Abstract:
A fuel supply system and fuel filter for a vehicle prevent bleed down of the fuel filter and minimizes the amount of any air or vapor delivered to the fuel supply line. The fuel filter includes a housing enclosing a filter media. The filter includes an inlet for receiving fuel from the fuel pump. The filter also includes first and second outlets. The first outlet supplies filtered fuel to the fuel supply line. The second outlet supplies filtered fuel to the jet pump. In this way, by providing a single outlet from the fuel pump to the fuel filter, and providing two outlets from the fuel filter which separately leads to the fuel supply line and the jet pump, bleed down is prevented and vapors within the fuel supply line are reduced.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to fuel filters, and more particularly relates to fuel filters internalized within the fuel tank and incorporated into a fuel delivery module.  
       BACKGROUND OF THE INVENTION  
       [0002]     The fuel supply system of a vehicle typically includes a fuel tank having a fuel pump therein for providing fuel to the engine via a fuel supply line. Typically, the fuel pump forms a portion of a fuel delivery module which includes a reservoir for collecting fluid from the tank for supplying the engine. An outlet of the fuel pump is linked to a manifold on the exterior of the fuel delivery module. The manifold diverts some fuel to the engine and some fuel to a jet pump. The jet pump includes a nozzle which sprays fuel into an internal standpipe, thereby creating a vacuum and drawing in fuel off the bottom of the tank. As is known, the jet pump allows fuel to be sucked from the bottom of the fuel tank when fuel levels are low.  
         [0003]     A fuel filter is typically connected to the fuel supply line for filtering fuel flowing to the engine from the fuel pump. Unfortunately, when the vehicle is turned off, the fuel in the filter tends to bleed down back into the tank via the manifold and jet pump. In turn, the lack of fuel in the filter causes a hard start and/or a long crank issue with the vehicle. More specifically, the fuel filter must be replenished with fuel before the fuel supply line is pressurized and fuel is delivered to the engine. Furthermore, any air or vapor in the filter may also be delivered to the fuel supply line.  
         [0004]     Accordingly, there exists a need to provide a fuel supply system having a fuel filter which does not bleed down into the tank when the vehicle is turned off, and which minimizes or eliminates any air or vapor delivered to the fuel supply line.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     The present invention provides a fuel supply system for a vehicle which prevents bleed-down of the fuel filter and minimizes the amount of any air or vapor delivered to the fuel supply line. The system generally includes a fuel tank, a fuel delivery module, a fuel supply line and a jet pump. The fuel delivery module has a reservoir and a fuel pump pressurizing fuel from the reservoir. The fuel supply line leads from the fuel tank to the engine of the vehicle. The jet pump collects fuel from the bottom of the fuel tank and supplies the collected fuel to the reservoir of the fuel delivery module. The filter includes a housing enclosing a filter media. The filter includes an inlet for receiving fuel from the fuel pump. The filter also includes first and second outlets. The first outlet supplies filtered fuel to the fuel supply line. The second outlet supplies filtered fuel to the jet pump. In this way, by providing a single inlet from the fuel pump to the fuel filter, and by providing two distinct outlets from the fuel filter which separately lead to the fuel supply line and the jet pump, bleed down is prevented and vapors within the fuel supply line are reduced.  
