EP2505727A1 - Drain valve for a cistern - Google Patents

Abstract

The valve (1) has a closure body (5) provided in a valve housing (2) and moved from a closure position in which the closure body stays in fluid-tight contact with a valve seat (4), and a flush position in which the body is spaced apart from the seat. The body is moved from the flush position into the closure position after completion of flushing process. A hydraulic damping element (25) dampens movement of the body from the flush position into the closure position so that the movement of the body is decelerated before contacting the seat. The element uses flush water as a damping medium.

Description

TECHNICAL AREA

The present invention relates to a drain valve for a cistern according to the preamble of claim 1.

STATE OF THE ART

Drain fittings or drainage valves for cisterns are known from the prior art. Typically, such drain fittings comprise a valve seat, which is arranged in front of an outlet opening, through which the rinse water can flow out of the cistern, and a cooperating with this valve seat sealing element of an overflow pipe. When a flushing process is triggered, the overflow pipe is raised and the sealing element is raised equally by the valve seat. Consequently arises between the valve seat and sealing element, a gap through which the water can flow out of the cistern. After flushing the overflow pipe is moved together with the sealing element again against the valve seat, so that the waste set can be closed again.

For example, the shows EP 1 854 926 a waste set. With the waste set after the EP 1 854 926 could be minimized flushing noise.

Another waste set is from the EP 1 672 130 known, this drain set allows an intermediate flush.

Although very good results have been achieved with regard to minimization of flushing noise and also with the intermediate flushing with the drainage systems just mentioned, there is There is still a need to further minimize the noise during or immediately after flushing.

PRESENTATION OF THE INVENTION

Based on this prior art, the invention has for its object to provide a drain valve, the noise in a flushing is further minimized.

Such a problem is solved by a drain valve according to the features of claim 1. Accordingly, a drain valve for a cistern comprises a valve housing with an outlet opening and with a valve seat and a closure body which cooperates with the valve seat at a lower end. The closure body is displaceable in the valve housing from a closure position, in which the closure body is in fluid-tight contact with the valve seat, into at least one rinsing position, in which the closure body is spaced from the valve seat. After the rinsing process, the closure body is displaceable from the rinsing position into the closed position. The drain valve further comprises a hydraulic damping element, which damps the movement of the closure body from the rinsing position to the closure position, so that the movement of the closure body can be delayed before contacting the valve seat.

By provided with the damping element damping of the closure body does not hit the valve seat with full force or speed, but is deposited relatively slowly or gently on the valve seat, which leads to a minimization of noise and also to a minimization of the impact force.

The hydraulic damping element preferably uses rinsing water, which is located in the cistern, as a damping medium. As a result, maintenance of the damping element can largely be avoided or greatly reduced.

The damping element preferably comprises an integrally formed on the closure body damping surface which at least partially in itself in the cistern or in Valve housing located damping medium is immersed.

Preferably, the damping element is a related to the closure body or a molded on the closure body damping plate and filled with a damping medium cavity, wherein in the movement from the rinsing position into the closure position, the absorbed by the cavity damping medium can be displaced or flowed through the damping plate.

Preferably, the cavity is filled with a Spülwasserrestmenge, whereby the damping medium consists essentially of rinse water.

Preferably, the cavity is provided by a sidewall and a bottom wall of the valve housing.

Preferably, the damping medium in the cavity provides a spatially limited area with increased pressure, wherein in the movement from the rinsing position into the closed position, the damping plate or the damping surface are movable through the cavity, so that the cavity located in the damping medium from the through the cavity spatially limited area can be overflowed by a defined cross-section in a zone outside the spatially limited area with lower pressure.

The cross section is provided in particular by at least one opening through which the water can flow out, wherein the cross section of the opening is preferably adjustable.

In other words, it can be said that the free cross-section or opening necessary for this operating principle can be achieved in a preferred embodiment by the difference between the area of the damping plate and the surrounding spatial separation of the chamber for the damping medium. The opening can also be provided both as a passage from the cavity and / or as an opening in the damping plate. Due to the adjustability of the cross section, the damping effect can be adjusted.

The at least one opening is preferably arranged such that the water can be flowed out of the cavity in a vertical and / or horizontal and / or inclined direction to the movement axis of the closure body.

Preferably, the damping surface or the damping plate is integrally formed on the closure body, so that a one-piece structure can be provided.

