Method for operating a pneumatic system of a vehicle, pneumatic system, vehicle and compressed air supply unit and pneumatic unit for a pneumatic system with a heating function of at least one of the pneumatic solenoid valves

Abstract

The invention relates to a method (2000, 2000') for operating a pneumatic system (1200), having the steps of: - providing (2100) compressed air (120), - conducting (2200) the compressed air (120) to a compressed air supply connection (2) via at least one first pneumatic line (10), - conducting (2300) the compressed air (120) from the compressed air supply connection (2) via at least one second pneumatic line (316) of a connected pneumatic unit (300), - energizing (2420) at least one pneumatic solenoid valve (20) in a selective manner using a heating control current (SI2) in order to heat at least one of the pneumatic solenoid valves (20), and - energizing (2430) at least one of the pneumatic solenoid valves (20) using a deflection control current (SI1) which is greater than the heating control current (SI2) in order to deflect said solenoid valve from a base position (G). The invention additionally relates to a corresponding pneumatic system (1200), to a compressed air supply unit (100), to a pneumatic unit (300) for a pneumatic system (1200), and to a vehicle comprising the pneumatic system (1200).

Description

[0001] Method for operating a pneumatic system of a vehicle, pneumatic system, vehicle and compressed air supply system and pneumatic system for a pneumatic system with heating of at least one of the pneumatic solenoid valves

[0002] The present invention relates to a method for operating a pneumatic system of a vehicle by heating at least one of the pneumatic solenoid valves, in particular for operating a pneumatic system of a passenger car, as well as a corresponding pneumatic system, a vehicle, a compressed air supply system, and a pneumatic system for a corresponding pneumatic system.

[0003] In vehicle pneumatic systems, compressed air supply systems are used to supply pneumatic systems with compressed air. For this purpose, compressed air is supplied to the compressed air supply system via the compressed air connection by a compressed air source such as a compressor. Compressor and compressor are used synonymously in this description and refer to units that compress air. Such a compressed air source, together with the compressed air supply system and a pneumatic system, forms the pneumatic system. Such a pneumatic system is preferably controlled via an electronic control device, for example, a control unit (ECU).

[0004] Pneumatic systems include, for example, sensor cleaning systems that use compressed air as a cleaning fluid, or air spring systems that use compressed air to fill air springs. They have in common that they feature a plurality of pneumatic solenoid valves for controlling the distribution or release of the compressed air provided by the compressed air supply system.

[0005] In most vehicles, drying the compressed air supplied by the compressed air supply system for the pneumatic system is necessary to prevent frost-related malfunctions of the pneumatic solenoid valves and functional impairments at temperatures below freezing. Due to temperature fluctuations, it may also be necessary for safety reasons to provide dried compressed air even at temperatures just above freezing to prevent frost-related malfunctions of the pneumatic solenoid valves. This is particularly necessary for pneumatic solenoid valves in vehicle areas that are not permanently heated by the waste heat of a compressor or any engine.

[0006] For providing dried compressed air, air dryers with a drying substrate are also known. This drying substrate is designed to adsorb moisture from the compressed air flowing through pneumatic lines. This adsorption of moisture reliably prevents frost-related malfunctions, as the dry compressed air is not prone to condensation, and consequently, ice formation in the system is not to be expected at temperatures below freezing. This severely limits the flexibility in the design of compressed air supply systems or pneumatic systems, as it must always be ensured that only dried compressed air comes into contact with pneumatic solenoid valves in vehicle areas away from the compressor or any engine.

[0007] The operating life of the air dryer in pneumatic systems with a sensor cleaning system is limited by the saturation of the drying substrate in the air dryer. Increasing the amount of air dryer granulate requires a larger air dryer size. To increase the operating life, the air dryer in air suspension systems is regenerated using the dry system air from the air suspension system.

[0008] To utilize waste heat, WO 2022 / 017807 further discloses using the vehicle's heat source, for example an internal combustion engine or fuel cell, to heat a sensor cleaning device, i.e., a pneumatic system. Such heating can also prevent or at least reduce the occurrence of frost-related malfunctions and frost damage. A disadvantage, however, is that the waste heat only allows sufficient warming after the vehicle has been in operation for a certain period. Therefore, particularly after extended periods of downtime, there is still a risk of frost-related malfunctions upon resumption of operation due to the compressed air, which is sometimes still moist, flowing into the respective valve. Furthermore, EP 2 562 015 A2 discloses a pneumatic system designed as an air spring system, which comprises a heating device with a heating element integrated into a valve block.Although such a heating device can also prevent or at least reduce the occurrence of frost-related malfunctions, heating the valve block over a large area is inefficient and leads to a more complex structure and increased manufacturing costs.

[0009] This is where the invention comes in, the task of which is to reliably prevent frost-related malfunctions in pneumatic systems with compressed air supply systems and pneumatic systems and at the same time to increase reliable control of the compressed air in the pneumatic system and to reduce complexity.

[0010] The invention solves the problem mentioned above in a first aspect by a method for operating a pneumatic system of a vehicle, in particular a passenger car, comprising the steps:

[0011] Providing compressed air through a compressed air generator to a compressed air connection,

[0012] Leading the compressed air provided at the compressed air connection via at least one first pneumatic line to a compressed air supply connection of a compressed air supply system,

[0013] Leading the compressed air provided at the compressed air supply connection via at least one second pneumatic line of a pneumatic system connected to the compressed air supply connection,

[0014] selectively energizing one or more pneumatic solenoid valves with a heating control current for heating at least one of the pneumatic solenoid valves, and

[0015] Selectively energizing one or more of the pneumatic solenoid valves with a deflection control current that is greater than the heating control current, to deflect the solenoid valve from a home position. The possibility of heating the aforementioned valves reduces the risk of frost-related malfunctions in the pneumatic system as a whole. This applies not only to the sensor cleaning device or other pneumatic systems, but also in particular to the compressed air supply system. Using the solenoid valves for self-heating eliminates the need for additional heating elements. It should be understood that heating the solenoid valves is particularly necessary before opening, since only when the respective solenoid valve opens does moist compressed air flow through the pneumatic line, which can lead to icing and thus to frost-related malfunctions.The applied heating control current must not cause the solenoid valve to open, in order to prevent an uncontrolled supply of compressed air through the respective pneumatic line. By differentiating between a deflection control current and a heating control current, the solenoid valve is heated, but the resulting magnetic force is not sufficient to open the respective solenoid valve.

[0016] Further developments of the invention are specified in the dependent claims, which further develop the concept of the invention with regard to advantageous features within the scope of the task and with regard to further advantages.

[0017] The method preferably further comprises blocking at least one of the first and second pneumatic lines by one or more pneumatic solenoid valves energized with the heating control current. It should be understood that the solenoid valves preferably block the respective first or second pneumatic line in a basic position. These are therefore preferably normally closed solenoid valves. The magnetic force applied to the solenoid valve as a result of the heating control current acts away from the basic position towards an operating position, but this magnetic force is not sufficiently strong to actually cause the pneumatic line to be released by the solenoid valve. Energizing the solenoid valve before it actually opens prevents it from freezing due to heating of the solenoid valve, which preferably occurs continuously during operation.

