Vehicular exhaust structure

A vehicular exhaust structure is provided for exhausting gas used for cooling down a battery arranged under a seat in a vehicle into a luggage compartment of the vehicle behind the seat and including an underfloor storage box arranged under a deck board. The structure includes an exhaust duct and an exhaust conduit. The exhaust duct is arranged behind the battery with an inlet thereof located at a first end facing the battery and an outlet thereof located at a second end facing upward. The exhaust conduit includes a box section communicated with the outlet of the exhaust duct and defined by surfaces of a front portion of the underfloor storage box arranged over the outlet of the exhaust duct. One of the surfaces faces a back surface of a backrest of the seat and has a through hole that opens toward a front side of the vehicle.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2012-284916 filed on Dec. 27, 2012. The entire contents of the priority application are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a vehicular exhaust structure.

BACKGROUND

A known vehicle with an on-board battery as a power source, such as a hybrid vehicle and an electric vehicle, has a battery temperature control system that control a temperature of the on-board battery (battery pack) by blowing air to the battery. The air blown to the battery needs to be cooled down and exhausted. For such a purpose, an exhaust duct is provided in a luggage compartment of the vehicle. The exhaust duct extends from the luggage compartment to the outside and thus the exhaust air from the battery is discharged to the outside of the vehicle.

One example of such vehicles is described in Japanese published patent application No. 2010-149647.

The configuration with which the exhaust air from the battery is discharged to the outside of the vehicle may require a long exhaust duct. If the exhaust duct is long, the exhaust duct takes up a large part of space in the luggage compartment and thus a size of usable space in the luggage compartment decreases. This is not desirable. A configuration in which space between assembly parts of the luggage compartment (e.g., an underfloor storage box and a vehicle body is configured as a part of an exhaust path (instead of an exhaust duct) to reduce a length of the exhaust duct.

If the space between assembly parts of the luggage compartment is used as a part of the exhaust path, the airtightness of the exhaust path is low in comparison to an exhaust duct. Exhaust gas may leak from an unexpected part of the exhaust path such as space between assembly parts.

The leaking exhaust gas may make occupants of the vehicle uncomfortable. For example, cool air may be forced into the occupant side by the leaking exhaust gas and the occupants feel uncomfortable with the cool air. If a spare tire in the luggage compartment of the vehicle is exposed to the exhaust gas, the occupants may feel uncomfortable due to the smell of the spare tire.

SUMMARY

The technology described herein has been made in view of the aforementioned circumstances. An objective of the technology is to provide a door trim including a front trim and a rear trim with sufficient rigidity around a boundary between the front trim and the rear trim without additional reinforcement parts.

A vehicular exhaust structure is provided for exhausting gas used for cooling down a battery arranged under a seat in a vehicle into a luggage compartment of the vehicle behind the seat and including an underfloor storage box arranged under a deck board. The vehicular exhaust structure includes and exhaust duct and an exhaust conduit. The exhaust duct is arranged behind the battery with an inlet thereof located at a first end facing the battery and an outlet thereof located at a second end facing upward. The exhaust conduit receives an exhaust gas from the exhaust duct so as to direct the exhaust gas away from the battery. The exhaust conduit includes a box section communicated with the outlet of the exhaust duct and defined by surfaces of a front portion of the underfloor storage box arranged over the outlet of the exhaust duct. One of the surfaces of the front portion of the underfloor storage box faces a back surface of a backrest of the seat and has a through hole that opens toward a front side of the vehicle.

DETAILED DESCRIPTION

First Embodiment

A vehicle10is an electric vehicle or a hybrid vehicle in which a battery11is installed. In the vehicle10, front seats (not illustrated) and rear seats15are installed (seeFIG. 1).

Each rear seat15(a vehicular seat) includes a seat cushion15A and backrest15B. The seat cushion15A includes a seat surface on which an occupant of the vehicle10sits. The backrest15B supports a back and a lower back of the occupant. The backrest15B rises upward from a rear portion of the seat surface of the seat cushion15A.

The rear seat15includes a reclining mechanism (not illustrated) for adjusting a tilt of the backrest15B. A plurality of the rear seats15(two in this embodiment) are arranged in the width direction of the vehicle10in a compartment of the vehicle10.

