Compressed air system, utility vehicle having a compressed air system, and method for operating a compressed air system

Abstract

The present invention relates to a compressed air system (1), in particular for use in a utility vehicle (2), comprising a control unit (10), a pressure processing unit (20), a first pressure sensor (12) and a second pressure sensor (14), and a switchable valve (30), in particular an electrically or magnetically switchable valve. The switchable valve (30) is designed to connect a compressed air inlet (3) to the pressure processing unit (20). The pressure processing unit (20) is connected to a compressed air outlet (5), wherein the control unit (10) is designed to communicate with the pressure sensors (12, 14) and / or the switchable valve (30). The control unit (10) is designed to be connected to the switchable valve (30) in order to control the switchable valve (30). The first pressure sensor (12) is arranged on the compressed air system (1) and is designed so as to determine a pressure at the compressed air inlet (3), and the second pressure sensor (14) is arranged on the compressed air system (1) and is designed so as to determine a pressure at the compressed air outlet (5). The invention further relates to a utility vehicle (2) having a compressed air system (1), and to a method for operating the compressed air system (1).

Description

[0001] Compressed air system, commercial vehicle with a compressed air system and method for operating a compressed air system

[0002] The present invention relates to a compressed air system, a commercial vehicle with a compressed air system and a method for operating a compressed air system.

[0003] Compressed air systems are used in a variety of different applications in commercial vehicles. For example, safety-critical systems, such as a commercial vehicle's braking system, are actuated by air pressure from a pressure reservoir. Furthermore, other technical functions can also be achieved by supplying compressed air to the axles. This allows, for example, the air pressure in the tires connected to that axle to be adjusted while the commercial vehicle is in operation. The individual applications are often contained in individual modules and are controlled within these modules. While they operate partially independently of one another, they each require their own data processing units and pneumatic control units, such as valves or lines.

[0004] As a result, a large number of data processing units currently have to be installed in a commercial vehicle to provide different functions. This can lead to increased communication overhead and associated failures, as well as increased costs.

[0005] Therefore, it is an object of the present invention to reduce the number of data processing units and increase the efficiency of a commercial vehicle. The present invention solves the above problem with a compressed air system having the features of claim 1, a commercial vehicle having the features of claim 17, and a method having the features of claim 18.

[0006] According to one aspect of the present invention, a compressed air system is provided, in particular for use in a commercial vehicle, comprising a control unit, a pressure processing unit, a first pressure sensor and a second pressure sensor, a switchable, in particular electrically or magnetically switchable, valve, wherein the switchable valve is designed to connect a compressed air inlet to the pressure processing unit, wherein the pressure processing unit is connected to a compressed air outlet, wherein the control unit is designed to communicate with the pressure sensors and / or the switchable valve, wherein the control unit is designed to be connected to the switchable valve in order to control the switchable valve, wherein the first pressure sensor is arranged on the compressed air system and is designed to determine a pressure at the compressed air inlet,and wherein the second pressure sensor is arranged on the compressed air system and is designed to determine a pressure at the compressed air outlet.,

[0007] Compared to the known prior art, the invention proves to be particularly advantageous because it uses already known pressure information from an electronic braking system to control the compressed air supply at the compressed air outlet and then supplements it with an additional pressure sensor. Furthermore, the necessary signals can be processed in a control unit, which is already part of the electronic braking system. This offers the advantage that several functions can be executed integrally in one control unit, reducing the number of data processing elements.

