U.S. patent application number 11/601476 was filed with the patent office on 2007-05-24 for pressure balanced spool poppet valves with printed actuator coils.
This patent application is currently assigned to Sturman Digital Systems, LLC. Invention is credited to Steven E. Massey, Oded Eddie Sturman.
Application Number | 20070113906 11/601476 |
Document ID | / |
Family ID | 38052302 |
Filed Date | 2007-05-24 |
United States Patent
Application |
20070113906 |
Kind Code |
A1 |
Sturman; Oded Eddie ; et
al. |
May 24, 2007 |
Pressure balanced spool poppet valves with printed actuator
coils
Abstract
Pressure balanced spool poppet valves with printed actuator
coils minimize valve leakage and facilitate efficient manufacturing
and reliable operation. The spool poppet valves may be configured
like a conventional spool valve, but further include a poppet valve
at one end of the spool to proved much better sealing when the
poppet valve is closed. Various features are disclosed, including
pressure balancing for high pressure operation. The printed
actuator coils for the spool poppet valves are formed by the
interconnection of conductive coils on each of multiple layers of a
multiple layer printed circuit board, which circuit board may have
a hole there through for accommodation of mechanical and/or magnet
requirements, and may include similar printed actuator coils for
one or more additional spool poppet valves as well as electronic
devices associated with the operation thereof. The spool poppet
valves may be advantageously constructed without printed actuator
coils, and the printed actuator coils may be advantageously used in
actuators of other designs.
Inventors: |
Sturman; Oded Eddie;
(Woodland Park, CO) ; Massey; Steven E.; (Woodland
Park, CO) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN
12400 WILSHIRE BOULEVARD
SEVENTH FLOOR
LOS ANGELES
CA
90025-1030
US
|
Assignee: |
Sturman Digital Systems,
LLC
|
Family ID: |
38052302 |
Appl. No.: |
11/601476 |
Filed: |
November 16, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60738859 |
Nov 21, 2005 |
|
|
|
Current U.S.
Class: |
137/625.65 |
Current CPC
Class: |
F16K 31/0613 20130101;
Y10T 137/86622 20150401; F16K 11/02 20130101; H01F 5/003 20130101;
F15B 13/0402 20130101; F15B 13/044 20130101 |
Class at
Publication: |
137/625.65 |
International
Class: |
F15B 13/044 20060101
F15B013/044 |
Claims
1. A valve comprising: a spool valve body having a poppet valve
seat at one end thereof, the spool valve body having a source port
for coupling to a source of fluid under pressure at one side of the
poppet valve seat, and a control port and a vent port on the other
side of the poppet valve seat; a spool within the spool valve body
having a poppet valve at a first end thereof cooperatively disposed
to engage the poppet valve seat when the spool is in a first
position to seal; the spool and spool valve body coupling the
control port to the vent port and blocking the source port from the
control port when the spool is in the first position; and, the
spool and spool valve body coupling the source port to the control
port and blocking the control port from the vent port when the
spool is in a second position; whereby fluid flow from the source
port to the control port or vent port when the spool is in the
first position is blocked by both the poppet valve resting on the
poppet valve seat and by the spool and spool valve body.
2. The valve of claim 1 wherein the angle of the poppet valve seat
is slightly greater than the angle of the poppet valve so that the
poppet valve seals on the edge of a bore in the spool valve
body.
3. The valve of claim 2 further comprised of a hydraulic surface
adjacent a second end of the spool exposed to the source of fluid
under pressure.
4. The valve of claim 3 wherein the hydraulic surface has an area
equal to the area of the bore in the spool valve body, thereby
pressure balancing the spool when in the first position.
5. The valve of claim 1 further comprised of an actuator to
controllably move the spool to the second position, and a return to
return the spool to the first position when the actuator is not
active.
6. The valve of claim 5 wherein the return is a return spring.
7. The valve of claim 5 wherein the actuator is an electromagnetic
actuator.
8. The valve of claim 7 wherein the actuator is a magnetic latching
actuator.
