JPH05238419

PURPOSE:To improve the rigity by extending a middle cross member in the direction of width of a car on the rear end of a floor tunnel part, providing a rear frame extended backward on the right and left end areas thereof, and disposing a connecting frame between the rear frame and the middle cross member. CONSTITUTION:A middle cross member 26 is formed by a horizontal part 30 and a vertical part 31, in which flanges 30a, 30a are formed respectively, and a floor tunnel part 33 is positioned in front of the center of the middle cross member. Both side areas of the floor tunnel part 33 are extended downward and fixed to a floor 34 at the end areas thereof below the floor 34. Further, A rear frame is extended from both ends of the middle cross member 26 backward, and connected to the middle cross member by a connecting frame 29. Thus, the rigidity can be improved in a simple structure.