[0018] More preferably, the method further comprises selectively energizing one or more of the pneumatic solenoid valves with a holding control current that is smaller than the deflection control current to apply a magnetic force. Applying the deflection control current preferably releases at least one of the first and second pneumatic lines. Applying the magnetic force by applying the deflection control current is intended to release at least one of the first and second pneumatic lines, and applying the magnetic force by applying the holding control current is intended to keep at least one of the first and second pneumatic lines free. In particular, the holding control current holds an armature of the solenoid valve in a working position or the working position deflected from the basic position to release at least one of the first and second pneumatic lines.

[0019] The strength of the force that the magnetic field exerts on the solenoid valve, particularly on an armature of the solenoid valve, at constant coil current depends on the distance of the armature relative to the magnetic field. At a greater distance, a weaker magnetic field acts. In the home position, the armature is at a greater distance from the magnetic field of the solenoid valve. In order to move the armature from the home position to the working position, an increased current is required to excite a magnetic field with a higher magnetic field strength due to this greater distance. If the armature now moves towards the working position into the magnetic field, the distance of the armature to the magnetic field decreases. In this position, a reduced control current, in this case the holding control current, is sufficient to prevent the armature from returning to its home position.By reducing the control current applied to the solenoid valve to a holding control current that is smaller than the deflection control current, the energy efficiency of the method for controlling the solenoid valve is improved.

[0020] More preferably, energizing one or more of the pneumatic solenoid valves with the heating control current comprises energizing an electrical coil to apply the magnetic force, which is smaller than a spring force applied to one or the armature of the pneumatic valve by a spring. The method is thus particularly designed for controlling directly controlled solenoid valves. In directly controlled solenoid valves, a spring force acts in the direction of the home position, and during operation, when a current is applied, a magnetic force caused by the magnetic field of the coil also acts on the armature of the solenoid valve against the direction of the home position. The armature remains in the home position until the magnetic force exceeds the spring force and then moves into the so-called working position. In the case of normally closed solenoid valves, the respective pneumatic line is released in the working position.The heating control current thus creates a magnetic field by energizing the coil, but does not deflect the armature from its home position. This ensures continued precise control of the distribution and delivery of compressed air through the solenoid valve, which can then be energized with the deflection control current after being energized with the heating control current. The heating control current is preferably less than 70% of the deflection control current. This ensures sufficient tolerance ranges to prevent unintentional release of the pneumatic line when the heating control current is applied.

[0021] Particularly preferably, the heating control current is less than 80% of the holding control current. This ensures that even if the valve opens unintentionally, it will then close automatically again, since the heating control current is below the holding control current. The reason for unintentional opening can be, for example, a brief acceleration acting on the armature in the opening direction.

[0022] Preferably, one or more of the pneumatic solenoid valves are energized with a heating control current for a predefined period of time, in particular intermittently, for a plurality of predefined periods of time. A sufficient period of time must be selected in the method so that sufficient heating is initially ensured during operation of the solenoid valve before the deflection control current is applied and compressed air flows through the solenoid valve.

[0023] According to an alternative preferred embodiment, the method for energizing one or more of the pneumatic valves with the heating control current, the deflection control current, and preferably the holding control current comprises providing a direct current from an energy source, in particular a vehicle battery, and regulating the time period or duty cycle in which the direct current is provided to the one or more solenoid valves. This process is referred to as pulse width modulation (PWM). Pulse width modulation is a type of digital modulation in which a technical variable (e.g., electrical voltage or electrical current) alternates between two values. A rectangular pulse is modulated at a constant frequency, the width, or length of which varies. The relationship between the pulse and the frequency period is referred to as the duty cycle.Although the pulse width modulation signal is an alternating voltage, or rather a mixed voltage, it can be used to regulate the power of direct current consumers such as solenoid valves that are supplied by a direct current source such as a vehicle battery. Instead of controlling these parts and components via the operating voltage or current, pulse width modulation simply interrupts the voltage or current for a short time. This creates a specific ratio between voltage or current pulses and pauses. This ratio determines the effective voltage or current. This means that the vehicle battery, for example, can be advantageously used to power the solenoid valve. It should be understood that the heating control current, the deflection control current, and the holding control current can all be effective currents.Pulse width modulation advantageously enables the use of existing power sources in the respective vehicle using direct current. This eliminates the need for additional power sources. The power supply to the solenoid valves is preferably controlled via transistors. In this case, electrical energy is usually taken from the vehicle's battery electrical system, i.e., a direct current source, and converted into magnetic energy of varying magnitude. This energy is then used to move a solenoid valve from a basic position—i.e., the position of the valve without the influence of a magnetic field—to at least one desired operating position when exposed to a magnetic field, or simply to heat the valve or to hold it in the operating position.

[0024] More preferably, the method further comprises detecting an ambient temperature of the vehicle and / or a temperature of a compressed air sensor and / or an air humidity within the pneumatic system and / or an ambient humidity and / or an electrical resistance of the coil by at least one sensor, and determining the predefined time period or the duty cycle, in particular by a control device, as a function of the ambient temperature of the vehicle and / or the temperature of the compressed air sensor and / or the air humidity within the pneumatic system and / or the ambient humidity and / or the electrical resistance. It should be understood that according to the method, the determined time period is preferably 0 seconds at temperatures above freezing, in particular above 0°C, in particular 5°C. In such a case, preheating of the solenoid valve is not necessary.Furthermore, at temperatures well below freezing, it is also possible to specify a longer period of time during which the solenoid valve is supplied with the heating control current or to specify a changed duty cycle that results in a higher effective current than the heating control current. This ensures sufficient preheating of the solenoid valve to avoid frost-related malfunctions. Monitoring the electrical resistance represents a simple method of temperature monitoring, as the resistance changes depending on the temperature. To achieve a predefined effective current, the duty cycle must be adjusted when the resistance changes depending on the temperature. Since the resistance correlates with the temperature, the temperature can also be monitored, whereby the specific period of time is preferably 0 seconds at temperatures above freezing, in particular above 5°C.

[0025] In the case of a pressure-balanced solenoid valve, the method preferably comprises, when energizing one or more of the pneumatic solenoid valves with a heating control current, further energizing an electrical coil for applying a magnetic force which is smaller than a spring force applied by a spring to one or the armature of the pneumatic solenoid valve.

[0026] In the case of a non-pressure-balanced solenoid valve, the method preferably comprises energizing one or more of the pneumatic solenoid valves with a heating control current, and further energizing an electric coil to apply a magnetic force that is smaller than a spring force applied by a spring to one or the armature of the pneumatic solenoid valve. Furthermore, the magnetic force is preferably also smaller than the difference between the spring force and a pneumatic force acting on the armature.

[0027] In non-pressure-balanced solenoid valves, not only does a magnetic force act on the armature, but a compressive force, caused by a pressure difference between the inlet and outlet of the solenoid valve, also acts on a pressure surface of the armature to deflect the armature from its home position to its working position. This compressive force may act cumulatively with the magnetic force and creates a force component acting from the armature's home position. Applying a heating control current, which generates a force acting from the armature's home position that is smaller than the difference between the spring force and the compressive force acting against the spring force, thus ensures that the solenoid valve is not inadvertently switched from its home position to its working position when a heating control current is applied.According to an alternative embodiment, the method for energizing one or more of the pneumatic solenoid valves with the heating control current, the deflection control current, and preferably the holding control current further comprises providing a corresponding variable control current by a variable energy source. A variable energy source enables the provision of a current of variable magnitude. Thus, a single energy source can optionally provide the deflection control current, the heating control current, and preferably also the holding control current. The control of this energy source for providing the respective control current preferably takes place depending on the signals from the sensor.

