U.S. patent number 3,661,183 [Application Number 05/045,825] was granted by the patent office on 1972-05-09 for electromagnetically operated valve with two seats.
This patent grant is currently assigned to Robert Bosch GmbH. Invention is credited to Waldemar Hans, Iwan Komaroff, Ewald Ziegler.
United States Patent |
3,661,183 |
Komaroff , et al. |
May 9, 1972 |
ELECTROMAGNETICALLY OPERATED VALVE WITH TWO SEATS
Abstract
An electromagnetically operated valve wherein a spherical valve
member normally engages one of two seats to thereby connect a port
for spent fluid with a port which is connected with a consumer of
pressurized fluid. The valve member is held in such position by the
plunger of an armature which is accommodated in a fluid-filled
chamber provided in the valve housing and communicating with a
fluid-admitting port. When the winding of the electromagnet is
energized, the plunger is retracted to permit movement of the valve
member into engagement with the other seat whereby the port which
is connected to the consumer communicates with the fluid-admitting
port. The plunger can be held in a position in which the valve
member engages the one seat by fluid pressure in the chamber and/or
by a spring.
Inventors: |
Komaroff; Iwan (Korntal,
DT), Ziegler; Ewald (Leonberg, DT), Hans;
Waldemar (Ludwigsburg, DT) |
Assignee: |
Robert Bosch GmbH (Stuttgart,
DT)
|
Family
ID: |
5739005 |
Appl.
No.: |
05/045,825 |
Filed: |
June 12, 1970 |
Foreign Application Priority Data
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Jul 15, 1969 [DT] |
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P 19 34 212.2 |
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Current U.S.
Class: |
137/625.65;
251/50 |
Current CPC
Class: |
F16K
31/0631 (20130101); F16K 31/0693 (20130101); Y10T
137/86622 (20150401) |
Current International
Class: |
F16K
31/06 (20060101); F16k 031/06 () |
Field of
Search: |
;137/625.65,625.64,625.67,625.66 ;251/138,129,50 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Nelson; M. Cary
Assistant Examiner: Miller; Robert J.
Claims
We claim:
1. An electromagnetically operated valve, comprising a housing
including two seats and having first, second and third ports, one
of said ports being connected with a source of pressurized fluid
and said housing further having a fluid-filled chamber
communicating with said one port; a valve-member disposed
intermediate said seats and movable between a first position in
which it engages one of said seats to thereby connect said first
and second ports and a second position in which it engages the
other seat to thereby connect one of said first and second ports
with said third port; and an electromagnet including an armature
reciprocable with clearance in said fluid-filled chamber and
normally holding said valve member in engagement with said one
seat, and winding means energizable to effect movement of said
armature so that said valve member can move into engagement with
said other seat.
2. A valve as defined in claim 1, wherein said one port is said
third port, wherein said first port is connected with a consumer of
pressurized fluid and said second port is connected with a return
line for spent fluid.
3. A valve as defined in claim 1, wherein said armature comprises a
plunger which normally holds said valve member in said first
position and further comprising annular guide means provided in
said housing for said plunger and spring means for biasing said
plunger against said valve member.
4. A valve as defined in claim 1, wherein said armature comprises a
differential piston arranged to normally maintain said valve member
in said first position under the action of fluid pressure in said
chamber.
5. A valve as defined in claim 1, wherein said armature is movable
axially in response to energization of said winding means from an
extended position in which it holds said valve member in said first
position to a retracted position in which said armature is out of
contact with said valve member in the latter's second position.
6. A valve as defined in claim 5, wherein said electromagnet
further includes a core fixedly mounted in said housing and said
armature comprises a plunger having an end face which abuts against
the core in said retracted position.
7. A valve as defined in claim 1, wherein said valve member is a
sphere and said seats have coaxial bores one of which connects said
first and second ports and the other of which connects said third
port with one of said first and second ports.
Description
BACKGROUND OF THE INVENTION
The present invention relates to valves in general, and more
particularly to improvements in electromagnetically operated valves
of the type wherein the valve member is movable between two
seats.
An electromagnetically operated valve with two seats is disclosed
in Swiss patent No. 416,252. The patented valve comprises a valve
member which is movable between the two seats and a polarized
electromagnet which is outwardly adjacent to the housing of the
valve and is energizable to move the valve member to one of its
positions. A drawback of such valves is that the plunger which
effects movements of the valve member must be machined with a high
degree of precision and that the housing of the valve must be
provided with accurately machined guide surfaces for the plunger in
order to avoid jamming. Such precise finish of the plunger and of
guide surfaces involves considerable expenses. Moreover, the
plunger is rather bulky and has a relatively large surface for
action of pressurized fluid; therefore, the frequency at which the
valve member can move between its positions is rather low.
