Tire pressure valve assembly and tire pressure valve assembly group

Description

TECHNICAL FIELD OF THE INVENTION

[0001] In commercial vehicles, tire pressure control systems (hereinafter also referred to as tire pressure monitoring systems) are used to establish and maintain the desired pressure in the tires. For this purpose, the tire pressure control systems have tire pressure valve assemblies that rotate with the tire and are particularly mounted on a rim. In a locked position, the tire is blocked, pressure is supplied to the tire in an inflated position, and the tire is deflated in a deflated position. To supply the tire pressure valve assembly with compressed air and to control the tire pressure valve assembly to achieve the different switching positions, it is known to connect the tire pressure valve assembly to a control circuit and a supply circuit in a dual-circuit tire pressure control system.The supply circuit provides the compressed air to inflate the tire, while the control circuit supplies a control pressure to switch the tire pressure valve assembly to the various switching states. Single-circuit tire pressure control systems are also known, in which the compressed air in the single circuit serves, on the one hand, to supply the tire pressure valve assembly with compressed air and thus to inflate the tire, while, on the other hand, the pressure level in the circuit serves as the control pressure to switch the tire pressure valve assembly to the various switching states.Since the compressed air supply for the tire pressure control system is fixed to the vehicle and any pneumatic components for processing the pressures in at least one circuit are also fixed to the vehicle, the two circuits of the dual-circuit tire pressure control system or one circuit of the single-circuit tire pressure control system are connected to the tire pressure valve assembly and the tire rim via a rotary union that allows relative rotation. The tire pressure control system can also be used to specifically change the pressure in the tires. This is advantageous, for example, for changing the pressure depending on the condition of the road surface. For example, a higher tire pressure can be used for a hard and smooth road surface than for a rougher and / or softer surface, such as a gravel road or a road with sand or arable soil. STATE OF THE ART

[0002] DE 2 141 087 A1 discloses a single-circuit tire pressure control system in which the pressure in the single circuit can be set via a valve manually operated by a handle, which can be moved into a ventilation position, a blocking position, and a venting position depending on the position of the handle. The circuit is connected to an associated vehicle wheel via a rotary union. To inflate a tire, the handle of the adjustment valve is moved from the venting position to the ventilation position, opening the valve device attached to the rim in such a way that compressed air from the circuit enters the tire. After the vehicle tire has been inflated, the handle is returned to its original position, venting the circuit. In the venting position, the valve device blocks the tire.Since the circuit is depressurized in this case, the seals of the rotating union are not subjected to any pressure, which leads to low friction and low wear. If the tire pressure then needs to be reduced (e.g. after unloading the vehicle or when changing from hard road surface to terrain with soft ground), the adjustment valve is manually moved back to the ventilation position, which then causes the tire to be vented to the atmosphere through the wheel-side valve device. The adjustment valve can also be designed as a stepped valve, which vents the circuit in one switching position, generates a minimum tire pressure in the circuit in one switching position, and generates a maximum tire pressure in the circuit in another switching position.

[0003] WO 2008 / 068599 A2 discloses an electronic single-circuit tire pressure control system in which all tires can be connected to a central line, which can be connected to a compressor and / or a compressed air tank to increase the tire pressure and to the atmosphere to vent the tires. An electronically controlled inflation and deflation valve is arranged upstream of the rotary union on the vehicle side of each tire, while an electromagnetically controlled shut-off valve is arranged on the tire side of the rotary union. In the shut-off position of the shut-off valve, the pressure once created in the tire is maintained, while in the open position of the shut-off valve, the tire can be inflated or deflated depending on the switching position of the vehicle-side inflation and deflation valve.

[0004] In the electronic tire pressure control system according to DE 10 2007 036 201 A1, an electronic control device communicates wirelessly with a pressure sensor located in a tire. The sole circuit for operating a valve device assigned to the vehicle wheel is vented to lock the valve device and thus maintain the pressure in the tire. To transfer the valve device to a venting position, a first pressure is electronically applied to the circuit, while to transfer the valve device to a venting position, a second pressure greater than the first pressure is applied to the circuit.

[0005] In contrast, document EP 2 308 698 B1, which represents the closest prior art, discloses an electronically controlled single-circuit tire pressure control system in which the valve device is blocked for a low pressure below a threshold value, the valve device is moved into a venting position for a first pressure in the circuit, and the valve device is moved into a ventilation position for a second pressure in the circuit which is greater than the first pressure.

[0006] The following requirements in particular apply to agricultural vehicle tyre pressure control systems: An agricultural vehicle tire pressure control system is designed to maintain a predetermined pressure in at least one tire. This may require the agricultural vehicle tire pressure control system to shut off the pneumatic connection to the tire. The agricultural vehicle tire pressure control system can also vent the tire to refill any gradual leakage. If the air in the tire heats up, the agricultural vehicle tire pressure control system may also be required to vent the tire to maintain constant pressure. It is also possible that, depending on the load of the agricultural vehicle, a load-dependent pressure change must be compensated for by the agricultural vehicle tire pressure control system.Agricultural vehicle tire pressure control systems can be used to take into account the operating conditions of the agricultural vehicle, and in particular the contact conditions of the tire with the ground, by modifying the pressure in the tire. For example, it is known to reduce the pressure in a tire using an agricultural vehicle tire pressure control system if there is undesirable slippage of the tire relative to the ground. It is also possible that, if an undesirable inclination of the agricultural vehicle is detected (for example, because the agricultural vehicle is standing on uneven ground or a slope), the inclined position of the agricultural vehicle can be counteracted by changing the pressures in the tires of one axle or one side of the vehicle. DE 10 2011 085 040 A1 discloses an agricultural tractor with an agricultural vehicle tire pressure control system in which the tire pressure is regulated depending on the slippage of the tires on the ground.Alternatively or additionally, tire pressure can be regulated based on the tractive effort of the agricultural tractor and / or the working depth of a tool or attachment on the agricultural tractor. Additional control criteria that influence tire pressure regulation can include driving speed, driver input, tire type, soil type, soil conditions, and / or axle load distribution. If the agricultural vehicle is used on public roads, low fuel consumption, manufacturer regulations and legal requirements, and dynamic driving stability require relatively high tire pressure.On the other hand, when an agricultural vehicle is driving over arable land, a lower tire pressure may be desired to increase the tire's contact area with the soil. This results in reduced surface pressure for the tire to press against the soil, which at least reduces the risk of unwanted soil compaction. When changing the operation of the agricultural vehicle from driving on the road to driving over arable land (and vice versa), the agricultural vehicle's tire pressure control system must ensure the necessary pressure changes in the tires.

[0007] EP 1 435 302 A1 discloses a generally closed, single-circuit vehicle tire pressure control system that can be filled by a compressor drawing in ambient air through a filter. The compressor pumps the air to a reservoir on the one hand and to a central line via a central 3 / 2-way valve on the other.

[0008] The central line branches off via branch lines to the commercial vehicle's tires. In each branch line, a 3 / 2-way axle valve and a tire valve designed as a 2 / 2-way shut-off valve are arranged upstream of the assigned tire. The 3 / 2-way axle valves are attached to the vehicle frame, while the tire valves are held on the vehicle wheel and rotate with it. The 3 / 2-way axle valve and the tire valve are connected to each other via a rotary union, with the compressed air in the connecting line being used both as the supply pressure for the tire valve and as the pneumatic control pressure for the tire valve. If the pressure in the reservoir is greater than the pressure in the tire, the tire can be filled without operating the compressor. Otherwise, the compressed air from the reservoir is further compressed by the compressor and fed to at least one tire for inflation.Finally, it is also possible to fill a tire by supplying it with compressed air drawn from the environment and compressed by the compressor. To deflate a tire, however, the tire can be connected to a suction side of the compressor. In this case, the compressed air drawn from the tire by the compressor can either be fed to the reservoir while being compressed by the compressor or vented into the atmosphere. A unit inside the tire rotates with the vehicle wheel. This unit, in addition to the tire valve and a throttle, has a pressure sensor, a temperature sensor, and a transmitter. Using the transmitter, a pressure signal and / or temperature signal can be transmitted wirelessly to a receiver of an electronic control unit, which controls the vehicle's tire pressure control system.

