WO2024037810A1 - Plug-in coupling with leakage indicator for fluid lines - Google Patents

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

“Plug coupling with leakage indicator for fluid lines”

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

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

A plug-in coupling for pressure medium systems is known from EP 0 913 618 A1. With this plug-in coupling, a plug part is first inserted into a pre-locking position in the receiving opening, in which case the plug-in coupling is not able to seal a system pressure. As a result, if the plug part is not fully inserted, a signal is generated in the form of a controlled escape of the fluid, which is particularly perceivable acoustically. To ensure a completely sealed arrangement of the plug part, it is pushed over in the plugging direction the pre-locking position is transferred to a full locking 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 provides for the use of a multi-part holding element which has two axially spaced holding edges, so that the plug part can be locked in the coupling part both in the pre-latching position and in the fully latching position. A disadvantage of the known plug-in coupling has been found that the plug-in coupling cannot be released without being destroyed, which makes repeat assembly particularly complex. Furthermore, the holding part of this plug connection is inaccessible from the outside, so that inspection and maintenance are also associated with obstacles.

Another plug-in coupling is known from EP 1 714 068 B1. The plug-in coupling of this type has a coupling body with molded-on holding parts which extend axially in the plug-in direction and are designed as locking arms. From EP 1 714 068 B1 it is known to transfer the holding arms from a locking position into a radially expanded release position using a tool. In practice, when using the release tool, a large radial space is required perpendicular to the receiving opening, so that the space required for using the release tool is not sufficient, particularly during dismantling. Due to the axial locking arms as holding elements, the plug-in coupling is also susceptible to dirt and contamination.

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 reduces the effort in use and improves operational safety.

The task is solved by a plug-in coupling with the features of claim 1. Because the holding part is designed to be radially elastic and can be displaced relative to the coupling part radially to the receiving opening between a locking position that locks the plug part and a release position that releases the plug part, repeat assembly can be made possible. Especially for maintenance purposes, e.g. B. a check and / or replacement of wearing parts, it is not necessary to damage parts of the plug-in coupling in the embodiment according to the invention.

Furthermore, at the same time, by separating a partially inserted, incompletely sealed pre-locking position of the plug-in coupling and, on the other hand, a fully inserted, completely pressure-tight sealed full locking position of the plug-in coupling, the assembly position is conveyed to the fitter by means of two significant increases in force during the insertion process, each when overcoming the pre- and fully locked positions. Furthermore, the pre-locking position offers protection against loss of the plug part from falling out of the coupling part, in that at least one tooth structure formed on the holding part can engage behind a holding edge of the plug part.

According to the invention, the pre-locking position has the advantage, in addition to preventing loss, that the fluid to be conducted from the plug-in coupling can escape in a controlled manner due to the intentionally incomplete sealing. The controlled leakage enables early detection and prevention of errors, especially after commissioning, so that installation safety is improved.

Due to the axially adjacent arrangement of the tooth structures, the respective tooth structures can be designed to suit the application requirements. In particular, the tooth structure for the latching connection for locking the plug part in the pre-locking position can be designed differently, in particular in a more material-saving manner, than the tooth structure for the latching connection for locking the plug part in the fully latching position. The at least one holding edge of the plug part to be assembled is expediently designed to correspond to the tooth structures in such a way that the tooth structures can engage behind the at least one holding edge to form a locking connection.

In an advantageous embodiment, the holding 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 extend the spring arms each to a free end. For an advantageous locking of the plug shaft, the spring arms protrude into the receiving opening in a relaxed resting state in such a way that the plug part can be locked in the pre-latching position and the fully latching position. In order to provide non-destructive release, the embodiment provides in particular that in a radially elastically expanded tension state of the spring arms, the plug part can be removed from the receiving opening against the plugging direction. In particular, the spring arms do not protrude into the receiving opening in the tensioned state or only slightly in comparison to the rest state, so that in particular the plug shaft can be guided past the spring arms with its at least one holding edge.

