Abstract:
A door assembly is provided that includes integral impact regions that obviate the need for a separate impact beam. The door assembly includes an outer panel and an inner panel, operably connected to the outer panel so that a compartment is formed therebetween. At least one hardware-mounting surface is integrally formed from the inner panel and extends towards the outer panel. Each of the hardware mounting surfaces is operable to mount a hardware component between the inner and outer panels. At least one integrally-formed impact region is provided on the inner panel that is operable to strengthen the door assembly and increase its intrusion resistance of the vehicle door during a collision. The inner panel has substantially no large access openings that would be deleterious to impact resistance and substantially seals the vehicle passenger compartment from the external environment. The at least one impact region is also displaced at least as far away from the outer panel as the at least one hardware mounting surface.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a module for a motor vehicle door body. More particularly, the present invention relates to a structural module that both strengthens the motor vehicle door body, reduces the packaging size of the door and acts as a hardware carrier for hardware subsystems in order to minimize subsequent assembly operations. 
       BACKGROUND OF THE INVENTION 
       [0002]    A motor vehicle door typically includes an outer sheet metal panel and an inner sheet metal panel connected together to form a cavity therebetween. An equipment module is often mounted to the inner sheet metal panel within the cavity. In addition, an impact beam is typically welded to the inner sheet panel to resist deformation of the door during a side impact collision. The use of equipment modules and side impact beams increases the thickness of the door, and can increase assembly costs of the vehicle door. 
         [0003]    U.S. Pat. No. 7,040,688 to White and Chernoff, incorporated by reference herein, discloses the use of an inner door panel having an integrated impact beam. The inner panel is formed to include corrugated regions that extend convexly outwards from its wet side surface (i.e., facing towards the exterior of the vehicle). The corrugated regions provide sufficient intrusion resistance to obviate the need for an additional impact beam. To accommodate equipment mounted to the wet side surface of the inner panel (such as the rails to the window regulator), interruptions in the corrugated regions are provided. 
         [0004]    While the above-noted inner door panel disclosed by White and Chernoff improves the strength and reduces the thickness of the door assembly relative to a conventional vehicle door, it is not without its drawbacks. 
         [0005]    First, the corrugated regions of the integrated impact beam are limited in their size and geometry as to accommodate wet-side mounted equipment, such as providing space between the outer sheet metal and the panel for the travel of the window glass. Furthermore, the corrugated regions must be spaced apart from the outer panel as to allow free travel of the window glass. 
         [0006]    Second, the inner panel has a large hole in it to accommodate the window regulator drive assembly. This has a deleterious effect on the structural integrity of the inner door panel, causing the design to use many more corrugations to achieve a particular side impact resistance. In addition, despite the large access hole for the window regulator motor assembly, the door assembly does readily enable certain door hardware such as the window regulator subsystem to be installed on a high speed manufacturing line. Moreover, the White and Chernoff inner panel must still be sealed to prevent moisture and road dirt from entering the passenger cabin. 
         [0007]    It is thus desirable to provide a door assembly that includes an inner door panel that provides a high level of intrusion resistance but still allows for hardware components to be easily mounted while minimizing the thickness of the door assembly. 
       SUMMARY OF THE INVENTION 
       [0008]    According to one aspect of the invention, an inner panel having an integrated impact beam is provided for a motor vehicle door assembly, wherein the inner panel substantially seals the motor vehicle passenger cabin from the external environment. 
         [0009]    According to another aspect of the invention, an inner panel having an integrated impact beam is provided for a motor vehicle door assembly, wherein a latch is mounted within a cavity on a dry side of the inner panel, facing the passenger cabin. 
