Sealing system

Abstract

Valve for controlling fluid flows, with a valve housing comprising two housing parts forming two first and second bodies (2, 3) of a sealing system (1) that are opposed to each other in an axial direction (6) and are to be sealed relative to each other, the sealing system (1) also comprising an annular seal (4) which, in its operating position, is axially integrated between the two bodies (2, 3) and is in sealing contact with these two bodies (2, 3), the sealing system having, for sealing against at least the second body (3), an annular sealing projection extending axially from a base section (25) towards the second body (3), which bears against an annular sealing surface (28) of the second body (3) facing the first body (2) with a free-ending end-face sealing section (44), characterized in that the annular sealing surface (28) of the second body (3) has a conical first sealing surface section (32),which extends obliquely radially outwards from an inner end region (32a) to an outer end region (32b) at an axial distance from the first body (2) and which transitions at its outer end region (32b) into a second sealing surface section (33) of the annular sealing surface (28), which is formed by the base surface of an annular indentation (35) of the second body (3), wherein the sealing projection is formed by a sealing lip (43) tapering towards the sealing section (44), which in the operating position of the seal (4) is axially compressed by axial action from the annular sealing surface (28) of the second body (3) and is thereby convexly curved radially inwards in the intermediate region (47) between the sealing section (44) and the base section (25) under elastic deformation with a convex curvature on the radial inner circumference.

Description

[0001] The invention relates to a valve for controlling fluid flows, with a valve housing which has two housing parts which form two first and second bodies of a sealing system which are opposite one another in an axial direction and are to be sealed relative to one another, the sealing system also having an annular seal which, in its position of use, is axially integrated between the two bodies and is in sealing contact with these two bodies, which, for sealing against at least the second body, has an annular sealing projection which, starting from a base section, extends axially in the direction of the second body and which bears with a freely ending end-face sealing section against an annular sealing surface of the second body facing the first body.

[0002] DE 196 21 261 A1 discloses a sealing system comprising a plate-shaped sealing arrangement composed of a rigid support plate and annular seals molded thereon. The annular seals are strip-shaped and each have a substantially trapezoidal base section attached to the support plate and a bead-shaped sealing projection protruding axially from this base section. In its use position, the sealing arrangement is inserted between two bodies to be sealed against each other, with a free-ending end-face sealing section of the sealing projection resting against one of the two bodies, forming a seal.

[0003] A disadvantage of the known sealing system is that, due to the seal's limited deformation capacity, it allows only limited tolerance compensation. In particular, a secure seal between two axially adjacent bodies cannot be guaranteed if the axial distance between the two bodies varies due to tolerances. Therefore, tight tolerances must be maintained during the manufacture of the bodies to be sealed against each other, which increases manufacturing costs.

[0004] DE 697 20 312 T2 discloses a multi-valve equipped with a mask-shaped sealing means for sealing two adjacent bodies. The sealing means has a carrier made of a mesh material, onto which a bead made of an elastomeric material is molded, serving as a seal.

[0005] DE 10 2007 047 703 A1 discloses a valve device with several block-shaped bodies attached to one another. A frame-shaped seal is inserted between adjacent bodies. This seal has two sealing sections arranged at a radial distance from one another and connected by a web-like intermediate region. When the two bodies are connected to one another, the sealing sections are axially compressed between the two bodies. This seal is also not very suitable for compensating manufacturing tolerances.

[0006] The invention is based on the object of creating a valve with a sealing system for the mutual sealing of two bodies, which ensures reliable sealing even with high manufacturing tolerances and can be manufactured cost-effectively.

[0007] To achieve this object, in conjunction with the features mentioned at the outset, it is provided that the annular sealing surface of the second body has a conical first sealing surface section which extends obliquely radially outwards from an inner end region to an outer end region at an axial distance from the first body and which, at its outer end region, merges into a second sealing surface section of the annular sealing surface which is formed by the base surface of an annular indentation of the second body, wherein the sealing projection is formed by a sealing lip which tapers towards the sealing section and which, in the position of use of the seal, is axially compressed by axial loading from the annular sealing surface of the second body and is curved radially inwards under elastic deformation in the intermediate region lying between the sealing section and the base section.

