Vehicle seat

1. A vehicle seat including a seat back that forms a backrest surface, comprising:

a seat back pad which is a cushion material of the seat back;

a skin material which covers the seat back pad;

a first engagement portion, wherein a part of the first engagement portion is embedded inside the seat back pad and another part of the first engagement portion is exposed to a seat rear surface of the seat back;

a second engagement portion which is attached to an end portion of the skin material on a side of the seat rear surface of the seat back;

a third engagement portion which is embedded in the seat back pad and is provided in the vicinity of a groove formed on a seat front surface of the seat back; and

a fourth engagement portion which is attached to an end portion of the skin material on a side of the seat front surface of the seat back;

wherein the first engagement portion engages with the second engagement portion so that the skin material is suspended and fixed to the seat rear surface of the seat back;

wherein the third engagement portion engages with the fourth engagement portion so that the skin material is suspended and fixed to the seat front surface of the seat back,

wherein the seat back pad includes a convex portion that is provided at a center portion of the seat back pad in a seat width direction and the first engagement portion is provided at the convex portion of the seat back pad,

wherein the first engagement portion and the third engagement portion are respectively a wire for suspending the rear surface side skin material and a wire for suspending the front surface side skin material and are separate members from each other, and

wherein the wire for suspending the rear surface side skin material is located above the wire for suspending the front surface side skin material.

2. The vehicle seat according to claim 1 ,

wherein the first engagement portion is the wire including an embedded portion which is embedded inside the seat back pad and an exposed portion which extends from the embedded portion and is exposed from the seat back pad,

wherein the second engagement portion includes a hook-shaped portion, and

wherein the hook-shaped portion engages with the exposure portion.

3. The vehicle seat according to claim 1 ,

wherein the skin material is suspended and fixed to the seat rear surface of the seat back at a position of a lower end portion of the seat back pad on the side of the seat rear surface.

4. The vehicle seat according to claim 1 ,

wherein the first engagement portion is provided at a center portion of the seat back in the seat width direction, and

wherein the skin material is suspended and fixed to the seat rear surface of the seat back at one point of the center portion.

5. The vehicle seat according to claim 1 ,

wherein the first engagement portion is disposed at a position different from a position in which a duct hole of a ventilation unit is provided.

6. The vehicle seat according to claim 5 ,

wherein an air blowing portion of the ventilation unit is disposed at a position that is above the engagement position between the first engagement portion and the second engagement portion and between front and rear surfaces of the seat back pad.

7. The vehicle seat according to claim 6 ,

wherein the air blowing portion is located above the first engagement portion.

8. The vehicle seat according to claim 5 ,

wherein at least a part of a duct of the ventilation unit is located above the first engagement portion.

9. The vehicle seat according to claim 1 ,

wherein the seat back pad includes a seat upper portion and a seat lower portion respectively having different hardness, and

wherein the seat upper portion is formed to have hardness and density lower than those of the seat lower portion.

10. The vehicle seat according to claim 1 ,

wherein concave portions are provided at both sides, in the seat width direction, of the convex portion in the seat back pad, and

wherein the first engagement portion is disposed between the concave portions.

11. The vehicle seat according to claim 10 ,

wherein a duct of a ventilation unit is disposed in one of the concave portions.

12. A vehicle seat including a seat back that forms a backrest surface, comprising:

a seat back pad which is a cushion material of the seat back;

a skin material which covers the seat back pad;

a first engagement portion, wherein a part of the first engagement portion is embedded inside the seat back pad and another part of the first engagement portion is exposed to a seat rear surface of the seat back; and

a second engagement portion which is attached to an end portion of the skin material on a side of the seat rear surface of the seat back,

wherein the first engagement portion engages with the second engagement portion so that the skin material is suspended and fixed to the seat rear surface of the seat back,

wherein the vehicle seat further comprises a ventilation unit that includes a duct and an air blowing portion,

wherein the first engagement portion is disposed at a position different from a position in which a duct hole of the ventilation unit is provided, and disposed at a same height as the duct hole, and

wherein the duct of the ventilation unit is located in an outer side of the first engagement portion in the seat width direction.

13. The vehicle seat according to claim 12 ,

wherein the first engagement portion is a wire including an embedded portion which is embedded inside the seat back pad and an exposed portion which extends from the embedded portion and is exposed from the seat back pad,

wherein the second engagement portion includes a hook-shaped portion, and

wherein the hook-shaped portion engages with the exposure portion.

14. The vehicle seat according to claim 12 ,

wherein the skin material is suspended and fixed to the seat rear surface of the seat back at a position of a lower end portion of the seat back pad on the side of the seat rear surface.

15. The vehicle seat according to claim 12 ,

wherein the first engagement portion is provided at a center portion of the seat back in the seat width direction, and

wherein the skin material is suspended and fixed to the seat rear surface of the seat back at one point of the center portion.

16. The vehicle seat according to claim 12 ,

wherein the air blowing portion of the ventilation unit is disposed at a position that is above the engagement position between the first engagement portion and the second engagement portion and between front and rear surfaces of the seat back pad.

17. The vehicle seat according to claim 12 ,

wherein the seat back pad includes a seat upper portion and a seat lower portion respectively having different hardness, and

wherein the seat upper portion is formed to have hardness and density lower than those of the seat lower portion.

18. The vehicle seat according to claim 12 , further comprising:

a third engagement portion which is embedded in the seat back pad and is provided in the vicinity of a groove formed on a seat front surface of the seat back; and

a fourth engagement portion which is attached to an end portion of the skin material on the side of the seat front surface,

wherein an end portion of the skin material on the side of the seat front surface is drawn into the groove, the third engagement portion engages with the fourth engagement portion, and the skin material is suspended and fixed to the seat front surface of the seat back.

19. The vehicle seat according to claim 12 ,

wherein the air blowing portion is located above the first engagement portion.

20. The vehicle seat according to claim 12 ,

wherein at least a part of the duct of the ventilation unit is located above the first engagement portion.