According to a preferred embodiment of the invention, the holding part has at least two holding projections projecting radially from the spring arms towards the receiving opening. Particularly preferably, the holding part has four holding projections which project radially from the spring arms towards the receiving opening. The two, or better four, holding projections can advantageously be distributed around the circumference of the receiving opening and, in particular, engage evenly in a holding edge of the plug with at least one tooth structure.

It is expedient to have two tooth structures that are axially spaced apart from one another in relation to the insertion direction and are formed on at least one holding projection, in particular on each holding projection. Advantageously, for a uniform arrangement of the holding areas and for the locking connections for blocking the plug part against the plugging direction, two holding areas are arranged on each radially elastic spring arm in such a way that the spring arms are preferably designed to be mirror-symmetrical to one another in cross section. In particular, this design prevents the plug shaft from tilting in the receiving opening.

The holding projections have particularly advantageous axial clearances. The clearances can completely or partially penetrate the holding projections axially. The clearances prevent the occurrence of material accumulations in the production of the holding part, especially in the injection molding process. Material and weight are also saved. An embodiment that is particularly advantageous for disassembly provides that the radially elastic spring arms and the coupling part are designed in such a way that when the holding part is displaced radially from the locking position to the release position, the spring arms are elastically spread from the rest state into the radially expanded tension state. The radial deformation of the holding arms is expediently brought about simultaneously with the radial displacement of the holding part. In particular, this has the advantage that you do not, for example, B. with a release tool, which must act on the locking arms, 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 adding a release tool.

An advantageous elastic deformation of the spring arms is expediently generated in that two holding projections are formed opposite the connecting section at the free ends of the spring arms. The holding projections merge, in particular in a beveled control contour, into a web section of the respective spring arm that is offset radially outwards. It has proven to be advantageous that the control contour points towards the connecting section, the control contours being designed in such a way that during the radial displacement of the holding 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.

In an extended variant of the invention, the control contours each have a holding slope. The holding bevel serves in particular to ensure that the holding part can only be partially displaced in a radially outward direction relative to the coupling part. This advantageously prevents the holding part from being displaced beyond the release position or from falling out of the coupling part. The holding bevels are therefore preferably designed in such a way that in the tensioned state of the spring arms, the holding bevel is aligned perpendicular to the direction of the radial displacement of the holding part from the locking position into the release position. It has also proven to be preferred that in the release position the holding bevel rests on a correspondingly designed bearing edge, so that further displacement of the holding part pointing radially outwards beyond the release position is positively blocked. For this purpose, the bearing edge is expediently aligned parallel to the holding slope with the spring arms in the tensioned state.

Advantageously for operational safety, according to a preferred variant of the invention, the radially elastic holding part and the coupling part are designed such that in a fully latched position the radial displacement of the holding part from the locking position to the release position is blocked and/or the radially elastic deformation of the holding part is blocked in a form-fitting manner. In particular, an unwanted displacement of the holding part into the release position is prevented and a radial expansion of the holding part is blocked, so that the risk of the plug part being released against the plugging direction is reduced.

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 radially elastic deformation of the spring arms the rest state is blocked in the radially expanded tension state, in particular in a form-fitting manner.

In order to avoid the unintentional detachment of the plug part from the receiving opening, according to a preferred embodiment of the invention, a blocking edge is formed on the side facing the opposite direction to the insertion direction of the front tooth structure axially opposite to the insertion direction. The blocking edge protrudes axially from the tooth structure in the opposite direction to the insertion direction. It has proven to be advantageous that the blocking edge is followed by a support surface pointing radially outwards, which is axially offset in the insertion direction. These are advantageous Blocking edge and the support surface are designed in such a way that in a fully locked position of the plug-in coupling, the holding part with the support surface rests axially on a bearing surface of the coupling part pointing in the plugging direction and rests with the blocking edge radially against a peripheral surface of the receiving opening.

