Plug-in coupling with leakage indicator for fluid lines

Abstract

The present invention relates to a plug-in coupling (100) for fluidic line systems, in particular for compressed air brakes of motor vehicles, comprising a coupling part (102) and a holding part (104) for a plug part (106). A plug shaft of the plug part (106) can be inserted, such that it is peripherally sealed, into a receiving opening (108) of the coupling part (102) in an insertion direction E, and, by means of the radially elastic holding part (104) radially protruding into the receiving opening (108), the plug part can be locked against release opposite the insertion direction (E), in one case with the plug-in coupling (100) in a partially inserted, incompletely sealed preliminary latching position and in another case with the plug-in coupling (100) in a completely inserted, completely pressure-tightly sealed full latching position. In order to form the preliminary latching position and the full latching position, the holding part (104) has at least two axially spaced tooth structures (110a, 110b) formed on it and can be moved relative to the coupling part (102), radially with respect to the receiving opening (108), between a locking position and a release position. The invention also relates to a release tool (118) for a plug-in coupling (100) of this type, said release tool having an action body (172) extending along a longitudinal axis (170) and a spreading body (174) adjoining the action body (172), the action body (172) being elastically deformable about the longitudinal axis (170) and being substantially stiff axially with respect to the longitudinal axis (170).

Description

[0001] “Plug-in coupling with leak indicator for fluid lines”

[0002] The invention relates to a plug-in coupling for fluidic line systems, in particular for compressed air brakes of motor vehicles, comprising a coupling part and a holding part for a plug part. The plug part can be inserted into a receiving opening of the coupling part in a plug-in direction in a circumferentially sealed manner by means of a plug shaft. By means of the radially elastic holding part projecting radially into the receiving opening, the plug part to be inserted can be locked against release counter to the plug-in direction in a partially inserted, incompletely sealed pre-locking position of the plug-in coupling on the one hand, and in a fully inserted, completely pressure-tight, fully locked position of the plug-in coupling on the other. To form the pre-locking position and the fully locked position, the holding part has at least two axially spaced tooth structures for engaging behind at least one retaining edge formed on the plug part.The holding part can be displaced radially to the receiving opening between a locking position that locks the plug part and a release position that releases the plug part relative to the coupling part.

[0003] Furthermore, the invention relates to a release tool for an aforementioned plug-in coupling for transferring the holding part from the locking position into the release position.

[0004] EP 0 913 618 A1 discloses a plug-in coupling for pressure medium systems. In this plug-in coupling, a plug part is first inserted into the receiving opening in a pre-locking position. In this position, the plug-in coupling is unable to seal off system pressure. If the plug part is not fully inserted, a signal is generated in the form of a controlled escape of fluid, which is particularly perceptible acoustically. To ensure a completely sealed arrangement of the plug part, it is moved in the plugging direction from the pre-locking position to a fully locked position. In this position, the plug part is sealed with its plug shaft against an inner peripheral wall of the coupling part.To lock the plug part, EP 0 913 618 A1 proposes the use of a multi-part retaining element with two axially spaced retaining edges, allowing the plug part to be locked in the coupling part in both the pre-locking and fully locked positions. A disadvantage of the known plug-in coupling has been found to be that the plug-in coupling cannot be removed without damage, which makes repeated assembly particularly complex. Furthermore, the retaining part of this plug-in connection is inaccessible from the outside, thus also presenting obstacles for inspection and maintenance.

[0005] Another plug-in coupling is known from EP 1 714 068 B1. This plug-in coupling has a coupling body with molded-on holding parts designed as locking arms that extend axially in the plug-in direction. EP 1 714 068 B1 discloses moving the holding arms from a locked position into a radially expanded release position using a tool. In practice, the use of the release tool requires a large radial space perpendicular to the receiving opening, so that the space required to use the release tool is insufficient, particularly during disassembly. Due to the axial locking arms as holding elements, the plug-in coupling is also susceptible to dirt and contamination.

[0006] The invention is based on the object of providing a plug-in coupling or a plug-in connection which overcomes the disadvantages known from the prior art, in particular reducing the effort in use and improving operational reliability.

[0007] This object is achieved by a plug-in coupling having the features of claim 1. Since the retaining part is radially elastic and can be displaced radially relative to the receiving opening between a locking position that locks the plug part and a release position that releases the plug part, repeatable assembly is possible. In particular, for maintenance purposes, e.g., checking and / or replacing wear parts, it is not necessary to damage parts of the plug-in coupling with the design according to the invention.

[0008] Furthermore, the assembly position is communicated to the installer by simultaneously separating a partially mated, incompletely sealed pre-locking position of the plug-in coupling from a fully mated, completely pressure-tight, fully locked position of the plug-in coupling. This is achieved by applying two significant force increases during the insertion process, each when overcoming the pre-locking and fully locked positions. Furthermore, the pre-locking position provides protection against the plug part falling out of the coupling part, as at least one toothed structure formed on the retaining part can engage behind a retaining edge of the plug part.

[0009] According to the invention, the pre-locking position, in addition to preventing loss, has the advantage that the intentionally incomplete seal allows the fluid to be conveyed from the plug-in coupling to escape in a controlled manner. This controlled leakage enables early detection and error prevention, especially after commissioning, thus improving assembly reliability.

[0010] Due to the axially adjacent arrangement of the tooth structures, the respective tooth structures can be designed to meet the application requirements. In particular, the tooth structure for the locking connection for locking the plug part in the pre-locking position can be designed differently, in particular with less material, than the tooth structure for the locking connection for locking the plug part in the fully locked position. The at least one retaining edge of the plug part to be mounted is expediently designed to correspond to the tooth structures in such a way that the tooth structures can engage behind the at least one retaining edge to form a locking connection.

[0011] In an advantageous embodiment, the retaining part has two radially elastic spring arms. The spring arms are expediently connected to one another on one side via a connecting section. Starting from the connecting section, the spring arms each extend to a free end. For advantageous locking of the plug shaft, the spring arms, in a relaxed resting state, protrude into the receiving opening such that the plug part can be locked in the pre-locking position and the fully locked position. To ensure non-destructive release, the embodiment provides, in particular, that when the spring arms are in a radially elastically expanded tension state, the plug part can be removed from the receiving opening in the opposite direction to the plugging direction.In particular, the spring arms do not protrude into the receiving opening in the tensioned state or only protrude slightly compared to the resting state, so that in particular the plug shaft can be guided past the spring arms with its at least one retaining edge.

[0012] According to a preferred embodiment of the invention, the retaining part has at least two retaining projections protruding radially from the spring arms toward the receiving opening. Particularly preferably, the retaining part has four retaining projections protruding radially from the spring arms toward the receiving opening. The two, or better yet, four, retaining projections can advantageously be distributed around the circumference of the receiving opening and, in particular, engage evenly with a retaining edge of the plug having at least one toothed structure.

[0013] Two toothed structures spaced axially apart from each other relative to the plugging direction are advantageously formed on at least one retaining projection, in particular on each retaining projection. Advantageously, for a uniform arrangement of the retaining areas and for the locking connections for blocking the plug part relative to the plugging direction, two retaining areas are arranged on each radially elastic spring arm such that the spring arms are preferably mirror-symmetrical to each other in cross-section. In particular, this design prevents the plug shaft from tilting in the receiving opening.

[0014] It is particularly advantageous for the retaining projections to have axial cutouts. The cutouts can fully or partially penetrate the retaining projections axially. The cutouts prevent the occurrence of material accumulations during the production of the retaining part, particularly during injection molding. Material and weight are also saved. A design that is particularly advantageous for disassembly provides that the radially elastic spring arms and the coupling part are designed in such a way that upon radial displacement of the retaining part from the locked position to the released position, the spring arms are elastically spread from the rest state into the radially expanded stress state. The radial deformation of the retaining arms is expediently brought about simultaneously with the radial displacement of the retaining part. This has the particular advantage that there is no need to exert pressure on the locking arms, e.g. with a release tool, which could lead to damage.Furthermore, the holding part can be designed and arranged in such a way that the radial displacement from the release position to the locking position or from the locking position to the release position can be brought about from the outside, if necessary by using a release tool.

