ENGINE VALVE WITH A COMBINED ENGINE OIL FILTER
AND VALVE ACTUATOR SOLENOID
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a screen filter assembly for use with an
engine oil flow control valve.
2. Background Art
An internal combustion engine design commonly used in
contemporary vehicles includes an engine lubricating oil flow circuit with an
engine lubrication oil pump. Engine lubrication oil cools engine components and
provides a lubrication oil film at the cylinder walls. Engine oil may be used also as
a fluid medium for engine hydraulic valve lifters. A solenoid operated engine oil
control valve can be used to activate and deactivate the engine valve lifters as well
as switch latching mechanisms in valve lifters, roller rocker arms and lash
adjusters.
A presence of particles with magnetic properties, such as certain
ferrous particles, as well as other non-ferrous particles, in the engine lubrication oil
supply will interfere with the function of the valve lifters and will adversely affect
the performance of other lubricated moving components of the engine. It is a
known design practice, therefore, to provide a screen filter as part of an engine oil
control valve to prevent migration of such particles in the engine lubrication oil
passages.
One example of an engine oil control valve with an engine oil filter
in a hydraulic valve lifter system is disclosed in U.S. Patent No. 6,581,634. The
engine oil control valve disclosed in the '634 patent includes a permanent magnet
situated at the flow inlet side of a solenoid actuated control valve to capture ferrous
particles in the engine oil flow stream before they enter the engine oil flow circuit
leading to movable engine components, including pressure operated valve lifters.
Another example of a solenoid operated engine oil flow valve is
disclosed in U.S. Patent No. 6,209,563. which includes a filter screen on the
upstream side of the valve. That valve assembly, however, does not include a
magnet in the engine oil flow stream as in the case of the design shown in the '634
patent.
SUMMARY OF THE INVENTION
The present invention comprises a solenoid operated engine oil flow
control valve in which a filter screen, a magnet and a solenoid operated valve can
be combined into a single assembly. This involves combining three components
into a single part during manufacture. It will permit the single part to be
customized for a special customer requirement. It is an objective of the invention,
furthermore, to provide an engine oil flow control valve and filter that can be
manufactured at reduced costs and with reduced manufacturing time.
According to a further feature of the invention, the magnet is
molded into a separate filter body, which can be pressed into a valve body or
otherwise secured in the valve body during manufacture. The magnet has a
magnetic field in proximity to the filter screen itself, thereby magnetizing the filter
screen and enhancing the ability of the assembly to capture particles in the engine
oil flow circuit before they can be distributed to moving parts of the engine.
During manufacture of an engine, numerous machining operations
are required. Machining debris, such as small chips and microscopic particles, may
be retained in an engine block and cylinder head prior to assembly of the engine in
an automotive vehicle powertrain. The filter screen assembly of the invention will
effectively capture such debris during repetitive circulation of the engine
lubrication oil through the engine from an engine oil pump.
According to another feature of the invention, the filter screen may
be in contact with the magnet or in close proximity to the magnet so that the entire
screen is magnetized, thereby increasing the ability of the screen filter assembly to
capture particles with magnetic properties, such as ferrous particles.
According to another feature of the invention, the filter screen is
provided with a significantly increased flow area in comparison to prior art filter
designs, thereby further enhancing the ability of the assembly to capture ferrous
particles and other non-ferrous particles.
According to a further feature of the invention, the filter screen is
used to provide a screening function at the flow outlet side of main engine oil flow
port in the filter assembly, whereby the filter assembly has a second opportunity to
capture particles that may not have been captured at the main oil flow port.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE la is a partial sectional isometric view of a filter assembly
for an engine oil flow circuit that includes the invention;
FIGURE lb is a partial cross-sectional view of the filter assembly
and engine oil flow control valve illustrated partially in Figure la;
FIGURE 2 is a cross-sectional isometric view of the filter assembly
used in the construction of Figures la and lb;
FIGURE 3 is a isometric overall view of the filter assembly of
Figure 2;
FIGURE 4 is an end view of the filter assembly seen in Figure 3;
FIGURE 4a is a cross-sectional view as seen from the plane of
section line 4a-4a of Figure 4; and
FIGURE 4b is a cross-sectional view as seen from the plane of
section line 4b-4b of Figure 4.
