Electric vehicle battery pack having bottom strike shield
An electric vehicle battery pack with a strike shield affixed to its bottom. The strike shield provides structural support to withstand ground strikes without damaging the batteries within the battery pack. The strike shield is a mixed material sandwich bottom plate structure having a composite top layer, a middle core with one or more hollow members adhesively connected or welded together, or a single integrated structure with elongated stiffeners and/or a base member with elongated channels for stiffness, and a composite bottom layer.
1. A battery pack, comprising:
a frame for surrounding batteries positioned in an interior space therein; and
a strike shield comprising:
an upper layer facing the frame;
a middle core, the upper layer positioned between the frame and the middle core, the middle core comprising a number of smaller and larger rigid and elongated U-shaped members arranged in an alternating manner; and
a lower layer comprising alternating U-shaped channels, arranged in the alternating manner of the U-shaped members and having an upper surface that is affixed to a bottom surface of the U-shaped members, the middle core positioned between the upper layer and the lower layer.
2. The battery pack of claim 1 , wherein the rigid and elongated U-shaped members comprise extruded aluminum.
3. The battery pack of claim 1 , wherein the upper layer comprises one or more of carbon fibers, glass fibers, or aramid fibers.
4. The battery pack of claim 1 , wherein the upper layer comprises a fiber layer having a thickness of approximately 2 mm.
5. The battery pack of claim 1 , wherein the lower layer comprises one or more of carbon fibers, glass fibers, or aramid fibers.
6. The battery pack of claim 1 , wherein the lower layer comprises a steel layer, the steel layer having a thickness between approximately 0.4 mm and approximately 0.8 mm.
7. A strike shield for a battery pack, the strike shield comprising:
an upper layer having a first surface for attachment to a frame of the battery pack, and an opposing second surface;
a middle core connected to the second surface of the upper layer, the middle core comprising a number of smaller and larger rigid and elongated U-shaped members arranged in an alternating manner; and
a lower layer comprising alternating U-shaped channels arranged in the alternating manner of the U-shaped members and having an upper surface that is affixed to a bottom surface of the U-shaped members so that the middle core is positioned between the upper layer and the lower layer.
8. The strike shield of claim 7 , wherein the rigid and elongated U-shaped members each have a wall thickness between approximately 1.5 mm and approximately 3.5 mm.
9. The strike shield of claim 8 , wherein the wall thickness is approximately 2.5 mm.
10. The strike shield of claim 7 , wherein the rigid and elongated U-shaped members comprise extruded aluminum.
11. The strike shield of claim 7 , wherein the upper layer comprises one or more of carbon fibers, glass fibers, or aramid fibers.
12. The strike shield of claim 7 , wherein the upper layer comprises a fiber layer having a thickness between approximately 1 mm and approximately 3 mm.
13. The strike shield of claim 12 , wherein the thickness of the fiber layer is approximately 2 mm.
14. The strike shield of claim 7 , wherein the lower layer comprises one or more of carbon fibers, glass fibers, or aramid fibers.
15. The strike shield of claim 7 , wherein the lower layer comprises a steel layer.
16. The strike shield of claim 15 , wherein the steel layer has a thickness between approximately 0.4 mm and approximately 0.8 mm.
17. The strike shield of claim 16 , wherein the thickness of the steel layer is approximately 0.6 mm.
18. The battery pack of claim 1 , wherein the middle core is formed with areas of differing elevation to form a number of elongated members therein.
19. The strike shield of claim 7 , wherein the middle core is formed with areas of differing elevation to form a number of elongated channels therein.
20. A strike shield comprising:
an upper layer having a first surface for attachment to a frame of a battery pack, and an opposing second surface; and
a middle core connected to the second surface of the upper layer, the middle core comprising a number of rigid and elongated U-shaped members, wherein:
the number of the rigid and elongated U-shaped members comprise first U-shaped members having a first size and second U-shaped members having a second size different than the first size;
the first U-shaped members and the second U-shaped members are arranged in an alternating manner; and
a lower layer connected to the middle core so that the middle core is positioned between the upper layer and the lower layer, wherein the lower layer comprises alternating U-shaped channels arranged in the alternating manner of the U-shaped members and having an upper surface that is affixed to a bottom surface of the U-shaped members.