DE2821167B2 - Membrane to keep two neighboring rooms separate - Google Patents

Description

As is known, membranes have a wide variety of uses. When used as regulating diaphragms, they transform the signal pressure of a control medium into a rod force for actuating a switching, control or Display device. Conversely, pump diaphragms have the task of converting a rod force into a fluid pressure to convert. Finally, elastic separating membranes should be used in pressure accumulators and pressure equalization vessels a change in volume between two almost identical rooms with the lowest possible intrinsic resistance enable. Finally, membranes are part of shut-off valves, e.g. B. diaphragm valves and membrane gate valves, leather use case

places specific requirements on the membrane to be used - on the shape, the strength, the Flexibility and the possible hub.

In the case of the membranes known up to now, considerable changes in shape occur during a working stroke stress the membrane material heavily. It is also known by the different shape of the Membrane, e.g. B. plate, beading, plate or hat shape, the particularly harmful deformation by fulling like this to be kept as short as possible in order to achieve the longest possible service life. This in its basic form more or less flat membranes generally allow only a very limited stroke. at The material would be stretched over long strokes, which would allow rolling diaphragms to be subjected to additional stress In contrast, a large stroke, the membrane thickness and the strength of the material that can be used however, there are limits due to the strong changes in shape.

Other membrane constructions are relatively thick and show in cross-section a more or less curved arcuate course running in one direction. You are like that clamped between housing parts that between the outer and the middle clamping point in the top and bottom corner position the arched course is retained. But you suffer from that Disadvantage that only a small stroke can be used to avoid turning over.

All previous diaphragms that have an arcuate cross-section of part of the diaphragm ring surface or the have the entire annular membrane area between the outer and central clamping point, limit the Sequence of movements on this membrane area; the center of the membrane cannot take part in the change in shape participate, as they are rigid and intended for the fixed connection of the adjustment elements for controlling the membrane is. So only part of the entire membrane surface, a circular section, is used for the sequence of movements utilized.

The invention relates to a membrane for keeping two adjacent spaces the same or separate different prints made of flexible material of permanent, defined basic shape with or without Fabric inlay or overlay, the flange-like edge of which is clamped between two housing parts, the directly adjoining this section on the side facing the clamping edge in all positions the movement forms a circumferential ring vault.

A membrane of the design described above is known from DE-AS 25 10 428. This includes a shut-off valve with a straight flow and with an inclined to the direction of flow, the valve housing having the valve seat with a clamped between the housing lower and upper part, in its middle area as likewise inclined, like a flap from the open to the closed position pivotable valve closure piece formed membrane and with an oblique to the flow direction arranged, with the center of the valve closure piece articulated valve spindle. The Membrane between its clamped edge and the valve closure piece one in the open position and Closed position, seen from the valve seat, trough-shaped, concave curvature. This for a shut-off valve A membrane created with a special design is not symmetrical in cross-section or viewed from above, because the locking piece to the clamping plane

is arranged obliquely and the arc length of the curvature of the membrane is seen in the direction of flow steadily shrinking from one end of the membrane to the other

From US-PS 32 07 472 it is known in a membrane in a valve for a tap that the flange-like clamping edge of the membrane drawn inward and between the cover and the metallic part of the locking piece clamped kt

The present invention is based on the object Ό to create a membrane that allows a variety of uses with a uniform basic shape, in their Movement is subject to only minor changes in shape when foreign components and supporting organs are omitted and in relation to their diameter and their surface a large one, each according to their use modified stroke enables In particular, it is intended to seal under high differential pressure standing media and the print side can be freely selected. In addition, the aim is the elasticity and reducing the strength of the membrane or reducing the size of the membrane working area Breakthroughs for the adjustment elements for the control are avoided.

To solve this problem, a membrane is used to keep two adjacent rooms separate same or different print made of flexible material with a permanent, defined basic shape with or without fabric inlay or overlay, their flange-like edge between two housing parts is clamped, with the directly there; to the subsequent section on the clamping edge facing side in all positions of the movement forms a circumferential ring vault, according to the invention suggested that with increasing wall thickness of the membrane in the direction from the Einspanrirand to it In the middle, the ring vault on the underside of the membrane and the convex curvature of the top of the membrane merges into a reversal curve in the middle area of the membrane

A membrane with these characteristics is versatile. So it can be applied as a Stabilizer for lifting, damping or pushing. It can also be used as a membrane in a variable speed drive or as a membrane in a shut-off valve.

