U.S. patent application number 09/559698 was filed with the patent office on 2002-01-10 for reaction chamber check valve and gaseous fuel engine using same.
Invention is credited to Ibrahim, Dan R..
Application Number | 20020002962 09/559698 |
Document ID | / |
Family ID | 22450787 |
Filed Date | 2002-01-10 |
United States Patent
Application |
20020002962 |
Kind Code |
A1 |
Ibrahim, Dan R. |
January 10, 2002 |
Reaction chamber check valve and gaseous fuel engine using same
Abstract
An internal combustion engine comprises an engine housing which
defines a main combustion chamber that is separated from a
precombustion chamber by a flame communication passageway. The
engine housing further defines a fuel supply passage with one end
and an opposite end. A source of fuel is fluidly connected to the
opposite end of the fuel supply passage. A check valve which
includes a valve body with a valve seat and a valve member is
positioned between the one end of the fuel supply passage and the
precombustion chamber. The valve member is movable between an open
position and a closed position. The valve body and the valve member
define a relatively wide fluid passage that fluidly connects the
fuel supply passage to the precombustion chamber when the valve
member is in the open position. The valve body and the valve member
define a relatively narrow stagnation region separating the valve
seat from the precombustion chamber when the valve member is in the
closed position.
Inventors: |
Ibrahim, Dan R.;
(Bloomington, IL) |
Correspondence
Address: |
Liell and McNeil
Attn: Michael B McNeil
511 S Madison St
Bloomington
IN
47402
US
|
Family ID: |
22450787 |
Appl. No.: |
09/559698 |
Filed: |
April 27, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60131735 |
Apr 30, 1999 |
|
|
|
Current U.S.
Class: |
123/276 |
Current CPC
Class: |
Y02T 10/30 20130101;
Y02T 10/125 20130101; F02B 19/12 20130101; F02B 17/005 20130101;
F02B 23/101 20130101; Y02T 10/12 20130101; Y02T 10/32 20130101;
F02B 43/00 20130101; F02B 2023/102 20130101 |
Class at
Publication: |
123/276 |
International
Class: |
F02F 003/26 |
Claims
1. An internal combustion engine comprising: an engine housing
defining a main combustion chamber separated from a precombustion
chamber by a flame communication passageway, and further defining a
fuel supply passage with one end and an opposite end; a source of
fuel fluidly connected to said opposite end of said fuel supply
passage; a check valve, which includes a valve body with a valve
seat and a valve member, positioned between said one end of said
fuel supply passage and said precombustion chamber, and said valve
member being movable between an open position and a closed
position; said valve body and said valve member defining a
relatively wide fluid passage that fluidly connects said fuel
supply passage to said precombustion chamber when said valve member
is in said open position; and said valve body and said valve member
defining a relatively narrow stagnation region separating said
valve seat from said precombustion chamber when said valve member
is in said closed position.
2. The engine of claim 1 wherein said source of fuel is a source of
gaseous fuel.
3. The engine of claim 1 wherein said valve member includes a
cylindrical portion; said valve body includes an internal
cylindrical wall; and said relatively narrow stagnation region
includes a diametrical clearance between said cylindrical portion
and said internal cylindrical wall.
4. The engine of claim 1 wherein said valve member and said valve
body include a common centerline; and those portions of said valve
member and said valve body that define said relatively narrow
stagnation region are located at nonoverlaping positions along said
centerline when said valve member is in said open position.
5. The engine of claim 1 wherein said valve body defines a guide
bore; said valve member includes a guide surface guided in said
guide bore and a valve surface positioned adjacent said valve seat;
and said valve seat, said guide bore, said guide surface and said
valve surface all share a common centerline.
6. The engine of claim 1 wherein said valve member has a
cylindrical guide surface bounded on opposite ends by fluid
chambers in fluid communication with said source of fuel when said
valve member is in said closed position.