[0028] Preferably, the method further comprises flushing at least one of the first pneumatic lines and / or the second pneumatic lines with one or more of the pneumatic solenoid valves with compressed air dried by an air dryer and discharging the compressed air via a vent line. Flushing the pneumatic lines allows residues in the lines to be removed and, in particular, allows air with an increased moisture content to be released from the compressed air supply system to the vent connection via the vent line. This ensures that the respective solenoid valves do not suffer frost-related malfunctions or icing due to freezing residual moisture in the compressed air in the pneumatic line or the flow path of the solenoid valve, even after extended downtime.This allows the heating control current to be used solely to preheat the solenoid valve, eliminating the need to first melt any residual frozen moisture within the solenoid valve to enable operation. The time required to apply the heating control current can thus be significantly reduced, allowing for more precise control of the solenoid valve. The energy required to heat the valve is thus minimized.

[0029] In a second aspect, the invention leads to a pneumatic system according to claim 10. The invention proposes a pneumatic system of a vehicle, in particular a passenger car, with a compressed air generator, in particular a compressor, for providing compressed air at a compressed air connection, a compressed air supply system connected to the compressed air generator via the compressed air connection for providing compressed air at a compressed air supply connection, which compressed air supply system has at least one first pneumatic line, a pneumatic system connected to the compressed air supply connection of the compressed air supply system with at least one second pneumatic line, and a plurality of pneumatic solenoid valves which are designed to selectively block and release at least one of the first and second pneumatic lines.The invention achieves the object mentioned at the outset according to the second aspect by means of a control device which is control-technically connected to the pneumatic solenoid valves and which is designed to selectively supply one or more of the pneumatic solenoid valves with a heating control current, a deflection control current and preferably a holding control current, wherein the pneumatic solenoid valves are designed to heat up when a heating control current is applied and to release at least one of the first and second pneumatic lines when a deflection control current is applied, wherein the deflection control current is greater than the heating control current. The holding control current, in turn, is smaller than the deflection control current. The possibility of heating up the said valves reduces the risk of frost-related malfunctions in the pneumatic system as a whole. This applies not only to the sensor cleaning device orother pneumatic systems, in particular the compressed air supply system. Utilizing the existing coil of the solenoid valves eliminates the need for additional heating elements. Such a pneumatic system utilizes the advantages described above with regard to the method. Preferred embodiments and advantages according to the first aspect of the invention are thus also preferred embodiments and advantages according to the second aspect of the invention, and vice versa.

[0030] The solenoid valve is preferably a directional control valve. Directional control valves are used in pneumatic systems to control, i.e., to direct or stop, the flow of compressed air within a compressed air supply system and to or within a pneumatic system. The directional control valves can preferably have two or more pneumatic connections and perform various circuit functions. The pneumatic solenoid valves preferably each comprise a coil for generating a magnetic force, a valve seat, a spring for applying a force towards the valve seat, and an armature. The armature is movable by the magnetic force against the spring force and is configured to be moved away from the valve seat against the spring force when the deflection control current is applied to the coil. When the heating control current is applied to the coil, the coil is configured to heat the pneumatic solenoid valve.

[0031] The pneumatic solenoid valve preferably comprises a magnetic part and a pneumatic part. The pneumatic part preferably comprises a housing with a mostly cylindrical recess. Furthermore, the pneumatic part has one or more pneumatic connections connected to the cylindrical recess. The pneumatic connections comprise a first compressed air passage and a second compressed air passage. By moving the armature back and forth through the recess, various pneumatic connections can be connected or closed. The magnetic part preferably has the electrical coil and the armature, which can be actuated magnetically and under the influence of a spring force and is movably received in the cylindrical recess. Furthermore, the magnetic part preferably has a fixed, magnetizable core. An air gap is formed between the armature and the core. The air gap defines the possible stroke of the armature.In the pneumatic part, in particular in the cylindrical recess, an abutment surface pointing in the direction of the armature is preferably formed.

[0032] The solenoid valve is preferably directly controlled. In directly controlled solenoid valves, the armature is held in at least one basic position by a spring force and, when the deflection control current is applied to the electrical coil, is deflected from the basic position into one or more operating positions solely by the resulting magnetic field. More preferably, the solenoid valve is a monostable solenoid valve. When the power supply is interrupted, the monostable solenoid valve, also referred to as a "single-acting" solenoid valve, returns to a single, predefined basic position. The force required to move the armature can be relatively low in monostable solenoid valves, since air pressure has only a minor influence on the force required to deflect the armature. The spring force can also be selected to be relatively low in monostable solenoid valves. Therefore, the solenoid valves generally consume very little power.Alternatively, the solenoid valve can be a bistable solenoid valve. Bistable solenoid valves have two basic positions to which the armature can return. The solenoid valve is preferably designed to block the respective pneumatic line in at least one of the basic positions. Preferably, the first pneumatic lines or the first pneumatic line comprise a pneumatic main line for conducting compressed air from the compressed air connection to the compressed air supply connection, and at least one pneumatic solenoid valve is arranged in the pneumatic main line. Thus, solenoid valves arranged in the pneumatic main line—and thus relevant for the compressed air supply—are also protected from frost-related malfunctions.

[0033] According to a preferred embodiment, the compressed air supply system has a vent connection for venting the compressed air supply system, wherein the first pneumatic lines comprise a pneumatic main line and a vent line leading from the pneumatic main line to the vent connection, and at least one of the pneumatic solenoid valves is designed as a vent valve and arranged in the vent line. Due to its arrangement in the vent line near the vent connection, the vent valve is significantly exposed to weather influences. Designing such a vent valve to heat up when a control current is applied reduces the risk of frost-related malfunctions.

[0034] The pneumatic system preferably comprises a switching device which is designed to regulate a control current provided to the solenoid valve, in particular direct current from a direct current source, by means of pulse width modulation. By regulating the control current, the switching arrangement is preferably designed to selectively provide a heating control current, a deflection control current, and preferably a holding control current to the solenoid valve. Further preferably, the switching device is designed to communicate with the control device such that the control device controls a power supply to the switching device. Further preferably, the control device is connected to a power source, in particular a direct voltage source, such as a vehicle battery, and is designed to connect the direct voltage source to the switching device.The switching device preferably has at least one transistor for pulse width modulation.

[0035] In a third aspect, the invention leads to a pneumatic system according to claim

[0036] 14. The invention proposes a pneumatic system for a pneumatic system, in particular a pneumatic system according to the second aspect of the invention, comprising a compressed air consumer that can be connected to a compressed air supply connection for supply by a compressed air supply system, one or more (second) pneumatic lines, and a plurality of pneumatic solenoid valves configured to distribute and discharge the compressed air provided at the compressed air supply connection by selectively blocking and releasing at least one of the pneumatic lines. The pneumatic system is configured for control-related connection to a control device.The control device is designed to selectively supply one or more of the pneumatic solenoid valves with a heating control current and a deflection control current, wherein the pneumatic solenoid valves are designed to heat up when a heating control current is applied and to release at least one of the pneumatic lines when a deflection control current is applied, wherein the deflection control current is greater than the heating control current. By means of appropriately designed solenoid valves and the connectability to the control of a corresponding pneumatic system, the pneumatic system incorporates the advantages described with regard to the second aspect of the invention. Embodiments and advantages described with regard to the second aspect of the invention are therefore also preferred embodiments and advantages of the pneumatic system.

