Fluid system for vehicle

Abstract

The present disclosure relates to a fluid system for a vehicle, preferably for a vehicle chassis, the fluid system comprising: a pump for conveying a fluid wherein the pump has a first fluid connection and a second fluid connection; the pump is designed to convey fluid to be conveyed in a first conveying direction and a second conveying direction opposite to the first conveying direction, so that when the pump is conveyed in the first conveying direction, the fluid is conveyed in the second conveying direction; the actuator is fluidly pressurized by the pump via the first fluid connection when the pump conveys in a first conveying direction, and is fluidly separated from the first fluid connection depending on the position of the actuator valve when the pump conveys in a second conveying direction, or the actuator is fluidly depressurized by the pump via the first fluid connection.

Description

Technical Field

[0001] The present disclosure relates to a fluid system for a vehicle, preferably for a vehicle chassis. The fluid system comprises a pump for conveying a fluid. In addition, the fluid system comprises an actuator, which can be connected to the pump in a fluid-connected manner via an actuator valve, so that fluid pressure can be applied to the actuator by the pump. Background Art

[0002] Fluid systems of this type are known in the prior art. Pneumatic systems, i.e. compressed air systems, are often used in particular for vehicle chassis, such as motor vehicle chassis. Known pneumatic systems are constructed in such a way that an actuator is assigned to a shock absorber or at least to each vehicle axle in order to selectively raise and / or lower the vehicle.

[0003] In order to be able to raise the vehicle, pneumatic pressure is selectively applied to the actuators in each case by a pump. In order to be able to lower the vehicle, the pneumatic system usually comprises a complex valve arrangement. In the prior art, the individual valves of such a valve arrangement are electronically controlled to regulate the raising and lowering of the individual actuators.

[0004] Furthermore, lowering a vehicle using known pneumatic systems always requires that the vehicle have a certain deadweight, so that the actuator is compressed by the vehicle mass when the vehicle is lowered.

[0005] The fluid systems known from the prior art have the disadvantage that they often require complex valve arrangements. Furthermore, electronically controlled valves are relatively expensive to produce and are also relatively susceptible to errors. Last but not least, the known pneumatic systems have the problem that they can usually only be lowered to a limited extent. In particular, when the vehicle is parked on a slope and / or tilted, it cannot always be ensured that the actuator is compressed to the desired extent. Summary of the invention

[0006] The object of the present disclosure is to provide a fluid system for a vehicle which at least partially overcomes the disadvantages of the prior art. A particular object of the present disclosure is to provide a fluid system for a vehicle which can be produced economically and efficiently, functions reliably, and has low susceptibility to errors during operation.

[0007] This object is solved by the features of claim 1. Advantageous further developments are evident from the dependent claims, the description and the drawings.

[0008] According to the present application, a fluid system for a vehicle is proposed, preferably for a vehicle chassis. The fluid system can be, for example, a hydraulic system, wherein the fluid is preferably a hydraulic liquid, in particular a hydraulic oil. The fluid system comprises a pump for conveying a fluid, wherein the pump has a first fluid connection and a second fluid connection, and the second fluid connection is preferably a different fluid connection relative to the first fluid connection. In addition, the fluid system actuator can be connected to the first fluid connection in a fluid-connected manner via an actuator valve. The pump is designed to convey the fluid to be conveyed in a first conveying direction and a second conveying direction opposite to the first conveying direction. According to the present application, when the pump conveys in the first conveying direction, the actuator is pressurized by the fluid via the first fluid connection. When the pump conveys in the second conveying direction, the actuator is separated from the first fluid connection fluid according to the position of the actuator valve, or the actuator is depressurized by the pump fluid via the first fluid connection.

[0009] In this article, the term actuator refers to a structural unit that converts pressure changes in the structural unit into mechanical movement. The pressure changes in the structural unit are preferably caused by changes in fluid pressure in the structural unit. For example, the "actuator" can be a hydraulic actuator.

[0010] In this context, the term "fluid pressure relief" is understood to mean a static pressure relief, wherein the fluid pressure in the actuator is at least compensated by an external force on the actuator. According to the present application, i.e. when the pump delivers in the second delivery direction, the fluid pressure in the actuator is caused by the pump as a supplement or alternative to the external force.

