Seat back panel, seat back frame and vehicle seat

A seat back frame comprising:

• a frame main body provided at a seat back of a vehicle seat, the frame main body being formed in a frame shape as seen in a front-and-rear direction of the seat back;
• and
• a seat back panel being disposed at a rear side of the seat back relative to the frame main body, the seat back panel comprising:
• a panel main body disposed at a posterior portion of the seat back of the vehicle seat, the panel main body structuring a portion of a main body portion of the seat back frame, and an aperture being formed in the panel main body at a location opposing a dorsal region of a seat occupant;
• and
• a separate panel attached to the main body portion and closes up the aperture, and at a time of a rear-end collision of a vehicle, the separate panel receiving a load from the dorsal region and relatively displacing toward the rear side of the seat back with respect to the panel main body,
• wherein the panel main body is fixed to the frame main body and structures the main body portion,
• wherein the separate panel is coupled to the main body portion via a resilient member, and configured to be retained at a usual position that closes up the aperture of the panel main body during usual times when no rear-end collision load is applied,
• wherein the separate panel comprises an abutting portion that abuts against a rim portion of the aperture from the rear side of the seat back, and
• wherein distal end portions of the abutting portion of the separate panel are inflected toward a front side of the seat back and inserted into penetrating holes formed in the panel main body.