VEHICLE SEAT STRUCTURE

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The invention relates to a vehicle seat structure that allows the air heated by a battery pack arranged under a vehicle seat (heated air) to be appropriately discharged into a passenger compartment.

2. Description of the Related Art

[0002] According to a technology described in Japanese Patent Application Publication No. 2001-354039 (JP-A-2001-354039) (refer to FIGs. 4 and 5, etc.), a relatively high-capacity power supply device (battery pack) for, for example, an electric vehicle or a hybrid vehicle is arranged under a seat base of a vehicle seat, and the air heated due to cooling of the battery pack is discharged to the outside of the vehicle via an exhaust duct. According to another technology, the heated air is discharged directly into a passenger compartment.

[0003] Japanese Patent Application Publication No . 2004- 16569 (JP-A-2004- 16569) (refer to FIGs. 2 and 3, etc.) describes a vehicle seat structure that allows the air from an air blower provided inside a vehicle seat to be discharged into a passenger compartment. With this vehicle seat structure, the air from the air blower is not directly discharged into the passenger compartment, instead the air is directed to a space formed inside the seat, and then discharged from the space into the area behind the vehicle seat in the passenger compartment.

[0004] Other related technologies are described in Japanese Patent Application Publication No. 2004-17855 (JP-A-2004- 17855) and Japanese Patent Application Publication No. 2006-137405 (JP-A-2006- 137405).

[0005] However, the vehicle seat structure described in JP-A-2001-354039, which allows the air heated by the battery pack to be discharged to the outside of the vehicle through the exhaust duct, is complicated, because the exhaust duct needs to be arranged inside the passenger compartment, an opening that provides communication between the

passenger compartment and the outside of the vehicle needs to be formed in a vehicle body, etc. This structure increases the number of components, which incurs a cost increase. In addition, discharging the heated air through the exhaust duct involves a problem that noise may be caused by, for example, an air-blowing fan.

[0006] Also, discharging the air heated by the battery pack directly into the passenger compartment is not preferable, because the air heated by the battery pack, which flows from under the vehicle seat, directly hits mainly the lower body of a passenger, which may cause the passenger to feel uncomfortable.

[0007] According to the technology disclosed in JP-A-2004- 16569, the problem that the exhaust air from the air blower arranged inside the seat intensively hits a passenger sitting in a rear seat is avoided by once taking the exhaust air into the space inside the seat, and then discharging the exhaust air to the rear of the seat at a reduced rate (speed) through a relatively large discharge port that provides communication between the space and the passenger compartment. However, the problem that the exhaust air hits mainly the lower body of the passenger sitting in the vehicle seat remains unsolved.

[0008] That is, if the air at a relatively high temperature, for example, the air heated by the battery pack, is discharged into the passenger compartment even at a reduced flow rate, the vehicle seat structure described in JP-A-2004- 16569 causes the exhaust air to hit mainly the lower body of the passenger sitting in the vehicle seat, which may cause the passenger to feel uncomfortable. In particular, as can be understood from the construction in which the air blower and the discharge port are arranged at the same position in a backrest, the vehicle seat structure merely causes the exhaust air from the air blower to flow to the rear of the seat at a reduced speed. With the vehicle seat structure described in JP-A-2004- 16569, the exhaust air is not cooled. Therefore, for example, a cooling device needs to be further provided to cool the exhaust air.

SUMMARY OF THE INVENTION

[0009] The invention provides a vehicle seat structure that allows the air, heated by a battery pack arranged under a vehicle seat, to be appropriately discharged into a passenger

compartment.

[0010] A first aspect of the invention relates to a vehicle seat structure for a vehicle seat including a seat base under which a battery pack is arranged. According to the first aspect of the invention, an inflow port, through which the air under the seat base is introduced into a backrest, is formed in the lower portion of the backrest, and a discharge port, through which the air introduced into the backrest through the inflow port is discharged into a passenger compartment, is formed in the upper portion of the backrest.

[0011] A passage, which provides communication between a space under the seat base and the inflow port, may be formed in the seat base. A flow guide member, which guides the air around the battery pack into the inflow port, may be provided to the seat base. The flow guide member may be a canopy member that surrounds the entirety of the battery pack when the vehicle seat is viewed from above.

[0012] The discharge port may be formed in the upper end portion, the side end portion, or the rear face portion of the backrest.

[0013] The discharge port may be provided with a filter member having a mesh structure. A space, which provides communication between the inflow port and the discharge port, may be formed inside the backrest. A heat insulating member may be provided between a front cover member of the backrest and the space.

[0014] The battery pack may be arranged directly on a body floor of a vehicle.

[0015] According to the first aspect of the invention, the air under the seat base heated by the battery pack is guided into the inflow port formed in the lower portion of the backrest, passes through the space (inside) of the backrest, and is discharged into the passenger compartment through the discharge port formed in the upper portion of the backrest. Therefore, it is possible to appropriately discharge the air into the passenger compartment without giving a sense of discomfort to the passenger sitting in the vehicle seat.