Due to the contact of the blocking edge on the peripheral surface of the receiving opening, the spring arms of the holding part cannot expand radially and the holding part also cannot be transferred from the locking position to the release position radially to the coupling part.

It has proven to be expedient for the coupling part or the receiving opening of the coupling part to be dimensioned with an insertion path for the plug shaft, with the holding part having axial play relative to the coupling part. The axial play preferably corresponds at least to the extent of the blocking edge in the axial direction. For the purpose of assembly, the holding part can be transferred from the release position to the locking position, with the tooth structures locking with the holding edge(s) when the plug shaft is inserted in the insertion direction. When the plug part is fully inserted into the receiving opening and the locking connection required for the full grid position between the tooth structures and the retaining edge(s) has been established, the plug part can be moved against the plugging direction in accordance with its insertion path by means of a restoring force on the plug part against the plugging direction. The blocking edge is advantageously arranged radially next to the peripheral surface of the receiving opening and blocks the radial displacement of the holding part and the radial expansion of the spring arms. In particular, this restoring force is generated in a depressurized state of the plug-in coupling by a dirt seal, which advantageously cooperates with the coupling part. The restoring force generated by the dirt seal is expediently increased by the system pressure when the plug-in coupling is in a pressure state.

To release the locking connection or the blockage through the blocking edge, the plug part is preferably moved in the plugging direction at least over the axial length of the blocking edge, so that the blocking edge and the Do not overlap the circumferential surface of the receiving opening. The elastic deformation of the spring arms and the radial displacement of the holding part are released again.

For the purpose of 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 peripheral 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 in order to transfer it by hand and/or with a tool. The release contour on the holding part is preferably designed to point towards the coupling part. Alternatively or additionally, the release contour on the coupling part is designed to point in particular towards the connecting section of the holding part.

It has proven to be advantageous that the release contour of the holding part and/or the coupling part are designed in such a way that they form an insertion opening that is open in the insertion direction. The insertion opening is in particular designed in such a way that a cross-sectional area of the insertion opening is reduced over a ramp section pointing against the insertion 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 reduces 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 outwardly pointing release force acts on the holding part when the release tool is axially displaced against the insertion direction. This advantageously allows the release tool to be guided parallel to the insertion direction in a space-saving manner in order to move the holding part into the release position.

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 locking and releasing function described is guaranteed, in a preferred embodiment of the plug-in coupling there is a radial to the connecting section of the holding part Coupling part facing mandrel formed. This dome can be inserted into a corresponding recess in the circumference of the coupling part in such a way that, at least in the fully locked position, the mandrel engages in the recess in the circumference of the coupling part. In particular, if the holding part is incorrectly assembled, the dome abuts against the circumference of the coupling part in such a way that the holding part cannot be transferred from the release position into the locking position radially to the insertion direction. In addition, the fitter can easily identify incorrect assembly visually based on the protruding dome and the holding part that protrudes radially from the coupling part.

For an advantageous force absorption of the force transmitted from the holding edges of the plug part to the tooth structures, e.g. B. in the event of a tensile load on the assembled plug part in the fully latched position against the plugging direction, at least one of the tooth structures is designed such that it has a radius at a bending point that is maximally loaded by the latching connection between the tooth structure and the retaining edge of the plug part. The advantage of the radius is that a contact surface between the tooth structure and the retaining edge can be better utilized.

According to a special embodiment of the invention, the receiving opening of the coupling part has a cylindrical sealing section and a control section which adjoins the cylindrical sealing section and points against the insertion direction. In particular, the receiving opening in the control section has a larger diameter than in the sealing section. By changing the diameter, the sealing sections can expediently have different functions, e.g. B. Arrangement of seals. In particular, the plug-in coupling is designed in such a way that the plug shaft is only sealed against the control section in the pre-locking position, so that incomplete assembly can be recognized by a controlled leakage.

