U.S. patent application number 09/402772 was filed with the patent office on 2002-05-09 for pressure regulating valve.
Invention is credited to FREI, WALTER, GIERER, GEORG, MAYR, KARLHEINZ, REMMLINGER, HUBERT, RUNGE, WOLFGANG, SCHMID, WOLFGANG, SCHMIDT, THILO.
Application Number | 20020053362 09/402772 |
Document ID | / |
Family ID | 26035859 |
Filed Date | 2002-05-09 |
United States Patent
Application |
20020053362 |
Kind Code |
A1 |
FREI, WALTER ; et
al. |
May 9, 2002 |
PRESSURE REGULATING VALVE
Abstract
Pressure regulating valve comprising a connection for a pressure
line (P), a connection for a working line (A), a connection for an
outlet line (T) communicating with the ambient pressure and at
least two diaphragm stages with defined or definable drag, the two
diaphragm stages being connected to each other in a variable manner
and subject to mechanical or hydraulic action according to the
principle of the hydraulic half bridge. The two variable diaphragm
stages are provided as the inlet and outlet diaphragms of a
pressure regulating chamber (7) and each has a sealing element,
said sealing element (5) of the inlet diaphragm (3) is designed as
ball, or calotte, or truncated cone, or cylinder and/or the sealing
element of the outlet diaphragm is designed as ball, or calotte, or
truncated cone, or cylinder.
Inventors: |
FREI, WALTER;
(FRIEDRICHSHAFEN, DE) ; GIERER, GEORG;
(KRESSBRONN, DE) ; RUNGE, WOLFGANG; (RAVENSBURG,
DE) ; REMMLINGER, HUBERT; (FRIEDRICHSHAFEN, DE)
; MAYR, KARLHEINZ; (WASSERBURG, DE) ; SCHMID,
WOLFGANG; (LANGENARGEN, DE) ; SCHMIDT, THILO;
(MECKENBEUREN, DE) |
Correspondence
Address: |
ANTHONY G M DAVIS
DAVIS AND BUJOLD
500 NORTH COMMERCIAL STREET
FOURTH FLOOR
MANCHESTER
NH
03101
|
Family ID: |
26035859 |
Appl. No.: |
09/402772 |
Filed: |
October 7, 1999 |
PCT Filed: |
April 11, 1998 |
PCT NO: |
PCT/EP98/02128 |
Current U.S.
Class: |
137/596.17 |
Current CPC
Class: |
Y10T 137/87217 20150401;
G05D 16/2024 20190101; Y10T 137/86622 20150401 |
Class at
Publication: |
137/596.17 |
International
Class: |
F15B 013/044 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 1997 |
DE |
197 44 696.5 |
Apr 18, 1997 |
DE |
197 16 135.9 |
Claims
1. Pressure regulating valve having a connection for a pressure
line (P), a connection for a working pressure line (A) and a
connection for an outlet line (T) to the ambient pressure and with
at least two diaphragm stages with defined or definable drag of
which two diaphragm stages (109, 111) are connected with each other
in variable manner and subject to mechanical or hydraulic action
according to the principle of the hydraulic half bridge,
characterized in that the two variable diaphragm stages are
provided as inlet and outlet diaphragms of a pressure regulating
chamber and each one has a sealing element, the sealing element of
the inlet diaphragm being designed as ball, or calotte, or
truncated cone, or cylinder and/or the sealing element of the
outlet diaphragm being designed as ball, or calotte, or truncated
cone, or cylinder.
2. Pressure regulating valve according to claim 1, characterized in
that it is constructed as system of two variable diaphragm stages
(109, 111) connected subject to mechanical or hydraulic action.
3. Pressure regulating valve according to claim 1, characterized in
that it is constructed as system of three diaphragm stages having a
first fixed diaphragm stage (103) on the pressure side and two
variable diaphragm stages(109, 111) connected subject to mechanical
or hydraulic action.
4. Pressure regulating valve according to any one of the preceding
claims, characterized in that it is used to regulate the hydraulic
pressure for actuating transmission shifting elements.
