DE102014012646B4 - Compressed air supply system, pneumatic system and method for controlling a compressed air supply system - Google Patents

Abstract

Compressed air supply system (10, 10'), in particular in a partially closed design, for operating a pneumatic system (100), in particular an air spring system of a vehicle (1000), having: - a compressed air supply (1), to which on the air supply side an air compressor (21) with a two-stage Compressor (21.1) is connected, - a compressed air connection (2) to the pneumatic system (90) - a vent connection (3) to the environment - a pneumatic main line (60) between the compressed air supply (1) and the compressed air connection (2), which has an air dryer ( 62),- a vent line (70) between the compressed air port (1) and the vent port (3), wherein a vent valve (71) is connected to a valve port (71X, 71Y) in the vent line (70), and wherein- a Pressure accumulator (92) is connected directly to the air compressor (21) via an accumulator branch line (92ZL), characterized in that a pneumatic connection of the pneumatic main line (60) and a pneumatic connection of the accumulator branch line (92ZL) are connected to at least one switchable in at least two switching states Directional valve (30, 30'), wherein in a first switching state (30A, 30A') of the switchable directional valve (30, 30'), the compressed air supply (1) and the compressed air connection (2) via the air dryer (61) in the pneumatic Main line (60), wherein in the first switching state (30A, 30A') of the switchable directional valve (30, 30') on the compressed air supply side an air supply connection (0) is connected to the compressed air supply (1) and in a second switching state (30B, 30B') of the switchable directional control valve (30, 30'), the compressed air supply (1) and the compressed air connection (2) are connected in the pneumatic main line (60), bypassing the air dryer (61), with the switchable directional control valve being in the second switching state (30B, 30B'). (30, 30') on the compressed air supply side to the compressed air supply (1) the storage branch line (92ZL) is connected.

Description

The invention relates to a compressed air supply system according to the preamble of claim 1. The invention also relates to a pneumatic system with such a compressed air supply system. The invention also relates to a method for controlling a compressed air supply system, in particular for operating a pneumatic system.

A compressed air supply system is used in vehicles of all kinds, in particular for supplying compressed air to an air spring system of a vehicle. Air spring systems can also include level control devices with which the distance between the vehicle axle and the vehicle body can be adjusted. An air spring system of a pneumatic system mentioned at the outset comprises a number of air bellows which are pneumatically connected to a common line (gallery) and which can raise the vehicle body as the filling increases and correspondingly lower it as the filling decreases. As the distance between the vehicle axle and the vehicle body or ground clearance increases, the spring deflections become longer and even larger bumps in the ground can be overcome without coming into contact with the vehicle body. Such systems are used in off-road vehicles and sport utility vehicles (SUV). With SUVs in particular, it is desirable with very powerful engines to provide the vehicle with comparatively low ground clearance for high speeds on the road on the one hand and with comparatively high ground clearance for off-road on the other hand. It is also desirable to change the ground clearance as quickly as possible, which increases the requirement for speed, flexibility and reliability of a compressed air supply system.

A compressed air supply system for use in a pneumatic system with a pneumatic system, for example an air spring system described above, is operated with compressed air from a compressed air supply, for example at a pressure level of 5 to 20 bar. The compressed air is made available to the compressed air supply with an air compressor (compressor, optionally also a multi-stage compressor, in particular a TWIN compressor with two stages). To supply the pneumatic system, the compressed air supply is pneumatically connected to a compressed air connection and, on the other hand, pneumatically connected to a ventilation connection. The compressed air supply system can be vented to the environment via a venting valve arrangement forming solenoid valve arrangement by venting air in one or more venting connections.

To ensure long-term operation of the compressed air supply system, it has an air dryer with which the compressed air is to be dried. This avoids the accumulation of moisture in the pneumatic system, which could otherwise lead to valve-damaging crystal formation at comparatively low temperatures and also to undesired defects in the compressed air supply system and in the pneumatic system. An air dryer has a desiccant, usually a bed of granules through which the compressed air can flow, so that the bed of granules--at comparatively high pressure--can absorb moisture contained in the compressed air by adsorption. An air dryer can optionally be designed as a regenerative air dryer. This can be done in that the dried compressed air from the air suspension system flows through the bulk granules in countercurrent or cocurrent relative to the filling direction during each venting cycle--at comparatively low pressure. To do this, the vent valve arrangement can be opened. For such an application--also referred to as pressure swing adsorption--it has proven to be desirable to design a compressed air supply system flexibly and at the same time reliably, in particular to enable comparatively rapid venting with a pressure swing that is nevertheless sufficient for regeneration of the air dryer.

In addition, it is also desirable to fill the pneumatic system as effectively as possible, in particular also taking into account the ability of the air dryer to regenerate. In particular, this should also be the case when filling takes place in a comparatively short time and with a comparatively high pressure amplitude. Previously known methods are still in need of improvement, particularly with regard to the aforementioned aspects.

EP 1 243 447 B1 discloses a so-called closed level control system for vehicles, through which the vehicle body is cushioned in relation to at least one vehicle axle. This contains suitable pressure medium chambers that can be filled with compressed air from an air compressor formed with a single-stage compressor via an air dryer. A pressure medium reservoir is provided, which is connected via the compressor to the pressure medium chambers in such a way that pressure medium can be transferred from the pressure medium reservoir via the compressor into each pressure medium chamber. For this purpose, the compressor inlet is equipped with a first directional control valve connected through-connected compressed air line with the pressure medium reservoir and the compressor outlet via a second connected through compressed air line with a directional control valve with the pressure medium chamber. In addition, pressure medium can be transferred from each pressure medium chamber via the compressor into the pressure medium reservoir; for this purpose, a third compressed air line connected through with a directional control valve and a fourth compressed air line connected through with a directional control valve are provided. Such closed systems have a comparatively limited field of application and can still be improved.

DE 100 55 108 A1 also discloses a closed system of a compressed air supply system for an air suspension of a vehicle, with a pump, at least one storage tank and a circuit connecting these units being provided, with the pressure side of the pump being connected to the storage or the air springs. With such an air spring system, a comparatively low energy consumption can be achieved with a small construction volume, but a filling function with only a single-stage compressor and within the framework of the closed system and the further design of the system is comparatively limited.

DE 10 2008 034 240 A1 discloses a level control system with a compressed air supply system of the type mentioned at the outset, in which the capacity limitation of closed systems is eliminated in that a drain valve is provided in a partially closed design of the compressed air supply system, which is arranged in an atmosphere line and which has a two-stage or multi-stage compressor with a first compression stage and a second stage of compression switchable in communication with the atmosphere. A pressure medium line is also provided to connect a pressure medium reservoir to the second compression stage of the compressor via an electrically controllable 2/2-way valve. While such a compressed air supply system is basically already well designed in terms of capacity and flexibility, it can still be further improved - particularly with regard to the above-mentioned regeneration ability of the air dryer and its efficiency and flexibility.

This is where the invention comes in, the object of which is to specify a compressed air supply system, a pneumatic system and a method that allow a pneumatic system to be operated with high capacity and which can still be operated efficiently and flexibly, in particular taking into account the regeneration ability of the air dryer . In particular, air consumption should be comparatively reduced by means of the compressed air supply system. In particular, control and regulation of the compressed air supply system should be designed with regard to flexibility and efficiency; preferably in terms of shorter control times and improved control quality. The compressed air supply system should be operable with normal and increased capacity, depending on requirements, taking into account the above task.

