Valve

Abstract

The invention relates to a valve (1), the valve (1) having an axially movable piston (2), the piston (2) being arranged in a valve seat (3), the piston (2) having a circumferential groove (6) with a groove base (7), in which groove a sealing ring (12) is arranged, according to the invention, at least in an axial sectioning plane, the sealing ring (12) is arranged in the groove (6). In an axial region (21) surrounding a contact point (13) between the sealing ring (12) and the groove base (7), the distance between the piston axis (10) and the groove base (7) has at least two different values.

Description

Technical Field

[0001] The invention relates to a valve having an axially movable piston, wherein the piston is arranged in a valve seat, wherein the piston has a surrounding groove with a groove base, in which a sealing ring is arranged. Such valves are widely used in practice. Summary of the invention

[0002] The object of the invention is to provide a valve with improved use characteristics and sealing properties. This object is achieved by the features of the independent claim. Advantageous embodiments are described in the dependent claims.

[0003] It should be noted that the features listed individually in the dependent claims can be combined with each other in any technically meaningful way and define further embodiments of the present invention. In addition, the features given in the claims are described and explained in detail in the description, wherein further preferred embodiments of the present invention are presented.

[0004] To achieve this object, the invention provides the features of claim 1. In particular, to achieve this object, it is proposed according to the invention in a valve of the type mentioned at the outset that, at least in an axial section plane, in an axial region around the contact point formed between the sealing ring and the groove base, the distance between the piston axis and the groove base has at least two different values. As a result, the sealing properties of the valve can be improved. In this way, indifferent equilibrium positions of the sealing ring at the groove base (which allow a plurality of equal positionings of the sealing ring) can also be avoided. In particular, very small local movements of the sealing ring (which would lead to a reduction in the sealing properties) can thus be avoided.

[0005] The valve is preferably designed as a sanitary valve and is used in sanitary areas, for example in the kitchen, toilet and / or bathroom.

[0006] In an advantageous embodiment of the invention, it can be provided that the two different values ​​are located on different sides of the contact point. Thus, the service life of the sealing ring can be increased, since the contact between the base of the groove and possible defective parts of the sealing ring is minimized. Alternatively, the two different values ​​can be located on the same side of the contact point. For example, such defective parts may occur at the equatorial part, in particular when the sealing ring is constructed as an O-ring. It has been found that at the equatorial part, which usually coincides with the mold separation line, components or parts may be damaged when removing the protrusion. Such damage can reduce the sealing effect. This embodiment allows the sealing ring to be placed outside its equatorial part. Therefore, it can be achieved that the defective part has no effect or only a small effect on the sealing.

[0007] In a valve of the type mentioned at the outset, alternatively or additionally to the aforementioned solution according to the invention for achieving the stated object, provision can be made for the contour of the groove base in, for example, the already mentioned axial region to define a single resting position of the sealing ring at the groove base. The reliability of the sealing properties of the sealing ring can thus be increased. Preferably, the axial region is the second contact point.

[0008] An axial region is understood to mean, for example, a region which is formed in the axial direction around, for example, the already mentioned contact point between the sealing ring and the groove base.

[0009] Preferably, the rest position is configured along the entire circumference of the sealing ring around the piston. Thus, the mechanical manufacture of the piston together with the groove can be improved.

[0010] In a valve of the type mentioned at the outset, alternatively or additionally to the above-described solution according to the invention for achieving the object, provision can be made that, at least in the axial section plane, the connecting line between the contact points and the touch points mentioned, for example, forms a straight line through the center of the cord of the sealing ring, wherein the contact points are formed between the groove base and the sealing ring and the touch points are formed between the sealing ring and the valve seat. As a result, the positioning of the sealing ring under static or dynamic stresses can be improved and the sealing properties can be increased.

[0011] Here, the center can be characterized, for example, by a region extending around the center point of the wire of the sealing ring with a radius of no more than 10%, in particular no more than 5%, of the thickness of the wire of the sealing ring and / or with a radius of at most five times, in particular at most twice, the manufacturing tolerance of the sealing ring. Such a configuration of the center and the arrangement of the contact points and the touch points have proven to be particularly advantageous for the sealing properties of the sealing ring. Thus, it can also be achieved that the force lines between the points at which the sealing ring is tensioned during sealing are guided near the center point or through the center point. This can improve the support.

