Abstract:
The invention relates to a motor vehicle body, the support structure ( 10 ) of which is composed of large-size partial modules ( 12, 34, 50, 66 ), a basic module ( 12 ) comprising lateral longitudinal members ( 15 ) and a body floor ( 14 ) and reaching laterally as far as front wall columns ( 20 ), and, when the support structure ( 10 ) is assembled, the basic module ( 12 ) being connected to a front end module ( 34 ) which belongs to the front crumple zone of the motor vehicle and is supported in a crash stable manner on the basic module ( 12 ).  
     In order to provide a motor vehicle body, in which the front end module ( 34 ) even without a roof construction is fixed in a sufficiently stable manner on the basic module ( 12 ), a front end region ( 36 ) of the body floor ( 14 ) belongs to the front end module ( 34 ) and extends rearward over a considerable length region of the basic module ( 12 ) between lateral longitudinal member sections ( 16 ).

Description:
BACKGROUND AND SUMMARY OF THE INVENTION  
       [0001]     This invention relates to a motor vehicle body.  
         [0002]     A body having a support structure which is composed of essentially four large-size partial modules, is already known from German publication DE 198 33 395 A1. One of the partial modules is designed as a basic module, which reaches laterally as far as front wall columns and has lateral longitudinal members and a body floor. When the support structure is assembled, the basic module is connected to a partial module, which is designed as a front end module, belongs to the front crumple zone of the motor vehicle, and is supported in a crash stable manner on the basic module. By supplementing the basic module and the front end module with a roof module, or by roof sections provided at the front end of the basic module, a stable connection of the front end module to the basic module is produced.  
         [0003]     This invention has as one object the object of providing a motor vehicle body, in which the front end module is fixed in a sufficiently stable manner to the basic module even without a roof construction.  
         [0004]     This object is achieved according to the invention by the claimed features.  
         [0005]     Advantageous refinements of the invention are apparent from the dependent claims.  
         [0006]     In body support structure according to the invention, a front end region of the body floor belongs to the front end module, which region extends rearward over a considerable length region of the basic module between lateral longitudinal member sections. This provides a particularly stable support of the front end module on the basic module of the support structure, so that, for example in the case of a head-on crash, a desired deformation sequence is achieved, in which the front end structure acts in a particularly effective manner as an energy-absorbing crumple zone and the shape of the passenger safety cell together with the floor is maintained to the greatest possible extent. The very stable fastening of the front end module to the basic module enables the support structure to be used for vehicles of different construction, since the front end module is fastened in a sufficiently stable manner to the basic module even without a roof construction. This also renders the support structure particularly suitable for open motor vehicles.  
         [0007]     A particularly stiff and stable connection of the front end module to the basic module is provided if the front end module has longitudinal member sections which laterally bound the front end region of the body floor and are to be connected to the lateral longitudinal member sections of the basic module. In this case, the connection between the front end module and basic module is particularly stable if the mutually assigned, lateral longitudinal member sections of the front end module and of the basic module are connected to each other via joining surfaces matched to one another, the joining surfaces extending over the at least approximately entire overlapping length of the mutually assigned longitudinal member sections or of the two modules.  
         [0008]     The stability of the connection of the front end module to the basic module is further assisted by the lateral longitudinal member sections of the front end module and of the basic module each having a box profile which is closed in cross section. After the longitudinal member sections which are assigned to one another in each case are joined together, lateral longitudinal members which have a box profile, which is doubled in cross section, and are particularly stiff are therefore provided.  
         [0009]     If upwardly protruding column sections are arranged at the front ends of the lateral longitudinal member sections of the basic body, then the front end module and the basic module can also be connected to each other in the vertical direction, and a stable fastening of the two modules arises overall. In this case, the upwardly protruding column sections preferably extend approximately at right angles to the direction of extent of the longitudinal members.  
         [0010]     In a further refinement of the invention, the front end module also comprises upwardly protruding column sections which are fastened to the lateral longitudinal member sections thereof. This enables the mutually assigned, upwardly protruding column sections of the front end module and of the basic module to be connected to each other via joining surfaces, which are matched in each case to each other, to form front door columns, so that, on the one hand, a particularly good connection of the front end module to the basic module is produced and, on the other hand, stiff and stable door columns are provided-preferably up to the level of the side wall edge of the support structure. A front end wall which stiffens the door columns in the transverse direction of the vehicle preferably extends between the door columns.  
