WO2024099682A1

WO2024099682A1 - Pneumatic system and compressed air supply installation with throttle arrangement, vehicle and method

Info

Publication number: WO2024099682A1
Application number: PCT/EP2023/078409
Authority: WO
Inventors: Jörg Meier
Original assignee: Zf Cv Systems Europe Bv
Priority date: 2022-11-10
Filing date: 2023-10-12
Publication date: 2024-05-16
Also published as: DE102022129769A1

Abstract

The invention relates to a pneumatic system (10), comprising a compressor (101), a pneumatic installation (200) having at least one compressed air consumer (220), a reservoir (202) connected via a storage line (204), and a compressed air supply installation (100) for supplying the pneumatic installation (200), having a compressed air connection (1) to the compressor (101), a compressed supply connection (2) to the pneumatic installation (200), and a venting connection (3) to the surroundings (A) and a pneumatic main line (112) between the compressed air connection (1) and the compressed air supply connection (2) to an air dryer (102), and a venting line (113) leading away from the pneumatic main line (112) to the venting connection (3). The invention proposes a throttle arrangement (130) which is arranged between the air dryer (102) and reservoir (202), in particular between the air dryer (102) and valve block (210), with a nominal width (N1, N2) which, depending on the pressure (P) in the pneumatic main line (112), is changeable downstream of the throttle arrangement (130) in the conveying direction (R). The invention also relates to a compressed air supply installation (100), to a vehicle (1000) and to a method (2000) for operating a pneumatic system (10).

Description

Pneumatic system and compressed air supply system with throttle arrangement, vehicle and method

According to the preamble of claim 1, the present invention relates to a pneumatic system for a vehicle, in particular a passenger car, comprising a compressor, in particular a compressor, for providing compressed air with a supply pressure in a conveying direction, a pneumatic system, in particular an air spring system, with at least one compressed air consumer, a reservoir connected via a storage line, and a compressed air supply system for supplying the pneumatic system with compressed air at a gallery pressure. The compressed air supply system comprises a compressed air connection to the compressor, a compressed air supply connection to the pneumatic system and a vent connection to the environment as well as a pneumatic main line between the compressed air connection and the compressed air supply connection with an air dryer and a vent line leading from the pneumatic main line to the vent connection.

The invention also relates to a compressed air supply system for a corresponding pneumatic system, a vehicle with such a pneumatic system and a method for operating such a pneumatic system.

A compressed air supply system is used in all types of vehicles, in particular to supply a pneumatic system, such as an air suspension system of a vehicle, with compressed air. The compressed air supply system forms a pneumatic system together with a compressor and the pneumatic system. Air suspension systems can also include level control devices with which the distance between the vehicle axle and the vehicle body can be adjusted. An air suspension system of a pneumatic system mentioned above includes a number of air spring bellows pneumatically connected to a common line (gallery) as compressed air receivers, which can raise the vehicle body as it is filled up and lower it accordingly as it is filled down. As the distance between the vehicle axle and the vehicle body increases or ground clearance, the spring travel becomes longer and even larger uneven ground can be overcome without coming into contact with the vehicle body. A gallery pressure is understood to be a predefined maximum bellows pressure of the air spring bellows. Preferably, such systems are increasingly being used in off-road vehicles and sport utility vehicles (SUVs). In SUVs in particular, with very powerful engines, it is desirable to provide the vehicle with comparatively low ground clearance for high speeds on the road on the one hand, and comparatively high ground clearance for off-road use on the other. It is also desirable to implement a change in ground clearance as quickly as possible, which increases the requirements in terms of speed, flexibility and reliability of a compressed air supply system.

To ensure long-term operation of the compressed air supply system, a pneumatic main line of the compressed air supply system has an air dryer with which the compressed air is dried. This prevents the accumulation of moisture in the pneumatic system. At comparatively low temperatures, moisture can lead to crystal formation that damages valves and also to undesirable defects in the compressed air supply system and in the pneumatic system. An air dryer has a desiccant, usually a drying granulate, through which the compressed air flows in such a way that the drying granulate can absorb the moisture contained in the compressed air by adsorption. An air dryer can, if necessary, be designed as a regenerative air dryer. This can be done by flowing through the drying granulate with compressed air from a reservoir - usually in countercurrent, but sometimes also in cocurrent relative to the filling direction. Regeneration of the air dryer is essentially made possible by a pressure change on the air dryer, whereby the pressure present during regeneration is usually lower than that for adsorption in order to enable moisture to be released from the drying granulate. For this purpose, the vent valve arrangement can be opened, whereby the regeneration ability of the air dryer is regularly dependent on the pressure conditions and the pressure change amplitude in the compressed air supply system. It has also proven desirable for such a so-called pressure swing adsorption to have a The compressed air supply system must be designed to be flexible and reliable at the same time. In particular, a comparatively rapid venting of the pneumatic system and in particular of the air spring bellows of the air spring system must be possible, while at the same time a low air pressure must be available for regeneration of the air dryer with a sufficiently high pressure change amplitude.

