Abstract:
A floor structure of a motor vehicle is provided that includes, but is not limited to a mounting for a starter battery in a cross member adjoining wheel arches for rear wheels. The cross member comprises two stiffening webs and is designed tub-shaped between the stiffening webs. Because of this, the starter battery is reliably protected against a crash.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to German Patent Application No. 102009031779.1, filed Jul. 6, 2009, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The invention relates to a floor structure for a motor vehicle with side members arranged in driving direction laterally delimiting the floor structure, with a floor panel, with stiffening webs mounted on the floor panel arranged transversely to the driving direction and interconnecting the side members and with wheel arches for front and rear wheels. 
     BACKGROUND 
     Floor structures are frequently used in modern motor vehicles and are known from practice. Cross members form the stiffening webs with which the floor structure is stiffened. Various components to be arranged in the motor vehicle are usually mounted on rails, brackets or the like fastened to the floor panel. Because of this, the components require a lot of space which particularly in the rear region of the floor structure limits the possibility of arranging a spare wheel or a preferably large volume of a fuel tank. The brackets or rails can additionally limit the arrangement of the cross members, so that ensuring a required stiffness of the floor structure requires major effort. Great stiffness of the floor structure is particularly necessary in the passenger compartment under the seats in order to guarantee crash safety. 
     Embodiments of the invention are at least based on solving the problem of further developing the floor structure of the type mentioned at the outset so that it preferably provides a lot of space for various components and particularly great stiffness. In addition, other problems may be solved, and 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 
     According to an embodiment of the invention, this problem is solved in that two stiffening webs adjoining the wheel arches of the rear wheels delimit a mounting for additional components. 
     Through this configuration a mounting of stiffening webs in the region of the wheel arches is formed. Because of this, additional brackets to be mounted can be avoided. Since the mounting is arranged directly on the stiffening webs the components to be mounted to the floor structure can be mounted in a particularly space-saving manner. Furthermore, the components mounted in the mounting are reliably protected from the stiffening webs, the wheel arches of the rear wheels and the side members in the event of a crash. 
     If the mounting is arranged above a torsion tube of a rear axle this additionally contributes to the space-saving arrangement of the mounting. If the mounting is arranged below or immediately behind a rear seat of the motor vehicle, this contributes to a further increase of the crash safety of the floor structure. This arrangement of the mounting below or immediately behind the rear seat of the motor vehicle additionally has the advantage that the components arranged in the mounting are protected in a particularly crash-safe manner since the passenger compartment with the rear seats usually has particularly great stiffness. 
     According to another further embodiment of the invention the mounting can contribute to the stiffening of the floor structure if the mounting is designed tub-shaped, open in its side facing away from the floor panel. 
     According to another advantageous further development of the invention the mounting can be produced particularly cost-effectively if an individual cross member interconnecting the side members and welded to the floor panel comprises the two stiffening webs. A further advantage of this configuration consists in that the cross member comprising the stiffening webs is stiffened through the tub-shaped mounting. This cross member can thus be formed particularly wide to accommodate the additional components. 
     The floor structure is particularly simple in design if the stiffening webs are arranged on two cross members interconnecting the side members and welded to the floor panel. 
     The floor panel could for example form a floor of the mounting. However, this results in that the components inserted in the mountings are arranged very high. According to another embodiment of the invention, components inserted into the mounting can be arranged particularly low if the floor panel has a clearance for the mounting. 
     According to another embodiment of the invention, components arranged in the mounting can be simply connected with the electrical network of the motor vehicle if the cross member comprising the stiffening webs and the mounting has an opening between the stiffening webs for routing through electrical lines. 
     It contributes to the further simplification of the assembly of the floor structure according to the invention if a member forms a pre-assembled constructional unit with the starter battery and is glued into the mounting. Preferentially the plastic member in addition to the gluing is positively connected to the mounting for example through screw connection. 
     The member could be manufactured of steel sheet for example. The floor structure according to an embodiment of the invention however has a particularly low weight if the member is manufactured of plastic, light-metal or a composite material. 
