U.S. patent application number 11/206794 was filed with the patent office on 2005-12-22 for valve for controlling a fluid flow.
This patent application is currently assigned to MANN & HUMMEL GMBH. Invention is credited to Dworatzek, Klemens, Muenkel, Karlheinz.
Application Number | 20050279336 11/206794 |
Document ID | / |
Family ID | 30468986 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050279336 |
Kind Code |
A1 |
Dworatzek, Klemens ; et
al. |
December 22, 2005 |
Valve for controlling a fluid flow
Abstract
A valve for controlling a fluid flow, in particular for
crankcase venting of an internal combustion engine, including a
base body, a valve body and a biasing means, the base body having a
valve side and an opposite side situated opposite the valve side, a
part of the valve body protruding through an opening situated in
the base body, the biasing means, in particular a compression
spring, being arranged between the opposite side of the base body
and the valve body and supported against the opposite side of the
base body.
Inventors: |
Dworatzek, Klemens;
(Edingen, DE) ; Muenkel, Karlheinz;
(Oberderdingen-Flehingen, DE) |
Correspondence
Address: |
CROWELL & MORING LLP
INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
MANN & HUMMEL GMBH
Ludwigsburg
DE
|
Family ID: |
30468986 |
Appl. No.: |
11/206794 |
Filed: |
August 19, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11206794 |
Aug 19, 2005 |
|
|
|
10619553 |
Jul 16, 2003 |
|
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Current U.S.
Class: |
123/572 |
Current CPC
Class: |
B01D 35/1576 20130101;
F16K 17/0413 20130101; B01D 29/23 20130101; Y10T 137/7934 20150401;
B01D 35/16 20130101; B01D 35/30 20130101; B01D 2201/204 20130101;
B01D 2201/295 20130101; B01D 36/001 20130101; B01D 2201/162
20130101; Y10T 137/7933 20150401; B01D 35/147 20130101; B01D 35/157
20130101; B01D 35/1573 20130101 |
Class at
Publication: |
123/572 |
International
Class: |
F02B 025/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 16, 2002 |
DE |
102 32 045.4 |
Claims
What is claimed is:
1. A valve for controlling a fluid flow comprising a base body, a
valve body, and a spring, said base body comprising a valve side
and an opposite side situated opposite said the valve side, wherein
a part of the valve body protrudes through an opening in the base
body, and the spring is disposed between the opposite side of the
base body and the valve body and supported against said opposite
side of the base body, and wherein the part of the valve body which
protrudes through the opening in the base body is constructed as a
guide dome which is guided in a valve body guide on the base
body.
2. A valve according to claim 1, wherein said spring comprises a
compression spring.
3. A valve according to claim 1, wherein another part of the valve
body which protrudes through another opening in the base body is
constructed as an abutment for the spring.
4. A valve according to claim 3, wherein the another part of the
valve body which protrudes through another opening in the base body
is constructed as a snap hook.
5. A valve according to claim 1, wherein operating characteristics
of the valve, which are defined by the combination of the spring
with the valve body and the base body, are adjustable in a
controlled manner.
6. A valve according to claim 5, wherein the valve characteristic
is variable by an axial adjustment of the abutment.
7. A valve according to claim 5, wherein the operating
characteristics of the valve are variable by replacing the
spring.
8. A valve according to claim 7, wherein the spring is replaceable
manually without the use of tools.
9. A valve according to claim 1, further comprising a sealing
element provided directly on the valve body.
10. A valve according to claim 9, wherein said sealing element is
made of an injection moldable material integrally molded on the
valve body.
11. A valve according to claim 1, further comprising a sealing
element provided directly on said base body.
12. A valve according to claim 11, wherein said sealing element is
made of an injection moldable material integrally molded on the
base body.
13. A valve according to claim 1, wherein the spring is made of an
injection moldable material integrally molded on the base body.
14. A valve according to claim 1, further comprising a clamping
device which acts upon the valve body in at least one end position
thereof with a clamping force exerted in a direction transverse to
a direction of movement of the valve body.
15. A valve according to claim 1, wherein said valve is disposed in
a filter housing on a crankcase gas vent line extending between an
internal combustion engine crankcase and an air intake tract of the
internal combustion engine.
16. A filter device for purifying a fluid stream comprising a
filter housing having an inlet, an outlet, a filter element in said
housing sealingly separating the inlet from the outlet, a housing
cover, and a pressure relief valve for releasing excess pressure
from within said housing, wherein said valve is a valve according
to claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of patent application Ser.