[0008] The compressed air system can be part of the commercial vehicle. The compressed air system can comprise pressure-carrying lines (pressure lines) and connectors, as well as attachments designed to provide pressure connections. A volume can be defined by the compressed air system. This allows the compressed air system to be separated from the environment. Furthermore, the compressed air system can be designed to carry a fluid and, in particular, to provide a differential pressure between the fluid within the compressed air system and the surrounding atmospheric air pressure. The fluid is preferably in a gaseous state during normal use of the commercial vehicle. The commercial vehicle within the meaning of the invention can, in particular, be a vehicle having a permissible total weight of more than 3.5 t, preferably of more than 7.5 t, particularly preferably of more than 15 t, and particularly preferably of more than 18 t.The commercial vehicle can be a trailer, in particular a semi-trailer, and / or a towed vehicle. The commercial vehicle can in particular be a roadworthy and / or road-bound vehicle. A control unit can be a computer-like unit designed to acquire, process, and output data. The control unit can comprise a memory for storing the data. The control unit can communicate and / or exchange data, in particular via a communication interface. In a preferred embodiment, the control unit is designed as a closed-loop control unit, which controls actuators, monitors measured values, and evaluates them. The communication interface can enable wireless and / or wired data exchange.This allows the control unit to communicate with different devices and interfaces, thereby increasing flexibility. The pressure processing unit can be designed to vary the energy content of the fluid conducted in the compressed air system. This can have the effect that energy is transported and / or transmitted via the fluid. The pressure processing unit can be designed to vary a pressure and / or a flow velocity of the fluid conducted in the compressed air system. This allows energy to be stored in the fluid in a particularly advantageous manner and in a usable form for the commercial vehicle. In this context, varying can mean both increasing and reducing. The pressure processing unit can be designed to communicate with the control unit. The first pressure sensor can be designed to measure a static pressure.Additionally or alternatively, the first pressure sensor can be designed to measure a flow velocity of the fluid. This allows the fluid pressure to be determined mathematically and / or an additional measured variable to be determined. The first pressure sensor can be designed to communicate, in particular, with the control unit. The second pressure sensor can have the same functional properties as the first pressure sensor, in particular be a first pressure sensor. The switchable valve can comprise supply and / or discharge pressure lines, in particular can be arranged between the supply and / or discharge pressure lines. The switchable valve can be designed to at least partially connect the supply and discharge pressure lines. Furthermore, the switchable valve can vary a connection between at least one of the supply and at least one of the discharge pressure lines, i.e., open or close it.In other words, the switchable valve can control a portion of an inlet area belonging to one of the inlet pressure lines and / or a portion of an outlet area belonging to one of the outlet pressure lines. This can, for example, throttle a fluid flow. Furthermore, the switchable valve can comprise an actuator which moves the valve mechanically. This can achieve particularly simple control of the valve. The actuator can be electrically operated. The switchable valve can be designed to communicate, in particular, with the control unit. Communication can comprise receiving data and / or sending data and / or exchanging data. The control unit can be connected to the switchable valve via a physical connection and communicate via this physical connection.Additionally or alternatively, the control unit can also communicate wirelessly with the switchable valve. The switchable valve can receive and execute control commands from the control unit. One of the supply pressure lines of the valve can be the compressed air inlet. One of the discharge pressure lines of the valve can be the compressed air outlet. The pressure processing unit can be arranged and / or located downstream of the switchable valve. The switchable valve can be designed to control a fluid flow to the pressure processing unit. The control unit can be designed to receive data from the first pressure sensor and / or the second pressure sensor. Data can comprise electrical signals. The first pressure sensor can be arranged in the supply pressure line, in particular at the compressed air inlet, in particular forming part of the supply pressure line.This allows the first pressure sensor to detect a pressure present upstream of the switchable valve. The second pressure sensor can be arranged in the discharge pressure line, in particular at the compressed air outlet, in particular forming part of the discharge pressure line. This allows the second pressure sensor to detect a pressure present downstream of the switchable valve. The first pressure sensor and the second pressure sensor can, in particular, be the same type of sensor. This reduces the variety of variants and simplifies and reduces the cost of maintaining the compressed air system.

[0009] The control unit can preferably be an electronic control and / or monitoring unit (ECU), or preferably a subcomponent of an ECU (Electronic Control Unit). In other words, the control unit can be configured to send outgoing electrical signals and / or data depending on incoming electrical signals and / or data. Furthermore, outgoing signals and / or data can be generated by the control unit. This offers the advantage that the control unit can provide intelligent control of actuators. Furthermore, the control unit can be configured to provide closed-loop control of physical states, in particular air pressure, within the compressed air system. This can advantageously expand the functionality of the commercial vehicle.

[0010] Preferably, at least one pneumatic consumer can be connected and / or is connected to the compressed air outlet. The pneumatic consumer can comprise a volume that is connectable and / or connected to the compressed air outlet. This allows fluid to flow into the consumer. The consumer can be an axle. Additionally or alternatively, the or another consumer can be a tire and / or a braking system. It is also conceivable that the or another consumer is an air spring. The compressed air system can thus provide a broad and expandable range of functionality for the commercial vehicle.

