EP2080914B1 - Pressure device for a vehicle - Google Patents

Description

The invention relates to a pressure medium device of a vehicle having a pressure medium source, a pressure medium chamber, wherein the pressure medium source communicates with the pressure medium chamber via a first pressure medium line, and a dryer, which is arranged between the pressure medium source and the pressure medium chamber in the first pressure medium line, wherein during filling at least one pressure medium chamber through the pressure medium source at least a portion of the moisture of the conveyed pressure medium via a vent port of the dryer in the environment is deliverable to dissipate moisture from the dryer.

A pressure medium device of the type mentioned is from the DE3919438A1 known. The pressure fluid device known from this publication has a pressure medium source, an air spring as a consumer, a connecting line from the pressure medium source to the air spring and an adsorption dryer. When the air spring is acted upon by the pressure medium source with pressure medium, the adsorption dryer is operated in a drying operation. In this case, moisture is deposited from the pressure medium in a desiccant desorption dryer and stored. To empty the air spring, the adsorption dryer is flowed through in the opposite direction in the regeneration mode, with part of the moisture deposited on the desiccant being able to be discharged into the atmosphere via an outlet of the adsorption dryer. A disadvantage of the known device is that the operation of the dryer requires a drying operation and a regeneration operation and thus the pressure medium device can only be operated cyclically. A further disadvantage is that a filling process of an air spring may have to be interrupted due to the drying capacity of the dryer which is too low.

From the DE3015071 a vehicle Höheneinstellvorrichtung with a pressure medium source, a lifting device and a water separator is known, which in a connecting line between the pressure medium source and the lifting device is arranged. The water separator is optionally connectable to the atmosphere or the lever device. The disadvantage of this device is that only a cyclical drying operation of the compressed air is made possible and the separated water is stored in the device. The stored water may cause damage to failure of the height adjuster.

From the DE3231519A1 is a compressed air generation plant with a compressed air generator, a compressed air storage and an air dryer known. The air drying plant has two drying tanks, which alternately dry the compressed air flowing through them by means of a changeover or regenerate the desiccant with a portion of the dry compressed air. The disadvantage of this device is the large space requirement and the technical control effort of the air drying plant with two dryers and a switching system. Another disadvantage is that the moisture is stored in the drying containers.

From the EP1536959B1 is known as a semi-closed system formed Luftfederungsanlage for a vehicle, with a first component with a connection to the atmosphere, which serves solely for the suction of air from the atmosphere, and a second component with a connection to the atmosphere, which is used exclusively for venting compressed air in the atmosphere serves, as well as with an air dryer, which is always traversed in the same direction of the compressed air in any operating condition of the air suspension system. The compressed air conveying device communicates with the first component on the suction side and with the air dryer on the outlet side, wherein the air dryer has an inlet connection and an outlet connection and the outlet connection of the air dryer is in communication with the second component. The disadvantage of this air suspension system that a simultaneous and parallel filling of the air springs by the compressed air conveyor and a regeneration of the air dryer with removal of moisture is virtually impossible, as is performed by the discharge valve of the second component, a pressure reduction in the air dryer and thus the required higher pressure in the air springs can not be adjusted. Therefore, the regeneration of the air dryer is performed outside the filling of the air springs or accumulator.

The object of the invention is to provide a suitable for a vehicle pressure fluid device that allows continuous operation and their space is low.

This object is achieved by the features of claim 1. In the pressure medium device according to the invention, during the filling of a pressure medium chamber by the pressure medium source at least a portion of the moisture of the required pressure medium via a vent port of the dryer in the environment can be delivered to dissipate moisture from the dryer.