     According to another embodiment of the invention, great protection of a starter battery can be simply achieved if a starter battery of a combustion engine of the motor vehicle is arranged in the mounting. Because of this, the starter battery is protected from damage and thus leaking in the event of a crash. In addition it can be largely prevented by this that terminals of the starter battery come in contact with metal components of the motor vehicle body. In addition to the starter battery and electronic control devise can additionally be arranged in the mounting. 
     It contributes to the further simplification of the assembly of the motor vehicle comprising the floor structure if the member closes the opening for routing through electrical lines. Preferentially the plastic member has a permanently elastic seal for closing the opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
         FIG. 1 . is a schematic view of a motor vehicle with a floor structure according to an embodiment of the invention; 
         FIG. 2 . is a perspective view of the floor structure from  FIG. 1  with a starter battery arranged therein; 
         FIG. 3 . is an enlarged sectional representation through the floor structure from structure  2  along the line III-III; 
         FIG. 4 . is a perspective view a member with a starter battery from  FIG. 2 ; 
         FIG. 5 . is a view of a cross member with a mounting arranged between two stiffening webs for the member from  FIG. 5 ; and 
         FIG. 6 . is a view of a part region of a further embodiment of the floor structure of the motor vehicle. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description. 
       FIG. 1  shows a motor vehicle with a floor structure  1  and with front seats  2  arranged veering in driving direction and with rear seats  3 . The floor structure  1  has wheel arches  4 , 5  for front and rear wheels  6 , 7  and a trough  8  for a spare wheel  9 . 
     The floor structure  1  is perspectively shown in  FIG. 2 . Here it is evident that the floor structure  1  comprises a floor panel  10  and size delimited laterally by side members  11 ,  12  facing in driving direction. The side members  11 , 12  are interconnected via a cross member  13  in the region of the rear wheel arches  5  and thus immediately behind the rear seats  3 . The cross member  13  is thus located in front of the trough  8  for the spare wheel  9  and comprises two stiffening webs  14 , 15  interconnecting the side members  11 , 12 . Between the stiffening webs  14 , 15  a mounting  16  for a starter battery  17  is arranged. 
       FIG. 3  shows in a sectional representation through the floor structure  1  from  FIG. 2  along the line III-III that the starter battery  17  is arranged on a member  18  which is glued and additionally screwed into the cross member  13  at mounting position  42 , which may represent a weld or screw. The cross member  13  is welded to the floor panel  10  of the floor structure  1  from the bottom at welds  40 ,  41 . In addition,  FIG. 3  shows that a fuel tank  19  is arranged in driving direction in front of the cross member  13 . In  FIG. 3  a torsion tube  20  of a rear axle not shown in more detail is shown at various bump depths. The cross member  13  with the mounting  16  for the starter battery  17  is elevated in such a manner that contact with the torsion tube  20  even with maximum bump is excluded. Seen in driving direction behind the trough  8 , a rear cross member  21  is additionally arranged. A cover  43  may be provided, as shown in  FIG. 3  and omitted in the other Figs. 
       FIG. 4  perspectively shows the member  18  with the starter battery  17  from  FIG. 2  and  FIG. 3 . Here it can be seen that the member  18  is designed tub-shaped. An electrical line  22  for the plus terminal of the starter battery  17  is routed downwards and away through the member  18 . 
       FIG. 5  shows the cross member  13  with the mounting  16  for the starter battery  17  before the assembly to the floor structure  1 . Here it can be seen that the stiffening webs  14 , 15  are arranged vertically and have flanges  23 , 24  for connecting to the floor panel  10  shown in  FIG. 3 . Between the stiffening webs  14 , 15  the mounting  16  is arranged. The mounting  16  additionally has an opening  25  for the electrical line  22  of the starter battery  17 . The opening  25  is closed by the member  18  shown in  FIG. 4 . 
       FIG. 6  shows a further embodiment of the floor structure  1 , wherein a mounting  26  for the starter battery  17  (schematically shown) is arranged between two separate cross members  27 ,  28 . The cross members  27 ,  28  each have stiffening webs  29 , 30  adjoining the mounting and interconnect two side members  31 , 32 . Horizontal webs  33 ,  34  of the cross members  27 ,  28  form a pedestal elevated with respect to a floor panel  35 . 
     While at least one exemplary embodiment has been presented in the foregoing summary and 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 in any way. Rather, the foregoing summary and 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 as set forth in the appended claims and their legal equivalents.