         [0010]    According to yet another aspect of the invention, there is provided a door assembly that includes integral impact resistant regions. The door assembly includes an outer panel and an inner panel, operably connected to the outer panel so that a cavity is formed therebetween. At least one hardware mounting surface is integrally formed from the inner panel and extends towards the outer panel. Each of the hardware mounting surfaces is operable to mount a hardware component between the inner and outer panels. At least one integrally-formed impact region is provided on the inner panel that is operable to strengthen the door assembly and increase its intrusion resistance of the vehicle door during a collision. The at least one impact region is displaced at least as far away from the outer panel as the at least one hardware mounting surface. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Preferred embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein: 
           [0012]      FIGS. 1A and 1B  are perspective views of a door assembly according to a first embodiment of the invention; 
           [0013]      FIG. 2  is a perspective view of the door assembly shown in  FIGS. 1A and 1B  with a trim component removed; 
           [0014]      FIG. 3A  is a perspective view of the wet side of an inner panel for the door assembly shown in  FIGS. 1A and 1B ; 
           [0015]      FIG. 3B  is a perspective view of the dry side of the inner panel for the door assembly shown in  FIGS. 1A and 1B ; 
           [0016]      FIGS. 4A and 4B  are perspective views of a door assembly (without trim) according to a second embodiment of the invention,  FIG. 4A  showing the dry side of the inner panel and  FIG. 4B  showing the wet side of the inner panel; 
           [0017]      FIGS. 5A and 5B  are partially exploded views of the second embodiment showing a hardware carrier which is insertable in the compartment between the inner and outer door panels; 
           [0018]      FIGS. 6A and 6B  are detail views of a window regulator motor assembly employed by the second embodiment; and 
           [0019]      FIG. 7  is a partially exploded view of a door assembly according to a third embodiment, showing a variant of the hardware carrier which is insertable in the compartment between the inner and outer door panels. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Referring now to  FIGS. 1A ,  1 B and  2 , a first embodiment of a door assembly is shown generally at  10 . Door assembly  10  includes an exterior-facing “wet side” ( FIG. 1A ) and an interior-facing “dry side” ( FIG. 1B ). Door assembly  10  includes an outer panel  12 , inner panel  14  operably connected to outer panel  12  as to form a compartment therebetween, and at least one trim component  16 . A plurality of components are mounted to door assembly  10 , including a side mirror  18 , latch assembly  20 , speaker  22 , inner handle assembly  24  ( FIG. 2 ), outer handle assembly  26 , electrical wiring harness  28 , door hinges  30  and a window regulator motor  32  operable to power a window regulator (not shown) to raise or lower a window glass (also not shown). A set of hinges  33  are provided to operably connect door assembly  10  to a motor vehicle (not shown). The presently-illustrated door assembly  10  is frameless, but framed door assemblies are also within the scope of the invention. 
         [0021]    Outer panel  12  is shaped to present a streamlined and contoured exterior surface. Inner panel  14  provides a generally complementary contoured surface. Referring now to  FIGS. 3A and 3B , inner panel  14  is described in greater detail. Inner panel  14  includes an inboard panel region  34  that is displaced away from the outer panel  12  by web portions  36  to form the compartment. A flange  38  is provided along the edges of inner panel  14  to provide a positive contact surface for bonding to outer panel  12  by welding, hemming, or fastening. Inner panel  14  is generally around 2 mm thick and is preferably manufactured from an aluminum-magnesium sheet stock such as AA 5083 H18, although other suitable alloys can be used. 
         [0022]    Inner panel  14  includes a number of integrally-formed components operable to decrease the assembly time of door assembly  10  such as fastening locators  40  to assist in situating inner panel  14  relative to outer panel  12  and trim fastening locators  42  to assist in situating trim components  16  on inner panel  14 . A wiring harness pass-thru  44  is provided to allow the passage of wiring harness  28 , and a handle pass thru  46  is provided to allow the passage of a handle cable (not shown). On the dry side, inner panel  14  further includes a mounting surface  48  for an inner handle assembly (not shown), and a speaker housing  50 . On the wet side, inner panel  14  includes a window regulator motor mounting surface  52 , a latch attachment  54 , and rail mounting surfaces  56  to locate the rails for a window regulator (not shown). Motor mounting surface  52  and rail mounting surfaces  56  are raised away from inboard panel region  34  towards outer panel  12 . Other integrally-formed components for inner panel  14  will occur to those of skill in the art. 
