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Patent Abstract
A solenoid valve has a rod that pushes a ball off a valve seat when
the coil is energized. The rod is distanced from the ball when the
coil is deenergized, such that upon energization of the coil, the
rod can gain momentum before contacting the ball, thereby more quickly
pushing the ball off the valve seat against the force of fluid pressure
and, thus, enabling the valve to have a quick turn-on response time.
The valve housing is made integrally with a winding bay and other
features are provided to avoid unduly restrictive manufacturing
tolerances.
Patent Claims
We claim:
1. A solenoid valve, comprising: a valve housing supporting a coil;
a ball in the valve housing; a valve seat in the valve housing;
and a rod reciprocatingly disposed in the valve housing between
a deenergized configuration, wherein the coil is de-energized, the
ball is against the valve seat, and the rod is distanced from the
ball by between one tenth and eight-tenths of a millimeter (0.1
mm-0.8 mm) inclusive, and an energized configuration, wherein the
coil is energized and the rod is urged against the ball to move
the ball away from the valve seat.
2. The valve of claim 1, wherein the valve housing defines the
valve seat and is made integrally with a winding bay, the coil being
wound in the winding bay.
3. The valve of claim 1, wherein the rod includes a shaft and a
pin engaged with the shaft and contacting the ball when the rod
is in the energized configuration, the pin being made of a material
that is harder than the shaft.
4. The valve of claim 3, wherein the pin is made of a ferromagnetic
material and the shaft is made of a non-ferromagnetic material.
5. The valve of claim 1, further comprising a plunger staked to
a portion of the rod, at least a part of the portion of the rod
being formed with grooves.
6. The valve of claim 1, further comprising a plunger engaged with
a portion of the rod, the rod defining a ball contact end, the rod
being formed with first and second guiding surfaces between the
ball contact end and portion ad defining a first diameter, the rod
being formed with a stepped region intermediate the first and second
guiding surfaces and defining a second diameter smaller than the
first diameter.
7. The valve of claim 1, wherein the valve housing is formed with
at least one ball retainer rib defining a supply port having a first
diameter, the ball being disposed between the rib and valve seat
and defining a second diameter larger than the first diameter such
that the rib retains the ball from passing outward through the supply
port.
8. The valve of claim 1, wherein the valve housing is formed with
at least one supply port, the ball being disposed between the supply
port and valve seat, the valve housing also defining a control port
and an exhaust port, fluid communication being blocked through the
supply port and established through the exhaust and control ports
in the de-energized configuration, fluid communication being blocked
through the exhaust port and established through the supply and
control ports in the energized configuration.
9. The valve of claim 1, further comprising a vehicle fluid system
communicating with the valve.
10. A solenoid valve for a vehicle, comprising: a housing holding
a rod, a ball, and a valve seat therebetween, the rod being disposed
in the valve housing when in a de-energized configuration to permit
the rod, when moving toward an energized configuration, to pre-travel
a distance before contacting the ball that is sufficient to reduce
a response time of the valve compared to a response time when the
rod contacts or is very near to the ball in the de-energized configuration.
11. The valve of claim 10, wherein the rod is distanced from the
ball by between one tenth and eight-tenths of a millimeter (0.1
mm-0.8 mm) inclusive in the de-energized configuration.
12. The valve of claim 10, wherein the valve housing defines the
valve seat and is made integrally with a winding bay, a coil being
wound in the winding bay.
13. The valve of claim 10, wherein the rod includes a shaft and
a pin engaged with the shaft and contacting the ball when the rod
is in the energized configuration, the pin being made of a material
that is harder than the shaft.
14. The valve of claim 13, wherein the pin is made of a ferromagnetic
material and the shaft is made of a non-ferromagnetic material.
15. The valve of claim 10, further comprising a plunger staked
to a portion of the rod, at least a part of the portion of the rod
being formed with grooves.
