Abstract:
A vehicle body structure includes: a floor tunnel bulging from a center of a floor of a vehicle chamber; a pair of seats flanking the floor tunnel from left and right sides of the floor tunnel; a load receiving member placed on an upper part of the floor tunnel; a left floor cross member extending from a left side of the floor tunnel in the vehicle width direction; and a right floor cross member extending from a right side of the floor tunnel in the vehicle width direction. The load receiving member contacts the seat when the seat receives an impact load from a side of the vehicle body. In addition, the load receiving member transmits the impact load to the floor of the vehicle body. Left and right side rim parts of the load receiving member are connected respectively to the left and right floor cross members.

Description:
BACKGROUND OF THE INVENTION 
     The present application claims priority on Japanese Patent Application No. 2009-074138, filed Mar. 25, 2009, the content of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a vehicle body structure which transmits an impact load, entered from a side direction of the vehicle body, to a floor via a seat on which a passenger is seated. 
     DESCRIPTION OF THE RELATED ART 
     According to a known vehicle body structure, an impact load, entered to a seat from a side direction of the vehicle body when the vehicle collides laterally, is quickly transmitted to a floor of the vehicle body. This known vehicle body structure is configured so that an impact receiving member is placed on an upper part of a floor tunnel placed between a left seat and a right seat. The impact receiving member comes in contact with a side part of the seat when the vehicle collides laterally. In this way, the impact receiving member transmits the impact load to the floor tunnel. (See, for example, Japanese Unexamined Patent Application, First Publication, No. 2005-67427 (hereinafter referred to as “Patent Document 1”).) 
     According to the vehicle body structure disclosed in Patent Document 1, the impact receiving member includes a console box. The console box is placed on the upper part of the floor tunnel. As a result, when the vehicle collides laterally, the impact load applied to the seat is transmitted to the floor tunnel through the console box. 
     However, since the above known vehicle body structure is configured so that the impact receiving member is placed on the upper part of the floor tunnel, the impact load entered to the floor tunnel from the seat acts as a large moment to the floor tunnel. Therefore, there is a concern in that the floor tunnel might be distorted and deformed. 
     SUMMARY OF THE INVENTION 
     The present invention is made considering the problems described above. Accordingly, an object of the present invention is to provide a vehicle body structure which quickly transmits an impact load, applied to a seat when the vehicle collides laterally, to a floor of the vehicle body without triggering a distortion or a deformation of the floor tunnel. 
     (1) Namely, a vehicle body structure according to an aspect of the present invention includes a floor tunnel bulging from a center of a floor of a vehicle chamber in a vehicle width direction; a pair of seats flanking the floor tunnel from a left side and a right side of the floor tunnel; a load receiving member placed on an upper part of the floor tunnel; a left floor cross member extending from a left side of the floor tunnel in the vehicle width direction; and a right floor cross member extending from a right side of the floor tunnel in the vehicle width direction. The load receiving member contacts the seat when the seat receives an impact load from a side of the vehicle body. In addition, the load receiving member transmits the impact load to the floor of the vehicle body. Furthermore, a left side rim part of the load receiving member is connected to the left floor cross member. Meanwhile, a right side rim part of the load receiving member is connected to the right floor cross member. 
     As a result, the left floor cross member and the right floor cross member, which flank the floor tunnel, are connected to the load receiving member. Thus, the left floor cross member and the right floor cross member support the load entered from the seat to the load receiving member when the lateral collision occurs. 
     (2) In addition, the above vehicle body structure may further include an upper cross member. The upper cross member strides over a peak part of the floor tunnel. The upper cross member also connects the left floor cross member and the right floor cross member. The left side rim part of the load receiving member is connected to the left floor cross member via the upper cross member. In addition, the right side rim part of the load receiving member is connected to the right floor cross member via the upper cross member.
 
(3) In addition, the above vehicle body structure may be configured as follows: the left side rim part and the right side rim part of the load receiving member are fastened to an upper surface of the upper cross member.
 
     According to the vehicle body structure described in (1) above, the left floor cross member and the right floor cross member support the load entered from the seat to the load receiving member when a lateral collision occurs. Thus, it is possible to reduce the amount of load which is entered directly to the floor tunnel from the load receiving member. Therefore, the floor tunnel is prevented from distorting or deforming. In addition, the load entered to the seat can be quickly transmitted to the floor of the vehicle body. 