[0008] In this valve, the annular seal of the sealing system has a sealing lip that seals against the second body. The sealing lip tapers in cross-section toward its free end facing away from the first body and terminates in a front-end sealing section that, when the two bodies are joined together, ideally extends into an annular recess in the second body that is open toward the first body. The base area of ​​this annular recess forms a second sealing surface section of an annular sealing surface formed on the second body, intended for sealing interaction with the sealing lip. The second sealing surface also has an annular first sealing surface section that adjoins the second sealing surface section radially inward.The first sealing surface section is conical and extends from an inner end region with an inclined profile radially outwards to an outer end region which merges into the second sealing surface section. The inclined profile of the first sealing surface section with respect to the axial direction has the positive effect that the sealing lip with its sealing section can slide along it and is guided to the annular indentation when the two bodies are joined axially and, due to manufacturing tolerances, the sealing section of the sealing lip is not exactly axially aligned with the annular indentation. This results in a self-centering effect. The conical first sealing surface section also offers the advantage that the sealing contact between the sealing lip and the second body is not lost if the sealing lip is deformed radially inwards due to external overpressure.Although the sealing lip may eventually emerge from the annular recess, its sealing section continues to rest against the conical first sealing surface section. Furthermore, the sealing effect of the sealing lip is pressure-assisted, regardless of whether a pressure differential is applied to its radial outer side or to its radial inner side. In both cases, the sealing lip is pressed against the sealing surface by the differential pressure acting on it, in addition to the inherent elastic forces. The shape of the sealing lip, which tapers towards the sealing section, not only promotes deformation behavior but also, due to its optimal demoldability, facilitates production by injection molding.The seal offers a high degree of tolerance compensation not only in the radial direction, but also in the axial direction, as it can be axially compressed by the assembly forces of the two bodies acting on it with low joining force. The compensation for the axial compression results in a radially inward bulging of the intermediate region of the sealing lip located between the base section and the sealing section. The sealing lip is preferably designed such that the intermediate region is clearly and unilaterally bulged radially inward during axial compression of the sealing lip. This has the positive effect that the sealing lip, which bends in the process, can increasingly contact the first sealing surface section.

[0009] Advantageous further developments of the invention emerge from the subclaims.

[0010] The valve is preferably designed such that the sealing lip, in the position of use of the seal, ideally dips into the annular indentation with its front sealing section and comes into contact with the second sealing surface section while sealing.

[0011] Preferably, the sealing lip rests radially slidingly against the conical first sealing surface section with its end-face sealing section. This allows it to be deflected radially outward and pressed into the annular recess upon axial joining of the two bodies. Furthermore, the sealing lip can slide against the first sealing surface section while maintaining its sealing function when exposed to varying radial differential pressures during operation.

[0012] The second sealing surface section formed by the base of the annular recess preferably has an arcuate, i.e., rounded, shape when viewed in cross-section. However, the annular recess can also have a pronounced corner at its base.

[0013] Preferably, the second body is provided with a conical insertion surface located upstream of the annular indentation in the direction of the first body. This insertion surface is oriented axially towards the first body and at the same time radially inward, such that the diameter defined by it widens towards the first body. If the two bodies are joined axially with a radial offset to one another, the sealing lip can partially run onto the conical insertion surface with its end-face sealing section in order to slide along this insertion surface as the two bodies are further joined and ultimately to be radially deformed so far that it can enter the axially adjoining annular indentation. The conical insertion surface therefore results in a further increase in the radial tolerance band with regard to the manufacture and assembly of the two bodies.

[0014] Preferably, the conical insertion surface does not merge directly into the annular indentation, but rather with the interposition of a preferably cylindrical transition surface which is formed on the second body axially between the insertion surface and the second sealing surface section.

[0015] The annular, self-contained sealing lip is advantageously shaped such that, even in the axially non-compressed neutral state, it is convex on its radial inner circumference, i.e., curved toward the center of the annular sealing lip. Particularly in conjunction with such a design, it is advantageous if, viewed in the axially non-compressed neutral state, the sealing lip also has a radially outer curvature, albeit a concave one.

[0016] Viewed in a cross-section through the annular body of the sealing lip, whose sectional plane is spanned by the axial and radial directions of the seal, the sealing lip in its neutral, axially non-compressed state has a predominantly arcuate shape. One could describe it as a banana contour. This shape is associated with a particularly clear preferred direction of radial bulging of the sealing lip when the sealing lip is axially compressed by the two joined bodies.

