Abstract:
A method for mounting a door to a vehicle body without the aid of a door-to-body mounting fixture. The method utilizes statistical process control data from previously assembled doors to determine the locations of holes that are pierced in hinges just prior to hinge installation. A pair of hinges are provided with the pierced holes to ensure self-alignment of the door.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a method and apparatus for attaching a door to a vehicle body.  
         BACKGROUND OF THE INVENTION  
         [0002]    In automotive assembly, hinges are typically provided with oversized holes to allow for dimensional variations in manufacturing of the hinges, doors, vehicle body and hole locations. Briefly, a typical automotive door hinge has an upper and a lower hole used to attach a door to the hinge. Typically, each of these holes are oversized to allow for manufacturing tolerances. In this manner, the door can be adjusted relative to the hinges to properly position the door relative to the body.  
           [0003]    A typical method for attaching a door to a vehicle involves positioning a pair of hinges relative the body with a hinge-to-body fixture and attaching the hinges to the body. A door-to-hinge (body) fixture is then used to properly position the door relative the body and the door is then attached to the hinges.  
           [0004]    The door-to-body fixture requires set-up time and expense to ensure proper positioning of the door. These expenses can include manpower, specialized fastening items, and equipment. The door typically includes threaded mounting studs or nuts that are welded to the door to complement the general location of the oversized, or clearance, holes in the hinges when the hinges are attached to the body. When the door is aligned to the body and the studs or nuts are aligned within the clearance holes, a washer is placed over each clearance hole and an appropriate fastening element installed at each fastening location. Current manufacturing methods require that, after painting of the door and body together, the door is then removed to facilitate final assembly of the door and vehicle interior. The door is then reattached to the body.  
           [0005]    One typical method for ensuring that the door-to-body re-attachment does not require the door-to-body fixture is disclosed in commonly owned U.S. Pat. No. 6,178,599, wherein the hinge pins can be removed from hinges, thus separating the door from the body.  
           [0006]    Another typical method for ensuring that the door-to-body re-attachment does not require the door-to-body fixture involves affixing washers to the hinges in conjunction with the initial installation with the fixture. In this method, shoulder studs connected to the doors extend through the clearance holes in the hinges and size-on-size (closely fitting) holes in the washers. The washers can be welded to the hinge or a high strength adhesive applied between the hinge and washer. When the washers are affixed to the hinges, the doors can be detached from the hinges and later re-attached in the same position without the aid of a door-to-body fixture. The mating surface of the nut is recessed around the threaded opening to accommodate the non-threaded shoulder of the stud that protrudes through the washer. In this manner, the mating surface of the nut contacts the washer to properly secure the hinge to the door.  
           [0007]    While the prior art assembly methods have performed satisfactorily, the continued development of vehicle assembly methods have been directed toward developing methods that produce a more consistent result, eliminate or reduce specialized assembly items and equipment, and reduce manpower requirements.  
           [0008]    What is needed is a method for attaching a door to a vehicle body hinge that does not require a door-to-body fixture, requires less hardware, and can allow the door to be removed and reinstalled without the need for a door-to-body fixture.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention provides a method for mounting a door to a vehicle body without the use of a mounting fixture.  
           [0010]    In one aspect, the present invention provides a pair of hinges with one door mounting clearance aperture within each hinge. The remainder of the door mounting holes are pierced in the hinge just prior to hinge installation. The location of each piercing is determined through an analysis of statistical process control data collected from previously installed doors. The pierced aperture in the upper hinge is a size-on-size hole that accommodates a fastener diameter without significant additional diameter for adjustment of the door relative to the hinge. The pierced aperture in the lower hinge is an elongated slot with a minor diameter that is slightly larger than the fastener diameter. The orientation of the elongated slot is such that a line defining its major diameter intersects the other door mounting holes within the pair of hinges. The hinges are attached to the vehicle body using a hinge-to-body fixture to ensure proper positioning of the hinges relative the body and the door is then attached to the hinges. The size-on-size hole and the elongated slot ensure that the door is properly positioned relative the body after the door-to-hinge attachment. In this manner, welding, adhesives, recessed nuts and door-to-body fixtures are not required to mount the door to the body of a vehicle.  
           [0011]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0013]    [0013]FIG. 1 is a perspective view of a portion of a vehicle in accordance with a preferred embodiment of the present invention; and  
         [0014]    [0014]FIG. 2 is a perspective view illustrating the hinges of FIG. 1.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0016]    With reference to FIG. 1, an exemplary vehicle is generally indicated by reference numeral  10 . The vehicle  10  includes a body  12  with hinge mounting connections  14   a ,  14   b . A hinge-to-body fixture (not shown) is used to properly position the hinges  16   a    16   b , relative the body  12  and hinges  16   a ,  16   b  are fastened to hinge mounting connections  14   a ,  14   b.    
