U.S. patent application number 13/580215 was filed with the patent office on 2012-12-13 for proportional valve, in particular for a camshaft adjuster.
This patent application is currently assigned to SCHAEFFLER TECHNOLOGIES AG & CO. KG. Invention is credited to Jens Hoppe, Stefan Konias, Yi Wang.
Application Number | 20120312396 13/580215 |
Document ID | / |
Family ID | 43842702 |
Filed Date | 2012-12-13 |
United States Patent
Application |
20120312396 |
Kind Code |
A1 |
Hoppe; Jens ; et
al. |
December 13, 2012 |
PROPORTIONAL VALVE, IN PARTICULAR FOR A CAMSHAFT ADJUSTER
Abstract
A proportional valve (1), including a piston guide sleeve (4)
and a valve piston (3) that can be moved in the piston guide sleeve
(4), and further including a check valve (13) arranged in a
pressure medium inlet (10) to the proportional valve (1). According
to the invention a proportional valve (1) is provided, in which the
adaption of the check valve (13) to the proportional valve (1) is
improved with respect to the prior art. This is achieved in that
the check valve (13) is arranged in an annular gap (14) surrounding
the piston guide sleeve (4) in a region of the pressure medium
inlet (10).
Inventors: |
Hoppe; Jens; (Erlangen,
DE) ; Konias; Stefan; (Erlangen, DE) ; Wang;
Yi; (Erlangen, DE) |
Assignee: |
SCHAEFFLER TECHNOLOGIES AG &
CO. KG
Herzogenaurach
DE
|
Family ID: |
43842702 |
Appl. No.: |
13/580215 |
Filed: |
January 25, 2011 |
PCT Filed: |
January 25, 2011 |
PCT NO: |
PCT/EP2011/050977 |
371 Date: |
August 21, 2012 |
Current U.S.
Class: |
137/511 ;
29/890.12 |
Current CPC
Class: |
F01L 1/344 20130101;
Y10T 137/7837 20150401; Y10T 29/49405 20150115 |
Class at
Publication: |
137/511 ;
29/890.12 |
International
Class: |
F16K 21/04 20060101
F16K021/04; B21D 51/16 20060101 B21D051/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 26, 2010 |
DE |
10 2010 009 401.3 |
Claims
1. Proportional valve comprising: a piston guide sleeve, a valve
piston that can move in the piston guide sleeve, and a check valve
arranged in a pressure medium inlet to the proportional valve, the
check valve is arranged in an annular gap surrounding the piston
guide sleeve in an area of the pressure medium inlet.
2. Proportional valve according to claim 1, wherein the annular gap
is limited by an insert-molded part at least partially surrounding
the piston guide sleeve and a receptacle sleeve comprising at least
one sub-region of the insert-molded part.
3. Proportional valve according to claim 2, wherein the receptacle
sleeve has, on an axial end thereof, a receptacle gap that forms a
sub-region of the annular gap and in which the check valve is
inserted.
4. Proportional valve according to claim 2, wherein the piston
guide sleeve provided with the insert-molded part is connected with
a material-fit connection to the receptacle sleeve.
5. Proportional valve according to claim 2, wherein the piston
guide sleeve provided with the insert-molded part is connected with
a non-positive-fit connection to the receptacle sleeve.
6. Proportional valve according to claim 1, wherein the check valve
is constructed as a spring sleeve with slots in an axial
direction.
7. Proportional valve according to claim 1, wherein the check valve
is produced from a metallic material.
8. Proportional valve according to claim 2, wherein the
insert-molded part includes, on a outer lateral surface thereof, a
stop that is active in a radial direction in an opening direction
of the check valve.
9. Proportional valve according to claim 2, wherein the receptacle
sleeve forms, on an inner lateral surface thereof, a stop that is
active in the radial direction in a closing direction of the check
valve.
10. Installation method for a proportional valve with a piston
guide sleeve, a valve piston that can move in the piston guide
sleeve, and a check valve arranged in a pressure medium inlet to
the proportional valve, comprising inserting the check valve into a
receptacle gap of the receptacle sleeve forming a sub-region of the
annular gap and then inserting the piston guide sleeve provided
with the insert-molded part into the receptacle sleeve and
connecting the piston guide sleeve to the receptacle sleeve.
11. Proportional valve according to claim 2, wherein the piston
guide sleeve provided with the insert-molded part is connected with
a positive-fit connection to the receptacle sleeve.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a proportional valve with a piston
guide sleeve, a valve piston that can move in the piston guide
sleeve, and also a check valve arranged in a pressure medium inlet
to the proportional valve. The invention also relates to an
installation method for such a proportional valve.
BACKGROUND
[0002] Such a proportional valve is known from DE 10 2005 060 111
A1. This proportional valve is designed for a camshaft adjuster for
an internal combustion engine and is integrated into a central
screw for attaching the camshaft adjuster to a camshaft. Here, the
proportional valve has a check valve that has a spring disk-shaped
construction and is arranged in an annular pressure medium inlet
laterally next to the proportional valve on the outer periphery of
the central screw. During installation, care must be taken that
this check valve arranged separate to the proportional valve is
installed and there is also the risk of damage at least when
screwing the central screw holding the proportional valve into the
camshaft.
