COLD START VALVE WITH FILTER ON INLET PORT BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] This invention relates to a valve for use in controlling fluid flow between a fuel tank and a fuel delivery system for an engine in a flexible fuel vehicle and, in particular, to a valve with a filter disposed within the valve inlet for use in preventing contamination of the valve and downstream components while also allowing maintenance and reuse of the filter.

2. Discussion of Related Art

[0002] Flexible fuel vehicles include a fuel system that enables more than one fuel to be used for driving the vehicle engine. Under most operating conditions, a primary fuel is drawn from a primary fuel tank and provided to the engine. The primary fuel may comprise gasoline, alcohol or a mixture of these or other fuels. A sensor installed in the exhaust system detects the composition of the fuel that is being used. The decision on the composition of fuel to be used may be made by the driver for a variety of reasons including cost, availability and improved emissions. Because of the relatively low volatility of alcohol, however, it can be difficult to start the engine where the composition of the fuel approaches 100% alcohol—particularly in cold temperatures. Most flexible fuel vehicles therefore have an additional, small reservoir or secondary fuel tank (typically having a capacity of about 2 liters) that is filled only with a secondary fuel such as gasoline—primarily for use in starting the engine during cold temperatures, but also for possible use during cold phase operation of the vehicle. [0003] The primary and secondary fuels in a flexible fuel vehicle are stored in separate fuel tanks. Fluid flow from the primary fuel tank to the vehicle's fuel delivery system and engine occurs in a conventional manner. Fluid flow from the secondary fuel tank to the fuel delivery system and engine is controlled by a valve. In order to prevent contaminants in the fuel from damaging engine components and fuel delivery system components, it is known to include a filter downstream from the valve. The filter is typically placed in a hose downstream from the valve. This placement of the filter has several

disadvantages, however. First, contamination of the valve can still occur because the filter is downstream from the valve. Second, the filter cannot be removed for maintenance (cleaning) and reuse. [0004] The inventors herein have recognized a need for a valve that will minimize and/or eliminate one or more of the above- identified deficiencies.

SUMMARY QF THE INVENTION

[0006] The present invention provides a valve for controlling fluid flow between a secondary fuel tank and an engine in a flexible fuel vehicle having a primary fuel tank configured to contain a primary fuel and said secondary fuel tank configured to contain a secondary fuel .

[0007] A valve in accordance with the present invention includes a housing defining an inlet configured to receive the secondary fuel from the secondary fuel tank and an outlet configured to provide the secondary fuel to a fuel delivery system disposed between the primary and secondary fuel tanks and the engine. The valve further includes a valve member disposed within the housing, the valve member movable between an open position allowing fluid flow from the inlet of the valve to the outlet of the valve and a closed position prohibiting fluid flow from the inlet of the valve to the outlet of the valve. The valve further includes a filter disposed within the inlet of the valve.

[0008] A valve in accordance with the present invention represents an improvement over conventional valves used in the fuel systems of flexible fuel vehicles. In particular, the location of the filter in the valve inlet prevents contaminants from entering the valve and prevents damage to the valve. Further, the location of the filter enables relatively easy removal of the filter for maintenance, thereby allowing reuse of the filter. [0009] These and other advantages of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawings illustrating features of this invention by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a diagrammatic view of a vehicle fuel system incorporating a valve in accordance with the present invention.

[0011] Figure 2 is a plan view of a valve in accordance with the present invention.

[0012] Figure 3 is a cross-sectional view of the valve of Figure 2 taken along lines 3-3.

[0013] Figure 4 is a plan view of a filter used in the valve of Figures 2-3.

[0014] Figure 5 is a plan view of the filter of Figure 4.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0015] Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views, Figure 1 illustrates a fuel system 10. System 10 is particularly adapted for use in an automobile or light truck, but it should be understood that the invention described herein could be used for fuel systems on other types of vehicles and in a variety of fluid handling systems for vehicular and non-vehicular applications. System 10 is also particularly adapted for flexible fuel ("flex- fuel") applications in which a plurality of fuels are used to power an internal combustion engine 12. System 10 provides a means for storing and transporting fuel to engine 12. System 10 may include primary and secondary fuel tanks 14, 16, pumps 18, 20, a valve 22, a fuel delivery system 24, a controller 26, a temperature sensor 28 and a fuel sensor 30.