DE 39 19 438 A1 shows a pneumatic system with a compressed air supply system and a consumer, such as an air spring system. The compressed air supply system has a regenerative air dryer, which is arranged in a pneumatic main line. Furthermore, an expansion tank is provided, which serves to take in air from the emptying consumers and to deliver air to the air dryer in regeneration mode. If the compressed air flows in countercurrent from the consumer or the expansion tank towards the air dryer, it passes through a regeneration throttle, which reduces the pressure through a correspondingly small flow-through nominal diameter in order to enable moisture to be released from the drying granulate.

However, this regeneration throttle increases the venting time required for compressed air to escape from the consumer. In the case of an air suspension system as a consumer, for example, this leads to increased lowering times and thus to restrictions in driving dynamics.

This is where the invention comes in, the object of which is to provide a pneumatic system, a compressed air supply system, a vehicle and a method for operating a pneumatic system, which enable efficient regeneration of the air dryer by appropriate throttling of the compressed air guided through the pneumatic main line and at the same time short venting times.

The object is achieved in a first aspect of the invention by a pneumatic system according to claim 1.

The invention proposes a throttle arrangement arranged in the pneumatic main line between the air dryer and the reservoir, in particular between the air dryer and the valve block, with a nominal diameter which, depending on a pressure in the pneumatic main line in the conveying direction downstream of the throttle arrangement is variable in terms of a control variable proportional to the flow rate. A throttle arrangement with a variable nominal width can be used to respond to the different requirements for venting and regeneration. Venting affects the compressed air consumers of the pneumatic system. If these are vented, short venting times must be achieved, even if this is disadvantageous for regeneration of the air dryer. The actual regeneration of the air dryer is carried out with compressed air from the reservoir. The flow direction is determined here by the conveying direction of the compressor. Accordingly, a pressure downstream of the throttle arrangement is a pressure in relation to the conveying direction of the compressor behind the throttle arrangement.

The compressed air connection here refers to a connection or an interface of the compressed air supply system to the compressor outlet. The compressor - if this is provided as a separate unit - is assigned an intake connection for sucking in air from the environment. The compressor can also be assigned a so-called booster connection, which represents a connection between a second compressor stage and the reservoir; pre-compressed compressed air can be supplied to the compressor from this. In particular, the second compressor stage can be supplied with compressed air from the reservoir via this booster connection for quickly filling the pneumatic system. If the compressor should also be part of the compressed air supply system, the intake connection and possibly also the booster connection would be assigned to the compressed air supply system designed with a compressor.

The inventors recognized that the pressure of the compressed air in the reservoir differs from the pressure of the compressed air discharged from the at least one compressed air consumer. The control variable is determined exclusively by the pressure in the conveying direction downstream of the throttle arrangement and not by a pressure difference between the compressed air in the conveying direction upstream and in the conveying direction downstream of the air dryer.

The identification of a regeneration of the air dryer by compressed air from the reservoir or a venting of the compressed air receiver can thus be carried out by means of the pressure in the pneumatic main line in the conveying direction downstream of the By adjusting the nominal diameter of the throttle arrangement depending on the pressure in the pneumatic main line, a short venting time can be achieved on the one hand and the flowable nominal diameter can be reduced accordingly for sufficient throttling of the compressed air for regeneration of the air dryer on the other.

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

The throttle arrangement is preferably designed to switch from a first throttle position, in which a maximum nominal width of the throttle arrangement can flow through, to a second throttle position, in which a minimum nominal width of the throttle arrangement can flow through. By means of a throttle arrangement that can be switched between two throttle positions in this way, a minimum nominal width can be provided during the regeneration of the air dryer by switching the throttle arrangement to the second throttle position, so that the compressed air is expanded to a high degree before flowing through the air dryer. By switching the throttle arrangement to the first throttle position, on the other hand, a maximum nominal width is provided and thus a short venting time is achieved when venting the compressed air consumer(s).

A maximum nominal diameter is to be understood as a nominal diameter that is reduced compared to the nominal diameter of the main pneumatic line. By slightly reducing the nominal diameter to the extent of the maximum nominal diameter of the throttle arrangement, the compressed air is slowed down when venting the compressed air consumers at least to such an extent that an acceptable level of noise is achieved when the compressed air exits the vent connection.

Further preferably, the control variable is a control pressure and the throttle arrangement can be actuated by the application of the control pressure in order to switch to the second throttle position. The control pressure corresponds to a pressure in the pneumatic main line in the conveying direction downstream of the throttle arrangement above the gallery pressure. Thus, the control pressure is supplied via the pneumatic main line. By a Such pneumatic actuation of the throttle arrangement reduces the complexity of the pneumatic system as a whole. The use of a control pressure as a control variable for the throttle arrangement also enables an immediate reaction to changed pressure conditions in the pneumatic main line. These pressure conditions indicate whether compressed air is being fed to the air dryer for regeneration of the air dryer at a pressure above the gallery pressure or whether it is compressed air from the compressed air consumers, which should be fed to the vent connection with a short venting time. A pressure in the pneumatic main line above the gallery pressure reliably indicates the provision of compressed air from the reservoir for regeneration of the air dryer. An appropriately selected pressure threshold of the control pressure thus enables a reliable distinction to be made between regeneration operation, in which the pressure in the pneumatic main line is above the gallery pressure and thus corresponds to the control pressure, and venting of the compressed air consumer with a pressure in the pneumatic main line below the gallery pressure and consequently below the control pressure that is necessary to actuate the throttle arrangement.

