WO2022117648A1

WO2022117648A1 - Valve device

Info

Publication number: WO2022117648A1
Application number: PCT/EP2021/083771
Authority: WO
Inventors: Philipp Eichhorn
Original assignee: Robert Bosch Gmbh
Priority date: 2020-12-01
Filing date: 2021-12-01
Publication date: 2022-06-09
Also published as: EP4256254A1; DE102020215115A1; CN116783432A

Abstract

The invention relates to a valve device (10), in particular an expansion valve, for controlling a flow of a fluid, particularly for a refrigerant circuit in a vehicle, the valve device (10) comprising a valve element housing (12) with at least three ports (22a, 22b, 22c), and a valve element (14), the valve element (14) having a control flow hole (30) for a main fluid flow (32) and at least one expansion cutout (40), the ports (22a, 22b, 22c) being fluidically connected to an inner volume (26) inside the housing, the inner volume (26) being formed between the valve element (14) and the valve element housing (12), at least one of the ports (22a, 22b, 22c) being a fluid inlet (23a, 23b, 23c) and at least one of the ports (22a, 22b, 22b) being a fluid outlet (23a, 23b, 23c). According to the invention, the valve element (14) has a separation element (42) designed to fluidically separate the expansion cutout (40) from the control flow hole (30) within the valve element (14).

Description

description

title

valve device

The invention relates to a valve device and a valve element for a valve device according to the species of the independent claims.

State of the art

Valves for controlling a fluid flow are already known. In particular, DE 10 2017 208 181 A1 discloses a valve with a recess on the surface.

Disclosure of Invention

advantages

The present invention describes a valve device, in particular an expansion valve, for controlling a fluid flow of a fluid, in particular for a refrigerant circuit of a vehicle, having a valve element housing with at least three openings and a valve element, the valve element having a control passage for a main fluid flow and at least one expansion recess, wherein the openings are fluidically connected to an interior volume arranged in the interior of the housing, wherein the interior volume is formed between the valve element and the valve element housing, at least one opening being formed as a fluid inlet and at least one opening being formed as a fluid outlet. According to the invention, the valve element has a separating element has, which is designed to fluidly separate the expansion recess and the control passage within the valve element from each other.

The expansion valve according to the invention with the features of the independent claim has the advantage that in the main flow position of the control passage, backflow from the control passage via the expansion recess into the interior of the housing can be prevented by the separating element.

In the context of the present invention, the term fluid is understood to mean a medium which, depending on the prevailing thermodynamic conditions, can be present both in a liquid phase and in a gaseous phase. A fluid of the type in question is a heat transfer medium which circulates within the fluid circuit. In particular, the fluid is a natural refrigerant such as hydrocarbons, carbon dioxide, ammonia, propane, butane, propene, water or a synthetic refrigerant such as chlorofluorocarbons or hydrofluorocarbons.

In the context of the present invention, a separating element can be understood to mean an element which is designed to be essentially impermeable to a fluid of the type in question here. The separating element is preferably designed to be liquid-impermeable. A particularly preferred embodiment of the invention provides that the separating element inside the valve element is also designed to be gas-impermeable. A gas-permeable valve element can be understood to mean a separating element which only allows a leakage rate which is less than 10 ^-7 mbar Z/s, preferably less than 10 ^-8 mbar Z/s. particularly preferably less than 5*10 ^-8 mbarZ/s. This leakage rate corresponds approximately to a leak diameter of 0.4 pm per 2 mm wall thickness and an average gas loss of approximately 3 cm ³ of gas per year, with the leakage rate being able to be determined quantitatively using a test gas leak detector, for example. Helium or hydrogen forming gas is preferably used as the test medium.

The separating function of the separating element is provided within the valve element. The separating element interrupts the fluidic connection between the expansion recess and the control passage. In other words, within the inner volume of the valve element spanned by the outer lateral surface of the valve element, the separating element fluidly separates the expansion recess from the control passage volume in the sense of a blocking element. In order to test the separating function of the separating element within the valve element, it is therefore advantageous to essentially prevent a flow path outside the inner volume of the valve element.

The measures listed in the dependent claims result in advantageous developments and improvements of the independent features.

