Quick coupling for connecting

Abstract

Quick coupling for aggressive media for the 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 sleeve (1) and a second coupling part designed as a nipple (2), wherein a) the sleeve (1) and the nipple (2) each have a hollow housing (10, 20) arranged at least partially rotationally symmetrically to a central axis (M) for plugging together b) a first valve body (12) is arranged within the sleeve (1) and a second valve body (22) is arranged within the nipple (2), and an elastic element (124, 224) is arranged in the axial direction adjacent to the respective valve body (12, 22), wherein c) the fluid channel (FK) extends 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), whereby 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) has a spiral concentrically encircling the central axis (M) with a hollow space (126, 226) arranged inside the spiral. characterized in that f) the elastic element (124, 224) has a positive opening (128, 228) directed radially towards the central axis (M), which serves as a fluid channel (FK) in a fully compressed elastic element (124, 224) in which the spirals abut one another.

Description

The invention relates to a quick coupling for aggressive media such as strong acids and bases. Such quick-action couplings serve for the central or direct 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, which is arranged at least partially rotationally symmetrically with respect 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 and an elastic element is arranged adjacent to the respective valve body in the axial direction. The fluid channel runs at least partially outside and / or at least partially inside the elastic element in the radial direction. The valve body is displaceable and preloadable in the axial direction by the elastic element, whereby the fluid channel between the housing and the valve body is opened or closed. The valve body and the elastic element form a one-piece component, wherein the elastic element has a spiral which runs concentrically around the central axis and has a cavity arranged inside the spiral.A quick-action coupling is already known from DE 28 26 344 A1, in which a nipple is guided into a sleeve and a valve body prestressed by spring elements is arranged within each of these two components. For a seal between the inner surface of the sleeve and the outer surface of the nipple, a plurality of sealing and spacer elements are provided which move relative to the sleeve and on the inner surface of the sleeve when the coupling is closed and opened.According to DE 36 18 233 C2, a quick 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 lies in a tubular spring holder. The valve member and the compression spring form a total of two components.The publication WO 95 / 24584 describes a valve insert which is designed as a one-piece component. The valve insert has a retaining element, a valve spring and a valve seat. The valve spring is adjoined by a sleeve-shaped extension which carries the valve seat. The extension has an internal thread into which a screw plug is screwed in a gas-tight manner. The component functional as a valve body is in two parts and consists of the valve insert and the functionally necessary screw plug for sealing the cavity. The valve body is tightly closed all around, whereby the cavity is designed as a pneumatic spring.According to US 2012 / 031515 A1, a quick-action coupling of the generic type having valve bodies and elastic elements is known, wherein the elastic elements are hollow, serve as a fluid channel and are flowed through in the radial direction. If spiral springs serve as elastic elements, a distance between the spirals as a fluid channel in the radial direction is provided by the elastic element even in a maximally compressed state of the spiral springs.US 2006 / 260699 A1 describes a quick-action coupling of the generic type with valve bodies and elastic elements, in which the elastic elements are configured in meander form and are surrounded by the fluid.The object of the invention is to design and arrange 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.The object is achieved according to the invention by the features of claim 1.The one-piece construction eliminates the need to align the elastic element and the valve body axially and radially with respect to one another in alignment. In a two-part design, this is absolutely necessary since the elastic element could otherwise exert an eccentric and decentral force on the valve body, as a result of which the latter could no longer self-center itself and there is a risk of crossing and blocking. In the two-part embodiment, this results in the forced need to guide at least the valve body, better still the valve body and the elastic element, axially. According to the invention, this need is dispensed with, since the elastic element always exerts a central force on the valve body due to the one-piece structure with the valve body.Due to the unnecessary positive guidance with