Pneumatic device with one-way valve and additional exhaust path with sealing device

Abstract

The invention relates to a pneumatic device (1) for a vehicle (200), comprising: a main venting path (17) for venting a pressure-bearing section in a venting direction (R); a one-way valve (19) located in the main exhaust path (17) to exhaust a pressure in the pressure bearing section (15) exceeding a predetermined exhaust pressure threshold; a secondary exhaust path (21) for discharging the residual pressure from the pressure-bearing section (15); and a sealing device (23) located in the secondary exhaust path (21), the sealing device (23) being adapted to switch at least between a normal state (Z1) and a sealed state (Z2). In a normal state, it is possible to flow through the sub-exhaust path (21), and in a sealed state (Z2), the sub-exhaust path (21) is hermetically blocked. The invention also relates to a pneumatic brake system and to a method for venting a pressure-bearing section of a pneumatic device.

Description

Field of the Invention

[0001] The present invention relates to a pneumatic device for a pneumatic braking system of a vehicle and a pneumatic braking system having such a pneumatic device. The present invention also relates to a method for exhausting a pressure-bearing section of the pneumatic device. Background Art

[0002] In particular, pneumatic devices of the above type can be used in pneumatic braking systems of vehicles, especially for commercial vehicles, such as brake valves and / or relay valves therefor. The pneumatic device typically has a pneumatic connection to the environment of the pneumatic device, for example, to discharge excess pressure from the pressure-bearing section of the pneumatic device. However, such a pneumatic connection to the environment of the pneumatic device may allow foreign media located in the environment to enter the pneumatic device.

[0003] Generally, pneumatic devices of the above type are used in environments where various foreign media may be present. In particular, pneumatic braking devices and their components (such as relay valves) can be exposed to water from their environment, for example, during cleaning, during operation in the rain or after rain, in the event of flooding or when intentionally fording a body of water. In particular, the intrusion of a liquid such as water can impair the function of the pneumatic device. In the case of a pneumatic braking system, for example, the intrusion of foreign media (especially water) can cause corrosion or, for example, complete failure of the braking system due to water freezing. Therefore, measures must be taken to make the unintentional intrusion of foreign media more difficult or, optimally, to prevent such unintentional intrusion.

[0004] In the prior art, pneumatic devices with sealing devices are known, which are designed to prevent the unintentional intrusion of small amounts of sprayed water or water below a certain level.

[0005] Among them, DE 10 2020 108 757 A1 discloses such a pneumatic device, which has an exhaust path for exhausting the pressure-bearing section of the pneumatic device in the exhaust direction and a sealing device arranged in the exhaust path. The sealing device is provided by a sealing seat and a spherical sealing body guided in a cage. The sealing seat is defined by the inner diameter of the exhaust passage, and the spherical sealing body is dimensioned accordingly. The sealing body floats on water and is arranged downstream of the sealing seat in the outflow direction. In the case of water intrusion, the sealing body floats against the sealing seat, thereby sealingly blocking the exhaust path.

[0006] In addition, CN213619717U relates to a utility model, which discloses a mechanical device for preventing water intrusion in an exhaust path.

[0007] The described sealing device can provide protection against water intrusion, but can also cause vibrations due to the oscillating spherical sealing body. However, this may have to be prevented.

[0008] In addition, since the exhaust gas passing through the exhaust path needs to meet the exhaust time requirement, the diameter of the exhaust path is relatively large, and thus the diameter of the sealing body is also correspondingly large. Therefore, the oscillation of the relatively large sealing body results in destructive noise. Therefore, it is necessary to reduce (or further lower) the noise level and oscillation of the pneumatic device and further improve the protection against water intrusion. Summary of the Invention

[0009] In this regard, an object of the present invention is to be able to safely operate a pneumatic device of the type described at the beginning even in an environment where water intrusion from, for example, the bottom side of the pneumatic device is prevalent.

[0010] In a first aspect, the object is solved by a pneumatic device according to claim 1. In particular, the object is solved by a pneumatic device comprising: a main exhaust path for exhausting a pressure-bearing section of the pneumatic device in an exhaust direction; and a non-return valve arranged in the main exhaust path and configured to enable the pressure-bearing section to exhaust in the exhaust direction when the pressure in the pressure-bearing section exceeds a predetermined exhaust pressure threshold. The pneumatic device according to the invention further comprises: a secondary exhaust path for exhausting residual pressure from the pressure-bearing section in the exhaust direction; and a sealing device arranged in the secondary exhaust path. The sealing device is adapted to switch at least between a normal state and a sealed state, wherein in the normal state of the sealing device, flow through the secondary exhaust path in the exhaust direction is possible, while in the sealed state of the sealing device, the secondary exhaust path is sealed and blocked at least in a direction opposite to the exhaust direction. In other words, the pneumatic device has a main exhaust path defining a main exhaust path for meeting the response exhaust time requirement, which is protected from the environment by a non-return valve arranged in the main exhaust path. On the other hand, residual pressure below the predetermined exhaust pressure threshold cannot be exhausted via the non-return valve and will remain in the pressure-bearing section if not exhausted in some other way. For this purpose, the pneumatic device according to the invention also has a secondary exhaust path for exhausting residual pressure and for balancing the pressure in the pressure-bearing section with atmospheric pressure. The secondary exhaust path can be defined by a flow path extending through the pneumatic device or by a balancing port or at least a small gap, thereby allowing the residual pressure to equilibrate with the atmosphere. However, the secondary exhaust path is configured to allow the discharge of pressurized air below the pressure value required to open the non-return valve. Since the secondary exhaust path must also be protected from the intrusion of unwanted media, a sealing device is accordingly arranged in the secondary exhaust path. In the absence of an exhaust response time requirement for the secondary exhaust path, the cross-section of the secondary path can preferably be smaller than the cross-section of the main exhaust path.

