System and method for leveling an air-suspended structural unit of a motor vehicle

Abstract

The invention concerns a system (10) for leveling an air-suspended structural unit, preferably comprising a cab (110) and / or a chassis and / or a seat, of a motor vehicle (100). The system (10) comprises at least one air spring (12a-d), wherein the at least one air spring (12a-d) comprises a level control means (14), preferably wherein the level control means (14) comprises an air discharge valve (14a) and / or is integrated into the at least one air spring (12a-d). The system (10) further comprises an air storage (18) and a fluid connection (20a) between the at least one air spring (12a-d) and the air storage (18). The system (10) further comprises a valve (22), wherein the valve (22) is arranged externally of the at least one air spring (12a-d) and is integrated into the fluid connection (20a) and wherein the valve (22) is configured to be switched into a first switching state (A) and into a second switching state (B), preferably dependent on an economic-operation-condition (EC) of the motor vehicle (100). In the first switching state (A) an air supply from the air storage (18) to the at least one air spring (12a-d) is enabled and in the second switching state (B) the air supply from the air storage (18) to the at least one air spring (12-d) is blocked. The system (10) preferably comprises a determination device (25), wherein the determination device (25) is configured to determine economic-operaation-condition (EC) of the motor vehicle (100).

Description

[0001] SYSTEM AND METHOD FOR LEVELING AN AIR-SUSPENDED STRUCTURAL UNIT OF A MOTOR VEHICLE

[0002] Description

[0003] The invention concerns a system for leveling an air-suspended structural unit of a motor vehicle, a motor vehicle comprising a system and a method for leveling an air-suspended structural unit of a motor vehicle.

[0004] Motor vehicles may comprise air springs as suspension elements. Typically, the air springs of the suspension elements (e. g cab suspension elements) may have a leveling system to position the air-suspended unit (e. g. cab) in a nominal position independent of the weight of the suspended unit (e. g. cab). The variation of the air-suspended unit’s weight, which may be dependent on the unit itself, the interior equipment, the driver’s loading and the driver / passen- ger, etc. can be levelled to the nominal position by the leveling system of the air springs.

[0005] A disadvantage of these known techniques is that these systems are always active and levels the unit (e. g. cab) in conditions, where it is not necessary. In other words, current leveling systems inflate or evacuate the air spring as soon as a deviation to the nominal position is detected. This consumes a lot more air volume than needed, since e. g. road induced cab movements don’t automatically need an adjustment of the cab level. This may increase the air consumption and / or reduce energy efficiency.

[0006] It is therefore an objective of the invention to provide a particularly improved technique for leveling an air-suspended structural unit of a motor vehicle. Specifically, it is - for instance - an objective to provide a more energy efficient technique. In particular, it is an objective to provide a simpler and / or retro-fittable solution.

[0007] The objective is solved by the features of the independent claims. Advantageous further embodiments are specified in the dependent claims and the description.

[0008] According to a first general aspect of the invention, a system for leveling an air-suspended structural unit of a motor vehicle is provided.

[0009] Preferably, the air-suspended structural unit comprises (or consists of) a cab and / or a chassis and / or a (e. g. driver’s and / or passenger’s) seat.

[0010] Preferably, the cab is a driver’s cab of a motor vehicle. However, it is also possible that the motor vehicle e. g. is an unmanned motor vehicle. Preferably, the motor vehicle is a utility vehicle.

[0011] The system comprises at least one air spring, an air storage and a fluid connection between the at least one air spring and the air storage.

[0012] The system further comprises a valve.

[0013] The at least one air spring comprises a level control means. Preferably, the level control means comprises an air discharge valve. Optionally, the level control means is integrated into the at least one air spring.

[0014] The valve is arranged externally of the at least one air spring and is integrated into the fluid connection (e. g. into an air pressure pipe of the fluid connection).

[0015] The valve is configured to be switched (e. g. selectively and / or alternately) into a first switching state and / or into a second switching state (e. g. dependent on an economic-operation-condition of the motor vehicle).

[0016] In the first switching state an air supply from the air storage to the at least one air spring is enabled (e. g. allowed and / or facilitated). In the second switching state the air supply from the air storage to the at least one air spring is blocked (e. g. cut and / or closed and / or shut down).

