DE102017006398A1 - Compressed air supply system, pneumatic system, vehicle and method for operating a pneumatic system, in particular an air suspension system of a vehicle - Google Patents

Abstract

The invention relates to a compressed air supply system (10) for operating a pneumatic system (90), in particular an air suspension system (90 ') of a vehicle (1000). According to the invention, both the first and the second compression volume (51, 52) are connected to the air feed (0) on the suction side of the compressor (50), the first and second compression volumes (51, 52) being directed to the air feed (0). are connected in parallel such that the first and the second compression volume (51, 52) both in a first operating mode (MOD1) and in a second operating mode (MOD2) can collect supply air via the air supply (0), and- pressure side of the compressor (50) for providing the compressed air in the first operating mode (MOD1), the first and the second compression volume (51, 52) to the compressed air supply (1) switchable and connected in parallel.

Description

The invention relates to a compressed air supply system for operating a pneumatic system, in particular switchable open or closed compressed air supply system, preferably with a connected via a switching valve assembly pneumatic system, in particular a pneumatic system in the form of an air spring system and / or level control system of a vehicle, according to the preamble of claim 1. The invention further a pneumatic system and a vehicle with the compressed air supply system.

The invention also relates to a method for operating a pneumatic system, in particular an air spring system and / or level control system, according to the preamble of claim 16.

A compressed air supply system is used in vehicles of all kinds, in particular for supplying an air spring system of a vehicle with compressed air. An air suspension system may also include a level control system with which a distance between the vehicle axle and vehicle body can be adjusted.

An air spring system is for example as a closed level control system as in EP 1 243 447 B1 disclosed is feasible.

In principle, a compressed air supply system can also be realized as an open compressed air supply system, that is to say with a venting connection. Thus, a closed or open compressed air supply system is used regularly to operate a pneumatic system such as the aforementioned air suspension system and / or level control system of a vehicle. Such designed as an air spring system and / or level control system pneumatic system is thus connected to form a pneumatic system to the compressed air supply system.

An air suspension system and / or level control system regularly comprises a number of on a common line (gallery) pneumatically connected air bellows, which can increase the vehicle structure with increasing filling and lower accordingly with decreasing filling. With increasing distance between the vehicle axle and vehicle body or ground clearance and larger bumps are overcome without causing a contact with the vehicle body. Preferably, such systems are used in off-road vehicles and sport utility vehicles (SUVs). Especially with SUVs, it is desirable for very powerful engines to provide the vehicle on the one hand for high speeds on the road with relatively low ground clearance and on the other hand to provide for the terrain with a relatively large ground clearance. It is further desirable to implement a change in ground clearance as quickly as possible, which increases the requirements for speed, flexibility and reliability of a compressed air supply system. This applies in particular to compressed air supply systems which are designed to deliver comparatively large volumes of air with comparatively high pressures as required and to which have a compressor with a first and second compression volume.

That's how it is DE 10 2008 034 240 discloses a level control system of the applicant for vehicles, by which a vehicle body is sprung against at least one vehicle axle and having a two- or multi-stage compressor and which is realized as a closed level control system. The compressor has a first compression volume with a first suction chamber and a first compression chamber, wherein a pressure medium line connects the first suction chamber of the compressor with the atmosphere. Furthermore, the compressor has a second compression volume with a second suction space and a second compression space, wherein the first compression space and the second suction space communicate with each other. It is possible to realize by means of a valve that conveys the first compression volume of the compressor practically in a circle and to transfer the suction in the first suction and compressed in the first compression chamber pressure medium via an outlet valve and said switched valve in a pressure medium line to the power save the first compression volume or reduce in a predetermined manner. From the mentioned pressure medium line, the pressure medium is then transferred either in the first suction or in the atmosphere. Such a system is thus able to reduce or save a first compression volume, so that only the second compression volume contributes to the compression of the pressure medium. However, such a level control system in terms of their flexibility is still improved.

EP 2 222 488 B1 In contrast, again shows a comparatively simple constructed closed level control system with a compressor, which is compressed in a first operating mode both in a first compression volume and in a second compression volume and compressed air reaches consumers of the level control system, so that a particularly large amount of air can be transferred to the level control system , For this purpose, a second compression volume can be switched to the first compression volume via a 3/2-way valve; are at the 3/2-way valve a Saugraumleitung a first compression volume and an outlet of a second compression volume connected. In this way, compressed air can be transferred into the outlet line only in a first operating mode from a first compression volume. In a further operating mode, it is also possible for the named suction chamber line to be blocked and the said outlet line to be switched through, so that the second compression volume is connected to the first compression volume. The 3/2-way valve is electrically controlled. In the latter case, where both compression volumes are involved in the delivery of compressed air, the maximum available compressed air is delivered by the compressor. The connection of the second compression volume to the first compression volume is preferably used when the pressure in the suction chamber is low. Also, such a level control system is in terms of their flexibility even better.

DE 103 21 771 A1 describes a method for limiting the power of a compressor, which compresses an air flow in at least two stages of compression to a predetermined pressure, wherein the compressed air flow is tuned to the performance of an electric drive, characterized in that when reaching the predetermined power limit of a higher power compressor capable of Pressure of at least one of the compression stages, which is upstream of the last compression stage, the pressure of their respective upstream compression stage is adjusted.

The object of the invention is to provide an improved solution for a compressed air supply system. In particular, a flexible operation should be made possible at the same time high volume and pressure performance of the compressed air supply system. In particular, this should be realized for a pneumatic system with said compressed air supply system and a pneumatic system, in particular in the form of a level control system and / or air suspension system of a vehicle. Preferably, the compressed air supply system and / or the pneumatic system and the pneumatic system to burden a vehicle electrical system of a vehicle to a reduced extent. In particular, a compressed air supply system and / or a pneumatic system and a pneumatic system of the type mentioned should be selectively operable as an open or closed system. Furthermore, it is an object of the invention to provide a vehicle provided with similar advantages and a method for operating a compressed air supply system and / or pneumatic system, in particular a pneumatic system.

The task relating to the compressed air supply system is achieved with a compressed air supply system of claim 1.

The invention relates to a compressed air supply system, in particular switchable open or closed compressed air supply system, for operating a pneumatic system, preferably a connected via a switching valve assembly pneumatic system, in particular a pneumatic system in the form of an air spring system and / or level control system of a vehicle. The compressed air supply system comprises: an air supply for supplying supply air to a compressor having a first compression volume and a second compression volume for compressing the supply air to compressed air; a compressed air supply for supplying the compressed air from the compressor, wherein the compressor is designed as a two-cylindrical compressor with the first compression volume and with the second compression volume.

According to the invention, both the first and the second compression volume are connected to the air supply on the intake side of the compressor, the first and second compression volumes being connected in parallel to the air supply in such a way that the first and second compression volumes are in a first mode of operation also in a second operating mode together can receive supply air via the air supply.

According to the concept of the invention, it is provided that on the pressure side of the compressor for providing the compressed air in the first operating mode (open operation), the first and second compression volumes are connected to the compressed air supply in a switchable and parallel manner.

According to the concept of the invention, it is provided that in the second operating mode (closed operation) only the first compression volume is switchably connected to the compressed air supply.

In the first mode of operation, the first and second compression volumes may deliver compressed air to the compressed air supply out of phase; insofar parallel connected and clocked. In the second mode of operation, the first compression volume - in particular only the first compression volume - deliver compressed air to the compressed air supply, wherein in the second mode of operation, the second compression volume is wegschaltbar means of a return valve such that the second compression volume in the second mode of operation no compressed air to the Can deliver compressed air supply. The return valve is pneumatically controllable by means of a control pressure line for Recirculation valve, which is designed to guide control pressure for the pneumatic control of the return valve.

