Vehicular battery pack device

1. A battery pack device in which a battery module is incorporated in a battery case and a rear floor panel is disposed between a rear seat and a back panel that is disposed in a rear of the rear seat, and which is mounted on a vehicle body via a subframe so as to be disposed in an opening of the rear floor panel, and is provided with an air intake duct through which to send a cooling wind to inside the battery case and an air discharge duct through which to discharge air from inside the battery case, wherein:

the subframe has a support frame which surrounds the battery case and a support member which is attached to a rear end portion of the support frame so as to extend downward so that its bottom end portion is located below a bottom-front portion of a rear bumper;

a bottom cover is attached to the subframe so as to cover a bottom portion of the battery case;

a rear end portion of the bottom cover is provided with a guide plate which covers a bottom portion of a space interposed between the battery case and the rear bumper, is opposed to the rear bumper with a gap formed in between, and is supported by the bottom end portion of the support member; and

an air outlet of the air discharge duct is opened in a first space that is surrounded by the guide plate, the rear bumper, a rear side surface of the battery case, a rear side surface of the support member, and the rear floor panel.

2. The battery pack device according to claim 1 , wherein:

second spaces are formed outside two respective end portions, in the vehicle width direction, of the guide plate so as to have respective openings in front of the rear bumper at the bottom of the vehicle;

the air outlet is opened at the center of the first space in the vehicle width direction, and back panel is disposed between the air outlet and the rear bumper in the vehicle front-rear direction so as to extend in the vehicle width direction; and

the back panel is formed with first slant surfaces which extend in the vehicle width direction and incline rearward as the position goes outward in the vehicle width direction so as to extend from a position opposed to the air outlet to positions adjacent to the second spaces, respectively.

3. The battery pack device according to claim 2 , wherein the back panel is formed with a second slant surface which extends in the vehicle top-bottom direction and inclines rearward as the position goes downward so as to extend from a position opposed to the air outlet to a position adjacent to the gap.

4. The battery pack device according to claim 3 , wherein the support member inclines so that its bottom portion is located in the rear of its top portion, and a rear slant surface of the support member is set parallel with the second slant surface of the back panel.

5. The battery pack device according to claim 1 , wherein a shield plate is attached to the support member so as to cover the support member from behind in the vehicle front-rear direction and to extend from a position the same in height as the support frame to the guide plate.

6. The battery pack device according to claim 2 , wherein a shield plate is attached to the support member so as to cover the support member from behind in the vehicle front-rear direction and to extend from a position the same in height as the support frame to the guide plate.

7. The battery pack device according to claim 3 , wherein a shield plate is attached to the support member so as to cover the support member from behind in the vehicle front-rear direction and to extend from a position the same in height as the support frame to the guide plate.

8. The battery pack device according to claim 4 , wherein a shield plate is attached to the support member so as to cover the support member from behind in the vehicle front-rear direction and to extend from a position the same in height as the support frame to the guide plate.