QUICK COUPLING FOR CONNECTING

Description

[0001] The invention relates to a quick-action coupling for aggressive media such as strong acids and bases. Such quick-action couplings are used for the direct or indirect connection of two lines transporting a medium via a fluid channel running through the quick-action coupling. The quick-action coupling has a first coupling part designed as a sleeve and a second coupling part designed as a nipple, wherein the sleeve and the nipple each form a hollow housing arranged at least partially rotationally symmetrically to a central axis M for plugging together. A first valve body is arranged within the sleeve and a second valve body is arranged within the nipple, as well as an elastic element adjoining the respective valve body in the axial direction. The fluid channel runs in the radial direction at least partially outside and / or at least partially inside the elastic element.The valve body can be axially displaced and preloaded by the elastic element, opening or closing the fluid channel between the housing and the valve body. The valve body and the elastic element form a one-piece component, with the elastic element having a spiral concentrically encircling the central axis with a hollow space located within the spiral.

[0002] A quick coupling is already known from DE 28 26 344 A1, in which a nipple is inserted into a socket, and a valve body preloaded by spring elements is arranged within each of these two components. To create a seal between the inner surface of the socket and the outer surface of the nipple, several sealing and spacer elements are provided. These elements move relative to the socket and along the inner surface of the socket when the coupling is closed and opened.

[0003] According to DE 36 18 233 C2, a quick-action coupling is known in which a compression spring for the valve member is inserted into the cylinder section of the valve member, and one end of the compression spring is located in a tubular spring holder. The valve member and the compression spring form two components.

[0004] Publication WO 95 / 24584 describes a valve insert designed as a one-piece component. The valve insert comprises a retaining element, a valve spring, and a valve seat. A sleeve-shaped extension supporting the valve seat is attached to the valve spring. The extension has an internal thread into which a screw plug is screwed in a gas-tight manner. The component functioning as the valve body is two-part and consists of the valve insert and the functionally necessary screw plug for sealing the cavity. The valve body is sealed all around, forming the cavity as a pneumatic spring.

[0005] According to US 2012 / 031515 A1, a generic quick coupling with valve bodies and elastic elements is known. The elastic elements are hollow, serve as fluid channels, and are flowed through in a radial direction. If coil springs serve as elastic elements, a distance between the coils is provided by the elastic element, forming a fluid channel in a radial direction, even when the coil springs are in their maximum compression state.

[0006] US 2006 / 260699 A1 describes a generic quick coupling with valve bodies and elastic elements, in which the elastic elements are designed in a meandering shape and are surrounded by the fluid.

[0007] The invention is based on the object of designing and arranging a quick coupling for use with strong acids and strong bases in such a way that it is safer and thus also easier to assemble and maintain.

[0008] The object is achieved according to the invention by the features of claim 1.

[0009] The one-piece design eliminates the need to align the elastic element and the valve body axially and radially to one another. This is essential with a two-piece design because otherwise the elastic element could exert an eccentric and decentralized force on the valve body, making it impossible for it to center itself and running the risk of becoming sideways and jammed. This results in the unavoidable need for the two-piece design to at least axially guide the valve body, or better still, the valve body and elastic element. The invention eliminates this need because the elastic element, being a single piece with the valve body, always exerts a central force on the valve body.

[0010] Because the housing eliminates the need for forced guidance, axial guidance is no longer necessary. This eliminates the need for complex manufacturing of a fit between the valve body and the housing, nor do any additional guidance components. The radial clearance of the valve body, which is achieved due to the absence of a fit, has the further advantage of allowing the elastic element to be designed with a lower spring constant, since no frictional forces can occur between the valve body and the housing or other unnecessary components.

[0011] The one-piece design, combined with the resulting advantages described above, ensures the valve closes securely, as the valve body cannot remain stuck in the open position. This results in the further advantage that when assembling the quick coupling, only one component is inserted into the housing and positioned with a retaining ring.

[0012] Apart from a sealant inserted into the sleeve, it is thus possible to reduce the number of individual components that have to be inserted into the respective housing, independent of a fuse, to one component.