An advantageous further development provides that a transition section is formed axially between the control section and the sealing section, which adjusts the diameter of the receiving opening in the control section Diameter of the receiving opening in the sealing section reduced. The transition section particularly facilitates the centering of the plug shaft of the plug part during insertion.

Furthermore, axially extending grooves are optionally formed as leakage paths in the peripheral surface of the control section. This ensures the controlled fluid exit as an assembly indicator. In particular, at least one leakage path is provided, preferably the number of leakage paths can 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. Preferably, the leakage paths are arranged uniformly over the circumference of the transition section.

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 with a front main seal pointing in the plugging direction and arranged in a main sealing groove rests against the control section and in particular is also arranged in the transition section and in the fully locked position the plug shaft with the main seal is arranged adjacent to the sealing section. As a result of the change in diameter between the control section and the sealing section, the main seal is expediently pressed more strongly in the fully locked position, so that greater resistance to internal pressures is provided. At the same time, the main seal in the pre-locking position can cause a leak in a controlled manner under a pressure load due to the control section with an enlarged diameter, so that the incomplete assembly can be recognized.

In addition to the previous embodiment, it can be advantageous for the control section of the coupling part to be designed in such a way 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 pointing in the plugging direction. The control section is advantageous and - If present - the transition section is also designed in such a way that the dirt seal can be elastically braced against the peripheral surface of the receiving opening, at least in the fully latched position. The dirt seal is expediently clamped both radially against the peripheral surface in the control section and, if necessary, in the transition section and axially due to the change in diameter from the control section to the transition section. Due to the axial tensioning of the dirt seal, an axial restoring force acts on the plug part in such a way that the plug part is displaced against the plugging direction, which improves the contact of the tooth structures on the holding edges. In a further positive aspect, together with the blocking edge and the over-plugging path, there is a self-locking effect, so that after the plug part has been completely plugged in and when the insertion force acting on the plug part in the plugging direction for plugging in the plug part is reduced, the plug part is secured by the restoring force of the dirt seal together with the holding part attached to the plug part is displaced axially relative to the coupling part against the plugging direction. As a result, the blocking edge is expediently brought into a radially acting, positive blockage with the peripheral surface of the receiving opening.

Furthermore, the object on which the invention is based is achieved with a release tool according to the features of claim 18.

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 into the release position. According to the invention, the release tool has an attack body extending along a longitudinal axis and an expansion body adjoining the attack 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.

In particular, the elastic deformability around the longitudinal axis prevents incorrect application due to “leveraging”, as is known from the prior art. According to the invention, the release tool is parallel to the receiving opening of the coupling part and thus perpendicular to the radial displacement direction of the holding part. Damage and wedging, which can result from "prirying open", are advantageously avoided and at the same time the radial space required for transferring the holding part from the locking position to the release position radially next to the plug-in coupling is kept to a minimum.

According to a further developed variant of the plug connection, a maximum displacement path of the holding part radially to the coupling part, which the holding part requires in order to move from the locking position to the release position, corresponds to a depth of the expansion body of the release tool. This expediently ensures that only the required displacement of the holding part is always brought about and, in particular, that displacement beyond the release position is prevented.

Another optional variant of the plug connection provides that the expansion body of the release tool is designed in a fork-like manner with two expansion tabs that protrude axially 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 such guide contours that the release tool can always be used correctly. In particular, the expansion tabs are designed in such a way that when the expansion tabs are inserted into a release contour, a mandrel optionally formed on the connecting section is encompassed.

Further advantageous embodiments of the invention result from the following description of the figures and the dependent subclaims.

