U.S. patent application number 12/686819 was filed with the patent office on 2011-07-14 for fuel cap with emissions protection.
This patent application is currently assigned to Eaton Corporation. Invention is credited to Matthew Lorenz Erdmann, Vaughn K. Mills.
Application Number | 20110168715 12/686819 |
Document ID | / |
Family ID | 44257742 |
Filed Date | 2011-07-14 |
United States Patent
Application |
20110168715 |
Kind Code |
A1 |
Erdmann; Matthew Lorenz ; et
al. |
July 14, 2011 |
FUEL CAP WITH EMISSIONS PROTECTION
Abstract
A fuel tank cap for use with a fuel storage tank includes: a
vapor storage receptacle; a purge path in fluid communication with
the vapor storage receptacle; and a liquid discriminating membrane
configured to be disposed at least in part between the vapor
storage receptacle and fuel in the fuel storage tank. A fuel
storage system includes: a fuel storage tank; a fill inlet
connected to the fuel storage tank; and a fuel tank cap. The fuel
tank cap includes: a vapor storage receptacle; a purge path in
fluid communication with the vapor storage receptacle; and a liquid
discriminating membrane configured to be disposed at least in part
between the vapor storage receptacle and fuel in the fuel tank.
Inventors: |
Erdmann; Matthew Lorenz;
(Ypsilanti, MI) ; Mills; Vaughn K.; (Chelsea,
MI) |
Assignee: |
Eaton Corporation
Cleveland
OH
|
Family ID: |
44257742 |
Appl. No.: |
12/686819 |
Filed: |
January 13, 2010 |
Current U.S.
Class: |
220/373 |
Current CPC
Class: |
B60K 2015/03514
20130101; B60K 15/0406 20130101; B60K 2015/03547 20130101; B60K
2015/03552 20130101; B60K 15/03504 20130101 |
Class at
Publication: |
220/373 |
International
Class: |
B65D 51/16 20060101
B65D051/16 |
Claims
1. A fuel tank cap for use with a fuel storage tank, comprising: a
vapor storage receptacle; a purge path in fluid communication with
the vapor storage receptacle; and a liquid discriminating membrane
disposed at least in part between the vapor storage receptacle and
liquid fuel in the fuel storage tank.
2. The fuel tank cap of claim 1, wherein the fuel tank cap defines
a cavity, and the vapor storage receptacle is disposed in the
cavity.
3. The fuel tank cap of claim 1, wherein the vapor storage
receptacle is connected to the fuel tank cap.
4. The fuel tank cap of claim 1, wherein the vapor storage
receptacle comprises a canister.
5. The fuel tank cap of claim 1, wherein the vapor storage
receptacle comprises an absorbent granulated carbonaceous
material.
6. The fuel tank cap of claim 1, wherein the vapor storage
receptacle comprises a carbon bed.
7. The fuel tank cap of claim 1, wherein the purge path comprises a
purge line configured for active purge.
8. The fuel tank cap of claim 1, wherein the purge path is
configured for passive purge.
9. The fuel tank cap of claim 1, further comprising a filter
disposed between the vapor storage receptacle and the purge
line.
10. The fuel tank cap of claim 1, wherein the purge path
corresponds with a tether for the fuel tank cap.
11. The fuel tank cap of claim 1, wherein the membrane is
configured to impede liquid from contacting the vapor storage
receptacle.
12. The fuel tank cap of claim 1, wherein the membrane is vapor
permeable.
13. The fuel tank cap of claim 1, wherein the membrane is
configured so that the vapor storage receptacle is fluidly sealed
from the fuel storage tank.
14. The fuel tank cap of claim 1, wherein the membrane is directly
connected to the vapor storage receptacle.
15. The fuel tank cap of claim 1, further comprising a support,
wherein the membrane is configured for connection to the
support.
16. The fuel tank cap of claim 1, wherein the vapor storage
receptacle comprises an aperture in fluid communication with
atmospheric air.
17. The fuel tank cap of claim 1, further comprising an orifice
plate disposed in the purge path.