[0013] The valve body with the elastic element is preferably made of a fluorinated plastic or a polymer consisting of fluorine and carbon, and in particular of perfluoroalkoxy polymers (PFA) or polytetrafluoroethylene (PTFE). These plastics are resistant to acids and bases. Due to the plastic, the elastic element has a relatively low spring constant. Therefore, the stroke and thus the deflection of the two closure parts is selected accordingly large so that, depending on the flow direction, the relevant valve body closes reliably and quickly against the dynamic pressure of the medium when the sleeve and nipple are separated. As becomes clear from the description of the figure, the stroke also affects the flow cross-section of the fluid channel, which is also quantified by the diameter ratios between the inner surface of the sleeve and the outer surface.Unlike metal, plastic is resistant to acids and bases, thus ensuring a long-term stable spring constant and spring force, resulting in a better seal. Further preferably, the housing, the valve body, the elastic element, and the complete locking mechanism, comprising a sleeve, a carrier with claws, and a spring element, are made of plastic, in particular perfluoroalkoxy polymers (PFA) or polytetrafluoroethylene (PTFE).

[0014] However, it is important to note that for these types of quick couplings used for aggressive media such as strong acids and bases, they must be drip-free and completely corrosion-resistant when closing and opening. Due to the low mass flow rates for such media, they must function absolutely reliably even with small line cross-sections and thus with small sizes. Joints and gaps are particularly disadvantageous due to crystalline deposits of the acids and bases. Even with cross-sectional areas inside the housing between 7 mm² and 30 mm², the features according to the invention provide sufficient safety.It should be taken into account that the flow cross-sections inside the housing are reduced by up to 80% by the valve bodies and the elastic elements, so that, based on the cross-sectional areas inside the housing, flow cross-sections of less than 5 mm2< can be achieved for the fluid channel.

[0015] From a manufacturing perspective, it is advantageous that the valve body and the elastic element form a component made of the same material. The one-piece design allows a blank produced, for example, by injection molding, to be machined in a single operation. This is especially true for plastic blanks, specifically those made of perfluoroalkoxy polymers (PFA) or polytetrafluoroethylene (PTFE).

[0016] With regard to the largest possible flow cross-section, it is advantageous if the valve body and / or the elastic element has an opening directed radially towards the central axis M, which serves as a fluid channel. The opening in the valve body is provided in the transition area between the closed area of ​​the valve body and the elastic element. The opening in the elastic element can be provided at any point in the axial direction along the elastic element and around the central axis M around the elastic element. The medium can flow through the opening from the annular channel past the closed valve body into the center of the housing into the elastic element and further in the axial direction out of the housing and, in the opposite direction, in the opposite flow direction. The flow cross-section is larger in the center of the housing.

[0017] With regard to a simple geometry and a non-over-determined seal in the valve seat of the valve body, it is advantageous if the valve body is centered exclusively via a valve seat in the housing. A conical sealing surface is preferably provided, which causes self-centering when the valve is closed. This is supported by the guidance in the axial direction described above and achieved by the one-piece design. The preferably one-piece valve body has a closure part, on which a sealing element is applied, which can be placed on a sealing surface conical to the central axis M or the respective inner surface of the housing of the sleeve or the nipple by moving the valve body, at least in the axial direction, wherein the sealing element closes the fluid channel in a sealing manner. The conical section forms the valve seat.

[0018] The fixed positioning of the sealing element on the valve body also contributes to reducing wear and, due to the lack of movement between the sealing element and the valve body, increases tightness. In the valve according to the invention, a closure part (e.g., a plate, cone, ball, or needle) is moved, as is conventional, essentially parallel to the direction of fluid flow. The flow is interrupted by closing the valve by pressing the closure part with its sealing surface against a suitably shaped opening, the valve seat. The pressing force is applied by the respective elastic element.

[0019] The one-piece valve body has an area adjacent to the closure part and opposite the elastic element, which is designed as a valve stem. The two valve stems can be placed directly or indirectly against one another in the axial direction when closing the quick coupling and opening the fluid channel. The length of the valve stem or the sum of the lengths of both valve stems in the axial direction is selected such that the valve stems first touch when inserting the nipple into the sleeve as soon as the nipple's outer surface is in sealing contact with the sealant fixed in the sleeve. This geometry makes it possible for the two valve bodies to push each other away in the axial direction against the preload of their elastic elements and only then open the fluid channel when the quick coupling is sealed to the outside by the nipple contacting the sealant fixed in the sleeve.