The problem relating to the compressed air supply system is achieved by a compressed air supply system of the type mentioned at the outset, in which, according to the invention, the features of the characterizing part of claim 1 are also provided. The concept of the invention also leads to a pneumatic system with the compressed air supply system of the aforementioned type according to the features of claim 14.

The object with regard to the method is achieved by the invention with a method of the type mentioned in the introduction, in which the method steps of the characterizing part of claim 15 are provided according to the invention.

The invention is based on the consideration that, in order to increase the capacity of a compressed air supply system, it is essential to design it as an open system, ie with an air compressor that is pneumatically connected to the environment on the air supply side and venting side. In addition, the invention has recognized that it is necessary for a sufficient capacity of a compressed air supply system to provide the air compressor with a two-stage compressor, in particular with a compressor with a first compressor stage and a second compressor stage. Based on this concept of a compressed air supply system in a partially closed design with a two-stage compressor, the invention is also based on the consideration that this approach fundamentally enables single-stage operation of the compressor as well as normal two-stage operation of the compressor (normal operation). On the other hand, the invention has recognized that with conventional systems of the prior art, the efficiency of the system can still be improved with regard to air dryer regeneration, especially for boost operation. The invention is based on the consideration that air from the pressure accumulator that has usually been dried beforehand in boost mode must be passed through the air dryer again when the pneumatic system is being filled. For this reason, the content or the volume of the air dryer—that is, an air dryer content—is usually lost during venting after boosting. In addition, the invention has recognized that when the air dryer is also filled in boost operation, a delay in the lifting process is to be expected precisely in this efficient operating mode is. In addition, moisture is shifted in the direction of the pneumatic system. In boost mode, the air dryer tends to be particularly prone to bottoming out. The concept of the invention has recognized that it is necessary to design the compressed air supply system in such a way that at least in boost mode, in particular only in boost mode, the air dryer can be bypassed pneumatically.

Based on this consideration, a further development provides a pneumatic bypass line that runs between the switchable directional control valve and the compressed air connection and thus provides a pneumatic bypass for bypassing the air dryer. In order to also provide a sufficiently flexible mode of operation of the compressed air supply system geared towards normal and boost operation, the development also provides that the switchable directional control valve is a 5/2-directional control valve. The 5/2-way valve can be switched in such a way that the bypass for bypassing the air dryer is available for boost operation, in particular only for boost operation. In boost operation, a compressed air supply is preferably supplied only from the pressure accumulator, but possibly also with the operation of the first and/or—preferably—second compressor stage of the air compressor. The second-stage compressor preferably has a first compressor stage and a second compressor stage, with the second compressor stage of the two-stage compressor being connected directly to the pressure accumulator via an accumulator branch line.

The concept of the development with regard to the method provides that, for filling the pneumatic system, a switching 5/2-way valve is designed in the first switching state for normal filling with flow through the air dryer and in a second switching state for boost filling without flow through the air dryer.

In particular, in a second switching state of the at least one switchable directional valve, in particular the 5/2-way valve, the accumulator branch line between the pressure accumulator and the second compressor stage is open. As part of a particularly preferred development, it has proven to be advantageous for the 5/2-way valve to have a first switching state, with the pneumatic connection of the main pneumatic line being open and the pneumatic connection of the storage branch line being disconnected; and/or the 5/2-way valve has a second switching state, the pneumatic connection of the pneumatic main line being disconnected and the pneumatic connection of the accumulator branch line being open. In other words, the bypass line is disconnected in the first switching state and the bypass line is open in the second switching state—designed in particular for boost operation.

The 5/2-way valve, which is designed as an improved boost valve, is designed to direct the already dry air past the air dryer in connection with the bypass line, the pneumatic main line and the pneumatic accumulator branch line --in boost mode--; this is then a pneumatic system, z. B. a gallery of the same available. In addition, it has proven to be advantageous not only to bypass the air dryer pneumatically by means of the bypass line, but also to bypass a throttle that may be present in the main pneumatic line and/or a non-return valve that may be present in the main pneumatic line.

The improved boost filling by switching the 5/2-way valve to the second switching state is ended in a particularly preferred development of the method before a pressure in the pressure accumulator falls below a pressure in a first compressor stage. This prevents humid air from being conveyed past the air dryer into the pneumatic system, in particular a gallery of the same.

As a result, the concept achieves several advantages over a previously known high-capacity compressed air supply system. Thus, during boost operation with pneumatic bypassing of at least the air dryer, faster filling of the pneumatic system can be achieved; namely because the air dryer no longer has to be filled with compressed air when it is present at the compressed air connection. If there is a throttle and/or a check valve in a main pneumatic line, a pressure resistance of the throttle and/or the check valve no longer has to be overcome, particularly during boosting, preferably only during boosting. On the other hand, only the lines in the pneumatic system are opened during a venting process. During a venting process, an air dryer in the main pneumatic line is regularly depressurized with almost atmospheric pressure, so that no additional air consumption is required. In addition, the 5/2-way valve, which is designed and connected as an improved boost valve, can also remain in a second switching state (boost position) during venting; this is the case if, in individual cases, regeneration of the air dryer is not required or should not take place.

Preferred developments of the invention can be found in the dependent claims, which specify advantageous options in detail, the concept explained above within the scope of the task benstellung as well as to realize other advantages.

As part of a particularly preferred development, a non-return valve, in particular a pilot-operated non-return valve, in the pneumatic main line also prevents moist air from being introduced in a return flow into the compressed air supply system if the pressure in the pressure accumulator is too low. This ensures that only dry air is transported during a filling process of the pneumatic system, in particular of the pressure accumulator, as well as during a venting process or when boost operation is terminated.

As part of a modified development, a check valve can also be omitted if instead --if necessary. but also in addition to the check valve-- suitable pressure data is known. A vehicle controller or another control module for controlling the compressed air supply system should preferably know what pressure there is in the pressure accumulator. This can be achieved, for example, when a pressure accumulator is connected to a pressure sensor in such a way that the pressure sensor is able to determine a pressure in the pressure accumulator. If the pressure in the pressure accumulator is known to a vehicle controller, suitable control and/or regulating means can be provided on the controller side in order to close a main pneumatic line. In addition, a threshold pressure can preferably be known on the control side, from which the first compressor stage of the two-stage compressor can again take over the charging of the second compressor stage. As a result, the controller can then assess whether a residual pressure in the pressure accumulator offers advantages over normal operation with a first and/or second compressor stage.

The pneumatic bypass line between the 5/2-way valve and the compressed air connection is preferably designed in such a way that the air dryer and the pilot operated check valve are bypassed by the bypass line or can be bypassed pneumatically.

In a modification, the main pneumatic line preferably has a throttle and the pneumatic bypass line between the 5/2-way valve and the compressed air connection is designed in such a way that the air dryer and the pilot-operated check valve and the throttle are bypassed by the bypass line or can be bypassed pneumatically.

In particular, the pneumatic bypass line branches off between the 5/2-way valve and a branch connection for the bypass line in the pneumatic main line, the branch connection being formed between the air dryer and the compressed air connection to the pneumatic system; In particular, the branch connection can be formed between the releasable check valve and the compressed air connection or, in the aforementioned modification, can be arranged between the throttle and the compressed air connection.

In other words, depending on an aforementioned modification of an arrangement of pneumatic components in the pneumatic main line, the bypass line can bypass only the air dryer or optionally the air dryer and the check valve or optionally the air dryer and the check valve and the throttle or optionally the air dryer and the throttle .

