Abstract:
The vehicle body structure is suitable for use in two-door automobiles. The strength of a rearward part of the vehicle body is increased to reliably suppress the deformation of the vehicle body in a possible collision from behind the vehicle. The vehicle body structure includes: a rear wheel house arranged to the rear of a center pillar; and a reinforcement member directly connecting a front part in front of the top portion of the rear wheel house with the center pillar, the front part being inclusive of the top portion of the rear wheel house.

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present application relates to a vehicle body structure suitable for use in two-door automobiles. 
     (2) Description of the Related Art 
       FIG. 11  is a schematic diagram showing a rear part of a conventional two-door vehicle body. As shown in  FIG. 11 , at the lower part of the vehicle body  100 , side members  101  extend in the longitudinal direction of the vehicle body on both sides of the vehicle body. Each side member  101  has a step-like difference in level in the vicinity of a position at which a rear tire W is disposed, in order to avoid interference with suspension components (not illustrated). Thus, as shown in  FIG. 11 , the side member  101  is bent at bend portions  101   a  and  101   b.    
     Here, a cross member  102  extending in the widthwise direction of the vehicle body is provided at a position where a suspension of the vehicle is disposed, and this cross member extends between the side members on both sides at the rear of the vehicle body. This cross member  102  improves the rigidity of the vehicle body against an input from the suspension. 
     Further, as shown in  FIG. 11 , the cross member  102  is connected with a rear pillar (C pillar)  105  of the vehicle body via a reinforcement  104 . Here, the reinforcement  104  is disposed along the rear pillar  105 , and a closed cross section is formed by a combination of the rear pillar  105  and the reinforcement  104 . 
     The lower end of the reinforcement  104  is lengthened to be connected with the cross member  102 , thereby providing the vehicle body with further improved rigidity. Note that reference character  106  in  FIG. 11  denotes the center pillar of the vehicle. 
     In addition to the above prior art, Japanese Patent Application Laid-Open No. HEI 11-291947 discloses an art in which a wheel house of a vehicle body is connected with the rear pillar of the vehicle by means of a first reinforcement, and in which the first reinforcement is connected with the center pillar of the vehicle by means of a second reinforcement. 
     There are technologies in which vehicle bodies are deformed to absorb impact energy caused in a collision. However, at the time of a collision from behind a vehicle, protecting a fuel tank is a high priority, and thus there is a demand for an art for absorbing (or converting) impact energy without deforming the vehicle body. To realize this, deformation of the vehicle body should be considerably suppressed. 
     However, in the art as shown in  FIG. 11 , since the side member  101  has a step-like level difference thereof, the side member  101  tends to be deformed, at the time of a collision from behind, in the direction indicated by the arrow in  FIG. 11  with the bend portions  101   a  and  101   b  as base points, so that the side member  101  could be greatly deformed in such a manner as shown by dotted lines in  FIG. 11 . 
     In addition, in the above-described art, since the reinforcement  104  is provided for the purpose of ensuring rigidity of the vehicle body, it does not contribute much to the improvement of the strength of the vehicle body. Thus, it is not easy for the above-described reinforcement  104  to suppress a considerable deformation caused when a large load is applied in a collision from behind the vehicle. 
     When the reinforcement  104  is used to suppress the vehicle body deformation, there is a problem that the effect of deformation suppression greatly depends on a positional relationship between the rear pillar and the cross member. For example, in a case where a positional relationship between the rear pillar and the cross member is such as that shown in  FIG. 11 , the reinforcement  104  is capable of enduring an input from the lower direction in  FIG. 11 , but incapable of enduring an input from behind the vehicle (an input from the right in  FIG. 11 ), so that it is impossible to suppress the deformation of the vehicle body. 
     Further, in the art disclosed in the above-mentioned patent application, the load caused at the time of a collision from behind the vehicle is transferred to the rear pillar via the first reinforcement, and is also transferred to the center pillar via the second reinforcement. In this art, the first reinforcement is approximately vertically connected with the rearward part of the wheel house from above. Thus, when load is input from behind (at the time of a collision from behind the vehicle), it is impossible to sufficiently suppress the forward deformation of the wheel house. 
     That is, at the time of a collision from behind, the load is transferred to the first reinforcement, which is approximately orthogonal to the load input direction, and then is transferred to the second reinforcement, which extends in the longitudinal direction of the vehicle body, whereby the load is transferred to the rear pillar and the center pillar via the first reinforcement and the second reinforcement, respectively. 
     However, as already described, the first reinforcement is connected to the rear wheel house, and the connection direction is orthogonal to the load input direction. Thus, moment, not compressive load, is input to the first reinforcement, so that it is impossible to suppress the deformation of the vehicle body. 
     With the foregoing problems in view, it is an object of the present invention to provide a vehicle body structure in which the strength of the rearward part of the vehicle body is improved so that the deformation of the vehicle body at the time of a collision from behind the vehicle is reliably suppressed. 
