Pillar framework structure and vehicle body module structure

1. A pillar framework structure comprising:

a pillar lower that extends in a vehicle vertical direction;

a joining member that is joined to an upper portion of the pillar lower, and that is configured from die-cast aluminum; and

a pillar upper that is joined to the joining member, and that extends in a vehicle upward direction and a vehicle rearward direction.

2. The pillar framework structure of claim 1 , wherein:

the joining member is provided with an extension portion extending toward a vehicle width direction inner side; and

the extension portion is joined to an end portion of a cowl reinforcement extending in a vehicle width direction.

3. The pillar framework structure of claim 2 , wherein, in the joining member, each of a lower joining portion that is joined to the pillar lower in a state in which the pillar lower is inserted into the lower joining portion, an upper joining portion that is joined to the pillar upper in a state in which the pillar upper is inserted into the upper joining portion, and the extension portion, which is joined to the cowl reinforcement in a state in which the cowl reinforcement is inserted into the extension portion, is formed with a U-shaped cross-section profile as viewed along a respective insertion direction of the respective portion.

4. The pillar framework structure of claim 3 , wherein:

the upper joining portion and the lower joining portion are formed so as to be continuous with one another in the vehicle vertical direction; and

the upper joining portion and the lower joining portion are open toward a vehicle width direction outer side.

5. The pillar framework structure of claim 3 , further comprising a weld portion at a step formed by a wall of the cowl reinforcement and an end face of the extension portion.

6. A vehicle body module structure comprising the pillar framework structure of claim 1 , wherein:

the vehicle body module structure includes a roof module including the pillar upper and an underside module including the pillar lower, as a plurality of vehicle body modules configuring a vehicle body; and

the roof module and the underside module are fastened together using a bolt to form a pillar that includes the pillar upper and the pillar lower.

7. The vehicle body module structure of claim 6 , wherein the vehicle body is formed by:

fixing the joining member to one of the pillar upper or the pillar lower in advance by welding; and

fastening the joining member to the other of the pillar upper or the pillar lower using the bolt.