The present invention relates generally to pressure regulators and, more particularly, to a pressure regulator assembly for a fuel system of a vehicle.
It is known to provide a fuel tank in a vehicle to hold fuel to be used by an engine of the vehicle. It is also known to provide a fuel pump inside the fuel tank to pump fuel to the engine and a fuel pressure regulator fluidly connected to the fuel pump to regulate the pressure of the fuel to the engine. Typically, the fuel pressure regulator includes an elastomeric diaphragm, a precision machined metal valve seat, a heavy rate spring, and a mating valve cooperating with the valve seat to check pressure. However, these fuel pressure regulators generally contain between fifteen (15) and twenty (20) separate components. Also, these fuel pressure regulators are relatively costly and are subject to fuel pressure regulation shift due to aging of the elastomeric diaphragm as well as degradation from exposure to alcohol fuels.
It is also known to provide a fuel pressure regulator that does not use an elastomeric diaphragm. This particular fuel pressure regulator overcomes the disadvantages associated with elastomeric diaphragms, but has relatively high pressure regulation gain. Also, the fuel pressure regulator has poor gain control when compared to existing elastomeric diaphragm pressure regulators. Further, the fuel pressure regulator may use a leaf spring construction, making the regulator non-linear in construction and non-interchangeable with existing diaphragm type pressure regulators.
It is, therefore, desirable to provide a new pressure regulator assembly for a fuel system of a vehicle. It is also desirable to provide a pressure regulator assembly that uses no elastomeric materials. It is further desirable to provide a pressure regulator assembly that requires fewer component parts. It is still further desirable to provide a pressure regulator assembly that improves upon the poor gain control of non-elastomeric diaphragm pressure regulators. Therefore, there is a need in the art to provide a pressure regulator assembly for a fuel system that meets these desires.
Accordingly, the present invention is a pressure regulator assembly for a fluid system including a housing having at least one cavity therein and a valve seat disposed in the at least one cavity and having an aperture extending therethrough. The pressure regulator assembly also includes a movable valve member disposed in the at least one cavity of the housing. The valve member has a closed position to engage the valve seat to prevent fluid from flowing into the at least one cavity and an open position to disengage the valve seat to allow fluid to flow into the at least one cavity. The pressure regulator assembly further includes a biasing mechanism disposed in the at least one cavity to bias the valve member toward the valve seat to close the aperture. The valve seat and the valve member and the biasing mechanism are aligned linearly along an axis of the valve housing.
One advantage of the present invention is that a new pressure regulator assembly is provided for a fuel system of a vehicle. Another advantage of the present invention is that the pressure regulator assembly provides a nearly constant fluid pressure over a wide range of flows. Yet another advantage of the present invention is that the pressure regulator assembly uses no elastomeric materials. Still another advantage of the present invention is that the pressure regulator assembly reduces the number of components over conventional fuel pressure regulators. A further advantage of the present invention is that the pressure regulator assembly is interchangeable with existing diaphragm type pressure regulators. Yet a further advantage of the present invention is that the pressure regulator assembly could be applied to other fluid systems such as a lubrication system. Still a further advantage of the present invention is that the pressure regulator assembly has a relatively lower cost and robustness to pressure control shift caused by aging or chemical attack of an elastomeric diaphragm. Another advantage of the present invention is that the pressure regulator assembly improves upon the poor gain control of non-elastomeric pressure regulators.
Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.
Referring to the drawings and in particular
Referring to
The housing 22 includes a guide portion 30 extending axially into the second cavity 28 from one end of the body portion 24. The guide portion 30 has a passageway 32 extending axially therethrough for a function to be described. The passageway 32 has a generally circular cross-sectional shape. The passageway 32 includes an enlarged opening 34 at one end thereof. The housing 22 includes at least one, preferably a plurality of fluid outlets 36 spaced circumferentially about the enlarged opening 34 and extending axially through a closed end of the body portion 24. The fluid outlets 36 fluidly communicate with the second cavity 28. The housing 22 may include at least one, preferably a plurality of barbs 38 spaced axially and extending circumferentially about the body portion 24 for connection to the first fluid inlet line 18. The body portion 24 and guide portion 30 are made of a rigid material such as metal. It should be appreciated that the housing 22 is a monolithic structure being integral, unitary, and one-piece.
