U.S. patent application number 09/741993 was filed with the patent office on 2001-09-20 for pressure regulating valve and method for producing a pressure regulating valve.
This patent application is currently assigned to Robert Bosch GmbH. Invention is credited to Bueser, Wolfgang, Drutu, Lorenz, Ittlinger, Ralph, Maier, Martin, Schwegler, Helmut.
Application Number | 20010022193 09/741993 |
Document ID | / |
Family ID | 7934465 |
Filed Date | 2001-09-20 |
United States Patent
Application |
20010022193 |
Kind Code |
A1 |
Schwegler, Helmut ; et
al. |
September 20, 2001 |
Pressure regulating valve and method for producing a pressure
regulating valve
Abstract
The pressure regulating valve (2) proposed here can be designed
with the aid of the outflow throttle restriction (28) downstream of
the valve seat (22) in such a way that the pressure regulating
valve (2), as the fluid flow becomes greater, sets or adjusts a
smaller pressure difference at the pressure regulating valve (2),
as a result of which the line losses that can never be avoided can
be compensated for. The pressure regulating valve is suitable in
particular for a fuel supply system of a motor vehicle having an
internal combustion engine.
Inventors: |
Schwegler, Helmut;
(Pleidelsheim, DE) ; Ittlinger, Ralph; (Weissach,
DE) ; Bueser, Wolfgang; (Freiberg, DE) ;
Maier, Martin; (Moeglingen, DE) ; Drutu, Lorenz;
(Moeglingende, DE) |
Correspondence
Address: |
Ronald E. Greigg
Greigg & Greigg P.L.L.C.
1423 Powhatan Street
Unit One
Alexandria
VA
22314
US
|
Assignee: |
Robert Bosch GmbH
|
Family ID: |
7934465 |
Appl. No.: |
09/741993 |
Filed: |
December 22, 2000 |
Current U.S.
Class: |
137/514 |
Current CPC
Class: |
Y10T 137/7928 20150401;
F02M 69/54 20130101; Y10T 137/7852 20150401; G05D 16/12 20130101;
Y10T 137/785 20150401 |
Class at
Publication: |
137/514 |
International
Class: |
F16K 021/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 24, 1999 |
DE |
1 99 62 960.9 |
Claims
We claim:
1. A pressure regulating valve for regulating a pressure of a
fluid, in particular in a fuel supply system of an internal
combustion engine, the regulating valve having: a fluid inlet (6),
having a fluid continuation (8), having a dividing wall (10)
dividing the fluid continuation (8) from the fluid inlet (6), a
fluid opening (18) leading from the fluid inlet (6) through the
dividing wall (10) into the fluid continuation (8), having a
closing body (20, 20a, 20b) which normally closes the fluid opening
(18), a valve seat (22) surrounding the fluid opening (18), the
valve seat (22) being located at least indirectly on the dividing
wall (10), and a spring device (24, 24a) urging the closing body
(20, 20a, 20b) against the valve seat (22), characterized in that
an outflow throttle restriction (28, 28a) is provided downstream of
the valve seat (22).
2. The pressure regulating valve in accordance with claim 1,
characterized in that an intermediate pressure chamber (30) is
provided between the valve seat (22) and the outflow throttle
restriction (28).
3. The pressure regulating valve in accordance with claim 2,
characterized in that an intermediate pressure of the fluid in the
intermediate pressure chamber urges the closing body (20, 20a, 20b)
in the opening direction.
4. The pressure regulating valve in accordance with claim 1,
characterized in that the outflow throttle restriction (28, 28a) is
disposed on one side, with respect to the fluid opening (18).
5. The pressure regulating valve of claim 1, characterized in that
a closing body guide (26) guiding the closing body (20, 20a, 20b)
is provided.
6. The pressure regulating valve in accordance with claim 5,
characterized in that the outflow throttle restriction (28, 28a) is
provided radially outside the closing body guide (26).
7. The pressure regulating valve of claim 5, characterized in that
the closing body guide (26) is formed by a sheath (14), and that
the outflow throttle restriction (28, 28a) is provided in the
sheath (14).
8. The pressure regulating valve of claim 6, characterized in that
the closing body guide (26) is formed by a sheath (14), and that
the outflow throttle restriction (28, 28a) is provided in the
sheath (14).
9. The pressure regulating valve of claim 1, characterized in that
the outflow throttle restriction (28, 28a) is formed by a throttle
opening (38a).
10. The pressure regulating valve in accordance with claim 1,
characterized in that the closing body (20, 20a, 20b) is formed by
at least one ball (20a) urged against the valve seat (22).
11. The pressure regulating valve in accordance with claim 1,
characterized in that the closing body (20, 20a, 20b) is formed by
at least two balls (20a, 20b) solidly joined to one another.