[0020] With regard to safe operation of the quick coupling, it is advantageous if, when the valve body is closed, the valve body protrudes axially into the housing by a dimension Ma relative to a housing opening. This ensures that the valve body is not accidentally opened if the nipple or sleeve is touched at the open end. The closed valve body lies tightly against the inside of the housing. From this closed position, the valve body moves away from the housing opening into the housing when the fluid channel is opened. The dimension Ma depends on the inner diameter of the housing at the housing opening, depending on the desired level of safety. The dimension Ma is preferably at least 0.1 mm or at least the dimension of the axial length of a chamfer on the housing opening.

[0021] To achieve the largest possible flow cross-section, it is advantageous if the fluid channel is limited in the radial outward direction over at least 50% of the axial length of the elastic element between an outer surface of the elastic element and the inner surface of the housing. This means that the maximum inner diameter of the housing is used for the fluid channel. In a further flow section, the fluid channel can also run within the elastic element, depending on the geometry of the elastic element. For small quick couplings, it is advantageous if the fluid channel surrounds both the valve body and the elastic element over the entire axial length of the valve body and the entire axial length of the elastic element. The fluid channel preferably forms an annular gap between the inner housing wall and the valve body as well as the elastic elements.

[0022] With regard to a large flow cross-section, it is further advantageous for the elastic element to have a spiral concentrically circulating around the central axis M with a hollow space arranged inside the spiral. According to the invention, the hollow space forms part of the fluid channel. In this axial region, the medium flows around and through the spiral-shaped elastic element. The medium flows radially outward and inward through the spiral.

[0023] With regard to safe operation, it is advantageous that the opening between the spirals is maintained when the elastic element is fully compressed. This creates a positive opening which, even with maximum compression of the elastic element, ensures a fluid channel through which the medium can flow radially through the elastic element. With regard to safe operation, it is provided that a sealing means is provided in a radial direction between the inner surface of the housing of the sleeve and the outer surface of the nipple, and the sealing means is fixed to the sleeve or nipple in the axial direction, wherein, when the valve is closed, the distance between the first valve body and the center plane of the sealing means in the axial direction is at least the dimension Ma.

[0024] Furthermore, it can be advantageous to provide a groove on the inner surface of the sleeve for securing the sealant. This allows the sealant to rest axially against the flanks of the groove, and the inner diameter of the sealant can be increased at the same time.

[0025] It can be advantageous if the outer surface of the nipple forms a sealing surface for the sealant that is arranged coaxially to the central axis M. The sealing surface acts in a radial direction and seals when the coupling is closed with the sealant in the sleeve before the two valve bodies come into contact. The area of ​​the nipple housing can be referred to as the grommet, which has the outer circumferential sealing surface. The grommet is passed through the sealant when the coupling is connected, thereby sealing the two housings. This geometry makes it possible for the two valve bodies to push each other away in the axial direction against the preload of their elastic elements and only open the fluid channel when the quick coupling is tight or the two housings are sealed against each other by the sealant contacting the grommet.The same principle in reverse order applies when opening and pulling apart the quick coupling.

[0026] The required distance between the first valve body and the center plane of the sealant ensures that the valve bodies or their valve stems only touch when the quick coupling is closed, when the nozzle is already sealingly against the sealant.

[0027] With regard to the required safety for cross-sectional areas inside the housing between 7 mm² and 30 mm², it is preferred that the inner diameter of the housing in the area of ​​the nozzle be between 2 mm and 6 mm. The valve stem of the nipple is positioned and guided in the nozzle within the housing. The annular gap around the valve stem in the nipple housing usually provides the smallest flow cross-section due to the reduced diameter of the nipple compared to the sleeve.

[0028] It can also be advantageous if a nozzle is provided on the housing of the sleeve and the housing of the nipple for connecting one end of a line, and the elastic element can be preloaded in the axial direction via a retaining ring that can be secured in the nozzle. This allows the line connection and the preload of the elastic element to be combined. Preferably, an internal thread is provided in the nozzle for securing the retaining ring. Furthermore, the elastic element is centered via the nozzle.