     SUMMARY OF THE INVENTION 
     In order to accomplish the above object, according to the present invention, there is provided a vehicle body structure, including: a rear wheel house arranged to the rear of a center pillar; and a reinforcement member directly connecting a front part in front of the top portion of the rear wheel house with the center pillar, the front part being inclusive of the top portion of the rear wheel house. 
     Therefore, according to the vehicle body structure of the present invention, at the time of a collision from behind, it is possible, with a simple structure, to efficiently transfer impact energy to a center pillar via a reinforcement. As a result, the impact energy is converted to kinetic energy which will give the vehicle acceleration, so that it is possible to reliably suppress the deformation of the vehicle body. Further, the vehicle body structure of the present invention is advantageous in that the vehicle body deformation is suppressed irrespective of the positional relationship between the rear pillar and the cross member. In consequence, it is possible to suppress the relative displacement of a fuel tank, so that the fuel tank is protected from damages thereto. 
     Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the relevant accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing a construction of an important part of a vehicle body structure according to one preferred embodiment of the present invention; 
         FIG. 2  is a diagram showing a construction of the vehicle body structure of the present embodiment, and is a cross section along the line A-A of  FIG. 1 ; 
         FIG. 3  is a diagram showing a construction of the vehicle body structure of the present embodiment, and is a cross section along the line B-B of  FIG. 1 ; 
         FIG. 4  is a schematic perspective view showing the shape of a side outer panel assembly which is applied to the vehicle body structure of the present embodiment; 
         FIG. 5  is a schematic perspective view showing a side outer reinforcement assembly which is applied to the vehicle body structure of the present embodiment; 
         FIG. 6  is a schematic perspective view showing a quarter inner panel assembly which is applied to the vehicle body structure of the present embodiment; 
         FIG. 7  is a schematic perspective view showing a side outer panel which is applied to the vehicle body structure of the present embodiment; 
         FIG. 8  is a schematic perspective view showing a belt line reinforcement of a vehicle body structure of the present embodiment; 
         FIG. 9  is a schematic perspective view showing a quarter inner panel upper which is applied to the vehicle body structure of the present embodiment; 
         FIG. 10  is a schematic perspective view showing a quarter inner panel lower which is applied to the vehicle body structure of the present embodiment; and 
         FIG. 11  is a diagram for describing an example of a prior art. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to the relevant drawings, a description will be made hereinbelow of a vehicle body structure according to one preferred embodiment of the present invention. In  FIG. 1 , reference character  20  denotes a body structure of vehicle body (here a two-door automobile) to which the present invention is applied. The body structure  20  has a rear wheel house  4  arranged to the rear of a center pillar  3 , and the rear wheel house  4  accommodates a rear wheel (rear tire) W therein. 
     As shown in  FIG. 1 , side members  1  are provided at the lower part of the vehicle body. The side members  1  extend along the longitudinal direction of the vehicle body on both sides thereof. Each side member  1  has a step-like difference in level (height) in the vicinity of a position at which a rear tire is disposed, in order to avoid interference with suspension components (not illustrated). Thus, as shown in  FIG. 1 , the side member  1  is bent at bend portions  1   a  and  1   b.    
     Here, a cross member (not illustrated) extending in the widthwise direction of the vehicle body is provided at a position where a suspension of the vehicle is disposed, and this cross member extends between the side members on both sides at the rear of the vehicle body. 
     Further, a belt line reinforcement (reinforcement member)  2 , as shown in  FIG. 1  and  FIG. 8 , is disposed between the rear wheel house  4  and the center pillar  3 . Here, as shown in  FIG. 1 , the rear end of the belt line reinforcement  2  is connected with a vehicle body part in front part of the top portion W of the rear wheel house  4 , and the direction in which the belt line reinforcement  2  is connected with the rear wheel house  4  is identical to the direction in which the rear fire W is displaced at the time of a collision from behind. 
     More specifically, as shown in  FIG. 1 , the rear end X of the belt line reinforcement  2  has a first side  2   a , which extends approximately vertically from fight above and connected to the vicinity of the top of the rear wheel house  4 , and a second side  2   b  which extends from diagonally above the rear wheel house  4  and connected to the rear wheel house  4 . The first side  2   a  suppresses an upward displacement of the rear tire W at the time of a collision from behind (see arrow a); the second side  2   b  suppresses a diagonally forward displacement of the rear tire W at the time of a collision from behind (see arrow b). Here, the direction in which the rear tire will be displaced at the time of a collision from behind is between arrow a and arrow b, that is, between the upward direction and the diagonally upper front direction relative to the center of the rear tire. 
     Further, the front end Y of the belt line reinforcement  2  is connected with the center pillar  3  from the horizontal direction so that the belt line reinforcement  2  is approximately orthogonal to the center pillar  3 . Furthermore, a connection part between the belt line reinforcement  2  and the center pillar  3  is located higher than a connection part between the belt line reinforcement  2  and the rear wheel house  4 . Here, the belt line reinforcement  2  is not directly connected with a rear pillar  7 , but is indirectly connected with the rear pillar  7  via a quarter inner panel assembly  9  (quarter panel) (see  FIG. 6 ) which will be described below. 