In a pneumatic system, it is particularly preferred to design the pressure accumulator to be pressure-sensitive; A pressure sensor is preferably connected to the pressure accumulator directly and/or pneumatically to the gallery of a pneumatic system. As part of a particularly preferred development of the method, it has proven to be advantageous that it is checked separately whether a residual pressure in the pressure accumulator is sufficiently high to --if necessary. in addition to a one-stage compressing and/or two-stage compressing normal operation-- to carry out a boost operation, d. H. either with compressed air alone from the pressure accumulator and/or to operate the compressor in a first variant with only the first or second compressor stage and/or in a second variant of the first and second compressor stage. In the case of the aforementioned first variant, the conveying or further compression of compressed and dry compressed air from the compressed air reservoir by means of boost operation has proven particularly advantageous. In the aforementioned second variant, the suction of air from the atmosphere has proven to be particularly advantageous. i.e. it can be checked whether a residual pressure in the pressure accumulator brings with it advantages of boost operation over normal operation. For example, a directional control valve connected upstream of the pressure accumulator, which is also referred to as an accumulator valve, can be suitably switched for such a pressure measurement.

A particularly preferred further development provides for a pneumatic connection, referred to here as a so-called inshot connection, such as a pneumatic line or the like, to be provided between the pneumatic accumulator branch line and the bypass line. The pneumatic in-shot connection is preferably provided with a check valve function. Preferably, a pneumatic inshot line with a pneumatic check valve verse hen that automatically opens from the pneumatic storage branch line to the bypass line and blocks from the pneumatic bypass line to the storage branch line.

Such or a similar check valve function with an automatic opening direction from the accumulator branch line to the bypass line is preferably provided for boost operation. Basically it is also possible to pre-fill the pneumatic system, in particular a gallery of the same, to briefly open an accumulator valve upstream of the pressure accumulator; In addition or as an alternative, it is preferable to use a non-return valve function in accordance with the development described here. This allows any residual pressure from the pressure accumulator to be routed past the air compressor and into the bypass line. As a result, a response time of a control process for boost operation is advantageously reduced and, moreover, a compressor running time of the air compressor is reduced.

It has proven to be particularly preferable for the constructive realization that a non-return valve function provided in the 5/2-way valve is made available. In particular, this is integrated in the second switching state of the 5/2-way valve in order to provide the aforementioned pneumatic in-shot connection from the accumulator branch line to the bypass line; ie in a boost operation of the method can be activated with a check valve function which opens automatically from the accumulator branch line to the bypass line.

The concept of the invention and its developments can in principle be applied to a wide variety of configurations of a vent valve in a solenoid valve arrangement; This is also the case with a directly controlled vent valve, i. H. without an upstream control valve. The latter can have speed advantages when bleeding.

However, it has also proven to be particularly preferred that a solenoid valve arrangement has a control valve for controlling the vent valve. The control valve has, for example, two valve connections that are connected in the control line, the control valve being in the form of a 3/2-way valve that has a valve connection to the environment.

The control valve is preferably connected to a valve connection in a pneumatic control line connected to a pressure control connection of the ventilation valve. The pneumatic control line particularly preferably branches off from the pneumatic main line, so that a control pressure can be derived from the pneumatic main line--then fed in particular from a bellows pressure. This enables a comparatively simple and reliable activation of the venting valve for a venting process using the pressure present in the pneumatic system, in particular a bellows pressure. The control line particularly preferably branches off from the main pneumatic line at a branch connection for the bypass line. The vent valve preferably closes against a residual pressure in the pneumatic system under the action of a valve spring of the vent valve.

It has also proven particularly advantageous to provide a pilot operated non-return valve in the main pneumatic line. A particularly preferred development provides for the check valve to be configured so that it can be unlocked by means of the control valve. A pressure control connection is particularly preferably kept under control pressure when the check valve is unlocked. It has proven to be particularly preferred that the pressure control connection is formed as a pressure control connection that is jointly available to the ventilation valve and the pilot-operated check valve. Structurally, the common pressure control connection can be realized, for example, via a pneumatic piston that opens the vent valve at the same time as the check valve is unlocked.

• 1 ein Systemschaltbild eines pneumatischen Systems mit einer Druckluftversorgungsanlage und einer Pneumatikanlage gemäß einer bevorzugten Ausführungsform mit einem Boostventil in Form eines schaltbaren 5/2-Wegeventils zwischen dem zweistufigen Kompressor und dem Druckluftanschluss bzw. zwischen der Druckluftzuführung und dem Druckluftanschluss bzw. zwischen dem zweistufigen Kompressor und dem Druckspeicher - in 1 ist das 5/2-Wegeventil in einem ersten Schaltzustand zur Realisierung eines Normalbetriebs, bei dem die pneumatische Verbindung der pneumatischen Hauptleitung geöffnet und die pneumatische Verbindung der Speicherzweigleitung und der Bypassleitung zur Umgehung des Lufttrockners getrennt ist;
• 2 das pneumatische System der 1, bei welchem das Boostventil in einer zur Realisierung des Boostbetriebs zweiten Schaltzustand gezeigt ist, d. h. die pneumatische Verbindung der pneumatischen Hauptleitung getrennt ist und die pneumatische Verbindung der Speicherzweigleitung und der Bypassleitung zur Umgehung wenigstens des Lufttrockners geöffnet ist;
• 3 eine abgewandelte, besonders bevorzugte weitere Ausführungsform, bei welcher zwischen der pneumatischen Speicherzweigleitung und der Bypassleitung im 5/2-Wegeventil eine mit einer Rückschlagventilfunktion versehende pneumatische Inshot-Verbindung vorgesehen ist, die selbsttätig bei einem Restüberdruck im Druckspeicher von der Speicherzweigleitung zur Bypassleitung gegen Federdruck öffnen kann;
• 4 ein Schema mit einem beispielhaft verdeutlichenden grundsätzlichen Ablauf von Verfahrensschritten zum Befüllen einer Pneumatikanlage, wobei Möglichkeiten und Vorteile eines Normalbetrieb für eine Befüllung in der Pneumatikanlage über den Lufttrockner (in einstufigen oder zweistufigen Betrieb) gemäß 1, einem boostoptimierten Betrieb unter Boost befüllen durch Schalten des 5/2-Wegeventils im zweiten Schaltzustand als auch eines Boost-Inshot-Betriebs durch Schalten des 5/2-Wegeventils in den zweiten Schaltzustand verdeutlicht ist.