The advantage of the invention lies in the fact that the one or more pressure medium container can be filled with pressure medium continuously and without interruption, so that any number of filling operations can be carried out without overloading the dryer with moisture. Another advantage is that with a single dryer at least one pressure medium chamber can be befiillt and at the same time the moisture can be removed from the dryer and thus from the system of the pressure medium device. It is also advantageous that no regeneration phase of the dryer is required, during which the pressure medium source is out of operation or can not claim in the pressure medium chambers. Another advantage is that little or no moisture or no water is stored in the dryer, but the moisture extracted from the pressure medium by the dryer during the filling process of the pressure medium chamber (s) can be discharged directly into the environment. The risk of deterioration of the pressure medium device by moisture or water in the form of corrosion or freezing is reliably prevented. A further advantage is that the filling process of the pressure medium chamber at any operating point, ie at any required pressure of the pressure medium chamber, can be performed while parallel and simultaneously the drying process is performed by returning a portion of the conveyed and dried pressure medium in the dryer and run moisture from the dryer into the atmosphere can be used.

The advantage of the vent connection is that the moisture removed from the pressure medium by the dryer is discharged directly from the dryer into the environment, thus saving long lines of passage.Another advantage is that the conveyed and dried pressure medium for the discharge of moisture from the dryer into the dryer Environment is usable.

According to the invention, the dryer has a venting space, which is connected via the venting connection to the atmosphere, and wherein a second pressure-medium line is connected to the venting space, which branches off from the first pressure-medium line. The advantage lies in the fact that the dryer has a pressure chamber and a vent space, which communicate with each other through a water-permeable or water-vapor-permeable separating layer. The pressure medium conveyed by the pressure medium source is conducted into the pressure chamber of the dryer, where at least part of the moisture of the pressure medium is transported by diffusion through the separating layer into the venting space of the dryer. The moisture in the vent chamber is dissipated by pressure medium from the pressure hammer of the dryer via the vent port into the atmosphere. The advantage is that only a small part of the pressure medium from the pressure chamber of the dryer is transferred into the venting chamber of the dryer and finally via the vent port into the atmosphere. The other and larger part of the pressure medium can be used for filling at least one pressure chamber or the like.

According to one embodiment of the invention according to claim 2, it is provided that the second pressure medium line branches off from the first pressure medium line, wherein the branch point lies in particular between the dryer and the pressure medium chamber. The advantage of this development is the fact that a small part of the dry pressure medium is used to carry out the moisture in the atmosphere.

According to one embodiment of the invention according to claim 3, it is provided that the second pressure medium line has a throttle. The advantage of this development is to see that the pressure in the first pressure medium line is maintained and the pressure in the venting chamber can be lowered to approximately atmospheric pressure.

According to one embodiment of the invention according to claim 4, it is provided that a portion of the moisture of the conveyed pressure medium by the return of the pressure medium source promoted and / or dried by the dryer pressure medium can be discharged into the environment. The advantage of this development is the fact that the moisture removed from the pressure medium by the dryer is discharged directly from the dryer by means of the subsidized and / or dried pressure medium into the environment.

According to a development of the invention according to claim 5 is provided; that the proportion of the recirculated, demanded by the pressure medium source and / or dried by the dryer pressure medium, which is deliverable into the environment, is controllable and / or controllable. The proportion of the pressure medium conveyed and / or dried by the dryer, which is used for carrying out the moisture from the dryer into the environment, can be regulated or controlled as a function of the ambient temperature, the ambient pressure and / or the ambient humidity. The higher the ambient temperature and / or the ambient humidity, the higher the proportion of the dried pressure medium for the purpose of causing moisture to be selected in order to set the desired pressure dew point in the pressure medium chamber or the pressure medium device. The advantage of this development is the fact that the amount of pressure fluid used to fill the pressure fluid chamber can be adapted to the requirements of the necessary pressure dew point reduction in the pressure medium chamber, taking into account the ambient conditions. The pressure medium device can thus be used very efficiently and can be adapted precisely to the required pressure dew point reduction by the control and / or control.

According to one embodiment of the invention according to claim 6, it is provided that the control and / or control of the proportion of the recycled, dried by the dryer pressure medium, which can be discharged into the environment, with a proportional valve is feasible. The advantage of this development is to be seen in that the regulation and / or control of the portion of the recirculated, funded by the pressure medium source and / or dried by the dryer pressure medium, which is deliverable into the environment, cost feasible with simple means.