[0011] Preferably, the pressure at the compressed air inlet that can be determined by the first pressure sensor can essentially correspond to a supply pressure of the compressed air system, and / or the pressure at the compressed air outlet that can be determined by the second pressure sensor can essentially correspond to an axle pressure. In other words, the first pressure sensor can be arranged to detect a supply pressure of a supply pressure vessel and / or a pressure source. The first pressure sensor can be arranged in the supply pressure vessel and / or configured as part of the pressure source. This can provide the advantage that the first pressure sensor can be assigned to another, in particular additional, assembly. The second pressure sensor is preferably designed and arranged to detect an axle pressure of an axle, in particular a commercial vehicle axle. The second pressure sensor can be arranged in the axle and / or form part of the axle.It is also conceivable that the second pressure sensor or another pressure sensor is located in a wheel that is or can be fluidly connected to the axle. This allows for efficient acquisition or analysis of data and / or signals that provide direct information about the state of the compressed air in the tires or the tire inflation system.

[0012] The pressure processing unit can preferably comprise a pressure booster unit. The pressure processing unit can be configured to vary the potential of the fluid, in particular a gaseous fluid. In other words, the pressure booster unit can increase the pressure of the fluid by means of the pressure booster unit. This allows a required working pressure to be achieved, which is predetermined in particular by the control unit. The pressure processing unit can preferably have a compressed air outlet and / or a pressure relief valve. The pressure processing unit can thus be configured to release pressure, in particular to the environment.

[0013] The pressure booster unit can preferably be a pump, a pressure compensator, a pressure rocker, a peristaltic pump, a turbocharger, a radial compressor, and / or an axial compressor. The selection of the respective pressure booster system depends on the requirements for the required compressed air volume, the pressure difference to be provided by the pressure booster unit, and the energy source available on the vehicle to drive the pressure booster unit. Piston pumps are particularly easy to implement and reliably deliver large pressure differences for relatively low air mass flows. Turbochargers and similar compressors with a continuous flow passage, on the other hand, can deliver larger air mass flows, but are limited in terms of the achievable pressure difference.

[0014] The pressure booster unit can preferably have one or two double pistons or double-acting cylinders and / or double-acting pistons. This allows the pressure booster unit to be designed particularly flat and can be integrated particularly advantageously into the compressed air system. A pressure booster unit designed as a double-piston pump can provide a particularly uniform pressure increase with a high pressure gradient and high fluid volume.

[0015] The pressure booster unit can preferably have a power connection, whereby the energy required for the pressure increase can be supplied to the pressure booster unit through the power connection. The power connection can comprise a connecting element that can be configured for power supply and can be coupled to the on-board electrical system of the commercial vehicle.

[0016] The pressure boosting unit can preferably provide a pressure increase by a factor in a range from 1.05 to 2.6, preferably in a range from 1.1 to 2.0, and particularly preferably in a range from 1.2 to 1.8. A pressure change can relate to both a pressure increase and a pressure reduction, which occur relative to one another upstream of and downstream of the pressure processing unit in the direction of flow. The first range of a preferred pressure increase includes a particularly large spread, whereby different pneumatic consumers can be supplied. In the second range, overloading of individual pneumatic consumers can be avoided. The third range represents a particularly advantageous pressure ratio for filling the commercial vehicle axle and / or a wheel arranged thereon. It is also conceivable for the pressure boosting unit to provide no pressure change in an operating state.In other words, the pressure boosting unit can be inactive in one state. Preferably, the pressure processing unit can comprise a bypass, in particular a pressure line, between the switchable valve and the compressed air outlet. This allows the fluid to be passed at least partially, and in certain applications even completely, from the switchable valve to the compressed air outlet without increasing the pressure.

[0017] Preferably, the bypass can be arranged or can be arranged parallel to the pressure booster unit. The parallel arrangement of the bypass can be designed as a fluid-mechanical parallel connection or bridging. The bypass can be designed so that moved fluid only flows partially via the pressure booster unit. If the pressure present at the compressed air inlet It is also conceivable that the fluid can flow completely via the bypass between the switchable valve and the compressed air outlet. In particular, when the first compressed air sensor reaches a sufficient threshold value, the controllable valve can be activated by the control unit such that the air pressure present at the compressed air inlet via the bypass corresponds to the air pressure present at the compressed air outlet. This can have the effect of completely bypassing the pressure booster unit or allowing the fluid to flow through it without actuation. Consequently, energy can be saved.In an alternative embodiment, the pressure processing unit comprises only the bypass. This solution is particularly advantageous for commercial vehicles where the pressure in the compressed air supply is already reliably high enough and additional pressure boosting by a pressure booster unit is not required. In this case, the pressure booster unit can advantageously be omitted, saving installation space and costs.

