DE102015219613A1 - Integrated air supply unit with air dryer and air spring system, as well as control of an air supply unit - Google Patents

Abstract

Integrated air supply unit (1), in particular for an air spring system for a motor vehicle, comprising an air compressor (2) with electric motor (3), an air dryer (4) and a pneumatic block (5), inside the pneumatic block (5) the air compressor ( 2) and partly a reversing valve device (10) are arranged for air dryer control, wherein the air dryer (4) comprises a first chamber (11) with an adsorbent and a second chamber (12) with an adsorbent.

Description

The invention relates to an integrated air supply unit according to the preamble of claim 1 and an air spring system. Furthermore, the invention relates to a method for controlling an integrated air supply unit.

In known air suspension systems compressed air compressors are needed for level control. These preferably dry-running compressors provide the required for operation pressures in the individual components, such. As air springs or compressed air storage ready. For this purpose, the compressors suck in air from the environment, compress it to a certain pressure level and feed it to the components of the system.

The sucked ambient air, however, contains water or moisture which is used to freeze individual components, such as e.g. Valves, in operation can lead. To prevent this, the dew point of the sucked air is lowered by means of a dryer. That The air is dried or dehumidified by means of a desiccant / adsorbent, for example silica gel, in a dryer. The sucked air thus releases its moisture to the dryer and is then z. B. forwarded in the air springs.

The moisture absorption of the adsorbent, however, depends on the air temperature. Silica gel allows a good water absorption at about 60 ° C. At higher temperatures from about 80 ° C, the adsorbent for the first time to provide cooling of the intake air, whereby the usable adsorption is reduced by 1/3 of the bed length of the dryer and so-called dead zones arise.

At some point, the dryer is saturated and the adsorbent can only partially fulfill its drying function. Therefore, the dryer must be regenerated.

Desorption causes a regeneration of the dryer. That The moisture contained in the adsorbent is absorbed by air flowing through and discharged to the environment. In this case, the air flows, for example, from a compressed air reservoir via a throttle for further expansion of the air in countercurrent through the dryer and is discharged via a drain valve to the environment.

For the regeneration of the adsorbent heated air is advantageous because at higher temperatures, the air can absorb the moisture from the adsorbent better. The temperature of the air usually corresponds to the ambient temperature of the components of the air suspension system and is further cooled by the relaxation. As a result, a poor regeneration efficiency is achieved, which is based only on the principle of pressure swing regeneration in counter or DC.

In order nevertheless to create a sufficient working capacity of the dryer, this would have to be larger or it would have more regeneration air to be passed through the dryer. However, a larger dryer has the disadvantage of more weight and space. Furthermore, large amounts of regeneration air in open air spring systems are usually only possible when unloading the air suspension system from full to empty load. However, these are exceptions, since in operation more often a load change between two people with luggage and empty load takes place, but this leads to small amounts of regeneration air with correspondingly poor desorption. In a closed air spring system, the described possibilities for deflation are due to the system not available. Here, when filling the system, only a portion of the system air can be used for the regeneration, otherwise the system is not filled. This proportion should be as small as possible in order to minimize the compressor run times for filling. In these cases, the air control is usually carried out by the at least existing actuators such as air spring valve, pressure accumulator valve, reversing valve with closed systems or drain valve.

As a result, there is always the risk of breakthrough of water or moisture in the system. This is particularly the case if due to leaks in the air suspension system, the system air is only conditionally available for the regeneration of the dryer, since the compressor must constantly fill the system with air.

As an alternative to adsorption and regeneration, there are improved drying principles which require additional lines and actuators. In particular, additional cabling and electrical connectors are undesirable because they lead to additional components on the compressor with a correspondingly high construction and cost.

Such a compressor for air spring systems is from the DE 199 11 933 A1 known. A dryer filled with a desiccant is connected via a first line to a compressor. Thus, the dryer entrance is directly connected to the cylinder head. However, the compressed air in the cylinder head is highly heated (usually about 180-200 ° C) and is fed into the dryer on the shortest route. However, this highly heated air worsens the adsorption in the dryer. To regenerate the desiccant, the air also returns through the dryer in the same way.