No. 10/619,553, filed Jul. 16, 2003, the entire disclosure of which
is incorporated herein by reference. Priority is claimed based on
German Patent Application No. DE 102 32 045.4, filed Jul. 16,
2002.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a valve for controlling a
fluid flow comprising a base body, a valve body and a biasing
means, particularly a valve for regulating a flow of crankcase
gases from an internal combustion engine crankcase vent, and to a
filter device comprising a flow regulating valve of the
aforementioned type.
[0003] Examples of valves of this type are disclosed in published
German Patent Application No. DE 199 49 564 A1; in German Patent
No. DE 196 05 426 C2, and in German Utility Model No. DE 200 04 431
U1. In each case the actual valve always comprises at least four
parts, namely a base body and a valve body, each correspondingly
designed to achieve a sealing effect, a biasing element and a
support for this biasing element. Thus, it is always necessary to
provide support by a supporting structure independently of the
valve. In a simple case, this may require only a supporting dome,
but in a more complex case it requires supporting brackets, which
present the least possible obstacle to flow. This makes the
manufacturing process complex and expensive.
SUMMARY OF THE INVENTION
[0004] The object of the invention is to provide an improved valve
having a simple design.
[0005] Another object of the invention is to provide a valve which
can be used universally.
[0006] A further object of the invention is to provide a valve
which takes up very little space.
[0007] An additional object of the invention is to provide a valve
which is relatively inexpensive to manufacture.
[0008] It is also an object of the invention to provide a valve
which can be used as a pressure regulating valve or as a
straight-way valve.
[0009] These and other objects are achieved in accordance with the
present invention by providing a valve for controlling a fluid flow
comprising a base body, a valve body, and a biasing means, said
base body having a valve side and an opposite side situated
opposite said the valve side, wherein a part of the valve body
protrudes through an opening in the base body, and the biasing
means is disposed between the opposite side of the base body and
the valve body and is supported against said opposite side of the
base body.
[0010] Advantageous further refinements and preferred embodiments
are additionally described in detail hereinafter.
[0011] The valves of the invention are preferably used in filter
systems used for filtering a stream of gas or liquid, e.g.,
crankcase vents or oil modules in internal combustion engines.
However, they may also conceivably be used in any other devices in
which control valves or opening valves and/or overflow valves are
used to control and/or regulate fluid flow.
[0012] The valve of the present invention includes a base body,
which is preferably constructed radially and disk-shaped and has an
integrated valve body guide and through openings. This base body,
which connects the valve to the particular housing in which the
valve is installed, may have any basic shape, i.e., it may be
angular, spherical or cylindrical. The valve body guide integrated
into the base body is preferably designed as a radial hollow
cylinder to securely guide the valve body on the inside and/or
outside wall surface and to prevent tilting of the valve body.
Likewise, however, this guide may comprise a plurality of cylinders
or it may have an angular base area. The opening integrated into
the base body should allow a fluid to pass through while also
allowing one or more parts of the valve body to protrude through
the base body. The shape of the opening is freely selectable and
may be chosen individually. In a preferred case there are multiple
openings in the form of sectors of circles to allow the fluid
passage and for protrusion of parts of the valve body, which serve
to accommodate the biasing means, and also a radial through opening
to accommodate a guide dome for the valve body.
[0013] The valve body may be designed in the shape of a ball, a
cylinder, a plate or a cone, or it may have some other shape known
from the state of the art. First, it must achieve a mating seal
with the base body, and second, it must offer a possibility of
accommodating a biasing means. The valve body is preferably
designed as a circular plate having portions which protrude through
the base body for accommodating the biasing means. The biasing
means is a resilient element, which may be designed, e.g., as a
block spring, a coil or helical spring, a rubber band or as a
resilient plastic foam. A helical spring is preferred to achieve an
axial force which is uniformly distributed radially and to make it
possible to obtain different spring characteristic curves with
springs having the same outside dimensions. However, any resilient
elements known in art may conceivably be used. Likewise,
compression springs are preferable to tension springs because they
offer advantages in terms of the technical design and
economics.