the aid of the housing, guidance in the axial direction can be dispensed with. As a result, no complicated production of a fit between the valve body and the housing and likewise little further components are necessary for guidance. The play of the valve body in the radial direction, which is due to the unnecessary fit, has the further advantage that the elastic element can be realized with a lower spring constant, since no frictional forces can occur between the valve body and the housing or other components not necessary here.Closing of the valve is ensured by the one-piece connection in conjunction with the advantages resulting therefrom and described above, since the valve body cannot become stuck in the open position. The further advantage results that during assembly of the quick coupling only one component is inserted into the housing and is positioned functionally with a securing ring.Apart from a sealing means inserted into the sleeve, it is thus possible to reduce the number of individual components, which must be inserted into the respective housing independently of a securing means, to one component.Preferably, the valve body with the elastic element is made of a fluorinated plastic or of a polymer consisting of fluorine and carbon and in particular of perfluoroalkoxy polymers (PFA) or of polytetrafluoroethylene (PTFE). These plastics are resistant to acids and bases. The elastic element has a relatively low spring constant because of the plastic. Therefore, the stroke and thus the deflection of the two closure parts is selected to be correspondingly large so that, depending on the flow direction, the relevant valve body reliably and rapidly closes against the dynamic pressure of the medium when separating the sleeve and nipple. As is clear from the description of the figures, the stroke also acts on the flow cross section of the fluid channel, which is also quantified, however, by the diameter ratios between the inner surface of the sleeve and the outer surface. In contrast to metal, plastic is resistant to acids and bases and thus ensures a spring constant and spring force which is stable over a long period of time, which leads to a better seal. Further preferably, the housing, the valve body, the elastic element and the complete locking device comprising a sleeve, a carrier with claws and a spring element are produced from plastic, in particular from perfluoroalkoxy polymers (PFA) or from polytetrafluoroethylene (PTFE).However, it must be noted in principle that in the case of quick-action couplings of the aforementioned type which are used for aggressive media such as strong acids and bases, it is necessary for them to be free from drops and absolutely corrosion-resistant during closing and opening and, owing to the low mass flows for such media, to function absolutely reliably even in the case of small line cross sections and thus in the case of small structural sizes. In particular, gaps and gaps are disadvantageous because of crystalline deposits of the acids and bases. Even with cross-sectional areas in the interior of the housing of between 7 mm 2 and 30 mm 2 the features according to the invention provide sufficient safety. It must be taken into account here that the flow cross sections present in the interior of the housing are reduced by up to 80% by the valve bodies and the elastic elements, so that flow cross sections of less than 5 mm 2 can be realized for the fluid channel starting from the cross-sectional areas in the interior of the housing.In terms of production, it is advantageous that the valve body and the elastic element form a component identical in material. The one-piece construction makes it possible to machine a blank produced, for example, by injection molding in a working process by machining. This also applies in particular to blanks made of plastic, in particular made of perfluoroalkoxy polymers (PFA) or of polytetrafluoroethylene (PTFE).With regard to a flow cross section that is as large as possible, it is advantageous for the valve body and / or the elastic element to have an opening that is directed in the radial direction toward the central axis M and serves as a fluid channel. The opening in the valve body is provided in the transition region between the closed region of the valve body and the elastic element. The opening in the elastic member may be provided at any location in the axial direction along the elastic member and circumferentially around the central axis M around the elastic member. Through the opening, the medium can flow from the annular channel, downstream of the closed valve body, into the middle of the housing, into the elastic element, and further out of the housing in the axial direction, and correspondingly opposite in the opposite direction in the case of the reverse flow direction. In the middle of the housing, the flow cross section is larger.With regard to a simple geometry and a seal in the valve seat of the valve body that is not overdetermined, it is advantageous that the valve body is centered exclusively via a valve seat in the housing. In this case, a conical sealing surface is preferably provided, which brings about self-centering in the closed state of the valve. This is supported in the axial direction by the guidance described at the beginning and achieved by the one-piece capability. 