         [0023]    Inner panel  14  further includes at least one integral impact region  58 . Each integral impact region  58  is a corrugated portion of the inner panel, comprising a series of ridges and troughs. Ridges on the wet side of inner panel  14  are troughs on the dry side, and troughs on the wet side are ridges on the dry side. Motor mounting surface  52  and rail mounting surface  56  extend closer towards outer panel  12  than the ridges of the impact regions  58  towards outer panel  12 . Preferably, ridges facing the wet side are at least as far away from outer panel  12  as the surface of inboard panel region  34 . Thus, packaging interference by the impact region  58  is minimized between the wet side of inner panel  14  and outer panel  12 , allowing for a narrower compartment between outer panel  12  and inner panel  14 . Preferably, inner panel  14  includes multiple impact regions  58  running non-parallel to each other to provide the maximum intrusion resistance from differing impact angles. Different impact regions  58  can have differing numbers of corrugations as to provide the desired level of intrusion resistance while still providing sufficient flat mounting surface area to meet door packaging requirements. In the currently illustrated embodiment, impact regions  58  bisect each other in region  52  to provide the maximum intrusion resistance at the preferred sitting position of the vehicle occupant. The impact regions  58  extend across a substantial length of inboard panel region  32  without interruption. While the intrusion resistance can vary in impact regions  58  based upon different design requirements, testing has shown that door assembly  10  with impact regions  58  can require approximately five times the side impact force to be displaced an equivalent distance in a conventional door. 
         [0024]    According to the presently preferred embodiment of the invention, inner panel  14  is manufactured using combination of forming techniques. A blank is preheated (typically to a temperature between 450-550° C. and placed into a multi-piece stamping tool to form into an intermediary shape. The raw stock is generally 2-3 mm thick. Apertures such as wiring harness pass-thru  44  are removed from the sheet metal stock and the stock is pressed into a intermediate form subject to the limitations of stamping and the malleability of the stock. 
         [0025]    After passing through the warm-forming stage, inner panel  14  is further formed by a super plastic forming operation (SPF). As known to those of skill in the art, the elasticity of alloys with a fine grain microstructure (such as aluminum AA 5083 H18) can increase up to several hundred percent when exposed to high heat and pressure. Under high heat (typically between 400-550° C.) and pressure, the stock is formed into the contoured shape of the mould at a controlled rate and pressure. Using SPF, a deeper draw can be achieved in the stock over typical stamping processes. By pre-heating and pre-stamping the stock, the time required to super-plastic form the final shape of inner panel  12  is reduced. 
         [0026]    Door assembly  10  reduces the part count and weight while increasing the intrusion resistance over conventional doors. In addition, the location and angling of impact regions  58  provides for a thinner yet stiffer door than the prior art. 
         [0027]      FIGS. 4A ,  4 B,  5 A,  5 B show a second embodiment of a door assembly  100 , which includes an outer panel  112  and an inner panel  114 , defining a compartment  113  therebetween. The inner panel  114  includes an integrated intrusion beam  158  comprising corrugated portions of the inner panel. 
         [0028]    In this embodiment, a cavity  154  (seen best in  FIG. 5B ) is formed on the dry side of inner panel  114  for attachment of a latch  155  (seen best in  FIG. 4A ) thereto. A latch cover/reinforcement member  156  may also be optionally mounted to the inner panel  114 . Locating the latch on the dry side of the inner panel  114  has a number of advantages, including eliminating access hole  54 A of the first embodiment in order to gain access to the wet side of the inner panel, making it easier to install or bolt the latch to the panel. In addition, placing the latch  155  on the dry side eliminates the possibility of opening or tampering with the latch  155  by inserting a tool (such as a “slim jim”) into the compartment  113  between the outer and inner panels  112 ,  114  through the top of the compartment  113  or window slot. 
         [0029]    Door assembly  100  also includes a hinge reinforcement member  162  (seen best in  FIG. 4B ), which is preferably adhesively bonded to the wet side of the inner panel  114 . An epoxy adhesive has been found suitable for this purpose. Hinges  130  (see  FIG. 4A ) are mounted to the inner panel  114  and the hinge reinforcement member  162 . 
         [0030]    A number of other components are bolted or otherwise fastened directly to the dry side of the inner panel  114 . These include an inner door handle  124  wiring harness  128 , and speaker  122  all of which are mounted to suitably shaped mounting surfaces on the inner panel  114 . 
