Relay valve for compressed air system of vehicle

Abstract

The invention relates to a relay valve for a compressed air system of a vehicle, comprising a housing, a pressure medium inlet, a pressure medium outlet, a control inlet, a relief, and a relay valve piston having a radially outer edge and a central through-opening into which a guide tube of the housing protrudes, the relay valve piston is movably guided on a radial inner wall of the housing by means of a radial outer edge and is movably guided on a radial outer circumferential surface of the guide tube by means of a radial inner circumferential surface of the through-opening, a sealing arrangement is provided by means of which the relay valve piston is sealed against the radial inner wall of the housing on one hand and against the radial outer circumferential surface of the guide tube on the other hand, the sealing assembly comprises a sealing element, which has a first sealing surface and a second sealing surface facing away from the first sealing surface, and is designed to seal the guide tube with respect to the radial outer circumferential surface of the guide tube. The relay valve piston is sealed with respect to a radial inner wall portion of the housing by means of the first sealing surface and with respect to a radial outer peripheral surface of the guide tube by means of the second sealing surface.

Description

Technical field

[0001] The invention relates to a relay valve for a compressed air installation for a vehicle according to the preamble of claim 1, an electro-pneumatic module having such a relay valve according to claim 17, a compressed air installation for a vehicle having such an electro-pneumatic module according to claim 18, and a vehicle having such a compressed air installation according to claim 19. Background art

[0002] A relay valve of this genus is known from EP 1 844 999 A1. The sealing elements therein include a first sealing element and a second sealing element. The first sealing element is fixed in a groove in the radially outer edge of an annular part of the relay valve piston and seals relative to the radially inner wall part of the housing. The second sealing element is fixed in a recess in the guide tube of the housing and seals relative to the radially outer peripheral surface of the guide tube. Here, the first sealing element has a dynamic (moving) first sealing surface and a static second sealing surface. The first sealing surface seals relative to the radially inner wall part of the housing, and the second sealing surface seals relative to the groove in the radially outer edge. Similarly, the second sealing element has a dynamic (moving) third sealing surface and a static fourth sealing surface. The third sealing surface seals relative to the radially outer wall part of the guide tube, and the fourth sealing surface seals relative to the recess in the radially outer peripheral surface of the guide tube. Thereby, the number of static and dynamic sealing sites is relatively large, that is, a total of at least four sealing surfaces are required, which also results in a relatively high production cost and assembly cost of the relay valve. Summary of the invention

[0003] The invention is based on the following task: to provide a relay valve that can be produced and assembled more simply. Similarly, an electro-pneumatic module having such a relay valve, a compressed air installation for a vehicle having such an electro-pneumatic module, and a vehicle having such a compressed air installation should be provided.

[0004] This task is solved by the features of claims 1, 17, 18, and 19.

[0005] The relay valve according to the invention is an air volume - enhancing, pneumatically controlled valve that controls a large compressed air volume with a small compressed air volume. The large compressed air volume is, for example, used for the brake cylinder of a compressed air brake of a vehicle. For this purpose, the relay valve has a relay valve piston that acts as a control piston. The relay valve piston can be loaded with a control pressure via a control chamber on one side and can be loaded with a working pressure provided by a consumer via a working chamber and a pressure medium output connected thereto on the other side. An inlet valve is arranged between the charging chamber and the working chamber. The charging chamber can be connected to a pressure medium source via a pressure medium input, and the working chamber can be connected to a consumer via a pressure medium output. An exhaust valve is arranged between the working chamber and a bleed section leading to the atmosphere.

