Valve device and compressor unit, in particular for a commercial and / or rail vehicle

Abstract

The present invention relates to a valve device (100) for a compressor unit (1), preferably of a commercial and / or rail vehicle, having a valve piston (110) which has a front side (111) for being at least partially charged with compressed air, and a valve housing for receiving the valve piston (110), wherein the front side (111), the compressor pressure portion and the conveying pressure portion (114) are provided such that the predefinable opening pressure is greater than the predefinable closing pressure. The present invention also relates to a compressor unit (1) and a vehicle, in particular a commercial and / or rail vehicle.

Description

[0001] DESCRIPTION

[0002] Valve device and compressor unit, in particular for a commercial and / or rail vehicle

[0003] The present invention relates to a valve device, in particular for a compressor unit of a commercial and / or rail vehicle, such a compressor unit and a vehicle.

[0004] Compressors for commercial and / or rail vehicles, such as vane compressors, are typically oil-lubricated. However, to maintain oil circulation and thus oil lubrication, oil pumps are not typically used. Instead, oil lubrication is achieved through pressure differentials within the compressor housing.

[0005] However, compared to stationary systems, for example, there are significant differences in the use of vane or screw compressors in commercial or rail vehicles, particularly with regard to the fluctuation range of the air pressure at the discharge outlet or in the discharge line.

[0006] In commercial or rail vehicles, the discharge line or discharge outlet of such compressor units is vented to atmospheric pressure after the final pressure is reached to allow regeneration of the air dryer. This pressure drop usually occurs very quickly, resulting in a sudden pressure drop inside the compressor housing until a minimum pressure valve closes.

[0007] Subsequently, provided the compressor drive is switched off, the pneumatic pressure within the compressor unit is slowly reduced further via the internal housing vent. The resulting difference between the shut-off pressure of the air dryer and the closing pressure of the minimum pressure valve can cause the oil in the oil sump to foam. Generally, with every rapid pressure drop, the flow velocity in the air de-oiling element or oil separator briefly increases to values ​​that no longer allow, or do not sufficiently allow, the separation of the oil or oil particles from the air stream. In such a case, oil, or too much oil, is pumped into the downstream (compressed) air system.

[0008] When the compressor unit continues to deliver against the minimum pressure valve and the depressurized delivery line to avoid condensate formation, the internal pressure of the compressor unit fluctuates between the closing pressure and the opening pressure of the minimum pressure valve.

[0009] The resulting constantly recurring rapid pressure drop, particularly caused by the minimum pressure valve, leads to a repeated, increased oil discharge from the compressor unit into the downstream (compressed) air system.

[0010] In addition, the design of common minimum pressure valves and their wear contribute to such pressure drops and the resulting increased oil ejections.

[0011] To achieve the best possible seal in the minimum pressure valve, soft seals are typically used. Furthermore, the opening pressure is selected to be low in order to minimize the necessary closing force on the sealing edge of the seal in the minimum pressure valve.

[0012] Since the (operating) temperature in the compressor housing is approximately 80-125 °C, the sealing edge must also be designed with a wide width to prevent damage to the seal due to the resulting closing force. However, this results in a large (closing) hysteresis and an oscillating opening / switching behavior of the minimum pressure valve, with typical hysteresis values ​​of approximately 2.5 bar.

[0013] The object of the present invention is to provide a valve device that has optimized installation space requirements, improved durability and service life, and reduced manufacturing and / or maintenance costs, as well as allowing efficient oil separation in the context of a compressor unit. Furthermore, the object of the present invention is to provide a compressor unit with such a valve device and a vehicle.

[0014] This object is achieved according to the invention by a valve device according to independent claim 1, with regard to the compressor unit by the subject matter according to claim 11 and with regard to the vehicle by the subject matter according to claim 15. Preferred embodiments are specified in the dependent claims.