[0011] Since the residual pressure does not have to be discharged via the main exhaust path, the check valve remains firmly closed as long as the pressure in the pressure-bearing section is below a predetermined exhaust pressure threshold. Thus, in one aspect, the check valve is not susceptible to oscillations caused by pressure changes or simply by the flow of pressurized air in the pressure-bearing section of the pneumatic device.

[0012] It should be understood that the exhaust direction is generally defined as the direction from the pressure-bearing section of the pneumatic device to the environment. Air can be discharged in the exhaust direction via different exhaust paths or ports.

[0013] Preferably, the sealing device is adapted to block the secondary exhaust path in the exhaust direction and opposite to the exhaust direction in the sealed state.

[0014] Preferably, the sealing device is adapted to change from the normal state to the sealed state when the liquid in the secondary exhaust path exceeds a threshold level. The threshold level can be determined such that the presence of an external medium equal to or below the threshold defines the normal operating conditions of the pneumatic device. The presence of an external medium above the threshold level defines special operating conditions, in which the pneumatic device can be exposed to water from its environment, such as during cleaning, operation in rain or after rain, or when encountering a flood. Thus, it is ensured that the sealing device reliably changes to the sealed state under the said special operating conditions. In particular, the external medium is water. Hereinafter, the term "water" should also be understood to include aqueous liquids and mixed fluids that mainly or to a large extent contain water (such as mud, pond water or swamp water).

[0015] Preferably, the sealing device includes a sealing body and a sealing seat, wherein the sealing body is configured to abut against the sealing seat in a sealing manner in the sealed state. Preferably, the sealing body is adapted to float in water. If the sealing body floats in water or another external medium, it means the principle that the upward force exerted by the water on the sealing body exceeds the gravity. For example, the sealing body includes a polymer, especially polyoxymethylene (POM).

[0016] Preferably, the sealing seat faces downstream in the exhaust direction, and the sealing body is arranged downstream of the sealing seat in the exhaust direction. Thus, the sealing body is pushed towards the sealing seat by a force opposite to the exhaust direction to sealingly block the secondary exhaust path.

[0017] In a preferred embodiment, the sealing body is resting in a first position in the normal state and moves to a second position in the sealed state. In the first position, the sealing body is positioned such that an exhaust flow via the secondary exhaust path is allowed and remains in the normal state as long as no water intrusion into the pneumatic device occurs. In the second position, even after water intrusion into the pneumatic device, the sealing body ensures that the water level inside the pneumatic device does not rise above a specific level or, for example, above the level of the sealing body. To move the sealing body to the second position, the sealing body moves from an abutment surface on the bottom side of the sealing body to a sealing seat on the upper side of the sealing body. It should be noted that in the second position, an exhaust flow via the main exhaust path is still possible, where the secondary flow path is sealed and blocked by the sealing body.

[0018] Preferably, the sealing seat or a section thereof has a normal in the exhaust direction, which has at least one component parallel and co - directional with the exhaust direction in the region of the sealing device. In other words, the scalar product between this normal and the exhaust direction in the region of the sealing device is greater than zero.

[0019] Further preferably, the sealing device further includes a holding part arranged downstream of the sealing body in the exhaust direction, where the sealing body rests at the holding part in the first position in the normal state. In other words, the holding part is arranged to hold the sealing device in the first position and prevent the sealing body from falling along the exhaust direction through the secondary exhaust path. According to one embodiment, the holding part includes the above - mentioned bottom - side abutment surface. Preferably, the holding part is attached to the piston by a snap - fit connection. The abutment surface preferably faces the sealing seat to abut the sealing body, and an inlet leading to the exhaust passage is provided in the abutment surface. In the normal state, the sealing body rests at the abutment surface of the holding part in the first position. At the first position, the sealing body partially overlaps the inlet leading to the exhaust passage. The residual pressure can flow around the sealing body through the part of the inlet leading to the exhaust passage released by the sealing body into the exhaust passage.

