Abstract:
A method of attaching functional components to a roof element of a vehicle, including applying a curable material in a low-viscosity state which is molded in sections by means of a first mold surface, wherein a second mold surface is used which serves for shaping further sections of the curable material, an opening remaining accessible towards the environment through which the curable material can be introduced.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/765,362 filed on Feb. 12, 2013, which claims foreign priority to DE 10 2012 003 045.2 filed Feb. 16, 2012, under 35 U.S.C. §119, the contents each of which are incorporated herein by reference thereto. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a method of attaching functional components to a roof element of a vehicle, including applying a curable material in a low-viscosity state which is molded in sections by means of a first mold surface. The invention further relates to a roof element for a vehicle. 
       BACKGROUND 
       [0003]    The roof element may, more particularly, be a cover or a module element as are used in modern motor vehicles. The cover is usually part of a sliding roof here and can be shifted between a closed position and various open positions by a suitable mechanism. The module element may be configured to be panel-shaped and constitute a stationary part of the vehicle roof, for example the stationary parts of the roof skin that are arranged laterally of a sliding roof cover, or the part arranged behind the sliding roof cover, as viewed in the direction of travel. 
         [0004]    It is known that a so-called foamed casing or portion can be used for covers of sliding roofs, in particular glass covers, which in most cases consists of polyurethane. The latter is introduced into a foaming mold so that a polyurethane frame or other polyurethane formations are formed which firmly adhere to the cover. A disadvantage here is the fairly great effort involved in producing the foaming molds, which are required to ensure the necessary sealing action in view of the foaming pressure occurring, so that the polyurethane cannot reach any surfaces where it impairs the function and/or the visual appearance of the cover. 
         [0005]    EP 1 577 080 discloses a method of manufacturing a gasket on a glass cover, in which polyurethane is applied in a spraying method. In this process, the cover is placed into an open mold having a mold surface onto which the curable polyurethane is sprayed. This allows, in particular, a frame to be obtained that surrounds the cover on all sides. Here, the mold surface is formed in a mold part made from a resilient material, for example silicone, so that a good sealing action on the cover is achieved. 
         [0006]    A drawback of this method is that only few geometries are possible, namely those that are feasible when using a dish-like mold part which holds the very flowable polyurethane. 
       SUMMARY OF THE INVENTION 
       [0007]    One object of the invention resides in further developing the method of the type initially mentioned in such a way as to also allow more complex geometries to be configured from the curable material on the roof element with little effort. 
         [0008]    To achieve this object, according to various embodiments of the invention provision is made in a method of the type initially mentioned that a second mold surface is used which serves for shaping further sections of the curable material, an opening remaining accessible towards the environment through which the curable material can be introduced. Furthermore, embodiments of the invention provide a roof element manufactured by means of such a method. Embodiments of the invention are based on the finding that the advantages of the two methods described above can be combined with each other. The use of more than one mold surfaces allows more complex geometries to be produced than can be produced when an open, dish-like mold part is used. It is not required, however, to use a closed molding tool here; rather, the method can be carried out in an open system in which mold surfaces are provided at those places where necessary but, basically, the curable material is introduced freely, more particularly can flow in freely. 
         [0009]    According to a further configuration of the invention, provision is made that the first mold surface is formed on a first mold part. This mold part can be made use of in particular for molding from outer contours that are exposed later. 
         [0010]    It is also possible for the first mold surface to be formed on a functional part which is firmly connected with the roof element by means of the curable material. In this configuration, the functional part to be attached is used for limiting the spreading of the curable material. At the same time, the functional part is firmly connected with the roof element by means of the curable material. 
         [0011]    According to one embodiment of the invention, provision is made that the second mold surface is formed on a second mold part. This allows a plurality of mutually independent mold surfaces to be used for shaping the curable material. 
         [0012]    According to a further configuration of the invention, provision is made that the second mold part is brought into position after part of the curable material was applied onto the first mold surface. This allows the curable material to be first applied freely and without hindrance onto a surface to be coated, for example by means of a spraying method, and the second mold part to be brought into position only subsequently. The second mold surface of the second mold part then provides for the desired contour of the curable material. In this way, it is also possible to produce geometries which would not otherwise be producible when using the low-viscosity curable material, for example because the material would not fully flow into the dedicated space between the roof element and the mold surface. 
         [0013]    According to one configuration of the invention, provision is made that the second mold part is used to hold in position the functional component to be attached. This ensures a high positional accuracy of the mold part to be inserted in relation to the geometries generated by the mold surfaces. 
         [0014]    Preferably, the curable material is polyurethane. This material has turned out to be particularly suitable with regard to its properties and its processing options. 
         [0015]    The functional part may be an integral part of the cured material. For example, the functional part may be an adhesive surface by means of which the roof element can be adhesively bonded to a vehicle structure, or a sealing lip that serves to seal against other structural parts. 