Preferably remains after flushing as the damping medium a Spülwasserrestmenge in the region of the valve housing, wherein damping surface or damping plate immersed in the movement of the flushing position in the closed position either in the Spülwasserrestmenge or already immersed in the Spülwassermenge, the attenuation by the immersion resistance and / or the surface resistance of the moving in the Spülwasserrestmenge moving damping surface or damping plate is provided.

In the region of the front end, the closure body preferably has a concavely curved surface which can be flowed through by the rinsing water during the rinsing process, so that a buoyancy force on the closure body results from the rinsing water.

Preferably arises during the movement of the rinsing position into the closed position by the flow of the concave curved surface with increasing approach of the closure body to the valve seat, a suction while air at the same time by an overflow opening through the closure body is nachziehbar, resulting in a gently expiring rinsing.

A cistern assembly comprises a cistern and a drain valve according to the above description, wherein the drain valve is preferably connected via a drain opening with the cistern.

Further embodiments are given in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

eine perspektivische Ansicht von Teilen eines Ablaufventils für einen Spülkasten mit einem teilweise geschnitten Ventilgehäuse;

Fig. 2

eine weitere perspektivische Ansicht des Ablaufsventils von einer anderen Seite;

Fig. 3

eine teilweise geschnittene Seitenansicht des Ablaufventils nach Figur 1 mit Teilen des Spülkastens, wobei sich das Ablaufventil in der Verschlussposition befindet;

Fig. 4

eine teilweise geschnittene Seitenansicht des Ablaufventils nach Figur 1 mit Teilen des Spülkastens, wobei sich das Ablaufventil in der Spülposition befindet; und

Fig. 5

eine Detailansicht der Figur 3.

Preferred embodiments of the invention will be described below with reference to the drawings, which are given by way of illustration only and are not to be interpreted as limiting. In the drawings show:

Fig. 1

a perspective view of parts of a drain valve for a cistern with a partially cut valve housing;

Fig. 2

another perspective view of the drain valve from another side;

Fig. 3

a partially sectioned side view of the drain valve after FIG. 1 with parts of the cistern, wherein the drain valve is in the closed position;

Fig. 4

a partially sectioned side view of the drain valve after FIG. 1 with parts of the cistern, wherein the drain valve is in the flushing position; and

Fig. 5

a detailed view of the FIG. 3 ,

DESCRIPTION OF PREFERRED EMBODIMENTS

In the FIGS. 1 and 2 is shown a perspective view of a drain valve 1 for a cistern, wherein the cistern is not shown in these two views.

The drain valve 1 essentially comprises a valve housing 2 with an outlet opening 3 and a valve seat 4 and a closure body 5 which cooperates with the valve seat 4 at a lower end 6. In the present embodiment, the closure body 5 rests with the lower end 6 on the valve seat 4. The closure body 5 is displaceable in the valve housing 2 from a closure position in which the closure body 5 is in fluidtight contact with the valve seat 4, into at least one rinsing position, in which the closure body 5 is spaced from the valve seat 4. In the rinsing position, which in the FIG. 2 Accordingly, rinsing water can flow out through the gap 34 between the closure body 5 and the valve seat 4. After the rinsing process, the closure body 5 is again in the rinsing position the lock position is displaceable. In the FIG. 3 the closure body is in the closed position and in the FIG. 2 and 4 shown in the rinsing position.

In the FIG. 2 can also be well recognized that the housing 2 has a nozzle 21 at a lower end, which is here via two oppositely arranged webs 33 with the housing 2 in conjunction. The nozzle 21 can, as in the FIG. 3 can be fixed in a known manner to the bottom 22a of a box body 22 of a cistern 13. The nozzle 21 forms here the outlet opening 3 with the valve seat 4 forms.

At the lower end 6, the closure body 5 has a sealing disk 23 revolving around the closure body 5, which rests on the valve seat 4 in the closed position and thus provides a fluid-tight connection. The sealing disc 23 is embedded in a groove 24 on the closure body 5.

The closure body 5 can be raised with a tie rod, not shown, for triggering a flushing from the closure position into the flushing position. The pull rod can be arranged on a dual-quantity actuation device and engages on the closure body 5. The dual-quantity operating device has, for example, keys and pushers. Such a suitable operation is for example from the WO 01/46528 or the EP 1 672 130 have become known to the applicant. With this two different strokes are possible. In a first stroke for a partial flush of the closure body 5 is raised less high than when triggering a full flush. Consequently, there are two rinsing positions here, namely one for the partial rinse and one for the full rinse.