[0015] Advantageous elastic deformation of the spring arms is advantageously achieved by providing two retaining projections opposite the connecting section at the free ends of the spring arms. The retaining projections, in particular, merge into a radially outwardly offset web section of the respective spring arm in a beveled control contour. It has proven advantageous for the control contour to point toward the connecting section, with the control contours being designed such that, upon radial displacement of the retaining part from the locking position to the release position, the control contours slide over an axial separating web of the coupling part.The control contours and the separating webs are designed in particular in such a way that the control contours slide over the separating web during the radial displacement of the holding part from the locking position into the release position in such a way that the spring arms are advantageously elastically spread radially outwards into the tension state.

[0016] In an extended variant of the invention, the control contours each have a retaining bevel. The retaining bevel serves in particular to ensure that the retaining part can only be partially displaced radially outwards relative to the coupling part. This advantageously prevents the retaining part from being displaced beyond the release position or from falling out of the coupling part. The retaining bevels are therefore preferably designed such that, when the spring arms are under tension, the retaining bevel is oriented perpendicular to the direction of radial displacement of the retaining part from the locking position into the release position. It has also proven preferable for the retaining bevel to rest on a correspondingly designed bearing edge in the release position, so that further displacement of the retaining part radially outwards beyond the release position is positively blocked.For this purpose, the bearing edge is aligned parallel to the retaining bevel with the spring arms in the tension state.

[0017] According to a preferred variant of the invention, the radially elastic retaining part and the coupling part are advantageously designed for operational reliability, such that, in a fully engaged position, the radial displacement of the retaining part from the locking position to the release position is blocked and / or the radially elastic deformation of the retaining part is positively blocked. In particular, an unintentional displacement of the retaining part into the release position is prevented, and a radial expansion of the retaining part is blocked, thus reducing the risk of the plug part becoming loose against the plugging direction.

[0018] In this inventive sense, it is particularly advantageous if the holding part has spring arms which interact with the coupling part in such a way that in the fully locked position the radial displacement of the holding part from the locking position to the release position is blocked and / or the radial elastic deformation of the spring arms from the rest state to the radially expanded stress state is blocked, in particular in a form-fitting manner.

[0019] In order to prevent the plug part from accidentally coming loose from the receiving opening, according to a preferred embodiment of the invention, a blocking edge is formed on the side of the axially foremost tooth structure facing away from the plug-in direction. The blocking edge protrudes axially from the tooth structure facing away from the plug-in direction. It has proven advantageous for the blocking edge to be followed by a bearing surface axially offset in the plug-in direction, pointing radially outwards. The blocking edge and the bearing surface are advantageously designed such that when the plug-in coupling is in a fully engaged position, the holding part rests axially with the bearing surface on a bearing surface of the coupling part facing in the plug-in direction, and rests radially with the blocking edge against a circumferential surface of the receiving opening.

[0020] Due to the blocking edge being in contact with the circumferential surface of the receiving opening, the spring arms of the holding part cannot expand radially and the holding part cannot be moved radially to the coupling part from the locking position to the release position.

[0021] It has proven expedient to dimension the coupling part or the receiving opening of the coupling part with a plug-in path for the plug shaft, wherein the holding part has an axial play relative to the coupling part. The axial play preferably corresponds at least to the extension of the blocking edge in the axial direction. For the purpose of assembly, the holding part can thus be transferred from the release position to the locking position, wherein the tooth structures engage with the holding edge(s) when the plug shaft is inserted in the plug-in direction. Once the plug part has been fully inserted into the receiving opening and the locking connection between the tooth structures and the holding edge(s) required for the fully locked position has been established, the plug part can be moved against the plug-in direction in accordance with its plug-in path by means of a restoring force on the plug part.Advantageously, the blocking edge is positioned radially next to the circumferential surface of the receiving opening, blocking the radial displacement of the retaining part and the radial expansion of the spring arms. In particular, this restoring force is generated in a pressureless state of the plug-in coupling by a dirt seal, which advantageously interacts with the coupling part. The restoring force generated by the dirt seal is advantageously amplified by the system pressure when the plug-in coupling is pressurized.

[0022] To release the locking connection or the blocking by the blocking edge, the plug part is preferably displaced in the plugging direction at least over the axial length of the blocking edge, so that the blocking edge and the peripheral surface of the receiving opening do not overlap. The elastic deformation of the spring arms and the radial displacement of the retaining part are released again.

[0023] For transferring the holding part from the locking position to the release position, the connecting section of the holding part and / or the coupling part optionally has a release contour in a circumferential section radially adjacent to the connecting section of the holding part. The release contour can be designed in such a way that it is easier to act on the holding part for the purpose of transferring it by hand and / or with a tool. Preferably, the release contour on the holding part is designed to point toward the coupling part. Alternatively or additionally, the release contour on the coupling part is designed to point, in particular, toward the connecting section of the holding part.

[0024] It has proven advantageous that the release contour of the holding part and / or the coupling part are designed such that they form an insertion opening that is open in the plug-in direction. The insertion opening is designed in particular such that a cross-sectional area of ​​the insertion opening decreases via a ramp section pointing counter to the plug-in direction. The ramp section can expediently be formed on the release contour of the holding part and / or on the release contour of the coupling part. A release tool can expediently be inserted into the insertion opening through the insertion opening, which decreases in cross-section via the ramp section(s). In particular, by means of a contact between the release tool and the ramp section(s), a radially outward-pointing release force acts on the holding part upon axial displacement of the release tool counter to the plug-in direction.This advantageously allows the release tool to be guided parallel to the plug-in direction in a space-saving manner in order to move the holding part into the release position.

[0025] In order to avoid potential assembly errors and, in particular, to insert the holding part correctly into the coupling part in such a way that the described locking and release function is guaranteed, a preferred embodiment of the plug-in coupling features a mandrel pointing radially towards the coupling part on the connecting section of the holding part. This mandrel can be inserted into a corresponding recess in the circumference of the coupling part such that, at least in the fully engaged position, the mandrel engages in the recess in the circumference of the coupling part. In particular, if the holding part is incorrectly assembled, the mandrel abuts the circumference of the coupling part in such a way that the holding part cannot be moved radially to the plug-in direction from the release position to the locking position. In addition, the fitter can easily visually identify incorrect assembly based on the protruding mandrel and the holding part projecting radially from the coupling part.

[0026] To ensure optimal absorption of the force transmitted from the retaining edges of the connector part to the toothed structures, e.g., when the assembled connector part is subjected to tensile stress in the fully engaged position against the insertion direction, at least one of the toothed structures is designed such that it has a radius at a bending point subjected to maximum load by the locking connection between the toothed structure and the retaining edge of the connector part. The advantage of the radius is that it allows for better utilization of the contact surface between the toothed structure and the retaining edge.

[0027] According to a particular embodiment of the invention, the receiving opening of the coupling part has a cylindrical sealing section and a control section adjoining the cylindrical sealing section, facing counter to the plug-in direction. In particular, the receiving opening has a larger diameter in the control section than in the sealing section. The changing diameters can expediently allow the sealing sections to provide different functions, e.g., the arrangement of seals. In particular, the plug-in coupling is designed such that the plug shaft is sealed only against the control section in the pre-locking position, so that incomplete assembly can be detected by a controlled leak.

[0028] An advantageous further development provides for a transition section formed axially between the control section and the sealing section, which reduces the diameter of the receiving opening in the control section to the diameter of the receiving opening in the sealing section. The transition section particularly facilitates centering the plug shaft of the plug part during insertion.

