CN107206992B

CN107206992B - Device and method for supplying compressed air to a commercial vehicle

Info

Publication number: CN107206992B
Application number: CN201680006880.0A
Authority: CN
Inventors: L·巴洛格
Original assignee: Knorr Bremse Systeme fuer Nutzfahrzeuge GmbH
Current assignee: Knorr Bremse Systeme fuer Nutzfahrzeuge GmbH
Priority date: 2015-01-23
Filing date: 2016-01-21
Publication date: 2020-03-17
Anticipated expiration: 2036-01-21
Also published as: WO2016116546A1; DE102015000893A1; EP3247603A1; CN107206992A; DE102015000893B4; BR112017014520A2

Abstract

The invention relates to a device for supplying compressed air to a commercial vehicle, comprising an electronic control unit (1) connected to at least one sensor (2); the device comprises a compressed air inlet (4) and a pressure control outlet (16), wherein the compressed air inlet and the pressure control outlet are respectively connected with a compressor; having a discharge outlet (6); having a filter-drying cartridge (5); has an outlet (7) to at least one pressure accumulator and has a solenoid valve (3) which can be actuated by an electronic control device (1). According to the invention, a pressure control valve (8; 13; 14; 15) is provided, the switching state of which is dependent directly on the pressure in the outlet (7) to the at least one pressure accumulator or in relation to the switching state of the solenoid valve (3) and which can assume a switching state in which the outlet (7) to the at least one pressure accumulator is connected to the filter drying box (5) via the solenoid valve (3) on the side opposite the compressed air inlet (4).

Description

Device and method for supplying compressed air to a commercial vehicle

Technical Field

The invention relates to a device or a method for supplying compressed air to a commercial vehicle.

Background

In commercial vehicles, various devices, in particular brakes, are usually operated by means of compressed air. For this purpose, a compressor is provided, which is driven by the motor of the vehicle and which normally always operates together. In order to ensure a continuous supply of compressed air, an accumulator is also provided, which is filled with excess compressed air. When the pressure accumulator is filled and has a predetermined nominal pressure, the compressed air compressed by the compressor, which is just unneeded, is discharged to the environment, so that the compressor operates virtually in idle operation without counterpressure. The initiation of such a process is usually performed through a control outlet of the respective load pressure.

In modern commercial vehicles, the brake system is divided into at least two circuits for safety reasons. The whole compressed air system even handles four circuits: two circuits are used for the brake system, one for the parking brake and one for other devices, such as springs. Each of these compressed air circuits contains its own accumulator. The division of the compressed air into the four circuits is achieved by means of a four-circuit protection valve which ensures that, in the event of a pressure loss in one of the circuits, the other circuit can continue to operate.

Because of the corrosive materials which are formed in the compressed air consumer, the compressed air used must be dry. The brake system must also be protected against icing in the winter season. The compressed air must also be filtered in order not to damage the sealing means and the guiding means. For this purpose, filter-drying cartridges are usually provided through which the compressed air compressed by the compressor is conducted before it is output to the different circuits and to the pressure accumulator. Here, the compressed air flows through the filter membrane and dries the particles.

The filter drying cartridge must be regenerated in order to prolong its service time. For this purpose, a dry and clean air flow is guided through the filter drying box counter to the original filter direction. Here, the particles are dried again and the filter membranes are cleaned. The compressed air loaded with moisture and dirt particles is then released virtually pressureless into the environment through the discharge opening. Regeneration of the filter-drying cartridge is often carried out by a separate regeneration reservoir.

The electronic control unit is generally responsible for controlling the compressed air supply system and receives the information necessary for the control via various sensors. Then, solenoid valves operated by an electronic control device are used for regulating the system. Furthermore, a pressure control valve is usually necessary in order to be able to control all functions.

However, solenoid valves having the required number of different operable states are very expensive or even not commercially available. The function is thus divided over a plurality of solenoid valves. However, the use of several solenoid valves is also expensive here.