[0015] According to the present invention, a valve device for a compressor unit, preferably of a commercial and / or rail vehicle, is provided with a valve piston having a front side for at least partial exposure to compressed air, and a valve housing for receiving the valve piston, such that the valve piston is arranged displaceably within the valve housing, in particular displaceably in the longitudinal direction. The valve piston is movable in the valve housing by means of a predeterminable opening pressure from at least one closed position into at least one open position, and by means of a predeterminable closing pressure from the at least one open position into the at least one closed position.The front side can be subjected to air pressure in the at least one open position, wherein the front side of the valve piston can be subdivided or divided into at least one compressor pressure section and one discharge pressure section in the at least one closed position of the valve device, and the compressor pressure section and the discharge pressure section can be subjected to different air pressures. The front side, the compressor pressure section, and the discharge pressure section are designed or provided such that the predeterminable opening pressure is greater than the predeterminable closing pressure.

[0016] The invention is based on the basic idea that the design and configuration of the (pressure-effective) front side or individual (pressure-effective) surface portions of the valve piston, i.e. the compressor pressure section and the discharge pressure section in at least one closed position, can significantly influence a (response) behavior as well as the stability or durability of the valve device.

[0017] Accordingly, the present invention provides a novel valve device which has both a sufficiently high opening and closing pressure and a low (closing) hysteresis in the event of a pressure change, in particular in the event of a (sudden) pressure drop, in the delivery line or at the delivery outlet of the compressor unit, for example in the event of a sudden venting of the delivery outlet to atmospheric pressure.

[0018] Furthermore, the present invention can also ensure that damage to the sealing seat is avoided under the influence of closing forces and high (operating) temperatures.

[0019] In the context of the present invention, the front side of the valve piston is understood to mean, in particular, the side that is exposed to pneumatic pressure or compressed air and / or allows a switching action with a view to establishing and interrupting a pneumatic flow path. Preferably, both the switching action and the forwarding of the compressed air can be provided along the same surfaces of the valve piston.

[0020] In particular, it is provided that in at least one open position, the at least substantially identical air pressure is applied along the front side or can act on it. In at least one closed position of the valve device or the movable valve piston, at least one compressor pressure section and one discharge pressure section can be formed or separated from one another, at least temporarily, along the front side of the valve piston, wherein different air pressures can act on the compressor pressure section and the discharge pressure section.

[0021] In this case, it is provided that a pneumatic separation occurs in the closed position of the valve device, so that two pneumatically separated pressure zones are present along the (pressure-effective) front side of the valve piston. In particular, based on the at least one closed position of the valve device or the valve piston, a pressure zone to the compressor of the compressor unit can be separated from a pressure zone of the delivery outlet or the delivery line of the compressor unit.

[0022] Furthermore, in the sense of the present invention, an air pressure or the application of an air pressure can be understood as both the application of compressed air and the venting, e.g. to an atmospheric air pressure, in particular so that a complete controllability is provided by or with the valve device according to the invention.

[0023] Furthermore, it is provided that the predeterminable opening pressure is greater than the predeterminable closing pressure.

[0024] Preferably, such a switching behavior of the valve device can be achieved by a suitable design, in particular geometric design, of the (pressure-effective) front side of the valve piston, the compressor pressure section and / or the delivery pressure section of the valve piston.

[0025] By means of a targeted configuration of the (temporarily) formable compressor pressure section and / or delivery pressure section along a specifically designed front side of the valve piston, the switching behavior of the valve device, in particular the opening pressure and / or the closing pressure, can be expediently influenced or predetermined.

[0026] In particular, the valve device and the valve piston can be designed such that an opening pressure in the at least one closed position of the valve piston can only act on the compressor pressure section along the front side of the valve piston. In the at least one open position, a closing pressure can act on the pressure-effective front side of the valve piston. Thus, the opening and closing behavior of the valve device according to the invention can preferably be designed depending on the surface areas and / or their (geometric) configuration along the (pressure-effective) front side of the valve piston. According to the present invention, a cost- and space-efficient valve device can be provided which has advantageous switching characteristics, in particular improved hysteresis or optimized hysteresis-Z switching behavior.

[0027] According to a preferred embodiment of the present invention, in the at least one closed position of the valve piston, at least one sealing section can be provided between the compressor pressure section and the delivery pressure section along the front side of the valve piston, wherein the sealing section can be designed or is designed such that the delivery pressure section and the compressor pressure section can be subjected to different air pressures.

