Pneumatic pressure control valve

Abstract

A pneumatic pressure control valve is described, comprising a housing in which a first valve chamber (2) is formed with a supply opening (3) for supplying compressed gas into the first valve chamber (2), and with a connecting opening (4) which opens into a connecting channel (16) for connection to a cushion to be filled with gas, wherein a diaphragm (8) is arranged in the first valve chamber (2), wherein a spring element (12) is arranged in a first region (9) and is mechanically connected to the diaphragm (8) and exerts a force thereon, and wherein an actuating pin (13) of a valve disk (14) is arranged in a second region (10) and is connected to the diaphragm (8).A second valve chamber (2a) is formed in the housing, which has a first opening with a first cross-section (A1), which opens into the connecting channel (16), and a second opening with a second cross-section (A2), which is connected to the ambient pressure (P0), wherein a tappet (11) with a sealing element (6) is arranged in the second valve chamber (2a), wherein the sealing element (6) closes or opens the first opening, and wherein the second valve chamber (2a) is connected to the first region (9) of the first valve chamber (2) via a pressure equalization channel (16a), and wherein an SMA actuator (20) acting on the tappet (11) is arranged in the housing, the actuation of which actuator moves the tappet (11) into the first or second position.

Description

[0001] The invention relates to a pneumatic pressure control valve, comprising a housing in which a first valve chamber is formed with a supply opening for supplying compressed gas into the first valve chamber, and with a connecting opening which opens into a connecting channel for connection to a cushion to be filled with gas, wherein in the first valve chamber there is arranged a diaphragm which is connected airtight to the valve chamber wall and divides the first valve chamber into two regions, wherein in a first region there is arranged a spring element which is mechanically connected to the diaphragm and exerts a force thereon, and wherein in a second region there is arranged an actuating pin of a valve disk which is connected to the diaphragm,wherein the valve disc is arranged on the outside of the first valve chamber and opens or closes the supply opening depending on the position of the diaphragm due to the force of the spring element acting on the diaphragm and the pressure in the first region via the actuating pin.

[0002] Such a pressure regulator is shown and described on the website en.wikipedia.org / wiki / Pressure_regulator# / media / File:Single-stageregulator.svg and in the Fig. 1 shown.

[0003] DE 10 2018 205 016 A1 relates to a pressure reducer with a housing and with a valve which, when closed, separates an upstream pressure chamber from a downstream pressure chamber and, when open, connects the upstream pressure chamber and the downstream pressure chamber. The valve has a diaphragm acting on a valve tappet, on which a spring force of a spring element acting in the opening direction of the valve and a force acting in the closing direction of the valve, dependent on the pressure prevailing in the downstream pressure chamber, acts, providing a pressure reducer function. The valve has a valve body attached to the valve tappet. The spring element is arranged between two spring plates, wherein the spring element is firmly connected to a spring plate facing the diaphragm and to a spring plate facing away from the diaphragm, and wherein the spring plate facing the diaphragm is firmly connected to the valve tappet.The spring plate facing away from the diaphragm is operatively connected to an actuating element, via which the spring plate facing away from the diaphragm can be displaced relative to the spring plate facing the diaphragm in such a way that, depending on the relative position between the spring plates, the spring element acts as a compression spring, providing the pressure reducer function, or as a tension spring, providing a closing valve function.

[0004] DE 10 2021 203 190 A1 relates to a pneumatic valve, with a housing in which an air chamber is formed with a supply opening for supplying compressed air into the air chamber, a connecting opening for connecting the air chamber to an air cushion and a discharge opening for discharging compressed air from the air chamber, wherein an actuator with a movable closing element is arranged in the housing, wherein the closing element is provided with a first sealing element for closing the supply opening, with a second sealing element for closing the discharge opening and with a sealing element arranged between the first and the second sealing element and which, in the deactivated state, presses against the supply opening or the discharge opening.the drain opening is formed by an elastic element pressing on it, wherein a plunger projecting through the drain opening is arranged on the second sealing element, and wherein the actuator further comprises a printed circuit board, an actuating element which has an actuating section for acting on the plunger and a bending section connected to the actuating section and the printed circuit board, and an actuator element which has a first end which is mechanically connected to the actuating section and a second end which is mechanically and electrically connected to the printed circuit board, wherein the actuator element is designed to bend the bending section when energized such that the actuating section, by acting on the plunger, opens the drain opening by pressing the second sealing element against the elastic element.