12. The pressure regulating valve of claim 1, characterized in that
a damping device (40) is provided, and the closing body (20, 20a,
20b) has one side (20c) toward the fluid inlet (6) and one side
(20d) remote from the fluid inlet (6), and the damping device (40)
is formed in that on the side (22) of the closing body (20, 20a,
20b) remote from the fluid inlet (6), a damper chamber (32) is
provided, and that a delivery throttle opening (36, 36a, 36b) leads
from the fluid inlet (6) into the damper chamber (32), and a
discharge throttle opening (38, 38a) leads from the damper chamber
(32) into the fluid continuation (8).
13. The pressure regulating valve in accordance with claim 12,
characterized in that the delivery throttle opening (36, 36a, 36b)
is formed by a gap between the closing body (20, 20a, 20b) and the
closing body guide (26) that guides the closing body (20, 20a,
20b).
14. The pressure regulating valve in accordance with claim 12,
characterized in that the discharge throttle opening (38, 38a) is
formed by a hole (38a) connecting the damper chamber (32) to the
fluid continuation (8).
15. The pressure regulating valve in accordance with claim 13,
characterized in that the discharge throttle opening (38, 38a) is
formed by a hole (38a) connecting the damper chamber (32) to the
fluid continuation (8).
16. The pressure regulating valve in accordance with claim 12,
characterized in that the spring device (24, 24a) acts on the
closing body (20, 20a, 20b) is formed by a spring (24a) disposed in
the damper chamber (32).
17. A method for producing a pressure regulating valve serving to
regulate a pressure of a fluid, the regulating valve having: a
fluid inlet (6), a fluid continuation (8), a dividing wall (10)
dividing the fluid continuation (8) from the fluid inlet (6), a
fluid opening (18) leading from the fluid inlet (6) through the
dividing wall (10) towards the fluid continuation (8), a closing
body (20, 20a, 20b), which normally closes the fluid opening (18)
but can be opened by means of fluid pressure at the fluid inlet
(6), a valve seat (22) surrounding the fluid opening (18), a
closing body guide (26) guiding the closing body (20, 20a, 20b),
and a spring device (24, 24a) urging the closing body (20, 20a,
20b) with a closing force against the valve seat (22),
characterized in that the closing body guide (26) is formed on a
sheath (14) that can be connected to the dividing wall (10),
wherein upon assembly of the pressure regulating valve (2), after
the spring device (24, 24a) and the closing body (20, 20a, 20b)
have been installed, the sheath (14) is retained relative to the
dividing wall (10), transversely to the longitudinal axis of the
closing body guide (26), with an aligning force, the aligning force
being less than a centering force that is engendered by the action
on the closing body (20, 20a, 20b) and is exerted on the sheath
(14) by the valve seat (22) via the closing body (20, 20a, 20b),
and that after a resultant centering of the closing body guide (26)
relative to the valve seat (22), the sheath (14) is fixed relative
to the dividing wall (10).
18. The method of claim 17, characterized in that the fixation of
the sheath (14) relative to the dividing wall (10) is effected by
means of a materially bonded connection (16).
19. The method of claim 18, characterized in that the materially
bonded connection (16) is a welded connection (16) that retains the
sheath (14) on the dividing wall (10).
20. The method of claim 17, characterized in that a clamping piece
(46), connected to the dividing wall (10) via a clamp connection,
is provided, and the clamping piece (46) fixes the sheath (14)
relative to the dividing wall (10).
Description
FIELD OF THE INVENTION
[0001] The invention is based on a pressure regulating valve and a
method for producing a pressure regulating valve.
BACKGROUND OF THE INVENTION
[0002] German Published, Unexamined Patent Application DE 197 54
243 A1 shows a pressure regulating valve of a fuel supply system. A
supply line leads to the pressure regulating valve, and a line
extending onward carries the fuel away from the pressure regulating
valve. Depending on the change in magnitude of the fluid flow
flowing through the pressure regulating valve, the flow resistances
in the supply line and in the line leading onward vary. These
fluctuations in flow resistances cause troublesome fluctuations in
the pressure level that is to be regulated by the pressure
regulating valve in the fuel supply system. Because especially the
line leading onward is often relatively long and should have the
smallest possible cross section, the flow resistances in the line
leading onward fluctuate considerably, as a function of the
magnitude of the fluid flow. As a result, the pressure level
regulated by the pressure regulating valve undesirably fluctuates
very greatly as well.
[0003] Additionally, in the pressure regulating valve shown in DE
197 54 243 A1, a damping device is provided, which is intended to
prevent excessive oscillation of the closing body of the pressure
regulating valve. However, in the known pressure regulating valve,
the damping device has the disadvantage that for lack of an
adequate flow through the damper chamber, gas can accumulate, which
can very severely impair the damping action of the damping device.
Another disadvantage is that the closing body has a complicated
shape, making its production relatively complicated and expensive.
Another disadvantage is that the tappet connecting the damper
piston to the ball is immediately adjacent the closing body in the
region of the valve seat, and as a result dimensional imprecisions
arise that can lead to leakage, which cannot be allowed. A further
disadvantage is that if adequate damping action is to be achieved,
the damper piston must be guided with very tight play. This means
the pressure regulating valve is severely vulnerable to dirt.
