DE102010018606A1 - Device for sensing three pressures, particularly in pilot unit for relay valve of vehicle system of vehicle, has valve arrangement for selective adjustment of three pressures in sensor pressure fluid line and pressure sensor - Google Patents

Abstract

The device has a valve arrangement for selective adjustment of three pressures in a sensor pressure fluid line (52) and a pressure sensor (54) for sensing the pressures. The pressure sensor is coupled with the sensor pressure fluid line. The pressure sensor is arranged at the sensor pressure fluid line and interacts with the sensor pressure fluid line and the valve arrangement, such that each pressure is selectively sensed by the pressure sensor.

Description

The present invention relates to an apparatus and a method for sensing at least three pressures, which is optionally used in a pilot control unit for a relay valve of a vehicle such as a utility vehicle. In this case, additionally or alternatively, a pressure control z. B. may be provided in connection with the sensing of the pressures as a function of a control unit, in particular with respect to the pressure at the outlet of the device, which may affect a ventilation or venting.

Such devices are z. B. used in pneumatically operated systems such as air suspension or braking systems for commercial vehicles. By reducing the number of components used, the air spring or brake system can be more cost-effectively manufactured and made more reliable with easier and less error-prone mounting. Furthermore, it is a desire that with a device a plurality of independently acting units can be controlled, especially if they are to be supplied with the amount of compressed air they need at specific pressure. Since the air spring or brake system controlled units may require different pressures, a separate pressure sensor is usually provided for each controlled unit to ensure that each unit is pressurized to the correct pressure. Since the number of units controlled by the systems is constantly increasing, in particular due to increased safety and comfort requirements, there is the disadvantage in devices of the type mentioned that the number of pressure sensors required also increases. As a result, the dimensions, complexity, cost and probability of failure of the systems increase.

The DE 196 38 545 A1 discloses a two-way valve with two inputs and one output. A valve body exposed to the two input pressures respectively connects the input leading to the higher input pressure to the output. In the valve housing a pressure sensor or pressure switch detecting the respective output pressure is arranged.

The object of the present invention is to reduce the aforementioned disadvantages and to provide a simplified device and a method for sensing at least three pressures.

The object is achieved with a device for sensing at least three pressures, in particular pressures in a pilot control unit for a relay valve of a vehicle, with a valve arrangement for selectively setting the at least three pressures in a pressure fluid line, in particular in a sensor pressure fluid line, and one with the sensor pressure fluid line coupled pressure sensor for sensing the pressures, which is arranged on the sensor pressure fluid line and cooperates with the sensor pressure fluid line and the valve arrangement such that optionally one of the at least three pressures by means of the pressure sensor is sensible. Preferably, the pressure sensor is arranged substantially between at least two of the valves of the valve assembly and can, for. B. be arranged centrally or approximately centrally in the valve assembly. Furthermore, the pressure sensor can be arranged directly on the sensor pressure fluid line. This results in a well controllable, reliable working structure, in particular an immediate pressure measurement.

In this connection, not only the qualitative detection of the presence of a pressure, but also its quantitative determination, e.g. In Pascal or bar. Since, according to the invention, at least three pressures can be sensed with a pressure sensor, the number of pressure sensors can be reduced in comparison with the devices known from the prior art in which a pressure sensor is required per sensed pressure. Reducing the number of components reduces costs, makes assembly easier, makes the system less prone to errors, and reduces the amount of space required. Furthermore, a resource saving is achieved. Since the probability of failure of a device decreases with a reduced number of components, the reliability of a device according to the invention is higher.

An advantage of the invention lies not only in the possibility of sequentially sensing at least three pressures. In the controlled unit via the valve unit and the pressure at the output can be controlled according to the control chamber of a relay valve. D. h., According to the invention, a stepped venting of the relay valve or its control chamber with two different input pressures, shut off in accordance with a hold of the pressure and a stepped venting done.