[0017] Preferably, the system further comprises a determination device, wherein the determination device is configured to determine the economic-operation-condition of the motor vehicle.

[0018] Advantageously, blocking the air supply in the second switching state may prevent an undesired feeding of air into the air spring during the operation (e. g. driving) of the motor vehicle. This may reduce the air consumption of the air springs of the air suspension and therefore may save energy. Overall, an optimization of air consumption and / or longer driving ranges may be achieved.

[0019] The technique enables a simple mechanical solution with low complexity and high robustness and a regulation of external valve with high flexibility and therefore an easy-to-integrate solution into existing infrastructure.

[0020] The level device may be embodied as an internal level device, which may be advantageous with regard to the package space (in particular compared to external level devices). The economic-operation-condition may indicate an economic driving mode (e. g. a mode, in which the motor vehicle drives with reduced air consumption). The economic-operation-condition may also indicate a mode, in which the motor vehicle is parked with reduced air consumption, for instance. The saved energy amount may be used to extend the driving range.

[0021] The first switching state could be used in a normal operation mode (e. g. normal driving mode or normal parking mode).

[0022] In particular, the motor vehicle is a semi-autonomous or autonomous motor vehicle. The motor vehicle may comprise an electric machine and / or a combustion engine.

[0023] The air supply preferably is a pressurized air supply and / or an air tank.

[0024] The level control means optionally may be configured to discharge air to an external environment of the at least one air spring.

[0025] The valve may be activated, for example, by an (electric, pneumatic, hydraulic, etc.) impulse or a signal or may be manually operated.

[0026] According to an embodiment, in the second switching state an air discharge from the at least one air spring to an external environment of the valve may be blocked. Thereby, it may be possible to inhibit an air discharge from the at least one air spring regardless of the level position. This may be advantageous, for instance, in order to avoid unnecessary leveling activity and / or in order to increase air consumption efficiency.

[0027] According to an embodiment the control device may be further configured to switch the valve into the second switching state upon (e. g. caused by a) determination of the economic-operation-condition. For instance, it is possible that the control device receives a signal indicating that the cab is (or will shortly) be in the economic-operation-condition. Further, it is possible that the control device is adapted to automatically switch the valve into the second switching state, when said signal is received. However, the control device may also be e. g. manually operated and / or e. g. impulse-controlled. The regulation of the external valve could also be linked with a timer to have the levelling of the air-suspended structural unit (e. g. cab) at certain time increments. Thereby, the ease-of-use, operating safety and / or comfort may be further increased.

[0028] According to an embodiment, the control device may be configured to execute a cyclic-level- ing-mode. In the cyclic-leveling-mode, the control device switches the valve into the first switching state and into the second switching state alternately (e. g. periodically and / or repeatedly). For instance, it is possible that the control device is adapted to automatically cycle between the first switching state and the second switching state. Thereby, the energy efficiency may be further increased.

[0029] According to an embodiment, the control device may be further configured (e. g. in the cyclic- leveling-mode) to switch the valve into the first switching state for a predetermined first time interval and into the second switching state for a predetermined second time interval. Optionally, the first time interval and / or the second time interval are provided on (e. g. pre-stored or transmitted to) the control device. The first time interval and / or the second time interval may be individually based on experience and requirements. The first time interval may comprise a different duration than the second time interval or the same duration as the second time interval. Thereby, a particularly simple technical solution may be provided.

[0030] According to an embodiment, the control device may be further configured to switch the valve into the first switching state so as to level the air-suspended structural unit to a nominal level position. The nominal level position may be a vertical position and / or provided on (e. g. prestored or transmitted to) the control device.

[0031] According to an embodiment, the system may comprise a deviation detection device configured to detect a deviation of a current level position (e. g. in height direction) of the air-suspended structural unit from a nominal level position (e. g. in height direction). The control device may be further configured to control the valve dependent on the detected deviation.

[0032] According to an embodiment, the control device may be further configured, when the valve is in the first switching state, to keep the valve in the first switching state until the detected deviation lies within a predetermined range. The predetermined range may be provided on (e. g. pre-stored or transmitted to) the control device.

