Abstract:
This disclosure relates to vehicle frame components that are comprised of composite materials. Vehicle frame component structures are disclosed that address the relative lack of the compressive strength of composites compared to conventional metal materials used in vehicle frames. One desirable frame structure is a box frame rail structure that is comprised of composite materials and that has an enhanced capacity to accommodate compressive loads. In addition, the disclosed box frame rail structures provide protective routing options for wiring and pneumatic plumbing.

Description:
SUMMARY 
       [0001]    This disclosure relates to vehicle frame components that are comprised of composite materials. Vehicle frame component structures are disclosed that address the relative lack of the compressive strength of composites compared to conventional metal materials used in vehicle frames. One desirable frame structure is a box frame rail structure that is comprised of composite materials and that has an enhanced capacity to accommodate compressive loads. In addition, the disclosed box frame rail structures provide protective routing options for wiring and pneumatic plumbing. 
         [0002]    The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a perspective view of a portion of an exemplary composite frame for use in vehicles, such as truck tractors and trailers. 
           [0004]      FIG. 2  is an end view of the frame of  FIG. 1 . 
           [0005]      FIG. 3  is an exploded perspective view of the frame of  FIG. 1 . 
           [0006]      FIG. 4  is an exploded top view of the frame of  FIG. 1 . 
           [0007]      FIG. 5  is an exploded end view of the frame of  FIG. 1 . 
           [0008]      FIG. 6  is an exploded perspective view of exemplary inside supports and inserts of the frame of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Described herein are embodiments of a composite box frame for a vehicle. The following description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Various changes to the described embodiments may be made in the function and arrangement of the elements described herein without departing from the scope of the invention. 
         [0010]    The vehicle frame  2  shown in  FIGS. 1-6  comprises two longitudinally extending box frame rails  3 , each comprising an outside rail section  4  and an inside rail section  6 , and wherein the frame rails are connected together by at least one crossmember  8 . The assembled frame rail sections desirably comprise box frame rail sections that define an internal passageway therebetween. The frame  2  can further comprise internal supports  10  and inserts  14  positioned within the box sections  3 , and brackets  12  at the juncture of the crossmember  8  and the box sections. 
         [0011]    Each outside rail section  4  can comprise an outer wall such as a vertically oriented outer side wall  20 , a transverse upper wall such as a horizontally oriented top wall  22  extending inwardly from a top edge portion of the side wall  20 , a transverse bottom wall such as a horizontally oriented bottom wall  24  extending inwardly from a bottom edge portion of the side wall  20 , a top flange  26  extending upwardly from an inner edge portion of the top wall  22 , and a bottom flange portion  28  extending downwardly from an inner edge portion of the bottom wall  24 . The outside rail sections  4  can thus have a “hat” shaped cross-section. That is, the outside rail sections  4  can be described as generally U-shaped in cross section with a base and first and second leg portions with diverging distal end flange portions that are spaced from the base. Similarly, each frame rail  3  can further comprise an inner rail section  6  joined to the outer rail section  4 . The inner rail section can comprise an upright inner wall such as a vertically oriented side wall  30  spaced from wall  20 , a transverse upper wall such as a horizontally oriented top wall  32  extending inwardly from a top edge portion of the side wall  30 , a transverse lower wall such as a horizontally oriented bottom wall  34  extending inwardly from a bottom edge portion of the side wall  30 , a top flange portion  36  extending upwardly from an inner edge portion of the top wall  32 , and a bottom flange portion  38  extending downwardly from an inner edge portion of the bottom wall  34 . The inner rail sections  6  can have a shallower “hat” shaped cross-section compared to the outside rail sections  4 . That is, the inner rail sections  6  can also be described as U-shaped in cross-section with a base and first and second leg portions with diverging distal end flange portions spaced from the base. The leg portions of the inner rail section are desirably shorter than the leg portions of the outer rail section so that a substantially enclosed box is provided between the outer and inner rail sections. 