5. Pressure regulating valve according to any one of the preceding
claims, characterized in that the two variable diaphragm stages are
lodged in one part wherein one diaphragm is designed as inlet
diaphragm in a pressure regulating chamber (7) in the form of a
hole through a valve housing (1), which hole can be covered with a
sealing element and the other diaphragm is designed as outlet
diaphragm in the form of a seat valve in which one axial wall
surface (4) of the valve housing (1) covers a sealing surface (6)
of a sealing element, particularly of an armature rod (10), and
wherein a stud-shaped control shift valve (12) which abuts in axial
direction on the armature rod (10), can push the sealing element of
the inlet diaphragm out of its seat and thus connect the two
diaphragms by, on one hand, establishing the inlet diaphragm cross
section by covering the intake hole surface with the sealing
element and, on the other, determining the outlet diaphragm surface
by the spacing between the axial wall surface (4) and the sealing
surface (6).
6. Pressure regulating valve according to any one of the preceding
claims, characterized in that a cage (14) is provided for lodging
the sealing element (5).
7. Pressure regulating valve according to any one of the preceding
claims, characterized in that the sealing element is designed in
one piece with the control shift valve (12).
8. Pressure regulating valve according to any one of the preceding
claims, characterized in that both mechanically connected
diaphragms are regulated by a control shift valve (12) which has a
double-sided cone with a tapering in the center.
9. Pressure regulating valve according to any one of the preceding
claims, characterized in that it can be magnetically actuated.
10. Pressure regulating valve according to any one of the preceding
claims, characterized in that it can be piezo-electrically or
pneumatically actuated.
11. Pressure regulating valve according to anyone of the preceding
claims, characterized in that the two connected diaphragm stages
(109, 111) are regulated diaphragms which are lodged in one part
wherein one of the regulated diaphragms is designed as inlet
diaphragm in a cylindrical pressure regulating chamber (7) in the
form of at least one radial intake hole through a valve housing (1)
and the other is designed as outlet diaphragm in the form of a seat
valve in which an axial wall surface (4) of the valve housing (1)
covers a sealing surface (6) of an armature rod (10) and wherein a
control shift valve (12) consisting of one sleeve (105) and one
connecting piece (8) to the armature rod (10) mechanically
connected adjusts the two diaphragms by, on one hand, establishing
the inlet diaphragm cross section by covering the intake hole
surface with its sleeve surface and, on the other, by determining
the outlet diaphragm surface by the spacing between the axial wall
surface (4) and the sealing surface (6).
12. Pressure regulating valve according to anyone of the preceding
claims, characterized in that its positioning force is applied by
the force which an electromagnet exerts on the induced, magnetic
torque of a soft-iron armature, the armature (13) being pressure
upon the armature rod (10).
13. Pressure regulating valve according to any one of the preceding
claims, characterized in that the armature rod (10) and the control
shift valve (12) are designed in one piece.
14. Pressure regulating valve according to any one of the preceding
claims, characterized in that the inlet diaphragm has in the valve
housing (1) several radial intake holes which are connected via an
annular duct with a front-mounted, fixed diaphragm as first
diaphragm stage.
15. Pressure regulating valve according to anyone of the preceding
claims, characterized in that the sealing surface (6) is provided
on a front side of the armature rod (10).
16. Pressure regulating valve according to claim 15, characterized
in that the area between the front surface of the armature rod (10)
and the control shift valve (12) is frustoconically designed.
Description
[0001] The invention relates to a proportional pressure regulating
valve of the 3/2 directional type consisting of a valve housing
which has a regulating pressure chamber and with a pressure medium
sump line and with at least two diaphragm stages with defined or
definable drag of which two diaphragm stages are connected with
each other according to the principle of the hydraulic half
bridge.
[0002] DE-C 44 26 152 describes an electromagnetic pressure
regulating valve, especially for regulating the shift pressure of
automatic motor vehicle transmission, which has a valve housing and
control shift valve actuatable by a magnetic armature and connected
therewith, which controls connections from a pressure medium intake
to a consumer connection or a return flow or tank. The control
shift valve is situated in a rear and in a front bearing point in
the valve housing and is prestressed via an adjusting spring. With
this pressure regulating valve there are throughout the service
life no changes of the valve characteristic resulting from problems
caused by dirty oil, since a pressure drop relative to a through
flow, especially of the dirt-sensitive armature chamber, is
prevented. In the inlet area on the bearing gap and on the outlet
opening of the current path from the ventilation hole, the same
velocity energy potential prevails.
[0003] U.S. Pat. No. 3,915,932 has further disclosed a valve which
has two diaphragm stages connected according to the principle of
the hydraulic half bridge and is used as volume governor for
dividing a pressure medium flow in a main and an accessory
flow.
