U.S. patent application number 13/094882 was filed with the patent office on 2012-11-01 for fluid pressure control valve.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to Joseph J. Moon, David R. Staley.
Application Number | 20120272932 13/094882 |
Document ID | / |
Family ID | 47007880 |
Filed Date | 2012-11-01 |
United States Patent
Application |
20120272932 |
Kind Code |
A1 |
Moon; Joseph J. ; et
al. |
November 1, 2012 |
FLUID PRESSURE CONTROL VALVE
Abstract
A valve assembly configured to provide feed-back control of
pressurized fluid in a gallery includes a housing and a pressure
chamber. The valve assembly also includes a first passage for
providing continuous flow of fluid through the gallery and a second
passage for supplying the pressurized fluid to the gallery. The
valve assembly additionally includes a piston moveable within the
pressure chamber between a first position that opens the second
passage and a second position that closes the second passage. The
piston includes a third passage that provides fluid communication
between the first passage and the pressure chamber. Furthermore,
the valve assembly includes a spring configured to move the piston
to the first position when gallery fluid pressure is less than a
threshold pressure value and permit the piston to shift to the
second position when gallery fluid pressure is equal to or greater
than the threshold pressure value.
Inventors: |
Moon; Joseph J.; (Clawson,
MI) ; Staley; David R.; (Flushing, MI) |
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS
LLC
Detroit
MI
|
Family ID: |
47007880 |
Appl. No.: |
13/094882 |
Filed: |
April 27, 2011 |
Current U.S.
Class: |
123/90.55 ;
251/337 |
Current CPC
Class: |
F01L 2003/256 20130101;
F01L 2003/255 20130101; F01L 1/2405 20130101; F01L 2820/01
20130101; F01L 2810/02 20130101; F01L 1/245 20130101; F01L 1/24
20130101 |
Class at
Publication: |
123/90.55 ;
251/337 |
International
Class: |
F01L 1/14 20060101
F01L001/14; F01L 3/10 20060101 F01L003/10 |
Claims
1. A valve assembly configured to provide feed-back control of
pressurized fluid in a gallery, the valve assembly comprising: a
housing; a pressure chamber; a first passage configured to provide
continuous flow of fluid through the gallery; a second passage
configured to supply the pressurized fluid from an external source
to the gallery; a piston configured to move within the pressure
chamber between a first position and a second position and having a
third passage configured to establish fluid communication between
the first passage and the pressure chamber, wherein the first
position of the piston opens the second passage and the second
position of the piston closes the second passage; and a spring
disposed between the piston and the housing, the spring being
configured to move the piston to the first position when pressure
of the fluid in the gallery is less than a threshold fluid pressure
value and permit the piston to move to the second position when
pressure of the fluid in the gallery is equal to or greater than
the threshold fluid pressure value.
2. The valve assembly of claim 1, wherein the pressure chamber
includes a reaction surface configured to generate a hydraulic
force sufficient to overcome the spring and move the piston to the
second position when the fluid pressure is at or above the
threshold fluid pressure value.
3. The valve assembly of claim 2, further comprising a cap
assembled onto the housing, wherein the reaction surface is
arranged on the cap.
4. The valve assembly of claim 1, wherein the third passage is
arranged substantially perpendicular to the first passage.
5. The valve assembly of claim 1, further comprising a fourth
passage configured to purge fluid that escapes from the pressure
chamber past the piston.
6. The valve assembly of claim 1, wherein the third passage
includes an orifice configured to establish a rate of movement of
the piston within the pressure chamber in response to fluid
pressure changes in the gallery.
7. The valve assembly of claim 1, wherein the external source
supplying pressurized fluid to the gallery is a fluid pump.
8. The valve assembly of claim 1, wherein the gallery is arranged
in an internal combustion engine, the fluid is engine oil, and the
gallery is configured to supply the oil to a hydraulic lash
adjuster in a valve train system of the engine.
9. An internal combustion engine comprising: a cylinder; a valve
train system configured to open and close an entryway into the
cylinder and having a hydraulic lash adjuster configured to control
a clearance in the valve train; a pump configured to pressurize an
oil; a gallery configured to supply the pressurized oil to the lash
adjuster; and a valve assembly configured to provide feed-back
control of the pressurized oil in a gallery, the valve assembly
comprising: a housing; a pressure chamber; a first passage
configured to provide continuous flow of oil through the gallery; a
second passage configured to supply the pressurized oil from the
pump to the gallery; a piston configured to move within the
pressure chamber between a first position and a second position and
having a third passage configured to establish fluid communication
between the first passage and the pressure chamber, wherein the
first position of the piston opens the second passage and the
second position of the piston closes the second passage; and a
spring disposed between the piston and the housing, the spring
being configured to move the piston to the first position when
pressure of the oil in the gallery is less than a threshold oil
pressure value and permit the piston to move to the second position
when pressure of the oil in the gallery is equal to or greater than
the threshold oil pressure value.
