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Patent Abstract
A solenoid valve includes a housing that establishes a supply port,
a control port, and an exhaust port. A fluted bushing is statically
affixed within the housing and a poppet slides within the bushing.
The poppet is movable between a de-energized configuration wherein
flow is prohibited between the control port and the exhaust port,
and permitted between the control port and the supply port, plural
partially energized configurations wherein flow is permitted between
the supply port and the control port, between the control port and
the exhaust port, and between the exhaust port and the supply port,
and a fully energized configuration wherein flow is prohibited between
the control port and the supply port and flow is permitted between
the control port and the exhaust port.
Patent Claims
We claim:
1. A solenoid valve, comprising: a housing; a bushing statically
disposed within the housing; at least one flute established by the
bushing, the flute extending the axial length of the bushing and
establishing a fluid flow path through the solenoid valve; and a
poppet slidably disposed within the bushing.
2. (Cancelled)
3. The valve of claim 2 claim 1, wherein the bushing is formed
with at least one radially formed vent hole.
4. valve of claim 1, wherein the poppet comprises: an enlarged
base, the enlarged base having an outer diameter slightly smaller
than an inner diameter of the bushing.
5. The valve of claim 4, wherein the poppet further comprises:
a proximal end extending from the enlarged base; a first poppet
rod extending from the proximal end; a second poppet rod extending
from the enlarged base opposite the proximal end; and a distal end
established by the second poppet rod opposite the proximal end.
6. The valve of claim 5, further comprising: a coil spring around
the second poppet rod within the bushing.
7. The valve of claim 1, wherein the housing forms a supply port,
a control port, and an exhaust port, the poppet being movable to
block flow through one or more of the ports.
8. The valve of claim 7, wherein the poppet is movable between
a de-energized configuration wherein flow is prohibited between
the control port and the exhaust port, and permitted between the
control port and the supply port, plural partially energized configurations
wherein flow is permitted between the supply port and the control
port, between the control port and the exhaust port, and between
the exhaust port and the supply port, and a fully energized configuration
wherein flow is prohibited between the control port and the supply
port and flow is permitted between the control port and the exhaust
port.
9. A solenoid valve, comprising: a housing; a supply port established
by the housing; a control port established by the housing; an exhaust
port established by the housing; a bushing statically disposed within
the housing, the bushing having at least one flute extending the
axial length thereof; a poppet slidably disposed within the bushing;
and wherein the poppet is movable between a de-energized configuration
wherein flow is prohibited between the control port and the exhaust
port, and permitted between the control port and the supply port,
plural partially energized configurations wherein flow is permitted
between the supply port and the control port, between the control
port and the exhaust port, and between the exhaust port and the
supply port, and a fully energized configuration wherein flow is
prohibited between the control port and the supply port and flow
is permitted between the control port and the exhaust port.
10. (Cancelled)
11. (Cancelled)
12. The valve of claim 9, wherein the bushing is formed with at
least one radially formed vent hole.
13. The valve of claim 9, wherein the poppet comprises: an enlarged
base, the enlarged base having an outer diameter slightly smaller
than an inner diameter of the bushing.
14. The valve of claim 13, wherein the poppet further comprises:
a proximal end extending from the enlarged base; a first poppet
rod extending from the proximal end; a second poppet rod extending
from the enlarged base opposite the proximal end; and a distal end
established by the second poppet rod opposite the proximal end.
15. The valve of claim 14, further comprising: a coil spring around
the second poppet rod within the bushing.
16. A fluid control system, comprising: a fluid supply; a hydraulically
controlled device; a fluid exhaust; and a solenoid valve in fluid
communication with the fluid supply, the hydraulically controlled
device, and the fluid exhaust, the solenoid valve including a bushing
statically disposed therein, the bushing having at least one flute
extending the axial length thereof, and a poppet slidably disposed
within the bushing.
17. (Cancelled)
18. (Cancelled)
19. The system of claim 16, wherein the bushing is formed with
at least one radially formed vent hole.
20. The system of claim 16, wherein the poppet comprises: an enlarged
base, the enlarged base having an outer diameter slightly smaller
than an inner diameter of the bushing.
