Patent Publication Number: US-2006000149-A1

Title: Modular vehicle door construction

Description:
FIELD OF THE INVENTION  
      The invention relates generally to vehicle doors, and more particularly to a modular vehicle door assembly.  
     BACKGROUND OF THE INVENTION  
      Vehicle door constructions typically feature a metal door frame with a sheet metal outer panel or skin that defines the door&#39;s exterior and an inner sheet metal panel secured to the door frame about their abutting edges to form a hollow shell. Various door components, including window regulator rails, audio speakers, latches, and the like, are fastened in openings defined in the inner sheet metal panel. Covering the inner door panel is a removable trim panel that provides an aesthetically pleasing facade viewed by occupants seated in the passenger compartment of the motor vehicle. Typically disposed between the inner sheet metal panel and trim panel is a water and/or sound barrier that closes the various openings and prevents water infiltrating the interior of the door from wetting the interior surface of the trim panel. A wire harness communicates electrical connections between mechanisms attached to the vehicle door and controls on the trim panel and a cable connects the latch to an inner release handle.  
      An assembly line worker fastens the door components to the inner sheet metal panel and then installs the trim panel. To provide access to the interior of the door after installation, trim panels are provided with an access opening and a removable bolster covering the access opening. The access opening must be large enough to permit assembly line workers or service technicians to access the door components while the interior trim panel remains fixed to the door frame. For example, the assembly line worker must install the fasteners for the window regulator rails and drive motor through the access opening. Large access openings tend to weaken the structure of the trim panel, require additional water seals, require additional time to assemble on the production line, and restrict styling.  
      Another vehicle door construction initially mounts the door components to the trim panel. After the trim panel is delivered to the assembly line and positioned relative to the door frame, the assembly line worker secures the door components with fasteners to the inner sheet metal panel of the door frame. The door components are again accessed through an access opening in the trim panel. An audio speaker is directly fastened to the door frame by fasteners installed through the trim panel. After the fasteners have been installed, a speaker grill is typically applied to the trim panel and a bolster is loaded into the access opening.  
      Yet another vehicle door construction mounts the door components to a carrier plate and delivers the carrier plate as a separate preassembled module to the assembly line. The carrier plate is fastened to the door frame with fasteners, and then a trim panel is installed. After assembly, the carrier plate operates as a structural member that supports the door components. For example, the window regulator rails transfer the weight of the door window pane directly to the carrier plate. Therefore, most carrier plates are formed from steel or a structural composite material with sufficient strength to support the door components. A disadvantage of this style of carrier plate is that multiple fasteners are required to complete assembly. Another disadvantage is that the trim panel and the carrier panel comprise distinct units that are delivered separately to the assembly line.  
      What is needed therefore is a modular automotive door construction that addresses these and other deficiencies of conventional door constructions.  
     SUMMARY OF INVENTION  
      The invention provides a vehicle door assembly for a motor vehicle comprising of a door frame, a trim panel secured removably to the door frame, and a carrier plate positioned between the door frame and the door trim panel. The vehicle door assembly further includes a door component fastened to the door frame and to the carrier plate. This assembly differs from conventional vehicle door assemblies in that the door component is secured to both the door frame and the carrier plate.  
      In another embodiment of the invention, a vehicle door assembly for mounting to a door frame of a motor vehicle includes a carrier plate, a door component fastened to the carrier plate, and a door trim panel secured removably to the carrier plate. This assembly differs from conventional vehicle door assemblies in that the door trim panel is removably secured to the carrier plate for the door component.  
      In yet another aspect of the invention, a method of assembling a vehicle door of a vehicle includes mounting a carrier plate to a door frame of the vehicle and removing the trim panel from the carrier plate to reveal a door component secured to the carrier plate. The method further includes fastening the door component to the door frame and then re-securing the trim panel to the carrier plate after the door component is fastened to the door frame.  
      These and other objects and advantages of the present invention shall become more apparent from the accompanying drawings and description thereof. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention.  
       FIG. 1  is a perspective view depicting a motor vehicle door assembly, including a carrier plate in accordance with the invention;  
       FIG. 2  is a perspective view of the motor vehicle door assembly of  FIG. 1  with the carrier plate affixed to the door frame and the trim panel removed from the carrier plate;  
       FIG. 3  is a perspective view of the motor vehicle door assembly of  FIG. 2  depicting the trim panel re-installed to the carrier plate;  
       FIG. 4  is a perspective view of a carrier plate in accordance with an alternative embodiment of the invention; and  
       FIG. 5  is a perspective view of a carrier plate in accordance with another alternative embodiment of the invention. 