[0009] WO 2017 / 116628 A1 relates to a dual-circuit agricultural vehicle tire pressure control system designed to enable rapid inflation and deflation of a large-volume tractor tire for switching between driving across a field and driving on a road (and vice versa). The tractor has a compressor that can be used to fill a main reservoir and several auxiliary reservoirs. A supply line of the agricultural vehicle tire pressure control system can be supplied with compressed air either from the main reservoir or from the auxiliary reservoirs. The supply line branches into branch lines, each connected to an associated tire. Automatically operable ventilation valves are arranged in each of the branch lines, and a venting valve is connected to each of these, allowing inflation and deflation of the tires.A pressure sensor detects the pressure in the main reservoir. Furthermore, the vehicle wheels can each have pressure sensors that detect the pressure in the tire. The pressure signal is transmitted wirelessly. The inflation and deflation valves are located in front of a rotary union of the vehicle wheel. Pneumatically controlled ventilation valves are interposed between the rotary unions and the interior of the tire. These valves are connected to two separate pneumatic paths of the rotary unions, via which a supply pressure and a control pressure are transmitted to the pneumatically controlled ventilation valve.The pneumatically controlled ventilation valve integrated into the vehicle wheel is designed as a 2 / 2-way valve or shut-off valve, so that in an open position it enables ventilation and venting through the ventilation and venting valves mounted on the vehicle frame, while in the shut-off position the pneumatically controlled ventilation valve shuts off the interior of the tire. The ventilation valve and the venting valve arranged in the branch line can be designed as solenoid valves. Instead of separately designed ventilation and venting valves, a 3 / 3-way valve can also be used, which has a shut-off position, a ventilation position, and a venting position. The pneumatic control circuit for controlling the shut-off valves integrated into the vehicle wheel is neither further described nor illustrated in WO 2017 / 116628 A1.According to WO 2017 / 116628 A1, at least one tire is filled by first enabling rapid filling by connecting the at least one tire to the main reservoir and the auxiliary reservoirs. Once pressure equalization has occurred, the pressure in the tire can be further increased by isolating the auxiliary reservoirs from the compressor and increasing the pressure in the at least one tire by operating the compressor via the main reservoir. The tires are vented directly into the environment through the vent valves. In addition to controlling the valves via an electronic control device, manual control by the user is also possible.

[0010] EP 0 365 953 A2 relates to a tire pressure control system for an off-road vehicle, which also aims to enable a rapid change in the pressure in a tire for switching between driving on the road and driving in deep terrain. In the tire pressure control system, the pressure in a reservoir is converted via a relay valve, which is controlled by fine control valves and 3 / 2 solenoid valves, into a pressure in an output-side supply line that corresponds either to the tire pressure for driving on the road or to the tire pressure for driving in deep terrain. The supply line is connected to a tire via an inlet of a shuttle valve, a wheel shut-off valve designed as a ventilation valve, a rotary union, a quick-release valve, and a downstream wheel control valve designed as a pneumatically controlled shut-off valve.The quick-release valve and the wheel control valve rotate with the vehicle wheel. The wheel control valve can be opened via a pressure pulse on the supply line, and closed via a closing pressure in a control line at any time and at any pressure level. The pressure in the control line is set by an electronically controlled closing pressure valve. The closing pressure valve can be electrically actuated by the vehicle driver and an electronic control device. The control line also runs via the rotary union.In order to avoid a situation in which the pressure in the tire in the tire pressure control system does not reach the target value or only reaches it very slowly (for example because the tire to be inflated is defective or because the compressor power is insufficient), a closing pressure signal from the closing pressure valve would be generated very late or would not be generated at all, with the result that there would be constant pressure at the rotary union and the seals of the rotary union would wear out quickly, EP 0 365 953 A2 proposes arranging a double pressure switch downstream of the relay valve, the two switching points of which are below the target pressure values ​​for driving on the road and in deep terrain by a sufficient safety margin.Once the pressure values ​​of the double pressure switch are reached, a time delay is activated, after which the closing pressure valve is forcibly actuated, which results in the wheel control valve being closed and thus also the venting of the supply line and the relief of the rotary union.

[0011] EP 3 354 488 A1 discloses a dual-circuit tire pressure control system for an off-road vehicle, in which shut-off valves arranged upstream of the tires and rotating with the vehicle wheels are supplied with both a supply pressure and a pneumatic control pressure via rotary unions. The control pressure is set for all tires by a central solenoid valve, while the supply pressure for tires assigned to an axle can be set individually via independent solenoid valves. Alternatively, EP 3 354 488 A1 proposes using electronically controlled 2 / 2-way valves as shut-off valves rotating with the vehicle wheels. In this case, the supply pressure and an electrical control signal are transmitted via the rotary union.

[0012] Further prior art is known in particular from the documents DE 10 2014 007281 A1, WO 2022 / 035497 A1, JP H05 246218 A, EP 3 904 126 A1, EP 1 051 302 B1, EP 3 703 321 B1 and EP 3 401 129 B1. OBJECT OF THE INVENTION

[0013] The invention is based on the object of proposing a tire pressure valve assembly and a group of tire pressure valve assemblies which enables multifunctional use of components and / or leads to increased operational reliability and / or enables reduced requirements for ensuring and maintaining the required switching pressures and / or enables simplification and / or improvement of the structural design. SOLUTION

[0014] The object of the invention is achieved according to the invention with the features of the independent patent claims. Further preferred embodiments of the invention can be found in the dependent patent claims. DESCRIPTION OF THE INVENTION

[0015] The invention relates to a single-circuit tire pressure valve assembly comprising a control and supply channel and a tire pressure valve.

[0016] The tire pressure valve has a control inlet connected to the control and supply channel via a branch and a control branch. Furthermore, the tire pressure valve has a supply inlet connected to the control and supply channel via the branch and a supply branch. The tire pressure valve also has a vent outlet and a tire connection.

[0017] In a first switching position, the tire pressure valve closes off the tire connection, keeping the compressed air volume in the tire constant. The tire pressure valve also has a second switching position. In the second switching position, the tire pressure valve connects the tire connection to the vent outlet. This allows compressed air from the tire to be fed to the vent. The tire pressure valve also has a third switching position. In the third switching position, the tire pressure valve connects the tire connection to the supply inlet, allowing compressed air from the supply inlet to be fed to the tire.

[0018] The tire pressure valve has a switching characteristic such that the first switching position is assumed when the pressure at the control and supply channel is at least temporarily lower than the first threshold. However, if the pressure at the control and supply channel is greater than the first threshold and less than a second threshold, the tire pressure valve is transferred from the first switching position to the second switching position. Finally, if the pressure at the control and supply channel is greater than the second threshold, the tire pressure valve is transferred from the first switching position or the second switching position to the third switching position.

[0019] In this respect, the tire pressure valve assembly and the tire pressure valve used therein can in principle be designed in accordance with the document EP 2 308 698 B1 mentioned at the beginning.

[0020] The invention is based in particular on the finding that pressure fluctuations in the control and supply channel of the tire pressure valve assembly can lead to undesired changes in the switching positions of the tire pressure valve, which can then lead to undesired ventilation, venting or blocking of the tire, which can, for example, delay a ventilation or venting process of the tire or lead to undesired traction conditions of the tire and / or undesired dynamic driving conditions of the vehicle.

[0021] According to the invention, the tire pressure valve assembly has a self-holding function. A self-holding function is understood to be a function that ensures that a switching position, which has been brought about by a switching pressure at the control and supply channel, is also maintained if the pressure at the control and supply channel falls below the switching pressure briefly, for a predetermined period of time, or even permanently. The self-holding function can be such that the switching position is maintained as long as the pressure is below the switching pressure by a predetermined pressure margin.

[0022] The self-holding function according to the invention is a passive self-holding function, meaning that it is not directly triggered by electronic control, but rather by the pressure conditions at and within the tire pressure valve assembly, in particular at the control inlet and the supply inlet of the tire pressure valve and / or the control and supply channel. It is possible for the tire pressure valve assembly to be designed entirely as a passive valve, meaning that it has no electronic control unit, no electronic control connection, and no solenoid valves.

[0023] According to the invention, the self-holding function is ensured by a self-holding valve. The self-holding valve ensures that, after the tire pressure valve is moved to the third switching position, the third switching position is maintained even if the pressure in the control and supply channel temporarily falls below the second set value (but possibly by a maximum of a predetermined pressure range).

