To reduce a burden of an occupant when a vehicle collides.

This head restraint device 10 has a belt type air bag 16, a connecting member 40 to which an upper end of the belt type air bag 16 is connected, an actuator 42 to move the connecting member 40 upward in collision and a high pressure gas generator 44 to expand the belt type air bag 16 by supplying high pressure gas to it in collision. The actuator 42 raises the connecting member 40 immediately after detecting collision, the high pressure gas is supplied to the belt type air bag 16 and a bag 16a of the air bag 16 is instantly expanded. The occupant D tends to move in the vehicle proceeding direction (X direction) as speed of the vehicle is reduced by collision, and consequently, a jaw and a chin of a head part Da of the occupant D are restrained by the risen bag 16a of the air bag 16.

COPYRIGHT: (C)2007,JPO&INPIT