[0011] Fluid pressure relief of the actuator by reversing the delivery direction of the pump has the effect of reliably releasing or compressing the actuator regardless of the position of the vehicle, in particular the inclination. In addition, in the fluid system according to the present application, the number of valves can be reduced to a minimum, which further reduces the production cost. In addition, in the fluid system according to the present application, the construction of the valve can be made less complicated, so the production cost is also relatively low. The fluid system according to the present application has the additional advantage that it ensures high reliability during operation at a low production cost.

[0012] In an exemplary embodiment of the fluid system, the pump is designed so that the fluid to be delivered, preferably a hydraulic liquid, is delivered from the second fluid connector to the first fluid connector along a first delivery direction. And along the second delivery direction, the fluid to be delivered, preferably a hydraulic liquid, can be delivered from the first fluid connector to the second fluid connector. In other words, when the pump delivers the fluid to be delivered along the first delivery direction, the second fluid connector can be the low-pressure inlet of the pump. At the same time, when the pump delivers the fluid to be delivered along the first delivery direction, the first fluid connector can form the high-pressure outlet of the pump. When the pump delivers the fluid to be delivered along the second delivery direction, the second fluid connector can form the high-pressure outlet of the pump, and the first fluid connector can be the low-pressure inlet of the pump. The exemplary embodiment advantageously has the effect that two delivery connectors must be provided specifically for different delivery directions on the pump. This has the advantage that the structural construction of the pump can be relatively simple and therefore particularly economical and efficient.

[0013] In another exemplary embodiment, the pump is a rotary pump. The pump can be, for example, an internal gear pump, an external gear pump or a rotary vane pump. The pump is preferably a rotary pump vane. If the pump is designed as a rotary pump, a change in the direction of rotation of the pump can lead to a change in the delivery direction. For example, this achieves the technical advantage that the pump can be used more effectively in a fluid system. This is because the suction and pressurization functions of the pump can be directly actively utilized. Therefore, the advantage of this pump is that no additional valves and / or additional pumps are required for fluid pressure relief. Instead, it may be sufficient to connect the pump to the actuator in a fluid-connected manner.

[0014] The actuator valve can be designed so that the actuator valve can be moved back and forth or switched between a first actuator valve position and a second actuator valve position, in particular a second actuator valve position different from the first actuator valve position. Preferably, the actuator valve forms a check valve in the first actuator valve position. To this end, the actuator valve can have a closing element, such as a ball, which can change back and forth between a blocking position and a flow-through position. In the blocking position, the closing element preferably prevents the fluid from flowing through the actuator valve. In the flow-through position, a fluid, in particular a hydraulic fluid, can flow through the actuator valve. Preferably, the flow pressure generated by the fluid flow on the blocking body causes the blocking body to be pressed into the blocking position or the flow-through position depending on the flow direction.

[0015] The actuator valve can also be designed, for example, so that the actuator valve forms a check valve in the first actuator valve position. For this reason, in addition to the closing element, the actuator valve can have a reset element. The reset element can be designed to apply a reset force on the blocking body. Preferably, the reset force causes the blocking body to be pressed into the blocking position. The predetermined flow pressure of the fluid flow can cause the blocking body to be pressed into the flow-through position against the reset force of the reset element. The reset element can be, in particular, a spring, whose spring force presses the blocking body into the blocking position. In addition or as an alternative, the actuator valve can be designed so that the actuator valve forms a fluid channel in the second actuator valve position. This means that the fluid can flow out of the actuator in the second actuator position.

[0016] The actuator valve as described in the previous paragraph has the advantage that it can be produced simply and cost-effectively. In addition, such an actuator valve, in particular in combination with a pump that can deliver in two opposite delivery directions, can ensure particularly reliable fluid pressurization, blocking and / or release of the actuator.