         [0006]     According to more detailed aspects, the second outlet preferably includes a standpipe having a receiving end position within the top half of the filter housing. When the receiving end is positioned adjacent the top of the filter housing, fuel is prevented from leaking down into the tank through the jet pump. Additionally, any air or vapors which do collect within the filter will rise to the top of the filter, and will be purged through the jet pump upon start-up. The first outlet also preferably includes a standpipe having its receiving end positioned within the bottom half of the filter housing. By positioning the first outlet&#39;s receiving end adjacent the bottom of the filter housing, a continuous supply of fuel is available to the engine. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     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:  
         [0008]      FIG. 1  is a plan view of a fuel supply system constructed in accordance with the teachings of the present invention;  
         [0009]      FIG. 2  is a perspective view, taken from the top, of a fuel filter forming a portion of the fuel supply system depicted in  FIG. 1 ;  
         [0010]      FIG. 3  is a side view of the fuel filter depicted in  FIG. 2 ;  
         [0011]      FIG. 4  is a cross-sectional view about the line  4 - 4  of  FIG. 3 ; and  
         [0012]      FIG. 5  is a schematic depicting the operation of the fuel supply system and fuel filter depicted in  FIGS. 1-4 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]     Turning now to the figures,  FIG. 1  depicts a front view of a fuel delivery system  8  constructed in accordance with the teachings of the present invention. The fuel supply system  8  generally includes a fuel delivery module  10  and a fuel filter  20  connected thereto. The fuel supply system  8  provides pressurized fuel to a fuel line  12  leading to the engine of a vehicle. The fuel delivery module  10  includes a housing  11  defining a reservoir for maintaining a collection of fuel for use by a fuel pump  70  ( FIG. 5 ) to supply pressurized fuel to the fuel line  12  and engine. The fuel delivery module  10  generally includes an upper portion  14  and a lower portion  16 . The lower portion  16  has a smaller outer diameter than the upper portion  14 , and is sized to receive the fuel filter  20  about its periphery. The filter  20  includes a number of deflectable tabs  32  which releasably engage various projections  18  or apertures  19  formed in the fuel delivery module  10 . It will be recognized that numerous types of connection features can be employed to attach the fuel filter  20  to the fuel delivery module  10 .  
         [0014]     Turning now to  FIGS. 2 and 3 ,  FIG. 2  depicts a perspective view of the fuel filter  20  and  FIG. 3  depicts a side view of the filter  20 . The filter  20  includes a housing  22  defining an internal chamber  23  ( FIG. 4 ) for filtering fuel. The filter housing  22  is preferably constructed of an electrically conductive plastic for electric static discharge. The housing  22  generally comprises an inner annular wall  24  and an outer annular wall  26 . The inner and outer walls  24 ,  26  are connected by an upper wall  28  and a lower wall  30 . A filtering media (not shown) is disposed within the chamber  23  for filtering fuel supplied to the vehicle&#39;s engine. The filter media is chosen based on OEM requirements, but is preferably constructed of paper to achieve high capacity and retention of small particle contaminants.  
         [0015]     The filter  20  includes an inlet  34  generally comprising a standpipe  40 . The distal end  42  of the standpipe  40  defines connection features for connecting the inlet  34  to an outlet of the fuel pump  70  on the fuel delivery module  10 . Suffice it to say that the inlet  34  receives pressurized fuel from the fuel pump  70  and fuel delivery module  10 . The inlet  34  is located on the outer periphery of the housing  22 , and hence the outer periphery of the internal chamber  23 . Fuel flows through the filtering media toward the inner wall  24  of the filter housing  22 .  
         [0016]     Uniquely, the fuel filter  20  includes two outlets  36 ,  38  located adjacent the inner wall  24  on the inner periphery of the chamber  23  for receiving filtered fuel. The first outlet  36  generally includes a standpipe  44  extending from outside the housing  22  to the interior chamber  23 . The free end  36  of standpipe  44  extends outside upper wall  28  of the filter housing  20  generally includes connection features for fluidically connecting the first outlet  36  to the fuel supply  12  and engine. The standpipe  44  includes an internal portion  48  located within the housing  22  having a receiving end  50  for taking up filtered fuel. As best seen in the side view of  FIG. 3 , the internal standpipe  48  has its receiving end  50  located in the bottom half of the filter  20  and its housing  22 . More specifically, the receiving end  50  is positioned adjacent the bottom of the filter housing  22  and proximate to the lower wall  30 . In this way, filtered fuel will be pulled from the bottom of the filter  20 , eliminating the potential for air pockets to enter the fuel supply line  12 .  
         [0017]     The second outlet  38  generally includes a standpipe  52  extending out of the bottom wall  30  of the filter housing  22 . As best seen in  FIG. 3 , the standpipe  52  generally includes an internal portion  54  which is located within the internal chamber  23 . The internal portion  54  of standpipe  52  includes a receiving end  56  positioned within the top half of the filter  20  and its housing  22 . More specifically, the receiving end  56  is positioned adjacent the top of the filter housing  22  and proximate to the upper wall  28 .  