[0016] In addition, the air under the seat base heated by the battery pack is cooled while being taken in the backrest through the inflow port formed in the lower portion of the backrest, flowing through the backrest, and being discharged into the passenger

compartment through the discharge port formed in the upper portion of the backrest. Accordingly, it is possible to appropriately discharge the air into the passenger compartment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The foregoing and further objects, features and advantages of the invention will become apparent from the following description of an example embodiment with reference to the accompanying drawings, wherein the same or corresponding portions will be denoted by the same reference numerals and wherein:

FIG. 1 is a cross-sectional view illustrating a vehicle seat structure according to a first embodiment of the invention;

FIG. 2A is a schematic view showing the manner in which the air heated by a battery pack flows according to the first embodiment of the invention;

FIG. 2B is a plan view illustrating a vehicle seat according to the first embodiment of the invention;

FIG. 3 is a perspective view of a flow guide member according to the first embodiment of the invention;

FIG. 4 is a view illustrating a discharge port according to a modified example of the first embodiment of the invention, and showing the manner in which the air heated by the battery pack flows;

FIG. 5 is a view illustrating a discharge port according to another modified example of the first embodiment of the invention, and showing the manner in which the air heated by the battery pack flows;

FIG. 6 is a cross-sectional view illustrating a vehicle seat structure according to a second embodiment of the invention; and

FIG. 7 is a perspective view illustrating the entirety of the vehicle seat according to each of the first and second embodiments of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Hereafter, example embodiments of the invention will be described in detail with reference to the accompanying drawings.

[0019] Hereafter, a first embodiment of the invention will be described in detail. FIG. 1 is a cross-sectional view showing a vehicle seat structure according to the first embodiment of the invention. FIG. 7 is a perspective view showing the appearance of a vehicle seat having the vehicle seat structure in FIG. 1. A vehicle seat 100 according to the first embodiment of the invention is formed of a seat base 10, and a backrest 20 provided with a headrest 27. As shown in FIG. 7, the seat base 10 is fitted to a body floor A of the vehicle via a slide mechanism that allows the vehicle seat 100 to slide in the longitudinal direction of the vehicle. The backrest 20 is placed on the seat base 10, and coupled with the seat base 10 via a reclining mechanism 500.

[0020] Under the seat base 10 of the vehicle seat 100 according to the first embodiment of the invention, a battery pack 200 is arranged between right and left slide mechanisms 400 provided under the seat base 10, and is fixed to the body floor A. The battery pack 200 is used in electric vehicles and hybrid vehicles, which require a relatively high capacity power supply device. The battery pack 200 is formed of a lower case 210, an upper case 220, and a battery module 230, for example, a lithium ion battery. The lower case 210 is fixed directly to the body floor A. In some cases, the upper case 220 is also fixed directly to the body floor A.

[0021] As shown in FIG. 1, the backrest 20 is formed of a frame member 21, a cover member 22 (a front cover member 22a and a rear cover member 22b), a cushion member 23, and a spring member 24 provided over the frame member 21. A space S is formed between the cushion member 23 and the rear cover member 22b of the backrest 20. An inflow port 25, through which the air heated by the battery pack 200 arranged under the seat base 10 flows into the space S, is formed in the lower portion of the backrest 20. A discharge port 26, through which the air introduced into the space S through the inflow port 25 is discharged into the passenger compartment, is formed in the upper portion of the backrest 20. The discharge port 26 is provided with a filter member having a mesh structure.

[0022] Just as with the backrest 20, the seat base 10 is formed of a frame member 11, a cover member 12, a cushion member 13, and a spring member 14 provided over the frame member 11. In the seat base 10, a cavity C, which opens toward the battery pack - 200, is formed between the bottom face of the seat base 10, which faces the battery pack 200, and the lower end portion of the cushion member 13. A passage 15, which provides communication between a space under the seat base 10 and the inflow port 25 of the backrest 20, is formed in the seat base 10. The passage 15 provides communication between the cavity C and the inflow port 25 of the backrest 20.

[0023] The seat base 10 has a heat insulating member I arranged between the cushion member 13 and the cover member 12 on the seating face side. Likewise, the backrest 20 has a heat insulating member I arranged between the cushion member 23 and the front cover member 22a that contacts a passenger sitting in the vehicle seat 100.

[0024] In the thus constructed vehicle seat 100 according to the first embodiment of the invention, as shown in FIG. 1, the air heated by the battery pack 200 arranged under the seat base 10 flows into the cavity C formed in the seat base 10 by natural convection, and then flows into the space S through the passage 15 and the inflow port 25 formed in the backrest 20. Then, the heated air introduced into the space S of the backrest 20 is discharged through the discharge port 26 formed in the upper portion of the backrest 20. According to the first embodiment of the invention, as shown in FIG. 2A, the discharge port 26 is formed in the upper end portion of the backrest 20 to which a headrest 27 is attached, so that the heated air is discharged into the area, which is above the backrest 20, in the passenger compartment.