[0004] The valves, already known, often have the disadvantage that
they either reach a minimum working pressure near zero bar or that
the leakage flow of the pressure medium is minimized to nearly zero
when the working pressure is minimal.
[0005] The problem on which this invention is based is to provide a
proportional pressure regulating valve, especially for the
regulation of shift pressure in automatic motor vehicle
transmissions, in which the minimal working pressure is almost zero
and the leakage flow of the pressure medium in the end position of
the control shift valve is minimized to almost zero with minimal
working pressure and which makes possible an adaptation of the flow
properties of the valve to the conditions existing during
utilization.
[0006] Departing from a pressure regulating valve of the kind
specified above, this problem is solved with the features stated in
the characteristic part of claim 1: advantageous developments of
the invention are described in the sub-claims.
[0007] The pressure regulating valve is designed as connected
throttle or diaphragm system (hereinafter the expression diaphragm
will be used to mean throttle or diaphragm). The connected
diaphragm system consists of two mechanically of hydraulically
connected regulating diaphragms. The regulating diaphragms are
according to the principle of the hydraulic half bridge. Before the
two regulating diaphragms can be front-mounted a fixed diaphragm.
This connected diaphragm system has three connections: a pressure
medium supply line (connection P), a working pressure line to the
consumer (connection A) and a pressure medium sump line to the
pressure medium sump (connection T). The connection P is situated
on the inlet side before the first regulating diaphragm or fixed
diaphragm, the connection A is situated, e.g. between the two
regulating diaphragms and the connection T is located on the outlet
side behind the second regulating diaphragm. Each one of the
diaphragms constitutes a drag. The two regulating diaphragms are at
the same time adjustable drags. The operating principle of said
pressure regulated valve works similarly to the one of an electric
voltage divider with two connected adjustable slide resistances or
with a front-mounted fixed resistance and two connected adjustable
slide resistances. Each one of the diaphragms produces a certain
pressure drop. On the input side of the first regulating diaphragm
or of the fixed diaphragm supply pressure prevails, while on the
output side, after the second regulating diaphragm, ambient
pressure prevails. The pressure between the two regulating
diaphragms is adjustable, according to the opening of the
diaphragms, between ambient pressure and supply pressure. At the
same time, the two regulating diaphragms form inlet and outlet
openings of a pressure regulating chamber and each has a sealing
element for opening and closing the diaphragms. According to the
invention, the sealing element of the inlet diaphragm is designed
as ball, or calotte, or truncated cone, or cylinder and/or of the
sealing element of the outlet diaphragm as ball, calotte, or
truncated cone, or cylinder, i.e. on one hand, a sealing element in
the inlet or outlet is designed as ball, calotte, truncated cone,
or cylinder. On the other hand, both sealing elements can be
designed as ball, calotte, or truncated cone, or cylinder, it being
possible for both sealing elements to have either the same or
different shape. The inflowing and outflowing characteristic of
both regulating diaphragms can thus be advantageously adjusted as
best as possible to the existing condition of use of the valve. The
type, e.g. of each separate diaphragm as seat or shift valve and
thus the shape of the sealing surface, the same as the pressure
intensification through each diaphragm, is at the same time
individually adjustable.
[0008] Both regulating diaphragms are connected by a control shift
valve. The diaphragms, especially the sealing elements, do not have
to be rigidly or integrally connected with the control shift valve,
but can also be separately designed and loosely abut on the control
shift valve, the contact force being produced in the pressure
medium flow by the drag of a loose diaphragm. By moving the control
shift valve in one direction, the cross section of the inlet
diaphragm is enlarged and that of the outlet diaphragm is
simultaneously reduced. When the control shift valve moves in
opposite direction, the cross sections change in inverse manner.
This corresponds to the operation principle of a hydraulic half
bridge. Depending on the configuration of the connection, positions
of the control shift valve can result in which one diaphragm is
already fully open while the other still is not fully closed
(negative overlapping of the leading edges). In a possible
condition of operation, the inlet diaphragm is already completely
open and the outlet diaphragm still not fully closed. In this
condition of operation, the system of the two connected regulating
diaphragms becomes reduced to a system having fixed inlet diaphragm
and regulatable outlet diaphragm.