         [0016]    The functional part may also be a separate component, for example a spacer, a rail, a centering pin, or a screw-on dome. Such a functional part can be reliably attached to the roof element with high precision and a high holding force in the manner described, involving little effort. 
         [0017]    In one embodiment, a method of attaching functional components to a roof element of a vehicle is provided. The method including the steps of applying a curable material in a low-viscosity state which is molded in sections by means of a first mold surface, wherein a second mold surface is used which serves for shaping further sections of the curable material, an opening remaining accessible towards the environment through which the curable material can be introduced. 
         [0018]    In another embodiment, a roof element for a vehicle roof is provided. The roof element having a functional component attached thereto by a method including the steps of: applying a curable material to a portion of the roof element in a low-viscosity state; molding the curable material in sections by a first mold surface and a second mold surface, wherein the second mold surface is defined by a pair mold parts, wherein one of the pair of mold parts is applied to the curable material after it has been applied to the portion of the roof element and an opening remains between the pair of mold parts after they are applied to the curable material, wherein the opening is accessible towards the environment through which the curable material can be introduced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention will be described below with reference to various embodiments, which are illustrated in the accompanying drawings, in which: 
           [0020]      FIG. 1  schematically shows a vehicle roof of a motor vehicle; 
           [0021]      FIG. 2  schematically shows a section along the line II-II of  FIG. 1 ; 
           [0022]      FIG. 3  schematically shows a step in the manufacture of a roof element according to the invention; 
           [0023]      FIG. 4  schematically shows a first step in the manufacture of a roof element according to the invention; 
           [0024]      FIG. 5  schematically shows a second step in the manufacture of the roof element of  FIG. 4 ; 
           [0025]      FIG. 6  schematically shows the roof element of  FIG. 5  in the assembled condition; 
           [0026]      FIG. 7  schematically shows a first variant embodiment; 
           [0027]      FIG. 8  schematically shows a second variant embodiment; and 
           [0028]      FIG. 9  shows a perspective view of a mold with a roof element placed therein. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]      FIG. 1  schematically shows a roof  2  of a motor vehicle, which has a roof opening  4  in a roof skin  3 . Arranged in the roof opening  4  is a cover  10  of a sliding roof system that is not illustrated in more detail here. 
         [0030]    The roof skin  3  may be made of a plastic material or of glass, as is generally known with modern composite module roofs. The roof module preferably is an assembly intended to be connected with the vehicle structure in a preassembled condition, in particular with side beams of the vehicle body and with transverse beams that constitute the upper end of a windshield or of a rear window. 
         [0031]    As can be seen in  FIG. 2 , attached to a side beam  5  is a composite part  12  which is formed from two panels  14 ,  16  adhesively bonded to each other, with the outer panel  14  forming the roof skin. 
         [0032]    The composite part  12  formed from the panels  14 ,  16  is provided with a foamed portion  18  which consists of polyurethane and, for one thing, engages around the front faces of the panels  14 ,  16 , with a sealing lip  20  being integrally molded with the exterior face. The sealing lip  20  rests against the vehicle body. 
         [0033]    In addition or alternatively to the foamed portion  18 , which engages around an outer edge of the roof element  10 , the curable material may also be used to form an integrally foamed portion  19  which adheres to a surface of the roof element  10 . The integrally foamed portion  19  serves to firmly connect a rail  22  with the composite part  12 . To this end, for one thing, an exterior web  24  of the rail  22  is firmly embedded in the foamed portion  18 . For another thing, an opening  26  is provided in the rail  22  through which the integrally foamed portion  19  engages. 
         [0034]    The rail  22  firstly serves to connect the composite part  12  firmly with the side beam  5  of the vehicle body. For this purpose, provision is made for an adhesive bead  28  by means of which a connecting surface of the rail  22  is adhesively bonded firmly to the side beam  5 . The rail  22  further serves to receive various seals  30 ,  32  which cooperate with the cover  10 , only schematically shown here, of the sliding roof system. 
         [0035]    The foamed portion  18  not only functions to fasten the rail  22  to the composite part  12 , but also has the purpose of forming a variety of functional formations. For one thing, this is the sealing lip  20  already mentioned, which is configured in one piece with the foamed portion  18 . For another thing, the foamed portion  18  is provided with a pressure surface  34  on the interior edge of the composite part  12 , the pressure surface  34  cooperating with the seal  30  and pressing the latter onto a holding web on the rail  22 . 
         [0036]      FIG. 3  schematically shows the general basic principle of a method that can be used for applying the curable material from which the foamed portion  18  can be produced. This method is disclosed in EP 1 577 080. Here, a mold part  70  is used which has a mold surface  72 . The latter is configured to be open to the top and may be generally referred to as dish-shaped in the cross-section shown. The curable material  74  is sprayed into the mold surface  72  by means of a dosing head  76 , so that the foamed portion  18  eventually forms on the mold surface  72  and firmly adheres to the cover  10 . 
