Patent Publication Number: US-2018036841-A1

Title: Polymeric preassembly device and assembly method

Description:
TECHNICAL FIELD 
     This disclosure relates generally to an assembly method, and more particularly to loosely connecting first and second metallic components of an assembly using a polymeric preassembly device. 
     BACKGROUND 
     Automotive vehicles are commonly assembled by passing various metallic components through a succession of work stations associated with an assembly line. For example, a vehicle structural frame is assembled by attaching body side assemblies to underbody and roof components (e.g., headers, bows, etc.). Metallic toy tabs are used to connect components of the vehicle structural frame. The toy tabs are designed to prevent the components from disconnecting from one another prior to reaching welding stations of the assembly line. The metallic toy tabs can increase the cost and complexity of the assembly process. 
     SUMMARY 
     An assembly according to an exemplary aspect of the present disclosure includes, among other things, a first metallic component, a polymeric preassembly device affixed to the first metallic component, and a second metallic component received over the polymeric preassembly device to loosely connect the first metallic component and the second metallic component. 
     In a further non-limiting embodiment of the foregoing assembly, the first metallic component and the second metallic component are sheet metal components. 
     In a further non-limiting embodiment of either of the foregoing assemblies, the first metallic component is a handoff bracket and the second metallic component is a roof header or roof bow. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the assembly is a subassembly of a vehicle structural frame. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the polymeric preassembly device is received through a first opening of the first metallic component and through a second opening of the second metallic component. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the first opening and the second opening are oval shaped. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the polymeric preassembly device includes a base and a pin that protrudes from the base. 
     In a further non-limiting embodiment of any of the foregoing assemblies, fins or projections protrude radially outwardly from the pin. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the base is positioned proximate a bottom surface of the first metallic structure and the pin is positioned proximate a top surface of the first metallic structure. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the polymeric preassembly device is rotatable between a first position in which fins or projections of the polymeric preassembly device are aligned with a longitudinal axis of an opening of the first metallic component and a second position in which the fins or projections are perpendicular to the longitudinal axis. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the polymeric preassembly device includes a pin having a tapered tip portion. 
     In a further non-limiting embodiment of any of the foregoing assemblies, the polymeric preassembly device includes a base, a pin extending outwardly from the base, and projections that protrude from the pin, and the projections each include an angled surface. 
     An assembly method according to another exemplary aspect of the present discourse includes, among other things, securing a polymeric preassembly device to a first metallic component, loading a second metallic component over the polymeric preassembly device to loosely connect the first metallic component and the second metallic component, and bonding the first metallic component and the second metallic component together. 
     In a further non-limiting embodiment of the foregoing assembly method, the method includes removing the polymeric preassembly device after the welding. 
     In a further non-limiting embodiment of either of the foregoing assembly methods, the securing includes inserting the polymeric preassembly device through an opening of the first metallic component and rotating the polymeric preassembly device to lock its position relative to the first metallic component. 
     In a further non-limiting embodiment of any of the foregoing assembly methods, fins or projections of the polymeric preassembly device are aligned with a longitudinal axis of the opening during the inserting and are perpendicular to the longitudinal axis after the rotating. 
     In a further non-limiting embodiment of any of the foregoing assembly methods, the polymeric preassembly device is secured to the first metallic component after the first metallic component arrives at a work station of an assembly line. 
     In a further non-limiting embodiment of any of the foregoing assembly methods, the loading includes inserting a pin of the polymeric preassembly device through an opening of the second metallic component. 
     wont In a further non-limiting embodiment of any of the foregoing assembly methods, the bonding includes welding the second metallic component to the first metallic component. 
     In a further non-limiting embodiment of any of the foregoing assembly methods, the securing includes positioning a base of the polymeric preassembly device proximate to a bottom surface of the first metallic component and positioning a fin or projection of the polymeric preassembly device proximate to a top surface of the first metallic component. 
     The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
     The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates a vehicle structural frame. 
         FIG. 2  illustrates an assembly that includes a polymeric preassembly device. 
         FIGS. 3A and 3B  illustrate the polymeric preassembly device of the assembly of  FIG. 2 . 