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 on the respective inner surface of the housing of the sleeve or of the nipple by moving the valve body at least in the axial direction, wherein the sealing element sealingly closes the fluid channel. The conical section forms the valve seat.The fixed positioning of the sealing element on the valve body also contributes to reducing wear and increases the tightness due to the lack of movement between the sealing element and the valve body. In the valve according to the invention, as usual, a closure part (e.g. plate, cone, ball or needle) is moved substantially parallel to the flow direction of the fluid. The flow is interrupted by the closing of the valve by pressing the closure part with the sealing surface against a suitably shaped opening, the valve seat. The force for pressing is applied by the respective elastic element.The one-piece valve body has a region which adjoins the closure part and lies opposite the elastic element and is designed as a valve stem. The two valve shafts can be placed on one another in the axial direction indirectly or directly when the quick coupling is closed and for opening the fluid channel. The length of the valve stem or the sum of the lengths of the two valve stems in the axial direction is selected such that the valve stems touch one another for the first time when the nipple is introduced into the sleeve, as soon as the nipple sealingly bears with its outer surface against the sealing means fixed in the sleeve. This geometry makes it possible for the two valve bodies to press mutually away in the axial direction counter to the prestress of their elastic elements and to open the fluid channel only when the quick-action coupling is sealed off towards the outside by the contact of the nipple on the sealing means fixed in the sleeve.With regard to a reliable operation of the quick coupling, it is advantageous that, when the valve body is closed, the valve body protrudes back into the housing by a dimension Ma in the axial direction relative to a housing opening of the housing. This ensures that the valve body is not opened unintentionally when the nipple or else the sleeve is contacted at the respectively open end. The closed valve body sealingly abuts the inner side 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 degree of safety. Preferably, the dimension Ma is at least 0.1 mm or at least the dimension of the axial length of a chamfer at the housing opening.For the largest possible flow cross section, it is advantageous if the fluid channel is bounded in the radial direction outwards over at least 50% of the axial length of the elastic element between an outer lateral surface of the elastic element and the inner surface of the housing. As a result, the maximum inner diameter of the housing for the fluid channel is utilized. In a further flow section, the fluid channel can also extend within the elastic element depending on the geometry of the elastic element. In the case of small quick-action 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 over the entire axial length of the elastic element. In this case, the fluid channel preferably forms an annular gap between the inner housing wall and the valve body and the elastic elements.With regard to a large flow cross section, it is further advantageous that the elastic element has a spiral which circulates concentrically about the central axis M and has a cavity arranged inside the spiral. According to the invention, the cavity forms part of the fluid channel. In this axial region, the medium flows around the helical elastic element and flows through it. The medium flows radially outwardly and inwardly through the spiral.With regard to a reliable mode of operation, it is advantageous that in a completely compressed state of the elastic element, the opening between the spirals is maintained. In order to ensure reliable operation, a forced opening is provided which, even in the event of maximum compression of the elastic element, ensures a fluid channel through which the medium can flow in the radial direction through the elastic element. In order to ensure reliable 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 in the axial direction on the sleeve or on the nipple, wherein, when the valve is closed, the distance between the first valve body and the central plane of the sealing means is at least the measure Ma.Furthermore, it can be advantageous if a groove for fixing the sealing means is provided on the inner surface of the sleeve. As a result, the sealing means bears against the flanks of the groove in the axial direction and the inner diameter of the sealing means can be increased at the same