SUMMARY OF THE INVENTION
An object of the invention is to provide an electromagnetically
operated valve with two seats wherein the valve member is movable
at a high frequency, wherein the means for effecting movements of
the valve member between its positions need not be machined or
finished with a high degree of precision but are still capable of
operating without jamming, and wherein the parts which are used to
effect movements of the valve member are properly lubricated at all
times.
Another object of the invention is to provide a novel and improved
construction and mounting for an electromagnet which is used to
effect movements of the valve member between two valve seats.
A further object of the invention is to provide a valve wherein the
ports of the valve housing are sealed in a novel and improved
way.
The improved electromagnetically operated valve comprises a housing
including two seats and having first, second and third ports one of
which is connected with a source of pressurized fluid, a
fluid-filled internal chamber provided in the housing and
communicating with the one port, a valve member disposed
intermediate the seats and movable between a first position in
which it engages one of the seats to thereby connect the first and
second ports (e.g., to connect the port which supplies pressurized
fluid to a consumer with the port which returns spent fluid from
the consumer to a tank) and a second position in which the valve
member engages the other seat to thereby connect the first or
second port with the third port (e.g., to connect the port which is
connected with the source of pressurized fluid with the port which
conveys such fluid to the consumer), and an electromagnet including
an armature which is reciprocable, preferably with at least some
clearance, in the fluid filled chamber of the housing and normally
holds the valve member in engagement with the one seat. The
electromagnet further comprises winding means which is energizable
at frequent or less frequent intervals to thereby effect movement
of the armature so that the valve member can move into engagement
with the other seat, e.g., in response to fluid pressure.
The novel features which are considered as characteristic of the
invention are set forth in particular in the appended claims. The
improved valve itself, however, both as to its construction and its
mode of operation, together with additional features and advantages
thereof, will be best understood upon perusal of the following
detailed description of certain specific embodiments with reference
to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an axial sectional view of an electromagnetically
operated valve with two seats which embodies one form of the
invention; and
FIG. 2 is a similar sectional view of a second valve.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is shown an electromagnetically
operated valve which comprises a housing including a valve body 1
and two coaxial seats 3, 4 mounted in an axial bore 2 of the body
1. The seats 3 and 4 are spaced from each other in the axial
direction of the body 1 and are provided with concave sealing
surfaces 5, 6 disposed at the axial ends of two bores 38, 38a. A
spherical valve member or stopper 7 is disposed between the seats
3, 4 and is normally biased against the sealing surface 5 to
thereby permit communication between a first radial port 27 of the
housing and a second radial port 28 as well as to seal the ports
27, 28 from an axial fluid-admitting third port 29. The latter is
connected with a pump (not shown) or another suitable source of
pressurized fluid, e.g., oil. The valve member 7 is held in the
illustrated first position by the plunger 8 of a reciprocable
armature which forms part of an electromagnet and is movable
axially of the housing 1. The plunger 8 is slidable in an annular
guide member or bearing 10 which is fixedly mounted in the housing
and serves as a retainer for one end of a helical spring 9 which
bears against a collar 12 abutting against a conical shoulder 11 on
the plunger. The spring 9 reacts against the guide member 10 and
urges the plunger 8 axially toward the port 29 whereby the
left-hand end face of the plunger maintains the valve member 7 in
sealing engagement with the surface 5 of the left-hand seat 3. The
guide member 10 consists of nonmagnetic material and the spring 9
is accommodated in a smaller diameter portion 2a of the axial bore
in the body 1.
The armature further comprises a ring-shaped element 13 of
magnetizable material which is fixedly secured to the right-hand
portion of the plunger 8 and is received with clearance in an
axially extending fluid-filled chamber 15 of the valve housing. The
right-hand end face 14 of the plunger 8 extends slightly beyond the
element 13 and abuts against the adjacent face 17 of a core 16 when
the armature is moved axially from the illustrated extended
position to a retracted position in which the plunger 8 is slightly
spaced from the valve member 7 even if the latter abuts against the
sealing surface 6 of the right-hand seat 4. The electromagnet
further comprises a yoke 18 for windings 19. The yoke 18 surrounds
the core 16. A portion of the core 16 is surrounded by a sleeve 18'
of nonmagnetic material which serves as a means for preventing
escape of fluid from the chamber 15, namely, along the right-hand
end face of the guide member 10. The housing of the valve further
includes a cupped shell 20 which surrounds the parts 16, 18 and 19
of the electromagnet. The shell 20 has an inturned collar 21 which
overlies a shoulder 22 provided on an annular coupling member 23
which forms part of the housing and has a second annular shoulder
24 overlapped by an inturned collar 25 of the body 1.