Exemplary embodiments of the invention are now described below with reference to the drawing in comparison to the prior art, some of which are also shown. This is not necessarily intended to represent the exemplary embodiments to scale, rather the drawing, where useful for explanation, is in schematic and/or slightly distorted form. With regard to additions to the teachings that can be seen directly from the drawing, reference is made to the relevant state of the art. In this context, it must be taken into account that a wide variety of modifications and changes relating 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 both individually and in any combination for the further development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the drawing 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 any subject matter which would be limited compared to the subject matter claimed in the claims. In the case of specified design ranges, values lying within the specified limits should also be considered Limit values are disclosed and can be used and claimed as desired. Further advantages, features and details of the invention result from the following description of the preferred exemplary embodiments and from the drawing; this shows in:

• 1 a system circuit diagram of a pneumatic system with a compressed air supply system and a pneumatic system according to a preferred embodiment with a boost valve in the form of a switchable 5/2-way valve between the two-stage compressor and the compressed air connection or between the compressed air supply and the compressed air connection or between the two-stage compressor and the accumulator - in 1 the 5/2-way valve is in a first switching state to implement normal operation, in which the pneumatic connection of the main pneumatic line is opened and the pneumatic connection of the storage branch line and the bypass line for bypassing the air dryer is disconnected;
• 2 the pneumatic system of 1 , in which the boost valve is shown in a second switching state for realizing the boost operation, ie the pneumatic connection of the pneumatic main line is disconnected and the pneumatic connection of the accumulator branch line and the bypass line for bypassing at least the air dryer is open;
• 3 a modified, particularly preferred further embodiment, in which a pneumatic in-shot connection with a check valve function is provided between the pneumatic accumulator branch line and the bypass line in the 5/2-way valve, which automatically opens against spring pressure in the event of a residual overpressure in the pressure accumulator from the accumulator branch line to the bypass line can;
• 4 a scheme with an example illustrating the basic sequence of steps for filling a pneumatic system, with the possibilities and advantages of normal operation for filling in the pneumatic system via the air dryer (in one-stage or two-stage operation) according to FIG 1 , a boost-optimized operation under boost filling by switching the 5/2-way valve in the second switching state and a boost-inshot operation by switching the 5/2-way valve in the second switching state.

1 shows a pneumatic system 100 with a compressed air supply system 10 and a pneumatic system 90 in the form of an air spring system for a vehicle 1000, not shown in detail. A vehicle controller and a data bus can be provided in vehicle 1000 in order to transmit suitable control signals and/or control currents for energizing magnetic coils to provide electrically controllable valves of the pneumatic system 100; these are shown in detail only to the extent that this makes sense. In order to implement suspension or a change in level of a vehicle body--for example with a front axle and a rear axle--the pneumatic system 90 provides a number of bellows 91, each bellows 91 being part of an air spring. A bellows valve 93 in the form of a directional control valve, in particular a magnetic directional control valve, namely a 2/2-way valve in this case, is connected upstream of each bellows 91 in a bellows line 91L. The bellows lines 91 L each in the form of a branch line each branch off from a gallery 95 forming a collecting line, which in turn is connected to a further pneumatic line 96 . The further pneumatic line 96 connects to the compressed air connection 2 of the compressed air supply system 10 .

Bellows 91 can be filled or vented via the gallery 95 via the compressed air connection 2 and the main pneumatic line 60 connected to it of the compressed air supply system 10 or the additional pneumatic line 96 . The pneumatic system 90 also has a pressure accumulator 92 connected to the gallery 95 via an accumulator line 92L, to which a pressure sensor 97 is connected directly as a stress-pressure sensor for measuring an accumulator pressure in the pressure accumulator 92; a memory pressure is thus constantly available on a data bus of a control device. In a modification, a pressure sensor can, additionally or alternatively, be connected to the gallery 95 or to the storage line 92L or to a storage branch line 92ZL branching off therefrom; in this case, a pressure measurement can be carried out after the accumulator valve 94 has opened. The pressure accumulator 92 is preceded by an accumulator valve 94 as a 2/2-way valve in the accumulator line 92L. The magnetic directional valves, namely the bellows valves 93 and the accumulator valve 94 are presently combined in a 5-fold valve block 98 as a structural unit.

The accumulator branch line 92ZL is connected to the accumulator line 92L at a branch port between the accumulator valve 94 and the accumulator 92 . Furthermore, the memory branch line 92ZL leads to at least one in at least two switching states 30A, 30B (in the 1 , 2 marked with A and B for reasons of space) switchable directional control valve 30. The directional control valve 30 in the present case acts as a boost valve and is implemented in the form of a 5/2-way valve 30.5. The directional control valve 30 acting as a boost valve is via a magnetic coil 30M as a magnetic directional valve switchable against a valve spring 30F. The accumulator branch line 92ZL is only one of five lines that are connected to the 5/2-way valve 30.5, with the other lines being explained below.

In detail, the compressed air supply system 10 has a supply line 20 and an air compressor 21 connected to it. The air compressor 21 is presently formed as a two-stage compressor 21.1, which is driven by a motor M--here by an electric motor 21.2--and has a first compressor stage 21.1A and a second compressor stage 21.1B. On the air supply side, the air supply line connects to an air supply connection 0, which at the same time forms a ventilation connection 3 to the environment. On the ambient side, a filter 0.1 is connected upstream of the air supply connection or ventilation connection 0/3, which has a filter effect for air intake and a sound-dampening effect for ventilation. The further course of the supply line 20 continues between the first compressor stage 21.1A and the second compressor stage 21.1B as an intermediate line 20.1, in order to then be connected to the compressed air supply 1 as an output line 20.2 after the second compressor stage 21.1B.

The main pneumatic line 60 runs between the compressed air supply 1 and the compressed air connection 2. A ventilation line 70 is also connected to the compressed air supply 1, which leads to the ventilation connection 3 via a first and second valve connection 71X, 71Y of a ventilation valve 71. The vent valve 71 is part of a solenoid valve arrangement 80 which also includes a control valve 81 designed as a solenoid directional control valve and, in the present case, a pilot operated check valve 61 . The pilot-operated check valve 61 and the vent valve 71 can be actuated via a single control piston, which can be actuated via a pneumatic actuator 71S, e.g. B. a pressure control port, is movable as a relay piston. A suitable control pressure can be supplied to the pressure control connection 71 S via the control valve 81 . In the present case, the control pressure is a control pressure switched via the control valve 81 and branched off from the main pneumatic line 60 at the branch connection 63 into a control line 110 .

In the present case, the control valve 81 is in the form of a 3/2-way valve, which can be controlled via an electric control line 81S to energize the magnetic coil 81M and can be actuated against a valve spring 81F. in the in 1 In the de-energized state of the solenoid coil 81M shown, the control line 110 is connected in a first part 110.1 to a first valve connection 81X and is pneumatically separated from a second part 110.2 connected to the pneumatic actuator 71S, which in turn is connected to a second valve connection 81Y; the 3/2-way valve is in a normally closed state with respect to the control line 110 . For this purpose, the second part 110.2 is vented via a third valve connection 81Z to a further vent line 117, with the further vent line 117 being brought together at a branch connection 7 with the vent line 70 and both continuing to the vent connection 3 as a common vent line 70.

A third part 110.3 of the control line 110 branches off from the first part 110.1 between the branch connection 63 and the control valve 81 and is routed directly to the relay piston of the vent valve 71, but without normally switching the vent valve 71 against the pressure of the valve spring 71F of the vent valve 71 . As a result, this leads to faster switching activity in the case of venting, i. H. when the control valve 81 changes to the second switching state when the magnetic coil 81M is energized accordingly--in the energized state--and pneumatically connects the first and second parts 110.1, 110.2 of the control line 110 with one another, so that the control pressure is applied to the pneumatic actuator 71S. Then the relay piston is moved, i. H. the control pressure moves both the relay piston 71K of the vent valve and the relay piston 61K of the pilot-operated check valve via the pressure control port or similar pneumatic actuator 71S shown here. As a result, the air dryer 62 provided in the main pneumatic line 60 is opened both on the side of the ventilation line 70 and on the side of the compressed air connection 2--ie on both sides--. In addition, a pressure limiting function can be provided in the compressed air supply system, in particular in the vent line 70. If the pressure in the system or the main line 60 is too high, the relay piston 71K can preferably counteract the spring force, in particular a spring force of the valve spring 71F of the vent valve, beyond a limiting pressure 71 open.