[0017] For example, the first actuator valve and / or the second actuator valve each comprise a pin-shaped extension, which is designed to transfer the closing element from a closed position, in which the closing element is located in the valve seat, to an open position, in which the closing element is spaced from the valve seat. The valve prevents the fluid from escaping from the first actuator via the first actuator valve or from the second actuator via the second actuator valve. In principle, no additional return spring is required for this purpose. Thus, in the closed state of the entire fluid system, the actuator remains closed, which has advantages in the specific application of the vehicle chassis, i.e., a stable chassis state is achieved when the vehicle is parked. Therefore, the closing element is in principle kept in the closed state due to the internal pressure of the actuator, wherein the internal pressure of the actuator is caused by the dead weight of the vehicle. When the first actuator valve and / or the second actuator valve is actuated by the corresponding switching position of the control valve, the pin-shaped extension acts directly on the closing element and lifts the closing element from the valve seat.

[0018] In another exemplary embodiment, the fluid system has a control valve. The control valve is preferably designed to control an actuator valve, in particular a fluid-controlled actuator valve. When the pump is conveyed in the second conveying direction, the control valve can be connected to the second fluid connection of the pump in a fluid-connected manner. When the pump is conveyed in the first conveying direction, the control valve is preferably fluidly separated from the second fluid connection of the pump. For example, this can be ensured by arranging a check valve between the control valve and the second fluid connection of the pump.

[0019] The control valve may be designed to fluidically connect the control connection of the actuator valve to the second fluid connection of the pump when the pump delivers in the second delivery direction. When the control valve is in the first control valve position, the control valve preferably fluidically connects the control connection of the actuator valve to the second fluid connection of the pump. When the control connection of the actuator valve is fluidically connected to the second fluid connection of the pump, the fluid pressure at the control connection of the actuator valve may exert a control pressure on the actuator valve. The control pressure preferably causes the actuator valve to change the actuator valve position, in particular from the first actuator valve position to the second actuator valve position.

[0020] The control valve can be designed to fluidically disconnect the control connection of the actuator valve from the second fluid connection of the pump when the pump delivers in the second delivery direction. In a first switching position of the control valve, the control connection of the second actuator valve is preferably fluidically connected to the second connection of the pump. In a second switching position of the control valve, both actuator valves are connected to the pump, and in a third position of the control valve, the second actuator valve is disconnected from the pump and only the first actuator valve remains connected.

[0021] A control valve for controlling an actuator valve, in particular a control valve for fluid-controlled actuator valves, can advantageously make it unnecessary for the actuator valve to be controlled electronically. This has the advantage that electronic components on the actuator valve can be omitted, thereby reducing the production cost and the probability of failure of the actuator valve.

[0022] For example, the control valve is hydraulically controllable. This achieves the technical advantage that, for example, a complex control device is no longer required to control the control valve. For example, the control valve can be controlled via different fluid pressures, which are achieved by targeted control of the rotational speed of a specified pump. Therefore, the fluid can be delivered by the pump along a second delivery direction, wherein the rotational speed of the pump is related to a specific fluid pressure on the control valve. Therefore, a specific applied fluid pressure corresponds to a specific switching position. The hydraulic fluid flows out of the control valve and flows back to the reservoir via the orifice opening. For example, this can occur independently of the rotational speed of the pump and therefore can also occur independently of the pressure level applied to the radial opening.

[0023] In an exemplary further development of the fluid system, the fluid system comprises a measuring device. The measuring device is preferably designed to determine a setting position of the actuator.

[0024] In addition, the fluid system can have a feedback control device. The feedback control device and the measuring device are preferably connected to each other in an information exchange manner. As a result, for example, it is possible for the measuring device to transmit a specific setting position of the actuator to the feedback control device. The feedback control device can be designed to control the actuator valve and / or the control valve based on the specific setting position, so that the setting position of the actuator is controlled by the feedback control device.

[0025] In an embodiment with a measuring device and a feedback control device, the actuator can be controlled via a closed feedback control circuit. This has the advantage that the setting position of the actuator can be controlled particularly reliably.

[0026] In another exemplary embodiment, the control valve can be electronically controllable. This means that, in particular, the control valve position of the control valve can be changed via an electronic input signal. For this purpose, for example, the control valve can have an electronic control unit.

