Vehicle rear structure

1. A vehicle rear structure for a fuel cell vehicle, the vehicle rear structure comprising:

a pair of left and right side members, each of which extends in a vehicle longitudinal direction on a rear side of the fuel cell vehicle and has a hat shape whose cross section perpendicular to an extending direction is projected upward and which has an opening on a lower side and flanges on both sides of the opening on the lower side;

a fuel tank that is arranged between the pair of side members with an axial direction being along a vehicle width direction and that stores gas to be supplied to a fuel cell; and

a floor panel that has a front floor panel and a rear floor panel, wherein,

the front floor panel covering an upper portion of the fuel tank and having a roof section located above height positions of the flanges of the side members,

the rear floor panel being arranged at the rear of the front floor panel and having a bottom surface located below the height positions of the flanges of the side members; rear left and right vertical wall sections raised upward from both of left and right sides of the bottom surface, and rear left and right flat sections extended to the left and the right from upper ends of the rear left and right vertical wall sections and joined to upper surface sides of the flanges on a vehicle inner side of the pair of the side members; and

the front floor panel includes:

front left and right vertical wall sections that fall downward from both of left and right sides of the roof section, and

front left and right flat sections that are folded to the left and the right at lower ends of the front left and right vertical wall sections and are joined to the upper surface sides of the flanges on the vehicle inner side of the pair of the side members.

2. The vehicle rear structure according to claim 1 , wherein

in the floor panel, a rear end of the front floor panel and a front end of the rear floor panel are joined to each other by welding.

3. The vehicle rear structure according to claim 2 , wherein

the floor panel includes:

a main body section in which a front portion corresponding to the roof section of the front floor panel and a rear portion corresponding to the rear floor panel are integrally molded; and

front left and right wall members having front left and right flat sections joined to the upper surface sides of the flanges on the vehicle inner side of the left and right pair of side members, and front left and right vertical wall sections raised upward from the front left and right flat sections toward the roof section of the front floor panel, and

the front left and right wall members are respectively joined to both of left and right ends of the front portion by welding.

4. The vehicle rear structure according to claim 1 , wherein

the floor panel includes:

a main body section in which a front portion corresponding to the roof section of the front floor panel and a rear portion corresponding to the rear floor panel are integrally molded; and

front left and right wall members having front left and right flat sections joined to the upper surface sides of the flanges on the vehicle inner side of the pair of side members, and front left and right vertical wall sections raised upward from the front left and right flat sections toward the roof section of the front floor panel, and

the front left and right wall members are respectively joined to both of left and right ends of the front portion by welding.

5. The vehicle rear structure according to claim 1 , wherein

the fuel tank is arranged in a collision energy absorption zone on a vehicle rear side of a cabin zone located in front of vehicle rear wheels.

6. A vehicle rear structure for a fuel cell vehicle, the vehicle rear structure comprising:

a pair of left and right side members, each of which extends in a vehicle longitudinal direction on a rear side of the fuel cell vehicle and has a hat shape whose cross section perpendicular to an extending direction is projected upward and which has an opening on a lower side and flanges on both sides of the opening on the lower side;

a fuel tank that is arranged between the pair of side members with an axial direction being along a vehicle width direction and that stores gas to be supplied to a fuel cell; and

a floor panel that has a front floor panel and a rear floor panel, wherein,

the front floor panel covering an upper portion of the fuel tank and having a roof section located above height positions of the flanges of the side members,

the rear floor panel being arranged at the rear of the front floor panel and having a bottom surface located below the height positions of the flanges of the side members; rear left and right vertical wall sections raised upward from both of left and right sides of the bottom surface, and rear left and right flat sections extended to the left and the right from upper ends of the rear left and right vertical wall sections and joined to upper surface sides of the flanges on a vehicle inner side of the pair of the side members;

the floor panel includes:

a main body section in which a front portion corresponding to the roof section of the front floor panel and a rear portion corresponding to the rear floor panel are integrally molded, and

front left and right wall members having front left and right flat sections joined to the upper surface sides of the flanges on the vehicle inner side of the pair of side members, and front left and right vertical wall sections raised upward from the front left and right flat sections toward the roof section of the front floor panel; and

the front left and right wall members are respectively joined to both of left and right ends of the front portion by welding.