The compressed air supply system is in particular a switchable open or closed compressed air supply system for operating a pneumatic system, preferably a pneumatic system connected via a switching valve arrangement, in particular a pneumatic system in the form of an air spring system and / or level control system of a vehicle.

The invention also leads to a pneumatic system with said compressed air supply system and a pneumatic system, in particular in the form of an air spring system and / or a level control system of claim 14. The invention also leads to a vehicle of claim 15.

The task concerning the method is achieved according to the invention with a method for operating a compressed air supply system and / or pneumatic system according to claim 16.

• - eine Luftzuführung zu einem Verdichter, der ein erstes Verdichtungsvolumen und ein zweites Verdichtungsvolumen jeweils zur Verdichtung der Zuluft zu Druckluft aufweist,
• - eine Druckluftzuführung zur Bereitstellung der Druckluft von dem Verdichter, wobei der Verdichter als ein zwei-zylindrischer Verdichter mit dem ersten Verdichtungsvolumen und mit dem zweiten Verdichtungsvolumen ausgebildet ist.

The invention relates to a method for operating a pneumatic system, preferably a pneumatic system connected via a switching valve arrangement, in particular a pneumatic system in the form of an air spring system and / or level control system of a vehicle, wherein the compressed air supply system, in particular a switchable open or closed compressed air supply system comprises:

• an air supply to a compressor, which has a first compression volume and a second compression volume respectively for compressing the supply air to compressed air,
• a compressed air supply for supplying the compressed air from the compressor, wherein the compressor is designed as a two-cylindrical compressor with the first compression volume and with the second compression volume.

• - druckseitig des Verdichters zur Bereitstellung der Druckluft in dem ersten Betriebsmodus in dem ersten Betriebsmodus das erste und das zweite Verdichtungsvolumen an die Druckluftzuführung schaltbar und parallel angeschlossen sind und in dem zweiten Betriebsmodus nur das erste Verdichtungsvolumen an die Druckluftzuführung schaltbar angeschlossen ist, wobei das Verfahren die Schritte aufweist:
• - Abgeben von Druckluft in dem ersten Betriebsmodus, wobei das erste und das zweite Verdichtungsvolumen Druckluft an die Druckluftzuführung phasenverschoben abgeben, und
• - Abgeben von Druckluft in dem zweiten Betriebsmodus, wobei das zweite Verdichtungsvolumen mittels eines Rückführventils derart wegschaltbar ist, dass das zweite Verdichtungsvolumen in dem zweiten Betriebsmodus keine Druckluft an die Druckluftzuführung abgeben kann, wobei das Rückführventil pneumatisch angesteuert wird, mittels einer Steuerdruckleitung zum Rückführventil zum pneumatischen Steuern des Rückführventils.

According to the invention, both the first and the second compression volume are connected to the air supply on the intake side of the compressor, the first and second compression volumes being connected in parallel to the air supply in such a way that the first and second compression volumes are in a first mode of operation also in a second operating mode together can receive supply air via the air supply, which are insofar particularly parallel connected and clocked operable, and

• - The pressure side of the compressor for providing the compressed air in the first operating mode in the first operating mode, the first and the second compression volume to the compressed air supply switchable and connected in parallel and connected in the second operating mode, only the first compression volume to the compressed air supply switchable, the method Steps:
• - Dispensing compressed air in the first mode of operation, wherein the first and the second compression volume deliver compressed air to the compressed air supply out of phase, and
• - Dispensing compressed air in the second operating mode, wherein the second compression volume can be switched off by means of a return valve such that the second compression volume can deliver in the second mode of operation no compressed air to the compressed air supply, the return valve is pneumatically controlled by means of a control pressure line to the return valve to the pneumatic Controlling the return valve.

In particular, the first operating mode (open operation) of the compressed air supply system is assigned a first switching state of the return valve, preferably for pneumatic separation of the line of the return valve to prevent a compressed air flow, and the second operating mode (closed operation) of the compressed air supply system is a second switching state of the return valve, preferably for pneumatic connection of the line of the return valve to allow a compressed air flow assigned.

It is preferably provided that in the second operating mode only the first compression volume can deliver compressed air to the compressed air supply, in particular only the first compression volume can operate in the compression mode.

Taking into account the aforementioned aspects, the invention is already based on a compressed air supply system of the type mentioned in the introduction. Essentially comprises: an air supply and a compressed air supply, wherein the compressor is designed as a two-cylindrical compressor with a first compression volume and with a second compression volume. In principle should - simplified - shown in a first mode of operation, the first and the second compression volume can deliver compressed air and can deliver in a second mode of operation, only the first compression volume of compressed air. The invention has also recognized that it is advantageous if the compressor is able to work in parallel with both compression volumes; that is, in contrast to the sequential circuit of a first and second compression volume provided in the prior art.

In this respect, the concept of the invention is such that both the suction side of the compressor the first and the second compression volume is connected to the air supply, wherein the first and the second compression volume are connected to the air supply in parallel such that the first and the second compression volume in both a first operating mode and in a second operating mode together via the air supply Zuluft can accommodate, but the pressure side of the compressor for providing the compressed air in the first operating mode, the first and the second compression volume to the compressed air supply switchable and connected in parallel, and in the second operating mode, only the first compression volume is connected to the compressed air supply switchable.

According to the invention, it is provided that in the first operating mode, the first and the second compression volume compressed air to the compressed air supply ( 1 In the second operating mode, the second compression volume can be switched away by means of a return valve such that the second compression volume in the second operating mode can not deliver compressed air to the compressed air supply ,

The first operating mode is also referred to below as "open mode" and the second operating mode as "closed mode". The return valve is pneumatically controllable, by means of a control pressure line to the return valve, which is designed to guide control pressure for the pneumatic control of the return valve.

The concept of the invention has the advantage that a common compressed air generation of the first and second, connected in parallel to the compressed air connection, compression volume is possible. This increases the flexibility as well as the speed of available compressed air production.

Furthermore, the concept of the invention provides the basis for a more advantageous design of the compressed air supply system. Thus, in the context of an advantageous option for the regeneration of the air dryer, d. H. with venting of the pneumatic system, or in the manner of the first and / or second operating mode, a compressed air can also be delivered to the vent port or only be delivered to the vent port.

Furthermore, the concept of the invention offers the possibility of making the first and second compression volumes similar, which has many advantages in the realization of the compressor. In particular, the return valve arrangement is designed such that in the second operating mode, only the first compression volume can deliver compressed air to the compressed air connection. With a similar design of the first and second compression volumes, it is particularly advantageously possible to expand the concept such that in the second operating mode only the second compression volume is able to deliver compressed air to the compressed air connection and / or the vent connection. Advantageously, as part of a further development by means of the return valve arrangement can be selected as needed, which of the first compression volume or the second compression volume is able to deliver compressed air to the compressed air connection.

For this reason, the invention expressly devises less a switching valve arrangement as in the prior art for connecting a second compression volume or switching off a first compression volume, but rather a return valve arrangement with a return valve preferably connected between pressure side and suction side of the compressor. According to the invention, it is provided that in the second operating mode, the second compression volume is switched off by means of a return valve, wherein the return valve is pneumatically controlled, wherein the control pressure in a control pressure line is fed to the return valve for pneumatic control.