time.It can be advantageous here if the outer surface of the nipple forms a sealing surface for the sealing means which is arranged coaxially with respect to the central axis M. The sealing surface acts in the radial direction and seals with the sealing means in the sleeve before the two valve bodies touch one another when the coupling is closed. The region of the housing of the nipple can be referred to as a grommet, which has the sealing surface running circumferentially on the outside. The grommet is guided through the sealing means during the plugging together and thereby seals the two housings. This geometry makes it possible for the two valve bodies to press away from one another in the axial direction counter to the prestress of their elastic elements and to open the fluid channel only when the quick-action coupling is sealed off or the two housings are sealed off from one another by the contact of the sealing means on the bushing. The same principle in the reverse sequence is used when opening and pulling apart the quick coupling.The required distance between the first valve body and the center plane of the sealing means ensures that the valve bodies or their valve shafts do not touch each other until the quick-action coupling is closed, when the spout already sealingly abuts the sealing means.With regard to the required safety with cross-sectional areas in the interior of the housing of between 7 mm 2 and 30 mm 2 it is preferred that the inner diameter of the housing in the region of the spout is between 2 mm and 6 mm. In this case, the valve stem of the nipple is positioned and guided in the bushing in the housing. The annular gap around the valve shaft in the housing of the nipple usually provides the smallest flow cross section due to the diameter of the nipple reduced compared to the sleeve.For this purpose, it can also be advantageous if a connecting piece for connecting one end of a line is provided on the housing of the sleeve and on the housing of the nipple, and the elastic element can be prestressed in the axial direction via a securing ring which can be fixed in the connecting piece. This allows the line connection and the prestress of the elastic element to be combined. Preferably, an internal thread is provided in the connecting piece for fixing the securing ring. In addition, the elastic element is centered over the connecting piece.It can furthermore be advantageous if a locking mechanism is provided between the sleeve and the nipple, which locking mechanism comprises a sleeve and a spring element and claws adjoining the spring element in the axial direction, wherein the claws positively fix or lock the nipple in the sleeve by the prestress of the spring element. Because the locking can only be released by manually moving the claws against the prestress of the spring element, unintentional release or opening of the quick coupling is achieved. For this purpose, up to eight claws are arranged on a carrier, wherein the spring element prestresses the claws in the axial direction via the carrier.It is also particularly advantageous for this purpose that a plurality of openings are provided in the sleeve, through which openings a respective claw is led from the outside of the sleeve to the inside. The claws thus engage through the housing of the sleeve into a groove in the housing of the nipple, whereby the locking of the nipple in an axial direction in the sleeve takes place automatically on account of the elastic prestress of the claws in the radially inward direction. The carrier and the claws are produced as a one-piece and material-identical component. The plastic used for the carrier, the claws and the spring element is polyetheretherketone (PEEK) from the group of polyaryletherketones.It is provided here that the outer surface of the nipple forms a ramp which extends outwards in the radial direction and by means of which the claws can be spread outwards in the radial direction by pushing on the ramp. Subsequently, for a further interaction, it is necessary for the outer surface of the nipple to form, in an axial direction after the ramp, a groove in which the claws engage in the radial direction. For fixing the claws in the groove, the carrier is prestressed by the spring element.For operating the locking, it is advantageous that a sleeve for releasing the locking of the nipple is provided, which sleeve is placed over the spring element and / or the claws and is displaceable in the axial direction. The locking can be easily released by the sleeve.The quick coupling is constructed in such a way that the spring force of the elastic elements and the claws is overcome solely by a force in the axial direction which is to be applied when the nipple is inserted into the sleeve, the valve bodies open and the nipple automatically locks in the sleeve.Further advantages and details of the invention are explained in the patent claims and in the description and are illustrated in the figures. It shows: FIGS. 1-4 are sectional views of a quick