[0005] US 2022 / 0 341 496 A1 relates to a seat support assembly for a valve, comprising an annular seat support body with an annular projection projecting radially into a central passage, and an annular plastic sealing ring molded onto the annular projection, the annular plastic sealing ring defining a seat seal.

[0006] DE 10 2018 216 876 A1 relates to a pneumatic valve for a fluid bladder of a pneumatic adjustment device of a vehicle seat. The pneumatic valve comprises a first valve chamber that is connectable to a fluid source, a separate second valve chamber that is connectable to the fluid bladder, a separate third valve chamber that is connectable to an environment of the pneumatic valve, a separate fourth valve chamber that is connected to the first valve chamber via a first fluid passage, to the second valve chamber via a second fluid passage, and to the third valve chamber via a third fluid passage, and an actuator unit that has a diaphragm element arranged in the fourth valve chamber and an actuator element arranged in the third valve chamber, which actuator element is coupled to the diaphragm element and is designed to move the diaphragm element between a first position,in which the first fluid passage is open and the third fluid passage is closed, and a second position in which the first fluid passage is closed and the third fluid passage is open.

[0007] The main function of such a pressure control valve is to adjust the gas flow through the regulator to the gas demand while maintaining a sufficiently constant output pressure. As the load flow decreases, the regulator flow must also decrease. As the load flow increases, the regulator flow must increase to prevent the regulated pressure from decreasing due to a lack of gas in the pressure system. It is desirable that the regulated pressure does not deviate significantly from the setpoint over a wide range of flow rates, but it is also desirable that the flow through the regulator be stable and that the regulated pressure is not subject to excessive oscillations.

[0008] A pressure regulator comprises a limiting element, a loading element and a measuring element: The restricting element is a valve that can provide variable flow restriction, such as a globe valve, butterfly valve, poppet valve, etc. The load element is a part that can exert the required force on the limiting element. This load can be provided by a weight, a spring, a piston actuator, or a diaphragm actuator in combination with a spring. The measuring element serves to determine when the inlet flow equals the outlet flow. The diaphragm itself is often used as a measuring element. It can also serve as a combined element.

[0009] In the Fig. In the single-stage regulator shown in Figure 1, a force balance on the diaphragm 8 is used to actuate a poppet valve 13, 14 to regulate the pressure. With no inlet pressure, the spring 12 above the diaphragm 8 pushes it onto the poppet valve 13, 14 and holds it open. Once the inlet pressure is introduced, the open poppet 14 allows flow to the diaphragm 8 and the pressure in the upper chamber 9 rises until the diaphragm 8 is forced upwards against the spring 12, causing the poppet 14 to reduce flow and eventually stop any further pressure rise. By adjusting the upper screw 7, the downward pressure on the diaphragm 8 can be increased, requiring more pressure in the upper chamber 9 to maintain balance. In this way, the output pressure of the regulator is regulated.

[0010] The loading element is acted upon by an adjusting screw 7, by means of which the preload of the loading element, e.g. a spring 12, between a plate 6 arranged at the end of the adjusting screw 7 and the membrane 8 can be adjusted almost continuously.

[0011] In vehicles, fillable, elastic cushions are used to shape seat contours. These cushions are typically filled with air. Electrically operated valves are used to control the air flow. Shape memory wire (SMA = shape memory alloy) is increasingly being used as an actuator for such valves. This wire shortens in length when a current flows and the resulting heat builds up.

