Abstract:
The present invention refers to a fuel pressure regulator assembly and method for regulating the pressure of the fuel supplied to the fuel rail at a predetermined pressure. The fuel pressure regulator includes a housing and fuel cover for containing the fuel pressure regulator and submersing the fuel pressure regulator in fuel at all times. A valve element allows excess fuel to exit the fuel pressure regulator and return to the fuel tank for reuse. The fuel component assembly also allows for a method of reducing turbulent fuel flow and for controlling noise and hydrocarbon emissions. The method is achieved by providing a containment assembly that submerges the pressure regulator in fuel for containing and directing fuel flow path.

Description:
FIELD OF THE INVENTION 
   This invention relates to fuel regulators for combustion engine applications in power automotive vehicles. 
   BACKGROUND OF THE INVENTION 
   It is known to mount a fuel pressure regulator on a fuel rail assembly to regulate the pressure of the fuel that is supplied to the fuel injectors mounted on the fuel rail. The pressurized fuel that is delivered to the fuel rail is pumped from a fuel tank through a fuel supply conduit and excess fuel is returned from the fuel pressure regulator&#39;s return port through a fuel return conduit to the tank. This type of system is called a return type system. A typical fuel pressure regulator used in this system provides a movable wall or diaphragm dividing the regulator into chambers on opposite sides thereof at different pressures. The difference in pressure determines the position of the diaphragm, which in turn determines the size of a flow passage through the regulator. Thus, depending upon the difference in pressure on opposite sides of the diaphragm, the flow through the regulator is regulated to a predetermined pressure. 
   Another type of fuel injection system does not have a fuel return conduit and is called a returnless (non-return or dead head) fuel system. In this system, the diaphragm controls the position of a ball valve which is spring-based toward a valve-seat. Fuel flows past the spring and normally opened ball valve into a compartment on one side of the diaphragm for flow to a fuel rail. The opposite side of the diaphragm may have a vacuum reference. It will be appreciated that the difference in pressure between the chambers on the opposite sides of the diaphragm displaces the diaphragm, which in turn mounts a post for moving the ball valve away from the seat or permitting the ball valve to move toward the seat under the spring bias. 
   Such systems are satisfactory for use in providing fuel to a fuel rail at a predetermined regulated pressure. While such pressure regulators have proven satisfactory, there is a need to maximize performance of the combustion engine to which fuel is supplied from the fuel pressure regulator. A combustion engine should not be supplied fuel that is turbulent or aerated. To avoid turbulent flow and aerated fuel, it is generally desirable to maintain a constant level of fuel within and about the fuel pressure regulator. This requires submersing the fuel pressure regulator in fuel. An added benefit from this is the potential reduction in noise. There has developed a need in the mechanical fuel system for a fuel pressure regulator which provides the desired engine performance for a simple and inexpensive means to keep a fuel pressure regulator submersed in fuel. 
   SUMMARY OF THE INVENTION 
   In accordance with one aspect of this invention, a fuel pressure regulator assembly residing in a fuel tank comprising: a containment assembly for submerging a fuel pressure regulator in fuel; a valve element for regulating a fuel pressure and directing excess fuel flow in a fuel system wherein the valve element rests on a valve seat in a closed position to prohibit the fuel flow; and a fuel cover for directing a fuel flow exiting the fuel pressure regulator assembly into the fuel tank. 
   In accordance with another aspect of this invention, a method for reducing noise and hydrocarbon emissions of fuel in a fuel pressure regulator, the method comprising: providing a containment assembly for containing fuel; regulating fuel pressure in a fuel system wherein a valve element rests on a valve seat in a closed position and the valve element displaces axially off the valve seat in an open position; and submerging the fuel pressure regulator in fuel. 
   It is an object of the present invention to provide a fuel pressure regulator that reduces the turbulence and aeration of the fuel that flows to the combustion engine. 
   It is a further object of the present invention to provide a fuel pressure regulator that dampens the noise or vibration of the system. 