10. The engine of claim 9, wherein the pressure chamber includes a
reaction surface configured to generate a hydraulic force
sufficient to overcome the spring and move the piston to the second
position when the oil pressure is at or above the threshold oil
pressure value.
11. The engine of claim 10, wherein the valve assembly additionally
includes a cap assembled onto the housing, and wherein the reaction
surface is arranged on the cap.
12. The engine of claim 9, wherein the third passage is arranged
substantially perpendicular to the first passage.
13. The engine of claim 9, wherein the valve assembly additionally
includes a fourth passage configured to purge oil that escapes from
the pressure chamber past the piston.
14. The engine of claim 9, wherein the third passage includes an
orifice configured to establish a rate of movement of the piston
within the pressure chamber in response to oil pressure changes in
the gallery.
15. A vehicle comprising: a drive element; and an internal
combustion engine configured to generate torque for rotating the
drive element, the engine having: a cylinder; a valve train system
configured to open and close an entryway into the cylinder and
having a hydraulic lash adjuster configured to control a clearance
in the valve train; a pump configured to pressurize an oil; a
gallery configured to supply the pressurized oil to the lash
adjuster; and a valve assembly configured to provide feed-back
control of the pressurized oil in a gallery, the valve assembly
comprising: a housing; a pressure chamber; a first passage
configured to provide continuous flow of oil through the gallery; a
second passage configured to supply the pressurized oil from the
pump to the gallery; a piston configured to move within the
pressure chamber between a first position and a second position and
having a third passage configured to establish fluid communication
between the first passage and the pressure chamber, wherein the
first position of the piston opens the second passage and the
second position of the piston closes the second passage; and a
spring disposed between the piston and the housing, the spring
being configured to move the piston to the first position when
pressure of the oil in the gallery is less than a threshold oil
pressure value and permit the piston to move to the second position
when pressure of the oil in the gallery is equal to or greater than
the threshold oil pressure value.
16. The vehicle of claim 15, wherein the pressure chamber includes
a reaction surface configured to generate a hydraulic force
sufficient to overcome the spring and move the piston to the second
position when the oil pressure is at or above the threshold oil
pressure value.
17. The vehicle of claim 16, wherein the valve assembly
additionally includes a cap assembled onto the housing, and wherein
the reaction surface is arranged on the cap.
18. The vehicle of claim 15, wherein the third passage is arranged
substantially perpendicular to the first passage.
19. The vehicle of claim 15, wherein the valve assembly
additionally includes a fourth passage configured to purge oil that
escapes from the pressure chamber past the piston.
20. The vehicle of claim 15, wherein the third passage includes an
orifice configured to establish a rate of movement of the piston
within the pressure chamber in response to oil pressure changes in
the gallery.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a fluid pressure control
valve.
BACKGROUND
[0002] A valve is a device that regulates the flow of a fluid by
opening, closing, or partially obstructing various passageways.
Some valves are operated manually, while others are configured to
operate automatically in response to changing conditions with the
subject fluid passage. Valves may be used in complex automatic
control systems and may require an actuator, such as a solenoid, to
actuate a particular valve based on an external input.
[0003] Valves are employed in a multitude of industries and are
often used to regulate flows of various fluids in motor vehicles.
In vehicle internal combustion engines, valves are commonly
employed for regulating flows of coolant and oil. For example,
valves may be used to control the engine's valve train by
regulating a supply of pressurized oil to the engine's hydraulic
lash adjusters.
SUMMARY
[0004] A valve assembly configured to provide feed-back control of
pressurized fluid in a gallery includes a housing and a pressure
chamber. The valve assembly also includes a first passage
configured to provide continuous flow of fluid through the gallery
and a second passage configured to supply the pressurized fluid
from an external source to the gallery. The valve assembly
additionally includes a piston configured to move or shift within
the pressure chamber between a first position and a second position
and having a third passage configured to establish fluid
communication between the first passage and the pressure chamber.
The first position of the piston opens the second passage and the
second position of the piston closes the second passage.
Furthermore, the valve assembly includes a spring disposed between
the piston and the housing. The spring is configured to move the
piston to the first position when pressure of the fluid in the
gallery is less than a threshold fluid pressure value. The spring
is also configured to permit the piston to shift to the second
position when pressure of the fluid in the gallery is equal to or
greater than the threshold fluid pressure value.
[0005] The pressure chamber may include a reaction surface
configured to generate a hydraulic force sufficient to overcome the
spring and shift the piston to the second position when the fluid
pressure is at or above the threshold fluid pressure value.
[0006] The valve assembly may also include a cap assembled onto the
housing. The reaction surface may then be arranged on the cap.
[0007] The third passage may be arranged substantially
perpendicular to the first passage.