[0016] Primary fuel tank 14 is provided for storage of the primary fuel for system 10. In one embodiment of the invention, the primary fuel may comprise alcohol, gasoline or a mixture of alcohol, gasoline and/or other fuels that are less volatile and less highly enriched than traditional hydrocarbon based fuels. Tank 14 is conventional in the art. Fuel tank 14 has an outlet 32 through

which fuel may exit tank 14 and an inlet (not shown) through which fuel may be enter tank 14 from a fuel filler neck (not shown) . [0017] Secondary fuel tank 16 is provided for storage of the secondary fuel for system 10. In one embodiment of the invention, the secondary fuel may comprise gasoline. The secondary fuel may be more volatile and more highly enriched than the primary fuel. The secondary fuel is provided for applications in which a more volatile and more highly enriched fuel is required such as starting the engine in cold weather. Tank 16 is also conventional in the art. Although tank 16 is illustrated as similar in size to tank 14, it should be understood that tank 16 will often be smaller in size and contain less fuel than tank 14 given the more limited use of the secondary fuel. Fuel tank 16 has an outlet 34 through which fuel may exit tank 16 and an inlet (not shown) through which fuel may be enter tank 16 from a fuel filler neck (not shown) . [0018] Pumps 18, 20 provide a means for drawing fluid out of tanks 14, 16, respectively. Pumps 18, 20 are conventional in the art. Pump 18 may be disposed between fuel tank 14 and fuel delivery system 24. Pump 20 may be disposed between fuel tank 14 and valve 22. Pump 20 may be electronically controlled responsive to control signals from controller 26 (e.g., through a pulse-width modulated (PWM) signal) .

[0019] Valve 22 is provided to control the flow of fuel from tanks 16 to fuel delivery system 24. Valve 22 may comprise an electronically controlled valves that operate responsive to control signals from controller 26. The structure of valve 22 will be described and illustrated in greater detail hereinbelow with references to Figures 2-4.

[0020] Fuel delivery system 24 provides a means for transporting fuel from fuel tanks 14, 16 to engine 12. Fuel delivery system 24 is conventional in the art and may include fuel lines 36 and a fuel rail 38. It should be understood, however, that the particular structure of fuel delivery system 24 may vary. Fuel lines 36 are provided to transport fuel between fuel tanks 14, 16 and fuel rail 38. Fuel lines 36 are conventional in the art and are generally tubular. Fuel lines 36 may comprise pipes or hoses made from metals

and metal alloys such as steel or from plastics or a combination of metals, metal alloys and plastics. Fuel rail 38 provides a local fluid reservoir and a means for mounting of, and fuel delivery to, conventional fuel injectors (not shown) . Fuel rail 38 is conventional in the art.

[0021] Controller 26 is provided to control pump 20 and valve 22. Controller 26 may comprise a programmable microprocessor or microcontroller or may comprise an application specific integrated circuit (ASIC) . Controller 26 may include a central processing unit (CPU), memory, and an input/output (I/O) interface. Through the interface, controller 26 may receive a plurality of input signals including signals generated by temperature sensor 28 and fuel sensor 30. Also through the interface, controller 26 may generate a plurality of output signals including one or more signals used to control pump 18 and valve 20. The type of output signals may vary depending on engine type and operating conditions, but generally pulse width modulation (PWM) signals are used.

[0022] Temperature sensor 28 and fuel sensor 30 are provided to generate signals indicative of a measured engine temperature and a composition of the fuel being used in engine 12. Sensors 28, 30 are conventional in the art and transmit a temperature indicative signal and fuel indicative signal, respectively, to controller 26 for use in controlling pump 18 and valve 20. When the engine temperature is below a certain temperature (e.g., typically 10 ⁰ C) and the fuel sensor indicates that the fuel in tank 14 has a relatively low volatility (e.g., the fuel composition is 100% alcohol) , controller 26 generates signals to start pump 20 and open valve 22. [0023] Referring now to Figures 2-3, the structure and operation of valve 22 will be described in greater detail. Valve 22 is provided to control the flow of fuel from secondary fuel tank 16 to fuel delivery system 24 and, ultimately, engine 12. Valve 22 may include a housing 40, bracket 42, an electromagnetic core 44, a conductor 46, a terminal 48, a seal 50, a spring 52, and a valve member 54. In accordance with the present invention, valve 22 may also include a filter 56.

[0024] Housing 40 provides structural support to the other components of valve 22 and protects the components of valve 22 from foreign objects and elements. Housing 40 defines an inlet 58 and an outlet 60. Inlet 58 is configured to receive the secondary fuel from secondary fuel tank 16 (indirectly through pump 20) . Outlet 60 is configured to provide the secondary fuel to fuel delivery system 24. Referring to Figure 3, inlet 58 and outlet 60 define tubular passageways extending from a central bore 64 within housing 40. Inlet 58 further defines an internal shoulder 66 for a purpose described hereinbelow. In the illustrated embodiment, valve 22 comprises a two-way valve with a single inlet 58 and a single outlet 60. It should be understood, however, that valve 22 may assume alternative structures and may, for example, comprise a three-way valve .