[0033] According to an embodiment, the level control means may be configured to discharge air comprised in the at least one air spring to an external environment of the at least one air spring (for instance: automatically or controlled by the control device) so as to control a level position of the air-suspended structural unit. This may reduce the technical effort, costs and / or construction space.

[0034] According to an embodiment, the determination device may further comprise a sensor element and / or a user input element. The sensor element may be configured to detect the economic- operation-condition of the motor vehicle. This may be a particularly convenient solution.

[0035] Alternatively or additionally, the determination device may be configured to determine the economic-operation-condition of the motor vehicle upon a user input via the user input element. For instance, the user may indicate an intended eco-drive-mode by pressing a button (for instance located in or at the cab). This may further reduce technical effort and / or costs.

[0036] According to an embodiment, the system may comprise a further fluid connection. The further fluid connection may fluidically connect the level control means via the valve to an external environment of the valve. In the first switching state, an air discharge from the at least one air spring via the level control means and via the further fluid connection to the external environment may be enabled. Preferably, the control device as disclosed herein is configured to switch the valve in the second switching state upon determination of the economic-operation-condition. In the second switching state an air discharge from the at least one air spring via the level control means and via the further fluid connection to the external environment may be blocked. The further fluid connection may be a separate fluid line that connects the level control means to the valve. In the first switching state the valve may be configured to discharge air comprised in the at least one air valve essentially in a regulated and / or controlled manner, while in the second switching state a remaining air pressure may optionally prevail in the at least one air spring. The remaining air pressure may be desired in particular when unnecessary leveling of the air-suspended structural unit shall be prevented while the air discharge from the at least one air spring may be desired in a normal drive mode.

[0037] According to an embodiment, the valve may comprise a 4 / 2-valve. However, this is just an example. Generally, any valve that is configured as disclosed herein could be used.

[0038] Alternatively or additionally the air discharge valve may be integrated into the at least one air spring.

[0039] Alternatively or additionally, the system may comprise the air-suspended structural unit (e. g. comprising the cab and / or the chassis and / or the seat), wherein the at least one air spring supports the air-suspended structural unit.

[0040] Alternatively or additionally, the valve may be electrically, pneumatically and / or hydraulically activated.

[0041] Alternatively or additionally the at least one air spring may comprise two front air springs arranged opposite each other in width direction of the air-suspended structural unit. Preferably, the at least one air spring may comprise two rear air springs arranged opposite each other in width direction of the air-suspended structural unit.

[0042] According to a further general aspect, a motor vehicle (for instance a utility vehicle) is provided. The motor vehicle comprises a system as disclosed herein. Optionally, the motor vehicle is a utility vehicle and in particular a tractor unit. In other words, it can be a motor vehicle that is designed for transporting people, transporting goods or towing trailers.

[0043] According to a further general aspect a method for leveling an air-suspended structural unit (e. g. comprising a cab and / or a chassis and / or a seat) of a motor vehicle (for instance as disclosed herein or comprising a system as disclosed herein) is provided. The method comprises the steps:

[0044] Determining an economic-operation-condition of the motor vehicle.

[0045] Blocking an air supply from an air storage to at least one air spring supporting the air-suspended structural unit upon the determining of the economic-operation-condition.

[0046] Preferably, the method comprises blocking an air discharge from the at least one air spring to an external environment upon the determining of the economic-operation-condition.

[0047] Optionally, the method comprises a providing of a motor vehicle comprising a cab and a system as disclosed herein.

[0048] According to an embodiment, the method comprises the step of blocking and enabling the air supply from an air storage to at least one air spring alternately in a cyclic-leveling-mode upon the determining of the economic-operation-condition.

[0049] The embodiments, variants and features of the invention described above can be combined with one another as desired. Further details and advantages of the invention are described below with reference to the accompanying drawings.