coupling in different positions of a sleeve to a nipple; FIG. 3 a shows a detailed view according to FIG. 3 ; FIG. 5 is an exploded view of the sleeve of FIGS. 1 to 4; FIG. 6 is an exploded view of the nipple according to FIGS. 1 to 4; FIG. 7 is a detailed view of the sleeve according to FIG. 1 ; FIG. 8 shows a detailed view of the nipple according to FIG. 1 ; FIG. 9 ashows a first perspective detailed view of a valve body with elastic element as a one-piece component; FIG. 9 bshows a second perspective detailed view of a valve body with elastic element as a one-piece component.In principle, the radial and axial directions indicated relate relative to the central axis. One or both directions are detected axially. Pipes or tubes are referred to as pipes, wherein blanks made of metal and / or plastic can be produced in one piece or as a composite. In particular, pipes are referred to as plastic hoses or pipes which are made of polyethylene (PE), polypropylene (PP) or other plastics or plastic mixtures. The medium suitable for such quick couplings is flowable. Besides aggressive gases, acids and bases in the liquid aggregate state are particularly suitable.In all figures, the same quick couplings with the same components are shown, except for one exception. The representations in FIGS. 1 to 4 differ primarily in the relative position between the sleeve 1 with its components and the nipple 2 with its components. The exception is shown in Figures 1 and 2. Compared to the representations in FIGS. 3 to 5, the cross-sectional area of the profile of the spiral of the spring element 33 is rectangular and substantially larger. The plastic provided for this exemplary embodiment requires a larger cross-sectional area for a sufficiently strong spring raft. In the exemplary embodiments according to FIGS. 3 to 5, the spring element 33 is made of metal, wherein metal can be disadvantageous because of the lack of resistance to corrosion, but can be more advantageous with regard to the spring force.In FIG. 1, with respect to the central axis M, the axial direction is represented by "A" and the radial direction by "R". Identical components bear identical reference numerals. Like components shown in different figures are not always assigned a reference numeral with reference line for reasons of clarity.The quick coupling consists essentially of two coupling parts, namely a socket 1 and a nipple 2, The nipple 2 is inserted into the socket 1 for connecting the quick coupling (FIG. 1 ). In an end position shown in FIG. 4, the sleeve 1 is tightly connected to the nipple 2 and mechanically secured against unintentional detachment or removal of the sleeve 1 from the nipple 2.The sleeve 1 has a housing 10 and a connecting piece 11 which adjoins the housing 10 in the axial direction. The housing 10 is formed rotationally symmetrically to the central axis M with an inner surface 100 and an outer surface 106 such that the socket 1 is continuously hollow on the inside. The socket 11 is likewise hollow on the inside and has an internal thread 110 on its inside for fastening a securing ring 14. The housing 10 and the connector 11 are manufactured in one piece and form the radially outer boundary for a fluid channel FK for the fluid.A construction similar to the sleeve 1 in this respect is also found in the nipple 2, which likewise has a housing 20 and a connecting piece 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 on the inside. The hollow connector 21 has an internal thread 210 on its inner side for fastening a securing ring 23. The housing 20 and the connecting piece 21 are also produced in one piece and form the outer boundary for the fluid channel FK in the radial direction.The respective connecting piece 11, 21 and the respective internal thread 110, 210 also serve for connecting a respective line L 1, L 2 according to FIG. 4 The two connected lines are connected to one another by the two fluid channels FK of the sleeve 1 and the nipple 2. The direction of flow in the quick coupling is arbitrary, as can the aggregate state of the fluid be liquid or gaseous.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 fluid channel FK can be closed in the sleeve 1 or in the nipple 2 by the valve body 12, 22. The closing prevents the fluid supplied via the line L 1, L 2 from flowing out of the sleeve 1 or out of the nipple 2. the principle of opening and closing the two valve bodies 12, 22 is the same for both coupling parts, namely for the sleeve 1 and for the nipple 2. In the sleeve 1, the valve body 12 seals on the inner surface 100 of the housing 10 by means of a first sealing element 121 which extends around the valve body 12. For this purpose, a sealing surface 101 is provided in the inner surface 100, which sealing surface is of conical design. Solely as a result of the conical shape, the valve body 12 is centered in the housing 10 in the closed state, since the sealing element 121 bears against the inner surface 100.In the nipple 2, a second sealing element 221 is correspondingly