HYDRAULIC SYSTEM FOR A VEHICLE OR A CONTAINER, AND VEHICLE OR CONTAINER HAVING SUCH A HYDRAULIC SYSTEM

Abstract

Hydraulic system and vehicles and containers having such a hydraulic system. The hydraulic system has at least two supporting cylinders for extending ground supports, and at least two hydraulic pumps connected to a hydraulic main line, and at least one supporting cylinder is provided on each of the two hydraulic main lines. The hydraulic system also has a main valve via which the two hydraulic main lines can be connected to one another or disconnected from one another.

Claims

1. A hydraulic system for supporting a vehicle or a container on a substrate, the hydraulic system comprising: at least two supporting cylinders for extending ground supports; at least two hydraulic pumps each connected to a hydraulic main line; at least one supporting cylinder being assigned to a first of the hydraulic main lines; at least one supporting cylinder being assigned to a second of the hydraulic main lines; and a main valve via which the two hydraulic main lines can be connected to one another or disconnected from one another.

2. The hydraulic system as claimed in claim 1, wherein the supporting cylinders are assigned to the first hydraulic main lines and the second hydraulic main lines such that when the main valve is closed at least one of the supporting cylinders is fed exclusively by one of the hydraulic pumps and at least one of the supporting cylinders is fed exclusively by the other of the hydraulic pumps.

3. The hydraulic system as claimed in claim 1, further including an electric motor assigned to each of the at least two hydraulic pumps.

4. The hydraulic system as claimed in claim 1, wherein the at least one supporting cylinder of the first hydraulic main line comprises a front supporting cylinder for extending a front ground support, and the at least one supporting cylinder of the second hydraulic main line comprises a rear supporting cylinder for extending rear ground supports.

5. The hydraulic system as claimed in claim 1, wherein the hydraulic system has at least one hydraulic motor or a further working cylinder.

6. The hydraulic system as claimed in claim 5, wherein the hydraulic system has at least two hydraulic motors or two further working cylinders for driving a common unit or a common system, and the two hydraulic motors or the two further working cylinders are provided on different hydraulic main lines.

7. The hydraulic system as claimed in claim 1, wherein: each supporting cylinder is assigned a supporting cylinder valve, the supporting cylinder being able to be individually connected by the supporting cylinder valve to the hydraulic main line assigned thereto or disconnected therefrom; and/or the hydraulic system includes two further working cylinders for driving a common unit or a common system, and each further working cylinder is assigned a control valve, the working cylinder being able to be individually connected by the control valve to the hydraulic main line assigned thereto or disconnected therefrom.

8. (canceled)

9. The hydraulic system as claimed in claim 1, wherein the hydraulic system has two separate return lines each connecting at least one pressure chamber of at least one supporting cylinder or at least one working cylinder acting in a retracting direction to one of the hydraulic pumps.

10. The hydraulic system as claimed in claim 1, wherein: a common hydraulic fluid tank is provided for feeding the at least two hydraulic pumps; and/or the hydraulic system has an outflow pressure compensator configured to provide a synchronous outflow of at least two of the supporting cylinders.

11. A vehicle comprising: at least two extendable ground supports; a hydraulic system for supporting the vehicle and extending and retracting the ground supports, the hydraulic system comprising: at least two supporting cylinders for extending the respective ground supports; at least two hydraulic pumps each connected to a hydraulic main line; at least one supporting cylinder being assigned to a first of the hydraulic main lines; at least one supporting cylinder being assigned to a second of the hydraulic main lines; and a main valve via which the two hydraulic main lines can be connected to one another or disconnected from one another.

12. The vehicle as claimed in claim 11, wherein the vehicle is configured as a caravan trailer, a mobile home, or a utility vehicle.

13. The vehicle as claimed in claim 11, wherein the vehicle has a movement system for moving the vehicle, and the movement system is driven by at least one hydraulic motor or at least one working cylinder of the hydraulic system.

