Battery pack having crash beam and drain structure

1. A battery pack, comprising:

a plurality of battery modules stacked in a first direction;

a tray including an interior space where the plurality of battery modules are positioned;

a plurality of beam frames traversing an upper surface of the tray to partition spaces where the plurality of battery modules are positioned; and

a plurality of heatsinks having a hollow structure through which a coolant flows,

wherein each heatsink is coupled to a part of a respective one of the plurality of beam frames and faces a side surface of a respective one of the plurality of battery modules facing the first direction to be between the plurality of battery modules,

wherein at least one drainage hole is provided at the tray and at least one drainage hole is provided in one beam frame of the plurality of beam frames,

wherein the at least one drainage hole of the tray is aligned with the at least one drainage hole of the beam frame, and

wherein the at least one drainage hole of the tray and the at least one drainage hole of the beam frame are provided below the heatsink.

2. The battery pack according to claim 1 , wherein each beam frame of the plurality of beam frames comprises a drainage path having a concave shape.

3. The battery pack according to claim 2 , wherein the at least one drainage hole of the tray is a plurality of drainage holes and the at least one drainage hole of the beam frame is a plurality of drainage holes, and

wherein the plurality of drainage holes of the tray and the plurality of drainage holes of the beam frame are provided along the drainage paths at predetermined intervals.

4. The battery pack according to claim 3 , wherein each drainage path is inclined in at least one direction.

5. The battery pack according to claim 1 , wherein a first part of the plurality of beam frames are I-type beam frames and each I-type beam frame has a column and recessed portions formed at both sides of the column, and

wherein each heatsink is mounted to a respective recessed portion of a respective I-type beam frame.

6. The battery pack according to claim 5 , wherein each heatsink has a shape corresponding to a shape of the respective recessed portion and is adhered to the respective recessed portion by a thermal conductive adhesive.

7. The battery pack according to claim 5 , wherein a second part of the plurality of beam frames, different from the first part, is a single center frame that traverses a center position of the tray, and the I-type beam frames intersect the center frame and are disposed on the tray at regular intervals, and

wherein the plurality of battery modules are arranged in a 2×N matrix.

8. The battery pack according to claim 7 , wherein each of the heatsinks has an input port and an output port provided respectively at a first end and a second end of the heatsink to provide coolant flow through the heatsink, and

wherein the input port and the output port traverses the upper surface of the tray along the respective I-type beam frame through the center frame.

9. The battery pack according to claim 8 , further comprising:

a pack cover covering the upper surface of the tray and two side frames covering both side surfaces of the tray, respectively,

wherein the two side frames are provided in the form of a manifold tube communicating with the input ports and the output ports of the heatsinks to form a path for supplying and discharging the coolant.

10. The battery pack according to claim 7 , wherein the center frame is in the form of an angled tube having a plurality of holes formed at an outer side surface of the center frame, and

wherein a connecting module is provided in the center frame to connect the plurality of battery modules in series and/or in parallel.

11. The battery pack according to claim 1 , wherein a part of the plurality of beam frames is an angled beam frame with a hollow therein, and

wherein each heatsink is located inside a respective angled beam frame.

12. The battery pack according to claim 1 , further comprising:

a heat conduction medium interposed at a thermal interface between each heatsink and the respective battery module.

13. The battery pack according to claim 12 , wherein each heat conduction medium has a plate surface attached to one surface of the heatsink and at least one protrusion extending from the plate surface, and

wherein the at least one protrusion elastically deforms when an external pressure is applied thereto.

14. The battery pack according to claim 13 , wherein each heat conduction medium is made of a silicon rubber.

15. The battery pack according to claim 1 , wherein each of the plurality of battery modules has a bottom wall, a top wall and a plurality of side walls,

wherein the bottom wall contacts the upper surface of the tray, and

wherein electrode terminals extend from one of the plurality of side walls.

16. An electric vehicle, comprising the battery pack defined in claim 1 .