OBJECT AND SUMMARY OF THE INVENTION
[0004] The pressure regulating valve according to the invention and
the method for producing a pressure regulating valve have the
advantage over the prior art that a substantially simpler to
produce and markedly better-functioning pressure regulating valve
is available. In particular, excellent values regarding tightness,
pressure regulation quality, and the desired small structural size
are attainable.
[0005] In particular, the advantage is obtained that whenever the
closing body has lifted at least partly away from the valve seat, a
pressure backs up upstream of the outflow throttle restriction, and
this backed-up pressure additionally acts on the closing body in
the opening direction. This has the advantage that when the fluid
flow flowing through the pressure regulating valve increases, the
closing body, at a large fluid flow, lifts increasingly far from
the valve seat, and that as a result, as the fluid flow becomes
larger, the flow resistance through the pressure regulating valve
decreases. Since often in the line upstream of the pressure
regulating valve and especially in the line downstream of the
pressure regulating valve the resistance rises as the fluid flow
increases, the possibility exists, because of this decreasing
characteristic curve of the pressure regulating valve, of
compensating for these flow resistances in the lines, so that the
pressure to be regulated by the pressure regulating valve can be
kept constant, largely independently of the magnitude of the fluid
flow.
[0006] If the outflow throttle restriction is disposed on one side
relative to the fluid opening, this has the advantage that the
closing body is pressed unilaterally against its guide. As a
result, conditions that are defined precisely in terms of
hydraulics and mechanics are advantageously obtained in the region
between the closing body and the valve seat and also between the
closing body and the closing body guide. This has the advantage
that the closing body rests eccentrically on one side on the
closing body guide, always in the same way, and that as a result,
an easily controlled, unchanging, predictable, constant regulating
behavior of the pressure regulating valve is assured. Another
advantage is that between the closing body guide and the closing
body, always-constant, easily controlled frictional forces are
assured. These frictional forces offer the advantage of an
additional easily controlled damping. The overall result obtained
is a constant, easily controlled regulating behavior of the
pressure regulating valve.
[0007] Because the outflow throttle is provided radially outside
the closing body guide, a relatively large annular gap is obtained
around the valve seat between the closing body and the dividing
wall, so that the fluid flowing through between the closing body
and the valve seat can flow through with uniform distribution over
the circumference and can then flow tangentially around the closing
body in the direction of the outflow throttle restriction and can
then flow out in the direction of the fluid continuation.
[0008] If the closing body guide is formed by a sheath and the
outflow throttle restriction is provided in the sheath, in which
case the outflow throttle restriction can be formed in a very
simple way by a simple hole in the sheath, the overall result is an
especially low production cost.
[0009] If the closing body is formed by at least one ball, this has
the advantage of ease of manufacture, and very good quality is also
attainable at low effort and expense.
[0010] If the closing body is formed by at least two balls solidly
joined together, this has the advantage that especially good
throttling with a relatively large gap is attainable at low
production cost and effort for the delivery throttle opening. The
relatively large gap that is allowed offers the advantage of less
vulnerability to dirt, and production variations, which can never
be avoided entirely, are not as critical. Another advantage is that
if balls are used, canting of the closing body in the closing body
guide need not be feared.
[0011] With the damping device, through which the fluid flow flows
constantly when the closing body is lifted from the valve seat,
having the damper chamber, and with the delivery throttle opening
and the discharge throttle opening, the advantage is attained that
no gas bubbles can accumulate in the damper chamber. Because the
damper chamber has a fluid flow flowing through it, even the
smallest air bubbles or outgassing of fuel are entrained constantly
by the fluid flow. This has the advantage that the damping action
functions highly reliably.
[0012] Since a fluid flow constantly flows through the damper
chamber when the fluid opening is at least partly open, and since
where there is a throttle restriction the flow resistance typically
rises quadratically as a function of the fluid flow, very good
damping action is obtained. The damping action in this damping
device is substantially greater than in a damping device that has a
damper chamber without a flow through it. As a result, the flow
cross-sectional areas of the delivery throttle opening and the
discharge throttle opening can be substantially larger than in a
damping device with a damper chamber that does not have a fluid
flow flowing through it. Production is therefore substantially
simpler, and in particular the dimensional and shape tolerances to
be adhered to are not as close, and the damping device is
substantially less vulnerable to dirt.
[0013] If the gap between the closing body and the closing body
guide is used to act as a delivery throttle opening, this has the
advantage that the delivery throttle opening can be produced
without additional expense.
[0014] If the hole that forms the discharge throttle opening is
disposed such that it points upward out of the damper chamber, this
has the advantage that entrainment of gas bubbles from the damper
chamber can be improved still further and is assured highly
reliably.
