Patent Publication Number: US-2005116460-A1

Title: Method of manufacturing a frame assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of U.S. Provisional Application No. 60/512,167, filed Oct. 17, 2003, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      This invention relates in general to methods of manufacturing frame assemblies. In particular, this invention relates to an improved method of manufacturing a vehicular frame assembly that facilitates the manufacture of fast-to-market, low-volume, customized vehicles in a cost-effective manner.  
      Many land vehicles in common use, such as automobiles, vans, and trucks, include a frame assembly that is supported upon a plurality of ground-engaging wheels by a resilient suspension system. The structures of known frame assemblies can be divided into two general categories, namely, separate and unitized. In a typical separate frame assembly, the structural components of the frame portion of the vehicle are separate and independent from the structural components of the body portion of the vehicle. When assembled, the frame portion of the assembly is resiliently supported upon the vehicle wheels by the suspension system and serves as a platform upon which the body portion of the assembly and other components of the vehicle can be mounted. Separate frame assemblies of this general type are found in most older vehicles, but remain in common use today for many relatively large or specialized use modern vehicles, such as large vans, sport utility vehicles, and trucks. In a typical unitized frame assembly, sometimes referred to as a space frame assembly, the structural components of the body portion and the frame portion are combined into a single integral unit that is resiliently supported upon the vehicle wheels by the suspension system. Unitized frame assemblies of this general type are found in many relatively small modern vehicles, such as automobiles and minivans.  
      Traditionally, a vehicular or other type of frame assembly has been manufactured by providing a plurality of stamped structural components, supporting some or all the structural components on a fixture in a desired orientation relative to one another, and securing the structural components together in the desired orientation using traditional welding techniques, such as by resistance spot welding. Often, the stamped structural components are sequentially joined together by laying them on the vehicle piecemeal (or in large, semi-rigid subassemblies), one layer on top of another with each layer being welded to one or more of the previous layers. This manufacturing method results in a variety of unfavorable conditions. First, the number of discrete structural components is very large, requiring a large number of stamping tools, assembly fixtures, and welders to assemble them. Also, a relatively lengthy set-up time is necessary to properly support the plurality of structural components in the desired orientations prior to securement. Although at least some of these numerous structural components could be combined into relatively large, monolithic stampings to facilitate the assembly process, the manufacture of such physically large stampings would likely require enormous and expensive tools and presses. Second, a large amount of the welding of the assembly must typically take place in the final manufacturing location (i.e., not at the manufacturing location of a supplier to its customer). This increases the amount of capital and tooling that is required by the customer to manufacture the frame assemblies and reduces the opportunities for outsourcing from the customer to the supplier. Third, resistance spot welding and other conventional welding techniques typically have a relatively long cycle time, resulting in low weld speeds. Also, the weld tips usually require frequent maintenance in the form of cleaning and dressing, which further hampers productivity. These cleaning issues, while a minor inconvenience with steel alloys, can become more pronounced with coated steels or aluminum structures. Also, the use of traditional welding processes, such as resistance spot welding, usually requires physical access to both sides of the structural components to be joined, which can be problematic. Fourth, the opportunity of a supplier to supply large, value added modular components to a customer is diminished because the number of structure components that can be integrated into a subassembly in the supplier&#39;s manufacturing location is severely limited by weld access. Lastly, those subassemblies that are manufactured at the supplier&#39;s manufacturing location will be somewhat flexible and, therefore, not fully structurally sound during transit from the supplier&#39;s manufacturing location to the customer&#39;s manufacturing location, thus presenting the potential for damage in transit that can result in quality issues. Thus, although this traditional method of frame manufacture has functioned satisfactorily, particularly in the manufacture of high volumes of a single frame assembly structure, it has been found that this traditional method does not readily lend itself to the efficient manufacture of fast-to-market, low-volume, customized vehicle or other frame assemblies.  
      More recently, it has been proposed to manufacture a vehicular or other frame assembly using modular techniques. For example, it has been proposed to manufacture a vehicular frame assembly by initially manufacturing an underbody assembly and a pair of bodyside assemblies, then joining the underbody and bodyside assemblies together to form the vehicular frame assembly. However, known methods of manufacturing the frame assembly using modular techniques have suffered from the same deficiencies as the traditional method for manufacturing the frame assembly described above. Thus, it would be desirable to provide an improved method of manufacturing a vehicular or other frame assembly that facilitates the manufacture of fast-to-market, low-volume, customized vehicles or other articles in a cost-effective manner, without compromising styling and performance.  
