U.S. patent application number 13/119580 was filed with the patent office on 2011-07-21 for balanced fluid valve.
This patent application is currently assigned to Isomatic A/S. Invention is credited to Soeren Kristoffersen.
Application Number | 20110174394 13/119580 |
Document ID | / |
Family ID | 41211761 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110174394 |
Kind Code |
A1 |
Kristoffersen; Soeren |
July 21, 2011 |
BALANCED FLUID VALVE
Abstract
It is proposed to design a fluid flux regulating unit (1, 28,
35, 41, 53, 56, 58), comprising a first fluid port (3), a second
fluid port (4) and a valve means (6) , in a way that the valve
means (6) comprises at least one fluid pressure balancing means
(13, 25, 30, 31, 33, 52).
Inventors: |
Kristoffersen; Soeren;
(Hadsund, DK) |
Assignee: |
Isomatic A/S
Randers
DK
|
Family ID: |
41211761 |
Appl. No.: |
13/119580 |
Filed: |
September 17, 2009 |
PCT Filed: |
September 17, 2009 |
PCT NO: |
PCT/DK09/00205 |
371 Date: |
March 28, 2011 |
Current U.S.
Class: |
137/505 |
Current CPC
Class: |
Y10T 137/7801 20150401;
G05D 16/106 20130101; Y10T 137/7798 20150401; G05D 7/005 20130101;
G05D 7/0133 20130101; Y10T 137/7808 20150401; Y10T 137/7796
20150401; Y10T 137/7793 20150401; Y10T 137/7797 20150401 |
Class at
Publication: |
137/505 |
International
Class: |
G05D 7/01 20060101
G05D007/01 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2008 |
EP |
08016556.6 |
Claims
1. A fluid flux regulating unit, comprising a first fluid port, a
second fluid port and a valve means, wherein said valve means
comprises at least one fluid pressure balancing means.
2. The fluid flux regulating unit as claimed in claim 1, wherein
said valve means comprises at least one movable valve part, wherein
preferably said movable valve part comprises at least one of said
fluid pressure balancing means.
3. The fluid flux regulating unit as claimed in claim 1, wherein
said valve means comprises an axially movable tubular unit, wherein
preferable said tubular unit comprises an inner passage.
4. The fluid flux regulating unit as claimed in claim 1, wherein
said fluid pressure balancing means is designed and arranged in a
way that at least part of the surface parts, being in fluid
communication with said first fluid port and having a surface
normal at least partially in parallel to the moving direction (A)
of said movable valve part, are fluid pressure balanced.
5. The fluid flux regulating unit as claimed in claim 1, wherein
said fluid pressure balancing means is at least in part designed
and arranged in a way that for each surface part, being in fluid
communication with said first fluid port, a fluid pressure
balancing surface is provided, being also in fluid communication
with said first fluid port, wherein the fraction of the force,
generated by the fluid pressure on the first fluid port side and
pointing in a direction parallel to the moving direction (A) of
said movable valve part, are opposing each other.
6. The fluid flux regulating unit as claimed in claim 1, wherein
said fluid pressure balancing means is at least in part designed
and arranged in a way that said movable valve part essentially
shows no surface parts, being in fluid communication with said
first fluid port and having a surface normal at least partially in
parallel to the moving direction (A) of said movable valve
part.
7. The fluid flux regulating unit as claimed in claim 6, wherein
said movable valve part comprises tapered surfaces on surface
parts, particularly on surface parts, being in fluid communication
with said second fluid port.
8. The fluid flux regulating unit as claimed in claim 7, wherein
said movable valve part shows balanced surfaces on surface parts,
which are in fluid communication with said second fluid port.
9. The fluid flux regulating unit as claimed in claim 1, wherein
said fluid flux regulating unit is designed and arranged as a fluid
pressure regulator.
10. The fluid flux regulating unit as claimed in claim 1, wherein
said fluid flux regulating unit is designed and arranged as a an
actuated valve.
11. The fluid flux regulating unit as claimed in claim 10, wherein
pilot pressure applying means are provided, which preferably can be
selectively connected to said first fluid port and/or said second
fluid port.
12. The fluid flux regulating unit as claimed in claim 11, wherein
said pilot pressure applying means can be connected to a respective
fluid pressure reservoir via a fluid throughput reducing means.
13. The fluid flux regulating unit as claimed in claim 1, wherein
at least one valve closing biasing means is provided, which
preferably biases said movable valve part in the direction of a
closing position.
14. The fluid flux regulating unit as claimed in claim 1,
comprising at least a third fluid port.
15. The fluid flux regulating unit according to claim 1, wherein
said valve means is at least in part influenced by the fluid, which
is controlled by the fluid flux regulating unit.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is entitled to the benefit of and
incorporates by reference essential subject matter disclosed in
International Patent Application No. PCT/DK2009/000205 filed on
Sep. 17, 2009 and European Patent Application No. 08016556.6 filed
on Sep. 19, 2008.
FIELD OF THE INVENTION
[0002] The invention relates to a fluid flux regulating unit,
comprising a first fluid port, a second fluid port and a valve
means.