[0012] In an advantageous embodiment of the invention, it can be provided that the sealing ring has an axial play in the groove.

[0013] In the prior art, sealing rings are usually inserted on both sides of the groove in a contacting manner, even with a preload, so that no axial play exists.

[0014] The advantage of constructing the gap is that an additional degree of freedom is introduced for the positioning of the sealing ring, with which the sealing ring can be positioned very finely adjusted to manufacturing tolerances. By constructing the axial gap, the sealing ring and the valve seat can be more easily aligned with each other and geometric overconstraints can be avoided.

[0015] In practice, when the valve is closed, a punctiform contact is formed between the sealing ring and the valve seat, which is expanded by further introduction of the piston to a linear and partially flat contact in the circumference of the sealing ring.

[0016] Due to the axial gap formation, the sealing ring can be displaced in such a way that a circumferential seal between the sealing ring and the valve seat is achieved.

[0017] Preferably, the gap is dimensioned at least to such an extent that it exceeds the manufacturing tolerances of the dimensions of the recess, thereby enabling an axially load-free reception.

[0018] In an advantageous embodiment of the invention, it can be provided that the axial region is no greater than one quarter of the axial extension of the sealing ring, and additionally or alternatively, the axial region can be selected to be arbitrarily small. Preferably, the axial region is no greater than one eighth of the axial extension of the sealing ring. Thus, the prestress on the sealing ring can be better controlled and adjusted. Thus, a sufficiently small structure can also be provided, which defines the position of the sealing ring.

[0019] In an advantageous embodiment of the invention, it can be provided that the reset element acts on the piston. Preferably, the reset element is a spring. The valve can thus be used as a backflow preventer, for example as an RV valve core. Backflow preventers are used to prevent undesired backflows, for example backflows of used water, or to protect pressure-sensitive devices in the event of system pressure fluctuations. The opening and closing direction of the piston can extend along the piston axis. The piston axis can extend parallel to the flow lines of the water flow, in particular the flow direction.

[0020] In an advantageous embodiment of the present invention, it can be provided that the valve seat has a mating contact surface on which the sealing ring abuts. Preferably, the sealing ring abuts against the mating contact surface in a sealing manner. Thus, the sealing performance of the sealing ring can be improved.

[0021] In an advantageous embodiment of the invention, it can be provided that the mating contact surface is arranged obliquely relative to the piston axis and additionally or alternatively arranged curved relative to the piston axis. Thus, the mechanical load on the sealing ring can be reduced and the service life of the sealing ring can be increased.

[0022] In an advantageous embodiment of the invention, it can be provided that the base of the groove has a region which forms an angle of no more than 20° with the mating contact surface. Preferably, the angle is no more than 10°. Particularly preferably, the angle is no more than 5°. Thus, the positioning of the sealing ring can be adjusted. The invention has here for the first time recognized that such a configuration of the angle is particularly advantageous. Thus, it is also possible to clamp the sealing ring between parallel or almost parallel surfaces. This can save material.

[0023] In an advantageous embodiment of the present invention, it can be provided that the base of the groove has a gap portion so that the equatorial portion of the cord of the sealing ring remains contactless. The circular or elliptical cross section of the sealing ring can be referred to as the cord of the sealing ring. For example, the gap portion can be constructed as a contact portion of two planes, wherein the normal vectors of the planes converge at an obtuse or acute angle. An acute angle is defined as an angle between 0° and 90°. An obtuse angle is defined as an angle between 90° and 180°. The gap portion can alternatively be constructed as a groove, wherein the groove depth is constant. The gap portion can alternatively be constructed as a groove, wherein the groove depth is non-constant, in particular variable. Therefore, by the structural design of the gap portion, it can be achieved that the equatorial portion of the cord of the sealing ring remains contactless and no load is generated on possible defective parts of the sealing ring. Therefore, in the prior art, defective parts or parts with reduced mechanical stability often appear in the equatorial region of the cord of the sealing ring due to the manufacturing process of the sealing ring. The structure proposed here is intended to reduce or completely prevent loads on such defective parts.