An advantageous development of the invention provides that the valve element can be rotated about an axis of rotation and the valve element has a rotationally symmetrical base body, preferably a spherical or cylindrical base body. Such a valve element can be manufactured particularly easily and inexpensively. The valve element preferably has an engagement which enables interaction with a valve stem moved by the electric drive. In the context of the present invention, a valve element can in particular also be understood to mean a valve means or a valve body. Preferably, the valve member is rotatably mounted on a valve stem. The valve element is movably, preferably rotatably, arranged within the valve element housing. Depending on the position of the valve element, in particular the rotational position within the valve element housing, the valve element allows flow through the valve device, wherein the fluid flow can be expanded or compressed depending on the valve position and the flow direction, or can flow through the valve device unhindered.

An advantageous development of the invention provides that the control passage has a first passage opening and a second passage opening along the direction of flow. It is further provided that the expansion recess is arranged in the area of the second passage opening of the control passage and the separating element is arranged between the expansion recess and the second passage opening of the control passage.

The separating element is thus arranged in the area of the through-opening, which is in contact with a fluid outlet in a main flow position of the valve device. Such a separating element can thus advantageously prevent a partial fluid flow from flowing back in the region of the fluid outlet. The efficiency of the valve device in the main flow direction is advantageously improved.

An advantageous development of the invention provides that in a main flow position, the first through-opening is fluidically connected largely completely to a fluid inlet and the second through-opening is largely completely connected to a fluid outlet, with the Separating element is designed to fluidly separate the expansion recess in the main flow position from the fluid outlet. In the context of the present invention, a main flow position of the valve device means an arrangement of the valve element relative to the valve element housing in which a main fluid stream can flow through the valve essentially uncompressed, ie without a significant flow cross-section reduction. In the main flow position, a low-pressure gas is preferably present at the fluid inlet of the valve device, and this gas is passed on to a fluid outlet with little pressure loss. A refrigerant compressor is preferably connected to this fluid outlet.

According to an advantageous development of the invention, a sealing seat is arranged at the fluid outlet, with the separating element lying fluidically tight against the sealing seat in the main passage position of the valve device.

According to an advantageous development of the invention, the fluid outlet is essentially cylindrical. The sealing seat preferably has an essentially cylindrical inner surface, which is arranged in the area of the opening. The flow resistance to the flowing fluid is thus minimized. The sealing seat preferably has a sealing seat edge against which, according to a preferred embodiment of the invention, the racing element bears in contact.

According to an advantageous development of the invention, the expansion recess has a flow cross section which is designed such that it increases in the direction of the second passage opening of the control passage, in particular in the direction of the separating element. The flow cross section in the expansion position can be regulated as a function of the rotational position. An advantageous development of the invention provides that the separating element is designed as a separating wall, preferably as a separating wall extending in the radial direction, particularly preferably as a separating wall adjoining the expansion recess in the circumferential direction.

An advantageous development of the invention provides that the separating element is designed in one piece or in one piece with the valve element base body. In this way, the expansion volume can be separated from the control passage in a structurally simple manner.

According to an advantageous development of the invention, the separating element extends over a circumferential angle of between 5° and 15°, preferably between 8° and 12°, particularly preferably essentially over 10° of the valve element. Such a dimensioning of the separating element on the one hand enables an efficient, fluid-tight separation of the expansion recess, and on the other hand the length of the expansion recess is optimized with regard to the setting of the expansion cross sections. The separating element is advantageously designed with thin walls. It is also conceivable that the valve element has a diffusion-inhibiting barrier layer, particularly in the area of the separating element.

An advantageous development of the invention provides that the expansion recess extends in a radial plane perpendicular to the axis of rotation, the expansion recess preferably being arranged in a plane of symmetry of the valve element.

An advantageous development of the invention provides that the expansion recess is designed as an expansion groove in a lateral surface of the valve element. It is advantageous that the expansion recess is formed on the surface of the valve element is. Such a recess, which is open at least on one side, advantageously enables simple regulation of the fluid flow through the inner volume of the valve element housing in the expansion position of the valve device.

A special low-pressure-loss valve can be provided in particular in that the openings of at least one fluid outlet and at least one fluid outlet are essentially aligned. In the main flow position, the fluid can thus flow through the valve, starting from the fluid inlet to the fluid outlet, through the straight control passage opening unhindered, uncompressed and straight. Pressure losses are significantly reduced. The control orifice preferably extends centrally through the centerline of the valve element.

According to a particularly preferred embodiment of the invention, it is provided that the valve element has exactly one control passage, the control passage being essentially straight. The control passage is essentially free of curvature, in particular without projections and deflections.