BACKGROUND OF THE INVENTION
[0003] Fluid flux regulating units are used, when it comes to
influencing the amount of fluid flow through a device and/or to
influence the direction into which a fluid flow is directed. The
influencing behaviour can be based on a variety of parameters, of
course. For example, it is possible that a fluid flow is regulated
in a way that the fluid pressure in a certain part of a machine is
set to a certain pressure, in particular a constant pressure. In
other cases, a simple opening and interruption of the fluid flow is
intended. In yet other applications, an incoming fluid flow has to
be selectively directed to a first fluid port, to a second fluid
port or has to be split up into two parts, the respective part
going to a first fluid port and to a second fluid port.
[0004] Fluid flux regulating units for performing these type of
tasks are well known in the state of the art.
[0005] In U.S. Pat. No. 3,890,999 and in U.S. Pat. No. 2,777,458
fluid pressure regulators are described. These fluid pressure
regulators have a fluid inlet port and a fluid outlet port. Fluid
at a high pressure enters the pressure regulator through the fluid
inlet port. Inside the fluid pressure regulator, the high fluid
pressure is reduced to a lower set level. The fluid leaves the
pressure regulator at reduced pressure through a fluid outlet port.
For most applications, it is desired that the fluid outlet pressure
is constant, independent on the fluid flux, passing through the
fluid pressure regulator and in particular independent of the fluid
pressure at the fluid inlet port.
[0006] Another problem is that fluid pressure regulators usually
need a minimum outlet pressure to completely shut off. This is even
true with a completely released pressure regulation spring device.
Also, fluid pressure regulators according to the state of the art
are usually ratio regulating devices, i.e. they are usually
dependent on the inlet pressure, at least to a certain extent.
Therefore, the diameter of the inlet orifice usually corresponds to
the diameter of the fluid outlet, which in turn means that the
regulator's output pressure will generally be affected by
variations in the inlet pressure.
[0007] In EP 0 566 543 A1, DE 102 47 098 A1, U.S. Pat. No.
6,955,331 B2, U.S. Pat. No. 2,799,466, GB 846 106 and EP 1803 980
A1 actuated valves are described, where the fluid flow through the
valve can be influenced by an external signal. The external signal
can be applied as an external mechanical force (GB 846 106), as an
electric signal (DE 102 47 098 A1, U.S. Pat. No. 2,799,466) or as a
pilot pressure, applied to the valve (EP 0 566 543 A1, U.S. Pat.
No. 6,955,331 B2, EP 1 803 980 A1). Even here it is desired that
the signal to be applied to the actuated valve is essentially
independent of other parameters, in particular independent of the
fluid pressure on the high pressure side and/or on the low pressure
side.
[0008] Although presently known fluid regulators and valves work
quite well in practical applications, there is still room for
further improvements. In particular, improvements are desired, when
it comes to the independency of the respective device on the fluid
pressure at the fluid inlet port and, where necessary, at the fluid
outlet port.
SUMMARY OF THE INVENTION
[0009] The object of the invention is therefore to provide for a
fluid flux regulating unit, showing an improved independency on
fluid pressure.
[0010] It is suggested to design a fluid flux regulating unit,
comprising a first fluid port, a second fluid port and a valve
means in a way that said valve means comprises at least one fluid
pressure balancing means. The fluid flux regulating unit is
preferably designed in a way that said one or several fluid
pressure balancing means provided are balancing the fluid flux
regulating unit essentially completely. This essentially complete
balancing can be provided in connection with the first fluid port,
the second fluid port or both fluid ports. Each fluid pressure
balancing means usually has the effect that the influence of the
fluid pressure at the respective port on the valve means is
reduced. This way, the fluid flux regulating unit can become
essentially independent of the fluid pressure at the first fluid
port, the second fluid port, or both.
[0011] Preferably, said valve means comprises at least one moveable
valve part, wherein preferably said moveable valve part comprises
at least one of said fluid pressure balancing means. Using such a
movable valve part, the valve means can be designed in an easy and
cost-effective way. The regulation of the fluid flow through the
fluid flux regulating unit can be performed by a mechanical opening
and closing of an opening, through which the fluid can flow.
Furthermore, a leakage proof closing of the valve means can usually
be easily achieved. However, pressure influences on the valve means
usually stem from pressure influences on the movable valve part.
Here, the imposed pressure can a create force, which in turn can
lead to a movement of the movable valve part, thus creating an
influence of the valve means on the applied fluid pressure. By
providing said fluid pressure balancing means in connection with
said movable valve part, the described effects can usually easily
be accounted for and can be even avoided.
[0012] A preferred embodiment can be achieved if said valve member
comprises an axially movable tubular unit, wherein preferably the
tubular unit comprises an inner passage. Using this design, a fluid
flux regulating unit can be provided in which a relatively small
movement of the movable valve part can lead to a relatively large
change in fluid flow cross section. By this, a wide range of fluid
fluxes through the unit can be achieved. Furthermore, the tubular
unit can be easily designed more elongated, so that it is easy to
provide one or even a plurality of fluid pressure balancing means
along the tubular unit. Another advantage of the proposed tubular
shape of the movable valve part is that directional changes of the
fluid, flowing through the fluid flux regulating unit, can be made
relatively small. Hence, fluid flow resistance of the fluid flux
regulating unit can be decreased. The movable valve part can be
provided in connection with a valve seat, which can have an
essentially even surface, in particular in connection with the
plate like valve seat. Using such a valve seat, an essentially
rotationally symmetric fluid flux regulating unit can be achieved,
so that it is possible to even further reduce the fluid flow
resistance of the fluid flux regulating unit.