A membrane with the features according to the invention has the following properties:

1. With great lifting capacity, it has only slight changes in its spatial _{shape when it moves} , so that no bends or flexes occur;

2. when applied from above, the control pressure forces resting on the diaphragm are due to the vault shape to an externally ring-shaped acting reaction force and in the middle of the Membrane to a point acting reaction force, so that when used in one Control drive or a slightly higher control pressure in a shut-off valve is sufficient, in order to generate the necessary higher pressure and sealing forces in the area of the middle of the membrane;

3. the membrane is evenly acted upon on its entire surface with direct pneumatic or hydraulic loading, so that the specific stress per unit area reaches its minimum and thus a locally strong load as with membranes ΓΤΐίι in ucr iviitiC HngrciiCriuCn vcrsiCuOinncinun gen is avoided;

4. the membrane is supported on its entire surface when a change in position is initiated;

5. when a liquid is used to actuate the diaphragm, there is no counterpressure no further or additional stress on the membrane material;

6. the membrane material, e.g. B. rubber, is no longer under operational stress in any phase Train, but only under pressure and thus in the cheapest and most gentle way for an elastomer at all;

7. There is no friction between the membrane and the housing, causing mechanical destruction is avoided;

8. Because of the arching effect of its arches, the membrane is suitable for high pressure without changing its shape to withstand;

9. A decrease in strength of the membrane material used at higher temperatures because of the required small pressure difference between control and operating medium does not or not noticeably disturbing;

10. The membrane itself takes on the leadership and positioning of the closure piece or the Center of the diaphragm and not one on the side of the diaphragm facing away from the valve seat Lying special guide device required in previous diaphragm valves;

11. when the membrane is acted upon by a Inert hydraulic fluid is also a high level of protection against aging, for example against atmospheric oxidation or that under the influence of ozone under static or dynamic stress caused cracking given. As is well known, one caused by aging progresses Destruction of membranes in shut-off valves regularly from the outside to the inside, i.e. to the Operating medium. This was achieved through the use of the membrane according to the invention Anti-aging is also of particular importance because anti-aging agents are added to the rubber provide protection to the rubber only under static load, but not under dynamic stress.

In a further embodiment of the invention it is proposed that, seen in cross section, the arched convex arching curves of the ring vault intersect in the middle of the membrane. By this proposal consists of the entire top of the membrane from the ring vault. But underneath it is also to understand that the curves can intersect in the extension of the domed membrane top and im In the middle area there is a convex rounding of a small area. This will be discussed in further proposed embodiment according to the invention that the convex surface of the membrane top Ring vault makes up more than about 70%, in particular more than 90% of the total membrane top. With this stipulation, the further advantages are achieved:

12. For a given diameter, the membrane has in all its positions while maintaining the Vault shape because of the largest possible interpretation of the membrane gusts a large stroke. the

only leads to a very small deformation or change in the shape of the space;

13. The stroke is greatest in the center of the membrane and steadily decreases towards the outside. At the hub is the entire diaphragm area involved, but each point concentric around the one on another Center of the diaphragm described circle point is, outwardly with a smaller one Path. The membrane thus only displaces a relatively small volume during one working stroke, So that only to an equally large small consumption volume of tax or Working medium leads. When a pneumatic drive is used, there is therefore less air consumed than with a drive with the same mub, in which in the previous manner a cylindrical space had to be filled with one working stroke.

The solution according to the invention is particularly advantageously used as a valve in which the membrane is through a hydraulic fluid is applied. In this valve, a displacement piston works against the above the membrane is filled with a liquid space. Because of the center of the membrane ever larger bow thrust is already due to a relatively small volume displacement a great stroke achieved. The actuation forces required are also extremely low, since the area of Displacement piston and diaphragm are in a reduction ratio.

The advantages of the direct pressurized membrane already mentioned can now be used for the first time can be used with a diaphragm valve. The usually more or less large Punktueil Attacking actuating forces are replaced by one that is distributed over the entire membrane surface Force with minimal stress per unit area; occur in the diaphragm material in each actuation phase exclusively compressive stresses - no more tensile stresses; effective through the center When the arc thrust is developed, all forces acting on the membrane surface, depending on the point of application, become whole or partially used for the closing movement and the required sealing forces; the diaphragm valve is suitable as a high-pressure valve, as the diaphragm is constantly affected by the hydraulic fluid over its entire surface is supported and the membrane is always so stable due to its vault shape to the To be able to transmit sealing forces.