[0018] The bypass can preferably comprise a check valve. The check valve is advantageously arranged in the bypass such that a flow direction runs along the direction from the switchable valve to the compressed air outlet. A complementary blocking direction of the check valve can be configured to correspond to the opposite direction. This can ensure that no fluid or air pressure can escape from the compressed air outlet via the bypass and be supplied to the compressed air inlet. This can, for example, maintain the inflation state in the axle or tire even when the compressed air supply is shut off.

[0019] The switchable valve can preferably be a 2 / 2-way valve. In other words, the switchable valve can have two ports, which can serve as the supply and discharge pressure lines. Furthermore, the switchable valve can be movable between two switching positions, with a first switching position completely blocking the fluid flow through the valve and a second switching position completely opening the fluid flow through the valve. It is also conceivable for there to be a certain number of intermediate positions between the first switching position and the second switching position, which have smaller switching intervals from one another. This allows the fluid flow through the switchable valve to be controlled in stages, or, with infinitesimally small switching intervals, even continuously.

[0020] The switchable valve can preferably be a 3 / 2-way valve or a 4 / 2-way valve. Accordingly, the switchable valve can also have three or four connections. It is conceivable for the switchable valve to have two or, in particular, three supply pressure lines and two or one discharge pressure line(s). This can provide the advantage that more than one pressure source can be connected and combined or consolidated in the switchable valve. Consequently, the highest fluid pressure present at the switchable valve can be used and passed on, at least partially, in particular completely, to the compressed air outlet via the switchable valve.

[0021] The compressed air system can preferably comprise a housing. The housing can enclose the compressed air system, particularly partially. As a result, the compressed air system, particularly parts of the compressed air system, can be particularly advantageously integrated into the commercial vehicle as a unit. This provides the advantage of a simple modular solution for equipping different commercial vehicles with the same compressed air systems.

[0022] The housing can preferably comprise a metallic material, in particular aluminum. This can increase the housing's resilience to external forces. Alternatively, the housing is preferably made of plastic, which is more cost-effective than metal and also reduces weight. For both material variants, it is also conceivable for the housing to be designed as part of the commercial vehicle, in particular integrated into the geometry of the commercial vehicle. This can provide the advantage of multiple functions. On the one hand, the protection of the compressed air system and, on the other hand, the formation of stiffening and / or load-bearing structures for the commercial vehicle.

[0023] Preferably, the pressure booster unit and one of the pressure sensors can be configured as a single unit. In other words, the pressure booster unit and one of the pressure sensors, in particular the second pressure sensor, can be in contact with one another. It is also conceivable for the pressure booster unit and the at least one pressure sensor, in particular the second pressure sensor, to be arranged side by side and connected to one another in a supporting manner via an intermediate element. This can provide the advantage that the resulting unit can be easily integrated into the compressed air system and replaced. The resulting increased manageability can also be beneficial for a possible retrofitting of this unit into the compressed air system.

[0024] Preferably, the unit comprising the pressure booster unit and one of the pressure sensors can be arranged outside the housing. This can advantageously increase accessibility to the resulting unit. It is also conceivable that this could facilitate possible maintenance and / or repair work on the pressure booster unit.

[0025] Preferably, the first pressure sensor and / or the second pressure sensor can each be connected to the control unit via a cable. This enables particularly secure communication between the pressure sensors and the control unit. Furthermore, wired communication provides a simple and cost-effective way of exchanging data and / or signals, since expensive transmitters and receivers of wireless signals can be dispensed with. Preferably, the first pressure sensor and / or the second pressure sensor can be arranged on a circuit board of the control unit. In other words, in this embodiment, the first pressure sensor and / or the second pressure sensor can be part of the control unit. This allows a particularly simple and cost-effective design of the control unit with the first and / or the second pressure sensor to be achieved.Because there is no cable between the control unit and the first and / or second pressure sensor, data transmission errors can be reduced.