Show it:

1 is a perspective view of a coupling part,

2 is a perspective view of a holding part, Fig. 3 is a top view of the device directed against a plugging direction

Holding part according to Fig. 2,

4 is a perspective view of a plug part,

5 is a perspective view of a release tool,

Fig. 6 is a partial sectional view parallel to the insertion direction

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

Fig. 7 is a partial sectional view parallel to the insertion direction

Plug-in coupling according to FIG. 6 with an inserted plug connector in a plug-in position,

Fig. 8 is a partial sectional view parallel to the insertion direction

Plug-in coupling according to FIG. 6 with a fully inserted plug connector in a fully locked position,

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

10 is a detailed view of area B according to FIG. 9,

11 shows a detailed view of the area C according to FIG. 8,

12 shows a sectional view parallel to the insertion direction of a variant of a plug connector according to the invention with an inserted plug connector in a plug-in position and a release tool in a pre-release position, Fig. 13 is a sectional view parallel to the insertion direction of the

12 with an inserted connector in a plug-in position and a release tool in a release position,

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

13 with the holding part in a release position and

Fig. 15 is a partial sectional view parallel to the insertion direction through a

Sleeve section of the coupling part according to Fig. 1.

In the various figures of the drawing, the same parts are always provided with the same reference numbers.

The following description claims that the invention is not limited to the exemplary embodiments and not to all or several features of the combinations of features described, but rather each individual partial feature of the/each exemplary embodiment is also detached from all other partial features described in connection therewith also in combination with any features of another exemplary embodiment of importance for the subject matter of the invention.

1 shows a coupling part 102 of a plug-in coupling 100 according to the invention for fluidic connections shown in FIGS. 6 to 8. The plug-in coupling 100 is shown in different assembly positions in FIGS. 6 to 8. The plug-in coupling 100 also has a holding part 104 shown in FIGS. 2 and 3 for a plug part 106. The plug part 106 is in particular designed as a male plug part 106 with a plug shaft, as shown in FIG. 4.

The plug part 106 can be inserted with the plug shaft in a circumferentially sealed manner into a receiving opening 108 of the coupling part 102 in a plug-in direction E. 6 to 8, the plug part 106 is inserted into the coupling part 102.

The holding part 104 is designed to be 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 in such a way 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 designed in such a way that the holding part 104 can only be arranged on the holding part 104 for an initial assembly and a repeat assembly or separation after the initial assembly is blocked, in particular is blocked in such a way that non-destructive disassembly is not possible is possible.

The plug part 106 is on the one hand, via the radially elastic holding part 104, which projects radially into the receiving opening 108, in a partially inserted, incompletely sealed pre-locking position of the plug-in coupling 100, as shown in FIG 8, can be locked against loosening against the insertion direction E.

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 designed to grip 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.

In particular, the at least one holding edge 112a, 112b is designed to correspond to the tooth structures 110a, 110b in such a way that the tooth structures 110a, 110b each engage behind at least the holding edge 112a, 112b formed correspondingly on the plug part 106 to be mounted. The plug part 106 shown in FIG. 4 has in particular two holding edges 112a, 112b which are axially spaced apart from one another in the plugging direction E. It is expediently shown in FIGS. 6 to 8 and 11 how the tooth structures 110a, 110b in the different ones Mounting positions engage behind the holding edges 112a, 112b of the plug part 106. The tooth structures 110a, 110b engage behind the retaining edge(s) 112a, 112b, forming a locking connection.

The tooth structures 110a, 110b and the holding edges 112a, 112b expediently have a Christmas tree-like profile, the tooth structures 110a, 110b having an oblique tooth contact edge 114 pointing against the insertion direction E, over which a holding contact edge 116 of the holding edge 112a pointing in the insertion direction E, 112b slides in the plugging direction E when the plug part 106 is inserted.

In particular, the plug part 106 has two holding 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 to be advantageous that the respective holding edge 112a, 112b extends in one piece around the circumference of the plug part 106, as shown in FIG. 5. In particular, a circumferential holding edge 112a, 112b allows the plug part 106 to be rotated in the receiving opening 108 about its own axis without getting caught or tilted. 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 a lower assembly force than the rear retaining edge 112b, pointing in the plugging direction E. In particular, this is caused by a smaller diameter of the holding edge 112a compared to the rear holding edge 112b.