[0006] If the control chamber is loaded with a control pressure, the relay valve piston moves into the working chamber. By the movement of the relay valve piston, first the exhaust valve is closed and then the inlet valve is opened. Thereby, pressure is established in the working chamber, and this pressure acts against the control pressure on the relay valve piston. In the case of an equilibrium state of the interacting pressures, the relay valve piston moves back against its initial movement. The inlet valve closes without opening the exhaust valve, so that this pressure remains in the working chamber and below the pressure medium output. When the control chamber is vented, the relay valve piston moves further in the opposite direction to its initial movement direction, and the exhaust valve opens until the pressure in the working chamber drops to a value at which there is again a force equilibrium state on the relay valve piston and the exhaust valve closes again. When the control chamber is completely vented, the working chamber and thus the downstream - connected consumer are also completely vented.

[0007] The relay valve can be integrated together with other components in a valve device. Here, the valve device can be, for example, an electronic air preparation device, an electronic pneumatic parking brake module, or an electronic pneumatic pressure regulation module.

[0008] The invention discloses a relay valve for a compressed air installation of a vehicle, which relay valve at least has the following:

[0009] a) A housing and a pressure medium input constructed on or in the housing and connectable to a compressed air source, at least one pressure medium output connectable to a consumer, at least one control input, at least one bleed section leading to the atmosphere, and at least one relay valve piston guided along an axis in the housing, wherein,

[0010] b) The relay valve piston has a radially outer edge and a central through - opening, and a guide tube of the housing extends into the central through - opening, and wherein,

[0011] c) The relay valve piston is guided in a displaceable manner on the radial inner wall portion of the housing by means of its radial outer edge and is guided in a displaceable manner on the radial outer peripheral surface of the guide tube by means of the radial inner peripheral surface of its central through-opening, and wherein,

[0012] d) A sealing assembly is provided, by means of which the relay valve piston is sealed, on the one hand, relative to the radial inner wall portion of the housing (in particular dynamically) and, on the other hand, relative to the radial outer peripheral surface of the guide tube (in particular dynamically).

[0013] For example, when viewed in the circumferential direction, the radial inner wall portion of the housing surrounds the guide tube and the relay valve piston.

[0014] The relay valve is characterized in that,

[0015] e) The sealing assembly includes at least one sealing element, which has a first sealing surface and a second sealing surface pointing away from the first sealing surface, wherein the sealing element is configured to seal the relay valve piston relative to the radial inner wall portion of the housing by means of the first sealing surface and relative to the radial outer peripheral surface of the guide tube by means of the second sealing surface.

[0016] Such a sealing element should be understood as a sealing element that, on the one hand, together with the first and second sealing surfaces, serves as a seal, but on the other hand, also serves, to a limited extent, as a guiding function for guiding the relay valve piston on the radial inner wall portion of the housing and on the radial outer peripheral surface of the guide tube of the housing. For the sealing function and optionally additionally also for the guiding function, the first sealing surface and / or the second sealing surface can have at least one sealing lip. Therefore, preferably, the at least one sealing element can be configured as a lip seal.

[0017] Preferably, the sealing element of the sealing assembly is the only (in particular dynamic) seal between the relay valve piston and the radial outer peripheral surface of the guide tube on the one hand and the radial inner wall portion of the housing on the other hand.

[0018] Therefore, at least one, preferably the only, sealing element of the sealing assembly is only arranged or fixed on the relay valve piston, and in particular all the sealing surfaces of the sealing element are configured on the relay valve piston. Then, the same and in particular the only sealing element of the sealing assembly performs an advantageous dual function in such a way that the sealing element also provides a second sealing function at the same time. In contrast, the guide tube can be configured, for example, as a smooth cylinder. In addition, only three sealing surfaces are required in total, namely the above-mentioned (dynamic) first and second sealing surfaces and the (static) third sealing surface, which is configured and provided to prevent compressed air from penetrating the sealing element relative to the relay valve piston. Overall, this results in a significant simplification of the production and assembly of the relay valve.