[0015] The invention will be better understood and further objects
and advantages thereof will become more apparent from the ensuing
detailed description of preferred embodiments taken in conjunction
with the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a longitudinal section through a selected,
preferred, especially advantageous exemplary embodiment;
[0017] FIG. 2 is a graph showing the dependency between the
hydraulic supplementary closing force F and the fluid flow Q
flowing the damper chamber; and
[0018] FIGS. 3-5 each show one longitudinal section through three
further differently embodied, preferably selected and especially
advantageous exemplary embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The pressure regulating valve embodied according to the
invention serves to regulate a pressure in a chamber that contains
a fluid, for instance for regulating a pressure difference between
a chamber at a higher pressure and another chamber at a lower
pressure. The pressure regulating valve is suitable especially in
fuel supply systems, and the fluid is preferably a liquid,
especially fuel and preferably gasoline, but it can also be diesel
fuel. The pressure regulating valve can be used preferably in
internal combustion engines in which a pressure of the fuel in the
fuel supply system is to be regulated. The pressure regulating
valve is mounted at some suitable mounting point in the fuel supply
system. The mounting point is for instance an opening in a fuel
distributor tube belonging to the fuel supply system, or an opening
in a housing of a fuel pump of the fuel supply system, or a cap of
a fuel tank, or the pressure regulating valve is installed in the
housing of a fuel filter.
[0020] By means of the fuel supply system, fuel pumped by a fuel
pump flows via a pressure line to the mounting point that receives
the pressure regulating valve and thus reaches the fluid inlet of
the pressure regulating valve. From the fluid continuation of the
pressure regulating valve, fuel is returned to the fuel tank, for
instance, or flows to a consumer that receives the fuel, such as an
injection valve that meters the fuel to an internal combustion
engine. The fuel is preferably gasoline, and the engine together
with the fuel supply system is preferably installed in a motor
vehicle.
[0021] FIG. 1 shows a longitudinal section through an especially
advantageous pressure regulating valve 2 selected as a preferred
example for the explanation herein. This exemplary pressure
regulating valve 2 is a substantially rotationally symmetrical
structure.
[0022] The pressure regulating valve 2 is built into a housing 4,
for instance, which is shown only in part. The housing 4 is the
housing of a fuel filter, for instance. In the housing 4, there is
a fluid inlet 6 and a fluid continuation 8. From a fuel pump, not
shown, the pumped fluid passes via the fluid inlet 6 to the
pressure regulating valve 2, and from the pressure regulating valve
2, via the fluid continuation 8, the fluid returns to a fuel tank,
not shown. The pressure of the fluid in the fluid inlet 6 should be
greater, by a specific pressure difference, than the pressure of
the fluid in the fluid continuation 8. A dividing wall 10 divides
the fluid continuation 8 from the fluid inlet 6. The dividing wall
10 is joined in fluid-tight fashion to the housing 4 via a crimped
edge 12 extending all the way around.
[0023] A thimble-like sheath 14 is solidly joined to the dividing
wall 10, for instance via a materially bonded connection 16. By way
of example, the materially bonded connection 16 is a spot weld, in
particular a resistance-welded spot, or an adhesive bond, by way of
which the sheath 14 is affixed to the dividing wall 10. A fluid
opening 18 is provided in the dividing wall 10. Depending on a
position of a closing body 20, the fluid inlet 6 communicates with
the fluid continuation 8 through the fluid opening 18. The closing
body 20 has one side 20c toward the fluid inlet 6 and one side 20d
remote from the fluid inlet 6.
[0024] In the preferred exemplary embodiment, a circular valve seat
22 is provided on the side of the dividing wall 10 toward the fluid
continuation 8, on the circumference of the fluid opening 18. A
spring device 24 urges the closing body 20 against the valve seat
22. The spring device 24 engages the side 20d of the closing body
20 and presses the side 20c against the valve seat 22. In the
preferred exemplary embodiment selected, the sheath 14 has an end
portion 14a remote from the fluid opening 18, a cylindrical portion
14b, and a radially widened portion 14c on the end of the
cylindrical portion 14b remote from the end portion 14a. The sheath
14 has a shoulder 14d between the cylindrical portion 14b and the
widened portion 14c.
[0025] The inner jacket face of the cylindrical portion 14b of the
sheath 14 forms a closing body guide 26. The closing body guide 26
serves to guide the closing body 20. As a function of the pressure
difference between the pressure in the fluid inlet 6 and the
pressure in the fluid continuation 8, the closing body 20 lifts
more or less far away from the valve seat 22, counter to the force
of the spring device 24.
[0026] An outflow throttle restriction 28 is provided in the
widened portion 14c of the sheath 14. An intermediate pressure
chamber 30 extending all the way around is formed, bounded by part
of the closing body 20, by the valve seat 22, by part of the
dividing wall 10, by the widened portion 14c of the sheath 14, and
by the shoulder 14d of the sheath 14.
[0027] The outflow throttle restriction 28 is formed by a throttle
opening 28a provided in the widened portion 14c or on the widened
portion 14c of the sheath 14. The throttle opening 28a is easily
produced in the form of a slot made on the sheath 14, or a bore
made in the sheath 14.