9. The valve of claim 7 wherein the actuator moves the spool to the
second position and retains the spool in the second position using
a relatively high current pulse to move the spool to the second
position followed by a relative low holding current to retain the
spool in the second position.
10. The valve of claim 7 wherein the electromagnetic actuator
includes at least one actuator coil formed by the interconnection
of conductive coils on each of multiple layers of a multiple layer
printed circuit board.
11. The valve of claim 10 wherein the multiple layer printed
circuit board includes at least one additional actuator coil formed
by the interconnection of additional conductive coils on each of
multiple layers for another valve having an electromagnetic
actuator.
12. The valve of claim 10 wherein the multiple layer printed
circuit board has an opening through the center of the actuator
coil.
13. A valve comprising: a spool valve body having a poppet valve
seat at one end thereof, the spool valve body having a source port
for coupling to a source of fluid under pressure at one side of the
poppet valve seat, and a control port and a vent port on the other
side of the poppet valve seat; a spool within the spool valve body
having a poppet valve at a first end thereof cooperatively disposed
to engage the poppet valve seat when the spool is in a first
position to seal between the poppet valve and the poppet valve
seat, a hydraulic surface adjacent a second end of the spool for
coupling to the source of fluid under pressure; the spool and spool
valve body coupling the control port to the vent port and blocking
the source port from the control port when the spool is in the
first position; the spool and spool valve body coupling the source
port to the control port and blocking the control port from the
vent port when the spool is in a second position; and, an actuator
to controllably move the spool to the second position, and a return
to return the spool to the first position when the actuator is not
active; whereby fluid flow from the source of fluid under pressure
to the control port or vent port when the spool is in the first
position is blocked by both the poppet valve resting on the poppet
valve seat and by the spool and spool valve body.
14. The valve of claim 13 wherein the angle of the poppet valve
seat is slightly greater than the angle of the poppet valve so that
the poppet valve seals on the edge of a bore in the spool valve
body.
15. The valve of claim 14 wherein the hydraulic surface has an area
equal to the area of the bore in the spool valve body, thereby
pressure balancing the spool when in the first position.
16. The valve of claim 13 wherein the return is a return
spring.
17. The valve of claim 13 wherein the actuator is an
electromagnetic actuator.
18. The valve of claim 17 wherein the actuator is a magnetic
latching actuator.
19. The valve of claim 17 wherein the actuator moves the spool to
the second position and retains the spool in the second position
using a relatively high current pulse to move the spool to the
second position followed by a relative low holding current to
retain the spool in the second position.
20. The valve of claim 17 wherein the electromagnetic actuator
includes at least one actuator coil formed by the interconnection
of conductive coils on each of multiple layers of a multiple layer
printed circuit board.
21. The valve of claim 20 wherein the multiple layer printed
circuit board includes at least one additional actuator coil formed
by the interconnection of additional conductive coils on each of
multiple layers for another valve having an electromagnetic
actuator.
22. The valve of claim 21 wherein the multiplayer printed circuit
board includes electronic devices associated with the operation of
the valves.
23. An electromagnetic actuator comprising: a stationary magnetic
member; a moveable magnetic member moveable from a first position
to a second position in response to a magnetic field linking the
stationary magnetic member and the moveable magnetic member; an
actuator coil disposed to cause a magnetic field linking the
stationary magnetic member and the moveable magnetic member as a
result of a current in the actuator coil; the actuator coil being
formed by the interconnection of conductive coils on each of
multiple layers of a multiple layer printed circuit board.
24. The electromagnetic actuator of claim 23 wherein the multiple
layer printed circuit board has an opening through the center of
the actuator coil.
25. The electromagnetic actuator of claim 23 wherein the multiple
layer printed circuit board includes at least one additional
actuator coil formed by the interconnection of additional
conductive coils on each of multiple layers for another valve
having an electromagnetic actuator.
26. The electromagnetic actuator of claim 25 further comprised of
at least one electronic device associated with operation of a
electromagnetic actuator mounted on the printed circuit board.