[0037] In a fourth aspect, the invention leads to a compressed air supply system according to claim 15. The invention proposes a compressed air supply system for a pneumatic system, in particular a pneumatic system according to the second aspect of the invention, comprising a compressed air connection for connection to a compressed air generator configured to provide compressed air, a compressed air supply connection for connection to a pneumatic system, one or more (first) pneumatic lines, and a plurality of pneumatic solenoid valves configured to distribute and discharge the compressed air provided at the compressed air connection by selectively blocking and releasing at least one of the pneumatic lines. The compressed air supply system is configured for control-related connection to a control device.The control device is designed to selectively supply one or more of the pneumatic solenoid valves with a heating control current and a deflection control current, wherein the pneumatic solenoid valves are designed to heat up when a heating control current is applied and to release at least one of the pneumatic lines when a deflection control current is applied, wherein the deflection control current is greater than the heating control current. Through appropriately designed solenoid valves and the connectability to the control of a corresponding pneumatic system, the compressed air supply system incorporates the advantages described in relation to the second aspect of the invention. Embodiments and advantages described in relation to the second aspect of the invention are therefore also preferred embodiments and advantages of the compressed air supply system.

[0038] In a fifth aspect, the invention provides a vehicle, in particular a passenger car according to claim 16, with a pneumatic system according to the second aspect of the invention. By means of a corresponding pneumatic system, the vehicle incorporates the advantages described in relation to the second aspect of the invention. Embodiments and advantages described in relation to the second aspect of the invention are therefore also preferred embodiments and advantages of the vehicle according to the fifth aspect.

[0039] Embodiments of the invention are now described below with reference to the drawing. These are not necessarily intended to represent the embodiments to scale; rather, where useful for explanation, the drawing is schematic and / or slightly distorted. With regard to additions to the teachings immediately apparent from the drawing, reference is made to the relevant prior art. It should be noted that numerous modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, in the drawing and in the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of ​​the invention is not limited to the exact form or detail of the preferred embodiment shown and described below, or limited to an object that would be limited compared to the object claimed in the claims. In the case of specified dimensioning ranges, values ​​lying within the stated limits are also intended to be disclosed as limit values ​​and to be used and claimed as desired. Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawings, which show:

[0040] FIG. 1 shows a vehicle with a pneumatic system in a perspective view;

[0041] FIG. 2 shows a circuit diagram of a pneumatic system according to a first embodiment;

[0042] FIG. 3 shows a solenoid valve for a pneumatic system according to FIG. 2;

[0043] FIG. 4 shows a switching device for switching a solenoid valve according to FIG. 3 according to a first embodiment;

[0044] FIG. 5 shows a switching device for switching a solenoid valve according to FIG. 3 according to a second embodiment;

[0045] FIG. 6 is an exemplary diagram of the position of the solenoid valve according to FIG. 3 depending on the control by the switching device according to FIG. 4;

[0046] FIG. 7 shows a method for operating a pneumatic system according to FIG. 2 according to a first embodiment; and

[0047] FIG. 8 shows a method for operating a pneumatic system according to FIG. 2 according to a second embodiment.

[0048] FIG. 1 shows a vehicle 1000, in particular a passenger car 1100, with a pneumatic system 1200, which is shown in detail in FIG. 2 and FIG. 3.

[0049] FIG. 2 shows a vehicle 1000, in particular a passenger car 1100, in a schematic circuit diagram. The passenger car 1100 comprises a pneumatic system 1200 with a compressed air supply system 100 and a pneumatic system 300 connected to the compressed air supply system 100 via a compressed air supply connection 2, and a compressed air generator 200 for providing compressed air 120. The compressed air generator 200 here comprises a compressor 202 with an electric motor 203 and is connected to the compressed air supply system 100 via the compressed air connection 1.

[0050] The compressed air supply system 100 comprises a number of first pneumatic lines 10 for conducting the compressed air 120, which comprise a pneumatic main line 12. The compressed air connection 1 is connected to a compressed air supply connection 2 via the pneumatic main line 12. The pneumatic system 300 is connected to the compressed air supply system 100 via the compressed air supply connection 2 and has one or more second pneumatic lines 316 for conducting the compressed air 120. Furthermore, the compressed air supply system 100 preferably has an air dryer 5 arranged in the pneumatic main line 12.

[0051] Furthermore, the first pneumatic lines 10 comprise a vent line 13.1 leading from the pneumatic main line 12 to a vent connection 3. The vent connection 3 is configured to vent the pneumatic main line 12.

[0052] The vent valve arrangement 23 has a control valve 23.5, which is designed as a solenoid valve 20, in particular in the form of a 3 / 2-way solenoid valve. Furthermore, a vent valve 23.1 is designed as a pneumatically actuated vent valve 23.1. The control valve 23.5 can be controlled via electrical control signals in the form of a voltage and / or current signal. When controlled, the control valve 23.5 can be moved from a normally closed position to a pneumatically open position, in which a pressure derived from the pneumatic main line 12 via a pneumatic control line 23.5A is passed on to the pneumatic control of the controllable vent valve 23.1 by means of a bypass 23.5B.

[0053] When closed, the control valve 23.5 separates the control line 23.5A and is pneumatically connected to the vent port 3 via a further pneumatic line 23.5C. The vent line 13.1 is a first vent line 13.1 in the present case, and the compressed air supply system 100 further comprises a compressor vent line 13.2. The compressor vent line 13.2 branches off from the pneumatic main line 12 upstream of a main line switching valve 25. The main line switching valve 25 is also preferably designed as a solenoid valve 20. The vent valve arrangement 23 further comprises a compressor vent valve 23.4 in the compressor vent line 13.2, which is preferably designed as a solenoid valve 20. The line volume between the compressed air generator 200, in this case preferably a compressor 202, and the main line switching valve 25 can be vented through the compressor vent line 13.2.The starting resistance for compressor 202 is thus reduced.

[0054] The vent valve 23.1 can preferably also be designed as a solenoid valve 20, in particular a normally closed solenoid valve.

[0055] The pneumatic system 300, which in this case is a sensor cleaning device 301, further comprises a first nozzle valve 302 and a second nozzle valve 303, which are configured to selectively block the second pneumatic lines 316 and represent the compressed air receivers of the pneumatic system 300. The nozzle valves 302, 303 are also designed as solenoid valves, in particular normally closed solenoid valves 20.

[0056] The pneumatic system 1200 further comprises a control device 1300 for controlling the compressed air supply system 100 and preferably the pneumatic system 300. The control device 1300 is configured to control the main line switching valve 25 for selectively releasing the main line 12, optionally the vent valve 23.1 for selectively releasing the vent line 13.1 or the compressor vent valve 23.4 for selectively releasing the compressor vent line 13.2.

