Vehicle floor structure

1. A vehicle floor structure, comprising:

a center floor;

a plurality of longitudinal members attached to a bottom surface of the center floor; and

a battery assembly having a battery case disposed under the center floor and a through bolt passing through the battery case,

wherein the through bolt is aligned with respect to at least one longitudinal member among the plurality of longitudinal members, and

the through bolt is joined to the at least one longitudinal member.

2. The vehicle floor structure according to claim 1 , wherein the plurality of longitudinal members include:

two first longitudinal members facing each other in relation to a central longitudinal axis of the center floor; and

two second longitudinal members disposed on both side edges of the center floor, respectively.

3. The vehicle floor structure according to claim 2 , wherein each of the first longitudinal members includes a bottom wall having an inner side edge facing an interior of a vehicle and an outer side edge facing an exterior of the vehicle, an inner sidewall extending from the inner side edge of the bottom wall toward the center floor, an outer sidewall extending from the outer side edge of the bottom wall toward the center floor, an inner flange extending from a top end of the inner sidewall toward the interior of the vehicle, and an outer flange extending from a top end of the outer sidewall toward the exterior of the vehicle, and

the inner flange and the outer flange are joined to the bottom surface of the center floor.

4. The vehicle floor structure according to claim 2 , wherein front ends of the first longitudinal members are joined to front side members,

rear ends of the first longitudinal members are joined to a rear floor, and

the rear floor is disposed behind the center floor.

5. The vehicle floor structure according to claim 2 , wherein a pair of side sills are attached to both side edges of the center floor, respectively, and

the second longitudinal members are joined to the corresponding side sills, respectively.

6. The vehicle floor structure according to claim 2 , wherein each of the second longitudinal members includes a bottom wall, an inner sidewall extending from an inner side edge of the bottom wall toward the center floor, an inner flange extending from a top end of the inner sidewall toward an interior of a vehicle, and an outer flange extending vertically from an outer side edge of the bottom wall toward the battery assembly,

the inner flange is joined to the bottom surface of the center floor, and

the outer flange is joined to a corresponding side sill.

7. The vehicle floor structure according to claim 2 , wherein front ends of the second longitudinal members are joined to front side members,

rear ends of the second longitudinal members are joined to rear side members, and

the rear side members are disposed behind the center floor.

8. The vehicle floor structure according to claim 1 , further comprising a plurality of long seat rails disposed in cavities of the plurality of longitudinal members, respectively,

wherein the through bolt is vertically aligned with respect to the at least one longitudinal member among the plurality of longitudinal members and at least one long seat rail among the plurality of long seat rails.

9. The vehicle floor structure according to claim 8 , wherein the long seat rail has a guide portion guiding a roller of a vehicle seat assembly.

10. The vehicle floor structure according to claim 8 , further comprising a reinforcing member disposed in the cavities of the longitudinal members,

wherein the reinforcing member is located under the long seat rail,

a nut is fixed to the reinforcing member, and

the through bolt is screwed into the nut.

11. The vehicle floor structure according to claim 8 , wherein the long seat rail includes a guide portion guiding a roller of a vehicle seat assembly, and a reinforcing portion integrally connected to the guide portion,

the reinforcing portion has a plurality of reinforcing ribs,

a nut is fixed to the reinforcing portion, and

the through bolt is screwed into the nut.

12. The vehicle floor structure according to claim 1 , wherein the center floor has a first opening for mounting a roller of a vehicle seat assembly, and a second opening for guiding a movement of a seat support frame of the vehicle seat assembly, and

a width of the second opening is less than a width of the first opening.

13. The vehicle floor structure according to claim 1 , further comprising a plurality of crossmembers perpendicular to the plurality of longitudinal members,

wherein the plurality of crossmembers guide a roller of a vehicle seat assembly in a width direction of a vehicle.

14. The vehicle floor structure according to claim 1 , wherein the through bolt is vertically aligned with respect to the at least one longitudinal member among the plurality of longitudinal members and with respect to the center floor.

15. The vehicle floor structure according to claim 1 , wherein the through bolt passes through the at least one longitudinal member.