The invention has recognized that this results in the above-mentioned synergies and, moreover, is able to realize at least one recirculation valve, preferably at least one first and one second recirculation valve, of the recirculation valve arrangement, without great additional expenditure. Nevertheless, the concept of the invention makes it possible to provide different switching states both for a gallery of a pneumatic system and for a compressed air reservoir of the pneumatic system.

Advantageous developments of the invention can be found in the dependent claims, which realize the concept of the invention within the scope of the task with further advantages.

Preferably, at least via the return valve on the pressure side of the compressor, the first and / or the second compression volume to the compressed air supply, and / or suction side of the compressor, the first and / or the second compression volume to the air supply, connected switchably. To the compressed air supply, a pneumatic main line comprising an air dryer and a compressed air connection may be connected to a switching valve arrangement. The compressed air supply to the pneumatic main line can between a first part and a second part of a connecting line be connected, wherein the connecting line between the first and the second compression volume is connected.

In the context of a particularly preferred development, the recirculation valve arrangement has a return valve connected between the pressure side and the suction side of the compressor and / or a second isolation valve connected on the pressure side between the first and second compression volumes. The development has recognized that the realization of the recirculation valve arrangement with the recirculation valve and the isolation valve increases the flexibility of an operation of the recirculation valve arrangement and nevertheless offers a comparatively simple realization compared with a comparatively complex switching valve, in particular a 3/2-way valve, of the prior art. In particular, this allows the advantageous operation in the first operating mode, in which the first and the second compression volume are connected in parallel and can deliver compressed air together to the compressed air connection

Advantageously, the connected between the pressure side and suction side of the compressor recirculation valve, a 2/2-way valve and / or a pressure side connected between the first and the second compression volume separating valve is a check valve. Both options can be realized alone, alternatively or in combination for the return valve arrangement. The said possibility of a return valve in the form of a 2/2-way valve is a comparatively simple way; In addition, there are other ways of implementing a return valve.

Furthermore, a return valve arrangement preferably has at least the return valve and / or an isolation valve. The first and / or the second compression volume are preferably connected on the pressure side to the compressed air supply via the return valve arrangement in a line.

Specifically, the following arrangements of a separating valve and / or a corresponding control pressure line have proven to be advantageous. In particular, a second and / or further, separating valve can be arranged on the output side of the outlet valve of the first or second compression volume. It can be arranged in the discharge line of the first or second compression volume, the second and / or further isolation valve.

The first and / or further isolation valve may be arranged in the supply line of the first or second compression volume. For example, in a first preferred variant, the first and / or further isolation valve may be arranged in the supply line upstream of the inlet valve in the direction of flow of the inlet valve of the first or second compression volume.

For example, in a second preferred variant, the first and / or further isolation valve may be arranged in the supply line downstream of the inlet valve in the direction of flow of the inlet valve of the first or second compression volume.

Preferably, the first and / or second isolation valve is a non-return valve opening in the direction of the compressed air supply.

A realization of the first, second and / or further isolation valve in each case as a check valve is a comparatively simple possibility; In addition, there are other possibilities of realization of the second isolation valve; e.g. as a 2/2-way valve. In particular, the first and / or second isolation valve is a 2/2-way valve of a return valve arrangement.

A synergistic combination of a 2/2-way valve and a check valve has the advantage that it is not only simple, but also pneumatically controlled feasible. This has the advantage that an electrical control requirement of the return valve assembly by the electric vehicle system largely eliminated. Preferably, it is provided that the inlet valve of the first or second compression volume is integrated in the first and / or second isolation valve or the first and / or second isolation valve acts on the inlet valve of the first or second compression volume such that the inlet valve is pressurized when the first and / or second compression volume. or second isolation valve remains closed.

• - die Steuerdruckleitung an eine Bypass-Leitung der Leitung, und/oder
• - die Steuerdruckleitung an eine Zuführleitung der Leitung, und/oder
• - die Steuerdruckleitung an eine Abführleitung der Leitung angeschlossen ist.

So it is particularly advantageous in the context of a development that the switched between the pressure side and suction side of the compressor recirculation valve is pneumatically controlled. Particularly advantageously, the return valve with a suction-side control pressure can be controlled. This can be provided comparatively easily by a compressed air reservoir or a gallery of the pneumatic system. Preferably, it is provided that concerning a line to the first compression volume

• - The control pressure line to a bypass line of the line, and / or
• - The control pressure line to a supply line of the line, and / or
• - The control pressure line is connected to a discharge line of the line.

In particular, an adjustable threshold pressure can be provided in the return valve or further return valve and / or in the first or further isolation valve. Of the Threshold pressure can be adjusted advantageously via the valve spring of the return valve or the valve spring of the separating valve.

Preferably, the return valve is transferred only at a pressure in the control line above a threshold value of a first switching state to a second switching state. The first switching state is assigned in particular to the first operating mode. The second switching state is assigned in particular to the second operating mode. The threshold value of the return valve is preferably adjustable in a range of 2 bar to 8 bar above the atmospheric pressure.

The first, second or further return valve in the form of a 2/2-way valve can be realized comparatively easily as a 2/2-way valve opening against a valve spring force. In addition or as an alternative, the separating valve in the form of a check valve can be realized comparatively easily as a non-return valve which self-opens against a valve spring force, so that an electrical activation of the second separating valve can also be omitted here.

Advantageously, the compressed air supply system is further developed by a vent connection, wherein the pressure side of the compressor, the first and / or the second compression volume are connected to the vent port, the vent port is associated with a further isolation valve of the return valve assembly, the further isolation valve switchable a vent line to the vent port, preferably uncontrolled , pneumatically separated. Preferably, the further isolation valve is formed as a 2/2-way valve.

The return valve arrangement can be adjusted particularly advantageously so that it separates pneumatically in the uncontrolled state. Preferably, it is provided that in the first operating mode, the first and / or second return valve connected between the pressure side and the suction side of the compressor preferably pneumatically separates the 2/2-way valve pressure side and suction side of the compressor, in particular pneumatically disconnects uncontrolled. That is, especially in the case of a pneumatically controlled first and / or fourth return valve, preferably the 2/2-way valve, this separates the pressure side and suction side pneumatically for the case that in particular no pressure at the suction side of the first and / or fourth return valve.

In the second operating mode, it is preferably provided that the first and / or fourth return valve connected between the pressure side and the suction side of the compressor, preferably activated, pneumatically connects the pressure side and suction side of the compressor. In particular, it is provided that in the case of a pressure applied on the suction side (in particular used as control pressure) from reaching a threshold pressure, the first and / or fourth return valve against the spring force of the valve spring automatically, that is pneumatically controlled opens. Thus, while in the pneumatically uncontrolled state of the first and / or fourth return valve, the pressure side and suction side of the compressor are pneumatically separated (pneumatically open state of the first return valve), both compression volume of the compressor are capable of parallel and common air from the environment from the air supply suction and also together and in parallel to promote compressed air to the compressed air connection.

In contrast, only the second compression volume can deliver compressed air to the compressed air connection in the second operating mode. For this purpose, a second return valve connected on the pressure side between the first and second compression volumes may remain closed, a check valve which automatically opens from the second compression volume in the direction of the first compression volume. The compressed air generated by the first compression volume is thus promoted against the reverse direction of the check valve instead in the pneumatic main.

With regard to the pneumatic system, it has proved to be advantageous that a switching valve arrangement is connected to the compressed air connection, which is designed optionally to pressurize a first or second compressed air reservoir of a pneumatic system with compressed air. A first compressed air reservoir may in particular be a bellows and a second compressed air reservoir may in particular be an accumulator of an air spring system of a vehicle.