27. The electromagnetic actuator of claim 23 further comprised of
at least one electronic device associated with operation of the
electromagnetic actuator mounted on the printed circuit board.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/738,859 filed Nov. 21, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of valves, and
systems using a plurality of solenoid actuators.
[0004] 2. Prior Art
[0005] Embodiments of the present invention provide improved
devices for fluid control in various applications. Typical examples
include the control of a high pressure fuel injector, and hydraulic
engine valve actuation systems. Two-way poppet valves (open and
closed) are often used due to their low leakage characteristics. In
many applications, it is highly desirable to use a three-way valve
for improved performance and control, but this is difficult due to
a three-way valve's inability to pressure balance completely unless
it is a spool valve, which leaks excessively. For purposes of this
disclosure, a three-way valve will be described as a valve coupling
a source (S) passage to a control (C) passage or coupling the
control passage to a vent (V), though other port identifications
may be more appropriate depending on the use of the three-way
valve.
[0006] The choices for a three-way valve are:
[0007] Spool valve. A spool valve can create the required hydraulic
paths, but while in either position (S-C or C-V) the valve has a
very short leak (seal) path from a high-pressure area to a vented
area, which can lead to high system parasitic losses. This valve
can be designed to have a hydraulic short circuit (momentarily
coupling of source and vent when transitioning from one position to
the other) or not, depending on the application. The advantages are
primarily in its pressure balance, thereby requiring very low
actuation forces, and in the ability to be designed to avoid the
short circuit.
[0008] Three-way hard-seat valve (Poppet). This type of valve can
have no leakage in either position, but when the valve is
transitioning from one position to the other, there necessarily
exists a direct flow path between the source and the vent that
could lead to large losses of energy and system noise. This type of
valve cannot be completely pressure balanced, and therefore
requires greater actuating forces than a typical pressure balanced
spool valve.
[0009] Two two-way hard-seat valves (Poppet). This option has no
leakage and can have a direct flow path between the source and the
vent or not, depending on control of the system. The disadvantage
of this system is that twice as many control valves are needed to
achieve three-way control, adding system and control complexity,
and further requiring more room to package.
[0010] Thus the current choices and their disadvantages are:
[0011] Spool Valve: High static leakage.
[0012] Three-way hard-seat valve: High actuating force requirements
(due to pressure imbalance) and short circuit loss.
[0013] Two, two-way hard seat valves: Cost and complexity.
[0014] Solenoid actuators for valves of various types are also well
known. Such actuators may be single coil spring return, with or
without magnetic latching or double coil, with or without magnetic
latching (see U.S. Pat. Nos. 3,743,898 and 5,640,987). However
configured, solenoid actuators generally have a relatively simple
mechanical configuration, with the solenoid coils being relatively
inexpensive to wind. However, in certain applications, the number
of solenoid actuated valves preferably used may be relatively
large, giving rise to quite a substantial wiring problem.
Superimposed on this in certain applications is a combination of
heat and vibration that can cause premature wiring failure, and
thus possibly giving rise to unsatisfactory reliability of the
system. One such application to which preferred embodiments of the
present invention are directed is in diesel engines, and more
specifically, to hydraulic engine valve actuation systems as are
currently in development, and diesel engine fuel injection systems,
as well as fuel air cells incorporating both hydraulic engine valve
actuation and fuel injection in a single assembly for each engine
cylinder. Because most diesel engines are multiple cylinder
engines, such as 6 and 8 cylinder engines, each having intake
valves, exhaust valves and a fuel injector, all three of which must
be independently controlled for each cylinder, and preferably for
greater flexibility each engine valve actuator and each fuel
injector will have more than one solenoid valve, the number of
solenoid valves preferably used in a multi-cylinder engine can be
quite substantial. Accordingly, wiring of the individual solenoid
coils to a harness for connection to a control box would be
complicated and expensive and may not have the reliability inherent
in the rest of the diesel engine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a cross section of one embodiment of pressure
balanced spool poppet valve in accordance with the present
invention.
[0016] FIG. 2 is an exploded perspective view of a multilayer
printed circuit board having printed coils on each layer of the
board.