21. The system of claim 20, wherein the poppet further comprises:
a proximal end extending from the enlarged base; a first poppet
rod extending from the proximal end; a second poppet rod extending
from the enlarged base opposite the proximal end; and a distal end
established by the second poppet rod opposite the proximal end.
22. The system of claim 21, further comprising: a coil spring around
the second poppet rod within the bushing.
23. The system of claim 16, wherein the solenoid valve includes
a housing, the housing forming a supply port, a control port, and
an exhaust port, the poppet being movable to block flow through
one or more of the ports.
24. The system of claim 23, wherein the poppet is movable between
a de-energized configuration wherein flow is prohibited between
the control port and the exhaust port, and permitted between the
control port and the supply port, plural partially energized configurations
wherein flow is permitted between the supply port and the control
port, between the control port and the exhaust port, and between
the exhaust port and the supply port, and a fully energized configuration
wherein flow is prohibited between the control port and the supply
port and flow is permitted between the control port and the exhaust
port.
Patent Description
TECHNICAL FIELD
[0001] The present invention relates generally to hydraulic solenoid
valves.
BACKGROUND OF THE INVENTION
[0002] A typical automobile includes numerous systems that use
one or more solenoid valves to control the flow of fluid within
the system and to control the flow fluid to and from the system.
Many of these solenoid valves are three port solenoid valves that
require hydraulic fluid to be isolated or modulated between a supply,
control, and exhaust port. In order to properly isolate or modulate
the flow of the hydraulic fluid, the geometry around a supply-to-control
(S/C) valve seat and the geometry around a control-to-exhaust (C/E)
valve seat must be customized as a function of the poppet travel.
In most cases, especially linear pressure control solenoid valves,
poppet alignment and/or the presence of a spring in the hydraulic
flow path can result in significant variation in the functional
performance of the solenoid valve.
[0003] A typical three port solenoid valve uses a rod and ball
configuration to control the flow of fluid between the ports. The
rod can have an area that interfaces with one seat and a portion
that extends to push a ball away from a second seat. Moreover, the
ball has a spring behind it that helps keep it seated or in contact
with the rod. This type of configuration produces two annular orifices
with a radially floating ball that is sensitive to component alignment.
Since the spring is typically within the flow path, it can significantly
restrict the flow of hydraulic fluid within the solenoid valve.
[0004] The present invention has recognized these prior art drawbacks,
and has provided the below-disclosed solutions to one or more of
the prior art deficiencies.
SUMMARY OF THE INVENTION
[0005] A solenoid valve includes a housing in which a preferably
"I"-shaped bushing is statically disposed. A flute is
formed by the bushing and the flute establishes a fluid flow path
through the solenoid valve and connects the control and exhaust
ports. Moreover, a poppet is slidably disposed within the bushing.
[0006] In a preferred embodiment, the poppet includes an enlarged
base that has an outer diameter that is slightly smaller than an
inner diameter of the bushing. Preferably, the poppet also includes
a proximal end that extends from the enlarged base. A first poppet
rod extends from the proximal end and a second poppet rod extends
from the enlarged base opposite the proximal end. Further, a distal
end is established by the second poppet rod opposite the proximal
end.
[0007] Preferably, a coil spring is disposed within the bushing
around the second poppet rod formed by the poppet. In a preferred
embodiment, the housing forms a supply port, a control port, and
an exhaust port. The poppet is movable between a de-energized configuration,
a partially energized configuration, and a fully energized configuration.
In the de-energized configuration, flow is prohibited between the
control port and the exhaust port, and permitted between the control
port and the supply port. In the partially energized configuration,
flow is permitted between the supply port and the control port,
between the control port and the exhaust port, and between the exhaust
port and the supply port. Moreover, in a fully energized configuration
flow is prohibited between the control port and the supply port
and flow is permitted between the control port and the exhaust port.
[0008] In another aspect of the present invention, a solenoid valve
includes a housing that establishes a supply port, a control port,
and an exhaust port. In this aspect, a bushing is statically disposed
within the housing and a poppet is slidably disposed within the
bushing. The poppet is movable between a de-energized configuration,
a partially energized configuration, and a fully energized configuration.