According to a preferred embodiment, the throttle arrangement comprises a first throttle having the maximum nominal width and a second throttle having the minimum nominal width. Two throttles, each with a different nominal width, provide two flow cross-sections independently of one another, which can be used in the first throttle position and in the second throttle position, respectively.

The throttle arrangement preferably comprises a bypass line associated with the second throttle with a check valve which opens in the second throttle position when a pressure in the conveying direction upstream of the throttle arrangement is present which is higher than a pressure in the conveying direction downstream of the throttle arrangement. This enables a throttle-free routing of compressed air via the bypass line to fill the pneumatic system as soon as the pressure in the conveying direction downstream of the throttle is higher than the pressure upstream. To fill the gallery or to fill the reservoir by the compressor, the pressure in the gallery and thus also in the pneumatic main line downstream of the throttle arrangement rises to a level corresponding to the Pressure corresponding to the reservoir pressure. This leads to a reduced nominal size of the throttle arrangement down to a minimum nominal size. This reduction in the nominal size leads to a back pressure in front of the throttle point and would lead to a reduced delivery capacity when filling the pneumatic system. However, the bypass line with the check valve effectively prevents the reduction in delivery capacity, since the back pressure above the pressure downstream of the throttle arrangement opens the check valve. The filling times are thus reduced.

According to a preferred embodiment, the throttle arrangement comprises a control line which is connected to the pneumatic main line downstream of the air dryer in the conveying direction and which is designed to apply a pressure force to the throttle arrangement acting in the direction of the second throttle position by guiding compressed air. In the event that the pressure of the guided compressed air corresponds to the control pressure, the throttle arrangement switches accordingly. Thus, an increase in the pressure in the pneumatic main line downstream of the air dryer in the conveying direction simultaneously leads to an increased pressure force which acts in the direction of the second throttle position. As the pressure in the pneumatic main line increases, the throttle arrangement thus moves in the direction of the second throttle position and ultimately provides a minimum flow-through nominal diameter for relaxing the compressed air used to regenerate the air dryer.

The throttle arrangement preferably has a spring which is designed to apply a spring force acting in the direction of the first throttle position. When vehicles are in operation, in the case of an air suspension system as a pneumatic system, the vehicle body regularly sinks and thus there is a need to quickly release compressed air from the air bellows. A spring which permanently applies a force in the direction of the first throttle position thus enables the maximum nominal width of the throttle arrangement to be used until a counteracting force of the same magnitude is provided. Thus, in normal operation, in which no additional forces are applied to the throttle arrangement, the pneumatic system can be quickly vented without switching the throttle position. Preferably, the spring is designed in such a way that the spring force is smaller than the pressure force acting when the pressure is applied. The pressure force thus overcomes the spring force as soon as the pressure in the pneumatic main line in the conveying direction downstream of the air dryer is above the gallery pressure. This is particularly the case when compressed air is fed from the reservoir to the air dryer.

Preferably, the throttle arrangement is arranged at least partially in the main pneumatic line. This makes the pneumatic system more compact overall.

More preferably, the maximum nominal width is in a range from 3 mm to 6 mm and the minimum nominal width is in a range from 0.4 mm to 1.2 mm. Thus, sufficient venting times are achieved through the maximum nominal width and at the same time, the minimum nominal width in the corresponding range enables sufficient relaxation of the compressed air for regeneration of the air dryer.

According to a preferred embodiment, the storage line has a reservoir valve which is designed to selectively block the storage line. Such a reservoir valve preferably interacts with the throttle arrangement, so that actuation of the reservoir valve simultaneously leads to a change in the nominal width of the throttle arrangement, in particular a switching of the throttle arrangement into the second throttle position.

The pneumatic system preferably further comprises a pressure sensor which is designed to monitor the gallery pressure. Such a sensor preferably interacts with the throttle arrangement and delivers a control signal for controlling an electrically actuatable throttle. The throttle is in particular an electromagnetically actuatable throttle.

In a second aspect, the invention leads to a compressed air supply system for supplying a pneumatic system, in particular an air spring system, with compressed air at a gallery pressure. The compressed air supply system comprises a compressed air connection to a compressor, a compressed air supply connection to the pneumatic system and a vent connection to the environment as well as a pneumatic main line between the compressed air connection and the compressed air supply connection. An air dryer is arranged in the pneumatic main line and the compressed air supply system further comprises a vent line leading from the pneumatic main line to the vent connection. The invention solves the problem mentioned at the outset in a second aspect by means of a throttle arrangement arranged between the air dryer and the compressed air supply connection with a nominal width that can be changed depending on the pressure in the pneumatic main line in the conveying direction downstream of the throttle arrangement. By means of such a throttle arrangement, the invention makes use of the advantages described in relation to the first aspect of the invention. Advantages and preferred embodiments according to the first aspect of the invention are thus also preferred embodiments and advantages of the second aspect of the invention.

