Abstract:
Various aspects of the present invention relate to a vehicle seat assembly supportable on a floor of a vehicle having a battery pack disposed behind the vehicle seat, operable to help cool the battery pack, a vehicle battery pack cooling system, and a method of cooling a vehicle battery pack. In at least one embodiment, the vehicle seat assembly comprises a seat bottom comprising a structural support portion made of a first material and a foam seat cushion supported on the structural support portion, with the first material being more resilient than the foam. The structural support portion is supportable on the vehicle floor and, when supported on the floor, communicates with the vehicle floor to form an air flow passage extending under the seat bottom to provide air flow to the battery pack.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 11/755,301 filed May 30, 2007, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a seat assembly that provides an air flow path to cool batteries. 
         [0004]    2. Background Art 
         [0005]    Vehicle battery cooling systems are known. Examples of known vehicle battery cooling systems include U.S. Pat. Nos. 6,902,020; 6,662,891, 6,541,151; 6,220,383; and 5,937,664; and U.S. Patent Application Publication No. 2005/0011692. 
       SUMMARY OF THE INVENTION 
       [0006]    According to at least one aspect of the present invention, a vehicle seat assembly is provided. In at least one embodiment, the vehicle seat assembly is supportable on a floor of a vehicle having a power source disposed behind the vehicle seat. The vehicle seat assembly comprises a seat bottom and a seat back extending adjacent the seat bottom. In at least this embodiment, the seat bottom comprises a structural support member made of a structural foam material and a cellular foam seat member supported on the structural support portion with the structural foam material being more resilient than the cellular foam seat member. The structural support member is supportable on the vehicle floor and, when supported on the floor, is configured to provide an air flow passage extending under the seat bottom to provide air flow to the power source. 
         [0007]    According to at least another aspect of the present invention, a vehicle battery pack cooling system is provided. In at least one embodiment, the vehicle battery pack system comprises a vehicle floor, a seat assembly supported on the vehicle floor, and a battery pack, for providing at least some of the power to the vehicle, supported behind the seat assembly. The vehicle seat assembly comprises a seat bottom and a seat back extending generally vertically from the seat bottom. In at least this embodiment, the seat bottom comprises a structural support portion made of a first material and a foam seat cushion supported on the structural support portion. The structural support portion is supported on the vehicle floor and the structural support portion communicates with the vehicle floor to form at least a portion of an air flow passage extending under the seat bottom. The structural support portion further has a plurality of spaced-apart support members cooperating with the vehicle floor to help support the seat assembly of the vehicle floor. 
         [0008]    According to yet at least another aspect of the present invention, a method of cooling a vehicle battery pack located in a vehicle having a vehicle floor is provided. In at least one embodiment, the method comprises supporting a seat assembly on the vehicle floor and supporting a battery pack for providing at least some of the power to the vehicle behind the seat assembly. The vehicle seat assembly comprises a seat bottom and a seat back. In at least this embodiment, the seat bottom comprises a structural support portion made of a first material and a foam seat cushion supported on the structural support portion, with the first material being at least as resilient as the foam. In at least this embodiment, the structural support portion communicates with the vehicle floor to help form an air flow passage extending under the seat bottom. In at least this embodiment, the method further comprises directing air flow through the air passage under the seat to provide cooling to the battery pack. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic perspective view of a system in accordance with an embodiment of the present invention; 
           [0010]      FIG. 2  is a schematic sectional side view of components illustrated in  FIG. 1 , taken through line  2 - 2 ; 
           [0011]      FIG. 3  is an exploded view of components illustrated in  FIGS. 1 and 2 ; and 
           [0012]      FIG. 4  is a schematic perspective view depicting the underside of a component illustrated in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0013]    As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The Figures are not necessarily to scale, some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention. 
         [0014]    Moreover, except where otherwise expressly indicated, all numerical quantities in this description and in the claims are to be understood as modified by the word “about” in describing the broader scope of this invention. Practice within any numerical limits stated is generally preferred. Also, unless expressly stated to the contrary, the description of a group or class of materials by suitably or preferred for a given purpose in connection with the invention implies that mixtures of any two or more members of the group or class may be equally suitable or preferred. 