[0029] Furthermore, axially extending grooves are optionally formed in the circumferential surface of the control section as leakage paths. This ensures controlled fluid discharge as an assembly indicator. In particular, at least one leakage path is provided; the number of leakage paths can preferably be adapted to the operating conditions and the fluidic properties of the fluid to be transferred; for example, four or even eight leakage paths are possible. The leakage paths are preferably arranged evenly over the circumference of the transition section.

[0030] The functions of the control section and the sealing section are particularly advantageously separated in that, in particular, the sealing section and the control section are arranged relative to one another in such a way that, in the pre-locking position, the plug shaft is arranged with a front main seal, facing in the plugging direction and arranged in a main sealing groove, adjacent to the control section and in particular also to the transition section, and in the fully locked position, the plug shaft is arranged with the main seal adjacent to the sealing section. The change in diameter between the control section and the sealing section expediently compresses the main seal more strongly in the fully locked position, thus providing greater resistance to internal pressures.At the same time, the main seal in the pre-locking position can cause a leak in a controlled manner under pressure load due to the control section with an enlarged diameter, so that the incomplete assembly can be detected.

[0031] In addition to the previous embodiment, it may be advantageous for the control section of the coupling part to be designed such that the dirt seal of the plug part is arranged in the control section. The dirt seal can be arranged in particular in a rear sealing groove of the plug shaft facing in the plugging direction. The control section and - if present - also the transition section are advantageously designed such that the dirt seal can be elastically clamped against the circumferential surface of the receiving opening, at least in the fully engaged position. The dirt seal is expediently clamped both radially against the circumferential surface in the control section and, if applicable, in the transition section, and also axially due to the change in diameter from the control section to the transition section.The axial tensioning of the dirt seal creates an axial restoring force on the plug part, causing the plug part to be displaced against the plugging direction, thereby improving the engagement of the tooth structures on the retaining edges. Another positive aspect is that, together with the blocking edge and the plug-in path, this creates a self-locking effect. Once the plug part has been fully inserted and the insertion force acting on the plug part in the plugging direction for inserting the plug part is released, the restoring force of the dirt seal means that the plug part, together with the retaining part attached to the plug part, is displaced axially relative to the coupling part against the plugging direction. This expediently brings the blocking edge into radially acting, positive-locking engagement with the circumferential surface of the receiving opening.

[0032] Furthermore, the object underlying the invention is achieved with a release tool according to the features of claim 18.

[0033] The release tool according to the invention for a plug-in coupling according to one of the aforementioned embodiments serves to transfer the holding part from the locking position to the release position. According to the invention, the release tool comprises an engaging body extending along a longitudinal axis and an expanding body adjoining the engaging body. The release tool is designed such that the engaging body is elastically deformable about the longitudinal axis and is essentially rigid axially of the longitudinal axis.

[0034] In particular, the elastic deformability around the longitudinal axis prevents incorrect use due to "levering," as is known from the prior art. According to the invention, the release tool is guided parallel to the receiving opening of the coupling part and thus perpendicular to the radial displacement direction of the holding part. Damage and jamming, which can result from "levering," are advantageously avoided, and at the same time, the radial space required to transfer the holding part from the locking position to the release position radially next to the plug-in coupling is minimized.

[0035] According to a further developed variant of the plug-in connection, the maximum displacement of the retaining part radially relative to the coupling part, which the retaining part requires to move from the locked position to the release position, corresponds to the depth of the expansion body of the release tool. This effectively ensures that only the required displacement of the retaining part is achieved and, in particular, prevents displacement beyond the release position.

[0036] Another optional variant of the plug-in connection provides for the expansion body of the release tool to be fork-shaped with two expansion tabs that protrude axially relative to the longitudinal axis and are separated by a central separating slot. In particular, the holding part and / or the coupling part can have guide contours designed in this way; in particular, the release contour has guide contours such that the release tool can always be inserted correctly during assembly. In particular, the expansion tabs are designed in such a way that, when the expansion tabs are inserted into a release contour, they engage around a mandrel that is optionally formed on the connecting section.

[0037] Further advantageous embodiments of the invention emerge from the following description of the figures and the dependent subclaims.

[0038] They show:

[0039] Fig. 1 is a perspective view of a coupling part,

[0040] Fig. 2 is a perspective view of a holding part, Fig. 3 is a plan view of the

[0041] Holding part according to Fig. 2,

[0042] Fig. 4 is a perspective view of a plug part,

[0043] Fig. 5 is a perspective view of a release tool,

[0044] Fig. 6 is a partial sectional view parallel to the plugging direction of a

[0045] Variant of a plug-in coupling according to the invention with an incompletely inserted connector in a pre-locking position,

[0046] Fig. 7 is a partial sectional view parallel to the plugging direction of the

[0047] Plug-in coupling according to Fig. 6 with a plugged-in connector in a plug-in position,

[0048] Fig. 8 is a partial sectional view parallel to the plugging direction of the

[0049] Plug-in coupling according to Fig. 6 with a fully inserted connector in a fully locked position,

[0050] Fig. 9 is a sectional view along the section line A - A according to Fig. 8 through the plug-in coupling with the fully inserted connector in a fully locked position according to Fig. 8,

[0051] Fig. 10 is a detailed view of area B according to Fig. 9,

[0052] Fig. 11 is a detailed view of area C according to Fig. 8,

[0053] Fig. 12 is a sectional view parallel to the plug-in direction of a variant of a connector according to the invention with a plugged-in connector in a plug-in position and a release tool in a pre-release position, Fig. 13 is a sectional view parallel to the plug-in direction of the

[0054] Connector according to Fig. 12 with a plugged-in connector in a plug-in position and a release tool in a release position,

[0055] Fig. 14 is a partial sectional view along the section line D - D according to Fig.

[0056] 13 with the holding part in a release position and

[0057] Fig. 15 is a partial sectional view parallel to the plugging direction through a

[0058] Sleeve section of the coupling part according to Fig. 1.

[0059] In the various figures of the drawing, identical parts are always provided with the same reference symbols.

[0060] With regard to the following description, it is claimed that the invention is not limited to the exemplary embodiments and not to all or several features of described combinations of features, but rather each individual partial feature of the / each exemplary embodiment is also important for the subject matter of the invention, even independently of all other partial features described in connection therewith, and also in combination with any features of another exemplary embodiment.

[0061] Figure 1 shows a coupling part 102 of a plug-in coupling 100 for fluidic connections according to the invention, shown in Figs. 6 to 8. The plug-in coupling 100 is shown in Figs. 6 to 8 in different assembly positions. The plug-in coupling 100 further comprises a holding part 104, shown in Figs. 2 and 3, for a plug part 106. The plug part 106 is designed in particular as a male plug part 106 with a plug shaft, as shown in Fig. 4.

[0062] The plug part 106 is circumferentially sealed with the plug shaft and can be inserted into a receiving opening 108 of the coupling part 102 in a plugging direction E. In Figs. 6 to 8, the plug part 106 is inserted into the coupling part 102.

[0063] The holding part 104 is radially elastic and projects radially into the receiving opening 108 of the coupling part 102. In particular, the holding part 104 can be detached from the coupling part 102 in a non-destructive manner such that the holding part 104 and the coupling part 102 can be separated from one another and reassembled. The holding part 104 and the coupling part 102 can also be expediently designed such that the holding part 104 can only be arranged on the holding part 104 for initial assembly, and repeated assembly or separation after the initial assembly is blocked, in particular blocked in such a way that non-destructive disassembly is not possible.

[0064] The plug part 106 can be locked against loosening counter to the plug-in direction E by means of the radially elastic holding part 104 projecting radially into the receiving opening 108, on the one hand in a partially plugged, incompletely sealed pre-locking position of the plug-in coupling 100, as shown in Fig. 6, and on the other hand in a fully plugged, completely pressure-tight sealed full lock-in position of the plug-in coupling 100, as shown in Fig. 8.

[0065] To form the pre-locking position and the full-locking position, the holding part 104 has at least two axially spaced tooth structures 110a, 110b for engaging behind at least one holding edge 112a, 112b formed on the plug part. The tooth structures 110a, 110b are shown in particular in Figs. 6 to 8 and 11 to 13.