In a third aspect, the invention leads to a vehicle, in particular a passenger car, with a pneumatic system according to the first aspect of the invention. By means of a corresponding pneumatic system, the vehicle makes use of the advantages described at the beginning with regard to the first aspect of the invention. Furthermore, preferred embodiments according to the first aspect of the invention are also preferred embodiments according to the third aspect of the invention.

In a fourth aspect, the invention leads to a method for operating a pneumatic system, in particular a pneumatic system according to the first aspect of the invention. The method comprises the steps:

Providing compressed air with a supply pressure at a compressed air connection of a compressed air supply system,

Filling a reservoir connected via a storage line, drying the compressed air provided at the compressed air connection by an air dryer arranged in a pneumatic main line,

Supplying the pneumatic system with compressed air at gallery pressure through the compressed air supply system,

Venting the pneumatic system by passing compressed air from the pneumatic system through the pneumatic main line to a vent connection, and Regenerating the air dryer by passing compressed air from the reservoir through the pneumatic main line to the vent connection, wherein a throttle arrangement arranged between the air dryer and the reservoir, in particular between the air dryer and the valve block, provides a modified nominal diameter when regenerating the air dryer compared to when venting the pneumatic system, depending on the pressure in the pneumatic main line in the conveying direction downstream of the throttle arrangement.

Due to the fact that in the process, a throttle arrangement is used depending on the pressure in the pneumatic main line in the conveying direction downstream of the

When regenerating the air dryer, a different nominal width is provided by the throttle arrangement compared to venting the pneumatic system, the method makes use of the advantages described at the beginning in relation to the first aspect of the invention. Advantages and preferred embodiments described in relation to the first aspect of the invention are therefore also advantages and preferred embodiments of the method according to the fourth aspect of the invention.

Embodiments of the invention are now described below with reference to the drawing in comparison to the prior art, some of which is also shown. This is not necessarily intended to show the embodiments to scale; rather, where useful for explanation, the drawing is in a schematic and/or slightly distorted form. With regard to additions to the teachings immediately apparent from the drawing, reference is made to the relevant prior art. It should be noted that a wide variety of modifications and changes can be made to the shape and detail of an embodiment without deviating from the general idea of the invention. The features of the invention disclosed in the description, the drawing and the claims can be essential for the development of the invention both individually and in any combination. 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 shape or detail of the preferred embodiment shown and described below or limited to an object that would be limited compared to that in the claims. claimed object. For specified design ranges, values within the stated limits should also be disclosed as limit values and can be used and claimed as desired.

Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing, which shows in:

Fig. 1 shows a pneumatic system according to the prior art in a venting mode;

Fig. 2 shows a pneumatic system according to the prior art in a regeneration mode;

Fig. 3 shows a pneumatic system according to a first preferred embodiment;

Fig. 4a shows a throttle arrangement in a first throttle position;

Fig. 4b the throttle arrangement according to Fig. 4a in a second throttle position; and

Fig. 5 shows a method for operating a pneumatic system according to Fig. 3.

Fig. 1 and Fig. 2 show a pneumatic system 10 with a compressed air supply system 100 and a pneumatic system 200 in the form of an air spring system 201. The pneumatic system 10 shown corresponds to the state of the art.

The compressed air supply system 100 is used to operate the pneumatic system 200.

The compressed air supply system 100 has a compressed air connection 1 and a compressed air supply connection 2 to the pneumatic system 200. The compressed air connection 1 is presently connected to a suction connection 0, a suction line 111, an air filter 0.3 arranged upstream of the suction connection 0 and a The compressor 101 is connected to the suction connection 0 downstream. The compressor 101 is a compressor driven by a motor M. The compressor 101 uses the compressor to provide compressed air with a supply pressure Pv in a conveying direction R via the compressor outlet at the compressed air connection 1.

A first pneumatic connection is formed here with a pneumatic main line 112 between the compressed air connection 1 and the compressed air supply connection 2.

The compressed air supply system 100 also has a vent connection 3 and a second pneumatic connection, namely the vent line 113, which is pneumatically connected to the pneumatic main line 112 and the vent connection 3. An air dryer 102 is also arranged in the pneumatic main line 112. In the present case, the vent line 113 connects to the pneumatic main line 112 between the compressed air connection 1 and the air dryer 102. A controllable vent valve 104 is provided in the vent line 113. The controllable vent valve 104 is presently an indirectly switched pilot valve part of a solenoid valve arrangement 110 for indirectly switching a compressed air volume of the vent line 113 that can be filled from the pneumatic main line 112. The solenoid valve arrangement 110 has a control valve 107 in the form of a 3/2-way solenoid valve. The control valve 107 can be controlled via electrical control signals in the form of a voltage and/or current signal. When controlled, the control valve 107 can be transferred from a normally closed position shown in Fig. 3 to the pneumatically open position shown in Fig. 1 and Fig. 2, in which a pressure derived from the pneumatic main line 112 via a pneumatic control pressure line 107.1 is passed on to the pneumatic control of the controllable vent valve 104 by means of a branch line 104.1. The controllable vent valve 104 is additionally provided with a pressure limiter 104.2. The pressure limiter 104.2 taps a pressure via a pneumatic line in front of the vent valve 104, which, when a threshold pressure is exceeded, lifts a piston of the vent valve 104 from the valve seat against the force of an optionally adjustable vent valve spring 104.3, thus the controllable vent valve 104 is opened even without control via the control valve 107. position. This prevents unwanted excessive pressure from building up in the pneumatic system 10.