[0014] Through a corresponding combination of base body, valve body
and tension or biasing element, a releasable sealing connection is
achieved between the valve body and the valve side of the base body
facing the valve body. For this purpose, a part of the valve body
extends through an opening in the base body, which may have any
desired shape, and provides a seat for accommodating the biasing
means, which is consequently supported between the side of the base
body facing away from the valve body and the part of the valve body
protruding through the base body. In an advantageous embodiment of
this invention, this seat or support on the valve body is provided
by an abutment, in particular a snap hook. However, simple hooks,
notches, a bore with a pin and other accommodation possibilities
known in the state of the art are also conceivable. In the basic
state, the biasing means is supported between the base body and the
valve body and thus reverses the induction of force of the holding
force known in the state of the art, so the valve is pulled closed
instead of being pushed to close it. If a sufficient force counter
to the direction of force exerted by the biasing element is exerted
on the valve body because of a pressure difference which overcomes
the force of the biasing element, the valve body will be lifted up
from the base body, thereby opening the valve, which is closed in
the basic state. For sealing, sealing means such as sealing rings
or the like may be provided.
[0015] Due to this design, it is possible on the one hand for the
valve to be used universally, regardless of the presence of a
support on the housing side, thus simplifying production of the
housing, while on the other hand, the manufacturing cost and the
manufacturing complexity of the valve are extremely low. In an
ideal case, this valve may consist of two simple parts. This means
minimizing the design down to what is essential without any loss of
function. Likewise, this results in a much smaller space
requirement than is the case with traditional valves according to
the state of the art, and traditional systems based on tension
springs can be replaced easily by the system presented above.
[0016] According to one advantageous embodiment of this invention,
the valve body includes a guide dome which extends through the base
body through the corresponding valve body guide and thus prevents a
radial displacement in relation to the base body or tilting of the
valve body so that a reliable seal is ensured. This guide dome may
be designed as a cylindrical pin, a hollow cylinder or intersecting
webs, and many embodiments known from the state of the art may be
used. Likewise, a plurality of guide domes may be arranged in a
distributed configuration. However, the guide dome must be designed
to correspond to the design of the valve body guide.
[0017] According to another embodiment of this invention, the valve
guide of the base body may be designed with a possibility of
controlled adjustment of the combination of the biasing means with
the valve body and the base body and thus the valve characteristic.
Thus, valves having essentially the same design may have completely
different characteristics. Due to the varying opening times, this
results in different flow volumes and an altered opening and/or
closing behavior of the valve. In the case of a valve with a soft
setting, a lower pressure difference is sufficient for opening the
valve; likewise, the valve then also closes later and thus permits
a greater volume flow between the opening and closing of the valve.
When there is an increase in the holding force, i.e., when the
valve setting becomes harder, the valve opens only at a greater
pressure difference and it closes sooner. The targeted adjustment
may be continuous or occur in stages, and thus any desired valve
characteristic can be achieved in a controlled manner. The
advantage results from the possibility of adapting valves having
the same construction to different pressure situations, which
possibly change during operation, and using these similarly
constructed valves in different devices.
[0018] In yet another advantageous embodiment, the adjustment
described above can be carried out by adjusting the abutment. This
preferably refers to an axial adjustment with a thread on the valve
guide of the base body, for example, and a nut, which increases or
decreases the load on the biasing means. Likewise, spacers,
designed for example as disks, arranged on the side of the base
body which contacts the biasing means or on the valve body may
accomplish this adjustment. As an alternative, a locking or
clamping means may also be provided to alter the characteristic
curve of the biasing means. With an appropriate design, such
adjustment options could preferably be accomplished without the use
of tools so that, if necessary, the spring curve can be adjusted
regardless of location or the availability of tools.
[0019] Likewise, in another embodiment, the valve characteristic,
namely the opening and/or closing pressure, can be changed by a
simple and quick replacement of the biasing means. To do so, the
biasing means is removed from the valve guide of the valve body and
then a replacement biasing means having a different spring
characteristic is inserted. In a modification of this design, this
replacement can be accomplished without the use of tools, with the
biasing means being supported by snap hooks in the valve guide of
the valve body and these snap hooks being elastically compressible
by hand to release the biasing means. Because of the permanent
resilient elasticity of the snap hooks, the new biasing means,
preferably a helical spring, can also be introduced again
permanently. However, other tool-less replacement options, e.g., a
wing nut, which represents the abutment and is secured via an end
stop or similar solutions known from the state of the art, are also
conceivable.