[0028] In the preferred, selected, especially advantageous
exemplary embodiment, the closing body 20 comprises a first ball
20a, toward the valve seat 22, and a second ball 20b. The first
ball 20a and the second ball 20b are solidly joined together, for
instance via a spot weld 20s. The side 20c is located on the first
ball 20a, and the side 20d is located on the second ball 20b.
[0029] The ball 20a of the closing body 20 has a face that is
surrounded by the valve seat 22 and is acted upon hydraulically by
the inflow pressure prevailing in the fluid inlet 6; this face will
be hereinafter called the inlet pressure face 20e.
[0030] Between the valve seat 22 and the narrowest point between
the ball 20a and the closing body guide 26, there is an
encompassing annular face 20z, which is acted upon by the
intermediate pressure prevailing in the intermediate pressure
chamber 30. This face will hereinafter be called the intermediate
pressure face 20z. Of the intermediate pressure face 20z, it is the
area component of the cross-sectional area transverse to the
direction of motion of the closing body 20 that is hydraulically
operative.
[0031] As the drawing shows, the spring device 24 comprises a
helically wound spring 24a, which is braced on one end on the end
portion 14a of the sheath 14 and on the other on the side 20d of
the second ball 20b of the closing body 20.
[0032] A damper chamber 32 is formed, bounded in the axial
direction by the side 20d of the second ball 20b of the closing
body 20 on one side and by the end portion 14a of the sheath 14 on
the other, and in the radial direction by the inner jacket face of
the cylindrical portion 14b of the sheath 14.
[0033] At the narrowest point between the first ball 20a of the
closing body 20 and the closing body guide 26, a first guidance gap
36a is created, and at the narrowest point between the second ball
20b and the closing body guide 26, a second guidance gap 36 is
created. An intermediate chamber 34 is formed between the two
guidance gaps 36a and 36b. The first guidance gap 36a and the
second guidance gap 36b are connected in series in hydraulic terms
and form a delivery throttle opening 36. In the end portion 14a, a
hole 38a is provided at the highest point of the sheath 14, in
terms of the installed position. The hole 38a forms a discharge
throttle opening 38.
[0034] If the pressure in the fluid inlet 6 is enough higher than
in the fluid continuation 8 that the closing body 20 has lifted
from the valve seat 22, then the fluid flowing out of the fluid
inlet 6 through the outflow throttle restriction 28 into the fluid
continuation 8 is throttled at the outflow throttle restriction 28.
This creates a pressure in the intermediate pressure chamber 30
that is higher than the pressure in the fluid continuation 8. The
pressure prevailing in the intermediate pressure chamber 30 will
hereinafter be called the intermediate pressure. Because of the
pressure difference between the intermediate pressure in the
intermediate pressure chamber 30 and the pressure in the fluid
continuation 8, some of the fluid flows through the delivery
throttle opening 36 into the damper chamber 32 and from there
through the discharge throttle opening 38 into the fluid
continuation 8.
[0035] The outflow throttle restriction 28, or in concrete terms
the throttle opening 28a, is disposed such that the fluid flow
flowing through the delivery throttle opening 36, the damper
chamber 32, and the discharge throttle opening 38 rejoins the fluid
flow, flowing through the outflow throttle restriction 28,
downstream of the outflow throttle restriction 28.
[0036] The cross-sectional areas of the delivery throttle opening
36 and of the discharge throttle opening 38 are adapted to the
cross-sectional area of the throttle opening 28a of the outflow
throttle restriction 28 in such a way that the fluid flow flowing
through the damper chamber 32 is substantially less than the fluid
flow flowing through the outflow throttle restriction 28.
[0037] The intermediate pressure prevailing in the intermediate
pressure chamber 30 also acts in the opening direction on the
intermediate pressure face 20z of the closing body 20. With
increasing overpressure in the fluid inlet 6, for instance if the
fluid flow that is supposed to flow out of the fluid inlet 6 into
the fluid continuation 8 is greater, then the first ball 20a lifts
increasingly far from the valve seat 22. As a result, the
intermediate pressure in the intermediate pressure chamber 30 also
rises accordingly, which causes the closing body 20 to lift still
farther from the valve seat 22. With the outflow throttle
restriction 28 and by means of the intermediate pressure thus
engendered, it can be attained that with increasing magnitude of
the fluid flow, the closing body 20 lifts disproportionately far
from the valve seat 22. The effect of the disproportionate lifting
of the closing body 20 is that with an increasing fluid flow, the
pressure difference between the pressure in the fluid inlet 6 and
the pressure in the fluid continuation 8 lessens. Accordingly, a
regulated pressure is obtained that decreases as a function of the
increasing fluid flow. By a choice of the free cross-sectional area
of the outflow throttle restriction 28, the increase in proportion
between the pressure difference at the pressure regulating valve 2
and the fluid flow can be adapted to the flow resistances, which
increase as the fluid flow increases, in the lines upstream and
downstream of the pressure regulating valve 2 in such a way that
overall, regardless of the magnitude of the fluid flow, a constant
pressure prevails in the chamber whose pressure is to be regulated
with the pressure regulating valve 2. With the aid of the
intermediate pressure in the intermediate pressure chamber 30, it
is easily possible to compensate for line resistances that are
dependent on the magnitude of the fluid flow.