According to one embodiment of the invention according to claim 7 it is provided that the vent port can be blocked by a vent valve. The advantage of this development is that the vent port can be selectively opened and closed with a vent valve.

According to one embodiment of the invention according to claim 8 it is provided that the vent valve is controlled by pressure medium. The advantage of this development is that the control of the vent valve is carried out by pressure medium, which can be removed from the pressure medium device, which is simple and inexpensive to carry out.

According to one embodiment of the invention according to claim 9 it is provided that the vent valve is controllable by the outlet pressure of the pressure medium source. When operating the pressure medium source is in the outlet before an increased pressure, which is used to control the vent valve, so that the valve can always be opened during operation of the pressure medium source.

According to one embodiment of the invention according to claim 10, it is provided that the vent valve is controllable by the suction pressure of the pressure medium source. The advantage of this development is the fact that the pressure medium device generates a negative pressure in the inlet area during operation. This vacuum is used to control the vent valve during operation of the pressure medium source.

According to one embodiment of the invention according to claim 11 it is provided that the vent valve is electrically controlled. The advantage of this development is to see that the vent valve can also be opened and closed independently of the operation of the pressure medium source.

According to one embodiment of the invention according to claim 12, it is provided that the pressure medium in the first pressure medium line can flow only in one direction from an outlet of the dryer in the direction of the pressure medium chamber. The advantage of this development is the fact that no pressure fluid is discharged from a pressure medium chamber through the dryer into the environment.

According to one embodiment of the invention according to claim 13, it is provided that in the first pressure medium line between the dryer and the pressure medium chamber, a valve is arranged, which releases the first flow direction of the pressure medium from the dryer to the pressure medium chamber and blocks the second flow direction of the pressure medium chamber to the dryer. The advantage of this development is the fact that only the one direction of the pressure medium from the dryer to the pressure medium chamber can be fixed simply, safely and inexpensively by means of, for example, a check valve or a solenoid valve.

• Fig. 1 ein erstes schematisches Schaltbild einer offenen Niveauregelanlage,
• Fig. 2 ein zweites schematisches Schaltbild einer offenen Niveauregelanlage,
• Fig. 3 ein schematisches Schaltbild einer geschlossenen Niveauregelanlage,
• Fig. 4 ein schematisches Schaltbild einer Ablassschaltung einer Niveauregelanlage,
• Fig. 5 Trockner -Schnittzeichnung.

Exemplary embodiments and further advantages of the invention are explained in connection with the following figures, in which:

• Fig. 1 a first schematic diagram of an open level control system,
• Fig. 2 a second schematic diagram of an open level control system,
• Fig. 3 a schematic diagram of a closed level control system,
• Fig. 4 a schematic diagram of a discharge circuit of a level control system,
• Fig. 5 Dryer cut-to-size.

The FIG. 1 shows a schematic diagram of a pressure medium device 1, which is designed as an open level control system. The pressure medium device 1 includes a control unit 30, a compressor 2, an air dryer 10, two air spring 4a, 4b, a pressure accumulator 6 and a pressure sensor 20. The compressor 2 is arranged over a arranged in the first pressure medium line 8 air dryer 10 and a check valve 18 and a first and second solenoid valve 24a, 24b connected to the air springs 4a, 4b and via a pressure accumulator valve 26 to the pressure accumulator 6. In order to discharge compressed air from the pressure medium device is one of the solenoid valves 24a, 24b or 26 to operate and at the same time to switch the exhaust valve 28, so that compressed air either from the air springs 4a, 4b or the pressure accumulator 6 through the filter 22 into the atmosphere. The pressure in the first pressure medium line 8 is measured by the pressure sensor 20, wherein the pressure value can be processed and stored by the control unit 30.