[0024] In an advantageous embodiment of the invention, it can be provided that the groove base has at least one step, which contacts the sealing ring. Preferably, the step is rounded. Thus, an improved positioning of the sealing ring in the groove can be achieved.

[0025] The step can be formed at one of the two contact points between the groove wall and the groove base. The groove area formed orthogonally to the piston axis defined above is called the groove wall. The groove area bounded by the groove wall is defined as the groove base. The groove wall is the last contour section before the piston exterior.

[0026] In an advantageous embodiment of the invention it can be provided that the radius of curvature of the groove base is greater than the radius of curvature of the cord of the sealing ring. Thus, a low-load rolling or sliding of the sealing ring along the groove base can be achieved.

[0027] In an advantageous embodiment of the invention, it can be provided that the groove base has an inclined portion which forms an angle with the piston axis of less than 45°, additionally or alternatively an angle of greater than 0°. Preferably, the angle is greater than 5°. Thus, the mechanical load on the sealing ring can be reduced.

[0028] In an advantageous embodiment of the invention, it can be provided that the drive of the piston is realized by a drive device. Preferably, the drive device is a screw drive and additionally or alternatively a hydraulic drive. Thus, a reliable and low-maintenance piston drive can be provided.

[0029] In an advantageous embodiment of the invention, it can be provided that the recesses are basin-shaped or converge at an angle, in particular the angle is less than 180°. Preferably, the angle is less than 175°. Thus, a mechanical structure that is simple to manufacture and inexpensive can be provided.

[0030] In an advantageous embodiment of the invention, it can be provided that the sealing ring is designed as a round wire ring and additionally or alternatively as an oval wire ring. Preferably, the sealing ring is designed as an O-ring. Thus, a sealing ring can be provided which can be produced cost-effectively.

[0031] In an advantageous embodiment of the invention, it can be provided that the sealing ring remains contact-free on at least one groove wall. Preferably, the groove wall is arranged orthogonally to the piston axis. The groove wall can be regarded as the last contour section before the outer region of the groove. Thus, an improved sealing performance can be achieved, especially in dynamic applications.

[0032] In a valve of the type mentioned at the outset, alternatively or additionally to the aforementioned solution according to the invention for achieving the stated object, provision can be made that, at least in the closed state of the valve, the contact point between the sealing ring and the base of the groove is arranged spaced apart from the equatorial portion of the sealing ring. The line of the cord of the sealing ring extending through the cord center point of the sealing ring and arranged orthogonally to the piston axis of the piston is called the equatorial portion. As a result, the loads acting on possible defective locations of the sealing ring, which are caused by the manufacturing process and often occur at the equatorial portion, can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention will now be described in more detail with reference to several embodiments, but is not limited to these few embodiments. Further inventive variants and embodiments are produced by combining the features of single or multiple claims with each other and / or with single or multiple features of the embodiments of the device according to the invention and / or the previously described variants.

[0034] In the attached picture:

[0035] Figure 1 shows a perspective view of the valve, and

[0036] FIG. 2 shows a cross-sectional view of a prior art valve, and

[0037] Figure 3 A sectional view of a valve according to the invention and an enlarged detail view associated therewith are shown, and

[0038] Figure 4 Show Figure 3 A cross-sectional view of the valve without showing the actuator, and

[0039] Figure 5 A detail view showing a cross-sectional view of the groove geometry of a valve according to the invention, and

[0040] Figure 6 A detail view of a cross-section showing another groove geometry of a valve according to the invention, and

[0041] Figure 7A detail view of a cross-section showing another groove geometry of a valve according to the invention, and

[0042] Figure 8 A detail view of a cross-section showing another groove geometry of a valve according to the invention, and

[0043] Fig. 9 Show Figure 7 Detail of a cross-sectional view of the groove geometry of a valve in the presence of back pressure. DETAILED DESCRIPTION

[0044] In the following description of various exemplary embodiments of the present invention, elements which correspond in terms of their function are provided with corresponding reference numerals even in different designs or shapes.

[0045] For greater clarity, not all reference numerals are provided in the figures, but the elements may well be present in the figures. However, the same reference numerals represent components and functional units that are functionally and / or structurally identical.

[0046] Figure 1 A perspective view of a valve 1 is shown.