[0019] Accordingly, a dynamic sealing surface should be understood as a sealing surface that moves relative to another component. Here, this applies to the first sealing surface of the sealing element and also to the second sealing surface of the sealing element. The first sealing surface moves relative to the radial inner wall portion of the housing parallel to the axis, and the second sealing surface moves relative to the outer peripheral surface of the guide tube parallel to the axis. A static sealing surface, on the other hand, should be understood as a sealing surface that cannot move relative to the component that supports it. Here, this applies to the third sealing surface, which is supported by the relay valve piston and is configured and arranged to prevent compressed air from penetrating the sealing element relative to the relay valve piston.

[0020] Preferably, at least the first sealing surface and the second sealing surface are arranged substantially on the same level relative to the axis. In particular, this axis can be the central longitudinal axis of the relay valve.

[0021] If at least one sealing element is in form-locking connection with the relay valve piston, a particularly good connection between the relay valve piston and the at least one sealing element is produced. Then, the connection between the relay valve piston and the at least one sealing element can be implemented in a particularly additive-free manner.

[0022] It can contribute to further simplifying the manufacture and assembly of the relay valve that the sealing element forms an injection-molded part made of at least one plastic and / or at least one elastomer, which is injection-molded together with at least a section of the relay valve piston. Because then the sealing element and the relay valve piston together form a one-piece structural unit, which can be assembled in the housing in a single assembly step.

[0023] Viewed in cross-section, the sealing element as an injection-molded part can be constructed in a single layer, where the sealing element is completely produced in a single injection process. This variant has the advantage of quickly and simply manufacturing the sealing element.

[0024] Alternatively, viewed in cross-section, the sealing element as an injection-molded part can be constructed in multiple layers, where each of the multiple layers is produced by a separate injection process. This multi-layer construction enables the use of different materials in the process of manufacturing the sealing element. For example, the first layer can form a (rigid) carrier layer made of a first material having a first modulus of elasticity (E-Modul), which is greater than the second modulus of elasticity of the second layer made of a second material. The second layer is in direct contact with the radial inner peripheral surface of the housing, for example, by means of the first sealing surface, and is in direct contact with the outer peripheral surface of the guide tube by means of the second sealing surface.

[0025] Preferably, the sealing element as an injection-molded part can at least partially surround or encircle the above-mentioned section of the relay valve piston, and / or extend into at least one opening of the section of the relay valve piston or also pass through the at least one opening, i.e., protrude through the opening. Here, at least one opening section of the opening can be parallel to the axis. The following implementation is also possible: In this implementation, since at least one seal passes through one or more openings of the section of the relay valve piston, when viewed in cross-section, there is at least one undercut (Hinterschneidung) between the section of the relay valve piston and the at least one sealing element, and this undercut then forms a form-fit between the at least one sealing element and the section of the relay valve piston. In this case, it is also possible to dispense with an adhesion promoter (Haftvermittler) between the at least one sealing element and the section of the relay valve piston.

[0026] However, in the case where there is no such opening in the relay valve piston, an undercut or a form-fit between the at least one sealing element and the section of the relay valve piston can also be constructed, for example, by the following method: at least this section of the relay valve piston is wrapped or injection-molded by the at least one sealing element.

[0027] As described above, the sealing element can have a third sealing surface, which is configured and arranged to prevent compressed air from penetrating the sealing element in the region of the section of the relay valve piston.

[0028] Particularly preferably, the relay valve piston has a tubular part and an annular part. The tubular part has a central inner through-opening, and the annular part protrudes radially outward away from the tubular part. A radially outer edge is formed on the radial outside of the annular part. Here, preferably, the annular part can form the above-mentioned section of the relay valve piston. When viewed in the circumferential direction, the radial inner wall part of the housing preferably also surrounds the annular part and the tubular part of the relay valve piston.

[0029] The annular part can also have a first end face and a second end face perpendicular to the axis respectively, and the sealing element covers at least a part of the first end face and / or the second end face. An undercut between the sealing element and the section of the relay valve piston can also be formed thereby. In addition, when the relay valve piston abuts against a section of the housing by means of the first end face and / or the second end face, especially in at least one end position (Endlage), the sealing element can also form an elastic abutment surface for the relay valve piston relative to the housing.