         FIG. 4  illustrates another exemplary polymeric preassembly device. 
         FIGS. 5A, 5B, 5C, and 5D  illustrate yet another exemplary polymeric preassembly device. 
         FIGS. 6, 7, 8, 9, 10, 11 and 12  schematically illustrate an assembly method. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure describes an assembly and an associated assembly method. The assembly includes a first metallic component and a second metallic component that are loosely connected to one another using a polymeric preassembly device. The polymeric preassembly device temporarily maintains a positioning of the first metallic component relative to the second metallic component prior to welding the metallic components together. These and other features are discussed in greater detail in the following paragraphs of this detailed description. 
       FIG. 1  illustrates an exemplary vehicle structural frame  10 . The vehicle structural frame  10  is positioned at a work station  12  of an assembly line. Among various other components, the vehicle structural frame  10  includes body side assemblies  14 , an underbody  16 , and roof components  18  (e.g., headers, bows, brackets, etc.). 
     In a non-limiting embodiment, the work station  12  is a welding station of the assembly line. The body side assemblies  14 , which may include right and left side assemblies, may be welded to the underbody  16  and the roof components  18  at the work station  12 . The vehicle structural frame  10  is depicted in what is referred to as its body in white (BIW) state. BIW generally refers to a state of the vehicle structural frame  10  prior to installation of the powertrain, the exterior trim, and the interior components of a vehicle. 
     It may be desirable to loosely connect the components of the vehicle structural frame  10  so they are in proper welding position upon reaching the work station  12 . This disclosure contemplates polymeric preassembly devices designed for this purpose. In particular, and as described in greater detail below, the polymeric preassembly devices of this disclosure maintain a positioning of the metallic components of an assembly as the assembly passes from work station to work station of an assembly line and prior to reaching welding stations where the metallic components will become permanently connected. 
       FIG. 2  illustrates an assembly  20 . The assembly  20  may be a subassembly of the vehicle structural frame  10  of  FIG. 1 , for example, or could be any other assembly. It should be understood that the teachings of this disclosure are not limited to vehicle assemblies and could extend to any assembly that is assembled on an assembly line. 
     The exemplary assembly  20  includes a first metallic component  22 , a second metallic component  24 , and a polymeric preassembly device  26 . The polymeric preassembly device  26  is adapted to loosely connect the first metallic component  22  and the second metallic component  24  to construct the assembly  20 . Although a single polymeric preassembly device  26  is shown in  FIG. 2 , the assembly  20  could employ any number of such devices to loosely, or temporarily, hold metallic components relative to one another. 
     The polymeric preassembly device  26  is received through an opening  28  of the first metallic component  22  and may then be rotated to affix the polymeric preassembly device  26  to the first metallic component  22 . The second metallic component  24  may then be received over the polymeric preassembly device  26  such that it at least partially overlaps the first metallic component  22 . The polymeric preassembly device  26  is received through an opening  30  of the second metallic component  24  to loosely connect these components. 
     The polymeric preassembly device  26  substantially prevents the first and second metallic components  22 ,  24  from becoming dislodged from one another during an assembly process. For example, in a non-limiting embodiment, the polymeric preassembly device  26  maintains a positioning of the second metallic component  24  relative to the first metallic component  22  as the assembly  20  travels along an assembly line prior to reaching welding stations where the first and second metallic components  22 ,  24  will be permanently connected. 
     In a non-limiting embodiment, the first and second metallic components  22 ,  24  are sheet metal components. In another non-limiting embodiment, the first metallic component  22  is a handoff bracket and the second metallic component  24  is a header or roof bow of a vehicle structural frame. However, other metallic components could also be loosely connected using the polymeric preassembly device  26  or a series of such devices. 
       FIGS. 3A and 3B  illustrate an exemplary polymeric preassembly device  26 . The polymeric preassembly device  26  may be made of any suitable polymer or combination of polymers. In a non-limiting embodiment, the polymeric preassembly device  26  is made of a nylon material. 
     The polymeric preassembly device  26  may include a base  32  and a pin  34  that protrudes outwardly from the base  32 . In a non-limiting embodiment, the base  32  is rectangular and the pin  34  is cylindrical. However, this disclosure is not limited to these specific shapes. 