[0020] In advantageous embodiments, the valve body and/or the base
body is made of materials suitable for injection molding. Preferred
materials here include, e.g., polyamide [nylon], which is
characterized by a good thermal stability, strength and a certain
resistance to corrosive media. The temperatures normally prevailing
in a crankcase vent or an oil module are approximately in a range
between a starting temperature of approx. -20.degree. C. up to an
operating temperature of approx. 130.degree. C. Due to the simple
design of the valve part, the injection mold can be produced
readily, which has a positive effect on the overall cost of the
valve. The valve material can thus be adapted to the particular
requirements of the installation situation. A simple and
nevertheless secure seal between the valve seat and the valve body
can be achieved in this way by integrally molding the sealing means
on the valve body or on the base body, in particular by the
two-component injection molding technique with polyamide, for
example, as the base component and a thermoplastic elastomer as the
soft, seal-forming component. A preferred seal is an annular
gasket. However, a sealing bead or some other sealable embodiment
known from the state of the art may also be used.
[0021] In another embodiment, the biasing means, preferably a
plastic compression spring or a resilient elastomer block is
injection molded directly onto the base body, in addition to the
sealing means. This yields an advantageous valve which consists of
only two elements and is thus simple to manufacture and easy and
universal in use.
[0022] In another advantageous embodiment, a clamping device
associated with the valve is provided, which acts upon the valve
body in at least one of its two end positions with a clamping force
which is exerted transversely to the direction of valve body
movement. To influence the spring characteristic and the opening
and/or closing behavior, the valve may be provided with a clamping
device which acts upon the valve body with a clamping force which
is exerted in the radial direction transversely to the direction of
valve body movement and securely clamps the valve body in the valve
body guide. The clamping device includes an additional tension or
biasing element, in particular a spring, which is designed in
particular as a compression spring. This additional biasing means
is connected at both axial ends to locking elements, in particular
locking balls, which are urged radially outwardly with a clamping
force due to the force of the additional biasing means and are
pressed into locking recesses, which are preferably formed in the
inside wall of the valve body guide and are advantageously adapted
to the shape selected for the locking balls. Likewise, however,
friction-locking connections are also conceivable.
[0023] The clamping device is in its locked position when the valve
is in the closed position, so that a greater pressure difference is
necessary for switching the valve to the open position than is the
case in embodiments without the clamping device. The level of the
additional pressure required for releasing the clamping device and
switching the valve to the open position can be influenced through
the force of the additional biasing means and through the geometry
of the locking elements acted upon by the additional biasing means
and the geometry of the locking recesses. After reaching the
limiting pressure above which the valve is switched to the open
position, the locking elements are first forced inward against the
force of the additional biasing means because of the axial
adjusting movement of the valve body in the direction of the
opening position, and as the opening movement progresses they
contact the inside wall of the valve body guide. The clamping
force, which is exerted by the clamping device on the inside wall
of the valve body guide in the switching section between the closed
and open positions is much lower than the clamping force in the
closed position of the valve, because in the locked end position,
the clamping device assumes a form-fitting locked position, but in
the intermediate switching section, it only glides along the inside
wall. In addition, it should also be noted that in the resting
position of the valve body, initially a greater static friction
must be overcome between the locking elements acted upon by the
additional spring and the locking recesses, whereas when the valve
body is moving, only a slight sliding effect occurs between the
locking elements that are urged outward and the inside wall of the
valve body guide. This sharp drop in the clamping force changes the
total spring characteristic and the opening behavior of the valve.
In comparison with embodiments from the state of the art, the valve
body can be switched from the closed position to the open position
at a higher switching speed. An abrupt switch to the open position
is possible with this valve.
[0024] Likewise, another clamping device is also conceivable,
having a design corresponding to that of the first clamping device
and including a second additional biasing element and axial locking
elements acted upon by the second additional biasing element. The
locking elements engage in locking recesses which are preferably
formed in the inside wall of the valve body guide. In this way, the
valve body is in a locked position in both its closed position and
its open position, from which it can be switched to the opposite
end position only by applying an increased force in comparison with
embodiments without the clamping devices. As a result, a desired
movement characteristic may be imparted to the valve, which can
lead to abrupt opening and/or closing of the valve.
[0025] The valve described above in various embodiments may be used
in a filter device, in particular in a crankcase vent having a
filter housing and a cover, with at least one inlet and at least
one outlet, the inlet and outlet being separated by a filter
element sealingly mounted in the housing. The inlet and outlet may
be arranged in any manner in the cover or in the filter housing.