[0028] In particular, the delivery pressure section can be subjected to a different air pressure exclusively when the valve piston is in the at least one closed position. Preferably, such a delivery pressure-effective portion or delivery pressure section along the front side of the valve piston can be subjected to air pressure, i.e., for example, compressed air or atmospheric pressure, from the delivery pressure connection or the delivery pressure line in the closed position, while the compressor pressure section or compressor pressure-effective portion along the front side of the valve piston is subjected to air pressure from the compressor or the compressor unit or is exposed to such air pressure.

[0029] According to the present invention, the front side of the valve piston, in addition to the delivery pressure section and / or the compressor pressure section, can be subdivided into further sections or regions in the closed position. In particular, in addition to a delivery pressure-Zcompressor pressure-effective section, it can also have or form a sealing section in order to implement at least one expedient closed position along and by means of the front side of the valve piston. In particular, a closed position or a sealing function can be integrally designed or provided based on the front side of the valve piston in the valve device according to the invention.

[0030] According to a further preferred embodiment, in the at least one closed position of the valve device, the compressor pressure section can have a larger pressure-effective area than the delivery pressure section, so that a hysteresis of the valve device can be reduced, in particular a hysteresis switching behavior for moving the valve piston between the at least one closed position and the at least one open position can be optimized.

[0031] For the purposes of the present invention, the pressure-effective surface is to be understood in particular as the surface which is exposed to air pressure or which can be subjected to air pressure.

[0032] Accordingly, in a closed position, the front side of the valve piston cannot be completely subjected to a single, uniform air pressure, but only to the discharge pressure section or the compressor pressure section. In contrast, in an open position of the valve piston, the (pressure-effective) front side can be subjected to a uniform air pressure or be exposed to a uniform air pressure.

[0033] Furthermore, the valve piston can be arranged along the front side in the at least one closed position

[0034] - have an at least partially annular compressor pressure section and / or a spherical segment-shaped delivery pressure section, wherein preferably the at least partially annular compressor pressure section surrounds the centrally arranged spherical segment-shaped delivery pressure section, or

[0035] - have a mushroom-shaped geometry that is or can be divided into at least the surrounding compressor pressure section and the centrally arranged discharge line pressure section. Based on the design of the surface areas of the compressor and discharge pressure sections, as well as, among other things, their geometric design, an advantageous switching hysteresis behavior of the valve device can be achieved.

[0036] The front side of the valve piston can be configured such that the compressor pressure section has an at least substantially annular structure. In particular, a portion of the compressor pressure section can form a ring shape. Furthermore, the discharge pressure section can have, at least substantially, a spherical segment-shaped geometry or a circular segment-shaped cross-section.

[0037] Furthermore, the compressor and delivery pressure sections, which can be formed temporarily in at least one closed position, can be formed integrally with one another along the front side of the valve piston, preferably so that the compressor pressure section surrounds the delivery pressure section.

[0038] In addition, a sealing section along the front side of the valve piston in the at least one closed position can preferably have or assume a circular or annular shape or geometry.

[0039] In particular, due to the advantageous, at least temporary design or subdivision of the compressor and delivery pressure sections along the (pressure-effective) front side of the valve piston, oscillation behavior or hysteresis during the transition to an open and / or closed position can be avoided.

[0040] Thus, oil entrainment effects within the compressor unit, particularly along an air deoiling element or oil separator of the compressor unit due to strongly fluctuating air pressure or excessively high flow velocities, can be reduced or avoided. Preferably, a hysteresis or a hysteresis behavior of the valve device of less than 2.5 bar, in particular less than 1.5 bar, can be achieved or provided by means of the valve device according to the invention.

[0041] According to a preferred embodiment, an area ratio between the compressor pressure section and the delivery pressure section can be designed such that the predeterminable closing pressure is smaller than the predeterminable opening pressure, preferably by 1.3 bar smaller, particularly preferably by 1.0 bar smaller, than the predeterminable opening pressure.

[0042] In this way, in the event of a (sudden) pressure drop, a quick or timely transition of the valve piston into at least one closed position can be provided.

[0043] Due to the lower pressure difference during the transition to the closed position, especially during the initial initiation of the transition to the closed position, the closing forces of the valve device or the valve piston are advantageously adjusted or reduced.

[0044] According to a further preferred embodiment, the valve housing can be designed to be open on one side, in particular open over the front side of the valve piston.