[0012] Due to the thermal actuation principle, switching processes in SMA valves are slower than in corresponding solenoid or piezo valves. This applies particularly to the actuator's shutdown process, which can also vary depending on ambient conditions (temperature, flow, etc.). This makes it difficult to precisely shut off when a target pressure is reached, and the achieved pressure becomes increasingly inaccurate the shorter the filling or venting process.

[0013] Rapidly reaching the target pressure is particularly necessary for highly dynamic functions, such as fast massage sequences, as well as for functions that require cushion adjustment depending on driving dynamics.

[0014] The following state-of-the-art options are available for quickly and accurately setting different target pressures: When using an SMA actuator with a high surface-to-volume ratio (e.g., very thin wire or strip), cooling occurs quickly. However, with small actuator cross-sections, its service life is reduced, as defects lead more quickly to fracture and thus to actuator failure.

[0015] DE 10 2023 202 254 B3 describes a valve arrangement in which the precise switching on and off of the air flow is carried out with a fast-switching magnetic or piezoelectric pilot valve and only the distribution of the air to different cushions is carried out with SMA valves.

[0016] DE 10 2005 060 217 B4 describes an SMA valve with targeted shielding of the wire from air flow. If this principle is further developed, it can also be reversed, for example, to quickly cool the wire with targeted air flow.

[0017] A pneumatic pressure control valve as described above can be adjusted to the desired target pressure using the adjusting screw, ensuring that this target pressure is reliably achieved even with a slow-acting SMA valve. However, to accommodate a wide range of customer functions, different target pressures are required for different functions.

[0018] Multiple pressure regulators can be set to different pressures and optionally connected to outlet-side consumers using pilot valves. However, the pilot valves must be designed for the maximum flow rate.

[0019] DE 10 2019 208 051 B4 describes a valve with an SMA actuator, wherein the pivot point of a bender and the SMA wire are arranged on different sides of a circuit board.

[0020] The object of the invention is to provide a pneumatic pressure control valve for setting at least two different target pressures, which can be switched by means of a simple electrically controllable actuator.

[0021] The object is achieved in a generic pressure control valve in that a second valve chamber is arranged in the housing, which second valve chamber has a first opening with a first cross-section which opens into the connecting channel, and a second opening with a second cross-section which is connected to the ambient pressure, wherein a plunger, on which a sealing element located in the second valve chamber is arranged, projects through both the first and the second opening, wherein the sealing element closes the first opening in a first position of the plunger and opens the first opening in a second position of the plunger, and wherein the second valve chamber is connected to the first region of the first valve chamber via a pressure equalization channel, and in that an SMA actuator acting on the plunger is arranged in the housing, the actuation of which actuator moves the plunger into the first or second position.

[0022] A known mechanical pressure regulator is combined with at least one valve, which can be actuated by an SMA actuator and has at least two switching positions. In at least one switching position, the SMA valve influences the pressure in the first valve chamber of the pressure control valve, allowing its output pressure to be set to different values. The SMA valve acts as a pressure divider: The pressure in the second valve chamber is adjusted according to the ratio of a constant and a variable nozzle cross-section. In the resting position, the SMA valve does not cause any leakage.

[0023] The SMA actuator easily changes the pressure in the second valve chamber and, via the pressure equalization channel, also the pressure in the first area of ​​the first valve chamber, so that the output pressure in the connecting channel can be set to at least two different values ​​by electrical control.

[0024] In an advantageous embodiment of the pneumatic pressure control valve, the actuator has: - a circuit board arranged in the actuator chamber, - an actuating element arranged in the actuator chamber, which has an actuating section for acting on the plunger and a bending section connected to the actuating section and the circuit board, and - an actuator element arranged in the actuator chamber, which has a first end which is mechanically connected to the actuating section, and a second end which is mechanically and electrically connected to the circuit board, wherein the actuator element is designed to bring the actuating element into a first state in which it presses the sealing element against the first opening via the plunger, and to bring the actuating element into a second state in which the actuating section exerts less force on the plunger, so that the first opening is opened, in a de-energized state.

