To restrain stress concentration on a specific part, when reinforcing a curved part or the vicinity of its part of a vehicle body frame constituted by using a pipe material, by a reinforcing member.
A left side frame part 100L has a seat rail 140L, a sub-frame 150L, a gusset 160L and a reinforcing bracket 170L. The reinforcing bracket 170L is installed in the rear of a connecting part of the sub-frame 150L and the seat rail 140L. The reinforcing bracket 170L has an outside joining part 172L, an inside joining part 173L and an intermediate part 174L. In a tip part 170f of the reinforcing bracket 170L, the length L2 of the inside joining part 173L running along the longitudinal side of the sub-frame 150L, is shorter than the length L1 of the outside joining part 172L running along the longitudinal side.
OZAWA TOSHIAKI
Masakazu Ito
Shunichi Takahashi
Ichitaro Ito