14. A container comprising: at least two extendable ground supports; a hydraulic system for extending and retracting the ground supports, the hydraulic system comprising: at least two supporting cylinders for extending the respective ground supports; at least two hydraulic pumps each connected to a hydraulic main line; at least one supporting cylinder assigned to a first of the hydraulic main lines; at least one supporting cylinder assigned to a second of the hydraulic main lines; and a main valve via which the two hydraulic main lines can be connected to one another or disconnected from one another.

15. The vehicle as claimed in claim 11, wherein the vehicle has an extendable space, a closing element, a lifting platform or an entry system which is movable by a working cylinder of the hydraulic system.

16. A method for operating a hydraulic system as claimed in claim 1, the method comprising the following step: opening the main valve; while the main valve is open, initially at least one supporting cylinder of the one hydraulic main line is partially extended; subsequently, while the main valve is open, at least one supporting cylinder of the other hydraulic main line is partially extended; subsequently the main valve is closed; and the supporting cylinders of both hydraulic main lines are extended further simultaneously by the respective hydraulic pumps.

17. The method for operating a hydraulic system as claimed in claim 16, comprising at least one of the following steps: during the extension of a supporting cylinder this supporting cylinder is fed during a partial phase by both hydraulic pumps and during a different partial phase by only one of the hydraulic pumps; and/or if a malfunction of one of the hydraulic pumps is ascertained, the main valve is opened so that the remaining functional hydraulic pump can feed all of the supporting cylinders; and/or a pumping capacity of the hydraulic pumps is adapted by changing a rotational speed of the hydraulic pumps or deactivating one of the hydraulic pumps.

18. The hydraulic system as claimed in claim 4, wherein: two front supporting cylinders are assigned to the first hydraulic main line and two rear supporting cylinders are assigned to the second hydraulic main line; or a front supporting cylinder is assigned to the first hydraulic main line and two rear supporting cylinders are assigned to the second hydraulic main line.

19. The hydraulic system as claimed in claim 5, wherein: the hydraulic motor or the further working cylinder is configured for controlling the movement of an extendable space, an interior of the vehicle or the container being able to be enlarged thereby; and/or the hydraulic motor or the further working cylinder is configured for controlling a closing element of a storage space or an interior of the vehicle or the container; and/or the hydraulic motor or the further working cylinder is configured for controlling a lifting platform provided on the vehicle or on the container; and/or the hydraulic motor or the further working cylinder is configured for controlling an entry system; and/or the hydraulic motor is configured for driving a movement system for moving the vehicle.

20. The hydraulic system as claimed in claim 9, wherein the hydraulic system comprises a second main valve via which the two return lines are connectable to one another or disconnected from one another.

21. The container as claimed in claim 14, wherein the container has an extendable space, a closing element, a lifting platform or an entry system which is movable by a working cylinder of the hydraulic system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further advantages and aspects of the invention are found in the claims and the following description of preferred exemplary embodiments of the invention which are explained hereinafter with reference to the figures.

[0038] FIGS. 1 to 4 show various vehicles and a container which are provided in each case with a hydraulic support system, and in some cases with further hydraulically driven components.

[0039] FIG. 5 shows in a schematic view a hydraulic system for driving the hydraulic support system and the further hydraulically driven components.

[0040] FIGS. 6A to 11 show a sequence by way of example relating to the use of the hydraulic system in the example of a mobile home.

[0041] FIG. 12 shows an alternative embodiment of a hydraulic system in a schematic view.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0042] FIGS. 1 to 3 show various vehicles 100 according to the invention which are provided in each case with a hydraulic system 10 according to the invention. FIG. 4 shows a container 110 with such a hydraulic system 10, wherein such a container is generally moved by means of a truck or a pick-up vehicle between different locations.