The housing preferably has a cylindrical shape, but it may also be
designed in any desired shape. Crankcase vents are preferably used
in internal combustion engines, regardless of whether stationary or
moving. In addition, they may be used wherever the pressure in a
pressure space (such as a crankcase) is to be kept within a
pressure range, and fluid from that space, e.g., a gas-oil mixture,
is to be purified and/or separated. In the case of an internal
combustion engine, the pressure in the crankcase should always be
in the partial vacuum range from approximately -5 mbar to
approximately. -15 mbar relative to atmospheric pressure. This
negative pressure is needed to exhaust the so-called blow-by gases
formed in the combustion process, which go past the piston rings
into the crankcase, and not allow any gas to enter the combustion
chamber in the opposite direction. In rare cases, the pressure
range may vary between approximately -5 mbar and approximately +5
mbar relative to atmospheric pressure. These values are achieved,
for example, when the crankcase is connected directly to the
atmosphere, but this is neither desirable or allowed for
environmental protection reasons. Crankcase gases are drawn by the
crankcase vent out of the crankcase, because a relative partial
vacuum prevails within the crankcase vent with respect to the
crankcase. The oil-laden gases, which are withdrawn from the
crankcase, are purified as they pass through the filter element and
their oil content is separated.
[0026] If, because of some adverse circumstance, an excess pressure
should prevail in the filter housing upstream from the filter
element, it can be vented to the atmosphere through a pressure
relief valve. Oil which collects in the filter element can be
recycled back to the crankcase through a bypass valve integrated
into the filter element and a separate oil drain. An outlet on the
clean side of the filter system is connected to the air intake line
of the engine and is subjected to a relative partial vacuum, which
fluctuates greatly. These pressure fluctuations can be compensated
by a pressure regulating valve connected between the clean side of
the filter and the outlet to prevent any excessive pressure
difference from breaking through to the crankcase.
[0027] These three valves, which differ in function, can be
implemented by embodiments of the simplest valve. These embodiments
also allow very great volume flows of more than 1000 L/min, such as
those required in industrial motors, for example, without requiring
as much installation space as valves known from the state of the
art.
[0028] One advantageous construction of this filter device includes
a pressure regulating valve, in which embodiments of the valve
described above are supplemented with a roller diaphragm,
preferably on the outer radial end of the valve body end disk,
which separates a control pressure space from a passage through
which the fluid flow regulated by the valve flows. The control
side, which is preferably situated on the outside of the housing,
is accordingly connected to a control pressure, preferably
atmospheric pressure, whereas on the side through which the fluid
flows, the pressure difference of the flowing fluid prevails, here
preferably the pressure difference between the clean side and the
intake manifold pressure. This roller diaphragm, which unrolls to
maintain a seal between the valve body and a housing wall as the
valve body moves preferably axially, has the advantage that it
exerts virtually no force on the valve body and nevertheless makes
it possible for the valve body to move along a longer path to
control larger volume flows while at the same time taking up only a
very small amount of space. The valve characteristic is achieved
mainly through the biasing means and can thus be influenced in a
controlled manner through the embodiments mentioned above.
[0029] In a preferred embodiment of the filter device, the biasing
means of the pressure regulating valve is mounted on the control
side of the valve. This in turn produces the simple possibility of
maintaining and adjusting the valve characteristic utilizing the
possibilities described above for adjusting the biasing means,
because in preferred embodiments, the control side is accommodated
on the outside of the housing, which thus permits good
accessibility.
[0030] These and other features of preferred embodiments of the
invention, in addition to being set forth in the claims, are also
disclosed in the specification and/or the drawings, and the
individual features each may be implemented in embodiments of the
invention either alone or in the form of subcombinations of two or
more features and can be applied to other fields of use and may
constitute advantageous, separately protectable constructions for
which protection is also claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The invention will be described in further detail
hereinafter with reference to illustrative preferred embodiments
shown in the accompanying drawings in which:
[0032] FIG. 1 is a perspective view of a filter device having a
pressure relief valve arranged in the housing cover;
[0033] FIG. 2 is a longitudinal sectional view of the filter device
of FIG. 1;
[0034] FIG. 3 is a schematic diagram of a pressure relief valve
having a valve body which is acted upon by a clamping device
exerting a clamping force which acts transversely to the direction
of displacement of the valve body;
[0035] FIG. 4 shows a modified pressure relief valve embodiment
with two separately designed clamping devices which exert a
clamping force on the valve body of the pressure relief valve in
both its closed position and in its open position;
[0036] FIG. 5 is a perspective view of a simplified valve
embodiment having an integrated gasket and a compression spring as
a biasing element;
[0037] FIG. 6 is a schematic view of the simplified valve
embodiment of FIG. 5; and
[0038] FIG. 7 is a structural diagram of a pressure regulating
valve having a roller diaphragm in an open position, indicating the
direction of flow and the parts of interest on the housing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0039] The filter device 1 shown in FIG. 1 has a filter element,
through which a medium that is to be purified flows, disposed in a
generally cylindrical housing 2, which is closed by a removable
housing cover 3. The medium to be purified can be introduced into
the interior of the filter device in the direction of the arrow 5
through an inlet 4 situated on the side of the filter housing 2.
