Battery pack and method of manufacturing battery pack

1. A battery pack comprising a plurality of stacked single battery cells, a case for housing the plurality of stacked single battery cells, and a vehicle body fastening member for fastening the case to a vehicle body frame,

wherein the vehicle body fastening member is provided separately from the case, is connected to at least one of two side wall parts opposing each other in a width direction of the case by a hooking structure facing an upper surface and a lower surface of the side wall part, and is independently provided at a plurality of arbitrary positions along a length direction of the case,

wherein the vehicle body fastening member has a clamping part which abuts the upper surface and the lower surface of the side wall part to clamp the side wall part from above and below, and the vehicle body fastening member is hooked and connected to the side wall part by the clamping part.

2. The battery pack according to claim 1 , wherein

the vehicle body fastening member has a clamping projected part or a clamping groove part on an inner surface of the clamping part respectively opposite to the upper surface and the lower surface of the side wall part; and

an engaging groove part corresponding to the clamping projected part or an engaging projected part corresponding to the clamping groove part is provided on the upper surface and the lower surface of the side wall part,

wherein the vehicle body fastening member is hooked and connected to the side wall part by engagement of the clamping projected part or the clamping groove part and the engaging groove part or the engaging projected part.

3. The battery pack according to claim 2 , wherein the engaging groove part or the engaging projected part are provided along the length direction of the case, and

the vehicle body fastening member is independently provided at a plurality of arbitrary positions along a length direction of the engaging groove part or the engaging projected part by the clamping part.

4. The battery pack according to claim 1 , wherein the vehicle body fastening member further comprises a flange part which is provided so as to protrude from an upper part of the clamping part to a side of the case and forms a fastening part with the vehicle body frame, and a beam part which extends obliquely from the clamping part to the flange part.

5. The battery pack according to claim 4 , wherein the vehicle body fastening member has a thinned part which is thinned with the beam part left on an outer side of the clamping part, and

the flange part has a bolt insertion hole which vertically penetrates through the flange part and is opened toward the thinned part.

6. A method of manufacturing a battery pack comprising a plurality of stacked single battery cells, a case for housing the plurality of stacked single battery cells, and a vehicle body fastening member for fastening the case to a vehicle body frame, the method comprising:

extrusion-molding the case with a metal material along a stacking direction of the single battery cells; and

at a plurality of arbitrary positions along a length direction of the case, connecting the vehicle body fastening member, which is provided separately from the case, independently to at least one of two side wall parts opposing each other in a width direction of the case by a hooking structure facing an upper surface and a lower surface of the side wall part, and afterwards, bonding the vehicle body fastening member respectively to the case by friction stir welding from at least one direction in a vertical direction of the case with the upper surface or the lower surface of the side wall part as a load receiving surface,

wherein the vehicle body fastening member has a clamping part which abuts the upper surface and the lower surface of the side wall part to clamp the side wall part from above and below, and

when the vehicle body fastening member is independently connected to the plurality of arbitrary positions along the length direction of the case, the vehicle body fastening member is hooked and connected to the side wall part by the clamping part.

7. The method of manufacturing a battery pack according to claim 6 , wherein the vehicle body fastening member has a clamping projected part or a clamping groove part on an inner surface of the clamping part opposite to the upper surface and the lower surface of the side wall part; and

an engaging groove part corresponding to the clamping projected part or an engaging projected part corresponding to the clamping groove part is provided on the upper surface and the lower surface of the side wall part, and

when the vehicle body fastening member is independently connected to the plurality of arbitrary positions along the length direction of the case, the vehicle body fastening member is hooked and connected to the side wall part by engagement of the clamping projected part or the clamping groove part and the engaging groove part or the engaging projected part.

8. The method of manufacturing a battery pack according to claim 7 , wherein the engaging groove part or the engaging projected part is provided along the length direction of the case, and

when the vehicle body fastening member is independently connected to the plurality of arbitrary positions along the length direction of the case, the positions along the length direction of the case are adjusted by sliding and moving the vehicle body fastening member along the engaging groove part or the engaging projected part through the clamping part.