   It is also an object of the present invention to keep the fuel pressure regulator submerged in fuel. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention 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  refers to a cross section view of the fuel pressure regulator according to the present invention. 
       FIG. 2  refers to a cross section view of the fuel pressure regulator with a fuel cover. 
       FIG. 3  refers to a cross section view of the fuel pressure regulator with a fuel conduit to the fuel tank. 
       FIG. 4  refers to a perspective view of a fuel cover. 
       FIG. 5  refers to a perspective view of an alternative embodiment of the fuel cover. 
   

   DETAILED DESCRIPTION 
     FIGS. 1-3  refer to various embodiments of the submersed fuel pressure regulator assembly  10  in accordance with the present invention. Each embodiment includes a fuel pressure regulator assembly  10 , which comprises a fuel pressure regulator  20  that preferably resides in a fuel tank  30 . Fuel tank  30  may be a fuel reservoir (which resides in a fuel tank) or a fuel tank where the fuel pressure regulator assembly  10  is positioned in the line going to the engine on the supply side or in a returnless system where excess fuel is contained in the fuel tank  30  and only consumed fuel is sent to the engine. 
   As also shown in  FIGS. 1-3 , each embodiment includes a housing  40  to contain and house the fuel pressure regulator  20 . Housing  40  acts as a wall to collect fuel spray released from the fuel pressure regulator  20 . The preferred shape of the housing  40  is generally a tubular shape but others skilled in the art may select other shapes including oval, circular, and as necessary for convenient packaging. Likewise, each embodiment includes a valve element  50  disposed on fuel pressure regulator  20 , which allows fuel that is at an excess pressure to exit the fuel pressure regulator  20 , while retaining fuel not at an excess pressure within fuel pressure regulator  20 . The preferred type of valve element  50  may be a convex plate but others skilled in the art may select a flat disk, a biased member, a spring, a ball valve or another equivalent relief-type valve. If the fuel pressure exceeds the desired maximum pressure, the valve element  50  which rests on a valve seat  55  allows excess fuel to exit fuel pressure regulator  20  and the fuel is free to fly out in a variety of directions. Valve seat  55  cooperates with valve element  50  that is movably disposed between an open and closed position. In a closed position, the valve element  50  contacts and seals against the seating surface of the valve seat  55  and prevents fuel flow past the valve seat  55 . Pressurized fuel accumulates in fuel regulator  20  until the pressurized fuel contacts the bottom surface of the valve element  50 . The pressurized fuel will then push valve element  50  off of valve seat  55  into an open position allowing fuel to flow. Valve element  50  may be a free floating design where it is not retained by other components of the assembly. Others skilled in the art may have a valve element  50  fastened to fuel pressure regulator  20  where the valve element  50  includes an aperture (not shown) or other release mechanism (not shown) to release the pressure and fuel accumulating in the fuel pressure regulator  20 . Others skilled in the art may use a hermetic seal, weld, crimp, or clamp to fasten the valve element  50  to the valve seat  55 . 
   A containment means may be utilized to insure that fuel pressure regulator  20  remains submersed in fuel. The expected spray pattern, packaging requirements and other factors will dictate the type and geometry of the containment means utilized in the invention. Three different containment means are described below. 
   In the first aspect of the invention, which is shown in  FIG. 1 , the containment means consists of housing  40 , which is used to collect the spray of excess fuel exiting the fuel regulator  20 . Housing  40  is a cylindrical wall that surrounds fuel regulator  20 . The expected spray pattern will dictate the height and geometry of housing  40 . In the preferred embodiment, the height of housing  40  will be at least equivalent to the height of valve element  50 . Housing  40  is extended and designed to stand in a generally upright position to allow substantially all of fuel regulator  20  to be maintained submersed in fuel. Housing  40  must be extended such that fuel tank  30  allows the fuel pressure regulator  10  to sit in a pocket of fuel at all times. This submersion minimizes or reduces the amount of air from entering the fuel supply system going to the fuel rail and thus minimizes air bubbles forming in the fuel. Similarly, if the spray pattern of fuel is spread in a variety of directions including horizontal and vertical spray for example when a vehicle is idling, then the fuel will break the surface of the collected fuel in regulator  20  and consequently make noise and produce free hydrocarbons thus increasing emissions from the tank  30  by shooting against the components of the fuel pressure regulator assembly  10 . Thus a need for a fuel cover  60  would be beneficial in this case. 
