Patent Publication Number: US-2006000454-A1

Title: In-tank fuel supply unit having long life filter

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to long life fuel filters for automotive applications, and more particularly relates to locating such a filter in the fuel tank as part of a fuel delivery module.  
     BACKGROUND OF THE INVENTION  
      Fuel filters for automobiles are used to protect engine components and are typically installed between a fuel pump located near the fuel tank and the fuel injectors of the engine. These filters have historically been installed on the chassis fuel lines external to the fuel tank, and are designed to have a long life, preferably serviced at 30,000 to 60,000 mile increments. More recently, automobile designers have started to move this fuel filter into the fuel tank as part of a fuel delivery module. Depending on the particular manufacturer, some require that this in-tank fuel filter be serviceable.  
      One of the main problems with moving the fuel filter into the fuel tank is the packaging space required. An in-tank fuel supply unit typically includes a fuel delivery module (FDM) that needs to fit through a tank opening for installation as well as for removal for servicing. With varying tank heights and sizes, it can be difficult to find the packaging space necessary to incorporate a filter, while still easily fitting the filter on the FDM and into the fuel tank opening. Some solutions package the filter in a cylindrical canister which is mounted inside the reservoir of the fuel delivery module. Unfortunately, this takes up a significant portion of the reservoir capacity. Other solutions employ a filter that mounts around the fuel pump or on top of the fuel delivery module. Unfortunately, these solutions limit the tank heights that the fuel delivery module can be used with, as the assembly typically becomes much taller.  
      Accordingly, there exists a need to provide an in-tank fuel supply unit having a fuel delivery module and fuel filter which can easily be placed through the opening in the fuel tank during assembly or service, and which also does not limit the reservoir capacity or the size of the fuel tank on which the unit may be employed.  
     BRIEF SUMMARY OF THE INVENTION  
      The present invention provides an in-tank fuel supply unit having a fuel filter attached to a fuel delivery module for in-tank placement that does not limit the capacity of the unit or increase the size of the unit in a manner that creates undesirable packaging issues. The fuel supply unit generally comprises a fuel delivery module having a housing and a fuel pump. A fuel filter is rigidly attached to a side of the housing such that the fuel delivery module and fuel filter are placed within the fuel tank through the opening as a single unit. The fuel delivery module and fuel filter form an L-shape which permits the entire unit to be inserted through the standard opening which is sized for the fuel delivery module alone.  
      According to more detailed aspects, the housing of the fuel delivery module has a greatest width W h  which is less than or equal to the smallest width of the opening in the fuel tank W o . The fuel filter preferably has a width W f  less than or equal to W h . The fuel filter preferably has a height H f  less than or equal to W h . Most preferably, the square of the fuel filter height (H f   2 ) plus the square of the fuel housing width (W h   2 ) is less than or equal to the square of the smallest width of the opening (W o   2 ).  
      By controlling the width and height of the fuel filter, the entire in-tank fuel supply unit may be placed into and out of the fuel tank as a single unit for installation and service. At the same time, the length of the fuel filter may be sized based on the required amount of filtering capacity. The fuel filter is preferably removably attached to the fuel delivery module for selective attachment to the fuel delivery module. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:  
       FIG. 1  is a front view of an in-tank fuel supply unit constructed in accordance with the teachings of the present invention;  
       FIG. 2  is a perspective view of the fuel filter forming a portion of the fuel supply unit depicted in  FIG. 1 ;  
       FIG. 3  is a perspective view, taken from the bottom showing the fuel filter attached to the fuel delivery module; and  
       FIG. 4  is a perspective view, taken from the top, of the fuel filter and fuel delivery module depicted in  FIG. 3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Turning now to the figures,  FIG. 1  depicts a front view of an in-tank fuel supply unit  20  constructed in accordance with the teachings of the present invention. The fuel supply unit  20  generally comprises a fuel delivery module  22  having a fuel filter  24  attached thereto. The fuel delivery module  22  (FDM) generally comprises a housing  26  defining a reservoir  28  therein ( FIG. 4 ). The fuel delivery module  22  also includes a fuel pump (not shown), although the fuel pump may be located at various positions on the FDM  22  including directly attached to the housing  26  or contained therein. It can be seen in  FIG. 1  that the flange  32  is used to close off an opening  12  formed in an upper wall of the fuel tank  10 , as is known in the art. The smallest width of the opening  12  has been denoted W o . The greatest width of the housing  26  of the fuel delivery module  22  has been denoted W h . Generally, the housing width W h  is less than or equal to the width of the opening W o  such that the fuel delivery module  22  may be easily placed directly through the opening  12  in the fuel tank  10 .  