18. A fuel storage system, comprising: a fuel storage tank; a fill
inlet connected to the fuel storage tank; and a fuel tank cap
having: a vapor storage receptacle; a purge line in fluid
communication with the vapor storage receptacle; and a liquid
discriminating membrane disposed at least in part between the vapor
storage receptacle and fuel in the fuel storage tank.
19. A fuel tank cap for use with a fuel storage tank, comprising: a
carbon bed; a purge path in fluid communication with the carbon
bed; a filter disposed between the carbon bed and the purge line;
and a vapor permeable and liquid discriminating membrane disposed
between the carbon bed and fuel in the fuel storage tank to fluidly
seal the carbon bed from the fuel storage tank, wherein the
membrane discriminates between liquid fuel and fuel vapor and
impedes liquid from contacting the carbon bed.
Description
TECHNICAL FIELD
[0001] The present invention generally relates to a fuel tank cap
for use with a fuel storage tank, including a fuel tank cap with an
integrated vapor storage receptacle and liquid discriminating
membrane to protect the integrated vapor storage receptacle from
liquid fuel.
BACKGROUND
[0002] Small engine equipment powered by internal combustion
engines generally include a fuel tank. It is commonly necessary to
vent a fuel tank to relieve pressure build-up which may occur when
the fuel tank cap is in place and to permit the escape of air
during normal filling operations when the fuel tank cap is removed.
An evaporative control system is generally used for such venting
operations. A typical evaporative control system vents fuel vapor
to a vapor storage container, such as a carbon canister. The
evaporative control system is generally configured to prevent fuel
vapors and/or raw fuel from the tank from flooding the vapor
storage container during normal engine operation and/or during
filling. Current environmental control laws and regulations may
require an evaporative control system for fuel tanks found even in
small engine applications or portable fuel containers. The compact
size of such engines may create challenges.
SUMMARY
[0003] A fuel tank cap for use with a fuel storage tank includes: a
vapor storage receptacle; a purge path in fluid communication with
the vapor storage receptacle; and a liquid discriminating membrane
configured to be disposed at least in part between the vapor
storage receptacle and liquid fuel in the fuel storage tank.
[0004] A fuel storage system includes: a fuel storage tank; a fill
inlet connected to the fuel storage tank; and a fuel tank cap. The
fuel tank cap includes: a vapor storage receptacle; a purge path in
fluid communication with the vapor storage receptacle; and a liquid
discriminating membrane configured to be disposed at least in part
between the vapor storage receptacle and liquid fuel in the fuel
storage tank.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Embodiments of the invention will now be described, by way
of example, with reference to the accompanying drawings,
wherein:
[0006] FIG. 1A is a side elevation view of a fuel storage system
according to an embodiment of the invention.
[0007] FIG. 1B is a side elevation view of a fuel storage system of
the type shown in FIG. 1A illustrated in a substantially filled
condition.
[0008] FIG. 2 is a bottom view of an embodiment of a fuel tank cap
with an integrated canister.
[0009] FIG. 3 is a cross-sectional view of a fuel storage system
according to an embodiment of the invention and shown taken along
line 3-3 of FIG. 2.
[0010] FIG. 4 is a cross-sectional view of a fuel storage system
according to another embodiment of the invention.
DETAILED DESCRIPTION
[0011] Reference will now be made in detail to embodiments of the
present invention, examples of which are described herein and
illustrated in the accompanying drawings. While the invention will
be described in conjunction with embodiments, it will be understood
that they are not intended to limit the invention to these
embodiments. On the contrary, the invention is intended to cover
alternatives, modifications and equivalents, which may be included
within the spirit and scope of the invention as embodied by the
appended claims.
[0012] FIGS. 1A and 1B generally show a fuel storage system 10. The
fuel storage system 10 may include a fuel storage tank 12
operatively connected to an engine (not shown). Fuel storage tank
12 may contain fuel (e.g., with an indicated level L). Fuel storage
tank 12 may be connected to a fill inlet (e.g., filler tube) 14.