    
    
     DETAILED DESCRIPTION  
      With reference to  FIGS. 1-3 , a vehicle door assembly  10  includes a trim panel  12  and a carrier plate  14  carrying the trim panel  12  that are collectively configured to be installed to an interiorly facing or inboard side  15  of a door frame  16  attached to a motor vehicle. When the vehicle door assembly  10  is installed to the inboard side  15  of the door frame  16 , an inboard side  18  of the trim panel  12  faces into a passenger compartment of the motor vehicle and an outboard side  20  of the trim panel  12  confronts an inboard side  22  of the carrier plate  14 . An outboard side  24  of the carrier plate  14  faces toward the inboard side  15  of door frame  16 . An exterior panel or skin member  26  is secured to the outboard side of the door frame  16  that faces out of the passenger compartment. As used in this description, the terms such as “outboard,” “outer” and “outward” indicate a direction or orientation away from or farther from a longitudinal centerline of the motor vehicle of which the vehicle door assembly  10  forms a part. Conversely, “inboard,” “inner” and “inward” indicate a direction or orientation toward or closer to the longitudinal centerline.  
      The trim panel  12  is supported on and releasably secured with the carrier plate  14  by multiple connectors  28 . The connectors  28  are configured for releasing trim panel  12  from the carrier plate  14 , while securing the carrier plate  14  with the door frame  16 , so that an assembly line worker or service technician can access various function components positioned inside of the interior space defined between the trim panel  12  and the carrier plate  14 . To that end, a portion of each connector  28  affixes the carrier plate  14  to the door frame  16  and another portion of each connector  28  is removable with the trim panel  12 . Suitable connectors  28  are disclosed in co-pending and commonly-owned U.S. patent application Ser. No. 10/709,544, which is hereby incorporated by reference herein in its entirety. The connectors  28  are received in suitably positioned fastener openings  30  in the door frame  16  when the trim panel  12  and carrier plate  14  are initially installed to the door frame  16 . The connectors  28  fixedly attach the carrier plate  14  to the door frame  16 . However, the trim panel  12  is removable by an assembly line worker after installation and, subsequently, is removable by a service technician for gaining access to the inboard side  22  of the carrier plate  14 .  
      Penetrating through the carrier plate  14  are a terminal connector  32  of a wiring harness and a rod or cable  34  that mechanically links a door latch  36  with an inner release handle  38  positioned on the inboard side  18  of trim panel  12 . The inner release handle  38  is operative for opening and closing the door latch  36 . The terminal connector  32  of the wiring harness, which is coupled with a switchbox  40  located on the outboard side  20  of the trim panel  12 , is electrically coupled with controls  42  on the inboard side  18  of trim panel  12 . The inner release handle  38  and controls  42  are accessible to an occupant seated in the passenger compartment of the motor vehicle. The inboard side  18  of the trim panel  12  may also include other integral parts, such as an armrest  44 , a pocket  45 , a bolster  46 , and a speaker grill  48 .  
      A side impact absorber  50  is positioned on the outboard side  20  of the trim panel  12 . The side impact absorber  50 , which may be constituted by foam blocks, is supplied as a single piece. This contrasts with conventional door constructions in which, due to the presence of the access opening and removable bolster, the side impact absorbers are divided into smaller portions separated by a gap.  
      With continued reference to  FIGS. 1-3 , several door components, such as the door latch  36 , an audio speaker  52 , and window regulator rails  54 ,  56 , are supported temporarily on the carrier plate  14  by fasteners  58 , such as threaded fasteners, fastened to the carrier plate  14 . The door latch  36  is carried by a bracket  60  depending from the carrier plate  14  at a location suitable to be received in an opening  62  in the door frame  16 . The fasteners  58  are then driven into fastener openings  64  in the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  registered with corresponding fastener openings  66  defined in the door frame  16 . This fixedly mounts the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  to the door frame  16 . Accordingly, the door frame  16  provides at least a portion of the structural support for the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  in the assembled condition. The door frame  16 , rather than the carrier plate  14 , preferably carries the majority of the weight of the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  in the assembled condition. A support arm (not shown) may be coupled at opposite ends with the window regulator rails  54 ,  56  and a motor (not shown) may be coupled with the support arm to adjust the vertical position of the support arm on the rails  54 ,  56  for opening and closing a window pane (not shown) supported by the support arm.  
      The door frame  16  includes slotted cutouts  68 ,  70  ( FIG. 1 ) shaped to receive the window regulator rails  54 ,  56 , a rectangular cutout  69  shaped for passage of the door latch  36 , and a circular cutout  72  shaped to receive the backside of the audio speaker  52 . Fastener openings  74  in the door frame  16  are registered during assembly with fastener openings  76  in the carrier plate  14  for receiving fasteners  78  ( FIG. 2 ), such as threaded fasteners, that affix the carrier plate  14  to the door frame  16 . Locator pins  80 ,  82  on the door frame  16  are positioned to engage locator openings  84 ,  86 , respectively, in the carrier plate  14  that, when engaged, assist in assembly.  
      An assembly line worker or service technician may gain unhindered access to the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  by removing the interior trim panel  12  from the carrier plate  14 . The removability of the entire trim panel  12  permits the fasteners  58  to be located arbitrarily within the outer perimeter of the door frame  16 . More specifically, the trim panel  12  preferably lacks a bolster, which provides an unbroken single-piece and unitary construction as opposed to conventional door constructions that require a removable bolster to permit access for driving fasteners to secure the door components to a door frame. This permits considerable flexibility in locating the fastener openings  66  in door frame  16 .  