         [0015]    Referring now to the Figures, where like numerals are used to designate like structures throughout the drawings, a schematic vehicle seat assembly in accordance with at least one embodiment of the present invention is generally shown at  10  in  FIG. 1 . While the vehicle seat assembly  10  is illustrated in  FIG. 1  to be a bench seat assembly, it should be understood that the principles of the invention are applicable to other types of seat assemblies, such as bucket, captain and other types of seat assemblies. It should also be understood that the principles of this invention are applicable to all types of vehicle seat assemblies as well as non-vehicle seat assemblies. 
         [0016]    Referring to  FIG. 1 , the vehicle seat assembly  10  is shown secured to a vehicle floor pan or a vehicle floor  12 . The vehicle seat assembly  10  can be secured in any suitable manner. A battery pack, schematically illustrated as  14 , or any other suitable power source, such as an electric motor, is shown to be disposed behind the seat assembly  10 . In the illustrated embodiment, the battery pack  14  is disposed upon a ledge of the vehicle floor  12  behind the seat assembly  10 . The power source  14  can be any suitable battery pack or power source such as an electric motor, for helping to power the vehicle. For instance, the battery pack  14  could be a battery pack or electric motor for an electric vehicle, a hybrid vehicle, or other types of vehicles. As will be explained below in further details, the seat assembly  10  along with the vehicle floor  12  forms an air flow path  15  which helps direct air, schematically illustrated as  17 , from the vehicle occupant compartment  13  to the battery pack  14  to cool the battery pack. The air can be from the vehicle occupant compartment or it can be conditioned air from a unit specifically directed into the flow path  15 . 
         [0017]    The vehicle seat assembly  10  includes a seat back, generally indicated at  16 , and a lower seat assembly, generally indicated at  18 . In at least the illustrated embodiment, the lower seat assembly  18  has a cushion composite  20  covered by a trim material  22 . The seat back  16  can be any suitable type of seat back. 
         [0018]    The vehicle seat assembly  10  may also include a seat frame, (not shown) having a plurality of mounting brackets (not shown) adapted to operatively secure the seat frame within a vehicle. The seat frame may be constructed from any material suitable for application within a vehicle seat assembly  10 , such as aluminum, steel or other metal alloy, composite material, or a suitable polymer. Further, the seat frame may be manufactured using techniques commonly known in the art, and relative to the type of material employed. By way of example, manufacturing techniques may include stamping, welding, fastening or molding a suitable material to form the seat frame. 
         [0019]    As will be explained further below, it should be understood that the frame could optionally be omitted as desired. The cushion composite  20  is received on or around the frame and the trim material  22  is adapted to engage the cushion composite  20  and/or the frame in a covering relationship. 
         [0020]    In at least one embodiment, the cushion composite  20  includes a structural layer  30 , disposed over a frame (not shown), and a cushion layer  32  that is disposed over the structural layer  30 . 
         [0021]    In at least one embodiment, the structural layer  30  can be any suitable structural foam material. In at least one embodiment, suitable structural materials will have a rigidity and/or density that is higher than conventional open-cell (cellular) polyurethane foam that is typically employed in seat cushions. In at least one embodiment, suitable structural foam materials have a density of at least 1.75 pounds per cubic foot (pcf), and less than 7.0 pcf. In at least another embodiment, suitable structural foam materials will have a density of 2.0 to 4.0 pcf, and in yet other embodiments of 2.5 to 3.5 pcf. Density of the structural foam material can be measured in accordance with ASTM test method No. D3575. 
         [0022]    In at least one embodiment, suitable structural materials will have a compressive strength, at 50% strain, of 0.30 to 0.50 MPa, in at least another embodiment of 0.32 to 0.42 MPa, and in at least another embodiment of 0.35 to 0.39 MPa. Compressive strength can be measured by ASTM test method No. D3575. In at least one embodiment, suitable structural materials will have a tear strength of 1.8 to 3.2 gms/mm, in at least another embodiment of 2.2 to 3.0 gms/mm, and in at least another embodiment of 2.4 to 2.8 gms/mm, as measured in accordance with ASTM test method No. D3575. In at least one embodiment, suitable structural materials will have flexural modulus of 12.5 to 18 MPa, in at least another embodiment of 13.25 to 17 MPa, and in at least another embodiment of 13.5 to 15.5 MPa, as measured in accordance with ASTM test method No. D3575. 