     SUMMARY OF THE INVENTION  
      This invention relates to an improved method of manufacturing a vehicular or other frame assembly that facilitates the manufacture of fast-to-market, low-volume, customized frames or other articles in a cost-effective manner, without compromising styling and performance. The method of manufacturing the frame assembly includes the steps of providing an underbody assembly including a plurality of structural components that are secured together so as to be generally planar in shape; providing first and second sidebody assemblies that each include a plurality of structural components that are secured together so as to be generally planar in shape; and securing the underbody assembly to the first and second sidebody assemblies to form a frame assembly. The underbody assembly can be formed by securing first and second longitudinally extending, closed channel beams to a plurality of closed channel cross members. Each of the sidebody assemblies can be formed by securing a closed channel lower rocker rail and closed channel upper roof rail to a plurality of pillars. Each of the pillars can be formed by initially securing a first stamping to the lower rocker rail and the upper roof rail, then securing a second stamping to each of the first stampings. The underbody assembly can be secured to the first and second sidebody assemblies by magnetic pulse welding to form the frame assembly.  
      Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view illustrating a first step in a method of manufacturing an underbody assembly for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 2  is a perspective view illustrating a second step in a method of manufacturing an underbody assembly for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 3  is a perspective view illustrating a third step in a method of manufacturing an underbody assembly for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 4  is a perspective view illustrating a fourth step in a method of manufacturing an underbody assembly for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 5  is a perspective view illustrating a fifth step in a method of manufacturing an underbody assembly for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 6  is a side elevational view of a plurality of underbody assemblies that have been manufactured in accordance with the steps illustrated in  FIGS. 1 through 5 , shown stacked and nested within one another.  
       FIG. 7  is a perspective view illustrating a first step in a method of manufacturing a pair of bodyside assemblies for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 8  is a perspective view illustrating a second step in a method of manufacturing a pair of bodyside assemblies for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 9  is a perspective view illustrating a third step in a method of manufacturing a pair of bodyside assemblies for use in a vehicle frame assembly in accordance with this invention.  
       FIG. 10  is a side elevational view of one of the bodyside assemblies illustrated in  FIG. 9 .  
       FIG. 11  is a side elevational view similar to  FIG. 10  of a first alternative embodiment of one of the bodyside assemblies.  
       FIG. 12  is a side elevational view similar to  FIG. 10  of a second alternative embodiment of one of the bodyside assemblies.  
       FIG. 13  is a side elevational view similar to  FIG. 10  of a third alternative embodiment of one of the bodyside assemblies.  
       FIG. 14  is a side elevational view similar to  FIG. 10  of a fourth alternative embodiment of one of the bodyside assemblies.  
       FIG. 15  is a perspective view illustrating a first step in a method of manufacturing a vehicle frame assembly in accordance with this invention.  
       FIG. 16  is a perspective view illustrating a second step in a method of manufacturing a vehicle frame assembly in accordance with this invention.  
       FIG. 17  is a perspective view illustrating a third step in a method of manufacturing a vehicle frame assembly in accordance with this invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring now to the drawings, there is illustrated in  FIGS. 1 through 5  a method of manufacturing an underbody assembly for use in a vehicle or other frame assembly in accordance with this invention. In a first step of the method illustrated in  FIG. 1 , first and second longitudinally extending beams  10   a  and  10   b  are provided. The first and second longitudinal beams  10   a  and  10   b  can be formed from any desired material or combination of materials and may have any desired shape or shapes, including different shapes than as shown. Each of the illustrated first and second longitudinal beams  10   a  and  10   b  is formed from a single, closed channel structural member. However, either or both of the first and second longitudinal beams  10   a  and  10   b  can be formed from an assembly of multiple pieces. Furthermore, either or both of the first and second longitudinal beams  10   a  and  10   b  can be formed either partially or completely from open channel structural members. In the illustrated embodiment, the first and second longitudinal beams  10   a  and  10   b  are shown positioned in a side-by-side manner, which can be achieved by appropriate fixtures. However, it will be appreciated that the first and second longitudinal beams  10   a  and  10   b  can be positioned in any desired orientation relative to one another, and further may be positioned at separate workstations, at least during the initial steps of the assembly method of this invention.  