[0050] Figure 1 a schematic diagram of an exemplary air consumption of an air spring and an exemplary amplitude of the air spring (prior art);

[0051] Figs. 2A-C schematic illustrations of the functioning of an air suspension (prior art);

[0052] Figure 3 a schematic illustration of a system according to one embodiment;

[0053] Figs. 4A-H schematic illustrations of the functioning of a system according to one embodiment;

[0054] Figure 5 a schematic illustration of an air spring according to one embodiment; and

[0055] Figure 6 a schematic flow chart of a method according to one embodiment. The embodiments shown in the figures are at least partially identical, so that similar or identical parts are provided with the same reference signs and reference is also made to the description of the other embodiments or figures in order to avoid repetitions.

[0056] In some of the figures, exemplary X-, Y- and Z-directions are illustrated. Just exemplarily, the X-direction correlates to the longitudinal direction of the motor vehicle 100, the Y-direction correlates to the width direction of the motor vehicle 100 and the Z-direction correlates to the vertical direction of the motor vehicle 100.

[0057] Figure 1 shows an exemplary air consumption of an air spring 1002 known in the art over an exemplary amplitude of the air spring 1002.

[0058] Typically, known air springs 1002 of cab suspension have a leveling system to position the cab 1010 in a nominal position N’ independent of the weight of the cab 1010. The variation of cab weight, which is dependent e. g. on the cab 1010, the interior equipment, the driver’s loading and the driver / passenger, etc. can be levelled to the nominal position N’ by the leveling system of the air springs 1002. Fig. 1 shows an example how the air consumption is linked to the amplitude of the air spring 1002 and is triggered by a mechanical valve system.

[0059] Figures 2A-C show schematic illustrations of the functioning of a known air spring 1002 provided in a motor vehicle 1000.

[0060] As previously mentioned, the air springs 1002 of the cab suspension have a leveling system to position the cab 1010 in a nominal position N’ independent of the weight of the cab 1010. Dependent on the variation of cab weight, which is dependent on the cab 1010, the interior equipment, the driver’s loading and the driver / passenger, etc. the cab 1010 can be levelled to the nominal position N’ (see Figure 2A) by the leveling system of the air springs 1002. If the cab 1010 is lower than the nominal level N’ (see Figure 2B), the leveling system detects the deviation and opens a valve to add air and lifts up the air spring 1002. If the cab 1010 is higher than the nominal level N’ (see Figure 2C), the leveling system detects the deviation and opens a valve to evacuate air out of the air spring 1002 to lower the cab 1010. This function is always active and levels the cab 1010 in conditions, where it is not necessary and increases the air consumption.

[0061] This is undesirable, because these known techniques lead to an increased air consumption and hence to a decreased energy efficiency. In certain situations (e. g. in an “eco-drive-mode” of the motor vehicle) it is desirable to save air and reduce the air consumption for the air springs 1002, which will save energy provided by the motor vehicle 1000 (e. g. a truck).

[0062] Figure 3 shows a schematic illustration of a system 10 for leveling an air-suspended structural unit of a motor vehicle 100 according to one embodiment.

[0063] The air suspended structural unit preferably comprises a cab 110 (see Figures 4A-H). In embodiments not illustrated, the air suspended structural unit may also comprise a chassis and / or a (e. g. driver’s or passenger’s) seat, wherein these are just examples and any other air-suspended structural unit is possible.

[0064] The system 10 may be comprised by the motor vehicle 100.

[0065] The system 10 comprises at least one air spring 12a-d, an air storage 18, a fluid connection 20a between the at least one air spring 12a-d and the air storage 18.

[0066] The at least one air spring 12a-d may particularly comprise two front air springs 12a-b arranged opposite each other in width direction Y of the air-suspended structural unit (e. g. the cab 110). Optionally, the at least one air spring 12a-d may comprise two rear air springs 12c-d arranged opposite each other in width direction Y of the air-suspended structural unit (e. g. the cab 110). It is possible that these air springs 12a-d may be supplied with air by individual fluid lines and / or individual branches of a main fluid line. The at least one air spring 12a-d supports the airsuspended structural unit (e. g. the cab 110).

[0067] The at least one air spring 12a-d comprises a (e. g. internal) level control means 14. Optionally, the level control means 14 comprises an air discharge valve 14a and / or is integrated into the at least one air spring 12a-d (see e. g. Figure 5).

[0068] The level control means 14 may be configured to discharge air comprised in the at least one air spring 12a-d to an external environment of the at least one air spring 12a-d so as to control a level position (e. g. in height direction Z) of the cab 110 or of the motor vehicle 100.