In the FIG. 3 the box body 22 is filled with rinse water 17. The water surface 18 is in this case below an overflow opening 5a of the closure body 5. The amount of water that is present in the cistern 13, for example, 9 or 6 liters. The overflow opening 5a extends through the entire closure body 5 and serves for the removal of rinse water, if the water level rises unintentionally.

The drain valve 1 further comprises a damping element 25, which in particular in of the FIG. 1 easy to recognize. The damping element 25 damps the movement of the closure body 5 from the rinsing position into the closure position, so that the movement of the closure body 5 can be delayed before contacting the valve seat 4. The damping element 25 has the advantage that the closure body 5 does not impinge on the valve seat 4 at full speed, so that the associated noise development is massively reduced. In particular, the sound of the impact is massively reduced. The closure body 5 is, as will be explained below, moved substantially by its gravity against the valve seat.

The damping element 25 is a hydraulic damping element, which provides the damping due to a water displacement or by the sheet resistance of the damping element 25 in a damping medium. Particularly preferably, the flushing water 17 located in the cistern 13 is the hydraulic damping medium, which has the advantage of a simple design of the damping element 25.

The damping element 25 can be designed in various ways. In the present embodiment, the damping element 25 is a damping surface 26 integrally formed on the closure body 5. This damping surface is then submerged in a flushing water residue quantity 27 which is located in the cistern 23 or in the valve housing 2 or can be moved by the flushing water remaining quantity 27. By dipping in the rinsing water remaining amount 27 and moving through the rinsing water remaining amount 27, the above-mentioned damping effect is provided. The damping effect, if it is the damping surface 26 is not yet in the Spülwasserrestmenge 27, two stages, since the movement of the closure body 5 when immersed in the Spülwasserrestemenge 27 and also in the subsequent movement by the Spülwasserrestemenge 27 is attenuated. By varying the filling level of the residual rinsing water quantity 27, therefore, the closing time of the closure body 5 can be optimized from the rinsing position into the closing position. A low water level means a short closing time and a high water level means a higher closing time.

The Spülwasserrestmenge 27 is in the FIG. 4 shown. There is the Spülwasserrestmenge 27 in the interior of the valve housing 2. If now the Closure body 5 of the in FIG. 4 shown rinsing position is moved back into the closed position, the damping surface 26 comes with the flushing water 27 remaining in contact. In order to allow movement after this contact on, escapes the Spülwasserrestmenge 27 along the arrow P. Consequently escapes here the Spülwasserrestmenge 27 first perpendicular to the closure body 5 and is then deflected by the valve housing 2 upwards and then moves parallel to the closure body. 5 Alternatively, the damping surface 26 could also be in connection with the closure body 5, that this impinges on the Spülwasserrestmenge 27 'in the cistern 13 and not in the valve housing 2 in the movement from the rinsing position to the closure position. In both embodiments can be said that the damping surface 26 is at least partially submerged in the flushing water remaining amount 27, 27 '.

In other words, it can also be said that the damping element 25 comprises a damper plate 28 in communication with the closure body 5 and a water-filled cavity 29, wherein the damper plate 28 is movable with respect to the cavity 29 therein and in the movement of the rinsing position in the closed position, the water absorbed by the cavity 29 can be displaced by the damping plate 28. The damping plate 28 in this case comprises the above-mentioned damping surface 26. Preferably, the cavity 29 is filled by the Spülwasserrestmenge.

The damping plate 28 is here formed on the outside of the closure body 5, whereby a one-piece structure can be created. In this case, the damping plate 28 with respect to the closure body 5 circumferentially or partially formed circumferentially. In the present embodiment, the damping plate 28 is partially formed circumferentially. The damping plate 28 is additionally connected via reinforcing ribs 35 with the closure body 5 in connection.

With respect to the damping plate 28 and the damping surface 26 may be mentioned at this point that in the case of a partial flush, so if the cistern empty, for example, only half, the damping surface 26 has the same effect. Again, the damping plate 28 by the Spülwasserrestmenge, in which the damping plate 28 is moved, and thus this movement is damped. The water level of Spülwasserrestmenge is then slightly higher in this case than a full flush.

In summary, therefore, it can be said that the damping surface 26 or the damping plate 28 either during the movement of the rinsing position in the closed position impinge on the Spülwasserrestmenge and then immerse or is already submerged before the movement in the Spülwasserrestmenge.

