RELAY VALVE DEVICE AND BRAKE DEVICE FOR A VEHICLE WITH SUCH A RELAY VALVE DEVICE

Description

[0001] The invention relates to a relay valve device, in particular for commercial vehicles, and a braking device for a vehicle, in particular for a commercial vehicle, with such a relay valve device.

[0002] Relay valve devices, such as proportional relay valves, are used in vehicles, among other things, to meter compressed air to consumers such as brake or air suspension systems. In commercial vehicles, for example, they are also used in this context for EBS braking systems to specify the brake pressure for the brake cylinders according to the corresponding control.

[0003] EP 1 391 363 A1, for example, discloses a design of a proportional relay valve for wheel and axle modulators of EBS brake systems. In this proportional valve, an inlet valve can be opened by a relay piston movable via a control pressure in order to introduce a supply pressure into a relay working chamber. An intermediate element with an orifice is provided between the piston plate of the relay piston and the relay working chamber to delay pressure equalization between the supply pressure and the control pressure. To control the time delay exclusively via the orifice and to avoid turbulence, the intermediate element is sealed with a sealing element relative to the piston pin of the relay piston and the housing wall.Due to the changing pressure conditions and the associated relative movements or at least forces, the sealing elements are subject to wear, which can have an impact on the tightness.

[0004] In this context, WO 2011 / 029495 A1 also discloses a relay valve device with a housing, a longitudinally movable relay piston arranged in the housing, a working valve device actuatable by the relay piston, an outlet chamber between the relay piston and the working valve device and an intermediate wall arranged in the outlet chamber, which divides the outlet chamber into a chamber on the relay piston side and a relay working chamber facing away from the relay piston, wherein the working valve device is arranged in the relay working chamber, and wherein the intermediate wall has a device for pressure equalization between the chamber on the relay piston side and the relay working chamber.

[0005] A further embodiment of a valve device is disclosed in DE 34 43 079 A1.

[0006] In view of the above statements, it is therefore an object of the present invention to provide a relay valve device and a brake device with such a relay valve device, in which at least one seal between the intermediate element and the housing can be achieved without an additional sealing element.

[0007] This object is achieved by a relay valve device and a braking device for a vehicle with such a relay device according to the independent claims. Advantageous developments of the invention are contained in the dependent claims.

[0008] According to the invention, a relay valve device, in particular for commercial vehicles, a relay piston arranged in a housing, which has a piston pin extending from a piston plate in a longitudinal direction and is movable in the longitudinal direction in a piston plate guide, wherein the piston plate divides an interior of the housing into a volume on the piston pin side and a volume facing away from the piston pin, a valve device which is actuated by the piston pin in order to be able to introduce a fluid from a supply pressure reservoir into the volume on the piston pin side, and an intermediate element arranged around the piston pin and movable in the longitudinal direction in an intermediate element guide relative thereto, which in turn divides the volume on the piston pin side into a volume on the piston plate side and a volume facing away from the piston plate and limits the flow rate of the fluid to the piston plate via at least one through-opening, wherein the relay valve device has an intermediate element stop which limits the movement of the intermediate element in the direction of the piston plate and against which the intermediate element can be brought into sealing contact via the fluid pressure.

[0009] The relay piston is moved longitudinally in the piston plate guide in a direction away from the volume remote from the piston pin, for example by a control pressure applied to the piston plate in the volume remote from the piston pin. In engagement with the valve device, for example by engagement of an end section of the piston pin remote from the piston plate with a surface of the valve device facing the remote end section of the piston pin, and a corresponding protruding or further movement of the relay valve, the valve device can open a fluid connection from the supply pressure reservoir to the volume on the piston pin side. The volume of the volume on the piston pin side remote from the piston plate can have a consumer connection via which the supply pressure can be transmitted to a consumer, such as a brake cylinder.To equalize the pressure between the control pressure present in the volume remote from the piston pin and the supply pressure present in the volume on the piston pin side, the intermediate element has at least one through-opening. By designing this at least one through-opening of the intermediate element, the flow rate of the fluid introduced from the supply pressure reservoir can be regulated to a flow rate that delays pressure equalization by a predetermined time. To avoid vibrations and the associated noise generation and / or associated material stresses, the relay valve device is configured such that the intermediate element can be pressed against the intermediate element stop by the fluid pressure of the fluid introduced from the supply pressure reservoir in order to be brought into sealing contact therewith.Such a seal does not have to be completely fluid-tight, but can also be sealed to the extent that any remaining fluid permeability does not significantly contribute to vibration excitation and the associated noise generation and / or material stress with respect to specified tolerances. Such a seal between the intermediate element and the intermediate element stop via the fluid pressure applied to the intermediate element in the volume facing away from the piston plate eliminates the need for a sealing element at this point.