[0017] Preferably, the annular seal is attached to the first body by its base section, forming a seal. In this way, the first body and the seal constitute a uniformly handleable structural unit. This facilitates the joining of the two bodies. It is considered particularly advantageous if the seal is molded onto the first body in a fluid- and pressure-tight manner, which is preferably done by means of an injection molding process. The structural unit consisting of the first body and the seal can be realized in particular by a two-component injection molding process, in which a rigid plastic material is used for the first body and a plastic material that has rubber-elastic properties after curing is used for the seal.

[0018] Preferably, the valve is designed such that the seal bridges an axial gap existing between the two bodies to be sealed against each other, wherein it is bulged or bent radially inwards to varying degrees depending on the axial gap width and the resulting different axial compression of the sealing lip.

[0019] The annular seal preferably extends axially between an annular wall section of the first body and an annular wall section of the second body. Even after the two bodies have been joined together, these two annular wall sections are arranged at an axial distance from one another, leaving a gap, which is bridged by the annular seal inserted between them. It is particularly advantageous if there is a radially continuous, free space between the two wall sections both radially outside and radially inside the sealing lip. In order to keep the risk of contamination as low as possible, the outer space should be kept as small as possible in the structural design of the sealing system.However, with regard to the internal space, it is advisable to choose a design that extends from the inner end region of the first sealing surface section across the entire axial length of the sealing lip to the first body, so that the seal's installation space on its inner side, i.e., in the annular space enclosed by it, is not limited by a wall. This promotes the free radial deformability of the sealing lip when it is compressed during the axial joining of the two bodies, thereby buckling or bulging radially inward.

[0020] With the valve according to the invention, an ideal compression between the sealing lip and the second body can be achieved, which is sufficiently large to prevent leaks, but which is also not too high, so that the joining forces required to assemble the two bodies can be relatively low, which in turn reduces the requirements for the strength of the components and thus also the manufacturing costs.

[0021] In principle, the valve can also be realized with an annular seal, which is inserted as a loose insert seal between the two bodies, without being attached to either of these two bodies. In this context, a design of the annular seal is advantageous which is mirror-symmetrical with respect to the base section to a reference plane perpendicular to the longitudinal axis of the sealing ring. In this case, the seal has two annular seals projecting from the base section in opposite axial directions, each of which cooperates with one of the two bodies to be sealed against each other, wherein the first body is designed in the same way as the second body for interaction with its associated sealing lip.

[0022] The valve is also preferably equipped with fastening means by which the two first and second bodies belonging to the sealing system can be or are clamped axially together in a block. In this case, it is provided that in the clamped state there is an axial distance between two opposite annular wall sections of the two bodies, with the annular seal being incorporated into the gap resulting from this axial distance, bridging the gap and simultaneously being in sealing contact with the two bodies. Even if the axial distance between the two annular wall sections varies due to tolerances when the two bodies are clamped together, the annular seal always offers a reliable, fluid-tight and pressure-tight seal.

[0023] The invention is explained in more detail below with reference to the accompanying drawings, which show: Fig. 1 a preferred first embodiment of the valve according to the invention in a perspective view, Fig. 2 the valve Fig. 1 in a side view looking in the direction of arrow II, the figure being partially broken away to show internal fastening means by which the two bodies are clamped together in a block, Fig. 3 a longitudinal section through the valve according to section plane III-III Fig. 1, the fastening means are not illustrated for the sake of clarity, Fig. 4 the same longitudinal section as Fig. 3, however, in a two-dimensional illustration, with a dash-dotted section in the area of ​​the annular sealing lip assuming its position of use also being illustrated again in a separately enlarged manner, Fig. 5 the valve of the Fig. 1 to 4 in the not yet joined state of the two bodies during the joining process, in which the two bodies approach each other in an axial direction, Fig. 6-8 in an enlarged section of the Fig. 4 shows different phases in joining the two bodies of the sealing system, and Fig. 9 in a Fig. 6 to 8, a further phase of joining two bodies is shown, wherein such a radial offset is shown that the sealing lip cooperates with a preferably present insertion surface of the second body.

[0024] The sealing system designated in its entirety by reference number 1 comprises two first and second bodies 2, 3 formed separately from one another and an annular seal 4, preferably made of a material with rubber-elastic properties, which is used to seal the two bodies 2, 3 against each other.

[0025] In the exemplary embodiment, the two bodies 2, 3 represent two housing parts of a valve housing of a valve used to control fluid flows. However, this is only one of many possibilities for implementing the sealing system 1. The two bodies 2, 3 can be components of any device that are to be sealed against each other.

