Compressed-air supply system and method to operating a compressed-air supply system

1. A compressed-air supply system for operating a pneumatic installation, the compressed-air supply system comprising:

an air supply, comprising an air compressor unit configured to supply compressed air to a compressed air supply;

a compressed air port to the pneumatic installation;

an air removal port configured to release air to the environment;

a pneumatic main line between the compressed air supply and the compressed air port, the pneumatic main line comprising an air dryer and a throttle;

an air removal line between the compressed air port and the air removal port, the air removal line branching from the pneumatic main line;

an exhaust valve connected in the air removal line, wherein the exhaust valve comprises a pressure control port connected to the compressed air supply and a pressure counter control port connected to the compressed air port,

wherein the exhaust valve comprises a control chamber that is fluidically partitioned by a diaphragm configured to switch the exhaust valve between an opened and a closed state, the diaphragm having an effective area pressurizable via the pressure control port and an opposing effective area pressurizable via the pressure counter control port, and

wherein the exhaust valve is configured to be normally opened.

2. The system according to claim 1 , wherein the pressure control port and the pressure counter control port are fluidically connected to each other, independently of pressure, via the air dryer and the throttle.

3. The system according to claim 1 , wherein the exhaust valve is configured to switch to and/or remain in the closed state if a force exerted on the effective area is higher than a counterforce exerted on the opposing effective area, and is configured to switch to and/or remain in the open state if a force exerted on the effective area is lower than a counterforce exerted on the opposing effective area.

4. The system according to claim 1 , wherein the exhaust valve is configured to relieve, in a charging cycle, compressed air into the air removal line if the absolute pressure on both sides of the diaphragm exceeds 16 bar.

5. The system according to claim 1 , wherein the exhaust valve comprises an orifice defining a valve seat, and a plunger having a valve seal for opening and closing the orifice, wherein the plunger is coupled to the diaphragm.

6. The system according to claim 5 , wherein the diaphragm and the valve seal are arranged on opposite sides of the orifice.

7. The system according to claim 5 , wherein the exhaust valve comprises a valve spring that is serially coupled to the diaphragm and arranged to hold the exhaust valve normally opened.

8. The system according to claim 7 , wherein the exhaust valve comprises a counter spring that is serially coupled to the diaphragm and arranged to counteract the valve spring.

9. The system according to claim 8 , wherein the diaphragm is coaxially arranged to the orifice.

10. The system according to claim 8 , wherein a preload of the counter spring is adjustable.

11. The system according to claim 8 , wherein the valve spring and the counter spring have identical spring constants.

12. The system according to claim 1 , wherein the effective area and the opposing effective area are equal in effective size.

13. The system according to claim 1 , wherein the throttle has an orifice diameter between 0.7 mm and 1.2 mm.

14. A pneumatic system comprising a compressed-air supply system according to claim 1 and a pneumatic installation in form of an air-suspension system of a vehicle.

15. A method for operating a compressed-air supply system, the method comprising:

in a charge cycle, the steps of:

operating an air compressor unit configured to supply compressed air to a compressed air supply;

guiding a flow of compressed air from the compressed air supply to a pressure control port and thereby pressurizing an effective area of an exhaust valve in order to switch the exhaust valve into a closed state;

guiding a flow of compressed air from the compressed air supply via an air dryer and a throttle to a compressed air port in order to supply a pneumatic installation connected to the compressed air port;

guiding a flow of compressed air from the compressed air supply via the air dryer and the throttle to a pressure counter control port and thereby pressurizing an opposing effective area of the exhaust valve; and

holding the exhaust valve in a closed state if a force exerted on the effective area is higher than a counterforce exerted on the opposing effective area,

and/or, in a regeneration cycle, the steps of:

keeping the air compressor unit suspended from operation;

guiding a flow of compressed air from the compressed air port to the counter pressure control port and thereby pressurizing the opposing effective area of the exhaust valve;

guiding a flow of compressed air from the compressed air port to the pressure control port via the air dryer and the throttle and thereby pressurizing the effective area of the exhaust valve;

switching the exhaust valve into the opened state if a force exerted on the effective area is lower than a counterforce exerted on the opposing effective area;

guiding a flow of compressed air from the compressed air port via the air removal line to the air removal porta,

wherein the exhaust valve is configured to be normally opened.

16. The method according to claim 15 , further comprising, in the charge cycle the step of:

switching the exhaust valve into the opened state if a force exerted on the effective area is lower than a counterforce exerted on the opposing effective area.

17. The method according to claim 15 , wherein the exhaust valve is held in and/or switched into the closed state if a force exerted on the effective area due to pressurizing the effective area of the exhaust valve is higher than a counterforce exerted on the opposing effective area due to pressurizing the opposing effective area of the exhaust valve.

18. The method according to claim 15 , wherein the exhaust valve is held in and/or switched into the opened state if a force exerted on the effective area due to pressurizing the effective area of the exhaust valve is lower than a counterforce exerted on the opposing effective area due to pressurizing the opposing effective area of the exhaust valve.

19. The method according to claim 16 , wherein the force exerted on the effective area comprises a first force component originating from compressed air acting on the effective area and a second force component originating from a counter spring.

20. The method according to claim 16 , wherein the counterforce exerted on the opposing effective area comprises a first counterforce component originating from compressed air acting on the opposing effective area and a second counterforce component originating from a valve spring.