Disclosure of Invention

The invention is based on the following tasks: the device and the method for supplying compressed air to a utility vehicle are designed in such a way that costs can be saved without safety being overlooked.

The object is achieved according to the invention by a device or a method for supplying compressed air to a commercial vehicle. By installing the pressure control valve, a second solenoid valve can be dispensed with, which also has to be actuated by the electronic control unit. The switching state of the pressure control valve is dependent on the pressure in the outlet to the at least one pressure accumulator, either directly or in conjunction with the switching state of the solenoid valve. The pressure control valve can assume a switching state in which the outlet to the at least one pressure accumulator is connected to the filter drying box via the solenoid valve on the side opposite the compressed air inlet. In this way, only a single solenoid valve is required, and the electronic control unit only has to operate a single solenoid valve.

To avoid high costs, as simple a pressure control valve as possible is used. In particular, a two-position two-way valve is considered here, i.e. a valve having two connections (in addition to the switching connection to which the switching pressure is applied) and two switching states. In its simplest form, the two interfaces are either connected to each other (open position) or the connection between the two interfaces is separated (closed position). One of the two switching states is a rest position, which the pressure control valve assumes when the pressure at the switching interface is less than the switching pressure. If the pressure at the switching interface increases to a value that exceeds the switching pressure and the pressure control valve is actuated as a result, the valve switches into the other switching state.

In a first embodiment of the device according to the invention, a pressure-controlled two-position two-way valve is used in which the connection between the two interfaces is closed in the non-actuated rest state of the pressure-controlled valve. The switching pressure should be about 1bar below the maximum pressure of the device. The valve is integrated into the device in such a way that: the pressure prevailing at the outlet to the at least one pressure accumulator is at the switching interface of the pressure control valve and the pressure control valve is thus switched from one switching state to the other depending on the pressure.

In a further exemplary embodiment, a pressure-controlled two-position two-way valve is used, in which the connection between the two connections is opened in the non-actuated rest state of the pressure-controlled valve. In this embodiment, the same applies to the first embodiment. Here, the valve is in the open position when the pressure at the outlet to the at least one pressure accumulator is below the switching pressure, here also about 1bar below the maximum pressure. The valve is closed above the switching pressure.

However, it is not absolutely necessary to use a pressure-controlled two-position two-way valve. It is also possible to use a two-position three-way valve, i.e. a valve with three connections, but also with only two switching states. Such a valve with three connections and two switching states is constructed similarly to the solenoid valve, but is not electrically controlled directly by an electronic control unit, but by the pressure at the switching connections. Since this pressure is in turn controlled by the electronic control unit via the pressure sensor, the electronic control unit indirectly influences the switching state of the pressure control valve.

In this pressure-controlled two-position three-way valve, there is also an inoperative rest position, which it occupies when the pressure at the switching interface is below the switching pressure, and it occupies the operating position when the pressure at the switching interface exceeds this threshold value (switching pressure). In this exemplary embodiment, the connection between the two connections is opened in the inoperative rest state of the pressure control valve, wherein one of the two connections is connected to the discharge outlet and the other connection is connected to a side of the filter-drying cartridge which is opposite the compressed air inlet.

In a further exemplary embodiment with a pressure-controlled two-position three-way valve, the connection between the two connections is opened in the non-actuated rest state of the pressure control valve, wherein one of the two connections is connected to the pressure control outlet. In this position, the other of the two connections is also connected to a side of the filter-drying cartridge, which is opposite the compressed air inlet.

In the pressure-free state (non-actuated rest state), the switching state of the pressure control valve is stabilized by the spring force. For this purpose, a spring acting against the switching pressure is provided. The force of the spring is designed in such a way that: a pressure acting on the switching connection, which pressure exceeds the switching pressure, overcomes the spring force and switches the valve into its actuating position. The strength of the spring is then decisive for the adjustment of the switching pressure.

