Fuel pressure regulator

Information

  • Patent Grant
  • 6481418
  • Patent Number
    6,481,418
  • Date Filed
    Monday, October 23, 2000
    24 years ago
  • Date Issued
    Tuesday, November 19, 2002
    22 years ago
Abstract
A fuel pressure regulator for supplying fuel to the intake of an internal combustion engine at a substantially constant pressure. The fuel pressure regulator includes a housing defining a fuel chamber in fluid communication with a fluid inlet. The housing further includes a fuel outlet opening in fluid communication with the fuel chamber. The housing defines a seating surface around the outlet opening. A valve body is moveably disposed within the housing and moves between open and closed positions. The valve body contacts and seals against the seating surface and prevents fuel flow through the outlet opening when the valve body is in the closed position. The valve body is biased into the closed position. The valve body includes an extension with at least a portion thereof disposed in the fuel outlet opening to guide the valve body.
Description




TECHNICAL FIELD




This invention relates generally to a fuel pressure regulator and more specifically to a fuel pressure regulator for a fuel injector system in an internal combustion engine.




BACKGROUND OF THE INVENTION




Fuel injection systems for automotive engines commonly include electromagnetic fuel injectors that deliver fuel from a fuel rail to the engine inlet manifold adjacent the engine combustion chamber inlet ports. Such fuel injection systems ordinarily include a fuel pressure regulator to control the pressure of the fuel in the rail. In such a system, the pressure in the fuel rail is usually controlled to maintain a constant pressure difference across the injector (i.e. from the pressure in the fuel rail to the pressure in the manifold). The fuel pressure regulator is connected to the inlet manifold to sense the manifold pressure, and to the fuel rail to sense fuel pressure in the rail and to discharge excess fuel from the rail so the fuel pressure in the rail varies with the manifold pressure and is maintained at the desired difference above the manifold pressure.




Conventional fuel pressure regulators include a valve and a valve seat, both made of metal and including precisely machined and polished surfaces designed to contact each other to form a seal. The valve is biased into the closed position by a coil spring that may bias the valve laterally with respect to the seat. Lateral spring bias may cause the valve to seat improperly, causing leakage or other problems. Existing fuel pressure regulators, such as that disclosed in U.S. Pat. No. 4,756,289 to Rock et al. include a ball and socket arrangement to align the valve with the valve seat to provide the necessary rotational motion of the valve to permit alignment of the valve seating surface with the seating surface of the seat. This arrangement includes numerous parts that require high precision machining and polishing operations, as well as numerous assembly steps due to the relatively large number of parts.




SUMMARY OF THE INVENTION




One aspect of the present invention is a fuel pressure regulator for supplying fuel to the intake of an internal combustion engine at a substantially constant pressure. The fuel pressure regulator includes a housing defining a fuel chamber in fluid communication with a fluid inlet. The housing further includes a fuel outlet opening in fluid communication with the fuel chamber. The housing includes a seating surface around the outlet opening. A valve body is moveably disposed within the housing and moves between open and closed positions. The valve body contacts and seals against the seating surface and prevents fuel flow through the outlet opening when the valve body is in the closed position. The valve body is biased into the closed position, and includes an extension with at least a portion thereof disposed in the fuel outlet opening to guide the valve body.




Another aspect of the present invention is a fuel pressure regulator for supplying fuel at a substantially constant pressure. The fuel pressure regulator includes a housing having a fuel inlet and defining a fuel chamber in fluid communication with the fuel inlet. The housing also includes a fuel outlet in fluid communication with the fuel chamber, and a seating surface adjacent the fuel outlet. A valve body is disposed within the housing and is moveable between an opened position permitting fuel flow through the fuel chamber and a closed position preventing fuel flow through the fuel chamber. The valve body is normally biased into the closed position. The valve body includes a rigid molded polymer body portion and an elastomeric seal configured to engage the seating surface when the valve body is in the closed position.




Yet another aspect of the present invention is a fuel pressure regulator for supplying fuel at a substantially constant pressure. The fuel pressure regulator includes a housing having a fuel inlet and a fuel outlet and defining a seating surface. A valve body is moveably disposed within the housing and is moveable between an open position permitting fuel flow through the housing, and a closed position preventing fuel flow through the housing. The valve body includes a guide member, at least a portion of which is disposed in a selected one of the fuel inlet and the fuel outlet to guide the valve body. The valve body has a body portion made of a rigid material, and a seal that is made of a material that is soft relative to the body portion. The valve body is normally biased into the closed position and configured to shift to the open position when pressurized fuel is present in the inlet.




These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a schematic view of an internal combustion engine having a fuel system incorporating the fuel pressure regulator of the present invention;





FIG. 2

is a cross-sectional view of a fuel pressure regulator embodying the present invention; and





FIG. 3

is a cross-sectional view of the fuel pressure regulator of

FIG. 2

taken along the line III—III.