The holding part 104 can be displaced relative to the coupling part 102 radially to the receiving opening 108 between a locking position that locks the plug part 106, shown as an example in FIG. 9, and a release position that releases 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 FIGS. 12 and 13. 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 distances of the tooth structures 110a, 110b are statistically designed so that the front tooth structure 110a in the insertion direction E carries the load acting against the insertion direction E almost completely, preferably completely, during operation under a system pressure load. Preferably, the front tooth structure 110a in the insertion direction E carries 85% to 100%, in particular 90% to 95%, in particular 93%, of the load acting against the insertion direction E during operation under a system pressure load.

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

In particular, the front tooth structure 110a in the insertion direction E can be designed 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 low.

It can 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 in such a way that when there is a pressure load on 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 comes with the correspondingly designed holding edges 112a, 112b.

According to a variant of the invention, the holding part 104, as shown in FIG. 2, has two spring arms 122 which are 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, they stand out Spring arms 122 in a relaxed rest state, shown in FIG. 9, into the receiving opening 108 in such a way that the plug part 106 to be locked can be locked in the pre-locking position, shown in FIG. Furthermore, a preferred development provides that in a radially elastically expanded tension state of the spring arms 122, shown in FIG. 14, the plug part 106 can be removed from the receiving opening 108 against the plugging direction E. The tooth structures 110a, 110b are formed in particular on the spring arms, as shown in FIG. 2.

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 insertion direction E towards an outer surface of the coupling part 102 in such a way that the spring arms 122 each have one axially Grip around the separating web 130 of the coupling part 102 that runs in the direction of insertion 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. 9 and 14 advantageously 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.

Preferably, the holding part 104 has at least two, in particular four, holding projections 124 that protrude from the spring arms 122 radially to the receiving opening 108. It is expedient to have two tooth structures 110a, 110b spaced apart axially to the insertion direction E in at least one holding projection 124, in particular in each holding projection 124. 6 to 8 only show the section through a holding projection 124 with two tooth structures 110a, 110b spaced axially from one another in relation to the insertion direction E. In particular, two holding projections 124 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, in particular in the cross section shown in FIG. 9. The holding projections 124 are expediently supported on the plug shaft of the plug part 106 and/or the holding edges 112a, 112b of the plug part 106, in particular with the tooth structures 110a, 110b formed on the holding projections 124. The symmetrical arrangement of the holding projections 124 promotes advantageous insertion and prevents the plug part 106 and/or the holding part 104 from tilting. Furthermore, the symmetrical arrangement has a particularly advantageous effect on a displacement of the holding 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 reshaping can take place evenly.

In particular, the holding projections 124, as shown in FIG. 3, have axial clearances. The clearances 126 have an advantageous effect on the filling behavior when producing the holding part 104 in a casting process, in particular an injection molding process. It is particularly advantageously provided that the clearances 126 completely penetrate the holding projections 124 axially.

A particularly preferred embodiment of the invention can be seen from FIGS. 9 and 14. According to this embodiment, the radially elastic spring arms 122 and coupling part 102 are designed such that when the holding part 104 is radially displaced from the locking position to the release position, the spring arms 122 are elastically spread from the rest state into the radially expanded tension state. The plug part 106 is expediently decoupled from the function of radially expanding the spring arms 122. Likewise, manual intervention by a fitter directly on the spring arms 122 is not necessary, which avoids errors in assembly or disassembly.

According to a further development of the plug-in coupling 100, two retaining projections 124 are opposite the connecting section 120 free ends of the spring arms 122 are formed. These holding projections 124, as shown in FIGS. 3, 9 and 14, expediently merge into a beveled control contour 128 into a web section of the respective spring arm 122 that is offset radially outwards. In particular, the control contour 128 points towards 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 the control contours 128 slide over the axial separating web 130 of the coupling part 102 during the radial displacement of the holding part 104 from the locking position into the release position, so that the spring arms 122 point radially outwards the stress state can be spread elastically. 14 in particular shows how the illustrated spring arm 122 is expanded radially into the tension 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 version, manual intervention by a fitter directly on the spring arms 122 is not necessary. The potential for errors during assembly or disassembly is effectively reduced.