Fill inlet 14 may extend to an inlet opening 16, such as, for
example, a conventionally-threaded fuel inlet opening, which may
open to the atmosphere and may be adapted to connect to and/or
receive a fuel tank cap 18. In accordance with an embodiment of the
invention, the fuel tank cap 18 may be particularly useful for
small engine applications and/or portable fuel containers in
embodiments of the invention.
[0013] Fuel tank cap 18 may be configured to be disengaged and
removed from inlet opening 16, such as during a refueling process,
without causing an unacceptable level of interference between fuel
tank cap 18 and inlet opening 16. Fuel tank cap 18 may be comprised
of plastic (e.g., fuel-resistant plastic) in accordance with an
embodiment of the invention. Although plastic is mentioned in
detail, fuel tank cap 18 may comprise various other materials in
other embodiments of the invention. Referring now to FIGS. 2-4,
fuel tank cap 18 may include an outer surface 18a and an inner
surface 18b and may further include a partially threaded surface
18c. The partially threaded surface 18c may extend from the
interior surface 18b of the fuel tank cap 18 in an embodiment of
the invention. The partially threaded surface 18c of fuel tank cap
18 can be configured to engage fuel inlet opening 16, which can
result in effectively securing fuel tank cap 18 to filler tube 14.
A seal 20 may be provided between fill inlet (e.g., filler tube) 14
and fuel tank cap 18, effectively sealing fill inlet (e.g., filler
tube) 14 and fuel tank 12 from the atmosphere. Some embodiments of
the invention may not use a seal 20, but may still be configured to
result in effective sealing of fill inlet (e.g., filler tube) 14
and fuel tank 12 from the atmosphere. In some embodiments, the
threaded engagement of fuel tank cap 18 and filler tube 14 may
allow atmospheric air to pass between the fuel tank cap 18 and
filler tube 14. In such a configuration, the internal pressure in
fuel storage tank 12 and fill inlet (e.g., filler tube) 14 is
generally greater than the atmospheric pressure. The outer surface
18a, inner surface 18b, and/or partially threaded surface 18c may
define a cavity 22.
[0014] Fuel tank cap 18 may include a vapor storage receptacle 24.
The vapor storage receptacle 24 may be coupled with the fuel tank
cap 18 in an embodiment of the invention. In an embodiment, the
vapor storage receptacle 24 may be coupled with the inner surface
18b of the fuel tank cap 18. The vapor storage receptacle 24 may be
located within cavity 22 of fuel tank cap 18. When fuel tank cap 18
is in an installed position (i.e., engaging inlet opening 16 of
fill inlet 14), the vapor storage receptacle 24 may be located in
fuel tank cap 18 so as to face fuel storage tank 12 and/or extend
in a downward direction toward fuel storage tank 12. Vapor storage
receptacle 24 may be coupled with fuel tank cap 18 by any method
and/or in any manner that is known and/or conventional in the art.
For example and without limitation, the vapor storage receptacle 24
may be snap-fit into an aperture located on the fuel tank cap 18
(e.g., a portion 26 of vapor storage receptacle 24 may be snap-fit
into an aperture 28 located on fuel tank cap 18) such as generally
illustrated in FIG. 3. Alternatively and without limitation, vapor
storage receptacle 24 may be coupled to the fuel tank cap 18 by
forming the vapor storage receptacle 24 and fuel tank cap as an
integral unit, by threaded engagement (e.g., both inner surface 18b
and the vapor storage receptacle 24 may have corresponding threaded
surfaces that may be screwed together), by welding (e.g.,
ultrasonic welding, spin welding, electro-mechanical welding, or
the like), and/or by a friction fit forming between the vapor
storage receptacle 24 and the partially threaded surface 18c of the
fuel tank cap 18. For example and without limitation, referring now
to FIG. 4, the vapor storage receptacle 24 may be substantially
friction fit within the cavity 22 formed by the fuel tank cap 18.
In some embodiments, fuel tank cap 18 and vapor storage receptacle
24 may be coupled in such a manner as to allow fuel tank cap 18 to
rotate independently of vapor storage receptacle 24.