[0027] As an alternative, the control valve can be fluid-controllable. This means that, in particular, the control valve position of the control valve can be changed via a fluid control pressure. The control valve is preferably controllable according to the fluid pressure generated by the pump in the second delivery direction. For example, the control connection of the control valve can be fluidically connected to the second fluid connection of the pump. By changing the fluid pressure, in particular by changing the rotational speed of the pump, different pressure levels can be applied to the control connection of the control valve. Therefore, the fluid can be delivered by the pump along the second delivery direction, wherein the rotational speed of the pump is related to a specific fluid pressure on the control valve. Therefore, a specific applied fluid pressure corresponds to a specific switching position. The hydraulic fluid flows out of the control valve and flows back to the reservoir via the orifice opening. For example, this can occur independently of the rotational speed of the pump and therefore can also occur independently of the pressure level applied to the radial opening.

[0028] Each pressure level preferably corresponds to a control valve position of the control valve.

[0029] The advantage of this embodiment is that the position of the actuator can be controlled via changing the delivery direction of the pump and via the fluid pressure provided by the pump. Thus, the electronic components of the fluid system can be reduced to an absolute minimum, which greatly reduces production costs and the susceptibility of the fluid system to errors.

[0030] In an advantageous further development, the fluid system comprises a plurality of actuators. Each actuator can preferably be connected to the first fluid connection in a fluid-connected manner via a respective actuator valve. Such a further development advantageously has the effect that a plurality of actuators can be fluid-pressurized and / or fluid-depressurized by a single pump. This has the advantage that the number of components, in particular the number of required pumps, can be reduced and thus the production costs of the fluid system can be reduced.

[0031] In an embodiment in which the fluid system has a control valve and a plurality of actuators with a plurality of actuator valves, the control valve may be designed to control all actuator valves, preferably fluidly control all actuator valves. Such an embodiment advantageously has the effect that a plurality of actuator valves may be controlled by a single control valve. In this respect, the actuator positions of a plurality of actuators may also be controlled via a single control valve. This has the advantage that the number of components may be reduced and therefore the production costs of the fluid system may also be reduced.

[0032] The fluid system may have, for example, a first actuator and a second actuator different from the first actuator. The first actuator may be connected to a first fluid connection of a pump in a fluidic manner, in particular via a first actuator valve. The second actuator may be connected to the first fluid connection of the pump in a fluidic manner via a second actuator valve. Preferably, the first actuator valve and the second actuator valve are separated from each other. The control valve of the fluid system may be connected to the second fluid connection of the pump in a fluidic manner and is preferably designed to control the first actuator valve and / or the second actuator valve.

[0033] In the above exemplary fluid system, for example, the control valve may be designed as a 4 / 3 directional control valve.

[0034] Preferably, the second fluid connection of the pump can be connected to a reservoir, in particular a fluid reservoir, in a fluid communication manner via a non-return valve. For example, the non-return valve can be designed such that when the pump delivers in a first delivery direction, it connects the second fluid connection of the pump to the reservoir in a fluid communication manner. When the pump delivers in a second delivery direction, the non-return valve can separate the second fluid connection of the pump from the reservoir fluid.

[0035] Such a non-return valve advantageously has the effect that the pump can draw in the fluid to be delivered from the reservoir when the pump delivers in a first delivery direction. When the pump delivers in a second delivery direction, the non-return valve can prevent the pump from pumping the fluid to be delivered into the reservoir. This has the advantage that the fluid pressure generated by the pump is not lost when the pump delivers in the second delivery direction, but is maintained in the fluid system. Thus, the delivery pressure in the delivery system can be used as control pressure, in particular for controlling the actuator valve.

[0036] As mentioned several times above, the fluid in the fluid system can be a hydraulic fluid, in particular a hydraulic oil. Hydraulic liquids have lower compressibility than gases. Therefore, the actuator can be controlled more simply and more effectively with hydraulic liquids.