The pneumatic system 90 is then vented via a first throttle 64 in the pneumatic main line 60 and a second throttle 74 in the vent line 70. In the present exemplary embodiment, a nominal width of the first throttle 64 is larger than a nominal width of the throttle 74, on the one hand to ensure efficient venting to allow the best possible regeneration of the air dryer 62 while avoiding an excessive sound or pressure amplitude.

The bellows 91 or the pressure accumulator 92 of the pneumatic system 90 can be filled in 1 shown de-energized open position of the 5/2-way valve designated as boost valve 30.5 in the main pneumatic line 60 between the compressed air supply and the compressed air connection 2. In detail, the compressor 21 can make compressed air available at the compressed air supply 1 --both under normal operation with single-stage compression and optionally with two-stage compression NORM--and this--with the 5/2-way valve 30.5 open without current in the main pneumatic line 60--via apply the air dryer 62 and the automatically opened pilot operated check valve 61 as well as the first throttle 64 to the compressed air connection 2. The intermediate line 20.1 is also connected via an intermediate branch line 20.3 to the 5/2-way valve 30.5 referred to as a boost valve, specifically in the present case via a further non-return valve 22 in the intermediate branch line 20.3 which is closed in the blocking direction.

in the in 1 In the first switching state of the boost valve shown, the pneumatic connection of the main pneumatic line 60, ie between the first and second valve ports X, Y of the boost valve, is thus open. The intermediate branch line 20.3 branching off from the intermediate line 20.1 with the further check valve 22 is connected to the third valve connection Z of the boost valve in the blocking direction of the further check valve 22.

The aforementioned storage branch line 92ZL is connected to the fourth valve connection W. in the in 1 In the first switching state of the boost valve shown, the pneumatic connection of the accumulator branch line 92ZL, ie in the present case the pneumatic connection between the fourth valve connection W and the third valve connection Z of the boost valve, is disconnected.

Following the concept of the invention, a pneumatic bypass line 65 is connected to the fifth valve connection V of the boost valve, which in the present case leads to the aforementioned branch connection 63 of the control line 110, i. H. between the first throttle 64 and the compressed air connection 2, reconnects to the main pneumatic line 60. The pneumatic bypass line 65 runs between the fifth valve connection V of the boost valve and the branch connection 63 of the control line 110, bypassing the air dryer 62, bypassing the pilot-operated check valve 61 and bypassing the first throttle 64. In the currentless open state for the pneumatic main line 60 of the boost valve --d. H. normally open state of the 5/2-way valve 30.5 between the first and second ports X, Y - the bypass line at the fifth valve port V is closed against the branch port 63.

While the pneumatic system can be filled via the main pneumatic line 60 with single-stage or two-stage compressor operation of the compressor 21.1; In the present case, the pneumatic system 90 can also be vented by releasing the pilot operated non-return valve 61 and via the air dryer 62 into the vent line 70 - i.e. in the present case with regeneration of the air dryer 62. This is one of the reasons why the operation of the compressed air supply system --be it in the filling operation, be it in venting operation - referred to as normal operation NORM, when the 5/2-way valve 30.5 in the first switching state 30A of 1 as a normally open state for the pneumatic main line 60 is located.

2 shows the same in 1 Compressed air supply system 10 shown with pneumatic system 90, the same reference numerals being used for identical or similar parts or parts with an identical or similar function. Here, in addition or as an alternative to the third part 110.3 of the control line, a pressure limiter 76 can be provided at the vent valve 71 and, if necessary, also act to actuate the pneumatic actuator 71S. The compressed air supply system 10 is in 2 shown for a second switching state 30B of the 5/2-way valve 30.5, namely in the boost position (e.g. with at least one open bellows valve 93), ie in an open state energized for the bypass line 65 and the pressure accumulator branch line 92ZL. 2 illustrates a boost operation BOOST of the compressed air supply system. To this end, the main pneumatic line 60 between the first and second valve connections X, Y is pneumatically separated. In contrast, the bypass line 65 between the first and fifth valve ports X, V is pneumatically open. Likewise, the accumulator branch line 92ZL between the third and fourth valve ports Z, W is open. Specifically, the accumulator branch line 92ZL is open to the third intermediate branch line 20.3 with automatic opening of the further check valve 22, ie from the pressure accumulator 92 to the second compressor stage 21.1B of the compressor 21.1. The bypass line is pneumatically opened from the first valve connection X to the fifth valve connection V in the filling direction, i.e. from the second compressor stage 21.1B bypassing the air dryer 62 of the pilot-operated check valve 61 and the first throttle 64 to the branch connection 63 and thus to the compressed air connection 2. As a result, an improved boost operation BOOST is realized; this if necessary as an alternative to two-stage compression, in which the air compressor 2 is operated with the first and the second compressor stage 21.1A and 21.1B. Compressed air is made available at the compressed air supply 2 from the pressure accumulator 92 via the accumulator branch line 92ZL and the automatically unlocked additional check valve 22 and the second compressor stage 21.1B. If necessary this improved boost function can also take place under compressor operation.

In the improved boost mode BOOST, however, the compressed air present at the compressed air supply 1 - since it is already dried out of the compressed air reservoir 92 - is made available past the air dryer 62 into the further pneumatic line 96 and gallery 95 via the compressed air connection 2. In addition, the releasable check valve 61 and the first throttle 64 are also bypassed via the bypass line 65, so that their switching resistance does not initially have to be overcome. The improved boost function according to the second switching state of the 5/2-way valve 30.5, ie according to the energized in 2 shown position, only serves to allow faster filling of the gallery 95 and bellows 91 when the accumulator pressure is too low, but also has advantages for initiating a venting function. It has been proven that the boost valve, ie the 5/2-way valve 30.5 even with the venting function in the in 2 shown to leave energized second switching state. After Bosten, however, the 5/2-way valve 30.5 is usually, ie practically always, switched back to its initial state practically immediately in order to ensure regeneration of the dryer during venting or, during a normal filling process, the humid air through the dryer to the reservoir or forward bellows. This also prevents the accumulator pressure from being permanently at the second stage and preventing the compressor from starting up. The further check valve 22 in the intermediate branch line 20.3 is connected downstream of the 5/2-way valve 30.5 in order to prevent the backflow of moist air from the first compressor stage when the storage pressure in the pressure accumulator 92 is too low. This ensures that compressed air for use with the improved boost function is always dry in the accumulator. If the residual accumulator pressure drops below the pressure of the first compressor stage during boosting, the system switches to NORM normal operation. Firstly, this means that no moist air can get past the dryer and into the system, and secondly, there are no performance losses due to the insufficient pre-pressure upstream of the second stage. Moreover, the possible venting via the bypass line 65 represents an advantage in that the air dryer 62—unless intended for regeneration—remains pressureless.

This reduces air consumption and thus overall the energy consumption of the compressed air supply system 10 both when venting and when filling the pneumatic system 90. This applies in particular to purely venting the gallery 95 after a boost operation BOOST. In this case, comparatively little volume is available, which is distributed among other things into the air dryer 62 when the venting assembly is switched and the piloted check valve 61 is forced to be actuated. As a rule, however, the air dryer 62 is ventilated, in particular in combination with a lowering of the vehicle. In this case, the 5/2-way valve 30.5 can optionally remain closed.