16. The valve of claim 10, further comprising a plunger engaged
with a portion of the rod, the rod defining a ball contact end,
the rod being formed with first and second guiding surfaces between
the ball contact end and portion and defining a first diameter,
the rod being formed with a stepped region intermediate the first
and second guiding surfaces and defining a second diameter smaller
than the first diameter.
17. The valve of claim 10, wherein the valve housing is formed
with at least one ball retainer rib defining a supply port having
a first diameter, the ball being disposed between the rib and valve
seat and defining a second diameter larger than the first diameter
such that the rib retains the ball from passing outward through
the supply port.
18. The valve of claim 10, wherein the valve housing is formed
with at least one supply port, the ball being disposed between the
supply port and valve seat, the valve housing also defining a control
port and an exhaust port, fluid communication being blocked through
the supply port and established through the exhaust and control
ports in the de-energized configuration, fluid communication being
blocked through the exhaust port and established through the supply
and control ports in the energized configuration.
19. The valve of claim 10, further comprising a vehicle fluid system
communicating with the valve.
20. A valve for a vehicle, comprising: a housing forming a valve
seat; seat blocking means in the valve housing and movable toward
and away from the valve seat for selectively blocking the valve
seat; actuation means in the valve housing for moving the valve
seat blocking means; and energization means in the valve housing
and controllable to move the actuation means against the valve seat
blocking means, wherein the actuation means is configured and disposed
such that it builds up substantial momentum under the influence
of the energization means when moving toward the valve seat blocking
means, prior to contacting the valve seat blocking means.
21. The valve of claim 20, wherein the valve seat blocking means
is a ball, the actuation means includes at least a rod, and the
energization means is a coil.
22. The valve of claim 21, wherein the rod is reciprocatingly disposed
in the valve housing between a de-energized configuration, wherein
the coil is de-energized, the ball is against the valve seat, and
the rod is distanced from the ball by between one tenth and eight-tenths
of a millimeter (0.1 mm-0.8 mm) inclusive, and an energized configuration,
wherein the coil is energized and the rod is urged against the ball
to move the ball away from the valve seat.
23. The valve of claim 21, wherein the valve housing defines the
valve seat and is made integrally with a winding bay, the coil being
wound in the winding bay.
24. The valve of claim 21, wherein the rod includes a shaft and
a pin engaged with the shaft and contacting the ball when the rod
is in the energized configuration, the pin being made of a material
that is harder than the shaft.
25. The valve of claim 21, further comprising a plunger staked
to a portion of the rod, at least a part of the portion of the rod
being formed with grooves.
26. The valve of claim 21, further comprising a plunger engaged
with a portion of the rod, the rod defining a ball contact end,
the rod being formed with first and second guiding surfaces between
the ball contact end and portion and defining a first diameter,
the rod being formed with a stepped region intermediate the first
and second guiding surfaces and defining a second diameter smaller
than the first diameter.
27. The valve of claim 21, wherein the valve housing is formed
with at least one ball retainer rib defining a supply port having
a first diameter, the ball being disposed between the rib and valve
seat and defining a second diameter larger than the first diameter
such that the rib retains the ball from passing outward through
the supply port.
28. The valve of claim 21, wherein the valve housing is formed
with at least one supply port, the ball being disposed between the
supply port and valve seat, the valve housing also defining a control
port and an exhaust port, fluid communication being blocked through
the supply port and established through the exhaust and control
ports in the de-energized configuration, fluid communication being
blocked through the exhaust port and established through the supply
and control ports in the energized configuration.
29. The valve of claim 21, further comprising a vehicle fluid system
communicating with the valve.
Patent Description
FIELD OF THE INVENTION
[0001] The present invention relates to solenoid valves.
BACKGROUND OF THE INVENTION
[0002] Solenoid valves have many industrial applications. As one
non-limiting example, vehicles can have numerous vehicle subsystems
that are designed to increase the comfort and safety of drivers
and passengers, such as anti-lock braking systems, traction control
systems, speed control systems, vehicle stability enhancement control
systems, and so on, and each subsystem can include numerous electromagnetic
sensors and solenoid valves.
