Abstract:
The invention relates to a composite component comprising an insert made of expanded metal surrounded by foamed material, particularly a steering column collision protection element.

Description:
BACKGROUND 
   The invention relates to a composite component, particularly an impact absorber, a motor vehicle body component, a motor vehicle inside molding component, a structural component, such as a closure cap, as well as a vehicle seat, and to a method for producing a composite component. 
   From DE 101 61 155 A1, a composite component made of polyurethane comprising an insert is known. The insert is an object, which can be included entirely or partially in the fiber-reinforced polyurethane layer by foaming. The inserts are made of polymer and/or metal, such as steel, copper, zinc, aluminum or alloys thereof. 
   SUMMARY OF THE INVENTION 
   In contrast, it is the object of the invention to create an improved composite component, particularly an impact absorber, a steering column collision protection element, a motor vehicle body component, a motor vehicle inside molding component, a structural components such as a closure cap, as well as a vehicle seat, and to create a method for producing a composite component. 
   The invention creates a composite component comprising an insert made of expanded metal, which insert is surrounded by foamed material. Compared to conventional inserts made of metal, the insert made of metal according to the invention offers various advantages. In particular, less metal is required for achieving a certain rigidity of the composite component, resulting in weight and cost advantages. Furthermore, due to the wire openings of the expanded metal, a more homogeneous bond can be achieved between the metal and the foamed material. As a result, the mechanical load tolerance of the composite component can be improved. 
   According to one embodiment of the invention, the foamed material is polyurethane. Depending on the application, it can be a soft, medium hard or hard foamed material. To further increase the rigidity of the composite component, reinforcing materials, such as mineral fibers or glass fibers, can be added to the foamed material. 
   According to one embodiment of the invention, the insert made of expanded metal is disposed such that it abuts a surface of the composite component. The insert is therefore surrounded completely by foamed material and is provided in the vicinity of one of the surfaces of the composite material. This is advantageous for a variety of applications, particularly for applications as impact absorber and as a seat backrest. 
   According to one embodiment of the invention, the expanded metal is steel, copper, zinc, aluminum or an alloy. 
   According to one embodiment of the invention, the expanded metal has a wire structure with wire openings measuring about 10 mm to 30 mm in length, particularly 20 mm, and about 5 mm to 15 mm in width, particularly 10 mm. 
   According to one embodiment of the invention, the composite component forms an impact absorber. Such impact absorbers are installed, for example, in motor vehicles to improve the safety of the passengers in the event of a collision. 
   According to a further embodiment of the invention, the composite component is configured as a steering column collision protection element. A steering column collision protection element is configured for installation under the steering column between the steering wheel and the dashboard. The steering column collision protection element particularly serves as knee protection in the event of a collision, when the driver&#39;s knees are thrown in the direction of the steering column. 
   It is preferable if the insert made of expanded metal is disposed such that it abuts a surface of the steering column collision protection element, which is provided on the steering column after installation, so that the impact of the knees is with the side of the composite component opposite the insert in the event of a collision. 
   According to a further embodiment, the composite component is configured as a motor vehicle body component. It is particularly advantageous that the vehicle weight can be reduced, while maintaining or improving crash safety. Particularly the use of polyurethane also affects the acoustics advantages of such a motor vehicle body component according to the invention. 
   According to a further embodiment of the invention, the composite component is configured as a motor vehicle inside molding component. Such a motor vehicle inside molding component may serve purely decorative purposes and/or serve as an impact absorber. Furthermore, it can be a structural component, such as a closure cap, particularly a glove compartment cover, or a hat rack. 
   In a further aspect, the invention relates to a vehicle seat with an insert made of expanded metal covered in foam. Particularly the backrest of the vehicle seat may comprise such an insert covered in foam. By using the expanded metal, the weight can be reduced, while maintaining comfort and rigidity. 
   In a further aspect, the invention relates to a method for producing a composite component. First, an insert is produced by expanding a metal. The insert is given a wire-shaped structure, for example. The insert is placed in a mold. Then, a foaming reaction mixture is poured into the cavity formed by the mold. It is particularly advantageous that the foaming reaction mixture can homogeneously bond with the insert due to the wire-shaped structure of the insert. 