[0020] Preferably, the holding part has an exhaust passage extending in the exhaust direction. Further preferably, the exhaust passage at least partially defines the secondary exhaust path. The exhaust passage extending in the exhaust direction preferably communicates with the ambient fluid. Thus, water and other media present in the environment will be guided through the exhaust passage to the sealing body and will meet the sealing body at a predetermined position, where the water or other media are blocked from further movement. Therefore, the threshold level can be easily calculated.

[0021] Preferably, the secondary exhaust path is at least partially defined by a check valve. Thus, the exhaust direction and the exhaust direction extend parallel at least in the region of the check valve. It should be understood that the secondary exhaust path can also extend through the check valve. Thus, a more compact arrangement of the pneumatic device is provided.

[0022] In a preferred embodiment, the one-way valve includes a valve seat, a movable piston, and a spring. The movable piston is configured to selectively abut against the valve seat in the closed state of the one-way valve, and the spring is configured to urge the piston towards the valve seat. Accordingly, the spring force of the spring urging the piston defines a pressure threshold.

[0023] Preferably, the piston at least partially defines a secondary exhaust path. In particular, the secondary exhaust path extends through the piston. Accordingly, a more space-saving arrangement is provided.

[0024] Further preferably, the piston has a receiving space, and a sealing device is arranged in the receiving space. Accordingly, the sealing device can effectively block the secondary exhaust path that preferably extends through the piston.

[0025] Preferably, the one-way valve further has a valve guide including the valve seat, and the valve guide is configured to at least partially receive the movable piston. Preferably, the valve guide has a low-friction surface for guiding the piston. Accordingly, the piston is reliably guided and positioned within the pneumatic device. Since the valve guide includes the valve seat, a more compact arrangement of the one-way valve is provided, allowing for repeatable movement of the piston.

[0026] Preferably, the piston has a plurality of ribs configured to align the piston in the main exhaust path. Preferably, the ribs are configured to align the piston in the valve guide that defines a part of the main exhaust path. Accordingly, the alignment of the piston is improved and unwanted oscillations are reduced.

[0027] Preferably, the piston has a sealing member configured to at least sealingly abut against the valve seat in the closed state of the one-way valve. Preferably, the sealing member includes a rubber part. Accordingly, the sealing member improves the sealing of the first exhaust path in the closed state. Even in a challenging environment, the rubber part provides sufficient sealing properties and durability. Preferably, the sealing member is attached to the piston by form fit. In particular, the sealing member is formed as a sealing ring, and the piston has a groove corresponding to the sealing ring, wherein the sealing ring is received in the groove.

[0028] Preferably, the sealing member extends at least partially along the piston. In particular, the sealing portion includes an elastomeric layer extending along the piston. Suitable sealing materials generally have low stiffness and thus sufficient damping properties.

[0029] Preferably, the piston further includes a damping member having a rubber part. The damping member may preferably be disposed between the upper section of the piston and the valve guide. The elastomeric layer according to an embodiment of the present invention is configured to damp the oscillatory movement experienced by the piston when the exhaust gas passes through, for example, the main exhaust path. Preferably, the damping member is attached to the piston by form fit. In particular, the damping member includes one or more O-rings received in corresponding grooves of the piston.

[0030] Preferably, the sealing device is adapted to sealingly block the secondary exhaust path in a direction opposite to the exhaust direction in a sealed state and to allow the flow through the secondary exhaust path in the exhaust direction in a normal state. Thus, even in an environment where the liquid level is higher than a predetermined threshold level, the residual pressure can still be discharged while preventing the intrusion of liquid.

[0031] In a second aspect, the present invention relates to a braking system including the pneumatic device according to the first aspect of the present invention. By having such a pneumatic device, the braking system enjoys the above-mentioned advantages regarding the pneumatic device. Thus, the preferred embodiments and benefits of the pneumatic device according to the first aspect are also the preferred embodiments and benefits of the braking system according to the second aspect. Therefore, reference is made to the above description of the pneumatic device according to the first aspect of the present invention, particularly the description of the dependent claims. Preferably, the pneumatic device of the braking system is a brake valve device of the braking system.

[0032] According to a third aspect of the present invention, the above problem is solved by a method for exhausting a pressure-bearing section of a pneumatic device (in particular, the pneumatic device according to the first aspect of the present invention), the method comprising the following steps: a) providing a check valve in the main exhaust path, wherein the check valve is configured to enable the pressure-bearing section to exhaust along the exhaust direction when the pressure in the pressure-bearing section exceeds a predetermined pressure threshold; b) when the pressure in the pressure-bearing section exceeds the predetermined pressure threshold, exhausting the pressure-bearing section along the exhaust direction via the check valve; c) providing a sealing device in a secondary exhaust path adapted to switch at least between a normal state and a sealed state; d) discharging the residual pressure lower than the predetermined pressure threshold from the pressure-bearing section along the exhaust direction via the sealing member; and e) preventing fluid from intruding into the secondary exhaust path by switching the sealing device from the normal state to the sealed state.