[0038] Because of the shoulder 14d of the sheath 14, the
intermediate pressure chamber 30 extending annularly all the way
around is given a relatively large cross-sectional area, as FIG. 1
shows. This offers the advantage that the fluid can flow out of the
fluid opening 18 over the entire circumference of the fluid opening
18 between the valve seat 22 and the ball 20a into the intermediate
pressure chamber 30, and because of the large cross-sectional area
of the intermediate pressure chamber 30, the fluid can flow largely
unthrottled through the intermediate pressure chamber 30 to the
outflow throttle restriction 28. Because of the large
cross-sectional area of the intermediate pressure chamber 30, the
intermediate pressure can act on the intermediate pressure face 20z
everywhere and uniformly.
[0039] It is proposed that only a single throttle opening 28a be
provided for the outflow throttle restriction 28 in the sheath 14,
preferably in the widened portion 14c of the sheath 14. A plurality
of throttle openings distributed uniformly over the circumference
in the widened portion 14c is possible. The unilateral disposition
of the throttle opening 28a assures that as soon as the ball 20a
has lifted from the valve seat 22, the closing body 20 is pressed
radially in the direction of the throttle opening 28a against the
closing body guide 26. As a result, a precisely defined location of
the closing body 20 is attained that remains constant. Thus
hydraulically precisely defined conditions are obtained with regard
to the fluid flow flowing through the damper chamber 32. Also by
the contact of the closing body 20 with the closing body guide 26,
mechanical friction is achieved, which makes an additional
contribution to the hydraulic damping device 40 to prevent
oscillation of the closing body 20.
[0040] The delivery throttle opening 36, the damper chamber 32, and
the discharge throttle opening 38 in cooperation form the damping
device 40.
[0041] As soon as the closing body 20 has lifted somewhat from the
valve seat 22, some of the fluid flow flows out of the intermediate
pressure chamber 30 through the delivery throttle opening 36, or
more precisely through the first guidance gap 36a into the
intermediate chamber 34 and then through the second guidance gap
36b into the damper chamber 32, and then from the damper chamber 32
through the discharge throttle opening 38 into the fluid
continuation 8. The delivery throttle opening 36 and the discharge
throttle opening 38 form two throttles, connected hydraulically in
series, as a result of which a pressure arises in the damper
chamber 32 that in terms of the pressure value is between the
pressure in the fluid inlet 6 and the pressure in the fluid
continuation 8, or between the pressure in the intermediate
pressure chamber 30 and the pressure in the fluid continuation
8.
[0042] The pressure prevailing in the damper chamber 32 acts
hydraulically as a supplementary closing force F, in addition to
the force of the spring device 24, on the closing body 20 in the
closing direction. The graph shown in FIG. 2 illustrates the
dependency between the hydraulically acting supplementary closing
force F and the fluid flow Q flowing through the discharge throttle
opening 38. The dependency is parabolic.
[0043] Assuming a mean fluid flow Q1, as an example, the mean
hydraulic supplementary closing force F1 is obtained. Any possible
oscillation of the closing body 20 leads to oscillation of the
fluid flow Q flowing through the discharge throttle opening 38. For
the purposes of this explanation, let it be assumed that the fluid
flow Q fluctuates by the amount dQ, for instance. Because of the
dependency illustrated in FIG. 2, the hydraulic supplementary
closing force F then fluctuates by the amount dF. This fluctuation
of the supplementary closing force F by the amount dF is oriented
counter to the motion of the closing body 20. Because of the fluid
flow Q1 that flows constantly through the discharge throttle
opening 38, and because of the principle of throttling, even a
slight fluctuation dQ in the fluid flow Q produces a relatively
major fluctuation dF in the closing force F. It can be seen from
FIG. 2 that the fluctuation of the supplementary closing force F by
the amount dF depends on the magnitude of the mean fluid flow Q.
Without the mean fluid flow Q, the fluctuation dF in the
supplementary closing force F would be less; that is, the hydraulic
damping would be substantially less effective. The advantages thus
obtained that even with a relatively large gap between the closing
body 20 and the closing body guide 26, or in other words despite a
relatively large first guidance gap 36a and a relatively large
second guidance gap 36b, adequately good damping of the oscillation
of the closing body 20 can nevertheless be achieved. Because of the
relatively large guidance gaps 36a and 36b that are possible, the
expense for producing the guidance gaps 36a and 36b is relatively
slight, and little sensitivity to dirt is obtained, so that even
certain dirt particles in the fluid do not lead to seizing of the
closing body 20.
[0044] The branching off of the fluid flow, flowing through the
damper chamber 32, from the intermediate pressure chamber 30 has
the advantage that, when the fluid opening 18 is at least partly
open, and on account of the intermediate pressure backed up in the
intermediate pressure chamber 30, a constant flow through the
damper chamber 32 is assured, and nevertheless the advantage is
obtained that whenever the closing body 20 is seated on the valve
seat 22, a fluid flow flowing through the damper chamber 32 is
reliably prevented.