[0017] FIG. 3 is a face view of the multilayer printed circuit
board of FIG. 2.
[0018] FIG. 4 is a schematic diagram of an exemplary application of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] First referring to FIG. 1, a cross-section of a spool poppet
valve in accordance with an embodiment of the present invention may
be seen. The valve shown is a three-way valve, in that it may
connect a control port C to a supply port S or to a vent port V.
The valve includes a housing 20 and cap 22, both of which are of
magnetic materials, and an end cap 24, which may or may not be
fabricated of a magnetic material. Located within the housing 20 is
a spool 26 having a poppet valve 28 at the left end thereof, with a
coil spring 30 encouraging the spool and poppet valve to the right
position, as shown. In this position, the control port C is coupled
to the vent port V, with the poppet valve being firmly seated on
seat 32 on the housing to seal the high pressure fluid in the
source port S from the control port C.
[0020] At the right end of spool 26 is a magnetic armature 28 urged
against end 34 of the spool by a pressure balance piston 36, the
right end of which is also subjected to the fluid pressure of the
supply S. The diameter of the pressure balance piston 36 is the
same as the outer diameter of the spool 26, thus substantially
equal to the inner diameter of the housing 20 and cap 22. This,
coupled with the fact that the angle of the valve seat 32 is
slightly greater than the angle of the poppet valve 28 so that the
poppet valve seals on the edge of the bore in the housing 20, means
that the spool poppet valve is pressure balanced, the pressure of
the supply S on the poppet valve 28 acting over the same area as
the fluid in supply S acting on the end of pressure balance piston
36.
[0021] When a current is passed through coil 38, the armature 28 is
attracted to the left, overcoming the force of spring 30 to move
the spool to a left-most position when the armature 28 is attracted
flat against the end of housing 20. In this position, a magnetic
circuit is established through housing 20 and armature 28 that has
a substantially zero air gap. Thus in this position, the armature
28 may be retained by residual magnetism in the housing 20 and
armature 28, or alternatively, by a small holding current in coil
38, depending on the relative forces between spring 30 and the
holding force of the residual magnetism. Obviously, when the spool
moves to the left position, in this embodiment the coupling from
the control C to the vent V is first discontinued as poppet valve
opens, and then coupling from the control port C to the supply port
S is opened by the spool. Alternatively, if one wanted, one could
simultaneously close one port and open the other, or as a further
alternative, open the coupling between the control port C and the
supply port S before closing the coupling between the control port
C and the vent, though usually this is undesirable because of the
loss of energy by the momentary coupling of the supply port S
directly to the vent port V.
[0022] An advantage of the spool poppet valve of FIG. 1 is the fact
that when the poppet valve is closed, the leakage characteristic of
a spool valve is grossly reduced. This is of particular advantage
in applications where the fluid pressure in the supply S is quite
high and/or when the valve is used in an application where the
valve is used to couple the high pressure fluid in supply port S to
the control port C only a relatively small percentage of the
overall time of use of the valve. By way of specific example, a
valve in accordance with FIG. 1 might be used to control the fluid
pressure over an intensifier in an intensifier-type fuel injector.
In such an application, in a four-cycle diesel engine, the control
port C would be coupled to the supply port S over a crankshaft
angle of perhaps 90.degree. or less during each 720.degree.
rotation of the crankshaft. Thus in such applications, the leakage
from supply to vent is grossly reduced by the poppet valve. In that
regard, when the valve is actuated, the supply pressure in supply
port S will be communicated to the control port C, with leakage
past the spool to the vent port V, though as stated before, that
will occur only for a relatively small percentage of the use of the
valve. There will, of course, also be leakage from the supply port
S past the pressure balance piston 36 to vent V, although because
of the length of the leakage area, this leakage is also grossly
reduced in comparison to that of a relatively short stroke ordinary
spool valve.