     According to the vehicle body structure described in (2) above, the left side rim part and the right side rim part of the load receiving member are linked to the left floor cross member and the right floor cross member via the upper cross member. Thus, the length of protrusion of the left side rim part and the right side rim part of the load receiving member can be shortened. At the same time, the upper cross member can further enhance the rigidity of the connecting portion between the left floor cross member and the right floor cross member. 
     According to the vehicle body structure described in (3) above, the left side rim part and the right side rim part of the load receiving member are fastened to the upper surface of the upper cross member. As a result, the fastening operation can be conducted easily from the upper and lower directions. In this way, the operability of assembling the vehicle body structure can be improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross sectional view of a vehicle according to an aspect of the present invention. 
         FIG. 2  is an exploded perspective view showing a vehicle body structure of a vehicle according to an aspect of the present invention. 
         FIG. 3  is a schematic cross sectional diagram of a vehicle according to an aspect of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereunder, a first embodiment of the present invention is described with reference to  FIGS. 1-3 . 
       FIG. 1  is a diagram of a left seat  1  and a right seat  1  at a front row of a vehicle seen from a back side.  FIG. 1  is drawn so as to show only a skeletal member of seat  1 . In addition, only a portion of the right seat  1  is shown. 
     The seat  1  includes a seat cushion  2  which supports a bottom of a passenger, a seat back  3  which is linked to a rear end part of the seat cushion  2  and supports a hip and a chest (a back) of the passenger, and a head rest  4  which is supported by an upper part of the seat back  3  and supports a head and a neck of the passenger. 
     The seat cushion  2  includes a cushion frame at a rear end part of the seat cushion  2 . A rear part cross member  6  is fastened to the cushion frame. The rear part cross member  6  extends along the vehicle width direction. This cushion frame is provided on a vehicle body floor  9  via a seat rail  8 ,  8  so that the cushion frame can slide in the front-rear direction. Incidentally, reference numeral  10  in the diagram indicates a side sill provided on a lower end side part of the vehicle body. Reference numeral  11  indicates a center pillar which is provided at approximately a center of a side part of the vehicle body. Reference numeral  12  is a floor tunnel formed so as to expand upwards at a central region in a vehicle width direction on the vehicle body floor  9 . A console box  30  (a load receiving part) is fixed between the left seat  1  and the right seat  1  in a front row on the floor tunnel  12 . A storage part  30   a  (see  FIG. 2 ) is provided at an upper surface side of the console box  30 . 
     The seat back  3  includes a seat back frame  13  which is shaped approximately like a rectangular frame. The seat back frame  13  includes an upper frame  13   a , a left side frame  13   c , a right side frame  13   d , and a lower connecting plate  13   b . A lower end of the seat back frame  13  is hinge-connected to a rear end part of the cushion frame so that the seat back frame  13  can tilt. A supporting frame of the head rest  4  is provided at a central location in the width direction of the upper part frame  13   a  of the seat back frame  13 , so that the supporting frame of the head rest  4  can be elevated and lowered. 
     A plate member  14  is provided on a back side of the seat back frame  13 . The plate member  14  is approximately rectangular as seen from a frontal view. 
     The plate member  14  includes a plurality of concave and convex parts  15 . A ridge part a of the concave and convex parts  15  extends in the vehicle width direction. A wave-shaped cross section, formed by the concave and convex parts  15 , extends continuously in the longitudinal direction of the vehicle body. A left side rim and a right side rim of the plate member  14  are connected to the left side frame  13   c  and the right side frame  13   d . The height of an upper end part of the plate member  14  is set to be approximately equal to the height of the chest of the passenger sitting on the seat  1 . 
       FIG. 2  is an exploded perspective view showing a structure of a floor  9  area of a vehicle chamber between the left seat  1  and the right seat  1 . 
