U.S. patent application number 09/785566 was filed with the patent office on 2001-08-23 for arrangement for hydraulic actuation of a movable component on vehicles.
Invention is credited to Osterried, Jurgen, Schmied, Peter.
Application Number | 20010015127 09/785566 |
Document ID | / |
Family ID | 3670657 |
Filed Date | 2001-08-23 |
United States Patent
Application |
20010015127 |
Kind Code |
A1 |
Osterried, Jurgen ; et
al. |
August 23, 2001 |
Arrangement for hydraulic actuation of a movable component on
vehicles
Abstract
An arrangement for hydraulic actuation of a movable component on
vehicles, particularly a vehicle top, trunk lid, a cover or the
like, includes at least one double-action working cylinder (1)
whose working chambers are connected to a pressure source (5) via a
pressure line (4) or whose working chambers are at least
temporarily connectable thereto through a switching valve (11). To
make possible an automatic emergency operation of the normally
hydraulic operated vehicle component in a simple and secure manner
during failure of the pressure source, and in spite of the small
available space and the mounting site with its difficult
accessibility, a check valve (16) is inserted into the pressure
line (4) blocking in the direction of the pressure source (5) and a
pressure relief line (17) originates at a location between the
check valve (16) and the switching valve arrangement for the
working cylinder (1, 11) whereby a shut-off element (19) is
inserted in the pressure relief line that opens when the pressure
of the pressure source drops.
Inventors: |
Osterried, Jurgen;
(Pfronten, DE) ; Schmied, Peter; (Schongau,
DE) |
Correspondence
Address: |
Dykema Gossett PLLC
Suite 300 West
1300 I Street, N.W.
Washington
DC
20005-3306
US
|
Family ID: |
3670657 |
Appl. No.: |
09/785566 |
Filed: |
February 20, 2001 |
Current U.S.
Class: |
91/418 ;
91/446 |
Current CPC
Class: |
F15B 20/004 20130101;
F15B 13/10 20130101; B60J 7/1273 20130101 |
Class at
Publication: |
91/418 ;
91/446 |
International
Class: |
F15B 011/08 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 22, 2000 |
AT |
A 277/2000 |
Claims
We claim:
1. An arrangement for hydraulic actuation of a movable component on
vehicles, particularly a vehicle top, trunk lid, a cover or the
like, comprising at least one double-action working cylinder (1)
whose working chambers are connected to a pressure source (5) via a
pressure line (4) or which working chambers are at least
temporarily connectable thereto through a switching valve (11),
characterized in that a check valve (16) is inserted into said
pressure line (4) blocking in the direction of said pressure source
(5) whereby a pressure relief line (17) originates at a location
between said check valve (16) and the switching valve arrangement
for the working cylinder (1, 11), and whereby a shut-off element
(19) is inserted in said pressure relief line that opens when the
pressure of the pressure source drops.
2. An arrangement according to claim 1, wherein a throttle (20) is
provided in the pressure relief line (17) behind said shut-off
element (19).
3. An arrangement according to claim 1, wherein said shut-off
element (19) is a hydraulically blocking valve.
4. An arrangement according to claim 3, wherein said shut-off
element (19) is a hydraulically switchable check valve.
5. An arrangement according to claim 4, wherein the valve element
(24) of the hydraulically blocking check valve (19) may block
hydraulic medium via a hydraulic operated control piston (25)
having a larger surface than the valve seat (23).
6. An arrangement according to claim 5, wherein said control piston
(25) is designed in one piece together with said valve element
(24).
7. An arrangement according to claim 6, wherein the control line
(18) for the hydraulically switchable valve (19) originates at a
location in front of said check valve (16) of said pressure line
(4).
8. An arrangement according to claim 1, including at least one
differentially controlled double-action working cylinder (1) whose
piston-side working chamber may be connected to a pressure source
(5) via a switching valve (11) and possibly a check valve
arrangement (12), wherein the pressure relief line (17) originates
at a location in front of said switching valve (11) and possibly in
front of said check valve arrangement (12).