In a further embodiment according to the invention, the inner and outer limiting curves of the begin Ring vault from the outer edge with a steep (more than 45 °) angle.

In a further embodiment according to the invention, the entire upper side of the membrane is used as a work surface It is free of actuating devices or parts connected to the membrane of that. As a result, the entire top of the membrane takes part in the change in shape, so that the Curvature effectively extends unhindered to the middle of the membrane and also for actuating the Membrane in the middle area of the membrane is effective.

In order to achieve an additional reduction in the deformation of the diaphragm when it is actuated, however also in order to be able to carry out this with a small outer diameter, furthermore to make the membrane in Improved connection with hydraulic actuation between the upper part of the housing and the lower part of the housing To be able to clamp and seal, it is proposed in a further embodiment according to the invention that the flange-like clamping edge is drawn inwards and also by a small amount towards the outside protrudes.

In the case of a membrane that acts as a valve between a lower housing part through which the medium flows and is clamped in a housing upper part receiving the valve actuation, is further according to the invention Design proposed that between the membrane side and the inner surface of the upper housing part there is a space filled with a pressure medium which directly actuates the membrane. This pressure medium can be compressed air

! 5 act. Is particularly advantageous as a pressure medium however, a liquid such as glycerine, water, or oil. When applying pressure affects then the pressure fluid is applied to the entire membrane surface and actuates the membrane. The pressure can by means of a pressure-generating device via a line into the space between the upper part of the housing and the top of the membrane. Particularly advantageously protrudes into the space between the upper side of the membrane and inner surface of the upper housing part an axially displaceable piston into it, which at its Movement in the direction of the membrane increases the pressure of the liquid and thus increases the membrane indirectly actuated via the liquid. This solution is particularly advantageous because the piston is driven by a spindle, however can also be actuated by an electromagnet, since the forces to be exerted are only slight to need. The solution to control the membrane via a liquid now makes it possible that the space filled with the pressure medium »wipe the top of the membrane and the inner surface of the upper part of the housing is provided with a pressure gauge connection for pressure and position indication

The invention is explained in more detail in the drawing using a few exemplary embodiments.

Show it

IA to ID the membrane in vertical section in different positions,

F i g. 2 shows a horizontal section through the membrane according to FIG. 1B according to the local line H-II,

F i g. 3 the view of the membrane top,

F i g. 4 a membrane according to FIG. 1 as part of a variable speed drive,

F i g. 5 two membranes according to FIG. 1 as lifting cushion,
6 shows a membrane in connection with a

so thrust drive,

F i g. 7 shows a vertical section through a membrane in connection with a lifting cushion,

F i g. 8 a vertical section through two membranes as lifting cushions,

F i g. 9 a vertical section through two membranes, also as lifting cushions,

F i g. 10 in vertical section a membrane as a valve in a valve housing.
According to FIG. 1A, the membrane 10 consists of elastomers, in particular rubber. The F i g. 1A shows the upper position, FIG. IB the basic position. The basic position has the spatial shape of the production and thus the vulcanization shape. Fig. IC shows the lower position. FIG. ID shows in full lines the upper position according to FIG. 1A and in dashed lines the lower position according to FIG. IC From FIGS. 1A and 1D it can be seen that the membrane underside 11 in all positions of its movement in the range between

its clamping edge 12 and the center 11 has a circumferential concave annular vault R lying above the clamping edge and the wall thickness of the annular vault increases on the way from the clamping edge 12 to the center M of the membrane. From the representation in FIGS. 1A to 1D it can be seen that the membrane 10 is exposed to only minor changes in shape during its actuation, in particular flexing or rolling movements are avoided. There is also no bend in the vicinity of the clamping edge, as shown particularly clearly in FIG. 1D with the illustration of the two extreme positions. F i g. 1D also shows that the diaphragm allows a large stroke when actuated, in spite of slight deformation.

The F i g. 1 also shows that the wall thickness of the ι ^Γ > ring vault constantly increases in the direction from the clamping edge to the center of the membrane.

In Fig. IC it is shown that the upper outer annular arch surface Fl, whose diameter is drawn is, in the projection by more than 20% larger than the lower or inner annular vault surface F2, whose Diameter is also shown.

F i g. 2 shows that-II H, the surface F3 of the circular ring with the area F 4 of the circle in the three-dimensional shape of the membrane produced according to FIG. IB, in a section parallel to and subsequent to the flange 12 and its mounting in the middle M of the diaphragm 10 located is the same or approximately the same. By this provision it is achieved that the membrane stabilizes itself during its movements and no special guidance of the 3 "membrane is necessary.