       FIG. 2  illustrates a second step in a method of manufacturing an underbody assembly for use in a vehicle or other frame assembly in accordance with this invention. As shown therein, a first plurality of floor cross members  11   a  and a first floor pan subassembly  12   a  are secured to the first longitudinal beam  10   a.  Similarly, a second plurality of floor cross members  11   b  and a second floor pan subassembly  12   b  are secured to the second longitudinal beam  10   b.  Each of the illustrated floor cross members  11   a  and  11   b  is formed from a single, closed channel structural member. However, some or all of the floor cross members  11   a  and  11   b  can be formed either partially or completely from open channel structural members. The floor cross members  11   a  and  11   b  can be formed from any desired material or combination of materials and can be respectively secured to the first and second longitudinal beams  10   a  and  10   b  by any desired method, such as by magnetic pulse welding. Similarly, the floor pan subassemblies  12   a  and  12   b  can be formed from any desired material or combination of materials and can be respectively secured to the first and second longitudinal beams  10   a  and  10   b  and to the floor cross members  11   a  and  11   b  by any desired method, such as by resistance spot welding.  
       FIG. 3  illustrates a third step in a method of manufacturing an underbody assembly for use in a vehicle or other frame assembly in accordance with this invention. As shown therein, a plurality of cross members  13  and a center tunnel subassembly  14  are secured to the first and second longitudinal beams  10   a  and  10   b.  Each of the illustrated cross members  13  is formed from a single, closed channel structural member. However, some or all of the cross members  13  can be formed either partially or completely from open channel structural members. The cross members  13  can be formed from any desired material or combination of materials and can be respectively secured to the first and second longitudinal beams  10   a  and  10   b  by any desired method, such as by magnetic pulse welding. Similarly, the tunnel subassembly  14  can be formed from any desired material or combination of materials and can be secured to the first and second longitudinal beams  10   a  and  10   b  by any desired method, such as by resistance spot welding. The joining of the first and second longitudinal beams  10   a  and  10   b  by the plurality of cross members  13  and the center tunnel subassembly  14  provides a basic underbody assembly, indicated generally at  15 .  
       FIG. 4  illustrates a fourth step in a method of manufacturing an underbody assembly for use in a vehicle or other frame assembly in accordance with this invention. As shown therein, a pair of front torque box lower panels  16   a  and  16   b  are secured to the front end of the underbody assembly  15 , and a pair of rear torque box lower panels  17   a  and  17   b  are secured to the rear end of the underbody assembly  15 . The front and rear torque box lower panels  16   a,    16   b  and  17   a,    17   b  can be formed from any desired material or combination of materials and can be secured to the underbody assembly  15  by any desired method, such as by resistance spot welding. Similarly,  FIG. 5  illustrates a fifth step in a method of manufacturing an underbody assembly for use in a vehicle or other frame assembly in accordance with this invention. As shown therein, a rear seat panel  18  is secured to the underbody assembly  15 . The rear seat panel  18  can be formed from any desired material or combination of materials and can be secured to the underbody assembly  15  by any desired method, such as by resistance spot welding. The finished underbody assembly  15  illustrated in  FIG. 5  is intended to be representative of any desired structure for an underbody assembly for use in a vehicle frame assembly.  
       FIG. 6  is a side elevational view of a plurality of underbody assemblies  15  that have been manufactured in accordance with the steps illustrated in  FIGS. 1 through 5 , wherein the underbody assemblies  15  are shown stacked and nested within one another. As is apparent from this and from  FIGS. 1 through 5 , each of the underbody assemblies  15  is generally planar in shape, having a length and a width that are both substantially greater than a depth thereof. Such a generally planar structure is important for the underbody assemblies  15  because it facilitates stacking of a plurality of such underbody assemblies  15  in a space-saving manner, as clearly shown in  FIG. 6 . As a result, the shipment of the underbody assemblies  15  from a first location, such as a supplier manufacturing location where the underbody assemblies  15  are manufactured as described above, to a second location, such as a customer manufacturing location where the underbody assemblies  15  are assembled with other subassemblies to form a vehicular frame assembly as described below, is greatly facilitated. Also, the storage of such underbody assemblies  15  at both the first and second locations, is also greatly facilitated. Lastly, because all of the primary structural components of the underbody assembly  15  (i.e., the first and second longitudinal beams  10   a  and  10   b,  the floor cross members  11   a  and  11   b,  and the cross members  13 ) are formed from closed channel structural members, the underbody assembly  15  is inherently rigid, thus facilitating the transportation thereof from one manufacturing location to another and minimizing the potential for damage in transit that can result in quality issues.  
