Patent Document

FIELD OF THE INVENTION  
       [0001]     The present invention relates to low-emission fuel tank venting systems. Specifically, the invention relates to a tank-mounted fuel pump module having an integrated manifold for merging multiple vapor sources through a single vapor outlet in the module flange.  
       BACKGROUND OF THE INVENTION  
       [0002]     Controlling fuel vapor in vehicle fuel tanks has long been an objective for automobile manufacturers and suppliers of fuel systems components. Fuel vapor can be created in the fuel tank by temperature differences between the fuel tank and liquid fuel from a fuel pump, as well as by sloshing and agitation of the fuel tank during normal vehicle operation. The vapor collects in various high points within the fuel tank, and is normally released from the fuel tank through one or more vent valves located within the wall of the fuel tank. This prevents pressurization of the tank or the creation of a vacuum therein as a result of fluctuations in fuel volume due especially to changes in temperature or in atmospheric pressure or to the drop in fuel level as the fuel is drawn off.  
         [0003]     Once the fuel vapor has been discharged from the fuel tank, the vapor must be adequately stored and/or consumed to assure compliance with air pollution regulations. In some vehicle fuel systems, discharged fuel vapor is exhausted to a charcoal-filled vapor recovery canister designed to capture and store fuel vapor. These so-called “on-board” fuel vapor recovery systems are disclosed, e.g., in U.S. Pat. Nos. 4,770; 4,816,045; and 4,836,835. Other systems route the fuel vapor back to the engine, where it is combusted.  
         [0004]     Due to the size restraints of the vehicle, the fuel tank may have a complex shape. It often includes pockets in its upper wall, or areas liable to collect fuel vapor when the fuel reaches a high level in the tank and/or when the vehicle is on an incline. Each of these pockets therefore requires a means of venting the collected vapor to the outside of the tank. Multiple ventilation point may be connected directly to the outside of the tank, but due to permeation of fuel vapor through multiple vapor vent lines, increased vapor emissions are eminent.  
         [0005]     With the increasing requirements to reduce emissions, t becomes advantageous to route vapor vent lines inside the fuel tank, to a single exit point from the various vapor pockets created within the tank. Doing so reduces permeation emissions by containing multiple vapor lines inside the fuel tank. Furthermore under these increasing regulations to reduce emissions, where multiple vent valves used to be mounted in separate apertures through the fuel tank, it now becomes advantageous to mount them within the fuel pump mounting flange, thereby eliminating the need for additional holes through the tank and potential vapor emission sources.  
         [0006]     The need arose for a fuel pump module with an integrated manifold, combining the fuel vapor from multiple sources within a fuel tank, and discharging them through a single outlet port, located on the pump modular flange.  
       SUMMARY OF THE INVENTION  
       [0007]     It is therefore an object of the present invention to provide for a means for reducing permeation emissions of fuel vapor, by eliminating multiple vapor vent lines outside the tank.  
         [0008]     It is another object of the present invention to provide for a means of collecting fuel vapor from multiple sources within a fuel tank and merging them into a single outlet located on the fuel pump modular flange.  
         [0009]     A further object of the present invention is to provide a means of attaching one or more vapor vents directly to the modular flange, thereby incorporating multiple vapor inlets for fuel vapor collected remotely within the fuel tank.  
         [0010]     Another object of the present invention is to reduce fuel vapor emissions from a fuel tank by providing a fuel pump modular flange having one or more vapor valves incorporated within, thereby eliminating the need for additional holes through the fuel tank.  