[0025] According to the first embodiment of the invention, a flow guide member 300 is further provided to the seat base 10 to prevent the air heated by the battery pack 200 from diffusing toward the space around the vehicle seat 100, and to guide the heated air toward the inflow port 25 formed in the backrest 20 (the cavity C and the passage 15 formed in the seat base 10). As shown in FIGs. 2B and 3, the flow guide member 300 is a canopy member that surrounds the entirety of the battery pack 200 when viewed from above. The flow guide member 300 is arranged in such a manner that the end of the flow ^'

guide member 300, which defines a first opening of the flow guide member 300, is connected to the portion of the seat base 10, which defines the opening of the cavity C formed in the seat base 10, and the other end of the flow guide member 300, which defines a second opening of the flow guide member 300 that is larger than the first opening, surrounds the entirety of the battery pack 200 when viewed from above.

[0026] As shown in FIG. 1, the flow guide member 300 according to the first embodiment of the invention is attached to the bottom face of the seat base 10 so as to protrude downward from the seat base 10. A part of the battery pack 200 is positioned within the flow guide member 300. This allows the air, heated by the battery pack 200 and flows upward from under the seat base 10, to be efficiently introduced to the inflow port 25 formed in the backrest 20 (the cavity C and the passage 15 formed in the seat base 10). Instead of this structure, any alternative structures may be employed as long as the flow guide member 300 is arranged so as to surround the entirety of the battery pack 200 when viewed from above. For example, the flow guide member 300 may be formed and arranged in a manner such that a gap is formed between the top face of the battery pack 200 and the end of the flow guide member 300, which defines the second opening of the flow guide member 300.

[0027] Next, the manner in which the air heated by the battery pack 200 is discharged into the passenger compartment according to the first embodiment of the invention will be described. FIG. 2A shows the vehicle seat 100 according to the first embodiment of the invention when viewed from the rear. As shown in FIG. 2A, the air under the seat base 10 heated by the battery pack 200 ascends toward the bottom face of the seat base 10 by natural convection. According to the conventional technologies, the air around the seat base 10, which is heated by the battery pack 200, flows toward the passenger sitting in the vehicle seat by natural convection. However, according to the first embodiment of the invention, the heated air ascending toward the bottom face of the seat base 10 by natural convection is prevented from diffusing toward the space around the seat base 10 by the flow guide member 300 (see FIG. 2B), and is instead introduced into the cavity C formed in the seat base 10.

[0028] Then, the heated air introduced into the cavity C of the seat base 10 passes - through the passage 15 to be directed from the inflow port 25 of the backrest 20 to the inside of the backrest 20 (space S). After that, the heated air is discharged into the passenger compartment through the discharge port 26 formed in the upper end portion of the backrest 20, to which the headrest 27 is attached.

[0029] The vehicle seat 100 according to the first embodiment of the invention allows the air heated by the battery pack 200 to pass through the inside of the backrest 20 and be discharged into the area, which is above the lower body of the passenger sitting in the vehicle seat and also above the head of the passenger, in the passenger compartment. Therefore, the air heated by the battery pack 200 is appropriately discharged into the passenger compartment without giving a sense of discomfort to the passenger.

[0030] The air heated by the battery pack 200 causes the passenger sitting in the seat to feel uncomfortable, because the heated air flowing up from a lower area of the passenger compartment hits mainly the lower body of the passenger. However, the vehicle seat 100 according to the first embodiment of the invention minimizes a sense of discomfort given to the passenger, because the air heated by the battery pack 200 is discharged into the area, which is above the lower body of the passenger, preferably, above the head of the passenger, in passenger compartment.

[0031] FIGs. 4 and 5 each show the discharge port 26 formed in the backrest -20 according to modified examples of the first embodiment of the invention. The discharge port 26 is formed in the side end portion of the backrest 20 according to a modified example shown in FIG. 4. The discharge port 26 is formed in the rear face portion (on the rear cover member 22b side) of the backrest 20 according to another modified example shown in FIG. 5. As described above, the discharge port 26 according to the first embodiment of the invention is formed in the upper portion of the backrest 20. Through the discharge port 26, the air heated by the battery pack 200 is discharged to the area, which is above the head of the passenger, in the passenger compartment. In this way, the heated air is appropriately discharged into the passenger compartment. .

[0032] In addition, the air under the seat base 10 heated by the battery pack 200 is

cooled while passing through the inside of the backrest 20. Therefore, the air heated by the battery pack 200 is appropriately discharged into the passenger compartment without providing, for example, a cooling device.