         [0031]    The door assembly  100  of the second embodiment also employs a separate hardware carrier  170  (seen in isolation in  FIG. 5A ) that carries various hardware components, particularly, window regulator components described in greater detail below, for insertion as a unit into the compartment  113  between the outer and inner panels  112 ,  114 . In the preferred embodiment, the carrier  170  includes a belt line reinforcement member  172  that is a structural component in that it partially bears the load of a side and/or frontal impact. The belt line reinforcement member  172  is bolted to the inner panel  114  at mounting locations  174 A,  174 B. Locating lugs  176  are preferably provided for aligning the carrier  170  relative to the inner panel. 
         [0032]    The carrier  170  also carries a mirror flag  178 , and an integral glass run channel  180 . These components are pre-bolted to the preferred belt line reinforcement member  172 . 
         [0033]    The carrier  170  also holds many window regulator components. These include window regulator rails  182 , which are pre-bolted to the preferred belt line reinforcement member  172 , or otherwise to an alternative form of hardware carrier  170 . The rails  182 , in turn, carry window glass lifter plates  184 , pulleys  186  and associated cables  188 . In the illustrated embodiment ( FIGS. 4 &amp; 5 ), the only part of the window regulator motor assembly that is pre-connected to the window regulator is a cable drum  190  (seen best in  FIG. 5A ), which is situated on the wet side of the inner panel. The motor  132  and drive gear  192 , and the electrical connections to the motor  132 , are situated on the dry side of the inner panel  114 , and a connection is made between the cable drum  190  and drive gear  192 . More particularly, referring to the detail view of  FIGS. 6A and 6B , the cable drum  190  is preferably disposed in a housing  194  that includes or incorporates a series of hollow core, snap fit, prongs  196 . The inner panel  114  features a corresponding series of vias  198  (see  FIG. 5A ,  5 B) for accommodating the passage of the prongs  196 . The motor drive gear  192  is disposed in a housing  200  ( FIG. 6B ) which has a series of correspondingly situated mating receptacles  202 . As the cable drum housing  194  is preferably mounted to one of the rails  182 , which in turn are pre-mounted to the carrier  170  that is aligned on the inner panel  114 , the drum is thus consistently aligned on the wet side of the inner panel  114 . Hence, the assembler is able to easily align and interlock the cable drum housing  194  with the drive gear housing  200  utilizing the snap fit connection. In the process, an output shaft  204  of the drive gear  192  is mated to an internal gear  206  of the cable drum  190  via a shaft passageway  208  located in the inner panel  114 . If desired, bolts (not shown) may be driven through the hollow prongs  196  to seat in the receptacles  202 , thus mechanically affixing the cable drum housing  194  and the drive gear housing  200  to the inner panel  114 . In this manner, the window regulator is easily installed and the components of the motor assembly seal the inner panel. 
         [0034]    The cable drum  190  may be mounted in other ways within the scope of the invention. For example, the cable drum housing may be disposed on a web (not shown) connected to and disposed between the rails, thereby uniquely locating the cable drum within the compartment  113  between the outer and inner door panels. 
         [0035]    In a variant of the carrier  170 , shown in  FIG. 7 , carrier  170  holds an entire window regulator motor assembly  210 , which is thus situated entirely on the wet side of the inner panel  114 . The motor assembly  210  is ensconced within a small cavity  212  formed in or on the wet side of inner door panel, enabling the motor assembly  210  to be bolted to the inner panel at designated points thereat. 
         [0036]    In either variant, the vehicle window glass  215  may be pre-installed to the carrier  170 , and the whole unit inserted into the compartment  113  between the outer and inner door panels  112 ,  114 . Alternatively, the lifter plates  184  may be snap-in lifter plates as known in the art per se in which, once the window regulator is installed into the door assembly, the window glass  215  is thereafter inserted into the lifter plates  184  via a snap-fit connection. 
         [0037]    It will be seen from the foregoing that the second embodiment of the door assembly has no substantial openings or access holes therethrough, except for minor passageways to accommodate fasteners, wire passages or a drive-shaft. These minor openings do not substantially affect the rigidity or impact performance of the inner panel, and are easily sealed using plugs well known in the art per se. 
         [0038]    The above-described embodiments are intended to be examples of the present invention and those skilled in the art may effect alterations and modifications thereto without departing from the spirit of the invention.