In the de-energized configuration, flow is prohibited between the
control port and the exhaust port, and is permitted between the
control port and the supply port. In the partially energized configuration,
flow is permitted between the supply port and the control port,
between the control port and the exhaust port, and between the exhaust
port and the supply port. Additionally, in the fully energized configuration,
flow is prohibited between the control port and the supply port
and flow is permitted between the control port and the exhaust port.
[0009] In yet another aspect of the present invention, a fluid
control system includes a fluid supply, a hydraulically controlled
device, a fluid exhaust, and a solenoid valve that is in fluid communication
with the fluid supply, the hydraulically controlled device, and
the fluid exhaust. In this aspect, the solenoid valve includes a
bushing that is statically disposed therein and a poppet that is
slidably disposed within the bushing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will now be described, by way of example,
with reference to the accompanying drawings, in which:
[0011] FIG. 1 is a cross-section view of a three port solenoid
valve in a de-energized configuration;
[0012] FIG. 2 is a detailed cross-section view of the three port
solenoid valve taken at circle 2 in FIG. 1;
[0013] FIG. 3 is a cross-section view of the solenoid valve in
a partially energized configuration; and
[0014] FIG. 4 is a cross-section view of the solenoid valve in
a fully energized configuration.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring initially to FIG. 1, a three port solenoid valve
is shown and is generally designated 10. As shown, the solenoid
valve 10 defines a longitudinal axis 12 and preferably includes
a hollow, generally cylindrical frame 14 that defines an open proximal
end 16 and an open distal end 18 that is circumscribed by an internal
lip 20. FIG. 1 shows that the preferred solenoid valve 10 also includes
a housing 22 that defines a proximal end 24 and a distal end 26.
The proximal end 24 of the housing 22 can be circumscribed by a
flange 28 that has an external diameter approximately equal to the
internal diameter of the frame 14. The housing 22 can be disposed
within the frame 14 such that the distal end 26 of the housing 22
protrudes through and extends beyond the distal end 18 of the frame
14. Also, the flange 28 of the housing 22 can abut the internal
lip 20 of the frame 14.
[0016] Moreover, FIG. 1 shows that a generally cylindrical bore
30 can be formed through the housing 22 along the longitudinal axis
12. A generally disk-shaped internal wall 32 is established within
the housing 22, i.e., within the bore 30, approximately one-third
the length of the housing 22 away from the proximal end 24 of the
housing 22. As shown in FIG. 1, a control-to-exhaust (C/E) valve
seat 34 can be established in the center of the internal wall 32.
FIG. 1 further shows a valve fitting 36 disposed in the distal end
26 of the housing 22. In a preferred embodiment, a supply-to-control
(S/C) valve seat 38 is established in the center of the valve fitting
36.
[0017] As further shown in FIG. 1, a primary plate 40 can be disposed
within the frame 14 adjacent to the housing 22. The primary plate
40 includes a central hub 42 that extends into the housing 22 and
into the frame 14. The central hub 42 is further formed with a central
bore 44 and a generally cylindrical, hollow bushing 46 is disposed
therein. FIG. 1 also shows a generally I-shaped, hollow bobbin 48
that is disposed within the frame 14 adjacent to the primary plate
40. Preferably, a portion of the central hub 42 extends into the
bobbin 48. Further, a secondary plate 50 is installed in the proximal
end 16 of the frame 14 adjacent to the bobbin 48 such that the bobbin
48 is sandwiched between the primary plate 40 and the secondary
plate 50. In a preferred embodiment, the secondary plate 50 includes
a central hub 52 that extends at least partially into the bobbin
48. Moreover, the central hub 52 of the secondary plate 50 is formed
with a central bore 54.
[0018] FIG. 1 further shows a diaphragm spring 56 adjacent to the
secondary plate 50. A sandwich plate 58 is installed in the frame
14 adjacent to the diaphragm spring 56 which is sandwiched between
the secondary plate 50 and the sandwich plate 58. As shown, the
sandwich plate 58 is formed with a central bore 60. An adjuster
62, e.g., a screw, is installed within the central bore 60 of the
sandwich plate 58 and can be threadably engaged with the sandwich
plate 58.