[0030] The tubular part of the relay valve piston can also be implemented hollowly and form a part of the air release channel, which is connected to the air release part of the relay valve.

[0031] Particularly preferably, the (dynamic) first sealing surface and the (dynamic) second sealing surface seal the control chamber of the relay valve, which is connected to the control input, relative to the working chamber of the relay valve, which is connected to the pressure medium output, and seal the control chamber of the relay valve relative to the venting chamber of the relay valve. Preferably, the sealing element is the only (in particular dynamic) seal between the control chamber, the working chamber and the venting chamber.

[0032] As described above, the first sealing surface and / or the second sealing surface of the sealing element may have at least one sealing lip, which then interacts with the radially inner peripheral surface of the wall of the housing or with the radially outer peripheral surface of the guide tube.

[0033] The sealing lip is preferably arranged at an acute angle relative to a plane perpendicular to the axis in order to produce a pre-tensioning relative to the surface to be sealed.

[0034] If, according to an extension of this embodiment, at least the first sealing surface has two sealing lips, which are arranged at a distance from one another in the direction of the axis, and the intermediate space between the two sealing lips is connected to the venting section via an internal passage of the relay valve piston, an improved sealing effect is produced. The background of this measure is that, as described above, the sealing lips are arranged obliquely and a certain pre-tensioning against the surface to be sealed, here for example against the radially inner wall of the housing, is required for sufficient sealing effect. Such a pre-tensioning of the sealing lips can be produced by a sufficient pressure difference between the control chamber and the working chamber, but this pressure difference only occurs rarely. Since the intermediate space between the two sealing lips is now connected to the venting section and thus to the atmosphere, a pressure difference is created between the intermediate space on the one hand and the working chamber on the other hand and the control chamber on the other hand, which is sufficient to pre-tension the two obliquely arranged sealing lips against the radially inner wall of the housing and thus improve the sealing effect.

[0035] The invention also provides an electro-pneumatic module for a compressed air installation of a vehicle, which electro-pneumatic module comprises at least one relay valve as described above, and also provides a compressed air installation of a vehicle, which compressed air system comprises at least one such electro-pneumatic module, and provides a vehicle having such a compressed air installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Below, embodiments of the invention are shown in the drawings and explained in more detail in the following description. Shown in the drawings:

[0037] Figure 1 A partial cross-sectional view of a relay valve according to the invention in a preferred embodiment;

[0038] Figure 2 Shown Figure 1 an enlarged fragment;

[0039] Figure 3 Partial cross-sectional view of a relay valve according to the invention in another embodiment is shown. Detailed implementation

[0040] Figure 1 Partial cross-sectional view of a relay valve 1 according to the invention in a preferred embodiment is shown. Here, for example, a pneumatic relay valve 1 controls a large amount of compressed air with a small amount of compressed air. The large amount of compressed air is, for example, used for the brake cylinder of a compressed air brake of a vehicle. For this purpose, the relay valve 1 has a relay valve piston 2 that acts as a control piston. The relay valve piston delimits a control chamber 3 on one side and a working chamber 4 on the other side. The control chamber can be loaded with a control pressure via a control attachment end (not shown here), and the working chamber can be loaded with a working pressure provided by a consumer via a pressure medium output end (not shown here). An intake valve 6 is arranged between an inflation chamber 5 and the working chamber 4. The inflation chamber can be connected to a pressure medium source via a pressure medium input end (not shown here), and the working chamber can be connected to a consumer via a pressure medium output end. An exhaust valve 8 is arranged between the working chamber 4 and a deflation chamber 7. The deflation chamber is connected to a deflation part leading to the atmosphere (not shown here). The intake valve 6 and the exhaust valve 8 together form a double-seat valve that can be actuated by the relay valve piston 2.