         [0023]    In at least one embodiment, the structural layer  30  comprises a molded expanded polyolefin (EPO) layer. Suitable examples of expanded polyolefin (EPO) include, but are not necessarily limited to, expanded polyethylene (EPE), expanded polypropylene (EPP), expanded polybutylene (EPB), and copolymers of ethylene, propylene, butylene, 1,3-butadiene, and other olefin monomers, such as alpha-olefin monomers having from 5-18 carbon atoms, and/or cycloalkylene monomers such as cyclohexane, cyclopentene, cyclohexadiene, norbornene, and aromatic substituted olefins, such as styrene, alpha-methylstyrene, paramethylstyrene, and the like. 
         [0024]    In at least one particular preferred embodiment, the EPO is expanded polypropylene (EPP) and its copolymers with ethylene, propylene and butylene. Any suitable EPP may be used, however in at least one embodiment, suitable EPP&#39;s include, but are not limited to, ARPRO® EPP available from JSP International and EPP available from SCA Packaging North America. 
         [0025]    Expanded polyolefins can be prepared by a bead polymerization process in which relatively small uniform beads of polymer are produced, containing a gas which is later utilized to effect blowing during the molding process. The most commonly used gas is air although other gases including low boiling point liquids which produce gases at the molding temperatures may be used. Suitable gases include, but are not limited to air, nitrogen, carbon dioxide, pentene and the like. 
         [0026]    While the structural layer  30  can have any suitable size and configuration, in at least one embodiment, the structural layer  30  has an average thickness of 5 to 100 mm, in other embodiments of 20 to 70 mm, and in yet other embodiments of 30 to 50 mm. 
         [0027]    Although the structural layer  30  has been mainly referred to herein as a structural foam material, it should be understood that the structural layer  30  could also be made of a suitable plastic or metal, however, it has been found that structural foam provides certain benefits relating to recyclability and weight reduction. 
         [0028]    The cushion layer  32  can comprise any suitable cushion material, such as a suitable resilient polymer. In at least one embodiment, suitable cushion materials will have a density of 1.5 to 4.5 pcf, in another embodiment of 2.0 to 3.75 pcf, and in yet other embodiments of 2.7 to 3.0 pcf. Density of the cushion material can be measured by ASTM test method No. D3575. In at least one embodiment, suitable cushion materials will have a compressive strength, at 50% strain, of 0.017 to 0.030 MPa, in other embodiments of 0.018 to 0.024 MPa, and in yet other embodiments of 0.020 to 0.023 MPa. In at least one embodiment, suitable cushion materials will have a hysteresis of 18 to 30 KPa, in another embodiments of 20 to 28 KPa, and in yet other embodiments of 23-26 KPa. Hysteresis of the cushion material can be measured by ASTM test method No. D3575. 
         [0029]    In at least certain embodiments, the cushion material comprises conventional polyurethane foam, soy-based foam, silicone, thermoplastic olefins, thermoplastic urethanes, and/or natural oil-based expanded polyurethanes and the like. In at least one embodiment, because of its environmentally friendly nature, soy-based polyurethane is preferred. Soy-based polyurethane can be made with any suitable soy-based polyols, such as those available, but not necessarily limited to, from Bayer, Urethane Soy Systems, and Dow Chemical. Any suitable soy-based polyurethane may be used, however in at least one embodiment, suitable soy-based polyurethanes include, but are not necessarily limited to those available from Woodbridge Foam and Renosol. The cushion layer  32  can be any suitable size and shape, however, in at least one embodiment, the cushion layer  32  has an average thickness of 20 to 100 mm, and in at least another embodiment of 30 to 70 mm, and in still yet other embodiments of 40 to 60 mm. 
         [0030]    It should be understood that the structural layer  30  and the cushion layer  32  can have any suitable configuration, shape and size. For instance, as shown in the figures, each layer  30  and  32  have a similar size and construction with the cushion layer  32  being disposed over the structural layer  30 . 
         [0031]    As can be envisioned, many different configurations of the layers  30  and  32  can be encompassed by the present invention, even those which are not shown or described herein. 