      Referring now to  FIGS. 7 through 9 , there is illustrated a method of manufacturing a bodyside assembly for use in a vehicle or other frame assembly in accordance with this invention. In a first step of the method illustrated in  FIG. 7 , a lower rocker rail  20 , an upper roof rail  21 , a front valence member  22 , and a rear body side member  23  are provided for each of two bodyside assemblies to be manufactured. The lower rocker rail  20 , the upper roof rail  21 , the front valence member  22 , and the rear body side member  23  can be formed from any desired material or combination of materials and may have any desired shape or shapes, including different shapes than as shown. The lower rocker rails  20  and the upper roof rails  21  extend generally straight and parallel to one another. Each of the illustrated lower rocker rails  20  and the upper roof rails  21  is formed from a single, closed channel structural member. However, either or both of the lower rocker rails  20  and the upper roof rails  21  can be formed from an assembly of multiple pieces. Furthermore, either or both of the lower rocker rails  20  and the upper roof rails  21  can be formed either partially or completely from open channel structural members. The lower rocker rail  20  and the upper roof rail  21  can be formed or cut to length, allowing flexibility in the longitudinal length, or wheelbase, of the vehicle.  
      Next, as shown in  FIG. 8 , a plurality of outer pillar members  24   a,    25   a,  and  26   a  is provided that extend generally vertically between the lower rocker rail  20  and the upper roof rail  21 . The outer pillar members  24   a,    25   a,  and  26   a  can be positioned as desired relative to the lower rocker rail  20  and the upper roof rail  21  to provide flexibility in the styling and contour of the vehicle. Additionally, as will be explained in detail below, several types of vehicles can be constructed from the baseline structure described above by rearranging the existing components or by adding different components. In the illustrated embodiment, each of the outer pillar members  24   a,    25   a,  and  26   a  is formed from a stamping, although such is not required. The outer pillar members  24   a,    25   a,  and  26   a  can be formed from any desired material or combination of materials and may have any desired shape or shapes, including different shapes than as shown. The outer pillar members  24   a,    25   a,  and  26   a  can be respectively secured to the lower rocker rail  20  and the upper roof rail  21  by any desired method, such as by resistance spot welding. Other components, such as shown at  27 , can also be secured to the rear body side members  23  or other portions of the assembly as desired.  
      Then, as shown in  FIG. 9 , vertical closure panels  24   b,    25   b,  and  26   b  are respectively secured to each of the plurality of outer pillar members  24   a,    25   a,  and  26   a  to complete a pair of bodyside assemblies, each indicated generally at  28 . In the illustrated embodiment, each of the vertical closure panels  24   b,    25   b,  and  26   b  is formed from a stamping, although such is not required. The vertical closure panels  24   b,    25   b,  and  26   b  can be formed from any desired material or combination of materials and may have any desired shape or shapes, including different shapes than as shown. The vertical closure panels  24   b,    25   b,  and  26   b  can be respectively secured to the outer pillar members  24   a,    25   a,  and  26   a  by any desired method, such as by resistance spot welding.  
      Similar to the underbody assembly  15  described above, each of the bodyside assemblies  28  is generally planar in shape, having a length and a width that are both substantially greater than a depth thereof. Such a generally planar structure is important for the bodyside assemblies  28  because it facilitates stacking of a plurality of such bodyside assemblies  28  in a space-saving manner. As a result, the shipment of the bodyside assemblies  28  from a first location, such as a supplier manufacturing location where the bodyside assemblies  28  are manufactured as described above, to a second location, such as a customer manufacturing location where the bodyside assemblies  28  are assembled with other subassemblies to form a vehicular frame assembly as described below, is greatly facilitated. Also, the storage of such bodyside assemblies  28  at both the first and second locations, is also greatly facilitated. Lastly, because all of the primary structural components of the bodyside assembly  28  (i.e., the lower rocker rail  20 , the upper roof rail  21 , the front valence member  22 , and the rear body side member  23 , as well as the combinations of the outer pillar members  24   a,    25   a,  and  26   a  and the vertical closure panels  24   b,    25   b,  and  26   b ) are formed from closed channel structural members, the bodyside assembly  28  is inherently rigid, thus facilitating the transportation thereof from one manufacturing location to another and minimizing the potential for damage in transit that can result in quality issues.  