From the DE 10 2004 005 117 A1 Another similar compressor for air suspension is known, in which the dryer is connected via a line to the compressor, said line being longer than a stroke length of the piston crank device. However, even with this compressor, highly heated air from the cylinder head is led directly to the dryer, which also reduces the adsorption capacity.

It would be conceivable to design a larger cylinder head with suitable air flow for cooling air, but this leads to more space. Cylinder heads are usually made of die-cast aluminum and it turns out this difficult to realize inner air lines.

The DE 10 2010 036 742 A1 deals with the regeneration of the dryer. It is proposed to form the dryer as part of the drive motor of the compressor or as part of the compressor. For this purpose, for example, surrounds the dryer as a housing part of the electric motor or is designed as a double-walled cylinder of the compressor. The embodiments are intended to use the generated waste heat of the electric motor or the compressor to heat the dryer and thus to improve the moisture absorption of the outflowing air. However, this has a negative effect on the adsorption during operation, when air from the environment has to be sucked into the system and passed through the dryer. The adsorption capacity of the dryer in the heated state is lower than in the cool state.

Furthermore, from the DE 102 40 359 A1 and the DE 10 2009 003 396 A1 Air suspension systems for vehicles known in which air is sucked from the atmosphere by means of a compressor and fed via a dryer to the individual components, such as air springs and compressed air storage. These describe how can be done by means of the circuits of valves, the regeneration of a dryer.

Therefore, it is an object of the invention to provide a compact air supply unit, e.g. for air spring systems, with efficient drying properties.

Another object of the invention is to provide a method of controlling an air dryer which provides improved dryer availability.

The problem underlying the invention is achieved with the features of the independent claim.

According to the invention, an integrated air supply unit is provided, wherein the air supply unit comprises an air compressor with electric motor, an air dryer and a pneumatic block, wherein within the pneumatic block of the air compressor and partially a changeover valve device for air dryer control are arranged, the air dryer a first chamber with an adsorbent and a second chamber with an adsorbent comprises. Preferably, the integrated air supply unit is suitable for an air spring system for a motor vehicle.

Preferably, the first chamber and the second chamber are pneumatically connected in series.

Advantageously, such a chamber can be used for adsorption and the other chamber for simultaneous regeneration.

Preferably, in a pneumatic connection between the first and the second chamber, a first regeneration throttle arranged in parallel with a shuttle valve.

Preferably, the shuttle valve has an output port to a second switching valve device for air flow control.

Advantageously, in part so air can be passed over the regeneration choke in a chamber for regeneration and partially directed into the air spring system.

According to a preferred embodiment, the switching valve means is disposed between the air compressor and the air dryer, the switching valve means selectively connecting the air compressor to the first chamber or to the second chamber.

Preferably, the switching valve device is designed as a combination of four 2/2-way valves or two 3/2 way valves or a 4/2-way valve.

According to another preferred embodiment, a bleed valve is disposed between the switching valve device and the environment, wherein the switching valve means selectively connects the first chamber or the second chamber to the environment.

According to the invention, in a control of an integrated air supply unit for adsorption by the air dryer air through one of the chambers and for regeneration of the air dryer air passed through another of the chambers. Preferably, for adsorption by the air dryer, air is passed through one of the chambers and, at the same time, for regeneration of the air dryer, air is passed through another of the chambers

Advantageously, lower regeneration air volumes are needed as a result. During operation of the air compressor operation prevail stationary conditions for a long time for regeneration. The dry after adsorption and heated by the compression process air is beneficial for regeneration.

According to a preferred embodiment, in a first switching position of the switching valve device, air is conveyed from the air compressor into the first chamber and further into the second chamber and discharged from the second chamber via the switching valve device and the discharge valve into the environment.

Preferably, in a first switching position of the switching valve device, air is conveyed from the air compressor into the first chamber and further via the first regeneration throttle and into the second chamber and discharged into the environment from the second chamber via the switching valve device and the drain valve.

According to a further preferred embodiment, air is conveyed from the air compressor into the second chamber and further into the first chamber in a second switching position of the switching valve device and discharged from the first chamber via the switching valve device and the discharge valve into the environment.