         [0011]     The upwardly protruding column sections of the front end module and of the basic module preferably each comprise a box profile which is closed in cross section, so that, after the column sections which are assigned to one another laterally in each case are joined together, particularly stiff door columns with a box profile which is doubled in cross section are provided.  
         [0012]     After the large-size partial modules have been assembled, the support structure is to be lined with outer panel parts which cover the joining points of the partial modules with the outer panel parts. This ensures that, on the one hand, the partial modules can be joined with sufficient tolerances in a simple manner in terms of manufacturing and therefore cost-effectively and, on the other hand, that the joining points are covered, giving an impression of high quality.  
         [0013]     Further advantages, features and details of the invention emerge from the description below of a preferred exemplary embodiment and with reference to the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a perspective exploded illustration of the support structure of the motor vehicle body according to the invention, which support structure is assembled from large-size partial modules;  
         [0015]      FIG. 2  shows a further perspective exploded illustration of the support structure which is assembled from partial modules and is lined with outer panel parts;  
         [0016]      FIG. 3  shows a perspective view of a partial module of the support structure designed as a front end module;  
         [0017]      FIG. 4  shows a perspective view of a partial module of the support structure designed as a basic module;  
         [0018]      FIGS. 5   a  and  5   b  each show partial perspective views of the basic module and the front end module before they have been joined together;  
         [0019]      FIG. 6  shows a perspective view of the basic module and of the front end module after they have been joined together;  
         [0020]      FIG. 7  shows a perspective view of a partial module of the support structure designed as a rear module;  
         [0021]      FIG. 8  shows a perspective view of a partial module of the support structure designed as a roof module; and  
         [0022]      FIG. 9  shows a partial perspective view of the assembled support structure which in each case comprises a left and a right side wall module. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]      FIG. 1  shows, in a perspective exploded illustration, a support structure  10  of a motor vehicle body that is assembled from a plurality of large-size partial modules which are described in more detail below. In the exemplary embodiment shown here, the partial modules of the support structure  10  are produced in each case from a plurality of sheet-metal parts joined together; at the same time, however, the partial modules may also be premanufactured in different constructions, for example as a “space frame”, as plastic parts, metal cast parts, as components in a “sandwich construction” or the like. In particular, combinations of different constructions are also conceivable here for the joined together partial modules, depending on application and loading. The individual modules are joined together in particular via bonding connections, welding connections or the like. At the same time, other customary connections, such as screw connections or the like, are conceivable.  
         [0024]     A basic module  12  of the support structure  10 , which basic module can be seen in an overall view of  FIG. 1  and in  FIG. 4 , essentially comprises a body floor  14  which is bounded laterally by longitudinal members  15 . The basic module  12  reaches forward with longitudinal member sections  16  as far as column sections  18  of front wall columns  20  which protrude upward from the respectively assigned, front ends of the lateral longitudinal member sections  16 . The body floor  14  of the basic module  12  ends at a considerable distance behind the front end of the basic module  12  or behind the column sections  18  of the front wall columns  20 . In this case, the body floor  14  is provided here with a central tunnel  22  and with crossmembers  24  which extend outward from said tunnel and are connected fixedly to the longitudinal members  15 . At the rear, the basic module  12  ends behind rear wheel houses  26 , to the inside of which extensions  28  of the lateral longitudinal members  15  extend. Above the rear wheel houses  26 , wall regions  30  of the particular, rear side wall are arranged. The body floor  14  ends at the rear at a crossmember  32  which extends between the extensions  28  of the lateral longitudinal members  15  in the transverse direction of the vehicle level with the rear wheel houses  26 . The basic module  12  is already equipped as far as possible with the other partial modules before the joining together. Thus, for example, the inner lining, possibly the seat system, the electric and electronic device, or the underfloor system, e.g. with parts of the exhaust system, are already attached to the basic module and provided, if appropriate, with adapters, plug-in connections or the like which permit a connection to further components.  
