BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The invention relates to a motor vehicle component with a guide rail structure which is located at least partially on a sectional part which forms the bearing structure of the vehicle component. 
   2. Description of Related Art 
   German Patent Application DE 199 39 725 A1 and corresponding U.S. Pat. No. 6,460,920 disclose a motor vehicle component formed by a side roof member in which guide rails for an openable roof part are formed directly on an extruded section which forms the bearing structure of the roof member. An outer skin-lining section of plastic is attached thereto by cementing. The extruded section has several cavities and undercuts and is therefore very complex and expensive to produce. 
   SUMMARY OF THE INVENTION 
   A primary object of the present invention is to devise amotor vehicle component of the initially named type in which a guide rail structure can be easily produced. 
   This object is achieved in the initially mentioned vehicle component by the sectional part forming only one part of the guide rail structure and the other part of the guide rail structure being formed by another, second sectional part which can be connected to the first sectional part. 
   Because the guide rail structure is formed by two sectional parts which can be connected to one another, the guideways and cable guide channels which are otherwise made as undercuts can be made as simple moldings in the sectional parts. 
   According to a preferred embodiment, the first sectional part is made of plastic. On the one hand, this contributes to saving of weight, and on the other, a material with good sliding properties can be used as the plastic. 
   According to another preferred embodiment, the second sectional part is also made of plastic. The advantages here are the same. 
   Alternatively, the first sectional part and/or the second sectional part can also be formed from a metal section. In particular, lightweight metal sections, such as, for example, aluminum sections, are suited for this purpose. The guideways and the cable guide channels, in this case, can be coated with a slippery lacquer or a plastic layer with good sliding properties. 
   Preferably, the first sectional part forms the lower part of the guide rail structure and the second sectional part forms the top part of the guide rail structure. Both sectional parts, in this case, are preferably provided with a horizontal flange on which they are connected to one another. The connection takes place preferably by means of screws or rivets. 
   The first sectional part and the second sectional part, preferably, each have another flange on which they are connected to the lining part. The connection takes place, preferably, by adhesive surfaces. Alternatively, at least one of the connections can also be made by positive engagement of two complementary connecting elements. 
   The first sectional part and the second sectional part, preferably, jointly border a cable channel for guidance of a driving cable. Thus, this cable channel can likewise be made as an open section on one of the sectional parts which is added to a partially closed section after connection to the other sectional part. 
   The first sectional part and/or the second sectional part, preferably, have projections and/or receivers for attachment of adjacent seals or inside lining parts. 
   One especially preferred application for a motor vehicle component in accordance with the invention is that it is formed by a side roof member of an openable motor vehicle roof, as is the case in the initially described prior art, as per German Patent Application DE 199 39 725 A1 and corresponding U.S. Pat. No. 6,460,920. The openable motor vehicle roof is, preferably, made as a convertible with a folding top covering or as a convertible formed of rigid roof parts. However, also other applications are possible in which a supporting vehicle part is provided with a guide rail structure. The frame of a sliding roof is one example of this. 
   According to one especially advantageous embodiment, the first sectional part with the second sectional part and a lining part which is connected to these two sectional parts together forms a closed hollow section with a hollow chamber. In this way, the geometrical moment of inertia of the finished motor vehicle component, which is of primary importance for the bending, buckling and torsional stiffness, is greatly increased. In the initially described prior art of German Patent Application DE 199 39 725 A1 and corresponding U.S. Pat. No. 6,460,920, these hollow chambers are integrated directly into the extruded section which forms the support structure, by which its complexity is increased. 
   The motor vehicle component of the present invention is explained in detail below with reference to the accompanying drawings. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a motor vehicle with a roof having an openable roof part and side roof members which form the motor vehicle component; 
       FIG. 2  shows a cross section through the left side roof member taken along line II-II in  FIG. 1 ; 
       FIG. 3  is a view corresponding to that of  FIG. 2 , but shows a second embodiment of the roof member; 
       FIG. 4  is a view corresponding to that of  FIG. 2 , but shows a third embodiment of the roof member; and 
       FIG. 5  is a view corresponding to that of  FIG. 2 , but shows a fourth embodiment of the roof member. 
   


   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a motor vehicle roof  10  in which the front end of two roof lateral members  12  are attached to a front roof apron  11  and are attached to a roof cassette  18  at their back end. The apron  11 , the roof members  12  and the roof cassette  18  border a roof opening  14  which can be selectively closed or at least partially cleared by means of an openable roof part  13 . In the illustrated embodiment, the openable roof part  13  is made as a folding roof with a front guide bow  16  which is movably guided on a guide rail structure  15  which is located on the roof members  12 . The openable roof part  13 , which preferably is movable by means of an electric drive (not shown) in the direction of the arrow  17 , is completely opened in  FIG. 1 . In this state, it is completely retracted into the roof cassette  18 , and together with the cassette  18  and the rear window  19  which follows to the rear, can be stowed in a stowage space in the rear area of the vehicle, as is known. The roof members  12  can be swung onto the roof cassette  18  after the lock on the apron  11  is detached and jointly with the rear window  19 , and optionally, also with the C pillars can be lowered into the stowage space. Alternatively, manual removal of the side roof members  12  is also possible. 
