Abstract:
A joint for an automotive vehicle may be formed by applying an adhesive to at least one of a first member and a first surface of a composite member, placing the first member in contact with the first surface of the composite member, applying an adhesive to at least one of a second member and a second surface of the composite member, positioning a divot portion of the second member within an aperture of the composite member, placing the second member in contact with the second surface of the composite member, attaching the divot portion of the second member with the first member and curing the adhesives.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The invention relates to automotive structural joints and methods of making the same. 
         [0003]    2. Discussion 
         [0004]    Certain structural panels and joints are known. As an example, U.S. Pat. No. 3,256,669 to Seiwert discloses a reinforced metal panel assembly made by using a pair of metal panels and an intermediate core of suitable material such as plywood, balsa, Masonite, wall-board, aluminum or any of the other light metals. The panels are joined to produce a compressive interference fit between the panels and the core. The metal panels may be designated as an inner and an outer panel depending on their intended position in a finished structure. 
         [0005]    As another example, U.S. Pat. No. 4,791,765 to Noggle discloses a synthetic material structural body panel comprising a synthetic material. An aperture extends through the synthetic material panel. A metal attachment plate fixedly engages the synthetic material and spans the aperture. Noggle also discloses a joint between the synthetic material structural body panel and another structural body panel. The joint comprises a metal attachment plate as described above and means, such as spot welding, for securing the metal attachment plate to the other structural body panel. 
         [0006]    As yet another example, U.S. Pat. No. 6,291,792 to Fussnegger et al. discloses a welded joint made between a sheet-steel component and a sheet-aluminum component by way of a lap or web weld. Hat-like clip parts are pushed through openings in the sheet-aluminum component. The clip parts are welded at their bottom to the sheet-steel component and overlap an exposed flat side of the sheet-aluminum component with their flanges. An adhesive is introduced into a gap situated between the clip part and the sheet-aluminum component. 
       SUMMARY 
       [0007]    A joint for an automotive vehicle may comprise a composite member having opposing surfaces and including an aperture extending therethrough and a first metal member positioned adjacent to one of the opposing surfaces of the composite member. The joint may also include a second metal member positioned adjacent to the other of the opposing surfaces of the composite member. The second metal member includes a portion extending into the aperture of the composite member. The portion extending into the aperture is fixedly attached with the first metal member. The joint may further include a first uncured adhesive layer disposed between one of (i) the first metal member and the one of the opposing surfaces of the composite member and (ii) the second metal member and the other of the opposing surfaces of the composite member. 
         [0008]    A structural member for an automotive vehicle may include a composite panel having opposing sides and a surface defining an aperture therethrough. The structural member may also include first and second metal panels respectively adhesively bonded to the opposing sides of the composite panel. The first and second metal panels each include a button formed thereon. The buttons each extend into the aperture and are attached together. 
         [0009]    A structural joint for an automotive vehicle may comprise a composite member having opposing surfaces and including an aperture extending therethrough, a first member adhered with one of the opposing surfaces of the composite member and a second member adhered with the other of the opposing surfaces. The second member includes a portion extending into the aperture of the composite member. The portion extending into the aperture is fixedly attached with the first member. 
         [0010]    A method of forming a structural joint for an automotive vehicle may include applying an adhesive to at least one of a first member and a first surface of a composite member, placing the first member in contact with the first surface of the composite member and applying an adhesive to at least one of a second member and a second surface of the composite member opposite the first surface. The method may also include positioning a divot portion of the second member within an aperture of the composite member, placing the second member in contact with the second surface of the composite member, attaching the divot portion of the second member with the first member and curing the adhesives. 
         [0011]    While example embodiments in accordance with the invention are illustrated and disclosed, such disclosure should not be construed to limit the claims. It is anticipated that various modifications and alternative designs may be made without departing from the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of an embodiment of a portion of an automotive structural joint. 
           [0013]      FIG. 2A  is an exploded view, in cross-section, of the automotive structural joint of  FIG. 1 . 
           [0014]      FIG. 2B  is an assembly view, in cross-section, of the automotive structural joint of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Referring now to  FIG. 1 , a composite member  10  is sandwiched between members  12 ,  14  to form a structural joint  16 . The composite member  10  may comprise any synthetic material suitable for use as a structural member for an automotive vehicle. For example, the composite member  10  may comprise a non-reinforced or fiber-reinforced thermoplastic and/or a thermoset plastic. The material comprising the composite member  10  may be selected based on the particular application for which it is intended. Suitable commercially available fibers include glass fibers, carbon fibers, etc. and any combination thereof. Of course, other suitable materials may be used. 
         [0016]    The members  12 ,  14  may comprise any suitable metal, e.g., steel, aluminum, etc., for use in automotive applications. For example, the member  12  may comprise a steel doubling plate and the member  14  may comprise a structural steel rail configured to act as a load bearing member of a vehicle body. 
         [0017]    The composite member  10  of a chosen synthetic material may be formed or shaped into the desired configuration using any suitable technique. Such suitable techniques include injection molding, resin transfer molding and compression molding. The technique used may depend on the material employed. For example, compression molding techniques may be applied to sheet molding compounds (SMC) including a fiber-reinforced thermoset polyester. 
         [0018]    In the embodiment of  FIG. 1 , buttons  18 , e.g., divots, depressions, etc., are provided in the member  12  and extend into respective apertures  20  in the composite member  10 . The buttons  18  may be stamped or otherwise integrally formed with the member  12 . In other embodiments, the buttons  18  may be provided in the member  14  in addition to, or instead of, the member  12 . In certain of these embodiments, some of the buttons  18  provided in the members  12 ,  14  may extend into the same apertures  20  (and, for example, meet in a middle of the apertures  20 ) while other of the buttons  18  may extend into different apertures  20 . For example, the buttons  18  provided in the members  12 ,  14  may extend into every other of the apertures  20  in an alternating fashion. Of course, other configurations are also possible. 
