Vehicle underbody structure

A vehicle underbody structure, comprising:

• a pair of left and right floor frames that are provided between a pair of rockers and are provided so as to respectively extend along a vehicle front-rear direction;
• a floor tunnel provided between the floor frame on the left side and the floor frame on the right side, the floor tunnel comprising a tunnel portion that bulges upwards and opens downwards;
• and
• a brace comprising:
• a front-side coupling member fixed to the floor tunnel at both left and right sides of the tunnel portion so as to straddle the tunnel portion;
• a rear-side coupling member provided at a rear of the front-side coupling member, with one end side of the rear-side coupling member fixed to one of the floor frames, and with the other end side of the rear-side coupling member fixed to the other of the floor frames;
• and
• a load transmission section that connects the front-side coupling member to a portion of the rear-side coupling member further towards a left-right direction central side than a coupling portion of the rear-side coupling member to the floor frames, wherein the load transmission section comprises a pair of left and right outside load transmission members configured such that a length direction rear end of each of the outside load transmission members is connected to the rear-side coupling member further towards the left-right direction outer side than the length direction front end of the outside load transmission members and further towards the left-right direction central side than the coupling portion of the rear-side coupling member to the floor frames.