[0025] This results in a simple, space-saving SMA actuator.

[0026] In an advantageous design of the pneumatic pressure control valve, the diaphragm is clamped hermetically between two valve chamber wall sections. This allows for a very simple construction.

[0027] The membrane can have a thickening in its center on which the spring element can be supported, which enables a one-piece, simple design.

[0028] In a further advantageous embodiment of the pneumatic pressure control valve, a further spring element is arranged in the second valve chamber between the sealing element and the first opening in order to assist in releasing the first opening.

[0029] The first opening and the second opening of the second valve chamber can have the same or different cross-sections. This allows the pressure in the second valve chamber and, via a pressure equalization channel, also in the first area of ​​the first valve chamber, and thus the pressure in the connecting channel, i.e., the desired output pressure, to be adjusted.

[0030] In a particularly advantageous embodiment of the pneumatic pressure control valve, at least one further second valve chamber is provided, the first opening of which also opens into the connecting channel and which has a ratio of the cross sections of the first and the second opening that differs from the second valve chamber and any other further second valve chamber, wherein each further second valve chamber is connected to the first region of the first valve chamber via a pressure equalization channel assigned to it.

[0031] This allows two additional target pressures to be achieved with each additional second valve chamber, which can be adjusted by an SMA actuator assigned to each second valve chamber. The SMA actuators can essentially assume two end positions, whereby the first opening of a second valve chamber is either closed or opened by the respective associated sealing element. However, it would also be possible to only slightly open the first opening by appropriately controlling an SMA actuator, so that the pressure in the second valve chamber can also be controlled in this way. This would then require a sensor that determines the extent of the elongation of the SMA actuator element.

[0032] The invention will be described in more detail below using exemplary embodiments with the aid of figures. Fig. 1 a pressure control valve according to the state of the art, Fig. 2 the two valve chambers of a pressure control valve with a tappet actuated by an SMA actuator in an open state of the first valve chamber and a closed first opening of the second valve chamber, Fig. 3 the two valve chambers of the pressure control valve of the Fig. 2 with a plunger actuated by an SMA actuator in a closed state of the first valve chamber and closed first opening of the second valve chamber, Fig. 4 the two valve chambers of the pressure control valve of the Fig. 2 with a plunger actuated by an SMA actuator in an open state of the first valve chamber with the second valve chamber open, Fig. 5 a pressure control valve according to the invention with an SMA actuator in a first state and Fig. 6 the pressure control valve according to the invention with an SMA actuator in a second state.

[0033] The Fig. 2 to 4 show a first valve chamber 2 of a pneumatic valve, such as is used in a pressure control valve according to Fig. 5 and Fig. 6, each in a cross-sectional view, which essentially corresponds to the structure of the known valve chamber, as already described in Fig. 1 and described above. Identical parts are provided with the same reference numerals and, for the sake of clarity, are not identified in all figures.

[0034] In contrast to the pressure control valve of the prior art, the spring 12 is supported on the ceiling of the first valve chamber 2 and presses against the membrane 8, on which a thickening 8a is formed in order to be able to absorb forces better.

[0035] The diaphragm 8 is connected via an actuating pin 13 to a poppet valve 14, which is arranged outside the first valve chamber 2 in the gas supply area 3 and can open and close the first valve chamber 2 on the inlet side. A connecting opening 4 of the first valve chamber 2 opens into a connecting channel 16, which can be connected to a pneumatic load, for example additional valves or a cushion to be filled with the gas, e.g. air. When the pressure in the connecting channel 16 and thus in the second area 10 of the first air chamber 2 is lower than the force of the spring 12 and the restoring force of the diaphragm 8, the poppet valve 14 is opened and gas can flow into the air chamber via the supply opening 3. When the pressure in the second area 10 of the air chamber 2 has increased to such an extent that it reaches and exceeds these spring forces, the poppet valve 14 closes the opening and the target pressure in the connecting channel 16 is reached.