An enlarged portion 26 of the port 29 accommodates a filter 229 for
the fluid which is delivered to the housing from the source. The
port 27 is connected with one or more consumers of pressurized
fluid and the port 28 is connected with a tank or another
receptacle for spent fluid. The chamber 15 receives pressurized
fluid from the port 29 by way of a channel 30 in the body 1, a
ring-shaped space 31 which surrounds the guide member 10, and an
axially parallel groove 32 machined into the guide member. The
windings 19 of the electromagnet in the shell 20 are connected with
an energy source by way of conductors 34.
The body 1 is provided with circumferential grooves for elastic
sealing rings 35, 36, 37 and is sealingly received in a valve
block, not shown. The diameter of the bore 38 in the seat 3 equals
the diameter of the plunger 8.
The fluid which enters the body 1 by way of the port 29 fills the
bore 38 and exerts pressure against the valve member 7 which
engages the surface 5 of the seat 3. Such fluid also fills the
channel 30, space 31, groove 32 and chamber 15 to exert pressure
against the right-hand end face 14 of the plunger 8. This insures a
complete balance of hydraulic forces which act on the valve member
7 and plunger 8. Consequently, a relatively weak spring 9 suffices
to maintain the valve member 7 in the illustrated position.
When the winding 19 of the electromagnet is energized, the
ring-shaped element 13 is attracted by the core 16 so that the end
face 14 of the plunger 8 abuts against the face 17. The fluid
pressure in the bore 38 of the seat 3 then causes the valve member
7 to engage the surface 6 of the seat 4 and to permit communication
between the ports 27, 29 which are then sealed from the port 28.
Since the face 17 of the core is engaged only by the end face 14 of
the plunger 14, the armature is not likely to stick in its
retracted position so that the spring 9 can immediately expand as
soon as the circuit of the windings 19 is interrupted. The axial
length of the plunger 8 is such that, when the end face 14 abuts
against the face 17 of the core 16, the left-hand end face of the
plunger is slightly spaced from the valve member 7 even when the
latter engages the surface 6 of the seat 4. The armature 8, 13 is
of lightweight construction so that it can be moved back and forth
at a high frequency. Such high-frequency operation is further
enhanced by the fact that, when the electromagnet is deenergized,
the hydraulic forces acting on the valve member 7 are balanced by
hydraulic forces acting on the plunger 8. Consequently, a
relatively weak electromagnet and a relatively weak spring 9 will
suffice to effect movements of the valve member 7 between the seats
3 and 4. The stroke of the plunger 8 is preferably short, i.e., the
valve member 7 must cover a short distance to move from engagement
with the surface 5 into engagement with the surface 6 or vice
versa.
FIG. 2 shows a second valve which employs a hollow plunger 40
having a diameter which exceeds substantially the diameter of the
bore 38 in the seat 3. A hollow plunger is preferred in order to
reduce the mass of the armature. The right-hand end of the plunger
40 is sealed by a disk 1 received in a cap 42 of magnetizable
material. This cap is received in a fluid-filled chamber 43 of the
valve housing 46. The annular clearance between the peripheral
surface of the cap 42 and the surface surrounding the chamber 43 is
shown at 45. The clearance 45 connects the chamber 43 with an
annular space 44 which communicates with the fluid-admitting port
29' by way of the channel 30' in the valve housing 46. The latter
includes a cylindrical extension 47 received in a compartment 49
defined by an enclosure 48, e.g., a valve block. The enclosure 48
has an internal shoulder 50 engaging an elastically deformable
sealing ring 51. Two additional sealing rings 51 are installed in
the compartment 49 and one thereof engages a shoulder 56 of the
housing 46. The leftmost sealing ring 51 is adjacent to a steel
ring 52 having passages 53 in communication with the port 27' in
the extension 47. A second steel ring 55 is disposed between the
two right-hand sealing rings 51 and is provided with passages
communicating with the port 28'. The rings 51 are subjected to at
least some deforming stresses to insure a satisfactory sealing
action. Since the effective area of the right-hand end face of the
armature exceeds the diameter of the bore 38 in the seat 3, the
plunger 40 normally maintains the valve member 7 in engagement with
the surface 5. When the windings of the electromagnet are
energized, the core 16 attracts the cap 42 and the fluid pressure
in the bore 38 causes the valve member 7 to move against the
surface 6 of the right-hand seat 4. Thus, the armature acts not
unlike a differential piston and automatically holds the valve
member 7 in the illustrated lefthand end position when the windings
of the electromagnet are deenergized. Therefore, the valve spring 9
of FIG. 1 can be dispensed with. The port 29' of the extension 47
communicates with a conduit 60 in the enclosure 48; the conduit 60
is connected with the source of pressurized fluid.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can, by applying current
knowledge, readily adapt it for various applications without
omitting features which fairly constitute essential characteristics
of the generic and specific aspects of our contribution to the art
and, therefore, such adaptations should and are intended to be
comprehended within the meaning and range of equivalence of the
claims.
What is claimed as new and desired to be protected by Letters
Patent is set forth in the appended claims.
* * * * *