Abstract:
A filler neck assembly includes a funnel member having a tubular body defining a transition portion between an inlet opening and an outlet opening and a nozzle receptor disposed within the tubular body. The nozzle receptor positions a nozzle relative to the transition portion to create a suctioning effect that prevents fuel vapors from escaping into the atmosphere during fueling.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 10/615,485 filed on Jul. 8, 2003, which is a continuation of U.S. patent application Ser. No. 09/998,113 filed on Nov. 30, 2001 (now U.S. Pat. No. 6,588,459), which is a continuation-in-part of U.S. patent application Ser. No. 09/454,103 filed on Dec. 3, 1999 (now U.S. Pat. No. 6,330,893). The disclosures of the above applications are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to the fuel tank filler neck connected to the gas tank of an automobile. 
       BACKGROUND OF THE INVENTION 
       [0003]    Gas tank fuel systems with reduced gasoline vapor loss are becoming increasingly important in the automobile industry to reduce needless loss of fuel. The typical solution to this problem has been to reduce the diameter of at least a section of the fuel tank filler neck. Though this approach has been somewhat successful, it is limited because as the diameter of the filler neck is decreased, the resistance to flow of the gasoline is increased. The increased resistance causes the fill neck to become filled during vehicle refueling thereby blocking release of any pressure buildup and causing the fuel nozzle to shut off prematurely before the fuel tank is full. Another consideration in preventing the loss of fuel, is the permeability of the materials from which the fuel tank system is made. Fuel vapors escape by diffusing through the various types of mild steels of which components of fuel tank systems are typically made. This fuel escape is particularly apparent after the mild steel components have corroded to any degree. 
         [0004]    Another disadvantage of the current methods of reducing gasoline vapor losses is that typically the end of the gas line filler neck is flared out in order to provide a sufficient diameter to accept the gas nozzle during refueling. These filler necks are often made by a process of repeated reductions and expansions of a seamed welded tube. Accordingly, there is an increasing tendency for the integrity of the weld to leak as thinner diameter tubes are utilized. 
       SUMMARY OF THE INVENTION 
       [0005]    A filler neck assembly includes a funnel member having a tubular body defining a transition portion between an inlet opening and an outlet opening and a nozzle receptor disposed within the tubular body. The nozzle receptor positions a nozzle relative to the transition portion to create a suctioning effect that prevents fuel vapors from escaping into the atmosphere during fueling. 
         [0006]    The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0007]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0008]      FIG. 1  is a schematic of a fuel tank filler neck incorporated in a automobile fuel tank system; 
           [0009]      FIG. 2  is a fragmented cross sectional view of the fuel tank filler neck and an attached elongated member in the fuel tank system of  FIG. 1  according to one embodiment of the present invention; 
           [0010]      FIG. 3  is a schematic dimensional view of the filler neck as a funnel member according to an embodiment of the present invention; 
           [0011]      FIG. 4  is a cross sectional view of a rolled over top modification of the fuel tank filler neck according to another embodiment of the present invention; 
           [0012]      FIG. 5  is a cross sectional view of a barbed end design of the fuel tank filler neck according to another embodiment of the present invention; 
           [0013]      FIG. 6  is a cross sectional view of a hose bead modification of the fuel tank filler neck according to another embodiment of the present invention; and 
           [0014]      FIGS. 7   a - 7   i  are schematic illustrations of the method steps for making the fuel tank filler neck of this invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    With reference to  FIG. 1  a schematic of an embodiment of fuel tank filler neck  2  incorporated into automobile fuel tank system  4  is provided. Filler neck  2  for receiving fuel nozzle  6  for a motor vehicle fuel tank includes a one-piece funnel member  8  having a tubular body. One piece funnel member  8  may be made of a number of types of metals, suitable materials include but are not limited to cold rolled steel, zinc nickel, zinc galvanized, 304 stainless steel, 409 stainless steel, terne plate, tin plate, nickel plate, galvaneal, and aluminum. Funnel member  8  may also be made from injection molded plastics. Suitable injection molded plastics include, but are not limited to Acetal (25% glass fiber), PPH (40% glass fiber), Nylon 66 (33% glass fiber), Liquid Crystal Polymer (50% glass fiber) and Nylon 66 (60% glass ceramic fiber). The various grades of stainless steel are more desirable in that such materials are more efficient in preventing gasoline vapors from escaping into the environment. 
