Seal structure of battery pack

1. A seal structure of a battery pack, comprising:

a tray for storing a battery cell therein;

a cover covering the tray;

a gasket in pressure-contact with a seal surface of the tray and a seal surface of the cover, so as to close a clearance between the seal surfaces; and

a flange part for holding the gasket, which is forming integrally with the tray or cover,

wherein the gasket is held by the flange part at a position different from positions of the seal surfaces, and

wherein the gasket includes a leg part contacting one of the seal surfaces and a hollow wall part defining a space therein and contacting the other of the seal surfaces.

2. The seal structure according to claim 1 , further comprising:

a clip connecting the gasket and flange part to each other.

3. The seal structure according to claim 2 , wherein

the gasket is held at a position existing within the battery pack more inward than pressure contact portions of the gasket with the seal surfaces.

4. The seal structure according to claim 1 , wherein

the gasket is held at a position existing within the battery pack more inward than pressure contact portions of the gasket with the seal surfaces.

5. The seal structure according to claim 1 , wherein

a displacement amount of the hollow wall part is larger than a displacement amount of the leg part in a state that the gasket is pressure contacted with the seal surfaces.

6. The seal structure according to claim 5 , wherein

the leg part is pressure contacted with one of the seal surfaces of the tray and cover which holds the gasket, and

the hollow wall part is pressure contacted with the other of the seal surfaces different from the one of the seal surfaces.