In the closed state, the control valve 107 separates the control pressure line 107.1 and is pneumatically connected to the intake port 0 via a further pneumatic line 107.2 and can thus discharge compressed air 316 from a pilot control chamber of the vent valve 104 (not shown in detail) into the intake line 111.

A throttle 103 is arranged in the pneumatic main line 112 downstream of the air dryer 102. The throttle 103 is designed to relax the compressed air 313, 315 in countercurrent before it flows into the air dryer 102 only to such an extent that a sufficient venting time can still be achieved when venting the pneumatic system 200, as shown in Fig. 1. This leads in particular to restrictions in the regeneration operation, as shown in Fig. 2.

To reduce venting noise, a venting throttle 108 is preferably arranged in the venting direction downstream of the venting valve 104. The venting throttle 108 is preferably designed to slow down the compressed air 318 passing through the venting valve 104 in order to reduce the venting noise.

The control valve 107 is assigned a reservoir 106, which is designed to supply pressure from the pneumatic main line 112 through the control pressure line

107.1 flowing compressed air 317. Compressed air 317 from the accumulator 106 can be switched via the control valve 107 to the pilot chamber of the vent valve 104, whereby compressed air 318 is led to the vent connection 3 and released to the environment A. The accumulator 106 stores the compressed air 318 from the pneumatic main line 112 to the control valve 107 via the

The compressed air 317 guided through the control pressure line 107.1 is thus between until the control valve 107 is electrically actuated so that the compressed air 317 can pass from the accumulator 106 to the vent valve 104. The accumulator 106 is connected via a storage supply line

106.1 connected to the control valve 107. In this case, the air suspension system 201 has a number of four so-called air suspension bellows 223, 224, 225, 226 as compressed air receivers 220, each of which is assigned to a wheel of a vehicle 1000 (not shown in detail) and forms an air spring of the vehicle 1000. The vehicle 1000 is in particular a passenger car 1100. Furthermore, the air suspension system 201 has a reservoir 202 for storing quickly available compressed air for the air suspension bellows 223, 224, 225, 226. A solenoid valve 213, 214, 215, 216 is arranged upstream of the air spring bellows 223, 224, 225, 226, which serves as a level control valve for opening or closing an air spring formed with an air spring bellows 223, 224, 225, 226. The solenoid valves 213, 214, 215, 216 are designed as 2/2-way valves. A reservoir valve 212 is arranged upstream of the reservoir 202 in a storage line 204. The reservoir valve 212 is a solenoid valve in the present case. The reservoir valve 212 is designed to selectively open the storage line 204 in order to store compressed air 315 from the gallery 211 in the reservoir 202. The storage line 204 is connected to the compressor 101 via a filling line 206. A loading valve 109 is arranged in the filling line 206, which in this case is a 2/2-way solenoid valve. The reservoir 202 is designed to open the filling line 206 so that fluid can flow through it, in order to load a second stage of the compressor 101. The loading valve 109 is designed to open the filling line 206 so that fluid can flow through it pneumatically. Loading the second stage of the compressor 101 enables the air spring bellows 223, 224, 225, 226 to be filled quickly.

The solenoid valves 213, 214, 215, 216 and the reservoir valve 212 are connected to a common collecting line, a pneumatic line forming gallery 211. Gallery 211 is pneumatically connected to the compressed air supply system 100 via the compressed air supply connection 2. In the present case, the solenoid valves 213, 214, 215, 216 and the reservoir valve 212 are arranged in a valve block 210 with five valves. The solenoid valves 213, 214, 215, 216 and the reservoir valve 212 are shown in a de-energized state in Fig. 3 - the solenoid valves 213, 214, 215, 216 and the reservoir valve 212 are formed as normally closed solenoid valves. Other modified embodiments not shown here can realize a different arrangement of the solenoid valves 213, 214, 215, 216 and the reservoir valve 212 - fewer or more solenoid valves can also be used within the valve block 210. The compressed air in the pneumatic main line 112 has -- when flowing against the conveying direction R towards the vent connection 3 -- a first pressure Pi (in this case against the conveying direction R) downstream of the throttle 103. If compressed air 315 from the reservoir 202 is fed into the pneumatic main line 112, the first pressure Pi corresponds to a reservoir pressure PR and Pi(of the compressed air 315) = PR(of the compressed air in the reservoir 202). If, on the other hand, compressed air 313 from the gallery 211 is fed into the pneumatic main line 112, the first pressure Pi corresponds to a gallery pressure PG and Pi (of the compressed air 313 from the gallery 211) = PG. The compressed air in the pneumatic main line 112, on the other hand, has the supply pressure Pv when flowing in the conveying direction R, as described above.

Fig. 3 shows a vehicle 1000, which in this case is a passenger car 1110 with a pneumatic system 10 according to a preferred embodiment of the invention. The pneumatic system 10 is shown in a de-energized state and comprises a pneumatic system 200 corresponding to the pneumatic system 10 shown in Figs. 1 and 2. With regard to the pneumatic system 200, reference is made to the above description of the pneumatic system according to Figs. 1 and 2.