The F i g. 1A to 1D show that on the membrane upper side 13 of the membrane, the curved surface 14 of the annular arch R makes up almost 100% of the total surface of the upper side. The F i g. 1 shows that, seen in the cross section shown there, the upper left limiting curve 14Z. and the upper right limiting curve 14 /? cut in the middle of the membrane at an acute angle. 1A to ID also show that the outer limiting curves 14 and the inner limiting curves 15 of the annular vault have a spiral segment shape. This leads to the fact that in the upper end position according to FIG. 1A there is a circular arc shape, the ascending membrane arc in the vicinity of the clamping edge 12 changing its direction only slightly. This shape, which corresponds to the ideal shape of a pressurized surface, is made possible by the somewhat greater elasticity of the outer area both when pressure is applied from below and from above. During the transition to the lower end position, the steeper branch of the membrane arch also prevents a stronger turning, because the length of the steep arch branch leads to a smaller local change in direction, but overall it will allow the permissible movement of the membrane center. The pressure load either below or above the membrane continues to counteract a bending, because the membrane strives to assume a circular shape bo in the outer area during this downward stroke, while the middle part, due to its greater thickness and thus greater rigidity, maintains a favors flatter shape

Compared to a shape of the membrane arch as a semicircle or circular segment in the vulcanization position, the suggestion of the spiral shape with a steep outer branch of the curves 14 and 15, which merge in the arch form into the upper part 16 of the clamping edge 12, the change in shape in this transition area, which is known at other solutions are subject to particular stress, limited to a minimum.

Fig. IB with the representation of the vulcanization position of the membrane shows that the upper limit curves 14Z. and 14 /? Cut at the height of the top 16 of the clamping rim 12 at point 18. This intersection point 18 is to be indicated as the membrane center in the following consideration. Fig. 1A with the upper position of the membrane shows that the aforementioned point of intersection is 2/3 higher than the point of intersection in the illustration in Fig. IC. The two end positions are also shown in FIG. 1D clearly. By the proviso that the stroke of the membrane center with respect to the clamping plane determined by the inner clamping edge during the closing movement according to FIG. 1A distributed two-thirds above the clamping plane, the bending stresses in the membrane material, especially in the outer area, are also reduced more than with a stroke that would take place half above and half below the clamping plane.

The F i g. IA to ID also show that no rigid middle area is present. Previously known membranes have a pronounced dimensionally stable center piece, so that their central area does not contribute to the change in shape that enables the diaphragm stroke can, but the change in shape occurs exclusively in the smaller circular diaphragm working area plays.

In the present membrane, the entire area of the membrane is the membrane working area. Every change in position of the diaphragm thus leads to a simultaneous one Change in shape of the entire membrane surface. The membrane center performs the largest stroke, while the stroke continues to decrease towards the outside. According to the present solution is thus a large stroke of the membrane center is achieved with a small stroke volume. This particular property of the Diaphragm leads to their versatile use, for example for a diaphragm actuator. Even significantly less air is required for a stroke with pneumatic actuation than with previous diaphragm drives in which the middle part of the diaphragm is designed as a rigid plate and so that a displacement of a cylindrical space must take place.

The membrane, in which the arch shape or the ring vault is retained in every operating position, leaves pressure loads of more than 10 bar. It should be noted that with previous membranes regularly 10 bar represent the highest pressure load.

3 shows an upper side of the membrane, in which in the area of the middle of the membrane the upper limiting curves 14L and 14 /? merge into a concave arc 17. With this solution it is found that the outer curved surface of the ring vault makes up the greater part of the surface of the membrane and the surface F6, which is determined by the curve 17 of opposite inclination, is very small compared to the surface F5

The F i g. 1 also shows that on the underside of the membrane the limiting curve starting from the edge

ven ISi. and 15Λ in the central region of the membrane merge into a reversal curve 20 which represents a segment of a circle in the central region of the membrane. Furthermore, FIG. 1, like all other figures, shows that the flange-like clamping edge 12 is drawn in inwards and also protrudes outwards by a small amount. Also, as FIG. 1B shows, the flange-like edge 12 has an embedded reinforcing ring 21 provided.