[0069] The system 10 further comprises a valve 22.

[0070] The valve 22 is arranged externally of the at least one air spring 12a-d and is integrated into the fluid connection 20a. For instance, the valve 22 may be arranged outside of an inner volume of the at least one air spring 12a-d and / or be structurally independent of the at least one air spring 12a-d. The valve 22 is configured to be switched into a first switching state A and into a second switching state B selectively and / or alternately (for instance dependent on an economic-operation-condition EC of the motor vehicle 100).

[0071] In the first switching state A an air supply from the air storage 18 to the at least one air spring 12a-d is enabled (e. g. allowed and / or facilitated).

[0072] In the second switching state B the air supply from the air storage 18 to the at least one air spring 12-d is blocked (e. g. cut and / or closed and / or shut down).

[0073] Optionally, in the second switching state B, an air discharge from the at least one air spring 12a-d to an external environment of the valve 22 may be blocked (e. g. cut and / or closed and / or shut down).

[0074] The system 10 may comprise a control device 24, a determination device 25 and / or a deviation detection device 26.

[0075] The determination device 25 and / or the deviation detection device 26 may be signal connected to the control device 24 as disclosed herein.

[0076] The control device 24 may be configured to switch the valve 22 into the second switching state B upon determination of the economic-operation-condition EC.

[0077] In order to determine the economic-operation-condition EC, the system 10 may optionally comprise the determination device 25 (see e. g. Fig. 3). The determination device 25 may comprise a sensor element and / or a user input element. The sensor element may be configured to detect the economic-operation-condition EC of the motor vehicle 100. It is also possible that the determination device 25 may be configured to determine the economic-operation-condition EC of the motor vehicle 100 upon a user input via the user input element (for instance: located inside the cab 110).

[0078] For instance, the determination device 25 may be configured to generate a signal or impulse in response to the economic-operation-condition EC and to transmit the signal to the control device 24. Upon the receipt of the signal or impulse, the control device 24 may be configured to switch the valve 22 into the second switching state B.

[0079] Further, the determination device 25 may further be configured to determine a discontinuation of the economic drive-condition EC and to transmit a signal 28 or impulse (schematically indicated in Figure 4E) to the control device 24. Upon the receipt of this signal 28 or impulse, the control device 24 may be configured to switch the valve 22 into the first switching state A. Figure 3 shows an exemplary embodiment illustrating structural and / or functional connections between the components. Figure 3 shows partial sectional views S encircled by dashed lines for a better illustration of the inlets and / or outlets of the respective air springs 12a-d.

[0080] In the embodiment of Figure 3, a fluid connection 20a and a further fluid connection 20b is provided. A branch of the fluid connection 20a fluidically connects the valve 22 to respective inlets I of the two front air springs 12a, 12b. A further branch fluidically connects the valve 22 to an inlet I of one rear air spring 12c of the two rear air springs 12c, 12d. A further fluid connection 20b fluidically connects respective outlets O (e. g. the respective internal level device 14) of the two front air springs 12a, 12b and one rear air spring 12c to the valve 22. Further, an inlet / outlet I / O and an inlet I / O of the rear air springs 12c, 12d are fluidically connected via an interconnecting fluid connection 20c.

[0081] In the embodiment of Figure 3, the valve 22 - just exemplarily - is a 4 / 2-valve. The valve 22 hence can be switched into a first switching state A and a second switching state B selectively and / or alternately.

[0082] The control device 24, the determination device 25 and the deviation detection device 26 essentially operate as described above.

[0083] In the first switching state A an air discharge from the at least one air spring 12a-d via the level control means 14 and via the further fluid connection 20b to the external environment may be enabled. In the second switching state B, an air discharge from the at least one air spring 12a- d via the level control means 14 and via the further fluid connection 20b to the external environment may be blocked.

[0084] The achievable modes and respective switching states are summarized in below table:

[0085] Table 1

[0086] Figures 4A-H show an exemplary embodiment of a motor vehicle 100 comprising a system 10 in a time sequence.

