Method for controlling or regulating the air pressure in a compressed air supply device

1. A method for controlling and/or regulating the air pressure in a compressed air supply device for a utility vehicle, the method comprising the acts of:

detecting at least one pressure value in the compressed air supply device and/or in vehicle components connected to the compressed air supply device;

determining a moisture value indicative of the moisture content in an air filter unit belonging to the compressed air supply device;

opening a shiftable clutch connecting a drive to a compressor, and opening a discharge valve of the compressed air supply device when the pressure value lies above a predetermined minimum value and the moisture value overshoots a predetermined threshold value;

wherein the clutch is opened and the discharge valve remains closed when the clutch is engageable, the pressure value reaches a predetermined switch-off pressure, and the moisture value lies below the predetermined threshold value.

2. The method as claimed in claim 1 , wherein the moisture value is calculated, taking into account the conveyed air volume and the efficiency of the air filter unit.

3. The method as claimed in claim 2 , wherein the decrease in the efficiency of the air filter unit with the running time of the air filter unit is taken into account in the calculation of the moisture value.

4. The method as claimed in claim 3 , wherein the temperature of the surroundings is taken into account in the calculation of the moisture value.

5. The method as claimed in claim 3 , wherein the clutch remains closed and the discharge valve is opened when the clutch is not engageable on account of a defect, the pressure value reaches a predetermined switch-off pressure, and the moisture value lies below the predetermined threshold value.

6. The method as claimed in claim 2 , wherein the temperature of the surroundings is taken into account in the calculation of the moisture value.

7. The method as claimed in claim 2 , wherein the clutch remains closed and the discharge valve is opened when the clutch is not engageable on account of a defect, the pressure value reaches a predetermined switch-off pressure, and the moisture value lies below the predetermined threshold value.

8. The method as claimed in claim 1 , wherein the clutch remains closed and the discharge valve is opened when the clutch is not engageable on account of a defect, the pressure value reaches a predetermined switch-off pressure, and the moisture value lies below the predetermined threshold value.

9. The method as claimed in claim 1 , wherein the at least one pressure value and the moisture value are detected by an electronic control.

10. The method as claimed in claim 9 , wherein the electronic control is integrated into a compressed air preparation plant.

11. The method as claimed in claim 9 , wherein the electronic control communicates via an interface with a control integrated into a compressed air preparation plant.

12. The method as claimed in claim 1 , wherein the at least one pressure value is detected by a pressure switch which, when the switch-off pressure is reached, generates an electrical signal for opening the clutch.

13. A compressed air supply device for a utility vehicle for carrying out the method according to claim 1 .

14. A utility vehicle comprising:

a compressed air supply device, the compressed air supply device carrying out the method according to claim 1 .