[0024] Within the scope of the invention, there are a variety of possible designs for the self-holding valve included in the tire pressure valve assembly. For one structural design, the self-holding valve has a self-holding valve body that ensures the passive self-holding function.

[0025] The branch in the tire pressure valve assembly, via which the control and supply channel is connected to the control branch on the one hand and to the supply branch on the other, can be arranged at any location in the tire pressure valve assembly, particularly in the control and supply channel. One proposal integrates the branch into the self-holding valve body of the self-holding valve, allowing the self-holding valve body to be used multifunctionally.

[0026] Within the scope of the invention, it is possible for the self-holding valve body to interact with a self-holding valve seat. In a closed position of the self-holding valve, the self-holding valve body rests against the self-holding valve seat, thereby shutting off the self-holding valve. In this case, the control and supply channel is connected to the supply inlet of the tire pressure valve exclusively via a supply branch running through the self-holding valve body. In contrast, in the open position of the self-holding valve, the self-holding valve body and the self-holding valve seat form a bypass cross-section.In the open position of the self-holding valve, in addition to the connection of the control and supply channel to the supply inlet of the tire pressure valve via the supply branch running through the self-holding valve body, there is also an additional connection of the control and supply channel to the supply inlet of the tire pressure valve via the bypass cross-section. In this way, in the self-holding valve open position and thus in the venting position of the tire pressure valve assembly, an enlarged flow cross-section can be provided for rapid tire inflation.

[0027] According to one proposal, the pressure applied to the control and supply channel acts on a first control surface of the self-holding valve body in the closed position of the self-holding valve. Conversely, the pressure applied to the control and supply channel acts on a second control surface in the open position of the self-holding valve. The first control surface is smaller than the second control surface. In this way, the self-holding function can be provided in the form of a hysteresis.

[0028] For an embodiment of the tire pressure valve assembly according to the invention, the self-holding valve is connected to both a control branch and a supply branch. The control branch can be permanently connected to a vent via a throttle. In the control branch, when a shut-off valve is in the open position, a shut-off valve volume flow is supplied to the control branch via the self-holding valve. This shut-off valve volume flow is then greater than the volume flow vented from the control branch via the throttle. As a result, the pressure built up in the control branch can be used to switch the tire pressure valve to the second switching position. In contrast, in the control branch, when the shut-off valve is in the closed position, the shut-off valve volume flow is reduced such that the shut-off valve volume flow is smaller than the volume flow vented via the throttle.In this way, the reduced pressure in the control branch can contribute to switching the tire pressure valve to the third switching position.

[0029] In a further proposal of the invention, the self-holding valve body is additionally used for an additional purpose: In this case, the self-holding valve body of the self-holding valve interacts, on the one hand, with the self-holding valve seat to block or release the bypass cross-section. On the other hand, the self-holding valve body also interacts with a check valve seat of the check valve in the control branch. This multifunctionality of the self-holding valve body ensures that the blocking and release of the bypass cross-section necessarily correlates with the switching position of a check valve formed by the self-holding valve body and the check valve seat. In this case, the check valve is preferably responsible for releasing and shutting off the aforementioned check valve volume flow.

[0030] Further embodiments of the invention relate to the special design of the tire pressure valve used in the tire pressure valve assembly: For a structural design of the tire pressure valve, it has a vent valve and an overflow valve. The vent valve ensures the venting of the tire connection and thus the tire. The overflow valve preferably has an opening or overflow pressure at which the overflow valve is opened. In the tire pressure valve, the vent valve is arranged upstream of the vent outlet, while the overflow valve is arranged upstream of the tire connection.

[0031] Preferably, the valve bodies of the vent valve, on the one hand, and the overflow valve, on the other hand, are not independent of each other. Rather, according to one proposal of the invention, they can be mechanically coupled to each other (at least over a partial stroke). This allows the overflow valve to be opened not exclusively by the pressures acting on the overflow valve. Rather, the overflow valve can also be mechanically "pushed open" by the valve body of the vent valve. In extreme cases, the overflow valve can even be opened if no pressure is applied to the supply inlet, but rather a control piston actuating the vent valve opens the vent valve and, via the mechanical coupling, the overflow valve. This enables the tire pressure valve assembly to be in the deflation position.

[0032] According to one proposal of the invention, the valve body of the vent valve in the tire pressure valve can be actuated via a control piston. The control piston is then subjected to the control pressure at the control inlet. Preferably, the valve body of the vent valve is subjected to the pressure on the inlet side of the overflow valve, opposite to the effect of the control pressure on the control piston.

[0033] For a structural design of the tire pressure valve according to the invention, it has a housing. The housing has the control inlet, the vent outlet, the supply inlet and the tire connection as well as a valve chamber. The overflow valve is arranged in the housing with its overflow valve body. When the overflow valve body is in a closed position, the overflow valve separates the valve body from the tire connection so that the pressure in the tire is kept constant. Conversely, when the overflow valve body is in an open position, the overflow valve connects the valve chamber to the tire connection. Depending on whether the valve chamber is then connected to the vent outlet or the supply inlet, the tire can then be vented or ventilated in this open position of the overflow valve body. For this structural design, the vent valve with its vent valve body is also arranged in the housing.When the vent valve body is in the venting position, the vent valve connects the valve chamber to the vent outlet. Conversely, when the vent valve body is in the blocking position, the vent valve separates the valve chamber from the vent outlet. The control piston is also located in the housing. The control piston can be permanently connected to the vent valve body or be an integral part thereof. The control piston is mechanically coupled to the overflow valve body in such a way that, depending on the pressure at the control inlet and the pressure in the valve chamber, the overflow valve body can be moved from the blocking position to the open position.

[0034] The previously explained mechanical coupling of the control piston or vent valve body with the overflow valve body can be permanent, i.e., throughout the entire stroke of the valve body of the tire pressure valve. Preferably, however, this coupling occurs with a clearance such that the mechanical coupling is only established when the control piston and the vent valve body have completed a partial stroke. This partial stroke preferably corresponds to the stroke of the tire pressure valve from the first switching position to the second switching position.

[0035] A further aspect of the invention is dedicated to the coupling of the tire pressure valve with other pneumatic components of the tire pressure valve assembly. In this case, it is possible for the tire pressure valve to be arranged separately from the other components and connected to them via pneumatic lines. It is also possible for the tire pressure valve to be flanged to at least one other component, whereby a pneumatic connection of the tire pressure valve to the flanged component can then also be established by means of the flange connection. In a particular proposal of the invention, the housing of the tire pressure valve forms a sealing and mounting surface in the area surrounding the supply inlet and / or the control inlet. This surface can, for example, have a circular cross-section, in particular be cylindrical with a single diameter or stepped with different diameters.The sealing and mounting surface can form sealing areas, which can be designed, for example, as circumferential sealing grooves, in which sealing rings can then be arranged on both sides of the supply inlet or control inlet for sealing. The tire pressure control valve can be mounted via the sealing and mounting surface, sealing it with a sealing and mounting eyelet of a connection housing of another component of the tire pressure valve assembly. In the simplest case, the connection housing with the sealing and mounting eyelet is placed onto the cylindrical sealing and mounting surface of the tire pressure valve housing in such a way that it surrounds the sealing and mounting surface with the sealing areas. This can therefore be achieved by axially joining the connection housing to the sealing and mounting surface in the direction of the longitudinal axis of the cylindrical sealing and mounting surface.If the joined position is then secured against disassembly in an opposite axial direction, a particularly simple, leak-tight and reliable unit is formed from the tire pressure valve and the connection housing of the other pneumatic component.

[0036] In a further embodiment of the tire pressure valve, the control piston is supported by a control piston spring. The spring base of the control piston spring, which is not supported by the control piston, can be supported on the tire pressure valve housing. It is also possible, however, for a housing insert to be inserted into an interior space or internal bore of the housing, on which the control piston spring can then be supported. The control piston spring preferably acts on the control piston in a direction opposite to the direction in which the control piston is subjected to pressure at the control inlet.

[0037] It is possible for the housing insert to be used multifunctionally, in that, in addition to supporting the spring base of the control piston spring, it also forms a vent valve seat for the vent valve. The vent valve body of the vent valve can then be sealed against this vent valve seat of the housing insert when the vent valve is in the locked position.

