Rear vehicle body structure

1. A rear vehicle body structure comprising:

a front floor panel;

a rear floor panel that is disposed at a rear portion of the front floor panel and has a higher upper surface height than the front floor panel;

a pair of left and right side sills that are arranged outside the front floor panel and the rear floor panel in a vehicle width direction and extend substantially along a vehicle front-rear direction; and

a front cross plate that connects the rear portion of the front floor panel and a front wall of the rear floor panel and has an end portion on an outer side in the vehicle width direction coupled to the left and right side sills,

wherein the front wall of the rear floor panel has a plurality of bent corner portions each having a side view shape bent in a substantially L shape, and at least one of the bent corner portions constitutes a closed cross section extending along the vehicle width direction together with the front cross plate in a vertical height range of the left and right side sills.

2. The rear vehicle body structure according to claim 1 , wherein a plurality of the bent corner portions are arranged in the vertical height range of the left and right side sills.

3. The rear vehicle body structure according to claim 2 , wherein the front wall includes a first bent corner portion in the vertical height range of the left and right side sills and a second bent corner portion disposed on a rear upper side of the first bent corner portion, the front cross plate includes a rising wall rising upward from the rear portion of the front floor panel and a rear extending wall bending rearward and extending from an upper end portion of the rising wall, and

the first bent corner portion and the second bent corner portion of the front wall are joined to the rising wall and the rear extending wall of the front cross plate to constitute the closed cross section.

4. The rear vehicle body structure according to claim 1 , wherein a rear side frame extending toward a vehicle rear side is disposed on an inner side in the vehicle width direction of each of the left and right side sills,

left and right edge portions on the outer side in the vehicle width direction of an upper wall of the rear floor panel are joined to the corresponding left and right rear side frames,

left and right edge portions on the outer side in the vehicle width direction of the front wall of the rear floor panel are joined to the corresponding left and right side sills, and

the bent corner portion disposed in the vertical height range of the left and right side sills is disposed at least on the inner side in the vehicle width direction with respect to the rear side frame.

5. The rear vehicle body structure according to claim 4 , wherein the front wall of the rear floor panel includes a front wall body wall that extends above the side sill on the inner side in the vehicle width direction with respect to the rear side frame, and

a third bent corner portion continuous with the upper wall of the rear floor panel is disposed at an upper edge portion of the front wall body wall.

6. The rear vehicle body structure according to claim 5 , wherein in the front wall body wall, a central region in the vehicle width direction is offset toward the front side of the vehicle with respect to an end region on the outer side in the vehicle width direction in top view.

7. The rear vehicle body structure according to claim 3 , wherein a reinforcing plate extending along the vehicle width direction is joined to a back surface of the front cross plate facing the inside of the closed cross section.

8. The rear vehicle body structure according to claim 7 , wherein a floor tunnel having a rear end portion coupled to a wall constituting the closed cross section of the front cross plate is disposed at a center of the front floor panel in the vehicle width direction, and

the reinforcing plate is joined to a region of the front cross plate from a coupling portion with each of the left and right side sills to a vicinity of a coupling portion with the floor tunnel.

9. The rear vehicle body structure according to claim 6 , wherein an expanded width portion having a front-rear width expanded on the vehicle rear side with respect to a front surface of the central region in the vehicle width direction of the front wall body wall of the rear floor panel is provided at the end portion on the outer side in the vehicle width direction of the front cross plate,

an inclined surface inclined forward and downward between an upper ridgeline and a lower ridgeline extending in the vehicle width direction is provided on an upper surface side of the expanded width portion, and

the upper ridgeline and the lower ridgeline extend to a position where the upper ridgeline and the lower ridgeline overlap, in the vehicle width direction, the bent corner portion disposed within the vertical height range of the side sill in the front wall of the rear floor panel.

10. The rear vehicle body structure according to claim 1 , wherein the bent corner portion of the rear floor panel and the closed cross section formed by the front cross plate are formed in a rectangular shape in which a length in the vertical direction is longer than a length in the front-rear direction.