[0003] Typically, such valves include a rod attached to a plunger,
with both rod and plunger reciprocating under the influence of electromagnetic
force when a coil surrounding the plunger is energized and deenergized.
More specifically, when the coil is energized the rod moves against
a ball to push the ball away from a valve seat and thereby permit
fluid flow through the seat. On the other hand, when the coil is
deenergized the rod moves back to allow the ball (under the influence
of fluid pressure) to move back against the seat, closing off fluid
flow through the seat. To minimize rod wear against the ball, in
the deenergized configuration the rod is positioned against or very
close to (e.g., distanced very much less than 0.1 mm from) the ball.
[0004] As recognized herein, however, when the solenoid is energized
and the rod starts its motion against the ball from a position in
which it is in contact with the ball or very much less than 0.1
mm away from the ball, it builds up little or no momentum before
it must push the ball away from the seat against the force of fluid
pressure. This in turn translates to a relatively slow turn-on response
time, a drawback in many systems that require relatively quick valve
actuation times. The present invention, in addressing this problem,
notes further that it is desirable to provide a solenoid valve with
relatively fast turn-on response times without imposing unduly tight
manufacturing tolerances.
SUMMARY OF THE INVENTION
[0005] A solenoid valve includes a valve housing supporting a coil.
A ball is in the valve housing for selectively blocking a valve
seat in the valve housing. A rod is reciprocatingly disposed in
the valve housing between a deenergized configuration, wherein the
coil is deenergized, the ball is against the valve seat, and the
rod is distanced from the ball by between one tenth and eight-tenths
of a millimeter (0.1 mm-0.8 mm) inclusive, and an energized configuration,
wherein the coil is energized and the rod is urged against the ball
to move the ball away from the valve seat.
[0006] In a preferred embodiment the valve housing defines the
valve seat and is made integrally with a winding bay, with the coil
being wound in the winding bay.
[0007] The preferred rod may include a shaft and a pin engaged
with the shaft and contacting the ball when the rod is in the energized
configuration. The pin may be made of a material that is harder
than the shaft. The pin may be made of a ferromagnetic material
and the shaft is made of a non-ferromagnetic material.
[0008] A plunger can be staked to a portion of the rod that is
formed with grooves, to limit unwanted motion between the rod and
plunger during staking. Also, the preferred rod can be formed with
first and second guiding surfaces between the pin and plunger that
define a first diameter, with the rod being further formed with
a stepped region intermediate the first and second guiding surfaces
and defining a second diameter smaller than the first diameter.
[0009] If desired, the valve housing may be formed with at least
one ball retainer rib defining a supply port having a first diameter.
The ball is disposed between the rib and valve seat and has a diameter
larger than the first diameter such that the rib retains the ball
from passing outward through the supply port.
[0010] In one non-limiting embodiment, the valve housing is formed
with a supply port, a control port, and an exhaust port. Fluid communication
is blocked through the supply port and established through the exhaust
and control ports in the deenergized configuration. On the other
hand, fluid communication is blocked through the exhaust port and
is established through the supply and control ports in the energized
configuration. The valve may be part of a vehicle fluid system.
[0011] In another aspect, a solenoid valve for a vehicle includes
a housing holding a rod, a ball, and a valve seat therebetween.
The rod is disposed in the valve housing when in a deenergized configuration
to permit the rod, when moving toward an energized configuration,
to pre-travel a distance before contacting the ball that is sufficient
to reduce a turn-on response time of the valve compared to a turn-on
response time when the rod contacts or is very near to the ball
in the deenergized configuration.
[0012] In yet another aspect, a valve for a vehicle includes a
housing forming a valve seat, and seat blocking means in the valve
housing and movable toward and away from the valve seat for selectively
blocking the valve seat. Actuation means are in the valve housing
for moving the valve seat blocking means. Energization means are
also in the valve housing and are controllable to move the actuation
means against the valve seat blocking means. The actuation means
is configured and disposed such that it builds up substantial momentum
under the influence of the energization means when moving toward
the valve seat blocking means, prior to contacting the valve seat
blocking means.