[0038] It is also possible that the overflow valve body is supported by an overflow valve spring, in which case a spring base point of the overflow valve spring can be supported on the housing.

[0039] There are many different options for the design of the control inlet. For example, the control inlet can be formed directly by a control connection to which a control line can be connected, for example, using generally known fittings. According to one embodiment of the invention, the control inlet has a connection thread, preferably an internal thread. A coupling housing can then be screwed onto the connection thread. This coupling housing can then form the control connection, which enables the connection to a control line. Alternatively, the coupling housing can also form a sealing and mounting surface, which can then be mounted (as previously explained) with a sealing and mounting eye of a connection housing.

[0040] There are many possibilities within the scope of the invention for the structural design and geometry of the tire pressure valve assembly and its individual components. For example, it is possible for the tire pressure valve assembly to have a housing with a continuous or divided interior in which the individual valve elements can be spatially distributed. An elongated tire pressure valve assembly is also possible, in which individual components and valve elements are arranged next to one another. In a particular proposal of the invention, the branch, the control branch, the supply branch, and the tire pressure valve form a housing ring in the tire pressure valve assembly. This housing ring extends around a through-hole. The housing ring can, for example, be roughly rectangular or square. In this case, the supply inlet and the branch can be arranged in the region of a leg or a corner.From the branch, the supply branch then extends in one direction within the housing ring, while the control branch extends from the branch in another direction. The supply branch on the one hand and the control branch on the other are then joined by the tire pressure valve, which can extend along one leg of the housing ring. To give just one example of the structural design of the housing ring, the housing ring can consist of partial housings, each of which then forms a leg of the rectangular housing ring. It is also possible for the tire pressure valve forming one leg of the housing ring to have sealing and mounting surfaces in the area of ​​the associated corners of the housing ring, via which the housing of the tire pressure valve is then connected to the sealing and mounting eyes of the connecting or partial housings that adjoin the respective corner.

[0041] According to a further proposal of the invention, a check valve opening in the direction of the tire pressure valve is arranged in the supply branch. This check valve can increase operational reliability by preventing any unwanted transfer of compressed air in the supply branch to the valve chamber and / or any backflow in the opposite direction when the check valve is in the closed position.

[0042] In a further proposal, in a tire pressure valve assembly, the sealing and mounting surface of the tire pressure valve housing is sealed by a sealing and mounting eyelet of the connection housing, through which the supply branch extends. Alternatively or cumulatively, a coupling housing can be screwed into the connection thread of the control inlet. This coupling housing can then have a sealing and mounting surface that is sealed by a sealing and mounting eyelet of a connection housing. In this case, the control branch extends through the connection housing, the sealing and mounting eyelet of the connection housing, the sealing and mounting surface of the tire pressure valve housing, and the control inlet.

[0043] The connection via the interaction between sealing and mounting surfaces and sealing and mounting eyes can also be used for a special proposal of the invention in that the control branch housing has two sealing and mounting eyes that are part of the control branch. In this case, the sealing and mounting surface of the coupling housing screwed into the connection thread of the control inlet of the tire pressure valve can be accommodated in a sealing and mounting eye of a connection housing. In contrast, a sealing and mounting surface of another housing, in particular a housing of the self-holding valve and / or the shut-off valve, is accommodated in the other sealing and mounting eye of the connection housing.

[0044] A further solution to the problem underlying the invention is a group of tire pressure valve assemblies. The group of tire pressure valve assemblies has two subgroups: A first subgroup of tire pressure valve assemblies is designed as a single-circuit system. In contrast, the second subgroup of tire pressure valve assemblies is designed as a dual-circuit system. Such groups with two subgroups of tire pressure valve assemblies can, for example, be manufactured and offered by a manufacturer in order to offer single-circuit and dual-circuit tire pressure valve assemblies to the same or different customers. It is also possible for such different subgroups to be used by customers and vehicle manufacturers or trailer manufacturers to equip vehicles or trailers with a single-circuit or dual-circuit tire pressure control system as required.

[0045] According to the invention, the tire pressure valve assemblies of the two subgroups comprise identical tire pressure valves, with the formation of either the single-circuit tire pressure valve assembly or the dual-circuit tire pressure valve assembly being achieved by combining it with various additional pneumatic components to ensure single-circuit or dual-circuit configuration. The interfaces of the identical tire pressure valve are designed to enable pneumatic and mechanical coupling with these different components. This coupling is preferably achieved by the previously explained connection of at least one sealing and mounting surface of the tire pressure valve to at least one sealing and mounting eyelet of at least one connection housing of a component.

[0046] Advantageous further developments of the invention emerge from the patent claims, the description and the drawings.

[0047] The advantages of features and combinations of several features mentioned in the description are merely exemplary and can be effective alternatively or cumulatively, without the advantages necessarily having to be achieved by embodiments according to the invention.

[0048] With regard to the disclosure content – ​​not the scope of protection – of the original application documents and the patent, the following applies: Further features can be found in the drawings – in particular the illustrated geometries and the relative dimensions of several components to one another, as well as their relative arrangement and operative connection. The combination of features of different embodiments of the invention or features of different patent claims is also possible, deviating from the chosen references of the patent claims, and is hereby encouraged. This also applies to features that are illustrated in separate drawings or mentioned in their description. These features can also be combined with features of different patent claims.Likewise, features listed in the patent claims may be omitted for further embodiments of the invention, but this does not apply to the independent patent claims of the granted patent.

[0049] The number of features mentioned in the claims and the description is to be understood as meaning that exactly this number or a greater number than the stated number is present, without the need for the explicit use of the adverb "at least." Thus, for example, if reference is made to one element, this is to be understood as meaning that exactly one element, two elements, or more elements are present. The features mentioned in the claims may be supplemented by further features or may be the only features present in the subject matter of the respective claim.

[0050] The reference signs contained in the patent claims do not represent a limitation of the scope of the subject-matter protected by the patent claims. They serve solely to make the patent claims easier to understand. BRIEF DESCRIPTION OF THE CHARACTERS

[0051] In the following, the invention is further explained and described with reference to preferred embodiments shown in the figures. Fig. 1 shows a schematic of a single-circuit tire pressure valve assembly with one tire pressure valve. Fig. 2 shows a longitudinal section of the design of a tire pressure valve. Fig. 3 shows a sectional view of a tire pressure valve according to Fig. 2 in a single-circuit tire pressure valve assembly, with the tire pressure valve assembly in a locking position. Fig. 4 shows the tire pressure valve assembly according to Fig. 3 in a venting position. Fig. 5shows the tire pressure valve assembly according to Fig. 3 and 4 in a ventilation position. Fig. 6 shows in a spatial representation the arrangement of the tire pressure valve assembly according to Fig. 3 to 5 on a rim of a vehicle wheel. Fig. 7 shows the use of the tire pressure valve according to Fig. 2 in a dual-circuit tire pressure valve assembly. Fig. 8 shows in a spatial representation the arrangement of the dual-circuit tire pressure valve assembly according to Fig. 7 on a rim of a vehicle wheel. FIGURE DESCRIPTION

[0052] Fig. 1shows a tire pressure valve assembly 1 with a tire pressure valve 2. The tire pressure valve assembly 1 is single-circuit and has a control and supply connection 3, which can be connected to a control and supply line, in particular via a basically known fitting, wherein this control and supply line is then connected to a rotary union that enables the control and supply pressure to pass from the vehicle to the vehicle wheel. The pressure at the control and supply connection 3 is predetermined on the vehicle side by suitable valve devices with an associated compressed air treatment device and a compressor and / or a storage tank, wherein the different pressures at the control and supply connection 3, which are described below, for changing the operating position of the tire pressure valve assembly 1 can be predetermined by these valve devices.

[0053] Furthermore, the tire pressure valve assembly 1 has a tire connection 4, which can be screwed directly into a rim of a vehicle wheel, wherein the tire connection 4 can open directly or indirectly into the tire of the vehicle wheel.

[0054] The tire pressure valve assembly 1 has an overflow valve 5 and a vent valve 6, which are arranged here in pneumatic series between the control and supply connection 3 and the tire connection 4.

