Vehicle body structure
A vehicle body structure includes: a battery case that is disposed below a floor panel of a vehicle body and houses a battery; and a case-mounting frame that connects the battery case to a side sill provided on a side of the battery case in a vehicle width direction to support the battery case. The case-mounting frame includes a lower frame that straddles between the side sill and the battery case, and an upper frame that rises from the lower frame, supports the battery case, and is disposed side by side with the battery case in the vehicle width direction. The lower frame includes a fragile portion that is provided at a position located below the upper frame and is more fragile than another position other than the first position.
1. A vehicle body structure, comprising:
a battery case that is disposed below a floor panel of a vehicle body and houses a battery; and
a case-mounting frame that connects the battery case to a side sill provided on a side of the battery case in a vehicle width direction to support the battery case,
wherein the case-mounting frame comprises
a lower frame that straddles between the side sill and the battery case, and
an upper frame that rises from the lower frame, supports the battery case, and is disposed side by side with the battery case in the vehicle width direction,
the lower frame includes a fragile portion that is provided at a first position located below the upper frame and is more fragile than another position of the case-mounting frame other than the first position,
the lower frame includes:
a first horizontal portion that extends inward in the vehicle width direction from the side sill;
a first rising portion that is bent and extends upward from an inner end of the first horizontal portion in the vehicle width direction;
a second horizontal portion that extends outward in the vehicle width direction from the battery case; and
a second rising portion that is bent and extends upward from an outer end of the second horizontal portion in the vehicle width direction, and
the upper frame includes a frame body that straddles between an end of the first rising portion opposite the first horizontal portion and an end of the second rising portion opposite the second horizontal portion and is provided to protrude upward in a C shape in which a lower side opens.
2. The vehicle body structure according to claim 1 ,
wherein the upper frame includes
a frame body, and
at least one partition plate that is provided in the frame body and partitions an inside of the frame body into a plurality of rooms, and
at least the one partition plate is the fragile portion.
3. The vehicle body structure according to claim 1 ,
wherein the lower frame includes
a side sill-fixing surface fixed to the side sill, and
a case-fixing surface fixed to a bottom wall of the battery case,
the upper frame includes an upper wall surface that is separate from a side surface thereof in the vehicle width direction fixed to the battery case, and
a mechanical strength of a portion other than the side sill-fixing surface, the case-fixing surface, and the upper wall surface in the case-mounting frame is lower than mechanical strengths of the side sill-fixing surface, the case-fixing surface, and the upper wall surface and is equal to or higher than a mechanical strength of the fragile portion.
4. The vehicle body structure according to claim 3 ,
wherein each of the lower frame and the upper frame includes at least one hollow cell having a hollow shape,
two side walls of the hollow cell are the side sill-fixing surface and the upper wall surface, and
a mechanical strength of a side wall other than the side sill-fixing surface and the upper wall surface of the hollow cell is lower than the mechanical strengths of the side sill-fixing surface and the upper wall surface and is equal to or higher than the mechanical strength of the fragile portion.
5. The vehicle body structure according to claim 4 ,
wherein a plate thickness of the side wall other than the side sill-fixing surface and the upper wall surface of the hollow cell is thinner than plate thicknesses of the side sill-fixing surface and the upper wall surface and a plate thickness of the case-fixing surface and is equal to or thicker than a plate thickness of the fragile portion.
6. The vehicle body structure according to claim 3 ,
wherein a mechanical strength of the bottom wall of the battery case is lower than the mechanical strength of the case-fixing surface.
7. The vehicle body structure according to claim 1 , further comprising:
an outer impact-absorbing portion that is provided on an outer side of the upper frame in the vehicle width direction and reduces an impact of a side collision load on the vehicle body; and
an inner impact-absorbing portion that is provided on an inner side of the upper frame in the vehicle width direction and reduces the impact of the side collision load on the vehicle body.
8. The vehicle body structure according to claim 1 ,
wherein a portion of the lower frame outward from the upper frame in the vehicle width direction is configured by arranging a plurality of hollow cells having a hollow shape in the vehicle width direction.
9. The vehicle body structure according to claim 8 ,
wherein the fragile portion is provided on at least a lower surface of the lower frame.
10. The vehicle body structure according to claim 1 ,
wherein the case-mounting frame is integrally molded with a bottom wall of the battery case, and a refrigerant flow path through which a refrigerant flows is formed on the bottom wall of the battery case.
11. The vehicle body structure according to claim 1 ,
wherein a first fragile portion that extends inward in the vehicle width direction from the first horizontal portion and constitutes the fragile portion is integrally molded on the lower frame.
12. The vehicle body structure according to claim 11 ,
wherein the upper frame has a second fragile portion that straddles between the first rising portion and the second rising portion, extends in a horizontal direction, and constitutes the fragile portion.