[0036] The pneumatic valve has a second valve chamber 2a, which has a first opening 5a and a second opening 5b, in which a plunger 11 is movably mounted and connected to a sealing cushion 6. The plunger 11 can be designed according to the Fig. 5 and Fig. 6 can be actuated with an SMA actuator 20. In the unactuated state of the SMA actuator 20, it presses on the plunger 11, causing the sealing cushion 6 to close the first opening 5a of the second air chamber 2a.

[0037] The second air chamber 2a is connected to the first area 9 of the first air chamber 2 via a pressure equalization channel 16a, so that the same pressure is established there as in the second air chamber 2a. In the Fig. In the state of the closed first opening 5a of the second air chamber 2a shown in Figure 2, this is the ambient pressure P0. A first output target pressure P2 is then established at an input pressure P1, which is essentially determined by the predetermined force of the spring 12. This is shown in Figure 2. Fig. 3, where the poppet valve 14 is shown in the closed state. The output pressure P2 has reached a value sufficient to push the diaphragm 8 upward against the force of the spring 12.

[0038] In the Fig. 4 now shows a state in which the SMA actuator 20 releases the plunger 11. This is then guided upward by the pressure in the connecting channel, which presses against the sealing element 6, and in the illustrated embodiment also by the force of another spring 12a, thus pushing the sealing element 6 away from the first opening.

[0039] This creates a higher pressure P3 in the second air chamber 2a, which also flows through the pressure equalization channel 16a into the first area 9 of the first air chamber 2, where it supports the force of the spring 12 to hold the diaphragm 8 down. A higher output pressure is therefore required to press the poppet valve 14 against the supply opening 3 to set a second output target pressure P4.

[0040] This allows the pneumatic valve to Fig. 2 to 4 by means of an SMA actuator 20, two output target pressures P2 and P4 can be set in a simple manner without great effort.

[0041] It is now possible to provide several second air chambers, all of which open into the connecting channel 16 and are connected to the first air chamber 2 via respective associated pressure equalization channels, and which allow different pressures in their chambers, which can be achieved by a suitable choice of the ratio of the areas A1 and A2 of the first and second openings, as will be explained below.

[0042] In the following example, a relative pressure P0 = 0 is assumed for the ambient pressure P0. Furthermore, it is assumed that the force F of the spring 12 is designed for a first output pressure P2 of the pressure regulator and that the two cross-sectional areas A1 and A2 of the first and second openings of the second valve chamber 2a are equal.

[0043] In a first state, the SMA actuator 20 is not actuated and, consequently, the second valve chamber 2a is not pressure-connected to the connecting channel 16. When the force balances between the spring force and the pressure force on both sides of the diaphragm 8, an output pressure P2 of, for example, 200 hPa is established. The following applies to the forces: FFeather=FP2=200 hPa

[0044] In a second state, the SMA actuator 20 is actuated, and consequently the second valve chamber 2a is pressure-connected to the connecting channel 16. In the second valve chamber 2a and thus also in the first area 9 of the first valve chamber 2 of the pressure regulator, the pressure P3 ≈ P4 / 2 is now established. The following equations now apply to the forces: FP3=FP4 / 2 FFeather+FP3=FP4

[0045] And thus the output pressure of the pressure regulator P4 ≈ 400 hPa is: FFeather=FP2=FP4−FP4 / 2=FP4 / 2 FP4=FP2*2=400 hPa

[0046] With different ratios of the cross-sections, different output pressures can be achieved analogously.

[0047] In the Fig. Figures 2 to 4 each show two positions of the actuating section 23 of the SMA actuator 20. However, it is also easily possible to set intermediate positions.