[0033] It should be understood that, as described with respect to the first aspect of the present invention, the method of combining exhausting the pressure-bearing section along the exhaust direction via a one-way valve and exhausting the residual pressure along the exhaust direction via a sealing member has aspects similar or equivalent to those of the first aspect of the present invention, especially when they are described in the dependent claims. Therefore, reference is made to the above description of the pneumatic device according to the first aspect of the present invention.

[0034] Preferably, step e) includes providing a fluid in the secondary exhaust path of the pneumatic device above a threshold level and moving the sealing device from the normal state to the sealed state. In the normal state of the sealing device, fluid can flow through the secondary exhaust path in the exhaust direction, and the secondary exhaust path is sealed and blocked at least in a direction opposite to the exhaust direction in the sealed state of the sealing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In the drawings:

[0036] Figure 1 A schematic layout of a vehicle having a braking system including a pneumatic device according to the present invention is shown;

[0037] Figure 2a A schematic diagram of a pneumatic device according to a first embodiment of the present invention is shown;

[0038] Figure 2b A schematic diagram of a pneumatic device according to a second embodiment of the present invention is shown;

[0039] Figure 2c A schematic diagram of a pneumatic device according to a third embodiment of the present invention is shown;

[0040] Figure 3 A cross-sectional view of a pneumatic device according to the present invention in the normal state is shown; and

[0041] Figure 4 A cross-sectional view of a pneumatic device according to the present invention in the exhaust state is shown. DETAILED DESCRIPTION OF THE INVENTION

[0042] As Figure 1As shown, the vehicle 200 (especially a commercial vehicle) includes a front axle 204 and a rear axle 206. In order to brake the front wheels 208.1, 208.2 of the front axle 204 and the rear wheels 210.1, 210.2 of the rear axle 206, the vehicle 200 may include a braking system 100, which has a front axle braking circuit 102 for braking the front wheels 208.1, 208.2 and a rear axle braking circuit 104 for braking the rear wheels 210.1, 210.2. In order to brake the wheels 208.1, 208.2, 210.1, 210.2, the braking system 100 includes front axle brake actuators 106.1, 106.2 and rear axle brake actuators 108.1, 108.2. The front axle brake actuators 106.1, 106.2 are connected to a front axle brake modulator 110, and the rear axle brake actuators 108.1, 108.2 are connected to a rear axle brake modulator 112. In order to provide compressed air under supply pressure, the braking system 100 includes a compressed air supplier 114. Of course, it may include more than one air supplier.

[0043] In order to brake the vehicle 200, supply is required, especially to supply braking pressure to the front axle brake modulator 110 and the rear axle brake modulator 112. In order to provide braking pressure, the braking system 100 includes a pneumatic device 1 (see Figure 3 and Figure 4 ). In the Figure 1 illustrated embodiment, the pneumatic device 1 is a brake valve device 10.

[0044] The brake valve device 10 includes a lower housing 2 having a supply connection 7, a working connection 9 and an exhaust section 12. The exhaust section 12 includes an exhaust path 15 (see FIGS. 2 to 5). The supply connection 7 is connected via a supply line 120.1 to the compressed air supplier 114 for receiving pressurized air under supply pressure.

[0045] When actuated by a user or an electronic control unit (such as a unit for autonomous driving), the brake valve device 10 provides a braking pressure corresponding to the degree of actuation provided by the user or the corresponding signal. In order to allow actuation, the brake valve device 10 includes an actuation element 14, which in this embodiment is formed as a brake pedal. The brake valve device 10 is configured to modulate the braking pressure supplied to the working connection 9 depending on the degree of actuation of the actuation element 14. If the brake pedal 14 is only slightly actuated, a low braking pressure is supplied to the working connection 9, while when the brake pedal 14 is fully actuated, a high braking pressure is supplied to the working connection 9.

[0046] The brake valve device 10 is connected to the front axle brake modulator 110 and the rear axle brake modulator 114 via connecting pipelines 116 and 118 respectively. In this embodiment, the brake valve device 10 is formed as a single-circuit brake valve device 10 having only one working connection 9 for providing brake pressure. The front axle connecting pipeline 116 that connects the brake valve device 10 to the front axle brake modulator 110 and the rear axle connecting pipeline 118 that connects the brake valve device 10 to the rear axle brake modulator 112 are both connected to the same working connection 9 of the brake valve device 10.

[0047] In other embodiments, the brake valve device 10 can also be formed as a multi-circuit brake valve device 10 having a plurality of working connections 9 for supplying the same and / or different brake pressures to the brake circuits 102, 104.