[0009] In a system of two connected regulating diaphragms with
front-mounted fixed diaphragm, if the drag of the inlet regulating
diaphragm is clearly less than that of the front-mounted fixed
diaphragm, then the inlet regulating diaphragm for the
self-adjusting regulating pressure is no longer important. The
system comprised of one front-mounted fixed diaphragm with two
consecutive connected regulating diaphragms becomes reduced in this
operation condition to a system with fixed inlet diaphragm and
regulatable outlet diaphragm. According to the present state of the
art, by means of one such reduced system, e.g. mechanical shift
pressure for transmission control are regulated. This means that in
this operation condition, it is possible to apply the experience
acquired over the years with conventional seat valves.
[0010] Compared to the system having one regulating diaphragm and
one fixed diaphragm, the system having two connected regulating
diaphragms has the advantage that when the outlet diaphragm is
fully open the through flow is not maximal as in the system of
fixed and regulating diaphragms but is minimized to zero by the
sealing element of the inlet regulating diaphragm. The same also
applies to the case of additionally front-mounted fixed diaphragm.
The operation condition "fully open outlet diaphragm" corresponds
in both systems and in the reduced system with fixed inlet
diaphragm and regulatable outlet diaphragm to the minimal
regulating pressure. In the system having two connected regulating
diaphragms--with or without front-mounted fixed diaphragm--said
lowest, adjustable regulating pressure is minimized by blocking the
inlet to ambient pressure across the outlet, while in the system
comprised of fixed and regulating diaphragms a final residual
pressure remains due to the hydrodynamic effects. The medium
through flow is higher in the system comprised of fixed and
regulating diaphragms. This results in higher power losses compared
to the system having two connected regulating diaphragms. One other
advantage is that as a consequence of the low maximum through flow,
the pump for preparing the supply pressure can be given smaller
dimensions.
[0011] According to a first design of the invention, the pressure
regulating valve is constructed as a system of two variable
diaphragm stages mechanically or hydraulically connected. This
advantageously stands out by a simple, economical construction.
[0012] In an advantageous development of the invention, the valve
is constructed as a system of three diaphragm stages having one
first pressure-side, fixed diaphragm stage and two connected
variable diaphragm stages whereby more possibilities exist for
adjustment of the flow properties than in the above mentioned
design having only two variable diaphragm stages.
[0013] This pressure regulating valve, according to the invention,
is advantageously used for regulating the hydraulic pressure for
actuating transmission shifts.
[0014] In an advantageous development of the invention, two
variable diaphragm stages are lodged in one part. The inlet
diaphragm in the regulating pressure chamber is shown in the shape
of a hole through a valve housing that forms an intake which can be
covered with a sealing element. The outlet diaphragm is designed in
the form of a seat valve where an axial wall surface of the valve
housing covers a sealing or front surface of a sealing element,
particularly of an armature rod. A stud-shaped control shift valve,
which joins up in axial direction with the armature rod, can push
out from its seat the sealing element of the inlet diaphragm. The
control shift valve connects the two diaphragms, on one hand, by
establishing the cross section of the inlet diaphragm by covering
the intake surface with the sealing element and, on the other, by
determining the surface of the outlet diaphragm by the spacing
between the axial wall surface and the front face. When the outlet
is closed, the front sealing surface of the armature rod abuts on
the wall surface of the valve housing. The stud-shaped control
shift valve at the same time pushes the sealing element of the
inlet diaphragm out of its seat in the intake. The intake in the
pressure regulating chamber is completely released in this
position. Due to the axial movement of the control shift valve, the
outlet diaphragm opens and causes a pressure drop in the pressure
regulating chamber and thus in the working line. When the outlet
cross section is further opened, the stud-shaped control shift
valve is drawn further back. The sealing element of the inlet
diaphragm thus approaches the intake and the effective intake cross
section diminishes. When the outlet is almost completely open the
intake is fully blocked. The pressure regulating chamber is then
completely separated from the intake and an ambient pressure
appears.
[0015] The sealing element does not have to be integrally connected
with the control shift valve or the armature rod, i.e. the parts
designed with two or more pieces. The flow or the pressure of the
pressure medium allows it to abut on the control shift valve and
follows up the control shift valve when it retracts. For lodging
the sealing element, especially when it is not integrally connected
with the control shift valve, a cage is advantageously provided
which can also be used for targeted setting of the inflow
characteristic.
[0016] Since the intake opening forms one part of the front surface
of a cylindrical valve chamber, the force acting upon said surface
has an axial component so that a hydrostatic cohesion has to be
overcome to open said intake by axial displacement of the control
shift valve and thus removal of the sealing element from its seat
in the intake opening under different pressure in the pressure
regulating chamber and intake. The cohesion results from the
difference of the medium pressure in the intake and the pressure
regulating chamber multiplied by the surface of the intake opening.