To increase the pressure in the pressure accumulator 6, air is transferred from the atmosphere via the filter 22, the suction line 9, the compressor 2, the air dryer 10, the check valve 18, the pressure medium line 8, the accumulator valve 26 in the pressure accumulator 6. The same applies to the filling of the air springs 4a, 4b by means of the compressor 2 directly from the atmosphere. During the filling of the pressure accumulator 6 or the air springs 4a, 4b, a part of the already dried by the air dryer 10 compressed air via the second pressure medium line 13, the venting chamber 11, the switched vent valve 16 and the vent port 12 is discharged into the atmosphere. In this case, a portion of the compressed air is passed from the air dryer outlet 10b to the vent space 11. As in the example of FIG. 1 shown, the proportion of, during the filling of the pressure accumulator 6 discharged into the atmosphere, compressed air can be additionally controlled by a valve, such as a proportional valve 14. The valves 14, 16, 24a, 24b, 26, 28 are electrically controlled and controlled by the control unit 30.

The FIG. 2 shows a pressure fluid device 1, which only by the control of the exhaust valve 16 of the pressure medium device of FIG. 1 different. The exhaust valve 16 he FIG. 2 is driven by the pressure which exists between the compressor 2 and the air dryer inlet 10a. If this pressure exceeds a limit value, then the outlet valve 28 changes over to the second switching state (not shown) and switches the connection from the venting space 11 of the air dryer 10 to the venting connection 12.

The FIG. 3 shows a known per se closed pressure fluid device 1. Also in this closed pressure fluid device 1 is during the transfer of compressed air from the atmosphere through the compressor 2, via the air dryer 10 in the pressure accumulator 6 or one of the air springs 4a to 4d, a portion of the dried compressed air discharged from or behind the air dryer outlet 10b via the second pressure medium line 13 into the vent space 11 and from there via the then switched vent valve 16 to the vent port 12 into the atmosphere.

The FIG. 4 shows a further pressure medium device 1 with a compressor 2, an air dryer 10, a check valve 18, a first and second solenoid valve 24a, 24b and a first and second air spring 4a, 4b. Also in this pressure fluid device 1 is during the transfer of compressed air from the atmosphere through the filter 22, the suction line 9, through the compressor 2, via the air dryer 10 in one of the air springs 4a and / or 4b, a portion of the dried compressed air from or behind the air dryer outlet 10b discharged via the second pressure medium line 13 into the vent space 11 and from there via the then switched vent valve 16 via the vent line 12a to the vent port 12 into the atmosphere. The vent valve 16 is designed in this case as a 3/2-way valve with electrical control, wherein the electrical connection to the control unit of the pressure medium device 1 is not shown in detail. It is also possible to pneumatically actuate the vent valve 16, such as in Fig. 2 shown. In the first, shown switching state of the vent valve 16, the pressure line 8 is connected to the atmosphere.

The FIG. 5 11 shows a sectional view of an air dryer 10, which has an air dryer inlet 10a, an air dryer outlet 10b, a valve or a throttle 14, a second pressure line 13, a venting space 11 and a venting port 12. If compressed air is transferred via the air dryer inlet 10a in the air dryer 10 and forwarded via the air dryer outlet 10b, then a portion of the dried compressed air via the valve or the throttle 14, which are arranged in the second pressure medium line 13, in the vent space 11 transferred and forwarded from there to the vent port. The part of the dried compressed air, which is transferred into the venting space 11, absorbs the moisture removed from the compressed air and transports it to the venting port 12 in the atmosphere. The humidity of the compressed air is transferred via a membrane in the dryer in the vent space. The valve 14 may be implemented as a proportional valve, throttle, check valve, or a combination thereof.