3 shows a further developed embodiment of a compressed air supply system 10 'in one of 2 comparable energized position of a directional valve 30' (boost valve) which can be switched into at least two switching states, ie in the present case a modified 5/2-way valve 30.5' is again shown in the boost position, ie in the second switching state 30B' (the first and second switching states 30A', 30B' is in the 3 marked A, B for reasons of space); e.g. B. again with at least one open bellows valve 93. For the sake of simplicity, the same reference symbols are used for all other features and details of the compressed air supply system 10' and the 5/2-way valve 30.5' insofar as they are identical or similar parts or parts with an identical or similar function used. In the present case, the modified 5/2-way valve 30.5' is shown in a second switching state in which, as explained, the first valve connection X to the fifth valve valve connection V—ie to open the pneumatic connection of the bypass line 65—is open. In addition, the main pneumatic line 60 is open from the compressed air supply 1 to the branch connection 63 and then to the compressed air connection 2 via the bypass line 65 , bypassing the air dryer 62 and bypassing the first throttle 64 and the pilot-operated check valve 61 . Furthermore, in the direction of the automatic opening direction of the further check valve 22, the pressure accumulator branch line 92ZL is open from the pressure accumulator 92 in the direction of the second compressor stage 21.1B—namely via the intermediate branch line 20.3 and the intermediate line 20.1.

In addition, a pneumatic line 31 with yet another check valve 32 is provided in the modified boost valve--ie here in the directional valve 30' formed as a 5/2-way valve 30.5' and switchable in at least two switching states--to form an inshot connection. The pneumatic line 31 is connected between the accumulator branch line 92ZL and the bypass line 65, bypassing the air compressor in the 5/2-way valve 30.5'. This pneumatic connection with the pneumatic line 31, referred to as the in-shot connection, essentially runs between the pressure accumulator 92, accumulator branch line 92ZL, 5/2-way valve 30.5', the aforementioned pneumatic line 31 and, if necessary, the vent line 70 to the vent connection 3. Runs for in-shot ventilation these to the pneumatic bypass line 65 and via the compressed air connection 2 and the pneumatic line 96 to the gallery 95. The non-return valve 32, also known as the inshot valve, can open automatically in the direction of the vent line 70 or the bypass line 65 against a non-illustrated non-return valve spring against pneumatic pressure from the accumulator branch line 92ZL.

Will a regarding 2 If the improved boost operation BOOST described is required, the accumulator valve 94 can be opened briefly to prefill the gallery 95 .

Further, according to in 3 In the embodiment shown, a pneumatic in-shot connection with the check valve function described here as an example in the 5/2-way valve 30.5′ can be used to automatically open the storage branch line 92ZL to the bypass line 65 in the second switching state while pneumatically bypassing the air compressor 21; This also allows any residual excess pressure in the pressure accumulator 92 to be made available to the compressed air connection 2 -- past the air compressor 21 . This considerably reduces the response time of a control process for filling a gallery 95 and reduces the running time of the compressor 21.1.

A pressure sensor 97 attached directly to the pressure accumulator 92 is used to check separately whether a pressure in the pressure accumulator offers advantages over normal operation NORM described above with both compressor stages 21.1A, 21.1B of the two-stage compressor 21.1. In particular, it can be checked whether an overpressure is above a predetermined upper threshold pressure (i.e. is too high) and/or a residual pressure is below a predetermined lower threshold pressure (i.e. is too low) or is above a predetermined lower threshold pressure (i.e. is sufficiently high) . For this purpose, the accumulator valve 94 can be connected to the gallery 95 or--as in the present case--be connected directly to the pressure accumulator 92 in order to determine the accumulator pressure of the pressure accumulator 92 practically constantly. In addition, such or a similar pressure measurement of the pressure in the pressure accumulator ensures that an improved boost process is regulated, i. H. can be ended before an accumulator pressure determined via the pressure sensor falls below a pressure of the first compressor stage. This prevents humid air from being conveyed past the air dryer 62 into the gallery 95 .

The integration of the check valve 32, also referred to as an inshot valve, in at least one directional valve 30', which can be switched into at least two switching states, with the function of a boost valve, i.e. in the present case in the 5/2-way valve 30.5' for the inshot function, improves the protection of the entire pneumatic system against overpressure. This also applies if the pressure limitation does not pick up the pilot control pressure in the pilot control line 110 but in the ventilation line 70 . If the pressure accumulator 92 is thermally overloaded (ie, for example, after a sharp rise in temperature), the excess pressure can be increased via the inshot connection, e.g. B. to the pressure relief valve (vent valve 71 with pressure relief 76 of 2 ) or the like vent valve 71 without filling the air dryer 62.

4 shows an exemplary sequence of method steps, as is conceivable, for example, as part of a sequence of filling processes for filling the pneumatic system 90 or the bellows 91. In a first method step S1, normal operation NORM can be carried out by switching at least one directional valve 30,30′ that can be switched into at least two switching states--in this case the 5/2-way valve 30.5, 30.5′--into a first switching state, as is shown, for example, on the basis of 1 was explained. i.e. present that in the first switching state the pneumatic connection of the pneumatic main line 60 is open and the pneumatic connection of the storage branch line 92ZL and a bypass line 65 for bypassing at least the air dryer 62 is pneumatically separated.

Compressed air is generated via the compressed air supply 1 by means of an operation of the air compressor 21, namely to represent a normal two-stage compressor operation NORM, by means of operation of both the first and the second compressor stage 21.1A, 21.1B. This is achieved via the at least one directional valve 30, 30' that can be switched to at least two switching states, i.e. in the present case via the first and second valve connections X, Y of the 5/2-way valve 30.5, 30.5', the air dryer 62 and an automatically opened, pilot-operated check valve 61 made available to compressed air connection 2. When an accumulator valve 94 is opened, the compressed air can also be stored in the pressure accumulator 92 via the further pneumatic line 96 and the gallery 95 . The pressure of the compressed air in the pressure accumulator 92 is constantly available due to the pressure sensor 97 connected directly to the accumulator 92 .

If, in the further course of operation of the pneumatic system 90 for a driving state of the vehicle 1000, a boost operation BOOST becomes necessary, the gallery 95 can first be prefilled via a boost inshot function (BOOST INSHOT). For this purpose, it is first necessary to query whether the pressure of the pressure accumulator 92 supplied by the pressure sensor 97 in method step S2 is above a threshold pressure. The swelling pressure is like this set high that a residual overpressure in the pressure accumulator 92 offers advantages over the normal operation NORM with both compressor stages shown in method step S1. If this is the case, in a method step S3, the 5/2-way valve 30.5' can be converted into an in 3 shown second switching state are brought. Compressed air is then available via the above-mentioned in-shot connection in the pressure accumulator 92, first via the additional check valve 32 (in-shot valve) of the pneumatic line 31 in the 5/2-way valve 30.5' and then via the bypass line 65 at the compressed air connection 2 for filling of the pneumatic system 90. Also, using the second compressor stage 21.1B of the two-stage compressor 21.1, residual compressed air from the pressure accumulator 92 can be compressed again and -- since it is already dry -- via the first and fifth valve connections X, V of the 5/2-way valve 30.5' into the bypass line 65 and are made available to the compressed air connection 2 while bypassing the air dryer 62 .

The further check valve 32 can be adjusted with the non-illustrated check valve spring of the same so that it closes automatically below a certain threshold pressure and thus automatically opens accumulator compressed air via the further check valve 22 for lower residual accumulator pressures and the second compressor stage 21.1B compresses the compressed air supply and then the main pneumatic line 60 is made available into the bypass line 65; this boost function BOOST is shown in method step S4.

