US Patent 10183705 Lower vehicle-body structure of vehicle

In a lower vehicle-body structure of a vehicle which comprises a suspension cross member, a side member, and first and second reinforcing members which are provided in a closed cross section formed by the side member and a slant portion, the suspension cross member being fixed by fastening a bolt which is inserted through the suspension cross member to a weld nut which is vertically fixed to a bottom plate portion of the side member, the first reinforcing member is joined to a front-side semicircular portion of a peripheral portion of the weld nut and the second reinforcing member is joined to a rear-side semicircular portion of the peripheral portion of the weld nut.