[0019] As shown in FIG. 1, a coil 64 is wound or otherwise formed
around the bobbin 48. Additionally, a plunger 66 is slidably disposed
within the central hub 52 of the secondary plate 50. The plunger
66 is attached to the diaphragm spring 56 and a helical, coil-shaped
spring 67 is installed in compression between the adjuster 62 and
the plunger 66. Preferably, a plunger rod 68 extends from the plunger
66 through the length of the bobbin 48 and through the primary plate
40. As shown, the plunger rod 68 is supported by the bushing 46
within the primary plate 40. In a preferred embodiment, the plunger
rod 68 maintains contact with the poppet, described below.
[0020] In a preferred embodiment, a first fluid chamber 70 is established
within the housing bore 30 between the primary plate 40 and the
internal wall 32. Additionally, a second fluid chamber 72 is established
between the internal wall 32 and the valve fitting 36. An exhaust
port 74 is formed in the housing 22 near the proximal end 24 of
the housing 22 and extends into the first fluid chamber 70. Preferably,
a control port 76 can extend through the housing 22 into the second
fluid chamber 72. FIG. 1 further shows that a supply port 78 can
be formed in the distal end 26 end of the housing 22.
[0021] As shown in FIG. 1, a fluid supply 80, e.g., a pump, can
be connected to the supply port 78. Moreover, a hydraulically controlled
device 82, e.g., a brake cylinder or spool valve, can be connected
to the control port 76. A fluid exhaust 84, e.g., a reservoir, can
be connected to the exhaust port 74.
[0022] Referring now to the detailed view provided by FIG. 2, it
is shown that in a preferred embodiment, a generally "I"-shaped,
hollow bushing 86 is disposed within the housing bore 30, specifically
within the second fluid chamber 72 established therein. The bushing
86 is fixed with respect to the housing 22. Preferably, the bushing
86 is formed with plural flutes 88 to establish a fluid flow path
through the second fluid chamber 72. As shown in FIG. 2, a poppet
90 can be slidably disposed within the "I"-shaped bushing
86. Preferably, the poppet 90 is formed with an enlarged base 92
having a diameter slightly smaller than the internal diameter of
the "I"-shaped bushing 86. A frusto-conical proximal end
94 extends from the enlarged base 92 toward the C/E valve seat 34.
The frusto-conical proximal end 94 is sized and shaped to block
the C/E valve seat 34 when the solenoid valve is in the de-energized
configuration, shown in FIG. 1. Moreover, as shown in FIG. 2, a
first poppet rod 96 extends from the frusto-conical proximal end
94 of the poppet 90 and abuts the plunger rod 68.
[0023] FIG. 2 further shows that a second poppet rod 98 extends
from the enlarged base 92 opposite the frusto-conical proximal end
94 thereof. The second poppet rod 98 extends through a bore 100
formed in the "I"-shaped bushing 86 toward the S/C valve
seat 38. As shown, the second poppet rod 98 can terminate in a rounded
distal end 102 that is sized and shaped to block the S/C valve seat
38 when the solenoid valve 10 is fully energized as described in
detail below. Accordingly, the poppet 90 has a dual-sealing face,
i.e., the frusto-conical proximal end 94 and the rounded distal
end 102, and is decoupled from the poppet 66. It can be appreciated
that the frusto-conical proximal end 94 of the poppet 90 can be
rounded, e.g., like the distal end 102 of the poppet 90. Conversely,
the rounded distal end 102 of the poppet 90 can be frusto-conical,
e.g., like the proximal end 94 of the poppet 90.
[0024] In a preferred embodiment, a first spring contact face 104
is established radially around the poppet 90 at the transition between
the enlarged base 92 and the second poppet rod 98. Further, a second
spring contact face 106 is established within the "I"-shaped
bushing 86 such that it circumscribes the bore 100 established therein.