         [0018]     The opposing end of the standpipe  52  is fluidically connected to a jet pump  60  via a conduit  58 . The jet pump  60  generally includes a nozzle  62  defining a Venturi restriction which sprays fuel into a standpipe  74  ( FIG. 5 ) of the fuel delivery module  10 . As is known in the art, the jet pump  60  and its nozzle  62  draws fuel in from the bottom of the fuel tank with a vacuum created by the velocity of fuel flowing out of the nozzle  62 . Thus the jet pump  60  collects fuel when the level in the tank is low, and provides that fuel to the reservoir defined by the housing  11  of the fuel delivery module  10 . By positioning of the receiving end  56 , any air pockets will be forced to be released through the jet pump  60  thereby eliminating any potential adverse effect on drivability. The jet pump  60  is preferably integrally formed with the fuel filter  20  and its housing  22 . Additionally, the jet pump  60  is provided with filtered fuel further increasing its efficiency and durability.  
         [0019]     As best seen in the cross-sectional view of  FIG. 4 , the jet pump  60  is located radially inside the filter  20 , i.e., inside the inner wall  24 . The inward location of the second outlet  38  and the internal portion  54  of its standpipe  52  can be appreciated. It can also be seen that the inner wall  24  includes a clearance or depression  25  which is shaped to accommodate at least a portion of the standpipe  44  of the first outlet  36 . In this way, the space for the filtering media is enhanced and the standpipes  44 ,  52  do not adversely interfere with the filtering media.  
         [0020]     The unique operation of the fuel supply system  8 , and specifically the fuel filter  20 , in conjunction with the fuel delivery module  10  will now be described with reference to the schematic depicted in  FIG. 5 . The fuel filter  20  has been shown disconnected and positioned away from the fuel delivery module  10  for purposes of illustration. Arrows have been shown to illustrate the flow of fuel through the fuel delivery module  10  and fuel filter  20 . As previously discussed, the fuel delivery module  10  includes a housing  11  defining a reservoir receiving fuel from the fuel tank. The fuel delivery module  10  further includes a fuel pump  70  which provides pressurized fuel to the fuel filter  20  via a conduit  72 . The conduit  72  connects to the inlet  34  via its standpipe  40  and its end  42  having quick connection features. Fuel is supplied to the outer periphery of the internal chamber  23  of the filter  20 , and flows inwardly through the filtering media.  
         [0021]     Filtered fuel is then supplied to both the first and second outlets  36 ,  38 . The first outlet  36  includes standpipe  44  having internal portion  48  extending near the bottom of the filter  20  to a receiving end  50  which provides fuel to the engine via fuel line  12  and conduit  76  formed in the fuel delivery module  10 . The second outlet  38  includes standpipe  52  having internal portion  54  extending to receiving end  56  located at the top of the filter  20  for providing fuel to the jet pump  60 . As previously discussed, the jet pump  60  sprays through its nozzle  62  at high velocity to draw fuel from the bottom of the fuel tank and supplies the fuel to conduit  74  within the fuel delivery module  10 . Conduit  74  allows the fuel to flow into the reservoir defined by housing  11 .  
         [0022]     By utilizing standpipes  44 ,  52  for the first and second outlets  36 ,  38 , bleed down of the filter and air getting into the fuel line  12  is minimized. By locating the receiving end  56  of the second outlet  38  adjacent the top of the filter  20 , the jet pump  60  will always draw fuel from a top portion of the filter. In this way, very little fuel contained within the filter  20  will be allowed to flow through standpipe  52  and jet pump  60  into the fuel tank when the vehicle is turned off. Furthermore, any air or vapors which are found within the fuel filter  20  will be purged through the jet pump  60 . That is, any air or vapor within the filter  20  will be located at the top of the filter, and thus will flow through the second outlet  38  and jet pump  60  and will not be supplied to the engine or fuel line  12 . Additionally, the second outlet  36  obtains fuel from receiving end  50  located at the bottom of the filter  20 , thereby ensuring a solid supply of fuel for passage to the engine.  
         [0023]     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.