[0003] Another check valve is known from EP 1 291 563 A2. This
check valve is designed for and integrated in a proportional valve
constructed especially as a cartridge valve. Here, this check valve
is inserted in the area of a pressure medium inlet into a recess
provided on the inner periphery of the piston guide sleeve before
installation of the valve piston. Here, the installation costs of
such a check valve inserted into the piston guide sleeve are
considerable. In addition, the stroke of this check valve
constructed as a spring ring is not limited inwardly and the spring
ring consequently can collide with the valve piston. Such a
collision can lead to failure of the proportional valve.
SUMMARY
[0004] The invention is based on the objective of offering a
proportional valve, in particular for a camshaft adjuster of an
internal combustion engine, wherein the adaptation of the check
valve to the proportional valve is improved compared with the prior
art.
[0005] This objective is met in that the check valve is arranged in
an annular gap surrounding the piston guide sleeve in the area of
the pressure medium inlet. Through this construction, on one hand,
the check valve is integrated into the actual proportional valve so
that the check valve does not have to be installed as a separate
component during the installation of the proportional valve. On the
other hand, because the check valve is arranged outside of the
piston guide sleeve it is guaranteed that the check valve cannot be
moved in the radial direction against the valve piston.
Incidentally, the proportional valve constructed in this way is
preferably used for adjusting the camshaft of an internal
combustion engine.
[0006] In continuation of the invention, the annular gap is limited
by an insert-molded part at least partially surrounding the piston
guide sleeve and a receptacle sleeve comprising at least a
sub-region of the insert-molded part. Several advantages are
achieved with this construction. No additional installation expense
is required for the installation of the camshaft adjuster, wherein
the risks of installation errors due to an incorrectly installed,
an additional check valve or even no check valve at all are
minimized. Furthermore, no additionally processed installation
space on the cylinder head of the internal combustion engine is
necessary for a separate check valve and a hydraulically short
distance to the actual camshaft adjuster and thus a stiffer
hydraulic support is achieved.
[0007] In continuation of the invention, the receptacle sleeve has,
on its axial end, a receptacle gap that forms a partial region of
the annular gap and in which the check valve is inserted. This
construction allows an especially simple and reliable installation
of the check valve, in that this check valve is inserted into the
end-side receptacle gap without the use of tools and then the
piston guide sleeve is inserted into the receptacle sleeve. This
construction also reduces the processing costs for the components,
in particular, the piston guide sleeve. In contrast to the prior
art, in the construction according to the invention the piston
guide sleeve is not processed for forming the annular gap.
[0008] In another construction of the invention, the piston guide
sleeve provided with the insert-molded part is connected to the
receptacle sleeve with a material-fit connection. Here, according
to an installation method according to the invention, the check
valve is inserted in a receptacle gap of the receptacle sleeve
forming a partial region of the annular gap and then the piston
guide sleeve provided with the insert-molded part is inserted into
the receptacle sleeve and connected to this sleeve, for example,
with a material-fit connection. Alternatively, a non-positive-fit
or positive-fit connection could also be provided. The material-fit
connection could be realized, for example, by ultrasonic welding or
bonding. A non-positive connection is achieved, for example, by
pressing the piston guide sleeve provided with the insert-molded
part into the receptacle sleeve, while a positive-fit connection
can be realized by a snap connection. All of these constructions
have the advantage that they provide an extremely functional
proportional valve for a camshaft adjuster.
[0009] In continuation of the invention, the check valve is
constructed as a spring sleeve with slots in the axial direction,
wherein it can be produced, in turn, advantageously from a metallic
material, for example, sheet metal or stainless steel.
[0010] In another construction, the insert-molded part forms, on
its outer lateral surface, a stop acting in the radial direction in
the open position of the check valve and the receptacle sleeve
forms, on its inner lateral surface, a stop acting in the radial
direction in the closing direction of the check valve. In the
deactivated state, the check valve contacts the inner lateral
surface of the receptacle sleeve with no force or in a slightly
pretensioned state. If pressure medium fluid, in particular,
hydraulic fluid, flows from the outside in the radial direction
into the adjustment space of the proportional valve, then the check
valve is pressed by the pressure of the pressure medium fluid
against the outer lateral surface of the insert-molded part and
opens the inlet. If there are pressure fluctuations against the
flow, then the check valve closes against the radial pressure
medium inlet of the receptacle sleeve. This construction offers the
advantage that a reliable function is guaranteed. In each case it
must be guaranteed that a collision of the check valve with the
valve piston is excluded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Additional advantageous constructions of the invention can
be taken from the description of the drawings in which an
embodiment of the invention shown in the figures is described in
more detail.
[0012] Shown are:
[0013] FIG. 1 a perspective overall view of the entire proportional
valve for the camshaft adjuster,
[0014] FIG. 2 a longitudinal section view through the proportional
valve with the check valve in a closed position,
[0015] FIG. 3 a longitudinal section view through the proportional
valve with the check valve in an open position, and
[0016] FIG. 4 a cross sectional view through the proportional valve
with the check valve in a closed position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The proportional valve 1 according to the invention is
provided for a camshaft adjuster of an internal combustion engine.