[0048] A pressure control valve with such a design can therefore be easily adjusted electrically.

[0049] The SMA actuator changes the position of the plunger 11 in the pressure regulator so that its output pressure can be set to different values.

[0050] In the Fig. 5 and Fig.6 shows a pressure control valve in a non-actuated and an actuated state. The pressure control valve is formed with a housing having a first housing part 17, which in the illustrated embodiment is designed as a base plate. The housing also has a second housing part 18, which is designed as a cover, and finally a third cup-shaped housing part 19, which is designed as an insert between the first and second housing parts 17, 18 and onto which a supply connection 27 and a connecting connection 28 are formed. The first valve chamber 2 and the second valve chamber 2a, which is operatively connected to an actuator 20, are formed on the third housing part 19.

[0051] The first valve chamber 2 and the second valve chamber 2a are formed on the third housing part 19 by having cup-shaped projections into which a cover of each of the valve chambers 2, 2a is inserted. The connection between the cup-shaped projection and the cover is achieved, for example, by means of a press fit or a projection on the cover that engages a groove in the cup-shaped projection. It can be advantageous if the pressure and sealing forces are absorbed by such clipping, screwing, etc.

[0052] The first valve chamber 2 has a supply opening 3 and a connection opening 4, which opens into a connecting channel 16. In the illustrated embodiment, the supply opening 3 and the connection opening 4 are formed in the third housing part 19. Thus, a gas, for example compressed air, can be fed into the housing via the supply connection 27, for example from a compressor, wherein the compressed air can reach the first valve chamber 2 via the supply opening 3 and from there via the connection opening 4, the connecting channel 16 and the connection connection 28 into a connectable air cushion or another load, such as a downstream valve.

[0053] The actuator 20 is also arranged in the housing. The actuator 20 is formed with a circuit board 21, which is mounted on corresponding struts of the third housing part 19 and mechanically connected. Connected to the circuit board 21 is an actuating element 22, which has an actuating section 23 that is in direct contact with the plunger 11 and has a bending section 24 that is connected to the circuit board 21.

[0054] The actuator 20 further comprises an actuator element 26, which is preferably formed with a wire made of a shape memory alloy, which shortens when subjected to current supplied by a circuit (not shown) on the circuit board 21. In the non-activated state, the actuating element 22 is preloaded such that the actuating element 22 presses with its actuating section 23 against the plunger 11 and thus presses the sealing element 6 against the first opening of the second valve chamber 2a.

[0055] The actuator element 26 is connected - for example by means of crimp connections - both to the actuating element 23 and to the circuit board 21.

[0056] Advantageously, an end position detection element 25 is formed on the actuating element 22, which comes into contact with the circuit board 21 when the actuator 20 is actuated and enables a current flow, whereby it is detected that the end position has been reached, so that the current through the actuator element 26 can be switched off or at least reduced in order not to overload it.

[0057] This end position detection element 25 could also be developed into a position sensor in order to detect the height at which the actuating section 23 is located and thus the position of the tappet 11 in order to be able to set different positions of the sealing element 6 with respect to the first opening of the second valve chamber 2a.

[0058] The pressure control valve according to the invention can advantageously be followed by additional valves, such as SMA valves, which selectively transmit the pressure to different consumers. Such consumers can be, for example, air chambers for contour adjustment or for a massage function in vehicle seats.

[0059] The advantages of the above-mentioned designs compared to currently available state-of-the-art solutions are summarized below: Thanks to a switchable pressure regulator, slow-acting SMA actuators can also be used at a high supply pressure P1 (i.e., greater than the target pressure). Different pressure levels enable different intensities in the stroke or speed of a contour adjustment or massage sequence.

[0060] The control valve does not require rapid switching operations. It can also remain continuously actuated for extended periods (e.g., during a massage sequence with constant target pressures). Both of these factors favor the use of an SMA actuator for the control valve.