[0055] In the schematic representation in Fig. 1The overflow function of the overflow valve 5 is symbolized by the fact that the pressure at the control and supply connection 3 is supplied to an overflow function control inlet 7 via the dashed line. Opposite to the effect of the pressure at the overflow function control inlet 7, an overflow valve spring 8 acts on the overflow valve 5. For a pressure below a threshold value, which is predetermined by the stiffness and possible preload of the overflow valve spring 8 and the control surface, on which the pressure at the overflow function control inlet 7 acts, the overflow valve 5 switches from the Fig. 1effective first operating position to the second operating position. In the first operating position of the overflow valve 5, the overflow valve 5 connects the control and supply connection 3 to a vent 9a, with a throttle 10 arranged upstream of the vent 9a. A further throttle 11, which is only effective in the first operating position, is integrated into the vent valve 5. In contrast, in the second operating position, the vent valve 5 connects the control and supply connection 3 to an inlet of the vent valve 6.

[0056] The vent valve 6 has a control inlet 12. In the first operating position of the overflow valve 5, the control inlet is connected to the line between the overflow valve 5 and the throttle 10, which is connected to the vent 9a. Opposite to the pressure acting on the vent valve 6 by the control inlet 12, the vent valve 6 is acted upon by a vent valve spring 13. For a switching pressure at the control inlet 12 that is greater than a second threshold value, the switching of the vent valve 6 from the Fig. 1effective first operating position into the second operating position. The second threshold value depends on the area of ​​a control piston on which the pressure at the control inlet 12 acts, and the stiffness and any preload of the vent valve spring 13. In the first operating position, the vent valve 6 connects the overflow valve 5, i.e. in the second operating position of the overflow valve 5, the control and supply connection 3, with the tire connection 4, wherein in the first operating position a check valve 14 of the vent valve 6 is effective, which opens in the direction of the tire connection 4. In the second operating position, the vent valve 6 connects the tire connection 4 to a vent 9b.

[0057] The operation of the tire pressure valve assembly 1 according to Fig. 1is as follows: If the pressure at the control and supply connection 3 is lower than the first threshold value, the tire pressure valve assembly 1 is in the operating position according to Fig. 1 Both the overflow valve 5 and the vent valve 6 are in the first switching position. This results in the tire connection 4 being blocked by the check valve 14 of the vent valve 6. In this way, the pressure in the tire can be maintained. For this operating position, the control and supply connection 3 is connected to the vent 9a via the throttles 11, 10, which results in a low leakage flow. The pressure at the control inlet 12 is not high enough to switch the vent valve 6 to the second switching position. The tire is thus blocked.

[0058] If the pressure at the control and supply port 3 is increased to such an extent that it exceeds the first threshold value, the overflow valve 5 will not yet switch. However, the pressure increase at the control inlet 12 of the vent valve 6 causes the vent valve 6 to switch from the first switching position to the second switching position. The tire port 4, and thus the tire, is connected to the vent 9b via the vent valve 6. The pressure in the tire is thus reduced.

[0059] If the pressure at the control and supply port 3 is further increased so that it exceeds the second threshold value, the overflow valve 5 switches, while the control inlet 12 is vented via the throttle 10 and the vent 9a. Thus, the vent valve 6 assumes its first operating position (possibly with a delay predetermined by the throttle 10). The control and supply port 3 is then in its second operating position via the overflow valve 5, and the vent valve 6 is connected to the tire port 4 via the check valve 14. This results in the tire being inflated, with a concomitant increase in the pressure in the tire.

[0060] To give only some non-limiting examples of the invention, the first threshold value may be in the range from 2 bar to 4 bar, while the second threshold value may be in the range from 4 bar to 6 bar.

[0061] Fig. 2shows a structural design of a tire pressure valve 2 in a longitudinal section. The tire pressure valve 2 has a multi-part housing 15. The housing 15 has a control inlet 16, in the region of which a connecting thread 17 is provided. The connecting thread 17 opens into a control chamber 18, which is delimited by a control piston 19 slidably guided in the housing 15. The control piston 19 is firmly connected to a vent valve body 20, which, in the illustrated embodiment, is achieved by means of a screw 21.

[0062] In the illustrated embodiment, a housing insert 22 is inserted into an interior of the housing 15. The housing insert 22 is axially captured between a shoulder 23 of a housing part 24 forming the continuous interior and a housing cover 25 screwed into an internal thread of the housing part 24, which forms the control inlet 16 and the connecting thread 17. The housing insert 22 has a continuous recess through which the vent valve body 20 extends. In the end region facing away from the control piston 17, the vent valve body 20 has an extension which forms a vent valve plate 26. In the Fig. 2In the effective closed position of the vent valve 6, the vent valve plate 26 comes into contact with a vent valve seat 28 formed by the housing insert 22 in the associated end region, in a sealed manner, in particular as a result of a sealing ring 27 held by the vent valve plate 26. A prestressed vent valve spring 29 is trapped between the underside of the control piston 19 and a further shoulder of the housing insert 22. Both the housing insert 22 and the housing part 24 have radial recesses or bores that are connected to one another and to the environment that forms the vent 9b via a vent silencer 30 (also referred to as a "silencer," which can be annular and / or arranged in an annular chamber between the housing insert 22 and the housing part 24).

[0063] A valve chamber 31 is located below the vent valve body 20. A supply inlet 32 ​​opens into the valve chamber 31. If the vent valve body 20 is in the switching position in which the vent valve plate 26 is arranged spaced from the vent valve seat 28 and thus releases a transfer cross-section, the valve chamber 31 is connected to the vent 9b.

[0064] The valve chamber 31 is also limited by the overflow valve 5. The overflow valve 5 has an overflow valve body 33. An overflow valve spring 34 acts on an overflow valve plate 35 of the overflow valve body 33 in the direction of an overflow valve seat 36, counter to the effect of the pressure in the valve chamber 31 acting on the back of the overflow valve plate 35. In the Fig. 2In the effective switching position, as a result of this action by the overflow valve spring 34, the overflow valve 5 is closed, since the overflow valve plate 35 rests against the overflow valve seat 36 in a sealed manner, in particular with the interposition of a sealing ring 37 held on the overflow valve plate 35 or the overflow valve seat 36. If, however, the overflow valve 5 is transferred into the switching position in which the overflow valve plate 35 is arranged at a distance from the overflow valve seat 36, the transfer cross-section thus provided provides a pneumatic connection between the valve chamber 31 and the tire connection 4.

[0065] For the illustrated embodiment, the overflow valve body 33 has a guide sleeve 38 on the side facing away from the valve chamber 31. The guide sleeve 38 is slidably guided in an internal bore of the housing part 24. Furthermore, the guide sleeve 38 serves to accommodate the overflow valve spring 34. The guide sleeve 38 has transverse bores 96 through which compressed air can flow from the transfer cross-section of the overflow valve 5 to the tire connection 4. The overflow valve body 33 has an extension 39 that extends from the overflow valve plate 35 into the interior of the valve chamber 31. One end face of the extension 39 is arranged at a distance 40 from the end face of the vent valve body 20, in particular the vent valve plate 26.

[0066] A possible mode of operation with appropriate design of the valve and control surfaces as well as the preloads and stiffnesses of the various springs of the tire pressure valve 2 is as follows: If the pressure at the control inlet 16 and / or the supply inlet 32 ​​is below a first threshold value, the vent valve spring 29 holds the vent valve 6 in the closed position, and the overflow valve spring 34 holds the overflow valve 5 in the closed position. Thus, compressed air present at the supply inlet 32 ​​can neither be vented via the vent 9b nor reach the tire connection 4 to increase the pressure in the tire. Rather, the tire is shut off via the tire pressure valve 4.

[0067] If the pressure at the control inlet 16 increases so that the pressure is greater than the first threshold value but less than the second threshold value, the pressure acting at the control inlet 16 causes the control piston 19 to move the vent valve 6 into its venting position. The movement of the vent valve body 20 eliminates the gap 40, and the vent valve body 20 exerts an opening force component on the overflow valve body 33 with its end face. In addition, a pressure in the valve chamber 31 can act on the overflow valve plate 35 and generate a second opening force component. The superposition of the two opening force components then leads to the opening of the overflow valve 5. Thus, compressed air can flow from the tire connection 4 via the open overflow valve 5 and the open vent valve 6 to the vent 9b.

