Abstract:
A vehicle body structure includes a cross member extending across a lateral direction of a vehicle, wherein the cross member is coupled to a vehicle body component and a reinforcing member installed to the cross member wherein the reinforcing member is spaced apart from a coupling portion of the cross member and the vehicle body component. A method to reinforce a cross member of a vehicle body includes installing at least one reinforcing member along the cross member and locating at least one edge of the at least one reinforcing member a selected distance from at least one coupling portion between the cross member and a vehicle body component.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority from Japanese Patent Application No. 2007-094605, filed Mar. 30, 2007, the contents of which are hereby incorporated by reference in their entirety. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    1. Field of the Disclosure 
         [0003]    The present invention relates to a vehicle body structure wherein a reinforcing member is installed at a cross member extended along a lateral direction of a vehicle. 
         [0004]    2. Description of the Related Art 
         [0005]    Japanese Laid-Open Patent Publication No. 2003-95130 discloses a vehicle body structure wherein a cross member extended along a lateral direction of a vehicle is installed. In such a structure, an end of the cross member is coupled to a side member extended along a front-to-rear direction of the vehicle body via a coupling member. 
         [0006]    However, when a seat is attached to the cross member, for example, it may be advantageous to interpose a reinforcing member therebetween so as to increase the strength of attachment. 
         [0007]    Further, the reinforcing member may be installed so as to be extended to a coupling portion of the cross member and another vehicle body component. In such a case, when the force of an impact is exerted to the seat from the rear of the vehicle resulting in a forwardly bend of the cross and the reinforcing members, an impact load to the seat may be concentrated at a coupling between the cross member and another vehicle body component. 
       SUMMARY OF THE CLAIMED SUBJECT MATTER 
       [0008]    In one aspect, the present disclosure relates to a vehicle body structure including a cross member extending across a lateral direction of a vehicle, wherein the cross member is coupled to a vehicle body component and a reinforcing member installed to the cross member, wherein the reinforcing member is spaced apart from a coupling portion of the cross member and the vehicle body component. 
         [0009]    In another aspect, the present disclosure relates to a method to reinforce a cross member of a vehicle body including installing at least one reinforcing member along the cross member, and locating at least one edge of the at least one reinforcing member a selected distance from at least one coupling portion between the cross member and a vehicle body component. 
         [0010]    In another aspect, the present disclosure relates to a vehicle body structure including a cross member means for extending across a lateral direction of a vehicle, a means for coupling the cross member means to a vehicle body component, and a reinforcing means installed to the cross member means, wherein the reinforcing means is spaced away from the means for coupling. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]    Features of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings. 
           [0012]      FIG. 1  is a perspective view of a vehicle body constructed in accordance with an embodiment of the present disclosure. 
           [0013]      FIG. 2  is a plan view of the vehicle body shown in  FIG. 1 . 
           [0014]      FIG. 3  is a cross-sectional view taken along line A-A shown in  FIG. 2 . 
           [0015]      FIG. 4  illustrates a portion indicated by an arrow B shown in  FIG. 1 . 
           [0016]      FIG. 5  is a perspective view illustrating a state wherein a rear seat is attached to a rear floor shown in  FIG. 1 . 
           [0017]      FIG. 6  is a perspective view illustrating a state wherein a reclining device installed at the rear seat shown in  FIG. 5  is attached to the vehicle body shown in  FIG. 1 . 
           [0018]      FIG. 7  is a cross-sectional view taken along line C-C shown in  FIG. 1 . 
           [0019]      FIG. 8  illustrates a state wherein the cross member is bent to the front of the vehicle body shown in  FIG. 2 . 
           [0020]      FIG. 9A  illustrates a state before and after the cross member is bent to the front of the vehicle body at a position shown in  FIG. 3 . 
           [0021]      FIG. 9B  illustrates a state before and after the cross member is bent to the front of the vehicle body at a region corresponding to the cross-section taken along line D-D shown in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIG. 1  is a perspective view of a vehicle body structure constructed in accordance with an embodiment of the present disclosure.  FIG. 2  is a plan view of the vehicle body structure. The vehicle body structure is shown with a floor portion at a rear portion of the vehicle body. In  FIG. 1 , a direction indicated by an arrow FR represents the front of the vehicle body, a direction indicated by an arrow LH represents a left side of a lateral direction of the vehicle, and a direction indicated by an arrow UP represents an upper direction of the vehicle body. 