         [0019]    The buttons  18  of  FIG. 1  are sized relative to the apertures  20  so as to provide a clearance fit. In other embodiments, the buttons  18  may be sized relative to the apertures  20  so as to provide an interference fit. 
         [0020]    The structural joint  16  illustrated in  FIG. 1  includes three buttons positioned generally along an axis, A. Of course, a greater or fewer number of the buttons  18  may be used. In other embodiments, the buttons  18  may be positioned to form a grid or other desired pattern/layout. 
         [0021]    In some embodiments, a portion of each of the buttons  18  contact and are welded, as discussed below, to the member  14 . In other embodiments, the buttons  18  may be riveted, bolted or otherwise mechanically fastened to the member  14 . Additionally, the buttons  18  (and the apertures  20 ) may be of sufficient size so as to permit several welds per button  18 . 
         [0022]    The buttons  18  may be formed so that portions of the member  12  lie flush against the composite member  10 . For example, the buttons  18  may have a depth approximately equal to the thickness of the composite member  10 . The buttons  18  may also be formed so that portions of the member  12  are spaced away from the composite member  10 . For example, the buttons  18  may have a depth that is greater than the thickness of the composite member  10 . Other configurations and arrangements are also possible. 
         [0023]    The apertures  20  may be formed during the initial manufacture of the composite member  10 . For example, the apertures  20  may be cut into the composite member  10  or may be provided by appropriate design of the tooling used in molding the composite member  10 . 
         [0024]    The apertures  20  of  FIG. 1  have a shape complimentary to the buttons  18 . In other embodiments, the apertures  20  may, for example, have a shape non-complimentary to the buttons  18 . For example, the apertures  20  may have a square shape and the buttons  18  may have a conical shape. 
         [0025]    As discussed below, the members  12 ,  14  are bonded with the composite member  10  so as to span, e.g., cover, the apertures  20  of the composite member  10 . The buttons  18  of  FIG. 1  engage the apertures  20  to, inter alia, locate the member  12  relative to the composite member  10 . When the members  12 ,  14  are attached with the composite member  10 , at least a portion of the composite member  10  surrounding the apertures  20  is sandwiched between the members  12 ,  14 . The members  12 ,  14  may be adhesively bonded, as discussed below, or otherwise fixedly engaged with the composite member  10  so as to cover the apertures  20 . 
         [0026]    Adhesives for bonding the members  12 ,  14  with the composite member  10  may include an epoxy, urethane, acrylic, etc., applied, for example, as a tape, liquid, paste or pressure sensitive adhesive. Any suitable adhesive, however, may be used. The selection of a suitable adhesive may depend on the material comprising the composite member  10 , the cost of the adhesive, ease of processing the adhesive, the intended use of the structural joint  16 , etc. The adhesives may be cured by heat, room-temperature chemical reaction, induction or any other curing method. 
         [0027]    In some embodiments, gaps between the members  10 ,  12  and  10 ,  14  may be determined by glass beads, wires, stand-offs on any of the members  10 ,  12 ,  14 , assembly fixturing, etc. 
         [0028]    As apparent to those of ordinary skill, the composite member  10  and the members  12 ,  14  may have any configuration suitable for the environment and/or intended use of the structural joint  16 . For example, in embodiments where the member  14  is curved, the composite member  10  and member  12  may also be formed with corresponding curves to mate with the member  14 . Likewise, the apertures  20  and buttons  18  may have any suitable configuration for the environment and/or intended use of the structural joint  16 . For example, the apertures  20  may have a triangular, square or other suitable shape. Similarly, the buttons  18  may have a mating triangular, square or other suitable shape similar or dissimilar to the shape of the apertures  20 . 
         [0029]    Referring now to  FIGS. 2A and 2B , the following may be performed to assemble the structural joint  16 . An adhesive layer  22  is applied to one or both of the composite member  10  and the member  14 . The member  14  is then placed in contact with the composite member  10 . An adhesive layer  24  is applied to one or both of the composite member  10  and the member  12 . The member  12  is positioned relative to the composite member  10  such that the button  18  is in registration with the aperture  20 . The member  12  is then placed in contact with the composite member  10 . The button  18  is fixedly attached, e.g., spot welded, with the member  14  at weld  26 . The adhesive layers  22 ,  24  are then cured to bond the composite member  10  with the members  12 ,  14 . Because the button  18  is fixedly attached with the member  14  prior to curing, there is no need for fixturing or other machinery to hold the members  12 ,  14  in place relative to one another during the curing process. 
         [0030]    In other embodiments, the adhesive layer  24  may first be applied to one or both of the composite member  10  and the member  12 . The member  12  may then be positioned relative to the composite member  10  such that the button  18  is in registration with the aperture  20 . The member  12  may then be placed in contact with the composite member  10 . The adhesive layer  22  may next be applied to one or both of the composite member  10  and the member  14 . The member  14  may then be placed in contact with the composite member  10 . Welding, for example, of the button  18  with the structural member  14  and curing of the adhesive layers  22 ,  24  may follow. In still other embodiments, the adhesive layers  22 ,  24  may be applied at the same time, etc., prior to fixedly attaching and curing. Alternatively, a single adhesive layer may also be applied prior to fixedly attaching and curing. 
         [0031]    The structural joint  16  may be used in a variety of applications. For example, the structural joint  16  may be used to join a composite floorpan of an automotive vehicle to a steel frame rail, dash-panel and rear floor of the vehicle. The structural joint  16  may also be used to join a composite hood inner panel of an automotive vehicle to steel hinge reinforcements of the vehicle, etc. 
         [0032]    While only certain embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, 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.