         [0025]     A front end module  34 , which can be seen in an overall view in  FIG. 3 , belongs to the front crumple zone of the motor vehicle and is supported on the basic module  12  in a crash stable manner is connected to the basic module  12 . For this purpose, the front end module  34  comprises a front end region  36  of the body floor  14  which extends between lateral longitudinal member sections  38  of the front end module  34 . As can be seen from the views of  FIGS. 3, 5   a  and  5   b , the front end region  36  of the body floor  14  and the lateral longitudinal member sections  38  end at least approximately level at the rear. At the front, the front end region  36  of the body floor  14  ends at a front end wall  40  of the passenger cell, extending from the front end region  36  of the body floor  14  as far as approximately level with the side wall edge of the support structure  10 . The end wall  40  is bounded laterally by column sections  42  of the front wall columns  20  which protrude upward from the lateral longitudinal member sections  38  of the front end module  34 . Front longitudinal members  44  and front side wall regions  46  can be seen at the front end of the front end module  34 , between which members and regions parts  48  of the wheel house lining of the front wheel houses are arranged. At the front, the front end module  34  is adjoined by a front module  35 , part of which is illustrated in  FIG. 2 . This front module  35  comprises, for example, the front bumper, the nose region of the motor vehicle, the headlamps, parts of the radiator and parts of the wheel house lining. Like the basic module  12 , the front end module  34  is also already equipped as far as possible with the other partial modules before joining together. Thus, in particular, components and assemblies (not shown), such as the instrument panel, the air conditioning system, the pedal system etc, can already be attached to the front end module.  
         [0026]     A roof module  50 , which can be seen in the overall view of  FIG. 9 , can be placed onto the basic module  12  and the front end module  34  and here comprises lateral A-columns  54 , lateral roof columns  56  in the region of the roof  52 , and C-columns  58 . The lower ends of the A-columns  54  and of the C-columns  58  are connected to one another via a respective crossmember element  60 . When the support structure  10  is assembled, the A-columns  54  are supported both on the basic module  12  and on the front end module  34 . In other words, the A-columns  54  are supported at their lower ends both on the upwardly protruding column sections  18  and  42  of the basic module  12  and of the front end module  34 , which form the particular front wall column  20 . At the rear, joining surfaces  62  of the lower ends of the C-columns  58  are fastened with joining surfaces  64  to the respectively assigned, upper end of the wall regions  30 , for example by means of a bonding connection.  
         [0027]     At the rear, the basic module  12  is adjoined by a rear module  66 , which can be seen in the overall view of  FIG. 7  and which, when the support structure  10  is assembled together with the rear end region of the basic module  12 , belongs to the rear crumple zone of the motor vehicle and essentially comprises lateral, rear longitudinal member sections  68 , a rear crossmember  70  connecting the longitudinal member sections  68  and rear side wall regions  72 . When the support structure is assembled, the crossmember  32  and the longitudinal member extensions  28  of the basic module  12  and the longitudinal member sections  68  and the rear crossmember  70  of the rear module  66  form a supporting frame within which a spare wheel trough (not shown) can be fixed. It is apparent that the rear module  66  is connected to the basic module  12  and the roof module  50  along a transverse plane of the vehicle that runs vertically. The rear module  66  is fastened to the basic module  12  and the roof module  50  via flanges  74  on the longitudinal member extensions  28  or on the associated longitudinal member sections  68 , and via further joining points (not shown) between the modules  12 ,  50  and  66 . To the rear, the rear module  66  is adjoined by a rear end module  76 , part of which can be seen in  FIG. 2 . This rear end module  76  comprises, for example, the rear bumper or the rear lighting of the motor vehicle. It is to be regarded as a matter of course that both the roof module  50  and the rear module  66  can already be equipped as far as possible with linings, assemblies and components before the support structure  10  is joined together.  
         [0028]     In the case of the five-door motor vehicle shown here, a respectively assigned B-column  78  is fastened between the lateral roof column  56  of the roof module  50  and the lateral longitudinal member  15  of the basic module  12 .  
         [0029]      FIG. 2  illustrates, in a further perspective exploded illustration, the support structure  10  which is made of the partial modules  12 ,  34 ,  50 ,  66  and is lined with outer panel parts of plaster, sheet metal or the like. Front wing linings  80 , in particular, are thus designed in such a manner that the joining point  81  between the upwardly protruding column sections  18  and  42  of the basic module  12  and of the front end module  34  is covered and cannot be seen from the outside. In addition, the front wing linings  80  likewise cover the fastening points of the A-columns  54  of the roof module  50  to the basic module  12  and the front end module  34  and those fastenings points cannot be seen. Lateral sill linings  82  are designed in such a manner that the joining point  83  between the respective longitudinal member sections  16  of the basic module  12  and the longitudinal member sections  38  of the front end module  34  is covered in a manner such that it cannot be seen from the outside. Rear wing linings  84  are likewise designed in such a manner that the joining surfaces  62 ,  64  between the C-column  58  and the rear wall region  30  are likewise covered in a manner such that they cannot be seen from the outside. It is apparent that all of the joining points of the large-size partial modules  12 ,  34 ,  50  and  66  are therefore covered by the lining parts  80 ,  82 ,  84  and cannot be seen from the outside. This ensures that the partial modules can be joined with sufficient tolerances in a simple manner in terms of manufacturing and therefore cost-effectively and, on the other hand, the covering of the joining points conveys an impression of high quality.  
