Battery case structure for electric vehicle
A battery case structure for an electric vehicle, includes a side member in which a flange of the side member laterally provided in a battery case is deformed or broken from a partition to absorb an impact when a side collision occurs, minimizing the impact which is caused by the collision and is provided to penetrate into a battery. Furthermore, the partition of the side member is designed based on topology optimization to secure rigidity, protecting the battery against the impact.
1. A battery case structure for a vehicle, the battery case structure comprising:
a vehicle body floor panel including side sills at first and second lateral sides of the vehicle body floor panel;
a battery case coupled to a lower portion of the vehicle body floor panel; and
a side member including a partition coupled to each lateral side of the battery case, and a flange extending laterally from the partition and coupled to the side sills of the vehicle body floor panel, the partition being internally formed with at least one rib extending transversely,
wherein the at least one rib includes a third rib formed inside the partition and extending as inclined upwards from a region of an outward side, to which a lower portion of the flange is connected, to the inward side of the partition,
wherein a supporter is formed in a lower portion of the partition and protrudes from an inward side toward the battery case, and
wherein the supporter is positioned so that a lateral portion of the battery case is accommodated on the supporter, and includes an upper portion connecting and matching the third rib and a lower portion connecting and matching a bottom portion of the partition.
2. The battery case structure of claim 1 , wherein the partition and the flange of the side member are in a shape of boxes including a closed cross-section, the battery case is provided at the inward side of the partition, and the flange is coupled downwardly and on the outward side of the partition.
3. The battery case structure of claim 2 , wherein the at least one rib further includes a first rib formed inside the partition and extending as inclined upwards from a region of the outward side, to which an upper portion of the flange is connected, to the inward side of the partition.
4. The battery case structure of claim 3 , wherein the at least one rib further includes a second rib formed inside the partition and extending as inclined upwards from the first rib on the inward side to the outward side of the partition.
5. The battery case structure of claim 4 , wherein the second rib and the first rib form a ‘V’-shape therebetween.
6. The battery case structure of claim 1 , wherein the upper portion of the supporter is positioned higher than the lower portion of the flange.
7. The battery case structure of claim 2 , wherein the at least one rib further includes a fifth rib formed inside the partition and connecting the inward side and the bottom portion of the partition.
8. The battery case structure of claim 2 , wherein the at least one rib further includes a sixth rib formed inside the flange and extending to traverse the flange laterally.
9. The battery case structure of claim 8 , wherein the at least one rib further includes a fourth rib formed inside the partition and extending on a same line as the sixth rib to the inward side of the partition.
10. The battery case structure of claim 9 , wherein the sixth rib laterally extends across the inside of the flange to divide the inside of the flange into an upper space and a lower space, and is positioned so that the upper space is formed to have a smaller vertical height than a vertical height of the lower space.
11. The battery case structure of claim 10 , wherein the at least one rib further includes a seventh rib formed extendedly to traverse vertically inside the flange.
12. The battery case structure of claim 11 , wherein the seventh rib is positioned in a region where the side sills of the vehicle body floor panel is connected.
13. The battery case structure of claim 9 , wherein the at least one rib further includes:
a first rib formed inside the partition and extending as inclined upwards from a region of the outward side, to which an upper portion of the flange is connected, to the inward side; and
a third rib formed inside the partition and extending as inclined upwards from a region of the outward side, to which a lower portion of the flange is connected, to the inward side,
wherein the fourth rib is positioned between the first rib and the third rib.