Therefore, the intake opening is not given too large dimension in
order to obtain an acceptable valve characteristic. When the valve
is open the axial force upon the armature results as sum of the
product from a medium value of the pressure in the pressure
regulating chamber, which approximately corresponds to the working
pressure in the consumer, and the free armature surface (full
armature surface minus cross sectional surface of the control shift
valve) and by the force produced by the back pressure on the
sealing element.
[0017] The sealing element is advantageously designed in one piece
with the control shift valve.
[0018] In a technical variant both mechanically connected
diaphragms are regulated by a shift valve which projects through
both diaphragm openings and over its axial extension has a
double-sided cone with a tapering in its center. On its axially
outer ends the cross section of the control shift valve increases
in a manner such that it can completely seal the diaphragm
openings. By movement in one or other axial direction it thus seals
the inlet or outlet diaphragm.
[0019] In an advantageous development of this technical variant of
the invention, a fixed diaphragm is mounted in front of the two
mechanically connected diaphragms.
[0020] The pressure regulating valve is preferably magnetically
actuated. The displacement force of said pressure regulating valve
is at the same time the force which an electromagnet exerts on the
induced, magnetic torque of a soft-iron armature. The soft-iron
armature is advantageously pressed on the armature rod.
[0021] As technical variant, the pressure regulating valve can also
be actuated piezo-electrically or pneumatically.
[0022] In another advantageous development of the invention, three
diaphragms are lodged in a discrete part. The three diaphragms are
composed of one fixed diaphragm on the intake side and two
connected regulating diaphragms. The fixed diaphragm on the intake
side can here be designed as front-mounted diaphragm but also as
throttle in the shape of one or more holes. The connected
regulating diaphragms form the inlet and outlet of a regulating
pressure chamber. The regulated inlet diaphragm is shown by at
least one radial intake hole through a valve housing interacting
with a control shift valve which extends partially into the
cylindrical, hollow pressure regulating chamber. The control shift
valve is axially movable over a certain length within the pressure
regulating chamber. The control shift valve consists of one sleeve
which can accurately fitting slide in the cylindrical pressure
regulating chamber and at least one preferably web-shaped
connecting piece to a front surface of an armature rod. The front
surface is larger than the axial cross sectional surface of the
pressure regulating chamber. The cross sectional surface of the
inlet hole(s) can be sealed to any extent desired by the surface of
the sleeve. The axial outer wall of the sleeve constitutes at the
same time the leading edge of the inlet diaphragm wherein the
latter acts as control shift valve. The outlet diaphragm is formed
by a seat valve in which an axial wall surface of the valve housing
covers the front surface of the armature rod. The web-shaped
connecting piece constitutes the mechanical connection between the
leading edges. When the outlet is closed, the front surface of the
armature rod abuts on the wall surface of the valve housing. The
sleeve projects here into the cylindrical pressure regulating
chamber far enough so that the radial intake hole(s) be located
between sleeve and front surface of the armature rod. The intake
hole(s) is (are) completely released in this position. By axial
movement of the control shift valve, the outlet diaphragm opens and
causes a pressure drop in the pressure regulating chamber and thus
in the working line. When the outlet cross section is further
opened, the inlet leading edge begins to strike over the cross
section of the radial intake hole(s). When the outlet is almost
completely open, the intake hole(s) becomes (become) completely
blocked. The pressure regulating chamber is then completely
separated from the intake and ambient pressure appears there. In
this development of the invention the armature rod and the control
shift valve comprised of the web-shaped connecting piece and the
sleeve are advantageously designed in one piece. The production as
rotary part recommends itself wherein the end forming the control
shift valve is turned off as hollow cylinder and subsequently a
milling work cycle across the axis of rotation leaves residually as
webs two axially extending hollow cylinder segments which
constitute the connecting piece between armature rod and sleeve.
Since the inlet opening(s) is (are) situated on the surface of one
cylindrical valve chamber, the force acting upon said surface has
no axial component so that for opening said inlet (said inlets) by
axial displacement of the sleeve under different pressure in the
pressure regulating chamber and intake, no hydrostatic cohesions
have to be overcome. The axial force upon the armature results as
product of a medium value of the pressure in the pressure
regulating chamber, which nearly corresponds to the working
pressure in the consumer, and the full armature surface (free
armature surface plus cross sectional surface of the connecting
piece).