     FIG. 2  refers to an alternate embodiment of the fuel pressure regulator assembly  10  with fuel cover  60 . In this embodiment, the fuel cover  60  is not hermetically sealed to the housing  40 . Fuel cover  60  comprises extension tabs  61  and  62  to direct the flow of excess fuel back into fuel tank  30 . 
     FIG. 3  refers to an alternative embodiment of the invention whereby fuel pressure regulator  20  is hermetically sealed in a housing  40  by the fuel cover  60 . Others skilled in the art may select not to hermetically seal the fuel cover  60  to the housing  40  because any leakage of fuel will return back to the fuel tank  30  and therefore does not pose any problems. In this embodiment, any excess fuel is directed to the bottom of fuel tank  30  using fuel conduit  70 . In the preferred embodiment, the inlet  80  of fuel conduit  70  may be positioned near the top of housing  40  such that collected excess fuel may remain above the fuel pressure regulator  20  and then be directed toward the bottom of fuel tank  30 . However, there may be other factors (e.g. packaging requirements) that may warrant a different placement of inlet  80 . Preferably, outlet  85  should be disposed below a fuel fluid level in the fuel tank  30  to prevent air from entering the fuel pressure regulator assembly  10 . 
     FIG. 4  refers to fuel cover  60 . The fuel cover  60  is made of a plastic molded material and also includes at least one snap mechanism  90  allowing ease when being affixed to the housing  40 . In the preferred embodiment, the at least one snap mechanism  90  is a tab acting as a clip to hold the fuel pressure regulator  20  in place. One skilled in the art may choose not to affix a fuel cover  60  to the fuel pressure regulator  20 . Similarly, others skilled in the art may select to hermetically seal fuel cover  60  to housing  40 . Fuel cover  60  also acts to keep the fuel pressure regulator  20  submerged in fuel at all times during fuel flow which enhances durability of the fuel pressure regulator  20  as well as dampen any vibrating noise of the fuel pressure regulator assembly  10 . This aids in durability of the spring (not shown) used in the fuel pressure regulator assembly  10 . The accumulation of fuel in the chamber below the fuel cover  60  and above valve element  50  functions to keep pressure regulator  20  submerged in fuel. This configuration also protects the other regulator components i.e. flat spring (not shown) from damage during handling, shipping, &amp; assembly. Similarly, submergence of the fuel pressure regulator  20  in the fuel ensures that the fuel is not aerated which maximizes engine performance and that the fuel exits regulator in an organized flow back to the fuel tank  30 . Depending on the orientation of the fuel pressure regulator  20  and the fuel cover  60  the fuel cover openings  95  may be facing in a vertical direction which would then allow the flow of fuel to enter from the left and exit on the right. For example, in  FIG. 3 , those ordinary skilled in the art may rotate the fuel pressure regulator 90° allowing fuel to enter from the side as opposed to the bottom. 
     FIG. 5  refers to an alternative embodiment of fuel cover  60 . In this embodiment, fuel cover  60  includes as least three snap fit mechanisms  90  to affix the fuel cover  60  to housing  40 . Similarly, fuel cover  60  includes a fuel outlet  100  for directing the fuel path from the fuel pressure regulator  20  back to the fuel tank  30 . The fuel will hit the top surface  110  of the fuel cover  60  and then exit through side fuel outlet  100  to the fuel tank  30 . 
   While the foregoing description and drawings represent the preferred embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the true spirit and scope of the present invention.