US Patent 7819428 Vehicle frame structure

A frame structure is provided in which a sub-frame is fixed to a rear portion of a vehicle body frame, and serves as a suspension-supporting portion of the vehicle body frame. In the sub-frame, a rear member extends between a sub-frame upper pipe and a sub-frame lower pipe. The rear member includes a rear upper arm supporting portion and a rear lower arm supporting portion, for supporting proximal ends of an upper arm and a lower arm of a rear suspension. The frame structure hereof improves accuracy and rigidity of the suspension-supporting portion of the vehicle body frame, and provides a simplified structure as compared to conventional frame structures.