Seat cushion frame structure of seat for vehicle and seat for vehicle with seat cushion frame structure

A seat cushion frame structure of a seat for a vehicle comprises a seat cushion frame structure a rear end of which is connected to a lower end of a seat back frame structure in such a way that the seat back frame structure can be inclined relative to the seat cushion frame structure, said seat cushion frame structure includes a pair of side frames, each of which extends in a longitudinal direction of the vehicle, and an oblique wire on at least one of said pair of side frames, an upper end of which is fixed to a side portion of said at least one of pair of side frames and a lower end of which is fixed to said seat cushion frame structure at a position forward of said upper end, said oblique wire includes a characteristic such that, in a case where a load toward a rear side of the vehicle is loaded on said seat cushion frame structure, it has a tension force exerted on said seat cushion frame structure so as to alleviate a moment acting on said seat cushion frame structure caused by said load, while it does not resist a compressive force from outside thereof wherein a reinforcing bracket which extends in the longitudinal direction of the vehicle around an edge portion on the lower side of the vehicle and tapers in such a way that its width in the vertical direction is increased as a longitudinal position approaches the rear end of the vehicle and includes a flange on its upper and lower edges, respectively, is provided on at least one of said pair of side frames on which said oblique wire is provided.