[0026] The compressed air system can preferably comprise a tire inflation system and an electronic braking system. The tire inflation system can be designed as a standalone system for a commercial vehicle. This allows independent functionality of the tire inflation system to be provided. The same applies to the electronic braking system, which can also be designed as a standalone system for a commercial vehicle. It is conceivable that the tire inflation system and / or the electronic braking system is / are part of the compressed air system and at least partially forms / forms the compressed air system. This can provide the advantage that individual parts of the systems can be used redundantly. In other words, individual components can be shared between the respective systems, thus reducing the number of parts in a commercial vehicle.For example, one control unit can perform communication and data processing tasks for both the tire inflation system and the electronic braking system, whereby the control unit can be part of the compressed air system.

[0027] Preferably, the pressure-increasing unit and the second pressure sensor can be part of the tire inflation system, wherein both the tire inflation system and the electronic braking system are connected to the control unit such that the control unit controls the switchable valve and the pressure processing unit based on requirements of the tire inflation system and the electronic braking system. The control unit can communicate with both the tire inflation system and the electronic braking system. In other words, the control unit receives at least data and / or signals from the tire inflation system and / or the electronic braking system. Furthermore, the control unit can control the switchable valve depending on these data and / or signals. Furthermore, the control unit can also control the pressure-increasing unit depending on these data and / or signals.This can provide the advantage of providing a demand-based fluid pressure in the compressed air system, with the demand being determined by the tire inflation system and / or electronic braking system. The controllable valve can be actuated in such a way that the supply to the electronic braking system is prioritized over the supply to the tire inflation system. In other words, the tire inflation system can provide an additional pressure source for the electronic braking system. This can increase the road safety of the commercial vehicle, as the tire inflation system can be used as an emergency compressed air source for the braking system. Furthermore, there is the possibility of fluid, particularly pressurized fluid, being exchanged between the tire inflation system and the electronic braking system.In other words, the control unit can determine the fluid and / or fluid pressure requirements of both systems and distribute fluid and / or fluid pressure between the systems as needed. Additionally, fluid and / or fluid pressure can also be provided and distributed from the pressure source, in particular an additional pressure source.

[0028] Preferably, the switchable valve can be controlled depending on data and / or signals from two independent systems, in particular the tire inflation system and the electronic braking system. In other words, a switching strategy for the switchable valve can be provided which accepts several independent control variables. This makes it possible to provide intelligent control of the switchable valve, whereby both the functionality of the tire inflation system and that of the electronic braking system can be maintained. In particular, the tire inflation system and the braking system can be considered separate systems which have common components or even common data or signals, whereby the common data or signals do not correspond to the entirety of the data or signals of the tire inflation system or the electronic braking system.In particular, the switching strategy can also be designed in such a way that the tire inflation system is prioritized over the electronic braking system. This allows the braking system to be supplied with air pressure on a priority basis in safety-critical situations or when defects occur. It is also conceivable that the switchable valve can be strategically controlled depending on additional control variables, i.e., data and / or signals.

[0029] According to a further aspect of the present invention, a commercial vehicle is provided, comprising a compressed air system, wherein a compressed air inlet is advantageously connectable or connected to a pressure accumulator of the commercial vehicle, in particular comprising an air spring and / or a compressed air tank, and / or wherein a compressed air outlet is advantageously connectable or connected to a pressure chamber of an axle and / or a tire of the commercial vehicle. The pressure chamber of a tire within the meaning of the invention can be the volume enclosed by the tire, which must have a certain air pressure during operation in order to ensure proper rolling of the tire on the road. The commercial vehicle within the meaning of the invention can in particular be a vehicle which has a permissible total weight of more than 3.5 t, preferably of more than 7.5 t, particularly preferably of more than 15 t, and particularly strongly preferably of more than 18 t.The compressed air system can be designed as part of the commercial vehicle and / or at least partially form the commercial vehicle. The compressed air system can connect different compressed air sources, pressure accumulators and compressed air consumers to one another. For example, the air spring and the compressed air tank can be connected to one another via the compressed air system. In particular, the pressure chamber of an axle can be fluidly connected to at least one of the wheels of the commercial vehicle, whereby the pressure chamber of the axle can also be fluidly connected to the compressed air system. In the context of the present invention, a fluid connection is understood in particular to mean the possibility for a mutual exchange of fluid, preferably air which is present at pressures above ambient pressure. In particular, within the context of such a fluid connection, the exchange of energy can be understood, whereby the fluid, in particular air, is the energy carrier.In other words, the commercial vehicle's compressed air system can be designed to exchange energy from one of the pressure accumulators with a pneumatic consumer, for example, one or more tires. This allows the compressed air system to maintain a constant energy level, in particular a constant tire pressure, in the tire(s).