It has proved to be advantageous that the switching valve arrangement has a first pair of isolation valves and / or a second pair of isolation valves. Optionally, a bellows and / or a pressure accumulator of an air suspension system of a vehicle can be acted upon with compressed air and wherein the switching valve assembly comprising: a pair of bellows valves, in particular a first pair of 2/2-way valves associated with the first compressed air reservoir and / or a pair of storage valves, in particular a second pair of 2/2-way valves associated with the second compressed air reservoir.

In this respect, a first pair of isolation valves in a gallery may be associated with one or more bellows of an air spring system and / or a second pair of isolation valves may be associated with a pressure accumulator of the pneumatic system. The first and / or second pair of isolation valves is preferably formed as a first and / or second pair of 2/2-way valves.

Alternatively, the switching valve arrangement may alternatively also have a first 3/2-way valve which is assigned to the compressed air reservoir and / or has a second 3/2-way valve which is assigned to the second compressed air reservoir.

All or some of the aforementioned valves of the return valve arrangement are pneumatically actuated within the scope of a particularly preferred development, in particular automatically opening against a valve spring force.

Alternatively or additionally, one, some or all valves of the switching valve arrangement can also be realized as electrically controllable valves (for example solenoid valves) with electrical control.

All or some valves of the aforementioned switching valve arrangement are preferably pneumatically controlled within the scope of a particularly preferred development, that is to say self-opening against the pressure of a valve spring force. Alternatively or additionally, one, some or all of the valves of the switching valve arrangement can also be designed as electrically controllable valves, i. in particular with electrical control, realize.

The compressor preferably has a first check valve as the input valve of a first compression volume and a second check valve as the input valve of a second compression volume.

The compressor further preferably has a first check valve as the output valve of the first compression volume and a second check valve as the output valve of the second compression volume.

In addition, the compressed air supply system preferably has a first check valve on the air supply and a second check valve on the compressed air connection. In particular, the second check valve on the compressed air connection may be provided parallel to a throttle, which is advantageous for the regeneration of the air dryer.

These and other preferred developments and embodiments of the invention are the subject of the dependent claims and drawings and specify both the compressed air supply system and the method in terms of particularly advantageous embodiments, preferably in relation to an air suspension system of a vehicle. However, as explained in the general aspect of the invention, the concept of the invention is not limited to the development with respect to an air suspension system and / or level control system of a vehicle.

In particular, such embodiments of the invention are described below with reference to the drawing. This is not necessarily to scale the embodiments, but the drawing, where appropriate for explanation, executed in a schematized and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art. It should be noted that various modifications and changes may be made in the form and detail of an embodiment without departing from the general idea of the invention. The disclosed in the description, in the figures of the drawing and in the claims features of the invention may be essential both individually and in any combination for the development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the figures 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 article that would be limited in comparison with the subject matter claimed in the claims. For the given design ranges, values within the stated limits should also be disclosed as limit values and be arbitrarily usable and claimable. Identical or similar parts or parts of identical or similar function are, where appropriate, provided with the same reference numerals for the sake of simplicity.

• 1 eine besonders bevorzugte Ausführungsform eines pneumatischen Systems mit einer Druckluftversorgungsanlage, wobei ein pneumatisch ansteuerbares Rückführventil mit einer Steuerdruckleitung an einer Bypass-Leitung vorgesehen ist, sowie mit einer Pneumatikanlage in Form einer Luftfederanlage und Niveauregelanlage eines Fahrzeugs, wobei das pneumatische System als ein wahlweise offenes System der Druckluftversorgungsanlage und Pneumatikanlage in einem ersten Betriebsmodus des Rückführventils oder geschlossenes System der Druckluftversorgungsanlage und Pneumatikanlage in einem zweiten Betriebsmodus des Rückführventils realisiert ist und das pneumatische System zusätzlich einen über ein als Rückschlagventil ausgebildetes Trennventil schaltbaren Entlüftungsanschluss aufweist;
• 2A eine weitere Ausführungsform eines pneumatischen Systems mit einer Druckluftversorgungsanlage, wobei das Rückführventil in der Zuführleitung des zweiten Verdichtungsvolumens angeordnet ist - dies in Kombination mit einem Rückschlagventil als Einlassventil;
• 2B eine zu 2A leicht abgewandelte Ausführungsform eines pneumatischen Systems mit einer Druckluftversorgungsanlage, wobei das Einlassventil des zweiten Verdichtungsvolumens als ein Rückschlagventil in dem Rückführventil integriert ist,
• 3 eine besonders bevorzugte Ausführungsform eines pneumatischen Systems mit einer Druckluftversorgungsanlage ähnlich der 1, wobei ein pneumatisch ansteuerbares Rückführventil mit einer Steuerdruckleitung an einer Bypass-Leitung für ein zweites Verdichtungsvolumen und ein elektrisch ansteuerbares weiteres Rückführventil mit einer Steuerdruckleitung an einer Bypass-Leitung für ein erstes Verdichtungsvolumen vorgesehen ist;
• 4 die Ausführungsform des pneumatischen Systems der 1 in einem Schaltzustand einer Rückführventilanordnung mit dem Rückführventil und dem als Rückschlagventil ausgebildeten Trennventil für den ersten Betriebsmodus (offener Betriebsmodus), bei welchem mittels des Rückführventils die Druck- und Saugseite pneumatisch getrennt sind, also das Rückführventil unangesteuert pneumatisch trennt, derart dass das erste und das zweite Verdichtungsvolumen phasenverschoben Druckluft an die Druckluftzuführung abgeben können;
• 5 die Ausführungsform eines pneumatischen Systems der 1 in einem Schaltzustand der einer Rückführventilanordnung mit dem Rückführventil und dem als Rückschlagventil ausgebildeten Trennventil für den zweiten Betriebsmodus (geschlossener Betrieb), bei welchem das Rückführventil die Druck- und Saugseite pneumatisch verbindet, also in einem pneumatisch angesteuerten Zustand pneumatisch verbindet, sodass nur das erste Verdichtungsvolumen Druckluft an die Druckluftzuführung abgibt;
• 6 eine erste Ausführungsform einer Schaltventilanordnung zur Anbindung einer Pneumatikanlage der 1, wobei die Schaltventilanordnung in der beschriebenen Weise mit einem ersten Paar von 2/2-Wegeventilen und einem zweiten Paar von 2/2-Wegeventilen gebildet ist;
• 7 eine alternative Ausführungsform einer Schaltventilanordnung für eine vorgenannte Pneumatikanlage der 1, wobei die Schaltventilanordnung ein erstes 3/2-Wegeventil und ein zweites 3/2-Wegeventil aufweist;
• 8 eine schematische Darstellung eines Fahrzeugs mit einem pneumatischen System der 1, wobei eine Fahrzeugsteuerung (ECU) ausgebildet ist, einen ersten und zweiten Betriebsmodus für das pneumatische System vorzugeben und wobei die Rückführventilanordnung pneumatisch angesteuert und die Schaltventilanordnung elektrisch angesteuert wird.

Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and with reference to the following drawings. In detail, the drawing shows in:

• 1 a particularly preferred embodiment of a pneumatic system with a compressed air supply system, wherein a pneumatically controllable return valve is provided with a control pressure line to a bypass line, and with a pneumatic system in the form of an air spring system and level control system of a vehicle, the pneumatic system as an optional open system of Compressed air supply system and pneumatic system in a first operating mode of the return valve or closed system of the compressed air supply system and pneumatic system is realized in a second operating mode of the return valve and the pneumatic system additionally has a via a designed as a check valve separating valve switchable vent port;
• 2A a further embodiment of a pneumatic system with a compressed air supply system, wherein the return valve is arranged in the supply line of the second compression volume - this in combination with a check valve as an inlet valve;
• 2 B one too 2A a slightly modified embodiment of a pneumatic system with a compressed air supply system, wherein the inlet valve of the second compression volume is integrated as a check valve in the return valve,
• 3 a particularly preferred embodiment of a pneumatic system with a compressed air supply system similar to the 1 wherein a pneumatically controllable recirculation valve is provided with a control pressure line on a bypass line for a second compression volume and an electrically controllable further return valve with a control pressure line on a bypass line for a first compression volume;
• 4 the embodiment of the pneumatic system of 1 in a switching state of a return valve assembly with the return valve and designed as a check valve isolation valve for the first operating mode (open mode) in which by means of the return valve, the pressure and suction sides are pneumatically separated, so the return valve uncontrolled pneumatically separates, such that the first and the second compression volume out of phase can deliver compressed air to the compressed air supply;
• 5 the embodiment of a pneumatic system of 1 in a switching state of a return valve assembly with the return valve and designed as a check valve separating valve for the second operating mode (closed operation), in which the return valve pneumatically connects the pressure and suction side, so pneumatically connected in a pneumatically controlled state, so that only the first compression volume Delivers compressed air to the compressed air supply;
• 6 a first embodiment of a switching valve arrangement for connecting a pneumatic system of 1 wherein the switching valve assembly is formed in the manner described with a first pair of 2/2-way valves and a second pair of 2/2-way valves;
• 7 an alternative embodiment of a switching valve arrangement for an aforementioned pneumatic system of 1 wherein the switching valve assembly comprises a first 3/2-way valve and a second 3/2-way valve;
• 8th a schematic representation of a vehicle with a pneumatic system of 1 wherein a vehicle controller (ECU) is configured to specify a first and second operating mode for the pneumatic system and wherein the return valve arrangement is pneumatically controlled and the switching valve arrangement is electrically controlled.

1 shows a particularly preferred embodiment of a pneumatic system 100 with a compressed air supply system 10 and a pneumatic system 90 , where the pneumatic system 90 in the form of an air spring system 90 ' is formed, which also serves as a level control system. This is indicated by the pneumatic system 90 several at a gallery 95 pneumatically connected branches 98 on, to each a bellows 91 an air spring is connected. Every bellows 91 is for pneumatic release or pneumatic separation of the branch line 98 an electrically controlled 2/2-way valve 93 upstream. The 2/2-way valve 93 is designed as a solenoid valve. At the gallery 95 is also a pressure sensor 94 connected by means of which pressure p in the gallery 95 can be measured. The pneumatic system 90 also includes a compressed air reservoir 92 , which is another branch line 99 connected.

The aforementioned compressed air supply system 10 is used to operate the pneumatic system 90 and for supplying the same with compressed air or for discharging the compressed air from the pneumatic system 90 that means concretely from the bellows 91 and / or the compressed air storage 92 ; the pneumatic system 100 from compressed air supply system 10 and pneumatic system 90 also allows the transfer of compressed air between bellows 91 and / or the compressed air storage 92 ,

The compressed air supply system 10 puts on a compressed air connection 2 compressed and dried air as compressed air available. The air is to an air supply 0, namely via an air filter 0.1 and a check valve 0.2 sucked in via a feed line 0.3 to the air supply 0, in a compressor 50 compressed and at the compressed air supply 1 made available. In the present case, the compressor 50 a compressor with a first compression volume 51 and with a second compaction volume 52 in each case for the compression of the supply air to compressed air. A compressed air supply 1 is configured to provide the compressed air from the compressor, the compressor acting as a two-cylinder compressor with the first compression volume 51 and with the second compression volume 52 designed in parallel clocked operable. Suction side of the compressor 50 is both the first and second compression volumes 51 . 52 is connected to the air supply 0, wherein the first and the second compression volume 51 . 52 are connected in parallel to the air supply 0 in such a way that the first and the second compression volume 51 . 52 both in a first operating mode and in a second operating mode together can receive air supply via the air supply. Pressure side of the compressor 50 for providing the compressed air in the first operating mode is the first and the second compression volume 51 . 52 to the compressed air supply 1 switchable and connected in parallel. The first and second compression volumes 51 . 52 is here for the sake of clarity in the drawing throughout additionally denoted by "1" and "2".

The compressed air thus produced is then dried over an air dryer 61 in the pneumatic main 60 guided and then at the compressed air connection 2 provided by the compressed air through the air dryer and then via an automatically opening non-return valve 62 the pneumatic main 60 to the compressed air connection 2 to be led.

Conversely, when bleeding a bellows 91 or the compressed air storage 92 with closed check valve 62 the compressed air to be vented via the regeneration throttle 63 turn over the air dryer 61 for compressed air supply 1 - Under regeneration of the air dryer and entrainment of moisture from this - a vent port 3 fed. About the vent line 70 Finally, the compressed air can be through a silencer 71 be vented into the environment; this can be a separating valve 23 as a vent valve, namely here as a 2/2-way valve, are electrically controlled and in the vent line 70 the exhaust port 3 with the muffler 71 connect pneumatically.

Overall, this is the compressed air supply 1 and the vent port 3 with the pneumatic main 60 or the vent line 70 on a connecting cable 40 of the compressor 50 connected. To the connection line 40 is also connected via the air supply 0, the above-mentioned feed line 0.3.

In the context of the concept of the invention, the embodiment of the compressed air supply system 10 particular features to be highlighted, which are explained below.

Firstly, as explained above, to the connection line 40 the compressor 50 as a compressor with a first compression volume 51 and in parallel with a second compression volume 52 via the connecting cable 40 to the air supply 0 connected. Here is the first and the second compression volume 51 . 52 connected in parallel to the air supply 0, that this first and second compression volume 51 . 52 , as explained above, together and in total substantially simultaneously, although phase-shifted, ie clocked so far, can suck in air via the air supply 0. In the present case, the compressor is thus a compressor (TWIN compressor) with the first compression volume 51 and with the second compression volume 52 , wherein the following refers to the compression volume. In this respect, the description of the following embodiments is also marginal for compressors whose first and second compression volumes are designed as first and second compressor stages; However, according to the concept of the invention, the present embodiment is, above all, not a two-stage compressor, but rather a two-cylindrical compressor, as it is called here.

The compressor 50 is driven in the present case via an engine M and unspecified and only symbolically shown crankshaft and connecting rod connections, so that this mechanism in the first and second compression volume 51 . 52 the pistons shown here only symbolically are moved back and forth; this leads to the compression of the first and second check valve input valves 41 . 42 at the connection line 40 sucked air in the first and second compression volume 51 . 52 , The compressed air can present - following the inventive concept - from the first and / or second compression volume 51 . 52 and via a first and / or second check output valve 43 . 44 as well as the connecting cable 40 to the compressed air supply 1 be passed on.

According to the concept of the invention, the first and second compression volumes are 51 . 52 parallel to the connecting cable 40 and the compressed air supply and then via the pneumatic main line 60 to the compressed air connection 2 connected so that compressed air together and in total substantially at the same time, although phase-shifted, ie clocked so far, to the compressed air supply 1 and the compressed air connection 2 can be delivered.