[0010] In one embodiment, the intermediate element is designed to be plane-parallel or oblique in an area for contact with the intermediate element stop.

[0011] A plane-parallel design refers to a parallel design of the stop surface of the intermediate element to the stop surface of the intermediate element stop in order to create the largest possible contact area for sealing. With an oblique design of the stop area of ​​the intermediate element, at least one stop point for sealing can be created, almost independently of the design of the stop area of ​​the intermediate element stop.

[0012] According to a further development, the relay valve device has a sealing element which is provided in such a way that the intermediate element can be sealed to the piston pin via the sealing element.

[0013] The seal between the intermediate element arranged around the piston pin and the piston pin via the sealing element prevents, similar to the intermediate element stop, a significant introduction of fluid from the supply pressure reservoir into the piston plate-side volume outside of the at least one through-opening provided for this purpose. Here, too, the seal does not have to be completely fluid-tight, but can be limited to a needs-based seal as described above.

[0014] The seal via the sealing element is configured in particular such that the piston pin is movable in the longitudinal direction relative to the intermediate element, so that the seal between the intermediate element and the piston pin via the sealing element is independent of the contact of the intermediate element with an intermediate element stop.

[0015] In particular, the intermediate element stop is formed by the housing.

[0016] In principle, the intermediate element is to be sealed, particularly with respect to the longitudinal direction, radially inward toward the piston pin and in a radially outer region toward the intermediate element guide, in order to limit the introduction of fluid into the piston plate-side volume essentially to the at least one through-opening. Preferably, the intermediate element stop is provided at least for sealing the radially outer region toward the intermediate element guide, since this sealing is independent of the movement of the relay piston.

[0017] By forming the intermediate element stop through the housing, the radially outer region for guiding the intermediate element can be formed in a simple manner. Sealing is not achieved via radial surfaces in relation to the longitudinal direction, but rather via surfaces of the housing forming the intermediate element stop and the intermediate element that are adjacent or opposite one another in the longitudinal direction. Alternatively or in addition to an intermediate element stop formed through the housing, the intermediate element stop or at least one intermediate element stop section can also be formed by an intermediate element stop element, which is, for example, resiliently mounted on the piston plate side facing the piston pin-side volume.

[0018] According to a further development, the intermediate element guide is set back relative to the piston plate guide in a radial direction facing away from the piston pin with respect to the longitudinal direction in order to form the intermediate element stop, so that the transition between the piston plate guide and the intermediate element guide forms a shoulder as an intermediate element stop.

[0019] The housing directly or indirectly forms the intermediate element guide and the piston plate guide. Due to the offset of the intermediate element guide relative to the piston plate guide in the radial direction away from the piston pin in relation to the longitudinal direction, the intermediate element stop is created as a shoulder that limits the movement of the intermediate element in the longitudinal direction towards the piston plate and, when appropriate pressure is applied in the direction of the piston plate, brings the intermediate element into sealing contact with the intermediate element stop. Alternatively, the housing can also form the intermediate element stop via a projection pointing radially inward in the direction of the piston pin.

[0020] In one embodiment, the relay valve device has an intermediate element seat which is movable in the longitudinal direction in an intermediate element seat guide and is arranged between the valve device and the intermediate element, and wherein the intermediate element seat is configured such that the intermediate element seat can be brought into contact with the intermediate element at least in sections and the intermediate element seat can bring the intermediate element into sealing contact with the intermediate element stop via the fluid pressure.