[0013] Preferably, said fluid pressure balancing means is designed
and arranged in a way that at least part of the surface parts,
being in fluid communication with said first fluid port and having
surface normal at least partially in parallel to the moving
direction of said movable valve part, are fluid pressure balanced.
Usually these surface parts are the surface parts, generating the
largest influence on fluid pressure onto the opening and closing
behaviour of the valve means of the fluid flux regulating unit.
Therefore, by addressing the influence of these surface parts, the
usually largest improvements can be achieved. The respective
surface normal can be in parallel to the moving direction of the
movable valve part, for example. However, it is also possible that
the surface normal of the respective surface part is arranged at an
angle with the moving direction of the movable valve part. The
force, being generated by such an inclined surface, can be
vectorially split up into a force, being parallel to the moving
direction of the movable valve part and a force, being
perpendicular to the moving direction of the movable valve part.
However, usually only the force fraction, pointing in the direction
of the moving direction of the movable valve part, will create a
pressure influence on the fluid flux regulating unit. Therefore,
addressing this force fraction will usually yield the biggest
improvements.
[0014] It is possible that said fluid pressure balancing means is
at least in part designed and arranged in a way that for each
surface part, being in fluid communication with said first fluid
port, a fluid pressure balancing surface is provided, being also in
fluid communication with said first fluid port, wherein the
fraction of the forces, generated by the fluid pressure on the
first fluid port side and pointing into a direction parallel to the
moving direction of said movable valve part, are opposing each
other. This way, it is possible that by providing two (or more)
forces of the same magnitude, but of different directions, the
respective forces will cancel each other, so that the net force
will be zero. Therefore, the fluid flux regulating unit can be
designed in a way that the pressure dependency of the unit will be
very small or even not existent. This, of course, is very
advantageous. Usually, this can be done most effectively if the
corresponding "balancing" surfaces are of the same size
(considering the vectorial part with the surface normal parallel to
the moving direction of the movable valve part).
[0015] Furthermore, it is possible to design the fluid flux
regulating unit in a way that said fluid pressure balancing means
is at least in part designed and arranged in a way that said
movable part member essentially shows no surface parts, being in
fluid communication with said first fluid port and having a surface
normal at least partially in parallel to the moving direction of
said movable valve part. This way the problem of fluid pressure
dependency of the fluid flux regulating unit can be addressed at
the very root. In other words, surfaces are arranged in a way so
that no force fraction (vectorial force) is generated which could
tend to move the movable valve part in an opening and/or closing
direction. Instead, in general only forces are occurring, being
perpendicular to said moving direction of said movable valve part.
These forces, however, can be handled by immovable parts of the
fluid flux regulating unit and are therefore not generating any
opening and/or closing movement. Of course, a combination of the
avoidance of forces, being parallel to the moving direction of the
movable valve part and the balancing of such forces by
counteracting forces is possible. This combination of both
approaches can lead to even better results.
[0016] It is possible that said movable valve part comprises
tapered surfaces on surface parts, particularly on surface parts
being in fluid communication with said second fluid port. Using
such tapered surfaces, the fluid flow resistance of the resulting
fluid flux regulating unit can normally be further reduced. Also,
it is often possible to reduce vibrations and/or generated noise.
Also, by providing tapered surfaces, it is possible to provide
sharp edges, which can be used for providing particularly leakage
proof valve arrangements. If the tapered surfaces are arranged in
fluid communication with said second fluid port, the resulting
surface part will normally not be influenced by varying pressure on
the first fluid port side. In particular, the tapered surface can
be provided on the inner side of the tubular valve part, pointing
towards the valve seat of the valve member.
[0017] It is also possible, to provide said movable valve part with
balanced surfaces on surface parts, which are in fluid
communication with said second fluid port. The balancing principle
can be--as previously explained--based on avoiding pressure induced
forces in the direction of movement of the movable valve part
and/or based on creating counteracting pressure induced forces,
being in parallel to the moving direction of the movable valve
part. Using such a design it is possible, for example, to provide a
fluid flux regulating unit which is independent or less dependent
on the pressure at the second fluid port side of the fluid flux
regulating unit.
[0018] It is possible to design and arrange said fluid flux
regulating unit as a fluid pressure regulator. Particularly for
pressure regulators it is important to be relatively independent of
the pressure on the high pressure side (first fluid port; fluid
inlet port) of the fluid flux regulating unit. However, fluid
pressure regulators are usually highly dependent on the pressure on
the low pressure side (second fluid port side; fluid outlet port)
of the fluid flux regulating unit.
[0019] It is also possible to design and arrange the fluid flux
regulating unit as an actuated valve. For such valves, it is
usually desired that the valve can be actuated with a constant
force, being independent of the fluid pressure on the fluid inlet
side (first fluid port) and/or on the fluid outlet side (second
fluid port). Therefore, the suggested design of the fluid flux
regulating unit can be highly advantageous.
[0020] The fluid flux regulating unit can be provided with pilot
pressure applying means, which preferably can be selectively
connected to said first fluid port and/or said second fluid port.
This way, the resulting unit can be changed, using fluid pressures.