[0066] In particular, the at least one retaining edge 112a, 112b is configured to correspond to the toothed structures 110a, 110b such that the toothed structures 110a, 110b each engage behind at least the corresponding retaining edge 112a, 112b configured on the plug part 106 to be mounted. The plug part 106 shown in Fig. 4 has, in particular, two retaining edges 112a, 112b axially spaced from one another in the plugging direction E. Figs. 6 to 8 and 11 expediently show how the toothed structures 110a, 110b engage behind the retaining edges 112a, 112b of the plug part 106 in the different mounting positions. The toothed structures 110a, 110b engage behind the retaining edge(s) 112a, 112b, forming a latching connection.

[0067] The tooth structures 110a, 110b and the holding edges 112a, 112b expediently have a fir tree-like profile, wherein the tooth structures 110a, 110b have an obliquely running tooth contact edge 114 pointing against the plugging direction E, over which a holding contact edge 116 of the holding edge 112a, 112b pointing in the plugging direction E slides when the plug part 106 is plugged in the plugging direction E.

[0068] In particular, the plug part 106 has two retaining edges 112a, 112b corresponding to the tooth structures 110a, 110b, which are axially offset from one another, as shown in Fig. 5. It has also proven advantageous for the respective retaining edge 112a, 112b to extend circumferentially in one piece around the circumference of the plug part 106, as shown in Fig. 5. In particular, a circumferential retaining edge 112a, 112b enables the plug part 106 to be rotated in the receiving opening 108 about its own axis without snagging or tilting. Preferably, the front retaining edge 112a of the plug part 106, pointing in the plugging direction E, is designed such that, in cooperation with the tooth structures 110a, 110b, it requires less assembly force than the rear retaining edge 112b, pointing in the plugging direction E. In particular, this is achieved by a smaller diameter of the retaining edge 112a compared to the rear retaining edge 112b.

[0069] The holding part 104 is displaceable radially relative to the receiving opening 108 between a locking position locking the plug part 106, shown as an example in Fig. 9, and a release position releasing the plug part 106, shown in Fig. 14. For example, the radial displacement of the holding part 104 using a release tool 118 is shown in Fig. 12. The holding part 104 is shown in the locking position in Fig. 12 and in the release position in Fig. 13 and Fig. 14 (the sectional view of Fig. 13). Preferably, the axial spacings of the tooth structures 110a, 110b are statistically designed such that the front tooth structure 110a in the plugging direction E bears the load acting against the plugging direction E almost completely, preferably completely, during operation under system pressure.Preferably, the front tooth structure 110a in the plug-in direction E carries 85% to 100%, in particular 90% to 95%, in particular 93% of the load acting against the plug-in direction E during operation under a system pressure load.

[0070] A further embodiment provides that the rear tooth structure 110b in the plug-in direction E first comes into contact with a corresponding rear holding edge 112b of the plug part 106 at the beginning of a compressive load and begins to carry the load, and the front tooth structure 110a in the plug-in direction E only comes into contact with the corresponding holding edge 112a of the plug part 106 after a slight deformation of the rear tooth structure 110b and absorbs a part of the load, in particular a predominant part of the load.

[0071] In particular, the front tooth structure 110a in the insertion direction E can be formed with a smaller diameter than the rear tooth structure 110b. This makes the front tooth structure 110a stiffer, so that it can absorb greater forces and the extent of deformation is kept to a minimum.

[0072] It may also be expedient for the tooth structures 110a, 110b on the holding part 104 and the holding edges 112a, 112b on the plug part 106 to be designed such that, when pressure is applied to the plug part 106 against the plugging direction E, there is symmetrical contact between the front tooth structure 110a and the rear tooth structure 110b and the correspondingly designed holding edges 112a, 112b.

[0073] According to a variant of the invention, the holding part 104, as shown in Fig. 2, has two spring arms 122 connected to one another on one side via a connecting section 120. The spring arms 122 are expediently designed to be radially elastic. The spring arms 122 preferably each extend from the connecting section 120 to a free end. In particular, in a relaxed resting state, shown in Fig. 9, the spring arms 122 protrude into the receiving opening 108 such that the plug part 106 to be locked can be locked in the pre-locking position, shown in Fig. 6, and the fully locked position, shown in Fig. 8. Furthermore, a preferred development provides that in a radially elastically expanded stress state of the spring arms 122, shown in Fig. 14, the plug part 106 can be removed from the receiving opening 108 counter to the plugging direction E. The tooth structures 110a, 110b are particularly located on the spring arms, as shown in Fig.2 shown, formed.

[0074] The holding part 104 with the spring arms 122 expediently clasps the coupling part 102 in a sleeve section of the coupling part 102. The holding part 104 is preferably arranged with its connecting section 120 pointing radially to the plug-in direction E towards an outer surface of the coupling part 102 such that the spring arms 122 each engage around a separating web 130 of the coupling part 102 running axially to the plug-in direction E. In particular, the separating webs 130 are designed such that they each extend axially through a radial bearing opening 111 in the outer surface in the sleeve section of the coupling part 102. The holding part 104 preferably projects with its holding projections 124 of the spring arms 122 through the bearing openings 111 into the receiving opening. Advantageously, in Figs.9 and 14 show how the tooth structures 110a, 110b arranged on the spring arms 122 protrude through the bearing openings 111 of the coupling part 102 arranged radially in the sleeve section. In particular, the bearing openings 111 and the separating webs 130 are marked in Fig. 1.

[0075] The holding part 104 preferably has at least two, in particular four, holding projections 124 protruding radially towards the receiving opening 108 from the spring arms 122. Two toothed structures 110a, 110b spaced apart axially relative to the insertion direction E are expediently formed in at least one holding projection 124, in particular in each holding projection 124. Figs. 6 to 8 only show a section through one holding projection 124 with two toothed structures 110a, 110b spaced apart axially relative to the insertion direction E. In particular, two holding projections 124 are arranged on each radially elastic spring arm 122 such that the spring arms 122 are mirror-symmetrical to one another in cross-section, in particular in the cross-section shown in Fig. 9.The retaining projections 124 are expediently supported on the plug shaft of the plug part 106 and / or the retaining edges 112a, 112b of the plug part 106, in particular with the tooth structures 110a, 110b formed on the retaining projections 124. The symmetrical arrangement of the retaining projections 124 promotes advantageous insertion and prevents tilting of the plug part 106 and / or the retaining part 104. Furthermore, the symmetrical arrangement has a particularly advantageous effect on a displacement of the retaining part 104 between the locking position and the release position, so that, for example, a radially elastic deformation of the spring arms 122 or their recovery can occur evenly.

[0076] In particular, the retaining projections 124, as shown in Fig. 3, have axial cutouts. The cutouts 126 have an advantageous effect on the filling behavior during the production of the retaining part 104 in a casting process, in particular an injection molding process. It is particularly advantageous for the cutouts 126 to completely penetrate the retaining projections 124 axially.

[0077] A particularly preferred embodiment of the invention is shown in Figs. 9 and 14. According to this embodiment, the radially elastic spring arms 122 and coupling part 102 are designed such that, upon radial displacement of the holding part 104 from the locking position to the release position, the spring arms 122 are elastically spread from the resting state into the radially expanded tensioned state. This expediently decouples the plug part 106 from the function of radially expanding the spring arms 122. Likewise, manual intervention by a technician directly on the spring arms 122 is not necessary, thus avoiding errors during assembly or disassembly.