   The method according to the invention may particularly also be a reaction injection molding (RIM) method. Furthermore, it may also be high-speed RIM or reinforced RIM method, in which reinforcement materials such as mineral fibers or glass fibers are added to the reaction mixture. 
   According to one embodiment of the invention, the insert is not fastened to the mold, but instead is placed loosely in the mold, so that it can be moved at least with one degree of freedom. When placing the insert on the bottom of the cavity, for example, it can move in the direction of the side of the cavity opposite the bottom as the foaming reaction takes place. As a result, the insert is located such in the resulting composite component that it abuts the corresponding surface of the composite component. 
   Other aspects, features, and advantages of the present invention will be apparent to one skilled in the art from the description herein taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention will be explained in more detail hereinafter with reference to the drawings, wherein: 
       FIG. 1  shows a sectional view of the mold with the insert placed therein, 
       FIG. 2  shows the mold according to  FIG. 1  after adding a foaming reaction mixture during the course of the reaction, 
       FIG. 3  is the composite component obtained after the foaming reaction, 
       FIG. 4  shows a flow chart of a method for producing a composite component, 
       FIG. 5  is an insert made of expanded metal for an impact absorber, particularly a steering column collision protection element, 
       FIG. 6  is a steering column collision protection element with the insert according to  FIG. 5 , and 
       FIG. 7  is an installation position of the steering column collision protection element according to  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a mold  100  with an insert  102  made of expanded metal that is placed in the mold  100 . In the embodiment illustrated here, the insert  102  is placed on the bottom of the mold  100 . The insert  102  is not fastened in the mold  100 , but is instead placed loosely in the mold  100 . 
     FIG. 2  shows the mold  100  after a foaming reaction mixture  104  has been poured into the cavity formed by the mold  100 . During the reaction, the foaming reaction mixture  104  forms a homogeneous bond with the insert  102  and moves the insert  102  from the bottom of the mold  100  in the direction of the arrow  106  to the side of the mold  100  opposite the bottom. 
   After opening the mold  100 , the composite component  108  with the insert  102  is obtained, which insert is disposed such that it abuts a surface  110  of the composite component  108 , as is shown in  FIG. 3 . 
   The reaction mixture  104  poured into the mold  100  preferably comprises polymers, which are mixed with reactive components, such as polyol and isocyanate. 
   The composite component  108  is an impact absorber, for example, particularly a motor vehicle impact absorber, to improve the protection of passengers in the event of a collision. For example, the composite component  108  can be a steering column collision protection element, a motor vehicle body component, a motor vehicle inside molding component or another structural component. The composite component  108  can furthermore also be the seat surface or the backrest of a vehicle seat. In the latter case, the seat surface is formed by the surface  112  of the composite component opposite the surface  110 . 
     FIG. 4  shows a corresponding flow chart. In step  200 , an insert is produced by the expansion of metal. The insert produced this way has a wire-shaped structure with wire openings measuring, for example, 10 mm to 30 mm in length and 5 mm to 15 mm in width. In step  202 , the insert is placed in a mold. In step  204 , a reaction mixture capable of foaming is added to the cavity formed by the mold. After at least part of the reaction has taken place, the mold is opened (step  206 ), thus obtaining the composite component. 
     FIG. 5  shows one embodiment of the insert  102  made of expanded metal for the production of an impact absorber, particularly a steering column collision protection element. 
     FIG. 6  shows a steering column collision protection element  108 , which has been produced with the help of the insert  102  according to  FIG. 5  in a manner as explained with reference to  FIGS. 1 to 4 . 
     FIG. 7  shows an installation position of the steering column collision protection element  108  on a steering column  114  of a motor vehicle. The steering column collision protection element  108  is provided on the steering column  114  between a steering wheel  116  and a dashboard  118 . The surface  110  with the insert  102  abutting the surface  110  is located on the steering column  114 , thus allowing the driver&#39;s knees to impact the surface  112  of the steering column collision protection element  108  upon collision. 
   Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. 
   LIST OF REFERENCE NUMERALS 
   
       
         100  mold 
         102  insert 
         104  reaction mixture 
         106  direction of arrow 
         108  composite material, steering column collision protection element 
         110  surface 
         112  surface 
         114  steering column 
         116  steering wheel 
         118  instrument