         [0011]     The foregoing objects are achieved by a fuel pump module having an integrated vapor manifold within the mounting flange for the collection and release of fuel vapor accumulated within a fuel tank. The flange combines fuel vapor collected from multiple vapor inlets inside the fuel tank transported to the flange through internal vapor vent lines, and consolidate them into a single outlet through the modular flange. Furthermore, the modular flange provides for a means of attaching one or more vent valves directly to the manifold for merging vapors collected proximal to the flange with those of remote sources within the fuel tank. Once the vapors consolidate within the manifold, they are discharged through a single outlet to a remote located canister outside the fuel tank for storage. By eliminating the need for multiple apertures through the fuel tank and routing fuel vapor lines within the fuel tank, harmful vapor emissions into the atmosphere are significantly decreased.  
         [0012]     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  
       [0013]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0014]      FIG. 1  is a partial-sectional side view of the fuel tank with attached fuel pump module flange and remote vent valve.  
         [0015]      FIG. 2  is a partial-sectional side view of the fuel pump module flange and vapor-vent manifold with plural, integral vent valves.  
         [0016]      FIG. 3  is a detailed partial-sectional side view of the fuel pump module flange illustrating the junction point of the secondary manifold of  FIG. 4 .  
         [0017]      FIG. 4  is a sectional side view of the secondary manifold having a remote vapor inlet, for attachment of a secondary vent valve to the vapor vent manifold. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     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.  
         [0019]     Referring to the drawings, and particularly  FIGS. 1 and 2 , the invention consists of a fuel pump module having a modular flange  20  with an integrated fuel vapor manifold  22 , for attachment to an automobile fuel tank  11 . The flange  20  of the module  10  is attached to an opening in the fuel tank wall  11 , and seals the interior volume of the fuel tank from the outside atmosphere. As illustrated, the flange  20  comprises an integrated vapor manifold  22  for the collection of fuel vapor  17  from one or more vent valve inlets within the fuel tank  11  and merges them into a single outlet port  26  leading to a remote vapor storage canister  60  or other desired location. Optionally, the flange  20  is sealed to the fuel tank  11  by a sealing means  24 , but the scope of invention is not intended to be limited by the means in which the flange  20  is attached to the fuel tank wall  11 .  
         [0020]     The manifold  22  integrated into the modular flange  20 , consists of a manifold chamber  27  having an aperture at one end passing through the flange  20  defining a receptacle  21 , for receiving the interface portion  46  of an attached vent valve  40  on the bottom side of the modular flange  20 . In the preferred embodiment, the manifold  22  further defines a secondary vapor inlet  90  wherein the vapor collected from a secondary vent valve  50  or other remote source  14  within the fuel tank  11  enters the manifold  22  and combines with the vapor from the primary vent valve  40 . The combined fuel vapors from the multiple of vent valves within the tank  11  illustrated by the arrow  18 , merge and exit the manifold  22  through the outlet tube  26  as indicated. The outlet tube  26  attaches to an external vapor tube  62  which carries the fuel vapor to a remote canister  60  for storage, or holding prior to being routed to the engine and burned.  
         [0021]     As stated, the flange  20  and incorporated manifold  22  provide for the direct attachment of one or more primary vent valve  40  directly to the bottom side of the flange  20 . Each valve  40  is typically cylindrical in shape, and has a vapor inlet  42  wherein fuel vapor  17  travels from the interior of the fuel tank  11  into the valve  40  assembly as shown by the arrow  12 . Inside the vent valve  40  but not shown, is a check valve which allows the fuel vapor  17  to exit into the manifold  22  while preventing any fuel  19  that may splash onto the vent valve  40  from traveling up into the manifold chamber  27 . The valve  40  further serves to protect against fuel discharge through the vapor system in the event of inadvertently overfilling the tank  11  during refueling.  
         [0022]     Best illustrated in  FIG. 2 , the generally cylindrical interface portion  46  of the upper end of the valve  40  is concisely received by the corresponding valve receptacle  21  located on the manifold  22 . The interface portion comprises a vapor passage from the valve  40  to the manifold  22 , allowing vapor to pass from the valve  40  into the manifold chamber  27 . In the preferred embodiment, a sealing means such as an o-ring  47 , is shown implemented in an annular grove on the interface portion  46  of the valve  40  further preventing fuel  19  from passing up into the manifold chamber  27 . If the frictional fit between the interface portion  46  of the vent  40 , the receptacle  21  on the manifold  22  and the sealing means  47  is tight enough, the valve  40  will be retained securely by the flange  20 , wherein further means of attachment may not be necessary.  