[0029] Furthermore, it may be advantageous to provide a locking mechanism between the sleeve and the nipple, comprising a sleeve and a spring element, as well as claws adjoining the spring element in the axial direction. The claws positively secure or lock the nipple in the sleeve due to the preload of the spring element. Because the locking mechanism can only be released by manually moving the claws against the preload of the spring element, unintentional release or opening of the quick coupling is prevented. For this purpose, up to eight claws are arranged on a carrier, with the spring element preloading the claws in the axial direction via the carrier.

[0030] Another particularly advantageous feature is that the sleeve has several openings, each of which has a claw extending from the outside of the sleeve to the inside. The claws engage through the sleeve housing into a groove in the nipple housing, whereby the nipple is automatically locked in an axial direction within the sleeve due to the elastic preload of the claws in a radially inward direction. The carrier and claws are manufactured as a one-piece component made of the same material. Polyetheretherketone (PEEK), a member of the polyaryletherketone group of materials, is used as the plastic for the carrier, claws, and spring element.

[0031] The outer surface of the nipple is designed to form a ramp extending radially outward, allowing the claws to be spread radially outward by pushing them onto the ramp. Subsequently, for further interaction, the outer surface of the nipple must form a groove in an axial direction after the ramp, into which the claws engage radially. To secure the claws in the groove, the carrier is preloaded by the spring element.

[0032] To operate the locking mechanism, it is advantageous to have a sleeve for releasing the nipple's locking mechanism. This sleeve fits over the spring element and / or the claws and can be moved axially. The sleeve allows the locking mechanism to be easily released.

[0033] The quick coupling is designed in such a way that the spring force of the elastic elements and the claws is overcome solely by an axial force applied when inserting the nipple into the socket, the valve bodies open and the nipple is automatically locked in the socket.

[0034] Further advantages and details of the invention are explained in the claims and the description, and illustrated in the figures. It shows: Figures 1-4 each show a sectional view of a quick coupling in different positions of a socket to a nipple; Figure 3a a detailed view according to Figure 3 ; Figure 5 an exploded view of the sleeve according to the Figures 1 to 4 ; Figure 6 an exploded view of the nipple according to the Figures 1 to 4 ; Figure 7 a detailed view of the sleeve according to Figure 1 ; Figure 8 a detailed view of the nipple according to Figure 1; Figure 9a shows a first perspective detailed view of a valve body with an elastic element as a one-piece component; Figure 9b shows a second perspective detailed view of a valve body with an elastic element as a one-piece component.

[0035] Generally, the specified radial and axial directions refer to the central axis. Axial refers to one or both directions. Hoses or pipes are referred to as lines, whereby pipes made of metal and / or plastic can be made in one piece or as a composite. In particular, plastic hoses or pipes made of polyethylene (PE), polypropylene (PP), or other plastics or plastic blends are referred to as lines. The medium suitable for such quick couplings is fluid. In addition to aggressive gases, acids and bases in the liquid state are particularly suitable.

[0036] With one exception, all figures show the same quick couplings with the same components. The illustrations in the Figures 1 to 4 differ mainly in the relative position between the socket 1 with its components and the nipple 2 with its components. The exception is in the Figures 1 and 2 Compared to the illustrations in the Figures 3 to 5 The cross-sectional area of ​​the profile of the spiral of the spring element 33 is rectangular and significantly larger. The plastic used for this embodiment requires a larger cross-sectional area for a sufficiently strong spring force. In the embodiments according to the Figures 3 to 5 the spring element 33 is made of metal, whereby metal can be disadvantageous due to the lack of resistance to corrosion, but can be more advantageous with regard to spring force.

[0037] In Figure 1With respect to the central axis M, the axial direction is indicated by "A" and the radial direction by "R." Identical components bear identical reference numbers. For reasons of clarity, identical components shown in different figures are not always assigned a reference number with a reference line.

[0038] The quick coupling essentially consists of two coupling parts, namely a socket 1 and a nipple 2. The nipple 2 is inserted into the socket 1 to connect the quick coupling ( Figure 1 ). In a Figure 4 In the end position shown, the sleeve 1 is tightly connected to the nipple 2 and mechanically secured against unintentional loosening or movement of the sleeve 1 out of the nipple 2.

[0039] The sleeve 1 has a housing 10 and a nozzle 11 adjoining the housing 10 in the axial direction. The housing 10 is rotationally symmetrical to the central axis M, with an inner surface 100 and an outer surface 106, such that the sleeve 1 is completely hollow on the inside. The nozzle 11 is also hollow on the inside and has an internal thread 110 on its inside for attaching a retaining ring 14. The housing 10 and the nozzle 11 are manufactured as a single piece and form the outer boundary, in the radial direction, for a fluid channel FK for the fluid.