         [0030]     The A-columns  54 , the lateral roof columns  56  and the C-columns  58  are lined with column lining parts  86 ,  88 .  
         [0031]      FIGS. 5   a  and  5   b  illustrate, in partial perspective views, the joining together of the basic module  12  and of the front end module  34 , and  FIG. 6  illustrates, in a perspective view, the basic module  12  and the front end module  34  after they have been joined together. It can be seen that the front end region  36  of the body floor  14 , which region belongs to the front end module  34 , extends rearward over a considerable length region of the basic module  12  between the lateral longitudinal member sections  16 . It can furthermore be seen that the mutually assigned, lateral longitudinal member sections  16 ,  38  of the front end module  34  and of the basic module  12  have joining surfaces  83   a, b,  which are matched to each other, at the particular joining point  83  ( FIG. 2 ), which joining surfaces extend over the at least approximately entire overlapping length of the mutually assigned longitudinal member sections  16 ,  38 . In this case, the length of the joining surfaces  83   a, b  corresponds approximately to the length of the adjacent, front end region  36  of the body floor  14 . The lateral longitudinal member sections  16 ,  38  of the front end module  34  and of the basic module  12  have a respective box profile which is closed in cross section, so that, after the longitudinal member sections  16 ,  38  which are assigned to each other in each case have been joined together, lateral longitudinal members having a box profile which is doubled in cross section and is approximately 8-shaped are produced. The box profile of the lateral longitudinal member sections  16 ,  38  of the front end module  34  and of the basic module  12  in each case has a cross section which can be varied over its length and here is stepped. Of course, it would also be conceivable in this connection for the longitudinal member sections  16 ,  38  to each be designed as a partial shell which are then connected to one another to form a support.  
         [0032]     The upwardly protruding column sections  18 ,  42  of the basic module  12  and of the front end module  34  comprise joining surfaces  81   a, b,  which are matched in each case to each other, at the particular joining point  81  ( FIG. 2 ), via which the column sections  18 ,  42  are connected to form the front wall column  20 . The upwardly protruding column sections  18 ,  42  in each case comprise a box profile which is closed in cross section, so that after the respectively assigned column sections  18 ,  42  have been joined together, particularly stiff door columns  20  having a box profile, which is doubled in cross section and is approximately 8-shaped, are created. The joining surfaces  81   a, b  of the column sections  18 ,  42  and the joining surfaces  83   a, b  of the longitudinal member sections  16 ,  38  run here at least approximately at right angles to one another. The angular bonding of the column sections  18  to the longitudinal member sections  16  of the basic module  12  or the angular bonding of the column sections  42  to the longitudinal member sections  38  of the front end module  34  provides a particularly stiff supporting of the front end module  34  on the basic module  12 . The position of the basic module  12  and of the front end module  34  is therefore determined in the longitudinal direction of the vehicle and in the vertical direction of the vehicle by the joining surfaces  83   a, b  and  81   a, b . In the transverse direction of the vehicle, the position of the basic module  12  and of the front end module  34  is not determined by the joining surfaces  83   a, b  and  81   a, b  but rather, for example, by bearing surfaces of the basic module  12  and of the front end module  34  in the region of the central tunnel  22 . The front end region  36  of the body floor  14 , which end region belongs to the front end module, is connected in an overlapping manner to that region of the body floor  14  which belongs to the basic module  12 , as is apparent in particular from  FIG. 6 . In this case, the central tunnel  22  is molded both into the front end region  36  and into the body floor  14  and is provided with joining surfaces.  
         [0033]     Finally,  FIG. 9  shows, in a partial perspective view, the assembled support structure  10  which comprises in each case a left and right side wall module  100 , which extends from behind the front side doors as far as rear door pillars. The side wall module  100  is fastened to the basic module  12  above the assigned longitudinal member  15  and opposite the rear side wall  30 . In addition, the side wall module  100  is supported in relation to a crossmember  104  by a supporting arrangement  102  in the transverse direction of the vehicle.  
         [0034]     The basic module  12  and the side wall module  100  end level with a common joining surface  106  on which a different coupé roof module  50 ′ here is fixed with a side wall region  108 .