[0045] FIG. 3 shows a longitudinal section through a further
preferably selected, especially advantageous exemplary
embodiment.
[0046] In all the drawing figures, elements that are the same or
function the same are provided with the same reference numerals.
Unless otherwise noted or shown in the drawing, what is mentioned
and shown in conjunction with one of the drawing figures applies to
the other exemplary embodiments as well. Unless otherwise stated in
the explanation, the details of the various exemplary embodiments
can be combined with one another.
[0047] In the modified exemplary embodiment shown in FIG. 3, the
closing body 20 is embodied by the single ball 20a. Here the spring
24a of the spring device 24 acts on the single ball 20a that forms
the closing body 20.
[0048] In this exemplary embodiment as well, the outflow throttle
restriction 28 is formed by the throttle opening 28a provided in
the sheath 14. A closing body guide 26 is again provided on the
sheath 14. For the sake of simplicity in producing the pressure
regulating valve 2, a graduation of the sheath 14 to enlarge the
intermediate pressure chamber 30 has been dispensed with in this
exemplary embodiment.
[0049] In this exemplary embodiment, the sheath 14 is firmly
retained by a clamping piece 46. The clamping piece 46 is by way of
example a deep-drawn component made from a piece of sheet metal,
and it is tubular. The clamping piece 46 is pressed into the
cup-shaped dividing wall 10 so far that the clamping piece 46
presses the sheath 14 on its face end against the dividing wall 10.
As a result, the sheath 14 is firmly retained and fixed on the
dividing wall 10.
[0050] Openings 46a are provided in the tubular clamping piece and
enable a flow of the fluid flow in the direction of the fluid
continuation 8. The spring 24a of the spring device 24 is braced on
one end on the clamping piece 46 and on the other on the side 20d
of the closing body 20. By plastic deformation of the clamping
piece 46 in the axial direction that occurs after assembly, the
opening pressure of the pressure regulating valve 2 can be
adjusted.
[0051] FIG. 4 shows a further preferably selected, especially
advantageous exemplary embodiment.
[0052] In this exemplary embodiment, the sheath 14 is embodied as a
turned part. This makes it especially easy to provide the widened
portion 14c between the cylindrical portion 14b and the valve seat
22. As a result, it is easy to make the cross-sectional area of the
intermediate pressure chamber 30 relatively large in the
circumferential direction, so that the intermediate pressure in the
intermediate pressure chamber 30 can act uniformly over the entire
circumference on the intermediate pressure face 20z.
[0053] The closing body guide 26 is located on the inner jacket
face of the cylindrical portion 14b, and the throttle opening 28a,
in the region of the shoulder 14d, leads out of the intermediate
pressure chamber 30 through the sheath 14 in the direction of the
fluid continuation 8.
[0054] FIG. 5 shows a longitudinal section through a further
preferably selected, especially advantageous exemplary
embodiment.
[0055] In this exemplary embodiment, the sheath 14 is connected
firmly to the dividing wall 10 via the materially bonded connection
16. Resistance welding can for instance be employed as one possible
connection method.
[0056] In the exemplary embodiment shown in FIG. 5, the tube 14 is
an especially easily produced turned part or an especially easily
produced deep-drawn part, or a cold-headed part which is especially
easy to produce by plastic reshaping. However, here as well the
sheath 14 can be provided with a graduation, for the sake of
enlarging the intermediate pressure chamber 30.
[0057] The clamping piece 46, which serves to retain the spring 24a
of the spring device 24, is an easily produced sheet-metal part,
which is press-fitted into the cup-shaped inner region of the
dividing wall 10. By pressing the clamping piece 46 more or less
far into the dividing wall 10, the initial tension of the spring
24a and thus the opening pressure of the pressure regulating valve
2 can be adjusted or set.
[0058] In the preferred selected exemplary embodiments, there is
play 48 all the way around in the radial direction between the
sheath 14 and the inner jacket face of the cup-shaped dividing wall
10. This play 48 is provided so that before the sheath 14 is fixed
relative to the dividing wall 10, the sheath 14 can be displaced
radially relative to the dividing wall 10. The spacing or play 48
extending all the way around makes it possible to align the sheath
14 relative to the dividing wall 10.
[0059] In the exemplary embodiments selected for the drawings, the
valve seat 22 is located directly on the dividing wall 10. However,
it should be noted that the pressure regulating valve 2 can also be
modified, specifically in such a way that the valve seat 22 is
located directly on the dividing wall 10. This is the case for
instance whenever a ring is firmly press-fitted into the fluid
opening 18, specifically in such a way that the valve seat 22 is
located on an inner surrounding edge of the tightly press-fitted
ring.
[0060] The following method is proposed for assembling the pressure
regulating valve 2, in the exemplary embodiment shown in FIG.