     The pin  34  includes a main body  36  that extends to a tapered tip portion  38 . In a non-limiting embodiment, the tapered tip portion  38  embodies the shape of a truncated cone. Fins  40 , or projections, protrude radially outwardly from the main body  36 . Two fins  40  are depicted in the illustrated embodiment; however, the polymeric preassembly device  26  could be designed with more or less fins. In another non-limiting embodiment, the fins  40  taper in a direction that extends from the base  32  toward the tapered tip portion  38 . 
     Referring now to  FIGS. 2, 3A, and 3B , the fins  40  and the base  32  facilitate attachment of the polymeric preassembly device  26  to the first metallic component  22 . For example, the pin  34  of the polymeric preassembly device  26  may be inserted through the opening  28  of the first metallic component  22  such that the fins  40  are positioned on a first side of the first metallic component  22  and the base  32  is positioned on an opposite side of the first metallic component  22 . The polymeric preassembly device  26  may then be rotated to lock the device to the first metallic component  22 . Once rotated, the fins  40  create interference with the outer surface of the first metallic component  22  and thus prevent the polymeric preassembly device  26  from falling back through the opening  28 . In addition, once locked into place, the pin  34  of the polymeric preassembly device  26  acts as a temporary locator for receiving the second metallic component  24 . The first and second metallic components  22 ,  24  are considered loosely connected to one another once the second metallic component  24  is received over the pin  34  of the polymeric preassembly device  26 . 
     Another exemplary polymeric preassembly device  126  is illustrated in  FIG. 4 . The polymeric preassembly device  126  includes a slightly modified design compared to the polymeric preassembly device  26  of  FIGS. 3A and 3B . In this embodiment, the polymeric preassembly device  126  includes a base  132  and a pin  134  that protrudes outwardly from the base  132 . The pin  134  includes a main body  136  that extends to a tapered tip portion  138 . 
     Pegs  140  protrude from the main body  136 . In a non-limiting embodiment, the pegs  140  are more proximate to the base  132  than to the tapered tip portion  138 . The pegs  140  and the base  132  facilitate attachment of the polymeric preassembly device  126  to other components. 
       FIGS. 5A, 5B, 5C, and 5D  illustrate yet another exemplary polymeric preassembly device  226 . The polymeric preassembly device  226  includes a base  232  and a pin  234  that protrudes outwardly from the base  232 . The pin  234  may taper toward a tip portion  238 . 
     Projections  240  protrude radially outwardly from the pin  234 . Two projections  240  are depicted in the illustrated embodiment; however, the polymeric preassembly device  226  could be designed with more or less projections. In another non-limiting embodiment, the projections  240  are generally triangular shaped. For example, each projection  240  may include arms  241  and a web  243  that extends diagonally between the arms  241  (best illustrated in top view of  FIG. 5C ). 
     Together, the projections  240  and the base  232  facilitate attachment of the polymeric preassembly device  226  to a component, such as the first metallic component  22  of  FIG. 2 . For example, the pin  234  of the polymeric preassembly device  226  may be inserted through the opening  28  of the first metallic component  22  such that the projections  240  are positioned on a first side of the first metallic component  22  and the base  232  is positioned on an opposite side of the first metallic component  22 . The polymeric preassembly device  226  may then be rotated to lock the device to the first metallic component  22 . 
     The projections  240  may include angled surfaces  245 . The angled surfaces  245  act as lead-in surfaces for receiving and locking the first metallic component  22  between the base  232  and the projections  240  of the polymeric preassembly device  226 . 
     Once rotated, the projections  240  create interference with the outer surface of the first metallic component  22  and thus prevent the polymeric preassembly device  226  from falling back through the opening  28 . In addition, once locked into place, the pin  234  of the polymeric preassembly device  226  acts as a temporary locator for receiving another component, such as the second metallic component  24 . 
