Patent ID: 7950724

Claim:
A vehicle body rear structure, comprising: first and second rear frames disposed respectively on each side of a vehicle body; and first and second tank lower frames disposed respectively beneath the rear frame on the each side of the vehicle body, wherein the rear frames have a load-displacement characteristic having a ratio F/S of load F to displacement S larger than the ratio F/S of the tank lower frames, and a cross sectional deformation of the tank lower frames is suppressed so that the load F does not rapidly decrease after reaching a maximum of a bending strength, the vehicle body rear structure, further comprising: a rear floor end cross member ( 6 ) jointed to each rear end of the rear frames, a rear floor cross member ( 10 ) located ahead of the rear floor end cross member ( 6 ) and extending in the vehicle width direction and jointed to each of the rear frames, a middle floor cross member ( 3 ) extending in the vehicle width direction to be jointed to each of front floor frames ( 7 a ) and each of side sills ( 5 ); a rear floor panel extending toward a rear portion of the vehicle body (B) from the middle floor cross member ( 3 ), a pair of spare pan frames ( 9 ) extending in the front-rear direction between the rear floor end cross member ( 6 ) and rear floor cross member ( 10 ) and jointed to the rear floor end cross member ( 6 ) and rear floor cross member ( 10 ), each of the spare pan frames ( 9 ) being arranged to be located on each side of a spare pan which is disposed in a rear portion of the rear floor panel and having a concave portion for storing a spare tire, and the spare pan frames ( 9 ) being disposed substantially horizontally from the rear floor end cross member ( 6 ) to rear floor cross member ( 10 ), wherein each rear end of the tank lower frames is jointed to substantially a center of the rear floor cross member ( 10 ) in the vehicle width direction, each of the tank lower frames extends substantially in a V-shape toward each side of the vehicle body (B) from the rear floor cross member ( 10 ), and each front end of the tank lower frames is jointed to a portion close to a place, where the middle floor cross member ( 3 ) is jointed, of each of the side sills ( 5 ), wherein the tank lower frames are disposed beneath the rear frames and a fuel tank (T), and extend substantially horizontally toward the middle floor cross member ( 3 ) from the rear floor cross member ( 10 ), and a horizontal height of the tank lower frames is set to be substantially identical to the height of the spare pan frames ( 9 ).