In particular it is even possible to change the state of the fluid
flux regulating unit by the pressures, occurring in the fluid to be
influenced by the fluid flux regulating unit. Of course, it is
possible to form a switching of the pilot pressure actuated fluid
flux regulating unit, using a different switching means. The
switching means can be based on the fluid pressure, mechanical
forces, electricity, magnetic forces and the like, for example.
[0021] A particular useful design can be achieved, if said pilot
pressure applying means can be connected to a respective fluid
pressure reservoir via a fluid throughput reducing means. Such a
fluid throughput reducing means can be a throttle or an orifice
opening, for example. Using such a device, the "consumption" of the
actuating fluid can be advantageously decreased. Furthermore, it
possible to provide for a "soft" changeover between different
states of the valve unit, which can result in decreased wear of the
fluid flux regulating unit.
[0022] It is also possible to provide at least one valve closing
biasing means, which preferably biases said movable valve part in
the direction of a closing position. With such a valve closing
biasing means, it is possible, to provide for a secure closing of
the fluid flux regulating unit in case the fluid flux regulating
unit (or the device in which the fluid flux regulating unit is
used) is not in use or at a residual pressure level. This way, it
is possible to avoid the need for a separate shut off valve, for
example. The valve closing biasing means can be made of an
elastically deformable material. In particular, a spring can be
used. The spring is preferably a metal spring and/or a helically
wound spring.
[0023] It is possible to provide the fluid flux regulating unit
with at least a third fluid port. This way it is possible to
provide a changeover valve or the like with the previously
described features and advantages.
[0024] Preferably, the fluid flux regulating unit can be of an
in-line type design. Using such an in-line type design, the number
and size of deflections for the fluid stream, flowing through the
fluid flux regulating unit can be decreased. This way, vibrations
can be reduced and the pressure drop along the fluid flux
regulating unit can be decreased, for example. Also, usually less
movable parts are necessary in the design of the fluid flux
regulating unit.
[0025] The object of the invention is also solved by a fluid flux
regulating unit, comprising a first fluid port, a second fluid port
and a valve means, wherein said fluid flux regulating unit is
designed and arranged in a way that said valve means is at least in
part influenced by the fluid, which is controlled by the fluid flux
regulating unit. This way, it is possible to use a cheap and
efficient amplifying device and/or energy source for moving the
valve means. In particular, a small influencing force can be
amplified by the energy, stored in the fluid pressure of the fluid,
which is controlled by the fluid flux regulating unit, so that even
a relatively large and/or heavy valve means can be moved by a small
initial force. Because in fluid regulators and/or fluid valves a
pressure drop along the fluid flux regulating unit is normally not
problematic (or even desired), this suggested design can prove to
be particularly useful. This is, because pressure differences for
driving the valve means in both directions are usually already
present.
[0026] By the term "fluid", liquids (like liquid CO.sub.2, for
example), gases, mixture of gases and liquids and hypercritical
fluids are in encompassed. It is also possible that the respective
fluid can contain solid particles to a certain extent (e.g. smoke,
suspensions).
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The present invention and its advantageous will become more
apparent, when looking at the following description of possible
embodiments of the invention, which will be described with
reference to the accompanying figures, which are showing:
[0028] FIG. 1: is a first embodiment of a fluid pressure
regulator;
[0029] FIG. 2: is a second embodiment of a fluid pressure
regulator;
[0030] FIG. 3: is a first embodiment of an actuated valve;
[0031] FIG. 4: is a second embodiment of an actuated valve;
[0032] FIG. 5: is a third embodiment of an actuated valve;
[0033] FIG. 6: is a third embodiment of a fluid pressure regulator;
and
[0034] FIG. 7: is a fourth embodiment of a fluid pressure
regulator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] In FIG. 1, a schematical cross section through a first
possible embodiment of a pressure regulator 1 is depicted. The
pressure regulator 1 comprises a casing 2 with a fluid inlet port 3
and a fluid outlet port 4. Both fluid inlet port 3 and fluid outlet
port 4 have an inner thread 5, so that a corresponding fluid pipe
or fluid hose can be threadingly engaged in the respective fluid
port 3, 4.
[0036] Within the casing 2 of the pressure regulator 1, a valve
unit 6 is arranged. The valve unit 6 essentially consists of a
valve seat 7 and a valve tube 8. The valve tube 8 can be moved in
an axial direction (as indicated by double-headed arrow A) within
the casing 2 of the pressure regulator 1.
[0037] The valve tube 8 is designed to have a hollow interior 9,
forming an inner fluid line 9 through the valve tube 8. The
contacting area between valve seat 7 and valve tube 8 forms the
valve opening 10. If the valve tube 8 is in its leftmost position
(as drawn in FIG. 1), the valve seat 7 and the contacting edge 11
of the valve tube 8 contact each other, thus closing the valve
opening 10. In this position, no fluid flow is permitted between
fluid inlet port 3 and fluid outlet port 4. When the valve tube 8
is moving to the right, however, the contacting edge 11 of the
valve tube 8 and the valve seat 7 get out of contact from each
other, thus opening the valve opening 10. Hence, fluid can flow
from the fluid inlet port 3 to the fluid outlet port 4.
[0038] In the embodiment of the pressure regulator 1, shown in FIG.
