Patent Publication Number: US-7913670-B2

Title: Venturi jet structure for fuel delivery module of a fuel tank

Description:
This application claims the benefit of the earlier filing date of U.S. Provisional Application No. 60/936,404, filed on Jun. 18, 2007, which is hereby incorporated by reference into this specification. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to fuel delivery modules for automobile vehicles and, more particularly, to a venturi jet structure that can operate within a wide range of mounting orientations. 
     BACKGROUND OF THE INVENTION 
     A venturi jet of a fuel delivery module is used to draw fuel from a fuel tank into a separate reservoir inside of the fuel tank. A fuel pump delivers fuel from the reservoir to the engine of a vehicle. An example of the use of a venturi tube in a fuel delivery module using a single chamber fuel tank is disclosed in U.S. Pat. No. 6,951,208, the content of which is hereby incorporated by reference into this specification. 
     With reference to  FIG. 1 , a conventional venturi jet structure is shown generally indicated at  10  that is employed in a single chamber fuel tank. The structure  10  includes a jet inlet  12  having a nozzle  13 . The inlet  12  receives fuel from a pump (not shown) and as the fuel flow through the nozzle; a vacuum is created to draw fuel into inlet  14 . The inlets  12  and  14  are disposed upstream of a reduced diameter mixing tube  16 . The mixing tube  16  is connected with an outlet  18 . A fuel tank bottom is indicated at  22 . Table 1 below shows the different mounting options for the venturi jet structure  10  of  FIG. 1 . These five options require significant vertical packaging space. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Options 
                 Inlet to Outlet Ratio 
                 Typical Angle C 
               
               
                   
                   
               
             
            
               
                   
                 1 
                 A &lt; B 
                 +90 deg or −90 deg 
               
               
                   
                 2 
                 A = B 
                 +90 deg or −90 deg 
               
               
                   
                 3 
                 A &lt; B 
                 0 deg or 180 deg 
               
               
                   
                 4 
                 A &gt; B 
                 0 deg or 180 deg 
               
               
                   
                 5 
                 A = B 
                 0 deg or 180 deg 
               
               
                   
                   
               
            
           
         
       
     
     In Table 1, the angle C of 90 degrees (plus or minus) indicates that the venturi jet structure  10  is horizontally disposed with respect to the axis E of the mixing tube  16  (e.g., parallel to the bottom  22  of the tank). 
     In dual chamber fuel tank applications, only one side of the tank (main side) is equipped with a fuel pump. The second side of the tank contains usually only the level sensor unit. Since there will be fuel in the second side of the dual chamber fuel tank, it has to be pumped over to the main side. There are currently two concepts known to do this: 1), a venturi jet same as option no. 1 or 3 above (e.g., the jet is physically located on the second side, driven by a return flow coming into the second side or by a flow from the main side), or 2), a venturi jet same as option no. 2 or 4 or 5 (e.g., the jet is physically located on the main side). The second concept is preferred due to cost, since there is no need for two tubes from the main side to the second side and this allows for tighter integration into the main fuel module. 
     There is a need provide a venturi jet structure that can be mounted within a wide range of orientations on a main side of a fuel tank and that reduces packaging space and cost. 
     SUMMARY OF THE INVENTION 
     An object of the disclosed embodiments is to fulfill the need referred to above. In accordance with the principles of a disclosed embodiment, this objective is obtained by providing a fuel delivery system including a fuel tank having at least a main chamber. A reservoir, having a bottom, is disposed in the main chamber. 
     A fuel pump and venturi jet structure are provided in the reservoir. The venturi jet structure includes a jet inlet constructed and arranged to receive fuel from the fuel pump. The jet inlet includes a nozzle. A fuel inlet tube structure has a first end associated with the nozzle and a second end extending into a portion of the fuel tank. A mixing tube is in communication with, and downstream of, the jet inlet and the fuel inlet tube structure. An outlet is in communication with, and downstream of, the mixing tube. The venturi jet structure is constructed and arranged such that when fuel is passed through the nozzle, a vacuum is created to draw fuel from the portion of the fuel tank via the fuel inlet tube structure, through the mixing tube, and out of the outlet. A length of the fuel inlet tube structure is greater than a length of the outlet, and the mixing tube is mounted so that an axis thereof is generally horizontal ±39.90 degrees with respect to the bottom surface of the reservoir. 
     In accordance with another aspect of a disclosed embodiment, a fuel delivery system includes a fuel tank having at least a main chamber. A reservoir, having a bottom, is disposed in the main chamber. A fuel pump and means for drawing fuel are disposed in the reservoir. The means for drawing fuel includes an inlet constructed and arranged to receive fuel from the fuel pump. The inlet includes means for creating a vacuum. A fuel inlet tube structure has a first end associated with the means for creating a vacuum and a second end extending into a portion of the fuel tank. A mixing tube is in communication with, and downstream of, the inlet and the fuel inlet tube structure. An outlet is in communication with, and downstream of, the mixing tube. The means for drawing fuel is constructed and arranged such that when fuel is passed through the means for creating a vacuum, a vacuum is created to draw fuel from the portion of the fuel tank via the fuel inlet tube, through the mixing tube, and out of the outlet. A length of the fuel inlet tube structure is greater than a length of the outlet, and the mixing tube is mounted so that an axis thereof is generally horizontal ±39.90 degrees with respect to the bottom surface of the reservoir. 
     Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosed embodiments will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which: 
         FIG. 1  is a view of a conventional venturi jet structure for a fuel delivery module of a vehicle used in a single chamber fuel tank. 
         FIG. 2  is a front view of a venturi jet structure provided in accordance with the principles of a disclosed embodiment. 
         FIG. 3  is a schematic view of a fuel delivery system including the venturi jet structure of  FIG. 2  and a fuel pump in a main chamber of a dual chamber fuel tank. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT 
     For a given performance of a venturi jet, the jet has a given total length. This length does not change with the orientation (e.g. horizontally or vertically oriented or anything in-between). A more powerful and/or more efficient jet typically requires a longer length. Most dual chamber fuel tanks have a rather shallow design, making it difficult to package a fuel delivery module into it. A vertically oriented jet takes away directly from the available height the fuel module has to be packaged in, limiting the design and performance of the fuel delivery module. A more powerful jet is needed for cars with high engine output. A more efficient jet is needed for reducing the jet (inlet) flow. The flow comes from the fuel pump in addition to required engine fuel consumption, so less jet flow means a less powerful pump is needed. This decreases cost and current draw of the pump (enables higher miles per gallon for the vehicle). 
     With reference to  FIG. 2  a front view of a venturi jet structure is shown, generally indicated at  24 , in accordance with a disclosed embodiment. The venturi jet structure  24  is able to be packaged generally horizontally (or within the angle range C in Table 2 below) and therefore provides an advantage in regard to cost and performance of a fuel delivery module. Thus, the embodiment of  FIGS. 2 and 3  defines an option  6  as indicated in Table 2, with the parameters defined in  FIG. 1 ). 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Option 
                 Inlet to Outlet Ratio 
                 Typical Angle C 
               