PARTICULAR DESCRIPTION OF AN EMBODIMENT
OF THE INVENTION
Shown in Figures la and lb is a regulator valve and screen filter
assembly 10 that includes an embodiment of the invention. A valve body 12,
which may be cylindrical in shape, includes a central cylindrical opening 14. An
upper cylindrical portion 16 has a diameter that exceeds the diameter of the lower
portion 18. This feature defines a shoulder 20 that engages a shoulder formed on
an engine block or an engine cylinder head.
The engine block or cylinder head, not shown, can be provided with
a cylindrical opening that receives lower portion 18 of the assembly 10. A larger
diameter portion of the opening receives large diameter portion 16 of the assembly
10. Shoulder 22, seen in Figure lb, engages a third shoulder formed in the opening
in the cylinder block or cylinder head.
O-ring seal openings 24 and 26, seen in Figure lb. and o-ring seal
opening 27, seen in Figure la, receive o-ring seals that register with the multi-
diameter opening in the engine block or cylinder head.
A cylindrical filter body 28 is received in the cylindrical opening 14
in the lower portion 18 of the valve body. It can be secured in the lower portion 18
by a press-fit. In the alternative, it may be secured in the lower portion 18 by a
close-fit thread if adjustment of the axial position of the filter body with respect to
the valve body is desired.
As will be explained subsequently in the descriptions of Figures 3.
4, 4a and 4b, a regulated flow port, seen in Figure la at 30, is formed in the valve
body 12 for supplying fluid under pressure to the engine components. Multiple
elongated inlet oil flow passages formed in the filter body 28 communicate with
the port 30 through central opening 34. One of these flow passages is seen in
Figure la at 32.
Central opening 34 in filter body 28 is provided with a blind end.
An open end communicates with regulated flow port 30. The opening 34 has a
conical seat 36 that registers with a ball valve element 38.
Valve body 12 is provided with a central opening 40 that receives an
armature stem 42 that is engageable with ball valve element 38. The valve body 16
defines a valve seat at the lower end of the opening 40. The ball valve element 38
is adapted to register with the valve seat 36 and with the valve seat at the lower end
of central opening 40.
The valve seat in valve body 12 is identified in Figure la by
reference numeral 44. An exhaust port in the valve body 12, shown at 46, may
extend in a radial direction, as shown in Figure la.
The upper end of the central opening 40 in the valve body 12
defines a conical valve seat 48 which is adapted to register with a circular valve
element 50, which is loosely mounted on the armature stem 42. Valve spring 52,
seen in Figure lb, surrounds the armature stem 42 and urges the valve element 50
into sealing engagement with the valve seat 48.
Armature stem 42 comprises a part of armature 54, seen in Figure
lb. Armature 54 is slidably mounted in central opening 56 formed in an upper
portion 58 of the valve body 12. The upper end of the opening 56 is closed by a
cylindrical closure member 60. which may be secured in place by a press-fit or by
threads. A threaded connection between member 60 and the upper portion 58 of
the valve body 16 would be preferred if an adjustment feature is desired for varying
the spring force acting on the ball valve element 38.
A valve spring 62 seated in a central pocket in the armature 54 is
situated between the member 60 and the armature 54 for exerting a downwardly
directed spring force on the valve element 38.
The upper portion 58 of the valve body 16 defines an annular cavity
64 that receives a spindle comprising electrical solenoid windings 66. which
surround the armature 54.
Figure 3 is an isometric view of the filter body 28. The filter body
includes multiple flutes or extensions, two of which are shown at 68 and 70. The
openings between adjacent extensions define supply oil flow inlet passages, one of
which is shown in Figure la at 32, which communicate with central opening 34.
seen also in Figure la. Projections 72 are integrally formed at the upper end of
filter body 28 to provide an opening 73 between the upper end of the filter body
and the valve body 10. This opening provides communication between port 30.
seen in Figure la, and the central opening 34. Openings between the projections
72 are seen in Figure 3 at 74, 74 D, 74 D 0 and 74 ? ? D.
Figure 4a is a cross-sectional view taken along a plane that includes
the plane of extension 68 and the corresponding extension located at 180 degrees
from extension 68. A metallic screen 76 with magnetic properties, such as a
ferrous alloy, is molded within the filter body 28. Screen 76 surrounds the
openings 32 in the filter body. The upper end of the screen 76 is disposed in a
radial direction, as shown at 78, so that the portion of the screen shown at 78
covers the openings 74, 74D, 74DD and 74DDLL This provides screened
communication between the passages 32 in the filter body and the regulated oil
flow port, shown at 30 in Figure la.