     FIG. 2  shows a cross section through the left side roof member  12  which, in all embodiments, represents the “roof part” of the invention. The roof member  12  is composed of a first sectional part  20 , a second sectional part  30  and a lining part  40  which forms the outer side and which is connected to both. In all embodiments, the guide rail structure  15  is formed jointly by the first sectional part  20  and the second sectional part  30 . 
   The first sectional part  20  forms the lower part of the inner side of the side roof member  12 . It is composed of a bearing section  21  which is Z-shaped, and from near the top edge of which a horizontal bridge projects outward relative to the vehicle centerline (into the interior of the roof member  12 ). The top of the bridge forms the lower part  22  of the guide rail structure  15  with the guideways  23 ,  24 ,  25 ,  26  being made in the structure and separated from one another by vertical ridges. These guideways are adjoined by a short vertical wall  27  from which a horizontal flange  28  projects outward relative to the vehicle centerline. The horizontal flange  28  is molded onto the top edge of the vertical wall  27 . The lower part  22  of the guide rail structure  15  with the vertical wall  27  and the horizontal flange  28  forms a rectangular step so that the bottoms of the guideways  23 ,  24 ,  25 ,  26  are arranged parallel to the flange  28 . Near the lower edge of the first sectional part  20 , on its bearing section  21 , there is a surface which descends obliquely outward as a lower flange  29 . 
   The second sectional part  30  has a horizontal flange  38  that is parallel to the flange  28  of the first sectional part  20 . It is adjoined to the inside by an arc-shaped section with a cable channel  91  molded onto its inside as part of the annular cross section. The channel is adjoined to the top by a vertical wall  31 . From the vertical wall  31 , a top part  32  of the guide rail structure  15 , as a horizontal bridge, projects to the inside; guideways  33 ,  34  are formed on its bottom separated by a vertical ridge. The top part  32 , in turn, lies parallel to the flange  38  so that the bottoms of the guideways  33 ,  34  are located exactly parallel to the bottoms of the guideways  23 ,  24 ,  25 ,  26  on the bottom part  22  of the guide rail structure  15 . The guideways  23 ,  24 ,  25 ,  26  and  33 ,  34  are used to guide sliding elements or actuating elements (not shown) and which are necessary for movable support and for actuation of the openable roof part  13 . The required driving forces are directed into the pertinent sliding elements by a driving cable (not shown) and which is guided in the cable channel  91  by a connecting element (not shown) and which penetrates a slot which is formed on the inside between the flanges  28 ,  38 . 
   Above the top part  32  of the guide rail structure  15  spaced apart from the latter is a horizontal bridge  35  which projects to the inside on the second sectional part  30  and which, together with the top part  32 , borders a horizontal slot which is open to the inside as a receiver  36  for attachment of a seal  80  which is described below. The vertical wall  31  above the upper part  32  at the height of the horizontal bridge  35  is adjoined by a short horizontal bridge  37  which projects in a hook shape to the inside and which likewise is used to attach part of the seal  80 . Furthermore, another bridge which is adjoined by an upper flange  39  at a right angle to it branches off the vertical wall  31  obliquely upward and toward the outer side. 
   The upper flange  39  of the second sectional part  30  and the lower flange  29  of the first sectional part  20  are used to attach the lining part  40  which covers the side roof member  12  to the outside and which is preferably made as a plastic molding which is enameled or dyed completely in the vehicle color. The lining part  40  has an outside skin  49  in the form of a plate which is curved according to the vehicle contour. Near the lower edge of part  40 , there is a bridge  41  which projects at a right angle to the inside and which is adjoined by a bridge  42  which projects downward parallel to the outside skin  49 . The lower end of the outside skin  49  and the bridge  42  border a receiver  45  for attachment of a seal  70  which is described below. The bridge  42  is adjoined by another bridge  43  which is located parallel to the bridge  41  and which passes in an arc shape down into a lower flange  44  which, after joining the sectional parts  20 ,  30  to the lining part  40 , is located parallel to the lower flange  29 . Near the top edge of the outside skin  49 , another bridge projects from it roughly at a right angle to the inside and is adjoined by a short bridge  47  at a right angle and directed obliquely upward. The bridge  47  together with the top end  46  of the outside skin  49  forms a receiver  48  for attachment of another part of the seal  80 . 
