Torsion beam suspension

Abstract

In a torsion beam suspension including: a pair of left and right trailing arms; a torsion beamproviding connection between the trailing arms; and gussetswhich are U-shaped in section and substantially triangular in plane view and which are welded to inner side surfaces of connecting portions between the trailing armsand the torsion beam, seat surfacesare formed by crushing at left and right opposite end portions of a rear wallof the torsion beam, the seat surfacesbeing offset forward from a general outer surface of the rear wallby an amount e larger than a plate thickness t of the gussets, and each gussetincludes an inner end edge portionsuperposed on an intermediate portion in a lateral direction of the seat surface, and upper and lower front edge portionsconnected by a weld Wto upper and lower portions of an outer surface of the torsion beam. Thus, in the torsion beam, an abrupt increase in torsional rigidity is suppressed in the gusset inner end portion without reducing strength of the torsion beam to alleviate stress concentration, thereby providing a torsion beam suspension having a high durability.