provided, which extends around the second valve body 22 and seals on the inner surface 200 of the housing 20. The inner surface 200 also forms a conical sealing surface 201 in the nipple 2, which likewise alone ensures centering in the closed state of the valve body 22.The force required for the bearing of the respective sealing element 121, 221 is generated by an elastic element 124, 224 in each case, which is provided on the valve body 12, 22 and which is supported on the respective securing ring 14, 23. The elastic element 124, 224 is mounted centered on the securing ring 14, 23. The one-piece nature eliminates the need to align the elastic element 124, 224 and the valve body 12, 22 axially and radially with respect to one another in alignment. A forced guidance of the unit consisting of the valve body 12, 22 and the elastic element 124, 224 through the housing 10, 20 is thus not necessary. On the contrary, the distance between the valve body 12, 22 and the housing 10, 20 and the distance between the elastic member 124, 224 and the housing 10, 20 can be increased to such an extent that the fluid channel FK necessary for the fluid is provided. At the same time, the clearance of the valve body 12, 22 due to 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.The valve body 12, 22 has essentially 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.The two valve bodies 12, 22 close the fluid channel FK via their outer surface, for which reason 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 one another 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 sleeve 1, the two valve bodies 12, 22 come to bear against one another and are moved in the axial direction in each case in the direction of the neck 11, 21 counter to the spring force of the two elastic elements 124, 224. This mechanical feature is shown in FIGS. 2 to 4. The sealing contact is released by the movement of the valve bodies 12, 22, and the flow cross section of the fluid channel FK is enlarged after opening by the sealing element 121, 221 moving away from its sealing surface 101, 201.The elastic element 124, 224 is, like the valve body 12, 22, made of the same plastic in one piece. However, the plastic polytetrafluoroethylene (PTFE) used here cannot be injection molded as classic thermoplastics, for which reason the valve body 12, 22 and the elastic element 124, 224 are produced by machining.The length of the valve shaft 123, 223 in the axial direction or the sum of the lengths of both valve shafts 123, 223 in the axial direction is selected such that the valve shafts 123, 223 do not touch each other when the nipple 2 is inserted into the sleeve 1 until the nipple 2 sealingly abuts with its outer surface 204 against 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 which is arranged coaxially with respect to the central axis M. The region of the housing 20 of the nipple 2 at which the sealing surface 205 is provided is referred to as a grommet, which has the sealing surface 205 running circumferentially on the outside. The interaction of the bushing with the sealing means 5 makes it 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 off from the outside. In FIG. 2, this dense position is nearly reached. The sealing means 5 is almost seated on the sealing surface 205 of the spout. When the quick-action coupling is opened, the fluid channel FK is correspondingly first closed by the valve bodies 12, 22, before the seal between the two housings 10, 20 is released by the sealing means 5.The principle is illustrated in FIGS. 7 and 8. The seal between the sealing surface 205 and the sealing means 5 in the housing 10 is only achieved when the spout of the nipple 2 is inserted through the sealing means 5 to such an extent that the sealing means 5 is seated on the cylindrical sealing surface 205 in the region of its central plane 51. In order that the two valve bodies 12, 22 do not touch each other via their valve shafts 123, 223 when the quick coupling is closed until the seal is ensured via the sealing means 5 and the bushing, the distance Am between the valve shaft 123 of the first valve body 12 and the central plane 51 of the sealing means 5 is selected to match the geometry of the bushing and the position of the valve shaft 223 at the housing opening 208 of the bushing. The distance Am is at least the measure of the axial length Fb of the chamfer 209 at the housing opening 208 of the bushing. This is the case for the case depicted here, in which the valve stem 223 protrudes only by a small amount Ma and thus not significantly behind the housing opening 208 into the housing 20 or into the bushing.Due to the lack of positive guidance of the elastic element 124, 224 in the housing 10, 20 and the distance achieved thereby in the axial direction, the fluid channel FK is formed as an annular channel between the lateral 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 adjoining the spirals in the axial direction. The fluid reaches a cylindrical cavity 126, 226 within the respective