The compressed air supply system 100 comprises, in a known manner, a compressed air connection 1 to the compressor 101, which in the present case is designed as a compressor driven by a motor M with an intake connection 0, a compressed air supply connection 2 to the pneumatic system 200 and a vent connection 3 to the environment A. The compressed air supply system 100 also comprises a pneumatic main line 112 between the compressed air connection 1 and the compressed air supply connection 2 with an air dryer 102 and a vent line 113 leading from the pneumatic main line 112 to the vent connection 3. Corresponding to the compressed air supply system shown in Figs. 1 and 2, the compressed air supply system 100 according to Fig. 3 also comprises a solenoid valve arrangement 110 with a pneumatically actuated vent valve 104 and a control valve 107 designed as a pilot valve.

The compressed air in the pneumatic main line 112 has --when flowing against the conveying direction R, ie from the compressed air supply connection 2 towards the Vent connection (as shown in Fig. 3) -- a first pressure Pi (in the case) downstream of the throttle arrangement 130. The compressed air supply system 100 according to Fig. 3 differs from the compressed air supply system shown in Figs. 1 and 2 by a throttle arrangement 130 arranged between the air dryer 102 and the reservoir 202, which can be changed depending on a second pressure P2 in the pneumatic main line 112 in the conveying direction R downstream of the throttle arrangement 130.

If compressed air 315 from the reservoir 202 is fed into the pneumatic main line 112, the second pressure P2 corresponds to a reservoir pressure PR and P2 (of the compressed air 315 from the reservoir 202) = PR (of the compressed air in the reservoir 202) applies. If, however, compressed air 313 from the gallery 211 is fed into the pneumatic main line 112, the second pressure P2 corresponds to a gallery pressure PG and P2 (of the compressed air 313 from the gallery 211) = Pc (of the compressed air in the gallery 211) applies. The compressed air in the pneumatic main line 112, however, has the supply pressure Pv when flowing in the conveying direction R, as described above.

A pressure sensor 218 is connected to the gallery 211 and is designed to monitor the gallery pressure PG ZU. The sensor signal is preferably used to control the filling of the air bellows 223, 224, 225, 226.

As Fig. 4a and Fig. 4b in particular show in detail, the throttle arrangement 130 has a maximum nominal width N1 in a first throttle position B1, which is shown in Fig. 4a. Furthermore, the throttle arrangement 130 has a minimum nominal width N2 in a second throttle position B2, which is shown in Fig. 4b. The throttle arrangement 130 can be actuated pneumatically by applying a control pressure Ps, which in this case represents a control variable Ps for changing the nominal width. The control pressure Ps is applied to the throttle arrangement when the second pressure P2 present in the pneumatic main line 112 downstream of the throttle arrangement 130 in the conveying direction F is above the gallery pressure PG, i.e. for P2 > PG.

The throttle arrangement 130 is thus designed to switch to the second throttle position B2 shown in Fig. 4b when the said control pressure Ps is applied. The throttle arrangement 130 comprises a first throttle 132 having the first nominal width N1 and a second throttle 134 having the minimum nominal width N2. By switching the throttle arrangement 130 to the second throttle position B2, the second throttle 134 is brought into the area of the flow path of the compressed air 313, 315 flowing to the air dryer 102 through the pneumatic main line 112. By switching the throttle arrangement 130 to the first throttle position B1, the first throttle 132 is analogously brought into the area of the flow path of the compressed air 313, 315 flowing through the pneumatic main line 112.

The throttle arrangement 130 further comprises a bypass line 136 assigned to the second throttle 134 and having a check valve 137. The check valve 137 opens selectively in the filling direction, i.e. in the conveying direction R. This means that the check valve 137 opens selectively in the filling direction in the event that the first pressure Pi in the conveying direction R upstream of the throttle arrangement 130 is greater than the second pressure P2 downstream of the throttle arrangement 130. This means that the check valve 137 opens in the conveying direction R in the second throttle position B2 when a supply pressure Pv (in particular one that exceeds an ambient pressure) is applied in the conveying direction R upstream of the throttle arrangement 130, in particular when a supply pressure Pv is applied that is higher than a pressure P in the conveying direction R downstream of the throttle arrangement 130.

In the event that compressed air 311 is conveyed by the compressor 101 in the conveying direction R, the first pressure Pi corresponds to the supply pressure Pv. Thus, the check valve 137 opens the bypass line 136 so that it can flow pneumatically to fill the pneumatic system 200 in the event that a pressure below the gallery pressure PG and consequently also below the supply pressure Pv is present in the pneumatic system 200.

For pneumatic actuation of the throttle arrangement 130, the throttle arrangement 130 has a control line 138 connected to the pneumatic main line 112 downstream of the air dryer 102. Compressed air 313, 315 can be guided from the pneumatic main line 112 to the throttle arrangement 130 through the control line 138 and there apply a pressure force Fp to the throttle arrangement 130 acting in the direction of the second throttle position B2. If the pressure of the guided compressed air corresponds to the control pressure Ps, the throttle arrangement switches to the second Throttle position B2. Furthermore, the throttle arrangement 130 has a spring 139 which applies a spring force FF acting in the direction of the first throttle position B1.