[0041] If the control chamber 3 is loaded with a control pressure, the relay valve piston 2 moves into the working chamber 4. Due to the movement of the relay valve piston 2, first the exhaust valve 8 is closed, and then the intake valve 6 is opened. Thereby, pressure is established in the working chamber 8, and this pressure acts against the control pressure on the relay valve piston 2. In the case of a balanced state of the interacting pressures, the relay valve piston 2 moves back against its initial movement. The intake valve 6 closes without opening the exhaust valve 8, so that the pressure remains in the working chamber 4 and below the pressure medium output end.

[0042] When the control chamber 3 is deflated, the relay valve piston 2 moves further in the opposite direction to its initial movement direction, and the exhaust valve 8 opens until the pressure in the working chamber 4 drops to a value at which there is again a force balance state on the relay valve piston 2 and the exhaust valve 8 closes again. When the control chamber 3 is completely deflated, the working chamber 4 and thus the downstream-connected consumer (here, for example, the brake cylinder) are also completely deflated.

[0043] Specifically, the relay valve 1 has the following: a housing 9, a pressure medium input end that can be connected to a compressed air source, a pressure medium output end that can be connected to a consumer, a control input end, a bleeding section leading to the atmosphere, and a relay valve piston 2 guided along an axis 10 in the housing. The pressure medium input end, the pressure medium output end, the control input end, and the bleeding section are configured on or in the housing 9. The axis 10 can be the central longitudinal axis of the relay valve 1 as shown here.

[0044] The relay valve piston 2 has a radial outer edge 11 and, for example, a central inner through-opening 12 here. The guide tube 13 of the housing extends into this inner through-opening to guide the relay valve piston 2 in the direction of the axis 10. Particularly preferably, the relay valve piston 2 has a tubular part 14 and an annular part 15. The tubular part has the through-opening 12, and the annular part preferably projects radially outward from the tubular part 14 on the end side. The radial outer edge 11 is configured on the annular part. Preferably, the tubular part 14 of the relay valve piston 2 is hollow and forms, for example, part of a central bleeding channel 16 here, which is connected to the bleeding chamber 7 of the relay valve 1.

[0045] The relay valve piston 2 is guided in a movable manner on the radial inner wall part 17 of the housing 9 by means of the radial outer edge 11 and is guided in a movable manner on the radial outer peripheral surface 18 of the guide tube 13 by means of the radial inner peripheral surface of its radial inner through-opening 12. Additionally, a sealing assembly 19 is provided. The radial outer edge of the annular part 15 of the relay valve piston 2 is sealed by this sealing assembly against the radial inner wall part 17 of the housing 9 on the one hand and against the radial outer peripheral surface 18 of the guide tube 13 of the housing 9 on the other hand.

[0046] Viewed in the circumferential direction, the radial inner wall part 17 of the housing 9 surrounds the guide tube 13. The guide tube is preferably configured as a smooth cylinder on its radial outer peripheral surface and guides the relay valve piston 2 by means of this smooth cylinder-shaped radial outer peripheral surface 18. A narrow annular gap 20 is preferably configured between the smooth cylinder-shaped radial outer peripheral surface 18 of the guide tube 13 and the likewise preferably smooth cylinder-shaped radial inner peripheral surface of the tubular part 14 of the relay valve piston 2, and this annular gap is connected to the bleeding chamber 7.

[0047] Here, the sealing assembly 19 includes, for example, a single sealing element 21, which has a first sealing surface 22 and a second sealing surface 23. The second sealing surface points away from the first sealing surface 22 particularly when viewed in a direction perpendicular to the axis 10. Here, the sealing element 21 is connected to the annular part 15 of the relay valve piston 2 and is configured to seal the relay valve piston 2 against the radial inner wall part 17 of the housing 9 by means of the first sealing surface 22 and against the radial outer peripheral surface 14 of the guide tube 13 of the housing 9 by means of the second sealing surface 23.