The invention can advantageously be developed such that the valve arrangement has a plurality of two-way solenoid valves. This training allows different pressures in different Operating states of the device with only one pressure sensor to sense. Two-way solenoid valves are easily available and are characterized by high reliability.

In one embodiment, the valve arrangement may comprise at least three or four valves, in particular two-way valves. The use of two-way valves, for example, both 2/2-way and 3/2-way valves, allows a simple structure and good controllability of the pressures and the pressure measurement itself. Furthermore, in a simple way selective, optional ventilation of the valve assembly or a control chamber of the relay valve possible.

In an advantageous embodiment, the valve arrangement has at least one valve designed as a shut-off valve, wherein at least one valve connected thereto, optionally designed as a switching valve, can be provided for selectively setting a first or fifth pressure, in particular a supply pressure or air bellows pressure, of a fourth pressure. in particular a control pressure, and / or a third pressure, in particular a control chamber pressure in the respective pressure fluid line. By means of a single pressure sensor can thus be two, three or more pressures sequentially in any sequence or repetition measure, so that a compact, functionally reliable construction is achieved. The evaluation of a single pressure sensor is sufficient, and the accuracy of a scheme, eg. As a pressure control, can be increased only by the fact that no measurement inaccuracies between different pressure sensors must be considered.

According to one embodiment of the invention, the valve assembly comprises four valves, in particular 2/2-way valves, of which two valves can be identical and two valves normally open and the other two valves can be normally closed. Three of the four valves may be in direct communication with the pressure sensor, i. H. be arranged directly in connection with the pressure sensor, in particular via the sensor pressure fluid line. The fourth valve indirectly communicates with the pressure sensor via one of the other three valves. This fourth valve can be considered as an interface between the relay valve and a vent outlet, wherein the connection to the relay valve can be made preferably via the control chamber of the relay valve.

According to an advantageous embodiment of the device, the valve arrangement has a first and a second assembly, each with a valve designed as a shut-off valve and connected to this connected as a switching valve, wherein the corresponding pressure fluid line between the two modules is arranged. The modules can be identical, but also possibly differ with respect to spring forces, diameters or other parameters. Preferably, the pressure sensor is arranged between the two modules. Thus, three or more pressures can be sensed and at the same time or alternatively realize a selectively selectable or controllable ventilation or venting, in particular via the corresponding pressure fluid lines. Furthermore, a selective, optional ventilation or venting of a control chamber of the relay valve is possible.

In an advantageous embodiment, two valves of the valve assembly or an assembly can be controlled coupled to each other, for. B. by applying the same control signal to the optionally connected in series or parallel excitation coils of the two valves or the module. In this way, the control effort can be reduced or easily the switching reliability or accuracy increased and the operation can be standardized. Alternatively or additionally, two valves of the valve assembly or an assembly may be formed as two-stage solenoid valves, for. B. operable as a single exciter coil double anchor valve. Thus, the control and wiring effort is reduced and the reliability high, especially due to the also created thanks to this type of valve option to vent at least the outlet pressure of the valve assembly either via the relay valve or directly via a third pressure fluid line.

In accordance with one or more embodiments, a relay valve is provided, the z. B. for air suspension control or other purposes, eg. B. for a brake control, serves, and having a control chamber, which is connected to the valve assembly.

According to one exemplary embodiment of the invention, at least one valve of the valve arrangement is connected via the control chamber of the relay valve and via a seventh pressure fluid line and via a third pressure fluid line to the relay valve. In this case, a selective venting of the control chamber can be realized, in particular via a seventh pressure fluid line.

In one or more embodiments, the valve assembly may be provided with an air suspension system for damping and leveling a vehicle, e.g. As a commercial vehicle, or be connected to a brake system or other system, so that it is easy to measure several operating pressures of the system. In particular, a quick sensing and thus a rapid control of the respective pressures is possible according to the invention, so that z. B. a brake can react faster.

