Abstract:
The support structure of a body for a motor, vehicle is assembled from large-size partial modules. Two partial modules connected to each other comprise support sections and wall and/or floor sections connected thereto. Support sections of one partial module are connected to associated support sections of the other partial module at abutment points. In order to design a highly stressed connection between partial modules of the support structure in a very stable and simple manner, the support sections of the two partial modules, which support sections are assigned in each case to one another, are assembled to form a continuous support. Abutting surfaces of the assembled support sections run obliquely with respect to the direction of extent of the support. This oblique profile of the abutting surfaces creates a connection over a very large area in relation to the cross section of the support, which ensures an extremely stable connection of the two parts to each other.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION  
       [0001]     This invention relates to a body for a motor vehicle.  
         [0002]     A body of this type having a support structure assembled from large-size partial modules is already known from U.S. Pat. No. 4,133,549. In this body, two partial modules which are connected to each other in each case comprise support sections and wall and/or floor sections connected thereto, and support sections of the one partial module are assembled with associated support sections of the other partial module at abutment points to form a continuous support. In this case, the abutting surfaces of the assembled support sections run obliquely with respect to the direction of extent of the support.  
         [0003]     This oblique profile of the abutting surfaces produces a connection over a very large area in relation to the cross section of the support, which already ensures a stable connection of the two parts to each other. In addition, the oblique profile of the abutting surfaces already permits manufacturing tolerances to be compensated for in a simple manner since it is possible for the support sections to be adjusted within certain limits, both in the direction of extent of the support and in the vertical direction, by displacing the support sections with respect to each another in the direction of the extent of the support.  
         [0004]     A body of this type, the support structure of which is composed of essentially four large-size partial modules, is likewise already known from German document DE 198 33 395 A1. For example, each of a front end module and a basic module of this support structure comprises support sections and wall and/or floor sections connected thereto. When the partial modules are assembled, support sections of the one partial module are connected to associated support sections of the other partial module at abutment points.  
         [0005]     The invention is based on the object of providing a body of the type mentioned at the beginning with which a highly stressed connection between partial modules can be realized in an even more stable manner.  
         [0006]     This object is achieved according to the invention.  
         [0007]     Advantageous refinements of the invention.  
         [0008]     In the support structure according to the invention, the support sections are arranged at the sides of a basic module and of a front end module, as a result of which, when they are joined together, lateral sills of the support structure are produced. These sills ensure that the support structure is very highly stable in the connecting region of the two partial modules. The oblique profile of the abutting surfaces can also be formed by a plurality of steps which follow on from one another.  
         [0009]     Since upwardly protruding column sections are arranged at the front ends of the lateral longitudinal member sections of the basic module, which column sections are to be connected to upwardly protruding column sections of the lateral longitudinal member sections of the front end module, the overall result is an angled bonding of the column sections to the longitudinal member sections. This makes it possible, for example, for a particularly stiff supporting of a front end module on the basic module to be provided.  
         [0010]     If the abutting surfaces of the support sections assigned to one another are of planar design, then a particularly simple configuration of the support sections in the region of the abutting surfaces is possible.  
         [0011]     If each of the support sections is formed from a box profile which is closed on the end side by the particular planar abutting surface, then, when they are joined together, a particularly firm connecting region is produced, with the support having a doubled, approximately 8-shaped box profile in cross section.  
         [0012]     If the planar abutting surface and the respectively assigned box wall run at an acute angle with respect to each other and form a point of the support section, then the connection of the support section can be improved by means of a fastening tab arranged at the front end of the point. In this case, the fastening tab ensures a particularly good connection of the point of the one support section to the other, as a result of which, for example, a “peeling off”—i.e. a detaching of the one support section from the point—is particularly effectively avoided.  
         [0013]     An additional connection and stiffening of the two partial modules is provided if, in addition to the support sections, also the wall and/or floor sections of the modules are connected to one another in an overlapping manner.  
         [0014]     In addition, an even more stable connection of the basic module and front end module is produced if, in addition, upwardly protruding column sections of the two modules are connected to one another.  
         [0015]     Further advantages, features and details of the invention will emerge from the description below of a preferred exemplary embodiment and with reference to the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  shows 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;  
         [0017]      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;  
         [0018]      FIG. 3  shows a perspective view of a partial module of the support structure designed as a front end module;  
         [0019]      FIG. 4  shows a perspective view of a partial module of the support structure designed as a basic module;  
         [0020]      FIG. 5  shows a perspective plan view of the basic module and the front end module after they have been joined together; and  
         [0021]      FIG. 6  shows a partial side view of the basic module and the front module after they have been joined together. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]      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 pre-manufactured 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 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.  