[0040] A similar structure to the sleeve 1 is also found in the nipple 2, which also has a housing 20 and a nozzle 21 adjoining the housing 20 in the axial direction. The housing 20 is bounded in the radial direction by an inner surface 200 and an outer surface 204 and is hollow inside.

[0041] The hollow nozzle 21 has an internal thread 210 on its inside for fastening a retaining ring 23. The housing 20 and the nozzle 21 are also manufactured in one piece and form the outer boundary for the fluid channel FK in the radial direction.

[0042] The respective nozzle 11, 21 and the respective internal thread 110, 210 also serve to connect a line L1, L2 according to Figure 4 The two connected lines are connected by the two fluid channels FK from the socket 1 and the nipple 2. The flow direction in the quick coupling is arbitrary, just as the fluid state can be liquid or gaseous.

[0043] A first valve body 12 is mounted in the sleeve 1 and a second valve body 22 is mounted in the nipple 2, each of which is movable in the axial direction relative to the housing 10, 20. The valve body 12, 22 can close the fluid channel FK in the sleeve 1 or in the nipple 2. Closing prevents the fluid supplied via the line L1, L2 from escaping from the sleeve 1 or the nipple 2. The principle of opening and closing the two valve bodies 12, 22 is the same for both coupling parts, namely the sleeve 1 and the nipple 2. In the sleeve 1, the valve body 12 seals against the inner surface 100 of the housing 10 by means of a first sealing element 121 that runs around the valve body 12. For this purpose, a conical sealing surface 101 is provided in the inner surface 100.The conical shape alone centers the valve body 12 in the housing 10 when closed, since the sealing element 121 rests against the inner surface 100.

[0044] In the nipple 2, a second sealing element 221 is provided, which extends around the second valve body 22 and seals against the inner surface 200 of the housing 20. In the nipple 2, the inner surface 200 also forms a conical sealing surface 201, which also solely ensures centering in the closed state of the valve body 22.

[0045] The force required to engage the respective sealing element 121, 221 is generated by an elastic element 124, 224 provided on the valve body 12, 22 and supported on the respective retaining ring 14, 23. The elastic element 124, 224 is centered on the retaining ring 14, 23. The one-piece design eliminates the need to axially and radially align the elastic element 124, 224 and the valve body 12, 22. Forced guidance of the unit consisting of the valve body 12, 22 and the elastic element 124, 224 through the housing 10, 20 is therefore not necessary. On the contrary, the distance between the valve body 12, 22 and the housing 10, 20 and the distance between the elastic element 124, 224 and the housing 10, 20 can be increased to such an extent that the fluid channel FK required for the fluid is provided.At the same time, the clearance of the valve body 12, 22 given by the distance allows a lower spring constant for the elastic element 124, 224, since no direct frictional forces can occur between the valve body and the housing.

[0046] The valve body 12, 22 essentially has three sections in the axial direction: a closure part 122, 222, a valve stem 123, 223 adjoining the closure part 122, 222, and the elastic element 124, 224 adjoining the closure part 122, 222 opposite the closure part 122, 222. The sealing element 121, 221 is arranged in a groove 125, 225 surrounding the closure part 122, 122 and is designed as an O-ring.

[0047] The two valve bodies 12, 22 close the fluid channel FK via their outer surface, which is why they are not hollow and do not have a channel. According to the invention, they form self-contained valve bodies. To open the two valve bodies 12, 22, the two valve bodies 12, 22 abut against each other in the axial direction when the nipple 2 is inserted into the socket 1. For this purpose, the respective valve stem 123, 223 is designed to be correspondingly long. By moving the nipple 2 into the socket 1, the two valve bodies 12, 22 come into contact with each other and are moved against the spring force of the two elastic elements 124, 224 in the axial direction, each towards the nozzle 11, 21. This mechanical feature is described in the Figures 2 to 4As shown, the sealing system is released by moving the valve bodies 12, 22, and the fluid channel FK is enlarged in its flow cross-section after opening by the sealing element 121, 221 moving away from its sealing surface 101, 201.