[0048] In particular, the first sealing surface 22 and the second sealing surface 23 are dynamic sealing surfaces, since the first sealing surface 22 moves relative to the radially inner wall portion 17 of the housing 9 parallel to the axis 10, in particular, and the second sealing surface 23 moves relative to the radially outer peripheral surface 18 of the guide tube 13 parallel to the axis 10, in particular.

[0049] Particularly preferably, the (dynamic) first sealing surface 22 seals the control chamber 3 connected to the control input relative to the working chamber 4 connected to the pressure medium outlet, and the (dynamic) second sealing surface 23 seals the control chamber 3 relative to the bleed chamber 7 connected to the bleed portion.

[0050] Viewed perpendicular to the axis 10 respectively, the annular part 15 has a first end face 24 pointing to the control chamber 3 and a second end face 25 pointing to the working chamber 4, wherein the sealing element 21 covers at least a part of the first end face 24 and the second end face 25, as is particularly known from Figures 1 to 3 Furthermore, at the sealing element 21 there is a (static) third sealing surface 26, which is configured and arranged to prevent compressed air, in particular compressed air from the working chamber 4, from permeating (Unterwanderung) the sealing element 21. The static third sealing surface 26 is supported (tragen) by the relay valve piston 2, but preferably does not contact the housing 9 and is not movable relative to the relay valve piston 2. Preferably, the first sealing surface 22, the second sealing surface 23 and the third sealing surface 26 are substantially arranged on the same level on the annular part 15 with respect to the axis 10.

[0051] Although the first sealing surface 22 and the second sealing surface 23 are shown in Figures 1 to 3 in a simplified manner as partial circles (Teilkreise) for drawing reasons, in fact sealing lips can be respectively constructed there, for example, which are inclined radially away from the sealing element 21, whereby the sealing element 21 is preferably a lip seal. Viewed in cross-section, being inclined radially means an acute angle with respect to a plane perpendicular to the axis 10.

[0052] The sealing element 21 is preferably in a form-locking connection with the annular part 15 of the relay valve piston 2, in particular, this connection is carried out in an additive-free manner. Here, the sealing element 21 is, for example, an injection molded part injection molded from an elastomer, which is injection molded together with the annular part 15 of the relay valve piston 2, for example. Since then the sealing element 21 and the relay valve piston 2 form a one-piece structural unit, which can be placed and assembled in the housing 9 in a single assembly step.

[0053] Here, when viewed in cross-section, the sealing element 21 as an injection-molded part is preferably constructed in a single layer, since the sealing element is, for example, completely manufactured in a single injection process. Alternatively, when viewed in cross-section, the sealing element 21 as an injection-molded part can be constructed in multiple layers, since each of the multiple layers is produced by a separate injection process. This multi-layer construction enables the use of different materials during the manufacturing process of the sealing element 21.

[0054] The sealing element 21 as an injection-molded part at least partially (radially and axially with respect to the axis 10) surrounds the annular portion 15 of the relay valve piston 2, and here, for example, passes through an opening in the annular portion 15 of the relay valve piston 2, which opening preferably extends as a through-opening between the first end face 24 and the second end face 25 here. For example, the opening 27 is parallel to the axis 10. In the preferred embodiment shown here, a plurality of such openings 27 through which the sealing element 21 passes can be arranged in a manner distributed on the circumference of the annular portion 15. When viewed in cross-section, due to these passages, an undercut is also generated between the annular portion 15 of the relay valve piston 2 and the sealing element 21, and the undercut then forms a form-fit between the sealing element 21 and the annular portion 15 of the relay valve piston 2, as Figures 1 to 3 the left half of which is particularly shown respectively.

[0055] As Figures 1 to 3 the corresponding right half shown shows, the cross-section of the annular portion 15 can also be implemented (preferably locally in the circumferential direction) in a manner without such an opening. Then, nevertheless, a form-fit between the sealing element 21 and the annular portion 15 can still exist, here, for example, by the annular portion 15 being at least partially wrapped or injection-molded by the sealing element 21.