[0068] If, however, there is no pressure at the control inlet 16 and a pressure greater than the second threshold is present at the supply inlet 32, this results in the vent valve 6 being moved into the blocking position by the vent valve spring 29, while the pressure at the supply inlet 32 ​​causes an opening force on the overflow valve plate 35 that is sufficient to open the overflow valve 5. This results in compressed air being able to flow from the supply inlet 32 ​​via the open overflow valve 5 to the tire connection 4, thus inflating the tire.

[0069] Thus, in order to bring about the venting position of the tire pressure valve 2, the overflow valve 5 is opened at least partially mechanically by the venting valve 6, while in order to bring about the venting position of the tire pressure valve 2, the overflow valve 5 is opened purely pneumatically by the pressure acting on the overflow valve 5.

[0070] Fig. 3 to 5 show the use of the tire pressure valve 2 according to Fig. 2 in a single-circuit tire pressure valve assembly 1a. The tire pressure valve assembly 1a has a housing ring 41, which is rectangular or square in shape here and has a through-hole 42. The housing ring 41 has the housing 15 of the tire pressure valve 2, a connection housing 43, a self-holding valve housing 44 and a further connection housing 45, which each form a leg of the rectangular housing ring 41 and are arranged in this order in Fig. 3 Connect to each other clockwise.

[0071] To enable the connection of the connection housing 43 to the housing 15, the outer surface of the housing 15 has a cylindrical sealing and mounting surface 46 in the area surrounding the supply inlet 32. The sealing and mounting surface 46 can have circumferential grooves 47, 48 on both sides of the supply inlet 32, in which sealing rings 49, 50 are arranged.

[0072] The connection housing 43 has a through-bore forming a sealing and mounting eyelet 51. The sealing and mounting surface 46 of the housing 15 is received in the sealing and mounting eyelet 51 of the connection housing 43 with a precise fit and sealing effect, allowing compressed air to flow (with a seal to the outside) from the supply inlet 32 ​​to an interior space 52 of the connection housing 43 (and vice versa). The position of the connection housing 43 mounted in this manner on the housing 15 is secured by the connection housing 43 being captured between a shoulder 53 of the housing part 24 and a retaining ring 54 held on the outer surface of the lower end region of the housing part 24.

[0073] A coupling housing 55 is screwed into the connection thread 17 of the housing cover 25. The coupling housing 55 has (basically corresponding to the connection area between the housing 15 and the connection housing 43) a sealing and mounting surface 56 with grooves 57, 58 and seals 59, 60.

[0074] The connection housing 45 has (basically corresponding to the connection housing 43) a sealing and mounting eyelet 61. The sealing and mounting surface 56 is accommodated in the sealing and mounting eyelet 61 (with an outward seal) so that compressed air can pass between the control inlet 16 and a longitudinal channel 62 in a sealed manner. The mounted position of the connection housing 45 on the housing 15 is secured in that the connection housing 45 is pressed against an end face of the housing cover 25 by an extension 63, and thus the connection housing 45 is trapped between the extension 63 and the end face of the housing cover 25 in the area of ​​the sealing and mounting eyelet 61.

[0075] In the other end area, the longitudinal channel 62 of the connection housing 45 opens into another sealing and mounting eyelet 64 of the connection housing 45. A sealing and mounting surface 65 of the self-retaining valve housing 44 with associated grooves 66, 67 and sealing rings 68, 69 is received in the sealing and mounting eyelet 64. The mounted position is secured by the connection housing 45 being captured in the area of ​​the sealing and mounting eyelet 64 between a shoulder 70 of the self-retaining valve housing 44 and a retaining ring 71 held at the end of the self-retaining valve housing 44.

[0076] In the other end area, the self-holding valve housing 44 is screwed into an internal thread of the connection housing 43.

[0077] In the end region facing away from the tire pressure valve 2, the connection housing 43 has an internal thread 72 into which a connecting piece 73 is screwed in a sealed manner. The connecting piece 73 is designed for connecting a control and supply line 88 using conventional, known connection technologies. For the illustrated embodiment, the connection is formed with a screw cap 74, which can be screwed onto the connecting piece 73. The control and supply line 88 can then be clamped and secured between a sleeve-shaped extension, possibly with an elastically deformable clamping lug 75, and the screw cap 74.

[0078] The interior space 52 of the connection housing 43 connects the supply inlet 32 ​​of the tire pressure valve 2 to the control and supply connection 3. However, a check valve 76 opening toward the supply inlet 32 ​​is arranged in this path. Furthermore, a self-holding valve body 77 extends within the self-holding valve housing 44 and the connection housing 43. The inlet side of the check valve 76 is connected to the control and supply connection 3 via a supply branch 78 of the self-holding valve body 77.

[0079] The self-holding valve body 77 is displaceable under the action of a self-holding valve spring 79 depending on the pressure acting in the interior space 52 on the inlet side of the check valve 76 and acting on the front face of the self-holding valve body 77. For small pressures acting on the front face of the self-holding valve body 77, the self-holding valve spring 79 presses the self-holding valve body 77 (if necessary with a sealing ring 80 arranged in a groove) against a self-holding valve seat 81 formed here by the connection housing 43. In this case, the transfer from the control and supply connection 3 to the interior space 52 of the connection housing 43 is only possible via the supply branch 78.On the other hand, with a greater pressure acting on the front side of the self-holding valve body 77, the self-holding valve body 77 can be moved away from the self-holding valve seat 81 with increasing the load on the self-holding valve spring 79, whereby a bypass cross-section 101 is formed and the bypass cross-section 101 provides a bypass to the supply branch 78 for the transfer of compressed air from the control and supply connection 3 to the interior space 52.

[0080] The supply branch 78 has a branch 82, in the region of which a control branch section 83 branches off. The control branch section 83 creates a connection through the self-holding valve body 77 to the sealing and mounting surface 65, via which the control branch section 83 is connected to the longitudinal channel 62 (and therethrough to the control inlet 16).

[0081] In the tire pressure valve assembly 1a, the control and supply pressure at the control and supply connection 3 reaches the branch 82 via a control and supply channel 97, in the region of which a branch is made, on the one hand, to a supply branch 98 and, on the other hand, to a control branch 99. In the housing ring 41, the supply branch 98 and the control branch 99 extend from the branch 82 in opposite circumferential directions. For the illustrated embodiment, the supply branch 98 extends through the connection housing 43, while the control branch extends through the self-holding valve housing 44 and the connection housing 45. The supply branch 98 connects the branch 82 to the supply inlet 32 ​​of the tire pressure valve 2. The control branch 99 connects the branch 82 to the control inlet 16 of the tire pressure valve 2.

[0082] The self-holding valve body 77 and the self-holding valve seat 81 form a self-holding valve 100. In the closed position of the self-holding valve 100, the supply branch 98 is connected exclusively via the supply sub-branch 78 and the branch 82 and, via these, to the control and supply channel 97. In contrast, in the open position, the self-holding valve 100 creates a bypass cross-section 101, via which an additional connection of the supply branch 98 to the control and supply channel 97 is created.

[0083] The self-holding valve body 77 forms a closing body 102 in the end region facing away from the self-holding valve seat 81. If the self-holding valve body 77 is moved away from the self-holding valve seat 81, the closing body 102 comes into contact with a check valve seat 84 in a sealed manner. For the illustrated embodiment, the check valve seat 84 is formed by a shoulder of the self-holding valve housing 44, optionally with a sealing ring. In this way, the self-holding valve body 77, together with the closing body 102 and the check valve seat 84, forms a check valve 103. In the open position, the check valve 103 opens the control branch 99, allowing flow from the branch 82 via the supply branch 78 and the longitudinal channel 62 to the control inlet 16. In contrast, the shut-off valve 103 in the shut-off position shuts off the control branch 99 by blocking the connection between the branch 82 and the longitudinal channel 62.Here, the blocking position of the shut-off valve 103 corresponds to the opening position of the self-holding valve 103, while the opening position of the shut-off valve 103 corresponds to the closing position of the self-holding valve 103.

[0084] Downstream of the shut-off valve 103, the control branch 99 is connected to a vent 9 via a throttle 85. The throttle 85 is dimensioned such that, when the shut-off valve 103 is open, more compressed air flows from the branch 82 into the longitudinal channel 62 than is discharged via the throttle 85, allowing pressure to build up at the control inlet 16. However, if the shut-off valve 103 assumes its closed position, the control inlet 16 is vented via the throttle 85 to the vent 9.

