Vehicle rear structure

1. A vehicle rear structure comprising:

an impact beam extending in a vehicle front-rear direction inside a rear door;

a rocker outer rear and a rocker inner rear extending upward in a vehicle up-down direction from a rear portion of a rocker in the vehicle front-rear direction;

a rear wheel house outer including a front portion extending in the vehicle front-rear direction and placed between the rocker outer rear and the rocker inner rear; and

a bulk including:

a first wall provided between the rocker outer rear and the rocker inner rear and joined to the rocker outer rear;

a second wall bending from the first wall to extend toward the rocker inner rear; and

a third wall placed at a position where the third wall at least partially overlaps with the impact beam as viewed in a vehicle width direction, the third wall bending from the second wall and joined to the front portion of the rear wheel house outer.

2. The vehicle rear structure according to claim 1 , wherein

the third wall is joined to the front portion of the rear wheel house outer at a plurality of points which differ in position from each other at least in the vehicle front-rear direction.

3. The vehicle rear structure according to claim 1 , wherein

the second wall extends in a direction parallel to an extending direction of the impact beam as viewed in the vehicle width direction.

4. The vehicle rear structure according to claim 1 , wherein

a joining portion between the third wall and the front portion of the rear wheel house outer is provided at a position overlapping with the impact beam or on an extension line of the impact beam in an extending direction of the impact beam as viewed in the vehicle width direction.

5. The vehicle rear structure according to claim 1 , wherein:

the second wall includes a front-side portion placed at a position overlapping with the impact beam as viewed in the vehicle width direction, and a rear-side portion placed behind the front-side portion at a position that does not overlap with the impact beam as viewed in the vehicle width direction; and

a length of the rear-side portion of the second wall in the vehicle front-rear direction is equal to or longer than a length of the front-side portion of the second wall in the vehicle front-rear direction.

6. The vehicle rear structure according to claim 1 , wherein:

the bulk includes a fourth wall bending from a front end portion of the second wall to extend downward in the vehicle up-down direction;

the fourth wall includes an upper-side portion placed at a position overlapping with the impact beam as viewed in the vehicle width direction, and a lower-side portion placed below the upper-side portion in the vehicle up-down direction and not overlapping with the impact beam as viewed in the vehicle width direction; and

a length of the lower-side portion of the fourth wall in the vehicle up-down direction is equal to or longer than a length of the upper-side portion of the fourth wall in the vehicle up-down direction.

7. The vehicle rear structure according to claim 1 , wherein:

the rear wheel house outer includes a lateral extension portion bending from a rear end portion of the front portion in the vehicle front-rear direction so as to extend outwardly in the vehicle width direction;

the front portion and the lateral extension portion of the rear wheel house outer are joined to the rocker outer rear so as to form a closed section together with the rocker outer rear; and

the bulk is provided inside the closed section.

8. The vehicle rear structure according to claim 1 , wherein the third wall extends downward in a vehicle up-down direction from the second wall.