| 摘要 |
PROBLEM TO BE SOLVED: To provide a seat back frame capable of being made lightweight, and making a transverse frame efficiently exhibit high torsional rigidity.SOLUTION: A seat back frame includes side frames which vertically extend on right and left positions, and a transverse frame which connects both the side frames and horizontally extends, and a headrest fitting port is provided on the central part of the transverse frame. In the seat back frame, at least the transverse frame is made of resin; the transverse frame includes a U-shaped cross-sectional portion; the U-shaped cross-sectional portion extends along the extension direction of the transverse frame, including the installation portion of the headrest fitting port; and there is provided means for improving the torsional rigidity of the transverse frame when making the extension direction of the transverse frame to the U-shaped cross-sectional portion into the torsion shaft direction of the transverse frame. |