[0023] The sleeve connected via the web-shaped connecting piece
with the armature rod, by adequate matching of material, can be
directly lodged in the valve housing as hydraulic-side bearing.
[0024] The armature rod and the control shift valve are preferably
designed in one piece.
[0025] The inlet regulating diaphragm preferably has in the valve
housing several radial intake holes which are connected via an
annular duct with the front-mounted, fixed diaphragm.
[0026] In an advantageous embodiment of the invention, one sealing
surface is provided on one front side of the armature rod, said
sealing surface interacting with a corresponding sealing surface on
the valve housing and thus making possible a flat-seat sealing with
the best sealing properties.
[0027] In one other design, it is now proposed frustoconically to
design the area between the front surface of the armature rod
designed as sealing surface and the control shift valve. Thus are
advantageously combined by the truncated cone the good sealing
properties of a flat seat with a favorable, namely, as low as
possible, design of the pressure booster, the base of the truncated
cone being disposed on the front surface of the armature rod.
[0028] The invention is explained in detail herebelow with the aid
of the drawings in which advantageous embodiments are shown. The
drawings show:
[0029] FIG. 1 is a principle gearshift diagram of a pressure
regulating valve with two connected regulating diaphragms;
[0030] FIG. 2 is a principle gearshift diagram of a pressure
regulating valve with two connected regulating diaphragms and one
front-mounted, fixed diaphragm;
[0031] FIG. 3 is a section through a pressure regulating valve in a
first development of the invention;
[0032] FIG. 4 is a technical variant of this pressure regulating
valve according to the invention with a control shift valve which
penetrates through both diaphragm openings and has at its center,
over its axial extension, a conical tapering (the lower
illustration shows a design with an additional front-mounted, fixed
diaphragm);
[0033] FIGS. 5 and 6 are two sections offset by 90 degrees relative
to each other through the essential part of a second development of
the pressure regulating valve according to the invention;
[0034] FIG. 7 is a section along the line A-A of FIG. 6;
[0035] FIG. 8 is a connecting piece consisting of armature,
armature rod an control shift valve in the last development of the
invention;
[0036] FIG. 9 is a pressure flow leakage diagram; and
[0037] FIGS. 10 to 25 are diagrammatical illustrations of pressure
regulating valve having different combinations of the sealing
elements wherein the lower illustration essentially corresponds to
the upper, but shows in addition a front-mounted, fixed
diaphragm.
[0038] As shown in FIG. 3, the pressure regulating valve in the
first development of the invention acts as 3/2 directional valve
with blocking of the pressure medium in the pressure medium supply
line 2 with large working strokes. Here the operation corresponds
to that of a hydraulic half bridge. The pressure medium supply line
2 preferably discharges via an axially situated intake opening in
the pressure regulating chamber 7. The pressure regulating valve,
the housing of which is designated with 1, conventionally has an
electromagnet which moves an armature 13 in direction of the axis A
against the action of a spring. The armature 3 positions the
control shift valve 12 via an armature rod 10. The control shift
valve 12, which joins up with the front surface 6 of the armature
rod 10 designed as sealing surface, is designed in the shape of a
stud which can push out from its seat in the intake hole 8 a
sealing element 5 designed as ball. Armature rod 10, control shift
valve 12 and sealing element 5 can be made of one, two, three or
more pieces. In an end position of the pressure regulating valve,
the sealing element 5 seals completely the hole of the intake
opening 8 of the pressure medium supply line 2 in the regulating
pressure chamber 7. In the other end position, the front surface 6,
acting as leading edge 11 of the outlet abuts, on the wall surface
4 of the valve housing 1. The sealing element is simultaneously
pushed out from its seat by the stud-shaped control shift valve 12
and the intake opening 8 of the pressure medium supply line 2 is
released so that the pressure medium completely energizes with
pressure the pressure regulating chamber 7 and thus the consumer.
In both end positions of the armature rod 10 or of the control
shift valve 12, the pressure medium flow is interrupted by locking,
on one hand, the intake to the pressure regulating chamber 7 and,
on the other, the exit to the pressure medium sump. Therebetween,
while pressure p of the pressure medium flowing into the regulating
pressure chamber 7 increases, the volume flow Q reaches a maximum,
as results from FIG. 9.