[0043] All of the vehicles 100 and the container 110 have a support system with in each case a total of four ground supports 170 which are extended vertically during stationary mode of the vehicle or at the installation site of the container 110, in order to be able to support the weight force of the vehicle and the load thereof in a stable manner on a substrate. Each of these ground supports is assigned a supporting cylinder 60A to as shown in FIG. 5. The view selected here of vertically extendable ground supports 170 is only to be understood as an example. The ground supports could also be provided as pivotably movable ground supports or on horizontally extendable ground support carriers.

[0044] In addition to the ground supports 170, the vehicles 100 of FIGS. 1 to 3 have various further hydraulically operated functionalities. The assignment to the various vehicles or the container is only to be understood as an example. All of the aforementioned functionalities can be used in all of the units of FIGS. 1 to 4.

[0045] By way of example, a hydraulically extendable step 150 and an extendable space 120, which can be extended and retracted by two working cylinders 70 provided on either side of the extendable space 120, are provided as additional hydraulic functions on the mobile home 100 of FIG. 1.

[0046] In the case of the caravan trailer 100 of FIG. 2, a hydraulically foldable flap element 130 is shown, a storage space being able to be closed thereby.

[0047] In the case of the truck 100 of FIG. 3, a rear loading flap 140 with a pivoting and lifting movement is provided.

[0048] A hydraulic system according to the invention is configured at least to actuate the supporting cylinders 60A to of the ground supports 170. Preferably, however, such a system is configured to operate all of the aforementioned hydraulic components.

[0049] FIG. 5 shows such a hydraulic system 10 in a schematic view.

[0050] Supply lines 14, which feed into the aforementioned four supporting cylinders 60A, 60B, 60C, 60D, of which two supporting cylinders 60A, 60B are front supporting cylinders and two supporting cylinders 60C, 60D are rear supporting cylinders, extend to electrically switchable supporting cylinder valves 50 which control the inflow of hydraulic fluid in each case into one of the pressure chambers of the supporting cylinders 60A, 60C, 60D. Check valves 54 are provided between the supporting cylinder valves 50 and the supporting cylinders 60A, 60C, 60D, the check valves preventing a return flow of hydraulic fluid from the supporting cylinders 60 back in the direction of the supporting cylinder valves 50, up to a limit pressure. When the return line 16 is pressurized, however, the check valves 54 are opened for the purpose of retracting the supporting cylinders 60A, 60B, 60C, 60D.

[0051] The total of four supporting cylinder valves 50 are connected to two different hydraulic main lines 12A, 12B, namely the supporting cylinder valves 50 of the front supporting cylinders 60A, 60B to the hydraulic main line 12A and the supporting cylinder valves 50 of the supporting cylinders 60C, to the second hydraulic main line 12B. A hydraulic pump 20A, operated by an electric motor 30 is assigned in each case to both hydraulic main lines 12A, 12B. As a function of the rotational direction of these hydraulic pumps 20A, 20B, they pump hydraulic fluid in particular from the hydraulic fluid tank into their respective hydraulic main line 12A, 12B or into the return line 16, which is also provided with a check valve 58 which is opened in the case of limit pressure. The hydraulic pumps 20A, 20B are designed such that with a first rotational direction, and thus when pumping hydraulic fluid into the respective hydraulic main line 12A, 12B, the hydraulic fluid can flow back at the same time from the return lines 16 into the hydraulic fluid tank 90. With the reverse rotational direction, and when pumping hydraulic fluid into the return lines 16, hydraulic fluid can flow back from the hydraulic main lines 12A, 12B into the hydraulic fluid tank 90.

[0052] The two hydraulic main lines 12A, 12B can be switched between a connected state and a disconnected state by means of a switchable main valve 40. If the main valve 40 is closed, so that the hydraulic main lines 12A, 12B are disconnected from one another, the two pumps 20A, 20B can feed only hydraulic consumers on their respective hydraulic main line 12A, 12B. If the main valve 40 is opened, the two pumps 20A, 20B can respectively feed together or individually all of the hydraulic consumers on both hydraulic main lines 12A, 12B.