         [0037]      FIGS. 4 and 5  show how the curable material  74  is applied in order to provide a roof element as is shown in  FIG. 2 , for example. Here, too, a first mold part  70  is used which is suitably applied to the roof element  10 . The first mold part  70  is placed in a holder  78  here, which is provided with seals  80  that prevent an undesirable escape of the curable material  74 . A second mold part  82  which is likewise provided with seals  80  is placed onto the opposite side. Further arranged on this side of the roof element  10  is a holder  84  which holds a rail  22  and is also provided with a seal  80 . 
         [0038]    For the seals  80  a material is used to which the curable material will not adhere. Silicone is especially suitable. 
         [0039]    In a first method step, the curable material  74  is applied onto the first mold part  70  and also onto an edge region of the roof element  10  by means of the dosing head  76 . The curable material  74  will spread on the first mold surface  72  of the first mold part  70  and on the edge region of the roof element  10  as far as to a second mold surface  86  formed on the second mold part  82 . The seals  80  prevent the curable material from spreading onto surface regions in which it is not desired. The curable material  74  is also filled into a region between the rail  22  and the second mold part  82  where it spreads between a further mold surface  86  on the second mold part  82 , the surface of the roof element  10 , and the rail  22  as far as to the seal  80 . The viscosity of the curable material  74  is adjusted here such that it will reliably run under the rail  22 , where it will provide for a connection between the roof element  10  and the rail  22 . 
         [0040]    More particularly, polyurethane is suitable for use as the curable material, in particular the “COLO-FAST R 8959/109/WST” material of BASF. 
         [0041]    The curable material  74  is filled in between the second mold part  82  and the rail  22  until the required “filling level” is attained, whereas only a small quantity of the curable material  74  is initially applied onto the region between the first mold part  70  and the second mold part  82 . This quantity is essentially determined by the maximum height of the mold surface  72 . Subsequently, a movable mold part  83  is applied onto the first mold part  70 , the mold surfaces  86  of the movable mold part  83  making sure that the required outer contour is produced there. A further amount of curable material  74  is introduced through the space between the two mold parts  82 ,  83  until the required “filling level” is attained there as well. In the process, the mold surfaces  86  provided on the second mold parts  82 ,  83  ensure that further functional surfaces are formed on the foamed portion  18 . Finally, a spacer may be placed onto the foamed portion formed in the region between the two mold parts  82 , the spacer firmly connecting with the foamed portion  18 . 
         [0042]    In the two-stage filling-in process that is made use of for manufacturing the foamed portion  18 , the movable second mold part  83  is placed onto the first mold part  70  at a point in time at which the curable material has not yet cured to such a degree that deformation thereof would no longer be possible. In addition, it must be ensured that the material applied later between the two mold parts  82 ,  83  still combines with the material applied already earlier. 
         [0043]    By not applying the movable mold part  83  onto the first mold part  70  until a certain amount of the curable material  74  has already been applied there, it is made sure that it is even possible to reliably fill structures having very thin cross-sections. As can be seen in  FIG. 5 , for example a sealing lip  20  can be formed from the curable material without air being trapped. 
         [0044]      FIG. 6  shows the roof element  10  in the installed condition. One of the outer surfaces of the foamed portion  18 , which is molded by a mold surface  86  of the stationary mold part  82 , serves as an adhesive surface  88  here, which is firmly attached to a side beam  5  of the vehicle by means of an adhesive bead  28 . A spacer  90  applied to the foamed portion  18  ensures the correct positioning of the roof element  10  here. The integrally foamed portion  19  reliably fastens the rail  22  to the roof element  10 . Fitted to the rail  22  is, for example, a laterally guided roller blind  92 . 
         [0045]      FIG. 7  illustrates a variant embodiment in which a separate functional part  94 , more specifically a centering pin  94 , is incorporated into the foamed portion  18 . In the initial condition, the centering pin  94  is held within the second mold part  82  and remains firmly embedded in the molded portion  18  after the material applied has cured. 
         [0046]      FIG. 8  shows a further variant embodiment in which a functional part, more specifically a screw-on dome  96 , is incorporated in an integrally foamed portion  19 ; by means of the screw-on dome  96 , a roller blind case for the roller blind  92  can later be screwed on to the roof element  10 . Here too, the functional part  96  is initially held by the mold part  82  before it is firmly embedded into the integrally foamed portion  19 . 
         [0047]      FIG. 9  schematically shows a tool by means of which a roof element  10  can be manufactured such as, e.g., a large-area glass cover. The first mold part  70 , the movable mold part  83 , and a carrier  98  (see also  FIG. 8 ) can be seen here, to which the movable mold part  83  is attached. 
         [0048]    While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.