In the first throttle position B1 shown in Fig. 4a, the spring force FF is greater than the pressure force Fp, so that the throttle arrangement 130 can be pneumatically flowed through by the first throttle 132 with the maximum nominal diameter N1.

In Fig. 4b, the pressure force Fp is greater than the spring force FF, so that the throttle arrangement 130 in the second throttle position B2 can be pneumatically flowed through by the second throttle 134 with the minimum nominal width N2 against the filling direction and can also be pneumatically flowed through in the filling direction via the bypass line 136. The spring 139 is adapted to apply a spring force FF that is smaller than the pressure force Fp acting when a control pressure Ps is applied.

Fig. 5 shows a method 2000 for operating a pneumatic system 10 according to Fig. 3. The method comprises, in a first step 2100, the provision of compressed air 311 with a supply pressure Pv at the compressed air connection 1 of the compressed air supply system 100. In a second step 2200, the method comprises drying the compressed air 311 provided at the compressed air connection 1 by an air dryer 102 arranged in the pneumatic main line 112. In a third step 2300, the method 2000 comprises filling the reservoir 202 connected via the storage line 204 and, in a fourth step 2400, supplying the pneumatic system 200 with compressed air 313 with a gallery pressure PG through the compressed air supply system 100. In a fifth step 2500, the method 2000 comprises venting the pneumatic system 200 by passing compressed air from a compressed air consumer of the pneumatic system 200 through the pneumatic main line 112 to the vent connection 3. Finally, in a sixth step 2600, the method 2000 comprises regenerating the air dryer 102 by guiding compressed air 315 from the reservoir 202 through the pneumatic main line 112 to the vent connection 3. In the method, the throttle arrangement 130 arranged between the air dryer 102 and the reservoir 202, in particular between the air dryer 102 and the valve block 210, depending on the pressure P in the pneumatic main line 112 downstream of the throttle arrangement 130 during the regeneration of the Air dryer 102 in the sixth step 2600 is provided with a modified nominal width N2 compared to the venting of the pneumatic system 200 in the fifth step 2500. When regenerating the air dryer 102 in the sixth step, compressed air 315 is thus guided over the minimum nominal width N2 of the throttle arrangement 130 and when venting the pneumatic system 200 in the fifth step 2500, compressed air 313 is guided over the maximum nominal width N1 of the throttle arrangement 130.

Reference symbol (part of the description):

0 Intake connection

1 compressed air connection

2 compressed air supply connection

3 Vent connection

0.3 Air filter

10 pneumatic system

100 compressed air supply system

101 Compressors

102 Air dryer

103 Throttle

104 vent valve

104.1 Branch line

104.2 Pressure limitation

104.3 Bleed valve spring

106 Memory

106.1 Storage supply line

107 Control valve

107.1 Control pressure line

107.2 pneumatic line

108 Vent throttle

109 Loading valve

110 Solenoid valve arrangement

111 Intake pipe

112 pneumatic main line

113 Ventilation line

130 Throttle arrangement

132 first throttle

134 second throttle

136 Bypass line

137 Check valve

138 Control line

139 Spring 200 Pneumatic system

202 Reservoir

204 Storage line

206 Filling line

210 Valve block

211 Gallery

212 Reservoir valve

213, 214, 215, 216 Solenoid valves

218 Pressure sensor

220 compressed air receivers

223, 224, 225, 226 Air spring bellows

311 compressed air under supply pressure

313 compressed air under gallery pressure

314 compressed air under control pressure

315 Compressed air from reservoir

316 compressed air discharged into the intake line

317 compressed air flowing in control pressure line

318 Compressed air in vent line

1000 vehicle

1110 passenger cars

2000 procedures

2100 Providing compressed air with a supply pressure

2200 Filling the reservoir

2300 Drying of compressed air by air dryer

2400 Supplying the pneumatic system with compressed air

2500 Bleeding the pneumatic system

2600 Regeneration of the air dryer

A Environment

B1 first throttle position

B2 second throttle position

FF spring force

FP pressure force

M-Engine

N1 maximum nominal diameter N2 minimum nominal diameter

P Pressure

PG Gallery Print

Ps control pressure

Vp supply pressure

Claims

Patent claims:

1. Pneumatic system (10) for a vehicle (1000), in particular a passenger car (1110), comprising a compressor (101) for providing compressed air (311) in a conveying direction (R), a pneumatic system (200), in particular an air spring system (201), with at least one compressed air consumer (220), a reservoir (202) connected via a storage line (204), and a compressed air supply system (100) for supplying the

Pneumatic system (200) with compressed air (313) under a gallery pressure (PG), with a compressed air connection (1) to the compressor (101), a compressed air supply connection (2) to the pneumatic system (200) and a vent connection (3) to the environment (A) as well as a pneumatic main line (112) between the compressed air connection (1) and the compressed air supply connection (2) with an air dryer (102) and a vent line (113) leading from the pneumatic main line (112) to the vent connection (3), characterized by a throttle arrangement (130) arranged in the pneumatic main line (112) between the air dryer (102) and the reservoir (202), in particular between the air dryer (102) and the valve block (210), with a nominal width (N1, N2) which, depending on a pressure (P) in the pneumatic main line (112) in the conveying direction (R) downstream of the throttle arrangement (130) proportional control variable (Ps) is variable.

