Frame structure for motor vehicle superstructures

Abstract

A frame structure suited for motor vehicle superstructures includes first and second beams conjoined to form a “T” and a joint which is present between the two beams. To ensure that this frame structure is of optimal weight and stiffness, the first and second beams of the frame structure are made of tubes with elliptical cross sections having secondary axes which run parallel to one another. A joint is present at the second beam and is realized as an expansion of the diameter of the first beam. When viewed lengthwise along the second beam, the joint has a defined length from the outermost edge of the first beam spanning toward the second beam.

1 . A frame structure for a motor vehicle superstructure comprising: 
 first and second beams which are conjoined to form a “T,” and    a joint present between the beams,    wherein the first beam and the second beam are made of tubes with elliptical cross sections having secondary axes which run parallel to one another,    wherein the joint is realized as a cross section expansion emanating from the first beam, and    wherein the joint, when viewed lengthwise along the second beam, has a defined length from an outermost edge of the first beam spanning toward the second beam.    
     
     
         2 . The frame structure as claimed in  claim 1 , wherein the length of the joint is defined by:  
           L =(1.50 to 1.70)× {overscore (AC)}   wherein L is the length of the joint and ac is a distance from an outside origin of the joint to its junction with an area of a maximum diameter of the second beam.    
     
     
         3 . The frame structure as claimed in  claim 2 , wherein said distance is defined by:  
       
         
           
             
               
                 AC 
                 _ 
               
               = 
               
                 
                   
                     B 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     % 
                   
                   - 
                   B 
                 
                 2 
               
             
           
         
         wherein B % is equal to a maximum expansion of the joint and B is equal to the maximum diameter of the second beam.  
       
     
     
         4 . The frame structure as claimed in  claim 1 , wherein, when viewed from above the beam, a lateral edge of the joint defines a concave, continuous line.  
     
     
         5 . The frame structure as claimed in  claim 4 , wherein the continuous line both opens tangentially into the second beam and forms a sharp angle with respect to the outermost edge of the first beam where it is of maximum diameter.  
     
     
         6 . The frame structure as claimed in  claim 5 , wherein the sharp angle is between approximately 30° and approximately 42°.  
     
     
         7 . The frame structure as claimed in  claim 1 , wherein the cross section expansion is bulged through an internal high pressure forming process.  
     
     
         8 . The frame structure as claimed in  claim 7 , wherein the cross section expansion is bulged from the same piece as the second beam.  
     
     
         9 . The frame structure as claimed in  claim 1 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         10 . The frame structure as claimed in  claim 1 , wherein the beams are metal beams.  
     
     
         11 . The frame structure as claimed in  claim 2 , wherein, when viewed from above the beam, a lateral edge of the joint defines a concave, continuous line.  
     
     
         12 . The frame structure as claimed in  claim 11 , wherein the continuous line both opens tangentially into the second beam and forms a sharp angle with respect to the outermost edge of the first beam where it is of maximum diameter.  
     
     
         13 . The frame structure as claimed in  claim 2 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         14 . The frame structure as claimed in  claim 3 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         15 . The frame structure as claimed in  claim 4 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         16 . The frame structure as claimed in  claim 5 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         17 . The frame structure as claimed in  claim 6 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         18 . The frame structure as claimed in  claim 7 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         19 . The frame structure as claimed in  claim 8 , wherein the joint is connected to the first beam along a connecting curve.  
     
     
         20 . The frame structure as claimed in  claim 10 , wherein the joint is connected to the first beam along a connecting curve.