[0026] In the Fig. In the assembled state of the sealing system 1 shown in Figures 1 to 4, the two bodies 2, 3 are joined together in a joining area 5 in an axial direction defined by the axial direction of an imaginary axial axis 6. The joining process occurs by mutual axial convergence within the framework of an axially oriented joining movement 7 indicated by a double arrow.

[0027] The assembled state of the two bodies 2, 3 is defined in particular by the fact that the two bodies 2, 3 are axially clamped together. For this purpose, the sealing system is expediently equipped with fastening means 8. These fastening means 8 include, for example, a first support surface 12 arranged on the first body 2 and axially facing the second body 3, and a second support surface 13 arranged on the second body 3, opposite and facing the first support surface 12. In the assembled state of the sealing system 1, the two support surfaces 12, 13 rest against one another and thereby determine the axial relative position between the two bodies 2, 3. This relative position is fixed, for example, by a clamping screw 14, which is also part of the fastening means 8 and engages the two bodies 2, 3 in such a way that they are pulled towards one another and clamped together with their two support surfaces 12, 13.

[0028] In this assembled state of the sealing system 1, an axial gap 15 is located between the two bodies 2, 3, away from the fastening means 8, which is bridged by the annular seal 4, hereinafter referred to simply as the seal 4. For example, the two bodies 2, 3 together define an interior space 16, which, without the seal 4, would be freely accessible from the outside through the gap 15, but is sealed fluid-tight and pressure-tight from the environment due to the seal 4.

[0029] The gap 15 is preferably formed between two axially spaced-apart annular first and second wall sections 17, 18 of the two bodies 2, 3. The first wall section 17 belongs to the first body 2, the second wall section 18 to the second body 3. Each of these annular wall sections 17, 18 extends around the axial axis 6.

[0030] The axial length of gap 15 is set to a product-specific nominal dimension, which may vary depending on tolerances. For the seal 4, which is inserted between the two wall sections 17, 18, this means that it must fulfill its sealing function at different axial gap widths of gap 15.

[0031] The illustrated design of the fastening means 8 is only an example. A different design of the fastening means 8 is also possible.

[0032] The first body 2 is equipped with the aforementioned annular seal 4 on the front end face 22 facing the second body 3. The seal 4 has a preferably one-piece annular sealing body 23 that extends around a longitudinal axis 24 of the seal 4, which, in the assembled state of the sealing system 1, runs parallel and preferably coaxially to its axial axis 6.

[0033] The seal 4 has an annular base section 25 forming an integral part of the seal body 23. The seal 4 is secured to the front end face 22 of the first wall section 17 belonging to the first body 2 via this base section 25. Thus, the first body 2 and the seal 4 form a single, manageable structural unit that simplifies the assembly of the sealing system 1 because, during the joining movement 7, this structural unit 2, 4 can be handled as a single body.

[0034] The fixed connection between the base section 25 and the first body 2 is a sealed connection, so that no fluid passage is possible in the joining area between the seal 4 and the first body 2.

[0035] The seal 4 is expediently molded onto the first body 2 as part of a molding process. This is preferably done by injection molding, in particular as part of a so-called two-component injection molding process.

[0036] The first body 2 is expediently made of a hard thermoplastic material. The seal 4 is also expediently made of thermoplastic material, but, compared to the first body 2, has flexible and, in particular, rubber-elastic deformable properties.

[0037] In a non-illustrated embodiment, the first body 2 is made of metal.

[0038] The second body 3 is also a rigid body and consists of a material as mentioned above in connection with the first body 2.

[0039] The geometry of the preferably material-to-material connection between the base section 25 of the seal 4 and the first body 2 is fundamentally arbitrary. For example, to achieve a particularly tight connection, the base section 25 has an annular joining projection 26 that engages an annular groove of the first body 2 that is open toward the front end face 22.

[0040] In the exemplary embodiment, the ring structure of the seal 4 is not circular, but rectangular, resulting in a frame-like structure. However, the ring shape of the seal 4 can also deviate from these designs and, for example, have a circular or elliptical ring shape.

[0041] The annular wall section 18 belonging to the second body 3 has, on its front end face 27 facing the first body 2, a surface arrangement composed of several surfaces fulfilling different functions. This surface arrangement includes, among other things, an annular sealing surface 28 concentric with the axial axis 6, which, for simplicity, will be referred to simply as sealing surface 28 below. This sealing surface 28 faces axially toward the first body 2 and has an annular first sealing surface section 32 and a second sealing surface section 33 concentrically framing the first sealing surface section 32.

