Abstract:
A vehicle body includes a center pillar structure including an outer reinforcement having an outer wall and two side walls defining a channel. Two reinforcements are located within the channel, each rigidly interconnecting the outer wall with a respective one of the sidewalls. A tension panel preferably interconnects the two sidewalls. The center pillar structure is characterized by continuity of strength along its height and increased resistance to vertical compressive loads.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates to vehicle center pillar structures.  
       BACKGROUND OF THE INVENTION  
       [0002]     Passenger vehicles often include a center pillar, also sometimes referred to as a “B pillar,” between front and rear door openings. The center pillar typically extends from a floor pan and rocker panel upward to a vehicle roof. The center pillar typically supports a striker that engages a latch on a front door to releasably maintain the front door in a closed position. The center pillar also typically supports hinges that are pivotably connected to a rear door. Thus, the center pillar provides support for front and rear side doors as well as for the vehicle roof. Furthermore, the center pillar may be subjected to impact loads exerted on the doors in a vehicle side-impact scenario.  
         [0003]     The cross-sectional geometry of a typical center pillar is smaller above the beltline of the doors than below, in part to minimize obstruction of the view through the door windows. Further, the rear door causes strengthening of the center pillar structure between the upper and lower hinges; that is, the rear door structure reinforces the center pillar between its attachment points to the center pillar.  
       SUMMARY OF THE INVENTION  
       [0004]     A vehicle center pillar structure is provided. The center pillar structure includes a bodyside outer member that at least partially defines a front door opening and a rear door opening. The bodyside outer member includes a center pillar segment that is between the front door opening and the rear door opening. A center pillar outer reinforcement is aligned with the center pillar segment of the bodyside outer member and includes an outer wall and two sidewalls extending inboard from the outer wall. The outer wall and the two sidewalls cooperate to define a channel. A first channel reinforcement is positioned within the channel and is connected to both the outer wall and  
         [0005]     Referring to  FIG. 1 , an expanded vehicle body side structure  10  is schematically depicted. The side structure  10  includes a bodyside outer panel  14  that includes a lower segment  18 , an upper segment  22 , a front hinge pillar segment  26 , an A-pillar segment  30 , and a center pillar segment  34  that extends generally vertically to interconnect the lower segment  18  and the upper segment  22 . A portion  38  of the upper segment  22  and a portion  42  of the lower segment  18  cooperate with the center pillar segment  34  to partially define a rear door opening  46 . A portion  50  of the upper segment  22 , a portion  54  of the lower segment  18 , the A-pillar segment  30 , and the front hinge pillar segment  26  cooperate with the center pillar portion  34  to define a front door opening  58 .  
         [0006]     A center pillar structure  62  includes the center pillar portion  34  of the bodyside outer panel  14 , an outer reinforcement  66 , an upper inner panel  70 , a lower inner panel  74 , a first channel reinforcement  78 , a second channel reinforcement  82 , and a tension panel  86 .  
         [0007]     The center pillar portion  34  of the bodyside outer panel  14  defines two holes  90 . The outer reinforcement  66  defines two holes  94 , and the first channel reinforcement  78  defines two holes  98 . Referring to  FIGS. 1 and 2 , the outer reinforcement  66  is connected to the center pillar segment  34  such as by welding such that holes  94  align with holes  90 . The first and second channel reinforcements  78 ,  82  are connected to the outer reinforcement  66  such as by welding. The holes  98  in the first channel reinforcement  78  align with holes  90 ,  94 .  
         [0008]     Referring to  FIG. 3 , wherein like reference numbers refer to like components from  FIGS. 1 and 2 , the outer reinforcement  66  includes an outer wall  102  that abuts the center pillar segment of the bodyside panel (not shown in  FIG. 3 ). The outer reinforcement  66  defines a first sidewall  106  that extends inboard from the outer wall  102 . The outer reinforcement  66  also defines a second sidewall  110  that is spaced a distance apart from the first sidewall  106  and that extends inboard from the outer wall  102 . Flanges  114 ,  118  extend from respective sidewalls  106 ,  110 . The outer wall  102 , the first sidewall  106 , and the second sidewall  110  cooperate to define a channel  122 . one of the two sidewalls. A second channel reinforcement is positioned within the channel and is connected to both the outer wall and the other of the two sidewalls.  
         [0009]     In a preferred embodiment, one of the channel reinforcements extends below at least a portion of the upper rear door hinge such that the rear door strength is integrated with the reinforcement.  
         [0010]     In an exemplary embodiment, the center pillar structure also includes a panel that is operatively connected with respect to the two sidewalls to at least partially close the channel. The panel thus provides a closed cross section of the outer reinforcement. The panel cooperates with the channel reinforcements to maintain the cross-sectional geometry of the center pillar structure when subjected to a vertical load through the vehicle roof.  
         [0011]     The above features and advantages, and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a schematic, expanded, perspective view of a center pillar structure in accordance with the claimed invention;  
         [0013]      FIG. 2  is a schematic side view of a portion of the center pillar structure of  FIG. 1 ;  
         [0014]      FIG. 3  is a schematic cross-sectional view of the center pillar structure of  FIG. 1  taken along a horizontal plane above a door beltline;  
         [0015]      FIG. 4  is a schematic cross-sectional view taken along a vertical place of a portion of the center pillar structure of  FIGS. 1 and 2  and a hinge; and  
         [0016]      FIG. 5  is a schematic, perspective, partial cutaway view of the outboard side of the center pillar structure. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     The first channel reinforcement  78  is characterized by two segments  126 ,  130  separated by a curved segment  134 . Segment  126  is rigidly connected to sidewall  106  such as by welding. Segment  130  is rigidly connected to the outer wall  102  such as by welding. Thus, the first channel reinforcement  78  sufficiently interconnects the outer wall  102  and the sidewall  106  to transfer loads therebetween irrespective of load vector. Similarly, the second channel reinforcement  82  has two segments  138 ,  142  separated by a curved segment  146 . Segment  138  is rigidly connected to sidewall  110  such as by welding. Segment  142  is rigidly connected to outer wall  102  such as by welding. Thus, the second channel reinforcement  82  sufficiently interconnects the outer wall  102  and the sidewall  110  to transfer loads therebetween irrespective of load vector.  