In order to be able to regenerate the filter-drying cartridge, the dry and clean compressed air must be conducted through the filter-drying cartridge counter to the normal flow direction. For this purpose, the side of the filter drying cartridge facing the compressed air inlet has to be vented. A further pressure control valve is therefore provided, which has two connections and two switching states and which, in the operating state of the charging pressure, connects the compressed air inlet to the discharge outlet. This further pressure control valve is operated by the first pressure control valve (in combination with the solenoid valve).

The device for supplying compressed air to a commercial vehicle is operated at a specific setpoint pressure, which depends on various conditions. The nominal pressure is not understood to be a fixed value, but rather a range, the pressure in the device being able to vary between an upper and a lower limit of which range. The regeneration of the filter drying cartridge is introduced in the method according to the invention, in which the solenoid valve is switched above the upper limit of the setpoint pressure or below the lower limit of the setpoint pressure into a state in which the compressed air generated by the compressor is discharged into the environment, and in which the pressure control valve is simultaneously switched into a state in which the outlet to the at least one pressure accumulator is connected to the side of the filter drying cartridge which is opposite the compressed air inlet. In this way only solenoid valves controlled by the electronic control unit are required. In order to initiate the regeneration action, the nominal pressure must then only be briefly lowered or exceeded. The deviation from the nominal pressure is used in order to bring the pressure control valve into a switching state which, in conjunction with the switching position of the solenoid valve, enables the regeneration action of the filter drying cartridge.

Clean and dry compressed air is required for regeneration of the filter drying cartridge. The compressed air is taken from at least one pressure accumulator. The regeneration is effected by means of compressed air from the pressure accumulator via a pressure control valve, wherein the pressure control valve is switched when the pressure lies between 0.5 and 2bar below the maximum pressure. This range ensures that the process according to the invention can be carried out in two variants. Or the switching pressure of the pressure control valve is below the nominal pressure, whereupon the solenoid valve is also switched below the nominal pressure for initiating the regeneration action; or the switching pressure of the pressure control valve is above the nominal pressure and the solenoid valve is also switched above the nominal pressure for initiating the regeneration action. In particular in the latter case, a sufficiently large distance with respect to the maximum pressure is also maintained when the regeneration action is introduced, so that the safety of the system is in no way compromised.

In order to be able to carry out regeneration of the filter-drying cartridge, dry and clean compressed air must be conducted through the filter-drying cartridge counter to the usual direction. For this purpose, the pressure on the side of the filter drying box opposite the compressed air inlet must be higher than the pressure on the side of the compressed air inlet. The compressed air inlet is therefore advantageously vented via a further pressure control valve which is switched via the first pressure control valve or via a solenoid valve.

Drawings

Further details and advantages of the invention are given by the description of an embodiment, which is explained in detail with the aid of the drawings.

It shows that:

figure 1 is a schematic view of the pneumatic structure of the device according to the invention in three different switching states,

figure 2 a second embodiment of the device according to the invention,

in an alternative embodiment of the method of figure 3,

figure 4 a fourth embodiment of the device according to the invention,

FIG. 5 a fifth embodiment of the invention, an

Fig. 6 a sixth embodiment of the invention.

Detailed Description

The compressed air system of a commercial vehicle usually has a compressor, a supply device as discussed here, a multi-circuit protection valve and different compressed air load circuits, each of which usually contains its own pressure accumulator. A separate pressure accumulator is usually also provided for regeneration of the filter drying cartridges, so that no further safety-relevant pressure accumulator is necessary for the required regeneration. The compressed air produced by the compressor is either passed to the supply device or discharged to the environment (if it is not needed at the time and the accumulator is filled). If the process is controlled by means of a pressure control outlet, the pressure control outlet connects the supply device with the compressor. In the following, for reasons of simplicity and better comprehensibility, the connection between the supply device and the multi-circuit protection valve is simply referred to as the outlet to the accumulator.

The basic structure of the compressed air supply device according to the present invention is shown in fig. 1. The control of the supply device is taken care of by the electronic control device 1. The electronic control unit receives the measured value of the pressure sensor 2, which determines the pressure in the outlet to the pressure accumulator 7.