[0045] In particular, it can be provided that the valve piston can at least partially protrude or protrude from the valve housing of the valve device, which is open on one side.

[0046] For example, the valve piston can be attached or flanged to a housing of a compressor unit, wherein the valve piston can perform a sealing function in the closed position to provide pneumatic separation of the compressor pressure or the compressor-side air pressure and the air pressure at the discharge outlet of the compressor unit. In particular, the housing of the compressor unit can also be understood or conceived or provided as an integral part of the valve housing of the valve device. A space-saving, integral, and efficient design of the valve device according to the invention is available.

[0047] According to one embodiment, it can be provided that the valve device has a valve spring in the form of a compression spring, wherein the valve piston is prestressed into the at least one closed position by means of the valve spring and wherein the opening pressure along the compressor pressure section and / or the delivery pressure section and the closing pressure along the front side of the valve piston each counteract the prestress of or by the valve spring.

[0048] Preferably, the opening pressure and the closing pressure act on the valve piston in the same direction, with the closing pressure, which is lower than the opening pressure, causing the valve piston to move or return from the open position to the closed position by means of the valve spring. In contrast, the higher opening pressure can cause the valve piston to adjust or move from the closed position to the at least one open position against the spring force of the valve spring.

[0049] A simple, cost- and space-efficient design of the valve device can be ensured.

[0050] In a preferred embodiment, at least the part of the front side of the valve piston that is (temporarily) provided as the discharge pressure section in the closed position, preferably the entire valve piston, can be made of a temperature-resistant material, in particular a metal, aluminum, or the like. According to a further embodiment, the valve piston and the valve housing can be made of the same material, in particular a temperature-resistant material, preferably metal, aluminum, or the like.

[0051] Preferably, the durability and service life of the valve device can be significantly extended by using temperature-resistant material, and / or the tightness of the valve device can be improved over the entire service life of the valve device. By manufacturing the valve piston and the valve housing from a uniform or identical material, the formation of undesirable gaps and the like under the influence of high temperatures can be avoided. The valve piston and the valve housing react in the same way under the influence of elevated temperatures, whereby the functionality and tightness of the valve device can be ensured during continuous operation.

[0052] In a preferred embodiment, the valve device can be provided as a minimum pressure valve of the compressor unit.

[0053] Preferably, the function as a minimum pressure valve can be specifically and as needed adapted to the respective application based on the design of the valve piston, in particular the front side, the (temporarily configurable) compressor pressure section, and the (temporarily configurable) discharge pressure section. For example, a difference between the opening pressure and the closing pressure can be specifically adapted in order to implement or provide closure of the valve device or valve piston at a desired closing pressure below the opening pressure.

[0054] According to a subordinate aspect of the invention, a compressor unit, in particular for a commercial and / or rail vehicle, is provided with a valve device according to the invention, wherein the valve device is preferably provided as a minimum pressure valve. According to a preferred embodiment, the valve device can be arranged between a compressor of the compressor unit and a discharge outlet of the compressor unit, preferably between a discharge outlet or a discharge line connection and an oil separation device of the compressor unit.

[0055] The valve device according to the invention can provide advantageous switching hysteresis behavior between the open and closed positions, reducing or avoiding hysteresis or oscillation behavior. Furthermore, the durability of the valve device can be improved, among other things, by optimizing the closing force and improving the temperature resistance of the valve device.

[0056] In a preferred embodiment, the valve device can be at least partially integrated, preferably completely integrated, into a compressor housing of the compressor unit or can be attached or flanged or fastened to the compressor housing, so that the compressor unit, preferably the compressor housing, forms or has a corresponding sealing seat section for the valve device, in particular for the valve piston or the (pressure-effective) front side of the valve piston, particularly preferably for the sealing section of the valve piston.

[0057] An integral design of the compressor housing with the valve device according to the invention can be provided.

[0058] According to a further embodiment, it can be provided that the sealing seat section is designed to correspond to the front side of the valve piston, in particular to correspond to the sealing section of the valve piston in the at least one closed position, and at least partially has a conical shape, preferably corresponding to a spherical segment-shaped geometry along the front side of the valve piston of the valve device.