         [0012]    The inside rail sections  6  can be nested within the outside rail sections  4 , as shown in  FIGS. 1 and 2 , to form the box frame rails  3  and define internal spaces between the side walls  20  and  30 . To secure the inside rails  6  to the outside rails  4 , upper surfaces of the top walls  32  can be bonded or otherwise coupled to lower surfaces of the top wall  22 , and lower surfaces of the bottom walls  34  can be bonded or otherwise coupled to upper surfaces of the bottom walls  24 . In addition, the top flanges  26  and  36  can be bonded or otherwise coupled together and the bottom flanges  28  and  38  can be bonded or otherwise coupled together to further secure the inside and outside rails together. The large flanges on the rails can provide for a large surface area for bonding or bolting, and results in increased torsional rigidity. The composite box sections  3  thus provide high beam bending and torsional resistance, comparable to conventional C-channel metal frame rails, while weighing much less. The internal spaces in the box sections  3  can also serve as protecting or shielding conduits to route wires, plumbing, and other conduits. 
         [0013]    The frame  2  can comprise one or more, and desirably plural spaced apart crossmembers  8  that couple the box frame rails  3  together at different positions along the longitudinal length of the frame. Each crossmember  8  can comprise a top wall  40 , two side walls  42  extending downwardly from the respective side edge portions of the top wall  40 , and two bottom projections such as flanges  44  extending away from bottom edge portions of the side walls  42 . The top and bottom flanges can be horizontal and the side wall flanges  42  can be vertical. In some embodiments, one or more of the crossmembers  8  can be oriented upside down from the orientation shown, such that the top wall  40  is at the bottom and the bottom flanges  44  are at the top. The crossmember  8  can thus also have a “hat” or U-shaped cross-section, similar to the shape of outside and inside rails  4 ,  6 , which can provide increase torsional rigidity in the crossmember. 
         [0014]    One end of each of the crossmembers  8  can be coupled to one of the frame rails  3  and the other end of each of the crossmembers  8  can be coupled to the other frame rails  3 , as shown in  FIGS. 1 and 2 . At each end of the crossmember  8 , an upper surface of the top wall  40  of the crossmember  8  can be bonded or otherwise coupled to a lower surface of the top wall  32  of the inside rail section  6 . In addition, lower surfaces of the bottom flanges  44  of the crossmember can be bonded or otherwise coupled to upper surfaces of the bottom wall  34  of the inside rail  6 . 
         [0015]    End surfaces of the crossmember  8  can also be bonded or otherwise coupled to inner surfaces of the side walls  30  of the inside rail section  6 . Brackets  12  can be used to couple the crossmembers  8  to the inside rail sections  6 . The brackets  12  can comprise L-shaped or angle brackets comprising a base flange portion  48  and of a projecting flange portion  46  that extends away from the base flange portion. In the illustrated example, flanges  46 ,  48  are orthogonal to one another. Two of the brackets  12  can be used to couple an end of the crossmember  8  to the inner rail section  6 , with one bracket  12  coupling each side wall  42  to the inner rail section  6 . The flanges  46  of the bracket  12  can be bonded or otherwise coupled to the side walls  42  of the crossmember  8  and the side flanges  48  of the bracket  12  can be bonded or otherwise joined to the side walls  30  of the inner rails  6 , thereby coupling the end crossmember  8  to the box sections  3 . In addition, upper edge surfaces of the brackets  12  can be bonded or otherwise coupled to lower surfaces of the top walls  32  of the inner rail sections  6  and/or lower edge surfaces of the brackets  12  can be bonded or otherwise coupled to upper surfaces of the bottom walls  34  of the inner rails  6 . In other embodiments, there can be spaces between the upper ends of the brackets  12  and the top walls  32  of the inner rail sections  6  and/or spaces between the bottom ends of the brackets  12  and the bottom walls  34  of the inner rail sections  6 . Each end of the cross-members can be joined in the same manner by respective brackets to the proximate frame rail. The brackets  12  further provide increased strength in the high-stress areas where the crossmembers  8  are joined to the box sections  3 . 
