Abstract:
A cross member of a motor vehicle body is provided. The cross member is designed for forming a load-transmitting connection between two side members of the body and can be structurally connected to these. The cross member includes at least one floor portion that is depressed relative to a marginal rim, which together with at least one side wall adjoining thereon forms at least one stowage space for receiving items.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to German Patent Application No. 10 2011 118 181.8, filed Nov. 10, 2011, which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    This application pertains to a cross member of a motor vehicle body and a motor vehicle body equipped with such. 
       BACKGROUND 
       [0003]    Motor vehicle bodies, in particular self-supporting bodies provide load-bearing and load-transmitting structures in order to distribute on the one hand the weight force of the motor vehicle as evenly as possible over the vehicle wheels and on the other hand bear and discharge possible forces externally acting on the motor vehicle in a controlled manner. 
         [0004]    Motor vehicle bodies should generally be designed torsionally rigid, stable and mechanically loadable and also have as low as possible a dead weight. Self-supporting motor vehicle bodies typically comprise two side member structures spaced from each other in vehicle transverse direction (y) and each substantially extending in vehicle longitudinal direction (x), which are typically interconnected via a plurality of cross members substantially extending in vehicle transverse direction (y). The cross members in this case serve for a structural and load path-transmitting coupling of the side members substantially running parallel to each other. 
         [0005]    By means of one or a plurality of cross members, possible transverse forces that occur for example in the event of a lateral impact are to be absorbed in a defined manner and/or discharged in a controlled manner into regions of the motor vehicle body located opposite and facing away from the impact. In this regard, popular cross members are designed as a hollow profile closed in cross section, which extends between side members spaced from each other in vehicle transverse direction (y). 
         [0006]    Such hollow profiles of cross members of a motor vehicle body however are disadvantageous with respect to an efficient utilisation of the space that is available in motor vehicle. A closed hollow profile takes up comparatively matched space and reduces the stowage space that is generally available in the motor vehicle. 
         [0007]    Accordingly, it may be desirable to provide a cross member that is improved with respect to the space division of a motor vehicle, which takes up a comparatively small dimension of space. 
         [0008]    In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background. 
       SUMMARY 
       [0009]    Insofar, a cross member of a motor vehicle body is provided, which for forming a load-transmitting connection between two side members of the body generally lying spaced from each other in vehicle transverse direction (y). The cross member in this case can be connected to the side members located opposite in a structural, i.e. load-transmitting manner so that by means of the cross member possible corresponding transverse forces in the event of a lateral impact or a corresponding lateral intrusion into the body or upon a bending-through or twisting of the body can be discharged to a side member located opposite or onto other structures. 
         [0010]    The cross member furthermore comprises at least one floor portion that is depressed relative to a lateral margin, which floor portion together with at least one side wall of the cross member adjoining thereon forms at least one stowage space for receiving objects. The cross member generally comprises a circulating marginal rim or a plurality of marginal rims which via suitable side walls merge into a floor portion which with respect to the vehicle vertical direction (z) is located impressed thereto. Marginal rims, side walls and floor portion in this case can be largely formed unitarily, wherein the cross member is generally formed as a formed sheet metal part. It is furthermore conceivable that the cross member has a multi-part construction, wherein the side wall or wherein a plurality of side walls is/are separately connected to the floor portion and if applicable to the lateral margins adjoining the side wall. 
         [0011]    In that the cross member has a depressed floor portion with respect to its marginal rims generally formed as connecting flange it is formed accessible from the top and because of its trough-shaped contour offers additional stowage space for receiving items, in one example, motor vehicle components such as for example motor vehicle battery and/or fuel tank. 
         [0012]    According to one exemplary embodiment, it is provided that the cross member has a trough-like shaping and is designed for receiving at least one motor vehicle component. The trough-like depression of the cross member can be designed in one example, for receiving motor vehicle batteries and for receiving accumulators or battery modules for a possible electric drive of an electric vehicle or hybrid vehicle. Furthermore, the cross member can comprise in one example, in the region of its floor portion or inside on at least one side wall, fastening structures for fixing the vehicle components to be received on or in the cross member. 