[0053] In addition to the aforementioned supporting cylinders to 60D, two further hydraulic cylinders 70 are provided in the exemplary view of FIG. 5. These cylinders are working cylinders 70 of one or more of the aforementioned hydraulic additional functions of the vehicle. In particular, both working cylinders 70 can be assigned to the same additional function, for example they can represent the left-hand and right-hand working cylinders of the extendable space 120. The two working cylinders 70 are connected to different hydraulic main lines 12A, 12B. In each case, a control valve 52 and a check valve 56 are assigned to both working cylinders, which permits a return flow in the direction of the control valves 52 only in the case of pressure above a defined limit pressure.

[0054] The use of the hydraulic system 10 of FIG. 5 is explained with reference to FIGS. 6A to 11.

[0055] FIG. 6 shows a mobile home which stands at its intended target position on sloping terrain, and is to be supported here as intended.

[0056] For extending the four ground supports 170, the hydraulic system 10 is initially adjusted in the manner shown in FIG. 6B such the main valve 40 is opened, while only two supporting cylinder valves 50 are also opened, namely the supporting cylinder valves 50 of the front supporting cylinders 60A, 60B. In this state, the two hydraulic pumps 20A, 20B are operated such that they pump hydraulic fluid into the hydraulic main lines 12A, 12B which are connected together. Due to the hydraulic fluid flowing into the pressure chambers, the two supporting cylinders 60A, 60B are extended while the hydraulic fluid of the respectively opposing pressure chambers is discharged through the return line 16 and into the hydraulic fluid tank 90. In this phase, the check valve 58 is opened under the pressure of the hydraulic fluid coming from the supporting cylinders, which is above a relevant limit pressure of the check valve 58. As both pumps 20A, 20B together only extend two ground supports 170, this takes place at high speed. The movement initially ends as soon as the front ground supports 170 come into contact with the ground. This is detected by a sensor.

[0057] As a reaction thereto, the valve position of the hydraulic system 10 changes. In the manner illustrated in FIG. 7B, the supporting cylinder valves 50 of the supporting cylinders 60A, 60B are closed, while the supporting cylinder valves 50 of the rear supporting cylinders 60C, 60D are opened. In turn, the rear ground supports 170 are extended by being fed by both hydraulic pumps 20A, 20B until the state of FIG. 8A has been reached, i.e. all of the ground supports have made contact with the ground.

[0058] Now the main valve 40 is closed so that each of the two hydraulic pumps 20A, 20B can feed only the supporting cylinders 60A, 60B or 60C, 60D of the respectively dedicated hydraulic main line 12A, 12B. Then all of the supporting cylinder valves 50 are opened and the two pumps 20A, 20B can extend the supporting cylinders 60A, 60B, 60C, 60D directly assigned thereto, in a targeted manner respectively with a individually adapted volumetric flow and/or pressure until the lifted and oriented state of the vehicle 100 shown in FIG. 9A is reached. Since the vehicle is subjected to force and lifted very uniformly, the structural loading is negligible.

[0059] The vehicle 100 is now oriented horizontally relative to the vehicle longitudinal direction, but not yet horizontally relative to the vehicle transverse direction. Thus in the manner illustrated in FIG. 9B, with the main valve 40 still closed, the supporting cylinder valves 50 of the right-hand supporting cylinders 60B, 60D are now opened. As a result, the hydraulic pumps 20A, 20B can also orientate the vehicle 100 in the transverse direction so that the state of FIG. 10A is achieved.

[0060] Subsequently, in the manner illustrated in FIG. 10B, the main valve 40 is opened again and all of the supporting cylinder valves 50 are closed. At the same time, however, the two valves 52 of the working cylinders 70 are opened so that now the two hydraulic pumps 20A, 20B together extend the two working cylinders 70 and as a result bring the extendable space 120 into its use position of FIG. 11. Alternatively, the main valve 40 could also remain closed when the extendable space 120 is extended. The opened state, however, advantageously permits a very slow movement into the end position toward the end of the extension movement, by switching off one of the pumps.