[0047] The valve 1 has an axially movable piston 2, wherein the piston 2 is arranged in a valve seat 3. The valve 1 also has a valve body 4. A restoring element 5 acts on the piston 2. The valve 1 is preferably designed as a sanitary valve in the sanitary area. The restoring element 5 is preferably designed as a spring.

[0048] FIG. 2 shows a cross-sectional view of a valve 1 according to the prior art.

[0049] The valve 1 has an axially movable piston 2, wherein the piston 2 is arranged in a valve seat 3. The valve 1 also has a valve body 4. A reset element 5 acts on the piston 2. The piston 2 has a circumferential groove 6, which has a groove base 7. The groove base 7 is bounded by groove walls 8, 9. The groove walls 8, 9 are arranged orthogonally to the piston axis 10. The piston axis 10 is arranged parallel to the flow direction 11. The flow direction 11 is indicated by an arrow. The direction along the flow direction 11 is called the axial direction. The direction orthogonal to the flow direction 11 is called the radial direction. A sealing ring 12 is arranged in the groove 6. The sealing ring 12 touches the groove base 7 at the contact point 13. In the prior art, the groove 6 usually has a rectangular geometry; this means that the distance between the groove base 7 and the piston axis 10 is constant. This leads to undesirable loads on the sealing ring 12 and causes problems when the opening and closing pressures of the valve 1 are adjustable. The present invention starts from this and wants to avoid or eliminate the disadvantages of the prior art.

[0050] Figure 3 A valve 1 according to the invention is shown in cross-section and in enlarged detail views associated therewith.

[0051] The valve 1 here has similar elements to the valve 1 of FIG. 2 , wherein FIG. 2 shows the prior art and is not described separately here.

[0052] The piston 2 is arranged in the valve seat 3. The sealing ring 12 is contacted from the outside by the mating contact surface 13a at the contact point 20, wherein the mating contact surface 13a belongs to the valve seat 3 and is arranged obliquely with respect to the piston axis 10. The sealing ring 12 has an axial play 22 in the groove 6. Alternatively, the mating contact surface 13a can be curved. Figure 3 The difference from Figure 2 is that the groove 6 has an alternative groove geometry. The groove base 7 includes two faces, which converge with each other at an angle. Preferably, the angle is less than 180°, particularly preferably less than 175°. A gap 14 is formed between the contact areas of the two faces around the sealing ring 12 and in the contact areas of the two faces. The sealing ring 12 contacts the groove base 7 at two contact points 13 located above and below the gap 14, respectively. The terms above and below are to be understood with reference to the flow direction. The sealing ring 12 does not contact the groove walls 8, 9 here. The sealing ring 12 has an axial gap 22 in the groove 6. The sealing ring 12 also contacts the mating contact surface 13a of the valve seat 3 at the touch point 20. In the present embodiment, the sealing ring 12 is configured as a circular wire ring, preferably an O-ring. By configuring the gaps 14 to converge at the above-mentioned angle, it is ensured that there is no contact between the groove base 7 and the sealing ring 12 in the equatorial region of the wire of the sealing ring 12, wherein in the equatorial region of the wire of the sealing ring 12, there are often defective locations due to the manufacturing process of the sealing ring 12. Therefore, the present invention provides a remedy here.

[0053] The groove base 7 has a region which forms an angle of not more than 20°, preferably not more than 10°, particularly preferably not more than 5° with the mating contact surface 13 a.

[0054] Figure 4 Show Figure 3 sectional view of the valve 1 without explicitly showing the drive 15 .

[0055] For example, the drive 15 of the piston 2 can be a screw drive and additionally or alternatively a hydraulic drive. The screw drive can be operated mechanically and additionally or alternatively electrically and adjust the position of the piston 2. The hydraulic drive can be characterized by the ability to adjust the hydraulic force of the piston 2. Alternative drives 15 are also conceivable.

[0056] Figure 5 Detailed view of a cross-section showing the groove geometry of a valve 1 according to the invention.