         [0016]    A plurality of supports  10 , which can be comprised of composite material, can be positioned within the internal spaces of the frame rails  3  to provide increased structural support to the frame rails where they are coupled to crossmembers  8 . The supports  10  make the box sections of the frame rails  3  more resistant to crushing under compressive loads when other components are bolted or otherwise attached to the box sections. The supports  10  can also support the inserts  14 . The supports  10  can comprise first and second support portions, such as shown in  FIG. 6 , that cooperate to support the inserts  14 . The first and second support portions that comprise a support can be substantially identical mirror images of each other. Each support portion can comprise a top wall  60 , a bottom wall  62 , an inner wall  64 , and an outer wall  66  that are sized and shaped to match the internal dimensions of the box sections of the frame rails  3 . When the support portions are installed, the top wall  60  can be bonded or coupled to the top wall  22  of the outside rail  4 , the bottom wall  62  can be bonded or coupled to the bottom wall  24  of the outside rail  4 , the outer wall  66  can be bonded to the side wall  20  of the outer rail  4 , and the inner wall  64  can be bonded or coupled to the side wall  30  of the inside rail  6 , as shown in  FIG. 2 . The support portions can also each comprise a facing wall  68  that is bonded or coupled to the facing wall of the other support portion of a pair of first and second support portions. Each support portion can comprise one or more cavities  70  in the facing wall  68  such that when the facing walls of two support portions are coupled together, the cavities  70  cooperate to form an opening extending through the support. The illustrated embodiments comprise two such cavities  70  per support portion, though other embodiments can comprise any number of cavities per support portion. The support portions  70  can further comprise reinforcement portions  74  around the cavities  70 , as shown in  FIG. 6 . 
         [0017]    The openings formed by adjoining pairs of the cavities  70  can be configured to surround and retain the inserts  14 . The inserts  14  can comprise or consist of strong, durable materials, such as one or more of metal, composite, or polymer materials such as thermoset materials, as well as combinations thereof. In some embodiments, the inserts  14  can be made of a material that is stronger than the material of the supports  10  to provide added strength locally. The inserts can comprise an outer end portion  50 , an inner end portion  52 , and an intermediate portion  54 . The intermediate portion  54  can comprise corrugations, ribs, or other features  56  that engage, such as mate or fit with, corresponding features in the cavities  70  to retain the inserts  14  in position against movement relative to the associated support, such as axial inward or outward movement relative to the associated support. In addition, the inner and outer end portions  50 ,  52  of the inserts  14  can have a greater diameter than the intermediate portion  56  to further restrict movement of the inserts  14  relative to the supports  70 . The inserts  14  can be bonded or secured to the cavities  70 . The corrugated or featured shape of the intermediate portion  54  provides an increased bonding surface area. 
         [0018]    The inserts  14  desirably can have a generally cylindrical shape with a circular cross-section, as in the illustrated embodiment, but can have various other cross-sectional shapes in other embodiments, such as ovular, star-shaped, rectangular, triangular, or other non-circular cross-sectional shapes. The cavities  70  of the support portions can have a shape that matches the shape of the inserts  14 . 
         [0019]    The frame  2  can further comprise aligned holes in the various components through which the inserts  14  extend. For example, the outside rail sections  4  can comprise holes  80  in the side walls  20 , the inside rail sections  6  can comprise holes  82  in the side walls  30 , and the brackets  12  can comprise holes  84  in the side flanges  48 . The holes  80 ,  82 , and  84  can be formed with various processes, such as drilling or during manufacture of the frame rail sections. The holes  80 ,  82 ,  84  can be aligned with the cavities  70  in the supports  10  such that the inserts  14  can extend through the holes  80 ,  82 ,  84  as well as the supports  10 . The outer end portions  50  of the inserts  14  can extend through the holes  80  in the outer rail  4 . The outer end portions  50  can be flush with the outer surface of the side wall  20  of the outside rail  4 . The inner end portions  52  can extend through the holes  82  in the inside rails  6  and through the holes  84  in the brackets  12 . The inside end portions  52  can be flush with the inner surfaces of the side flanges  48  of the brackets  12 . 