DESCRIPTION OF THE PREFERRED EMBODIMENT




For purposes of description herein, the terms “upper,”“lower, ”“right, ”“left, ”“rear, ”“front, ”“vertical, ”“horizontal, ” and derivatives thereof shall relate to the invention as oriented in

FIGS. 1 and 2

. However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.




The reference numeral


1


(

FIG. 1

) designates a fuel pressure regulator embodying the present invention, which is particularly designed for use with a fuel injected internal combustion engine


2


, and other similar applications. In the illustrated example, fuel pressure regulator


1


supplies fuel to the intake


3


of the internal combustion engine


2


at a substantially constant pressure. With further reference to

FIG. 2

, the fuel pressure regulator


1


includes a housing


4


defining a fuel chamber


5


in fluid communication with a fuel inlet


6


. The housing


4


further includes a fuel outlet


7


in fluid communication with the fuel chamber


5


. The housing


4


defines a seating surface


8


around the outlet


7


. A valve body


10


is moveably disposed within the housing


4


, and moves between opened and closed positions. The valve body


10


contacts and seals against the seating surface


8


and prevents fuel flow through the outlet opening when the valve body


10


is in the closed position. A coil spring


11


biases the valve body


10


into the closed position. The valve body


10


includes an extension


12


with at least a portion thereof disposed in the fuel outlet


7


to guide the valve body


10


to maintain alignment of a valve body


10


with the valve seat surface


8


.




As shown schematically in

FIG. 1

, a gas or diesel internal combustion engine


2


includes a fuel system incorporating the fuel pressure regulator of the present invention. A fuel rail


13


that supplies fuel to a plurality of fuel injectors


14


which are mounted on an intake manifold


15


which includes a plurality of intake ports


16


leading to the combustion chambers. A fuel pump


17


draws fuel


20


from a fuel tank


18


through a fuel line


19


, and supplies high pressure fuel to the fuel rail


13


through a fuel line


21


. Excess fuel from the fuel rail


13


is metered through the fuel pressure regulator


1


and returned to the fuel tank


18


by a fuel return line


22


.




With reference to

FIG. 2

, the housing


4


of fuel pressure regulator


1


includes a lower portion


23


that is generally cylindrical in shape, with a fitting


24


that connects to the fuel rail


13


to provide pressurized fuel to the fuel inlet


6


. A ring-like member


25


is positioned within the cylindrical portion


23


of housing


4


. The ring-like member


25


includes a plurality of openings


26


spaced around member


25


. Openings


26


align with a plurality of openings


27


through a lower sidewall


29


of an inner member


28


. Inner member


28


includes a cylindrical inner flange


30


that extends upwardly from the lower sidewall


29


to retain a tubular member


31


that forms a portion of the fuel outlet


7


and seating surface


8


. An elastomeric seal ring


33


may be clamped onto outer edge portion


34


of ring-like member


25


by a clamp ring


32


, such that the seal ring


33


contacts the inner sidewall


35


of the lower portion


23


of housing


4


, and also contacts the outer surface


37


of inner member


28


, thereby preventing fuel flow through the gap


36


between ring-like member


25


and housing


4


.




Valve body


10


is preferably molded from a polymer material, such as polyphenylene sulfide (“PPS”), that is resistant to degradation that would otherwise be caused by contact with the fuel flowing through the fuel pressure regulator


1


. An elastomeric ring


38


is integrally molded with the valve body


10


, preferably without use of adhesives. Ring


8


seals against the ring-shaped seating surface


8


formed by outlet tube


31


. Alternately, the elastomeric ring


38


may be adhesively bonded to valve body


10


, and valve body


10


could be made of a conventional metal material. Elastomeric ring


38


provides a relatively soft contact surface, providing a seal regardless of dimensional imperfections in the seating surface


8


. This construction of the valve body


10


eliminates the high precision, machined metal surfaces found on conventional valve bodies for fuel pressure regulators, thus eliminating the costly machining operations associated with such conventional valve bodies. A flexible membrane


39


moveably positions the valve body


10


within the housing


4


, and seals the fuel within the fuel chamber


5


to prevent fuel flow into the interior cavity


42


of cup-shaped upper member


40


of housing


4


. A U-shaped flange


46


of inner member


28


clamps onto a flange


44


of cup-shaped upper member


40


, thus securing outer portion


43


of flexible member


39


. A clamp ring having upper portion


47


and lower portion


48


secures the U-flange


46


to an outwardly extending flange


45


of cylindrical lower portion


23


of housing


4


. A spring retainer


50


is secured to the cylindrical upper portion


49


of valve body


10


, and retains the coil spring


11


. The upper end


51


of coil spring


11


fits around indented portion


41


of cup-shaped upper member


40


. The upper and lower clamp rings


47


and


48


may be utilized to secure the fuel pressure regulator


1


to the fuel rail


13


.