[0042] The first sealing surface section 32 is conical and extends from an inner end region 32a with an oblique profile to a radially further outer end region 32b. The first sealing surface section 32 moves radially outwardly away from the first body 2, so that the outer end region 32b is at a greater distance from the front end face 22 of the first body 2 than the inner end region 32a.

[0043] The inner end region 32a expediently merges with a curvature into a peripheral inner circumferential surface 34 of the second wall section 18, which in the exemplary embodiment delimits the interior space 16 radially outwardly.

[0044] The outer end region 32b of the first sealing surface section 32 is preferably directly adjoined by the second sealing surface section 33, which is formed by the base area of ​​an annular indentation 35 of the second annular wall section 18. The annular indentation 35 is arranged concentrically to the axial axis 6 and, viewed in cross-section, is preferably arcuate. The cross-section is understood as a section in a plane spanned by the axial axis 6 and a radial axis 36 perpendicular thereto. Where reference is made elsewhere to a "cross-section", this lies in the same sectional plane unless otherwise specified in the individual case.

[0045] The second sealing surface section 33 preferably transitions, on its side opposite the first sealing surface section 32, into a cylindrical transition surface 37 oriented radially inward. The transition between the transition surface 37 and the second sealing surface section 33 is just as seamless and without steps as the transition between the second sealing surface section 33 and the first sealing surface section 32.

[0046] The cylindrical transition surface 37 adjoins the second sealing surface section 33 on the side facing the first body 2 and could, in principle, extend to a front end face 38 of the second wall section 18, which is closest to the first body 2. However, it is advantageous if an introduction surface 42 adjoins the front of the transition surface 37, which faces axially toward the first body 2 and simultaneously radially inward, and whose diameter increases from the transition surface 37 toward the first body 2. Relative to the axial axis 6, the introduction surface 42 is expediently provided with a smaller cone angle than the first sealing surface section 32.

[0047] The insertion surface 42 opens out at the front end surface 38 of the second wall section 18.

[0048] The annular seal 4 has an annular sealing lip 43 adjoining the base portion 25 and projecting axially from there in the direction of the second body 3. This sealing lip 43 is also preferably arranged coaxially to the axial axis 6.

[0049] The sealing lip 43 has a sealing section 44 axially opposite the base section 25, which is formed by the free end of the sealing lip 43. This sealing section 44 is preferably rounded in cross-section, in particular with a radius that at least substantially corresponds to the radius of the second sealing surface section 33.

[0050] Deviating from the exemplary embodiment, the sealing section 44 could also terminate with a sealing edge. The second sealing surface section 33 could also have a square cross-sectional contour, deviating from the preferred rounded cross-sectional shape, although this is not illustrated in the drawing.

[0051] The sealing lip 43 tapers from the base section 25 to the sealing section 44. This taper is preferably continuous. The taper is expressed in the fact that the radially measured thickness of the sealing lip 43 decreases from the base section 25 to the sealing section 44.

[0052] The diameter of the seal 4 preferably corresponds at least substantially to the diameter of the annular sealing surface 28. Thus, the seal 4 and the sealing surface 28 are axially directly opposite each other when the two bodies 2, 3 are aligned coaxially to each other before joining, as shown in Fig. 5 is illustrated.

[0053] Preferably, the sealing lip 43 is designed such that, in the stress-neutral state not yet engaged with the second body 3, it is convexly curved on its radial inner surface 45 and concavely curved on its opposite radial outer surface 46. These functional specifications refer to the cross-section of the seal 4 shown in the drawing. It can therefore be said that the radial inner surface 45 has a convexly curved profile starting from the base section 25 in the direction of the sealing section 44, while the radial outer surface 46 has a concavely curved profile starting from the base section 25 in the direction of the sealing section 44.

[0054] Viewed three-dimensionally, the sealing lip 43's convex outer contour appears as a concentric constriction. The inner contour, on the other hand, appears as a trumpet-like widening toward the sealing section 44.

[0055] In this way, the sealing lip 43 is curved in an arc shape over its length, for example comparable to the curvature of a banana.