         [0020]    The inserts  14  can further comprise an internal axially extending opening  58  extending entirely through the insert from the outer end portion  50  to the inner end portion  52 . In this case, the inserts in effect comprise a tube that can be of metal. The internal openings  58  can serve various purposes. For example, the internal openings  58  can be threaded and serve as bolt holes, such as for attaching other components to the frame  2 . The internal openings  58  can also serve as conduits for other objects to pass laterally through the box sections  3 . 
         [0021]    In some embodiments, bolts or other fasteners can be positioned through the internal openings  58  to clamp the brackets  12 , inside rail sections  6 , supports  10 , and outside rail sections  4  together, either permanently or temporarily, such as until bonding together of the frame components is complete. As an example of bonding, an adhesive can be used to accomplish the bonding, less desirably, welding or bolting can be used. 
         [0022]    The supports  10  and inserts  14  increase the strength of the frame rails  3  in bending, compression and torsion. The aligned combination of the crossmember  8  with the supports  10  and inserts  14  can support high lateral compressive loads on the frame. 
         [0023]    With the possible exception of the inserts  14 , which are desirably made of metal, the other components of the frame  2  can all be comprised of or consist entirely of composite materials, making the frame  2  lighter in weight compared to traditional metal frames. The composites used in the frame  2  can comprise any strong, lightweight composite or plurality of composites, such as fiber reinforced polymer composites. Examples of composite components include various fibers, resins, strengtheners, and other additives. Exemplary fibers include carbon fibers, glass fibers, aromatic polyamide fibers, such as Kevlar, and natural fibers, such as lignocellulosic fibers. Exemplary resins include phenolic resins, epoxies, polyesters, vinyl esters, polyetherketones, polyehterimides, polyethersulphone, high density polyethylenes, polycarbonates, acrylonitrile-butadiene-styrenes, polypropylene, nylon, and other thermoplastic and/or thermosetting polymers. 
         [0024]    Several components of the frame  2 , including the outside rail sections  4 , inside rail sections  6 , crossmembers  8 , and brackets  12 , can be manufactured using pultrusion processes, such as processes wherein unidirectional tows, woven mats, and/or other uncured composite materials are laid-up on a mandrel and pulled through a curing apparatus to form an elongated composite member having a generally constant cross-section. A more detailed description of exemplary fiber reinforced polymer materials and of exemplary pultrusion and related process, which can be used to manufacture components of the frame  2 , can be found in U.S. Patent Application Publication No. US-2011-0204611-A1, entitled “Fiber Reinforced Polymer Frame Rail,” which was filed on Feb. 17, 2011, and which is herein incorporated by reference in its entirety. 
       General Considerations 
       [0025]    For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed embodiments should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. 
         [0026]    As used herein, including in the claims, the terms “left”, “right”, “front”, “rear”, “top” and “bottom” refer to conventional portions of a vehicle in which the described box frame is configured to be incorporated, from the perspective of a driver of the vehicle. Thus, the left side is the driver&#39;s side in the United States, the right side is the passenger&#39;s side in the United States, the bottom is the portion of the vehicle closest to the ground, the front end is the leading end of the vehicle when the vehicle is traveling forward and the rear end is the leading end when the vehicle is traveling in reverse. The term “frontward” means toward the front and the term “rearward” means toward the rear. The term “upper” means toward the top and term “lower” means toward the bottom. Similarly, the terms “inner,” “inside” and “inwardly” mean toward a longitudinally extending vertical center plane of the vehicle that divides the vehicle into left and right halves, and the terms “outer,” “outside” and “outwardly” mean away from the center plane and toward the left or right side of the vehicle. 
         [0027]    As used herein, the terms “a”, “an” and “at least one” encompass one or more of the specified element. That is, if two of a particular element are present, one of these elements is also present and thus “an” element is present. The terms “a plurality of” and “plural” mean two or more of the specified element. 
         [0028]    As used herein, the term “and/or” used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase “A, B, and/or C” means “A,” “B,” “C,” “A and B,” “A and C,” “B and C” or “A, B and C.” 
         [0029]    As used herein, the term “coupled” generally means physically coupled or linked and does not exclude the presence of intermediate elements between the coupled items absent specific contrary language. 
         [0030]    In view of the many possible embodiments to which the principles disclosed herein may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope of these claims.