In this embodiment, the seat cushions15A of the rear seats15are connected to each other. Angles of the backrests15B of the rear seats15are independently adjustable. The backrest15B of the left rear seat15is not illustrated inFIG. 1.

The battery11installed in the vehicle10includes two batteries. As illustrated inFIG. 2, one of the batteries is arranged on a floor panel12under the seat cushion15A of the rear seat15on the left. The other battery is arranged on the floor panel12under the seat cushion15A of the rear seat14on the right. Each battery is an assembled battery including a plurality of cells (unit cells) connected to each other. The battery is covered with a metal cover.

Examples of the cells in the battery include lead-acid cells, nickel-cadmium cells, and nickel-hydrogen cells. The configuration and the kind of the battery are not limited to the above described configuration and kind, and can be altered as appropriate.

As described above, the battery11installed in the vehicle10includes two batteries arranged under the respective rear seats15. In the following description, the battery arranged on the left is referred to as the left battery11A and the battery arranged on the right is referred to as the right battery11B.

A luggage compartment13(a luggage compartment of the vehicle) is provided behind the rear seats15. A schematic configuration of the luggage compartment13is illustrated inFIG. 2. The floor panel12has a recessed portion12A that is recessed downward and opens upward. The recessed portion12A can hold a spare tire therein.

As illustrated inFIG. 1, underfloor storage boxes17A,17B, and30that can hold articles therein are provided in the luggage compartment13. As illustrated inFIG. 2, the underfloor storage boxes17A (17B) and30are located above the spare tire14. The underfloor storage boxes17A,17B, and30are arranged around the spare tire14in plan view.

Specifically, the underfloor storage boxes17A and17B are arranged on the right rear side and the left rear side of the luggage compartment13. The underfloor storage box30is arranged on the front side of the luggage compartment13. As illustrated inFIGS. 1 and 2, the underfloor storage box30is located at about the same level as the lower end portion of the backrest15B.

The underfloor storage box30has an opening at the top and an inside of the underfloor storage box30is storage recess31. The underfloor storage box30can store articles in the storage recess31. The underfloor storage box17A has an opening at the top and an inside of the underfloor storage box17A is storage recess18A. The underfloor storage box17B has an opening at the top and an inside of the underfloor storage box17B is storage recess18B.

As illustrated inFIG. 2, two deck boards19and20are arranged in the front-rear direction of the vehicle (in the left-right direction inFIG. 2) in the luggage compartment13. The deck board19arranged more to the rear of the vehicle than the other deck board20is placed over the underfloor storage boxes17A and17B.

The deck board20is arranged so as to cover the underfloor storage box30and supported by a portion of the underfloor storage box30around the opening thereof.

The vehicle10includes an exhaust structure for exhausting air used to cool down the batteries11A and11B to the luggage compartment13. Next, the exhaust structure will be described in detail.

The exhaust structure is provided for exhausting air used to cool down the batteries11A and11B to the luggage compartment13via space between the front edge of the deck board20and the backrests15B. The exhaust structure includes air ducts25A and25B and exhaust conduits defined by front end portions of the underfloor storage box30, front end portions of the deck board20, and other parts of the vehicle10.

As illustrated inFIG. 3, the underfloor storage box30includes two parts arranged in the width direction of the vehicle10. In the following description, the part of the underfloor storage box30on the left is referred to as a left box assembly part30A and the part on the right is referred to as a right box assembly part30B.

Main portions of the exhaust structure for exhausting the air used for cooling down the battery11A include the exhaust duct25A and an exhaust conduit defined by the front end portion of the left box assembly part30A and the front end portion of the deck board20. Main portions of the exhaust structure for exhausting the air from the battery11B include the exhaust duct25B and an exhaust conduit defined by the front end portion of the right box assembly part30B and the front end portion of the deck board20.

The portions of the exhaust structure related to the battery11A and the portions of the exhaust structure related to the battery11B have similar configurations except for the exhaust ducts25A and25B that are symmetric. Therefore, the portions of the exhaust structure related to the battery11A will be mainly described in the following description.