[0030] The commercial vehicle can preferably be a commercial vehicle trailer, in particular a semi-trailer. Furthermore, the commercial vehicle can be a towed vehicle. In other words, the commercial vehicle can be designed to be towed, in particular moved, by a tractor and accordingly does not have its own drive for propulsion. The commercial vehicle can, in particular, be a roadworthy and / or road-bound vehicle.

[0031] According to a further aspect of the present invention, a method for operating a compressed air system is provided, comprising the steps of determining a pressure at the compressed air outlet, comparing the determined pressure with a target pressure by the control unit, controlling the switchable valve by the control unit, and actuating the pressure increase unit of the tire inflation system if the determined pressure and / or a pressure at the compressed air inlet is below the target pressure. By means of a second pressure sensor arranged at the compressed air outlet, a pressure present there, in particular air pressure, can be detected. The second pressure sensor can communicate with the control unit and transmit data, in particular detected values. In addition, a first pressure sensor can also be arranged at a compressed air inlet and communicate with the control unit.The control unit comprises a memory in which the target pressure is stored, wherein the respective value of the target pressure is specified by the user of the vehicle, or transmitted by the control unit or another data processing system of the commercial vehicle to the memory and stored there at least temporarily. The control unit can compare the transmitted values, including the air pressure of the second pressure sensor and / or first pressure sensor, with the target pressure. Based on a difference between the transmitted values ​​and the target pressure, the control unit can control the switchable valve. In other words, the control unit's control commands to the switchable valve can depend on the transmitted values ​​and / or the target pressure. This allows the control unit to provide control behavior for the compressed air system. Furthermore, the control unit can control the pressure booster unit as needed.In other words, the control of the pressure booster unit depends on the transmitted values ​​and the target pressure. In particular, the pressure booster unit can be controlled by the control unit in such a way that the air pressure transmitted by the second pressure sensor is approximately adjusted to the target pressure value. Approximately, a deviation can comprise a standard measurement tolerance.

[0032] Individual embodiments and features can be combined with other embodiments and features to form new embodiments. Embodiments and advantages of the embodiments and features also apply analogously to the new embodiments. Furthermore, embodiments and advantages mentioned in connection with the devices also apply analogously to the respective other device and / or method, and vice versa.

[0033] Embodiments of the present invention will be described in detail below with reference to the accompanying figures.

[0034] Fig. 1 is a schematic representation of the compressed air system according to an embodiment of the present invention,

[0035] Fig. 2 is a schematic representation of the compressed air system according to another embodiment of the present invention,

[0036] Fig. 3 is a schematic representation of the compressed air system according to another embodiment of the present invention,

[0037] Fig. 4 is a schematic system overview of the compressed air system, including the tire inflation system and the compressed air system, and

[0038] Fig. 5 shows a flow diagram of a method according to one aspect of the present invention. Fig. 1 shows the compressed air system 1 in a schematic representation. A switchable valve 30 is arranged directly at a compressed air inlet 3, wherein the switchable valve 30 comprises an inlet and an outlet pressure line. A first pressure sensor 12 is arranged upstream of the switchable valve 30 and can measure the air pressure directly at the compressed air inlet 3. Downstream of the switchable valve 30 is the pressure processing unit 20, wherein the pressure processing unit 20 preferably comprises at least one pressure increasing unit 22 and a bypass 24. In this embodiment, the pressure increasing unit 22 is designed as a double-piston pump or double-acting piston pump. Other embodiments of the pressure increasing unit 22 are also conceivable. The bypass 24 is arranged fluidically parallel to the pressure increasing unit 22.The bypass 24 further comprises a check valve 26. The compressed air outlet 5 is located downstream of the pressure processing unit 20. A further pressure line is arranged parallel to the compressed air outlet 5, which preferably leads directly to a second pressure sensor 14. The second pressure sensor 14 can thus determine the air pressure at the compressed air outlet 5.