[0059] By designing the front side of the valve piston, in particular the delivery pressure section, and the sealing seat section of the compressor unit or the compressor housing corresponding to one another, a secure sealing of the pneumatic flow paths can be achieved in a closed position of the valve device, for the safe and reliable separation of the air pressures or the compressed air on the compressor side of the compressor unit from the delivery side or the delivery connection or the delivery line of the compressor unit.

[0060] In a further subordinate aspect of the present invention, a vehicle, in particular a commercial vehicle or a rail vehicle, is provided with a valve device according to the invention and / or a compressor unit according to the invention.

[0061] All advantages and technical effects achievable in connection with the valve device according to the invention and / or the compressor unit according to the invention can also apply individually or in combination to the vehicle according to the invention.

[0062] Further details and advantages of the invention will now be explained in more detail with reference to the embodiments shown in the drawings.

[0063] They show:

[0064] Fig. 1 is a schematic representation of a compressor unit with a minimum pressure valve;

[0065] Fig. 2 is a schematic representation of a valve device according to a preferred embodiment; and

[0066] Fig. 3 is a further schematic representation of the valve device according to the embodiment of Fig. 2.

[0067] Fig. 1 shows a schematic representation of a compressor unit 1 with a minimum pressure valve 50 from the prior art.

[0068] The compressor unit 1 has a compressor 10 in a compressor housing 2.

[0069] Compressor 2 is provided with a compressor inlet 12 for the air to be compressed and a compressor outlet 14 for the compressed air. The compressed air is guided from the compressor outlet 14 to the oil separator or oil separator element 20. The compressed air enters the oil separator 20 via an oil separator inlet 22.

[0070] The compressed clean air or compressed air is passed via an oil separator outlet 24 of the oil separator 20 or the compressor unit 1 in the direction of the delivery outlet or delivery line section 30.

[0071] A minimum pressure valve 50 is arranged between the oil separator outlet 24 and the discharge outlet 30. The minimum pressure valve 50 shown in Fig. 1 corresponds to commonly used minimum pressure valves from the prior art.

[0072] The minimum pressure valve 50 releases a pneumatic flow path to the delivery outlet 30 only when a minimum pressure of the compressed air is reached in the compressor unit 1 or in the compressor housing 2 or at the oil separator outlet 24.

[0073] Fig. 2 shows a schematic representation of a valve device 100 according to a preferred embodiment.

[0074] In particular, the valve device 100 according to Fig. 2 can be arranged or attached or flanged to the housing or compressor housing 2, preferably for at least the connection and transmission of compressed air with / from an oil separator outlet 24 to a discharge pressure outlet 30 of the compressor housing 2, as required.

[0075] In particular, the valve device 100 can be arranged directly or indirectly at the oil separator outlet 24 of the oil separator 20 or can be operatively connected thereto. Thus, as shown in Fig. 2, an indirect arrangement of the valve device 100 can be provided in the sense of connection to a corresponding flow path of the compressor housing 2.

[0076] The valve device 100 is formed with a valve piston 110 and a valve housing 120. The valve piston 110 is received in the valve housing 120 and arranged to be movable in the longitudinal direction.

[0077] The valve piston 110 can have a U-shaped cross-section or a pot-shaped basic shape. The valve piston 110 can be guided along its circumferential surface within the valve housing 120.

[0078] In addition, the valve housing 120 can have sealing elements, in particular for sealing the sliding surfaces with respect to the valve piston 110 and / or with respect to the compressor housing 2.

[0079] For example, a housing seal 140 can be provided along the contact surface of the valve housing 120 relative to the compressor housing 2, which seal is applied and suitably pressed when the valve device 100 is attached or fastened to the compressor housing 2.

[0080] The valve device 100 can also be provided as a spring-loaded valve, wherein the valve piston 110 is preloaded with a compression or valve spring 130.

[0081] The valve spring 130 can be suitably pre-tensioned and centered or arranged using a base plate in combination with a pre-tension screw to adjust the opening and closing pressure.

[0082] The valve piston 110 has a pressure-loadable or pressure-effective front side 111, ie a front side along which compressed air can actuate the valve piston and / or flow past or along from the oil separator outlet 24 to the delivery outlet 30.