1, the valve seat 7 is designed as a flat, circular plate. The
valve seat 7 is held in place by several holding bars 12. Between
the holding bars 12, openings are provided, so that fluid can pass
through. Corresponding to the design of the valve seat 7, the valve
tube 8 is designed to have a circular cross section. Consequently,
the contacting edge 11 shows a circular cross section. In the area
close to the valve opening 10, the valve tube 8 comprises tapered
edges 13 on the inner side 9 of the valve tube 8, thus forming
sharp contacting edges 11. The valve seat 7 is made of a slightly
deformable material, so that the contacting edges 11 can slightly
indentate the valve seat 7, thus forming a tight fluid seal.
[0039] In a normal working adjustment position (main spring 14
biased), the valve tube 8 is pushed out of contact with the valve
seat 7 (thus opening the valve opening 10) by means of the main
spring 14. The main spring 14 is supported on its right side (see
FIG. 1) by a circular web 15 integrally formed with the valve tube
8. On the left side, the main spring 14 is supported by a nut 16.
The nut 16 shows an inner thread 17, which is engaged to a
corresponding thread, arranged on the outer side of a collar like
extension 23 of the casing 2. By a turning action of the nut 16,
the nut 16 can be displaced in an axial direction A by means of the
thread 17. Therefore, the biasing force of main spring 14 can be
adjusted to the appropriate amount. For ease of manipulation, the
nut 16 is designed to have a plurality of openings 22 for insertion
of a part of an appropriate tool. Also, the casing 2 of the
pressure regulator 1 is designed with an access window 24 for easy
manipulation of the nut 16. Hence, the second interior space 19
within the casing 2 of pressure regulator 1 shows ambient pressure.
Therefore, sealing rings 21 are provided between first internal
space 18, second internal space 19 and third internal space 20,
respectively.
[0040] The working cycle of the pressure regulator 1 is as
follows:
[0041] Initially, the valve tube 8 is in its open position (right
side in FIG. 1; valve opening 10 is open). Fluid at high pressure
enters the fluid inlet port 3 of the pressure regulator 1. The
fluid flows through the first internal space 18, past the opened
valve opening 10, through the inner fluid line 9 of valve tube 8
into the third internal space 20. According to an actual fluid flow
demand, part of the fluid entering third internal space 20 leaves
the casing 2 of the pressure regulator 1 by fluid outlet port 4.
However, in an open position of the valve unit 6, a positive net
fluid flow into the third internal space 20 occurs. Therefore,
pressure builds up in the third internal space 20. With increasing
pressure, an increasing force is exerted on the piston surface 25
of the valve tube 8. At some point, the net force, pushing the
valve tube to the left exceeds the net force, pushing the valve
tube 8 to the right. Thus, the valve opening 10 closes and the
pressure within the third internal space 20 remains at its set
level. If the pressure inside the third internal space 20 drops
again due to fluid, leaving through fluid outlet port 4, the valve
tube 8 will move slightly to the right, thus opening the valve
opening 10 slightly. Hence, an equilibrium is achieved, so that the
pressure in the third internal space 20 remains constant.
[0042] Apart from the pressure, exerted by the fluid within third
internal space 20 onto the piston surface 25 of valve tube 8, an
additional force is exerted by means of an auxiliary spring 26. The
auxiliary spring 26 has a small spring constant, when compared to
the spring constant of main spring 14. Thus, in a normal adjustment
position of pressure regulator 1, the main spring 14 may easily
compensate for the pressure, exerted by auxiliary spring 26.
However, if the nut 16 is adjusted in a way that main spring 14 is
(essentially) in an unbiased state, the force, exerted by auxiliary
spring 26 is sufficient to safely close the valve unit 6 of the
pressure regulator 1. Therefore, no additional valve is needed,
although the functionality of a cut-off valve is implemented in the
pressure regulator 1.
[0043] The closed position of the pressure regulator 1 (main spring
14 unbiased), is also advantageous for shipping the pressure
regulator 1. In particular, normal vibrations during transportation
of the pressure regulator 1 will not be able to open and close the
valve unit 6 repetitively. Thus, a wear of the pressure regulator 1
during transportation can be avoided.
[0044] Another feature of the pressure regulator 1, shown in FIG.
1, is that the axially movable valve tube 8 shows no surface parts
within the first internal space 18 (high pressure chamber), which
have to be balanced. If a fluid pressure is present in first
internal space 18, every surface of the valve tube 8, being in
contact with the high pressure fluid in first internal space 18
shows a surface normal, being solely perpendicular to the moving
direction of the valve tube 8. Therefore, any pressure within first
internal space 18 will neither generate force, urging the valve
tube 8 in an opening direction, nor generate a force, urging the
valve tube 8 in a closing direction. Therefore, the high pressure
part of pressure regulator 1 is perfectly balanced, even without
balancing surfaces.
[0045] On the inner side of the valve tube 8 in the vicinity of the
valve opening 10, the movable valve tube 8 shows a tapered surface
13, creating a sharp edge 11. This way, fluid resistance is
reduced, if the valve opening 10 is open. Also, a tight seal can be
provided if the valve opening 10 is closed. It has to be noted that
the tapered part 13 of the valve tube 8 is additionally working as
a balancing surface for the respective surface part of the piston
surface 25 of the valve tube 8 (both fluidly connected to the fluid
outlet port 4). However, in the presently depicted embodiment of
FIG. 1, the pressure regulator 1 is still dependent on the fluid
outlet pressure, because a flange part 27 is provided for the valve
tube 8, showing a cross section, exceeding the cross section of
tapered surface parts 13.