According to another aspect of the invention, a method of sequentially sensing at least three pressures, e.g. B. in a pilot unit for a relay valve of a vehicle, in which a pressure at a pressure sensor is adjustable by means of a valve assembly and the valve assembly is then switched to set a different pressure on the pressure sensor, so that two pressures can be measured successively by means of the same pressure sensor. By re-switching the valve arrangement, a further pressure at the pressure sensor can be set, so that it can now measure three or more pressures in rapid succession and with little effort.

According to another aspect of the invention, a vehicle system, such as an air suspension system, a braking system for braking a vehicle or a stabilization system, for. B. a commercial vehicle or a commercial vehicle trailer, provided with a device according to one or more of the aforementioned or below described embodiments.

Advantageously, the vehicle system, for. As air suspension system or brake system, for the execution of the above or described below or shown in the drawings method.

A vehicle, for. As a commercial vehicle or other motor vehicle such as a car, can advantageously with such a vehicle system, for. B. air suspension system or brake system, be equipped.

Advantages that are listed for the device according to the invention apply equally to the method according to the invention, to the system according to the invention as well as to the vehicle according to the invention, e.g. B. commercial vehicle too.

The invention is explained below with reference to a drawing of preferred exemplary embodiments in detail. Show it:

1 an embodiment of the device according to the invention;

2 a further embodiment of the device according to the invention;

3 a variant of the further embodiment.

This in 1 illustrated embodiment of the device according to the invention has four valves 14 . 16 ' . 30 . 32 ' as well as a relay valve 42 on, with the four valves 14 . 16 ' . 30 . 32 ' designed as a solenoid valve, and especially the valves 14 . 30 can be designed as 2/2-way valves. The control chamber 42 ' of the relay valve 42 is via a (fourth) pressure fluid line 40 with the valve 30 connected as well as with the valve 32 ' via an eighth pressure fluid line 51 , Via a second pressure fluid line 26 is the valve 16 ' via a sensor pressure fluid line 52 in communication with the valve 14 , the valve 30 and the pressure sensor 54 , Input of the valve 14 is a fourth pressure p4, at the beginning of the valve 16 ' a first pressure p1 or a fifth pressure p5, and at the beginning of the valve 32 ' a venting pressure p3. The control chamber 42 ' is acted upon by the third pressure p4 ', wherein the relay valve 42 further via a seventh pressure fluid line 50 with a third pressurized fluid line 36 communicates, so that a venting pressure p3 in the seventh pressure fluid line 50 and in the third pressure fluid line 36 may be present, and being at the relay valve 42 a first pressure p1 and a second pressure p2 abut.

This in 2 illustrated embodiment of the device according to the invention 10 comprises a valve arrangement with a plurality of valves 14 . 16 . 30 . 32 for selectively adjusting one or more pressures in the device 10 , The valves 14 . 30 are designed as shut-off valves in the illustrated embodiment, while the valves 16 . 32 are designed as switching valves.

The valves 14 . 30 can optionally be used as solenoid valves, z. B. as 2/2-way valves, be formed. Also preferred are the valves designed as switching valves 16 . 32 as solenoid valves, z. B. as 3/2 Directional valves formed. I'm in the 2 Example shown are the valves 14 . 16 designed as solenoid valves that are controlled together, z. B. may be current controlled, as indicated by the broken line 20 is illustrated. The valves 14 . 16 can also be designed as double anchor valves with a single, both armature selectively moving exciter coil.

The valve 14 is about an example, first pressure fluid line 22 , z. B. a pneumatic line with a pressure fluid source such as a compressed air source or a control or actuation component of a vehicle 58 , z. Example, a component for adjusting the size of the distance between the chassis and the road surface, the spring rate, or a vehicle brake pedal connected to the operation or actuation of a fourth pressure p4, z. As a control pressure can be applied. The valve 16 is via a second pressure fluid line 26 , z. B. a pneumatic line with a pressure source or a pressure accumulator 28 , z. B. a pressure reservoir, connected, the or a first pressure p1, z. As an operating pressure, control pressure or supply pressure provides.