As illustrated inFIGS. 2 and 3, the exhaust duct25A is arranged more to the rear of the vehicle10than the battery11A. The exhaust duct25A has a duct inlet at one of ends (a first end) thereof. The duct inlet opens toward the battery11A.

As illustrated inFIG. 2, the exhaust duct25A extends in the front-rear direction of the vehicle10so as to incline toward the upper rear of the vehicle. The upper end (a second end) of the exhaust duct25A opens toward the top of the vehicle10. The opening of the exhaust duct25A at the upper end is a duct outlet27having a rectangular shape.

As illustrated inFIGS. 3 and 4, the left box assembly part30A includes a box main body32and a deck-board support40. The box main body32includes a recess and a front horizontal wall33that extends horizontally toward the front side of the vehicle10from a top edge of a front wall of the storage recess31. The front horizontal wall33is not necessary to be perfectly horizontal. The deck-board support40is coupled to the front horizontal wall33.

The front horizontal wall33of the box main body32(the front end portion of the underfloor storage box) has a long dimension in the right-left direction of the vehicle10. The front horizontal wall33is placed so as to cover the duct outlet27from above. At a portion of the front horizontal wall33that overlaps the duct outlet27, a rectangular through hole extending in the top-bottom direction of the vehicle10is provided.

The exhaust duct25A has a flange28around the duct outlet27at the upper end (the second end) thereof. As illustrated inFIGS. 4 and 7, a sealing member28A having a rectangular frame-like shape is arranged on the upper surface of the flange28.

The flange28is attached to a hole edge portion33B of the front horizontal wall33around the through hole33A via the sealing member28A. Namely, the hole edge portion33B is configured as a flange holding portion for holding the flange28.

The deck-board support40is included in a front portion of the underfloor storage box30. As illustrated inFIGS. 3 and 7, the deck-board support40extends in the horizontal direction and has a long dimension in the width direction of the vehicle10. The deck-board support40opens downward. The deck-board support40is arranged over the duct outlet27and the through hole33A to cover the duct outlet27and the through hole33A from above. The deck-board support40is a part used for defining a box section R2of the exhaust conduit together with the front horizontal wall33.

As illustrated inFIG. 7, the deck-board support40includes a top wall41, a rear wall42, and a front wall43. The top wall41is horizontally arranged over the duct outlet27and the through hole33A. The rear wall42is a vertical wall that extends downward from the rear edge of the top wall41. The rear wall42is not required to be perfectly vertical. The front wall43extends downward from the front edge of the top wall41. The rear wall42defines the front end of the storage recess31together with the front wall of the recess of the box main body32.

The front horizontal wall33(a lower wall) is arranged below the top wall41of the deck-board support40and opposite the top wall41. The box section R2is defined by the top wall41, the rear wall42, the front wall43, and the front horizontal wall33.

As illustrated inFIG. 8, the top wall41includes a mount projection41A that projects toward the front horizontal wall33from the lower surface of the top wall41. The mount projection41A has a stopper on a sidewall thereof. The front horizontal wall33includes a protrusion34that protrudes upward in an area thereof corresponding to the mount projection41A. The protrusion34has a through hole34A in the top wall thereof. The mount projection41A is passed through the through hole34A until it stops. When the mount projection41A stops, the stopper of the mount projection41A is held against the edge of the through hole34A from below.

The front edge of the deck board20is placed on the upper surface of the top wall41of the deck-board support40. Namely, the top wall41is configured as a support wall for supporting the deck board20from below. The rear wall42of the deck-board support40is supported by the upper surface of the front horizontal wall33at the lower edge thereof.

The front wall43of the deck-board support40is supported by the upper surface of the front horizontal wall33at the lower edge thereof. As illustrated inFIG. 7, a rib45is provided on the inner surfaces of the deck-board support40. The rib45extends all the way along the front wall43, the top wall41, and the rear wall42. The rib45is provided for enhancement of the deck-board support40.

The front wall43is arranged opposite the back surface15C (a surface on the rear side in the vehicle interior) of the backrest15B. As illustrated inFIG. 3, the front wall43has box exhaust outlets43A (exhaust outlets formed in the underfloor storage box30) having a rectangular shape. As illustrated inFIG. 8, each box exhaust outlet43A is opposite the back surface15C of the backrest15B, namely, opens toward the front of the vehicle10.