         [0017]    A door  20  is shown fastened to hinges  16   a ,  16   b . Door  20  includes a mounting panel  22  and threaded mounting studs  24  located on mounting panel  22 . Preferably, mounting studs  24  are not adjustable with respect to door  20 .  
         [0018]    With reference to FIG. 2, a pair of hinges  16   a ,  16   b  are shown wherein each hinge  16   a ,  16   b  includes a first member  30   a ,  30   b  and a second member  32   a ,  32   b . First and second members  30   a ,  30   b  and  32   a ,  32   b  are rotatably connected with a pin  34 . First member  30   a ,  30   b  preferably includes two vehicle mounting apertures  38 . Second member  32   a ,  32   b  preferably includes two door mounting apertures  40 . Upper hinge  16   a  is shown to include first member  30   a  and a second member  32   a  with a size-on-size door mounting aperture  42  and a door mounting clearance aperture  44  formed therein. Size-on-size door mounting aperture  42  is adapted to accommodate mounting stud  24  without significant additional diameter for adjustment of door  20  relative to hinge  16   a . Door mounting clearance aperture  44  is adapted to accommodate mounting stud  24  while providing additional diameter for adjustment of door  20  relative to hinge  16   a.    
         [0019]    Lower hinge  16   b  is shown in a preferred embodiment to include first member  30   b  and second member  32   b  with a door mounting clearance aperture  44  and an elongated aperture  46  formed therein. Elongated aperture  46  is adapted to accommodate a mounting stud  24  while providing clearance in one direction. Stud  24  received in elongated aperture  46  provides an anti-rotation function of the door  20  about size-on-size aperture  42 .  
         [0020]    With reference to FIGS. 1 and 2, upper hinge  16   a  is attached to an upper hinge mounting connection  14   a . Lower hinge  16   b  is attached to a lower hinge mounting connection  14   b . When hinges  16   a ,  16   b  are positioned adjacent hinge mounting connections  14   a ,  14   b  with a hinge-to-body fixture, hinges  16   a ,  16   b  are fastened to hinge mounting connections  14   a ,  14   b . In this manner, hinges  16   a ,  16   b  are properly positioned with respect to body  12 . Mounting studs  24  are disposed through door mounting apertures  40  and a fastening element  50  is coupled to each mounting stud  24 . Fastening element  50  is preferably a nut. Mounting studs  24  are essentially non-adjustable with respect to size-on-size door mounting aperture  42  and elongated aperture  46 . In this manner, door  20  is properly positioned with respect to body  12  as mounting studs  24  are positioned within size-on-size door mounting aperture  42  and elongated aperture  46  and, therefore, a door-to-body fixture (not shown) is not required. Elongated aperture  46  provides limited vertical adjustability for the attachment of lower hinge  16   b  to lower hinge mounting connection  14   b , but does not provide adjustment of door  20  inwardly or outwardly with respect to body  12 .  
         [0021]    Hinges  16   a ,  16   b  are prefabricated with vehicle mounting apertures  38  and clearance apertures  44  prior to staging at the assembly line. Size-on-size door mounting aperture  42  and elongated aperture  46  are cut within hinges  16   a ,  16   b  as vehicles  10  are assembled on the assembly line. The apparatus (not shown) used to form apertures  42 ,  46  is preferably adjustable such that the locations within hinges  16   a ,  16   b  for apertures  42 ,  46  can be infinitely adjusted as feedback is received from the line.  
         [0022]    After doors  20  are attached to body  12 , measurements are taken to determine the variation from the desired fit and finish provided in the building specification. While the individual building specification provides the location for these measurements, these locations are preferably taken at each hinge location and at least one additional location such as a latch point. The measurements are collected as process control data. The data collected from each vehicle measured is used to determine the trends (if any) in variation of fit and finish. When a trend is identified, an adjustment is made to the apparatus that cuts size-on-size door mounting aperture  42  and/or elongated aperture  46 . In this manner, the fit of door  20  relative to body  12  can be adjusted on the line to ensure that the variation in fit does not exceed the allowable values found in the building specification.  
         [0023]    Additional work, such as welding or attaching a washer to hinge  16   a ,  16   b  is not required and hinges with removable pins are not needed to enable removal and reinstallation of door  20  without a door-to-body fixture. Since washers are not required to fasten and align door  20  to hinges  16   a ,  16   b  fastening element  50  is not required to be a recessed nut in order to ensure proper fastening contact between fastening element  50  and second member  32   a ,  32   b.    
         [0024]    While door mounting panel  22  is depicted with attached studs and fastening element  50  is preferably a nut, one of ordinary skill in the art would appreciate that alternative fastening means, such as members with threaded apertures fixed on door mounting panel  22  and a fastening element  50  that is a bolt or a screw, could also be used to fasten door  20  to hinges  16 .  
         [0025]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.