[0048] The brake modulators 110, 112 receive the brake pressure provided by the brake valve device 10 and transfer it to the corresponding brake actuators 106.1, 106.2, 108.1, 108.2. Therefore, the brake modulators 110, 112 are also connected to the compressed air supplier via supply pipelines 120.2, 120.3. It should be noted that the front axle brake modulator 110 and / or the rear axle brake modulator 112 can also be configured to further modify the brake pressure. For example, the front axle brake modulator 110 can include an anti-lock braking system module (not shown) for providing the ABS function. In addition, the brake actuators 106.1, 106.2, 108.1, 108.2 can also be directly connected to the brake valve device 10.

[0049] To release the brakes of the vehicle 200, it is necessary to release the brake pressure from the brake actuators 106.1, 106.2, 108.1, 108.2. Therefore, the brake valve device 10 is configured to exhaust the brake actuators 106.1, 106.2, 108.1, 108.2 by connecting the working connection 9 to the exhaust section 12. To discharge the pressurized air, it is necessary to release the air to the environment through an opening. However, such an opening allows water to enter the brake system 100.

[0050] Brake valve devices, especially those with a brake pedal, or in some cases, even the brake modulators 110 and 112, are typically located at a relatively low position compared to the chassis of the vehicle 200. This limits the maximum wading depth of the vehicle 200 because when driving the vehicle 200 through water and the water level reaches the exhaust section, water can invade the brake system 100 via, for example, the exhaust section 12 of the brake valve device 10 and via the corresponding exhaust ports of the brake modulators 110 and 112. However, it should be noted that water intrusion can be considered a general problem for any brake valve (including brake modulators) in vehicles with a reduced ground clearance, such as buses.

[0051] In a conventional vehicle, the available maximum wading depth is sufficient, and standard brake valve device components can be used. However, if an increased wading depth is required, special measures need to be taken. Therefore, a wading form of the brake valve device and / or the brake valve device assembly and / or the brake modulator is disclosed in the present invention.

[0052] In Figure 1 it is shown that the brake valve device 10 has a housing 3 for receiving electronic components, and the housing 3 is connected to the exhaust port 11. The damping chamber 11 can be provided by an exhaust muffler. To release the brakes of the vehicle 200, the brake pressure is released from the brake actuators 106.1, 106.2, 108.1, 108.2 via the connecting pipelines 116, 118, the brake valve device 10, the housing 3 for receiving electronic components, the exhaust pipeline 122 and then via the exhaust port 11.

[0053] Figure 2a A pneumatic device 1 is shown, for example, an axle modulator 20. As shown in the schematic diagram according to Figure 2a the pneumatic device 1 according to the present invention includes a pressure-bearing section 15 that is in fluid communication with the main exhaust path 17 for discharging pressurized air in the exhaust direction R. The pneumatic device 1 includes a check valve 19 arranged in the main exhaust path 17. For example, in the case where the pressure in the pressure-bearing section 15 exceeds a predetermined exhaust pressure threshold, the check valve 19 is configured such that the pressure-bearing section 15 can exhaust along the exhaust direction R. In this way, the exhaust of the pressure-bearing section 15 via the main exhaust path 17 and the check valve 19 meets the exhaust response time requirements of the brake system 100 of the vehicle 200 (see Figure 1 ).

[0054] The check valve 19 is configured to allow the pressure-bearing section 15 to exhaust in the exhaust direction R and prevent any fluid from invading in the opposite direction. Therefore, liquid from the environment cannot pass through the check valve 19.

[0055] The pneumatic device 1 further includes a secondary exhaust path 21 that is in fluid communication with the pressure-bearing section 15. The pneumatic device 1 has a sealing device 23 disposed in the secondary exhaust path 21, and the sealing device 23 is adapted to switch at least between a normal state Z1 and a sealed state Z2. In the normal state Z1 of the sealing device 23, it is possible to flow through the secondary exhaust path 21 in the exhaust direction R in order to discharge the residual pressure. Generally speaking, the residual pressure is lower than a predetermined exhaust pressure threshold. In the sealed state Z2, the sealing device 23 sealingly blocks the secondary exhaust path 21. Therefore, the sealing device 23 is configured to prevent flow through the secondary exhaust path 21 in the sealed state Z2.

[0056] To switch from the normal state Z1 to the sealed state Z2, the sealing device 23 moves from a first position P1 to a second position P2. Preferably, the first position P1 is downstream of the second position P2 in the exhaust direction R. Preferably, the sealing device 23 is adapted to change from the normal state Z1 to the sealed state Z2 when the liquid in the secondary exhaust path 21 exceeds a threshold level S.

[0057] Figure 2b A second embodiment of the pneumatic device 1 is shown. Refer to Figure 2a the description of the embodiment shown. Figure 2b The embodiment shown is different from Figure 2a the embodiment shown in that a spring 35 that urges the one-way valve 19 towards its closed state Z3. In the open state Z4 indicated by the dashed line, it is possible to flow through the main exhaust path 17 in the exhaust direction R.