7. The engine of claim 1 further comprising a stop component
attached to said valve body; said valve member being in contact
with said stop component when in said open position, but being out
of contact with said stop component when in said closed
position.
8. The engine of claim 7 wherein said stop component is at least
one cylindrical dowel mounted in said valve body.
9. The engine of claim 1 wherein said valve member has a first
fluid pressure surface exposed to fluid pressure in said
precombustion chamber, and an opposing fluid pressure surface
exposed to fluid pressure in said fuel supply passage.
10. The engine of claim 1 wherein said valve member is mechanically
unbiased.
11. A gaseous fuel internal combustion engine comprising: an engine
housing defining a main combustion chamber separated from a
precombustion chamber by a flame communication passageway, and
further defining a fuel supply passage with one end and an opposite
end; a source of gaseous fuel fluidly connected to said opposite
end of said fuel supply passage; a check valve, which includes a
valve body with a conical valve seat and a valve member with a
centerline, positioned between said one end of said fuel supply
passage and said precombustion chamber, and said valve member being
movable between an open position and a closed position; said valve
body and said valve member defining a relatively wide fluid passage
that fluidly connects said fuel supply passage to said
precombustion chamber when said valve member is in said open
position; said valve body and said valve member defining a
relatively narrow stagnation region separating said valve seat from
said precombustion chamber when said valve member is in said closed
position; and those portions of said valve member and said valve
body that define said relatively narrow stagnation region are
located at nonoverlaping positions along said centerline when said
valve member is in said open position.
12. The engine of claim 11 wherein said valve member includes a
cylindrical portion; said valve body includes an internal
cylindrical wall; and said relatively narrow stagnation region
includes a diametrical clearance between said cylindrical portion
and said internal cylindrical wall.
13. The engine of claim 12 wherein said valve member has a first
fluid pressure surface exposed to fluid pressure in said
precombustion chamber, and an opposing fluid pressure surface
exposed to fluid pressure in said fuel supply passage.
14. The engine of claim 13 wherein said valve member includes a
guide surface which is bounded on opposite ends by fluid chambers
in fluid communication with said source of gaseous fuel when said
valve member is in said closed position.
15. The engine of claim 14 wherein said guide surface is guided in
a guide bore defined by said valve body; said valve member includes
a valve surface positioned adjacent said valve seat; said valve
seat, said guide bore, said guide surface and said valve surface
all share a common centerline that is concentric with said
centerline.
16. The engine of claim 15 further comprising a stop component
attached to said valve body; said valve member being in contact
with said stop component when in said open position, but being out
of contact with said stop component when in said closed
position.
17. The engine of claim 16 wherein said valve member is
mechanically unbiased.
18. The engine of claim 17 wherein said stop component is at least
one cylindrical dowel.
19. A combustion isolation check valve comprising: a valve body
having a valve seat and defining an inlet and an outlet; a valve
member positioned in said valve body between said inlet and said
outlet and being movable between an open position and a closed
position; said valve body and said valve member defining a
relatively wide fluid passage that fluidly connects said inlet to
said outlet when said valve member is in said open position; and
said valve body and said valve member defining a relatively narrow
stagnation region separating said valve seat from said outlet when
said valve member is in said closed position.
20. The check valve of claim 19 wherein said valve member has a
centerline and includes a cylindrical portion; said valve body
includes an internal cylindrical wall; said relatively narrow
stagnation region includes a diametrical clearance between said
cylindrical portion and said internal cylindrical wall; and those
portions of said valve member and said valve body that define said
relatively narrow stagnation region are located at nonoverlaping
positions along said centerline when said valve member is in said
open position.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119 of prior provisional application No. 60/131,735 filed
Apr. 30, 1999.
TECHNICAL FIELD
[0002] This invention relates generally to reaction chamber check
valves, and more particularly to a check valve for use adjacent a
precombustion chamber of a gaseous fuel internal combustion
engine.