Preferably, a helical, coil-shaped spring 108 is installed in compression
around the poppet 90, within the bushing 86, between the first spring
contact face 104 and the second spring contact face 106. As shown,
the spring 108 is located entirely within the confines of the "I"-shaped
bushing 86 and cannot restrict the flow of fluid through the second
fluid chamber 72. In a preferred embodiment, plural vent holes 110
are radially formed in the bushing 86 in order to equalize the control
pressure on the poppet 98.
[0025] Operation
[0026] Initially, when the coil 64 is de-energized, as shown in
FIG. 1, the solenoid valve 10 is in a de-energized configuration,
the frusto-conical proximal end 94 of the poppet 90 is seated against
the C/E valve seat 34 to block flow between the control port 76
and the exhaust port 74. In the de-energized configuration, the
rounded distal end 102 of the poppet 90 is distanced a maximum distance
from the S/C valve seat 38 to allow fluid flow between the control
port 76 and the supply port 78.
[0027] When the solenoid valve 10 is in a partially energized configuration,
shown in FIG. 3, the coil 64 is partially energized and the plunger
66 moves to the right, looking down at FIG. 3, and deflects the
diaphragm spring 56. The plunger 66 forces the poppet 90 to also
move to the right, which compresses the coil spring 108. As the
plunger 66 moves, the poppet 90 moves toward the S/C valve seat
38 and the frusto-conical proximal end 94 is unseated from the C/E
valve seat 34. In the partially energized configuration, fluid flow
is permitted between the supply port 78, the control port 76, and
the exhaust port 74.
[0028] When the solenoid valve 10 is in the fully energized configuration,
shown in FIG. 4, the current applied to the coil 64 has reached
a predetermined upper threshold. In this configuration, the plunger
66 reaches its maximum displacement, as shown in FIG. 4, wherein
the rounded distal end 102 of the poppet 90 engages the S/C valve
seat 38 to block fluid flow between the supply port 78 and the control
port 76 and between the supply port 78 and the exhaust port 74.
In this configuration, fluid flow between the control port 76 and
the exhaust port 74 is permitted.
[0029] As the current applied to the solenoid valve 10 decreases,
the coil spring 108 moves the poppet 80 to the left, looking at
FIGS. 1, 3, and 4. The diaphragm spring 56 also moves the plunger
66 to the left. When the solenoid valve 10 is de-energized, the
solenoid valve returns to the configuration shown in FIG. 1.
[0030] With the configuration of structure described above, the
solenoid valve 10 includes a spring 108 that is fully enclosed within
the bushing. Since the spring 108 is not within the flow path through
the second fluid chamber 72, it does not restrict the flow of hydraulic
fluid through the solenoid valve. Moreover, the ratio of the poppet
length to the poppet diameter can be maximized which, in turn, minimizes
leakage, component wear, and flow control performance variation,
due to misalignment of the poppet 90 with respect to the valve seats
34, 38.
[0031] While the particular THREE PORT SOLENOID VALVE as herein
shown and described in detail is fully capable of attaining the
above-described objects of the invention, it is to be understood
that it is the presently preferred embodiment of the present invention
and thus, is representative of the subject matter which is broadly
contemplated by the present invention, that the scope of the present
invention fully encompasses other embodiments which may become obvious
to those skilled in the art, and that the scope of the present invention
is accordingly to be limited by nothing other than the appended
claims, in which reference to an element in the singular is not
intended to mean "one and only one" unless explicitly
so stated, but rather one or more." All structural and functional
equivalents to the elements of the above-described preferred embodiment
that are known or later come to be known to those of ordinary skill
in the art are expressly incorporated herein by reference and are
intended to be encompassed by the present claims. Moreover, it is
not necessary for a device or method to address each and every problem
sought to be solved by the present invention, for it is to be encompassed
by the present claims. Furthermore, no element, component, or method
step in the present disclosure is intended to be dedicated to the
public regardless of whether the element, component, or method step
is explicitly recited in the claims. No claim element herein is
to be construed under the provisions of 35 U.S.C. section 112, sixth
paragraph, unless the element is expressly recited using the phrase
"means for."
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