Figure 4 is a top view of the filter body shown in Figure 4a. It also
indicates the location of the section lines for Figure 4a and Figure 4b.
Figure 4a and Figure 4b illustrate a permanent magnet 80, which
may be cylindrical, which is secured in an opening 82 formed in the lower end of
the filter body illustrated in Figures la, 2 and 4a.
The screen 76 extends downwardly, as indicated in the view of the
filter body seen in Figure 4a. and is situated in contact with the magnet 80. as
indicated at 84 in Figure 4a.
Figure 2 is an enlarged isometric view of the filter body and the
filter screen assembly, together with a magnet, which define the subassembly
indicated in the cross-sectional view of Figure 4a. The magnet 80 can be secured
in place, as shown in Figure 2, using any of a variety of assembly techniques,
including a press-fit or a threaded connection. In the disclosed embodiment, the
magnet 80 is over-molded in the molded filter body 28.
The filter body and the valve body in the embodiment disclosed can
be a molded one-piece assembly made of a moldable thermoplastic material, such
as a glass fiber reinforced thermoplastic material. The valve body can be inserted
in a machined opening in an engine cylinder block, or an engine cylinder head, or
otherwise located in the engine environment. The specific location is a design
choice. The filter screen 76 is secured within the molded filter body using an over-
molded technique. Ferrous particles can be separated from the flow of engine oil at
the location of the elongated passages 32, as well as at the location of the openings
74, 74D, 74DD and74DDD.
In the embodiment as shown in Figures la and lb, the valve element
38 is moved to a closed position as it engages the valve seat 36 under the force of
armature spring 62. When the solenoid windings 66 are energized, the inlet oil
flow passages 32 are brought into communication with valve body port 30. At this
time, the armature will accommodate lifting of the ball valve 38 from engagement
with the seat 36 toward the seat 44. As the ball valve moves in an upward
direction as viewed in Figure la, communication between opening 34 and port 30
is increased and communication between port 30 and opening 40 is decreased.
Valve element 50 normally is urged toward a closed position against
valve seat 48 by valve spring 52. Valve spring 52, which is seated on armature 54
as indicated in Figure lb, and the valve element 38 are calibrated so that a
calibrated minimum pressure will be regulated in port 30. thereby maintaining a
calibrated minimum pressure at the hydraulic engine valve lifters.
Although the disclosed embodiment of the invention is adapted for
filtering oil distribution from an engine oil pump to hydraulically actuated valve
lifters, it may be used as well in other engine applications. It may be used
furthermore in applications other than applications involving the use of an engine
oil pump and in other environments that require filtering of an oil distribution flow
path.
If it desired to change the flow rate, adjusting screw threads for the
member 60 can be used. Further, if a particular application for the filter body
assembly requires reduced flow through the screened orifices 74, 74 . 74 and
74D ? ?, one or more of the orifices can be plugged to reduce the rate of flow. The
ball valve element size also can be changed if a change in flow rate for a particular
application is needed.
In some applications for the filter body, adequate filtration may be
achieved when the magnet is not in place. If that is the case, the magnet can be
removed readily if it is secured, for example, by a threaded fitting.
Although an embodiment of the invention has been disclosed, it will
be apparent to persons skilled in the art that modifications may be made without
departing from the scope of the invention as defined by the following claims.
WHAT IS CLAIMED IS:
1. A fluid filter assembly for separating debris particles from a
fluid flow stream, the fluid filter assembly comprising a filter body, a fluid flow
entry passage and a fluid flow exit opening in the filter body,
a valve opening in the filter body defining a valve seat for a flow
control valve element, the fluid flow entry passage communicating with the fluid
flow exit opening through the valve opening; and
a filter screen embedded in the filter body, the filter screen covering
the fluid flow entry passage, the filter screen being an integral part of the filter
body whereby debris particles are separated from the fluid flow.
2. A fluid filter assembly for separating debris particles from a
fluid flow stream, the fluid filter assembly comprising a filter body, a fluid flow
entry passage and a first fluid flow exit opening in the filter body.
a valve opening in the filter body defining a valve seat for a flow
control valve element, the fluid flow entry passage communicating with the fluid
flow exit opening through the valve opening;
a filter screen over-molded in the filter body, the filter screen
covering the fluid flow entry passage, the filter screen being an integral part of the
filter body; and
a second fluid flow exit opening in the filter body, the filter screen
covering the second fluid filter exit opening as well as the first fluid flow entry
passage.