[0048] The elastic element 124, 224, like the valve body 12, 22, is made of the same plastic as the valve body 12, 22. However, the plastic used here, polytetrafluoroethylene (PTFE), cannot be injection-molded like conventional thermoplastics, which is why the valve body 12, 22 and the elastic element 124, 224 are manufactured by machining.

[0049] The length of the valve stem 123, 223 in the axial direction or the sum of the lengths of both valve stems 123, 223 in the axial direction is selected such that the valve stems 123, 223 only touch when the nipple 2 is inserted into the sleeve 1 when the nipple 2, with its outer surface 204, is in sealing contact with the sealing means 5 fixed in the sleeve 1. For this purpose, a sealing surface 205 for the sealing means 5 is formed on the outer surface 204 of the nipple 2, arranged coaxially to the central axis M. The area of ​​the housing 20 of the nipple 2, on which the sealing surface 205 is provided, is referred to as the grommet, which has the outer circumferential sealing surface 205. Due to the interaction of the nozzle with the sealant 5, it is possible that when the quick coupling is closed, the two valve bodies 12, 22 only open the fluid channel FK when the quick coupling is sealed to the outside. Figure 2This sealed position is almost reached. The sealant 5 is almost seated on the sealing surface 205 of the nozzle. When the quick coupling is opened, the fluid channel FK is first closed by the valve bodies 12, 22 before the seal between the two housings 10, 20 is released by the sealant 5.

[0050] In the Figures 7 and 8the principle is illustrated. The seal between the sealing surface 205 and the sealing means 5 in the housing 10 is only achieved when the nozzle of the nipple 2 is pushed far enough through the sealing means 5 that the sealing means 5 sits on the cylindrical sealing surface 205 in the region of its center plane 51. To ensure that the two valve bodies 12, 22 only touch each other via their valve stems 123, 223 when the quick coupling is closed when the seal is ensured via the sealing means 5 and the nozzle, the distance Am between the valve stem 123 of the first valve body 12 and the center plane 51 of the sealing means 5 is selected to match the geometry of the nozzle and the position of the valve stem 223 on the housing opening 208 of the nozzle. The distance Am is at least the dimension of the axial length Fb of the chamfer 209 on the housing opening 208 of the nozzle.This applies to the case shown here, where the valve stem 223 only protrudes a small amount Ma and thus not significantly behind the housing opening 208 into the housing 20 or into the nozzle.

[0051] Due to the lack of forced guidance of the elastic element 124, 224 in the housing 10, 20 and the resulting distance in the axial direction, the fluid channel FK is designed as an annular channel between the outer surface 127, 227 of the elastic element 124, 224 and the inner surface 100, 200 of the housing 10, 20. The fluid flows through the open valve past the closure part 122, 122 into the annular channel. From there, the fluid flows through the spirals of the elastic elements 124, 224 designed as spiral springs and through an opening 128, 228 adjacent to the spirals in the axial direction. The fluid reaches a Figure 2 respectively indicated and in the Figures 9a and 9bThe fluid flows into the cylindrical cavity 126, 226 shown within the respective spiral. From there, the fluid flows through a central opening in the retaining ring 14, 23, through the retaining ring 14, 23, and into the connected line L1, L2. Alternatively, the fluid flows in the opposite direction and in the reverse order through the individual components. In the sleeve 1 and the nipple 2, the fluid flows through the components in the reverse order, assuming the same flow direction in the quick coupling.

[0052] In order to ensure that the fluid can still flow through the elastic element 124, 224 even when the elastic element 124, 224 is fully compressed, i.e. when the spirals are in contact with each other, openings 128, 228 are provided as forced openings ( Figures 9a and 9b ). The openings 128, 228 are provided in the axial direction at the end of the respective spiral. The two openings for the

[0053] The elastic elements 124, 224 used for sleeve 1 and nipple 2 differ only in their sizes, so the features described in Figures 9a and 9b apply to both elastic elements 124, 224. A distinction is not important here. The elastic element 124 of the first valve body 12 has a larger outer diameter and / or a larger spring constant than the elastic element 224 of the second valve body 22. This allows different movements of the two valve bodies 12, 22 to be realized when they push each other away.