[0078] According to a further development of the plug-in coupling 100, two retaining projections 124 are formed opposite the connecting section 120 at the free ends of the spring arms 122. These retaining projections 124 expediently merge, as shown in Figs. 3, 9, and 14, into a beveled control contour 128 in a radially outwardly offset web section of the respective spring arm 122. In particular, the control contour 128 points toward the connecting section 120, as shown in Figs. 3, 9, and 14. It is particularly preferred that the control contours 128 are designed such that, upon radial displacement of the retaining part 104 from the locking position to the release position, the control contours 128 slide over the axial separating web 130 of the coupling part 102, so that the spring arms 122 are elastically spread radially outward into the tensioned state. In particular in Fig.Figure 14 shows how the spring arm 122 shown is radially expanded into the tensioned state by means of the interaction of the separating web 130 and the control contour 128. This particularly advantageously decouples the plug part 106 from the function of radially expanding the spring arms 122. Likewise, with this design, manual intervention by a technician directly on the spring arms 122 is also unnecessary. The potential for errors during assembly and disassembly is effectively reduced.

[0079] In particular, the control contours 128 each have a retaining bevel 132. The retaining bevel 132 is shown in particular in Figs. 3, 9 and 14. The retaining bevels 132 are preferably designed such that, in the tensioned state of the spring arms 122, the retaining bevels 132, as shown by way of example in Fig. 14, are preferably aligned approximately perpendicularly, preferably perpendicularly, to the direction of radial displacement of the retaining part 104 from the locking position into the release position. In the release position, it is particularly desirable for the retaining bevels 132, as shown in Fig. 14, to rest on a correspondingly designed bearing edge 134 which, in particular, is aligned parallel to the retaining bevel 132 with the spring arms 122 in the tensioned state. The bearing edge 134 is expediently formed on the separating web 130 of the coupling part 102. Advantageously, the retaining bevel 132 rests on the bearing edge 134 orIn particular, further displacement of the holding part 104 radially outward beyond the release position is positively blocked. In particular, Fig. 14 approximately shows how the retaining bevel 132 bears positively against the bearing edge 134, so that the spring arms 122 cannot expand further radially and the displacement of the holding part 104 radially in the direction of the release position is positively blocked.

[0080] Advantageously, the radially elastic holding part 104, in particular the spring arms 122, and the coupling part 102 are designed such that the holding part 104, in particular the spring arms 122, interacts with the coupling part 102 such that, as shown in Fig. 8, at least in the fully engaged position, the radial displacement of the holding part 104 from the locking position to the release position is blocked. Alternatively or additionally, it can be provided that the radially elastic deformation of the holding part 104, in particular of the spring arms 122, from the rest state to the radially expanded stress state is also blocked, in particular in a form-fitting manner.

[0081] In order to block the radial displacement of the holding part 104 from the locking position to the release position and / or to block the radially elastic deformation of the holding part 104, in particular of the spring arms 122, from the rest state to the radially expanded stress state, it has proven expedient, as shown in Figs. 8 and 11, to form a blocking edge 136 on the side facing opposite to the plug-in direction E of the axially foremost tooth structure 110b. In particular, the blocking edge 136 protrudes axially opposite to the plug-in direction E from the tooth structure 110a, 110b. A support surface 138, which is axially offset in the plug-in direction E, expediently adjoins the blocking edge 136 and points radially outwards. Advantageously, the blocking edge 136 and the support surface 138 are designed such that in a correctly assembled fully locked position of the plug-in coupling 100, as shown in Fig.8, the holding part 104 rests axially with the support surface 138 on a bearing surface of the coupling part 102 pointing in the plug-in direction E, as shown in Fig. 11.

[0082] In particular, in the event of an attempt to open and / or when the plug part 106 is pulled obliquely to the insertion direction E, the holding part 104 rests with the blocking edge 136 radially against a circumferential surface 140 of the receiving opening 108, so that the radial displacement of the holding part 104 from the locking position into the release position and / or the radial elastic deformation of the holding part 104, in particular of the spring arms 122, from the rest state into the radially expanded stress state is blocked.

[0083] It has proven expedient to dimension the coupling part 102 or the receiving opening 108 of the coupling part 102 with a plug-in path 142 for the plug shaft, wherein the holding part 104 has an axial play relative to the coupling part 102. Preferably, the axial play corresponds at least to the extension of the blocking edge 136 in the axial direction. For assembly purposes, the holding part 104 can thereby be transferred from the release position to the locking position, wherein the tooth structures 110a, 110b engage with the holding edge(s) 112a, 112b upon insertion of the plug shaft in the plugging direction E.When the plug part 106 has been fully inserted into the receiving opening 108 and the locking connection required for the fully locked position between the tooth structures 110a, 110b and the holding edge(s) 112a, 112b has been established, the plug part 106 can be displaced against the plugging direction E in accordance with its plug-in path 142 by means of a restoring force on the plug part 106. The blocking edge 136 is advantageously arranged radially next to the circumferential surface 140 of the receiving opening 108, as shown in Figs. 8 and 11, and blocks the radial displacement of the holding part 104 and the radial expansion of the spring arms 122. To release the locking connection or the blockage by the blocking edge 136, the plug part 106 is expediently pushed back, as shown in Figs.7 and 12, the plug-in coupling 100 is displaced at least over the axial length of the blocking edge 136 in the plug-in direction E into an over-plug position, so that the blocking edge 136 and the circumferential surface 140 of the receiving opening 108 do not overlap. The elastic deformation of the spring arms 122 and the radial displacement of the holding part 104 are released again.

[0084] In particular, to facilitate the disassembly or removal of the plug part 106 from the receiving opening 108 counter to the plugging direction E, the expedient connecting section 120 of the holding part 104 and / or the coupling part 102 has a release contour 144a, 144b in a circumferential section radially adjacent to the connecting section 120 of the holding part 104. The release contour 144a on the holding part 104 is shown in particular in Fig. 2. The release contour 144b on the coupling part 102 is shown in particular in Fig. 1. Preferably, the release contour 144a on the holding part 104 is designed to point towards the coupling part 102 and the release contour 144b on the coupling part 102 is designed to point towards the connecting section 120 of the holding part 104. These embodiments of the release contours 144a, 144b are shown in particular in Figs. 1 and 2 as well as Figs. 12 and 13, wherein Figs. 12 and 13 show the plug-in coupling 100 with a holding part 104 arranged in the coupling part 102.

[0085] In particular, the release contours 144a, 144b of the holding part 104 and / or the coupling part 102 are designed such that they, in particular together, form an insertion opening 146 open in the plug-in direction E. The insertion opening(s) 146 is / are shown in particular in Fig. 12. Advantageously, a cross-section of the insertion opening 146 is reduced via a ramp section 148 pointing against the plug-in direction E. The ramp section 148 enables, in particular, that a release tool 118, as shown in Fig. 13, can be inserted into the insertion opening(s) 146 and, by means of a contact with the ramp section 148, a radially outward-pointing release force acts on the holding part 104. In the case of an insertion opening 146 formed jointly by the holding part 104 and the coupling part 102, the insertion opening 146 of the coupling part 102 and / or the insertion opening 146 of the holding part 104 can expediently have a ramp section 148.

[0086] It has proven advantageous that, opposite the insertion opening 146, the release contour 144a, 144b is axially open in such a way that when a release tool 118 is inserted into the release contour 144a, 144b through the insertion opening 146, any dirt that may be present in the release contour 144a, 144b is displaced from the area of ​​the release contour 144a, 144b.

[0087] Advantageously, as shown in Fig. 2, a dome 150 pointing radially towards the coupling part 102 is formed on the connecting section 120 of the holding part 104. In particular, the dome 150 engages, at least in the locking position of the holding part 104, or at least in the fully engaged position of the plug-in coupling 100, in a correspondingly formed recess 152 in the circumference of the coupling part 102. The recess 152 is shown in particular in Fig. 1. Advantageously, the recess 152 is designed with an axial play relative to the dome 152 such that an axial displacement of the holding part 104 relative to the coupling part 102 is possible. In particular, the axial play is dimensioned such that the holding part 104 can be displaced in accordance with the plug-in path 142. For this purpose, the recess 152 is advantageously oval or designed as an elongated hole.