In a second switching position of the reversing valve device, air is preferably conveyed from the air compressor into the second chamber and further via the first regeneration throttle and into the first chamber and discharged into the environment from the first chamber via the reversing valve device and the drain valve.

Preferably, by means of the outlet connection of the shuttle valve, air is partly conveyed from one of the chambers into another of the chambers and partly to a second changeover valve device. Preferably, air is partially conveyed into the air spring system by means of the outlet connection of the shuttle valve.

According to a further preferred embodiment, air is passed from the second changeover valve device, bypassing the air compressor via the shuttle valve in one of the chambers for regeneration of the air dryer. For regeneration of the air dryer, air is preferably conducted from the second changeover valve device bypassing the air compressor via a second regeneration throttle and via the shuttle valve into one of the chambers.

The integrated air supply unit is used in an air spring system for a motor vehicle, in particular with the concept of the closed air supply.

The method for controlling an air supply unit in an air spring system for a motor vehicle is also used, in particular with the concept of the closed air supply.

Further preferred embodiments of the invention will become apparent from the dependent claims and the following description of an embodiment with reference to figures.

Show it

1 an exemplary integrated air supply unit with air dryer, and

2 a pneumatic circuit diagram of an air spring system with an exemplary integrated air supply unit with a two-chamber air dryer.

3 a pneumatic circuit diagram of an air spring system with an exemplary integrated air supply unit with a two-chamber air dryer

1 schematically shows an integrated air supply unit 1 for an air spring system for motor vehicles. Within a pneumatic block 5 is an air compressor 2 , which has a front-mounted electric motor 3 is driven. air compressor 2 consists essentially of a crankcase and at least 2 Reciprocating piston with corresponding cylinder heads together.

The pneumatic block 5 has not shown recordings for individual components. Schematically are several valves 7 indicated in part within the pneumatic block 5 and matching each other partially in an electronic control unit 6 are arranged.

The valves 7 are subdivided into drive units 7a and solenoid valve coils 7b where drive units 7a in the block 5 are arranged. drive units 7a include in detail not shown in detail a core, a sleeve, an anchor, a spring and a sealing seat and are firmly in the block 5 integrated. The corresponding solenoid valve coils 7b are preferably separate in the electronic control unit 6 arranged and electromechanically actuated. Solenoid valve coils 7b be fitting to the drive units 7a plugged and tolerance compensating, preferably held by means of resilient elements, in position.

The valves 7 For example, at least one air spring valve, a changeover valve device for dryer control, a reversing valve device for air flow control of the air spring system and a discharge valve for discharging system air into the environment.

In addition, contains block 5 not shown pneumatic lines. The pneumatic lines can be used as holes in the block 5 be realized. The pipes connect air compressors 2 , Air dryer 4 , Valves 7 and several pneumatic connections 8th among themselves.

Furthermore, the front of the block 5 an air dryer 4 arranged, which is for example designed as a two-chamber air dryer.

Pneumatic connections 8th are in appropriate shots of the block 5 arranged and serve to connect to other components of an air spring system such. B. several air springs or a compressed air reservoir.

In addition to a part of the valves 7 contains the electronic control unit 6 an electronic connection 9 , About connection 9 is the integrated air supply unit 1 fully connected to the vehicle electrical system and can thus be configured and read out. Via electronic control unit 6 be electric motor 3 and valves 7 driven.

There is also a pressure sensor in the block 5 integrated and with electronic control unit 6 be contacted.

2 shows a pneumatic circuit diagram of an air spring system with an exemplary integrated air supply unit with an air dryer 4 comprising two chambers 11 . 12 with adsorbent. Furthermore, the integrated air supply unit comprises an air compressor 2 with engine 3 , an electronic control unit 6 , several air spring valves 26 , a switching valve device 10 to the dryer control, a second switching valve device 32 for air flow control and a drain valve 24 , At the air spring valves 26 is a pressure sensor 25 arranged and by means of an ECU vent 30 and a manual vent 31 System air can be drained off.