[0025] Referring to Figure 2, bracket 42 provides a means for mounting valve 22. Bracket 42 may be coupled to housing 40 or may be formed integrally with housing 40 as a single unitary construction. In the illustrated embodiment, bracket 42 comprises a pair of wings or arms extending from housing 40. Bracket 42 may define apertures (not shown) configured to receive fasteners (not shown) for mounting valve 22 to fuel tank 16 or another structure. [0026] Referring to Figure 3, core 44 is provided to selectively attract valve member 54 to permit fluid flow from inlet 58 to outlet 60. Core 44 may be made from conventional metals and metal alloys or other materials having a relatively low magnetic reluctance. Core 44 is sized to be received within bore 64 of housing 40. Core 44 defines an end face 68 against which one end of spring 52 is disposed. Core 44 also defines an annular groove 70 configured to receive seal 50.

[0027] Conductor 46 is provided to create a magnetic circuit among core 44 and valve member 54. Conductor 46 may comprise a coil disposed on a bobbin or another conventional conductor. Conductor 46 may be disposed around at least portions of core 44 and valve member 54. Conductor 46 is connected to terminal 48 through which current is provided to conductor 46. Current is provided to conductor 46 responsive to control signals from controller 26.

[0028] Terminal 48 provides an electrical interface between controller 26 and conductor 46. Terminal 48 is conventional in the art and may comprise one or more pins 72 disposed within a recess 74 formed in housing 40.

[0029] Seal 50 prevents leakage of fuel from housing 40. Seal 50 may comprise a conventional O-ring seal of suitable material composition depending on the secondary fuel used in system 10. Seal 50 is disposed within groove 70 of core 44.

[0030] Spring 52 is provided to bias valve member 54 to a first position in which the flow of fuel from inlet 58 to outlet 60 is limited or prohibited. Spring 52 is disposed within a closed bore formed in valve member 54. One end of spring 52 is disposed against the end of the bore. The other end of spring 52 is disposed against end face 68 of core 44. Spring 52 is conventional in the art and may be made from conventional metals and metal alloys. [0031] Valve member 54 is provided to selectively allow or prohibit fuel from flowing between inlet 58 and outlet 60 of housing 40. Member 54 is disposed within bore 64 of housing 42 and defines a closed bore 76 in one end configured to receive spring 52. The other end of member 54 may define a frusto-conical surface 78 configured to mate with a complementary surface formed in housing 40. Valve member 54 is made from metals, metal alloys, or other materials having a relatively low magnetic reluctance. In the absence of current in conductor 46, spring 52 biases valve member 54 away from core 44 and surface 78 into engagement with the corresponding surface in housing 40 thereby limiting or prohibiting fuel flow between inlet 58 and outlet 60. When current is provided to conductor 46, and electromagnetic circuit is created between core 44 and valve member 54. The circuit urges member 54 towards ends face 68 of core 44 against the force or spring 52 and urges surface 78 away from the corresponding surface in housing 40 thereby allowing fuel flow between inlet 58 and outlet 60 of housing 40. [0032] Referring now to Figures 3-5, in accordance with the present invention, valve 22 further includes a filter 56 disposed within inlet 58 of housing 40. Filter 56 is provided to prevent contamination of the components of valve 22 and downstream

components in fuel delivery system 24 and engine 12. Filter 56 may be made from polymeric materials including nylon or polyacetal compositions. Filter 56 is substantially circular and is sized to be received within inlet 58. The outer diameter or surface of filter 56 varies to define a shoulder 80 proximate a first end 82 of filter 56. Shoulder 80 is configured to engage shoulder 66 within inlet 58 to position and retain filter 56 within inlet 58. In the illustrated embodiment, shoulder 80 tapers. It should be understood, however, that the shape of shoulder 80 may vary. The inner diameter or surface of filter 56 tapers moving from end 82 of filter 56 to an opposite end 84 of filter 56. [0033] A valve in accordance with the present advantage represents a significant improvement over prior art designs. By locating the filter 56 in the inlet port 58 of the valve 22, the valve components are protected from contamination unlike in conventional valves. Further, the filter 56 can be easily removed for maintenance and reuse unlike in conventional fuel systems. [0034] While the invention has been shown and described with reference to one or more particular embodiments thereof, it will be understood by those of skill in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.