[0039] The complete locking of the intake opening 8 of the pressure
medium supply line 2 by the sealing element 5 causes, therefore,
the pressure medium leakage to minimize, wherein on account of the
axial pressure medium supply line, the pressure medium exerts on
the sealing element 5 and thus on the control shift valve 12 and
the armature rod 10 a slight axial pressure conditioned by back up
pressure. However, the displacement forces to move the control
shift valve 12, i.e. to shift the sealing element 5 out of its seat
in the intake opening, are slight. The internal pressure feedback
from the pressure regulating chamber 7 to the sealing surface 6 of
the armature rod 10 acting as armature active surface makes
possible an uncomplicated regulation operation. The armature
chamber is pressureless like in the conventional seat valve
constructed in series described in DE-C 44 26 152. The problem
arising in the conventional 2/2 seat valves that said pressureless
armature chamber is flushed due to the entrance of the leakage
pressure medium and, at the same time, iron dust particles deposit
as dirt is reduced in the pressure regulating valve, according to
the invention, by blocking of the intake in the pressure regulating
chamber in the end position "minimal working pressure", for: in
conventional 2/2 direction pressure regulating seat valves, the
through flow is maximal in the position "minimal pressure" and thus
also the influx current and the entrance of the dirt particles.
There is finally obtained a large utilizable pressure area, since
no residual pressure conditioned by the back up pressure appears
(FIG. 9). Chips of up to 200 .mu.m diameter of the size
classification, such as appear as green assembly dirt, can be
clamped on the leading edge 9 formed by interaction of the sealing
element 5 and the intake hole. In this working stroke the intake
cannot be fully blocked. A small through flow to the pressure
medium sump remains. A jamming of the sealing element 5 by this
entrance of chips is not possible due to the slight displacement
forces in this position of the control shift valve 12, or in case
of a loose sealing element 5, as consequence of the slight back up
forces of the pressure medium on the sealing element 5. The slight
clamping forces due to the slight displacement forces do not lead
to damage of the leading edge by pressing of the chip. If the
intake hole again is opened during the next working stroke, the
chip is again released.
[0040] As partly and diagrammatically shown in FIGS. 5 to 8, the
pressure regulating valve in the second development of the
invention acts as 3/2 directional valve with blockage of the
energized pressure medium in the pressure medium supply line 2 with
great working strokes. The operation here corresponds to that of a
hydraulic half bridge with an additional, firmly adjusted,
front-mounted, intake diaphragm 3. The pressure medium supply line
2 preferably discharges, via several radially disposed intake
holes, in the pressure regulating chamber 7. In a conventional
manner, the pressure regulating valve, the housing of which is
designated with 1, has an electromagnet (not shown) which moves an
armature 13 in direction of the axis A against the action of a
spring. The armature 13 positions the control shift valve 12 via an
armature rod 10. The control shift valve 12, which joins up with
the sealing surface 6 of the armature rod 10, consists of two webs
108 and one sleeve 105. Armature 10 and control shift valve 12 are
designed in one piece. The connecting piece is made as rotary part
from armature rod 10 and control shift valve 12. On the front
surface 6 of the armature rod 10, i.e. on the passage of the
operating units armature rod 10 and control shift valve 12, the
diameter of said rotary part diminishes on the side of the control
shift valve 12. The control shift valve 12 is turned out as hollow
cylinder. In the zone of the connecting piece between armature rod
10 and sleeve 105, the hollow cylinder is milled across the axis of
rotation to an extent such that only two axially extending webs 108
remain from it. The diameter of said hollow cylinder from which the
sleeve 105 and web 108 are worked out is adapted to the diameter of
the pressure regulating chamber 7 in a manner such that the sleeve
105 can slide accurately fitting. In one of its end positions, the
sleeve 105 at the same time completely seals the intake holes of
the pressure medium supply line 2 in the regulating pressure
chamber 7. In the other end position, the sealing surface 6 acting
as leading edge 11 of the exit abuts axially on the wall surface 4
of the valve housing 1. The intake holes of the pressure medium
supply line 2 are simultaneously released so that the pressurized
pressure medium fully energizes with pressure the pressure
regulating chamber 7 and thus the consumer. In both positions of
the connection comprised of armature 3, armature rod 10 and control
shift valve 12, the pressure medium flow--similarly to the first
development of the invention--is interrupted by locking, on one
hand, the intake to the pressure regulating chamber 7 and, on the
other, the exist to the pressure medium sump. Therebetween the
volume flow Q reaches a maximum when the pressure p of the pressure
medium flowing in the pressure regulating chamber 7 increases, as
results from FIG. 9.
