Abstract:
A tunnel arrangement for a floor assembly ( 2 ) of a vehicle body has front and rear tunnel sections ( 24, 26 ) and a tunnel bridge ( 27 ) that increases stiffness. A floor assembly also is provided and has the tunnel arrangement.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 USC 119 to German Patent Appl. No. 10 2013 103 729.1 filed on Apr. 15, 2013, the entire disclosure of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a tunnel arrangement for a floor assembly of a vehicle body, having front and rear tunnel sections. The invention also relates to a floor assembly having such a tunnel arrangement. 
         [0004]    2. Description of the Related Art 
         [0005]    Floor assemblies with tunnel arrangements are well known. The floor assembly is part of the vehicle body and includes a floor front part, a floor central part and a floor rear part. DE 10 2009 057 986 A1 discloses a floor assembly where the floor central part is formed as a rolled profile and has a tunnel arrangement that is an integral constituent part. The tunnel arrangement functions to receive engine components or parts such as a drive shaft or a cooling water hose arrangement to guide these parts between the front and rear ends of the vehicle. A floor assembly of this type can be produced in a simple and inexpensive manner, but is bound to a particular vehicle type, and the associated vehicle length due to the spacing between the front and rear axles. 
         [0006]    It is therefore an object of the invention to provide a tunnel arrangement and a floor assembly that eliminate the above-mentioned disadvantage and that can be produced in a simple and inexpensive manner. 
       SUMMARY OF THE INVENTION 
       [0007]    The object is achieved by a tunnel bridge that increases stiffness. The front tunnel section preferably is produced from sheet-metal shell parts and the rear tunnel section is produced from a casting. More particularly, the front tunnel section preferably is produced from sheet-aluminum shell parts and the rear tunnel section preferably is produced as an aluminum pressure die casting. 
         [0008]    For simple assembly, the rear tunnel section may have a connecting flange element for the front tunnel section. The rear tunnel section also may have a fastening element for a chassis control unit. 
         [0009]    The tunnel bridge advantageously is produced from an extruded aluminum profile. 
         [0010]    The tunnel bridge also may have two rectangular base parts that are connected to one another by web parts arranged in an X-shape. 
         [0011]    The invention also relates to a floor assembly having the above-described tunnel arrangement. The floor assembly has floor parts connected to the tunnel arrangement via flanges. To ensure high stiffness and an optimum introduction of force into the vehicle body in the event of a side-on impact, the flange parts preferably run out at an angle α with respect to the tunnel arrangement. The angle α advantageously is between 10° and 70°. 
         [0012]    The invention is explained in more detail below on the basis of the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of a floor assembly of a vehicle body. 
           [0014]      FIGS. 2   a - 2   c  are a view from below of tunnel arrangements for the floor assembly of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0015]      FIG. 1  is a perspective view of a floor assembly  2 . The floor assembly  2  comprises floor parts  4 ,  6  that are arranged to the sides of a tunnel arrangement  8 . In a known way, the floor parts  4 ,  6  have front seat cross members  10 ,  12  and rear seat cross members  14 ,  16 . Furthermore, reinforcement elements  18  are provided. In a known way, the floor parts  4 ,  6  are connected to the tunnel arrangement  8  via single-piece or multi-piece flanges  20 ,  22 . In the present exemplary embodiment, the flanges  20 ,  22  are of single-piece form. The flanges  20 ,  22  are arranged at an angle to the tunnel arrangement  8  so that the flange parts run out from the tunnel arrangement  8  at an angle α to the vertical. In this way, stiffness is significantly increased with regard to a side-on impact against the motor vehicle. In the present embodiment, the angle α is approximately 30°. 
         [0016]    The tunnel arrangement is composed of a front tunnel section  24 , a rear tunnel section  26  and a tunnel bridge  28  ( FIG. 2 ). The front tunnel section  24  and the rear tunnel section  26  are arranged on the tunnel bridge  28  so that a continuous tunnel arrangement is provided. In this embodiment, the front tunnel section  24  is composed of sheet-aluminum shell parts, and the rear tunnel section  26  is composed of an aluminum pressure die casting. The rear tunnel section  26  has a connecting flange element  30  (see  FIG. 2 ) which is in the form of a double-shear connection and onto which the front tunnel section  24  is mounted. Reference sign  32  denotes a fastening element for a chassis control unit (not illustrated in any more detail). 
         [0017]      FIGS. 2   a ,  2   b  and  2   c  show view from below of embodiments of the rear tunnel section  26  with the tunnel bridge  28 . The tunnel bridge  28  functions to stiffen the rear tunnel section  26  and thus to stiffen the tunnel arrangement  8  as a whole. As can be seen from  FIGS. 2   a ,  2   b  and  2   c , the tunnel bridge  28  is composed of two rectangular base parts  34 ,  36  that are connected to one another by web parts  38 ,  40  arranged in an X-shape. In this way, in the non-installed state, the tunnel bridge  28  can be pulled apart or pushed together in the manner of an accordion, and can in this way be adapted to different lengths of the rear tunnel section. Accordingly,  FIG. 2   a  shows a rear tunnel section  26  composed of an aluminum pressure die casting that is used in non-shortened form,  FIG. 2   b  shows a rear tunnel section  26  composed of an aluminum pressure die casting that has been shortened in relation to the aluminum pressure die casting from  FIG. 2   a , and  FIG. 2   c  shows the shortest embodiment of a rear tunnel section  26 . Here, the original aluminum pressure die casting from  FIG. 2   a  should have all of the fastening surfaces  42  and openings  44  for all variants.