The valves 30 . 32 are in the example shown as well as the valves 14 . 16 designed as solenoid valves that are controlled together, z. B. may be current controlled, as indicated by the broken line 34 is illustrated. The valves 30 . 32 can also be designed as double anchor valves with a single, both armature selectively activating exciter coil.

The valves 14 . 16 . 30 . 32 can for targeted measuring, controlling and releasing a pressure z. B. an air suspension pressure or a brake pressure or a third pressure p4 ', in particular control chamber pressure in a control chamber 42 ' a relay valve 42 , operate. The valve 32 is via a third pressure fluid line 36 , z. B. a pneumatic line, and a vent outlet 38 with the environment of the device 10 connected and used for venting or pressure reduction in the control chamber 42 ' or in the device 10 , The valve 32 is via a fourth pressure fluid line 40 , z. B. a pneumatic line, with the relay valve 42 or its control chamber 42 ' connected. The relay valve 42 is via a fifth pressure fluid line 44 , z. B. a pneumatic line, and a first distribution point X1 with the second pressure fluid line 26 and via a fourth pressure fluid line 46 such as a pneumatic line with an element 48 , z. As an actuator, such as an air bladder or brake cylinder for braking the vehicle 58 , connected. Depending on the switching state of the valves 14 . 16 . 30 . 32 gives the relay valve 42 the passage between the fifth and fourth pressure fluid line 44 . 46 free, leaving the item 48 , z. B. the air bellows or brake cylinder, with the pressure in the accumulator 28 , z. B. pressure reservoir memory, applied applied first pressure p1 and thus to control, for. B. for leveling or braking the vehicle 58 , is operated. The relay valve 42 is about seventh pressure fluid line 50 , z. B. a pneumatic line and a second distribution point X2 with the vent outlet 38 connected so that the relay valve 42 depending on the switching state of the valve 32 is vented.

The valves 14 . 16 may alternatively be combined as two-stage solenoid valves. In this case, the valves can 14 . 16 be driven by a single electromagnetic coil, wherein the respective valve switching position is adjusted by current control of the coil current. Optionally, the valves can 30 . 32 combined be designed as two-stage solenoid valves. In this case, the valves can 30 . 32 be operated by means of a single electromagnetic coil, wherein the respective switching position is adjusted by current control of the coil current.

Alternatively, at the second pressure fluid line 26 and the fifth pressure fluid line 44 the first pressure p1 according to a supply pressure or the fifth pressure p5 be applied according to a bellows pressure or other pressure.

Alternatively, the first distribution point X1 can be omitted and on the second pressure fluid line 26 can z. B. the bellows pressure be applied directly. In this case, the fifth pressure fluid line 44 directly with the accumulator 28 connected, whereby the relay valve receives a pressure supply.

The valves 16 . 30 are connected to each other via a sensor pressure fluid line 52 , z. B. a pneumatic connecting line, connected to or in a pressure sensor 54 is arranged. Using the device according to the invention 10 It is possible to have several or all relevant pressures with the pressure sensor 54 to sensate. The valves 14 . 16 . 30 . 32 can each be either in a first, in 2 shown unactuated position or be brought by selective control in a second, actuated position. For the valves 14 . 16 . 30 . 32 This results in several alternative switching states. In de-energized switching state, the valves are located 14 . 16 . 30 . 32 in their basic position. In the illustrated embodiment, the valves are designed as 2/2-way valves 14 . 30 designed as "normally open" valves.

In the following, the pressure sensors are used for the different switching states 54 explained sensed pressures.