Furthermore, an electromagnetic two-position three-way valve 3 is actuated by the electronic control device 1. Through which the pressure control outlet 16 is connected either with the discharge outlet 6 or with the outlet 7 to the accumulator.

The first pressure-controlled two-position two-way valve 8 is actuated by the pressure prevailing in the outlet 7 to the pressure accumulator. The switching pressure at which the valve changes from the first switching state into the second switching state should lie approximately 1bar below the nominal pressure of the device.

The compressed air inlet 4 is supplied by a compressor which is not shown here. The inflowing compressed air is guided through the filter drying box 5. The cleaned and dried compressed air then passes via the second non return valve 12 into the outlet 7 to the accumulator. In the vicinity of the filter-drying cartridge, a further sensor, not shown here, can also be arranged, which determines the air volume passing through the filter-drying cartridge and transmits it to the electronic control unit 1.

The compressed air inlet 4 can be vented by means of a second pressure-controlled two-position two-way valve 9, in which it is connected to the discharge outlet 6. The second pressure control valve 9 is actuated by the first pressure control valve 8 in conjunction with the solenoid valve 3.

All three valves have two switching states: a rest position into which the valves are pressed by a spring; and an actuating position into which the valves are pressed either by electromagnetic force (solenoid) or by pneumatic force (compressed air). If both the solenoid valve 3 and the

pressure control valves

8 and 9 are in their actuated positions, a regeneration of the filter drying cartridge 5 can be carried out. In this case, compressed air flows from the pressure accumulator, not shown here, via the outlet 7 to the pressure accumulator, the solenoid valve 3, the first pressure control valve 8, the first non-return valve 10 and the throttle device 11 to the filter drying box 5. The compressed air penetrates the filter-drying cartridge 5 in the usual direction and is discharged to the environment through the second pressure control valve 9 and the discharge outlet 6. On passing through the filter-drying box 5 against the usual direction, dirt particles adhering in the filter material are carried along and moisture adsorbed in the dry particulate material is received.

The function of the embodiment of the invention shown in fig. 1 is explained in detail below. If compressed air produced by the compressor is required, the solenoid valve 3 is in the position shown in fig. 1A. The first pressure control valve 8 is also in the position shown. The pressure control outlet 16 is coupled to the drain outlet 6 via the solenoid valve 3 and is therefore not loaded with pressure.

If the regeneration of the filter drying cartridge 5 is not to be carried out, the solenoid valve 3 remains in the position shown until the upper limit of the nominal pressure is reached. At the switching interface of the first pressure control valve 8, a predetermined switching pressure of approximately 1bar below the upper limit of the nominal pressure is present, which moves the first pressure control valve 8 into the operating position. When the upper limit of the rated pressure is reached, the first pressure control valve 8 is closed.

The nominal pressure is controlled by the electronic control device 1 via the pressure sensor 2. If the upper limit of the setpoint pressure is reached, the solenoid valve 3 is switched by the electronic control unit 1 into the control position. This state is shown in fig. 1B. The pressure prevailing in the outlet 7 to the pressure accumulator is now at the pressure control outlet 16 via the solenoid valve 3. This control pressure causes the compressed air supplied by the compressor not to be conveyed further into the supply device via the compressed air inlet 4, but to be discharged into the environment.

The pressure prevailing in the outlet 7 to the pressure accumulator is always maintained by the control device 1 within the range of the nominal pressure by means of the solenoid valve 3 and the control pressure at the pressure control outlet 16. This means that if the pressure in the outlet 7 to the accumulator drops to the lower limit of the nominal pressure all the way through the consumption of compressed air, the solenoid valve 3 is switched into its rest position again, so that the pressure control outlet 16 is again coupled with the discharge outlet 6 and is therefore pressureless. In this state, the compressor again supplies compressed air into the supply device through the compressed air inlet 4. However, the lower limit of the setpoint pressure is still above the switching pressure for the pressure control valve 8, so that during normal operation the pressure in the outlet 7 to the accumulator is always maintained at a level in which the first pressure control valve 8 is prevented from returning into its rest position, so that the first pressure control valve 8 is always in the operating position, i.e. the closed position.