The cavity 29 is preferably provided by the interior of the valve housing 2, in particular by a side wall 11 and a bottom wall 12 of the valve housing 2. Consequently, the cavity 29 forms an integral part of the valve housing 2, which eliminates the provision of a separately formed element.

The cavity 29 is arranged here in the lower region of the valve housing 2. If the damping plate 28 or the damping surface 26 lowers when closing, the water below it flows from the spatially limited area with increased pressure, that can flow from the cavity 29 through a defined cross-section in a zone outside this boundary with lower pressure.

The cross section may for example be an opening 30, from which the water can flow out of the cavity 29. The opening 30 may be provided from a plurality of openings. In the present embodiment, the opening 30 is provided by the cross-section of the valve housing 2, which is not covered by the damping plate 28 or other elements, such as the float 9.

In other embodiments, the opening 30 may also be designed so that the cross section of the opening 30 is adjustable, so that a greater attenuation can be achieved by reducing the opening cross section or a smaller attenuation can be achieved by increasing the opening cross section.

Preferably, the at least one opening 30 is arranged such that the water can be flowed out of the cavity 29 in a vertical and / or horizontal direction to the movement axis M of the closure body 5.

In the FIG. 4 can also be recognized that the opening 30 'can also be arranged in the valve housing 2 and thus the rinse water is pressed into the box body 22 from the valve housing 2. The opening cross-section of the opening 30 'could be influenced by a slider 36, wherein the slider could also have other functions, such as influencing the float 8, 9.

In the figures, in particular in the detail view of FIG. 5 , It can also be seen that the closure body 5 has a concavely curved surface 31 in the region of the front end 6. The surface 31 is preferably formed circumferentially. When the flushing water 27 flows out, that is to say during the flushing process, this concavely curved surface 31 can be flowed through by the flushing water. Due to the formation of this surface 31 acts by the flushing water flowing past a resulting buoyancy force on the closure body, whereby this is supported in the movement from the closure position to the rinsing position. The shape of the surface 31 also supports the buoyancy of the closure body 5 in the open state of the purge valve. If a flushing pipe is used below the valve seat 4 in the direction of flow of the expiring rinse water, the suction force on the closure body 5 increases during the flushing process. The concave curved surface 31 generates a direct-acting buoyancy force as a function of the flow velocity of the rinse water. As a result of the described function of flow velocity, suction force and the resulting buoyancy force which is generated via the shape of the surface 31, the influence of a flushing pipe with variable length or other external influences in the hydraulically effective flushing flow can be largely decoupled from the functional behavior of the drainage valve 1.

During the movement from the scavenging position into the closed position, an approximation of the sealing disk 23 to the valve seat 4 and the presence of the still ongoing scavenging flow results in an acceleration or suction on the closure body 5. The curved surface 31 acts increasingly cross-sectionally narrowing during lowering. The flushing flow is thus continuously reduced by the immersion of the cone shape in the closing direction. At the same time 5 air is drawn through the overflow opening 5 a of the closure body, resulting in a gently expiring rinsing process. By the damping element 25 is a damping force against the suction force provided.

In summary, it can be said that the total force with which the closure body 5 impinges on the valve seat, the resultant of gravity, damping force and optionally the suction force.

In connection with the FIG. 4 is also noted that the closure body 5 can be raised so far from the valve seat that the end 32 of the closure body 5 comes to rest in a pressure-neutral zone. Under a pressure-neutral zone is understood that in the region of the end 32, the inflow of water into the closure body 5 can be largely avoided because prevail at the lower end of the tube almost balanced, so neutral, pressure conditions. This effect ensures that the weight of the moving parts of the valve to be retarded can not increase uncontrollably during the closing process due to the ingress of water. In addition, we support the immediate ventilation of the purge stream through the overflow opening 5a of the closure body 5, which the suction effect which is caused by the full filling of the flushing pipe, repeals.

With reference to the FIGS. 1 to 4 will be shown in the episode further features of the outlet valve. The damping plate has a passage 19 through which the adjusting element 10 projects with a tolerance range 10d and / or a thread 10c. At the lower end of the tolerance range 10d, a stop 10b is arranged, which is designed here as a thickening. Above the tolerance range 10d, the adjusting element 10 has a thread 10c into which an upper float 8 is screwed. By turning the adjusting element 10, the upper float 8 can be adjusted continuously in height. The adjusting element 10 also has an upper end 10a, which projects into a guide element 16, which is part of the valve housing 2, slidably. As can be seen, the adjusting element 10 is rod-shaped and serves to couple the upper float 8 to the closure body 5 during a partial flushing.