[0056] As described above, in addition, the sealing element 21 has a (static) third sealing surface 26, which is configured and arranged to prevent compressed air from penetrating the sealing element 21 in the region of the annular portion 15. For this purpose, the (static) third sealing surface 26 can, for example, seal against the radially outer peripheral surface 28 of the tubular portion 14 of the relay valve piston 2.

[0057] Figure 3Partial cross-sectional view of the relay valve 1 according to the invention in another embodiment. In this embodiment, for example, the first sealing surface 22 of the sealing element 21 has two sealing lips 29, which are arranged at an (axial) distance from each other in the direction of the axis 10 and which are in turn shown in a simplified manner as partial circles in the drawing. The intermediate space 30 between the two sealing lips 29 is connected to the bleed chamber 7 via the internal channel 31 of the annular part 15 of the relay valve piston 2, for example in a manner extending transversely to this axis. For this purpose, the channel 31 is connected to the bleed chamber 7 via a narrow annular gap 20 between the radially inner peripheral surface of the tubular part 15 and the radially outer peripheral surface 18 of the guide tube 13. By this connection of the intermediate space 30 between the two sealing lips 29 to the bleed chamber 7, an improved sealing effect is produced, since the inclined sealing lips 29 are pre-tensioned against the radially inner wall part 17 by the resulting pressure difference, as already described in the introduction section.

[0058] List of reference numerals

[0059] 1 Relay valve

[0060] 2 Relay valve piston

[0061] 3 Control chamber

[0062] 4 Working chamber

[0063] 5 Charging chamber

[0064] 6 Intake valve

[0065] 7 Bleed chamber

[0066] 8 Exhaust valve

[0067] 9 Housing

[0068] 10 Axis

[0069] 11 Radial outer edge

[0070] 12 Through-opening

[0071] 13 Guide tube

[0072] 14 Tubular part

[0073] 15 Annular part

[0074] 16 Bleed channel

[0075] 17 Radial inner wall part

[0076] 18 Radial outer peripheral surface

[0077] 19 Sealing assembly

[0078] 20 Annular gap

[0079] 21 Sealing element

[0080] 22 First sealing surface

[0081] 23 Second sealing surface

[0082] 24 First end face

[0083] 25 Second end face

[0084] 26 Third sealing surface

[0085] 27 Opening

[0086] 28 Radial outer peripheral surface

[0087] 29 Sealing lip

[0088] 30 Intermediate space

[0089] 31 Internal channel.

Claims

1. A relay valve (1) for a compressed air installation of a vehicle, the relay valve having at least the following: a) A housing (9) and a pressure medium input end constructed on or in the housing (9) and connectable to a compressed air source, at least one pressure medium output end connectable to a consumer, at least one control input end, at least one bleed section leading to the atmosphere, and at least one relay valve piston (2) guided along an axis (10) in the housing (9), wherein, b) The relay valve piston (2) has a radially outer edge (11) and a central through-opening (12), and a guide tube (13) of the housing (9) extends into the central through-opening, and wherein, c) The relay valve piston (2) is guided in a movable manner on a radially inner wall portion (17) of the housing (9) by means of the radially outer edge (11), and is guided in a movable manner on a radially outer peripheral surface (18) of the guide tube (13) by means of a radially inner peripheral surface of the central through-opening (12), and wherein, d) A sealing assembly (19) is provided, and the relay valve piston (2) is sealed with respect to the radially inner wall portion (17) of the housing (9) and with respect to the radially outer peripheral surface (18) of the guide tube (13) by means of the sealing assembly, characterized in that, e) The sealing assembly (19) includes at least one sealing element (21), the sealing element having a first sealing surface (22) and a second sealing surface (23) pointing away from the first sealing surface (21), wherein the sealing element (21) is configured to seal the relay valve piston (2) with respect to the radially inner wall portion (17) of the housing (9) by means of the first sealing surface (22) and with respect to the radially outer peripheral surface (18) of the guide tube (13) by means of the second sealing surface (23).