[0021] The engagement of the intermediate element with the intermediate element stop is thus supported by the fluid pressure of the fluid from the supply pressure reservoir acting on a side of the intermediate element seat facing away from the intermediate element in the longitudinal direction and the associated movement of the intermediate element seat in the longitudinal direction toward the intermediate element. In other words, the intermediate element is pressed against the intermediate element stop via the intermediate element seat.

[0022] A contact of the intermediate element seat only in sections with the intermediate element allows areas of the piston pin-side volume to be sealed against each other by the contact of the intermediate element seat with the intermediate element. Accordingly, for example, the fluid from the supply pressure reservoir can be passed through the sections not in contact when the valve device is open, for example, to reach a consumer connection and / or the at least one through-opening of the intermediate element. Alternatively or additionally, a corresponding passage can also be provided via at least one through-opening in the intermediate element and / or in the intermediate element seat.

[0023] In one embodiment, the intermediate element seat can be designed as a single piece with the intermediate element. The intermediate element seat and the intermediate element can therefore be moved together in this embodiment. In other words, the intermediate element can be designed such that, on a side facing away from the piston plate, it has an end section that corresponds to an intermediate element seat, for example, enabling the sealing with the valve device described below.

[0024] In particular, the relay valve device is configured such that the intermediate element seat is sealingly seated on the valve device in a position of the relay piston in which the valve device is not actuated.

[0025] The intermediate element seat therefore not only serves to transfer the intermediate element into contact with the intermediate element stop, but can also seal the piston pin-side volume towards the supply pressure reservoir.

[0026] According to a further development, the relay valve device has an intermediate element seat stop on the intermediate element side, which limits the movement of the intermediate element seat in the direction of the intermediate element and against which the intermediate element seat can be brought into contact via the fluid pressure.

[0027] The movement limitation of the intermediate element seat in the longitudinal direction in the direction of the intermediate element associated with the intermediate element-side intermediate element seat stop equally limits the force exerted on the intermediate element. The intermediate element can thus only be pressed against the intermediate element stop via the intermediate element seat with a predetermined maximum force. This can prevent wear and / or damage to the intermediate element and / or intermediate element stop. In other words, the intermediate element-side intermediate element seat stop can be used as overload protection for the intermediate element and / or the intermediate element stop.

[0028] In particular, the intermediate element seat stop on the intermediate element side is formed by the housing.

[0029] Similar to the design of the intermediate element stop, the intermediate element seat stop on the intermediate element side can also be formed in a simple manner by the housing.

[0030] Preferably, the intermediate element seat guide is set back relative to the intermediate element guide in a radial direction facing away from the piston pin with respect to the longitudinal direction in order to form the intermediate element-side intermediate element seat stop, so that the transition between the intermediate element guide and the intermediate element seat guide forms a shoulder as an intermediate element-side intermediate element seat stop.

[0031] The housing also forms the intermediate element seat guide and the intermediate element guide directly or indirectly, similar to the intermediate element stop.

[0032] Due to the offset of the intermediate element seat guide relative to the intermediate element guide in the radial direction away from the piston pin with respect to the longitudinal direction, the intermediate element seat stop on the intermediate element side is thus created as a shoulder that limits the movement of the intermediate element seat in the longitudinal direction toward the intermediate element and, when appropriate pressure is applied toward the intermediate element, brings the intermediate element seat into contact with the intermediate element seat stop on the intermediate element side. Alternatively, the housing can also form the intermediate element seat stop on the intermediate element side via a projection that otherwise points radially inward toward the piston pin.

[0033] According to a further development, the maximum distance of the intermediate element to the intermediate element stop in the longitudinal direction is less than or equal to the maximum distance of the intermediate element seat to the intermediate element-side intermediate element seat stop.