[0088] In a further embodiment of the invention, at least one of the tooth structures 110a, 110b, as shown in Fig. 11, is designed such that it has a radius 154 at a bending point subjected to maximum load by the locking connection between the tooth structure 110a, 110b and the retaining edge 112a, 112b of the plug part 106. In particular, the rear tooth structure 110b pointing in the plugging direction E, as shown in Fig. 11, has a radius 154 between the blocking edge 136 and the support surface 138. Preferably, the rear tooth structure 110b pointing in the plugging direction E, as shown in Fig. 11, alternatively or additionally has a radius 154 on the surface pointing in the plugging direction E and corresponding to the retaining edge 112b of the plug part 106. The radii on the front and / or rear tooth structure 110a, 110b have the advantage that a contact surface between the tooth structure 110a, 110b can be better utilized.In particular, the larger contact surface improves the absorption of the force transmitted from the retaining edges 112a, 112b of the plug part 106 to the tooth structures 110a, 110b, e.g., in the event of a tensile load on the mounted plug part 106 in the fully engaged position against the plugging direction E.

[0089] According to a variant of the invention shown in Figs. 6 to 8 and Figs. 12, 13 and 15, the receiving opening 108 of the coupling part 102 has a cylindrical sealing section 156 and preferably a particularly cylindrical control section 158 adjoining the cylindrical sealing section 156 and pointing counter to the plugging direction E. As shown in Figs. 6 to 8 and Figs. 12, 13 and 15, the receiving opening 108 expediently has a larger diameter in the control section 158 than in the sealing section 156. Advantageously, the change in diameter allows the sections 156, 158 to provide different functions, e.g., the arrangement of seals. In particular, the plug-in coupling 100 is designed such that the plug shaft, in the pre-locking position, is only sealed against the control section 158, so that incomplete assembly can be detected by controlled leakage.

[0090] Advantageously, a transition section 160 is formed axially between the control section 158 and the sealing section 156, as shown in Figs. 6 to 8 and Figs. 12, 13 and 15, which reduces the diameter of the receiving opening 108 in the control section 158 to the diameter of the receiving opening 108 in the sealing section 156. The transition section 160 facilitates, in particular, the centering of the plug shaft of the plug part 106 during insertion and preferably serves to support a dirt seal 162 arranged in the control section 158.

[0091] Advantageously, at least one groove 159 is formed axially in the circumferential surface 140a of the receiving opening 108 in the control section 158 as a leakage path. The groove 159 formed as a leakage path is shown in Fig. 15. In particular, at least one groove 159 formed as a leakage path is provided; the number of leakage paths can preferably be adapted to the operating conditions and the fluidic properties of the fluid to be transmitted; for example, four or even eight grooves 159 formed as leakage paths are possible. Preferably, the grooves 159 are arranged evenly over the circumference of the transition section 160, as shown in Fig. 15. The grooves 159 formed as leakage paths advantageously enable early detection of an incompletely inserted plug part 106, for example in the pre-locking position, by controlled generation of a leak, which can be detected, for example, visually or acoustically by a technician.

[0092] In a preferred embodiment, the sealing section 156 and the control section 158 are arranged or designed in relation to one another such that, in the pre-locking position, as shown in Fig. 6, the plug shaft is arranged with a front main seal 164 pointing in the plugging direction E, abutting the control section 158 and in particular also abutting the transition section 160. The main seal 164 is expediently arranged in a main sealing groove 166, as shown in Figs. 6 to 8, 12 and 13. The main sealing groove 166 is also shown by way of example in Fig. 4. The coupling part 102 or the control section 158 and in particular the transition section 160 are expediently designed such that, in the pre-locking position, a controlled leakage is provided between the main seal 164 and the circumferential surface 140a of the receiving opening 108 in the control section 158.This effect is advantageously improved by at least one axially extending groove serving as a leakage path. The controlled leakage serves to detect incomplete insertion of the plug part 106, as is the case, for example, in the pre-locking position shown in Fig. 6.

[0093] Advantageously, the coupling part 102 or the sealing section 156 is designed such that, in the fully engaged position, as shown in Fig. 8, the plug shaft with the main seal 164 can be arranged in the sealing section 156, resting against the peripheral surface 140b of the receiving opening 108. The sealing section 156 is designed such that the main seal 164 withstands a system pressure that occurs during operation of the plug-in coupling 100 in a fluidic line system and prevents fluid from escaping.

[0094] In a further development, the control section 158 of the coupling part 102 is advantageously designed such that a dirt seal 162 of the plug part 106 can be arranged in the control section 158. The dirt seal 162 is expediently arranged in a rear sealing groove 168 of the plug shaft pointing in the plugging direction E. The sealing groove 168 is shown in particular in Fig. 4. It is preferable if the control section 158, and in particular also the transition section 160, are designed such that the dirt seal 162 can be elastically clamped against the circumferential surface 140a of the receiving opening 108 in the control section 158, at least in the fully engaged position, as shown in Figs. 7 and 8.The dirt seal 162 is expediently clamped both radially against the circumferential surface 140 of the receiving opening 108 in the control section 158 and, if applicable, in the transition section 160, and axially due to the change in diameter from the control section 158 to the transition section 160. The axial and radial clamping is illustrated in particular in Figs. 7, 8, 12, and 13. Due to the axial clamping of the dirt seal 162, an axial restoring force R acts on the plug part 106 such that the plug part 106 is pressed against the plugging direction E. In particular, the retaining edges 112a, 112b of the plug part 106 are thereby pressed against the tooth structures 110a, 110b.

[0095] The coupling part 102 is preferably designed such that the dirt seal 162 exerts the restoring force R on the plug shaft, at least in the plug-in position, as shown in Figs. 7 and 12, so that the plug-in coupling 100 is automatically transferred into the fully engaged position. Advantageously, a self-locking feature can also be provided by the blocking edge 136, so that after the plug part 106 has been fully inserted and when the insertion force acting on the plug part 106 for inserting the plug part 106 in the plug-in direction E is withdrawn, the plug part 106, together with the holding part 104 fastened to the plug part 106, is displaced axially relative to the coupling part 102 against the plug-in direction E by the restoring force R of the dirt seal 162. The blocking edge 136 is thereby advantageously8 and 11, with the peripheral surface 140 of the receiving opening 108 brought into a radially acting positive locking blockade.

[0096] Preferably, the coupling part 102 and / or the holding part 104 is made of a polyamide, expediently with a glass fiber content of 15% to 45%, in particular 20% to 40%, preferably 25% to 35%. Advantageously, the coupling part 102 and / or the holding part 104 is manufactured using a casting process, in particular an injection molding process.

[0097] Fig. 5 shows a release tool 118 according to the invention for a plug-in coupling 100 according to at least one of the aforementioned exemplary embodiments. The release tool 118 serves to transfer the holding part 104 from the locking position into the release position. According to the invention, the release tool 118 has an engagement body 172 extending along a longitudinal axis 170 and an expansion body 174 adjoining the engagement body 172. The engagement body 172 is elastically deformable about the longitudinal axis 170 and is essentially rigid axially of the longitudinal axis 170.

[0098] In Figs. 5, 12 and 13, the elastic deformation direction around the longitudinal axis 170 of the expansion body is marked with the arrows F.

[0099] In particular, as shown in Fig. 5, the release tool 118 has recesses 176 which expediently create a meandering shape on the top and bottom sides, so that the flexibility or the elastic deformation potential about the longitudinal axis 170 is provided while maintaining the axial rigidity.

[0100] The release tool 118 is designed in such a way that it is flexible in the longitudinal axis 170, which reduces levering.

[0101] The use of the release tool 118 is described below with reference to Figs. 12 and 13.

[0102] To release the connection or to remove the plug part 106 from the receiving opening 108 opposite to the plugging direction E, the connection is in particular plugged over so that the plug-in coupling 100 is in the plug-over position shown in Fig. 12.