For this purpose, the compressed air supply system 10 Following the concept of the invention present here, a return valve assembly 20 on, which in the present case comprises three valves. The return valve 21 the return valve assembly 20 is in a bypass line 30 between the print side DS and the suction side SS of the compressor 50 connected; the return valve 21 could also be referred to as a bypass valve - ultimately it serves to relieve the pressure of the second compression volume 52 even if this compacts, as explained below. Also the control pressure line 45 to the return valve is to the bypass line 30 connected to the transmission a control pressure p on the pneumatic piston 46 the return valve 21 , In addition, there is a separating valve 22 in the outlet line or the connection line designated here 40 between the first and second compression volumes 51 . 52 switched on the pressure side. Another above already explained isolation valve 23 is in the vent line 70 arranged as a vent valve.

Thus, the return valve assembly includes 20 in the present case, a return valve designated here 21 in the form of a pneumatically controlled 2/2-way valve, wherein a control line 45 to divert a control pressure on the pneumatic piston 46 for controlling the return valve 21 , which is designed here as a pneumatically controlled 2/2-way valve, is given, and then opens the pneumatically controlled 2/2-way valve against the force of a valve spring 21 F.

The optional isolation valve 22 can be in the form of an automatically opening non-return valve RV be formed against the force of a valve spring 22F opens - namely when a threshold pressure in the connecting line 40 ,

The bleed valve is another optional isolation valve 23 the return valve assembly 20 is in the vent line 70 connected and opens at the corresponding electrical control signal to the solenoid, the vent line 70 against the spring force of the valve spring 23F ,

Furthermore, the pneumatic system 100 a pneumatic system 90 Form of an air spring and level control system and a switching valve arrangement 80 which is formed, optionally a first or second compressed air reservoir --here the bellows 91 and / or the compressed air storage 92 - the pneumatic system 90 either to pressurize with compressed air or to vent this. The isolation valve assembly 80 has a ventilation switching valve 81 on that, for the ventilation of the gallery 95 the corresponding filling line 85 between the compressed air connection 2 and the isolation valve assembly 80 pneumatically connects. The switching valve arrangement 80 also has a second switching valve 82 as a vent valve, which is designed to be the gallery 95 to the connection line 40 via a vent line 87 to vent. The first switching valve 81 separates the corresponding filling line 85 while the more pneumatic vent line 87 via the second switching valve 82 opened, that is pneumatically connected.

Similarly, the compressed air storage 92 via a third switching valve 83 in a corresponding further filling line 86 be filled and a corresponding fourth switching valve 84 in another vent line 87 be vented.

This in 1 illustrated pneumatic system 100 is therefore basically a closed pneumatic system in the form of a closed air spring and level control system. The pneumatic system 100 shows a particularly preferred addition of an optional acting as a vent valve separating valve 23 on, namely the aforementioned return valve assembly 20 with the return valve 21 and the optional further isolation valve 22 in the form of a pneumatically controllable 2/2-way valve or an automatically opening non-return valve RV - all with corresponding valve springs 21F . 22F respectively 23F and thus opening against a spring force. This is - as is the description of Fig. 4 and 5 turns out - the compressed air supply system 10 a switchable open or closed compressed air supply system 10 ,

2A shows a further embodiment of a pneumatic system with a compressed air supply system, wherein the first return valve 21 in the supply line 30.1 the second compression volume 51 . 52 is arranged - this in combination with a check valve, which in this case is separate from the return valve 21 is realized and as an inlet valve 42 is designated. Such a return valve 21 may also additionally or alternatively (not shown) on the output side of the exhaust valve 44 the second compression volume 52 be arranged as a further or alternative return valve.

2 B shows one too 2A modified embodiment of a pneumatic system with a compressed air supply system, wherein the inlet valve 42 the second compression volume in the return valve 21 integrated as a check valve. It may also additionally or alternatively (not shown) on the output side of the exhaust valve 44 the second compression volume 52 another such return valve may be arranged, wherein the outlet valve 44 the second compression volume 52 is integrated in the other such return valve. According to the embodiment of a pneumatic system of 2A and 2 B is in this respect the return valve 21 not in a bypass line 30 to the second compression volume 52 integrated but in a supply line 30.1 . 30.2 the second compression volume 52 ( 2A) or in a discharge line (not shown). Here you could see the return valve 21 Insofar as also designate a modified inlet or outlet valve, in the end it also serves to relieve the pressure of the second compression volume 52 even if this condenses, as will become clear below.

3 shows a particularly preferred embodiment of a pneumatic system with a compressed air supply system similar to the 1 , wherein a pneumatically controllable first Recirculation valve 21 and the control pressure line on a bypass line 30 is connected and an electrically controllable second return valve 24 and the control pressure line on a bypass line 30 ' connected. According to the embodiment of the 3 can for such a separating valve assembly 20 basically next to the recirculation valve 21 and the first and second isolation valves 22 . 23 also another return valve 24 be provided, which also has an adjustable threshold pressure; preferably a pneumatically, electronically and / or adjustable by means of a valve spring threshold pressure. In this respect, in the context of a further development, the return valve arrangement can be a second or even further return valve 24 - Namely, to relieve the first compression volume and / or optionally. Additional compression volumes as needed via a bypass line analogous to the operation of the first return valve 21 ,

In particular, according to the further embodiment of the 3 - One between the pressure side and suction side of the compressor 50 switched second return valve 24 in that according to the further embodiment of the 3 preferably in a second bypass line 30 ' the line switched second return valve 24 , preferably one between the pressure side and the suction side of the compressor 50 switched second return valve 24 as electrically or pneumatically controllable valve, be designed for pneumatic control to guide the control pressure, preferably via a control pressure line to the second return valve 24 like this in 3 is shown.

In a first operating mode, in particular in a first switching state of the return valve, could then - according to the further embodiment of the 3 - Between the pressure side and suction side of the compressor 50 switched first and / or second return valve 21 . 24 , preferably uncontrolled, pressure side and suction side of the compressor 50 separate pneumatically.

In the second operating mode, in particular in a second switching state of the return valve, that between the pressure side and suction side of the compressor 50 switched first and / or second return valve 21 . 24 , preferably controlled, pressure side and suction side of the compressor ( 50 ) connect pneumatically, in particular the first and / or second return valve 21 . 24 have an adjustable threshold pressure, preferably a settable by means of a valve spring threshold pressure.

4 and 5 Now show preferred operating modes of the compressed air supply system for operating the pneumatic system, that is to operate the pneumatic system 100 , wherein the pressurized air lines are shown in bold. The pneumatic system 100 includes - as in 4 and 5 apparent-- the compressed air supply system 10 and the pneumatic system 90 as well as the intervening at the compressed air supply connection 2 connected switching valve arrangement 80 ,

The example of filling for the compressed air storage 92 is in 4 a first operating mode (open operation) is shown in which the first return valve 21 in the bypass line 30 the bypass line 30 pneumatically disconnected ie a compressed air flow is prevented, namely in the non-pneumatically controlled state; that is, on the control line 45 there is no pressure p on, so that also not on the control piston 46 is applied.

As already indicated above, the air sucked in via the air feed 0 is sucked in on the suction side of the compressor via the first and second compression volumes connected in parallel thereto 51 . 52 together via the air supply 0, in particular clocked sucked. The air duct shown with bold line thickness has the common and parallel operation of the first and second compression volume 51 . 52 in which, in the first operating mode shown here (open operation of the compressed air supply system 10 ) the first and second compression volumes 51 . 52 also together compressed air to the compressed air supply 1 and the compressed air connection 2 submit.