1:
[0061] First, the spring 24a and then the closing body 20 are
placed in the sheath 14. Next, the sheath 14 is pressed, together
with the spring 24a and the closing body 20, against the face end
of the dividing wall 10 with slight force. When the sheath 14 is
pressed on its face end against the dividing wall 10, then the
spring 24a presses the ball 20a into the fluid opening 18 having
the valve seat 22 extending all the way around. Pressing the ball
20a into the circular fluid opening 18 against the valve seat 22
creates a centering force exerted on the ball 20a by the valve seat
22. By way of the tight play between the ball 20a and the closing
body guide 26 at the sheath 14, the centering force also acts on
the sheath 14, with the tendency to center the sheath 14, and thus
the closing body guide 26, relative to the valve seat 22. The
adequately dimensioned play 48 makes it possible to align the
sheath 14.
[0062] During the assembly and during the process of aligning the
closing body guide 26 relative to the valve seat 22, the sheath 14
is retained against the dividing wall 10. As a result, a force
hereinafter called the aligning force is created in the radial
direction, or in other words transversely to the longitudinal axis
of the closing body guide 26. It should be noted that during the
aligning of the closing body guide 26, the aligning force is less
than the centering force. In particular, care must be taken, during
the aligning, to press the sheath 14 against the dividing wall 10
only just strongly enough that the aligning force is still less
than the centering force.
[0063] If the aligning force that retains the sheath 14 in the
transverse direction is less than the centering force that centers
the sheath 14, then in the manner described, the sheath 14 is
centered relative to the valve seat 22 and thus relative to the
fluid opening 18 in a simple way but with excellent quality.
[0064] Once the sheath 14 has been centered relative to the valve
seat 22, the sheath 14 is fixed relative to the dividing wall 10.
The fixation of the sheath 14 relative to the dividing wall 10 can
be done by means of the materially bonded connection 16, for
instance. For the materially bonded connection 16, an attractive
option is to retain the sheath 14 on its face end against the
dividing wall 10 and to join the sheath 14 solidly to the dividing
wall 10 via a resistance welding process.
[0065] For the assembly of the various exemplary embodiments shown
in FIGS. 3 and 4, the following method is proposed:
[0066] First, the sheath 14 is placed on its face end against the
dividing wall 10. Then the clamping piece 46 is press-fitted into
the cup-shaped dividing wall 10. During this press-fitting of the
clamping piece 46, the spring 24a of the spring device 24 is placed
between the contact point at the clamping piece 46 and the side 20d
of the closing body 20. During the assembly, the sheath 14 can be
roughly aligned with the aid of a tool that reaches through the
openings 46a. As the clamping piece 46 is being press-fitted into
the dividing wall 10, the spring 24a presses the ball 20a into the
fluid opening 18 and against the valve seat 22. This creates a
centering force that acts from the valve seat 22 on the ball 20a,
counter to the closing force of the spring 24. This centering force
is transmitted from the ball 20a to the sheath 14. The result is
excellent centering of the closing body guide 26, provided on the
sheath 14, relative to the valve seat 22. In the exemplary
embodiments of FIGS. 3 and 4 as well, care must be taken that
during the centering operation, the aligning force be kept less
than the centering force.
[0067] Once the sheath 14 has been aligned relative to the valve
seat 22, the clamping piece 46 is press-fitted even substantially
more strongly into the cup-shaped dividing wall 10, causing the
clamping piece 46 to clamp the sheath 14 against the dividing wall
10 with such great force that slippage of the sheath 14 relative to
the dividing wall 10 can no longer ensue. In a simple way, this
assures a fixation of the sheath 14 and thus an excellent-quality
alignment of the sheath 14 relative to the valve seat 22. After
that, if the customer wishes it, the sheath 14 can be welded to the
dividing wall 10.
[0068] In the exemplary embodiment shown in FIG. 5, the following
method is proposed for the assembly of the pressure regulating
valve 2:
[0069] First, the sheath 14 is placed on its face end against the
bottom of the cup-shaped dividing wall 10. Next, the ball 20a
representing the closing body 20 is placed in the sheath 14. Then
with the aid of the spring 24a, the ball 20a is pressed against the
valve seat 22. This creates a centering force acting in the radial
direction on the closing body 20. This centering force also acts on
the sheath 14 via the ball 20a and thus assures centering of the
sheath 14 relative to the valve seat 22 and thus relative to the
fluid opening 18. Next, the clamping piece 46 is press-fitted so
far into the cup-shaped dividing wall 10 that the spring 24a is
prestressed so much that the desired opening pressure of the
pressure regulating valve 2 is assured. During the centering of the
sheath 14 and while the sheath 14 is being fixed on the dividing
wall 10, the sheath 14 can be retained with the aid of a tool that
reaches the openings 46a.
[0070] The foregoing relates to preferred exemplary embodiments of
the invention, it being understood that other variants and
embodiments thereof are possible within the spirit and scope of the
invention, the latter being defined by the appended claims.
* * * * *