[0103] In particular, the tooth contact edge 114 of the tooth structure 110a, 110b rests against the holding contact edge 116 of the holding edge 112a, 112b in such a way that an axial movement of the holding part 104 along the plug-in direction E is caused. Figs. 7 and 12 show how the plug part 106 has displaced the holding part 104 axially in the plug-in direction E.

[0104] For plugging, the plug part 106 is preferably pushed into the coupling part 102, in particular to the stop, pointing in the plugging direction E. In this case, the holding part 104 is preferably axially guided by the plug part 106, as described, to such an extent that the blocking edge 136, as shown in Figs. 7 and 12, is arranged axially above the circumferential surface 140 of the receiving opening 108. From this state, the holding part 104 can be transferred radially from the locking position to the release position, or the spring arms 122 can be radially elastically expanded into the tensioned state.

[0105] Subsequently, the release tool 118 is expediently inserted into the insertion opening 146 of the release contour(s) 144a, 144b parallel to the insertion direction E and further parallel, in particular parallel, to the longitudinal axis 170 of the release tool 118 opposite to the insertion direction E. In particular, Fig. 12 shows the release tool 118 in a pre-release position, while Fig. 13 shows the release tool 118 with the expansion body 174 inserted into the insertion opening 146 and arranged in a release position.

[0106] In particular, by means of the movement of the release tool 118, the expansion body 174 slides over the ramp section(s) 148 of the release contour(s) 144a, 144b. Due to the release contours 144a, 144b, the release tool 118 acts with its radially outwardly directed release force on the connecting section 120 of the holding part 104, so that the latter is transferred into the release position, as shown in Fig. 13.

[0107] As shown in Fig. 5, the release tool 118 expediently has curves 178 on the expansion body 174, which are designed such that the release tool 118 or the expansion body 174 can be easily inserted into the insertion opening(s) 146 of the release contour(s) 144a, 144b.

[0108] In particular, the curves 178 on the expansion body 174 and the release contours 144a, 144b, preferably with at least one formed ramp section 148, preferably have the consequence that in the event of a non-axial movement of the release tool 118 on the engagement body 172, in particular a bending about the longitudinal axis 170, the release tool 118 slips out of the release contour 144a, 144b and the holding part 104 cannot therefore be levered out, which could lead to damage to the holding part 104 and / or the coupling part 102.

[0109] As a further measure, a height of the release contour(s) 144a, 144b axially to the plug-in direction E was designed with the aid of the roundings in such a way that if excessive force is applied to the release tool 118, the latter is rotated out of the release contour(s) 144a, 144b and the holding part 104 is not pressed further radially out of the coupling part 102.

[0110] In particular, when transferring the holding part 104 from the locking position into the release position, spring arms 122, preferably due to the control contour 128 and the axial separating web 130, pivot with their tooth structures 110a, 110b, as shown in Fig. 14, so far into the coupling part 102, in particular over the holding edge 112a, 112b of the plug part 106, that the plug part 106 can be released from the locking connection.

[0111] It has been found to be advantageous that, if the holding part 104 opens on one side, in particular if one spring arm 122 expands radially, whereas the second spring arm 122 remains in the rest position, the holding part 104 is opened asymmetrically due to the expedient holding bevels 132 of the spring arms 122 and bearing edges of the coupling part 102, so that first the first spring arm 122 is opened until the holding bevel 132 rests on the bearing edge 134 and then the second spring arm 122 on the other side.

[0112] According to a further developed variant of the release tool 118, a maximum displacement path of the holding part 104 radially relative to the coupling part 102, which the holding part 104 requires to move from the locking position into the release position, corresponds to a depth 180 of the expansion body of the release tool 118. This expediently ensures that only the required displacement of the holding part 104 is brought about and, in particular, that displacement beyond the release position is prevented. A further optional variant of the release tool 118 provides that the expansion body 174 of the release tool 118 is designed in a fork-like manner with two expansion tabs 182 projecting axially relative to the longitudinal axis 170 and separated by a central separating slot.In particular, the holding part 104 and / or the coupling part 102 can have guide contours designed in such a way; in particular, the release contour 144a, 144b has guide contours such that the release tool 118 can always be used correctly during assembly. In particular, the expansion tabs 182 are designed in such a way that, upon insertion of the expansion tabs 182 into a release contour 144a, 144b, a mandrel 150 optionally formed on the connecting portion 120 is engaged.

[0113] The invention is not limited to the illustrated and described embodiments, but also encompasses all equivalent embodiments within the meaning of the invention. It is expressly emphasized that the embodiments are not limited to all features in combination; rather, each individual partial feature can also have an inventive significance in itself, independently of all other partial features. Furthermore, the invention is not yet limited to the combination of features defined in claim 1, but can also be defined by any other combination of specific features of all the individual features disclosed as a whole. This means that, in principle, practically every individual feature of claim 1 can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.

[0114] List of reference symbols

[0115] 100 plug-in couplings

[0116] 102 Coupling part

[0117] 104 Holding part

[0118] 106 Plug part

[0119] 108 Recording opening

[0120] 110a Anterior tooth structure

[0121] 110b Posterior tooth structure

[0122] 111 Warehouse opening

[0123] 112a Front retaining edge

[0124] 112b Rear retaining edge

[0125] 114 Tooth attachment edge

[0126] 116 Holding facility edge

[0127] 118 Release tool

[0128] 120 connecting section

[0129] 122 spring arm

[0130] 124 retaining projection

[0131] 126 franking

[0132] 128 Control contour

[0133] 130 divider

[0134] 132 retaining slope

[0135] 134 bearing edge

[0136] 136 Blockade Edge

[0137] 138 contact surface

[0138] 140 Circumferential area of ​​the receiving opening

[0139] 140a Circumferential surface of the receiving opening in the control section

[0140] 140b Circumferential surface of the receiving opening in the sealing section

[0141] 142 Overlap path

[0142] 144a Release contour on the holding part

[0143] 144b Release contour on the coupling part

[0144] 146 Insertion opening 48 Ramp section 50 Mandrel 52 Recess 54 Radius

[0145] 156 Sealing section

[0146] 158 Control Section

[0147] 159 groove

[0148] 160 transition section

[0149] 162 dirt seal

[0150] 164 Main seal

[0151] 166 Main seal groove

[0152] 168 Sealing groove

[0153] 170 Longitudinal axis

[0154] 172 attack bodies

[0155] 174 spreader bodies

[0156] 176 Recess of the release tool

[0157] 178 curves

[0158] 180 Depth of the spreader body

[0159] 182 expansion tabs

[0160] E Plug-in direction

[0161] F Deformation direction

[0162] R Restoring force

Claims

Claims 1 . Plug-in coupling (100) for fluidic line systems, in particular for compressed air brakes of motor vehicles, comprising a coupling part (102) and a holding part (104) for a plug part (106), wherein the plug part (106) can be inserted with a plug shaft in a circumferentially sealed manner into a receiving opening (108) of the coupling part (102) in a plug-in direction E and can be locked against release against the plug-in direction (E) by means of the radially elastic holding part (104) projecting radially into the receiving opening (108), on the one hand in a partially inserted, incompletely sealed pre-locking position of the plug-in coupling (100) and on the other hand in a fully inserted, completely pressure-tight sealed full-locking position of the plug-in coupling (100), wherein to form the pre-locking position and the full-locking position, the holding part (104) has at least two axially spaced tooth structures (110a, 110b) for engaging behind at least one of the plug part (106) formed retaining edge (112a, 112b),wherein the holding part (104) is displaceable radially to the receiving opening (108) between a locking position locking the plug part (106) and a release position releasing the plug part (106) relative to the coupling part (102).

