure of the fiber mat during the reshaping, relief can be achieved in areas of the fiber mat that are different from the weakened areas. This targeted relief of the areas different from the weakened areas simplifies the implementation of complicated geometries of the component, in particular the motor vehicle component.

In a further embodiment, it is provided that a fiber mat with natural fibers is provided as the fiber mat. This means that the fiber mat comprises at least natural fibers. Optionally, the fiber mat can include other fibers. In order to enable particular fibers of the fiber mat to be melted particularly well, it can be provided that the fiber mat comprises polymer fibers. In this case, the natural fibers can be designed as polymer fibers or additional fibers can be provided for the natural fibers in the fiber mat, which are designed as polymer fibers. Alternatively or in addition to the natural fibers, the fiber mat can include glass fibers and/or carbon fibers and/or fabric fibers.

In a further embodiment of the invention, it is provided that the fiber mat is provided, which comprises synthetic fibers in addition to the natural fibers. The plastic fibers can be provided in particular from a duroplastic or from a thermoplastic. In particular, the plastic fibers are polypropylene fibers. These polypropylene fibers can be fused particularly well with the natural fibers during the heating and subsequent shaping of the fiber mat, as a result of which the component can be provided with particularly high stability and thus with inherent rigidity. The fiber mat includes in particular up to 60% natural fibers. For example, the fiber mat can comprise approximately 50% natural fibers and approximately 50% synthetic fibers. As a result, a particularly large proportion of the fiber mat can be provided from the regenerative material of the natural fibers, whereas the strength and/or elasticity of the component, in particular the motor vehicle component, can be adjusted via the plastic fibers.

In a further embodiment of the invention it is provided that flax fibers and/or hemp fibers and/or wood fibers and/or cotton fibers and/or wool fibers are used as the natural fibers. These natural fibers are each particularly durable regenerative natural fibers. The component, in particular the motor vehicle component, can thus be provided with a particularly long service life and is provided at least partially from regenerative material. If necessary, the component can be made recyclable by using the natural fibers.

In a further embodiment of the invention, it is provided that fibers are laid one on top of the other and needled together in order to provide the fiber mat. Here, the natural fibers can be layered with the synthetic fibers. The fibers are needled together by working with at least one needle board. When needling the fibers, the fibers can be knit together. As a result, loose fibers can be connected to one another particularly easily and quickly to form the fiber mat.

In a further embodiment of the invention, it is provided that at least one opening resulting from the reshaping of a weakened point is filled by means of injection molding. In particular, an injection molding tool can be integrated into the forming tool, by means of which the at least one opening resulting from one of the weakened points is filled with a plastic by injection molding during and/or after the forming of the fiber mat. As a result, openings in the component caused by failure can be prevented from remaining open.

In a further embodiment of the invention, it is provided that at least one further component is molded onto the fiber mat. In this case, the at least one further component can be injected onto the fiber mat by means of the injection molding tool. In particular, the at least one further component is arranged on the fiber mat by injection molding during the forming of the fiber mat by means of the injection molding tool integrated into the forming tool. In particular, the at least one further component can be injected onto the fiber mat at the same time by means of the injection mold and the at least one opening resulting at the weakened point can be filled. This allows the component in particular few processing steps and in particular with particularly short cycle times.

In a further embodiment of the invention, it is provided that the fiber mat is formed into part of a vehicle door. In this case, the component, in particular the motor vehicle component, can be at least part of an interior paneling of the vehicle door. By means of the motor vehicle component, the vehicle door can thus be covered towards an interior of a motor vehicle having the vehicle door. The method described allows the motor vehicle component to be provided with a particularly large size, as a result of which the interior paneling of the vehicle door can be provided from a particularly small number of motor vehicle components and can therefore be provided in a particularly simple manner.

The invention also relates to a vehicle door for a motor vehicle, with a motor vehicle component that has been provided in a method as has already been described in connection with the method according to the invention for producing the motor vehicle component. In this case, the motor vehicle component is in particular part of an interior paneling of the vehicle door. The use of the motor vehicle component in the vehicle door makes it possible for a particularly large proportion of regenerative materials, in this case natural fibers, to be used for providing the vehicle door. Advantages and advantageous developments of the method according to the invention are to be regarded as advantages and advantageous developments of the vehicle door according to the invention and vice versa.