         [0032]    As discussed, the vehicle seat assembly  10  also includes trim material  22  which is adapted to engage the cushion composite  20  in a covering relationship. The trim material  22  may include any material known in the art. By way of example, some of the known materials include cloth, leather or polymers of sufficient quality and thickness for use in seat trim applications. Polymer trim materials may include a flexible close cell polymer skin material such as polyvinyl, polyvinyl chloride (PVC), polyester, nylon, thermoplastic olefin (TPO) or thermoplastic urethane (TPU). Additional materials for use as trim material  22 , may include a foam backing (not shown, but generally known in the art) which may be manufactured from a variety of polymer foam materials. By way of example, the foam backing may be polyethylene, polypropylene, polyurethane, or a polystyrene foam. Optionally, a mesh or reinforcing material (not shown, but generally known in the art) such as fiberglass, nylon, polyester or natural fibers may be applied to the foam backing or back of the trim material  22  for increase in strength without increasing rigidity. In at least one particularly preferred embodiment, the trim material  22  comprises polyester or nylon trim material having polyester or nylon trim fasteners (not shown) for securing the trim material  22  to one or more components (i.e., cushion  20  and/or frame) of the vehicle seat assembly  10 . 
         [0033]    In at least certain embodiments, the layers  30  and  32  of the cushion composite  20  are configured so that they can be easily assembled and disassembled to facilitate assembly and end of line disassembly for recycling. In at least one embodiment, the layers  30  and  32  are not secured to each other by a mechanical fastening. In this embodiment, the layers  30  and  32  are either placed over each other and/or within recesses of an adjustment layer and held together by the overlying trim material  22 . In other embodiments, the layers  30  and  32  can have one or more mechanical fastening component to secure the layers  30  and  32  to each other. 
         [0034]    Referring to  FIGS. 2 to 4 , the structural layer  30  of the lower seat assembly  18  includes a top surface  40 , a bottom surface  42 , a front surface  44  and a rear surface  46 . The front surface  44  has an opening  50  that communicates with to the bottom surface  42 . As shown in  FIG. 1 , a grill  52  or other suitable trim member is disposed over the opening  50  to cover the opening while allowing air to enter into the opening. The bottom surface  42  of the structural layer  30  includes a pair of side walls  56  that extend from the front  44  of the structural layer  30  to the rear  46  of the structural layer  30 . 
         [0035]    The bottom surface  42  of the structural layer  30  also includes a plurality of depending structures such as bars  64  and rods  66  which help to distribute the weight of the vehicle occupant evenly over the lower seat assembly  18  of the vehicle seat assembly  10 . Moreover, side walls  56  also cooperate with the bars  64  and rods  66  to distribute the weight of the vehicle occupant. 
         [0036]    Referring to  FIG. 3 , in at least the illustrated embodiment, the cushion layer  32  has a depending rim portion  70  that fits over at least a substantial portion of the front surface  44  of the structural layer  30 . The cushion layer  32 , at least in the illustrated embodiment, also includes an opening  74  that is positioned over opening  50  of the structural layer  30  and the trim cover  22  also includes an opening  78  that is positioned over openings  50  and  74 . 
         [0037]    In at least certain embodiments, when the seat assembly  10  is secured to the vehicle, the side walls  56  of the structural layer  30  extend from the bottom surface  42  of the structural layer  30  to the vehicle floor  12 . In at least certain embodiments, the vehicle floor  12  and the side walls  56  and the bottom surface  42  of the structural layer  30  cooperate to define an air flow path  15  that extends under the structural layer  30 , and thus the lower seat assembly  18 , to provide a path  15  for cooled air  17  to extend underneath the seat assembly  10  back toward the battery pack  14 . A fan, shown schematically at  13 , can be provided for drawing air to the battery pack  14 . While fan  13  is illustrated as being located behind battery pack  14  in  FIG. 2 , it should be appreciated that battery pack  14  could be located behind fan  13  or that fan  13  could be omitted or replaced with another air moving device. 
         [0038]    After the air flows into the opening  50  of the structural layer and through the air flow path  15  under the lower seat assembly  18 , the air is then directed out of the back of the lower seat assembly and behind the seat back  16  to the battery pack  14 . 
         [0039]    While embodiments to the invention has been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Moreover, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.