The box exhaust outlet43A is configured such that a lattice43B is in the box exhaust outlet43A. Specifically, a plurality of through holes are formed in the front wall43so that the lattice43B is in the box exhaust outlet43A. With the lattice43B, foreign substances are less likely to enter into the inside of the deck-board support40through the box exhaust outlet43A.

The box section R2is configured to receive the air from the exhaust duct25A through the through hole33A (an inlet of the box section R2) and exhaust the air from the box exhaust outlet43A. With this configuration, the air exhausted from the duct outlet27of the exhaust duct25A passes through the through hole33A and the box section R2. Then, the air exits from the box exhaust outlet43A.

As illustrated inFIGS. 5 and 6, the box exhaust outlets43A are located more to the front of the vehicle10(more to the bottom inFIGS. 5 and 6) than the duct outlet27. Two of the box exhaust outlets43A are provided in the front wall43.

The box exhaust outlets43A are located side by side along the width direction of the vehicle10(the horizontal direction inFIGS. 5 and 6). One of the box exhaust outlets43A is offset from the corresponding duct exhaust outlet27toward one of the sides of the vehicle10. The other box exhaust outlet is offset from the corresponding duct exhaust outlet27toward the other side of the vehicle10.

The back surfaces15C of the backrests15B opposite the box exhaust outlets43A are covered by seat skins16, respectively. The seat skin16may be made of synthetic resin, hide such as cowhide (genuine leather), woven fabric, non-woven fabric, or other material. The material of the seat skin16can be selected where appropriate.

Each seat skin16includes an extension portion21that extends from the lower edge of the back surface15C of the backrest15B (a member arranged between the back surface of the backrest and the front wall). As illustrated inFIG. 8, the extension portion21is extended from the lower edge of the backrest15B to a front end portion of the front horizontal wall33(the end located closer to the front end of the vehicle10) with a sag. Namely, the extension portion21is draped from the front end portion of the front horizontal wall33toward the lower edge of the back surface15C. A distal end of the extension portion21(an end of the member arranged between the back surface of the backrest and the front wall) is fixed to the front end portion of the front horizontal wall33with a fixing member such as a pin22.

The exhaust conduit located between the back surface15C of the backrest15B and the box exhaust outlet43A includes a first space section R3and a second space section R4. The first space section R3is defined by a front portion of the deck board20, the front wall43, and the front horizontal wall33. The second space section R4is space between a front end of the first space section R3and the back surface15C of the backrest15B. The extension portion21covers the second space section R4from below. Namely, the lower end of the second space section R4is defined by the extension portion21. The exhaust air or articles in the second space section R4are less likely to roll into space under the rear seat15.

The lower edge of the back surface15C of the backrest15B that is in the upright position is located lower than the front horizontal wall33. Therefore, the extension portion21extending from the lower edge of the back surface15C to the front horizontal wall33is located lower than the box exhaust outlet43A. Space defined by the back surface15C of the backrest15B and the extension portion21is referred to as a lower space section21A.

The base end of the extension portion21of this embodiment moves along the movement of the backrest15B. If the backrest15B is tilted forward, the base end of the extension portion21is at a position higher than the front horizontal wall33. If the backrest15B is in the upright position, the base end of the extension portion21is at a position lower than the front horizontal wall33. With this configuration, the extension portion21does not disturb the movement of the backrest15B. InFIGS. 7 and 8, the extension portion21and the backrest15B when the backrest15B is tilted forward are illustrated with chain double-dashed lines.

Each box exhaust outlet43A is located below the deck board20and more to the rear of the vehicle10than the front edge of the deck board20. The front edge of the deck board20is separated from the back surface15C of the backrest15B by a gap S2.

The exhaust duct25A (a duct section R1) and the box section R2form a first exhaust path H1for directing the air used for cooling down the battery11A toward the back surface15C of the backrest15B. The first space section R3and the second space section R4form a second exhaust path H2for directing the air that exits from the box exhaust outlet43A to the luggage compartment13. The exhaust structure provides an exhaust path including the first exhaust path H1and the second exhaust path H2.