[0083] The valve device 100 is shown in Fig. 2 in at least one closed position of the valve piston 110. Furthermore, the valve piston 110 can assume at least one open position. In the at least one open position of the valve piston 110, a substantially uniform / homogeneous air pressure can act on the (pressure-effective) front side 111.

[0084] In the at least one closed position according to Fig. 2, the (pressure-effective) front side 111 of the valve piston 110 can be subdivided into at least one compressor pressure section 112 and one delivery pressure section 114, in particular subdivided by pressure technology.

[0085] According to Fig. 2, the discharge pressure section 114 can be circular or spherical in shape and located in the center of the valve piston 110. The compressor pressure section 112 can be annular and surround the discharge pressure section 114.

[0086] In particular, a (significant) annular portion of the compressor pressure section 112 can be formed in a plane whose surface normal runs parallel to a longitudinal axis of the valve housing 120 or the longitudinal displacement direction of the valve piston 110.

[0087] The compressor pressure section 112 of the valve piston 110 is provided for connection to or for being pressurized with compressed air or an air pressure from the compressor 10 or the compressor housing 2 or the oil separator 20.

[0088] According to Fig. 2, in the closed position of the valve device 100 or the valve piston 110, it can be provided that the delivery pressure section 114 and the compressor pressure section 112 of the valve piston 110 are pressure-technically separated from one another by means of a sealing section 116 along the front side 111 of the valve piston 110 and a correspondingly designed sealing seat 40 of the compressor housing 2. In this sense, at least the compressor pressure section 112 and the delivery pressure section 114 can be or are temporarily formed in a closed position of the valve piston 110 along the front side 111 of the valve piston 110. The sealing seat 40 can be formed along the delivery pressure outlet 30 or at the delivery pressure outlet 30 in the compressor housing 2.

[0089] In the at least one closed position, the valve piston 110 can form a sealing connection around or at the delivery pressure outlet 30 along its front side 111 by means of the sealing section 116.

[0090] Thus, an air pressure or compressed air can act on the compressor pressure section 112, while a different air pressure, e.g. an atmospheric pressure, can act on the discharge pressure section.

[0091] By means of the valve device 100 or the valve piston 110, a separation of the air pressures between the delivery outlet 30 and the oil separator outlet 24 is possible or available.

[0092] Furthermore, the valve piston 110 can be moved into at least one open position. For this purpose, an air pressure or opening pressure can act, in particular, on the compressor pressure section 112 and / or the delivery pressure section 114, so that the valve piston 110 is moved longitudinally into the valve housing 120.

[0093] In particular, compressed air or an air pressure from the compressor can act on the compressor pressure section 112 in order to move the valve piston into the at least one open position and thus to establish or provide a connection or a flow path between the oil separator outlet 24 and the discharge pressure outlet 30 via the valve device 100.

[0094] The necessary (air) pressure to move the valve piston 110 into at least one opening position can be referred to as opening pressure.

[0095] An (air) pressure at which the valve piston 110 returns from the at least one open position to the closed position (as shown in Fig. 2) can be understood as the closing pressure. According to the present invention, the closing pressure can preferably be provided to be lower than the opening pressure, in particular 1.3 bar, preferably in particular 1.0 bar, below the opening pressure.

[0096] In particular, the closing pressure and the opening pressure can be predetermined based on the configuration and design of the front side 111, the compressor pressure section 112 and / or the discharge pressure section 114 of the valve piston 110, in particular with constant preload by the valve spring 130.

[0097] Furthermore, it can be provided that the valve piston 110 and / or the valve housing 120 comprises / comprising a temperature-resistant material, such as aluminum or a comparable metal.

[0098] Preferably, the valve piston 110 and the valve housing 120 are made of the same material. Thus, sealing properties, gap dimensions, and the like can be kept as constant as possible under the influence of high temperatures.

[0099] Fig. 3 illustrates a further schematic representation of the embodiment of the valve device 100 according to Fig. 2.

[0100] In particular, in contrast to the illustration in Fig. 2, Fig. 3 shows how the sealing section 116 of the valve piston 110 and the correspondingly designed sealing seat 40 of the compressor housing 2 abut against one another or fit into one another to form a sealing function or a sealing connection.

[0101] According to Fig. 3, the sealing seat 40 can subdivide the front side 111 of the valve piston 110 into several parts or portions or sections, with the discharge pressure section 114, a sealing portion 116, in sealing contact with the sealing seat 40, and the compressor pressure section 112.