The compressed air is thus in the connection line 40 while the engine M is the double compressor 50 (TWIN compressor). As already explained above, the compressed air thus compressed via the first and second output isolation valve 43 . 44 in the form of a respective check valve to the air supply 1 and then the pneumatic main 60 given, in the air dryer 61 dried and over the throttle 63 the compressed air supply 2 leave; over the filling line 86 and the opened third switching valve 83 the compressed air enters the compressed air reservoir 92 , For this first mode of operation, only the inlet check valve is 0.2, from the intake filter 0.1 opened to the air supply 0. The compressed air runs from the compressed air supply 1 over the dryer 63 and the compressed air supply 2 and finally via the third switching line 86 to the compressed air storage 92 ,

Similarly, when the third switching valve is closed 83 and thus closed filling line 86 the first switching valve 81 open so that the compressed air from the compressed air supply 2 over the further filling line 85 from the compressed air supply connection 2 to the gallery 95 can be directed.

With appropriate function is the second and third switching valve 82 . 84 available for venting, which is an example 5 is shown. 5 explains for the second mode of operation the venting of a bellows 91 , present of two bellows 91 , The corresponding bellows 91 upstream isolation valves 93 are opened as a 2/2-way valve, and the compressed air can via the second switching valve 82 and the vent line 87 to the connection line 40 be delivered.

With the second switching valve open 82 thus stands a bellows pressure from one of the bellows 91 over the vent line 87 as well as the connecting cable 40 on the control line 45 , and thus as tax pressure p on the control piston 46 the return valve 21 , at. The bellows pressure thus serves as a control pressure p for pneumatic actuation of the return valve 21 that like in 5 shown in the pneumatically connecting position merges and the bypass line 30 pneumatically connects, ie makes a compressed air flow possible.

While at the in 4 shown first operating mode (open operation), the high-volume promotion of compressed air is in the foreground, since the first and the second compression volume 51 . 52 is operated in parallel and out of phase - which means in so far together but clocked - sucks air and promotes compressed air - is at the in 5 shown second operating mode that between pressure side and suction side DS . SS of the compressor 50 switched recirculation valve 21 pneumatically in the bypass line 30 connected (closed operation of the compressed air supply system 10 ).

The movement of the piston in the second compression volume 52 Although leads to the suction of air from the air supply 0 and to move the same in the second compression volume 52 , However, the compressed air thus generated at low pressure and with open recirculation valve 21 no longer opening the isolation valve 22 cause. Rather, the isolation valve 22 in the form of the check valve by the spring 22F kept closed.

The compressed air only of the first compression volume 51 thus passes over the first check output valve 43 for compressed air supply 1 and from there exclusively in the pneumatic main 60 and the air dryer 61 , By contrast, the piston operation of the second compression volume 52 open so that when operating the piston only air from the first check valve input 42 over the second first check output valve 44 and the bypass line 30 finally into the pneumatically connecting filling line 86 to the compressed air storage 92 arrives.

Following the concept of the invention, therefore, the return valve is in the first operating mode 21 pneumatically not activated and separates the bypass line 30 while the self-opening check valve as a second isolation valve 22 against the spring force of the valve spring 22F is open. In the second operating mode is only the first compression volume 51 open and gives compressed air to the compressed air supply 1 and the compressed air connection 2 from. The second compression volume 52 is forced to a promotion in the circle, as explained above, without compressed air via the compressed air supply 1 arrives; or at most of the first check valve input 42 over the second first check output valve 44 and the bypass line 30 finally again about the first compression volume 51 into the pneumatically connecting filling line 86 to the compressed air storage 92 arrives. The first - open - operating mode (with supply of supply air via the inlet check valve 0.2, from the intake filter 0.1 for the air supply 0) thus enables the combined conveying of compressed air from the first and second compression volumes 51 . 52 during the second-closed mode of operation, the delivery of compressed air only from the first compression volume 51 allowed, during the second compression volume "switched off" is due to the promotion of the second compression volume "in the circle" via the bypass line 30 ,

The same effect is achieved by the return valve 21 in the supply line 30.1 the second compression volume 52 according to 2A and 2 B , If this opens, --also makes a compressed air flow possible - the corresponding compression volume no longer compresses - in the 2A and 2 B is that with " 2 "Designated second compression volume 52 , The second -closed-operating mode allows only then the delivery of compressed air only from the first compression volume 51 during the second compression volume 52 "Switched off" is due to the promotion of the second compression volume "back and forth" on the supply line 30.1 ,

Analogously, in another mode of operation similar to the first mode of operation (open mode as in FIG 4 ) the first switching valve 81 be open and the third switching valve 83 be closed. In this case, compressed air can be supplied from the compressed air supply 2 in the bellows 91 be promoted when the second, third and fourth switching valve 82 . 84 . 83 is closed, that is, the corresponding switching line is pneumatically separated.

Accordingly, for the second operating mode (closed operation, 5 ) the first and fourth switching valve 81 . 84 to be open. In that case, the compressed air storage 92 for delivery of a control pressure p over the control line 45 on the control piston 46 be used of the return valve, while on the first switching valve 81 and the gallery 95 the bellows 91 opened and filled. In particular, the return valve 21 first at a pressure p in the control line 45 above a threshold value p _S from a first switching state, namely the first operating mode MOD1 assigned, in a second switching state, namely the second operating mode MOD2 assigned, transferred. The threshold value p _{S of} the return valve 21 here is adjustable in a range of 2 bar up 8th bar above the atmospheric pressure.

6 shows again in detail the connection via a separating valve arrangement 80 for the pneumatic system 90 according to 1 and for the operating mode of 4 and 5 Therefore, reference is made to the above description with reference to the same reference numerals.

7 shows an alternative embodiment, in which the pair of 2/2-way valves 81 . 82 respectively 83 . 84 replaced by a 3/2-way valve 88 respectively 89 , The arrangement of the gallery 95 or the memory branch line 99 is the same.

8th shows a vehicle 1000 in form of SUV with a vehicle control ECU operating in a first operating mode MOD1 and a second mode of operation MOD2 is operable. A corresponding switching arrangement is connected via a switch S to the pneumatic system 100 with the compressed air supply system 10 , the switching valve assembly 80 and the pneumatic system 90 -the air suspension and level control system of the vehicle 1000 - given. The operating mode MOD1 and MOD 2 can via data lines shown here as an electrical signal to the electrically controllable valves of the compressed air supply system 10 , the switching valve assembly 80 and the pneumatic system 90 are given; However, in the manner outlined above, the return valve can in any case 21 and the second isolation valve 22 the return valve assembly 20 as pneumatically controlled valves 21 . 22 work reliably without electrical control. This leads to a significant discharge of the electrical system on board the vehicle 1000 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1243447 B1 [0004]
• DE 102008034240 [0007]
• EP 2222488 B1 [0008]
• DE 10321771 A1 [0009]

Claims (19)