Next, the mechanism of the exhaust structure related to the battery11A will be described. Air is blown by a blower (not illustrated) such as a fan installed in the vehicle10toward the battery11A and the air cools down the battery11A. Then, the air is drawn into the exhaust duct25A through the duct inlet26of the exhaust duct25A. This airflow is indicated by arrow F1inFIG. 2.

The updraft air in the exhaust duct25A (the duct section R1) is drawn into the deck-board support40(the box section R2) through the duct outlet27and the through hole33A. This airflow is indicated by arrow F2inFIG. 7.

The air drawn into the deck-board support40is discharged from two box exhaust outlets43A. This airflow is indicated by arrow F3inFIG. 6. The air is directed from the box exhaust outlets43A toward the back surface15C.

In this embodiment, the first exhaust path H1is provided for discharging the air used for cooling down the battery11A toward the back surface15C of the backrest15B. The first exhaust path H1is provided by the duct section R1and the box section R2.

The air discharged from the box exhaust outlets43A (outlets of the first exhaust conduit) passes through a first space section R3defined by the deck board20and the front horizontal wall33, and then enters the second space section R4defined by the backrest15B and the underfloor storage box30.

The bottom of the second space section R4that is located between the backrest15B and the underfloor storage box30is defined by the extension portion21. Therefore, the air entering the second space section R4flows upward without flowing downward. As a result, the air discharged form the box exhaust outlets43A flows through the gap S2between the front edge of the deck board20and the back surface15C of the backrest15B and enters the luggage compartment (more specifically, space above the deck board20behind the backrest15B). This airflow is indicated by arrow F4inFIG. 8.

In this embodiment, the second exhaust path H2is provided for directing the air from the box exhaust outlets43A into the luggage compartment13(for directing the air from the box exhaust outlets43A to the gap S2). The second exhaust path H2is provided by the first space section R3defined by the deck board20and the front horizontal wall33and the second space section R4defined by the backrest15B, the underfloor storage box30, and the extension portion21.

The second exhaust path H2is located between the box exhaust outlets43A and the back surface15C of the backrest15B. The first end of the second exhaust path H2continues from the box exhaust outlets43A and the second end thereof is the gap S2(a second exhaust outlet that is an outlet of the second exhaust conduit).

As described above, the exhaust path including the first exhaust path H1and the second exhaust path H2is provided for directing the air used for cooling down the battery11A to the first exhaust path H1, to the box exhaust outlet43A, to the second exhaust path H2, to the box exhaust outlets43A, and then to the luggage compartment13.

Next, the effects of this embodiment will be described. According to this embodiment, the air is discharged from the box exhaust outlets43A toward the back surface15C of the backrest15B. With this configuration, the air used for cooling down the battery11A is less likely to leak from unexpected portions. Furthermore, a part of the exhaust conduit for the battery11A is defined by the front portion of the underfloor storage box30(the deck-board support40and the front horizontal wall33). Therefore, the exhaust structure is provided in simple configuration.

The front horizontal wall33of the underfloor storage box30is arranged over the duct exhaust outlet27such that the front horizontal wall33covers the duct exhaust outlet27from above. With this configuration, the duct exhaust outlet27is hidden by the underfloor storage box30and thus invisible to an occupant of the vehicle10from above.

The front portion of the underfloor storage box30includes the rear wall42, the top wall41, and the front wall43. The rear wall42defines a part of the storage recess31. The top wall41extends from the top edge of the rear wall42toward the front of the vehicle10and supports the deck board20arranged in the luggage compartment13from below. The front wall43extending downward from the front edge of the top wall41is arranged opposite the back surface15C of the backrest15B. The box section R2is defined by the rear wall42, the top wall41, and the front wall43. The box exhaust outlets43A are through holes that extend all the way through the front wall43.

By providing the exhaust conduit with the box section R2defined by the top wall41, which is a support wall for supporting the deck board20, the configuration of the exhaust conduit can be simplified.

