Information
-
Patent Grant
-
6347639
-
Patent Number
6,347,639
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Date Filed
Thursday, July 6, 200024 years ago
-
Date Issued
Tuesday, February 19, 200222 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
- Ford Global Technologies, Inc.
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CPC
-
US Classifications
Field of Search
US
- 137 587
- 137 576
- 137 202
- 137 1501
- 137 1508
- 123 516
- 220 530
- 220 862
- 141 59
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International Classifications
-
Abstract
A fuel system 10 which selectively receives and stores volatile fuel. System 10 includes a dynamic seal or air intake inhibitor 26 which is operatively disposed within fuel filler pipe 20 and which minimizes the amount of air ingested by fuel tank 12. System 10 further includes an air separation portion or chamber 16 that includes a recirculation aperture 30 and tapered valve 34 that are effective to automatically regulate the rate of vapor recirculation within system 10 based upon the amount of fuel and vapor within portion 16.
Description
FIELD OF THE INVENTION
The present invention generally relates to a fuel system and more particularly, to a vehicular fuel system which is adapted to receive, store, and selectively transport vaporific fuel to an engine and which includes an air intake inhibitor and a self-regulating recirculation system for vapor recovery.
BACKGROUND OF THE INVENTION
Vehicular fuel systems or assemblies are adapted to selectively receive, store and deliver fuel for use within and/or by an engine (i.e., an internal combustion type engine), effective to allow a vehicle to be desirably operated and driven.
Conventionally, these assemblies include a tank into which volatile or vaporific fuel is selectively placed and stored and several devices and/or components (i.e., a treatment canister) which are communicatively coupled to the tank and which allow fuel and vapors to be selectively transferred from the tank to other portions of the vehicles (e.g., to the engine). For example and without limitation, these devices and/or components cooperatively allow air and fuel vapors to be selectively purged from the tank, treated, and controllably released into the ambient environment or atmosphere, effective to selectively and desirably reduce pressure within the tank, and to allow the air dissolved within currently received fuel to be released or recirculated.
While these prior or conventional fuel assemblies do desirably receive and store fuel, they suffer from some drawbacks. For example, these prior fuel systems undesirably allow a relatively large amount of air to be ingested into the fuel tank, thereby increasing the pressure within the tank and requiring a large amount of air and vapor to be removed from the tank. During the required removal of this air and/or fuel vapor, some of the fuel vapors may undesirably escape from the externally deployed and previously delineated devices and components, thereby being released into the atmosphere. Moreover, the recirculation of air and vapors within these prior tanks typically occurs at a relatively constant rate, and therefore cannot be appropriately regulated based upon specific circumstances which may require more or less recirculation.
The present invention provides a fuel system which addresses these drawbacks, which substantially reduces or minimizes the undesirable ingestion of air into the tank, and which provides for the self-regulating recirculation of air and vapors within the system.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide a fuel system which overcomes at least some of the previously delineated drawbacks of prior fuel systems.
It is a second object of the present invention to provide a fuel system which includes a dynamic seal which substantially reduces and/or minimizes the amount of air ingested by a fuel tank.
It is a third object of the present invention to provide a fuel system which includes a self-regulating vapor recirculation system.
According to a first aspect of the present invention, a fuel system is provided. The fuel system includes a fuel tank; a fuel filler pipe which is communicatively coupled to the fuel tank and which has a widened portion; and a dynamic seal which is operatively disposed within the widened portion of the fuel filler pipe and which is adapted to selectively engage an inner surface of the widened portion, effective to allow fuel to pass through the fuel filler pipe, while substantially preventing air and vapor from passing through the fuel filler pipe and into the fuel tank.