[0085] The self-holding valve body 77, the self-holding valve spring 79 and the self-holding valve seat 81 form a self-holding valve 100. If the self-holding valve 100 assumes the closed position (cf. Fig. 3), the pressure on the output side of the self-holding valve 100 in the supply branch 98 acts on an end face of the self-holding valve body 77, which is limited by the sealing contact with the self-holding valve seat 81, in particular with the sealing ring 80. This end face forms a first control surface 107. If, however, the self-holding valve 100 assumes its self-holding or open position, the pressure in the control branch 99 acts on an enlarged end face of the self-holding valve body 77, which for the illustrated embodiment is limited by the outer diameter of the seals 104, via which the self-holding valve body 77 is guided relative to the self-holding valve housing 44. This enlarged end face forms a second control surface 108. The enlarged effective area of ​​the pressure means that this open or self-holding position is maintained even when the pressure in the supply branch 98 drops.At the same time, in the open or self-holding position of the self-holding valve 100, the blocking position of the blocking valve 103 is maintained.

[0086] When the shut-off valve 103 is open, the compressed air enters the control branch 99 from the branch 82 through the control branch section 83, which extends through the self-holding valve body 77 and through radial bores 105 of the self-holding valve body 77 and an annular gap 106 between the closing body 102 and the self-holding valve housing 44 past the shut-off valve seat 84 to the longitudinal channel 82.

[0087] The function of the single-circuit tire pressure valve assembly 1a with the tire pressure valve 2 according to Fig. 2 is now based on the different operating positions according to Fig. 3 to 5 explained.

[0088] Fig. 3shows the tire pressure valve assembly 1a in the locked position, in which the tire connection 4 is blocked. The tire pressure valve assembly 1a assumes this locked position when the pressure at the control and supply connection 3 is below a first threshold value. In this state, the self-holding valve body 77 rests against the self-holding valve seat 81 in a sealed manner, so that the compressed air can only reach the interior 52 of the connection housing 43 via the supply branch 78. The check valve 76 is closed, which can be ensured by a check valve spring urging the check valve 76 into the closed position and / or by the pressure present on the output side of the check valve.The shut-off valve 103 is in the open position, so that compressed air can be supplied from the control and supply channel via the branch 82, the control branch section 83, and the longitudinal channel 62 to the control chamber 18 of the tire pressure valve 2. However, the pressure in the control branch 99 and thus at the control inlet 16 is not sufficient (also due to the venting via the throttle 85) to open the vent valve 6. The pressure present in the valve chamber 31 is also not sufficient to open the overflow valve 5.

[0089] If the pressure at the control and supply connection 3 is increased so that it is greater than the first threshold value, but less than the second threshold value, the tire pressure valve assembly switches from the blocking position according to Fig. 3 into the venting position according to Fig. 4In the venting position, the self-holding valve 100 remains in the closed position, whereby the shut-off valve 103 is in the open position. Due to the pressure increase in the control chamber 18, the control piston 19 can move the venting valve 6 into the venting position. During this opening movement of the venting valve 6, the distance 40 decreases to zero and an opening force is transmitted via the front side of the venting valve body 20 to the extension 39 of the overflow valve body 33. As a result of this opening force, the overflow valve 5 is moved into the open position. The tire connection 4 can thus be vented via the vent 9. The check valve 76 is blocked in this case.

[0090] If the pressure at the control and supply connection 3 is increased such that it is greater than a second threshold value, the check valve 76 opens. Furthermore, the pressure acting on the front side of the self-holding valve body 77 causes the self-holding valve body 77 to be moved away from the self-holding valve seat 81. The movement of the self-holding valve body 77 away from the self-holding valve seat 81 simultaneously causes the shut-off valve 103 to block the connection between the control branch section 83 and the longitudinal channel 62. The longitudinal channel 62 is connected to the vent 9 via the throttle 85, so that as a result of the previously explained blocking of the control branch section 83, the longitudinal channel 62 and thus the control chamber 18 are vented. As a result, the control piston 19 moves due to the action of the vent valve spring 29 in such a way that the vent valve 6 is moved into its blocking position.In the operating position according to . Fig. 5 Compressed air can flow through the interior 52 with the opening of the check valve 76 via the bypass cross-section 101 between the self-holding valve body 77 and the self-holding valve seat 81 and flow to the tire connection 4 via the supply inlet 32 ​​and the opened overflow valve 5.

[0091] It can be seen in the figures that the control surface 107 / 108, on which the pressure acts on the front side of the self-holding valve body 77, in the closed position of the self-holding valve body 77, in which it rests against the self-holding valve seat 81 ( Fig. 3 and 4 ) is smaller than in the position of the self-holding valve body 77 in which it is arranged at a distance from the self-holding valve seat 81 ( Fig. 5). This has the consequence that even if a smaller pressure acts on this end face after the self-holding valve body 77 has moved into the open position, this open position is maintained, allowing tire connection 4 to continue to be filled. This thus creates a self-holding function.

[0092] Fig. 6 shows the assembly of the tire pressure valve assembly 1a on a rim 86 of a vehicle wheel 87. For this single-circuit design of the tire pressure valve assembly 1a, a common control and supply line 88 is connected to the control and supply connection 3. It is possible that the housing 15 of the tire pressure valve 2 has an external thread 89 in the area of ​​the tire connection 4, with which the tire pressure valve 2 and thus the tire pressure valve assembly 1a is screwed directly into an internal thread of the rim 86.

[0093] Fig. 7shows the use of the same tire pressure valve 2 in a dual-circuit tire pressure valve assembly 1b. In this case, a coupling housing 90 is screwed into the connection thread 17 of the housing cover 27, which coupling housing is designed differently from the coupling housing 55: In this case, the coupling housing directly has a control connection 91. A connection housing 92, which is connected to the sealing and mounting surface 46 of the tire pressure valve 2, is also designed differently from the connection housing 43: In this case, the connection housing 92 only has a supply connection 93.

[0094] Fig. 8 shows the assembly of the dual-circuit tire pressure valve assembly 1b according to Fig. 7on a rim 86 of a vehicle wheel 87. A control line 94 is connected to the control port 91, while a supply line 95 is connected to the supply port 93. In this case, too, the tire pressure valve assembly 1b can be screwed to the rim 86 via the external thread 89.

[0095] It is possible that the housing 15 is conical in the area of ​​the external thread 89. A sealant such as a sealing paste can be used when screwing in the external thread 89.

[0096] Optionally, the interior space 52 may have a throttled vent 9 on the inlet side of the check valve 76. This throttled vent can be used for venting if the check valve 76 exhibits an undesirable leak in its closed position.

[0097] The valve chamber 31 can also be connected to a throttled vent 9. LIST OF REFERENCE SYMBOLS

[0098] 1Tire pressure valve assembly 2Tire pressure valve 3Control and supply connection 4Tire connection 5Bypass valve 6Vent valve 7Bypass function control inlet 8Bypass valve spring 9Vent 10Throttle 11Throttle 12Control inlet 13Vent valve spring 14Check valve 15Housing 16Control inlet 17Connection thread 18Control chamber 19Control piston 20Vent valve body 21Screw 22Housing insert 23Shoulder 24Housing part 25Housing cover 26Vent valve disc 27Sealing ring 28Vent valve seat 29Vent valve spring 30Vent silencer 31Valve chamber 32Supply inlet 33Bypass valve body 34Bypass valve spring 35Bypass valve disc 36Overflow valve seat 37Sealing ring 38Guide sleeve 39Extension 40Spacing 41Housing ring 42Through recess 43Connection housing 44Self-retaining valve housing 45Connection housing 46Sealing and mounting surface 47Groove 48Groove 49Sealing ring 50Sealing ring 51Sealing and mounting eye 52Interior 53Step 54Retaining ring 55Coupling housing 56Sealing andMounting surface 57 Groove 58 Groove 59 Sealing ring 60 Sealing ring 61 Sealing and mounting eye 62 Longitudinal channel 63 Extension 64 Sealing and mounting eye 65 Sealing and mounting surface 66 Groove 67 Groove 68 Sealing ring 69 Sealing ring 70 Shoulder 71 Retaining ring 72 Internal thread 73 Connection piece 74 Screw cap 75 Clamping lug 76 Check valve 77 Self-retaining valve body 78 Supply branch 79 Self-retaining valve spring 80 Sealing ring 81 Self-retaining valve seat 82 Branch 83 Control branch section 84 Check valve seat 85 Throttle 86 Rim 87 Vehicle wheel 88 Control and supply line 89 External thread 90 Coupling housing 91 Control connection 92 Connection housing 93 Supply connection 94Control line 95Supply line 96Cross bore 97Control and supply channel 98Supply branch 99Control branch 100Self-locking valve 101Bypass cross-section 102Closing body 103Stop valve 104Seal 105Radial bore 106Annular gap