The various switching states are illustrated in the following table. valves 14 . 16 valves 30 . 32 function pressure sensing 0 0 p4 '= p4 p4 0 1 Hold p4 0 2 bleed p4 1 0 Hold p4 ' 1 1 Hold - 1 2 bleed - 2 0 Ventilate with p1 - 2 1 Hold p1 2 2 bleed p1

The switching state 0 in the left-hand column of the table means that the valves 14 . 16 unconfirmed in their basic position. The switching state 0 in the second table column means that the valves 30 . 32 unconfirmed in their basic position. The switching state 1 in the left-hand column of the table means that the valve 14 actuated, that is, switched, while the valve 16 unconfirmed in its basic position. The switching state 1 in the second table column means that the valve 30 actuated, that is, switched, while the valve 32 unconfirmed in its basic position. The switching state 2 in the left-hand column of the table means that both valves 14 . 16 operated, ie are switched. The switching state 2 in the second table column means that both valves 30 . 32 operated, ie are switched.

In the first, in 2 In the case shown, all valves are in the unactuated ground state. The at the first pressure fluid line 22 adjacent fourth pressure p4 is in the device 10 and further into the sensor pressure fluid line 52 as well as to the control chamber 42 ' initiated so that the pressure sensor 54 the fourth pressure p4 sensed.

In the second case is the valve 30 pressed, so that the fourth pressure p4 is no longer through the valve 30 is passed through. The pressure sensor 54 still measures the fourth pressure p4, but unaffected by the control chamber pressure.

In the third case is next to the valve 30 also the valve 32 pressed, leaving the right of the valve 32 located compressed air through the vent outlet 38 discharged and the control chamber 42 ' This is vented. The pressure sensor 54 continues to sense the fourth pressure p4.

In the fourth case, the valve 14 actuated. All other valves 16 . 30 . 32 remain in the basic position. Now, no further compressed air is supplied from the outside, so that the pressure sensor 54 a third pressure p4 ', in particular control chamber pressure, ie the pressure in the control chamber 42 ' sensed. This may initially correspond to the fourth pressure p4.

In the fifth case, the valves are each 14 . 30 actuated. In this case, the pressure sensor measures 54 the pressure between the first two valves 14 . 30 ,

In the sixth case, the valves, 14 . 30 . 32 actuated. The from the pressure sensor 54 sensed pressure corresponds to the pressure measured in the fifth case. The control chamber 42 ' is now over the valve 32 vented.

In the seventh case, the valves 14 . 16 pressed while the other valves 30 . 32 are in the ground state. In this case, the control chamber 42 ' with the at the second pressure fluid line 26 applied first applied pressure p1. The pressure sensor 54 in this case senses the first pressure p1 and possibly also this dynamic loading process.

In the eighth case turn the valves 14 . 16 operated and also the valve 30 switched, thereby passing the compressed air through the valve 30 is interrupted. The pressure sensor 54 senses the on the second pressure fluid line 26 or at the relay valve 42 over the fifth pressure fluid line 44 adjacent first pressure p1, which may be the reservoir pressure.

In the ninth case, all valves are 14 . 16 . 30 . 32 pressed, The control chamber 42 ' is now over the valve 32 vented. The pressure sensor 54 senses the on the second pressure fluid line 26 or at the relay valve 42 over the fifth pressure fluid line 44 adjacent first pressure p1, which may be the reservoir pressure.

The solenoid valves may in one or more embodiments as two-stage solenoid valves according to the patent application PCT / EP2005 / 0077226 be educated.

The device according to the invention 10 is a part of a vehicle system according to one or more embodiments 56 , z. As an air suspension, a braking system or stabilization system, which in turn is part of the vehicle 58 , z. B. a commercial vehicle or a commercial vehicle trailer is.

The through at least three of the valves 14 . 16 . 30 . 32 formed valve assembly ensures in the embodiments described above, that even in case of failure of the on-board electronics, the supply of the vehicle system, eg. B. the air suspension or the brake system is ensured with compressed air, wherein the valve assembly in the ground state, a control pressure in the device 10 and optionally the control chamber 42 ' of the relay valve 42 can initiate. The valve arrangement can be reset by return means, for example by springs, in this basic state, if it is not activated. Additional components are not required.

The valves 30 . 32 can serve as a valve modulator device for controlling an air pressure z. B. for electronic air suspension systems, level or Lageregulierungen, brake systems, electronic stability systems, antilock braking systems and / or other security systems, is used or can be used. Again, these are components that can be easily integrated into the device according to the invention, without additional developments or designs are required.