[0034] Accordingly, the intermediate element seat can only be brought into contact with the intermediate element-side intermediate element seat stop when the intermediate element can also be brought into contact with the intermediate element stop. In other words, the movement of the intermediate element seat in the direction of the intermediate element is limited by the intermediate element-side intermediate element seat stop at the earliest when the intermediate element has been brought into contact with the intermediate element stop by the intermediate element seat.

[0035] Preferably, the maximum distance of the intermediate element from the intermediate element stop is smaller than the maximum distance of the intermediate element seat from the intermediate element seat stop on the intermediate element side. This ensures that the intermediate element can not only be brought into contact with the intermediate element stop via the intermediate element seat, but that the contact of the intermediate element with the intermediate element stop can also be subjected to pressure via a further movement of the intermediate element seat in order to improve the seal.

[0036] In one embodiment, the relay valve device has an intermediate element seat stop facing away from the intermediate element, which limits the movement of the intermediate element seat in a direction facing away from the intermediate element.

[0037] The intermediate element seat stop facing away from the intermediate element thus limits the movement of the intermediate element seat in a direction opposite to the intermediate element stop on the intermediate element side. In terms of the aforementioned maximum distance between the intermediate element seat and the intermediate element-side intermediate element seat stop, this maximum distance can be defined by the intermediate element seat stop facing away from the intermediate element.

[0038] The intermediate element seat stop facing away from the intermediate element can be used, in particular, to limit the required movement of the intermediate element seat to bring the intermediate element into contact with the intermediate element stop, regardless of the pressure conditions. Over the thus set distance, the intermediate element can be brought into contact with the intermediate element stop via the intermediate element seat within a predetermined time period.

[0039] Alternatively or additionally, the relay valve device can be configured such that the intermediate element seat, when in contact with the intermediate element seat stop facing away from the intermediate element, rests sealingly on the valve device in a position of the relay piston in which the valve device is not actuated. If the relay piston now moves the valve device longitudinally in a direction opposite to the volume facing away from the piston pin, the intermediate element seat cannot be moved due to the intermediate element seat stop facing away from the intermediate element. Due to the resulting spacing between the intermediate element seat and the valve device, fluid can be introduced from the supply pressure reservoir into the volume on the piston pin side. The intermediate element seat can thus cooperate with the valve device to introduce the fluid from the supply pressure reservoir and to terminate the introduction process.

[0040] In particular, the intermediate element seat stop facing away from the intermediate element is formed by at least one stop pin.

[0041] By designing it as at least one stop pin, the intermediate element seat stop facing away from the intermediate element takes up comparatively little space, so that the volume on the supply pressure reservoir side remains essentially unaffected. If such a stop pin is not integrally formed with the housing, it can also be easily replaceable. To be able to adjust the length of the stop pin as needed, the stop pin can also have a thread at least in sections at an end facing away from the intermediate element seat, which can be screwed, for example, to different depths into a stop pin receptacle, such as a housing wall.

[0042] According to a further development, the intermediate element seat and the intermediate element each have at least one contour section on opposite sides, wherein the contour sections are configured such that they can be brought into mutually positive engagement to form an anti-twist device with respect to the longitudinal direction.

[0043] The introduction of fluid from the supply pressure reservoir into the volume on the piston pin side can cause turbulence that could cause the intermediate element and / or the intermediate element seat to rotate relative to one another in the longitudinal direction. This can be prevented by the associated anti-rotation device via corresponding contour sections of the intermediate element and the intermediate element seat, which can be brought into engagement at least when pressurized by the fluid from the supply pressure reservoir. Corresponding contour sections can be designed, for example, as a toothed pair or a pin-pin receiving pair. With a full-circle contour design on the side of the intermediate element and / or the intermediate element seat, the intermediate element and the intermediate element seat do not necessarily have to be moved into a relative engagement position beforehand, or more orientation options arise.In addition, the contour sections can also be designed in such a way that, in addition to the positive connection, they also form at least one opening for fluid transmission between the intermediate element and the intermediate element seat.

[0044] A further aspect of the invention relates to a braking device for a vehicle, in particular a commercial vehicle, wherein the braking device has at least one relay valve device according to the above embodiments.

[0045] The use of the relay valve device for the braking system results in analogous advantages to those mentioned above.