spiral, which cavity is indicated in each case in FIG. 2 and is illustrated in FIGS. 9 aand 9 b. From there, the fluid flows further through a central opening in the securing ring 14, 23, through the securing ring 14, 23 and into the connected line L 1, L 2. Alternatively, the fluid flows through the individual components in opposite directions and in the opposite order. In the sleeve 1 and in the nipple 2, the components are each flowed through in the reverse sequence in the quick coupling in the same direction of flow.In order that the fluid can still flow through the elastic element 124, 224 even in the case of a fully compressed elastic element 124, 224, i.e. when the spirals abut one another, openings 128, 228 are provided as a forced opening (FIGS. 9 aand 9 b ). The openings 128, 228 are each provided at the end of the respective spiral in the axial direction. The two elastic elements 124, 224 respectively used for the sleeve 1 and for the nipple 2 differ exclusively in their sizes, so that the features described with reference to the two FIGS. 9 aand 9 bappear to the two elastic elements 124, 224. A distinction is not important here. The elastic element 124 of the first valve body 12 has an outer diameter and / or a greater spring constant that is greater 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 away from one another.An essential aspect of the solution according to the invention is achieved by the geometry of the elastic element 124, 224. The average pitch of the coils in the relaxed state of the elastic member 124, 224 does not change toward the ends of the respective coils. As a result, a forced opening is achieved when the elastic element 124, 224 is compressed. This advantage is achieved in particular when the elastic element 124, 224 is worked out of a plastic body by machining. The intermediate space between the spirals is thereby created by a milling tool. The milling tool is used to mill the intermediate space up to the end of the spiral, as a result of which the spacing of the spirals produced therewith does not change. It corresponds to the diameter of the milling tool.After the nipple 2 has been introduced into the socket 1, a mechanical connection is established between the socket 1 and the nipple 2 by means of a locking mechanism 3. The components of the locking device 3 shown in section in FIGS. 1 to 4 and in perspective in FIG. 5 comprise four claws 32 which are fastened to a carrier 31. The carrier 31 with the claws 32 is arranged around the sleeve 1 or is plugged onto the sleeve 1 and prestressed by a spring element 33 likewise plugged onto the sleeve 1. The claws 32 engage in a groove 207 on the outer side of the nipple 2 for locking. The detail IIIa indicated in FIG. 3 and shown enlarged in FIG. 3a is clear.In the sleeve 1, a plurality of openings 13 are provided, through each of which a claw 32 is passed and the claw 32 is angled flat in such a way that the claw 32 partially protrudes into the housing 10 of the sleeve 1 in the axial direction. This is more clearly shown in Figures 1 to 4 than in Figure 3a. For inserting the claws 32, it is provided that the outer surface 204 of the nipple 2 forms a relatively flat ramp 206 which extends outwards in the radial direction and by means of which the claws 32 can be spread outwards in the radial direction. 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 into the groove 207 in the radial direction due to the radial prestress generated by the ramp 206. For fixing the claws 32 in the groove 207, the carrier 31 is prestressed by the spring element 33.The angled claws 32 form, together with the groove 207 and the openings 13, a self-locking in the case where it is attempted to pull apart the sleeve 1 and the nipple 2 in the locked state. In this case, the claw 32 is pressed with its inner side against the flank of the groove 207 through the opening 13 and in the process slides in the axial direction under the housing 10 (see FIGS. 1 to 4 ). The housing 10 which engages over the claws 32 prevents the claws 32 from spreading outwards. The self-locking is enhanced in that the claw 32 has a relatively steep profile on its rear side 320, which does not slide out of the groove 207 easily on the flank of the groove 207.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 FIG. 3, against which the carrier 31 abuts in the axial direction. By means of this shoulder 341, the carrier 31 with the claws 32 can be pushed back to release the locking against the spring force of the spring element 33, whereby the claws 32 are lifted out of the groove 207.