The individual components of the integrated air supply unit are connected to pneumatic lines. The intersections of the pipes with the pneumatic block 5 in the pneumatic diagram represent the pneumatic connections, which, for example, for connection to the air springs 27 , the pressure accumulator 28 or the air filter 29 serve. The individual components of the integrated air supply unit are controlled 1 via the electronic control unit 6 ,

Between air compressor 2 and air dryer 4 is the switching valve device 10 arranged for drying control. This is for example designed as a 4/2-way valve. The switching valve device 10 is a discharge valve to the environment or atmosphere 24 downstream, over which air can be discharged into the environment. Between the first chamber 11 and the second chamber 12 of the air dryer 4 is a regeneration choke 13 with parallel-connected shuttle valve 15 arranged. From the shuttle valve 15 goes an output terminal or an output line via a second regeneration choke with check valve 14 to a second switching valve device 32 for air flow control.

For example, in the open air supply mode, air is released from the environment via air filters 29 and check valve 22 through the air compressor 2 with a power limiting valve 20 sucked. The moisture contained in the air should be through air dryers 4 adsorbed.

This is done by the air from the air compressor 2 over the check valve 21 by means of a first switching position of the reversing valve device 10 to the first chamber 11 directed. In the first chamber 11 the moisture contained in the air is adsorbed. After the first chamber 11 the air is partly to the second chamber 12 and partially by means of an output line of the shuttle valve 15 over the second check valve 14 to the second switching valve device 32 or directed into the air spring system. The second chamber 12 is gleichzeigt regenerated by the air flowing through. The air takes in the second chamber 12 already contained moisture and leads them over switching valve device 10 and drain valve 24 in the environment or atmosphere.

By way of example, a drying process may also be effected by means of the switching valve device 10 such that the second chamber 12 for adsorption and the first chamber 11 is used for regeneration.

This is done by the air from the air compressor 2 over the check valve 21 by means of a second switching position of the changeover valve device 10 to the second chamber 12 directed. In the second chamber 12 the moisture contained in the air is adsorbed. After the second chamber 12 Partially the air becomes the first chamber 11 and partially by means of a drain line of the shuttle valve 15 over the second check valve 14 to the second switching valve device 32 or directed into the air spring system. The first chamber 11 is gleichzeigt regenerated by the air flowing through. The air takes in the first chamber 11 already contained moisture and leads them over switching valve device 10 and drain valve 24 in the environment or atmosphere.

This is advantageous if another filling operation takes place in the open air supply mode and one of the chambers 11 . 12 already saturated.

Furthermore promotes air compressor 2 For example, in the closed air supply air from the air springs 26 or the accumulator 28 via the second switching valve device 32 (with appropriate switching position) to the air dryer 4 , Adsorption and regeneration the respective chambers 11 . 12 takes place in the same way as described in the example of the open air supply.

The regeneration of only one of the chambers 11 . 12 takes place according to the example such that air from the air spring 26 or the accumulator 28 by means of the second changeover valve device 32 , bypassing the air compressor 2 , about the second regeneration choke 14 and the shuttle valve in one of the chamber 11 . 12 of the air dryer 4 is directed. Thus, when discharging system air for the regeneration of the air dryer 4 be used.

3 shows a pneumatic circuit diagram of an air spring system according to 2 , wherein the second regeneration throttle with check valve 14 has been omitted.

LIST OF REFERENCE NUMBERS

1

 integrated air supply unit

2

 air compressor

3

 electric motor

4

 air dryer

5

 pneumatic block

6

 electronic control unit

7

 valves

7a

 drive units

7b

 Solenoid valve coils

8th

 pneumatic connections

9

 electronic connection

10

 Changeover valve device for drying control

11

 first chamber

12

 second chamber

13

 first regeneration choke

14

 second regeneration throttle with check valve

15

 Shuttle valve / double check valve

20

 Power limiting valve

21

 check valve

22

 check valve

24

 drain valve

25

 pressure sensor

26

 Air spring valves

27

 air springs

28

 accumulator

29

 air filter

30

 ECU breather

31

 manual venting

32

 second changeover valve device for air flow control

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

• DE 19911933 A1 [0011]
• DE 102004005117 A1 [0012]
• DE 102010036742 A1 [0014]
• DE 10240359 A1 [0015]
• DE 102009003396 A1 [0015]