[0015] The vapor storage receptacle 24 may be configured to
function as a storage receptacle for fuel vapors and/or to absorb
hydrocarbons which escape from the fuel storage tank 12, which
would otherwise be vented to the atmosphere. Hydrocarbons may then
be able to be combusted back to the engine, for example, in an
embodiment of the invention. The fuel tank cap 18 may be configured
to thereby reduce emissions in accordance with an embodiment of the
invention. The vapor storage receptacle 24 may include an outer
shell or canister 30. Canister 30 may comprise plastic (e.g.,
fuel-resistant plastic) in accordance with an embodiment of the
invention. Canister 30 may be generally cylindrical in shape and
may have a diameter that is smaller than the diameter of the inlet
opening 16. However, the canister 30 may comprise any of various
materials, shapes, and dimensions in other embodiments of the
invention. Canister 30 may be packed tightly with an absorbent
granulated carbonaceous material, such as but not limited to,
carbon pellets, charcoal, or the like, as is known in the art. The
vapor storage receptacle 24 may thus comprise a carbon bed. The
absorbent granulated carbonaceous material may be packed using
screens or filters 32. Screens or filters 32 may prevent the
absorbent granulated carbonaceous material from escaping from the
vapor storage receptacle 24. Screens 32 may generally comprise a
frame with a net of mesh, and filters 32 may generally comprise a
sponge. Screens or filters 32 may be generally configured to allow
air flow while retaining the carbonaceous material and/or carbon
bed of the vapor storage receptacle 24 in place. Screens or filters
32 are generally not configured for liquid discriminating functions
in accordance with some embodiments of the invention. Further, in
some embodiments, a spring loaded volume compensator plate may be
used to continually push upon the screens or filters 32 to keep the
absorbent granulated carbonaceous material in place. Referring now
to the embodiment generally illustrated in FIG. 4, the vapor
storage receptacle 24 may comprise a carbon bed of a different
structure than that generally illustrated in FIG. 3. For example,
the carbon bed may not necessarily include an outer shell or
canister 30, but may include any means known in the art to maintain
the shape and structure of the carbon bed.
[0016] The vapor storage receptacle 24 may be an actively purged
system or a passively purged system in various embodiments of the
invention. In accordance with an actively purged system, ambient
air may be drawn through the canister 30 by a vacuum created by the
intake system (e.g., intake manifold of engine). In accordance with
a passively purged system, ambient may be drawn through the
canister 30 by a vacuum created by normal diurnal temperature
variations in the temperature of the fuel tank 12. Canister 30 may
therefore include a purge path 34 in an embodiment of the
invention. Purge path 34 may comprise a purge line in accordance
with an embodiment of the invention and as generally illustrated in
FIG. 3. One or more apertures may be disposed in fuel tank cap 18
and/or canister 30 that are in fluid communication with purge path
34 (e.g., purge line) to direct vapors to purge path 34 (e.g.,
purge line). Purge path 34 (e.g., purge line) may be operatively
connected to a component of an engine, such as the intake manifold
of the engine in an actively purged system, for example. Referring
again to FIG. 3, screens and/or filters 32 may be disposed between
the vapor storage receptacle 24 and the purge path 34 (e.g., purge
line) in an embodiment of the invention. The screen and/or filter
32 may be configured to change the hydrocarbon percentage of the
fuel vapor prior to it being purged via purge path 34 (e.g., purge
line). Screens and/or filters 32 are disposed between the vapor
storage receptacle 24 and the atmosphere to allow air flow. Fuel
tank cap 18 may be loose and/or tethered in various embodiments of
the invention. A tethered system may, among other things, prevent
fuel tank cap 18 from being misplaced or lost. In an actively
purged system (e.g., as generally illustrated in FIG. 3), the purge
path 34 (e.g., purge line) may also serve as the tether for fuel
tank cap 18.