[0054] A key aspect of the inventive solution is achieved by the geometry of the elastic element 124, 224. The average spacing of the spirals in the relaxed state of the elastic element 124, 224 does not change towards the ends of the respective spirals. This results in a positive opening when the elastic element 124, 224 is compressed. This advantage is particularly achieved when the elastic element 124, 224 is machined from a plastic body. The space between the spirals is created by a milling tool. The milling tool mills the space up to the end of the spiral, whereby the resulting spacing between the spirals does not change. It corresponds to the diameter of the milling tool.

[0055] After inserting the nipple 2 into the sleeve 1, a mechanical connection between the sleeve 1 and the nipple 2 is established by a locking device 3. The Figures 1 to 4 on average and in Figure 5 The perspectively illustrated components of the locking device 3 comprise four claws 32, which are attached to a support 31. The support 31 with the claws 32 is arranged around the sleeve 1 or is plugged onto the sleeve 1 and is pre-tensioned by a spring element 33, which is also plugged onto the sleeve 1. The claws 32 engage in a groove 207 on the outside of the nipple 2 for locking. This is clearly shown in the Figure 3 indicated section IIIa, which in Figure 3a is shown enlarged.

[0056] In the sleeve 1, several openings 13 are provided, through each of which a claw 32 is passed and the claw 32 is angled so flat that the claw 32 protrudes partially in the axial direction into the housing 10 of the sleeve 1. This is shown in the Figures 1 to 4 clearer than in Figure 3a To insert the claws 32, the outer surface 204 of the nipple 2 forms a relatively flat ramp 206 extending radially outward, by means of which the claws 32 can be spread radially outward. The guide surfaces of the claws 32 required for sliding on the ramp 206 run parallel to the ramp 206. Following the ramp 206, the claws 32 spring radially into the groove 207 due to the radial preload generated by the ramp 206. To fix the claws 32 in the groove 207, the carrier 31 is preloaded by the spring element 33.

[0057] The angled claws 32, together with the groove 207 and the openings 13, form a self-locking mechanism in the event of an attempt to pull the sleeve 1 and the nipple 2 apart in the locked state. In this case, the claw 32 is pressed through the opening 13 with its inner side against the flank of the groove 207 and is thereby pushed in the axial direction under the housing 10 (see Figures 1 to 4 ). The housing 10, which extends over the claws 32, prevents the claws 32 from spreading outward. The self-locking effect is enhanced by the fact that the claw 32 has a relatively steep profile on its rear side 320, which does not easily slip out of the groove 207 on the flank of the groove 207.

[0058] To secure the locking, a sleeve 34 is placed over the carrier 31, the claws 32 and the spring element 33. The sleeve 34 has a shoulder 341 according to Figure 3against which the carrier 31 abuts in the axial direction. Through this shoulder 341, the carrier 31 with the claws 32 can be pushed back against the spring force of the spring element 33 to release the locking mechanism, thereby lifting the claws 32 out of the groove 207.

[0059] Furthermore, the housing 10 of the sleeve 1 has a shoulder 15 against which the sleeve 34 abuts in an axial direction and is thereby fixed on the housing 10.

[0060] In the perspective representations according to the Figures 5 and 6 All relevant components are shown. The sleeve 1 and the nipple 2, including the valve bodies 12, 22, the retaining rings 14, 23, and the three sealing elements designed as O-rings, namely the sealant 5 and the first and second sealing elements 121, 221, and the locking device 3, consist of a total of only twelve components.

[0061] The embodiments show a quick coupling with a fluid channel FK designed in the form of an annular gap for the direct or indirect connection of two lines L1, L2 transporting a fluid, comprising a first coupling part designed as a sleeve 1 and a second coupling part designed as a nipple 2, wherein a) the sleeve 1 and the nipple 2 are made of plastic and are rotationally symmetrical with respect to a central axis M, at least in some areas, and are arranged coaxially to the central axis M when used as intended, b) the sleeve 1 has a housing 10 for inserting the nipple 2, wherein the housing 10 is hollow and has an inner surface 100 and an outer surface 106, and c) the nipple 2 has a housing 20 for insertion into the sleeve 1, wherein the housing 20 is hollow and has an inner surface 200 and an outer surface 204, d) a first valve body 12 and a second valve body 22 are arranged in the sleeve 1, and a respective elastic element 124, 224 is arranged in the nipple 2, and the respective valve body 12, 22 is displaceable in the axial direction and the elastic element 124, 224 is prestressable in an axial direction,wherein a sealing means 5 is provided in a radial direction between the inner surface 100 of the sleeve 1 and the outer surface 204 of the nipple 2, and the sealing means 5 is fixed in the axial direction to the sleeve 1 or to the nipple 2.