[0087] In this embodiment, the control device 24 may be further configured to switch the valve 22 into the first switching state A so as to level the air-suspended structural unit to a nominal level position N. The system 10 may comprise a deviation detection device 26 configured to detect a deviation of a current level position (here exemplarily: in height direction Z) of the air-suspended structural unit from the nominal level position N (here exemplarily: in height direction Z),

[0088] The control device 24 may be further configured to execute a cyclic-leveling-mode. In the cy- clic-leveling-mode, the control device 24 switches the valve 22 into the first switching state A and into the second switching state B alternately (e. g. periodically and / or repeatedly).

[0089] Just exemplarily, in Figures 4A-D, the valve 22 is in the second switching state B, while in Figures 4E-H, the valve 22 is in the first switching state A.

[0090] Thus, in Figures 4A-D (second switching state B) an air supply from an air storage 18 to the at least one air spring 12a-d, and optionally an air discharge from the at least one air spring 12a- d to an external environment of the valve 22, may be blocked.

[0091] For instance, caused by road bumps or a change in the cab’s loading, the cab 110 may be deflected in height direction Z (see Figures 4B and 4C) and thus, a deviation from the nominal level position N may be detected by the deviation detection device 26.

[0092] However, as the air supply from an air storage 18 to the at least one air spring 12a-d and an air discharge from the at least one air spring 12a-d to an external environment of the valve 22 is blocked in the second switching state B, this deviation is not regulated. Thereby, a reduced air consumption may be achieved.

[0093] In Figure 4E, the determination device 25 may determine the cancellation of the economic- operation-condition EC and trigger a signal 28 or impulse that causes the control device 24 to switch the valve 22 into the first switching state A.

[0094] In the first switching state A, an air supply from an air storage 18 to the at least one air spring 12a-d and a regulated air discharge from the at least one air spring 12a-d via the level control means 14 to an external environment of the valve 22 is enabled.

[0095] If the deviation detection device 26 detects a deviation from the nominal level position N while the valve 22 is in the first switching state, the cab 110 is levelled to the nominal level position N.

[0096] For instance, if the detected level position of the cab 110 is lower than the nominal level position N (for instance: negative deviation detected; see Figure 4F), air is supplied from the air storage 18 into the at least one air spring 12a-d such that the cab 110 is raised. Further, if the detected level position of the cab 110 is higher than the nominal level position N (for instance: positive deviation detected; see Figure 4G), air is discharged from the at least one air spring 12a-d via the level control means 14 such that the cab 110 is lowered.

[0097] The control device 24 may be further configured to keep the valve 22 in the first switching state A until the detected deviation lies within a predetermined range. The predetermined range may be provided on (e. g. pre-stored on and / or transmitted to) the control device 24.

[0098] The switching into the first switching state A and into the second switching state B may also be triggered by time intervals.

[0099] For instance, the control device 24 may be further configured to switch the valve 22 into the first switching state A for a predetermined first time interval and into the second switching state B for a predetermined second time interval. Optionally, the first time interval and the second time interval are provided on (e. g. pre-stored on and / or transmitted to) the control device 24.

[0100] It is possible that the valve 22 shuts down the air supply as much as possible. The duration (e. g. the first time interval and / or the second time interval) can be defined individually based on the experience and requirements.

[0101] Within the first time interval the valve 22 shuts down the air supply, no air pressure is inflated into the air spring 12a-d nor evacuated, although the amplitude for the leveling mechanism (e. g. the predetermined range) is overrun by the cab 110. After a defined increment of time (e. g. at the end on the first time interval) the valve 22 turns on the air supply, triggered by an impulse or signal 28, and levels the cab 110 to the nominal level position N, if needed and a deviation is detected. Afterwards the valve 22 shuts down the air supply again and the process starts again, continuing loop by loop of “air supply shut down” (second switching state B) to “leveling cab” (first switching state A).

[0102] Figure 5 shows a sectional view of an air spring 12a-d according to one embodiment.

[0103] In this embodiment, pressurized air can be supplied into the air spring 12a-d thereby expanding the air spring 12a-d in vertical direction Z. For discharging air from the air spring 12a-d, the air spring 12a-d may comprise the level control means 14 schematically illustrated.

