Vehicle seat

1. A vehicle seat comprising:

a seat structure having a seat cushion frame including a first seat side member and a second seat side member, and a seat back frame;

a seat slide mechanism that movably locks the seat structure;

a first upper riser that is fixed to the seat slide mechanism and supports the first seat side member;

a second upper riser that is fixed to the seat slide mechanism and supports the second seat side member;

a first locking mechanism that locks and unlocks the first seat side member to and from the seat slide mechanism;

a second locking mechanism that locks the second seat side member to the seat slide mechanism when an excessive load is input

a first hinge mechanism that allows the first seat side member to rotate with respect to the first upper riser; and

a second hinge mechanism that allows the second seat side member to rotate with respect to the second upper riser;

wherein the second hinge mechanism includes a rotating hinge pin and a bush, and

a part of the bush is destroyed and the second seat member is movable when the excessive load is input; and

wherein the bush has a first hole into which the rotating hinge pin is inserted in an initial state and a second hole that is located in front of the first hole, and

partition walls of the first hole and the second hole are destroyed when the excessive load is inputted.

2. The vehicle seat according to claim 1 ,

wherein the bush is made of nylon.

3. The vehicle seat according to claim 1 ,

wherein the second locking mechanism includes a hook that is provided on the second upper riser and a second striker that is provided on the second seat side member, and

the second seat side member moves and the second striker is engaged with the hook when the excessive load is input.

4. The vehicle seat according to claim 3 ,

wherein the hook has a first concave portion and a second concave portion which open rearward, and

the second striker is formed of a U-shaped wire.

5. The vehicle seat according to claim 3 ,

wherein the first locking mechanism includes a first striker that is provided on the first upper riser and a locking device that is provided on the first seat side member, and

the locking device releases engagement with the first striker by operating an unlocking lever and the locking device engages the first striker by inserting the locking device into the first striker.

6. The vehicle seat according to claim 5 ,

wherein the first hinge mechanism includes a spring that assists rotation of the seat structure.

7. The vehicle seat according to claim 1 ,

wherein the first seat side member and the second seat side member are oriented in a first direction, and

the seat back frame is connected to the seat cushion frame by a recliner.

8. The vehicle seat according to claim 1 ,

wherein the seat slide mechanism includes a first lower rail that is oriented in a first direction, a first upper rail that is engaged with the first lower rail and moves along the first direction, a second lower rail that is oriented in the first direction, and a second upper rail that is engaged with the second lower rail and moves along the first direction,

the first upper riser is fixed to the first upper rail, and

the second upper riser is fixed to the second upper rail.

9. The vehicle seat according to claim 1 ,

wherein the seat back frame is folded into the seat cushion frame to allow the seat structure to be raised.