3. A fluid filter assembly set forth in claim 1 wherein the
screen is a metal having magnetic properties and wherein the filter assembly
comprises a magnet disposed adjacent the screen in the filter body:
the screen being magnetized by the magnet whereby the
effectiveness of the screen in capturing debris in the fluid flow is increased.
4. A fluid filter assembly set forth in claim 2 wherein the
screen is a metal having magnetic properties and wherein the filter assembly
comprises a magnet disposed adjacent the screen in the filter body;
the screen being magnetized by the magnet whereby the
effectiveness of the screen in capturing debris in the fluid flow is increased.
5. A fluid filter assembly forming a part of a fluid flow control
valve assembly in a fluid circuit that includes a pressure source and pressure
control port adapted to be connected to a pressure actuated mechanism;
the fluid filter assembly comprising a molded filter body, a fluid
flow entry passage and a fluid flow exit opening in the filter body, the fluid flow
exit opening communicating with the pressure control port, a valve opening in the
filter body defining a valve seat, a flow control valve element adapted to be seated
on the valve seat, the fluid flow entry passage communicating with the fluid flow
outlet port through the valve opening;
a filter screen over-molded and embedded in the filter body, the
filter screen covering the fluid flow entry passage, the filter screen being an integral
part of the filter body whereby debris particles are separated from the fluid flow;
and
a solenoid actuator for unseating the flow control valve element to
provide control pressure at the pressure control port.
6. A fluid filter assembly set forth in claim 5 wherein the filter
screen is formed of a metal with magnetic properties;
the filter assembly including a magnet disposed in the filter body;
the screen being magnetized by the magnet whereby the
effectiveness of the screen in capturing debris in the fluid flow is increased.
7. The fluid filter assembly set forth in claim 2 wherein the
fluid filter body includes a magnet effectively in contact with the screen whereby
the magnet magnetizes the screen.
8. The fluid filter assembly set forth in claim 6 wherein the
magnet is effectively in contact with the screen whereby the magnet magnetizes the
screen.
9. The fluid filter assembly set forth in claim 5 wherein the
solenoid actuator comprises an armature engageable with the valve element, a
valve spring acting on the armature with a spring force to seat the valve element on
the valve seat; and
means for adjusting the spring force to effect changes in a rate of
fluid flow through the pressure control port.
10. The fluid filter assembly set forth in claim 5 wherein the
fluid flow control valve assembly includes a pressure relief port, a pressure relief
valve providing controlled communication between the fluid flow outlet port and
the pressure relief port whereby a minimum pressure is maintained in the fluid flow
exit opening.
11. The fluid filter assembly set forth in claim 9 wherein the
solenoid actuator is mounted on the valve body;
the actuator having an armature engageable with the valve element;
the actuator being adapted to oppose the spring force to release the
valve element from the valve seat.
12. The fluid filter assembly set forth in claim 1 wherein the
filter body is formed with at least one fluid flow orifice providing communication
between the fluid flow entry passage and the fluid flow exit opening whereby
continuous flow through the fluid filter assembly is established.
13. The fluid filter assembly set forth in claim 12 wherein the
fluid flow orifice is covered by the filter screen.
14. The fluid filter assembly set forth in claim 1 wherein the
filter body is formed with at least one fluid flow orifice providing communication
between the fluid flow entry passage and the fluid flow exit opening whereby
continuous flow through the fluid filter assembly is established.
15. The fluid filter assembly set forth in claim 1 wherein the
fluid flow orifice is covered by the filter screen.
16. The fluid filter assembly set forth in claim 10 wherein the
solenoid actuator includes an armature and a relief valve spring supported by the
armature, the relief valve spring engaging the pressure relief valve to establish the
minimum pressure, the armature, the relief valve and the filter body being axially
aligned to establish compactness of the flow control valve assembly.

The disclosed fluid filter screen assembly includes a filter body with
an embedded filter screen, the filter screen being disposed in a fluid flow path
between flow inlet and flow outlet openings in the filter body. A magnet
effectively in contact with the filter screen increases the capacity of the filter
assembly to separate particles from the fluid flow path.