Due to the straight design of the control passage, pressure losses when flowing through the control passage can be prevented in an advantageous manner. A particularly simple, flow-optimized passage can be provided in that the control passage is designed as a through hole through the valve element.

A particularly simple, small valve can be provided in particular by arranging all three openings of the valve element housing in a common radial plane. The bottom of the valve element housing, i.e. the side opposite the actuator of the valve element housing is thus designed without a connection. A deflection of the fluid by 90° can advantageously be prevented. Inlet pipes or inlet flanges, which are mounted on the openings, are therefore all in one plane. Such a valve device can be designed to be significantly more space-saving. The axes of symmetry of the openings and the axis of rotation of the valve element preferably meet at a common center point.

In addition to the main passage position, the valve device advantageously has an expansion position in which the first passage opening is largely completely fluidically connected to a fluid outlet and the expansion recess is fluidically connected to a fluid inlet, the separating element in the expansion position being arranged at a distance from a first sealing seat arranged on the fluid inlet is. In this way, in the expansion position, the fluid can flow past the separating element through the interior of the valve element housing to the control passage.

drawings

In the drawings, exemplary embodiments of the valve device are shown and explained in more detail in the following description. Show it

Figure 1 is a perspective view of a valve housing element 12,

Figure 2a, a schematic representation of a plan view of a valve device 12 in a main flow position 55, Figure 2b, a schematic representation of a plan view of a valve device 12 in an expansion position 57. description

The same parts are given the same reference numbers in the different design variants.

Figure 1 shows a first embodiment of a valve device 10 according to the invention in a perspective view. The valve device 10 has an essentially cuboid housing, which is designed as a valve element housing 12 for a valve element 14 (not shown here). The valve element 14 is movably mounted, in particular rotatably relative to the valve element housing 12 about an axis of rotation 18 extending essentially in the axial direction 16 .

The valve means housing has an interior cavity 20 in which the valve element 14 is arranged when the valve device 10 is in the assembled state. In the mounted state, an internal volume 26 through which a flow can flow remains in the cavity 20 between the valve element 14 and the valve element housing 12. The valve element housing 12 has three openings 22a, 22b, 22c. The openings 22a, 22b, 22c are designed as through openings through the housing wall of the valve element housing 12.

According to the embodiment of the invention shown in FIG. 1, the openings 22a, 22b, 22c are designed as through holes. According to the embodiment of the invention shown in FIG. 1, the opening 22a is designed as a fluid inlet 23a, the opening 22b as a fluid outlet 23b and the opening 22c as a fluid outlet 23c. As can be clearly seen in FIG. 1, the openings 22a, 22b, 22c are arranged in one plane, the radial plane 24. The fluid inlet 22a and the fluid outlet 22b are arranged in alignment. Of the second fluid outlet 22c is orthogonal to fluid inlet 22a and fluid outlet 22b.

According to an advantageous embodiment of the invention, a sealing seat is arranged at least in the area of one of the openings 22a, 22b, 22c. The sealing seat is preferably designed as a sealing ring, which is arranged in the opening cross section of the at least one opening 22a, 22b, 22c.

The sealing seat is preferably arranged in a region of the at least one opening 22a, 22b, 22c that faces the inner volume 26 and encloses the opening 22a, 22b, 22c in the circumferential direction. essentially complete. According to an advantageous embodiment of the invention, the first opening 22a has a first sealing seat 27a and the second opening 22b has a second sealing seat 27b. It is also conceivable that all openings 22a, 22b, 22c each have a corresponding sealing seat 27a, 27b, 27c.

As can be seen in FIG. 1, the valve element housing 12 has a passage 30 for a valve stem 32, which is driven by an electric drive. The valve element 14 is arranged on the valve stem 32 . The valve stem 32 passes through the passage 30 of the valve element housing 12 and extends essentially in the axial direction 16. According to the embodiment of the invention shown in FIG. 1, the valve element housing 12 is designed as a valve center block. Such a valve center block is preferably made of aluminum or an aluminum alloy.