[0037] The fluid system can be provided for a vehicle, in particular a motor vehicle. For example, the fluid system can be arranged in a chassis of a vehicle, in particular a motor vehicle chassis. Preferably, the actuator of the fluid system forms a suspension strut actuator of the vehicle chassis, in particular a motor vehicle chassis. As an alternative, the actuator can also be assigned to a vehicle axle. Therefore, the vehicle chassis according to claim 15 also solves the initially proposed object. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] According to the present application, the above-mentioned different and exemplary features can be combined with each other as long as this is technically meaningful and appropriate. From the following description of exemplary embodiments and with reference to the accompanying drawings, other features, advantages and embodiments of the present application are apparent. In the accompanying drawings:

[0039] Figure 1 A schematic hydraulic diagram of an exemplary embodiment of a fluid system is shown. DETAILED DESCRIPTION

[0040] Figure 1 Exemplary embodiments of a fluid system 1 are shown. In a first exemplary embodiment, the fluid to be conveyed is a hydraulic fluid, in particular a hydraulic liquid. Figure 1 A schematic hydraulic diagram is also shown. In principle, Figure 1 The symbols in the hydraulic diagrams shown correspond to the general symbols of hydraulic diagrams known from mechanical engineering. For example, hydraulic pipes are represented by lines. Figure 1 The fluid system 1 shown comprises a pump 2 , a first actuator 7 and a second actuator 8 .

[0041] For this purpose, the pump 2 is designed to convey a hydraulic fluid and has a first fluid connection 3 and a second fluid connection 4. The pump 2 can be, for example, an internal gear pump, an external gear pump or a rotary vane pump. In a first conveying direction 5, the pump 2 conveys the hydraulic fluid from the second fluid connection 4 to the first fluid connection 3. This means that in the first conveying direction 5, the second fluid connection 4 forms a low-pressure connection for the pump 2. The first fluid connection 3 forms a high-pressure connection for the pump 2 in the first conveying direction 5. In addition, the pump 2 is designed to reverse the conveying direction. In other words, the pump 2 can have a second conveying direction 6. In the second conveying direction 6, the pump 2 conveys the hydraulic fluid from the first fluid connection 3 to the second fluid connection 4. In the second conveying direction 6, the first fluid connection 3 forms a low-pressure connection for the pump 2 and the second fluid connection 4 forms a high-pressure connection for the pump 2. In order to reverse the conveying direction, for example, it can be provided that the pump 2 changes its direction of rotation.

[0042] For example, the first actuator 7 may be a first actuator 7 in a vehicle chassis. The first actuator 7 may in particular be arranged on a shock absorber of the vehicle. The first actuator 7 is connected to the first fluid connection 3 of the pump 2 via a first actuator valve 9 .

[0043] The first actuator valve 9 can be moved back and forth or switched between two different actuator valve positions, namely a first actuator valve position and a second actuator valve position different from the first actuator valve position.

[0044] exist Figure 1 , the first actuator valve 9 is shown in the first actuator valve position. In the first actuator valve position, the first actuator valve 9 forms a check valve. To this end, the first actuator valve 9 has a blocking element 27 (not shown). The check valve is designed so that the existing internal pressure of the actuator presses the blocking element 27 into the blocking position. For example, the check valve can also be spring-loaded. If the blocking element 27 is in the blocking position, the first actuator valve 9 acts like a blocking valve in the first actuator valve position. This means that, in the first actuator valve position, the first actuator valve 9 prevents the fluid communication between the first actuator 7 and the first fluid connection 3 of the pump 2. This is especially true when the pump 2 delivers hydraulic fluid along the second delivery direction 6. In this case, the pump 2 sucks hydraulic fluid via the first fluid connection 3. The negative pressure generated by the suction effect interacts with the internal pressure of the first actuator 7 at the first actuator valve 9, so that the blocking element 27 is pressed into the blocking position. When the first actuator valve 9 is in the first actuator valve position and the pump 2 delivers in the second delivery direction 6 , no fluid communication between the first actuator 7 and the first fluid connection 3 of the pump 2 is possible.

[0045] In the first actuator valve position, when the pump 2 delivers hydraulic fluid in the first delivery direction 5, the check valve of the first actuator valve 9 allows fluid communication between the first actuator 7 and the first fluid connection 3 of the pump 2. This is because the hydraulic fluid flowing in from the first fluid connection 3 of the pump 2 is under such a pressure that the hydraulic fluid presses the blocking element 27 into the flow-through position against the internal pressure of the first actuator 7. In the flow-through position, the first actuator valve 9 forms a fluid channel. In other words, when the first actuator valve 9 is in the first actuator valve position and the pump 2 delivers hydraulic fluid in the first delivery direction 5, the hydraulic fluid can flow from the first fluid connection 3 into the first actuator 7 via the first actuator valve 9 and increase the oil amount in the first actuator 7.