Further advantages, features and details of the invention can result from the following description of possible exemplary embodiments and from the drawing. The features and feature combinations mentioned above in the description and the features and feature combinations shown below in the description of the figures and/or in the figures alone can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the invention to leave.

character list

• 1 ein Verfahrensschema für ein Verfahren zum Herstellen eines Bauteils, insbesondere eines Kraftfahrzeugbauteils aus einer Fasern, insbesondere Naturfasern umfassenden Fasermatte; und
• 2a, 2b ein im Rahmen des Verfahrens hergestelltes Kraftfahrzeugbauteil in einer Vorderansicht und in einer Rückansicht, wobei ein gezieltes Versagen des Kraftfahrzeugbauteils an vorgegebenen geschwächten Stellen im Rahmen der Herstellung des Kraftfahrzeugbauteils ausgelöst worden ist, um ein ungewolltes Versagen des Kraftfahrzeugbauteils in zu den vorgesehenen Stellen weiteren Bereichen des Kraftfahrzeugbauteils zu verhindern.

The drawing shows in:

• 1 a process diagram for a method for producing a component, in particular a motor vehicle component, from a fiber mat, in particular comprising natural fibers; and
• 2a , 2 B a motor vehicle component produced as part of the method in a front view and in a rear view, with a targeted failure of the motor vehicle component being triggered at predetermined weakened points during the production of the motor vehicle component, in order to prevent an unwanted failure of the motor vehicle component in areas of the motor vehicle component that are further from the intended points to prevent.

In the 2a and 2 B a motor vehicle component 10 is shown in a front view and in a rear view, which is part of a vehicle door of a motor vehicle in the present case. In the present case, this motor vehicle component 10 is produced from a fiber mat which comprises at least natural fibers.

In 1 a process diagram for a method for producing the motor vehicle component 10 is shown. The method provides for the fiber mat with the natural fibers to be provided in a first method step V1. Here, the fiber mat can comprise flax fibers and/or hemp fibers and/or wood fibers and/or cotton fibers and/or wool fibers as the natural fibers. In addition to the natural fibers, the fiber mat can have synthetic fibers. The fiber mat presently comprises flax fibers and polypropylene fibers. The batt is provided by layering the fibers and needling the fibers with a needle board.

In a second method step V2 of the method, provision is made for the fiber mat to be weakened in a targeted manner at at least one predetermined point. For targeted weakening, the fiber mat can be slit and/or perforated and/or cut at at least one point. In order to weaken the fiber mat, it is therefore provided that fibers of the fiber mat are severed at the points to be weakened. This targeted weakening of the fiber mat at the predetermined points can trigger a targeted failure of the fiber mat at these points when the fiber mat is deformed.

In a third method step V3 of the method, it is provided that the fiber mat is heated and then formed into the motor vehicle component 10 by means of a forming tool. A sequence of the steps of weakening the fiber mat, heating the fiber mat and shaping the fiber mat can be selected depending on material parameters of the fiber mat and/or depending on process parameters of the respective steps. By reshaping the fiber mat, the fiber mat is made to fail in a targeted manner at the at least one weakened point. The targeted failure of the fiber mat at the at least one weakened point can result in material stress on the fiber mat in to the at least one weakened area different areas of the fiber mat are kept particularly low. A failure of the fiber mat in the areas that differ from the weakened area can thus be at least essentially avoided. In the event of failure, the fiber mat can tear open at the at least one weakened point or expand as a result of the failure.

To close the openings 12 resulting from the failure of the fiber mat at the respective weakened points, these resulting openings 12 can be filled by injecting a plastic using an injection molding tool. The injection molding tool can in particular be integrated into the forming tool, so that the fiber mat can be both formed and the at least one opening resulting from the failure can be filled in a single cycle step. As part of the injection molding process, a further component can be injected onto the fiber mat using the injection molding tool. At the same time, the injection mold can be used to inject the at least one further component onto the fiber mat and at least one opening resulting from the failure at the weakened points can be filled by filling with the plastic.