On the housing 2, a lower float 9 is pivotally mounted. The storage of the lower float 9 on the housing 2 is carried out with a pivotable with the housing 2 in related pivot axis 9b.

At the lower float 9, a nose 9a is formed, which cooperates with a molded onto the closure body 5 gate 20. This gate 20 has a stop 20a, which is also designed as a laterally projecting nose or shoulder. The stopper 20a has a dual function. In one case, the stop 20a limits the stroke of the closure body 5 and in the other case, the closure body 5 is supported on the lower float 9.

The operation of the inventive drain valve will be explained in more detail. It should be noted that other types of operation of the movements described below are conceivable.

To trigger a partial flush the closure body 5 is raised by pressing the corresponding keys. Due to the buoyancy of the upper float 8, the adjustment member 10 is also slightly raised until the adjustment member is present at the guide member 16. Another buoyancy of the closure body 5 is prevented by the lower float 9, which rests with the nose 9a on top of the stop 20a. By the buoyancy of the upper float 8 of the closure body 5 in the in FIG. 2 shown position held. Since the closure body 5 is lifted from the valve seat 4, the valve is open and water 17 flows through the opening 3, preferably via a not shown Spülrohr, in a toilet bowl, not shown here. This is shown by arrows S. Accordingly, the water surface 18 drops. Now is the water surface 18 below the upper float 8, the buoyancy drops through this upper float 8 and the closure body 5 falls on the valve seat 4, wherein the movement of the closure body 5 is damped by the damping element 25 , The drain valve 1 is closed. Since the box body 22 is only partially emptied, is still in the box body 22 17, for example, 3 or 6 liters. About a here not shown per se known inlet valve, the box body 22 is now filled again until the in FIG. 1 shown water level is reached.

When triggering a full flush, in which, for example, purged with 6 or 9 liters, the closure body 5 is raised. The hub is a bit bigger than here when triggering a partial flush. The upper float 8 is also raised by the buoyancy with the adjusting element 10. The limitation of the movement occurs because in the lower region of the closure body, a shoulder 37 above the inserted seal 23 limits the maximum possible stroke against the housing halves 2. When lifting the closure body 5, the nose 9a slides along the slide 20 and finally reaches a position in which the nose 9a is located below the stop 20a. The closure body 5 now rests on the lower float 9, while the upper float 8 is ineffective during the flushing. The drain valve 1 is now also open and water 17 flows through the opening 3, preferably via a not shown flushing pipe, down into the toilet bowl. The water surface 18 is below the upper float 8, so it rests on the closure body 5, which remains in the open position, since it is supported on the lower float 9. The water surface 18 thus decreases further down and finally reaches the lower float 9. When the water surface 18 sinks into the area of the lower float 9, the buoyancy also drops away and the lower float 9 pivots due to its own weight and the weight of the closure body 5 away from the closure body 5. The closure body 5 is no longer supported and falls on the valve seat 4, wherein the movement of the closure body 5 is damped by the damping element 25. The cistern 13 is still only a residual amount of water 17. The drain valve 1 is closed. Again, the cistern 13 is automatically refilled via the inlet valve, not shown here. Finally, the in FIG. 1 reached shown position. The cistern 13 is now ready for a partial flush or full flush.

In summary, it can be said that the arrangement of the damping element 25 has the advantage that the movement of the closure body 5 is damped with decreasing distance to the valve seat 4, so that the impact of the closure body 5 on the valve seat with a smaller noise occurs.