[0039] The second pressure sensor 14 and the switchable valve 30 each have a communication interface, which is connected to a control unit 10 via a data transmission line. In the embodiment shown, the first pressure sensor 12 is arranged directly on a circuit board of the control unit 10, in particular embedded in the control unit 10. It is also conceivable for the first pressure sensor 12 to communicate with the control unit 10 via a data transmission line. This allows the first pressure sensor 12 to be easily maintained and / or replaced, for example.

[0040] Fig. 2 shows a further embodiment of a compressed air system 1 in a schematic representation, wherein the compressed air system 1 in Fig. 2 does not have a bypass 24 and thus also no check valve 26. As a result, a fluid and / or air pressure originating from the switchable valve 30 can only reach the compressed air outlet 5 via the pressure processing unit 20. Fig. 3 shows a further embodiment of a compressed air system 1 in a schematic representation, wherein the compressed air system 1 in Fig. 3 does not have a pressure processing unit 20. As a result, fluid and / or incoming air pressure coming from the switchable valve 30 cannot have its pressure changed, but is instead passed on directly after the switchable valve 30 to the compressed air outlet 5. The check valve 26 shown prevents any backflow of fluid to the switchable valve 30.

[0041] Fig. 4 shows a schematic system overview of the compressed air system 1, which is arranged in a commercial vehicle 2. It is also conceivable that the compressed air system 1 at least partially forms the commercial vehicle 2 or is part of the commercial vehicle 2. The compressed air system 1 includes a tire inflation system RBS and an electronic braking system EBS. The compressed air system 1 is designed in the form shown such that both the tire inflation system RBS and the electronic braking system EBS jointly comprise the control unit 10, the first pressure sensor 12 and at least the switchable valve 30. In other words, the functionality of the three aforementioned components of the compressed air system 1 can be used and / or is essential for both the tire inflation system RBS and the electronic braking system EBS.

[0042] Fig. 5 shows a flowchart of a method according to the invention for operating the compressed air system 1. In the first step, a pressure at the compressed air outlet 5 is determined S1. This can, for example, provide a conclusion about the air pressure within a pressure chamber of one of the tires, which is arranged, for example, in another pressure chamber of an axle of the commercial vehicle 2. In the next step, the control unit 10 compares S2 the determined pressure with a target pressure. For this purpose, the control unit 10 can comprise a memory for storing and retrieving data, such as the target value. A difference can be determined between this target value and the determined pressure, in particular a comparison can be carried out. Subsequently, the control unit 10 controls S3 the switchable valve 30.Finally, if the pressure at pressure inlet 3 is too low and, in particular, below the target pressure, the pressure boosting unit 22 of the tire inflation system (RBS) is actuated (S4). In other words, the tire inflation system (RBS) can be activated as needed by the control unit 10. It is conceivable that the pressure boosting unit 22 is also activated to allow the fluid flowing into it to flow out again unchanged, i.e., without increasing the pressure. In other words, the pressure boosting unit 22 can be switched to a position in which it merely conducts the fluid.

[0043] List of reference symbols:

[0044] 1 compressed air system

[0045] 2 commercial vehicles

[0046] 3 Compressed air inlet

[0047] 5 Compressed air outlet

[0048] 10 Control unit

[0049] 12 first pressure sensor

[0050] 14 second pressure sensor

[0051] 20 Print processing unit

[0052] 22 Pressure booster unit

[0053] 24 Bypass

[0054] 26 Check valve

[0055] 30 switchable valve

[0056] EBS electronic braking system

[0057] RBS tire inflation system

[0058] 51 Determine

[0059] 52 Compare

[0060] 53 Taxes

[0061] 54 Press

Claims

Claims 1 . Compressed air system (1), in particular for use in a commercial vehicle (2), comprising a control unit (10), a pressure processing unit (20), a first pressure sensor (12) and a second pressure sensor (14), a switchable, in particular electrically or magnetically switchable, valve (30), wherein the switchable valve (30) is designed to connect a compressed air inlet (3) to the pressure processing unit (20), wherein the pressure processing unit (20) is connected to a compressed air outlet (5), wherein the control unit (10) is designed to communicate with the pressure sensors (12, 14) and the switchable valve (30), wherein the control unit (10) is designed to be connected to the switchable valve (30) in order to control the switchable valve (30), wherein the first pressure sensor (12) is arranged on the compressed air system (1) and is designed to measure a pressure at Compressed air inlet (3) to determine,and wherein the second pressure sensor (14) is arranged on the compressed air system (1) and is designed to determine a pressure at the compressed air outlet (5).