BACKGROUND ART
[0003] Internal combustion engines which burn gaseous fuels
containing high amounts of methane, including natural gas or gas
produced from a landfill, have a tendency to produce high exhaust
emissions. One solution to reducing exhaust emissions from these
engines is to burn leaner gaseous fuel/air mixtures. Some engines
which use these leaner mixtures include a precombustion chamber
that is in fluid communication with the main combustion chamber. A
rich mixture is ignited in the precombustion chamber which serves
as the means for igniting the leaner mixture in the main combustion
chamber. While this engine configuration has been successful in
reducing exhaust emissions, other problems have been observed.
Engineers have found that solid deposits produced from the gaseous
fuel during the combustion process tend to accumulate on the valve
that separates the precombustion chamber from the fuel supply
passage, which can cause the engine to misfire.
[0004] For instance, engines using a precombustion chamber
typically use a ball check valve to separate the fuel supply
passage from the precombustion chamber. The ball valve in these
engines is mechanically unbiased and is moved by pressure
differentials existing between the fuel supply passage and the
precombustion chamber. In general, the pressure in the fuel supply
passage is constant while the pressure in the precombustion chamber
fluctuates with the engine cycle. These ball valves are not always
able to seal adequately due to the deposit of solids on the valve
seat, pressure wave dynamics, and other reasons not fully
understood. When the ball valve fails to seal sufficiently,
combustion gasses can flow into the fuel supply passage and cause
the engine to misfire.
[0005] The present invention is directed to overcoming one or more
of the problems described above and to improving performance of
gaseous fuel internal combustion engines.
SUMMARY OF THE INVENTION
[0006] An internal combustion engine comprises an engine housing
which defines a main combustion chamber that is separated from a
precombustion chamber by a flame communication passageway. The
engine housing further defines a fuel supply passage with one end
and an opposite end. A source of fuel is fluidly connected to the
opposite end of the fuel supply passage. A check valve, which
includes a valve body with a valve seat and a valve member, is
positioned between the one end of the fuel supply passage and the
precombustion chamber. The valve member is movable between an open
position and a closed position. The valve body and the valve member
define a relatively wide fluid passage that fluidly connects the
fuel supply passage to the precombustion chamber when the valve
member is in the open position. The valve body and the valve member
define a relatively narrow stagnation region separating the valve
seat from the precombustion chamber when the valve member is in the
closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a partial sectioned side diagrammatic view of an
internal combustion engine according to the present invention.
[0008] FIG. 2 is an enlarged sectioned side diagrammatic view of a
combustion isolation check valve mounted adjacent a precombustion
chamber according to the present invention.
[0009] FIG. 2a is a sectioned view through the combustion isolation
check valve of FIG. 2 through section lines 2a-2a.
[0010] FIGS. 3a and 3b are enlarged partial sectioned side
diagrammatic views of the combustion isolation check valve of FIG.
2 shown in its open and closed positions, respectively.
BEST MODE FOR CARRYING OUT THE INVENTION
[0011] Referring now to FIG. 1, a gaseous fuel internal combustion
engine 10 includes an engine housing 11 that defines a main
combustion chamber 12 separated from a precombustion chamber 13 by
a flame communication passageway 14. A combustion isolation check
valve 30 is positioned between precombustion chamber 13 and a
downstream end 16 of a fuel supply passage 15. A spark plug 19 or
any other suitable ignition device is positioned within
precombustion chamber 13. An upstream end 17 of fuel supply passage
15 is fluidly connected to a source of gaseous fuel 20. As with a
typical internal combustion engine, a piston 18 reciprocates in
main combustion chamber 12 with each engine cycle. Although only
one piston 18 is shown, those skilled in the art will appreciate
that the typical engine includes a plurality of pistons identical
to that shown in FIG. 1.