[0057] The distance between the groove base 7 and the piston axis 10 is variable here. The groove base 7 comprises three regions: an inclined region 16, a constant region 17, and a step region 18, in which the groove base 7 is arranged obliquely relative to the piston axis 10, in which the groove base 7 is arranged parallel to the piston axis 10, and in which a step 19 is formed. Preferably, the step 19 is rounded. In the flow direction 11, the order of the regions is as follows: inclined region 16, constant region 17, step region 18. The sealing ring 12 contacts the groove base 7 at two contact points 13, wherein one of the two contact points 13 is located in the inclined region 16 and the other of the two contact points 13 is located in the step region 18. The sealing ring 12 contacts the valve seat 3 at the contact point 20 at the mating contact surface 13a. The mating contact surface 13a is arranged obliquely relative to the piston axis 10. The mating contact surface 13a can alternatively be curved. The sealing ring 12 has a gap 22 in the groove 6 on both axial sides.

[0058] In the inclined region 16 , the groove base 7 has an inclination which forms an angle with the piston axis 10 of less than 45° and additionally or alternatively of more than 0°, preferably more than 5°.

[0059] The groove base 7 has a recess 14 so that the equatorial portion of the wire of the sealing ring 12 remains contactless. The recess 14 is wedge-shaped in the present embodiment, but the recess can also have another shape instead. The recess 14 is here between the inclined area 16 and the step 19.

[0060] The normal vectors of the groove base 7 and of the counter contact surface 13 in the inclined region 16 form an obtuse angle.

[0061] The groove walls 8, 9 are contact-free with respect to the sealing ring 12. The arrangement of the contact points 13 ensures that the mechanical loading of the sealing ring 12 is relatively low.

[0062] Figure 6 A detail view of a cross-section showing another groove geometry of a valve 1 according to the invention.

[0063] The groove 6 has groove walls 8, 9 and a groove base 7. The groove base 7 here comprises three regions: a step region 18, in which a step 19 is formed, which is preferably rounded; a constant region 17, in which the groove base 7 is arranged parallel to the piston axis 10; and an inclined region 16, in which the groove base 7 is arranged inclined relative to the piston axis 10. The groove base 7 has a region (in this case, the inclined region 16), which forms an angle of not more than 20°, preferably not more than 10°, and particularly preferably not more than 5° with the mating contact surface 13a. The mating contact surface 13a is arranged inclined relative to the piston axis 10. The mating contact surface 13a can alternatively be curved. In the flow direction 11, the order of the regions is as follows: step region 18, constant region 17, inclined region 16. The sealing ring 12 contacts the groove base 7 at two contact points 13, wherein one contact point 13 is in the step region 18 and the other contact point 13 is in the inclined region 16.

[0064] The sealing ring 12 contacts the valve seat 3 at the mating contact surface 13a at the touch point 20. The normal vectors of the groove base 7 and the mating contact surface 13a in the inclined area 16 form an acute angle. An acute angle defines an angle between 0° and 90°. An obtuse angle defines an angle between 90° and 180°.

[0065] The connecting line between the contact point 13 , which is located in the inclined region 16 and is formed between the groove base 7 and the sealing ring 12 , and the touch-down point 20 forms a straight line which extends through the center of the wire of the sealing ring 12 .

[0066] Here, the center can be characterized, for example, by a region extending around the center point of the wire of the sealing ring 12 with a radius not exceeding 10% of the wire thickness of the sealing ring 12, in particular not exceeding 5% of the wire thickness of the sealing ring 12, and / or with a radius of up to five times, in particular up to two times, the manufacturing tolerance of the sealing ring 12.

[0067] The groove walls 8, 9 are contact-free with respect to the sealing ring 12. The sealing ring 12 has an axial play 22 in the groove 6. The arrangement of the contact points 13 ensures that the mechanical loads on the sealing ring 12 are relatively low.

[0068] The groove base 7 has a recess 14 so that the equatorial portion of the wire of the sealing ring 12 remains contactless. The recess 14 is wedge-shaped in the present embodiment, but the recess can also have another shape instead. The recess 14 is here between the inclined area 16 and the step 19.

[0069] Figure 7 A detail view of a cross-section showing another groove geometry of a valve 1 according to the invention.