The pressure regulator assembly 10 includes a valve seat 40 disposed in the first cavity 26 at the other end of the housing 22 and spaced axially from the guide portion 30 of the housing 22. The seat 40 has a generally “C” cross-sectional shape. The seat 40 has a body portion 42 that is generally cylindrical in shape with a generally circular cross-sectional shape. The seat 40 also has a seat portion 44 extending radially from the body portion 42. The seat 40 also has an aperture 46 extending axially through the seat portion 44 to form an inlet. The seat 40 has a chamfer 48 at one end of the aperture 46 for a function to be described. The seat 40 is made of a rigid material such as metal. It should be appreciated that the seat 40 is secured to the body portion 24 of the housing 22 by a suitable mechanism such as press-fitting.
The pressure regulator assembly 10 also includes a valve member 50 disposed in the first cavity 26 and cooperating with the seat 40. The valve member 50 is of a ball type having a generally spherical shape. The valve member 50 extends into the aperture 46 of the seat 40 and engages the chamfer 48 in a closed position. It should be appreciated that, to reduce the non-linear performance at lower fluid flows, the interface between the valve member 50 and seat 40 may utilize either a square seat or an extremely small chamfer that approaches a square seat, thereby greatly reducing the amount of gain produced by the pressure regulator assembly 10.
The valve member 50 is made of a rigid material such as metal. The valve member 50 has a first or closed position engaging the seat 40 to close the aperture 46 of the seat 40 as illustrated in
The pressure regulator assembly 10 includes a sleeve 52 to hold the valve member 50. The sleeve 52 is generally cylindrical in shape and has a generally circular cross-sectional shape. The sleeve 52 has an aperture 54 extending axially therethrough. The valve member 50 extends into the aperture 54 of the sleeve and is held therein. The sleeve 52 is made of a rigid material such as metal. It should be appreciated that a lift generating/gain reducing geometry is integrated into the valve member 50 and sleeve 52 in contact with the fluid flow stream, and using Computational Fluid Dynamics (CFD), can be tailored to produce a desired gain curve. It should also be appreciated that it is typically desired to have a flat gain curve or a positive gain curve with a slope of less than 0.5 kPa/g/s, thereby causing very little pressure shift over a wide range of flows.
The pressure regulator assembly 10 also includes a poppet 56 disposed in the housing 22 to cooperate with the sleeve 52 to transmit a spring force to be described to the sleeve 52 and the valve member 50. The poppet 56 has a head portion 58 extending radially and a shaft portion 60 extending axially from the head portion 58. The head portion 58 is generally circular in cross-sectional shape. The head portion 58 has a diameter greater than a diameter of the shaft portion 60 to abut the sleeve 52. The shaft portion 60 is generally cylindrical with a generally circular cross-sectional shape. The shaft portion 60 is disposed in the passageway 32 of the guide portion 30 for sliding movement therein. The shaft portion 60 has a length to diameter ratio greater than a predetermined amount such as four (4) to provide balance between valve length and shaft diameter, resulting in better stability and/or reduction of wobble/rattle in the fluid stream. It should be appreciated that the interface between the poppet 56 and sleeve 52 can have respective surface finishes adjusted to optimize performance including allowing the valve member 50 to move enough to center itself in the seat opening on vehicle shut-down which allows fuel line pressure checking, but resist radial movement during operation which could cause oscillation of the valve member 50 and objectionable noise.
The pressure regulator assembly 10 further includes a biasing mechanism such as a spring 62 to urge the valve member 50 toward the seat 40. In one embodiment, the spring 62 is of a coil type. The spring 62 is disposed about the poppet 56 between the head portion 58 and the closed end of the body portion 24 of the housing 22. It should be appreciated that the spring 62 urges the poppet 56 and sleeve 52 toward the seat 40 such that the valve member 50 engages the chamfer 48 of the seat 40 in a closed position as illustrated in
In operation of the pressure regulator assembly 10, the valve member 50 engages the seat 40 to close the aperture 46 in the closed position as illustrated in
Referring to
The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.
Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.
The present invention claims the priority date of copending U.S. Provisional Patent Application Ser. No. 60/505,178, filed Sep. 23, 2003 and is a continuation-in-part of copending U.S. patent application Ser. No. 10/688,235, filed Oct. 17, 2003.
Number | Date | Country | |
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60505178 | Sep 2003 | US |
Number | Date | Country | |
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Parent | 10688235 | Oct 2003 | US |
Child | 10932763 | Sep 2004 | US |