     As shown in  FIGS. 1 and 2 , a pair of floor cross members  40 A and  40 B is provided in the left and right sides of the floor tunnel  12 . The floor cross members  40 A and  40 B extend in the vehicle width direction. The cross-section of each of the cross members  40 A and  40 B is channel shaped. The pair of floor cross members  40 A and  40 B is divided into two groups, i.e., a group located at a front end part of the seats  1 ,  1  on the vehicle body floor  9 , and another group located at a rear end part of the seats  1 ,  1  on the vehicle body floor  9 . In addition, both end parts of the floor cross members  40 A and  40 B are connected to the floor tunnel  9  and the side sill  10 . 
     The rim parts of the pair of floor cross members  40 A,  40 B positioned toward the center part of the vehicle body are connected with an upper cross member  41 . The upper cross member  41  strides over a peak portion of the floor tunnel  12  along the vehicle width direction. The cross section of the upper cross member  41  is channel shaped. A central region  41   a  of the upper cross member  41  in the longitudinal direction curves upwards along an external shape of the floor tunnel  12 . Both sides of the side rim part  41   b  in the longitudinal direction extend approximately horizontally. Connection flanges  42 ,  43  are provided as an extension of the central region  41   a  and the side rim part  41   b . The connection flange  42  of the central region  41   a  connects to an upper surface of the peak part of the floor tunnel  12 . The connection flange  43  of the side rim part  41   b  connects to an upper surface of the floor cross members  40 A,  40 B. In addition, bolt insertion holes  44   a ,  44   b  are provided on an upper surface of each side rim part  41   b  along the vehicle width direction. A weld-nut (not diagramed) is provided on a back side of each side rim part  41 . A bolt (not diagramed), which is inserted to the bolt insertion holes  44   a  and  44   b , are screwed into the weld-nut. 
     On the other hand, the console box  30  includes side walls  45 A,  45 B, a front wall  45 C, a rear wall  45 D, and a bottom wall  45 E. The interior of the bottom wall  45 E is reinforced by a plurality of frame parts and the like. An upper side of the bottom wall  45 E is the storage part  30   a . An extension wall  46  is provided on the lower rim of both side walls  45 A,  45 B. The extension wall  46  extends along an external surface of the floor tunnel  12 . A pair of fastening chips  46   a ,  46   a  is provided on a lower end of the extension wall  46  as an extension to the lower end. The fastening chips  46   a ,  46   a  bend in an approximately horizontal direction. A bolt insertion hole  47  is provided on each of the fastening chips  46   a . Each fastening chip  46   a  is stacked to an upper surface of the side rim part  41   b  of the upper cross member  41 . In this condition, the fastening chip  46   a  is bolt-fastened to the side rim part  41   b  from the upper side. 
     Here, each fastening chip  46   a  of the console box  30  is bolt-fastened to a bolt insertion hole  44   b  positioned toward the central part of the side rim part  41   b  of the upper cross member  41 . Meanwhile, a leg part  48 , provided in the inner side of the seat  1  in the vehicle width direction, is bolt-connected to a bolt insertion hole  44   a  located towards the outer side of the side rim part  41   b.    
     Incidentally, as shown in  FIG. 1 , a load transmission block  21  is provided on a position corresponding to an upper end part of a plate member  14  of the side frame  13   c . The load transmission block  21  protrudes from a side part of the seat back frame  13  towards the outer side in the vehicle width direction. When an impact load is entered from a side of the vehicle body, the load transmission block  21  transmits the load to the side frame  13   c  and the plate member  14 . The load transmission block  21  is formed as a honeycomb structure including a plurality of cylindrical parts extending along the vehicle width direction and positioned in parallel. Overall, the load transmission block  21  comprises resin, and is shaped as a parallelepiped elongated in the longitudinal direction. 
     The lower edge parts of the left side frame  13   c  and the right side frame  13   d  are connected with a lower cross member (not diagrammed). The lower cross member surrounds a hinge shaft which rotatably links the seat cushion  2  and a seat back  3 . The load transmission block  25  is provided on an external side surface of the side frame  13   c  in the vehicle width direction positioned along an extension of the lower cross member. The load transmission block  26  is provided on an inner side surface of the side frame  13   d  in the vehicle width direction positioned along an extension of the lower cross member. Similar to the load transmission block  21 , each of the load transmission blocks  25 ,  26  is formed as a honeycomb structure including a plurality of cylindrical parts extending along the vehicle width direction and positioned in parallel. Further, the load transmission block  26  toward the side frame  13   d  faces the side walls  45 A,  45 B of the console box  30  at a central portion in the vehicle width direction. 