         [0023]     A basic module  12  of the support structure  10 , which basic module can be seen in an overall view of  FIG. 1  with  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 the 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 this central 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 the lateral longitudinal members  15  extend. Above the rear wheel houses  26 , wall regions  30  of the particular, rear side wall are arranged. The basic module  12  is already equipped as far as possible with the other partial modules before it is joined together.  
         [0024]     A front end module  34 , which can be seen in the overall view of  FIG. 3 , belongs to the front crumple zone of the motor vehicle, is supported in a crash-stable manner on the basic module  12  in a manner described in more detail below, and 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 in the overall view of  FIG. 5 , 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  can be seen at the front end of the front end module  34 . Like the basic module  12 , the front end module  34  is also already equipped as far as possible with the other partial modules, assemblies and lining parts before it is joined together.  
         [0025]     A roof module  46  can be placed onto the basic module  12  and the front end module  34 . At the rear, the basic module  12  is adjoined by a rear module  48  which, when the support structure  10  is assembled, belongs together with the rear end region of the basic module  12  to the rear crumple zone of the motor vehicle.  
         [0026]     As illustrated in  FIG. 2 , the support structure  10 , which is assembled from the partial modules  12 ,  34 ,  46  and  48  is lined with outer panel parts of plastic, sheet metal or the like. Thus, in particular, front wing linings are formed in such a manner that the joining point 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. Lateral sill linings  50  are designed in such a manner that the joining point between the particular longitudinal member sections  16  of the basic module  12  and the longitudinal member sections  38  of the front end module  34  is covered such that it cannot be seen from the outside.  
         [0027]      FIGS. 5 and 6  illustrate the basic module  12  and the front end module  34  after they have been joined together, in a perspective plan view and in a partial side view, respectively. It can be seen that the front end region  36  of the body  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  are assembled at abutting surfaces  54 ,  56  of the support sections  16 ,  38 , which abutting surfaces run obliquely with respect to the direction of extent of the support, to form the continuous sill  15 . The lateral longitudinal member sections  16 ,  38  of the front end module  34  and of the basic module  12  are designed here as a box profile of two assembled sheet-metal shells, the longitudinal member sections  16 ,  38  being closed on the end side, on the mutually facing end sides, in each case by the associated, planar abutting surface  54 ,  56 . The abutting surfaces  54 ,  56  consist here of continuous, planar sheet-metal sections which are connected peripherally—for example via a welding connection—to the box profile of the longitudinal member sections  16 ,  38 . Of course, it would also be conceivable, instead of the continuous sheet-metal sections completely closing the cross section of the box profile, to make use just of flanges which can be arranged, for example, peripherally on the end side of the box profile. It would also be conceivable for the oblique profile of the abutting surfaces  54 ,  56  to be able to be formed by a plurality of steps following on from one another. The planar abutting surfaces  54 ,  56  enclose an acute angle α, with the respectively assigned box wall  60 ,  64  of the corresponding longitudinal member section  16 ,  38 , so that a point of the corresponding longitudinal member section  16 ,  38  is formed by the planar abutting surface  54 ,  56  and the respectively assigned box wall. A fastening tab  62  is provided in each case at the front end of the respective points  58  of the longitudinal member sections  38  of the front end module  34 , via which tab the longitudinal member sections  38  of the front end module  34  are additionally connected to the associated longitudinal member sections  16  of the basic module  34 . In this case, the fastening tabs  62  are formed by extensions of the lower box wall  64  of the longitudinal member sections  38  and ensure a particularly good connection of the point  58 , as a result of which, for example, a peeling off—i.e. a detaching of the support section  38  from the point  58  is particularly effectively avoided.  
         [0028]     As  FIGS. 5 and 6  show, the abutting surfaces  54 ,  56  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 abutting surfaces  54 ,  56  corresponds approximately to the length of the adjacent front end region  36  of the body floor  14 .  
         [0029]     After the longitudinal member sections  16 ,  38  which are assigned in each case to one another 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 abutting surfaces  54 ,  56  are fixed to one another via a bonding connection or similar joining connection and, if appropriate, also via a mechanical connection, such as a screw connection.  
         [0030]     The upwardly protruding column sections  18 ,  42  of the basic module  12  and of the front end module  34  comprise joining surfaces which are matched in each case to one another and 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 associated column sections  18 ,  42  in each case 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 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  provide a particularly stiff supporting of the front end module  34  on the basic module  12 . In the transverse direction of the vehicle, the position of the basic module  12  and of the front end module  34  are not determined by the joining surfaces  54 ,  56  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 . In other words, the partial modules  12 ,  34  are aligned in relation to one another in the transverse direction of the vehicle by displacement along the abutting surfaces  54 ,  56 . 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. 5 . 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.  
         [0031]     It should be considered as being included within the context of the invention that the abutting surfaces  54 ,  56  may also be of curved design.