         [0023]    In such a vehicle body structure, side members  3  extended along the front-rear direction of the vehicle body are coupled to both sides of a rear floor panel  1  in the lateral direction of the vehicle as a floor panel via welding operation. Further, a cross member  5  extended along the lateral direction of the vehicle is coupled to an approximate center portion of the rear floor panel  1  along the front-to-rear direction of the vehicle body via a welding operation. Also, both ends of the cross member  5  in the lateral direction of the vehicle are coupled to the side members  3  via a welding operation. 
         [0024]    Also, a pair of reinforcing members  7  is coupled to the cross member  5  via a welding operation having the center portion in the lateral direction of the vehicle interposed therebetween. The pair of the right and left reinforcing members  7  may be symmetrically formed. While welding operations are specifically mentioned in this disclosure, it should be understood by one of ordinary skill in the art that any means of connection known to one of ordinary skill in the art may be used. 
         [0025]    As shown in  FIG. 3 , which is a cross-sectional view taken along line A-A shown in  FIG. 2 , the cross member  5  is shown constructed as an opened cross-sectional structure with bottom rear floor panel  1  is adjacent to the opened side. The cross member  5  comprises: a mildly-inclined front surface  9  directed toward the vehicle front, a steeply-inclined rear surface  11  directed toward the vehicle rear, and a flat upper surface  13  directed toward the top of the vehicle and interconnecting front surface  9  and rear surface  11 . Flanges  9   a  and  11   a  of bottom end portions of front surface  9  and rear surface  11  are coupled to the rear floor panel  1  via a welding operation. 
         [0026]    Corresponding to a configuration of the cross member  5 , the reinforcing member  7  comprises a front surface portion  15  bonded to cover an upper portion of the mildly-inclined front surface  9  of the cross member  5 , a rear surface portion  17  bonded to cover an upper end portion of the steeply-inclined rear surface  11 , and an upper surface portion  19  for interconnecting the front and rear surface portions  15  and  17  and to cover the flat upper surface  13 . 
         [0027]    As shown in  FIG. 2 , each reinforcing member  7  is configured such that an outer end  7   a  of reinforcing member  7  in the lateral direction of the vehicle is positioned inboard of a coupling portion P of the cross member  5  and the side member  3 . In other words, the outer end  7   a  is located at a position, which is spaced apart (in an inward direction) from the coupling portion P. Further, as shown in  FIG. 3 , each reinforcing member  7  is configured such that a leading end  15   a  of the front surface portion  15  and a trailing end  17   a  of the rear surface portion  17  are located at positions spaced apart from coupling portions Q and R of the cross member  5  and the rear floor panel  1 , respectively. 
         [0028]    As such, each end  7   a ,  15   a  and  17   a  of the reinforcing member  7  is spaced apart from the coupling portions P, Q and R of the cross member  5  and other vehicle body components, respectively. Accordingly, a cross member  5  incorporating the reinforcing member  7  is provided with a weakened portion between each end  7   a ,  15   a  and  17   a  of the reinforcing member  7  and the coupling portions P, Q and R and another vehicle body components. Also, in the coupling portion P, the cross member  5  and the side member  3  are fixedly bonded at an upper portion side of the cross member  5  by using a connecting member  18 . 
         [0029]      FIG. 4  illustrates a view indicated by an arrow B shown in  FIG. 1 . As shown in  FIG. 4 , an opening  20  is provided in reinforcing member  7  extending from the rear surface portion  17  to a rear edge of upper surface portion  19  of reinforcing member  7  in an outer position in the lateral direction of the vehicle of the reinforcing member  7 . Thus, opening  20  includes an upper component  20   b  in upper surface portion  19  and a rear component  20   a  in rear surface portion  17 . Thus, opening  20  provides access to a ridge portion  21  which is a boundary portion of the flat upper surface  13  and the steeply-inclined rear surface  11  of the cross member  5 . 
         [0030]    Therefore, because opening  20  is provided in the reinforcing portion  7 , cross member  5  incorporating the reinforcing member  7  is also provided with a weakened portion corresponding to the location of opening  20 . 
         [0031]    Also, as shown in  FIG. 4 , the reinforcing member  7  is configured such that the height of the rear surface portion  17  laterally inward of opening  20  is shorter than the height of rear surface portion  17  surrounding opening  20 . 