[0057] The control device 1300 is preferably connected via a first signal line S1 to a sensor 9, which is preferably configured to monitor a temperature T of the compressed air generator 200. Alternatively or additionally, the or a further sensor 9 can be arranged at a different position and configured to monitor an outside temperature Tu. Alternatively or additionally, the or a further sensor 9 can be arranged at a different position and configured to monitor a humidity H within the pneumatic system 1200 or an ambient humidity Hu. The signal line S1 can be either wired or wireless. Furthermore, the control device 1300 is preferably connected via a second signal line S2 to the main line switching valve 25, via a third signal line S3 to the control valve 23.5, and via a fourth signal line S4 to the compressor vent valve 23.4.Furthermore, the control device 1300 is preferably connected to the pneumatic system 300, in particular the nozzle valves 302, 303, via a fifth signal line S5. The control device is connected to the compressed air generator 200 by means of a signal line S6. The signal lines S2, S3, S4, and S5 are wired and configured to conduct a current or control current Si (see FIG. 3).

[0058] The control device 1300 shown in FIG. 2 is connected to a power source 1400. The power source 1400 can be a direct current source, such as a vehicle battery 35 (see FIG. 4). In FIG. 2, the power source 1400 is preferably a variable power source 1410.

[0059] Regardless of the type of energy source 1400, the control device 1300 is configured to provide a control current Si equal to a deflection control current S11 (see FIG. 3) for opening the compressor vent valve 23.4, the control valve 23.5, and the main line switching valve 25 or the nozzle valves 302, 303. Furthermore, the control device 1300 is also configured to apply a heating control current S12 to one, several, or all of these valves.

[0060] A solenoid valve 20 is shown as an example in Fig. 3.

[0061] The solenoid valve 20 comprises a magnetic part 305 and a pneumatic part 306. The magnetic part 305 has an electrical coil 307 with an electrical resistance R (see FIG. 4), an armature 308.1 that can be actuated magnetically and under the influence of a spring force, and a fixed, magnetizable core 308.2. An air gap 309 is formed between the armature 308.1 and the core 308.2, which defines the possible stroke of the armature 308.1. The pneumatic part 306 comprises a first compressed air passage 310 and a second compressed air passage 311. The pneumatic part 306 further comprises a valve stem part.

[0062] 312, which has an abutment surface 313 pointing in the direction of the armature 308.1.

[0063] The solenoid valve 20 further comprises a valve spring 314, which is designed to exert a spring force FF in the direction of the valve stem part 312, in particular the abutment surface

[0064] 313, to be applied to the armature 308.1. In the open state of the solenoid valve 20, the armature 308.1 is spaced from a valve seat 315 of the pneumatic part 306.

[0065] The armature 308.1 is movably received in the magnetic part 305 and the pneumatic part 306. By energizing the electrical coil 307, it generates a magnetic field with a magnetic force FM. The resulting magnetic field generates a magnetic pole on the core 308.2, which attracts the armature 308.1 and moves it away from the valve seat 315 against the spring force FF of the valve spring 314, so that the first compressed air passage 310 and the second compressed air passage 311 are fluidly connected. The magnitude of the magnetic force FM depends on the applied control current Si, which is provided by the control device 1300. The deflection control current Sn required to open the solenoid valve 20 is greater than the holding control current Si3 required to hold the solenoid valve 20 in the open position. The magnitude of the force exerted by a magnetic field induced by the coil 307 on the armature 308.1 at a constant current depends on the distance of the armature 308.1 relative to the magnetic field, i.e. the size of the air gap 309 between armature 308.1 and core 308.2. At a greater distance, a weaker magnetic field acts. In the closed position, armature 308.1 is initially at a greater distance from the magnetic field, so that an increased current, namely a deflection control current Sn, is provided. The deflection control current Sn required to open solenoid valve 20 refers to the current required to reduce the distance between armature 308.1 and core 308.2 and thus the air gap 309. As soon as armature 308.1 moves into an open position, its distance from the magnetic field is reduced and a lower holding control current Si3 is sufficient to hold armature 308.1 in this position.Preferably, the control device 1300 is further configured to apply a heating control current S12 to the solenoid valve 20, which is smaller than the deflection control current S11, in particular also smaller than the holding control current S13, such that the solenoid valve 20 is heated in the closed state by the generated magnetic field. When the coil 307 is energized, magnetic fields are generated, which actuate the armature 308.1. If the energy source 1400 (see FIG. 2) is a direct current source instead of a variable energy source 1410 (see FIG. 2), the current supply to the coil 307 is controlled via a switching device 30 for PWM control, which is shown as an example in FIG. 4 and FIG. 5.

[0066] The current waveform of the direct current I in mA and the resulting positions—i.e., the basic position G and the working position A—of the solenoid valve 302 are shown in FIG. 6.

[0067] According to FIG. 4, to release the pneumatic line 10 (see FIG. 2), the power supply from a DC voltage source 35, in this case a vehicle battery 35, with a battery voltage of Ußat = 12 V, to the coil 307 is controlled via pulse width modulation (PWM). This PWM is implemented using a switching device 30.

[0068] The switching device 30 preferably comprises a first switching arrangement 31, for example, a transistor T1. This transistor T1 is preferably an n-channel MOS-FET with a DRAIN terminal D(T1) connected to the coil 307 and a SOURCE terminal S(T1) connected to ground M.

[0069] In PWM operation, the deflection control current Sn, the heating control current Si2, and the holding control current Si3 (see FIG. 3) are determined depending on a duty cycle Tein or a time period t during which the coil 307 is supplied with energy from the DC voltage source 35. The duty cycle Tein is defined as the ratio of the time period ton to the period of the PWM frequency. A preferred frequency of the switching device 30 in PWM operation is between 200 Hz and 2000 Hz. The operation is explained below using a normally closed solenoid valve as an example.

[0070] With an exemplary frequency of the switching device 30 in PWM operation of 1000 Hz and a duty cycle Tein of approximately 80%, this would lead to a time period ton of 0.80 ms in which the coil 307 is supplied with energy from the DC voltage source 35 and to a time period t ausof 0.2 ms, during which the coil 307 is not supplied with energy from the DC voltage source 35. A deflection duty cycle Tein = T n of approximately 80% + / - 5% or a time period ton = tu of 0.80 ms is suitable, for example, as the deflection control current Sn. For the holding control current S13, a holding duty cycle Tein = T 13 is preferably lower and is approximately 40% + / - 5%. A heating duty cycle Tein = T 12 for the heating control current S12 is preferably in a range of approximately 30% to 56% + / - 5%, in particular 30% to 40% + / - 5%, and is thus in any case lower than the deflection control current Sn or also lower than the holding current S13. The heating duty cycle T 12 preferably corresponds to 70% to 80% of the holding duty cycle T 13. The effective heating control current S12 caused by such a heating duty cycle T 12 is not sufficient to move the armature 308.1 from the basic position G into an operating position A, but leads to heating of the coil 307 and thus of the solenoid valve 302.

[0071] When transistor T1 is switched on, the current in coil 307 and thus the magnetic force acting on armature 308.1 initially builds up. If transistor T1 is then alternately switched on for the time period ton and off for the time period t aus switched off again, the armature 308.1 of the solenoid valve 302 (see FIG. 3) in the coil 307 experiences a reduced effective current due to the inertia of the structure.

[0072] When the transistor T1 is switched on in a clocked manner for a necessary deflection control current S11 of, for example, 1.2 A and an electrical resistance R of the coil 307 of 8 Ohm and a voltage UBAT of 12 V, a necessary deflection duty cycle Tn of at least 80% results.