[0046] The special design of the tapered surface 13 on the inner
side 9 of the valve tube 8 in the vicinity of the valve opening 10
insures that the pressure drop of the fluid, flowing through the
pressure regulator 1 will essentially occur in a very small area.
Therefore, this construction can be less effected by variations in
the pressure within first internal space 18. This is, because the
areas, being in contact with the high pressure fluid are extremely
small as compared to the areas, being in contact with the low
pressure fluid. The auxiliary spring 26 can put the pressure
regulator 1 in a shut off state, if there is no load on the main
spring 14 (or on the flange part 38 of valve tube 8 in the pressure
regulator 35, as shown in FIG. 3). Hence, the fluid regulator 1
described can work as a shut off valve as well.
[0047] Of course, it is also possible to design the flange part 27
in a different way, as long as the described functionality of the
flange part 27 is provided. For example, the flange part 27 could
be designed as a membrane for the like. Of course, such an
alternative design could be used in units of a different design as
well.
[0048] In FIG. 2, a second possible embodiment of a pressure
regular 28 is shown. Most parts of the present pressure regulator
28 are similar or the same as those used for pressure regulator 1,
as illustrated in FIG. 1.
[0049] As described in connection with first pressure regulator 1,
the presently used valve tube 32 comprises a tapered surface 30 in
the vicinity of the valve seat 7. The tapered surface 30, however,
is presently arranged on the outside of the valve tube 32, thus
facing towards the first internal space 18, being fluidly connected
to the fluid inlet port 3 of pressure regulator 28. This, however,
introduces a force, urging the valve tube 32 into an opening
direction, when high pressure is applied to the first internal
space 18. The effective opening force is the vectorial fraction of
the pressure force, pointing in the direction of movement of valve
tube 32. To balance for this force, the pressure regulator 28 is
provided with a balancing section 33. Within the balancing section
33, the fourth internal space 29 is provided, which is fluidly
connected to the first internal space 18 by a fluid channel 34.
Facing towards the fourth internal space 29, the valve tube 32 is
provided with a balancing web 31. The size of the balancing web 31
is chosen in a way that the resulting force, being exerted onto the
valve tube 32 when pressure is applied to fluid inlet port 3 (and
therefore to first internal space 18 and fourth internal space 29)
is of the same magnitude as the force generated by the tapered
surface 30. The direction of both forces, however, is opposite to
each other. Therefore, both forces cancel each other. Thus, the
pressure regulator 28 is balanced towards the high pressure side.
In other words, the output pressure characteristics of the pressure
regulator 28 is independent of the pressure at fluid inlet port
3.
[0050] An advantage of the proposed design with the tapered surface
30 on the outside of the valve tube 32 is that the dimensions of
the fluid tube 32 can be chosen from a very wide range. This is,
because generally speaking an almost arbitrary size of the surface
area on the front side of the valve tube 32 (near valve opening 10)
can be compensated by the counteracting force delivered by the ring
like web 31 of valve tube 32. Thus, a pressure regulator 28 of the
design proposed can be used with very high pressures.
[0051] As an example, the thickness of the walls of the valve tube
8, 32 is normally in the order of one millimetre (pressures in the
range from 200 to 300 bars). However, with the proposed design,
wall thicknesses for the valve tube 8, 32 in the area of several
millimetres can be easily realized.
[0052] Of course, the design of the pressure regulator 28, as shown
in FIG. 2, can be used for the design of a pilot driven valve 41,
53 as well (see FIGS. 4, 5). In particular, the arrangement of the
tapered surface 30 on the outside of valve tube 32 can be used for
pilot driven valves 41, 53. Of course, the tapered surface 30 on
the outside of the valve tube 32 can also be used in connection
with the pilot driven 37 fluid pressure regulator 35 design, as
depicted in FIG. 3.
[0053] In FIG. 3 another possible embodiment of a pressure
regulator 35 is illustrated. Here, the main spring 14 is omitted.
As a replacement for the main spring 14, a pilot pressure chamber
36 is provided. The pilot pressure chamber 36 is fluidly connected
to a pilot fluid port 37. On one side of the pilot pressure chamber
36, a flange part 38 of the valve tube 39 is located. Therefore, by
applying a pressure to the pilot pressure chamber 36, an
appropriate biasing force can be exerted on the valve tube 39. The
biasing can be changed by varying the pressure, applied to the
pilot pressure chamber 36. It has to be noted that this way an
automated change of biasing force can be easily implemented. The
backside volume 40 is of course at ambient pressure.
[0054] Apart from this, the pressure regulator 35, as depicted in
FIG. 3, resembles the pressure regulator 1, as shown in FIG. 1.
[0055] In FIG. 4, a first possible embodiment of a pilot driven
valve 41 is shown. The pilot driven valve 41 resembles the pressure
regulators 1, 28, 35, shown in FIGS. 1, 2 and 3 in several
aspects.
[0056] The casing 42 has a fluid inlet port 3 and a fluid outlet
port 4, both showing a female thread 5 for threadingly connecting a
fluid pipe or fluid hose with a corresponding outer thread. Similar
to the pressure regulators 1, 28, 35, the valve unit 6 comprises a
circular plate shaped valve seat 7, held in place by holding bars
12 inside the first internal space 18 of the pilot-driven valve 41.