[0041] The complete shut off of the intake holes of the pressure
medium supply line 2 by the sleeve 105 produces, therefore, as in
the first development of the invention, a minimizing of the
pressure medium leakage wherein, contrary to the first development
of the invention, the radial pressure medium supply lines exert no
back-up pressure conditioned axial force upon the sleeve 105.
Thereby the displacement forces to move the sleeve 105 are slight.
In the axial position of the control shift valve 12 in which the
leading edge 9 of the sleeve 105 precisely covers in part the
intake, the armature 13 connected with the control shift valve 12
is, in its position relative to the electromagnet, still in an
unfavorable position of weak magnetic forces. However, the weak
displacement forces of the sleeve 105 conditioned by the geometry
of the intake can, without effort, be applied by the magnet. The
sealing surface 6 of the armature rod 10 which produces the
internal pressure return from the pressure regulating chamber 7 to
the armature active surface makes possible an uncomplicated
regulation operation. By adequate selection of material of the
sleeve and of the valve housing, a low-friction bearing is directly
obtained on the hydraulic side for the seat valve 4, 6. The
connecting piece consisting of armature rod 10 and control shift
valve 12 is supported in the pressure regulating chamber 7, on one
hand, by a bearing point directly in front of the armature 13 and,
on the other, by the sleeve 105 of the control shift valve 12. The
fit dimension of the bearing on the armature side is dimensional so
as to prevent an entrance of iron dust particles. The same as in
the conventional seat valve constructed in series which was
described in DE-C 44 26 152, the armature in this second
development of the invention is pressureless. The problem arising
in conventional 2/2 seat valves, that said pressureless armature
chamber is flushed by the entrance of the leakage pressure medium
and iron dust particles deposit as dirt, is reduced in the pressure
regulating valve, according to the invention, in the second, the
same as in the first development of the invention, by blocking the
intake in the pressure regulating chamber in the end position
"minimal working pressure". Chips having a diameter of the size
classification of up to 200 .mu.m such as they appear, e.g. as
green assembly dirt, can be clamped between the leading edge 9, the
sleeve 105 and the intake hole. In this working stroke the intake
cannot be completely blocked. A small through flow to the pressure
medium sump remains. A jamming of the control shift valve 12 due to
this entrance of chips is not possible in this position of the
control shift valve 12 because of the weak displacement forces.
Similarly to the first development of the invention, the weak
clamping forces, resulting from the weak displacement forces, do
not lead to damage of the leading edge by the introduction of
chips. In the next working stroke, if the intake hole is again
opened, the chip is again released.
[0042] In FIGS. 10 to 13 are shown pressure regulating valves which
have, in the outlet diaphragm, a frustoconical sealing element, the
sealing surface 6 lying on the cone-shaped surface of the sealing
element. The sealing elements 5 of the inlet diaphragm 19, on the
other hand, are optionally formed by a cylinder (FIG. 10), a ball
(FIG. 11), or a truncated cone (FIG. 12) as seat valve or by a
cylinder (FIG. 13) as shift valve. At the same time, the sealing
elements 5 are by a case 14 which can also be used to form the
inlet diaphragm 109 (FIG. 13).
[0043] In FIGS. 14 to 17 are shown valve designs, which provide for
the outlet diaphragm 111, a cylindrical sealing element; the
sealing elements of the outlet diaphragm 111 are each designed as
ball in FIGS. 18 to 21, while in FIGS. 22 to 25 the sealing element
in the outlet 111 has a flat seat seal with a front-mounted,
truncated cone. The variants of the sealing elements 5 in the area
of the inlet diaphragm 109 correspond to the designs already
explained for FIGS. 10 to 13.
[0044] Reference numerals
[0045] 1 valve housing
[0046] 2 pressure medium intake
[0047] 3 inlet diaphragm
[0048] 4 wall surface/line
[0049] 5 sealing element
[0050] 6 front/sealing surface
[0051] 7 pressure regulating chamber
[0052] 8 intake opening
[0053] 9 leading edge (of the intake)
[0054] 10 armature rod
[0055] 11 leading edge (of the exit)
[0056] 12 control shift valve
[0057] 13 armature
[0058] 14 cage
[0059] 105 sleeve
[0060] 108 web
[0061] 109 inlet diaphragm
[0062] 111 outlet diaphragm
[0063] A working pressure line
[0064] T pressure medium sump line
[0065] P pressure line
[0066] p pressure
[0067] Q Flow rate
* * * * *