[0008] The valve assembly may additionally include a fourth passage
configured to purge fluid that escapes from the pressure chamber
past the piston.
[0009] The third passage may include an orifice configured to
establish a rate of movement of the piston within the pressure
chamber in response to fluid pressure changes in the gallery.
[0010] The external source supplying pressurized fluid to the
gallery may be a fluid pump.
[0011] The gallery may be arranged in an internal combustion engine
of a vehicle. In such a case, the fluid may be engine oil, and the
gallery may then be configured to supply the oil to a hydraulic
lash adjuster in a valve train system of the engine.
[0012] The above features and advantages and other features and
advantages of the present invention are readily apparent from the
following detailed description of the best modes for carrying out
the invention when taken in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 schematic plan view of a motor vehicle having an
internal combustion engine employing a valve train;
[0014] FIG. 2 is a schematic partial view of the valve train shown
in FIG. 1, wherein pressurized oil is supplied to the valve train
via a pump and the pressure of the oil is controlled by a valve
assembly;
[0015] FIG. 3 is a schematic cross-sectional view of the valve
assembly shown in FIG. 2, wherein the valve assembly is depicted in
an open state;
[0016] FIG. 4 is a schematic cross-sectional view of the valve
assembly shown in FIG. 2, wherein the valve assembly is depicted in
a closed state.
DETAILED DESCRIPTION
[0017] Referring to the drawings, wherein like reference numbers
refer to like components, FIG. 1 shows a schematic view of a motor
vehicle 10. The vehicle 10 incorporates a powertrain that includes
an internal combustion engine 12, such as a spark or a compression
ignition type. The engine 12 is configured to generate torque for
rotating a drive element 14 to drive one or more wheels 16 and
propel the vehicle 10.
[0018] The engine 10 includes cylinders 18 and a valve train system
20 configured to open and close an entryway for air or a fuel/air
mixture into the cylinders. As shown, the valve train system 20
includes a camshaft 22 and rocker arms 24 configured to actuate
intake valves 26 and a camshaft 23 configured to actuate exhaust
valves 28 for controlling intake, compression, ignition, and
exhaust cycles of the engine 12. The valve train system 20 also
includes hydraulic lash adjusters 30 configured to control
clearances in the valve train system 20. Each individual lash
adjuster 30 controls the clearance between a particular valve
actuating lobe 31 of camshaft 22 or 23, a respective rocker arm 24,
and either the intake valve 26 or the exhaust valve 28.
[0019] As shown in FIG. 2, the engine 12 also includes a fluid pump
32 configured to generate a flow of pressurized oil 34. The pump 32
may be employed to supply oil to the lubrication system (not shown)
of the engine 12 via a main gallery 36. The pump 32 also supplies
the pressurized oil 34 via the main gallery 36 to an oil gallery
38. The oil gallery 38 is configured to supply the pressurized oil
34 to the lash adjusters 30. The amount of oil pressure necessary
to maintain the lash adjusters 30 sufficiently pumped up for
controlling clearances in the valve train system 20 is a
predetermined value dependent on specific engine configuration. A
valve assembly 40 is disposed in the oil gallery 38 and in fluid
communication with the main gallery 36. The valve assembly 40 is
configured to provide feed-back control of the pressurized oil 34
in the oil gallery 38.
[0020] As shown in FIG. 3, the valve assembly 40 includes a housing
42 and a cap 44. The cap 44 is assembled onto the housing 42 by any
common means, such as a threaded interface or an interference fit.
The housing 42 and the cap 44 combine to encapsulate a piston 46
and a spring 48. As shown in FIG. 3, the spring 48 may be a
traditional helical compression spring. The internal surfaces of
the housing 42 and the cap 44, together with a pressure surface 50
of the piston 46 define a pressure chamber 52. The piston 46
includes a first narrowed section 54 that generates a first passage
56 through the valve assembly 40 and sustains continuous flow of
oil through the oil gallery 38.
[0021] The piston 46 additionally includes a second narrowed
section 58 that generates a second passage 60 between the pump 32
and the gallery 38. Consequently, the second passage 60 is
configured to supply the pressurized oil 34 from the pump 32 to the
gallery 38. The first narrowed section 54 of the piston 46 includes
a channel 62 that is fluidly connected to a third passage 64.
Accordingly, the third passage 64 is configured to establish fluid
communication between the first passage 56 and the pressure chamber
52. As shown, the third passage 64 is arranged substantially
perpendicular to the first passage 56 such that the oil flow
exiting the third passage 64 into the pressure chamber 52 is
directed toward the cap 44.