9. An arrangement according to claim 1, comprising a pressure
source that is provided with at least one single-action pump (6), a
tank (9) for the working medium and possibly auxiliary components
such as a check valve arrangement (7) and/or a pressure relief
valve (8) and/or a throttle (10), wherein said check valve (16) is
disposed in the pressure line (4) behind all auxiliary components
(6 through 10) of the pressure source (5), and wherein the pressure
relief line (17) is connected to the tank (9).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an arrangement for hydraulic
actuation of a movable component on vehicles, particularly a
vehicle top, trunk lid, a cover or the like, having at least one
double-action working cylinder which working chambers are connected
to a pressure source via a pressure line or which working chambers
are at least temporarily connectable thereto through a switching
valve.
[0003] 2. The Prior Art
[0004] Arrangements of this type are well known and make possible,
for example, automatic actuation of vehicle doors, hoods, service
access covers, covers for the trunk, the space for a convertible
top or the convertible top itself. In case of shut-off or failure
of the operating pressure (which means shut-off or failure of a
(hydraulic) unit during automatic operation), the cover, the
vehicle top or the like should remain hydraulically locked in a
particular position to prevent uncontrolled retraction and dangers
of injury related thereto.
[0005] This is achieved in most systems through a so-called
emergency hand-operated bolt, which blocks the connecting bore
between the two working chambers of the hydraulic working cylinder,
which in turn moves the component. Through this emergency
hand-operated bolt it is guaranteed that during closing of the
vehicle top, a pressure increase occurs at the piston-side, for
example, and at the same time the rod-side remains without pressure
(for systems in which the closing of the vehicle top is effected by
the extension of the working cylinder.) The same is applicable in
reversed order in a sense for the piston and the rod-side to open
the vehicle top. In case of failure of the (hydraulic) unit, the
emergency hand-operated bolt can be manually operated and the
rod-side may be opened thereby. The system is therefore without
pressure and the top or the cover or the like may be operated
manually whereby the hydraulic medium is urged to the working
chambers via the connecting bore.
[0006] Should the mounting site of the hydraulic unit be in an
unfavorable location, then the emergency hand-operated bolt may be
operated only with great difficulties. In most cases, the hydraulic
unit is mounted at the rear fender areas and therefore a flexible
shaft must be provided to be able to operate the emergency
hand-operated bolt from the trunk space. A version with an
electrically actuated 2/2-directional seat valve would again be
costly and susceptible to malfunctioning.
[0007] It is the object of the present invention to improve on the
known arrangement so that the described disadvantages are
prevented, particularly in reference to the small available space
and the mounting site with its difficult accessibility, and whereby
particularly during failure of the pressure source there is made
possible, in a simple and safe manner, manual emergency operation
in any direction of the normally hydraulic operated vehicle
component, such as the trunk lid, the cover, the vehicle top or the
like.
SUMMARY OF THE INVENTION
[0008] This object is achieved, according to the invention, in an
arrangement of the above-mentioned type in that a check valve is
inserted into the pressure line blocking in the direction of the
pressure source whereby a pressure relief line originates at a
location between the check valve and the switching valve
arrangement for the working cylinder, and whereby a shut-off
element is inserted in the pressure relief line that opens when the
pressure of the pressure source drops. Through employment of the
blocking check valve and the shut-off element, the emergency
hand-operated bolt can be eliminated all together and an automatic,
gradually engaging device is thereby provided for pressure relief
in the system, which then allows manual emergency operation of the
normally hydraulically operated vehicle component. In case of a
functioning hydraulic system, which means at normal operating
pressure, one or each working cylinder is supplied with working
medium through the pressure line. In case of malfunctioning of the
(hydraulic) unit, the pressure in the pressure line is reduced
because of pressure loss in the pressure source. The operating
pressure is at first maintained by the check valve. Only when the
shut-off valve is opened, the working medium may escape through the
pressure relief line and subsequently the pressure drops to such a
degree that the working cylinder--and thereby also the movable
vehicle component--can be manually operated. Depending on the
pressure by which the shut-off element is opened, an emergency
holding function can be realized, which means that a pressure may
be maintained within the system which hydraulically compensates for
the weight and/or closing force of the moving vehicle component
such as a trunk lid or a cover. Only when a pressure increase
occurs in addition to the blocking effect of the shut-off element
during manual operation, then the working medium is discharged
through the pressure relief line and the working cylinder may now
be operated manually. A possible throttle in the pressure relief
line prevents excessively rapid pressure drop in the system and
prevents thereby uncontrolled movements of the moving vehicle
component.