[0104] The level control means 14 and / or the air discharge valve 14a may be integrated into the at least one air spring 12a-d (e. g. by being arranged in the inner volume of the air spring 12a-d).

[0105] Air comprised in the at least one air spring 12a-d may be dischargeable via the level control means 14 thereby resulting in a contraction in vertical direction Z of the air spring 12a-d. For this purpose, the level control means 14 may comprise an air discharge valve 14a fluidically connecting an inner volume of the air spring 12a-d to an external environment of the air spring 12a-d or an air discharge fluid connection.

[0106] Figure 6 shows an flow chart illustrating the steps of a method for leveling an air-suspended structural unit (e. g. comprising a cab 110 and / or a chassis and / or a seat) of a motor vehicle 100 (for instance as disclosed herein or comprising a system 10 as disclosed herein) according to one embodiment.

[0107] The method comprises the steps:

[0108] Determining an economic-operation-condition EC of the motor vehicle 100.

[0109] Blocking an air supply from an air storage 18 to at least one air spring 12a-d supporting the air-suspended structural unit upon the determining of the economic-operation-condition EC.

[0110] Optionally, the method comprises a blocking an air discharge from the at least one air spring 12a-d to an external environment upon the determining of the economic-operation-condition EC.

[0111] Further, the method may comprise the step of blocking and enabling the air supply from an air storage 18 to at least one air spring 12a-d alternately in a cyclic-leveling-mode upon the determining of the economic-operation-condition EC.

[0112] Although the invention has been described with reference to specific embodiments, it is be apparent to a person skilled in the art that various modifications may be made and equivalents may be used as substitutes without departing from the scope of the invention. Consequently, the invention is not intended to be limited to the disclosed embodiments, but is intended to encompass all embodiments falling within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and features of the dependent claims independently of the referenced claims. All range specifications herein are to be understood as disclosed such that all values falling within the respective range are disclosed individually, e.g. also as preferred narrower outer limits of the respective range. List of reference signs

[0113] 10 System

[0114] 12a-d Air spring

[0115] 14 Level control means

[0116] 14a Discharge valve

[0117] 18 Air storage

[0118] 20a Fluid connection

[0119] 20b Further fluid connection

[0120] 20c Interconnecting fluid connection

[0121] 22 Valve

[0122] 24 Control device

[0123] 25 Determination device

[0124] 26 Deviation detection device

[0125] 28 Signal

[0126] 100 Motor vehicle

[0127] 110 Cab

[0128] 1000 Motor vehicle (prior art)

[0129] 1002 Air spring (prior art)

[0130] 1010 Cab (prior art)

[0131] 1018 Air storage (prior art)

[0132] A First switching state

[0133] B Second switching state

[0134] EC Economic-operation-condition

[0135] I Inlet

[0136] I / O Inlet / outlet

[0137] N nominal level position

[0138] N’ nominal position (prior art)

[0139] O Outlet

[0140] S partial sectional view

[0141] X Longitudinal direction

[0142] Y Width direction

[0143] Z Vertical direction

Claims

Patent Claims1. A system (10) for leveling an air-suspended structural unit, preferably comprising a cab (110) and / or a chassis and / or a seat, of a motor vehicle (100) comprising: at least one air spring (12a-d), wherein the at least one air spring (12a-d) comprises a level control means (14), preferably wherein the level control means (14) comprises an air discharge valve (14a) and / or is integrated into the at least one air spring (12a-d); an air storage (18); a fluid connection (20a) between the at least one air spring (12a-d) and the air storage (18); and a valve (22), wherein the valve (22) is arranged externally of the at least one air spring (12a-d) and is integrated into the fluid connection (20a) and wherein the valve (22) is configured to be switched into a first switching state (A) and into a second switching state (B), preferably dependent on an economic-operation-condition (EC) of the motor vehicle (100), wherein: in the first switching state (A) an air supply from the air storage (18) to the at least one air spring (12a-d) is enabled; and in the second switching state (B) the air supply from the air storage (18) to the at least one air spring (12a-d) is blocked; preferably a determination device (25), wherein the determination device (25) is configured to determine the economic-operation-condition (EC) of the motor vehicle (100).