The front portion of the underfloor storage box30includes the front horizontal wall33arranged below and opposite the top wall41. The box section R2is defined by the top wall41and the front horizontal wall33. The distal end of the extension portion21extending from the lower edge of the back surface15C of the backrest15B is fixed to the front end portion of the front horizontal wall33.

With this configuration, the space between the underfloor storage box30and the backrest15B can be closed with the extension portion21. Therefore, articles are less likely to fall into the space.

The exhaust duct25A has the flange28at the second end thereof. The front horizontal wall33has the through hole33A that is the inlet of the box section R2. The hole edge portion33B around the through hole33A is configured as a flange holding portion for holding the flange28.

With the configuration in which the flange28is held by the hole edge portion33B, the exhaust duct25A can be properly connected to the front horizontal wall33. As a result, the duct section R1and the box section R2are properly communicated.

The extension portion21is located below the box exhaust outlets43A.

With this configuration, articles dropped into the lower space section21A and received by the extension portion21are less likely to be at the height of the box exhaust outlets43S. Therefore, the articles are less likely to block the box exhaust outlets43A.

The exhaust structure includes the lower space section21A that is defined by the back surface15C of the backrest15B and the extension portion21. The lower space section21A is located lower then the first space section R3.

With this configuration, articles falling into the lower space section21A are held in the lower space section21A.

The extension portion21is a part of the seat skin16extending from the back surface15C of the backrest15B.

With this configuration, an additional part is not required to define a part of the lower end of the exhaust conduit. Therefore, the exhaust structure can be provided with a simple configuration. Furthermore, because the seat skin16is a designed part and the extension portion21is a part of the designed part, good appearance can be achieved.

The deck board20is arranged in the luggage compartment13. The box exhaust outlets43A are arranged below the deck board20and more to the rear of the vehicle10than the front edge of the deck board20.

With this configuration, air exits from the box exhaust outlets43A flows under the deck board20. Namely, the deck board20blocks updraft air.

The air used for cooling down the battery11A is discharged from the second exhaust outlet that is the gap S2between the front edge of the deck board20and the backrest15B of the rear seat15and directed to the luggage compartment13. With this configuration, the air used for cooling down the battery11A is less likely to leak from unexpected portions.

With the configuration in which air is exhausted from the second exhaust outlet that is the gap S2between the front edge of the deck board20and the backrest15B, the exhausted air is blocked by the backrest15B. Therefore, the exhausted air is less likely to flow toward an occupant of the vehicle10.

The gap S2between the front edge of the deck board20and the backrest15B of the rear seat15is configured as the second exhaust outlet. With this configuration, a distance from the battery11A to the second exhaust outlet (the gap S2) is relatively short. Additional parts are not required to configure the second exhaust outlet. Therefore, the exhaust structure can be provided with a simple configuration.

The box exhaust outlets43A open toward the back surface15C of the backrest15B. Namely, the box exhaust outlets43A open toward the front of the vehicle10.

With this configuration, exhausted air flows from the box exhaust outlets43A into the second space section R4(the second exhaust path H2). When the exhausted air hits the back surface15C of the backrest15B, the flow speed thereof decreases. Therefore, the exhausted air does not flow over the rear seat15and reach the occupant side.

The exhaust duct25A includes the duct inlet26at the first end and the duct outlet27at the second end. The duct outlet27opens upward. The box exhaust outlet43A is offset from the duct exhaust outlet27toward one of the sides of the vehicle10.

With this configuration, the exhaust air from the duct exhaust outlet27hits an area of the front wall43in which the box exhaust outlet43A is not provided. In comparison to a configuration in which the duct exhaust outlet27and the box exhaust outlet43A are aligned with respect to the front-rear direction of the vehicle10, the volume flow rate of the exhaust air that flows from the duct exhaust outlet27toward the front side of the vehicle10via the box exhaust outlet43A can be reduced. Namely, the volume flow rate of the exhaust air from the box exhaust outlet43A toward the back surface15C of the backrest15bcan be reduced.

Second Embodiment

A second embodiment will be described with reference toFIG. 9. The same components as those in the first embodiment will be indicated with the same symbols and will not be described. This embodiment includes an underfloor storage box130including a box assembly part130A that has a different configuration from the box assembly part30A.