After the medium is purified by passage through the filter element,
it is discharged in the direction of the arrow 7 through an outlet
6 also situated on the side of the housing. The medium to be
purified may be gaseous or liquid.
[0040] According to one preferred embodiment, the filter device 1
is designed as an oil separator in which oil droplets are separated
from an oil-air mixture, these droplets being formed, e.g., in the
crankcase of an internal combustion engine. The air discharged from
the crankcase is purified by filtration and then sent in particular
to an intake tract of the internal combustion engine. However, an
application in a gas filter or a liquid filter may also be
considered.
[0041] As shown in FIG. 1 in combination with FIG. 2, a pressure
relief valve 8 is integrated into the housing cover 3, which is
situated in the area of an axial end face of the filter housing 2.
This pressure relief valve is acted upon by the pressure on the
inlet or unfiltered side of the filter element and is moved into
its open position if an allowed limiting pressure is exceeded, so
that the medium introduced on the unfiltered side can exit the
filter housing and an overload is prevented.
[0042] On the clean side of the filter device, there is a pressure
regulating valve 9 in the area of the outlet channel 6 to prevent
an excessive partial vacuum from developing in the crankcase. A
relatively low partial vacuum must always prevail here, varying
within a very narrow pressure range. If there is a very high
partial vacuum on the intake manifold side, it will propagate
against the direction of outflow 7 through the pressure regulating
valve 9, which is open in the normal case, and against the
direction of inflow 5 into the crankcase. The pressure regulating
valve 9 is in the open position when a relative partial vacuum
within the desired pressure range prevails on the clean side
relative to the outside of the filter device 2. This is achieved by
a presetting of the pressure regulating valve 9 by appropriate
selection or adjustment of the valve spring 23. However, if the
relative partial vacuum with respect to the pressure on the outside
of the filter device 2 exceeds the initial tension force of the
valve spring 23 acting against this pressure, then the pressure
regulating valve 9 is moved into its closed position.
[0043] As also shown by the sectional diagram according to FIG. 2,
the medium to be purified is introduced through the inlet 4 into
the interior of the filter housing 2 in which there is a
cylindrical filter element 11 whose radial inside forms the
unfiltered side and through which the fluid to be purified flows
radially from the inside to the outside. In the case of a
separator, the separated oil droplets are diverted downward along
the radial inside of the filter element 11. The purified air passes
radially through the filter element from the inside to the outside,
is collected in an annular space radially surrounding the filter
element 11 and is conducted to the outside after passing through
the pressure regulating valve 9.
[0044] A certain quantity of oil collects in the interior of the
filter element 11 due to influx and deflection as well as expansion
and changes in velocity of the fluid flow. In the normal case, this
oil collected in the interior is gradually drawn through the filter
element 11 from the unfiltered side to the clean side due to the
pressure difference. In the event of a blockage of the filter
element 11 or an accumulation of too much oil, there is a bypass
valve 10 in the bottom area of the interior of the filter element
11, which is switched to its open position when a minimum pressure
is exceeded, whereupon the droplets of separated oil are discharged
toward the bottom through a conically tapered area of the filter
housing 2 as well as an outlet 12.
[0045] FIG. 3 shows a specific embodiment of a pressure relief
valve 8. This pressure relief valve 8 has a valve body 22, which is
movable axially in a valve body guide 27 in the direction indicated
by arrow 26 between the closed position illustrated in FIG. 5 and a
raised open position. The valve body guide 27 is designed in a
housing part 25. The valve body 22 is urged toward its closed
position by a valve spring 23, which is supported on a valve plate
24 that is fixedly connected to the valve body 22. If an excess
pressure which exceeds the closing force of the valve spring 23
develops in the interior of the housing, the valve body 22 will be
moved to its open position so that the excess pressure can
escape.
