Vehicle lower section structure

1. A vehicle lower section structure comprising:

a left and right pair of vehicle body frame members extending substantially along a vehicle front-rear direction;

a lower extension section joined to each of the left and right pair or vehicle body frame members, the lower extension section including:

a front lower extension section disposed at a predetermined position in the vehicle front-rear direction with respect to the vehicle body frame members and extending toward a vehicle lower side, and

a rear lower extension section disposed at a vehicle rear side of the front lower extension section and extending toward the vehicle lower side; and

a front-rear direction extension section that is disposed so as to bridge along the vehicle front-rear direction between the front lower extension section and the rear lower extension section, the front-rear direction extension section being provided with a lower arm support section that a lower arm is configured to be attached to so as to be pivotable in substantially a vehicle vertical direction, and the front-rear direction extension section being joined to the rear lower extension section at the vehicle rear side of the lower arm support section.

2. The vehicle lower section structure of claim 1 , wherein the rear lower extension section and the front-rear direction extension section are configured by discrete members.

3. The vehicle lower section structure of claim 2 , wherein at least one of a steering member or a stabilizer is configured to be disposed between the front lower extension section and the rear lower extension section.

4. The vehicle lower section structure of claim 1 , wherein a hound stopper is provided at the rear lower extension section so as to be capable of contacting the lower arm when the lower arm has pivoted toward substantially a vehicle upper side.

5. The vehicle lower section structure of claim 4 , wherein:

an inclined reinforcement section is formed at the rear lower extension section, the inclined reinforcement section being inclined toward a vehicle width direction inner side on progression toward the vehicle lower side and being joined to the front-rear direction extension section; and

the lower arm support sect on of the front-rear direction extension section is disposed at the vehicle lower side of a location where the inclined reinforcement section and the front-rear direction extension section are joined together.

6. The vehicle lower section structure of claim 5 , wherein:

the inclined reinforcement section includes a front face, a rear face facing the front face, and a collar provided between the front face and the rear face; and

the inclined reinforcement section is fastened to the front-rear direction extension section through a fastener that is inserted through the front face, the rear face, and the collar.

7. The vehicle lower section structure of claim 5 , wherein:

a contact reinforcement section that contacts a rear end portion of the front-rear direction extension section is attached to the inclined reinforcement section of the rear lower extension section; and

the contact reinforcement section is substantially plate-shaped, with a plate thickness direction thereof being substantially along the vehicle front-rear direction, and the contact reinforcement section is formed with a flange extending along the plate thickness direction.

8. The vehicle lower section structure of claim 1 , wherein an inclined portion is formed at a vehicle front side face of the front lower extension section, the inclined portion being inclined toward the vehicle rear side on progression toward the vehicle lower side.

9. The vehicle lower section structure of claim 1 , wherein the front lower extension section is respectively provided at the left and right pair of vehicle body frame members, and the front lower extension sections are linked together to each other in a vehicle width direction so as to form an integral body.