Claims (14)

Integrated air supply unit ( 1 ), in particular for an air spring system for a motor vehicle, comprising an air compressor ( 2 ) with electric motor ( 3 ), an air dryer ( 4 ) and a pneumatic block ( 5 ), wherein within the pneumatic block ( 5 ) the air compressor ( 2 ) and partly a switching valve device ( 10 ) are arranged for air dryer control, characterized in that the air dryer ( 4 ) a first chamber ( 11 ) with an adsorbent and a second chamber ( 12 ) with an adsorbent. Air supply unit ( 1 ) according to claim 1, characterized in that the first chamber ( 11 ) and the second chamber ( 12 ) are pneumatically connected in series. Air supply unit ( 1 ) according to claim 1 or 2, characterized in that in a pneumatic connection between the first and the second chamber ( 11 . 12 ) a first regeneration reactor ( 13 ) with parallel-operated shuttle valve ( 15 ) is arranged. Air supply unit ( 1 ) according to claim 3, characterized in that the shuttle valve ( 15 ) an output port to a second switching valve device ( 32 ) for air flow control. Air supply unit ( 1 ) according to one of claims 1 to 4, characterized in that the switching valve device ( 10 ) between the air compressor ( 2 ) and the air dryer ( 4 ), wherein the switching valve device ( 10 ) the air compressor ( 2 ) optionally with the first chamber ( 11 ) or with the second chamber ( 12 ) connects. Air supply unit ( 1 ) according to one of claims 1 to 5, characterized in that the switching valve device ( 10 ) is formed as a combination of four 2/2-way valves or two 3/2 way valves or a 4/2-way valve. Integrated air supply unit ( 1 ) according to one of claims 1 to 6, characterized in that between the switching valve device ( 10 ) and the environment a drain valve ( 24 ), wherein the switching valve device ( 10 ) optionally the first chamber ( 11 ) or the second chamber ( 12 ) connects to the environment. Air suspension system for vehicles, the air suspension system having an integrated air supply unit ( 1 ) according to at least one of claims 1 to 7. Method for controlling an integrated air supply unit according to one of claims 1 to 7, characterized in that for adsorption by the air dryer ( 4 ) Air through one of the chambers ( 11 ) and, in particular at the same time, for the regeneration of the air dryer ( 4 ) Air through another of the chambers ( 12 ). A method according to claim 9, characterized in that in a first switching position of the switching valve device ( 10 ) Air from the air compressor ( 2 ) into the first chamber ( 11 ) and further, in particular via the first regeneration reactor ( 13 ), into the second chamber ( 12 ) and by the second chamber ( 12 ) via the switching valve device ( 10 ) and the drain valve ( 24 ) is derived into the environment. A method according to claim 9, characterized in that in a second switching position of the switching valve device ( 10 ) Air from the air compressor ( 2 ) into the second chamber ( 12 ) and further, in particular via the first regeneration reactor ( 13 ), in the first chamber ( 11 ) and by the first chamber ( 11 ) via the switching valve device ( 10 ) and the drain valve ( 24 ) is derived into the environment. Method according to claim 10 or 11, characterized in that, by means of the outlet connection of the shuttle valve ( 15 ) Air from one of the chambers ( 11 ) partly into another of the chambers ( 12 ) and partly to a second switching valve device ( 32 ), in particular in the air spring system, is promoted. A method according to any one of claims 9 to 12, characterized in that for the regeneration of the air dryer ( 4 ) Air from the second switching valve device ( 32 ) bypassing the air compressor ( 2 ) via the shuttle valve ( 15 ) into one of the chambers ( 11 . 12 ). A method according to claim 13, characterized in that for the regeneration of the air dryer ( 4 ) Air from the second switching valve device ( 32 ) bypassing the air compressor ( 2 ) via a second regeneration reactor ( 14 ) and via the shuttle valve ( 15 ) into one of the chambers ( 11 . 12 ).

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