[0033] Further, according to the first embodiment of the invention, the air heated by the battery pack 200 is discharged into the passenger compartment by natural convection of the heated air itself, instead of being forcibly circulated by, for example, a fan. Therefore, the number of components is reduced, leading to a cost reduction.

[0034] Moreover, because the battery pack 200 is fixed directly to the body floor A, it is possible to enhance the efficiency in cooling the battery pack 200, thereby reducing the heat releasing from the battery pack 200. Thus, the air heated by the battery pack 200 is appropriately discharged into the passenger compartment by natural convection without providing a cooling device such as a fan.. In order to further enhance the efficiency in cooling the battery pack 200, the battery pack 200 may be fixed to the body floor A indirectly with, for example, a heat transfer member interposed between the lower case 210 and the body floor A.

[0035] Hereafter, a second embodiment of the invention will be described in detail

FIG. 6 is a cross-sectional view showing a vehicle seat structure according to the second embodiment of the invention. In the vehicle seat according to the second embodiment of the invention, the backrest 20 is not placed on the seat base 10. The vehicle seat according to the second embodiment is mainly used as a rear seat. The air heated by the battery pack 200 arranged under the seat base 10 is allowed to flow directly into the inflow port 25 formed in the backrest 20 without flowing through the inside of the seat base 10. Therefore, the cavity C and the passage 15 are not formed in the seat base 10, unlike the vehicle seat structure according to the first embodiment of the invention. However, a space S' is formed between the cushion member 13 and the cover member 12, just as with the backrest 20. The other structures of the vehicle seat according to the second embodiment of the invention are the same as those of the vehicle seat according to the first embodiment of the invention. Therefore, the same reference numerals will be assigned to the same components, and the description concerning these components will not

be provided below.

[0036] According to the second embodiment of the invention, the flow guide member 300 is arranged in such a manner that the end portion of the flow guide member 300, which defines the first opening of the flow guide member 300, is connected to the seat base 10 and the backrest 20 (the end portion of the backrest 20, which defines the inflow port 25) (in such a manner that the first opening encircles the inflow port 25), and the other end portion of the flow guide member 300, which defines a second opening that is larger than the first opening, surrounds the entirety of the battery pack 200 when viewed from above.

[0037] According to the second embodiment of the invention described above, the air heated by the battery pack 200 arranged under the seat base 10 ascends toward the bottom face of the seat base 10 by natural convection and is introduced directly to the inflow port 25 formed in the backrest 20. Then, the air introduced into the inside of the backrest 20 (space S) is discharged into the passenger compartment through the discharge port 26 formed in the upper end portion of the backrest 20, to which the headrest 27 is attached.

[0038] According to the first embodiment and the second embodiment of the invention, the space S inside the backrest 20 is formed between the cushion member 23 and the rear cover member 22b of the backrest 20. Alternatively, the space S may be formed in the cushion member 23, for example. That is, any structure may be employed as long as a space that serves as a flow path, through which the air introduced into the space from under the seat base 10 through the inflow port 25 is discharged from the discharge port 26, is formed inside the backrest 20.

[0039] In addition, multiple discharge ports 26 may be formed in at least two of the upper end portion to which the headrest 27 is attached, the side end portion, and the rear face portion (on the rear cover member 22b side) of the backrest 20.

[0040] The battery pack 200 is provided with a monitoring unit and a control unit, and therefore the amount of heat released from the battery pack 200 varies from portion to portion of the battery pack 200 in many cases. For example, if the monitoring unit is

arranged at the front side of the battery pack 200 when viewed from above (see FIG. 2B), a smaller amount of heat is released from the front side and a larger amount of heat is released from each of the other three sides. In such a case, the flow guide member 300 may be formed of, for example, a U-shaped member that opens toward the front of the vehicle when viewed from above, instead of the member that surrounds the entirety of the battery pack 200 when viewed from above which is employed in the first embodiment of the invention.

[0041] According to the first embodiment of the invention, the cavity C is formed in the seat base 10. Alternatively, the passage 15 may be formed in such a manner that communication is provided between the inflow port 25 and the space under the seat base 10 to guide the air heated by the battery pack 200 directly into the passage 15. Moreover, because the flow guide member 300 is provided, the opening of the cavity C may be smaller than the top face of the battery pack 200.

[0042] In the first embodiment and the second embodiment, the flow guide member 300 that extends from the seat base 10 to the body floor A may be arranged to conceal the battery pack 200. In this case, an intake port may be formed in the flow guide member 300 to take the air in the passenger compartment into the space around the battery pack 200.

[0043] While the invention has been described with reference to the example embodiments thereof, it is to be understood that the invention is not limited to the example embodiments and construction. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the example embodiment are shown in various example combinations and configurations, other combinations and configurations, including more, less or only a single element, are also within the scope of the invention.