Furthermore, the valve unit 6 comprises a valve tube 8, showing a
hollow interior 9, thus forming an inner fluid line 9. The valve
tube 8 is axially movable in the direction of double-headed arrow A
within the casing 42.
[0057] The valve tube 8 comprises a collar-like sleeve 44. The
collar-like sleeve 44 can be integrally formed with the valve tube
8.
[0058] In a second internal space 19, an opening spring 43 is
provided. The opening spring 43 is compressed and touches part of
the casing 42 (left side in FIG. 4) and part of the collar-like
sleeve 44 of the valve tube 8 (right side in FIG. 4). The opening
spring 43 is in a biased state and therefore opening spring 43
exerts a force on the valve tube 8 in the opening direction of
valve tube 8 (in FIG. 4 on the right side). The second internal
space 19 is connected through the outside via a pressure relief
channel 46. Therefore, second internal 19 is under ambient
pressure.
[0059] On the other side of the collar-like sleeve 44, a pilot
pressure chamber 45 is arranged within casing 42. If pilot pressure
chamber 45 is vented (ambient pressure or low pressure), the force,
exerted by opening spring 43 will prevail, thus moving the valve
tube 8 to the right side and opening valve 10. If, however, the
pressure in the pilot pressure chamber 45 exceeds a certain limit,
the force, exerted by the pressure within pilot pressure chamber 45
will prevail over the force exerted by opening spring 43, thus
moving valve tube 8 to the left and hence closing valve opening 10.
For this, a fluid connection between first internal space 18 and
pilot pressure chamber 45 can be established via feeding line 48
and connecting line 47. This way, fluid inlet port 3 can be
connected via first internal space 18, valve opening 10,
inner-fluid line 9 of valve tube 8, third internal space 22 to the
fluid outlet port 4, or the fluid connection can be closed,
according to the pressure level within pilot pressure chamber
45.
[0060] For switching the pilot driven valve 41, a piloting valve 50
is provided in the presently depicted embodiment. The piloting
valve 50 can be driven by electromagnetic forces, for example. If
the piloting valve 50 is in its closed position (as shown in FIG.
4) the connecting line 47, leading to pilot pressure chamber 45,
and the discharge line 49 are separated from each other. Therefore,
feeding line 48, connects the first internal space 18 under high
pressure to the pilot pressure chamber 45 via connecting line 47.
Therefore, pressure builds up in pilot pressure chamber 45, and the
valve unit 6 will eventually moves to its closed position. Within
feeding line 48, a throttling device 51 is arranged. The fluid flux
from first internal space 18 to pilot pressure chamber 45 is
therefore reduced to a relatively small level.
[0061] If the piloting valve 50 is switched to its open position,
the pilot pressure chamber 45 is vented via connecting line 47,
piloting valve 50 and discharge line 49 and third internal space 20
to the fluid outlet port 4. Therefore, the pressure in the pilot
pressure chamber 45 will decrease and at some point the valve tube
8 will move to the right side, thus opening valve opening 10. It
has to be remembered, that within feeding line 48, a throttling
device 51 is arranged. Therefore, the fluid flow through
discharging line 49 can easily outweigh the fluid flow through
feeding line 48. The more limiting the throttling device 51 is, the
lower are the fluid loses through feeding line 48. On the other
hand, a limited fluid flow through throttling device 51 will slow
down the closing movement of pilot driven valve 41.
[0062] It has to be mentioned that in the closed position of pilot
driven valve 41, piloting valve 50 is also closed, and therefore a
fluid flow through discharging line 49 is stopped, including the
piloting part of pilot driven valve 41. Therefore, pilot driven
valve 41 will be completely closed in its closed state, when
considered together with the piloting valve 50.
[0063] Of course, piloting valve 50 can be designed differently as
well. For example, a manual operation of piloting valve 50 is
possible. Also, piloting valve 50 can be constructed in a way that
intermediary states can be achieved. This can be achieved by
providing an intermediary mechanical position of the piloting valve
50. However, a proportional valve is possible as well. This could
be achieved by a modulated magnetic valve, for example.
[0064] As already described in connection with the pressure
regulators 1, 36, shown in FIGS. 1 and 3, a tapered surface 13 is
provided on the inside 9 of valve tube 8. Consequently, no tapered
surface is present on the outside of valve tube 8 within first
internal space 18. Therefore, no balancing surfaces with respect to
the high pressure in first internal space 18 have to be provided,
because the pilot driven valve 41 is already balanced by its basic
design, when considering the high pressure side 18 of the pilot
driven valve 41.
[0065] Considering the low pressure part 20 of the pilot driven
valve 41, the tapered surface 13, provided on the inner side of
fluid line 9 of the valve tube 8 will result in a vectorial
fractional force, directed in the opening direction of valve unit
6, if a (low) pressure is present on the low pressure side 20.
However, the end surface 52 of the valve tube 8 is fluidly
connected to the third internal space 20, being on the low pressure
level as well. The size of the end surface 52 corresponds to the
cross-sectional area of hollow valve tube 8. Because vectorial
fractions have to be considered, the force, being exerted to the
valve tube 8 via end surface 52, when the low pressure side 4 is
pressurized, is equivalent to the pressure being exerted to the
valve tube 8 by the tapered surface 13 in magnitude. However, the
directions of two forces are opposite to each other. Thus, the two
forces cancel each other.