In the 2a and 2 B the motor vehicle component 10 is shown with the openings 12 filled with the plastic. Furthermore, a plurality of further components 14 molded onto the motor vehicle component 10 can be recognized on the rear side of the motor vehicle component 10 .

The method therefore provides for the fiber mat to be weakened at the defined points, in that the fiber mat is in particular slit or perforated. In this case, a size and orientation of the respective weakening can be selected depending on the component geometry of the motor vehicle component 10 to be produced from the fiber mat. By weakening the fiber mat, the fiber mat is given the opportunity to give way or yield at the weakened points. The space liberated by the failure, in this case the openings 12, can be filled with injection material. The method enables parts of the motor vehicle component 10 to be minimized or a possible complexity of the motor vehicle component 10 made at least partially from natural fibers to be increased. When manufacturing the motor vehicle component 10, particularly small forming angles and radii can be implemented. Furthermore, due to the described method used, particularly large contour jumps can be implemented in the motor vehicle component 10 provided at least partially from the natural fibers. In other words, particularly steep demoulding angles, particularly small concise radii and particularly large contour jumps can be implemented in the motor vehicle component 10 due to the method.

The process enables a particularly large number of different uses of natural fibers. In addition, the method makes it possible for the motor vehicle component 10 to be provided in one piece and thus from a particularly small number of individual parts. The motor vehicle component 10 produced by means of the method can be produced with particularly low production costs. In addition, the motor vehicle component 10 can be provided in a particularly compact manner in the method, as a result of which an optimized package is possible. Furthermore, due to the natural fibers, the motor vehicle component 10 has a particularly low weight and a particularly advantageous CO ₂ balance. A plastic-like geometry of the motor vehicle component 10 can be represented by means of the motor vehicle component 10 produced within the scope of the method. Through a possible integration of otherwise necessary separate components, the geometry of which cannot be represented in natural fibers in the prior art, the motor vehicle component 10 can be provided from a particularly small number of individual parts, in the present case in one piece. In order to prevent areas of the fiber mat that are different from the weakened areas from failing, the fiber mat fails in a targeted manner. The use of the fiber mat with the natural fibers enables a particularly high proportion of regenerative material in the motor vehicle component 10 and a particularly low weight of the motor vehicle component 10.

Overall, the invention shows how the shaping of a motor vehicle component 10 can be optimized with natural fibers.

Reference List

10

motor vehicle component

12

opening

14

another component

V1-V3

respective procedural steps

Claims (10)

Method for producing a component (10), in particular a motor vehicle component, with the steps: - providing a fiber mat (V1), - weakening the fiber mat at at least one predetermined point (V2), - heating the fiber mat; and - forming the fiber mat by means of a forming tool to the component (10), whereby the fiber mat is brought to failure at the at least one weakened point by the forming process (V3). procedure after claim 1 , characterized in that for the provision of the weakening the fiber mat is slit and/or perforated and/or cut at the at least one point. procedure after claim 1 or 2 , characterized in that the fiber mat is provided, which has natural fibers. procedure after claim 3 , characterized in that the fiber mat is provided, which comprises synthetic fibers in addition to the natural fibers. procedure after claim 3 or 4 , characterized in that flax fibers and/or hemp fibers and/or wood fibers and/or cotton fibers and/or wool fibers are used as the natural fibers. Method according to one of the preceding claims, characterized in that for the preparation of the fiber mat, fibers are laid one on top of the other and needled together. Method according to one of the preceding claims, characterized in that at least one opening (12) resulting after the forming at the weakened point is filled by means of injection molding. Method according to one of the preceding claims, characterized in that at least one further component (14) is injection molded onto the fiber mat. Method according to one of the preceding claims, characterized in that the fiber mat is formed into part of a vehicle door. Vehicle door for a motor vehicle, with a motor vehicle component (10) which has been provided in a method according to one of the preceding claims.

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