FIG. 2a shows the sectional representation of a valve device 10 along the radial plane 24 in a main flow position. As can be clearly seen in FIG. 2a, the valve element housing 12 has at least three openings 20a, 20b, 20c. According to the embodiment of the invention shown in FIG. 2a, the opening 22a is designed as a fluid inlet 23a, the opening 22b as a fluid outlet 23b and the opening 22c as a fluid outlet 23c. As can be seen in FIG. 2a, the fluid inlet and fluid outlet openings 22a, 22b, 22c are arranged in the radial plane 24. Fluid inlet 22a and the first fluid outlet 22b are arranged in alignment with one another. The second fluid outlet 22c is orthogonal to the fluid inlet 22a and the first fluid outlet 22b.

According to the embodiment of the invention shown in FIG. 2a, a sealing seat 27a, 27b is arranged both on the fluid inlet 23a and on the first fluid outlet 23b, which is opposite the fluid inlet 23a. The sealing seats 27a, 27b are designed here, for example, as sealing rings, which are arranged in the opening cross section of 22a, 22b. The sealing seats 27a, 27b are arranged in a region facing the inner volume 26 and enclose the corresponding opening 22a, 22b in the circumferential direction. A first sealing seat 27a is arranged at the fluid inlet 23a, and a second sealing seat 27b at the first fluid outlet 23b.

According to the embodiment of the invention shown in FIG. 2a, the valve device 10 has a valve element 14, which has an essentially spherical base body 38. The valve element 14 is designed to be movable, in particular rotatable relative to the valve element housing 12 . Furthermore, the first valve means housing 12 has an internal volume 26 through which a fluid can flow.

A fluid of the type in question is preferably a heat transfer medium which circulates within the fluid circuit. In particular, the fluid is a natural refrigerant, such as hydrocarbons, carbon dioxide, ammonia, propane, butane, Propene, water or a synthetic refrigerant such as chlorofluorocarbons or hydrofluorocarbons.

A valve element housing 12 of the type in question can be designed in particular as a valve center block which is designed to be essentially gas-tight due to the thermodynamic conditions prevailing in an expansion valve. In a valve device 10 of the type under discussion here, the fluid in the flowable inner volume 26 of the valve element housing 12 is at least partially in a gaseous phase, with high pressures in the range between 1-30 bar and briefly up to 100 bar prevailing. Due to these thermodynamic boundary conditions, according to an advantageous embodiment of the invention, the valve element housing 12 can be made of a metal, preferably aluminum or an aluminum alloy.

However, it is also conceivable that at least one housing part of the valve element housing 12 has a plastic body with a diffusion-inhibiting barrier layer containing metal. Such a valve element housing 12 can be manufactured simply and inexpensively in comparison to an aluminum block housing. At the same time, due to the gas-tightness of the valve device, it can be used in fluid circuits in which the fluid is at least partially in a gaseous phase.

As can be seen in FIG. 2a, the valve element 14 has a control passage 30 for a main volume flow 32 of a fluid through the valve device 10. The control passage 30 has two passage openings 34 , 36 along the flow direction of the main volume flow 32 . The passage openings 34, 36 are on the lateral surface of the Valve element 14 is arranged, wherein the second passage opening 36 is arranged upstream of the first passage opening 34 .

The openings 22a, 22b, 22c are through bores formed through the wall of the valve element housing 12. The openings 22a, 22b, 22c preferably each have identical inside diameters. The axes of symmetry of the openings 22a, 22b, 22c intersect at a common point, which is preferably at least approximately the center point of the spherical valve element 14.

According to the embodiment of the invention shown in FIG. 2a, the control passage 30 is designed as a through opening, in particular as a through bore. In order to avoid flow losses, the control passage 30 is essentially straight, preferably the first passage opening 34 and the second passage opening 36 are arranged diametrically aligned with one another. The inner wall of the control passage 30 is preferably designed without any curvature or projections. In addition to the control passage opening 30, the valve element 14 has no further opening cross sections for a main volume flow 32 of the fluid.

The valve element 14 preferably has exactly one control passage 30 which is essentially straight. In the sectional representation shown in FIG. 2a, the axis of rotation 18 extends perpendicularly out of the plane of the image. All openings 22a, 22b, 22c of the valve element housing 12 are arranged in the radial plane 24.

In addition to the control passage opening 30 , the valve element 30 has an expansion recess 40 . As can be seen in Figure 2a, the expansion recess 40 is an expansion groove in the lateral surface 44 of the Valve element 14 formed. The expansion recess 40 is in the form of a surface notch. The expansion recess 40 extends on an imaginary circular line on the lateral surface 44 of the essentially spherical valve element 14. The expansion recess 40 extends a few millimeters deep into the valve element 14. The expansion recess 40 can in particular be designed as a channel-shaped element and an essentially rectangular one have cross section. However, other cross-sectional shapes are also conceivable. It is also conceivable, for example, for the expansion recess 40 to have essentially rounded edges.