The electronic control unit 1 continuously determines the amount of air compressed from the compressor through the filter drying cartridge 5 during operation. Starting from this, the following: the moisture content and the degree of contamination of the air did not change. However, both parameters can also be measured by corresponding sensors. In any case, the load on the filter drying cartridge 5 is determined or estimated by the electronic control device 1. If a certain load is reached, the filter drying cartridge 5 must be regenerated. For this purpose, clean and dry compressed air should be conducted through the filter-drying box 5 in the opposite direction.

If the electronic control device 1 determines that: if a correspondingly large amount of air has already been conducted through the filter drying box 5 and it is necessary to regenerate said filter drying box, the solenoid valve 3 is held by the electronic control device 1 in the operating position shown in fig. 1B, and the first pressure control valve 8 returns to its rest position even if the pressure in the outlet 7 to the pressure accumulator drops below the lower limit of the setpoint pressure to such an extent. In this way, the first pressure control valve 8 is switched into its open position. The pressure prevailing in the outlet 7 to the pressure accumulator is in this state at the pressure control outlet 16, so that the compressor discharges the generated compressed air to the environment. However, the pressure prevailing in the outlet 7 to the pressure accumulator is now also present in the line between the filter drying cartridge 5 and the second non return valve 12 via the first pressure control valve 8, the first non return valve 10 and the throttle device 11.

But via the first pressure control valve 8, the pressure is now also at the same time at the switching inlet of the second pressure control valve 9 and the second pressure control valve is switched into its operating position, i.e. the open position. Thereby, the compressed air inlet 4 is coupled with the discharge outlet 6 and is thus discharged. This state of the supply apparatus is shown in fig. 1C.

Clean and dry compressed air from the outlet 7 to the pressure accumulator is pressed through the filter-drying box 5 by the pressure on the side of the filter-drying box 5 opposite the compressed air inlet 4. Here, the filter drying cartridge 5 is dried and cleaned. The moist and dirt-laden air from the filter-dryer cartridge 5 is discharged to the environment through a discharge outlet 6.

If the pressure in the outlet 7 to the pressure accumulator drops to a minimum, the solenoid valve 3 is switched back into its rest position again by the control device. The line section between the first non-return valve 10 and the first pressure control valve 8 is now connected to the drain outlet 6 via the solenoid valve 3 and is vented, so that the second pressure control valve 9 is also switched into its rest position, i.e. its closed position, again. Since the pressure control outlet 16 is now also pressureless, the compressor again supplies compressed air to the compressed air inlet 4.

If the regeneration of the filter drying cartridge has not yet ended when the pressure in the outlet 7 to the pressure accumulator reaches a minimum pressure, the regeneration is carried out in a plurality of stages. Before the predetermined pressure is at the first pressure control valve 8, the solenoid valve 3 is switched for the next phase of the regeneration action. Since the solenoid valve 3 thus switches the pressure in the outlet 7 to the pressure accumulator to the first pressure control valve 8 when said first pressure control valve is still in the open rest position, the regeneration of the filter drying cartridge 5 can be carried out quickly and continuously. When the regeneration of the filter drying cartridge 5 is complete, the pressure in the outlet 7 to the pressure accumulator is only increased again by the electronic control unit 1 via the solenoid valve 3 to the upper limit of the setpoint pressure.

A modified embodiment of the device according to the invention is shown in fig. 2. The first pressure controlled two-position two-way valve 8 of fig. 1 is here replaced by a changed first pressure controlled two-position two-way valve 13 having an opposite switching state. The pressure control valve 8 of fig. 1 is open in its inoperative rest state, while the modified first pressure control valve 13 of fig. 2 is closed in its inoperative rest state.