[0009] According to an additional characteristic of the invention,
a throttle is provided behind the shut-off element in the pressure
relief line. A slower pressure drop is thereby guaranteed within
the system, which prevents excessively rapid and uncontrolled
movements after pressure failure in the pressure line.
[0010] When the shut-off element is a hydraulically switchable
valve as in an additional characteristic of the invention,
additional control systems for the shut-off element may be
eliminated, which have higher requirements in terms of construction
and control technology, and a fault-free simple shut-off element is
provided having a direct and immediate controlling effect through
the pressure in the pressure line.
[0011] It is advantageously proposed that the shut-off element is a
hydraulically blocking check valve. The hydraulic counterforce may
therefore be directly defined through adjustment of the
blocking-force of the valve, which is the counterforce to the
weight or closing force of the moving vehicle component during
failure of the hydraulic system, and thus the emergency holding
function is realized for said component. On the other hand, there
is guaranteed by the design of a check valve opening away from the
working cylinder, that during the use of manual supplementary force
onto the normally hydraulically moved component it is made possible
to open the valve element of the check valve. This is based on the
related pressure increase and discharge the working medium through
the pressure relief line, which therefore makes manual emergency
operation possible.
[0012] It is thereby advantageously proposed that the valve element
of the hydraulically blocking check valve may be blocked by a
hydraulically actuated control piston having a larger surface than
the one of the valve seat. This embodiment makes a secure locking
position of the valve easier since a lower pressure than the
operating pressure of the system is sufficient to shut the check
valve based on these surface ratios.
[0013] Additionally, it is of advantage if in the described version
of the shut-off element, which is functioning as a check valve, the
control piston is designed as one piece together with the valve
element. Structural and financial requirements are thereby reduced
and a high operational dependability (of the check valve) is
provided.
[0014] According to another characteristic of the invention, the
control line for the hydraulically switchable valve originates at a
location in front of the check valve of the pressure line. The
blocking effect of the valve controlling the pressure relief is
thereby immediately and directly dependent on the pressure in the
pressure line, and additional control circuits or control devices
may be eliminated thereby. Structural demands and space
requirements are therefore especially low and operational
dependability of the arrangement is considerably increased.
[0015] In an arrangement with at least one differentially
controlled double-action working cylinder, which piston-side
working chamber may be connected to a pressure source via a
switching valve or possibly a check valve arrangement, the object
of the invention is achieved in that the pressure relief line
originates at a location if front of the switching valve and
possibly in front of the check valve arrangement. Thereby there is
no danger of negative influence on the drive of the working
cylinder by the system component that is necessary for emergency
operation, and there is also no distinct structural separation of
the individual subordinate systems, which simplifies the
installation and maintenance of the entire unit.
[0016] The latter advantage does also exist if an arrangement with
a pressure source is provided with at least one single-action pump,
a tank for the working medium, and possibly auxiliary components
such as a check valve arrangement and/or a pressure relief valve
and/or a throttle, whereby the check valve is disposed in the
pressure line behind the auxiliary components of the pressure
source, and whereby the pressure relief line is connected to the
tank so that no working medium can escape or can negatively impact
the environment.
[0017] The invention will be better understood by reference to
accompanying drawings taken in conjunction with the following
discussion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows a schematic hydraulic circuit of an exemplary
hydraulic arrangement according to the invention.