[0017] In a passively purged system (e.g., as generally illustrated
in FIG. 4), the purge path 34 may comprise a port and/or opening,
for example. Still referring to FIG. 4, a filter 35 may be disposed
between the vapor storage receptacle 24 and the purge path 34
(e.g., purge port and/or opening) in an embodiment of the
invention. The filter 35 may be configured to change the
hydrocarbon percentage of the fuel vapor prior to it being purged
via purge path 34 (e.g., purge port and/or opening). The filter 35
may comprise a synthetic foam in accordance with an embodiment of
the invention. Although the filter 35 is described as a synthetic
foam in an embodiment of the invention, the filter 35 may comprise
any number of other materials in other embodiments of the
invention. While the purge path 34 (e.g., purge line) of the
actively purged system is generally illustrated as extending from
the fuel tank cap 18 toward the fuel storage tank 12 (e.g., in a
downward direction), and the purge path 34 (e.g., purge port) of
the passively purged system is generally illustrated as extending
from the fuel tank cap 18 away from the fuel storage tank 12 (e.g.,
in an upward direction), the purge path 34 may be disposed at any
location on the fuel tank cap 18 and may extend in any of various
directions in various embodiments of the invention.
[0018] The fuel tank cap 18 may further include a membrane 36.
Membrane 36 may be a vapor permeable membrane and may be configured
to allow fuel vapor to pass at a predictable rate. Membrane 36 may
comprise a liquid discriminating membrane and may be configured to
protect the vapor storage receptacle 24 (e.g., absorbent granulated
carbonaceous material of canister 30) from liquid fuel. Membrane 36
may thus be resistive to passage of liquid fuel. Membrane 36 may
comprise a microporous oleophobic membrane in accordance with an
embodiment of the invention. Membrane 36 may be surface treated to
improve repellency in accordance with an embodiment of the
invention. Although membrane 36 may be a microporous oleophobic
membrane and/or may be surface-treated to improve repellency in
accordance with embodiments of the invention, the membrane 36 may
comprise any number of materials or surface treatments or may be
untreated in other embodiments of the invention. Membrane 36 may be
formed with a porous non-woven substrate, thereby forming a
composite of a microporous membrane layer and a support layer
(e.g., the non-woven substrate) in an embodiment of the invention.
The support layer may be configured to enhance the mechanical
properties of the membrane 36. Although membrane 36 may be formed
with a non-woven substrate in an embodiment of the invention, the
membrane may be unsupported in accordance with other embodiments of
the invention. Membrane 36 may be configured to be disposed at
least in part between the vapor storage receptacle 24 and liquid
fuel in the fuel storage tank 12. Mechanical means found in
conventional fuel tank caps, such as liquid discriminator valves,
vapor vent valves, rollover valves, or the like involve moving
parts (e.g., which may affect reliability) and are relatively
complex. The liquid discriminating membrane 36 configured to
protect the vapor storage receptacle 24 from liquid fuel may not
require moving parts and may be of a less complex design. Membrane
36 is configured to allow the passage of air and/or fuel vapor to
vapor storage receptacle 24 (e.g., without being generally
configured to filter the fuel vapor and/or substantially change
(e.g., lower and/or increase) the hydrocarbon concentration of the
fuel vapor). Membrane 36 may also be configured to block the
passage of liquid fuel from entering the vapor storage receptacle
24. For example, during operation of the engine and/or the portable
fuel tank container, fuel may slosh about in fuel storage tank 12
and otherwise come into contact with vapor storage receptacle 24.
In other instances, fuel storage tank 12 may be accidentally or
intentionally turned upside down.
[0019] Membrane 36 may be operatively engaged with vapor storage
receptacle 24. Membrane 36 may be disposed between the fuel in fuel
tank 12 and the vapor storage receptacle 24. Membrane 36 may be
configured for connection with vapor storage receptacle 24 such
that the flow and/or passage of air and/or liquid cannot bypass
membrane 36 (i.e., fuel vapor must pass through membrane 36 to get
to the vapor storage receptacle 24). The membrane 36 may thus be
configured to fluidly seal the vapor storage receptacle 24.
