Airbag device

1. An airbag device comprising:

an inflator;

a main bag configured to be inflated when gas generated by the inflator is supplied into the main bag, the main bag configured to be deployed between first and second vehicle seats disposed adjacent to each other in a vehicle width direction in a vehicle front view and toward a lateral side of an occupant seated in the first vehicle seat; and

a sub-bag configured to be inflated when gas generated by the inflator is supplied from the main bag into the sub-bag, the sub-bag configured to be disposed between a portion of the main bag in an upper part of the main bag and the second vehicle seat, the sub-bag and the main bag are formed integrally with each other, the sub-bag protrudes from the portion of the main bag in the upper part above a center of the main bag in a vehicle vertical direction toward a seatback of the second vehicle seat when the gas generated by the inflator is supplied into the sub-bag from the main bag, in a deployed state, a surface of the sub-bag on a leading end side faces a surface, on a vehicle width direction inner side, of an upper portion of the seatback of the second vehicle seat in the vehicle width direction.

2. The airbag device according to claim 1 , wherein a pressure of the gas in the sub-bag is higher than a pressure of the gas in the main bag.

3. The airbag device according to claim 2 , wherein:

a partition wall configured to separate a space in the main bag and a space in the sub-bag is provided between the main bag and the sub-bag; and

the partition wall is provided with a check valve that allows a flow of the gas from the main bag side to the sub-bag side and prevents the flow of the gas from the sub-bag side to the main bag side.

4. The airbag device according to claim 1 , wherein the sub-bag is formed in a substantially trapezoidal shape so as to gradually narrow toward the second vehicle seat side in the vehicle front view after deployment.

5. An airbag device comprising:

a main bag configured to be inflated when gas is supplied into the main bag, the main bag configured to be deployed between first and second vehicle seats disposed adjacent to each other in a vehicle width direction in a vehicle front view and toward a lateral side of an occupant seated in the first vehicle seat; and

a sub-bag configured to be inflated when gas is supplied into the sub-bag, the sub-bag configured to be disposed between a portion of the main bag in an upper part of the main bag and the second vehicle seat, wherein:

a pressure of the gas in the sub-bag is higher than a pressure of the gas in the main bag;

the main bag and the sub-bag are provided on each of a first vehicle seat side and a second vehicle seat side;

the main bag and the sub-bag provided on the first vehicle seat side are deployed at a time of a side collision from the second vehicle seat side;

the main bag and the sub-bag provided on the second vehicle seat side are deployed at a time of a side collision from the first vehicle seat side; and

in a deployed state, the sub-bag is positioned above a center of the main bag in a vehicle vertical direction and between the upper part of the main bag and an upper part of a seatback of the second vehicle seat.

6. The airbag device according to claim 5 , wherein: a partition wall configured to separate a space in the main bag and a space in the sub-bag is provided between the main bag and the sub-bag; and the partition wall is provided with a check valve that allows flow of the gas from the main bag side to the sub-bag side and prevents flow of the gas from the sub-bag side to the main bag side.