     According to the configuration described above, when an impact load is entered from a side of the vehicle, and a side wall of the vehicle body such as a center pillar  11  and the like deforms in the direction of the seat back  3 , the load from the side wall is transmitted to the side frame  13   c  via at least one of the upper and lower load transmission blocks  21 ,  25 . 
     When an impact load is entered to the lower impact transmission block  25 , the entire seat moves towards the inner side in the vehicle width direction. At the same time, the impact transmission block  26 , provided at the inner lower side in the vehicle width direction, comes in contact with the console box  30 . At this time, the load is transmitted from the lower cross member, positioned below the seat back frame  13 , to the console box  30  via the load transmission block  26 . 
     Furthermore, when an impact load is entered to the upper load transmission block  21 , the load is transmitted from the load transmission block  21  to the side frame  13   c . The load is then transmitted to the side frame  13   d  at the inner side in the vehicle width direction, via the plate member  14  connected to a rear surface side of the side frame  13  and an upper and lower framework of the seat back frame  13  (i.e., the upper frame  13   a  and the lower connecting plate  13   b ). At this time, when an impact load enters from the side frame  13   c  to an upper end part of the plate member  14 , a stress is created in the shear direction at a plurality of regions divided by the ridge part a of each concave and convex parts  15  of the plate member  14 . Thus, the impact load which was entered is received by roughly the entire plate member  14 . 
     In this way, as the impact load is transmitted so as to be dispersed to the entire seat back frame  13 , the entire seat moves towards the inner side in the vehicle width direction. At the same time, the load transmission block  26  comes in contact with the console box  30 . The load is thus transmitted from the load transmission block  26  to the console box  30 . 
       FIG. 3  is a diagram showing a model of how the impact load is transmitted at the time of a lateral collision. In  FIG. 3 , the impact transmission blocks  21 ,  25 , and  26 , and the like, of each seat  1  are not diagramed. 
     As shown in  FIG. 3 , when an impact load is transmitted from the seat  1  to the side surface of the console box  30 , the load is transmitted to the left floor cross member  40 A and the right floor cross member  40 B via the upper cross member  41 . Thus, the left floor cross member  40 A and the right floor cross member  40 B support the moment applying in a direction toward which the console box  30  tilts. Therefore, the impact load entered from the seat  1  to the console box  30  is received by the left floor cross member  40 A and the right floor cross member  40 B. 
     As described above, according to the vehicle body structure based on the present invention, the console box  30 , which is a load receiving member, is connected to the left floor cross member  40 A and the right floor cross member  40 B while striding over the floor tunnel  12 . Thus, the impact load, transmitted from the seat  1  to the console box  30  at the time of a lateral collision, can be dispersed and supported by the left floor cross member  40 A and the right floor cross member  40 B. In this way, the amount of load which enters directly to the exploded part of the floor tunnel  12  can be reduced. Therefore, the impact load entered to the seat  1  can be quickly transmitted to the vehicle body floor  9  without causing a distortion or a deformation of the floor tunnel  12 . 
     In addition, according to the above vehicle body structure, an upper cross member  41  is provided, which strides over the floor tunnel  12  and connects the left floor cross member  40 A and the right floor cross member  40 B. The cross section of the upper cross member is closed. Each extension wall  46  at both sides of the console box  30  is bolt-fastened to the side rim part  41   b  of this upper cross member  41 . Thus, the length of the extension wall  46  can be shortened. In addition, the support strength of the console box  30  can be enhanced. At the same time, the upper cross member  41  can further enhance the rigidity of the connecting part between the left floor cross member  40 A and the right floor cross member  40 B. 
     Furthermore, according to the above embodiment of the present invention, the extension wall  46  of the console box  30  is bolt-fastened to an upper surface of the side rim part  41   b  of the upper cross member  41 . As a result, the console box  30  can be easily bolt-fastened during a process of assembling the vehicle. Therefore, the vehicle body structure according to the present invention can enhance the operability of the assembling process. 
     While a preferred embodiment of the present invention has been described above, it should be understood that these are exemplary of the invention and are not to be considered as limiting the present invention. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. The invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.