[0046] The invention is explained in more detail below with reference to the attached figure. The figure shows in detail: Figure 1 a schematic sectional view of a relay valve device according to an exemplary embodiment of the invention

[0047] Figure 1shows a schematic sectional view of a relay valve device 1 according to the invention in a longitudinal direction L according to an exemplary embodiment of the invention. The relay device 1 has a housing 10 in which a relay piston 30 is arranged to be movable in the longitudinal direction L. The relay piston 30 has a piston plate 31, via which the relay piston 30 is guided in a piston plate guide 11 formed by the housing 10 for movement in the longitudinal direction L. Starting from the piston plate 31, a piston pin 32 extends in the longitudinal direction L in the direction of a valve device 40. The relay piston 30 is guided via the piston pin 32 during a movement of the relay piston 30 in the longitudinal direction, also on a side lying radially inward with respect to the longitudinal direction L, by a piston pin guide 16.The piston plate 31 can be sealed to the piston plate guide 11 by means of a seal and divides the housing volume into a volume 70 facing away from the piston pin and a volume 80 on the piston pin side.

[0048] To actuate the valve device 40, compressed air, for example a control pressure in a relay valve for brakes, can be introduced into the volume 70 facing away from the piston pin. The compressed air acts on the piston plate 31, whereby the relay piston 30 is moved in the longitudinal direction L towards the valve device 40. When the end of the piston pin 32 facing away from the piston plate 31 reaches the valve device 40 and is moved further, the valve device is moved in the direction of movement of the relay piston 30. This opens a fluid connection between the valve device 40 and an intermediate element seat 60, described later, to the volume 80 on the piston pin side. Via the fluid connection, for example, a supply pressure can be introduced into the volume 80 on the piston pin side, which can be passed on to a consumer, such as a braking device, via a connection not shown here.

[0049] An intermediate element 50 is used to delay the pressure equalization between the volume 70 facing away from the piston pin and the volume 80 on the piston pin side to avoid vibrations and the associated damage and / or noise. The intermediate element 50 is arranged in a ring around the piston pin 32 and divides the volume 80 on the piston pin side into a volume 81 on the piston plate side and a volume 82 facing away from the piston plate. The volume 81 on the piston plate side and the volume 82 facing away from the piston plate are in fluid communication via a through opening 51 formed in the intermediate element 50.Since the intermediate element 50 is sealed radially to the piston pin 32 with respect to the longitudinal direction L via a sealing element 53 and is movable in an intermediate element guide 12 in the longitudinal direction L and thus against an intermediate element stop 14, the intermediate element 50 acts as a throttle or orifice to delay the pressure equalization. In other words, the delay in the pressure equalization can be significantly predetermined by the design of the through-opening 51. The intermediate element stop 14 formed between the piston plate guide 11 and the intermediate element guide 12 by the housing 10 sufficiently seals the intermediate element 50 from the housing, so that additional sealing elements in this area can be dispensed with.

[0050] The movement of the intermediate element 50 in the longitudinal direction L is limited in a direction facing the piston plate 31 by the intermediate element stop 14 and in a direction facing away from the piston plate 31 by the intermediate element seat 60. The intermediate element seat 60 is annular in this case and is movably guided in the longitudinal direction L in an intermediate element seat guide 13 formed by the housing 10. The movement of the intermediate element seat 60 in the longitudinal direction L is limited in a direction facing the intermediate element 50 by an intermediate element seat stop 15 on the intermediate element side and in a direction facing away from the intermediate element 50 by an intermediate element seat stop 20 facing away from the intermediate element, which is formed here by stop pins.The intermediate element seat stop 20 facing away from the intermediate element prevents the intermediate element seat 60 from moving in the longitudinal direction L with the valve device 40 to such an extent that the fluid connection to the piston pin-side volume for the supply pressure cannot open. The intermediate element seat stop 15 on the intermediate element side limits the contact forces that can be transmitted to the intermediate element 50 by the intermediate element seat 60 in order to prevent damage to the intermediate element 50 and / or the intermediate element seat 60 caused thereby. For adequate sealing, the maximum distance in the longitudinal direction L between the intermediate element 50 and the intermediate element stop 14 is less than or equal to the maximum distance between the intermediate element seat 60 and the intermediate element-side intermediate element seat stop 15.