         [0023]     Alternatively, a second means of attaching the valve  40  to the flange  20  as shown in  FIGS. 2 and 3  utilizes a snap-fit design, wherein a wedge-shaped vertical tab  44  on the exterior of the vent valve  40  biases the wall  32  of the flange  20  outward upon contact as the valve  40  is inserted upwards into the receptacle  21 . Once fully inserted, the tab  44  is received through an aperture  25  on the wall  32  allowing the wall  32  to snap back to its original position locking the vent valve  40  in position. This snap-fit means of attachment provides a more secure connection between the valve  40  and the modular flange  20 , which may be preferable in fuel vent applications that expose the fuel pump module  10  to more severe jarring.  
         [0024]     Often times as illustrated in  FIG. 1 , it is desirable to have a remotely mounted vapor vent valve  30  for the collection of vapor from a portion of a fuel tank  11  distal to the fuel pump modular flange  20  that may be vaporly compartmentalized due to the design of the tank. The remote vent valve  30  may be mounted to the tank  11  through a second aperture  15  in the tank wall or by some other means, but is not intended to limit the scope of the invention. The vent valve  30  discharges vapor to the internal vent line  34  that carries the vapor  17  from the remote valve  30  to the modular flange  20 , where it connects to a manifold adapter  80  illustrated in  FIG. 4 , which attaches to the modular flange  20  at surface  92 . The adaptor  80  comprises a vapor chamber  83  defined by walls  82 ,  84  and  86  which is open on the bottom defining a receptacle for receiving a secondary vent valve  50 , attached by similar means as the primary vent valve  40  is attached to the modular flange  20 , shown in  FIGS. 2 and 3 . Additional fuel vapor  17  may enter the secondary vent valve  50  through aperture  52 , as indicated by the arrow  16 .  
         [0025]     Referring to  FIGS. 3 and 4  together, the manifold adapter  80  comprises a remote vapor inlet tube  87  leading into the vapor chamber  83 , which connects with the internal vent line  34  from the remote vent valve  30  at end  81 . Fuel vapor which  17  enters the remote vent valve  30 , travels into the manifold adapter  80  as indicated by the arrow  14  wherein it merges with vapor collected through the secondary valve  50 . The combined vapors exit the manifold adapter  80  through a tapered exit port  89  in the top of the adapter  80 , defined by an extended outlet tube  88 , terminating within the manifold  22  when attached thereto. The adapter  80  in the preferred embodiment is welded to the underside of the manifold  22 , in a manner so as to maintain a small gap or passage around the extended outlet tube  88  as shown in  FIG. 3 . The extension of the outlet tube  88  provides for a high point of vapor exit from the manifold adapter  80  into the manifold  22 , while the gap allows fuel  19  that may inadvertently bypass the primary vent valve  40  to drain back into the tank  11  instead of undesirably entering the internal vent line  34 . The fuel vapors collected through arrows  14  and  16 , commingle with each other in the manifold adapter  80  before entering the manifold  22  and commingling with the vapors collected through the primary vent valve  40  as indicated by the arrow  12 . The combined vapors, now indicated by arrow  18 , exit the manifold  22  through the single outlet tube  26  which attaches to the external vapor tube  62 , carrying the fuel vapor to canister  60  for storage, prior to being routed to the engine and burned.  
         [0026]     There is thus provided a fuel pump module incorporating fuel vapor collected through one or more vapor vent valves both proximal and distal to the modular flange by an integrated manifold having a single outlet, which significantly reduces the potential sources for fuel vapor emissions into the atmosphere.

Technology Category: 7