2. Compressed air system (1) according to claim 1, wherein at least one pneumatic consumer can be connected and / or is connected to the compressed air outlet (5).

3. Compressed air system (1) according to one of claims 1 or 2, wherein the pressure at the compressed air inlet (3) that can be determined by the first pressure sensor (12) essentially corresponds to a supply pressure of the compressed air system (1), and / or wherein the pressure at the compressed air outlet (5) that can be determined by the second pressure sensor (14) essentially corresponds to an axle pressure.

4. Compressed air system (1) according to one of the preceding claims, wherein the pressure processing unit (20) comprises a pressure increasing unit (22).

5. Compressed air system (1) according to one of the preceding claims, in particular claim 4, wherein the pressure increasing unit (22) is a pump, a pressure compensator, a pressure rocker, a hose pump, a turbocharger, a radial compressor and / or an axial compressor.

6. Compressed air system (1) according to one of the preceding claims, in particular claims 4 or 5, wherein the pressure increasing unit (22) provides a pressure increase by a factor in a range of 1.05 to 2.6, preferably in a range of 1.1 to 2.0, and particularly preferably in a range of 1.2 to 1.

8.

7. Compressed air system (1) according to one of the preceding claims, wherein the pressure processing unit (20) comprises a bypass (24), in particular a pressure line between the switchable valve (30) and the compressed air outlet (5).

8. Compressed air system (1) according to one of the preceding claims, wherein the compressed air system (1) comprises a housing.

9. Compressed air system (1) according to one of the preceding claims, wherein the pressure increasing unit (20) and one of the pressure sensors (12, 14) are formed as a unit.

10. Compressed air system (1) according to one of the preceding claims, in particular claims 8 or 9, wherein the unit comprising the pressure increasing unit and one of the pressure sensors (12, 14) are arranged outside the housing.

11. Compressed air system (1) according to one of the preceding claims, wherein the first pressure sensor (12) and / or the second pressure sensor (14) are each connected to the control unit (10) via a cable.

12. Compressed air system (1) according to one of the preceding claims, wherein the first pressure sensor (12) and / or the second pressure sensor (14) are arranged on a circuit board of the control unit (10).

13. Compressed air system (1) according to one of the preceding claims, wherein the compressed air system (1) comprises a tire inflation system (RBS) and an electronic braking system (EBS).

14. Compressed air system (1) according to one of the preceding claims, in particular claim 13, wherein the pressure increasing unit (22) and the second pressure sensor (14) are part of the tire inflation system (RBS), wherein both the tire inflation system (RBS) and the electronic braking system (EBS) are connected to the control unit (10) such that the control unit (10) controls the switchable valve (30) and the pressure processing unit (20) based on requirements of the tire inflation system and the electronic braking system (EBS).

15. Compressed air system (1) according to one of the preceding claims, in particular claims 13 or 14, wherein the switchable valve (30) is controlled as a function of data and / or signals from two independent systems, in particular the tire inflation system (RBS) and the electronic braking system (EBS).

16. Compressed air system (1) according to one of the preceding claims, wherein preferably the commercial vehicle (2) is a commercial vehicle trailer, in particular a semi-trailer.

17. Commercial vehicle (2), comprising a compressed air system (1) according to one of the preceding claims, wherein the compressed air inlet (3) is advantageously connectable or connected to a pressure accumulator of the commercial vehicle (2), in particular comprising an air spring and / or a compressed air tank, and / or wherein the compressed air outlet (5) is advantageously connectable or connected to the pressure chamber of an axle and / or a tire of the commercial vehicle (2).

18. Method for operating a compressed air system (1), in particular according to one of the preceding claims 1 to 16, comprising the steps: - determining (S1) a pressure at the compressed air outlet (5), - comparing (S2) the determined pressure with a target pressure by the control unit (10), - Controlling (S3) the switchable valve (30) by the control unit (10), - Actuating (S4) the pressure increase unit (22) of the tire inflation system (RBS) if the determined pressure and / or a pressure at the compressed air inlet (3) is below the target pressure.

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