2. The relay valve according to claim 1, wherein The sealing element (21) is in form-locking connection with the relay valve piston (2).

3. The relay valve according to any one of the above claims, characterized in that, The sealing element (21) forms an injection molding made of at least one plastic and / or at least one elastomer, and the injection molding is injection molded together with at least a section (15) of the relay valve piston (2).

4. The relay valve according to claim 3, wherein In a cross-sectional view, a) The sealing element (21) as an injection molding is constructed in a single layer, wherein the sealing element is completely produced in a single injection process, or b) The sealing element as an injection molding is constructed in multiple layers, wherein each of the multiple layers is produced by a separate injection process.

5. The relay valve according to claim 3 or 4, characterized in that, a) The injection molding at least partially surrounds or encircles a section (15) of the relay valve piston (2), and / or b) The injection molding extends into or through at least one opening (27) of a section (15) of the relay valve piston (2).

6. The relay valve according to claim 5, characterized in that, At least one opening section of the opening (27) is parallel to the axis (10).

7. The relay valve according to any one of claims 3 to 6, characterized in that, The sealing element (21) has a third sealing surface (26), which is configured and arranged to prevent compressed air from penetrating the sealing element (21).

8. The relay valve according to any one of claims 3 to 7, characterized in that, The connection between the sealing element (21) and the section (15) of the relay valve piston (2) has at least one undercut.

9. The relay valve according to any one of the above claims, characterized in that, The relay valve piston (2) has a tubular part (14) and an annular part (15). The tubular part has the central through-opening (12). The annular part projects radially outward away from the tubular part (14), and a radially outer edge (11) is formed on the radially outer side of the annular part.

10. The relay valve according to any one of claims 3 to 8 and claim 9, characterized in that, The annular part (15) forms a section of the relay valve piston (2).

11. The relay valve according to claim 10, characterized in that, The annular part (15) has a first end face (24) and a second end face (25) perpendicular to the axis (10) respectively. The sealing element (21) covers or surrounds at least a part of the first end face (24) and / or the second end face (25).

12. The relay valve according to claim 11, wherein, When the relay valve piston (2) abuts against a section of the housing (9) at at least one end position by means of the first end face (24) and / or by means of the second end face (25), the sealing element (21) forms an elastic abutment surface for the relay valve piston (2).

13. The relay valve according to any one of claims 9 to 12, characterized in that, The tubular part (14) of the relay valve piston (2) is hollow and forms part of the air release channel (16), which is connected to the air release part.

14. The relay valve according to any one of the above claims, characterized in that, The first sealing surface (22) and / or the second sealing surface (23) of the sealing element (21) has at least one sealing lip (29).

15. The relay valve according to claim 14, wherein, At least the first sealing surface (22) has two sealing lips (29). Seen in the direction of the axis (10), the two sealing lips are arranged at a distance from each other. The intermediate space (30) between the two sealing lips (29) is connected to the air release part via the internal channel (31) of the relay valve piston (2).

16. The relay valve according to any one of the above claims, characterized in that a) the first sealing surface (22) and the second sealing surface (23) seal the control chamber (3) of the relay valve (1) connected to the control input end relative to the working chamber (4) of the relay valve (1) connected to the pressure medium output end, and b) the first sealing surface and the second sealing surface seal the control chamber (3) of the relay valve (1) relative to the air release chamber (7) connected to the air release part of the relay valve (1).

17. An electro-pneumatic module of a compressed air installation for a vehicle, characterized in that, The electro-pneumatic module includes at least one relay valve (1) according to any one of the above claims.

18. A compressed air facility for a vehicle, characterized in that, The compressed air facility includes at least one electro-pneumatic module according to claim 17.

19. A vehicle having the compressed air facility according to claim 18.

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