[0019] FIG. 2 shows a schematic illustration of the functioning of
a hydraulically blocking check valve used as a shut-off
element.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The arrangement for hydraulic actuation of a vehicle top, a
cover, a trunk lid or any other movable vehicle component
(illustrated in FIG. 1), is provided with two double-action
hydraulic cylinders 1, for example, which are joined on one side to
the vehicle and on the other side to a vehicle component, for
instance the vehicle top or an interconnected lever arrangement.
The working cylinders 1 are differentially driven whereby the
piston-side working chambers and the rod-side working chambers of
the working cylinder 1 are connected via lines 2, 3 to a hydraulic
unit 5, which serves as a pressure source and which advantageously
communicates with the electric circuit of the vehicle for the
supply of energy.
[0021] The hydraulic unit 5 includes a single-action pump 6 having
a drive motor, a check valve arrangement 7, a pressure relief valve
8 for adjustment of the maximum system pressure, and a tank 9 for
the working medium--the hydraulic oil. A throttle 10 may also be
installed in the hydraulic unit 5 just before the line exit.
[0022] A control valve 11 having a check valve arrangement 12 is
provided for the differential drive of the working cylinders 1 in
line 2 leading to the piston-side working chamber. The control
valve 11 alternately connects this working chamber with the
pressure line 4 and a secondary line 13, possibly via an inserted
throttle, to the tank 9 while the rod-side working chamber of one
or each working cylinder 1 continually remains in communication
with the pressure line 4.
[0023] Finally, connections 15 may also be provided for additional
hydraulic working units, such as additional working cylinders.
[0024] A check valve 16, blocking in the direction of the hydraulic
unit 5, is inserted in the pressure line 4 that leads from the
hydraulic unit 5 to the working cylinder 1, preferably in front of
the control valve 11 and/or the check valve arrangement 12. The
check valve 16 mainly maintains the operating pressure in the
following system section in case of failure of the hydraulic unit
5. A pressure relief line 17 branches off from the pressure line
behind the check valve 16 and leads to the tank 9. A shut-off valve
19, which is advantageously hydraulic and which may be switched via
the control line 18, is inserted in the pressure relief line 17,
and subsequently a throttle 20 may be inserted to prevent an
excessively rapid pressure drop in the system. Since the control
line 18 for the shut-off valve 19 originates at the location
between the hydraulic unit 5 and the check valve 16, an immediate
controlling effect for the shut-off valve 19 is guaranteed,
depending on the pressure supplied by the hydraulic unit 5. The
shut-off valve 19 is designed in itself in a manner whereby moving
in the shut-off direction is achieved by means of a closing spring
21, but which movement may be counteracted by a pressure increase
in the system behind the check valve 16 through a second control
line 22 or through functionally equivalent components or designs of
the shut-off valve 19 itself.
[0025] In FIG. 2 there is shown in a schematic illustration, an
advantageous embodiment of the shut-off valve 19 in the form of a
hydraulically blocking check valve. A valve seat 23 is designed in
the housing of the check valve 19 whereby the valve seat 23 may be
closed by a valve element 24. The valve element 24 has preferably a
conical shape and the cross section of the seat 23 is smaller than
the cross section of a control piston 25, which is biased by
pressure via the control line 18 that is in front of the check
valve 16. The valve element 14 and the control piston 25 are
preferably designed as one piece having a circumferential groove to
receive a seal 26. Thereby, the closing spring 21 also acts
directly upon the valve element 24 via the control piston 25 to
move the valve element 24. At normal operating pressure in the
pressure line 4, secure closing of the shut-off valve 19 is
guaranteed based on the surface cross section of the control piston
25 that is larger than the one of the valve seat 23. During a
pressure drop in front of the check valve 16, the pressure in the
control line 18 also drops to that value so that the opening
pressure of the shut-off valve 19 substantially depends now more on
the force of the closing spring 21. As long as this opening
pressure is met or is exceeded in the pressure line section, which
is arranged behind the check valve 16, the valve element 14 is
lifted from the valve seat 23 against the force of the closing
spring 21 and the working medium can thus escape through the
pressure relief line 17 into the tank 9 of the hydraulic system
5.
* * * * *