As illustrated inFIG. 9, the box assembly part130A includes a box main body132having a front portion133that slopes downward in the rear-to-front direction of the vehicle10. The front portion133includes a downslope portion133A located more to the front of the vehicle10than the box exhaust outlets43A.

The front portion133defines a lower edge of the box exhaust outlet43A. Because the front portion133slopes downward and the downslope portion133A that is located more to the front of the vehicle10than the box exhaust outlet43A slopes downward, articles dropped on the downslope portion133A is less likely to move toward the box exhaust outlet43A (toward the rear of the vehicle10).

In this embodiment, the extension portion21of the first embodiment is not provided. Instead of the extension portion21, an extension portion121that extends from the front edge of the downslope portion133A to the back surface15C of the backrest15B (a member arranged between the back surface of the backrest and the front wall) is provided. The extension portion121defines the lower end of the second space section R4that is located between the back surface15C of the backrest15B and the box exhaust outlets43A. With this configuration, the exhaust air or articles in the second space section R4are less likely to roll into space under the rear seat15.

Effects

According to a first aspect, the vehicular exhaust structure includes and exhaust duct and an exhaust conduit. The exhaust duct is arranged behind the battery with an inlet thereof located at a first end facing the battery and an outlet thereof located at a second end facing upward. The exhaust conduit receives an exhaust gas from the exhaust duct so as to direct the exhaust gas away from the battery. The exhaust conduit includes a box section communicated with the outlet of the exhaust duct and defined by surfaces of a front portion of the underfloor storage box arranged over the outlet of the exhaust duct. One of the surfaces of the front portion of the underfloor storage box faces a back surface of a backrest of the seat and has a through hole that opens toward a front side of the vehicle.

With this configuration, the gas is exhausted toward the back surface of the backrest through the through hole of the surface facing the back surface of the backrest. Therefore, the gas used for cooling down the battery is less likely to leak from unexpected portions. Furthermore, a portion of the exhaust structure is defined by the surfaces of the front portion of the underfloor storage box. The exhaust structure can be provided with a simple configuration.

The front portion of the underfloor storage box may be arranged over the outlet of the exhaust duct. Because the outlet of the exhaust duct is covered with the front portion, the outlet is not recognized by an occupant of the vehicle.

According to a second aspect, the box section of the exhaust conduit may be defined by the surfaces of a rear wall, a top wall, and a front wall of a deck-board support of the underfloor storage box for supporting the deck board from below. The deck-board support is a part of the front portion of the underfloor storage box. The rear wall extends upward at a front end of a storage recess of the underfloor storage box. The top extends from a top edge of the rear wall toward the front side of the vehicle. The front wall extends downward from a front edge of the top wall. The front wall includes the surface having the through hole.

By defining the box section of the exhaust conduit by the top surface of the deck-board support that supports the deck board, the configuration of the exhaust structure can be further simplified.

According to a third aspect, the box section of the exhaust conduit may be further defined by a top surface of a horizontal wall of the front portion of the underfloor storage box. The horizontal wall extends from the front end of the storage recess toward the front side of the vehicle and is located below the top wall of the deck-board support.

According to a fourth aspect, the box section of the exhaust conduit may be communicated with the outlet of the exhaust duct through a through hole in the horizontal wall. The exhaust duct may have a flange around the outlet thereof at the second end. The flange is held against a portion of the horizontal wall around the through hole.

With the configuration in which the flange is held against the portion of the horizontal wall around the through hole, the box section is further certainly communicated with the outlet of the exhaust duct.

According to a fifth aspect, the exhaust conduit may include a space section defined by a top surface of a front end portion of the horizontal wall in front of the front wall of the deck-board support, the back surface of the backrest, and a member arranged between the back surface of the backrest and the front wall.

With this configuration, the gas exhausted from the through hole of the front wall of the deck board support is directed toward the back surface of the backrest and then toward the luggage compartment.

According to a sixth aspect, the exhaust conduit may include a space section defined by a top surface of a front end portion of the horizontal wall in front of the front wall of the deck-board support, the back surface of the backrest, and a part of a seat skin extended from a lower end portion of the backrest with a distal end thereof fixed to the top surface of the front end portion of the horizontal wall.

