An active headrest apparatus for a vehicle seat according to the present invention, is attached to the upper side of the seat frame constituting the seat in an active headrest apparatus for a vehicle seat that projects the headrest formed on the sheet by an external impact, the upper side of the seat frame is vertically upright consists of a bracket shape to be bent so that one side is open to, the guide sphere made of a long hole in the form of a bilateral stop is formed, and both sides of the top with a guide that is made in the form of a semicircle at one side a portion forming pin seat being stepped Brackets; Seating plate which is secured to the seat frame to the bottom of the guide bracket; So that the guide bracket disposed on the upper side of the operation to be seated in the longitudinal direction of the pin seating portion pin; It is formed on the inner side of the guide bracket, locking by receiving the stop of one side of the operating pin which is adapted to be rotated on the pins by the impact detecting operation member driven by an external impact, forming a ring on the lower side; A return spring which is fastened to the operating pivot pin for pivoting the rocker to its original position by the elasticity; Jidoe done in yeonjangche extending in the receptor, and both sides of the receptor which one side is open to receive the open side of the guide bracket, at the same time guide bracket soon as sandwiched so that the ground in the lower portion of the ring shape of the rocker in the open inner side of the receptor nine vertical guide and guide from a guide through the nine, are formed in the lower part of the rocker body guide jams when the guide pipe bracket upward vertical movement takes place; The upper spring is fixed to the lower end of the pipe bracket and the top of the yeonjangche applying an elastic force to the upper side so as to be movable in the pipe bracket is fixed to the upper seat frame; And wherein each of the end side of the ground yeonjangche, the lower end of the headrest toward the image side is accommodated armature member for projecting the headrest upward by the vertical movement of the pipe bracket; it characterized in that the made of.
Thus, the present invention is to armature member is the upper side of the rocker has accommodate fixed by the pipe bracket and the headrest to be moved to the guide body upper side by the elastic force of the upper spring rocker when rotated by the impact detecting member operated by an external impact caused by the vehicle collision since the movement is fixed, according to the collision of the vehicle is moved to the head rest is upper been the occupant body protection giving bathyeo the neck or head of a passenger improve the stability of the vehicle while still a high price of the upper physically headrest without electrical devices to operate by projecting simple and quickly with the result that the headrest operation.