By provided in one embodiment of the invention relay valve 42 can be an increase in the amount of air of the output pressure, in particular the brake pressure, achieve. Through the relay valve 42 can be an otherwise required increase and increase in the cost of the vehicle system 56 avoid. It may be provided a pilot unit, which is the relay valve 42 controls and on the required pressures, z. B. air suspension pressures or brake pressures, is tuned. The pilot unit can be operated with reduced nominal values and volumes and designed accordingly low. Further, the relay valve 42 optionally not only adapted to the pressures required in the actuated components, but also adapted to the required air flow rate.

3 shows the in 2 illustrated embodiment in a variant in which the fifth pressure fluid line 44 not with the second pressure fluid line 26 is coupled via a distribution point. According to this variant, the first pressure p1 and the fifth pressure p5 can be adjusted independently of each other.

In the described embodiments of the device according to the invention 10 the valve arrangement acts as a switching component, so that by means of the pressure sensor 54 optionally, the inlet pressure as the first pressure, the outlet pressure or another pressure can be sensed. With the switching component of the pressure can be selected, which is currently being measured. Such a switching component, z. As the valve assembly, in contrast to another pressure sensor is a simpler structure, so that a simple construction is achieved in their use. In addition, there is the possibility with the switching component, the pressure sensor 54 to apply more than two pressures and also to contribute to an advantageous design of the device. The switching component contributes to the complexity of the circuits within the device 10 to reduce. The switching component can be actuated, for example, electrically or pneumatically or hydraulically by means of a control pressure. In this case, a switching threshold can be selected so that the switching component is not actuated until the pressure value of the control pressure exceeds the switching threshold.

Embodiments of the device according to the invention can also be in a magnetic sensor system, for. B. in an RSS system (RSS = roll stability support = Roll stabilization support) and / or use a trailer with or without drawbar.

From the sequence of method steps set out, no limitation is to be derived therefrom, but the method can be carried out in any desired sequence.

Furthermore, the invention relates to a vehicle, in particular a commercial vehicle, which is equipped with the system according to the invention.

The present invention has been described above in detail with reference to some embodiments. Modifications or additions which will become apparent to one skilled in the art from the description or the drawings, are not in any way departing from the spirit of the invention and are included within the scope of protection defined by the following claims. For example, the pneumatic conduits may generally be used as pressurized fluid conduits for carrying a pressurized fluid, e.g. As a hydraulic or pneumatic pressure fluid may be formed, wherein the controlled and controlling components are designed according to the pressure fluid used.

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 19638545 A1 [0003]
• EP 2005/0077226 [0048]

Claims (17)