               
                   
                   
               
             
            
               
                   
                 6 
                 A &gt; B 
                 +50.10 deg to 129.90 deg 
               
               
                   
                   
               
            
           
         
       
     
     With reference to  FIGS. 2 and 3 , the venturi jet structure  24  includes a jet inlet  26 , including a nozzle  13 , which is fed fuel from fuel pump  29  via line  31 . A vacuum is created by fuel flowing through the nozzle  13  to draw fuel into an inlet tube structure  28 , having an end  41  that is associated with the nozzle  13 . The other end  43  of the inlet tube structure  28  extends into the secondary chamber  25  of a dual chamber fuel tank  27 . The inlet tube structure  28  includes corrugated, flexible portions  45  such that portions of the inlet tube structure  28  can be bent to orient the inlet tube structure  28  within the fuel tank  27  as desired. Both the inlet  26  and inlet tube structure  28  are upstream of a mixing tube  30 . The mixing tube  30  is connected with a preferably tubular outlet  32  and has a diameter less than a diameter of each of the fuel inlet tube structure  28  and outlet  32 . 
     With reference to  FIG. 3 , and Table 2, the longitudinal axis E of the mixing tube  30  of the venturi jet structure  24  is disposed generally horizontally (horizontal, C=90 deg)±39.90 degrees. In other words, when horizontally disposed, the axis E of the mixing tube  30  is parallel with the bottom surface  35 . The venturi jet structure  24  and fuel pump  29  are disposed in the reservoir  40  in a main chamber  33  of the dual chamber fuel tank  27 . The dimension A in Table 2 is the length of the inlet tube structure  28 . The dimension B is shown in  FIG. 2  and is the length of the outlet  32 . The length A of the fuel inlet tube structure  28  is greater than the length B of the outlet  32 . 
     With reference to  FIG. 3 , the inlet tube structure  28  can include a tube portion  28 ′ that is disposed in the main chamber  33  of the fuel tank  27  for drawing fuel from the main chamber  28 . The length of the tube proton  28 ′ (e.g., dimension A in Table 2) is greater than the length B of the outlet  32 . Thus, if the inlet tube structure  28  includes only the tube portion  28 ′, the venturi jet structure  24  can be used in a fuel tank having only a main chamber  33 . 
     In the illustrated embodiment, an optional bucket  34  is provided to keep the mixing tube  30  filled with fuel. In the embodiment, the bucket  34  is made integral with the outlet  32 . Thus, fuel is expelled generally horizontally into the bucket  34  and the bucket fills vertically with fuel. This fuel will reduce the time it takes to “start” the venturi jet structure  24  (in order to create a vacuum the system has to be hydraulically “sealed”). A deflector  36  is preferably provided over an opened end  37  of the bucket  34 , and spaced therefrom. The deflector  36  is preferably part of a bracket  45  that holds a portion of the inlet tube  28 . The bracket  47  is coupled to the venturi jet structure  24  at connection  49 . The bracket  47  includes clip structure  50  constructed and arranged to couple the bracket  47  to the reservoir  40  thereby mounting the venturi jet structure  24  within the reservoir  40 . The underside of the deflector  36  facing the open end  37  of the bucket  34  preferably includes baffles or ribs  38  such that the deflector  36  prevents uncontrolled vertical fuel to spray out of the bucket  34 . Such uncontrolled fuel spray causes vapor generation, noise and reduces the amount of fuel being filled into the reservoir (as it could splash outside of it). Thus, the deflector  36  is constructed and arranged to deflect the spray of fuel from the vertical direction. 
     When the fuel pump operates, fuel from the pump  29  is sent through the nozzle  13  creating a vacuum to draw fuel from the secondary chamber  25  and/or the main chamber  33  of the fuel tank  27  via inlet tube structure  28  into the mixing chamber  30 . Fuel then exits the outlet  32  and cup  34  and dumps into the reservoir  40  to keep fuel in the reservoir to be pumped to the engine by the fuel pump  29 . Since the venturi jet structure  24  is disposed in the main chamber  33 , only one tube (e.g., main poring of the tube structure  28 ) is needed to extend into the secondary chamber  25 . Further, since the mixing tube  30  is disposed generally horizontally within the reservoir  40 , it reduces vertical packaging space and cost. 
     The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present embodiments, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, the embodiments include all modifications encompassed within the spirit of the following claims.