[0102] According to Fig. 3, the sealing section 116 can have a circular or annular geometry / shape in order to form a sealing contact between the front side 111 of the valve piston 110 and the sealing seat 40 of the compressor housing 2.

[0103] Depending on the specific position of the sealing section 116 along the front side 111, the compressor pressure section 112 may have exclusively an annular geometry or, as shown in Fig. 3, may have additional surface sections along the front side, e.g., a spherical ring-shaped surface section.

[0104] In the closed position of the valve piston 110, the discharge pressure section 114 is exposed to an air pressure, ie compressed air or atmospheric pressure, at the discharge connection 30 of the compressor housing 2.

[0105] The sealing section 116 is in contact with the sealing seat 40 of the compressor housing 2 to form a (compressed air) sealing connection, so that a pneumatic separation between the compressor air pressure, for example at the oil separator outlet 24 with the compressed clean air, and the discharge outlet 30 of the compressor unit 1 is provided or can be provided.

[0106] In particular, in the sense of the present invention, it is provided that the compressor pressure section 112 is designed larger than the delivery pressure section 114 in order to achieve an opening pressure that is greater than the closing pressure.

[0107] Furthermore, compared to the embodiment according to Fig. 2 and Fig. 3, further geometric configurations of the compressor pressure section 112 and / or the discharge pressure section 114, as well as of the sealing section 116 for interaction with the corresponding sealing seat 40, are conceivable.

[0108] For example, the front side of the valve piston 110 can have a mushroom-shaped overall structure, with corresponding subdivision into the compressor pressure section 112 and the discharge pressure section 114, preferably separated from one another by the sealing section 116 that can be formed therebetween. In summary, the present invention can provide an advantageous valve device 100 that has both optimized switching behavior with lower or no hysteresis, so that, among other things, oil entrainment effects can be prevented. The valve device 100 can preferably be used as a minimum pressure valve in a compressor unit of a commercial and / or rail vehicle, wherein the switching behavior can be adapted based on the design of the valve piston 110, in particular the front side 111, the compressor pressure section 112 and / or the discharge pressure section 114.

[0109] Furthermore, such a targeted and practical design, as well as the use of temperature-resistant materials, can provide optimized or reduced closing forces and improved sealing. In addition to a cost- and space-efficient design of the valve device, optimized durability and service life can be achieved with the present invention.

[0110] LIST OF REFERENCE SYMBOLS

[0111] 1 compressor unit

[0112] 2 compressor housings

[0113] 10 Compressor

[0114] 12 Compressor inlet

[0115] 14 Compressor output

[0116] 20 oil separators

[0117] 22 Oil separator inlet (for air to be cleaned)

[0118] 24 Oil separator outlet (for clean air)

[0119] 30 Conveyor outlet / conveyor line section

[0120] 40 Sealing seat section

[0121] 50 (minimum) pressure valve (according to the state of the art)

[0122] 100 valve device

[0123] 110 valve pistons

[0124] 111 Front

[0125] 112 Compressor pressure section

[0126] 114 discharge pressure section

[0127] 116 Sealing section

[0128] 120 valve housings

[0129] 130 valve spring

[0130] 140 valve body seal

Claims

PATENT CLAIMS 1 . Valve device (100) for a compressor unit (1), preferably of a commercial and / or rail vehicle, with - a valve piston (110) having a front side (111) for at least partial application of compressed air, and - a valve housing (120) for receiving the valve piston (110), such that the valve piston (110) is arranged displaceably within the valve housing (120), in particular displaceably in the longitudinal direction, wherein the valve piston (110) is movable in the valve housing (120) by means of a predeterminable opening pressure from at least one closed position into at least one open position and by means of a predeterminable closing pressure from the at least one open position into the at least one closed position, wherein the front side (111) can be subjected to air pressure in the at least one open position, wherein the front side (111) of the valve piston (110) can be subdivided into at least one compressor pressure section (112) and a delivery pressure section (114) in the at least one closed position of the valve device (100), and the compressor pressure section (112) and the delivery pressure section (114) can be subjected to different air pressures,wherein the front side (111), the compressor pressure section (112) and the discharge pressure section (114) are provided such that the predeterminable opening pressure is greater than the predeterminable closing pressure., 2. Valve device (100) according to claim 1, characterized in that in the at least one closed position of the valve piston (110) between the compressor pressure section (112) and the delivery pressure section (114) along the front side (111) of the valve piston (110) at least one sealing section (116) is provided, wherein the sealing section (116) can be formed such that the delivery pressure section (114) and the compressor pressure section (112) can be subjected to different air pressures.