Device for sensing at least three pressures, in particular in a pilot control unit for a relay valve ( 42 ) of a vehicle ( 58 ), with - a valve arrangement for selectively setting the at least three pressures in a sensor pressure fluid line ( 52 ), and - one with the sensor pressure fluid line ( 52 ) coupled pressure sensor ( 54 ) for sensing the at least three pressures thus applied to the sensor pressure fluid line ( 52 ) is arranged and in such a way with the sensor pressure fluid line ( 52 ) and the valve assembly cooperates, that optionally one of the at least three pressures by means of the pressure sensor ( 54 ) is sensible. Device according to claim 1, characterized in that the valve arrangement comprises at least three valves ( 14 . 16 . 16 ' . 30 . 32 . 32 ' ), wherein at least one of the at least three valves ( 14 . 16 . 16 ' . 30 . 32 . 32 ' ) a two-way valves ( 14 . 30 ). Device according to claim 1 or 2, characterized in that the valve arrangement has at least one valve designed as a shut-off valve ( 14 . 30 ) and at least one associated with this, designed as a switching valve ( 16 . 32 ) for selectively setting a first pressure, in particular a supply pressure (p1), a fourth pressure (p4), in particular a control pressure, and / or a third pressure (p4 '), in particular a control chamber pressure, in the sensor pressure fluid line ( 52 ) having. Device according to claim 1 or 2, characterized in that the valve arrangement has at least one valve designed as a shut-off valve ( 14 . 30 ) and at least one associated with this, designed as a shut-off valve ( 16 ' . 32 ' ) for selectively setting a first pressure, in particular a supply pressure (p1), a fourth pressure (p4), in particular a control pressure, and / or a third pressure (p4 '), in particular a control chamber pressure, in the sensor pressure fluid line ( 52 ) having. Apparatus according to claim 1, 2 or 3, characterized in that the valve arrangement comprises a first and a second, in particular of identical construction, each with a valve designed as a shut-off valve ( 14 . 30 ) and a valve connected to this as a switching valve ( 16 . 32 ), wherein the sensor pressure fluid line ( 52 ) is arranged between the two modules. Device according to claim 1, 2 or 4, characterized in that the valve arrangement comprises a first ( 14 . 16 ' ) and a second ( 30 . 32 ' ), in particular structurally identical assembly each having two valves designed as shut-off valves, wherein the sensor pressure fluid line ( 52 ) is arranged between the two modules. Device according to one of the preceding claims, characterized in that in each case two valves ( 14 . 30 ; 16 . 32 ) of the valve arrangement are coupled together or are designed as two-stage solenoid valves. Device according to one of the preceding claims, characterized by a relay valve ( 42 ), whose control chamber ( 42 ' ) is connected to the valve assembly. Apparatus according to claim 8, characterized in that a switching valve ( 32 ) of the valve arrangement on the one hand with the control chamber ( 42 ' ) of the relay valve ( 42 ) and on the other hand with the sensor pressure fluid line ( 52 ) or with a vent outlet ( 38 ) for selectively measuring the pressure of the control chamber ( 42 ' ) or for venting the control chamber ( 42 ' ) is connectable. Device according to one of the preceding claims, characterized in that the valve arrangement with a vehicle system ( 56 ), in particular an air suspension system for damping and for the level control of a commercial vehicle, or a brake system is connected. Device according to claim 1 or 2, characterized in that the valve arrangement comprises four valves ( 14 . 16 . 16 ' . 30 . 32 . 32 ' ), wherein three of the four valves ( 14 . 16 . 16 ' . 30 . 32 . 32 ' ) directly in connection with the pressure sensor ( 54 ) are arranged, and wherein the further valve of the four valves ( 14 . 16 . 16 ' . 30 . 32 . 32 ' ) between a vent outlet ( 38 ) and the relay valve ( 42 ), the connection to the relay valve ( 42 ) via the control chamber ( 42 ' ) of the relay valve ( 42 ) is made. Apparatus according to claim 11, characterized in that the four valves ( 14 . 16 . 16 ' . 30 . 32 . 32 ' ) of the valve assembly are 2/2-way valves. Device according to one of the preceding claims, characterized in that the device is designed for a stepped venting of the relay valve or its control chamber with two different input pressures and a shut-off according to holding the pressure and for a stepped venting. Method for sequentially sensing at least three pressures, in particular in a pilot control unit for a relay valve of a vehicle, comprising the steps of: - setting a pressure to a pressure sensor ( 54 ) by means of a valve arrangement, - switching the valve arrangement for setting a different pressure to the pressure sensor ( 54 ), and - re-switching the valve arrangement for setting a further pressure to the pressure sensor ( 54 ). Vehicle system ( 56 ), in particular air suspension system, brake system or stabilization system of a vehicle ( 58 ), in particular a commercial vehicle or a commercial vehicle trailer, characterized by a device according to one of claims 1 to 13. Air suspension system for springing a vehicle ( 58 ), in particular a commercial vehicle, characterized in that the air suspension system is designed for carrying out the method according to claim 14. Vehicle ( 58 ) characterized by a vehicle system ( 56 ) according to claim 15 or an air suspension system according to claim 16.

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