[0070] The distance between the groove base 7 and the piston axis 10 (shown only schematically) is variable. The sealing ring 12 contacts the groove base 7 at the contact point 13. The radius of curvature of the groove base 7 is greater than the radius of curvature of the wire of the sealing ring 12. The sealing ring 12 also contacts the mating contact surface 13a of the valve seat 3. The mating contact surface 13a is arranged obliquely with respect to the piston axis 10. The mating contact surface 13a can alternatively be configured to be curved. The groove walls 8, 9 are contactless with respect to the sealing ring 12. The sealing ring 12 has an axial gap 22 in the groove 6 on both sides of the groove walls 8, 9. The sealing ring 12 can slide on the curved groove base 7 under dynamic loading. The special design of the groove geometry described here has the advantage that the sealing ring 12 is only slightly loaded, which can increase its service life. An axial region 21 can be defined around the contact point 13, in which the distance between the piston axis 10 and the groove base 7 has at least two different values. The axial region 21 can be arranged arbitrarily around the contact point 13 ; both a symmetrical arrangement with respect to the contact point 13 and an asymmetrical arrangement with respect to the contact point 13 are possible.

[0071] The groove 6 has a curved region 19a.

[0072] Figure 8 A detail view of a cross-section showing another groove geometry of a valve 1 according to the invention. Figure 8 Shown with Figure 7 Generally similar groove geometry.

[0073] The distance between the groove base 7 and the piston axis 10 (shown schematically here) is variable. The groove base 7 comprises two curved areas 19a, 19b. The radius of curvature of the curved areas 19a and 19b is equal in size. The radius of curvature of the curved areas 19a, 19b is greater than the radius of curvature of the cord of the sealing ring 12.

[0074] The groove base 7 has a recess 14, on which the equatorial portion of the cord of the sealing ring 12 remains free of contact. Figure 7 and Figure 8 The main difference between the two is that the recess 14 is configured as a basin in the present embodiment. The recess 14 can alternatively be configured as a wedge or at an angle. The recess 14 can also alternatively be partially circular. The recess 14 is arranged between the curved area 19a and the curved area 19b.

[0075] The sealing ring 12 contacts the groove base 7 at the curved area 19a and the curved area 19b. The sealing ring 12 also contacts the mating contact surface 13a at the contact point 20, which is arranged obliquely with respect to the piston axis 10. The mating contact surface 13a can alternatively be designed to be curved. The groove walls 8, 9 remain contact-free with respect to the sealing ring 12. The sealing ring 12 has the axial play 22 already mentioned in the groove 6.

[0076] The design of the groove geometry in this embodiment ensures that the mechanical load on the sealing ring 12 is minimized in static or dynamic conditions.

[0077] Fig. 9 Show Figure 7 Detail of a cross-sectional view of the groove geometry of valve 1.

[0078] In the present embodiment, there is a back pressure. The sealing ring 12 contacts the groove base 7 at the contact point 13 and the groove wall 9. The other groove wall 8 remains contact-free relative to the sealing ring 12. The sealing ring 12 also contacts the mating contact surface 13a at the contact point 20. The mating contact surface 13a is designed to be inclined relative to the piston axis 10 (schematically shown). Alternatively, the mating contact surface 13a can be designed to be curved. The back pressure is characterized by a pressure that acts in opposition to the typically existing flow pressure. This can occur, for example, in a check valve.

[0079] The groove 6 has a curved region 19a.

[0080] It is proposed that in a valve 1, the valve 1 has an axially movable piston 2, the piston 2 is arranged in a valve seat 3, the piston has a circumferential groove 6 with a groove base 7, the sealing ring 12 is arranged in the groove, and at least in an axial section plane, in an axial region 21 around a contact point 13 between the sealing ring 12 and the groove base 7, the (position-dependent) distance between the piston axis 10 and the groove base 7 has at least two different values ​​(at two different axial positions).