List of Reference Numerals (part of the description)

1 -

Pressure medium device

2 -

compressor

4a -

first air spring

4b -

second air spring

4c -

third air spring

4d -

fourth air spring

6 -

accumulator

8th -

first pressure medium line

9 -

suction

10 -

dryer

10a -

Dryer inlet

10b -

Drier outlet

11 -

vent space

12 -

exhaust port

12a -

vent line

13 -

second pressure medium line

14 -

proportional valve

16 -

vent valve

18 -

check valve

20 -

pressure sensor

22 -

filter

24a -

first solenoid valve

24b -

second solenoid valve

24c -

third solenoid valve

24d -

fourth solenoid valve

26 -

Accumulator valve

27a -

first changeover valve

27b -

second changeover valve

28 -

outlet valve

30 -

control unit

Claims (13)

1. Pressure medium device (1) of a vehicle, having a pressure medium source (2), having a pressure medium chamber (4a, 4b, 4c, 4d, 6), wherein the pressure medium source (2) is connected to the pressure medium chamber (4a, 4b, 4c, 4d, 6) via a first pressure medium line (8), and having a dryer (10) which is arranged in the first pressure medium line (8) between the pressure medium source (2) and the pressure medium chamber (4a, 4b, 4c, 4d, 6), wherein, during the filling of a least one pressure medium chamber (4a, 4b, 4c, 4d, 6) by the pressure medium source (2), at least a part of the moisture of the delivered pressure medium can be released into the environment via a ventilation port (12) of the dryer (10) in order to discharge moisture from the dryer (10), characterized in that the dryer (10) has a ventilation chamber (11) which is connected to the atmosphere via the ventilation port (12), and wherein a second pressure medium line (13) which branches off from the first pressure medium line (8) is connected to the ventilation chamber (11).
2. Pressure medium device (1) of a vehicle according to Claim 1, characterized in that the second pressure medium line (13) branches off from the first pressure medium line (8), wherein the branching point is situated in particular between the dryer (10) and the pressure medium chamber (4a, 4b, 4c, 4d, 6).
3. Pressure medium device (1) of a vehicle according to Claim 1 or 2, characterized in that the second pressure medium line (13) has a restrictor (14).
4. Pressure medium device (1) of a vehicle according to one of Claims 1 to 3, characterized in that at least a part of the moisture of the delivered pressure medium can be released into the environment by means of the recirculation of a part of the pressure medium that is delivered through the dryer (10).
5. Pressure medium device (1) of a vehicle according to one of Claims 1 to 4, characterized in that that fraction of the recirculated pressure medium, delivered through the dryer (10), which can be released into the environment can be regulated and/or controlled.
6. Pressure medium device (1) of a vehicle according to Claim 5, characterized in that the regulation and/or control of that fraction of the recirculated pressure medium, delivered through the dryer (10), which can be released into the environment is performed by means of a proportional valve (14).
7. Pressure medium device (1) of a vehicle according to Claim 1, characterized in that the ventilation port (12) can be shut off by means of a ventilation valve (16).
8. Pressure medium device (1) of a vehicle according to Claim 7, characterized in that the ventilation valve (16) can be controlled by means of pressure medium.
9. Pressure medium device of a vehicle according to Claim 8, characterized in that the ventilation valve (16) can be controlled by means of the outlet pressure of the pressure medium source (2).
10. Pressure medium device (1) of a vehicle according to Claim 9, characterized in that the ventilation valve (16) can be controlled by means of the intake pressure of the pressure medium source (2).
11. Pressure medium device (1) of a vehicle according Claim 7, characterized in that the ventilation valve (16) is electrically controllable.
12. Pressure medium device (1) of a vehicle according to one of the preceding claims, characterized in that the pressure medium in the first pressure medium line (8) can flow only in one direction from an outlet (10b) of the dryer (10) in the direction of the pressure medium chamber (4a, 4b, 4c, 4d, 6).
13. Pressure medium device (1) of a vehicle according to Claim 12, characterized in that a valve (18) is arranged in the first pressure medium line (8) between the dryer (10) and the pressure medium chamber (4a, 4b, 4c, 4d, 6), which valve enables the first throughflow direction of the pressure medium from the dryer (10) to the pressure medium chamber (4a, 4b, 4c, 4d, 6) and blocks the second throughflow direction from the pressure medium chamber (4a, 4b, 4c, 4d, 6) to the dryer (10).

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