[0046] In the second actuator valve position, the first actuator valve 9 forms a fluid passage. This means that when the first actuator valve 9 is in the second actuator valve position, hydraulic fluid can flow out of the first actuator 7 in the direction of the reservoir 13. Figure 1 In the illustration shown, the first actuator valve 9 will move to the left in order to change from the first actuator valve position to the second actuator valve position. The first actuator 7 is only relieved of fluid when the pump 2 delivers hydraulic fluid in the second delivery direction 6 and the first actuator valve 9 is in the second actuator valve position.

[0047] Independently of the first actuator 7, the second actuator 8 may form a second actuator 8 in the chassis of the vehicle. The second actuator 8 may in particular be arranged on another shock absorber of the vehicle. The second actuator 8 is connected to the first fluid connection 3 of the pump 2 via a second actuator valve 10.

[0048] In the exemplary embodiment shown, the second actuator valve 10 is designed similarly to the first actuator valve 9 .

[0049] Figure 1 8 and 9. The second actuator valve 10 is also shown in the first actuator valve position. In the first actuator valve position, the second actuator valve 10 forms a check valve similar to the first actuator valve 9. In the first actuator valve position, the second actuator valve 10 acts like a shut-off valve when the pump 2 delivers in the second delivery direction 6. This means that the second actuator valve 10 in the first actuator valve position prevents fluid communication between the second actuator 8 and the first fluid connection 3 of the pump 2 when the pump 2 delivers in the second delivery direction 6.

[0050] In the first actuator valve position, the non-return valve of the second actuator valve 10 allows fluid communication between the second actuator 8 and the first fluid connection 3 of the pump 2 when the pump 2 delivers hydraulic fluid in the first delivery direction 5. In other words, when the second actuator valve 10 is in the first actuator valve position and the pump 2 delivers hydraulic fluid in the first delivery direction 5, hydraulic fluid can flow from the first fluid connection 3 of the pump 2 via the second actuator valve 10 into the second actuator 8 and can apply hydraulic pressure to the latter.

[0051] In the second actuator valve position, the second actuator valve 10 forms a fluid passage similar to the first actuator valve 9. This means that when the second actuator valve 10 is in the second actuator valve position, hydraulic fluid can flow from the second actuator 8 in the direction of the reservoir 13. Figure 1 In the illustration shown, the second actuator valve 10 will move to the left in order to change from the first actuator valve position to the second actuator valve position. Only when the second actuator valve 10 is in the second actuator valve position and the pump 2 delivers hydraulic fluid in the second delivery direction 6, the second actuator 8 is relieved of fluid.

[0052] exist Figure 1 In the exemplary embodiment shown, the two actuator valves 9, 10 are hydraulically controllable. This means that the first actuator valve 9 and / or the second actuator valve 10 can be moved or switched back and forth between a first actuator valve position and a second actuator valve position via hydraulic actuation. To this end, the first actuator valve 9 and the second actuator valve 10 each have a control connection (e.g. Figure 1 1 and 12). In order to control the actuator valve positions of the two actuator valves 9 and 10, the fluid system 1 has a control valve 11. In the exemplary embodiment shown, the control valve 11 is designed as a 4 / 3-way control valve. The control valve 11 is connected to the second fluid connection 4 of the pump 2 via a check valve 12. The check valve 12 has the effect that when the pump 2 delivers hydraulic fluid in the first delivery direction 5, the control valve 11 is fluidically separated from the second fluid connection 4 of the pump 2. However, when the pump 2 delivers hydraulic fluid in the second delivery direction 6, the control valve 11 and the second fluid connection 4 of the pump 2 are fluidically connected to each other via the check valve 12. This means that when the pump 2 delivers hydraulic fluid in the second delivery direction 6, the pressurized hydraulic fluid flows from the second fluid connection 4 of the pump 2 to the control valve 11.

[0053] The control valve 11 can be moved or switched back and forth between three different control valve positions, namely a first control valve position, a second control valve position and a third control valve position. To illustrate the operating mode of the control valve 11 , it is assumed in the following description that the pump 2 delivers hydraulic fluid in the second delivery direction 6 .