According to a second aspect of the present invention, a fuel system is provided. The fuel system includes a filler tube which selectively receives fuel from a fuel dispensing nozzle; a recirculation tube which is communicatively coupled to the filler tube; and a first tank portion which is communicatively coupled to and selectively receives fuel from the filler tube. The first tank portion includes an aperture which communicates with the recirculation tube, an amount of fuel, and a buoyant member which floats upon the fuel and which includes a tapered valve which is selectively disposed within the aperture, the tapered valve being effective to controllably vary an area within the aperture through which vapors may pass into the recirculation tube, thereby automatically regulating vapor recirculation within the fuel system based upon the amount of fuel and vapor within the first tank portion.
These and other aspects, features, and embodiments of the present invention will become apparent from a reading of the following detailed description of the preferred embodiment of the invention and by reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a sectional schematic view of a fuel system which is made in accordance with the teachings of the preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Referring now to
FIG. 1
, there is shown a fuel assembly or system
10
which is made in accordance with the teachings of the preferred embodiment of the invention and which is adapted for use within a vehicle. As shown, fuel assembly
10
includes a container, receptacle, or tank
12
having a first fuel storage portion
14
and a second air separation or extraction chamber or portion
16
which is communicatively coupled to portion
14
by an outflow regulating portion or assembly
18
. A fuel filler pipe or conduit
20
is communicatively connected to portion
16
and allows vaporific fuel to be selectively delivered to fuel tank
12
. Fuel filler pipe
20
includes a conventional nozzle receiving apparatus
22
, which is adapted to selectively and conformably receive a conventional fuel dispensing nozzle
24
having a vapor recovery port or passage
64
. Fuel filler pipe
20
further includes a dynamic seal assembly or air intake inhibitor
26
. A recirculation tube or conduit
28
communicatively connects fuel filler pipe
20
and separation chamber
16
.
Fuel storage portion
14
is a generally cylindrical fuel storage container or tank which includes a fuel supply line, tube or conduit (not shown) which selectively carries fuel to the vehicle's engine (not shown). Fuel storage portion
14
may also include a conventional electrical fuel pump (not shown) which assists in delivering fuel to the vehicle's engine. In one non-limiting embodiment, fuel containing portion
14
comprises a variable volume fuel tank, such as the pumpless fuel system described in U.S. Pat. No. 5,526,795 of Thompson which is assigned to the present assignee and which is fully and completely incorporated herein by reference.
Air or vapor extraction chamber or portion
16
, which may be integrally formed with portion
14
, includes a metered recirculation aperture or orifice
30
which is formed within the top surface of portion
16
and which allows gas or vapor within portion
16
to be selectively recirculated or transferred through recirculation tube
28
and into filler tube
22
and port
64
in the direction of arrows
65
. Portion
16
further includes a float or buoyant member
32
having a tapered top portion or needle valve
34
which selectively engages aperture
30
and is effective to fully close and/or seal aperture
30
when portion
16
is substantially full or completely filled with fuel, and to only partially close or engage aperture
30
when the portion
16
is only partially filled with fuel.
Outflow regulating portion
18
includes a tube or conduit
36
which includes a first end
38
which is communicatively coupled to portion
16
and a second end
40
which is selectively engaged by a spring loaded diaphragm or seal assembly
42
. Seal assembly
42
includes a generally circular diaphragm member
44
and a conventional spring member
46
which is coupled to diaphragm
44
and to housing portion
48
. Diaphragm
44
is selectively movable within portion
48
and more particularly, is movable from a first or “closed” position in which diaphragm
44
contacts end
40
of conduit
36
, thereby sealing end
40
and preventing fuel from entering portion
14
of tank
12
through outflow portion or conduit
50
, to a second or “open” position in which diaphragm
44
does not contact end
40
, thereby allowing fuel to be transferred from portion
16
to portion
14
through conduits
36
and
50
. Spring
46
normally holds and/or compressibly retains diaphragm
44
in its “closed” position (i.e., against end
40
). Housing portion
48
is communicatively coupled to the top portion of chamber
16
by conduit
51
.