According to the invention, it is now provided that the valve element 14 has a separating element 42 which is designed to fluidly separate the expansion recess 40 and the control passage 30 within the valve element 14 from one another. In other words, within the inner volume of the valve element 14 spanned by the lateral surface 44, the separating element 42 fluidly separates the expansion recess 40 from the control passage volume 30 in the sense of a blocking element. As can be clearly seen in FIG. 2a, the separating element 42 is designed as a separating wall, preferably as a separating wall extending in the radial direction. Due to the separating element 42 , any flow paths from the expansion recess 40 to the control passage 30 - vice versa - necessarily lead along outside of the inner volume of the valve element 14 spanned by the lateral surface 44 .

As already explained at the outset, the valve element 14 according to the embodiment of the invention shown in FIG. 2a has an essentially spherical shape. The separating element 42 closes in the circumferential direction along an imaginary separating wall adjoining the expansion recess 40 . The separator 42 extends over a circumferential angle cp of between 5° and 15°, preferably between 8° and 12°, particularly preferably essentially over 10° of the valve element 14. The expansion valve extends over a circumferential angle y of 30° to 50°. The valve element 14 is preferably designed such that the sum of the circumferential angle cp of the separating element 42 and the circumferential angle y of the expansion recess 40 is less than 90°, in particular less than 80°, particularly preferably less than 70°. The circumferential angle cp of the separating element 42 is preferably many times smaller than the circumferential angle y of the expansion recess 40.

FIG. 2a shows the valve device 10 in a main flow position 50. In the main flow position 55, the first passage opening 34 is largely completely fluidly connected to the fluid outlet 23a and the second passage opening 36 is largely completely fluidly connected to the opposite fluid outlet 23b. The respective passage openings 34, 36 are preferably within the coverage area of the fluid inlet 23a or the fluid outlet 23b. The passage openings 34, 36 are fluidically tight against the fluid seat. Passage openings 34, 36 and fluid inlet 23a and fluid outlet 23b are arranged in a line aligned with one another. The fluid flowing through the valve is guided through the valve essentially without deflections and thus with the lowest possible flow losses. As can be clearly seen in FIG. 2a, the separating element 42 rests against the second sealing seat 27b in a fluidically sealing manner in the main flow position 55. The separating element 42 is thus designed to fluidly separate the expansion recess 40 from the fluid outlet in the main flow position 55 . Backflows from the control passage 30 can be avoided in an advantageous manner. According to an advantageous development of the invention, the expansion recess 40 has a flow cross section which is designed in such a way that it increases in the direction of the first passage opening 36 of the control passage 30 , in particular in the direction of the separating element 42 .

Figure 2b shows the valve device shown in Figure 2a in an expansion position 57. As can be clearly seen in Figure 2b, the valve element 14 in the expansion position 57 is rotated by 90° about the axis of rotation 18 compared to the main flow position in such a way that the first passage opening 34 is now substantially completely rests against the second fluid outlet 23c, or the projection of the second fluid outlet 23c covers the first through-opening substantially over its entirety.

The second through-opening 36 is located in the interior 26 of the valve element housing 12. Due to the selected circumferential angle y of the expansion recess 40, the latter is now in contact with the fluid inlet 23a. As can be clearly seen in FIG. 2b, the expansion recess 40 sweeps over the first sealing seat 27a in the circumferential direction. In the expansion position 57, the fluid thus flows from the fluid inlet 23a, via the expansion recess 40, the interior space 26, through the control passage opening 30, and out of the fluid outlet 23c.

The separating element 42 faces the interior space 27 and is not in contact with the sealing seat. A flow gap 60 remains between the sealing seat 27a and the separating element 42. In this way, an expansion valve can be provided with particularly simple means, in which an opening on the housing base, ie on the side facing away from the electric drive, can be particularly advantageously avoided. At the same time, a constructive simple, light valve element housing 12 are provided, which is optimized in terms of costs and at the same time has lower pressure losses by avoiding deflections in the main flow position.