         [0032]    As shown in  FIG. 5 , a rear seat  22  is installed on the rear floor panel  1  forward of a cross member  5  (not visible) having a pair of members  7  (not visible). Rear seat  22  includes a seat cushion  22   c  and a seatback  22   b . The seatback  22   b  is divided into right and left parts at S. Further, the portion of cross member  5  in which the reinforcing member  7  is installed serves as a part of an attaching portion of the rear seat  22  to the vehicle body. 
         [0033]    That is, as shown in  FIG. 3 , an attaching plate  25  having a nut  23  on its inner side may be fixed to a back surface of the cross member  5  by a welding operation. Further, an attaching hole  27  is provided, wherein the attaching hole  27  passes through the attaching plate  25 , the mildly-inclined front surface  9  of the cross member  5  and the front surface portion  15  of the reinforcing member  7 . The attaching hole  27  serves as an attaching portion. The attaching hole  27  includes a through hole  15   b  provided in the front surface portion  15  of the reinforcing member  7 , a through hole  9   b  provided in the mildly-inclined front surface  9  of the cross member  5 , and a through hole  25   a  provided in the attaching plate  25 . 
         [0034]    Further, as shown in  FIGS. 1 and 2 , a bottom stud bolt  29  protrudes in a generally upper direction of the vehicle body from the rear floor panel  1  forward of reinforcing member  7  and cross member  5 . Bottom stud bolt  29  may serve to attach a portion of the rear seat  22 . Similarly, two stud bolts  31  may obliquely protruded inwardly and upwardly from each side member  3  to attach rear seat  22 . As such, the rear seat  22  may be fixed to the vehicle body using a total of six portions (three portions each in symmetrical positions). 
         [0035]    As shown in  FIG. 6 , the rear seat  22  may be attached via reclining devices  33  and  35 . With reclining device  33  in a center portion, a rear attaching bracket  33   b , which is protruded from a device body  33   a  laterally toward the center of the vehicle, may be fixed by fastening a bolt  37  to the nut  23  shown in  FIG. 3 . Further, a front attaching bracket  33   c , which is protrudes from the device body  33   a  toward the front of the vehicle body, may be fixed by fastening a nut  39  to bottom portion stud bolt  29 . 
         [0036]    Additionally, in the reclining device  35  at an outer side in the lateral direction of the vehicle, an attaching bracket  35   b , which is protruded from a device body  35   a  toward the front of the vehicle body, may be fixed by fastening a nut  41  to the stud bolt  31 . Further, as shown in  FIG. 7  illustrating a cross-section taken along line C-C shown in  FIG. 1 , an attaching portion of the attaching bracket  35   b  may be reinforced by fixedly bonding a side member reinforcing member  42  to an inner side of the side member  3  via a welding operation. 
         [0037]    Also, an upper edge of a bulkhead  43  may be fixedly bonded to a forward end of the rear floor panel  1  via a welding operation. Further, a coupling hole  43   b  may be provided in a flange  43   a  bent toward the rear of the vehicle body of the upper edge. A coupling projection (not shown) provided in a front lower portion of the seat cushion  22   c  of the rear seat  22 , may be inserted into the coupling hole  43   b  and therefore fixedly coupled thereto. 
         [0038]    Both ends of the bulkhead  43  in the lateral direction of the vehicle may be fixedly bonded to the side member  3  via a welding operation. A central bottom portion of the bulkhead  43  in the lateral direction of the vehicle may be fixedly bonded to two central members  45  extended along the front-to-rear (FR) direction of the vehicle body via a welding operation. 
         [0039]    Next, when the force of an impact load is exerted to a vehicle including the vehicle body structure described above from the rear of the vehicle body or when a sudden braking operation is performed, the seatback  22   b  of the rear seat  22  may be particularly subjected to impact due to a movement of the loaded articles housed within a luggage compartment in the rear of the vehicle body. 
         [0040]    As shown in  FIG. 8 , an impact load may be exerted to the seatback  22   b  (shown in  FIG. 5 ), such that a center portion of cross member  5  between a pair of the right and left reinforcing members  7  may become weakened and bent so as to protrude toward the front of the vehicle body (in direction FR). Referring now to  FIG. 9A , the solid line indicates a portion corresponding to  FIG. 3  (i.e., prior to a bending deformation) and the double dot-chain line indicates the portion following bending deformation. Further, in  FIG. 9B , the solid line indicates a portion corresponding to the cross-section taken along line D-D shown in  FIG. 2  prior to the bending deformation and the double dot-chain line indicates the portion after the bending deformation. 