[0023] Another aspect of the present invention is a construction of
the actuator coils 38 in the valve of FIG. 1, and for that matter,
their construction as it relates to systems using a plurality of
solenoid actuated valves, including but not necessary limited to,
valves of the specific type shown in FIG. 1. In particular, in some
applications, it may be desirable to use printed coils (copper
traces as in a printed circuit) for the actuator printed on the
same printed circuit board as the coils for other actuators and/or
on the same circuit board as electronic components used for such
purposes as control of the actuator coils.
[0024] By way of specific example, an exploded view of a portion of
a multi-layer printed circuit board can be seen in FIG. 2. As shown
therein, in this embodiment, each printed coil 38 has first and
second contacts 40 and 42. As may be seen in FIG. 2, alternate
layers of the windings are printed in an opposite sense. Also,
terminal 42 of an upper layer is aligned with terminal 42 of the
next layer, though terminal 40 of that next layer is rotated
90.degree. from terminal 40 of the upper layer. However, terminal
40 of the second layer is aligned with terminal 40 of the third
layer, etc. Consequently, drilling through holes 90.degree. apart
and plating through the through holes will connect the coils of
adjacent layers to provide a continuous coil of one winding sense
through the multi-layer printed circuit board 44. Actually, the
start connection on the upper layer and the finish connection on
the lower layer must be offset from each other if they are to be
brought out from the same layer to avoid connecting the end
terminals of the resulting composite coil together. Thus terminal
40 on the upper layer and terminal 40 on the lower layer would be
offset, typically circumferentially, from each other. With the
specific configuration shown in FIG. 2, eight coil layers would be
provided, with the four plated through hole pattern within the
inner diameter of the individual coil being offset 45.degree. from
the hole pattern of contacts 40 outside the outer diameter of the
individual coils.
[0025] The coils shown in FIG. 2 are shown as spirals, though as
one alternative, each coil may be a circular arc of somewhat less
than 360.degree. stepping inward (or outward) radially to the next
circular arc coil. Also, while plated through holes are used in a
preferred embodiment to contact the coils in adjacent layers, other
means of providing such inner connection may be used if desired.
Further, while in the embodiment disclosed, the overall start and
finish contacts for the final coil of interconnected windings are
made available at the upper layer, such contacts may be brought out
on the layer on which they occur, with contact made thereto at some
other positions on the board away from the coils themselves. This
avoids the need for angularly offsetting the start and finish
connections.
[0026] FIG. 2 shows slightly over three turns per printed coil, for
a total of 25 turns for eight layers of printed coils. This of
course is schematic only, as the number of turns per layer and the
number of layers used may be chosen as desired or required for a
particular application. In applications for preferred embodiments
of the invention, the spool poppet valves are fast acting, so while
a high current pulse though the coil is used for actuation of the
solenoid actuator, that pulse is of very short duration, and with
quite a low duty cycle, so that coil heating may be kept relatively
low. Also, if a holding current is used instead of magnetic
latching, the holding current may be quite low because of the
substantially zero air gap in the magnetic circuit when the
solenoid actuator is actuated, so it causes very little coil
heating. If desired or necessary for a particular application, high
thermal conductivity printed circuit board materials are
commercially available that could be used.
[0027] FIG. 3 shows a multi-layer board with eight or more layers
having eight windings, each comprised of eight individual windings,
such as is illustrated in FIG. 2. Thus, visible in FIG. 3 are the
plated through holes 40 around the OD of each coil, as well as the
plated through holes 42 around the ID of each printed coil. Also
visible in FIG. 3, as well as FIG. 2, is a central hole 46 in each
of the eight coils for the end 34 of the spool 26 for the
embodiment of the spool poppet valve shown in FIG. 1. In that
regard, the housing 20 and cap 22 shown in FIG. 1 may have a
circular or rectangular outer surface, or other shapes as desired.