[0012] Referring now to FIGS. 2 and 2a, engine housing 11 defines a
bore 22 within which combustion isolation check valve 30 is
threadably mounted. In order to facilitate this mounting
arrangement, check valve 30 preferably includes a valve body 31
with a lower cylindrical outer surface 34 separated from a hex head
32 by a set of threads 33. Valve body 31 is preferably generally
symmetrical about a centerline 29. An o-ring 26 is mounted about
the outer surface of valve body 31 in contact with bore 22 in order
to prevent leakage in a conventional manner. The bottom surface of
valve body 31 is separated from the precombustion chamber 13 by a
washer 25. When properly mounted within an engine, valve body 31
preferably defines a valve annulus 37 that is fluidly connected to
the downstream end 16 of the fuel supply passage 15.
[0013] Referring now in addition to FIGS. 3a and 3b, a valve member
50 is movably mounted in an internal guide bore 35 defined by valve
body 31. Valve member 50 is moveable between an upward closed
position as shown in FIGS. 2 and 3b, and a downward open position
as shown in FIG. 3a. Valve member 50 defines a valve member annulus
57 and includes a cylindrical guide surface 58 which is guided in
internal guide bore 35. A fluid cavity 53 is defined by valve body
31 and an opening fluid pressure surface 55 of valve member 50.
Pressure equalization passage 40 opens into fluid cavity 53 thus
exposing opening fluid pressure surface 55 to fluid pressure in
fuel supply passage 15. A cross passage 42 is defined by valve body
31 to open into valve member annulus 57. Cross passage 42 and
pressure equalization passage 40 act to expose opposite ends of
guide surface 58 to fluid pressure in fuel supply passage 15.
[0014] When valve member 50 is in its upward closed position, a
valve surface 52 of valve member 50, which is preferably rounded,
is received in contact with a conical valve seat 46 of valve member
31. When valve member 50 is in its downward open position, an upper
surface 51 of annulus 57 is in contact with at least one
cylindrical dowel 24. Each cylindrical dowel 24 is attached to and
mounted in a dowel bore 44 that is defined by valve body 31. While
check valve 30 has been illustrated as using a pair of cylindrical
dowels 24 as the stop component to limit the downward movement of
valve member 50, an alternate number or placement of dowels 24 or
another suitable stop component, such as an end cap, could be
substituted.
[0015] Valve member 50 includes a cylindrical portion 56 which
shares common centerline 29 with an internal cylindrical wall 48
that is included on valve body 31. When valve member 50 is in its
downward open position, cylindrical portion 56 and internal
cylindrical wall 48 are located at nonoverlaping positions along
centerline 29. A relatively wide fluid passage 43 that is defined
by valve member 50, valve body 31, cross passage 42 and pressure
equalization passage 40 fluidly connects the downstream end 16 of
fuel supply passage 15 to precombustion chamber 13 when valve
member 50 is in this open position. When valve member 50 is in its
upward closed position, a relatively narrow stagnation region 45 is
defined by a diametrical clearance area between cylindrical portion
56 and internal cylindrical wall 48. Stagnation region 45, which is
relatively narrow in relation to fluid passage 43, separates valve
seat 46 from precombustion chamber 13. While stagnation region 45
is relatively small in volume, the diametrical clearance area
between cylindrical portion 56 and internal cylindrical wall 48 is
preferably greater than the guide clearance between guide surface
58 and guide bore 35 to allow valve member 50 sufficient room to
move and seat.
[0016] When valve member 50 moves toward its upward closed
position, stagnation region 45 acts to inhibit combustion flow
near, and the deposit of solids on, valve seat 46 because of the
relatively close clearance between cylindrical portion 56 and
internal cylindrical wall 48. This relatively narrow stagnation
region 45 allows cylindrical portion 56 and internal cylindrical
wall 48 to come into close proximity to one another, thus
protecting the sealing surfaces of valve member 50. When valve
member 50 moves toward its downward open position, the shearing
force of fluid flowing through stagnation region 45 can act to
remove any solids that may have deposited on valve seat 46. Thus,
the shearing fluid force through the relatively narrow stagnation
region 45 when the valve begins to open can act to continually
clear the area of any built up solid deposits. Additionally, when
valve member 50 is in its downward open position, cylindrical
portion 56 and internal cylindrical wall 48 are in nonoverlaping
positions along centerline 29 such that adequate flow around valve
member 50 is possible.