LIST OF REFERENCE NUMBERS

1

drain valve

2

valve housing

3

outlet opening

4

valve seat

5

Closure body (valve tube)

5a

Overflow opening

6

The End

8th

upper float

9

lower swimmer

9a

nose

9b

swivel axis

10

Adjustment element (adjusting screw)

10a

top end

10b

lower end

10c

thread

10d

tolerance

11

Side wall

12

bottom wall

13

cistern

16

guide element

17

water

18

water surface

19

passage

20

scenery

20a

attack

21

Support

22

box body

22a

ground

23

sealing washer

24

groove

25

damping element

26

damping area

27

Spülwasserrestmenge

28

damping plate

29

cavity

30

opening

31

curved surface

32

The End

33

web

34

gap

35

reinforcing ribs

36

pusher

37

shoulder

P

arrow

Claims (15)

Drain valve for a cistern (13), comprising a valve housing (2) with an outlet opening (3) and with a valve seat (4) and a closure body (5) which cooperates with the valve seat (4) at a lower end (6), wherein the closure body (5) in the valve housing (2) from a closure position, in which the closure body (5) is in fluidtight contact with the valve seat in at least one rinsing position, in which the closure body (5) from the valve seat (4) is spaced, is displaceable, and after completion of the rinsing operation from the rinsing position to the closing position, is displaceable, characterized in that the drain valve further comprises a hydraulic damping element (25) which damps the movement of the closure body from the rinsing position to the closing position, so that the movement of the Lock body (5) before contacting the valve seat (5) is delayable. Drain valve according to claim 1, characterized in that the hydraulic damping element (25) uses flushing water (17), which is located in the cistern (13), as a damping medium. Drainage valve according to one of the preceding claims, characterized in that the damping element (25) comprises a damping body formed on the closure body (26) which at least partially in the cistern (23) or in the valve housing (2) located damping medium (27, 27 ') is submersible. Drain valve according to one of the preceding claims, characterized in that the damping element (23) with the closure body (5) in connection or on the closure body (5) integrally formed damping plate (28) and one with a damping medium (27, 27 ') filled Cavity (29), wherein during the movement from the rinsing position into the closed position, the damping medium (27, 27 ') accommodated by the cavity (29) can be displaced or flowed through by the damping plate (28). Drain valve according to one of the preceding claims, characterized in that the cavity (29) with a Spülwasserrestmenge (27, 27 ') can be filled. Drainage valve according to one of the preceding claims, characterized in that the cavity (29) by a side wall (11) and a bottom wall (12) of the valve housing (2) is provided. Drainage valve according to one of the preceding claims, characterized in that the damping medium in the cavity (29) provides a spatially limited area with increased pressure, wherein in the movement from the rinsing position into the closing position, the damping plate (28) or the damping surface (26) the cavity (29) are movable, so that in the cavity (29) located damping medium from the space through the cavity (29) spatially limited area by a defined cross section (30) in a zone outside the spatially limited area (29) with less Pressure is überströmbar, wherein the cross section is provided in particular by at least one opening (30) through which the water can flow, wherein the cross section of the opening (30) is preferably adjustable. Drainage valve according to one of the preceding claims, characterized in that the at least one opening (30) are arranged such that the water in a vertical and / or horizontal and / or inclined direction to the movement axis (M) of the closure body (5) from the cavity ( 29) is also flowed out. Drain valve according to one of the preceding claims, characterized in that the damping surface or the damping plate (26 or 28) extends radially from the closure body (5) and at least partially surrounds it. Drain valve according to one of the preceding claims, characterized in that the damping surface or the damping plate (26 or 28) is integrally formed on the closure body, so that a one-piece structure can be provided. Drain valve according to one of the preceding claims, characterized in that after the flushing process as a damping medium a Spülwasserrestmenge (27) in Area of the valve housing (5) remains, wherein the damping surface or damping plate (26, 28) immersed in the movement of the rinsing position in the closed position either in the Spülwasserrestmenge (27) or are already immersed in the Spülwassermenge (27), wherein the damping by the immersion resistance and / or the surface resistance of the moving in the Spülwasserrestmenge damping surface or damping plate (26, 28) is provided. Drainage valve according to one of the preceding claims, characterized in that the closure body (5) in the region of the front end has a concave curved surface (31) which can be flowed through during the rinsing process by the rinsing water, so that by the rinsing water a buoyancy force on the closure body results. Drainage valve according to claim 12, characterized in that during the movement from the rinsing position to the closure position by the flow of the concave curved surface (31) with increasing approach of the closure body (5) to the valve seat (4) creates a suction effect, while at the same time through air an overflow opening (5a) is nachziebar by the closure body (5) .. Drain valve according to claim 13, characterized in that the closure body (5) as far as the valve seat can be raised so that the end (32) of the closure body (5) comes to lie in a pressure-neutral zone. Cistern assembly comprising a cistern (13) and a drain valve (1) according to one of the preceding claims, wherein the drain valve (1) via a drain opening with the cistern (13) is in communication.

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