Claims

Claims Valve device (10), in particular expansion valve, for regulating a fluid flow of a fluid, in particular for a refrigerant circuit of a vehicle, having a valve element housing (12) with at least three openings (22a, 22b, 22c) and a valve element (14), the valve element (14) has a control passage (30) for a main fluid flow (32) and at least one expansion recess (40), the openings (22a, 22b, 22c) being fluidically connected to an interior volume (26) arranged in the interior of the housing, the interior volume ( 26) is formed between the valve element (14) and the valve element housing (12), at least one opening (22a, 22b, 22c) being formed as a fluid inlet (23a, 23b, 23c) and at least one opening (22a, 22b, 22c) is designed as a fluid outlet (23a, 23b, 23c), characterized in that the valve element (14) has a separating element (42) which is designed to separate the expansion recess (40) and the R to fluidically separate the control passage (30) within the valve element (14). Valve device (10) according to Claim 1, that the valve element (14) can be rotated about an axis of rotation (18) and wherein the valve element (14) has a rotationally symmetrical base body (38), preferably a spherical or cylindrical base body (38). Valve device (10) according to one of the preceding claims, characterized in that the control passage (30) has a first passage opening (34) and a second passage opening (36) along the direction of flow, the expansion recess (40) in the region of the second passage opening (36 ) of the control passage (30) is arranged and wherein the Separating element (42) between the expansion recess (40) and the second passage opening (36) of the control passage (30) is arranged. Valve device (10) according to one of the preceding claims, characterized in that in a main flow position (50) the first passage opening (34) largely completely with a fluid inlet (23a) and the second passage opening (36) largely completely with a fluid outlet (23b, 23c ) is fluidically connected, wherein the separating element is designed to fluidly separate the expansion recess (40) from the fluid outlet (23b, 23c) in the main flow position second sealing seat (27b) is arranged, wherein in the main passage position of the valve device (10) the separating element (42) bears fluidically tight on the second sealing seat (27b). Valve device (10) according to one of the preceding claims, characterized in that the expansion recess (40) has a flow cross section which is designed such that it flows in the direction of the second passage opening (36) of the control passage (30), in particular in the direction of the separating element ( 42) increases. Valve device (10) according to one of the preceding claims, characterized in that the separating element (42) is designed as a dividing wall, preferably as a dividing wall extending in the radial direction, particularly preferably as a dividing wall adjoining the expansion recess (42) in the circumferential direction. Valve device (10) according to one of the preceding claims, characterized in that the separating element (42) extends over a circumferential angle of between 5° and 15°, preferably between 8° and 12°, particularly preferably essentially over 10° of the valve element (14) extends. Valve device (10) according to one of the preceding claims, characterized in that the expansion recess (40) extends in a radial plane perpendicular to the axis of rotation (18), the expansion recess (40) preferably being arranged in a plane of symmetry of the valve element (14). Valve device (10) according to one of the preceding claims, characterized in that the valve element (14) has exactly one control passage, the control passage being essentially straight, preferably designed as a through hole through the valve element (14). Valve device (10) according to one of the preceding claims, characterized in that the openings (22a, 22b, 22c) of at least one fluid inlet (23a, 23b, 23c) and at least one fluid outlet (23a, 23b, 23c) are essentially aligned. Valve device (10) according to one of the preceding claims, characterized in that the expansion recess (40) is designed as an expansion groove in a lateral surface (44) of the valve element (14). Valve device (10) according to one of the preceding claims, characterized in that the at least three openings (22a, 22b, 22c) of the valve element housing (12) are arranged in the radial plane (24), the axes of symmetry of the openings (22a, 22b , 22c) and the axis of rotation (18) of the valve element (14) largely meet a common center point. Valve device (10) according to one of the preceding claims, characterized in that in an expansion position the first passage opening (34) is largely completely fluidly connected to a fluid outlet (23a, 23b, 23c) and the expansion recess (40) fluidly with - 21 - is connected to a fluid inlet (23a, 23b, 23c), the separating element (42) being arranged in the expansion position at a distance from a first sealing seat (27a, 27b, 27c) arranged at the fluid inlet (23a, 23b, 23c). . 15. Valve element (14) for a valve device (10) according to one of claims 1 to 14, wherein the valve element (14) has a control passage (30) for a main fluid flow (32) and at least one expansion recess (40), characterized in that the valve element (14) has a separating element (42) which is designed to fluidly separate the expansion recess (40) and the control passage (30) within the valve element (14) from one another.