      The modular vehicle door construction afforded by the trim panel  12  and carrier plate  14  facilitates quick and easy assembly of motor vehicle door  10 , including the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56 , and is well suited for manufacturing assembly lines. This reduces tooling requirements and the complexity of the door assembly as the motor vehicle moves along the assembly line. The presence of the carrier plate  14  eliminates the need for an access opening in the trim panel  12  and a removable door bolster covering the access opening. The trim panel  12  may be provided with an integral and non-removable bolster  46 , which eliminates the need for a bolster seal and serves to increase the robustness of the door construction. In addition, the trim panel  12  is provided with the integral speaker grill  48  that covers the audio speaker  40  after assembly. This eliminates the need to supply and attach a separate grill  48  to the trim panel  12 , which reduces labor cost. The bolster  46  and speaker grill  48  are molded with the trim panel  12 , which reduces manufacturing cost as separate grill covers and bolsters are not required. In an alternative embodiment of the invention, a back-loaded bolster  46  that cannot be removed from the passenger compartment may be provided to satisfy trim panel styling or trim panel cover stock requirements.  
      The carrier plate  14  is preferably non-structural in that the load presented by the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  is supported primarily by the door frame  16  after assembly. For example, the weight of a window pane is transferred by the window regulator rails  54 ,  56  to the door frame  16 . As a result, the carrier plate  14  may be formed from a lightweight and/or inexpensive non-load bearing material, such as polypropylene. The carrier plate  14  operates as a water, air and/or sound barrier in the assembled door, which protects the outboard side  20  of the trim panel  12 . A water seal (not shown) may be provided about the periphery of the carrier plate  14  and compressed between the carrier plate  14  and door frame  16 . The trim panel  12  is removably secured with the door frame  16  by the connectors  28  in the assembled door.  
      In use and with reference to  FIGS. 1-3 , a method of assembling an automotive door  10  will be described. Initially, the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  are positioned on the carrier plate  14 , and the trim panel  12  is releasably mounted to the carrier plate  14 . The trim panel  12  and carrier plate  14  may be pre-assembled at a remote location as a substantially integral module ready for attachment at any point during the vehicle&#39;s final assembly. As a result of the pre-assembly, the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  may be tested before installation and the door module consisting of the assembled trim panel  12  and carrier plate  14  may be delivered to the assembly line in a state appropriate for immediate installation. Accordingly, the awkward, inconvenient attachment of the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  through small access openings is substantially eliminated. The vehicle manufacturer benefits from lower inventory requirements and part counts and an improvement in overall product quality.  
      The carrier plate  14  is positioned relative to the door frame  16  so that the door latch  36  is inserted through cutout  69  and positioned in opening  62 , the connectors  28  are registered with the fastener openings  30  in the door frame  16 , and the fastener openings  64  in the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  are registered with corresponding fastener openings  66  in the door frame  16 . The locator pins  80 ,  82  on the door frame  16  are engaged with the locator openings  84 ,  86  in the carrier plate  14  to assist in positioning and registration. The trim panel  12  is removed from the carrier plate  14  so that an assembly line worker can access the inboard side  22  of the carrier plate  14 . The door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  are secured to the door frame  16  by driving fasteners  58  through the pairs of registered fastener openings  64 ,  66  so that, following assembly, the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56  are secured to both the door frame  16  and the carrier plate  14 . Preferably, the door frame  16  carries the majority (i.e., greater than or equal to 50 percent) of the weight of door components, such as the door latch  36 , audio speaker  52 , and window regulator rails  54 ,  56 , rather than the carrier plate  14 . The terminal connector  32  of the wiring harness is re-connected with switchbox  40  to establish electrical connections with the controls  42  on the trim panel  12 , the cable  34  connecting the door latch  36  with the inner release handle  38  is connected, and the trim panel  12  is reattached to the door frame  16 . The trim panel  12  is completely removable from the door frame  16 , in a manner similar to a non-modular door, so that a service technician may readily access the door latch  36 ,audio speaker  52 , and window regulator rails  54 ,  56 .  
      With reference to  FIGS. 4 and 5  in which like reference numerals refer to like features in  FIGS. 1-3  and in accordance with alternative embodiments of the invention, the carrier plate  14  may be provided with sealable openings to afford access to the space between the carrier plate  14  and the door frame  16 . In particular and with reference to  FIG. 4 , the carrier plate  14  may be provided with a sealable opening in the form of a fold down panel  88  that has an opened position affording access to the outboard side  24  of carrier plate  14  to, for example, install fasteners  58  for the window regulator rails  54 ,  56  or to position the latch  36  manually and a closed position that is substantially sealed to air, dust and water. Alternatively and with reference to  FIG. 5 , the sealable opening may consist of a sealable slit  90  extending through the thickness of the carrier plate  14 .  
      While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants” general inventive concept.