Abstract:
The present invention is directed to a frame assembly for motor vehicle in which one of the frame elements utilized as a fluid storage volume. An elongated rail portion of the frame assembly defines a closed section which is utilized as a fuel storage volume for an operational fluid of the vehicle. In particular, the present invention is contemplated for use with a fuel cell based in which a fluid storage volume may be used for storing hydrogen, compressed air, water or alternately a cooling fluid. Furthermore, the elongated rail may be provided with various design features for storing a diverse operational fluid as well as adapt the elongated rail for conventional uses as an attachment point for various vehicle components or the routing of wire harnesses and fuel or brake lines.

Description:
FIELD OF THE INVENTION  
       [0001]     The present is directed to a frame assembly for a motor vehicle, and more particularly to an elongated rail within the frame assembly which is adapted to provide a fluid storage volume therein.  
       BACKGROUND OF THE INVENTION  
       [0002]     Significant efforts are being made to commercialize a hydrogen powered motor vehicle employing a fuel cell as the principle component of the power plant for the vehicle. This technology has significantly different design constraints from those encountered by vehicle designers of conventional internal combustion engines. One such parameter relates to the packaging of the various components within a fuel cell based vehicle. In this regard, a power train component of a fuel cell based vehicle may be generally more distributed about the frame assembly as compared with conventional internal combustion designs. Thus, a fuel cell based vehicle lends itself to a modular packaging concept over conventional vehicle designs. However, the number and mass of the components associated with a fuel cell based vehicle present new design challenges to the vehicle engineer.  
         [0003]     One such challenge lies in providing an adequate source of the operational fluids for the fuel cell based power plant to achieve a suitable driving range for such a vehicle. Such operational fluids include the hydrogen-containing fuel and oxidant or air utilized as feed streams to the fuel cell stack for generation of electric energy. In addition, the operational fluid may include a cooling fluid to be circulated through the various components of the power plant to maintain the proper operational temperature thereof. Likewise, for vehicles which employ an on-board hydrogen reforming system, the operational fluids may further include a hydrocarbon-based fuel and a water utilized in the reforming process. An adequate source of each of these operational fluids must be provided on the vehicle to achieve the desired driving range.  
         [0004]     Accordingly, there is a need in the art to provide an adequate fluid storage volume on board the motor vehicle while minimizing the packaging volume and additional mass associated with such storage volumes. As such, a fluid storage system which employs existing structure would provide such an improvement.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention is directed to a motor vehicle of the type having a frame assembly in which one of the frame elements are utilized as a fluid storage volume. More particularly, an elongated rail portion of the frame assembly having a closed section is utilized as a fluid storage volume for an operational fluid of the vehicle. In one embodiment, the fluid storage volume is a pressurized volume utilized for hydrogen storage to provide a source of hydrogen-containing fuel for a fuel cell based power plant. In another embodiment, the present invention is directed to a fluid storage volume for providing a source of compressed air to the fuel cell based power plant. In yet another embodiment, the present invention is directed to a fluid storage volume for providing a source of cooling fluid to the vehicle&#39;s power plant. In still another embodiment, the present invention is directed to a fluid storage volume for providing a source of water or steam for the vehicle&#39;s power plant.  
         [0006]     Further aspects of the present invention are directed to the particular structural features of the elongated rail. More specifically, the internal volume of the elongated rail may be sectioned into discrete chambers for providing storage of diverse operational fluids. Alternately, the discrete chambers may be sealed from one another and utilized to provide an internal storage volume in addition to more conventional functions of the structural members such as providing a fastening surface for vehicle components and for routing support structure such as a wiring harness therethrough.  
         [0007]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0009]      FIG. 1  illustrates a first preferred embodiment of a motor vehicle incorporating a frame assembly in accordance with the present invention;  
         [0010]      FIG. 2  is a cross-sectional view of an elongated rail of the frame assembly shown in  FIG. 1 ;  
         [0011]      FIG. 3  is a cross-section of an alternate embodiment of an elongated rail of the frame assembly shown in  FIG. 1 ;  
         [0012]      FIG. 4  is a cross-section of another alternate embodiment of an elongated rail of the frame assembly;  
         [0013]      FIG. 5  is a cross-section of yet another alternate embodiment for an elongated rail of the frame assembly; and  
         [0014]      FIG. 6  is a second preferred embodiment of a motor vehicle with a frame assembly in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]     The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0016]     With reference now to drawings, the present invention is directed to a motor vehicle generally indicated at reference number  10 . The motor vehicle  10  has a frame assembly  12  which provides the primary support structure for the remaining components of the motor vehicle  10 . A set of wheels  14  are rotatably supported from the frame assembly  12  in a conventional manner. A power train  16  is supported on the frame assembly  12  and is operably coupled to the wheels  14  through shaft  18 . In this manner, power train  16  is operable to drive at least one of wheels  14 .  