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.The perspective representations according to FIGS. 5 and 6 show all relevant components. The sleeve 1 and the nipple 2 together with the valve bodies 12, 22 and the securing rings 14, 23 as well as the three sealing elements formed as O-rings, namely the sealing means 5 and the first and second sealing elements 121, 221 and the locking device 3, consist of a total of only twelve components.The exemplary embodiments show a quick-action coupling having a fluid channel FK designed in the form of an annular gap for the central or direct connection of two lines L 1, L 2 transporting a fluid, having 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 designed rotationally symmetrical at least in regions with respect to a central axis M and are arranged coaxially with the central axis M in intended use, 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 inserting 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 is arranged in the sleeve 1 and a second valve body 22 and in each case one elastic element 124, 224 are arranged in the nipple 2, and the respective valve body 12, 22 can be displaced in the axial direction and the elastic element 124, 224 can be prestressed 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.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 28 26 344 A1

[0002] DE 36 18 233 C2

[0003] WO 95 / 24584

[0004] US 2012 / 031515 A1

[0005] US 2006 / 260699 A1

[0006]

Claims

Quick coupling for aggressive media for the medium or direct connection of two lines (L1, L2) transporting a medium via a fluid channel (FK) running through the quick coupling, having 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) each have a hollow housing (10, 20), arranged at least partially rotationally symmetrically to a central axis (M), for plugging together, b) a first valve body (12) inside the sleeve (1) and a second valve body (22) inside the nipple (2), and an elastic element (124, 224) adjoining the respective valve body (12, 22) in each case in the axial direction, wherein c) the fluid channel (FK) is arranged at least partially outside and at least partially inside the elastic element (124, 224) in the radial direction, 224 ) and d) the valve body (12, 22) is displaceable and pre-tensioned in the axial direction by the elastic element (124, 224), whereby 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) has a spiral which concentrically circulates around the central axis (M) and has a cavity (126, 226) arranged inside the spiral, characterized in that f) the elastic element (124, 224) has a forced opening (128, 228) which is directed in the radial direction towards the central axis (M) and which, in the case of a fully compressed elastic element (124, 224) in which the spirals abut one another, serves as a fluid channel (FK).Quick coupling according to claim 1, characterised in that the valve body (12, 22) and the elastic element (124, 224) form a component identical in material.Quick coupling according to one of the preceding claims, characterized in that the valve body (12, 22) is centred in the housing (10, 20) exclusively via a valve seat (101, 201).Quick coupling according to one of the preceding claims, characterized in that, with a closed valve body (12, 22) of the sleeve (1) and of the nipple (2), the valve body (12, 22) protrudes back into 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).Quick coupling according to one of the preceding claims, characterized in that the fluid channel (FK) is bounded in the radially outward direction 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).Quick coupling according to claim 5, characterised in that in a fully compressed state of the elastic element (124, 224), the opening (128, 228) between the spirals is maintained.Quick coupling according to claim 6, characterised in that in an end position in which the sleeve (1) and the nipple (2) are tightly connected and mechanically secured against unintentional release or removal of the sleeve 1 from the nipple 2, the elastic elements (124, 224) are fully compressed.Quick coupling according to Claim 4, characterized in that a sealing means (5) is provided in a radial direction between the inner surface (100) of the housing (10) of the sleeve (1) and the outer surface (204) of the nipple (2), and the sealing means (5) is fixed in the axial direction on the sleeve (1) or on the nipple (2), wherein, when the valve is closed, the distance (Am) between the first valve body (12) and the centre plane (51) of the sealing means (5) in the axial direction is at least the measure Ma.Quick coupling according to one of the preceding claims, characterized in that a locking device (3) is provided between the sleeve (1) and the nipple (2), which locking device comprises a sleeve (1) and a spring element (33) and claws (32) adjoining the spring element (33) in the axial direction, wherein the claws (32) fix or lock the nipple (2) in the sleeve (1) in a positive-locking manner by the prestress of the spring element (33).Quick coupling according to claim 9, characterised in that a sleeve (34) is provided for releasing the locking mechanism (3) of the nipple (2), which sleeve is placed over the spring element (33) and / or the claws (32) and is displaceable in the axial direction.A system comprising a quick coupling according to any one of the preceding claims and a conduit system.

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