Fuel filler pipe
20
includes a widened portion
52
in which dynamic seal assembly
26
is operatively disposed. One or more support members or portions
54
are attached to housing
56
of assembly
26
and to the inner surface of portion
52
, thereby connecting and supporting assembly
26
within portion
52
. Assembly
26
includes a generally semi-spherical convex valve member
58
that is coupled to a compressible spring member
60
that is coupled to housing member
56
. Valve member
58
is selectively movable within portion
52
and more particularly, is movable from a first or “closed” position in which member
58
abuttingly engages the tapered portion or inner surface
62
of tube
20
, thereby preventing air or vapor from passing through tube
20
and into tank
12
, to a second or “open” position in which member
58
does not contact the inner surface of tube
20
, thereby allowing fuel to be transferred between surface
62
and member
58
and into tank
12
(e.g., into portion
16
of tank
12
). Spring
60
normally holds and/or compressibly retains member
58
in the first or “closed” position.
In operation, air intake inhibitor
26
substantially prevents and/or minimizes the ingestion of air and/or vapor during the refueling process. Particularly, during the refueling process, member
58
is held against tapered portion
62
until the weight and/or pressure of fuel from nozzle
64
causes spring
60
to compress, thereby allowing the fuel to pass through portion
52
. Importantly, by requiring the presence of fuel to actuate or move member
58
, assembly
26
minimizes the amount of air or vapor that is communicated into tank
12
through conduit
20
. The stiffness or “spring constant” of spring member
60
is determined or selected in order to control the movement of member
58
in response to the fuel flow rate provided by nozzle
24
(e.g., the greater the fuel flow rate, the greater the compression of spring
60
and the greater the resulting area that is available for fuel flow). In one non-limiting embodiment, the spring constant of spring
60
is selected to be proportional to the fuel flow rate. This controlled movement and the shape of member
58
and portion
62
cooperate to control the effective fuel flow area within pipe
20
, thereby controlling the pressure drop within the pipe
20
and further reducing the amount of ingested air and/or vapor. The generally spherical or bulbous shape of member
58
minimizes fuel flow disruption, while ensuring that the fuel flow completely engages the walls of pipe
20
, thereby maximizing the efficiency of the provided seal.
Portion
16
substantially ensures that any ingested and/or dissolved air which is subsequently released from the fuel is controllably recirculated. The size of the “air bubble” or released air and/or vapor, represented by length h
1
, is proportional to the amount of area in orifice
30
through which air and vapor may pass for recirculation. Particularly, due to the tapered shape of needle valve
34
, as length h
1
increases (e.g., and the amount of air and vapor in portion
16
increases), the diameter or size of the portion of valve
34
that is resident within orifice
30
decreases, thereby increasing the area through which air and vapor may enter recirculation tube
28
(i.e., increasing the rate of recirculation). Conversely, as the amount of air within portion
16
decreases (i.e., h
1
decreases), the diameter or size of the portion of valve
34
that is resident within orifice
30
increases, thereby decreasing the area through which air and vapor may enter tube
28
(i.e., reducing the rate of recirculation). Once portion
16
is substantially filled with fuel and substantially no air or vapor is resident within portion
16
, valve
34
seals orifice
30
, thereby preventing liquid fuel from entering recirculation tube
28
.
It should be realized that the air separation chamber
16
, valve
34
and tube
28
automatically and controllably regulate the amount of air and vapor recirculation in accordance with the amount of air or vapor within chamber
16
. In this manner, system
10
efficiently and automatically regulates the recirculation of vapor and substantially reduces the amount of vapor that is released into the atmosphere.
Outflow regulating portion or assembly
18
ensures that the air separation chamber
16
is substantially filled with fuel. Particularly, the stiffness or “spring constant” of spring
46
is determined or selected in order to allow spring
46
to be compressed, thereby moving diaphragm
44
from its “closed” position end
40
to its “open” position and allowing fuel to flow through end
40
of conduit
36
, only if the pressure in the chamber
16
equals the pressure generated by the fuel in chamber
16
is slightly less than height h
2
(e.g., when chamber
16
is substantially full).