[0061] The control valve can be designed for low flow and therefore low forces, since it only switches auxiliary air, while the main air flow only flows through the pressure regulator.

[0062] By combining a pressure regulator with several control valves, a variety of different output pressures can be represented with one pressure regulator and switched during operation.

Claims

[1] Pneumatic pressure control valve, with a housing in which a first valve chamber (2) is formed with a supply opening (3) for supplying compressed gas into the first valve chamber (2), and with a connecting opening (4) which opens into a connecting channel (16) for connection to a cushion to be filled with gas, wherein a membrane (8) is arranged in the first valve chamber (2) which is connected airtight to the valve chamber wall and divides the first valve chamber (2) into two regions, wherein a spring element (12) is arranged in a first region (9) which is mechanically connected to the membrane (8) and exerts a force thereon, and wherein an actuating pin (13) of a valve plate (14) is arranged in a second region (10) and is connected to the membrane (8), wherein the valve plate (14) is arranged on the outside of the first valve chamber (2) and, depending on the position of the membrane (8), opens or closes the supply opening (3) via the actuating pin (13) due to the force of the spring element (12) acting on the membrane (8) and the pressure in the first region (9), characterized by , that a second valve chamber (2a) is formed in the housing, which has a first opening with a first cross-section (A1), which opens into the connecting channel (16), and a second opening with a second cross-section (A2), which is connected to the ambient pressure (P0), wherein a tappet (11), on which a sealing element (6) located in the second valve chamber (2a) is arranged, projects through both the first and the second opening, wherein the sealing element (6) closes the first opening in a first position of the tappet (11) and opens the first opening in a second position of the tappet (11), and wherein the second valve chamber (2a) is connected to the first region (9) of the first valve chamber (2) via a pressure equalization channel (16a), and that an SMA actuator (20) acting on the plunger (11) is arranged in the housing, the actuation of which causes the plunger (11) to move into the first or second position. [2] Pneumatic pressure control valve according to claim 1, characterized by that the actuator (20) has: - a printed circuit board (21) arranged in an actuator chamber of the housing, - an actuating element (22) arranged in the actuator chamber, which has an actuating section (23) for acting on the plunger (11) and a bending section (24) connected to the actuating section (23) and the circuit board (21), and - an actuator element (26) arranged in the actuator chamber, which has a first end which is mechanically connected to the actuating section (23) and a second end which is mechanically and electrically connected to the circuit board (21), wherein the actuator element (26) is designed, in a non-energized state, to bring the actuating element (23) into a first state in which it presses the sealing element (6) against the first opening via the plunger (11), and, in an energized state, to bring the actuating element (23) into a second state in which the actuating section (23) exerts less force on the plunger (11), so that the first opening is opened. [3] Pneumatic pressure control valve according to claim 1 or 2, characterized by that the membrane (8) is clamped airtight between two valve chamber wall parts. [4] Pneumatic pressure control valve according to one of claims 1 to 3, characterized bythat the membrane (8) has a thickening in its center on which the spring element (12) is supported. [5] Pneumatic pressure control valve according to one of claims 1 to 4, characterized by that in the second valve chamber a further spring element (12a) is arranged between the sealing element (6) and the first opening in order to assist in releasing the first opening. [6] Pneumatic pressure control valve according to one of claims 1 to 5, characterized by that the first opening and the second opening have different cross-sections (A1, A2). [7] Pneumatic pressure control valve according to one of claims 1 to 5, characterized by that the first opening (A1) and the second opening (A2) have the same cross-sections. [8] Pneumatic pressure control valve according to one of claims 1 to 5, characterized bythat at least one further second valve chamber is provided, the first opening of which also opens into the connecting channel (16) and which has a ratio of the cross sections (A1, A2) of the first and the second opening which differs from that of the second valve chamber (2a) and any other further second valve chamber, each further second valve chamber being connected to the first region (9) of the first valve chamber (2) via a pressure equalization channel assigned to it.

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