       FIG. 10  is a side elevational view of one of the bodyside assemblies  28  shown in  FIG. 9 . The illustrated bodyside assembly  28 , which can be considered as a baseline model for this general bodyside design, is a relatively small four-door sedan and includes the rocker rail  20 , the roof rail  21 , the front valence  22 , the rear body side member  23 , and multiple vertical pillars, as described above. As is well known in the art of manufacturing vehicular frame assemblies, the four vertical pillars illustrated in  FIG. 10  can be referred to, from front to rear, as A, B, C, and D pillars. In the illustrated design, the C pillar has both an upper and a lower section. There are several features in this general bodyside design that contribute to its flexibility. First, the rocker rail  20  is a horizontal straight member having a generally constant cross sectional shape along a large part of its length. Also, the roof rail  21  has a straight section that runs parallel to the rocker rail  20  and also has a generally constant cross sectional shape. Finally, the C pillar upper section is relatively straight and is oriented in a vertical or near vertical position. The horizontal roof rail  21  gives flexibility to the styling of the car. The horizontal roof rail  21  allows facilitates the use of different curvatures in the styling of the roof, whereas if the roof rail  21  was itself curved, the styling of the roof would likely follow the curvature of the roof rail  21  with only a little room for variability. An added benefit to using horizontal rocker and roof rails  20  and  21  is wheelbase flexibility. The wheelbase of the vehicle can be changed simply by substituting respectively longer or shorter rocker and roof rails  20  and  21 . If the rocker and roof rails  20  and  21  are formed by roll-forming or extrusion, then they can simply be cut to different lengths during their manufacture. If the rocker and roof rails  20  and  21  are formed by stamping or hydroforming, then modular tooling can be used. The C pillar upper section provides a similar benefit to styling as the flat roof rail. The outer “skin” of the vehicle can be used to define the slope of the rear window independent of the underlying frame structure. The slope can vary from a vertical position, which matches the orientation of the illustrated C pillar upper section, to an extremely tapered slope. The rear styling could also be defined by the rear window itself, i.e., a wrap-around rear window or a hatchback. Many other options can be considered by varying the shape of the outer skin and the rear glass.  
      As shown in  FIGS. 11 through 14 , several other types of vehicle can be readily constructed from the baseline model for the general bodyside design illustrated in  FIG. 9 . Each of the other types of vehicles share a majority of structural components with the baseline model and can be constructed simply by rearranging the existing structure and by adding or swapping structural components. For example, as shown in  FIG. 11 , the sedan bodyside subassembly  28  can be converted into a station wagon bodyside subassembly  28 ′ simply by adding a roof rail extension  21 ′ and a D pillar extension  29 ′. The station wagon bodyside subassembly  28 ′ would have a longer flatter roof than the sedan bodyside subassembly  28 , but the underlying structure is virtually unaffected by the difference in roof line.  
      As shown in  FIG. 12 , the sedan bodyside subassembly  28  could be converted into two-door coupe bodyside subassembly, indicated generally at  28 ″, by relocating the B pillar rearwardly and adding a body side member  29 ″. The nature of the rocker rail  20  and the roof rail  21  (both being straight and parallel with relatively constant cross sections) allows the same B pillar structure to be used at any location their length.  
      As shown in  FIG. 13 , the two-door coupe bodyside subassembly  28 ″ can be rearranged to a convertible bodyside subassembly, indicated generally at  28 ′″, by swapping the B pillar  25   a  for a half-pillar  25   a ′″ and swapping the roof rail  21  with a stand alone A pillar upper  29 ′″.  
      Lastly, as shown in  FIG. 14 , the two-door coupe bodyside subassembly  28 ″ can alternatively be arranged in a four-door, B pillarless configuration (such as might be used for supporting a reverse opening rear door) simply by removing the B pillar structure  25   a  entirely. Reinforcements can be added around the C pillar and door latch area.  