It should be understood that the invention is not limited to the exact embodiment or construction which has been illustrated and discusesed above, but that various changes and modifications may be made without departing from the spirit of and the scope of the invention as is set forth in the fallowing claims.
Claims
- 1. A method for controlling vapor recirculation within a fuel tank comprising the steps of:providing a filler tube; connecting said filler tube to said fuel tank; providing a recirculation tube which is communicatively coupled to said filler tube; providing a first tank portion which is communicatively coupled to and selectively receives said fuel from said filler tube, said first tank portion including an aperture which communicates with said recirculation tube; controllably varying an area within said aperture through which air and vapors may pass into said recirculation tube, effective to automatically regulate air and vapor recirculation based upon an amount of fuel, air and vapor within said first tank portion; wherein said fuel tank further comprises a second tank portion which is communicatively coupled to said first tank portion and which selectively receives fuel from said first tank portion; and providing an outflow regulator which is disposed between said first tank portion and said second tank portion and which selectively controls the amount of fuel which is transferred from said first tank portion to said second tank portion, effective to ensure that said first tank portion remains substantially filled with fuel.
- 2. The method of claim 1 wherein said fuel tank is disposed within a vehicle.
- 3. The method of claim 1 further comprising the steps of:providing an amount of fuel within said first tank portion, and a buoyant member which floats upon said amount of fuel and which includes a tapered valve which is selectively disposed within said aperture, said tapered valve being effective to controllably vary said area within said aperture through which air and vapors may pass into said recirculation tube.
- 4. The method of claim 1 further comprising the steps of:providing a dynamic seal including a housing, a convex sealing member, and spring member coupled to said housing and said convex sealing member; and mounting said dynamic seal within said filler tube, effective to cause said convex sealing member to selectively engage an inner surface of said filler tube, effective to allow fuel to pass through said filler tube, while substantially preventing air from passing through said filler tube and into said fuel tank.
- 5. The method of claim 4 wherein said convex sealing member is semi-spherical in shape.
- 6. The method of claim 4 wherein said fuel is delivered to said filler pipe by use of a nozzle which provides a certain fuel flow rate, said method further comprising the steps of:selecting a spring constant of said spring member which is proportional to said fuel flow rate.
- 7. A fuel system comprising:a filler tube which selectively receives vaporific fuel from a fuel dispensing nozzle; a recirculation tube which is communicatively coupled to said filler tube; a first tank portion which is communicatively coupled to and selectively receives said vaporific fuel from said filler tube, said first tank portion including an aperture which communicates with said recirculation tube, an amount of fuel, and a buoyant member which floats upon said fuel and which includes a tapered valve which is selectively disposed within said aperture, said tapered valve being effective to controllably vary an area within said aperture through which vapors may pass into said recirculation tube, thereby automatically regulating vapor recirculation within said fuel system based upon an amount of fuel and vapor within said first tank portion; a second tank portion which is communicatively coupled to said first tank portion and which selectively receives and stores fuel from said first tank portion; and an outflow regulator which is disposed between said first tank portion and said second tank portion and which selectively controls the amount of fuel which is transferred from said first tank portion to said second tank portion.
- 8. The fuel system of claim 7 wherein said outflow regulator comprises a tube having a first end which communicates with said first tank portion and a second end which communicates with said second tank portion, and a diaphragm member which selectively engages said second end, thereby selectively controlling the flow of fuel from said first tank portion to said second tank portion.
- 9. The fuel system of claim 8 further comprising a spring member which compressibly retains said diaphragm member against said second end, until a predetermined amount of fuel is present within said first portion.
- 10. The fuel system of claim 7 wherein said filler tube comprises a widened portion, said fuel system further comprising:a dynamic seal which is operatively disposed within said widened portion and which is adapted to selectively engage an inner surface of said widened portion, effective to allow fuel to pass through said filler tube, while substantially preventing air and vapor from passing through said filler tube and into said first tank portion.
US Referenced Citations (7)