Claims

1. Single circuit tire pressure valve assembly (1) comprising a control and supply channel (97) and a tire pressure valve (2) with a control inlet (16) which is connected via a branching (82) and a control branch (99) to the control and supply channel (97), with a supply inlet (32) which is connected via the branching (82) and a supply branch (98) to the control and supply channel (97), with a vent (9) and with a tire port (4), wherein a) in a first switching position the tire pressure valve (2) closes the tire port (4), b) in a second switching position the tire pressure valve (2) connects the tire port (4) to the vent (9), c) in a third switching position the tire pressure valve (2) connects the tire port (4) to the supply inlet (32), d) the tire pressure valve (2) for an at least temporary pressure in the control and supply channel (97) - which is lower than a first threshold value is in the first switching position, - which is higher than the first threshold value and lower than the second threshold value is transferred from the first switching position into the second switching position and - which is higher than the second threshold value is transferred from the first switching position or from the second switching position into the third switching position, characterized in that a self holding valve (100) is provided which comprises a passive self holding function such that after transferring the tire pressure valve (2) into the third switching position the third switching position is upheld even if the pressure in the control and supply channel (97) temporarily falls below the second threshold value.

2. Tire pressure valve assembly (1) of claim 1, characterized in that the self holding valve (100) comprises a self holding valve body (77) which provides the passive self holding function.

3. Tire pressure valve assembly (1) of claim 2, characterized in that the branching (82) is integrated into the self holding valve body (77).

4. Tire pressure valve assembly (1) of claim 2 or 3, characterized in that the self holding valve body (77) cooperates with a self holding valve seat (81) wherein a) in a closed position of the self holding valve (100) the self holding valve body (77) rests on the self holding valve seat (81) and the control and supply channel (97) is exclusively connected via a supply sub-branch to the supply inlet (32) of the tire pressure valve (2), the supply sub-branch extending through the self holding valve body (77), and b) in an open position of the self holding valve (100) the self holding body (77) and the self holding valve seat (81) form a bypass cross section (101) and the control and supply channel (97) is connected both via the supply sub-branch (78) which extends through the self holding valve body (77) as well as via the bypass cross section (101) to the supply inlet (32) of the tire pressure valve (2).

5. Tire pressure valve assembly (1) of one of claims 2 to 4, characterized in that the pressure biasing the control and supply channel (97) biases a first control surface (107) in a closed position of the self holding valve (100) and biases a second control surface (108) in an open position of the self holding valve (100), the first control surface (107) being smaller than the second control surface (108).

6. Tire pressure valve assembly (1) of one of the preceding claims, characterized in that the self holding valve (100) is connected both to a control branch (99) as well as to a supply branch (98) wherein in particular the control branch (99) is permanently connected via a throttle (85) to a vent and in the control branch (99) - in an open position of a shut-off valve (103) a shut-off valve volumetric flow is transmitted via the self holding valve (100) to the control branch (99), the shut-off valve volumetric flow being higher than the volumetric flow which is vented from the control branch (99) via the throttle (5), the pressure build up in the control branch (99) in this way contributing to the switching of the tire pressure valve (2) into the second switching position, and - in a closed position of the shut-off valve (103) the shut-off valve volumetric flow is reduced such that the shut-off valve volumetric flow is smaller than the volumetric flow vented via the throttle (85), the pressure reduced in the control branch (99) in this way contributing to the switching of the tire pressure valve (2) into the third switching position.

7. Tire pressure valve assembly (1) of claim 6 when referring back to claim 4, characterized in that the or a self holding valve body (77) interacts a) both with the self holding valve seat (81) of the self holding valve (100) for shutting-of and opening the bypass cross section (101) b) as well as with a shut-off valve seat (84) of the shut-off valve (103) of the control branch (99).

8. Tire pressure valve assembly (1) of one of the preceding claims, characterized in that in the tire pressure valve (2) a) a venting valve (6) is arranged upstream from the vent (9) and b) an overflow valve (5) is arranged upstream from the tire port (4), c) wherein preferably valve bodies (20, 33) of the venting valve (6) and of the overflow valve (5) are mechanically coupled to each other at least over a part of the stroke.

9. Tire pressure valve assembly (1) of claim 8, characterized in that in the tire pressure valve (4) the venting valve body (20) of the venting valve (6) can be actuated by a control piston (19) which is biased by the control pressure at the control inlet (16), wherein preferably the venting valve body (20) of the venting valve (6) is biased by the pressure on the inlet side of the overflow valve (5) opposite to the effect of the control pressure on the control piston (19).

10. Tire pressure valve assembly (1) of claim 9, characterized in that a) the tire pressure valve (2) comprises a housing (15) which comprises the control inlet (16), the vent (9), the supply inlet (32) and the tire port (4) and a valve chamber (31), b) wherein the overflow valve (6) with the overflow valve body (33) is arranged in the housing (15), c) the overflow valve (6) in a shut-off position of the overflow valve body (33) separates the valve chamber (31) from the tire port (4) and in an open position of the overflow valve body (33) connects the valve chamber (31) to the tire port (4), d) the venting valve (6) with the venting valve body (20) is arranged in the housing (15), wherein in a venting position of the venting valve body (20) the venting valve (6) connects the valve chamber (31) to the vent (9) and in a shut-off position of the venting valve body (20) separates the valve chamber (31) from the vent (9), e) the control piston (19) is arranged in the housing (15), wherein the control piston (19) is mechanically coupled to the overflow valve body (33) in a way such that dependent on the pressure at the control inlet (16) and / or on the pressure in the valve chamber (31) the overflow valve body (33) can be transferred from the shut-off position into the open position.

11. Tire pressure valve assembly (1) of one of the preceding claims, characterized in that in the tire pressure valve (2) the housing (15) forms a sealing and assembly surface (46; 56) in the neighbourhood of the supply inlet (32) and / or the control inlet (16) by which it is possible to assemble the tire pressure control valve (2) under the provision of a sealing effect to a sealing and assembly eye (51; 61) of a connection housing (43; 45).

12. Tire pressure valve assembly (1) of one of the preceding claims, characterized in that the branching (82), the control branch (99), the supply branch (98) and the tire pressure valve (2) form a housing ring (41).

13. Tire pressure valve assembly (1) of one of the preceding claims, characterized in that a check valve (76) is arranged in the supply branch (98) which opens towards the tire pressure valve (2).

14. Tire pressure valve assembly (1) of one of the preceding claims, characterized in that a) a sealing and assembly surface (46) of the housing (15) of the tire pressure valve (2) is accommodated by a sealing and assembly eye (51) of a connection housing (43) under the provision of a sealing effect, the supply branch (98) extending through the connection housing (43), and / or b) a coupling housing (55) can be screwed in a connecting thread (17) of the control inlet (61), the coupling housing comprising a sealing and assembly surface (56) which is accommodated under the provision of a sealing effect by a sealing and assembly eye (61) of a connection housing (45), the control branch (99) extending through the connection housing (45) and through the sealing and assembly surface (56) to the control inlet (16), wherein preferably the connection housing (45) comprises two sealing and assembly eyes (61; 64) which are part of the control branch (99), wherein the sealing and assembly surface (56) of the coupling housing (55) is accommodated in a first sealing and assembly eye (61) of the connection housing (45) and a sealing and assembly surface (65) of a self holding valve housing (44) is accommodated in a second sealing and assembly eye (64) of the connection housing (45), the self holding valve housing (44) containing the self holding valve (100).

15. Group of tire pressure valve assemblies (1a, 1b) with a) a first group part of tire pressure valve assemblies (1a) according to one of the preceding claims, which are embodied with one single circuit only and b) a second group part of tire pressure valve assemblies (1b) which are embodies with two circuits, wherein the tire pressure valve assemblies (1a) of the first group part and the tire pressure valve assemblies (1b) of the second group part comprise tire pressure valves (2) having the same constructions.