         [0018]     The channel reinforcements  78 ,  82  are preferably formed of ultra high strength steel, and thus have a significantly higher strength than the outer reinforcement  66 . Referring again to  FIG. 2 , the vehicle includes a rear door assembly  148  and a front door assembly  150 . The rear door assembly  148  includes an inner panel  154  that at least partially defines a window opening  158  through which rear door window  162  extends. The inner panel  154  is connected to the center pillar structure  62  by an upper hinge  163  and a lower hinge  164 . The rear door assembly  148  is characterized by a beltline  166  which corresponds to the lower extent of the window opening  158 . The front door assembly  150  includes an inner panel  170  that at least partially defines a window opening  174  through which front door window  178  extends. The front door assembly  150  is characterized by a beltline  182  which corresponds to the lower extent of the window opening  174 . The front door assembly  150  is connected to the front hinge pillar segment, shown at  26  in  FIG. 1 , via hinges (not shown). Beltline  182  and beltline  166  are at substantially the same vertical height.  
         [0019]     The channel reinforcements  78 ,  82  extend from above the beltlines  166 ,  182 , at the upper segment  22  of the bodyside outer panel  14  near the vehicle roof (not shown), to below the beltlines  166 ,  182 . In the embodiment depicted, the first channel reinforcement  78  extends below, i.e., lower than, the upper extent  183  of the upper rear door hinge  163  to integrate the strength of the rear door assembly  148  with the above-belt channel reinforcement  78 . Referring to  FIGS. 2 and 4 , the upper rear door hinge  163  is mounted to the outboard side of the bodyside outer panel  14  with threaded fasteners such as bolts  184  that extend through respective holes  185  formed in the upper hinge  163 , holes  90  formed in the bodyside outer panel  14 , holes  94  formed in the outer reinforcement  66 , holes  98  formed in the first channel reinforcement  78 , and nuts  187  in nut plate  190 .  
         [0020]     Thus, the channel reinforcement  78  in the embodiment depicted extends sufficiently downward to be part of the “metal stack” at which the hinge  163  is mounted to the center pillar structure.  
         [0021]     Referring to  FIGS. 1 and 2 , lower rear door hinge  164  is mounted to the outboard surface of the bodyside outer panel  14  with mechanical fasteners through holes  194  in the bodyside outer panel  14 , holes  198  in the outer reinforcement  66 , and through nuts  202  in nut plate  206 .  
         [0022]     The striker (not shown) for engagement with the latch (not shown) of the front door assembly  150  is mounted to the center pillar structure  62  with mechanical fasteners that extend through holes  210  in the bodyside outer panel  14 , holes  214  in the outer reinforcement  66 , and through nuts  218  in nut plate  222 .  
         [0023]     Referring again to  FIG. 3 , tension panel  86  is rigidly connected to flanges  114 ,  118 , such as by welding, to extend across the open end of channel  122  and thereby close a portion of channel  122 . The upper inner panel  70  defines channel  226  and is welded to the tension panel  86  adjacent flanges  114 ,  118  so that tension panel  86  is between the upper inner panel  70  and the outer reinforcement  66  and separates channels  122 ,  226 . In the embodiment depicted, the tension panel is positioned to extend from below beltlines  166 ,  182  to above beltlines  166 ,  182 , but the optimal height at which the tension panel  86  is mounted may vary with vehicle characteristics such as center pillar size, center pillar discontinuities, the curvature of the center pillar (i.e., tumblehome), etc.  
         [0024]     The tension panel  86  stabilizes the cross sectional geometry of the center pillar structure  62  in the event of a vertical load exerted through the vehicle roof. More particularly, the tension panel  86  in cross section extends substantially linearly from flange  114  to flange  118 . When the center pillar structure is subjected to a vertical compressive load, the tension panel  86  resists flattening of the cross sectional geometry of the center pillar structure  62  by resisting separation of the flanges  114 ,  118 , whereby the tension panel  86  is subjected to a tensile load. The tension panel  86  thus prevents rotation of the channel reinforcements  78 ,  82  so that their strength is engaged in resisting deformation of the pillar structure.  
         [0025]     Referring to  FIG. 5 , wherein like reference numbers refer to like components from  FIGS. 1-4 , the outboard side of the center pillar structure  62  is schematically depicted with a portion of the center pillar segment of the bodyside outer panel  14  removed. The outer reinforcement  66  defines an engineered strength discontinuity such as groove  186 . Groove  186  is located below the lower rear door hinge and functions to provide deformation initiation near the base of the center pillar structure  62  in the event of a horizontal load exerted on the vehicle.  
         [0026]     Referring again to  FIG. 1 , in an exemplary embodiment, the upper inner panel  70  has a thickness of approximately-1.6 millimeters and is formed of DP800 material (i.e., dual phase steel having an ultimate strength of 780 MPa); the tension panel  86  has a thickness of approximately 0.8 millimeters and has a yield strength of approximately 340 MPa; the channel reinforcements  78 ,  82  have a thickness of approximately 1.5 millimeters and are formed of DP1000 material (i.e., dual phase steel having an ultimate strength of 980 MPa); and the outer reinforcement  66  has a thickness of approximately 1.8 millimeters and has a yield strength of approximately 210 MPa.  
         [0027]     While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.