Compressed air supply system (10) for operating a pneumatic system (90), in particular switchable open or closed compressed air supply system, preferably with a pneumatic system (90) connected via a switching valve arrangement (80), in particular a pneumatic system (90) in the form of an air spring system (90 ') and / or level control system (90 ') of a vehicle (1000), in particular a passenger car (1001), wherein the compressed air supply system (10) comprises: - an air supply (0) for supplying supply air to a compressor (50) having a first compression volume (51) and a second compression volume (52) each for compressing the supply air to compressed air, - a compressed air supply (1) for providing the compressed air from the compressor (50), wherein the compressor (50) as a two-cylindrical compressor with the first compression volume ( 51) and with the second compression volume (52), characterized in that - suction side of the V the compressor (50), both the first and the second compression volume (51, 52) is connected to the air supply (0), wherein the first and the second compression volume (51, 52) are connected in parallel to the air supply (0) such that the first and the second compression volume (51, 52) can receive supply air jointly via the air feed (0) both in a first operating mode (MOD1) and in a second operating mode (MOD2), and - on the pressure side of the compressor (50) for providing the Compressed air in the first operating mode (MOD1) the first and the second compression volume (51, 52) to the compressed air supply (1) switchable and connected in parallel, and in the second operating mode (MOD2) only the first compression volume (51) to the compressed air supply ( 1) is connected in a switchable manner, wherein in the first operating mode (MOD1) the first and second compression volumes (51, 52) discharge compressed air to the compressed air supply (1) out of phase k in the second operating mode (MOD2), the first compression volume (51) can deliver compressed air to the compressed air supply (1), wherein in the second operating mode (MOD2) the second compression volume (52) can be switched away by means of a return valve (21), that the second compression volume (52) in the second operating mode (MOD2) can not deliver compressed air to the compressed air supply (1), wherein - the return valve (21) is pneumatically controllable, by means of a control pressure line (45) to the return valve (21) formed Control pressure must be used to pneumatically control the return valve (21). Compressed air supply system according to Claim 1 , characterized in that in the second operating mode (MOD2) only the first compression volume (51) can deliver compressed air to the compressed air supply (1), in particular only the first compression volume (51) can operate in the compression mode. Compressed air supply system according to Claim 1 , characterized in that in the first operating mode (MOD1) the first compression volume (51) and the second compression volume (52) can deliver compressed air to the compressed air supply (1), in particular the first and the second compression volume (51, 52) operate in the compression mode can. Compressed air supply system according to one of Claims 1 to 3 , characterized in that - the control pressure line (45) to a bypass line (30) to the first compression volume (51), and / or - the control pressure line (45) to a supply line (30.1) to the first compression volume (51), and / or - the control pressure line (45) is connected to a discharge line (30.2) to the first compression volume (51). Compressed air supply system according to Claim 4 , characterized in that on the output side of the outlet valve (43, 44) of the first or second compression volume (51, 52) an isolation valve (22) is arranged. Compressed air supply system according to Claim 5 , characterized in that the return valve (21) and / or the separating valve (22) has a in the direction of the compressed air supply (1) opening check valve (RV). Compressed air supply system according to Claim 1 , characterized in that the return valve (21) in the supply line (30.1, 30.2) of the second compression volume (51, 52) is arranged. Compressed air supply system according to Claim 7 , characterized in that the return valve (21) in the supply line (30.1, 30.2) in front of the inlet valve (41, 42) is arranged, namely in the flow direction of the inlet valve (41, 42) of the first or second compression volume (51, 52) before the inlet valve (41, 42) is arranged. Compressed air supply system according to Claim 7 , characterized in that the return valve (21) in the supply line (30.1, 30.2) after the inlet valve (41, 42) is arranged in the flow direction of the inlet valve (41, 42) of the first or second compression volume (51, 52) after the inlet valve (41, 42) is arranged. Compressed air supply system according to one of Claims 8 or 9 characterized in that the inlet valve (41, 42) of the second compression volume (52) is integrated in the recirculation valve (21) or the recirculation valve (21) acts on the inlet valve (41, 42) of the second compression volume (52) the inlet valve (41,42) remains closed upon pressurization of the return valve (21, 22). Compressed air supply system according to one of Claims 1 to 10 , characterized in that the return valve (21) is a 2/2-way valve, in particular a return valve assembly (20) comprises the return valve (21) and the separating valve (22). Compressed air supply system according to one of Claims 1 to 11 , characterized in that the return valve (21) only at a pressure (p) in the control line (45) above a threshold value (p _S ) of a first switching state, in particular the first operating mode (MOD1) assigned, in a second switching state, in particular assigned to the second operating mode (MOD2), is transferred. Compressed air supply system according to Claim 12 , characterized in that the threshold value (p _S ) of the return valve (21) is adjustable, in particular in a range of 2 bar to 8 bar above the atmospheric pressure, is adjustable. Pneumatic system (100) with a compressed air supply system (10) according to one of Claims 1 to 13 and a switching valve arrangement (80) and a pneumatic system (90), which is in the form of an air suspension system (90 ') of a vehicle (1000)), in particular a passenger car (1001), and which has a gallery (95), comprising: - a branch line (98, 99) pneumatically connected to the gallery (95) with a bellows (91) and / or - a compressed air reservoir (92), and - a separating valve upstream of the bellows (91) and / or the compressed air reservoir (92), in particular wherein the upstream isolation valve (93) is electrically controllable. Vehicle (1000), in particular passenger cars (1001), with a pneumatic system according to Claim 14 and an electronic vehicle control unit (ECU), which electronic vehicle control unit (ECU) is free from an electronic control of at least the return valve (21) connected between the pressure side and intake side of the compressor (50), in particular the return valve (21) of a return valve arrangement (20) having a Separating valve (22). Method for operating a pneumatic system (90), preferably a pneumatic system (90) connected via a switching valve arrangement (80), in particular a pneumatic system (90) in the form of an air spring system (90 ') and / or level control system of a vehicle (1000), wherein the compressed air supply system (10), in particular a switchable open or closed compressed air supply system (10), comprising: - an air supply (0) to a compressor (50) having a first compression volume (51) and a second compression volume (52) respectively for the compression of the supply air Compressed air, - a compressed air supply (1) for providing the compressed air from the compressor, wherein the compressor is designed as a two-cylindrical compressor with the first compression volume (51) and with the second compression volume (52), characterized in that - suction side the compressor (50) both the first and the second compression volume (51, 52) to the air supply (0) is connected, wherein the first and the second compression volume (51, 52) are connected in parallel to the air supply (0) such that the first and the second compression volume (51, 52) both in a first operating mode (MOD1) as also in a second operating mode (MOD2) together via the air supply (0) can receive supply air, and - pressure side of the compressor (50) for providing the compressed air in the first operating mode (MOD1) the first and the second compression volume (51, 52) the compressed air supply (1) is switchable and connected in parallel and in the second operating mode (MOD2) only the first compression volume (51) is switchably connected to the compressed air supply (1), the method comprising the steps of: - discharging compressed air in the first operating mode (MOD1), wherein the first and the second compression volume (51, 52) supply compressed air to the compressed air supply (1) out of phase, and - discharge of compressed air in the z wide operating mode (MOD2), wherein the second compression volume (52) by means of a return valve (21) such wegschaltbar that the second compression volume (52) in the second operating mode (MOD2) can not deliver compressed air to the compressed air supply (1), wherein the Return valve (21) is pneumatically controlled, by means of a control pressure line (45) to the return valve (21) for the pneumatic control of the return valve (21). Method according to Claim 16 , characterized in that the return valve (21) is pneumatically controlled with a suction-side pressure as the control pressure (p) of a control pressure line (45), in particular wherein - the control pressure line (45) to a bypass line (30) to the first compression volume (51), and / or - the control pressure line (45) to a supply line (30.1) to the first compression volume (51), and / or - the control pressure line (45 ) to a discharge line (30.2) to the first compression volume (51) is connected. Method according to Claim 16 or 17 , characterized in that the return valve (21) above a threshold value (p _S ) of a first switching state, namely the first operating mode assigned MOD1, in a second switching state, namely the second operating mode MOD2, is transferred. Method according to Claim 18 , characterized in that the threshold value (p _S ) of the return valve (21) is adjusted, in particular in a range of 2 bar to 8 bar above the atmospheric pressure is set.

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