[0051] In addition, the intermediate element seat 60 has a contour section 61 on its side facing the intermediate element 50. The contour section 61 of the intermediate element seat 60 can be brought into contact with a corresponding contour section 52 of the intermediate element 50. By means of the corresponding and intermeshing contour sections, the intermediate element 50 and the intermediate element seat 60 can be held non-rotatably relative to one another with respect to the longitudinal direction L. The contour sections 52 and 61 are designed here as a tooth pair. The intermediate element seat 60 has, for example, a uniformly circumferential, continuous tooth structure as the contour section 61. The contour section 52 of the intermediate element 50 facing the intermediate element seat 60 has corresponding toothings for this purpose.However, these toothings are still continuously circumferential, but are spaced apart from one another in such a way that toothing structures of the contour section 61 remain exposed when the intermediate element seat 60 rests against the intermediate element 50. This creates a fluid connection to the piston pin-side volume 80 for a supply pressure that can be introduced via the valve device 40.

[0052] The invention is not limited to the described embodiments. Even if only one through-opening is shown in the embodiment described above, several through-openings can also be provided, for example. The intermediate element stop 14 can also be formed via an annular gap that is radial with respect to the longitudinal direction L. Furthermore, for example, the sealing element 53 can be omitted or a seal can be replaced by a comparatively narrow gap seal. Alternatively or additionally, an intermediate element stop can also be formed via the piston pin 32, i.e. on a side of the intermediate element 50 that is radially inward with respect to the longitudinal direction L. For this purpose, the piston pin 32 can have a section that is set back radially inward with respect to the longitudinal direction L or a projection that points radially outward.Even though the relay piston device 1 in the described embodiment has an intermediate element 50 and a separate intermediate element seat 60, the intermediate element 50 and the intermediate element seat 60 can also be formed as a single piece, regardless of further design features. For example, the single-piece combination of the intermediate element 50 and the intermediate element seat 60 can then be formed as shown in FIG. Fig. 1 be moved together in the longitudinal direction L between an end position facing the piston plate 31, which is determined by the intermediate element stop 14, and an end position facing away from the piston plate 31, which is determined by the intermediate element seat stop 20 facing away from the intermediate element. LIST OF REFERENCE SYMBOLS

[0053] 1 Relay valve device 10 Housing 11 Piston plate guide 12 Intermediate element guide 13 Intermediate element seat guide 14 Intermediate element stop 15 Intermediate element seat stop on the intermediate element side 16 Piston pin guide 20 Intermediate element seat stop facing away from the intermediate element (stop pin) 30 Relay piston 31 Piston plate 32 Piston pin 40 Valve device 50 Intermediate element 51 Through opening 52 Contour section (intermediate element) 53 Sealing element 60 Intermediate element seat 61 Contour section (intermediate element seat) 70 Volume facing away from the piston pin 80 Volume on the piston pin side 81 Volume on the piston plate side 82 Volume facing away from the piston plate L Longitudinal direction

Claims

1. Relay valve device (1), in particular for commercial vehicles, having: a relay piston (30), which is arranged in a housing (10), has a piston pin (32) extending in a longitudinal direction (L) from a piston plate (31) and can be moved in the longitudinal direction (L) in a piston plate guide (11), wherein the piston plate (30) divides an interior of the housing (10) into a volume (80) on the piston pin side and a volume (70) facing away from the piston pin, a valve apparatus (40), which can be actuated by the piston pin (32) in order to be able to introduce a fluid from a supply pressure reservoir into the volume (80) on the piston pin side, and an intermediate element (50), which is arranged around the piston pin (32) and divides the volume (80) on the piston pin side into a volume (81) on the piston plate side and a volume (82) facing away from the piston plate and limits the flow rate of the fluid to the piston plate (31) by means of at least one through opening (51), characterized in that the intermediate element (50) can be moved in the longitudinal direction (L) in an intermediate element guide (12) relative thereto and in that the relay valve device (1) has an intermediate element stop (14), which limits the movement of the intermediate element (50) in the direction of the piston plate (31) and against which the intermediate element (50) can be brought into sealing contact by means of the fluid pressure.