Extension


12


preferably comprises a tapered pin having an upper portion


52


with a radius


53


that fits closely against the radius


54


extending around the seating surface


8


of outlet tube


31


to guide valve body


10


into alignment with the seating surface


8


. Lower end


55


of extension pin


12


has a diameter that is substantially less than the inner diameter of outlet tube


31


. Extension


12


guides valve body


10


during assembly, and also maintains proper alignment of valve body


10


during operation of the fuel pressure regulator valve


1


. Coil spring


11


may generate side forces on valve body


10


, which would otherwise result in misalignment and leakage between the seating surface of valve body


10


and the seating surface of outlet member


31


. As illustrated in

FIG. 3

, extension pin


12


includes a plurality of flutes


56


extending vertically along the extension pin


12


to provide fuel flow through the flutes


56


when the valve body


10


is lifted from the seating surface


8


. Guide surfaces


65


are formed between flutes


56


. The guide surfaces


65


contact radius


54


of outlet tube


31


and/or inner cylindrical sidewall surface


66


of outlet tube


31


to guide valve body


10


. Flutes


56


could have a variety of cross-sectional shapes and sizes depending upon the particular application.




A lower tube structure


57


extends through the cylindrical sidewall


58


of lower portion


23


of housing


4


, and includes a fitting


59


that attaches to the fuel return line


22


. Fittings


24


and


59


are illustrated schematically in FIG.


2


. However, it should be understood that a suitable conventional high pressure fuel fitting or other suitable conventional connector is utilized for connecting the fuel pressure regulator


1


to the fuel system of the internal combustion engine


2


. A large annular groove


61


in the lower end


63


of outlet tube


31


receives an elastomeric sealing ring


60


that seals against the inner sidewall surface


64


of upwardly extending tubular portion


62


of tube structure


57


to seal off the lower pressure fuel exiting the fuel pressure regulator


1


from the incoming fuel entering through inlet


6


. The various housing components, such as lower portion


23


, cup-shaped upper portion


40


, inner member


28


, outlet tube


31


, and ring-like member


25


preferably formed of metal, or other suitable material.




The molded polymer valve body


10


provides a cost-effective construction utilizing a molded-in elastomeric ring


38


that eliminates the prior machined and polished surfaces previously required to seal conventional fuel pressure regulator valves. Further, extension


12


guides valve body


10


and maintains alignment between the seating surface of the valve body


10


and the seating surface


8


of the fuel outlet in the housing, thus eliminating the ball and socket arrangement utilized in conventional fuel pressure regulator valves. Furthermore, the guide extension


12


facilitates assembly of the fuel pressure regulator


1


by simplifying the alignment and assembly of the valve body and seating surfaces.




It will be understood by those who practice the invention and those skilled in the art, that various modifications and improvements may be made to the invention without departing from the spirit of the disclosed concept. The scope of protection afforded is to be determined by the claims and by the breadth of interpretation allowed by law.