[0066] Of course, sealing rings 21 are provided between first
internal space 18, second internal space 19, pilot pressure chamber
45, and third internal space 20, respectively.
[0067] In case that very high pressures (at or above 200 bars, 300
bars or even higher) are present at the fluid inlet port 3, it is
even possible to omit main spring 43. This is because independent
of the tapered surface 13, being arranged on the inside of valve
tube 8, a relatively small residual force, tending to move the
valve tube 8 in the open position of valve unit 6, can usually not
be completely avoided. This design is even possible in connection
with the embodiment shown in FIG. 5. However, the design with main
spring 43 is preferred, in particular with respect to a 3/2 valve,
as shown in FIG. 5, because in that case a clear positioning of
valve tube 8 is clearly preferred.
[0068] In FIG. 5, a second possible embodiment of a pilot driven
valve 53 is shown. Pilot driven valve 53 is of a 3/2 type, i.e.
three fluid connections are provided, and states of the pilot
pressure valve 53 are provided. The pilot pressure valve 53 is very
similar to the pilot driven valve 41, shown in FIG. 4. However, a
third fluid port 54 is provided.
[0069] The third fluid port 54 connects to a ring chamber 55,
surrounding the moving path A of the valve tube 8. The ring chamber
55 and the length of the valve tube 8 (i.e. the position of the end
surface 52 of valve tube 8) are arranged in a way that third fluid
port 54 connects to the third internal space 20, if the valve unit
6 is in its closed state. Therefore, third fluid port 54 and fluid
outlet port 4 are connected to each other. However, neither fluid
outlet port 4, nor third fluid port 54 is connected to the fluid
inlet port 3.
[0070] However, if the pilot driven valve 53 is in its fully open
position, the part of the valve tube 8 near the end surface 52
completely covers the ring chamber 55. Therefore, the third fluid
port 54 is cut off from the third internal space 20. However, fluid
inlet port 3 and fluid outlet port 4 are fluidly connected to each
other.
[0071] Of course, intermediary states are also possible for the
pilot driven valve 53.
[0072] In FIG. 6, a pilot controlled fluid pressure regulator 56 is
depicted. The pilot controlled fluid pressure regulator 56,
combines the features of the pressure regulators 1, 28, 35, shown
in FIGS. 1,2 and 3 and the pilot driven valves 41, 53, shown in
FIGS. 4 and 5.
[0073] More precisely, the pressure controlled fluid pressure
regulator 56 can be considered to be a fluid pressure regulator 1,
as shown in FIG. 1, in which a pilot control section 33, comprising
an additional closing chamber 57 is provided. The closing chamber
57 is fluidly connected to the first internal space 18 via a
feeding line 48 and a connecting line 47. The fluid flux through
the feeding line 48 is limited by a throttle 51, which can be
formed as a part of the feeding line 48. If the piloting valve 50
is in its closed position (as shown in FIG. 6), the pressure in the
closing chamber 57 will eventually be the same as the pressure in
the first internal space 18. Therefore, the pressure of the fluid
in closing chamber 57 exerts a force on the flange part 38 of valve
tube 8. This will cause the valve tube 8 to move to the left side,
i.e. pushing the valve tube 8 on the valve seat 7, thus closing the
valve unit 6. Therefore, the pilot controlled fluid pressure
regulator 56 can be safely closed, irrespective of the fluid
pressure in third internal space 20, i.e. irrespective of the fluid
pressure at the fluid outlet port 4. Of course, the second internal
space 19, lying on the flange part 38 of the valve tube 8, which is
opposite to the closing chamber 57, is vented to ambient pressure
via channel 46.
[0074] If the piloting valve 50 is switched to its open position,
however, a fluid connection is established between connecting line
47 and third internal space 20 via piloting valve 50 and discharge
line 49. Therefore, the pressure in the closing chamber 57 will
drop to the pressure level of third internal space 20. This is,
because the influx of fluid is limited by throttle 51. Because of
the falling pressure within closing chamber 57, the valve tube 8 is
now again free to move to the right side, i.e. into the open
position of valve unit 6. Whether this movement will actually take
place, or not, depends on the pressure in third internal space 20.
Therefore, the pilot controlled fluid pressure regulator 56 now
works as a standard fluid pressure regulator.
[0075] FIG. 7 is a modification of the pilot controlled fluid
pressure regulator 56, shown in FIG. 6. The presently shown pilot
controlled fluid pressure regulator 58 shows an additional
balancing section 33, which is equivalent to the balancing section
33 of the pressure regulator 28, shown in FIG. 2. In other words,
the fluid pressure regulator 28, shown in FIG. 2, can be modified
by providing a pilot control section 59. This way, a pilot
controlled fluid regulator 58, which is fluid pressure regulated
(in particular towards the high pressure side of the pilot
controlled fluid pressure regulator), can be realised.
[0076] Further information can be drawn from the application, which
was filed by the same applicant on the same date under applicant's
reference number DAN08004PE. The disclosure of said application is
fully integrated into the disclosure of the present application by
reference.
[0077] While the present invention has been illustrated and
described with respect to a particular embodiment thereof, it
should be appreciated by those of ordinary skill in the art that
various modifications to this invention may be made without
departing from the spirit and scope of the present.
* * * * *