2. Relay valve device (1) according to claim 1, wherein the intermediate element (50) is formed plane-parallelly or obliquely in a region for bearing against the intermediate element stop (14).

3. Relay valve device (1) according to claim 1 or claim 2, wherein the relay valve device (1) has a sealing element (53), which is provided in such a way that the intermediate element (50) can be sealed off with respect to the piston pin (32) by means of the sealing element (53).

4. Relay valve device (1) according to any one of the preceding claims, wherein the intermediate element stop (14) is formed by the housing (10).

5. Relay valve device (1) according to claim 4, wherein the intermediate element guide (12) is set back relative to the piston plate guide (11) in a radial direction facing away from the piston pin (32) in relation to the longitudinal direction (L) in order to form the intermediate element stop (14), with the result that the transition between the piston plate guide (11) and the intermediate element guide (12) forms a shoulder as an intermediate element stop (14).

6. Relay valve device (1) according to any one of the preceding claims, wherein the relay valve device (1) has an intermediate element seat (60), which can be moved in the longitudinal direction (L) in an intermediate element seat guide (13) and is arranged movably between the valve apparatus (40) and the intermediate element (50), and wherein the intermediate element seat (60) is configured in such a way that the intermediate element seat (60) can be brought into contact with the intermediate element (50) at least in some sections and the intermediate element seat (60) can bring the intermediate element (50) into sealing contact with the intermediate element stop (14) by means of the fluid pressure.

7. Relay valve device (1) according to claim 6, characterized in that the intermediate element seat (60) is sealingly placed on the valve apparatus (40) in a position of the relay piston (30) in which the valve apparatus (40) is not actuated.

8. Relay valve device (1) according to claim 6 or claim 7, wherein the relay valve device (1) has an intermediate element seat stop (15) on the intermediate element side, which limits the movement of the intermediate element seat (60) in the direction of the intermediate element (50) and against which the intermediate element seat (60) can be brought into contact by means of the fluid pressure.

9. Relay valve device (1) according to claim 8, wherein the intermediate element seat stop (15) on the intermediate element side is formed by the housing (10).

10. Relay valve device (1) according to claim 9, wherein the intermediate element seat guide (13) is set back relative to the intermediate element guide (12) in a radial direction facing away from the piston pin (32) in relation to the longitudinal direction (L) in order to form the intermediate element seat stop (15) on the intermediate element side, with the result that the transition between the intermediate element guide (12) and the intermediate element seat guide (13) forms a shoulder as an intermediate element seat stop (15) on the intermediate element side.

11. Relay valve device (1) according to any one of claims 8 to 10, wherein the maximum distance of the intermediate element (50) to the intermediate element stop (14) in the longitudinal direction (L) is less than or equal to the maximum distance of the intermediate element seat (60) from the intermediate element seat stop (15) on the intermediate element side.

12. Relay valve device (1) according to any one of claims 6 to 11, wherein the relay valve device (1) has an intermediate element seat stop (20) facing away from the intermediate element and which limits the movement of the intermediate element seat (60) in a direction facing away from the intermediate element (50).

13. Relay valve device (1) according to claim 12, wherein the intermediate element seat stop (20) facing away from the intermediate element is formed by at least one stop pin.

14. Relay valve device (1) according to any one of claims 6 to 13, wherein the intermediate element seat (60) and the intermediate element (50) each have at least one contour section (52, 61) on mutually opposite sides, and the contour sections (52, 61) are configured in such a way that they can be brought into mutual form-fitting contact in relation to the longitudinal direction (L) in order to form an anti-rotation means.

15. Braking device for a vehicle, in particular a commercial vehicle, wherein the braking device has at least one relay valve device (1) according to any one of claims 1 to 14.