         [0041]    As disclosed in the preceding figures and specification, a bending deformation amount of the cross member  5  to the front (i.e., a moving amount toward the front of the vehicle body) may be restrained by the reinforcing member  7 . Further, the reinforcing member  7  may be installed in a region in which the nut  23  is attached (shown in  FIG. 3 ). Thus, a disengagement of the nut  23  may be prevented when the impact load is exerted to the seatback  22   b  toward the front of the vehicle body. 
         [0042]    Advantageously, the reinforcing member  7  may be installed to cross member  5  such that outer side end  7   a  in the lateral direction of the vehicle is located at a position inboard and spaced from the coupling portion P of the cross member  5  and the side member  3 . Similarly, the leading end  15   a  of the front surface portion  15  and the trailing end  17   a  of the rear surface portion  17  may be located at positions spaced from the coupling portions Q and R of the cross member  5  and the rear floor panel  1 . By doing so, the regions wherein the reinforcing member  7  is not installed to cross member  5  may serve as weakened portions. 
         [0043]    Therefore, when a front buckling deformation of the cross member  5  occurs, elevated stress concentrations at each coupling portion P, Q and R may be avoided such that the stress resulting from the impact load may be dispersed. Therefore, the coupling integrity of the coupling portions P, Q and R may be maintained without resulting in fractures from elevated stress concentrations. That is, when the impact load is exerted, the cross member  5  begins to bend at the weakened portion provided around the end of the reinforcing member  7  (rather than fracture) and the stress of the impact load is dispersed. Therefore, elevated stress concentrations at the coupling portions of the cross member  3  and other vehicle body components may be prevented, thereby preventing the fractures. 
         [0044]    Further, as shown in  FIG. 4 , the opening  20  may serve as a weakened portion and may be provided in a portion from the rear surface portion  17  of reinforcing member  7  to trailing portion of the upper surface portion  19 . Thus, the cross member  5  may be easily deformed to bend to the front. Also, as shown in  FIG. 9A , a downward component of the bending deformation, particularly toward the front of the upper portion as shown in  FIG. 9B , may becomes larger than shown in  FIG. 9A . Therefore, the stress may be more dispersed. 
         [0045]    Also, the opening portion  20  is continuously provided in the ridge portion  21 , which is a boundary portion of the flat upper surface  13  and the steeply-inclined rear surface  11  of the cross member  5 . Further, the ridge  21  is partially exposed through the opening portion  20 . Thus, the deformation of the cross member  5  can be easily carried out, thereby avoiding the stress concentration to each coupling portion P, Q and R. 
         [0046]    Further, a pair of reinforcing members  7  may be installed at both sides of the cross member  5  having a center portion of the cross member  5  in the lateral direction of the vehicle interposed therebetween. Thus, when the impact load is exerted to the cross member  5  from the rear, the weakened portion of the center portion in the lateral direction of the vehicle may be bent, resulting in the stress dispersing effect. 
         [0047]    As described in reference to  FIG. 4 , the reinforcing member  7  is configured such that the height of the rear surface portion  17  laterally inward of opening  20  is shorter than that of the outer portion surrounding opening  20 . Thus, the weakened portion of the center portion in the lateral direction of the vehicle may be more able to bend. 
         [0048]    As such, reinforcing members  7  may be installed at the cross member  5  to increase a strength of the cross member  5  and an attaching strength of a rear seat  22 . However, when the impact load is exerted to the rear seat  22  from the rear of the vehicle body, the stress concentration at coupling portions (e.g., P, Q and R) of the cross member  5  and other vehicle body components (e.g., the side member  3  or rear floor panel  1 ) may be reduced. 
         [0049]    Accordingly, when an impact load is exerted to cross member  5 , the stress is first concentrated around an end of reinforcing member  7  and deformation tends to begin at this portion. Then, the stress of the impact load is dispersed so as to be transferred to a coupling portion (e.g., P, Q, and R) of the cross member  5  and another component of the vehicle body. Therefore, fracture from excess stress concentration to such a coupling portion may be prevented. 
         [0050]    While the disclosure has been presented with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the present disclosure. Accordingly, the scope of the invention should be limited only by the attached claims.