[0056] In an embodiment of the seal 4 not shown, a convex curvature is also present on the radial inner surface 45, while the radial outer surface 46 is, however, cylindrically shaped or has a convex curvature, the radius of curvature of which, however, is smaller than that of the radial inner surface 45.

[0057] The selected shape of the sealing lip 43 advantageously results in the sealing lip 43 bulging radially inward under elastic deformation in the intermediate region 47 located between the base section 25 and the sealing section 44 when an axial joining force FF is exerted on the sealing section 44. This axial joining force FF occurs when the two bodies 2, 3 are joined together because the seal 4 and the two bodies 2, 3 are adapted to one another in such a way that the sealing section 44 comes into contact with the annular sealing surface 28 of the second body 3 during the joining movement 7, before the fastening means 8 abut one another.

[0058] This means that the sealing lip 43 is in any case axially compressed in the assembled state of the sealing system 1, so that its length measured in the axial direction of the axial axis 6 is less than in the undeformed neutral state.

[0059] Preferably, the sealing system 1 is designed in its nominal dimensions such that the seal 4, during the joining movement 7, dips with its sealing section 44 directly into the annular indentation 35 and comes into contact with the associated second sealing surface section 33.

[0060] The Fig. 5, Fig. 6, Fig. 7, Fig. 8 and Fig. 4 illustrate successive phases of a preferred joining process when assembling the sealing system 1.

[0061] The Fig. 5 and Fig. 6 represent an initial state in which the two bodies 2, 3 are arranged with a relatively large axial distance from each other, but are already coaxially aligned with each other, so that the annular seal 4 is axially at least substantially aligned with the annular sealing surface 28 of the second body 2.

[0062] During the subsequent joining movement 7, the two bodies 2, 3 are brought axially closer to each other, with the seal 4 attached to the first body 2 following the movement of the first body 2. The joining movement 7 can be a simultaneous movement of both bodies 2, 3 or a movement of only one of these two bodies 2, 3 while the other body 3, 2 remains stationary.

[0063] The Fig. Figure 7 shows a joining phase in which the annular seal 4, with its sealing lip 43 leading, is partially immersed in the area enclosed by the annular second wall section 18. The sealing lip 43 is enclosed over part of its length in the region of its outer circumference at a radial distance from the insertion surface 42 and the transition surface 37. The sealing section 44 is axially spaced from the annular sealing surface 28.

[0064] The Fig. Figure 8 shows a phase of the joining process in which the sealing lip 43, with its sealing section 44, has come into contact with the first sealing surface section 32 of the sealing surface 28. Due to tolerance-related deviations, the sealing section 44 does not directly engage the annular recess 35 here.

[0065] During the further joining movement 7, the sealing section 44 is subjected to the aforementioned axial joining force FF by the first sealing surface section 32. This results in the sealing lip 43 being axially compressed, but at the same time sliding obliquely radially outward on the first sealing surface section 32 according to arrow 48 and thereby being deflected in the direction of the annular indentation 35.

[0066] This deflection movement ends when the sealing lip 43 has been deformed outwards so far that its sealing section 44 has reached the annular recess 35 and has come into contact there with the second sealing surface section 33.

[0067] The Fig. Figure 4 shows the final state of the joining movement 7 with the sealing system 1 fully assembled. The maximum bulging of the sealing lip 43, which is already pre-bent in the neutral state, in its intermediate region 47 radially inwards can be seen here. The reason for this is that the sealing lip 43 is bent in comparison to the intermediate state of the Fig. 8 was further axially compressed because the sealing surface 28 came even closer to the first body 2 during the joining movement 7.

[0068] The process of radially inward bulging of the sealing lip 43 can also be regarded as a buckling process.

[0069] In any case, this deformation preferably also serves the effect of causing the sealing lip 43, with its front end section 52 adjoining the sealing section 44, to bear against the conical first sealing surface section 32. This increases the sealing quality and also ensures very good mechanical support of the sealing lip 43 against forces acting on the sealing lip 43 from the radial outside. Such forces can, in particular, be compressive forces resulting from a higher pressure in the environment of the sealing system 1 compared to the pressure prevailing in the interior space 16.

[0070] The degree of radial bulging of the sealing lip 43 depends on how close the two bodies 2, 3 are brought to each other during their joining process. Preferably, the sealing system 1 is designed in such a way that the axial gap 15 already mentioned above between the two wall sections 17, 18 is still present even when the two bodies 2, 3 have assumed their relative final assembly position by the fastening means 8 or other measures, which in the embodiment shown in the Fig. 4 is illustrated. The annular seal 4 is here in its position of use.