With this configuration, the space between the deck box and the backrest is closed at a lower end thereof by the part of the seat skin. Articles are less likely to fall farther than the part of the seat skin.

According to a seventh aspect, the space section may be further defined by a lower surface of a front portion of the deck board located more to the front side of the vehicle than the front wall of the deck-board support and opposite the top surface of the front end portion of the horizontal wall.

With this configuration, the space section, the gas exhausted from the through hole of the front wall of the deck board support is directed under the deck board, the gas is less likely to flow upward immediately after it exits from the through hole.

According to an eighth aspect, the exhaust conduit may have an opening between a front surface of the deck board and a portion of the back surface of the backrest opposite the front surface of the deck board.

With this configuration, the exhaust gas is blocked by the backrest and thus the exhaust gas is less likely to flow toward the front of the vehicle.

According to a ninth aspect, a rear end of the box section may be closed by the rear wall of the deck board support and the horizontal wall of the front end portion of the underfloor storage box.

With this configuration, the gas is less likely to leak toward the rear of the vehicle.

According to a tenth aspect, the exhaust structure may further include a sealing member attached to a lower surface of the horizontal wall of the front portion of the underfloor storage box around the through hole therein. The upper surface of the flange of the exhaust duct is held against the portion of the horizontal wall via the sealing member.

With this configuration, a gap is less likely to form between the horizontal wall and the flange of the exhaust duct. Therefore, the gas is less likely to leak from between the horizontal wall and the flange.

According to an eleventh aspect, the exhaust conduit may include a space section defined by a top surface of a front end portion of the horizontal wall in front of the front wall of the deck-board support, the back surface of the backrest, and an extension portion of the front portion of the underfloor storage box extending from a front edge of the horizontal wall to the back surface of the backrest.

With this configuration, the space between the deck box and the backrest is closed at a lower end thereof by the extension portion. Articles are less likely to fall farther than the extension portion.

According to a twelfth aspect, a part of the space section may be defined by the extension portion that slopes downward.

With this configuration, if articles drop onto the extension portion, the articles are less likely to move toward the through hole of the front wall of the deck board support (the rear of the vehicle).

According to a thirteenth aspect, a part of the space section may be defined by the top surface of the front end portion of the horizontal wall that slopes downward.

With this configuration, if articles drop onto the horizontal wall, the articles are less likely to move toward the through hole of the front wall of the deck board support (the rear of the vehicle).

According to a fourteenth aspect, a part of the box section may be defined by the front wall that further includes a lattice in the through hole.

With this configuration, articles or foreign substances are less likely to enter into the deck board support.

According to a fifteenth aspect, a method may be provided for exhausting gas used for cooling down a battery arranged under a seat in a vehicle into a luggage compartment of the vehicle behind the seat and including an underfloor storage box arranged under a deck board. The method includes: directing the gas from the battery to a front portion of the underfloor storage box; passing the gas to space between the deck board and the front portion of the underfloor storage box through a through hole in the front portion; directing the gas from the space toward a front side of the vehicle; directing the gas upward with a back surface of a backrest of the seat; and exhausting the gas to the luggage compartment through a gap between the back surface of the backrest and a front surface of the deck board opposite the back surface of the backrest.

According to technologies described herein, the gas used for cooling down the battery is less likely to leak from unexpected portions.

Other Embodiments

The technology described herein is not limited to the above embodiments described in the above description and the drawings. The technology described herein may include the following embodiments.

(1) The exhaust structure may be installed in a two-seater vehicle including only a front row of seats (driver's seat and passenger's seat). The rear seats in the above embodiment can be applied to the front seats in the two-seater vehicle.

(2) The box exhaust outlets43A may be aligned with the front edge of the deck board20with respect to the front-rear direction of the vehicle10.

(3) The front horizontal wall33of the box main body32of the first embodiment may be tilted downward from the rear-to-front direction of the vehicle10.

(4) The shape of the exhaust duct25A or the direction in which the exhaust duct25A extends may be altered where appropriate. For example, a part of the exhaust duct25A may extend in the horizontal direction (the width direction) of the vehicle10.