In particular, the control contours 128 each have a holding slope 132. The holding bevel 132 is shown in particular in FIGS. 3, 9 and 14. The holding bevels 132 are preferably designed such that in the tensioned state of the spring arms 122, the holding bevels 132, as shown by way of example in FIG are. In the release position, it is particularly desirable for the holding bevels 132, as shown in FIG. The bearing edge 134 is expediently formed on the separating web 130 of the coupling part 102. The holding bevel 132 advantageously lies against the bearing edge 134 in such a way that, in particular, further displacement of the holding part 104 pointing radially outwards beyond the release position is positively blocked. 14 in particular shows approximately how the holding bevel 132 lies positively against the bearing edge 134, so that the spring arms 122 cannot expand further radially and the displacement of the holding part 104 is blocked radially in the direction of the release position in a form-fitting manner.

The radially elastic holding part 104, in particular the spring arms 122, and the coupling part 102 are advantageously designed in such a way that the holding part 104, in particular the spring arms 122, interacts with the coupling part 102 in such a way that, as shown in FIG. 8, at least in the fully locked 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 the spring arms 122, from the rest state into the radially expanded tension state is also blocked, in particular in a form-fitting manner.

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 the spring arms 122, from the rest state to the radially expanded tension state, it has proven to be expedient that 8 and 11, a blocking edge 136 is formed on the side of the tooth structure 110b which is axially at the front facing the insertion direction E and which is opposite to the insertion direction E. In particular, the blocking edge 136 protrudes axially from the tooth structure 110a, 110b in the opposite direction to the insertion direction E. The blocking edge 136 is expediently adjoined by a support surface 138 which is axially offset in the insertion direction E and points radially outwards. The blocking edge 136 and the support surface 138 are advantageously designed in such a way that in a correctly installed full locking position of the plug-in coupling 100, as shown in FIG Fig. 11 shown, rests axially.

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

It has proven to be expedient for the coupling part 102 or the receiving opening 108 of the coupling part 102 to be dimensioned with an insertion path 142 for the plug shaft, with the holding part 104 having an axial play relative to the coupling part 102. The axial play preferably corresponds to at least the extent of the blocking edge 136 in the axial direction. For the purpose of assembly, the holding part 104 can be transferred from the release position to the locking position, with the tooth structures 110a, 110b locking with the holding edge(s) 112a, 112b when the plug shaft is inserted in the insertion direction E. When the plug part 106 is completely inserted into the receiving opening 108 and the locking connection required for the full grid position between the tooth structures 110a, 110b and the retaining edge(s) 112a, 112b is established, this can be done by means of a restoring force on the plug part 106 against the plugging direction E Plug part 106 can be moved against the plugging direction E according to its plug-in path 142. 8 and 11, the blocking edge 136 is advantageously arranged radially next to the peripheral surface 140 of the receiving opening 108 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 7 and 12, at least over the axial length of the blocking edge 136 in the plugging direction E into a plug-in position of the plug-in coupling 100, so that the blocking edge 136 and the peripheral surface 140 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.

In particular, in order to facilitate the dismantling or removal of the plug part 106 from the receiving opening 108 against the plug-in direction E, the expedient connecting section 120 of the holding part 104 and / or the coupling part 102 points in a radial direction to the connecting section 120 of the holding part 104 adjacent circumferential section has a release contour 144a, 144b. The release contour 144a on the holding part 104 is shown in particular in FIG. The release contour 144b on the coupling part 102 is shown in particular in FIG. The release contour 144a on the holding part 104 is preferably 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 versions of the release contours 144a, 144b are shown in particular in FIGS. 1 and 2 as well as FIGS. 12 and 13, with FIGS.