3. Valve device (100) according to one of the preceding claims, characterized in that in the at least one closed position of the valve device (100), the compressor pressure section (112) has a larger pressure-effective area than the delivery pressure section (114), so that a hysteresis of the valve device (100) can be reduced, in particular a hysteresis behavior for the movement of the valve piston (110) between the at least one closed position and the at least one open position can be optimized.

4. Valve device (100) according to one of the preceding claims, characterized in that the valve piston (110) along the front side in the at least one closed position - an at least partially annular compressor pressure section (112) and / or a spherical segment-shaped delivery pressure section (114), wherein preferably the at least partially annular compressor pressure section (112) surrounds the centrally arranged spherical segment-shaped delivery pressure section (114), or - has a mushroom-shaped geometry which is divided at least into the surrounding compressor pressure section (112) and the centrally arranged delivery line pressure section (114).

5. Valve device (100) according to one of the preceding claims, characterized in that an area ratio between the compressor pressure section (112) and the delivery line pressure section (114) is designed such that the predeterminable closing pressure is smaller than the predeterminable opening pressure, preferably by 1.3 bar smaller, particularly preferably by 1.0 bar smaller, than the predeterminable opening pressure.

6. Valve device (100) according to one of the preceding claims, characterized in that the valve housing (120) is designed to be open on one side, in particular over the front side of the valve piston (100).

7. Valve device (100) according to one of the preceding claims, characterized in that the valve device (100) has a valve spring (140) in the form of a compression spring, wherein the valve piston (110) is prestressed into the at least one closed position by means of the valve spring (140), wherein the opening pressure along the compressor pressure section (112) and / or the delivery pressure section (114) and the closing pressure along the front side (111) of the valve piston (110) each counteract the prestress of the valve spring (140).

8. Valve device (100) according to one of the preceding claims, characterized in that at least the part of the front side (111) of the valve piston (110) provided as a delivery pressure section (114) in the closed position, preferably the entire valve piston (110), comprises a temperature-resistant material, in particular a metal, aluminum or the like.

9. Valve device (100) according to one of the preceding claims, characterized in that the valve piston (110) and the valve housing (120) have the same material, in particular a temperature-resistant material, preferably metal, aluminum or the like.

10. Valve device (100) according to one of the preceding claims, characterized in that the valve device (100) is provided as a minimum pressure valve.

11. Compressor unit (1), in particular for a commercial and / or rail vehicle, with a valve device (100) according to one of the preceding claims, wherein the valve device (100) is preferably provided as a minimum pressure valve.

12. Compressor unit (1) according to claim 11, characterized in that the valve device (100) is arranged between a compressor (10) of the compressor unit (1) and a delivery outlet (30) of the compressor unit (1), preferably between a delivery outlet (30) and an oil separation device (20) of the compressor unit (1).

13. Compressor unit (1) according to one of claims 11 or 12, characterized in that the valve device (100) is at least partially integrated, preferably completely integrated, into a compressor housing (2) of the compressor unit or can be fastened to the compressor housing (2), so that the compressor unit (1), preferably the compressor housing (2), forms a corresponding sealing seat section (40) for the valve device (100), in particular for the valve piston (110), particularly preferably for the sealing section (116) of the valve piston (110).

14. Compressor unit (1) according to claim 13, characterized in that the sealing seat section (40) is designed to correspond to the front side (111) of the valve piston (110), in particular to correspond to the sealing section (116) of the valve piston (110) in the closed position, and at least partially has a conical shape, preferably corresponding to a spherical segment-shaped geometry along the front side (111) of the valve piston (100) of the valve device (100).

15. Vehicle, in particular commercial and / or rail vehicle, with a valve device (100) and / or a compressor unit (1) according to one of the preceding claims.

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