[0073] The specific time span tein = tu is determined based on the deflection duty cycle Tn and the period length (= t ein + t aus ) certainly.

[0074] At a deflection duty cycle Tn of at least 80%, the coil 307 finally experiences a maximum effective current due to the inertia of the structure, for example 1.2 A, which corresponds to the deflection control current Sn, so that the armature 308.1 moves into its working position (see FIG. 3). In the working position A, the armature 308.1 can now also be held with a reduced holding control current S13 due to the changed distance relative to the core 308.2 and thus the magnetic field. If temperatures are close to freezing, the application of the deflection control current S11 can be preceded by an alternating switching on of the transistor T1 to apply a heating control current S12. In this case, the transistor T1 is switched on for a time period tein = ti2 with a heating duty cycle T12 of preferably 30%. As a result, the armature 308.1 of the solenoid valve 302 (see FIG.3) Due to the inertia of the structure, a reduced current flows in coil 307, which corresponds to the heating control current S12, and the armature 308.1 is heated by this heating control current S12.

[0075] If, for example, after a holding time of the deflection control current of 50 ms, the transistor T1 is alternately switched on to apply a holding control current S13 with a time period for switching on tein = ti3 and a corresponding time period for switching off t aus This results in a holding duty cycle T13 of preferably 40%. Due to the inertia of the structure, the armature 308.1 of the solenoid valve 302 (see FIG. 3) in the coil 307 experiences a reduced current, which corresponds to the holding control current S13, and the armature 308.1 is held in the working position A by this holding control current S13.

[0076] Preferably, the deflection control current is 1.2A, the heating control current is 0.45A and the holding control current is 0.6A.

[0077] A diode 37 is connected in parallel to the coil 307 and helps to draw off the coil current to block the pneumatic line 10 (see FIG. 2).

[0078] The illustration according to FIG. 5 differs from the illustration according to FIG. 4 in that it shows a freewheeling device 32, in particular a freewheeling transistor T2, which is connected in parallel with the coil 307 in order to preserve the energy in the coil 307. The freewheeling transistor T2 comprises a SOURCE terminal S(T2) and a DRAIN terminal D(T2), wherein the DRAIN terminal D(T2) is connected to the DC voltage source 35 and maintains the current flow during the PWM control in the coil 307. Anti-serial to this freewheeling transistor T2, in FIG. 5, a SOURCE terminal S(T3) of a clamping device 33, in particular a quenching or clamping transistor T3, is preferably connected to its SOURCE terminal S(T2) thereof. During the long-term switching-OFF of the magnetic field tAB (tAB » tpwiviaus, tAB - 1 -2 ms), the quenching or clamping transistor T3 quickly draws the current from the coil 307, so that the solenoid valve 302 moves back from the working position to the basic position G.The clamping transistor T3 has an anti-serial diode pair 34 and acts like a Zener diode during the turn-off process, which is realized with the help of the anti-serial diode pair 34. For example, to block the pneumatic line 10 (see FIG. 2), the coil current is quickly withdrawn. The DRAIN terminal D(T3) of the clamping transistor T3 is connected to the coil 307. The duration of the turn-off process tAB until the pneumatic line 10 is blocked again by the solenoid valve 302 in the basic position G is determined by the voltage of the clamping transistor T3. Thus, the diode 37 in FIG. 5 is replaced.

[0079] FIG. 7 shows a method 2000 for operating a pneumatic system 1200, which can also be used analogously to operate a compressed air supply system 100 or a pneumatic system 300 alone. It should be understood that the method 2000 or individual method steps, in particular relating to the supply of current, are therefore not limited to the operation of a pneumatic system 1200 according to FIG. 2.

[0080] The method 2000 comprises, in a first step 2100, the provision of compressed air 120 (cf. FIG. 2) by a compressed air generator 200 at a compressed air connection 1 and, in a second step 2200, the routing of the compressed air 120 (cf. FIG. 2) provided at the compressed air connection 1 via at least one first pneumatic line 10 to a compressed air supply connection 2 of a compressed air supply system 100. If the method 2000 is not used solely to operate a compressed air supply system 100, the method 2000 comprises, in a third step 2300, the routing of the compressed air 120 (cf. FIG. 2) provided at the compressed air supply connection 2 via at least one second pneumatic line of a pneumatic system 300 connected to the compressed air supply connection 2.Preferably carried out simultaneously therewith, the method 2000 preferably further comprises in step 2500 the detection of an ambient temperature Tu of the vehicle 1000 and / or a temperature T of a compressed air generator 200 and / or an air humidity H within the pneumatic system 1200 or the compressed air supply system 100 or the pneumatic system 300 and / or an ambient humidity Hu by at least one sensor 9 (cf. FIG. 2).

[0081] Furthermore, the method in step 2600 comprises determining a heating control current S12 and / or a time period tein, in which the solenoid valve(s) 20 are energized to apply the predefined heating control current S12. Step 2600 is preferably carried out by the control device 1300 (see FIGS. 2 and 5) depending on the ambient temperature Tu of the vehicle 1000, and / or the temperature T of the compressed air sensor 200, and / or the air humidity H, and / or the ambient humidity Hu, and / or the electrical resistance R of the coil 307, and / or the resulting duty cycle Tein. The direct determination of a required heating current Si2 can be carried out, for example, when using a variable voltage source 1410, so that the heating current S12 can be set directly. The control of the effective heating current St over the time period ton, however, enables control when using a DC voltage source, for example the battery 35, by means of a PWM.

[0082] Following the third step 2300 and preferably steps 2500 and 2600, the method in step 2400 comprises energizing one or more pneumatic solenoid valves 20 with a heating control current S12, a deflection control current S11 and preferably a holding control current S13. The energization in step 2400 preferably comprises, in a first sub-step 2410, the provision of a direct current I (cf. FIG. 4) by an energy source 1400, in particular a vehicle battery 35, and the regulation of a duty cycle Tein, Tu, T12, T13 of a switching device 30 or a time period tein attributable to the duty cycle Tein, Tu, T12, T13 at one or more pneumatic solenoid valves 20, in particular by pulse duration modulation, depending on whether a heating control current S12, a deflection control current S11, or a holding control current S13 is required. The duty cycle Tein, Tu, T12, T13 is determined as explained with reference to FIG. 4 to FIG. 6.

[0083] Subsequently, in sub-step 2420, the method 2000 comprises selectively energizing one or more pneumatic solenoid valves 20 with a heating control current S12 to heat at least one of the pneumatic solenoid valves 20, and in a third sub-step 2430, selectively energizing one or more of the pneumatic solenoid valves 20 with a deflection control current S11 that is greater than the heating control current S12 to deflect the solenoid valve 20 from a home position G (see FIG. 6), which, when the solenoid valve is normally closed, leads to the release of at least one of the first and second pneumatic lines 10, 316. In sub-step 2430, the armature 308.1 is preferably deflected from its home position G into a working position A (see FIG. 3).

[0084] The energization with the heating control current S12 in sub-step 2420 preferably comprises, in step 2421, the blocking of at least one of the first and second pneumatic lines 10, 316 by one or more pneumatic solenoid valves 20 energized with the heating control current S12.