Claims

1. A quick coupling for aggressive media comprising a direct or indirect connection of two lines (L1, L2) transporting a medium via a fluid channel (FK) running through the quick coupling, comprising a first coupling part designed as a coupling sleeve (1) and a second coupling part designed as a nipple (2), wherein a) the coupling sleeve (1) and the nipple (2) each have a hollow housing (10, 20) arranged at least partially rotationally symmetrical to a central axis (M) for plugging together b) a first valve body (12) is arranged inside the coupling sleeve (1) and a second valve body (22) is arranged inside the nipple (2) and an elastic element (124, 224) is subsequently arranged in each case in the axial direction on the respective valve body (12, 22), wherein c) the fluid channel (FK) runs in the radial direction at least partially outside and at least partially inside the elastic element (124, 224), and d) the valve body (12, 22) can be displaced and prestressed in the axial direction by the elastic element (124, 224), as a result of which the fluid channel (FK) between the housing (10, 20) and the valve body (12, 22) is opened or closed, e) the valve body (12, 22) and the elastic element (124, 224) form a one-piece component, wherein the elastic element (124, 224) comprises a spiral running concentrically around the central axis (M) with a hollow space (126, 226) arranged in the interior in the spiral, characterised in that f) the elastic element (124, 224) comprises a positive opening (128, 228) directed in the radial direction towards the central axis (M), which serves as a fluid channel (FK) when there is a completely compressed elastic element (124, 224), in which the spirals are adjacent to one another.

2. The quick coupling according to claim 1, characterised in that the valve body (12, 22) and the elastic element (124, 224) form a material-identical component.

3. The quick coupling according to any one of the preceding claims, characterised in that the valve body (12, 22) is centred exclusively via a valve seat (101, 201) in the housing (10, 20).

4. The quick coupling according to any one of the preceding claims, characterised in that, in the case of a closed valve body (12, 22) of the coupling sleeve (1) and of the nipple (2), the valve body (12, 22) is set back in the housing (10, 20) by a dimension Ma of at least 0.1 mm in the axial direction relative to a housing opening (108, 208) of the housing (10, 20).

5. The quick coupling according to any one of the preceding claims, characterised in that the fluid channel (FK) is delimited in the radial direction outwards over at least 50% of the axial length of the elastic element (124, 224) between an outer lateral surface (127, 227) of the elastic element (124, 224) and the inner surface (100, 200) of the housing (10, 20).

6. The quick coupling according to claim 5, characterised in that, in a completely compressed state of the elastic element (124, 224), the opening (128, 228) is maintained between the spirals.

7. The quick coupling according to claim 6, characterised in that in an end position, in which the coupling sleeve (1) and the nipple (2) are tightly connected and mechanically secured against unintentional release or movement of coupling sleeve 1 out of nipple 2, the elastic elements (124, 224) are completely compressed.

8. The quick coupling according to claim 4, characterised in that a sealing means (5) is provided in a radial direction between the inner surface (100) of the housing (10) of the coupling sleeve (1) and the outer surface (204) of the nipple (2) and the sealing means (5) is fixed in the axial direction on the coupling sleeve (1) or on the nipple (2), wherein the distance (Am) between the first valve body (12) and the central plane (51) of the sealing means (5) amounts to at least the dimension Ma in the axial direction when the valve is closed.

9. The quick coupling according to any one of the preceding claims, characterised in that a detent (3) is provided between the coupling sleeve (1) and the nipple (2), which comprises a coupling sleeve (1) and a spring element (33) as well as claws (32) adjoining the spring element (33) in the axial direction, wherein the claws (32) positively fix or lock the nipple (2) in the coupling sleeve (1) by the pretensioning of the spring element (33).

10. The quick coupling according to claim 9, characterised in that a sleeve (34) is provided for releasing the detent (3) of the nipple (2), which sleeve is pulled over the spring element (33) and / or the claws (32) and can be displaced in the axial direction.

11. A system comprising a quick coupling according to any one of the preceding claims and a line system.