[0058] Figure 2c A third embodiment of the pneumatic device 1 is shown. Refer to Figure 2a and Figure 2b the description of the embodiment shown in. Figure 2c The embodiment shown in is different from Figure 2b the embodiment shown in that the exhaust direction R and the exhaust direction R extend parallel to a section of the one-way valve 19 and the secondary exhaust path 21. The one-way valve 19 partially defines the secondary exhaust path 21. The sealing device 23 is disposed in the receiving space 37 of the one-way valve 19. Similar to the explanation provided regarding Figure 2b the sealing device 23 can float in water and close the secondary exhaust path 21 to prevent water intrusion. However, when the water moves the sealing device 23 to close the secondary exhaust path 21, the exhaust direction R can be used for the pressurized air to be discharged from the pressure-bearing section 15 towards the main exhaust path 17.

[0059] Figure 3 The pneumatic device 1 shown is an axle modulator 20, which includes a lower housing 2 and a relay valve piston 3. The operation of the axle modulator 20 according to this embodiment is as follows.

[0060] When receiving control pressure via control port 3.1, relay valve piston 3 reciprocates linearly within housing 2. Relay valve piston 3 includes an impact portion 3.2 that strikes against relay valve seat 92 to overcome the extension force of spring 35, thereby moving relay valve seat 92. Until this point, relay valve seat 92 is held in its position by stopper 99 against the extension force of spring 35.

[0061] In any case, when relay valve seat 92 moves downward, a connection between inlet port 94 and chamber 96 is established. This causes pressurized air leaving via outlet port 98 to ultimately be received in one or more of actuators 106.1, 106.2, 108.1, and 108.2 for applying braking.

[0062] However, during situations such as when it is necessary to activate the parking brake, when an air flow occurs via port 98 towards main exhaust path 17, such air flow passes through check valve 19, then to a muffler or damping chamber, then to exhaust port 11, and finally reaches the environment 5. Thus, when an air flow occurs via port 98 towards path 17, in this case, pressure-bearing section 15 can also receive air because it is connected to chamber 96 and / or port 98 and / or environment 5.

[0063] Figure 3 The check valve 19 and sealing device 23 are shown in more detail in Figure 4 and reference is made to the following description.

[0064] Sealing device 23 includes a sealing body 25 and a sealing seat 27. Sealing body 25 is spherical and is preferably adapted to float on water. Sealing seat 27 is arranged above sealing body 25 in the shown arrangement.

[0065] In Figure 4 sealing device 23 is shown in its normal state Z1, in which sealing body 25 rests at holding portion 28. Holding portion 28 is arranged downstream of sealing body 25 in the exhaust direction R. Spherical sealing body 25 is configured to abut sealingly against sealing seat 27 in a sealed state Z2, or to rest sealingly against abutting surface 28.1 of holding portion 28 in other states. Sealing seat 27 faces downstream in the exhaust direction R (see Figure 2c ). Sealing body 25 is arranged downstream of sealing seat 27 in the exhaust direction R.

[0066] Holding portion 28 preferably holds spherical sealing body 25 in a position close to sealing seat 27 via abutting surface 28.1.

[0067] Under the influence of gravity, sealing body 25 rests on or at abutting surface 28.1. When in direction R (see the comparisonFigures 2a to 2c and Figure 4 When an exhaust gas flow occurs at Figure 4 , the pressure of the exhaust gas pushes the piston 33 in the direction R against the resistance of the spring 35. Note that during the exhaust gas flow in the direction R, the sealing body 25 is firmly seated on the abutment surface 28.1 in its normal state Z1. When the piston 33 moves downward in the direction R, as the valve seat 31 moves in the direction R together with the piston 33, the sealing member 43 is lifted away from the valve seat 31. It can be understood that this creates a gap between the sealing member 43 and the valve seat 31, which defines a part of the main exhaust path 19 through which the exhaust gas flows and reaches the muffler 101 (see Figure 3 ), and from there to the exhaust port 11 (see Figure 1 ).

[0068] On the other hand, in the case where water or any other fluid in the sub-exhaust path 21 exceeds a predetermined threshold level S (see Figures 2a to 2c ), the sealing body 25 will float on the water and thus be lifted from the abutment surface 28.1 and move to contact the sealing seat 27 in its sealed state Z2. Thus, the sub-exhaust path 21 is blocked and unwanted water intrusion is avoided. It should be noted that when the water lifts the sealing body 25 and closes the path 21, exhaust in the direction R is still possible because, as described above, due to the exhaust gas pressure, the piston 33 moves in the direction R, creating a gap between the valve seat 31 and the sealing member 43.

[0069] Preferably, the holding part 28 is attached to the piston 33 by a snap connection.