Membrane 36 may be on the liquid side of the vapor storage
receptacle 24. In an embodiment of the invention, membrane 36 may
extend substantially across the cross-section of the fuel tank cap
10 in order to best keep liquid fuel from coming into contact with
the vapor storage receptacle 24. Membrane 36 may be directly
connected to the canister 30 in any manner, including without
limitation, welding, insert molding, heat sealing, and/or
adhesives, for example. FIG. 3 generally shows a configuration
where a membrane 36 is connected to the canister 30. FIG. 4
generally shows a configuration where a membrane 36 is connected to
a support 38. Support 38 may be disposed between the vapor storage
receptacle 24 and a portion of the fuel tank cap 18 that may face
and/or extend down toward the fuel tank 12 when in an installed
position. The support 38 may extend completely across the cavity 22
defined by the inner surface 18b or any other portion of the fuel
tank cap 18. The carbon canister and/or support 38 may include at
least one or more apertures 40 in various embodiments of the
invention. The particular material used for the membrane and the
surface area of the membrane may be varied in accordance with
different embodiments of the invention.
[0020] In accordance with some embodiments of the invention, the
fuel tank cap 18 may further include a protective member 42 that
may be configured to shield membrane 36 from fuel that may be
stored in fuel storage tank 12 when fuel tank cap 18 is in an
installed position. Protective member 42 may include an aperture 44
that may be centrally located in protective member 42 in accordance
with an embodiment of the invention. Although a protective member
42 is generally illustrated in the embodiment of FIG. 4, other
embodiments of the invention may not have such a member disposed
near the membrane 36. For example, FIG. 3 does not include a
protective member that would be disposed between the membrane 36
and the fuel storage tank 12 when the fuel tank cap 18 is in an
installed position.
[0021] Referring now to FIG. 3, in some embodiments, the vapor
storage receptacle 24 may include an air inlet or air aperture 46.
Air inlet or air aperture 46 may be in fluid communication with an
aperture 48 on fuel tank cap 18. Air inlet or air aperture 46 may
allow canister 30 to be open to the atmosphere, thereby allowing
atmospheric air to enter canister 30 and, among other things,
refresh the adsorbent granulated carbonaceous material. Vapor
storage receptacle 24, including canister 30 for example, may
include additional apertures to allow fuel vapors stored in the
vapor storage receptacle to escape in accordance with various
embodiments of the invention. The vapor storage receptacle 24
and/or the fuel tank cap 18 may not include additional apertures
(e.g., other than purge path 34) in accordance with some
embodiments, including the embodiment as generally illustrated in
FIG. 4.
[0022] In accordance with an embodiment of the invention, the fuel
tank cap 18 may configured to control vapor flow via a variable
orifice. For example and without limitation, the fuel tank cap 18
may include an orifice plate 50. The orifice plate 50 may comprise
a relatively thin plate with a central hole, for example. The
orifice plate 50 may be placed in the purge path 34 (e.g., purge
line) in accordance with an embodiment of the invention and as
generally illustrated in FIG. 3. In accordance with other
embodiments of the invention, the orifice plate 50 may be placed at
an end of the purge path 34, at either opposing end of the vapor
storage receptacle 24, and/or at any other location in the fuel
tank cap 18. The orifice plate 50 may generally be configured to
regulate the rate of fluid flow by changing the velocity and
pressure as the fluid reaches the orifice plate 50 with the central
hole that forces the fluid to converge to go through the central
hole. The fluid may then expand and the velocity and pressure may
change again after a certain point called the vena contracta point
located downstream of the orifice plate 50.
[0023] The foregoing descriptions of specific embodiments of the
present invention have been presented for purposes of illustration
and description. They are not intended to be exhaustive or to limit
the invention to the precise forms disclosed, and various
modifications and variations are possible in light of the above
teaching. The embodiments were chosen and described in order to
explain the principles of the invention and its practical
application, to thereby enable others skilled in the art to utilize
the invention and various embodiments with various modifications as
are suited to the particular use contemplated. The invention has
been described in great detail in the foregoing specification, and
it is believed that various alterations and modifications of the
invention will become apparent to those skilled in the art from a
reading and understanding of the specification. It is intended that
all such alterations and modifications are included in the
invention, insofar as they come within the scope of the appended
claims. It is intended that the scope of the invention be defined
by the claims appended hereto and their equivalents.
* * * * *