[0054] Figure 1The control valve 11 is shown in a first control valve position. In the first control valve position, hydraulic fluid is directed via the control valve 11 to the control connection of the second actuator valve 10. Due to the hydraulic pressure subsequently applied to the control connection of the second actuator valve 10, the second actuator valve 10 moves from the first actuator valve position to the second actuator valve position ( Figure 1 10). As a result, the second actuator 8 is depressurized by the fluid via the second actuator valve 10. In the first control valve position, the control connection of the first actuator valve 9 is connected to the reservoir 13 via the control valve 11. This means that when the control valve 11 is in the first control valve position, the first actuator valve 9 remains in the first actuator valve position. When the control valve 11 is moved or switched to the second control valve position, the control valve 11 is designed to direct the fluid pressure of the hydraulic liquid to the control connection of the first actuator valve 9 and the control connection of the second actuator valve 10. In this case, the two actuator valves 9, 10 will move from the first actuator valve position to the second actuator valve position. As a result, the first actuator 7 and the second actuator 8 will be depressurized by the fluid.

[0055] When the control valve 11 is moved or switched to the third control valve position, the control valve 11 is designed to direct the hydraulic fluid to the control connection of the first actuator valve 9. Due to the hydraulic pressure then applied to the control connection of the first actuator valve 9, the first actuator valve 9 moves from the first actuator valve position to the second actuator valve position ( Figure 1 ). As a result, the first actuator 7 is depressurized via the first actuator valve 9 fluid. In the third control valve position, the control connection of the second actuator valve 10 is connected to the reservoir 13 via the control valve 11. This means that when the control valve 11 is in the third control valve position, the second actuator valve 10 remains in the first actuator valve position. In the exemplary embodiment shown, the control valve 11 can be electrically controlled or feedback controlled. In another exemplary embodiment, the control valve 11 can also be hydraulically controlled or feedback controlled. For example, the control connection of the control valve 11 can be fluidically connected to the second fluid connection 4 of the pump 2. By changing the hydraulic pressure, for example by changing the rotational speed of the pump 2, different, in particular three different pressure levels can be applied to the control connection of the control valve 11. Each pressure level preferably corresponds to a control valve position of the control valve 11. The control valve 11 includes an orifice opening 23, which allows the hydraulic fluid to flow out of the control valve 11 into the reservoir 13. Thus, when hydraulic fluid is delivered by the pump 2 in the second delivery direction 6 , it can flow into the reservoir 13 independently of the rotational speed of the pump 2 , the pressure level applied to the radial opening 16 and the control valve position of the control valve 11 .

[0056] In an exemplary use of the first exemplary embodiment of the fluid system 1, provision can be made for each of the actuators 7, 8 to be assigned to an axle and / or a wheel suspension of the vehicle. For example, each actuator can be a suspension strut actuator. As an alternative, each of the actuators 7, 8 can be assigned to an axle. During the start-up of the vehicle, it can be envisaged, for example, that the pump 2 delivers hydraulic fluid in the first delivery direction 5. In this case, the pump 2 draws hydraulic fluid from the reservoir 13 via the second fluid connection 4. In the first delivery direction 5, the pump 2 pumps the hydraulic fluid further into the fluid system 1 via the first fluid connection 3. As shown in FIG. Figure 1 As shown, the two actuator valves 9, 10 are initially each in the first actuator valve position. This has the effect of pumping hydraulic fluid from the first fluid connection 3 of the pump 2 into the two actuators 7, 8, thereby causing the vehicle to be raised.

[0057] If it is desired to selectively lower the vehicle at a future time, the delivery direction of the pump 2 can be reversed, in particular from the first delivery direction 5 to the second delivery direction 6. One of the two actuators 7, 8 can then be fluidically relieved in the manner described above via the control valve position of the control valve 11. As an alternative, both actuators 7, 8 can also be fluidically relieved simultaneously, i.e. when the control valve 11 is in the second control valve position.