However, printed circuit board 40 extends beyond or out of the
housing 20 and cap 22 in a direction perpendicular to the plane of
the view of FIG. 1, so that the same multi-layer circuit board may
provide solenoid coils for multiple solenoid actuated valves,
whether of the configuration of FIG. 1 or of other configurations
and types. In that regard, if eight individual coils, as
illustrated in FIG. 2, are used on an eight layer board, one coil
layer, normally the top coil layer, would be exposed. Accordingly,
depending on the overall configuration used, it may be necessary to
insulate this layer from housing 20 or armature 28, which may be
done in various ways, including the use of an insulator which may
also serve as a seal to assure that any leakage past pressure
balance pin 36 is exhausted through the vent and cannot leak out
along the printed circuit board.
[0028] An exemplary application of this embodiment of the present
invention is schematically shown in FIG. 4. In this application, a
hydraulic engine valve actuation system for a four-cylinder engine
or for each bank of four cylinders of a V8 engine is schematically
shown. Here, eight valves (as well as other components of the valve
actuation system), such as valves 18 of FIG. 1, are shown, four for
controlling hydraulic actuators 48 for engine intake valves, and
four for controlling hydraulic valve actuators 50 for engine
exhaust valves. Such an assembly, by way of example, may be
provided on some interconnecting structure 52 for bolting to a
engine head over the intake and exhaust valves with spring return,
respectively. In that regard, hydraulic engine valve actuation
systems and methods of operating such systems are known in the
prior art. See, for instance, U.S. Pat. No. 6,739,293, which
discloses a two-stage system, though single-stage systems wherein a
solenoid actuated valve directly controls hydraulic fluid as
applied to the hydraulic valve actuators are also known. In any
event, in the system shown in FIG. 4, printed circuit board 40
spans all eight valves 18, and not only provides connections to the
eight coils and the interconnection of layers making up each coil,
but further provides printed circuit board space for various
electronic components 54 to provide solenoid coil drivers, signal
processing if engine valve position sensors are used, and various
other tasks. Preferably in such an embodiment, a single cable 56 is
used to provide power to the printed circuit board as well as such
purposes as providing control signals to the board, and if sensors
are used, sensor signals from the board. In that regard,
preferably, communication to and from the board is through a serial
bus, with the electronic components 54 on the printed circuit board
40 also including appropriate bus interfaces.
[0029] The advantage of an embodiment of the general type shown in
FIG. 4 may be appreciated by recognizing that a multi-layer board
in such applications is already required, so that the use of such a
multi-layer board to achieve not only the multiple solenoid coils
required in such a system, but to also make connections between the
coils and the electronic circuits on the multi-layer board is
achieved with little increase in cost.
[0030] The printed solenoid coil aspect of the present invention
has been illustrated herein schematically. By way of example, FIG.
3 shows a multi-layer printed circuit board that has a rectangular
planform and provision for eight actuator coils laid out in a
linear array. Obviously in typical applications, the printed
circuit board may not be rectangular, but may have regions of
increased and decreased width, have holes for access to bolts there
below, may have a larger or smaller number of printed solenoid coil
layers and/or have printed solenoid coils that are not laid out in
a linear array, depending on the specific application. By way of
further example, each cylinder of a multiple cylinder engine, such
as a diesel engine, may have one solenoid actuator for a valve
controlling the engine intake valves, a second solenoid actuator
for the engine exhaust valves and one or more additional solenoid
actuators for controlling the fuel injector, all of which may be
laid out on a printed circuit board, like printed circuit board 40,
to provide the desired interconnection as well as electronics on
the multi-layer printed circuit board. In that regard, the printed
circuit board may or may not include a central control processor
and associated memory, though if it does, cable 56 (FIG. 4) would
still provide power and signal information at least to and perhaps
from the printed circuit board, such as crankshaft angle, engine
operating conditions and environmental conditions. Including the
central control processor on the board can reduce costs by both
taking full advantage of the multilayer board and by minimizing the
communication needed to and from the board.
[0031] Thus the present invention has a number of aspects, which
aspects may be practiced alone or in various combinations or
sub-combinations, as desired. Also while certain preferred
embodiments of the present invention have been disclosed and
described herein for purposes of illustration and not for purposes
of limitation, it will be understood by those skilled in the art
that various changes in form and detail may be made therein without
departing from the spirit and scope of the invention.
* * * * *