         [0017]     In the first preferred embodiment of the present invention illustrated in  FIG. 1 , the power plant  16  includes a fuel cell  20  operable to convert hydrogen and oxygen into electrical energy, and an electric motor  22  electrically connected to fuel cell  20  and operable to drivingly rotate shaft  18 . In this regard, the motor  22  may include a transaxle gear assembly or other suitable drive train component for delivering rotary power to the wheels  14 . A radiator  24  is supported near the front portion of the frame assembly  12 . The radiator  24  is in fluid communication with the power train  16  such that a cooling fluid circulating therethrough functions to dissipate heat energy generated in the power plant  16 . A pair of fuel tanks  28  are oriented in a generally longitudinal direction and supported on frame assembly  12 . The fuel tanks  28  are in fluid communication with the power train  16  to provide a primary source of fuel in the form of a hydrogen-containing gas stream to fuel cell  20 .  
         [0018]     A second preferred embodiment of a motor vehicle  10 ′ is illustrated in  FIG. 6 . Motor vehicle  10 ′ is similar to motor vehicle  10  described above with the following exceptions. The power train  16 ′ of motor vehicle  10 ′ represents a distributed power train in that a drive motor  22 ′ is located adjacent each of the wheels  14 ′ and electrically coupled to the fuel cell  20 ′ by a series of wires forming a wiring harness  30 ′. Four fuel tanks  28 ′ are transversely oriented and supported on frame assembly  12 ′. The fuel tanks  28 ′ are in fluid communication with the fuel cell  20 ′ to provide a primary source of hydrogen feed gas thereto.  
         [0019]     With reference to both  FIG. 1  and  FIG. 6 , the frame assembly  12 ,  12 ′ includes a pair of longitudinal elongated frame rails  32 ,  32 ′ and a number of transverse, elongated cross rails  34 ,  34 ′ defining a generally ladder-type frame assembly  12 ,  12 ′. In this configuration, longitudinal rails  32 ,  32 ′ and cross rails  34 ,  34 ′ provide the primary structure and support for the remaining components of the motor vehicle  10 ,  10 ′. The frame assembly  12 ,  12 ′ further includes an auxiliary frame structure  36 ,  36 ′. The auxiliary frame structure  36 ,  36 ′ may perform various functions including providing attachment points for other components of the motor vehicle  10 ,  10 ′ such as the vehicle body (not shown). The auxiliary frame structure  36 ,  36 ′ may also define a crush zone  38 ,  38 ′. As illustrated in the figures, auxiliary frame structure  36 ,  36 ′ includes a pair of longitudinally oriented rails  40 ,  40 ′ extending generally parallel to frame rails  32 ,  32 ′. Front cross rails  42 ,  42 ′ and rear cross rails  44 ,  44 ′ connect the longitudinal rail  40 ,  40 ′ to longitudinal rail  32 ,  32 ′. Auxiliary frame structure  36 ,  36 ′ of the preferred embodiments are merely exemplary, and one skilled in the art will recognize that the auxiliary frame structure has a configuration dictated by the needs of a particular application.  
         [0020]     As previously discussed, the present invention provides an effective use of the enclosed volume defined within the frame rail components  32 ,  32 ′,  34 ,  34 ′ of frame assembly  12 ,  12 ′ to provide a fluid storage volume generally indicated at reference number  46 ,  46 ′ of the figures. In this regard, one or more of the elongated rails  32 ,  32 ′ and  34 ,  34 ′ may define a closed section for providing the fluid storage volume  46 ,  46 ′. A single elongated rail portions may be utilized to provide the fluid storage volume. Alternately, multiple elongated rail portions may be in fluid communication with one another such that the fluid storage volume is defined within multiple elongated rail portions.  
         [0021]     With reference to  FIGS. 2-5 , the cross-sectional configuration of an elongated rail providing the fluid storage volume is further described. It will be understood that the following discussion relates to any elongated rail portion such as longitudinal elongated rail  32 ,  32 ′ or transverse elongated rail portion  34 ,  34 ′. However, further reference will only be made to elongated rail  32 .  