         [0013]    Further provided according to one of various exemplary embodiments is that the cross member can be connected with at least one marginal rim to a lower side or inside of side members of the motor vehicle body located opposite. Thus, the cross member can for example be fastened to the lower side of the adjoining side member, generally welded or screwed thereto. According to another exemplary embodiment, it can also be provided that at least one side wall delimiting the stowage space in one example, a face wall substantially delimiting the longitudinal extension of the cross member can be structurally connected to at least one side member. The face wall of the cross member in this case can for example directly adjoin a side wall of the cross member directed to the inside and be connected to the latter. 
         [0014]    According to another exemplary embodiment, a body of a motor vehicle is additionally provided with two side members which are substantially spaced from each other in vehicle transverse direction (y) and in each case substantially in vehicle longitudinal direction (x), which by means of a cross member described before, are interconnected structurally and in a load-transmitting manner. In that the cross member has a trough-like depression, it can serve for maximising utilisable space that is effectively available in the motor vehicle without substantially increasing the gross weight of the motor vehicle. The cross member in this case is approximately U-profile-like in cross section and substantially open towards the top, seen in vehicle vertical direction (z), i.e. designed accessible from above, in order to arrange and fasten the components to be carried along in the motor vehicle such as for example batteries on or in the cross member. Together with the marginal rim or the marginal rims the cross member can also have a top hat-like profile in cross section. 
         [0015]    According to another exemplary embodiment, it can be provided here in one example, that the stowage space provided by the cross member extends approximately at the height of the side member. This means based on the vehicle vertical direction (z), the at least one cross member extends in the same plane in which the adjoining side members also run. In that the cross member is formed and arranged largely offset-free to the adjoining side members, possible transverse forces introduced into the side members can be absorbed comparatively well and for example be discharged into a cross member in each case located opposite. 
         [0016]    According to another exemplary embodiment, it is provided furthermore that the marginal rims, for example as marginal connecting flanges of the cross member come to lie substantially flush with the surface of at least one floor panel extending in vehicle longitudinal direction (x). Insofar, the cross member, viewed from above, can provide a trough-like depression between two floor panels adjoining the cross member approximately in vehicle longitudinal direction (x). The two floor panels arranged on opposite sides of the cross member can lie in a common plane. 
         [0017]    Here it can be provided in one example, that the cross member extends in vehicle longitudinal direction (x) between a rear-end floor panel and a floor panel for example formed as heel plate. Based on the overall vehicle geometry, the present cross member is generally designed as rear cross member, which comes to lie approximately in the region of rear wheel housings or spring strut mountings of the body. 
         [0018]    According to another exemplary embodiment, it can be provided furthermore that the side walls or faces of the cross member located in one example, in vehicle transverse direction (y) are structurally connected to side walls located inside of the respective adjoining side member. The corresponding side walls or faces of the cross member in this case can be welded in one example to the sides located inside of the adjoining side members or screwed to these. Here it is provided in one example, that the cross member also comprises at least one, generally a plurality of fastening flanges formed circulating about the cross-sectional profile of the cross member adjoining the face-end side walls, which on reaching an end installation position are generally structurally connected, generally welded to the respective adjoining side wall located inside of the side members over the full area. 
         [0019]    Finally, according to another one of various aspects, a motor vehicle, in one example, a passenger car is provided, which comprises a body described before or at least a cross member described before. 
         [0020]    It is noted furthermore at this point that all features mentioned with respect to the cross member equally apply to the body as well as to the motor vehicle and vice versa. 
         [0021]    A person skilled in the art can gather other characteristics and advantages of the disclosure from the following description of exemplary embodiments that refers to the attached drawings, wherein the described exemplary embodiments should not be interpreted in a restrictive sense. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
           [0023]      FIG. 1  is a schematic representation of a rear-end detail of a motor vehicle body; 
           [0024]      FIG. 2  is a perspective representation of the rear-end body structure viewed from obliquely below; 
           [0025]      FIG. 3  is a cross section of a cross member connection according to  FIG. 2  in the y-z-plane; and 
           [0026]      FIG. 4  is a comparable cross section through a cross member adjoining an inside of a side member. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or the application and uses of the present disclosure. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. 