[0070] The holding part 28 has an exhaust passage 29 extending in the exhaust direction R. The exhaust passage 29 partially defines the sub-exhaust path 21. The one-way valve 19 has a receiving space 37 at the piston 33. At least a part of the holding part 28 and the sealing body 25 are received in the receiving space 37. The sealing seat 27 is provided by the one-way valve 19 at the entrance of the receiving space 37 above the sealing body 25. Thus, the sub-exhaust path 21 is partially defined by the one-way valve 19.

[0071] Figure 4The check valve 19 therein is shown in the closed state Z3. The check valve 19 includes a piston 33 which is configured to selectively abut against a valve seat 31 in the closed state Z3 of the check valve 19. A spring 35 is guided by an annular surface of the piston 33 and abuts against a spring seat 36 provided by the piston 33. The piston 33 is movably received in a valve guide 39 including the valve seat 31. Thus, when an exhaust flow occurs in the direction R, since the sealing body 25 firmly abuts against the abutting surface 28.1, the piston 33 linearly moves downward in the direction R, which is oriented in this direction by means of the valve guide 39. In addition, a residual pressure below a predetermined value for moving the piston 33 can be discharged via a secondary exhaust path 21, where the sealing body 25 abuts against the abutting surface 28.1.

[0072] It can be noted that Figure 4 a damping member 44 having a rubber member 45 is shown, which is arranged between the piston 33 and the valve guide 39. According to Figure 4 the present illustration in, the purpose of the damping member 44 is to damp any oscillatory movement occurring between the piston 33 and the valve guide 39 due to an exhaust flow (at a relatively high pressure). The damping member 44 includes a first damping ring 44.1 and a second damping ring 44.2, and the piston 33 has corresponding first grooves 46 configured to receive the damping rings 44.1, 44.2.

[0073] According to Figure 4 the embodiment shown, one of the technical advantages of using the damping member 44 is that the generated exhaust noise is reduced by damping the oscillatory movement during exhaust.

[0074] On the other hand, the sealing member 43 ensures the state that an airtight interface is provided at the junction of the sealing member 43 and the valve seat 31 when the piston 33 does not move. In addition, the piston 33 has a second groove 47 configured to receive the sealing member 43 formed as a sealing ring. The sealing member 43 preferably has a rubber member 48.

[0075] List of reference numerals (a part of the specification)

[0076] 1 Pneumatic device

[0077] 2 Lower housing

[0078] 3 Relay valve piston

[0079] 3.1 Control port

[0080] 3.2 Impact part

[0081] 5 Environment

[0082] 7 Supply connection

[0083] 9 Working connection member

[0084] 10 Brake valve device

[0085] 11 Exhaust port

[0086] 12 Exhaust part

[0087] 14 Actuating element

[0088] 15 Pressure-bearing section

[0089] 17 Main exhaust path

[0090] 19 Check valve

[0091] 20 Axle modulator

[0092] 21 Secondary exhaust path

[0093] 23 Sealing device

[0094] 25 Sealing body

[0095] 27 Sealing seat

[0096] 28 Holding part

[0097] 28.1 Contact surface

[0098] 29 Exhaust passage

[0099] 31 Valve seat

[0100] 33 Piston

[0101] 35 Spring

[0102] 36 Spring seat

[0103] 37 Receiving space

[0104] 39 Valve guide

[0105] 41 Upper section of the piston

[0106] 43 Sealing member

[0107] 44 Damping member

[0108] 44.1, 44.2 Damping rings

[0109] 45 Elastomer, rubber part of the damping member

[0110] 46 (First) groove

[0111] 47 Second groove

[0112] 48 Rubber part of the sealing member

[0113] 92 Relay valve seat

[0114] 94 Inlet port

[0115] 96 Chamber

[0116] 98 Outlet port

[0117] 99 Stopper

[0118] 100 Braking system

[0119] 101 Muffler

[0120] 102 Front axle braking circuit

[0121] 104 Rear axle braking circuit

[0122] 106.1, 106.2 Front axle brake actuator

[0123] 108.1, 108.2 Rear axle brake actuator

[0124] 110 Front axle brake modulator

[0125] 112 Rear axle brake modulator

[0126] 114 Compressed air supply

[0127] 116 Front axle connecting pipeline

[0128] 118 Rear axle connecting pipeline

[0129] 120.1, 120.2, 102.3 Supply pipeline

[0130] 122 Exhaust pipeline

[0131] 200 Vehicle

[0132] 204 Front axle

[0133] 206 Rear axle

[0134] 208.1, 208.2 Front wheels

[0135] 210.1, 210.2 Rear wheels

[0136] F Liquid

[0137] R Exhaust direction

[0138] Z1 Normal state

[0139] Z2 Sealed state

[0140] Z3 Exhaust state

[0141] S Threshold level

[0142] P1 First position

[0143] P2 Second position.