[0085] In a further sub-step 2440, the method 2000 further comprises selectively energizing one or more of the pneumatic solenoid valves 20 with a holding control current S13 that is smaller than the deflection current S11, to apply a magnetic force to maintain the release of at least one of the first and second pneumatic lines 10, 316. In sub-step 2440, the armature 308.1 is preferably held in a working position A (see FIG. 3).

[0086] In a further sub-step 2450, the method 2000 preferably further comprises monitoring the current I applied to the coil 307.

[0087] It should be understood that one or more of the sub-steps 2420, 2430, 2440, 2450 can preferably be carried out one after the other in a varying order or even repeatedly.

[0088] After energizing the solenoid valves 20 with various control currents Si in step 2400, the method 2000 preferably further comprises, in step 2700, flushing at least one of the first pneumatic lines 10 and / or the second pneumatic lines 316 with one or more pneumatic solenoid valves 20 with compressed air 120 (see FIG. 2) dried by an air dryer 5 (see FIG. 2) and venting the compressed air 120 (see FIG. 2) via a vent line 13.1 (see FIG. 2). Thus, the pneumatic system 1200 or the compressed air system 100 or the pneumatic system 300 is cleaned of residues of moist compressed air 120 (see FIG. 2) in the pneumatic lines 10, 316 and in particular the solenoid valves 20. FIG. 8 shows a second embodiment of the method 2000', which differs only in the first sub-step 2410' of energizing one or more solenoid valves 20 with different control currents Si in step 2400.With regard to the remaining method steps, reference is made to the description of FIG. 7. Identical method steps have identical reference numerals here. In sub-step 2410' according to method 2000', a corresponding control current Si (see FIG. 3) is provided by a variable energy source 1410 (see FIG. 2). Thus, the control currents Si are controlled directly via the variable energy source 1410, and no additional pulse duration modulation is required.

[0089] Reference symbol (part of the description)

[0090] 1 Compressed air connection 2 Compressed air supply connection 3 Vent connection 5 Air dryer 9 Sensor 10 Pneumatic lines 12 Pneumatic main line 13.1 Vent line 13.2 Compressor vent line 20 Solenoid valve 23 Vent valve assembly 23.1 Vent valve 23.4 Compressor vent valve 23.5 Control valve 23.5A Control line 23.5B Bypass 23.5C Pneumatic line 25 Main line switching valve 30 Switching device 31 Switching assembly 32 Freewheel device 33 Clamping device 34 Diode pair 35 DC voltage source, vehicle battery 37 Diode 100 Compressed air supply system 120 Compressed air 200 Compressed air sensor 202 Compressor 203 Electric motor 300 Pneumatic system 301 Sensor cleaning device 302 First nozzle valve 303 second nozzle valve

[0091] 304 2 / 2-way valve

[0092] 305 magnetic part

[0093] 306 Pneumatic part

[0094] 307 coil

[0095] 308.1 actuatable anchor

[0096] 308.2 magnetizable core

[0097] 309 Air gap

[0098] 310 first compressed air passage

[0099] 311 second compressed air passage

[0100] 312 valve stem part

[0101] 313 impact surface

[0102] 314 valve spring

[0103] 315 valve seat

[0104] 316 second pneumatic lines

[0105] 1000 vehicles

[0106] 1100 passenger cars

[0107] 1200 pneumatic system

[0108] 1300 control device

[0109] 1400 Energy source

[0110] 1410 variable energy source

[0111] 2000, 2000' procedure

[0112] 2100 Provision of compressed air

[0113] 2200 Supplying compressed air via a first pneumatic line

[0114] 2300 Supplying compressed air via second first pneumatic line

[0115] 2400 Energizing pneumatic solenoid valves with a control current

[0116] 2410 Providing a direct current

[0117] 2410' Providing a variable control current

[0118] 2420 Energizing pneumatic solenoid valves with a heating control current

[0119] 2421 Blocking at least one of the first and second pneumatic lines

[0120] 2430 Energizing pneumatic solenoid valves with a deflection control current

[0121] 2440 Energizing pneumatic solenoid valves with a holding control current

[0122] 2450 Monitoring the coil current 2500 Detecting an ambient temperature and / or a temperature of the

[0123] compressed air sensor and / or humidity

[0124] 2600 Determining the predefined time period and / or a heating current

[0125] 2700 Flushing at least one of the first and second pneumatic lines

[0126] A Working position

[0127] G Basic position

[0128] T Temperature

[0129] Tu ambient temperature

[0130] H Humidity

[0131] Hu ambient humidity

[0132] FF spring force

[0133] FM magnetic force

[0134] 51 first signal line

[0135] 52 second signal line

[0136] 53 third signal line

[0137] 54 fourth signal line

[0138] 55 fifth signal line

[0139] 56 sixth signal line

[0140] Si control current

[0141] Sn deflection control current

[0142] 512 Heating control current

[0143] 513 Holding control current

[0144] Tein duty cycle

[0145] Tu deflection duty cycle

[0146] T12 Heating duty cycle

[0147] T13 Hold duty cycle t Time ton Time span switch on toff Time span switch off

[0148] I Current

[0149] U voltage

[0150] R electrical resistance

[0151] M mass

[0152] T1 transistor

[0153] T2 Transistor T3 Transistor

Claims

Patent claims 1. Method (2000, 2000') for operating a pneumatic system (1200) of a vehicle (1000) by heating at least one pneumatic solenoid valve of the system, in particular a passenger car (1100), comprising the steps: Providing (2100) compressed air (120) by a compressed air generator (200) at a compressed air connection (1 ), Leading (2200) the compressed air (120) provided at the compressed air connection (1) via at least one first pneumatic line (10) to a compressed air supply connection (2) of a compressed air supply system (100), guiding (2300) the compressed air (120) provided at the compressed air supply connection (2) via at least one second pneumatic line (316) of a pneumatic system (300) connected to the compressed air supply connection (2), energizing (2420) one or more pneumatic solenoid valves (20) selectively with a heating control current (S12) for heating at least one of the pneumatic solenoid valves (20), and Selectively energizing (2430) one or more of the pneumatic solenoid valves (20) with a deflection control current (S11) which is greater than the heating control current (S12) in order to deflect the pneumatic solenoid valve (20) from a basic position (G).

2. Method (2000, 2000') according to claim 1, wherein the deflection of the pneumatic solenoid valve (20) from the basic position (G) leads to the release of at least one of the first and second pneumatic lines (10, 316), and the method (2000, 2000) further comprises: Blocking (2421) at least one of the first and second pneumatic lines (10, 316) by one or more of the pneumatic solenoid valves (20) supplied with the heating control current (S12).

3. The method (2000, 2000') according to claim 1 or 2, further comprising: Releasing at least one of the first and second pneumatic lines (10, 316) by selectively energizing (2440) one or more of the pneumatic solenoid valves (20) with a holding control current (S13) which is smaller than the deflection control current (S11) to apply a magnetic force (FM(SI2)), wherein the holding control current (S13) in particular holds an armature (308) of the solenoid valve (20) for releasing at least one of the first and second pneumatic lines (10, 316) in a working position (A) deflected from a basic position (G).

4. Method (2000, 2000') according to one of the preceding claims, characterized in that the energizing (2420) of one or more of the pneumatic solenoid valves (20) with the heating control current (S12) comprises energizing an electrical coil (307) for applying a magnetic force (FM (S12)) which is smaller than a spring force (FF) applied by a spring (314) to one or the armature (308) of the pneumatic solenoid valve (302).

