Information
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Patent Grant
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6481418
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Patent Number
6,481,418
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Date Filed
Monday, October 23, 200024 years ago
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Date Issued
Tuesday, November 19, 200222 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
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US Classifications
Field of Search
US
- 123 514
- 123 463
- 123 447
- 123 467
- 123 457
- 137 510
- 137 54323
- 137 53325
- 251 332
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International Classifications
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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.
US Referenced Citations (14)