   The first sectional part  20  and the second sectional part  30  are joined on their flanges  28 ,  38  and by means of a connection  90 , which can be made preferably as a screw connection, as a riveted connection or also as a cemented connection, are securely connected to one another. In doing so, the lower part  22  and the upper part  32  of the guide rail structure  15  are combined into a whole, the guideways  23 ,  24 ,  25 ,  26 , and  33 ,  34  being positioned exactly relative to one another. At the same time, the part of the flange  28  projecting to the inside is added to the hollow section of the guide channel  91 , which section is open to there to the bottom. Then, the lining part  40  is joined to the unit comprised of the first sectional part  20  and the second sectional part  30 . This takes place in the embodiment, as shown in  FIG. 2 , by a cement  50  which is applied between the top flange  39  of the second sectional part  30  and the bridge  47  of the lining part  40  as a flat adhesive layer. In the lower area, the lining part  40  is connected via the lower flange  44  by means of a cement  60  which has been applied as a flat adhesive layer to the lower flange  29  of the first sectional part  20 . After curing of the cement  50 ,  60 , the first sectional part  20 , the second sectional part  30  and the lining part  40  jointly form a hollow section which includes a cavity  100 . This hollow section has a large geometrical moment of inertia and is thus very stable against bending, torsion, and buckling. 
   For sealing the side roof member  12  in its lower area there is a seal  70 . The seal  70  is inserted with a seal foot  73  into the receiver  45  on the lining part  40 . On its inner bottom side, with one leg  74  it extends around the lower flange  44  of the lining part  40  and the lower flange  29  of the first sectional part  20 , which lower flange is connected to it. The seal  70  has a lower hollow chamber  72  and an upper hollow chamber  71 , next to which the vehicle door or the vehicle window, on the one hand, is placed from underneath, on the other hand, laterally forming a seal. 
   For sealing the side roof member  12  opposite the openable roof part  13 , there is a seal  80  in its upper area. The seal  80  is inserted with the seal foot  81  into the receiver  48  on the lining part  40 . It is anchored with another foot  84  under the bridge  37  of the second sectional part  30 . In addition, one leg  87  of the seal  80  extends around the horizontal bridge  35  on the second sectional part  30  and is attached with the leg  87  in the receiver  36 . The seal  80 , with a projection  82  which is matched to the contour of the lining part  40 , extends over its top end  46 . Between the seal foot  81  and the foot  84 , an upper seal wall  83  extends, and after installation, in conjunction with the upper flange  39  of the second sectional part  30  and the bridge  47  on the lining part  40 , forms a type of hollow chamber. Between the foot  84  and the leg  87 , the seal  80  is made in the form of a horizontal bridge  85  with a top which forms a gutter in conjunction with a descending flank of the upper seal wall  83  and the opposing ascending flank of a sealing lip  86  which extends up on the inner side. The openable roof part  13 , in the closed state, is placed from overhead next to the free end of the sealing lip  86  and the upper seal wall  83 , forming a seal, and presses them somewhat downward. The shape of the seal  80 , in this embodiment, is matched to the openable roof part  13  which is made as a folding roof. It can also assume a different shape when the openable roof part is made as a fixed roof part, for example, in the form of a movable cover. 
   In  FIG. 2 , the second sectional part  30  is made as an aluminum sectional part and is joined to the lining part  40  by means of a cement  50 . In  FIG. 3 , the second sectional part  30 , which is likewise made as an aluminum sectional part, instead of the upper flange  39 , has a connecting element  39 A which is made in the form of an annular cross section which is partially opened to the top. The lining part  40 , in this case, instead of the bridge  47 , has a connecting element  47 A which has an essentially circular cross section which positively engages the connecting element  39 A in a complementary manner. The connection of the lining part  40  on the unit formed of the first sectional part  20  and the second sectional part  30  takes place, in this case, such that first the connecting element  47 A is inserted into the connecting element  39 A in the lengthwise direction, and then the lower flange  44  is connected to the lower flange  29  by the cement  60 . 
   The embodiment as shown in  FIG. 4  differs from the preceding one in that the second sectional part  30  is made as a plastic section. The second sectional part  30 , in the upper left area, has two bridges  39 C,  39 B which are spaced apart from one another and which, in this case, form a receiver for the seal foot  81  of the upper seal  80 . The outer side of the bridge  39 B, moreover, forms a flange on which the lining part  40  is connected to its inner side via a cement  50  which has been applied in the form of an adhesive surface. The connection of the bottom of the lining part  40  with the first sectional part  20  takes place as in the preceding embodiments via the lower flange  44 , the cement  60  and the lower flange  29  on the first sectional part  20 . 
   In the embodiment as shown in  FIG. 5 , the second sectional part  30  is likewise made in the form of a plastic section. The connection to the lining part  40  takes place analogously to  FIG. 3  via connecting elements  39 A and  47 A which positively engage one another. The connection of the bottom of the lining part  40  to the first sectional part  20  takes place, as in the preceding embodiments, via the lower flange  44 , the cement  60  and the lower flange  29  on the first sectional part  20 .
A motor vehicle component with a guide rail structure ( 15) which is located at least partially on a sectional part ( 20) which forms the bearing structure of the vehicle component. To simplify the guide rail structure ( 15) and make it cheaper, it is provided that the sectional part ( 20) forms only one part ( 22) of the guide rail structure ( 15) and the other part ( 32) of the guide rail structure ( 15) is formed by a second sectional part ( 30) which can be connected to the first sectional part ( 20). The divided execution makes it possible to form, much more easily, the guideways ( 24, 25, 26; 33, 34) and cable channels ( 91) which must otherwise be produced in a complex manner as undercut sectional parts.