         [0028]    The motor vehicle  10  that is merely shown in detail in the  FIGS. 1 and 2  comprises two side members  12 ,  13  substantially extending in vehicle longitudinal direction (x) and spaced from each other in vehicle transverse direction (y), which are connected to each other by means of a cross member  20  in a structural manner, i.e. in a load-transmitting as well as load path-transmitting manner. In addition, two floor panels  14 ,  18  which in vehicle longitudinal direction (x) adjoin the cross members  20  extend between the side members  12 ,  13 . The cross member  20  has a trough-like contour and geometry with front and rear side walls  24  as well as with a face-end side wall  28 , which towards the top, seen in vehicle vertical direction (z) merge into a circumferential marginal section  22 ,  30 ,  22  which is designed as fastening flange. 
         [0029]    On the other end, i.e. downwards, the side walls  24 ,  22  are connected to a floor portion  26  which, viewed in vehicle vertical direction (z), is designed as a depression relative to the circumferential margin  22 ,  30 ,  22  and accordingly is designed as stowage space  36  for receiving motor vehicle components or items  40  to be carried along in the motor vehicle, for example one or a plurality of battery modules. As is shown in  FIG. 2 , the cross member  20  with its circumferential marginal sections  22 ,  30 ,  22  adjoins a lower side  32  of the side member  12 . Here, the marginal sections  22  located in vehicle longitudinal direction (x), which are designed as connecting flange, come to lie in an approximately surface-flush manner to the adjoining floor panels  14 ,  18 . Alternatively to the configuration shown in  FIG. 2  it is conceivable furthermore that side walls  28  of the cross member  20  on the face end, i.e. located in vehicle transverse direction (y) directly adjoin side walls  38  in each case located inside of the cross members  12 ,  13  located opposite each other where they are structurally connected to these. Here it is conceivable in one example, that the face-end side wall  28  is also provided with fastening flange portions corresponding to the respective shaping of adjoining side members  12 ,  13  in order to provide a generally torsionally-rigid structural coupling of side members  12 ,  13  and the at least one cross member  20 . 
         [0030]    Furthermore it is shown in  FIG. 2  that the approximately rear-end floor panel  14  located at the back in travelling direction (x) has a further depression in the form of a spare wheel trough  16 . Said trough can come to lie in a plane approximately corresponding to the cross member based on the vehicle vertical direction (z). 
         [0031]      FIG. 3  finally shows a cross section through the cross member shown in  FIG. 2  in a y-z plane formed by vehicle vertical axis (z) and vehicle transverse axis (y). The cross member  20  in this case comes to lie on a lower side  32  of a side member  12  where it is welded to the side member  12  in the region of a marginal flange portion  30 . 
         [0032]      FIG. 4  shows a configuration deviating from this, wherein the cross member  20  comes to lie being braced on an inner side wall  38  of the side member  12  where it is connected, generally welded to the inside of the side member by means of a welding flange  30 . 
         [0033]    According to the respective position of the cross member  20  in vehicle vertical direction (z), a floor panel  14  located above or offset in vehicle vertical direction (z) to the floor portion  26  of the cross member  20  can be arranged at a different height (z) on the side members  12 ,  13  located opposite. In the configuration according to  FIG. 4 , the height of the mounting provided by the cross member  20  is predetermined through the construction height of the side member  12 . 
         [0034]    In the configuration of  FIG. 3  by contrast, a floor panel  14  adjoining the cross member  20  can also be arranged adjoining a lower margin of a side member  12  and thus be arranged located far deeper in the vehicle compared to a configuration according to  FIG. 4 . 
         [0035]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the present disclosure as set forth in the appended claims and their legal equivalents.