[0022] The piston 46 is configured to move or shift relative to the
housing 42 and within the pressure chamber 52 between a first
position 66 (shown in FIG. 3) and a second position 68 (shown in
FIG. 4). The first position 66 of the piston 46 is configured to
open the second passage 60 and the second position 68 is configured
to close the second passage. The spring 48 is disposed between the
piston 46 and the housing 42. The spring 48 is configured to shift
the piston 46 to the first position 66 when pressure of the oil in
the gallery 38 is less than a threshold oil pressure value. The
spring 48 is furthermore configured to permit the piston 46 to
shift to the second position 68 when pressure of the oil in the
gallery 38 is equal to or greater than the threshold oil pressure
value.
[0023] The threshold oil pressure value is indicative of the
magnitude of oil pressure which, if exceeded, may "over-pump" the
lash adjusters 30 and eliminate all valve train clearances. Such
over-pumping of the lash adjusters 30 may result in excessive
preloading of the valve actuating lobes 31 against the respective
rocker arms 24 and the valves 26, 28. Additionally, exceeding the
threshold oil pressure value may result in increased rate of oil
leakage that is generally detrimental to efficiency of the engine's
lubrication system. The threshold oil pressure value may be
predetermined or established based on requirements of a specific
engine configuration. In a particular embodiment, the threshold oil
pressure may be set at 60 Psi, or approximately 4 Bar.
[0024] With continued reference to FIG. 3, a reaction surface 72 is
arranged on the cap 44 directly across from the piston 46. The
reaction surface 72 has an area that is substantially equal to an
area of the pressure surface 50. The oil pressure generated inside
the pressure chamber 52 acts on both the reaction surface 72 and
the pressure surface 50 to generate a hydraulic force on the piston
46 in opposition to the force generated by the spring 48. The valve
assembly additionally includes a fourth passage 74. The fourth
passage 74 is configured to purge oil that may escape from the
pressure chamber 52, leak past the piston 46, and accumulate in the
cavity containing the spring 48. Additionally, the third passage
may include an orifice 76. The orifice 76 is configured to
establish a rate of movement of the piston 46 within the pressure
chamber 52 in response to oil pressure changes in the gallery 38.
The size or diameter of the orifice 76 controls the response rate
of the piston 46 to the increased pressure of oil in the gallery
38. Accordingly, the size of the orifice 76 may by adjusted to
generate the desired response of the piston 46.
[0025] During operation of the engine 12, the valve assembly 40
facilitates a continuous flow of oil to traverse the gallery 38 in
order to pressurize lash adjusters 30 without interruption.
Simultaneously, the valve assembly 40 is fed by the pressurized oil
34 from the pump 32 via the main gallery 36 to an oil gallery 38.
Due to the operation of the pump 32, the pressurized oil 34 is
primary delivered to the main gallery 36, and the oil pressure
inside the main gallery initially exceeds the pressure of the oil
in the gallery 38. As the pressure of the oil in the gallery 38
remains lower than the threshold oil pressure value, the piston 46
stays in the first position 66 and permits the pressurized oil 34
to be supplied into the gallery 38. As the pressurized oil 34
continues to be added to the gallery 38, the pressure inside the
gallery will rise and is likely to eventually reach the threshold
oil pressure value. As the pressure of the oil in the gallery 38 is
increased, the pressure is also increased inside the pressure
chamber 52 due to the oil from the gallery being supplied to the
chamber via the third passage 64.
[0026] When the oil pressure reaches the predetermined oil pressure
value the hydraulic force generated inside the pressure chamber 52
exceeds the force provided by the spring 48, and the piston 46
shifts to the second position 68. When the piston shifts to the
second position 68, the second passage 60 becomes substantially
closed such that the flow of pressurized oil 34 from the pump 32 is
generally blocked. As the pressure of the oil in the gallery 38
slowly decreases below the threshold oil pressure value due to
various factors, such as leakage, the pressure inside the pressure
chamber 52 is also decreased because of the chamber's communication
with the gallery via third passage 64. Such a decrease in pressure
inside the pressure chamber 52 permits the spring to shift the
piston 46 back toward the first position 66, which allows the
pressurized oil 34 to again be supplied into the gallery 38.
[0027] The described feed-back control of pressurized fluid by the
valve assembly 40 may be continuous during the entire operation of
the engine 12. Accordingly, because the pressure of oil in the
gallery 38 is not permitted to increase past the established
threshold oil pressure value, the actual amount of oil flowing
through the gallery is reduced. The feed-back control provided by
the valve assembly 40 serves to also reduce oil leakage in the
lubrication system of the engine 12 by controlling oil flow from
the second passage 60 to the first passage 56 according to the
threshold oil pressure value. Additionally, such reduced amount of
oil pressure and flow tends to reduce parasitic losses in the valve
train 20 and further improve operating efficiency of the engine
12.
[0028] While the best modes for carrying out the invention have
been described in detail, those familiar with the art to which this
invention relates will recognize various alternative designs and
embodiments for practicing the invention within the scope of the
appended claims.
* * * * *