[0061] If the mobile home is to be lowered again, the pumping direction of the hydraulic pumps 20A, 20B is changed so that these hydraulic pumps together pump hydraulic fluid into the return line 16. As a result, the supporting cylinders 60A, 60B, 60C, 60D and the working cylinders 70 are retracted. The hydraulic fluid, which is pumped into the pressure chambers of the supporting cylinders 60A, 60B, 60C, 60D during the lifting process, is forced in the direction of the supporting cylinder valves 50 due to the sufficiently high pressure in the return line 16, wherein the pressure is above the limit pressure of the check valves 54 and thus opens these check valves. Hydraulic fluid can flow back into the hydraulic tank at the closed supporting cylinder valves 50. A uniform return flow and thus a uniform retraction of the ground supports can be implemented by means of an outflow pressure compensator, not shown.

[0062] FIG. 12 shows an alternative design of the hydraulic system 10. Deviating from the design described above, two return lines 16A, 16B are provided here, wherein the return line 16A is connected to the pressure chambers 70 of the cylinders 60A, 60B of the first hydraulic main line 12A acting in the retracting direction and wherein the return line 16B is connected to the pressure chambers 70 of the cylinders 60C, 60D of the second hydraulic main line 12B acting in the retracting direction.

[0063] Similar to the hydraulic main lines 12A, 12B, the two return lines 16A, 16B are able to be connected to one another and disconnected from one another via a further main valve 42.

[0064] In addition to the components of the above design, the hydraulic system 10 of FIG. 12 also has check valves 51, 53 which are provided between the hydraulic main lines 12A, 12B and the supporting cylinder valves 50 or control valves 52. When the supporting cylinder valve 50 or control valve 52 is opened, these check valves prevent hydraulic fluid from being able to pass out of the supporting cylinders 60A, 60B, 60C, 60D or the working cylinders 70 back into the hydraulic fluid tank 90.

[0065] This design is advantageous, in particular, since when the supporting cylinders 60A, 60B, 60C, 60D or the working cylinders 70 are retracted, a differentiated control is possible.

[0066] If the main valve 42 is opened and the supporting cylinder valves 50 and the control valves 52 are closed, when the supporting cylinders 60A, 60B, 60C, 60D and the working cylinders 70 are retracted, the same behavior results as in the design of the hydraulic system according to FIG. 5. The fluid flow of both hydraulic pumps 20A, 20B acts simultaneously on all cylinders in the retracting direction. The hydraulic fluid which is respectively present in the other pressure chamber 70 of the cylinders 60A, 60B, 60C, 60D is forced out of the cylinders in the direction of the supporting cylinder valves 50 and the control valves 52 and thus passes directly back into the hydraulic fluid tank 90.

[0067] However, if some of the controllable valves are opened, for example all four supporting cylinder valves 50, the hydraulic fluid cannot initially escape out of the supporting cylinders 60A, 60B, 60C, 60D. It could open the check valves 54, which open with sufficient overpressure, but not the check valve 51. The supporting cylinders 60A, 60B, 60C, 60D are thus not initially retracted.

[0068] Instead, due to the pumping pressure of the hydraulic pumps 20A, 20B only the working cylinders 70 are initially retracted if the control valves 52 thereof are closed and thus permit the outflow of hydraulic fluid into the hydraulic fluid tank 90.

[0069] The above-described second main valve 42 can additionally be closed in order to disconnect the two return lines 16A, 16B from one another. If this is the case, each working cylinder 70 is driven by one of the hydraulic pumps 20A, 20B. If the hydraulic pumps 20A, 20B are adjusted to an identical flow rate, a uniform retraction is enforced thereby.