2. Pneumatic system (10) according to claim 1, wherein the throttle arrangement (130) is designed to switch from a first throttle position (B1), in which a maximum nominal width (N1) of the throttle arrangement (130) can be flowed through, to a second throttle position (B2), in which a minimum nominal width (N2) of the throttle arrangement (130) can be flowed through.

3. Pneumatic system (10) according to claim 2, wherein the control variable (Ps) is a control pressure (Ps) and the throttle arrangement (130) is controlled by a control pressure (Ps) corresponding to the pressure (P) in the pneumatic main line (112) in the conveying direction (R) downstream of the throttle arrangement (130). pneumatically actuated and designed to switch to the second throttle position (B2) when a control pressure (Ps) above the gallery pressure (PG) is applied.

4. Pneumatic system (10) according to claim 2 or 3, wherein the throttle arrangement (130) comprises a first throttle (132) having the maximum nominal diameter (N1) and a second throttle (134) having the minimum nominal diameter (N2).

5. Pneumatic system (10) according to claim 4, wherein the throttle arrangement (130) has a bypass line (136) associated with the second throttle (134) with a check valve (137) which opens in the second throttle position (B2) when a supply pressure (Pv) is applied in the conveying direction (R) upstream of the throttle arrangement (130) in the conveying direction (R), in particular when a supply pressure (Pv) is applied which is higher than an ambient pressure and higher than a pressure (P) in the conveying direction (R) downstream of the throttle arrangement (130).

6. Pneumatic system (10) according to one of claims 4 or 5, wherein the throttle arrangement (130) has a control line (138) which is connected to the pneumatic main line (112) downstream of the air dryer (102) in the conveying direction (R), in particular immediately downstream of the throttle arrangement (130), and which is designed to apply a pressure force (Fp) acting in the direction of the second throttle position (B2) to the throttle arrangement (130) by guiding compressed air (314) under control pressure (Ps).

7. Pneumatic system (10) according to one of claims 4 to 6, wherein the throttle arrangement (130) has a spring (139) which is designed to apply a spring force (FF) acting in the direction of the first throttle position (B1).

8. Pneumatic system (10) according to claim 7, wherein the spring (139) is designed such that the spring force (FF) is smaller than the pressure force (Fp) acting when a control pressure (Ps) above the gallery pressure (PG) is applied.

9. Pneumatic system (10) according to one of the preceding claims, wherein the throttle arrangement (130) is arranged at least partially in the pneumatic main line (112).

10. Pneumatic system (10) according to one of claims 2 to 9, wherein the maximum nominal width (N1) is in a range of 3 mm to 6 mm and the minimum nominal width (N2) is in a range of 0.4 mm to 1.2 mm.

11. Pneumatic system (10) according to one of the preceding claims, wherein the storage line (204) has a reservoir valve (212) that is designed to selectively block the storage line (204).

12. Pneumatic system (10) according to one of the preceding claims, wherein the pneumatic system (200) has a pressure sensor (218) which is configured to monitor the gallery pressure (PG).

13. Compressed air supply system (100) for supplying a pneumatic system (200), in particular an air spring system (201), with compressed air under a gallery pressure (PG), with a compressed air connection (1) to a compressor, a compressed air supply connection (2) to the pneumatic system (200) and a vent connection (3) to the environment (A) as well as a pneumatic main line (112) between the compressed air connection (1) and the compressed air supply connection (2) with an air dryer (102) and a vent line (113) leading from the pneumatic main line (112) to the vent connection (3), characterized by a throttle arrangement (130) arranged in the pneumatic main line (112) between the air dryer (102) and the reservoir (202) with a nominal width (N1, N2) which, depending on a pressure (P) in the pneumatic main line (112) in the conveying direction (R) downstream of the throttle arrangement (130) is variable.

14. Vehicle (1000), in particular a passenger car (1110), with a pneumatic system (10) according to one of claims 1 to 12.

15. Method for operating a pneumatic system (10), in particular a pneumatic system (10) according to one of claims 1 to 12, comprising the steps:

Providing compressed air (311) with a supply pressure (Vp) at a compressed air connection (1) of a compressed air supply system (100),

Drying the compressed air (311) provided at the compressed air connection (1) by an air dryer (102) arranged in a pneumatic main line (112), filling a reservoir (202) connected via a storage line (204),

Supplying the pneumatic system (200) with compressed air (313) at a gallery pressure (PG) through the compressed air supply system (100)

Venting the pneumatic system (200) by passing compressed air (313) from the pneumatic system (200) through the pneumatic main line (112) to a vent connection (3), and

Regenerating the air dryer (102) by guiding compressed air (315) from the reservoir (202) through the pneumatic main line (112) to the vent connection (3), wherein a throttle arrangement (130) arranged between the air dryer (102) and the reservoir (202), in particular between the air dryer (102) and the valve block (210), provides a nominal width (N1, N2) that is different from the venting of the pneumatic system (200) when regenerating the air dryer (102), depending on the pressure (P) in the pneumatic main line (112) in the conveying direction (R) downstream of the throttle arrangement (130).