[0046] To influence the spring characteristic and the opening
and/or closing behavior, the pressure relief valve 8 is provided
with a clamping device 28 which acts upon the valve body 22 with a
clamping force which is exerted in the radial direction indicated
by arrow 29 transversely to the direction of movement indicated by
arrow 26 and securely clamps the valve body 22 in the valve body
guide 27. The clamping device 28 is fixedly connected to the valve
body 22 and includes an additional spring 30, which is designed in
particular as a compression spring and whose spring action acts in
the direction of arrow 29. At both its axial end faces, the
additional spring 30 is connected to locking balls 31, which are
subjected to a clamping force due to the force of the additional
spring acting radially outward and are urged into locking recesses
32, which are formed in the inside wall of the valve body guide 27
and are advantageously adapted to the shape of the locking balls
31. The clamping device 28 is in its locked position when the valve
body 22 is in the closed position, so that a higher excess pressure
is necessary for switching the pressure relief valve 8 to the open
position than is the case with embodiments without the clamping
device 28. The amount of the additional pressure required for
releasing the clamping device 28 and switching the valve to the
open position can be influenced by the force of the additional
spring 30 and the geometry of the locking elements on which the
additional spring acts and the geometry of the locking
recesses.
[0047] After reaching the limiting pressure above which the valve
is switched to the open position, the locking balls 31 are first
forced inward against the force of the additional spring 30 because
of the axial adjusting movement of the valve body toward the open
position, and as the opening movement progresses, they contact the
inside wall of the valve body guide 27. The clamping force which is
exerted against the inside wall of the valve body guide by the
clamping device in the intermediate switching section between the
closed position and the open position is much lower than the
clamping force in the closed position of the valve, because in the
closed position, the clamping device assumes a form-fitting locked
position, but in the intermediate switching section, it merely
slides along the inside wall. In addition, it should be taken into
account that in the resting position of the valve body, a higher
static friction must first be overcome between the locking elements
which are urged by the additional spring into the locking recesses,
whereas during movement of the valve body, only a lower sliding
effect is operative between the locking elements that are urged
outward and the inside wall of the valve body guide.
[0048] This sharp drop in the clamping force alters the overall
spring characteristic and the opening response of the valve. The
valve body can be switched from the closed position to the open
position at a higher switching speed in comparison with embodiments
known from the state of the art. Thus, the valve can be switched
abruptly to the open position.
[0049] Again in the illustrative embodiment according to FIG. 4, a
pressure relief valve 8 is shown, which is in its closed position
and is moved axially in the direction indicated by arrow 26 between
the closed position and the open position. Like the valve in the
preceding illustrative embodiment, this valve has a clamping device
28 which acts upon the valve body 22 in the closed position with a
clamping force exerted in the direction indicated by arrow 29
transversely to the direction of valve body movement indicated by
arrow 26. In addition, a second clamping device 33 is provided,
having a design corresponding to that of the first clamping device
28 and also including another additional spring 34 and axial
locking balls 35 acted upon by the second additional spring 34. In
the open position of the valve, the locking balls 35 engage in
locking recesses 36 which are formed in the inside wall of the
valve body guide 27. In this way, in both the closed position and
the open position, the valve body 22 is in a locked position from
which it can be switched to the respective opposite end position
only by applying a high force in comparison with embodiments
without clamping devices. The closing movement of the valve is
supported here by the force of the valve spring 23. As soon as the
excess pressure in the interior of the housing exceeds a limiting
value, the force of the valve spring is sufficient to move the
valve body 22 axially toward its closed position against the
remaining excess pressure in the interior of the housing and
against the clamping force of the second clamping device 33. Like
the opening movement, abrupt closing of the valve can be achieved
with the help of the second clamping device 33, because the
clamping force is reduced abruptly as soon as the locking balls 35
of the second clamping device 33 have been lifted out of their
seats in the locking recesses 36.
