SEAT DEVICE FOR VEHICLE

The present invention relates to a vehicle-seat apparatus that is mounted on a vehicle seat and thus makes it possible to easily fold the vehicle seat and to accommodate the folded vehicle seat into an accommodate space thereunder. The vehicle-seat apparatus includes: a front link of which an upper end portion is connected by a hinge mechanism to a front portion of a seat cushion; a sliding member that is connected by the hinge mechanism to a lower end portion of the front link; a sliding guidance member that is fixedly installed on a bottom surface of the accommodation space in such as manner as to extend backward and forward, and guides linear backward and forward movements of the sliding member; an L-shaped main link of which a front end portion is connected by the hinge mechanism to a body of the front link and of which a rear upper end portion is connected by the hinge mechanism to a lower end portion of a seat back; a fixation bracket that is fixedly installed on an upper end portion of a rear wall of the accommodation space; and a rear support link of which a front upper end portion is connected by the hinge mechanism to a rear portion of the seat cushion, and of which a rear lower end portion is connected by the hinge mechanism to the fixation bracket. Thus, the stability of a seat and the prevention of shaking thereof can be achieved, and with a comparatively small force, the vehicle seat can be folded and accommodated into an accommodation space thereunder, or can be unfolded.