Claims

1. A pneumatic device (1) for a pneumatic braking system (100) of a vehicle (200), the pneumatic device (1) comprising: a main exhaust path (17) for discharging pressurized air along an exhaust direction (R); a check valve (19) arranged in the main exhaust path (17) and configured to enable the pressurized air to be discharged along the exhaust direction (R) when the pressure exceeds a predetermined exhaust pressure threshold; a secondary exhaust path (21) for discharging residual pressure from a pressure-bearing section (15) along the exhaust direction (RR); and a sealing device (23) arranged in the secondary exhaust path (21) and adapted to switch at least between a normal state (Z1) and a sealed state (Z2), wherein, in the normal state (Z1) of the sealing device (23), it is possible to flow through the secondary exhaust path (21) in the exhaust direction (R), and in the sealed state (Z2) of the sealing device (23), the secondary exhaust path (21) is at least sealedly blocked in a direction opposite to the exhaust direction (R).

2. The pneumatic device (1) according to claim 1, wherein, the sealing device (23) is adapted to change from the normal state (Z1) to the sealed state (Z2) when the intrusion level of a liquid (F) in the secondary exhaust path (21) exceeds a threshold level (S).

3. The pneumatic device (1) according to any one of the preceding claims, wherein, the sealing device (23) includes a sealing body (25) and a sealing seat (27), wherein the sealing body (25) is configured to abut against the sealing seat (27) in a sealed manner in the sealed state (Z2).

4. The pneumatic device (1) according to claim 3, wherein, the sealing body (25) is adapted to float on water.

5. The pneumatic device (1) according to any one of claims 3 or 4, wherein, the sealing seat (27) faces downstream (R) in the exhaust direction (R), and wherein the sealing body (25) is arranged downstream of the sealing seat (27) in the exhaust direction (R).

6. The pneumatic device (1) according to any one of claims 4-5, wherein, the sealing body (25) rests at a first position (P1) in the normal state (Z1) and moves to a second position (P2) in the sealed state (Z2), and wherein the first position (P1) is downstream of the second position (P2) in the exhaust direction (R).

7. The pneumatic device (1) according to any one of claims 5 or 6, wherein, the sealing device (23) further includes a holding part (28) arranged downstream of the sealing body (25) in the exhaust direction (R), and Wherein, in the normal state (Z1), the sealing body (25) rests on the holding part (28) at the first position (P1).

8. The pneumatic device (1) according to claim 7, wherein, the holding part (28) has an exhaust passage (29) extending in the exhaust direction (R), and the exhaust passage (29) at least partially defines the secondary exhaust path (21).

9. The pneumatic device (1) according to any one of the preceding claims, wherein, the one-way valve (19) includes: a valve seat (31); a moving piston (33) configured to selectively abut against the valve seat (31) in the closed state (Z3) of the one-way valve (19); and a spring (35) configured to urge the piston (33) towards the valve seat (31).

10. The pneumatic device (1) according to claim 9, wherein, the secondary exhaust path (21) is at least partially defined by the one-way valve (19), in particular, the secondary exhaust path (21) extends through the piston (33).

11. The pneumatic device (1) according to claim 9 or 10, wherein, the piston (33) has a damping member (44) including a rubber member (45) and is configured to damp the oscillation of the piston (33).

12. The pneumatic device (1) according to claim 11, wherein, the damping member (44) is attached to the piston (33) by form fit, preferably, the damping member (44) includes one or more damping rings (44.1, 44.2), and the piston (33) has corresponding grooves (46) configured to receive the damping rings (44.1, 44.2).

13. The pneumatic device (1) according to any one of claims 10, 11 or 12, wherein, the piston (33) has a receiving space (37), and the sealing device (23) is arranged in the receiving space (37).

14. The pneumatic device (1) according to any one of claims 10 - 13, wherein, the one-way valve (19) further has a valve guide (39) including the valve seat (31) and configured to at least partially receive the moving piston (33).

15. The pneumatic device (1) according to any one of claims 10 - 14, wherein, the piston (33) has a sealing member (43) configured to at least sealingly abut against the valve seat (31) in the closed state (Z3) of the one-way valve (19), wherein the sealing member (43) includes a rubber member (48).

16. The pneumatic device (1) according to any one of claims 14 or 15, wherein, the sealing member (43) is attached to the piston (33) by form fit.

17. The pneumatic device (1) according to any one of claims 13 - 16, wherein, The sealing member (43) is attached to the piston (33) by form fit, in particular, the sealing member (43) is formed as one or more sealing rings. Wherein, the groove (46) is a first groove (46), and the piston (33) has a corresponding second groove (47), which is configured to receive the sealing member (43).

18. The pneumatic device (1) according to any one of the preceding claims. Wherein, The sealing device (23) is adapted to sealingly block the secondary exhaust path (21) in a direction opposite to the exhaust direction (R) in the sealed state (Z2), and also enables flow through the secondary exhaust path (21) in the exhaust direction (R).

19. A pneumatic braking system (100) of a vehicle (200), comprising the pneumatic device (1) according to any one of the preceding claims, in particular a brake valve device (10) or an axle modulator (20).

Images