[0081] Reference numerals list

[0082] 1 valve

[0083] 2 Piston

[0084] 3 valve seat

[0085] 4 Valve body

[0086] 5Reset element

[0087] 6 grooves

[0088] 7 Grooved base

[0089] 8 groove wall

[0090] 9 (Other) groove wall

[0091] 10 Piston axis

[0092] 11 Flow direction

[0093] 12 Sealing ring

[0094] 13 touch points, each touch point

[0095] 13a Mating contact surface

[0096] 14 Gap

[0097] 15. Drive

[0098] 16 Tilt Area

[0099] 17 Constant region

[0100] 18 steps area

[0101] 19 steps

[0102] 19a Bending area

[0103] 19b (Other) bending area

[0104] 20 touch points

[0105] 21 Axial region

[0106] 22 Gap

Claims

1. A valve (1), in particular a sanitary valve, wherein: The valve (1) comprises an axially movable piston (2), wherein the piston (2) is arranged in a valve seat (3), wherein the piston (2) has a circumferential groove (6) with a groove base (7), in which a sealing ring (12) is arranged, characterized in that, at least in an axial section plane, in an axial region (21) around a contact point (13) constructed between the sealing ring (12) and the groove base (7), the distance between the piston axis (10) and the groove base (7) has at least two different values.

2. The valve (1) according to claim 1, characterized in that The two different values ​​are located on different sides of the contact point (13).

3. A valve (1) according to the preamble of claim 1 or according to any of the preceding claims, characterized in that The contour of the groove base (7) in the axial region (21), in particular the second contact point (13), preferably along the entire circumference of the sealing ring (12) around the piston (2), defines a single rest position of the sealing ring (12) at the groove base (7).

4. A valve (1) according to the preamble of claim 1 or according to any of the preceding claims, characterized in that At least in the axial section plane, a connecting line between the contact point (13) and the touch point (20) forms a straight line extending through the center of the cord of the sealing ring (12), wherein the contact point (13) is constructed between the groove base (7) and the sealing ring (12), and the touch point (20) is constructed between the sealing ring (12) and the valve seat (3).

5. Valve (1) according to any one of the preceding claims, characterized in that The sealing ring (12) has an axial play (22) in the groove (6).

6. Valve (1) according to any one of the preceding claims, characterized in that The axial region (21) is no larger than one quarter of the axial extension of the sealing ring (12), in particular no larger than one eighth of the axial extension of the sealing ring, and / or the axial region (21) can be selected to be arbitrarily small.

7. Valve (1) according to any one of the preceding claims, characterized in that A restoring element (5), in particular a spring, acts on the piston (2).

8. Valve according to any one of the preceding claims, characterized in that The valve seat (3) has a mating contact surface (13a) against which the sealing ring (12) preferably bears in a sealing manner.

9. Valve (1) according to any one of the preceding claims, characterized in that The mating contact surface (13a) is arranged obliquely and / or curved relative to the piston axis (10).

10. Valve (1) according to any one of the preceding claims, characterized in that The groove base (7) has a region which forms an angle of no greater than 20°, preferably no greater than 10°, particularly preferably no greater than 5° with the mating contact surface (13a).

11. Valve (1) according to any one of the preceding claims, characterized in that The groove base (7) has a gap portion (14) so ​​that the equatorial portion of the cord of the sealing ring (12) remains contactless.

12. Valve (1) according to any one of the preceding claims, characterized in that The groove base (7) has at least one, in particular rounded, step (19) which contacts the sealing ring (12).

13. Valve (1) according to any one of the preceding claims, characterized in that The radius of curvature of the groove base (7) is greater than the radius of curvature of the cord of the sealing ring (12).

14. Valve (1) according to any one of the preceding claims, characterized in that The groove base (7) has an inclined portion, which forms an angle with the piston axis (10) that is less than 45° and / or greater than 0°, in particular greater than 5°.

15. Valve (1) according to any one of the preceding claims, characterized in that The drive (15) of the piston (2) is realized by a drive device, in particular a spindle drive and / or a hydraulic drive.

16. Valve (1) according to any one of the preceding claims, characterized in that The recess (14) is in the form of a basin or converges at an angle, in particular, the angle is smaller than 180°, in particular smaller than 175°.

17. Valve (1) according to any one of the preceding claims, characterized in that The sealing ring (12) is designed as a round and / or oval wire ring, in particular an O-ring.

18. Valve (1) according to any one of the preceding claims, characterized in that The sealing ring (12) remains contact-free on at least one groove wall (8, 9), in particular, the groove wall (8, 9) is arranged orthogonally to the piston axis.

19. Valve (1) according to the preamble of claim 1 or according to any of the preceding claims, characterized in that At least in the closed state of the valve (1), the contact point (13) between the sealing ring (12) and the groove base (7) is arranged spaced apart from the equatorial portion of the sealing ring (12).

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