5. Method (2000, 2000') according to claim 4, characterized in that the heating control current (S12) is less than 70% of the deflection control current (S11), and / or the heating control current (S12) is less than 80% of the holding control current (S13).

6. Method (2000, 2000') according to one of the preceding claims, characterized in that the energizing (2420) of one or more of the pneumatic solenoid valves (20) with the heating control current (S12), the deflection control current (S11) and preferably the holding control current (S13) comprises the provision of a direct current (I) by an energy source (1400), in particular a vehicle battery (35), and regulating a time period (tein), in particular a duty cycle (Tein), in which the direct current (I) is provided to the one or more solenoid valves (20).

7. Method (2000, 2000') according to one of the preceding claims, wherein for energizing (2420) with the heating control current (S12) one or more of the pneumatic solenoid valves (20) are energized for a predefined period of time (ti2) and the method (2000, 2000') further comprises: Detecting (2500) an ambient temperature (Tu) of the vehicle (1000) and / or a temperature (T) of the compressed air sensor (200) and / or an air humidity (H) within the pneumatic system (1200) and / or an ambient air humidity (Hu) by at least one sensor (9) and / or an electrical resistance (R) of the coil (307) and / or a duty cycle (Tein), Determining (2600) the predefined time period (ti2) and / or a heating current (S12), in particular by a control device (1300), depending on the ambient temperature (Tu) of the vehicle (1000) and / or the temperature of the compressed air generator (200) and / or the air humidity within the pneumatic system (1200) and / or the ambient air humidity (Hu) and / or the electrical resistance (R) of the coil (307) and / or the duty cycle (Tein).

8. Method (2000, 2000') according to one of the preceding claims, characterized in that the method (2000, 2000') for energizing (2420) one or more of the pneumatic solenoid valves (20) with the heating control current (S12), the deflection control current (S11) and preferably the holding control current (S13) comprises: Providing (2410') a variable control current (Si) by a variable energy source (1410), or Providing (2410) a direct current (I) by an energy source (1400), in particular a vehicle battery (35), and regulating a time period (t) in which the direct current (I) is provided to the one or more solenoid valves (20) by pulse width modulation (PWM).

9. Method (2000, 2000') according to one of the preceding claims, further comprising: Flushing (2700) at least one of the first pneumatic lines (10) and / or the second pneumatic lines (316) with one or more of the pneumatic solenoid valves (20) with dried compressed air (120) and discharging the compressed air (120) via a vent line (13.1).

10. Pneumatic system (1200) of a vehicle (1000), in particular a passenger car (1100), with a compressed air generator (200), in particular a compressor (202), for providing compressed air (120) at a compressed air connection (1), a compressed air supply system (100) connected to the compressed air generator (200) via the compressed air connection (1) for providing compressed air (120) at a compressed air supply connection (2), which has at least one first pneumatic line (10) for conducting compressed air (120), a pneumatic system (300) connected to the compressed air supply connection (2) of the compressed air supply system (100), having at least one second pneumatic line (10) for conducting compressed air, a plurality of pneumatic solenoid valves (20) which are designed to selectively block and release at least one of the first and second pneumatic lines (10), characterized by a control device (1300) which is connected to at least one of the pneumatic solenoid valves (20) for control purposes and which is designed to selectively supply one or more of the pneumatic solenoid valves (20) with a heating control current (S12) and a deflection control current (S11), wherein the pneumatic solenoid valves (20) are designed to heat up when a heating control current (S12) is applied and to be deflected from a basic position (G) when a deflection control current (S11) is applied, wherein the deflection control current (Sn) is greater than the heating control current (S12).

11. Pneumatic system (1200) according to claim 10, characterized in that the pneumatic solenoid valves (20) each have a coil (307) for generating a magnetic force (FM), a valve seat (315), a spring (314) for applying a spring force (FF) acting counter to a spring force in the direction of the valve seat (315), and an armature (308), wherein the armature (308) is configured to be in a basic position (G) on the valve seat (315) when the heating control current (S12) is applied and to be moved away from the basic position (G) into a working position (A) against the spring force (FF) when the deflection control current (S11) is applied, and wherein the coil (307) is configured to heat the pneumatic solenoid valve (20) when the heating control current (S12) is applied.

12. Pneumatic system (1200) according to claim 11, characterized in that at least one pneumatic solenoid valve (20) is directly controlled, wherein the armature (308) is held in the basic position (G) by the spring force (FF) and, when the deflection control current (S11) is applied to the electrical coil (307), is deflected by the generated magnetic force (FM) relative to the basic position (G) into the working position (A) against the spring force (FF).

13. Pneumatic system (1200) according to one of claims 10 to 12, characterized in that the compressed air supply system (100) has a vent connection (3) for venting the compressed air supply system (100), wherein the first pneumatic line (10) has a pneumatic main line (12) and a vent line (13.1, 13.2) leading from a pneumatic main line (12) to the vent connection (3), and at least one of the pneumatic solenoid valves (20) is designed as a vent valve (23.4, 23.5) and is arranged in the vent line (13.1, 13.2).

14. Pneumatic system (300) for a pneumatic system (1200), in particular a pneumatic system (1200) according to one of claims 10 to 13, which can be connected to a compressed air supply connection (2) for supply by a compressed air supply system (100), with one or more (second) pneumatic lines (316), a plurality of pneumatic solenoid valves (20) which are designed to distribute and deliver the compressed air (120) provided at the compressed air supply connection (2) by selectively blocking and releasing at least one pneumatic line (316), characterized in that the pneumatic system (300) is designed for control-technical connection to a control device (1300), and the control device is designed to selectively supply one or more of the pneumatic solenoid valves (20) with a heating control current (S12) and a deflection control current (S11), wherein the pneumatic solenoid valves (20) are designedto heat up when a heating control current (S12) is applied and to release at least one of the pneumatic lines when a deflection control current (S11) is applied, wherein the deflection control current (Sn) is greater than the heating control current (S12).

15. Compressed air supply system (100) for a pneumatic system (1200), in particular a pneumatic system (1200) according to one of claims 10 to 13, with a compressed air connection (1) for connection to a compressed air generator (200) which is designed to provide compressed air (120), a compressed air supply connection (2) for connection to a pneumatic system (300), one or more (first) pneumatic lines (10), and a plurality of pneumatic solenoid valves (20) which are designed to distribute and deliver the compressed air (120) provided at the compressed air connection (1) by selective Blocking and releasing at least one of the pneumatic lines (10), wherein one or more of the pneumatic solenoid valves (20) are heatable, characterized in that the compressed air supply system (100) is set up for control-technical connection to a control device (1300), and the control device (1300) is designed to selectively supply one or more of the pneumatic solenoid valves (20) with current using a heating control current (S12) and a deflection control current (S11), wherein the pneumatic solenoid valves (20) are designed to heat up when a heating control current (S12) is applied, and to be deflected from a basic position (G) when a deflection control current (S11) is applied, wherein the deflection control current (Sn) is greater than the heating control current (S12).

16. Vehicle (1000), in particular passenger car (1100), characterized by a pneumatic system (1200) according to one of claims 10 to 13.

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