       FIGS. 6-12 , with continued reference to  FIGS. 1-5D , schematically illustrate an exemplary assembly method that utilizes the polymeric preassembly device  26  (or the polymeric preassembly devices  126  or  226 ).  FIGS. 6 through 12  illustrate, in sequential order, a non-limiting embodiment for assembling the assembly  20  of  FIG. 2 . In a non-limiting embodiment, the assembly  20  is a subassembly of the vehicle structural frame  10 . It should be understood that fewer or additional steps than are recited below could be performed and that the recited order of steps is not intended to limit this disclosure. 
     Referring first to  FIGS. 6 and 7 , the polymeric preassembly device  26  is inserted through the opening  28  of the first metallic component  22 . In a non-limiting embodiment, the opening  28  is oval to facilitate insertion of the polymeric preassembly device  26 . The polymeric preassembly device  26  may be inserted from a bottom side of the first metallic component  22  such that the base  32  is positioned proximate a bottom surface  50  of the first metallic component  22  and the fins  40  are positioned proximate a top surface  52  of the first metallic component  22  (best illustrated in  FIG. 7 ). During insertion, the fins  40  of the polymeric preassembly device  26  are substantially aligned with a longitudinal axis A of the opening  28  to ensure that the polymeric preassembly device  26  easily fits through the opening  28 . 
     The polymeric preassembly device  26  is next fixated to the first metallic component  22 . As shown in  FIG. 8 , the polymeric preassembly device  26  may be affixed to the first metallic component  22  by rotating the polymeric preassembly device  26 . In a non-limiting embodiment, the polymeric preassembly device  26  is rotated 90 degrees in a clockwise direction to lock it onto the first metallic component  22 . Depending on the configuration of the opening  28 , the polymeric preassembly device  26  could alternatively be rotated counterclockwise to lock it into position. 
     In the rotated position shown in  FIG. 8 , the fins  40  of the polymeric preassembly device  26  are generally perpendicular to the longitudinal axis A of the opening  28 . The fins  40  therefore create interference with the material surrounding the opening  28  to prevent the polymeric preassembly device  26  from dislodging from the first metallic component  22 . 
     In a first non-limiting embodiment, the polymeric preassembly device  26  arrives at the assembly line already connected to the first metallic component  22 . Stated another way, the polymeric preassembly device  26  may be preassembled to the first metallic component  22 . In another non-limiting embodiment, the polymeric preassembly device  26  is affixed to the first metallic component  22  after the first metallic component  22  arrives at the assembly line. 
     Next, as shown in  FIGS. 9 and 10 , the second metallic component  24  is loaded over top of the polymeric preassembly device  26 , which has already been affixed to the first metallic component  22 . The pin  34  (see  FIG. 10 ) of the polymeric preassembly device  26  act as a locator for positioning the second metallic component  24  relative to the first metallic component  22 . The pin  34  is received through the opening  30  of the second metallic component  24 , which may also be oval shaped. Once the second metallic component  24  is received over the pin  34  of the polymeric preassembly device  26 , the first and second metallic components  22 ,  24  are loosely connected and in proper welding position relative to one another. The second metallic component  24  at least partially overlaps the first metallic component  22  in this loosely connected position. 
       FIG. 11  schematically illustrates the arrival of the assembly  20  at a welding station of the assembly line. The first and second metallic components  22 ,  24  are welded together at the welding station. The welding station may utilize one or more welding tools  60  adapted to create multiple weld beads  62  for adjoining the first and second metallic components  22 ,  24 . 
     Finally, as shown in  FIG. 12 , the polymeric preassembly device  26  can be removed from the assembly  20  after the welding process. Thus, the weld beads  62  alone hold the positioning of the first and second metallic components  22 ,  24 . The polymeric preassembly device  26  may be removed by rotating it 90 degrees in an opposite direction from the fixation direction (here, counterclockwise). 
     In yet another non-limiting embodiment, the polymeric preassembly device  26  is a reusable device. Accordingly, the polymeric preassembly device  26  can be used to temporarily connect other sheet metal components once the assembly  20  has been welded. 
     The polymeric preassembly devices of this disclosure are designed to decrease costs and complexities associated with sheet metal assembly processes. The polymeric preassembly devices do not add weight to the assemblies since they are removed from the final assembly. 
     Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
     It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
     The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.