[0013] The details of the present invention, both as to its structure
and operation, can best be understood in reference to the accompanying
drawings, in which like reference numerals refer to like parts,
and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a cross-sectional view of the present solenoid
valve in the deenergized configuration, schematically showing the
processor, hydraulic system, and staking blades for engaging the
plunger with the rod;
[0015] FIG. 2 is cross-section showing the details of the ball
end of the valve; and
[0016] FIG. 3 is a side view of the preferred rod.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Referring initially to FIG. 1, a solenoid valve is shown,
generally designated 10, which, in one illustrative embodiment,
can be engaged with a vehicle hydraulic system 12 using one or more
of the below-described fluid ports. The hydraulic system 12 can
be any one of the systems mentioned above. The valve 10 can be controlled
by a processor 14 such as a vehicle engine control module that is
connected to terminals 16 of the valve 10 (only a single terminal
16 shown).
[0018] FIG. 1 shows that the valve 10 includes a preferably plastic
housing 18. As shown, the preferred housing 18 defines a coil winding
bay 20 in which a copper wire coil 22 is wound. If desired, the
coil 22 can be overmolded with a plastic sleeve 24, with a can 26
enclosing the coil 22 and being crimped, rolled, pressed, or staked
onto a preferably steel primary plate 28 that essentially is a disk
formed with openings through which the valve housing 18 extends.
The can 26 may be made of steel, ferrite, or other appropriate metal.
[0019] With the above disclosure in mind, it may now be appreciated
that in the preferred embodiment, the valve housing 18 is not a
separate component from the winding bay 20, but instead both are
made integrally together, eliminating the need to assemble two separate
components. To make the combination of structure shown in FIG. 1,
the primary plate 28 and terminals 16 can be held in a mold, and
then the valve housing is injection molded around the primary plate
28 and terminals 16, with the terminals 16 being positioned around
the winding bay 20 such that the coil 22 can be connected to the
terminals 16 once the coil 22 is disposed in the winding bay 20.
This further reduces the requirement to separately engage the primary
plate and terminals with the valve housing. During molding, the
plastic housing/winding bay material flows through and around the
primary plate 28 to form the winding bay 20 and below-described
remainder of the valve housing 18. Less desirably, slots can be
molded into the valve housing 18 through which components can be
inserted. In any case, the primary plate 28 provides a strong foundation
onto which the can 26 is mounted.
[0020] FIG. 1 also shows that an elongated hollow bushing 30 is
disposed centrally in the valve housing 18 and is pressed onto the
primary plate 28. The bushing 30, which may be made of steel, ferrite,
or other appropriate metal, supports a rod 32 that is made of non-magnetic
material and that reciprocates within the bushing 30 as indicated
by the arrows 34. To move the rod 32, a portion of the rod 32 is
engaged with (by, e.g., staking) a ferromagnetic plunger 36 which,
when the valve 10 is in the deenergized configuration discussed
more fully below, is distanced from the bushing 30 by an air gap
38.
[0021] FIGS. 1 and 2 show that the valve housing 18 defines a valve
seat 40 that is blocked by a ball 42 when the valve is in the deenergized
configuration to block fluid communication from a supply port 44
of the valve housing 18 to a control port 46 of the valve housing
18. In the deenergized configuration shown, an enlarged secondary
valve element 48 of the rod 32 is distanced from an exhaust port
50 of the valve housing 18 by gravity or by fluid pressure or by
a spring (not shown).
[0022] To move the ball 42 away from the valve seat 40, the preferred
non-limiting rod 32, most of which defines a shaft made of non-ferromagnetic
material, includes a preferably ferromagnetic or otherwise hardened
pin 52 that can be press fit into the enlarged secondary valve element
48 of the rod 32 to contact the ball 42 when in the energized configuration
as more fully disclosed below. Thus, the preferred rod 32 is a two-piece
rod, with most of the rod being non-ferromagnetic and with the portion
of the rod (i.e., the pin 52) that must repeatedly contact the ball
42 being hardened compared to the remainder of the rod, for better
wear.