2. The system (10) according to claim 1 , wherein in the second switching state (B) an air discharge from the at least one air spring (12a-d) to an external environment of the valve (22) is blocked.

3. The system (10) according any one of the preceding claims, comprising a control device (24), wherein the control device (24) is configured to switch the valve (22) into the second switching state (B) upon determination of the economic-operation-condition (EC).

4. The system (10) according to claim 3, wherein the control device (24) is further configured to execute a cyclic-leveling-mode, wherein in the cyclic-leveling-mode, the control device (24) switches the valve (22) into the first switching state (A) and into the second switching state (B) alternately.

5. The system (10) according to any one of claims 3 or 4, wherein the control device (24) is further configured to switch the valve (22) into the first switching state (A) for a predetermined first time interval and into the second switching state (B) for a predetermined second time interval, preferably wherein the first time interval and the second time interval are provided on the control device (24).

6. The system (10) according to any one of claims 3 to 5, wherein the control device (24) is further configured to switch the valve (22) into the first switching state so as to level the air-suspended structural unit to a nominal level position (N).

7. The system (10) according to any one of claims 3 to 6, comprising a deviation detection device (26) configured to detect a deviation of a current level position of the air-suspended structural unit from a nominal level position (N), wherein the control device (24) is further configured to control the valve (22) dependent on the detected deviation.

8. The system (10) according to claim 7, wherein the control device (24) is further configured, when the valve is in the first switching state (A), to keep the valve (22) in the first switching state (A) until the detected deviation lies within a predetermined range.

9. The system (10) according to any one of the preceding claims, wherein the level control means (14) is configured to discharge air comprised in the at least one air spring (12a-d) to an external environment of the at least one air spring (12a-d) so as to control a level position of the air-suspended structural unit.

10. The system (10) according to any one of the preceding claims, wherein the determination device (25) comprises: a sensor element, wherein the sensor element is configured to detect the economic- operation-condition (EC); and / or a user input element, wherein the determination device (25) is configured to determine the economic-operation-condition (EC) upon a user input via the user input element.

11. The system (10) according to any one of the preceding claims, comprising: a further fluid connection (20b), wherein the further fluid connection (20b) fluidically connects the level control means (14) via the valve (22) to an environment of the valve (22), wherein in the first switching state (A) an air discharge from the at least one air spring (12a-d) via the level control means (14) and via the further fluid connection (20b) to the environment is enabled and in the second switching state (B) an air discharge from the atleast one air spring (12a-d) via the level control means (14) and via the further fluid connection (20b) to the environment is blocked.

12. The system (10) according to any one of the preceding claims, comprising at least one of the following features: the valve (22) comprises a 4 / 2-valve; the air discharge valve (14a) is integrated into the at least one air spring (12a-d); the air-suspended structural unit, preferably comprising the cab (110) and / or the chassis and / or the seat, wherein the at least one air spring (12a-d) supports the air-suspended structural unit; the valve (22) is electrically, pneumatically and / or hydraulically activated; and the at least one air spring (12a-d) comprises two front air springs (12a-b) arranged opposite each other in width direction (Y) of the air-suspended structural unit and preferably two rear air springs (12c-d) arranged opposite each other in width direction (Y) of the air-suspended structural unit.

13. A motor vehicle (100), preferably a utility vehicle, wherein the motor vehicle (100) comprises a system (10) according to any one of the preceding claims.

14. A method for leveling an air-suspended structural unit, preferably comprising a cab (110) and / or a chassis and / or a seat, of a motor vehicle (100), preferably according to claim 13 or comprising a system (10) according to any one of claims 1 to 12, wherein the method comprises the steps: determining an economic-operation-condition (EC) of the motor vehicle (100); blocking an air supply from an air storage (18) to at least one air spring (12a-d) supporting the air-suspended structural unit upon the determining of the economic-operation-condition (EC); and preferably blocking an air discharge from the at least one air spring (12a-d) to an external environment upon the determining of the economic-operation-condition (EC).

15. The method according to claim 14, further comprising the step of: blocking and enabling the air supply from an air storage (18) to at least one air spring (12a-d) alternately in a cyclic-leveling-mode upon the determining of the economic- operation-condition (EC).

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