If the pressure accumulator 92 is just before a state that allows neither an automatic opening of the additional check valve 22 nor an automatic opening of the additional check valve 32, the at least one directional control valve 30, 30', which can be switched into at least two switching states, with the function of a boost valve, ie in the present case the 5/2-way valve 30.5 or 30.5′, revert to the de-energized state when there is no current. Specifically, it can be provided that in the event that the pressure sensor 97 measures a pressure in the pressure accumulator 92 that is below the threshold pressure, the energization of the boost valve is canceled and this at least one directional control valve 30, 30', which can be switched into at least two switching states, with the function a boost valve, ie in this case the 5/2-way valve 30.5 or 30.5', in the 1 shown de-energized, the pneumatic main line 60 between the first and second valve port X, Y opening state falls back; this is shown in method step S5 of the method scheme, which basically enables a single-stage or two-stage normal operation NORM of the compressor 21.1.

Reference List

1000

vehicle

0.1

filter

1

compressed air supply

2

compressed air connection

7

branch connector

3

vent port

10, 10'

compressed air supply system

20

supply line

20.1

intermediate line

20.2

output line

20.3

intermediate branch line

21

air compressor

21.1

two-stage compressor

21.2

electric motor

21.1A

first compressor stage

21.1B

second compressor stage

22

another check valve

30, 30'

Directional valve switchable in at least two switching states

30.5, 30.5'

5/2 way valve

30A, 30A'

first switching state of the switchable directional control valve 30, 30'

30B, 30B'

second switching state of the switchb. directional valve 30, 30'

30M, 30M'

magnetic coil

30F, 30F'

valve spring

31

pneumatic line (inshot connection)

32

another check valve (inshot valve)

60

pneumatic main line

61

unlockable check valve

61K

Pilot operated check valve relay piston

62

air dryer

63

branch connector

64

first throttle

65

bypass line

70

vent line

71

vent valve

71F

valve spring

71S

pneumatic actuator

71K

Bleed valve relay piston

71X

first valve connection of the vent valve 71

71Y

second valve connection of the vent valve 71

74

second throttle

76S

pressure control port

80

solenoid valve assembly

81

control valve

81F

valve spring

81S

electrical control line

81M

magnetic coil

81X

first valve connection of the control valve 81

81Y

first second valve connection of the control valve 81

81Z

third valve connection of the control valve 81

90

pneumatic system

91

bellows

92

accumulator

91L

bellows line

92L

storage line

92ZL

memory branch line

93

bellows valve

94

storage valve

95

gallery

96

pneumatic line

97

pressure sensor

98

valve block

100

pneumatic system

110

pneumatic control line

110.1

first part

110.2

second part

110.3

third part

117

further ventilation line

M

engine

X

first valve port

Y

second valve port

Z

third valve port

W

fourth valve port

V

fifth valve port

S1

first step in the process

S2

second process step

S3

third step

S4

fourth step

S5

fifth step

STANDARD

Normal operation of the compressed air supply system

BOOST

Boost operation of the compressed air supply system

BOOST INSHOT

Boost inshot function of the compressed air supply system

Claims (19)