         [0022]     Turning now to  FIG. 2 , elongated rail  32  is generally rectangular in cross-section having side wall  48  and end walls  49  (as shown in  FIG. 1 ) which define a closed section therein. A liner  52  is formed on the interior surface of side wall  48  to seal the storage volume  50  within the elongated rail  32 . The liner  52  may further function as insulation to prevent heat transfer from or to the ambient environment. Thus, the enclosed storage volume  50  is defined within liner  52 .  
         [0023]     In one aspect of the present invention, the fluid storage volume  50  may be adaptable as a rechargeable device to store and discharge hydrogen. Specifically, hydrogen is stored in a solid form and supplied as a gas when needed. To this end, the storage volume  50  is provided with a matrix  54  that form numerous open cells which have a solid hydrogen storage medium disposed therein. A tube  56  located within the storage volume  50  allows the hydrogen gas to transfer to and from the storage volume  50 . A conduit  58  is also disposed within the storage volume  50  and allows a heat transfer fluid in the form of water, air, another liquid or gas suitable for transferring heat to and from the storage volume  50  to circulate therethrough. In this manner, the elongated rail  32  functions effectively as a pressurized hydrogen fuel storage volume. As presently contemplated elongated rail  32  functions as a reserve or supplemental fuel storage volume which is substantially less than the volume of the fuel tanks  28 —in the range of less than 25% the capacity of fuel tanks  28 . Further details concerning the use of a solid hydrogen storage median within the storage volume  50  is disclosed in U.S. Pat. No. 6,015,041, the disclosure of which is expressly incorporated by reference herein.  
         [0024]     With reference now to  FIG. 3 , elongated rail  32  is generally rectangular in cross-section having a side wall  48  which divides the storage volume into discrete chambers  50 . 1 ,  50 . 2 . Each of the chambers  50 . 1 ,  50 . 2  have a liner  52 . 1 ,  52 . 2  formed on its inner surface. As presently preferred, the first chamber  50 . 1  houses a solid hydrogen storage media  54 , a port  56  and a conduit  58  as described above in reference to  FIG. 2 . The second chamber  50 . 2  provides a fluid storage volume separate and distinct from fluid storage volume  50 . 1 . In this manner, the second chamber may provide storage of a second operational fluid which is diverse from the operational fluid stored in first chamber  50 . 1 . For example, as illustrated, the second chamber  50 . 2  is adapted to store a liquid such as a cooling fluid or water usable by the power plant  16  of the motor vehicle  10 .  
         [0025]     With reference now to  FIG. 4 , elongated rail  32  is generally rectangular in cross-section having a side wall  48  providing a fluid storage volume  50 . 1  and a fastener channel  50 . 2 . The fluid storage volume  50 . 1  is adapted to include a matrix  54  having a solid hydrogen storage media disposed therein, a port  56  and a conduit  58  as heretofore described. An insulating liner  52  is disposed on the inner surface of fluid storage volume  50 . 1 . The fastener channel  50 . 2  defines an isolated fastener channel. In this manner, the fastener channel  50 . 2  is sealed from the fluid storage volume  50 . 1  such that a threaded fastener  60  may be secured through the side wall  48  of the rail  32  without disrupting or otherwise destroying the closed section of the fluid storage volume  50 . 1 . In this configuration, the elongated rail  32  may be utilized as an attachment surface for various components of the motor vehicle  10  without disrupting the fluid storage volume  50 . 1  occupying the internal space within the elongated rail  32 .  
         [0026]     With reference now to  FIG. 5 , elongated rail  32  is generally rectangular in cross-section having a side wall  48  which defines a fluid storage volume  50 . 1 , a fastener channel  50 . 2  and enclosed passageway  50 . 3 . An insulating liner  52  is disposed within fluid storage volume  50 . 1 . The fluid storage volume  50 . 1  has a matrix  54  with a solid hydrogen storage media disposed therein, a port  56  and a conduit  58  as heretofore described. The fastener channel  50 . 2  is formed in the elongated rail  32  similar to that described with reference to  FIG. 4 . In addition, an enclosed passageway  50 . 3  is provided in the elongated rail  32  which may be utilized for carrying vehicle components within the frame assembly  12 . For example, a wiring harness  62  may be carried within passageway  50 . 3 . Similarly, a tubular element  64  in the form of a fuel line or brake line may be disposed within passageway  50 . 3  for routing these elements within the frame assembly  12 .  
         [0027]     While the cross-sectional configurations shown in  FIGS. 2-5  have been illustrated as generally rectangular, one skilled in the art will recognize that the particular cross-sectional configuration of the elongated rail will vary depending upon the location and structural requirements thereof within the frame assembly. Thus, the present invention contemplates that an elongated rail having a variety of cross-sections could be utilized within the present invention.  
         [0028]     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.