         [0016]    One end of funnel member  8  is defined by inlet opening  10  which is attached to nozzle receptor  12 . Gas cap  14  screws directly into nozzle receptor  12 . Fuel tank system  4  attaches to automobile body  16  through opening  18 . Movable cover  20  conceals gas cap  14  when the vehicle is not being refueled. The other end of funnel member  8  is defined by outlet opening  22  that is attached to elongated tube member  24 . Elongated tube member  24  attaches to fuel tank  26 . 
         [0017]    During refueling gas cap  14  is removed and gas nozzle  6  is inserted into nozzle receptor  12 . Fuel flows out of gas nozzle  6  into funnel member  8 . Funnel member  8  induces a swirling motion in the fuel as the fuel proceeds to flow into elongated tube member  24 . The swirling motion of the fuel continues as the fuel fills fuel tank  26 . The swirling motion of the fuel created by funnel member  8 , creates a suctioning effect that prevents fuel vapors from escaping into the atmosphere during refueling. The swirling motion of the fuel also creates a central void that allows any pressure buildups created during refueling to vent, thereby preventing premature shutoff of the fuel nozzle. Vent tube  25  connects to funnel member  8  at funnel vent hole  27  and to fuel tank  26  at fuel tank hole  29 . Vent tube  27  allows displaced vapors in fuel tank  26  to be vented during refueling. The venting configuration defined by vent tube  27  may be replaced by a system that re-circulates the fuel vapor. Such system are known to individuals skilled in the art. 
         [0018]    With reference to  FIGS. 1 and 2 , funnel member  8  defines in off-set axial relation a relatively large inlet opening  10  adapted for attachment to a gas nozzle receptor  12  and a relatively small necked down outlet opening  22  adapted for attachment to inlet  28  of elongated tubular member  24 . The off-set axial relation between the inlet opening  10  and outlet opening  22  causes fuel emerging from gas nozzle  6  to impinge on side  30  of funnel member  8  and thereby causes fuel to spiral as the fuel proceeds forward to elongated tube member  24 . Gas cap  14  screws directly into gas nozzle receptor  6 . Filler neck  2  may optionally be provided with vent opening  27  for attachment to vent tube  25 . Vent opening  27  may either be drilled in funnel member  8  after it drawn or it may be incorporated in the sheet stock before funnel member  8  is drawn. 
         [0019]    Funnel member  8  is drawn and is therefore seamless. Funnel member  8  is provided with an cutouts  30 ,  32  adjacent to inlet opening  10  for attaching the nozzle receptor  6  to funnel member  8 . Cutouts  30 ,  32  allow nozzle receptor  6  to snap into position via wings  34 ,  36  that protrude out of nozzle receptor  6 . Because funnel member  8  is seamless, insert section  38  of nozzle receptor  6  is able to make intimate contact with funnel member  8  thereby creating a leak-proof seal via  0 -ring  40 . Funnel member  8  is attached to the elongated member inlet  28  by braised joint  42 . Optionally, filler neck  2  may be coated with an anti-corrosive coating  44 . 