[0023] FIG. 2 best shows that the valve housing 18 is formed with
at least one ball retainer rib 54 defining the supply port 44 and
having a diameter that is smaller than that of the ball 42 such
that the rib 54 retains the ball 42 from passing outward through
the supply port 44. The rib 54 may be annular or there may be several,
e.g., globular, ribs provided around the supply port 44, and the
rib or ribs may be deformable such that the ball 42 may be pressed
through the rib 54 into the location shown during installation,
with the rib 54 then re-assuming the configuration shown. In addition,
various o-rings 56 may be provided around the housing 18 for installation
purposes known in the art.
[0024] With the above structural disclosure in mind, it may now
be understood that the rod 32 is reciprocatingly disposed in the
valve housing 18 between the deenergized configuration shown and
an energized configuration. In the deenergized configuration, the
coil 22 is deenergized, the ball 42 is forced by fluid pressure
against the valve seat 40 to block fluid flow from the supply port
44 to the control port 46, and the secondary valve element 48 of
the rod 32 is distanced from the exhaust port 50 by fluid pressure
to allow fluid communication from the control port 46 through the
exhaust port 50. In contrast, in the energized configuration, the
coil 22 is energized to move the plunger 36 (and, hence, rod 32)
to the right in FIG. 1, causing the ball 42 to be distanced from
the valve seat 40 by the pin 52 to permit fluid flow from the supply
port 44 to the control port 46, and moving the secondary valve element
48 of the rod 32 against the exhaust port 50 to block fluid communication
therethrough.
[0025] In accordance with the present invention and as best shown
in FIG. 2, in the deenergized configuration, the end of the pin
52 of the rod 32 is distanced from the ball 42 by a distance "S"
of between one tenth and eight-tenths of a millimeter (0.1 mm-0.8
mm). Preferably, the distance "S" is approximately four-tenths
of a millimeter (0.4 mm). This permits the rod 32/plunger 36 structure
to pre-travel the distance "S" upon coil energization
before contacting the ball 42, with the distance "S" being
sufficient to reduce the turn-on response time of the valve compared
to the turn-on response time it would have were the pin 52 to be
spaced less than 0.1 mm from the ball 42 when in the deenergized
configuration. Stated differently, with the above-disclosed pre-travel
the rod 32/plunger 36 builds up substantial momentum under the influence
of the coil when moving toward the ball 42 but before contacting
the ball 42 such that when it does contact the ball 42, it quickly
moves the ball 42 away from the valve seat 40.
[0026] FIG. 3 shows various preferred features of the rod 32. As
shown, the portion 58 of the rod 32 that is received in the plunger
36 is formed with grooves 60. With this structure, the plunger 36
can be staked to the rod 32 using, e.g., stake blades 62 (which
are removed after staking) having a width "W". The blades
are sufficiently wide such that during staking, material from the
plunger 36 is evenly pushed into more than one groove 60 such that
the forces created by the material being pressed into the corner
of one groove are cancelled by the forces from material being pressed
into the corner of another groove, minimizing unwanted movement
between the plunger 36 and rod 32 during staking.
[0027] FIG. 3 also shows that to alleviate tolerance requirements,
only a portion of the preferred rod 32 need be made to fit precisely
in the bushing 30. More specifically, the rod 32 can be formed with
first and second guiding surfaces 64, 66 between the pin 52 and
grooved portion 58, with the guiding surfaces 64, 66 defining a
diameter "D1". Intermediate the guiding surfaces 64, 66,
the rod 32 is formed with a stepped region 68 that defines a diameter
"D2" which is smaller than the diameter "D1"
of the guiding surfaces 64, 66. Only the first and second guiding
surfaces 64, 66 need have tight tolerances for engaging the bushing
30.
[0028] While the particular 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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