Vehicle seat and vehicle

1. A vehicle seat that is provided in a vehicle equipped with a head portion protecting airbag that protects a head portion of a vehicle occupant at a time of a side collision, the vehicle seat comprising:

a head portion restraining portion that is at an upper portion side of a seatback so as to be able to tilt rearward from an upright state, and that restrains a head portion of a vehicle occupant, wherein,

when the seatback is tilted rearward beyond a predetermined angle with respect to a vertical direction, the head portion of the vehicle occupant can be protected due to at least a side portion of the head portion restraining portion that is at a vehicle transverse direction outer side covering a side of the head portion of the vehicle occupant,

the head portion restraining portion is a headrest that is a body separate from the seatback,

the headrest comprises a main body portion inward of the side portion in a vehicle width direction, and

when the seatback is tilted rearward beyond a predetermined angle with respect to a vertical direction, the side portion moves to a projected position that protrudes toward a vehicle front side from a usual position on an extended line extending outward from the main body portion in the vehicle width direction.

2. The vehicle seat of claim 1 , wherein:

the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion incorporates a hard pad therein.

3. The vehicle seat of claim 1 , wherein:

the vehicle can switch between an automatic driving mode and a manual driving mode, and

when the seatback is tilted rearward in the automatic driving mode, a side portion of the head portion restraining portion projects out toward a seat front side.

4. The vehicle seat of claim 3 , wherein, when the seatback is tilted rearward in the manual driving mode, the side portion of the head portion restraining portion does not project out toward the seat front side.

5. The vehicle seat of claim 3 , wherein, when the seatback is tilted rearward in the manual driving mode, at a driver's seat, the side portion of the head portion restraining portion is not projected out toward the seat front side, and, at a front passenger's seat, the side portion of the head portion restraining portion is projected out toward the seat front side.

6. The vehicle seat of claim 1 , wherein an amount of projection, toward a seat front side, of the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion is greater than an amount of projection, toward the seat front side, of a side portion that is at a vehicle transverse direction inner side of the head portion restraining portion.

7. A vehicle comprising:

the vehicle seat of claim 1 ; and

a head portion protecting airbag that is at a reverse surface side of a vehicle transverse direction outer side end portion of a roof head lining, and that, at a time of a side collision, inflates and expands toward a vehicle vertical direction lower side and protects a head portion of a vehicle occupant.

8. The vehicle of claim 7 , wherein the vehicle can switch between an automatic driving mode and a manual driving mode.

9. A vehicle seat that is provided in a vehicle equipped with a head portion protecting airbag that protects a head portion of a vehicle occupant at a time of a side collision, the vehicle seat comprising:

a head portion restraining portion that is at an upper portion side of a seatback so as to be able to tilt rearward from an upright state, and that restrains a head portion of a vehicle occupant,

wherein, when the seatback is tilted rearward beyond a predetermined angle with respect to a vertical direction, the head portion of the vehicle occupant can be protected due to at least a side portion that is at a vehicle transverse direction outer side of the head portion restraining portion covering a side of the head portion of the vehicle occupant,

the vehicle can switch between an automatic driving mode and a manual driving mode,

when the seatback is tilted rearward in the automatic driving mode, a side portion of the head portion restraining portion projects out toward a seat front side, and

when the seatback is tilted rearward in the manual driving mode, the side portion of the head portion restraining portion does not project out toward the seat front side.

10. The vehicle seat of claim 9 , wherein:

the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion incorporates a hard pad therein, and

when the seatback is tilted rearward, at least the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion projects out toward a seat front side.

11. The vehicle seat of claim 9 , wherein an amount of projection, toward a seat front side, of the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion is greater than an amount of projection, toward the seat front side, of a side portion that is at a vehicle transverse direction inner side of the head portion restraining portion.

12. The vehicle seat of claim 9 , wherein the head portion restraining portion is a headrest that is a body separate from the seatback.

13. A vehicle comprising:

the vehicle seat of claim 9 ; and

a head portion protecting airbag that is at a reverse surface side of a vehicle transverse direction outer side end portion of a roof head lining, and that, at a time of a side collision, inflates and expands toward a vehicle vertical direction lower side and protects a head portion of a vehicle occupant.

14. The vehicle of claim 13 , wherein the vehicle can switch between an automatic driving mode and a manual driving mode.

15. A vehicle seat that is provided in a vehicle equipped with a head portion protecting airbag that protects a head portion of a vehicle occupant at a time of a side collision, the vehicle seat comprising:

a head portion restraining portion that is at an upper portion side of a seatback so as to be able to tilt rearward from an upright state, and that restrains a head portion of a vehicle occupant,

wherein, when the seatback is tilted rearward beyond a predetermined angle with respect to a vertical direction, the head portion of the vehicle occupant can be protected due to at least a side portion that is at a vehicle transverse direction outer side of the head portion restraining portion covering a side of the head portion of the vehicle occupant,

the vehicle can switch between an automatic driving mode and a manual driving mode,

when the seatback is tilted rearward in the automatic driving mode, a side portion of the head portion restraining portion projects out toward a seat front side, and

when the seatback is tilted rearward in the manual driving mode, at a driver's seat, the side portion of the head portion restraining portion is not projected out toward the seat front side, and, at a front passenger's seat, the side portion of the head portion restraining portion is projected out toward the seat front side.

16. The vehicle seat of claim 15 , wherein:

the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion incorporates a hard pad therein, and

when the seatback is tilted rearward, at least the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion projects out toward a seat front side.

17. The vehicle seat of claim 15 , wherein an amount of projection, toward a seat front side, of the side portion that is at the vehicle transverse direction outer side of the head portion restraining portion is greater than an amount of projection, toward the seat front side, of a side portion that is at a vehicle transverse direction inner side of the head portion restraining portion.

18. The vehicle seat of claim 15 , wherein the head portion restraining portion is a headrest that is a body separate from the seatback.

19. A vehicle comprising:

the vehicle seat of claim 15 ; and

a head portion protecting airbag that is at a reverse surface side of a vehicle transverse direction outer side end portion of a roof head lining, and that, at a time of a side collision, inflates and expands toward a vehicle vertical direction lower side and protects a head portion of a vehicle occupant.

20. The vehicle of claim 19 , wherein the vehicle can switch between an automatic driving mode and a manual driving mode.