Claims
  • 1. A fuel pressure regulator for supplying fuel at a substantially constant pressure, comprising:a housing having a fuel inlet and a fuel outlet, and defining a seating surface; and a valve body movably disposed within said housing and movable between an open position permitting fuel flow through said housing, and a closed position preventing fuel flow through said housing, said valve body including a guide member, at least a portion of which is disposed in a selected one of said fuel inlet and said fuel outlet to guide said valve body, said valve body having a body portion made of a rigid material and a seal that is made of a material that is soft relative to said body portion, said valve body normally biased into said closed position and configured to shift to said open position when pressurized fuel is present in said inlet; and wherein: said body portion is molded of a polymer material, and said seal is made of an elastomeric material and integrally molded to said body portion without adhesive.
  • 2. A fuel pressure regulator for supplying fuel at a substantially constant pressure, comprising:a housing having a fuel inlet and a fuel outlet, and defining a seating surface; and a valve body movably disposed within said housing and movable between an open position permitting fuel flow through said housing, and a closed position preventing fuel flow through said housing, said valve body including a guide member, at least a portion of which is disposed in a selected one of said fuel inlet and said fuel outlet to guide said valve body, said valve body having a body portion made of a rigid polymer material and a seal that is made of a material that is soft relative to said body portion, said valve body normally biased into said closed position and configured to shift to said open position when pressurized fuel is present in said inlet.
  • 3. The fuel pressure regulator set forth in claim 2, wherein said guide comprises a pin.
  • 4. The fuel pressure regulator set forth in claim 3, wherein said pin includes at least one flute configured to permit fuel flow therethrough when said valve body is in said open position.
  • 5. The fuel pressure regulator set forth in claim 4, wherein said pin is tapered.
  • 6. The fuel pressure regulator set forth in claim 2, wherein said housing has a tubular portion forming said fuel outlet, said tubular portion having an inner end extending into said fuel chamber and forming said seating surface.
  • 7. A fuel pressure regulator for supplying fuel to the intake of an internal combustion engine at a substantially constant pressure, comprising:a housing defining a fuel chamber in fluid communication with a fuel inlet, said housing further including a fuel outlet opening in fluid communication with said fuel chamber, said housing defining a seating surface around said outlet; a valve body movably disposed within said housing and moving between open and closed positions, said valve body contacting and sealing against said seating surface and preventing fuel flow through said outlet opening when said valve body is in said closed position, said valve body biased into said closed position; said valve body includes an extension with at least a portion thereof disposed in said fuel outlet to guide said valve body; and wherein: said valve body is molded of a rigid polymer material and includes an elastomeric ring that contacts said seating surface when said valve body is in said closed position.
  • 8. The fuel pressure regulator set forth in claim 7, wherein said extension member includes at least one flute configured to provide fuel flow through said fuel outlet opening when said valve body is in said open position.
  • 9. The fuel pressure regulator set forth in claim 7, wherein said valve body is molded of a rigid polymer material and includes an elastomeric ring that contacts said seating surface when said valve body is in said closed position.
  • 10. A fuel pressure regulator for supplying fuel to the intake of an internal combustion engine at a substantially constant pressure, comprising:a housing defining a fuel chamber in fluid communication with a fuel inlet, said housing further including a fuel outlet opening in fluid communication with said fuel chamber, said housing defining a seating surface around said outlet; a valve body movably disposed within said housing and moving between open and closed positions, said valve body contacting and sealing against said seating surface and preventing fuel flow through said outlet opening when said valve body is in said closed position, said valve body biased into said closed position, said valve body including an extension with at least a portion thereof disposed in said fuel outlet to guide said valve body, said valve body molded of a rigid polymer material and including an elastomeric ring that contacts said seating surface when said valve body is in said closed position; and wherein: said elastomeric ring is integrally molded with said valve body and fixed thereto without adhesives.
  • 11. The fuel pressure regulator set forth in claim 7, wherein said extension member is an elongated tapered pin.
  • 12. The fuel pressure regulator set forth in claim 7, wherein said valve body is biased into said closed position by a spring.
  • 13. The fuel pressure regulator set forth in claim 7, including a flexible membrane having an outer perimeter fixed to said housing, and an opening through said membrane defining an inner edge, said inner edge fixed to said valve body and sealing off said fuel chamber.
  • 14. A fuel pressure regulator for supplying fuel at a substantially constant pressure, comprising:a housing having a fuel inlet and defining a fuel chamber in fluid communication with said fuel inlet, said housing including a fuel outlet in fluid communication with said fuel chamber, and a seating surface adjacent said fuel outlet; a valve body disposed within said housing and movable between an open position permitting fuel flow through said fuel chamber and a closed position preventing fuel flow through said fuel chamber, said valve body normally biased into said closed position; and wherein said valve body includes a body portion and an elastomeric seal configured to engage said seating surface when said valve body is in said closed position.
  • 15. The fuel pressure regulator set forth in claim 14, wherein said valve body includes a guide extending into said fuel outlet maintaining said elastomeric seal in alignment with said seating surface.
  • 16. The fuel pressure regulator set forth in claim 15, wherein said guide is a tapered pin.
  • 17. The fuel pressure regulator set forth in claim 16, wherein said tapered pin includes at least one flute configured to permit fuel flow therethrough when said valve body is in said open position.
  • 18. The fuel pressure regulator set forth in claim 17, wherein said housing has a tubular portion forming said fuel outlet, said tubular portion having an inner end extending into said fuel chamber and forming said seating surface.
  • 19. The fuel pressure regulator set forth in claim 18, including:a spring biasing said valve body into said closed position; and a flexible membrane having an outer perimeter secured to said housing to seal off said fuel chamber; said valve body fixed to said flexible membrane.
  • 20. The fuel pressure regulator set forth in claim 6, including:a spring biasing said valve body into said closed position; and a flexible membrane having an outer perimeter secured to said housing to seal off said fuel chamber; said valve body fixed to said flexible membrane.
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4505296 Field et al. Mar 1985 A
4635537 Field Jan 1987 A
4756289 Rock et al. Jul 1988 A
4903721 Maier Feb 1990 A
5186147 Bellis Feb 1993 A
5421306 Talaski Jun 1995 A
5482254 Greenwood et al. Jan 1996 A
5558063 Minagawa et al. Sep 1996 A
5609138 Mutschler Mar 1997 A
5673670 Powell et al. Oct 1997 A
6213413 Kojima et al. Apr 2001 B1