[0017] Although valve member 50 could be mechanically biased in one
direction or another by the inclusion of a spring, it is preferably
not mechanically biased such that fluid pressures existing in the
fuel supply passage 15 and the precombustion chamber 13 provide
whatever pressure differential that is needed to move valve member
50 in one direction or the other. Thus, valve member 50 can be
thought of as including an opening fluid pressure surface 55 that
is exposed to fluid pressure in fluid cavity 53, and a closing
fluid pressure surface 54 that is exposed to fluid pressure in the
lower portion of internal guide bore 35, which communicates with
precombustion chamber 13. Preferably, conical valve seat 46,
internal guide bore 35, guide surface 58 and valve surface 52 all
share a common centerline 29 to allow for better concentricity
between these seats and surfaces. By maintaining a common
centerline among these elements, there is less chance of unwanted
solids traveling upward into the guide region due to misalignment
of components.
[0018] Industrial Applicability
[0019] Although the present invention has been illustrated as
preferably for use as a combustion isolation check valve in a
gaseous fuel engine, it could potentially be used in other places
where there is a need to protect a valve seat of a valve positioned
adjacent a chemical reaction chamber, such as a combustion space.
Thus, the reaction chamber check valve of the present invention
could find potential application in stratified engines, if needed,
and possibly even in some non-engine applications where there is a
need to protect a valve seat from a chemical reaction, such as
combustion, occurring adjacent the valve.
[0020] Referring back to FIGS. 1 and 2, when engine 10 is
undergoing the intake portion of its cycle, check valve 30 opens
and allows relatively pure gaseous fuel (not mixed with air) to
flow into precombustion chamber 13. Due, at least in part to the
fluid connection provided by flame transfer passage 14, some air
from the relatively lean mixture existing in main combustion
chamber 12 makes its way into precombustion chamber 13 to provide a
relatively rich fuel/air mixture for ignition by spark plug 19.
When piston 18 begins moving upward for the compression stroke,
this raises pressure both in main combustion chamber 12 and
precombustion chamber 13 and provides a means by which some of the
air in the lean air mixture in main combustion chamber 12 can find
its way into precombustion chamber 13. As pressure rises, it
eventually produces a fluid pressure imbalance on valve member 50
causing it to move toward its closed position.
[0021] At an appropriate timing, the combustion event takes place.
Relatively narrow stagnation region 45 prevents substantial amounts
of combustion gasses and solids from traveling upward toward valve
seat 46, thus protecting valve seat 46 from the collection of solid
deposits. Further, when valve member 50 is allowed to move toward
its downward open position at the end of the combustion event, any
debris that might have accumulated on cylindrical portion 56 is
sheared away by the flow past valve member 50 when it first begins
to open. The present invention also prevents the penetration of
solid deposits into the area surrounding guide surface 58 not only
because guide surface 58 is positioned a relatively large distance
from pre-combustion chamber 13, but because guide surface 58 is
bound on both sides by equal pressure gaseous fuel. Because
pressure equalization passage 40 and cross passage 42 expose
opposing ends of guide surface 58 to equal pressure, it is unlikely
that undesirable solid material will penetrate into the area
surrounding guide portion 58.
[0022] It should be understood that the above description is
intended for illustrative purposes only, and is not intended to
limit the scope of the present invention in any way. For instance,
while a pair of cylindrical dowels have been illustrated as the
stop component for the present invention, it should be appreciated
that a different number of dowels or an end cap could be used.
Thus, those skilled in the art will appreciate that various
modifications could be made to the disclosed embodiment without
departing from the intended scope of the present invention, which
is defined in terms of the claims set forth below.
* * * * *