Here, the camshaft driven by the camshaft adjuster is used in an
internal combustion engine to open the gas exchange valves used for
pushing out combusted gases and for taking in fresh gases against
the force of valve springs installed on each gas exchange valve.
Fixed control times for the gas exchange valves represent a
compromise for the design with respect to the achievable medium
pressure maximum or torque maximum and their positions in the
usable rotational speed band, as well as the achievable output for
the rated rotational speed. An optimal adaptation of the control
times of the gas exchange valves can be achieved by a camshaft
adjuster according to the respective operating state.
[0018] The proportional valve 1 has, according to FIG. 1, an
electromagnetic control part 2 whose activation piston 6 interacts
with a valve piston 3 (FIGS. 2, 3, 4) in the proportional valve 1.
The activation piston 6 of the control part 2 moves the valve
piston 3 in a piston guide sleeve 4 of the proportional valve 1
between two end positions and therefore causes a regulated
adjustment of the control times on the camshaft adjuster. In
addition to the control part 2, the proportional valve 1 also
comprises the piston guide sleeve 4 (for a detailed representation,
see FIGS. 2 to 4) that is provided in the area of a pressure medium
inlet 10 and a working connection 11b with an insert-molded part 5
made from, in particular, plastic. In the piston guide sleeve 4,
the valve piston 3 can be moved by the control part 2 by the
activation piston 6 (FIGS. 2 and 3) against the force of a valve
spring 7.
[0019] The piston guide sleeve 4 provided with the insert-molded
part 5 is inserted in a receptacle sleeve 8 and fixed to this
sleeve by a snap connection 9 in an exact position on its end
facing away from the control part 2 (FIG. 2, 3). The proportional
valve 1 has four hydraulic fluid connections, namely a pressure
medium inlet 10 connected to a pump, two working connections 11a,
11b and a return connection 11c that is connected to a tank and
leads through the interior of the hollow cylindrical valve piston
3.
[0020] Through the pressure medium inlet 10, the hydraulic fluid,
in particular, the motor oil of the internal combustion engine, is
fed to the proportional valve 1 and fed through corresponding
passages in the receptacle sleeve 8, the insert-molded part 5, and
according to the position of the valve piston 3 via an annular
space 12 defined by the control pistons 12a and 12b as part of the
valve piston 3 to the working connections 11a, 11b.
[0021] From the working connection 11a, a connection to the return
connection 11c can be established via a connection opening 16 in
the valve piston 3. Ring filters 17 are provided on the pressure
medium inlet 10 and also the working connections 11a, 11b. These
are used to prevent the penetration of dirt into the proportional
valve 1.
[0022] Through this proportional valve 1 constructed according to
the invention, a defined adjustment of the camshaft relative to a
drive wheel activated, for example, by a toothed belt or chain is
achieved. This is achieved, for example, by one or more adjustment
pistons of the camshaft adjuster 1, wherein the piston or pistons
is/are connected to the camshaft and rotated relative to the drive
wheel by hydraulic fluid introduced through opposing adjustment
piston spaces connecting to the working connections 11a, 11b.
[0023] To prevent a return flow of the motor oil in the annular
space 12 back into the hydraulic fluid inlet 10, which could happen
due to the changing torque acting on the camshaft and thus on the
adjustment pistons of the camshaft adjuster, a check valve 13 is
inserted into the hydraulic fluid inlet 10, wherein this check
valve contacts the receptacle sleeve 8 in a closed position (FIG.
2) and contacts the insert-molded part 5 in an open position (FIG.
3). Here, the piston guide sleeve 4, the insert-molded part 5, and
the receptacle sleeve 8 form an annular gap 14 (FIG. 4) in which
the check valve 13 is arranged. To reliably position the check
valve 13 (reed valve) constructed as a spring sleeve with axial
slots in the annular gap 14, the receptacle sleeve 8 has a tab 15
that interacts with the insert-molded part 5. This tab 15 has the
effect that the check valve 13 cannot rotate within the annular gap
14. This prevents incorrect functioning. Furthermore, through the
construction according to the invention it is guaranteed that the
check valve 13 cannot come into contact with the valve piston 3 in
the open position.
LIST OF REFERENCE SYMBOLS
[0024] 1 Proportional valve [0025] 2 Control part [0026] 3 Valve
piston [0027] 4 Piston guide sleeve [0028] 5 Insert-molded part
[0029] 6 Actuation piston [0030] 7 Valve spring [0031] 8 Receptacle
sleeve [0032] 9 Snap connection [0033] 10 Pressure medium inlet
[0034] 11a, 11b Working connection [0035] 11c Return connection
[0036] 12 Annular space [0037] 12a, 12b Control piston [0038] 13
Check valve [0039] 14 Annular gap [0040] 15 Tab [0041] 16
Connection opening [0042] 17 Ring filter
* * * * *