      The fuel filter  24  has also been sized and structured so that it may be readily placed through the opening  12  in the fuel tank  10 , even while attached directly to the fuel delivery module  22 , as will be described herein with reference to  FIGS. 1 and 2 . As best seen in  FIG. 2 , the filter  24  generally includes a filter housing  40  which is enclosed by a filter cover  42 . The filter  24  also includes a mounting flange  44  having two opposing projections  46 , as will be described later herein and with reference to  FIG. 3 . The filter  24  also includes an appendage  48  which is generally cylindrical in nature and defines a filter inlet  50 . Fuel flows through the inlet  50  and through filter media contained within the housing  42 , and then out to the engine via a filter outlet  52 . Notably, the filter outlet  52  extends upwardly and laterally towards the fuel delivery module  22 , as best seen in  FIG. 1 .  
      The fuel filter  24  generally is defined by a length L f , a width W f , and a height H f . As shown in  FIG. 1 , the filter  24  is attached to the fuel delivery module  22  proximate its bottom end  66  to give the fuel supply unit  20  a general L-shape which permits the entire unit  20  to be placed through the opening  12  in the fuel tank  10 . In particular, the fuel filter width W f  and height H f  have been sized to permit easy placement of the unit  20  within the fuel tank  10 . In particular, the fuel filter width W f  is less than or equal to the housing width W h . Further, the fuel filter height H f  is less than or equal to W h .  
      As also seen in  FIG. 1 , a bottom surface  54  of the fuel filter  24  is preferably aligned with a bottom surface  56  of the fuel delivery module  22 . Ideally, the positioning of the fuel filter  24  and sizing of its height H f , is selected such that the fuel filter  24  does not rise above a vertical position denoted VP in  FIG. 1  on the housing  26  of the fuel delivery module  22 . This vertical position VP is measured from a bottom surface  56  of the housing  26  and is given by the equation: √{square root over (W o   2 −W h   2 )}. This vertical position VP and the equation for determining the same is selected to insure that the distance between the vertical position and the opposing lower corner of the housing  26  is not greater than the fuel tank opening width W o .  
      In this way, the in-tank fuel supply unit  20  is sized and structured to provide easy placement of the fuel delivery module  22  and fuel filter  24  through the opening  12  as a single unit. During placement, the entire unit  20  is rotated such that the fuel filter  24  may be first placed through the opening  12 . Then, the unit  20  is rotated and moves slightly vertically such that the fuel delivery module  22  has a vertical orientation as shown in  FIG. 1 . Then the entire unit  20  may be moved downwardly and the closing flange  32  secured to the fuel tank  10 .  
      It will also be seen that the length L f  the fuel filter  24  need not be limited for placement of the unit  20 , and thus the length L f  may be varied to accommodate additional filter media and to vary the filtering capacity of the filter  24 .  
      Turning now to  FIG. 3 , the fuel filter  24  has been shown attached to the fuel delivery module  22 . It can be seen that the housing  26  defines a recess  58  having two opposing slots  60 . As previously discussed, the fuel filter  24  includes a mounting flange  44  having two opposing projections  46 . As shown in  FIG. 3 , the recess  58  is sized to receive the flange  44 , and in particular the two slots  60  are sized to receive the two opposing projections  46 . Additional shapes or structures could be employed, as well as additional locking or retaining features such as snap features, as will be readily envisioned by those skilled in the art. It will thus be seen that fuel filter  24  is rigidly attached to the housing  26  of the fuel delivery module  22 , while at the same time being removably attached for independent manufacture, service and assembly.  
      Turning now to  FIG. 4 , a perspective view of the fuel supply unit  20  has been shown which reveals a depression  62  formed in the housing  26  of the fuel delivery module  22 . In particular, the depression  62  is semi-cylindrical in shape to correspond with the cylindrical appendage  48  projecting from the fuel filter  24 . The filter  24  includes an inlet  50  located on an end of the filter  24  that abuts the housing  26  of the fuel delivery module  22 . The housing  26  further defines a clip  68  having two arcuate fingers  70 . A tube  72  is preferably used to connect the inlet  50  of the fuel filter  24  to an outlet of the fuel pump. Accordingly, the clip  68  is used to retain the tubing  72  within the depression  62  of the housing  26 . It will readily be seen that by connecting the inlet  50  and tubing  72  to the housing  26  of the fuel delivery module  22 , the connection components are protected and the integrity of the connection is maintained during placement of the fuel supply unit  20  within the fuel tank  10 . Preferably, the depression  62  extends vertically from an upper end  64  to a lower end  66  of the housing  26 . The depression extends vertically.  
      The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.