Patent ID: 8899667

Claim:
A vehicle body rear part comprising: a back door opening section of a round structure provided in a vehicle body rear part; a rear side member hat-shaped in cross-section opened in an upper part that extends in a vehicle front-back direction provided on both left and right sides of a rear floor; a lower part of said back door opening section provided in a position higher than said rear side member, said rear floor is divided into a rear center floor and rear side floors on both the left and right sides with said rear side member placed therebetween in a vehicle width direction; a plurality of rear wheel house inner panels arranged adjacent to said rear side member; in said rear side members, rear side member upper panels configured to close an opening in the upper part of the rear side member and joined to flanges on both the left and right sides; the rear side member upper panels further including a plurality of upright sections extending upward in the vehicle at rear ends of said rear side member upper panels, said upright sections being joined to the lower part of said back door opening section and standing in an “L” shape, the thickness of the upright sections being set greater than the thickness of other peripheral components, wherein: in outer side sections of said rear side member upper panels, joining flanges standing upright opposed to said rear wheel house inner panels are provided along the vehicle front-back direction; said rear side member upper panels are joined to said rear wheel house inner panels via said joining flanges; in a position higher than said rear side member upper panels, a closed cross-section in the lower part of said back door opening section is provided; both left and right side portions in the vehicle width direction and standing portions standing from both the left and right side portions in a lower portion of the round structure of said back door opening section are configured by a pillar section, said pillar section standing from the lower part of said back door opening section is formed by a continuous closed cross-section; and the upright sections of said rear side member upper panels are joined to a member that forms the closed cross-section of said pillar section; and a reinforcing member connecting at least one of the upright sections of the rear side member upper panel and a lower part of the pillar section is provided along the vehicle up-down direction, an upper end of the reinforcing member is joined to the lower part of the pillar section, a lower end of the reinforcing member is joined to an upper end of the upright section of the rear side member upper panel, and the upright section of the rear side member upper panel and a member configuring a closed cross-section of the pillar section are coupled via the reinforcing member.