Patent attributes
A back frame attachment structure, wherein a hack frame includes a pair of side frames, wherein a lower end portion side of the side frame is attached to an upper portion of a lower arm member whose lower portion is fixed to a vehicle body side member, wherein the lower arm member includes two plate-like members superimposed with each other in a seat width direction, the upper portion and the lower portion being connected to each other by a front connection portion and a rear connection portion which are separated by a through-hole, and wherein, when a large load is applied to the back frame, the two plate-like members are configured to absorb energy by being deformed to be separated from each other in the seat width direction by a compressive load in an upper and lower direction generated in the front connection portion or the rear connection portion.