2. Plug-in coupling (100) according to claim 1, characterized in that the holding part (104) has two radially elastic spring arms (122) which are connected to one another on one side via a connecting section (120) and which each extend from the connecting section (120) to a free end, wherein the spring arms (122) in a relaxed rest state protrude into the receiving opening (108) in such a way that the plug part (106) can be locked in the pre-locking position and the fully locked position and in a radially elastically expanded tension state of the spring arms (122) the plug part (106) can be removed from the receiving opening (108) opposite to the plug-in direction (E). Plug-in coupling (100) according to claim 2, characterized in that the radially elastic spring arms (122) and the coupling part (102) are designed such that upon radial displacement of the holding part (104) from the locking position into the release position, the spring arms (122) are elastically spread from the rest state into the radially expanded tension state. Plug-in coupling (100) according to claim 2 or 3, characterized in that the holding part (104) has at least two, in particular four, holding projections (124) projecting radially from the receiving opening (108) from the spring arms (122), and in at least one holding projection (124), in particular in each holding projection (124), the two tooth structures (110a, 110b) spaced apart from one another axially in the plug-in direction (E) are formed, wherein two holding regions are arranged on each radially elastic spring arm (122) in such a way that the spring arms (122) are mirror-symmetrical to one another in cross-section.Plug-in coupling (100) according to claim 4, characterized in that the holding projections (124) have axial clearances (126) which axially penetrate completely through the holding projections (124). Plug-in coupling (100) according to claim 4 or 5, characterized in that the holding part (104) is arranged with its connecting section (120) pointing radially to the plug-in direction (E) towards an outer surface of the coupling part (102) in such a way that the spring arms (122) each engage around a separating web (130) of the coupling part (102) running axially to the plug-in direction (E), wherein the separating webs (130) are each designed to run axially through a radial bearing opening (111) in the outer surface of the coupling part (102), so that the holding projections (124) of the. Spring arms (122) protrude through the bearing openings (111) into the receiving opening (108). Plug-in coupling (100) according to claim 6, characterized in that two holding projections (124) are formed opposite the connecting section (120) at the free ends of the spring arms (122) and merge in a beveled control contour (128) into a radially outwardly offset web section of the respective spring arm (122), wherein the control contour (128) points towards the connecting section (120), wherein the control contours (128) are designed such that upon radial displacement of the holding part (104) from the locking position into the release position, the control contours (128) slide over an axial separating web (130) of the coupling part (102), so that the spring arms (122) are elastically spread radially outwardly into the tensioned state.Plug-in coupling (100) according to claim 7, characterized in that the control contours (128) each have a retaining bevel (132), wherein the retaining bevel (132) is designed such that, in the tensioned state of the spring arms (122), the retaining bevel (132) is oriented perpendicular to the direction of the radial displacement of the retaining part (104) from the locking position into the release position and, in the release position, rests on a correspondingly designed bearing edge (134) which is aligned in particular parallel to the retaining bevel (132) with the spring arms (122) in the tensioned state, so that further displacement of the retaining part (104) pointing radially outwards beyond the release position is blocked in a form-fitting manner. Plug-in coupling (100) according to one of claims 1 to 8, characterized in that the radially elastic holding part (104), in particular the spring arms (122) and the coupling part (102), is designed such that in a fully locked position. the radial displacement of the holding part (104) from the locking position into the release position is blocked and / or the radial elastic deformation of the holding part (104), in particular of the spring arms (122), from the rest state into the radially expanded stress state is blocked, in particular in a form-fitting manner.Plug-in coupling (100) according to claim 9, characterized in that a blocking edge (136) is formed on the side of the axially foremost tooth structure (110b) facing opposite to the plug-in direction (E), which blocking edge protrudes axially opposite to the plug-in direction (E) from the tooth structure (110b), wherein a support surface (138) axially offset in the plug-in direction (E) adjoins the blocking edge (136) and points radially outwards, wherein the blocking edge (136) and the support surface (138) are designed such that, in a fully engaged position of the plug-in coupling (100) in a correct assembly position, the holding part (104) rests axially with the support surface (138) on a bearing surface of the coupling part (102) facing in the plug-in direction (E) and rests with the holding edge radially against a circumferential surface (140) of the receiving opening (108).Plug-in coupling (100) according to one of claims 2 to 10, characterized in that the connecting section (120) of the holding part (104) and / or the coupling part (102) have a release contour (144a, 144b) in a circumferential section radially adjacent to the connecting section (120) of the holding part (104), wherein the release contour (144a) on the holding part (104) is designed to point towards the coupling part (102) and the release contour (144b) on the coupling part (102) is designed to point towards the connecting section (120) of the holding part (104). Plug-in coupling (100) according to claim 11, characterized in that the release contour (144a, 144b) of the holding part (104) and / or of the coupling part (102) is designed such that it forms an insertion opening (146) open in the plug-in direction (E), wherein a cross-section of the insertion opening (146) is reduced via a ramp section (148) pointing against the plug-in direction (E), so that a release tool (118) can be inserted into the insertion opening (146) and by means of a contact with the ramp section (148) a radially outwardly directed release force acts on the holding part (104). Plug-in coupling (100) according to one of claims 2 to 12, characterized in that a dome (150) pointing radially towards the coupling part (102) is formed on the connecting section (120) of the holding part (104), which dome engages, at least in the fully engaged position, in a correspondingly formed recess (152) in the circumference of the coupling part (102).Plug-in coupling (100) according to one of claims 1 to 13, characterized in that at least one of the tooth structures (110a, 110b) is designed such that it has a radius (154) at a bending point subjected to maximum load by the locking connection between the tooth structure (110a, 110b) and the retaining edge (112a, 112b) of the plug part (106). Plug-in coupling (100) according to one of claims 1 to 14, characterized in that the receiving opening (108) of the coupling part (102) has a cylindrical sealing section (156) and a control section (158) adjoining the cylindrical sealing section (156) and pointing counter to the plugging direction (E), wherein the receiving opening (108) has a larger diameter in the control section (158) than in the sealing section (156). Plug-in coupling (100) according to claim 15, characterized in that a transition section (160) is formed axially between the control section (158) and the sealing section (156), which transition section reduces the diameter of the receiving opening (108) in the control section (158) to the diameter of the receiving opening (108) in the sealing section (156), wherein in particular in the circumferential surface (140) of the control section axially extending grooves are formed as leakage paths.Plug-in coupling (100) according to claim 15 or 16, characterized in that the sealing section (156) and the control section (158) are arranged relative to one another in such a way that in the pre-locking position the plug shaft is arranged with a front main seal (164) pointing in the plugging direction (E) and arranged in a main seal groove (166) in contact with the control section (158), in particular also the transition section (160), and in the fully locked position the plug shaft is arranged with the main seal (164) in contact with the sealing section (156).Plug-in coupling (100) according to one of claims 15 to 17, characterized in that the control section (158) of the coupling part (102) is designed such that a dirt seal (162) of the plug part (106) can be arranged in the control section (158), which is arranged in particular in a rear sealing groove (168) of the plug shaft pointing in the plugging direction (E), wherein the control section (158), and in particular also the transition section (160), are designed such that the dirt seal (162) can be elastically clamped against the circumferential surface (140) of the receiving opening (108), at least in the fully engaged position. Release tool (118) for a plug-in coupling (100) according to one of claims 1 to 18 for transferring the holding part (104) from the locking position into the release position, characterized in that the release tool (118) has an engagement body (172) extending along a longitudinal axis (170) and an expansion body (174) adjoining the engagement body (172), wherein the engagement body (172) is elastically deformable about the longitudinal axis (170) and is substantially rigid axially of the longitudinal axis (170). Release tool (118) according to claim 19, characterized in that the maximum displacement path of the holding part (104) radially relative to the coupling part (102) corresponds to the depth (180) of the expansion body of the release tool (118).Release tool (118) according to claim 19 or 20, characterized in that the expansion body of the release tool (118) is fork-shaped with two expansion tabs (182) projecting axially to the longitudinal axis (170) and separated by a central separating slot, which are designed in particular such that when the expansion tabs (182) are inserted into the release contour (144a, 144b), a mandrel (150) optionally formed on the connecting section (120) is encompassed.

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