FIG. 4 shows that the membrane according to FIG. 1 is used as a regulating drive. For this purpose, the membrane is clamped between an upper housing 21 and a lower case 22 with the proviso that the two housings 21 and 22, the flange-like rim 12 of the diaphragm surround on four sides so that a i ^r> particularly good clamping and sealing the retaining edge takes place. A pressure medium is introduced between the upper side of the diaphragm and the housing 21 via the connection 23, which actuates the diaphragm, so that the plunger 26 is actuated against the pressure of a helical spring 25 via a shoe 24 resting against the underside of the diaphragm. With a vent opening is designated.

F i g. 5 shows the arrangement of two membranes 10, the undersides of which are opposite one another. Both membranes 2> 10 are held by a common ring 28, with pipe clamps assigned to each membrane 29 and 30 provide the necessary security. In the space between the two membranes, the Port 31 is filled with a pressure medium. This can be done in also be compressed air. The arrangement according to FIG. 5 can serve that a on the upper membrane 10 lying object 32 is lifted or its vibrations are damped. The lower one Membrane 10 is supported on a stool 32, which over » a flat iron 33 is connected to a foundation 34.

F i g. 6 shows a further control drive comparable to that according to FIG. 4, but with the proviso that the lower side of the membrane 10 in the area of its center to between the arches R has an approximately elliptical thickening 35 in cross-section, the outer edge 36 of which is in the area or below the clamping edge 12 and laterally in a part all around the bulge R protrudes so that an undercut is present. The thickening 35 is provided with an inner metallic reinforcement 37 which is designed in the shape of a lens and, as shown in FIG. 6, is in one piece with a plunger 38. The clamping of the membrane takes place between the two housing parts 21 M and 22 in basically the same way as that of FIG. 4 has been described. Even with the arrangement according to FIG. 6 there are two pressure chambers 39 and 40 to which a pressure medium can optionally be applied via associated connections 23 and 27.

F i g. 6 shows particularly clearly that the thickening 35, in which the reinforcement 37 is present, lies in an area outside the effective area of the annular vault R , so that the membrane has the properties that are shown in FIG. 1 have been described. ^{b ()}

7 shows that the membrane is formed as a thrust pad and is secured within the housing 21 in connection with a ring 41, the lens-shaped reinforcement 37 is provided with an outwardly projecting threaded stud 42 *>">, in a The support body 43 resting on the foundation 34 is screwed in. The object 32 can be raised or lowered accordingly by introducing a pressure medium via the connection 23 into the space 39. However, the membrane can also serve as a damper without a pressure medium being arranged in the space 39.

F i g. 8 shows that as a modification of FIG. 5 two diaphragms 10 facing each other with their undersides in a thickening 35, as has been described for FIG. 6, a lens-shaped reinforcement 37 in each case which are surrounded on all sides by the material of the membrane. Thus, the thickenings can be mutually exclusive nudge.

F i g. 9 shows that - deviating from the representation in FIG. 8 - the two membranes for their function as Thrust cushion or cushion cushion with their upper sides facing each other. You are held by that common ring housing 28 in connection with a ring 41 assigned to each membrane, the outer one has a circumferential groove which the inwardly protruding flange 12 of the membrane and the lower annular surface 44 reaches under the membrane. The ring housing 28 is at the two end faces with an inwardly directed Bead 45 provided. In the same way as in FIG. 7 described, the reinforcements 37 in FIG Thickening below the clamping edge a lens-shaped reinforcement 37, which extends outward into a threaded pin 42 which is screwed into a foot 43 continues.

Fig. 10 shows the membrane 10 in the application of a valve with the valve housing consisting of the from the medium flowed through housing 45 and the upper housing part 46, the actuation with the Handwheel 47 carries. The connection with the upper part of the housing takes place in the usual way, not in the drawing illustrated way. The housing 45 has an annular part 48 with an outwardly open groove 49, which after inside protruding flange 12 of the membrane and its underside 44 engages. The lower inner edge 50 of the upper housing part 46 engages around the slightly protruding outward beyond the membrane Flange part 51. The inwardly protruding fastening flange of the membrane initially leads to small dimensions of the housing.

Also, rubber suffers from the phenomenon of creep; H. it deforms under pressure or Tensile stress as a function of time. In the case of an outer chamber, the direction of pull falls from the Medium acted upon membrane and creeping clearing together. With the interior chambering shown on the other hand not. Here the medium has to crawl around a corner, as it were, which is caused by the significantly larger frictional forces is greatly reduced. The one with the flange protruding inward achievable interior chambers therefore have great advantages.