The regeneration of the filter drying cartridge therefore takes place somewhat differently in this embodiment. In the first pressure control valve 13, the predetermined switching pressure is above the upper limit of the rated pressure but still below the allowable maximum pressure. During normal operation, the first pressure control valve 13 is therefore always in the inoperative rest position. The electronic control unit 1, by actuating the solenoid valve 3, keeps the pressure at the outlet 7 to the at least one pressure accumulator approximately constant within the range of the setpoint pressure, without actuating the first pressure control valve 13 and bringing it into its open position.

If the filter drying cartridge is now to be regenerated, the electronic control device 1 increases the pressure at the outlet 7 to the at least one pressure accumulator beyond the setpoint pressure until the switching pressure of the pressure control valve 13 is exceeded. As a result, the first pressure control valve 13 is switched into its actuated open position.

Above the switching pressure of the pressure control valve 13, the solenoid valve 3 is now brought into its operating position by the electronic control unit 1. In this state, the pressure prevailing at the outlet 7 to the at least one pressure accumulator is in turn at the pressure control outlet 16, so that the compressor discharges the generated compressed air into the environment. At the same time, the pressure at the outlet 7 to the at least one pressure accumulator is connected via the first pressure control valve 13 to the switching connection of the second pressure control valve 9. The second pressure control valve moves into the piloted position so that venting of the inlet 4 through the drain outlet 6 begins. In this way compressed air from the outlet 7 to the at least one pressure accumulator can be conducted through the solenoid valve 3, the first pressure control valve 13, the first non-return valve 10 and the throttle device 11 up to the filter-drying cartridge 5 and through the latter to the discharge outlet 6.

If the pressure at the outlet 7 to the accumulator is again lower than the switching pressure of the first pressure control valve 13, the valve returns to its closed rest position. The regeneration action is thus interrupted. In order to connect the compressed air inlet 4 again to the compressor, the solenoid valve 3 is switched by the electronic control device into its rest position and thus vents the pressure control outlet 16.

Fig. 3 shows the possibility of using the first pressure to control the two-position three-way valve 14 instead of the first pressure to control the two-position two-

way valve

8 or 13. This valve likewise has three connections and two switching states, as solenoid valve 3. In the non-actuated rest state, the connection to the first non-return valve is vented via the exhaust outlet 6. This state of the device according to the invention is substantially identical to the state of the device in fig. 2. The function also corresponds to the device illustrated in fig. 2. Therefore, the function in this position should not be explained again.

In the device according to fig. 4, the first pressure-controlling two-position three-way valve 14 of fig. 3 is replaced by a first pressure-controlling two-position three-way valve 15 with a change of the switching state in the opposite direction. The first pressure control valve 14 of fig. 3 in its non-actuated, rest state vents the section between this valve and the first non-return valve 10, whereas the modified first pressure control valve 15 of fig. 4 in its non-actuated, rest state makes a connection between the solenoid valve 3 and the first non-return valve 10. Therefore, the illustrated arrangement state is the same as that in fig. 1A. Since in this case the function can be compared with that of the device of fig. 1, the regeneration of the filter drying cartridge 5 shall not be explained again here either.

In the exemplary embodiment shown in fig. 5, the second pressure control valve 9 is not actuated via the first pressure control valve 8, but rather directly via the solenoid valve 3. As soon as the solenoid valve 3 is switched, the pressure prevailing in the outlet 7 to the pressure accumulator is also present here at the switching interface. This type of actuation of the second pressure control valve naturally also occurs in the exemplary embodiments shown in fig. 2 to 4.

The exemplary embodiment shown in fig. 6 for actuating the first pressure control valve can also be transferred to all the exemplary embodiments described above. In this embodiment, the switching connection of the first pressure control valve is not connected directly to the outlet 7 to the pressure accumulator, but rather to the pressure control outlet 16, and in this way it can always be brought into the switching state required for the regeneration of the filter drying cartridge 5 when the solenoid valve 3 is also switched. Fig. 6 shows the actuation of the second pressure control valve provided in fig. 5, but the actuation shown here in fig. 1 to 4 is also possible.