[0050] FIG. 5 shows an exploded perspective view of a simplest
valve 43 which may be used as a pressure relief valve 8, a pressure
regulating valve 9 or a bypass valve 10. Valve 43 comprises a
cylindrical, essentially plate-shaped base body 37 which includes a
valve body guide 27 for accommodating a guide dome 38 on the
cylindrical essentially plate-shaped valve body 22. The base body
has a valve side 45, which has a sealing function, and an opposite
side 46. In addition, the valve body 22 has an abutment 48 arranged
radially around the guide dome 38. Accurate centering of the valve
body 22 is ensured by an accurate fit between the guide dome 38 and
the valve body guide 27. The seal between the valve body 22 and the
base body 37 is provided here by an annular gasket 40, which is
integrated into the valve body 22 and is in sealing contact with
the base body 37 when the valve is closed. The abutment 48 is
divided into a plurality of parts in order to be able to penetrate
through the base body 37 through the existing openings 47 and to a
form a support for the biasing means 23, in particular a helical
spring. The components 22 and 23 are assembled in the direction of
arrows "a" and "b" shown in FIG. 5.
[0051] FIG. 6 shows a schematic view of a simplest valve 43 in the
installed state. The parts corresponding to those in FIG. 5 are
identified by the same reference numerals. As can be seen from FIG.
6 in combination with FIG. 5, the biasing means 23 exerts a
compressive force on the base side 46 of the base body and thus
pulls the valve body 22 toward the biasing means and against the
valve side 45 of the base body 37, thereby forming a seal. This is
a reversal of the traditional principle in which the valve body is
pressed against the base body. In the open state the biasing means
23 is compressed against the opposite side 46 by an applied minimum
pressure difference, the sealing means 40 is lifted up from the
valve side 45 thereby enabling a fluid flow through the openings
47.
[0052] It can be seen here that this simplest valve can execute a
valve function with very few simple parts without requiring an
opposed support surface, which is otherwise conventional, in the
area of the installation housing. This yields not only a positive
cost factor on the valve side but also greatly simplifies the
design and manufacture of the installation housing.
[0053] FIG. 7 shows an embodiment of the simplest valve 43 as a
pressure regulating valve 9 in an enlarged detail view
corresponding to a portion of FIG. 2 in the open position. Parts
corresponding to those in FIG. 2 are identified by the same
reference numerals. The gases to be purified flow radially through
the filter element 11 from the inside to the outside and when the
pressure regulating valve 9 is open, the purified gases are
supplied to the intake air again through an outlet channel 6. The
pressure is regulated based on the difference between the pressure
in the outside chamber 44, which is situated in the outer area of
the housing on the side which is at atmospheric pressure and
through which the gases do not flow and which represents the
control side 49 here, and the pressure in the clean gas area on the
flow-through side 50 downstream from the filter element 11. The two
areas are separated by a roller diaphragm 39, which is connected to
the valve body 22 and allows the valve body 22 to move along a path
in the spring direction and while exerting virtually no force on
the overall system. The adaptation of the pressure regulating valve
9 to the required pressure difference is accomplished by
appropriate selection or adjustment of the spring force of the
valve spring 23. If the pressure difference is too great, i.e., if
the intake manifold vacuum is too great, the pressure regulating
valve 9 closes the path from the clean gas side to the outlet
channel 6 by lifting the valve body 22 from the base body 37 and
pressing the gasket 40 on the valve body 22 against a separating
collar 41. This separating collar 41 has essentially a radial
construction and ensures a plane of separation between a clean side
51 and an outlet side 52, both in the area of the through-flow side
50. In this way, the outlet channel 6 is closed. As soon as the
pressure difference drops again and the counteracting spring force
of the valve spring 23 is large enough, the valve body 22 is
released from the separating collar 41 and fluid is again able to
flow through the path from the clean side 51 to the outlet side 52.
The desired triggering pressure difference can be adjusted by
varying the spring force. On the basis of one embodiment of the
pressure regulating inventive valve, this change in the spring
force can be accomplished easily from the outside of the housing.
To do so, the protective cover 42 which is situated above the
outside pressure chamber 44 can be removed without the use of
tools, releasing the abutment 48 together with the clamped valve
spring 23. By simple radial compression of the snap hooks, which
form the abutment 48, the valve spring 23 can be removed and
replaced with another spring having a different characteristic.
Likewise an adjustment by varying the axial length of the space in
which the spring is compressed and the resulting change in spring
force is also conceivable.
[0054] The foregoing description and examples have been set forth
merely to illustrate the invention and are not intended to be
limiting. Since modifications of the described embodiments
incorporating the spirit and substance of the invention may occur
to persons skilled in the art, the invention should be construed
broadly to include all variations within the scope of the appended
claims and equivalents thereof.
* * * * *