In its center, the valve has the thickening of the lens-shaped cross section described for FIG 35 with the inner lens-shaped reinforcement 37, it being noted, however, that - different from the Diaphragm shape in Fig. 8 - this thickening is also present at the level of the flange 12 of the membrane 10 With this training, the functionality of the membrane is not impaired, as the ring vault only a partial stroke, namely the stroke upwards, must allow and the thickening 35 with the reinforcement 37 the Deformation of the ring vault is not impaired, since with the limited stroke it is outside its area of action isL The valve 10 is designed as a partial lift valve. In order to create an optimal solution here, the in F i g. 10 shown closed position with the plant of

formed as a thickening closure piece 35 on the valve seat ring 52 the vulcanization of the Membrane as shown in Fig. IB. Since the stroke movement is based on this vulcanization position upwards can make up two thirds of the total movement, and to release the flow cross-section a valve only needs a stroke of D / 4, the deformation of the diaphragm is reduced by the The closed position, as shown in FIG. 10, is very low in the open position.

The direction of flow of the medium in the housing 45 is indicated in the direction of arrow 53 with the result that the pressure of the medium in all positions of the diaphragm is directed towards the underside of the diaphragm. Between the top of the membrane and the inner surface 53 of the upper housing part 46 is a Liquid 54 present. It can be any inert liquid. There are also coming other incompressible liquids in question. The handwheel 47 is provided with a spindle 55 which is attached to has the displacer piston 56 at its front ends, which via the seal 57, 57a in the upper housing part 46 is sealed. Furthermore, a leakage ring 58 is present between the seals 57, 57a, via which the Liquid 54, provided it passes through the seals 57, 57a, can be drawn off. Unless the Piston 56 is moved downwards, this exerts a pressure on the liquid 54, which pressure is applied to the entire Surface of the membrane is distributed and the membrane moves downwards. Since the pressure in the direction of arrow 53 flowing medium on the underside of the membrane

ί pushes and this thus lifts off the valve seat 52, the membrane 10 is in Offenstellupg when the piston 56 is raised. By moving the piston 56 down via the handwheel 47 and the spindle 55, the pressure on the control fluid 54 is greater. As soon as the pressure

H) the liquid 54 is greater than the pressure of the medium present in the housing 45, the Diaphragm 10 in the closed position. Fig. 10 thus shows that the membrane 10 is hydraulically supported on both sides. To operate the valve it is only necessary that

r> the pressure of the liquid 54 by a small amount is greater than the pressure of the medium or the Liquid that flows in the housing 45 or is present there. Therefore it needs to be in the hydraulic fluid plunging pistons add little volume

2 <) displace. Accordingly, he can be proportionate can be kept small. The required actuation forces are also smaller due to the resulting smaller ones Reduction extremely low. Since at the same time the outer surface of the ring vault is used for the application of pressure effective projection is larger than the inner area, the pressure of the liquid can even be less than that of the medium in housing 45.

In addition 7 sheets of drawings

Claims (7)

Patent claims: 1. Membrane for keeping two adjacent spaces of the same or different pressure separate from flexible material of a permanent, defined basic shape with or without fabric inlay or overlay, the flange-like edge of which is clamped between two housing parts, the directly adjoining section on the side facing the clamping edge in all positions of movement a circulating one; Forms ring vault, characterized in that with increasing wall thickness of the membrane in the direction from the clamping edge (12) towards its center, the ring vault (R) of the membrane underside in each case (11) and the convex curvature of the membrane top merges into a reversal curve (20) in the central region of the membrane. 2. Membrane according to claim 1, characterized in that, seen in cross section, the arcuate convex curvature curves (14L, HR) of the annular vault (R) intersect in the middle of the membrane. 3. Membrane according to claim 1, characterized in that the convex surface of the ring vault (R) on the menibran top (13) makes up more than about 70%, in particular more than 90% of the entire membrane top (13). 4. Membrane according to claims 1 to 3, characterized in that the inner and outer limiting curves (15, 14) of the annular vault (R) start from the outer edge with a steep (more than 45 °) angle. 5. Membrane according to claims 1 to 4, characterized in that the entire, the clamping edge remote membrane top (13) is designed as a work surface. 6. Membrane according to claims 1 to 5, characterized in that the flange-like clamping edge (12) drawn inwards and also protrudes outwards by a small amount. 7. Membrane according to claims 1 to 6, which flowed through as a valve between one of the medium Housing part and a housing upper part receiving the valve actuation is clamped, thereby characterized in that between the membrane top (13) and the inner surface (53) of the housing part (46) a space filled with a pressure medium (54) is present, which the membrane directly actuated.