List of reference numerals

1 electronic control device

2 pressure sensor

3 electromagnetic valve

4 compressed air inlet

5 Filter drying box

6 discharge outlet

7 outlet to the pressure accumulator

8 first pressure control two-position two-way valve

9 second pressure control two-position two-way valve

10 first check valve

11 throttling device

12 second check valve

13 first pressure-controlled two-position two-way valve

14 first pressure control two-position three-way valve

15 first pressure control two-position three-way valve

16 pressure control outlet

Claims

1. Device for supplying compressed air to a commercial vehicle, comprising an electronic control unit (1) connected to at least one sensor (2); having a compressed air inlet (4) and a pressure control outlet (16) connected to the compressor, respectively; having a discharge outlet (6); having a filter-drying cartridge (5); having an outlet (7) to at least one pressure accumulator and having a solenoid valve (3) which can be actuated by the electronic control device (1), by means of which solenoid valve (3) a pressure control outlet (16) is connected either to a discharge outlet (6) or to the outlet (7) to at least one pressure accumulator, characterized in that a pressure control valve (8; 13; 14; 15) is provided, the switching state of which is dependent on the pressure in the outlet (7) to the at least one pressure accumulator directly or in connection with the switching state of the solenoid valve (3) and can assume a switching state in which the outlet (7) to the at least one pressure accumulator is connected to the filter-drying box (5) on the side thereof opposite the compressed air inlet (4) via the solenoid valve (3) and via the pressure control valve 5) Is communicated so as to carry out the regeneration action of the filtering and drying box (5).

2. Device according to claim 1, characterized in that the pressure control valve (8; 13) has two interfaces and two switching states.

3. The device according to claim 2, characterized in that the connection between the two interfaces is closed in the non-actuated rest state of the pressure control valve (8).

4. The device according to claim 2, characterized in that the connection between the two interfaces is open in the non-actuated rest state of the pressure control valve (13).

5. Device according to claim 1, characterized in that the pressure control valve (14; 15) has three connections and two switching states.

6. Device according to claim 5, characterized in that the connection between two interfaces, one of which is connected with the discharge outlet (6), is open in the non-manipulated rest state of the pressure control valve (14).

7. Device according to claim 5, characterized in that the connection between two interfaces, one of which is connected with the pressure control outlet (16), is open in the non-manipulated rest state of the pressure control valve (15).

8. The device according to any of claims 1 to 7, characterized in that the switching state of the pressure control valve (8; 13; 14; 15) is stabilized in the pressure-free state by a spring force.

9. Device according to any one of claims 1 to 7, characterized in that a further pressure control valve (9) is provided, which has two connections and two switching states, which in the pressure-loaded operating state connects the compressed air inlet (4) with the discharge outlet (6).

10. Method for supplying a commercial vehicle with compressed air, which is generated by a compressor, is supplied via a compressed air inlet (4), is cleaned and dried by a filter-drying cartridge (5), and is supplied at a predetermined nominal pressure via an outlet (7) to at least one pressure accumulator, characterized in that a regeneration action of the filter-drying cartridge (5) is introduced, in which method a solenoid valve (3) is switched into the following state above an upper limit of the nominal pressure or below a lower limit of the nominal pressure: in which the compressed air generated by the compressor is discharged into the environment and in which the first pressure control valve (8; 13; 14; 15) is simultaneously switched into a state in which the outlet (7) to the at least one pressure accumulator communicates by means of the solenoid valve (3) via the pressure control valve with a side of the filter-dryer cartridge (5) which is opposite the compressed air inlet (4) in order to carry out a regeneration action of the filter-dryer cartridge (5).

11. Method according to claim 10, characterized in that the regeneration is performed by means of compressed air from the pressure accumulator through a pressure control valve (8; 13; 14; 15), wherein the pressure control valve is switched at a pressure which is between 0.5 and 2bar below the highest pressure.

12. Method according to claim 11, characterized in that the compressed air inlet (4) is vented through a further pressure control valve (9) which is switched by the first pressure control valve (8; 13; 14; 15) or by the solenoid valve (3).