Compressed air supply system (10, 10'), in particular in a partially closed design, for operating a pneumatic system (100), in particular an air spring system of a vehicle (1000), having: - a compressed air supply (1), to which on the air supply side an air compressor (21) with a two-stage compressor (21.1) is connected, - a compressed air connection (2) to the pneumatic system (90) - a vent connection (3) to the environment - a pneumatic main line (60) between the compressed air supply (1) and the compressed air connection (2), which has an air dryer ( 62), - a vent line (70) between the compressed air port (1) and the vent port (3), wherein a vent valve (71) is connected to a valve port (71X, 71Y) in the vent line (70), and wherein - a The pressure accumulator (92) is connected directly to the air compressor (21) via an accumulator branch line (92ZL), characterized in that a pneumatic connection of the pneumatic main line (60) and a pneumatic connection of the accumulator branch line (92ZL) are connected to at least one switchable in at least two switching states Directional valve (30, 30'), wherein in a first switching state (30A, 30A') of the switchable directional valve (30, 30'), the compressed air supply (1) and the compressed air connection (2) via the air dryer (61) in the pneumatic Main line (60) are connected, wherein in the first switching state (30A, 30A ') of the switchable directional control valve (30, 30') on the compressed air supply side to the compressed air supply (1) an air supply connection (0) is connected and in a second switching state (30B, 30B') of the switchable directional valve (30, 30') the compressed air supply (1) and the compressed air connection (2) bypassing the air dryer (61) in of the pneumatic main line (60), wherein in the second switching state (30B, 30B') of the switchable directional control valve (30, 30') the accumulator branch line (92ZL) is connected to the compressed air supply line (1) on the compressed air supply side. compressed air supply system claim 1 characterized in that in the first switching state (30A, 30A') of the switchable directional control valve (30, 30'), on the compressed air supply side, an air supply connection (0) is connected to the compressed air supply (1) via an air compressor (21), preferably via a first and second compressor stage (21.1 A, 21.1B) of the air compressor (21), and in the second switching state (30B, 30B') of the switchable directional valve (30, 30') on the compressed air supply side to the compressed air supply (1) the accumulator branch line (92ZL) via an air compressor (21 ), preferably connected only via a compressor stage (21.1B). compressed air supply system claim 1 or 2 characterized in that - in the first switching state (30A, 30A') of the at least one directional valve (30, 30'), the pneumatic connection of the pneumatic main line (60) and the pneumatic connection of the accumulator branch line (92ZL) for normal operation (NORM, S1 , S5) can be switched, and/or - in the second switching state (30B, 30B') of the at least one directional control valve (30, 30'), the pneumatic connection of the pneumatic main line (60) and the pneumatic connection of the accumulator branch line (92ZL) for one Boost mode (BOOST, BOOST INSHOT, S3, S4) can be switched, with - in normal mode (NORM, S1, S5) and boost mode (BOOST, BOOST INSHOT, S3, S4) only one of the pneumatic connections consisting of a pneumatic main line (60) and memory branch line (92ZL), is open and the other is disconnected. compressed air supply system claim 3 characterized in that - in the first switching state (30A, 30A') of the at least one directional valve (30, 30'), the pneumatic connection of the pneumatic main line (60) is open and the pneumatic connection of the accumulator branch line (92ZL) is disconnected, and/ or - in the second switching state (30B, 30B') of the at least one directional control valve (30, 30'), the pneumatic connection of the pneumatic main line (60) is disconnected and the pneumatic connection of the accumulator branch line (92ZL) is open. Compressed air supply system according to one of Claims 1 until 4 characterized in that a pneumatic bypass line (65) between the at least one directional control valve (30, 30') which can be switched into at least two switching states and the compressed air connection (2) is designed to bypass at least the air dryer (62) pneumatically, wherein in the first switching state ( 30A, 30A') of the at least one directional valve (30, 30'), the bypass line (65) is disconnected and the bypass line (65) is open in the second switching state (30B, 30B') of the at least one directional valve (30, 30'). Compressed air supply system according to one of Claims 1 until 5 characterized in that the at least one switchable directional valve (30, 30') is a 5/2-way valve (30.5, 30.5'). Compressed air supply system according to one of Claims 1 until 5 characterized in that the at least one switchable directional control valve (30, 30') is one of a number of n/n directional control valves in a directional control valve arrangement, where n is a natural number. Compressed air supply system according to one of Claims 1 until 7 characterized in that a pneumatic in-shot connection provided with a non-return valve function is provided between the pneumatic storage branch line (92ZL) and the bypass line (65) in the second switching state (30B') with pneumatic bypass of the air compressor (21), the non-return valve function being carried out by the storage branch line (92ZL) to the bypass line (65) automatically opens, in particular a pneumatic in-shot connection provided with a check valve function as a pneumatic line (31) with a check valve (32) in a 5/2-way valve (30.5, 30.5') or a directional valve arrangement is formed with the at least one switchable directional control valve (30, 30') which opens automatically from the storage branch line (92ZL) to the bypass line (65). Compressed air supply system according to one of Claims 1 until 8th characterized in that a solenoid valve arrangement (80) has a control valve (81) for controlling the vent valve (71) and/or the main pneumatic line (60) has a check valve (61) which can be opened and which can be opened by means of the control valve (81). Compressed air supply system according to one of Claims 1 until 6 characterized in that the control valve (81) with a valve connection (81X, 81Y) is connected in a pneumatic control line (110) connected to a pneumatic actuator (71S) of the vent valve (71), and is designed to have a pneumatic actuator (71S), in particular when the valve connection (71X, 71Y) is open of the vent valve (71) in the vent line (70) and unblocked check valve (61) under control pressure, in particular wherein the control valve (81) has a first and a second valve port (81X, 81Y) which are in the control line (110) are connected, the control valve (81) being in the form of a 3/2-way valve which has a third valve connection (81Z) to the atmosphere and the control line (110) from the pneumatic main line (60) to a branch connection (63) for the bypass line (65) branches off. Compressed air supply system according to one of Claims 1 until 8th characterized in that - the pneumatic bypass line (65) is formed between the at least one switchable directional valve (30, 30'), in particular 5/2-way valve (30.5, 30.5'), and the compressed air connection (2), at least the air dryer ( 62), in particular also a pilot operated non-return valve (61), - in particular the main pneumatic line (60) has a first throttle (64) and the pneumatic bypass line (65) between the 5/2-way valve (30.5, 30.5') and the compressed air connection (2) is designed to pneumatically bypass the air dryer (62) and the pilot-operated check valve (61) and the throttle (64), - in particular the pneumatic bypass line (65) between the 5/2-way valve (30.5, 30.5 ') and a branch connection (63) for the bypass line (65) branches off in the pneumatic main line (60), the branch connection (63) between the air dryer (62) and the compressed air connection (2), in particular between the pilot-operated check valve (61) and the compressed air connection (2), in particular between the throttle (64) and the compressed air connection (2). Compressed air supply system according to one of Claims 1 until 8th characterized in that the pressure accumulator (92), in particular as part of a pneumatic system (90), is connected to a gallery (95) via an accumulator line (92L) and the accumulator branch line (92ZL) branches off from the accumulator line (92L), with a pressure sensor (97) is connected to the accumulator (92) directly and/or the gallery (95) and/or the accumulator line (92L) and/or the accumulator branch line (92ZL). Compressed air supply system according to one of Claims 1 until 12 characterized in that the two-stage compressor (21.1) has a first compressor stage (21.1A) and a second compressor stage (21.1B), the second compressor stage (21.1B) of the two-stage compressor (21.1) being connected directly to the pressure accumulator (92) is connected, in particular in a second switching state (30B, 30B') of the at least one switchable directional valve (30, 30'), in particular the 5/2-way valve (30.5, 30.5'), the accumulator branch line (92ZL) between the pressure accumulator (92) and the second compressor stage (21.1B) is open. Pneumatic system (100) with the compressed air supply system (10, 10 ') according to one Claims 1 until 13 and a pneumatic system (90), which is in the form of an air spring system, which has a gallery (95) and at least one branch line (91L, 92L) pneumatically connected to the gallery (95) with a bellows (91) and a pressure accumulator (92) and a directional control valve (93, 94) arranged upstream of the bellows (91) and/or the pressure accumulator (92), a pressure sensor (97) being connected directly to the pressure accumulator (92) and/or the gallery (95) and/or or the memory line (92L) and/or the memory branch line (92ZL). Method for controlling a compressed air supply system (10, 10') for operating a pneumatic system (90), in particular an air spring system of a vehicle (1000), in particular according to one of the preceding claims, wherein the compressed air supply system (10, 10') has: - a compressed air supply ( 1), to which an air compressor (21) with a two-stage compressor (21.1) is connected on the air supply side, -a compressed air connection (2) to the pneumatic system (90), -a venting connection (3) to the environment, -a pneumatic main line (60) between the compressed air supply (1) and the compressed air connection (2), which has an air dryer (62), - a ventilation line (70) between the compressed air connection (1) and the ventilation connection (3), wherein a ventilation valve (71) with a valve connection (71X , 71Y) is connected in the vent line (70), and wherein -a pressure accumulator (92) is connected directly to the air compressor (21) via an accumulator branch line (92ZL), with a pneumatic connection of the pneumatic main line (60) and a pneumatic connection the accumulator branch line (92ZL) to a directional valve (30, 30') that can be switched into at least two switching states (30A, 30A', 30B, 30B'), in particular in the form of a 5/2-way valve (30.5, 30.5') and/or a Directional valve arrangement, connected and switched by this are characterized in that the Method for filling the pneumatic system (90), the method steps: in a first switching state (30A, 30A') of the directional valve (30, 30'), connecting the compressed air supply (1) and the compressed air connection (2) via the air dryer (61) in the pneumatic main line (60), and in a second switching state (30B, 30B') of the directional control valve (30, 30'), connecting the compressed air supply (1) and the compressed air connection (2), bypassing the air dryer (61) in the pneumatic main line (60), wherein in the second switching state (30B, 30B') of the directional control valve (30, 30'), the pneumatic connection of the pneumatic main line (60) is disconnected and the pneumatic connection of the accumulator branch line (92ZL) and the bypass line (65) for bypassing at least the air dryer (62) is open. procedure after claim 15 , characterized by - normal filling (NORM, S1, S5) of the pneumatic system (90) by switching the at least one directional control valve (30, 30') to the first switching state (30A, 30A'), and/or - boost filling (BOOST, BOOST- INSHOT, S3, S4) by switching the at least one directional control valve (30, 30') to the second switching state (30B, 30B'). procedure after claim 15 or 16 , characterized in that - in the first switching state (30A, 30A'), the pneumatic connection of the pneumatic main line (60) is opened and the pneumatic connection of the accumulator branch line (92ZL) and a bypass line (65) for bypassing at least the air dryer (62) are disconnected in particular the compressor (21.1) is operated in one or two stages, compressed air being made available via the air dryer (62) at the compressed air connection (2). procedure after claim 15 , characterized in that in the second switching state (30B, 30B') - a pneumatic inshot connection (31) provided with a check valve function, in particular one provided in the 5/2-way valve (30.5, 30.5'), is opened between the pneumatic storage branch line (92ZL) and the bypass line (65) in the event that a pressure accumulator (92) has an overpressure and/or residual pressure that is beyond a predetermined threshold pressure, in particular an overpressure above a predetermined upper threshold pressure and/or a residual pressure below or is above a predetermined lower threshold pressure. Procedure according to one of Claims 15 until 18 , characterized in that for venting via the vent valve (71), the switchable directional valve (30, 30') in a first switching state (30A, 30A') for regenerating the air dryer (62) or in a second switching state (30B, 30B ') bypassing the air dryer (62) remains.

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