Claims

1. A fluid system (1) for a vehicle, preferably for a vehicle chassis, the fluid system (1) comprising: A pump (2) for conveying a fluid, wherein the pump (2) has a first fluid connection (3) and a second fluid connection (4), an actuator (7, 8) which can be connected in fluid communication to the first fluid connection (3) via an actuator valve (9, 10), wherein The pump (2) is designed to convey the fluid to be conveyed in a first conveying direction (5) and in a second conveying direction (6) opposite to the first conveying direction (5), so that When the pump (2) delivers in the first delivery direction (5), the actuator (7, 8) is pressurized by the pump (2) fluid via the first fluid connection (3), and When the pump (2) delivers in the second delivery direction (6), the actuator (7, 8) is fluidically separated from the first fluid connection depending on the position of the actuator valve (9, 10), or the actuator (7, 8) is fluidically depressurized by the pump (2) via the first fluid connection (3).

2. The fluid system (1) according to claim 1, characterized in that The pump (2) is designed so that the fluid to be transported is transported from the second fluid connection (4) to the first fluid connection (3) along the first transport direction (5), and the fluid to be transported is transported from the first fluid connection (3) to the second fluid connection (4) along the second transport direction (6).

3. Fluid system (1) according to any one of the preceding claims, characterized in that The pump (2) is a rotary pump (2), preferably a rotary vane pump (2), wherein the change in the delivery direction (5, 6) is caused by a change in the direction of rotation of the rotary pump (2).

4. Fluid system (1) according to any one of the preceding claims, characterized in that The actuator valve (9, 10) can be switched back and forth between a first actuator valve position and a second actuator valve position, wherein the actuator valve (9, 10) forms a check valve, preferably a spring-loaded check valve, in the first actuator valve position and forms a fluid passage in the second actuator valve position.

5. Fluid system (1) according to any one of the preceding claims, characterized in that The fluid system (1) has a control valve (11) for controlling, preferably for fluidly controlling, the actuator valve (9, 10), wherein when the pump (2) delivers in the first delivery direction (5), the control valve (11) is fluidically separated from the second fluid connection (4), and when the pump (2) delivers in the second delivery direction (6), the control valve (11) is connected to the second fluid connection (4) in a fluidically connected manner.

6. The fluid system (1) according to claim 5, characterized in that A measuring device determines the set position of the actuator (7, 8) and transmits it to a control device, wherein the control device controls the actuator valve (9, 10) and / or the control valve (11).

7. The fluid system (1) according to claim 5 or 6, characterized in that The control valve (11) is electronically controllable.

8. The fluid system (1) according to any one of claims 5 to 7, characterized in that The control valve (11) can be controlled according to the fluid pressure generated by the pump (2) along the second delivery direction (6).

9. Fluid system (1) according to any one of the preceding claims, characterized in that The fluid system (1) has a plurality of actuators (7, 8), each of which can be connected in a fluid-communicating manner to the first fluid connection (3) via an actuator valve (9, 10).

10. The fluid system (1) according to claim 9 and any one of claims 5 to 8, characterized in that The control valve (11) is designed to control, preferably fluidically control, all of the actuator valves (9, 10).

11. Fluid system (1) according to any one of the preceding claims, characterized in that The fluid system (1) comprises: a first actuator (7) which can be connected in fluid communication to the first fluid connection (3) via a first actuator valve (9), a second actuator (8) which can be connected in fluid communication to the first fluid connection (3) via a second actuator valve (10), and A control valve (11) which can be connected in a fluidic manner to the second fluid connection (4) and is designed to control the first actuator valve (9) and / or the second actuator valve (10).

12. The fluid system (1) according to any one of claims 5 to 11, characterized in that The control valve (11) is a 4 / 3 directional control valve.

13. Fluid system (1) according to any one of the preceding claims, characterized in that The second fluid connection (4) can be connected to a reservoir (13) in a fluid communication manner via a non-return valve (12).

14. Fluid system (1) according to any one of the preceding claims, characterized in that The fluid in the fluid system (1) is hydraulic liquid, preferably hydraulic oil.

15. A chassis for a vehicle, wherein the chassis comprises a fluid system (1) as claimed in any one of the preceding claims, and wherein the actuator (7, 8) is a suspension strut actuator (7, 8) of the chassis.

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