[0071] The seal 4 closes the radially continuous gap 15 between the two wall sections 17, 18. The two bodies 2, 3 are particularly designed such that the seal 4, on its radial inner side having the radial inner surface 45, is exposed radially inward over its entire length, starting from the inner end region 32a of the first sealing surface section 32 up to the base section 25 fixed to the first body 2, and is not flanked by either of the two bodies 2, 3, and in particular by either of the two wall sections 17, 18. Thus, the installation space for the seal 4 is unlimited radially inward and allows the seal 4 optimal elastic deformation to adapt to the respective relative position between the two bodies 2, 3.

[0072] The advantage associated with the inclined insertion surface 42 viewed in cross section is Fig. 9 particularly clear. The Fig.Figure 9 shows the process of axially joining the two bodies 2, 3, wherein, due to tolerances, a slight radial offset exists between the two bodies 2, 3, so that the sealing lip 43 with its end-face sealing section 44 is located, at least in some areas, radially further outward relative to the opposite annular indentation 35. Here, during the joining movement 7, the sealing lip 43 with the sealing section 44 strikes the insertion surface 42 and, as the joining movement 7 continues, slides diagonally radially inward according to arrow 53, so that it is elastically bent inward.As the joining movement 7 continues, the sealing section 44 thus first comes into contact with the transition surface 37 adjoining the insertion surface 42 and from there directly into the annular indentation 35 and thus into sealing contact with the second sealing surface section 33 of the sealing surface 28 formed by the base surface of the annular indentation 35.

[0073] Essential advantages and features of the preferred embodiment of the sealing system 1 are summarized again below.

[0074] The special shape of the annular seal 4 and the joining partners formed by the two bodies 2, 3 allows for both large manufacturing tolerances and large assembly tolerances while maintaining a small footprint. The seal 4 can be designed as a structural unit with the first body 2, particularly using two-component technology, or it can be used as a separate insert seal for the two bodies 2, 3.

[0075] Due to the relatively large permitted manufacturing and assembly tolerances, the individual components of sealing system 1 can be manufactured cost-effectively and installed safely, even economically using automated processes. This provides increased design freedom for the designer.

[0076] The functional principle of the annular seal 4 is economical for both large and small batch sizes. For large to very large batch sizes, a two-component, off-the-mold solution is recommended, in which the seal is molded onto the first body 2. The subsequent assembly can be highly automated. Implementing the seal 4 as a separate insert seal is particularly suitable for small and medium batch sizes.

[0077] With little installation space required, the seal 4 enables large tolerance compensation in both the axial direction defined by the axial direction of the axial axis 6 and the radial direction defined by the axial direction of the radial axis 36. In particular, in conjunction with the inclined introduction surface 42, self-centering of the sealing section 44 results in radial positional deviations. The conical first sealing surface section 32 axially opposite the sealing lip 43 can ensure, even in the event of positional deviations, that the axial joining force FF is introduced into the sealing lip 43 as desired during assembly of the sealing system 1. It also allows the sealing section 44 to slide and thus changes in position of the sealing section 44 during use of the sealing system without the sealing contact being lost.Such positional deviations can occur due to changing pressure differences between the radial outer side and the radial inner side of the sealing lip 43.

[0078] Preferably, fluid pressure support of the sealing function occurs both under positive and negative pressure of the medium radially applied to the seal 4, wherein this medium is, in particular, air. This prevents the contact pressure at the sealing point, i.e., in the contact area between the sealing section 44 and the sealing surface 28, from being generated solely by prestressing the elastomer material of the sealing lip 43.

[0079] The slim cross-sectional shape of the sealing lip 43 reduces the axial joining forces when joining the two bodies 2, 3, without this being detrimental to the sealing quality.

[0080] The axial compression of the sealing lip 43 results in a clear bulging or buckling direction for the intermediate region 47 of the sealing lip 43 radially inward, so that reproducible geometric conditions are always present.