      It can be seen that each of the illustrated bodyside assemblies discussed above includes a plurality of closed channel tubular components that are joined by a plurality of open channel stampings or stamped subassemblies. Tubular components are preferably used for the main longitudinal beams in the structure. This structure has two advantages. One, it reduces the number of physically large components. Second, by replacing the conventional large stampings (which have long seams for joining via spot welding) with the tubular components, the overall amount of joining processes that are required to assemble the bodyside assemblies is reduced. The tubular components may be manufactured by draw bending standard tubes (such as round or square section), hydroforming, or by roll forming and stretch bending. Roll forming and bending does not require tooling or machinery on the order of large stampings to manufacture. The tubular longitudinal components can be joined together by stamped components or subassemblies of stamped components. Stampings can be used to form elements of the structure including, but not limited to, the A, B, C, and D pillars, or similar vertical structures. Each vertical member includes an inner and outer stamping, forming a fully closed cross section after assembly. These vertical components are preferably provided as stampings because their cross sectional shapes can vary significantly from top to bottom, and this is not easily accommodated by tubular parts of constant or near constant cross sectional shape. The various stamped components can be joined to the tubular components via MIG welding, MIG brazing, laser welding, or any other joining process that preferably requires only single sided access. Stamped components may be joined to other stamped components by MIG welding, MIG brazing, or laser welding. Alternatively, conventional resistance spot welding or any other technique applicable to a joint with access from both sides can be used. The bodyside assembly would be inherently rigid because after assembly, all of the major components will have closed cross sections. Finally, the bodyside assembly would be a complete unit that could be manufactured by a supplier, shipped to a customer&#39;s final assembly location, and fixed to an underbody structure in a single assembly station, acknowledging that additional operations may be required to fully join the bodyside assemblies.  
      Referring now to  FIGS. 15, 16 , and  17 , there is illustrated a method of manufacturing a vehicle frame assembly in accordance with this invention. In a first step of the method illustrated in  FIG. 15 , an underbody assembly  15  and a pair of bodyside assemblies  28  are initially provided. The underbody assembly  15  can, if desired, be manufactured in accordance with the method described above and illustrated in  FIGS. 1 through 5 . Similarly, each of the bodyside assemblies  28  can, if desired, be manufactured in accordance with the method described above and illustrated in  FIGS. 7 through 9 . As discussed above, one of the advantage of manufacturing the underbody assembly  15  and the pair of bodyside assemblies  28  in accordance with the disclosed methods that they are inherently rigid, thus facilitating the transportation thereof from one manufacturing location to another and minimizing the potential for damage in transit that can result in quality issues. However, the underbody assembly  15  and the bodyside assemblies  28  can be manufactured in any desired manner.  
      The underbody assembly  15  and the bodyside assemblies  28  are initially aligned laterally with one another, as shown in  FIG. 15 , before being secured together in the manner described below. Prior to being secured together, one or more additional components can, if desired, be secured to the underbody assembly  15 , as shown in  FIG. 16 . In the illustrated embodiment, a front dash subassembly  19   a  and a pair of rear wheelhouse subassemblies  19   b  are secured to the underbody assembly  15 . The illustrated front dash subassembly  19   a  and rear wheelhouse subassemblies  19   b  are formed from stampings, although such is not required. The front dash subassembly  19   a  and rear wheelhouse subassemblies  19   b  can be formed from any desired material or combination of materials and may have any desired shape or shapes, including different shapes than as shown. The front dash subassembly  19   a  and rear wheelhouse subassemblies  19   b  can be respectively secured to the underbody assembly  15  by any desired method, such as by resistance spot welding. Other components (not shown) can be secured to the bodyside assemblies  28  as desired. Typically, these additional components are components that disturb the otherwise generally planar shapes of the underbody assembly  15  and the bodyside assemblies  28  described above. Thus, it is preferable that such additional components be secured to the underbody assembly  15  and the bodyside assemblies  28  at the final manufacturing location after shipment and storage for the sake of increase efficiency.  
      Regardless of whether such additional components are added, the final step of the vehicle frame assembly process is shown in  FIG. 17 . As shown therein, the two bodyside assemblies  28  are secured to the lateral sides of the underbody assembly  15  to form a vehicle frame assembly, indicated generally at  30 . The two bodyside assemblies  28  can be secured to the underbody assembly  15  by any desired method, such as by magnetic pulse welding and the like. For example, the pair of bodyside assemblies  28  can be secured to the underbody assembly at a magnetic pulse framing station, such as disclosed in co-pending Ser. No. 10/639,305 filed on Aug. 12, 2003. The disclosure of that pending application is incorporated herein by reference. If desired, other conventional components can be secured to portions of either or both of the underbody assembly  15  and the bodyside assemblies  28  to form the vehicle frame assembly  30 , as shown in  FIG. 17 . Thereafter, the vehicle frame assembly  30  can be shipped as a unit to a customer or, if assembled by the customer, moved to the next manufacturing station.  
      In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiments. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.