         [0020]    With reference to  FIG. 3 , relatively large diameter section  46  forming the inlet opening  10  and the spaced-apart relatively smaller diameter tubular section  48  forming the outlet opening  22  are in an axially offset relationship. The large diameter section  46  and the small diameter tubular section  48  are connected to one another by tapered section  50  which gradually blends from the large diameter section  46  to the small diameter section  48 . Tapered section  50  intersects large diameter section  46  at elliptically-shaped junction  52  which lies in a plane inclined at angle A which is 60-85 degrees from the axis of the tubular sections. The funnel inlet opening  10  has a diameter D 1  of 60 mm and the tubular section has a diameter D 2  of 25 mm with a coaxial offset at a distance X which is 15 mm. This offset axial relationship is sufficient to achieve fuel swirl during fuel filling. 
         [0021]    With reference to  FIG. 4 , a modification of filler neck  2  is illustrated. Rolled over top  54  is formed at the top of large diameter section  46 . In this modification, rolled over top  54  provides a sealing surface onto which gas cap  14  makes a seal. Gas cap  14  screws directly into nozzle receptor  12 . Nozzle receptor  12  is held in position by crimps  56 ,  58  which project into indentations  60 ,  62  in nozzle receptor  12 . 
         [0022]    With reference to  FIG. 5 , a modification of filler neck  2  is illustrated. The surface of the smaller diameter tubular section  48  is provided with barbs  64 ,  66 ,  68 . This modification allows for plastic or rubber tubing to be utilized for the formation of elongated tube member  24 . 
         [0023]    With reference to  FIG. 6 , a modification of filler neck  2  is provided. The surface of the smaller diameter tubular section  48  is provided with hose bead  70 . This modification allows for plastic or rubber tubing to be utilized for the formation of elongated tube member  24 . 
         [0024]    The fuel tank filler neck of this invention may be made by a number of processes which includes eyelet/progressive stamping, eyelet stamping, progressive die stamping, transfer die stamping, and hydroforming. If the fuel tank filler neck is made of plastic, injection molding and compression molding are suitable methods for manufacturing the fuel tank filler neck. 
         [0025]    The eyelet/progressive stamping method of manufacturing the fuel tank filler neck of this invention will now be described with reference to  FIGS. 1 ,  2 ,  3  and  7 . First, the filler neck  2  for motor vehicle fuel tank system  4  is formed by deep-drawing a seamless funnel member  8  having an elongated tubular body  24  with an enlarged inlet opening  10  at one end and a relatively small outlet opening  22  at the opposite end. A length of butt-seam tubing is cut to form a tubular member  24  of desired length. An end of the tubular member is telescopically aligned with outlet opening  22  of funnel member  8  and securely joins the funnel and tubular members together. Elongated tubular member  24  is bent to a desired shape. Nozzle receptor  12  is attached to funnel member  8  adjacent funnel inlet opening  10 . In a refinement of this embodiment, the configuration is then leak tested to verify the integrity of joining funnel member  8  to tubular member  24  and the attachment of nozzle receptor  12  to funnel member  8 , and the integrity of the butt-seam joint  42  and the tubular member  24  subsequent to bending. The funnel member  8  is attached to the tubular member  24  by braising, adhesive bonding, or welding. In yet another refinement of this embodiment, a portion of the filler neck  2  is configured to induce a sufficient swirl to create a hollow passage for suctioning fuel vapors into the tank  26  and to allow venting of any pressure buildup during in fuel tank  26  during refueling. 
         [0026]    With reference to  FIG. 7 , schematic illustrations of the method steps for making the fuel tank filler neck of this invention and attaching the elongated tube member are provided. In step  7 a, sheet stock is preformed into a circular blank that is drawn into a funnel shape in step  7   b.  The ends of the funnel shape are next trimmed in step  7   c  to remove excess stock and thereby form funnel member  8 . In step  7   d,  pipe stock is cut to desired length to form elongated tube member  24 . Elongated tube member  24  is then flared at the ends in step  7   i  in order to provide an attachment mechanism to the funnel member. The elongated tube and funnel member are then aligned in step  7   f  and brazed together in step  7   g.  The funnel member and elongated tube combination is then bent in step  7   h.  Nozzle receptor  12  is then inserted in step  7   i.    
         [0027]    While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.