Claims

[1] A valve for controlling fluid flows, comprising a valve housing having two housing parts forming two first and second bodies (2, 3) of a sealing system (1) which are opposite one another in an axial direction (6) and are to be sealed relative to one another, said sealing system also comprising an annular seal (4) which, in its position of use, is axially inserted between the two bodies (2, 3) and is in sealing contact with these two bodies (2, 3), said seal having, for sealing against at least the second body (3), an annular sealing projection which, starting from a base portion (25), extends axially in the direction of the second body (3), said annular sealing projection bearing against an annular sealing surface (28) of the second body (3) facing the first body (2), characterized bythat the annular sealing surface (28) of the second body (3) has a conical first sealing surface section (32) which extends obliquely radially outwards from an inner end region (32a) to an outer end region (32b) at an axial distance from the first body (2) and which merges at its outer end region (32b) into a second sealing surface section (33) of the annular sealing surface (28), which is formed by the base surface of an annular indentation (35) of the second body (3), wherein the sealing projection is formed by a sealing lip (43) tapering towards the sealing section (44),which, in the position of use of the seal (4), is axially compressed by axial loading from the annular sealing surface (28) of the second body (3) and is thereby curved radially inwards in the intermediate region (47) lying between the sealing section (44) and the base section (25) under elastic deformation with a convex curvature on the radial inner circumference. [2] Valve according to claim 1, characterized by that the sealing lip (43) in the position of use of the seal (4) dips with its front sealing section (44) into the annular indentation (35). [3] Valve according to claim 1 or 2, characterized by that the sealing lip (43) with its front sealing section (44) rests radially slidingly against the conical first sealing surface section (32). [4] Valve according to one of claims 1 to 3, characterized by that the sealing lip (43) is rounded at its front sealing section (44). [5] Valve according to one of claims 1 to 4, characterized by that the second sealing surface section (33) is curved when viewed in cross section. [6] Valve according to one of claims 1 to 5, characterized by that the second body (3) has a conical insertion surface (42) which is arranged upstream of the annular indentation (35) in the direction of the first body (2), which insertion surface points axially in the direction of the first body (2) and at the same time radially inwards and on which the sealing lip (43) can slide with its end-face sealing section (44) when the two bodies (2, 3) are joined axially. [7] Valve according to claim 6, characterized by that a radially inwardly facing, cylindrical transition surface (37) is formed on the second body (3) axially between the conical insertion surface (42) and the annular indentation (35). [8] Valve according to one of claims 1 to 7, characterized bythat the sealing lip (43) is convexly curved radially inward in the axially non-compressed neutral state. [9] Valve according to one of claims 1 to 8, characterized by that the sealing lip (43) is concavely curved radially outward in the axially non-compressed neutral state. [10] Valve according to one of claims 1 to 9, characterized by in that the sealing lip (43) is curved in an arcuate manner in the axially non-compressed neutral state, starting from the base section (25) towards the end-face sealing section (44), wherein the concave side of the curvature, viewed in the cross section of the sealing lip (43), is assigned to the radial outer side of the sealing lip (43). [11] Valve according to one of claims 1 to 10, characterized by that the seal (4) is fastened with its base section (25) to the first body (2) in a sealed manner, so that the first body (2) and the seal (4) form a uniformly manageable structural unit. [12] Valve according to one of claims 1 to 11, characterized by that the seal (4) with its base section (25) is formed onto the first body (2) in a sealing manner. [13] Valve according to claim 12, characterized by that the seal (4) with its base section (25) is molded onto the first body (2) by injection molding while sealing. [14] Valve according to one of claims 1 to 13, characterized by that the seal (4) bridges an axial gap (15) present between the two bodies (2, 3), wherein its sealing lip (43) can be curved or is curved radially inwards to varying degrees depending on the axial gap width. [15] Valve according to one of claims 1 to 14, characterized byin that the annular seal (4) extends axially between an annular wall section (17) of the first body (2) and an annular wall section (18) of the second body (3), wherein these two annular wall sections (17, 18) are arranged at an axial distance from one another in the position of use of the seal (4), forming a gap (15) axially bridged by the seal (4), wherein the seal (4) is uncovered on its radial inner side by the two wall sections (17, 18) over its entire axial length up to the base section (25), starting from the inner end region (32a) of the first sealing surface section (32) arranged on the second body (3). [16] Valve according to one of claims 1 to 15, characterized byin that it has fastening means (8) by means of which the two first and second bodies (2, 3) belonging to the sealing system (1) can be or are clamped axially together, wherein the annular seal (4) is incorporated between two annular wall sections (17, 18) of the two bodies (2, 3) arranged at an axial distance from one another and bridges an axial gap present between the two wall sections (17, 18) while providing a seal.

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