     Next, a description will be made of a rear part of the body structure  20 . The rear part of the vehicle body  20  is formed by a side outer panel assembly  8  ( FIG. 4 ), a side outer reinforcement assembly  12  ( FIG. 5 ), and a quarter inner panel assembly  9  ( FIG. 6 ). 
     The side outer reinforcement assembly  12  is connected with the inside of the side outer panel assembly  8  at a position forward of the center pillar  3 . The quarter inner panel assembly  9  is connected with the inside of the above-mentioned side outer panel assembly  8 , extending from the rear wheel house  4  to the vicinity of the center pillar  3 . 
     Here, the side outer panel assembly  8  includes: a side outer panel  5 , which is shown in  FIG. 7 ; the foregoing belt line reinforcement  2 . Further, the quarter inner panel assembly  9  includes: a quarter inner panel upper  6 , which is shown in  FIG. 9 ; a quarter inner panel lower  10 , which is shown in  FIG. 10 ; and a rear wheel house inner panel  11  (see  FIG. 6 ). 
     As shown in  FIG. 2 , the belt line reinforcement  2  is connected with the quarter inner panel upper  6  at the inside of the side outer panel  5 , thereby forming a closed cross section, and this will realize improved strength. 
     Further, as shown in  FIG. 3 , the center pillar  3  includes: a center pillar inner  3   a ; a center pillar outer  3   b ; and a center pillar reinforcement  3   c  interposed therebetween. The belt line reinforcement  2  is connected with the above center pillar outer  3   b . The side outer panel  5  is disposed outside the belt line reinforcement  2 , and the quarter inner panel upper  6  is disposed inside the center pillar  3 . 
     The flanges, i.e., the center pillar inner  3   a , the center pillar outer  3   b , the side outer panel  5 , and the quarter inner panel upper  6  are welded by spot welding or the like. 
     The belt line reinforcement  2  is welded approximately around its periphery to the quarter inner panel upper  6 , except for a connection part with the center pillar  3 . This arrangement provides two closed section structure members extending in the longitudinal direction of the vehicle body at different heights. More specifically, at a lower part of the vehicle body, a side member  1  forms a first closed section structure member extending in the longitudinal direction of the vehicle body; at an upper part of the vehicle body, a combination of the belt line reinforcement  2  and the quarter inner panel upper  6  forms a second closed section structure member extending in the longitudinal direction of the vehicle body. This arrangement enables suppressing deformation of the vehicle body as much as possible at the time of a collision from the front or from behind, and the arrangement also makes it possible to improve the strength against a lateral collision. 
     Since the vehicle body structure of the present embodiment has the above-described construction, if collision energy is input from behind the vehicle body at the time of a collision from behind, this energy is efficiently dispersed to the center pillar  3  and the rear pillar  7  via the belt line reinforcement  2 , so that deformation of the vehicle body is considerably suppressed. 
     More specifically, partly since the load input from behind to the rear wheel house  4  is input to the rear pillar  7  via the vicinity of the first side  2   a  of the belt line reinforcement  2  of  FIG. 1 , and partly since the load is also input to the center pillar  3  via the second side  2   b  of the belt line reinforcement  2 , it is possible to disperse the load input to the rear wheel house  4  to the two pillars  3  and  7 , so that deformation of the rear wheel house  4  is suppressed as much as possible. Accordingly, an unillustrated fuel tank&#39;s relative displacement is successfully suppressed, whereby damages to the fuel tank are prevented. 
     In addition, at the time of a collision from behind, the load is dispersedly input to a side member  1  (first closed section member) and to a closed section member (second closed section member) formed by the belt line reinforcement  2  and the quarter inner panel upper  6 , so that the energy is efficiently dispersed, resulting in reduction of the load input to the side member  1 . This makes it possible to suppress deformation of the side member  1  with the bend portions  1   a  and  1   b  of the side member  1  as base points. From this point of view, it is also possible to suppress damages to the fuel tank. 
     Further, differing from the prior art, in the above construction, the vehicle&#39;s body strength at the time of a collision from behind is not dependent on the positions of the cross member and the rear pillar, and this will bring about the following advantages. Freedom of design is improved; anti-collision performance is improved; the present art is applicable to a wide range of types of vehicles. 
     In addition, since the load input to the belt line reinforcement  2  is mainly transferred to the center pillar  3 , a thinner rear pillar  7  is made available, so that a blind spot is considerably reduced, and superior design is also made available. 
     Further, since the belt line reinforcement  2  connects between the center pillar  3  and the rear wheel house  4 , it is possible to improve the vehicle&#39;s body strength against a sideways collision. 
     Furthermore, the present invention should by no means be limited to the above-illustrated embodiment, but various changes or modifications may be suggested without departing from the gist of the invention. For example, although the above description is made of a two-door automobile, the present invention is also applicable to three-door automobiles and other types of automobiles.