In particular, the release contour 144a, 144b of the holding part 104 and/or the coupling part 102 are designed such that, in particular together, they form an insertion opening 146 that is open in the insertion direction E. The insertion opening(s) 146 is/are shown in particular in FIG. 12. A cross section of the insertion opening 146 is advantageously reduced via a ramp section 148 pointing against the insertion direction E. The ramp section 148 in particular makes it possible for a release tool 118, as shown in FIG. 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.

It has proven to be advantageous that, opposite the insertion opening 146, the release contour 144a, 144b is axially opened in such a way that when a release tool 118 is inserted into the release contour 144a, 144b through the insertion opening 146, a release contour 144a, 144b may possibly occur Dirt located in the area of the release contour 144a, 144b is displaced.

As shown in FIG. 2, a dome 150 pointing radially towards the coupling part 102 is advantageously formed on the connecting section 120 of the holding part 104. In particular, the mandrel 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, into a correspondingly designed recess 152 in the circumference of the coupling part 102. The recess 152 is shown in particular in FIG. The recess 152 is expediently designed with an axial play relative to the mandrel 152 in such a way 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 moved in accordance with the insertion path 142. The recess 152 is advantageously designed to be oval or as an elongated hole.

In a further embodiment of the invention, at least one of the tooth structures 110a, 110b, as shown in FIG 154 has. In particular, the rear tooth structure 110b pointing in the insertion 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 holding edge 112b of the plug part 106. The radii on the front and/or the 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 means that the force transmitted from the holding edges 112a, 112b of the plug part 106 to the tooth structures 110a, 110b is absorbed, e.g. B. when there is a tensile load on the assembled plug part 106 in the fully locked position against the plugging direction E.

According to a variant of the invention shown in FIGS. 6 to 8 as well as FIGS , in particular cylindrical control section 158 is formed. As shown in FIGS. 6 to 8 and FIGS. 12, 13 and 15, the receiving opening 108 in the control section 158 expediently has a larger diameter than in the sealing section 156. The sections 156, 158 can advantageously have different functions, e.g. B. Arrangement of seals. In particular, the plug-in coupling 100 is designed such that the plug shaft is only sealed against the control section 158 in the pre-locking position, so that incomplete assembly can be recognized by a controlled leakage.

A transition section 160 is expediently formed axially between the control section 158 and the sealing section 156, as shown in FIGS. 6 to 8 and FIGS 108 reduced in the sealing section 156. The transition section 160 particularly facilitates the centering of the plug shaft of the plug part 106 during insertion and preferably serves to store a dirt seal 162 arranged in the control section 158.

It is expedient to have at least one groove 159 running axially in the peripheral surface 140a of the receiving opening 108 in the control section 158 as a leakage path. The groove 159 designed as a leakage path is shown in FIG. 15. In particular, at least one groove 159 designed as a leakage path is provided, preferably the number of leakage paths can be adapted to the operating conditions and the fluidic properties of the fluid to be transferred, for example four or even eight grooves 159 designed as leakage paths are possible. Preferably, the grooves 159 are arranged uniformly over the circumference of the transition section 160, as shown in FIG. The grooves 159 designed as leakage paths advantageously enable early detection of a plug part 106 that is incompletely inserted, for example in the pre-locking position, by generating a leak in a controlled manner, which can be perceived, for example, visually or acoustically by a fitter.

In a preferred embodiment, the sealing section 156 and the control section 158 are arranged or designed relative to one another in such a way that in the pre-locking position, as shown in FIG. 6, the plug shaft with a in the plugging direction E facing front main seal 164 is arranged adjacent to the control section 158 and in particular also adjacent to the transition section 160. The main seal 164 is expediently arranged in a main seal groove 166, as shown in FIGS. 6 to 8, 12 and 13. The main sealing groove 166 is also shown as an example in FIG. The coupling part 102 or the control section 158 and in particular the transition section 160 are expediently designed in such a way that in the pre-locking position a controlled leakage is provided between the main seal 164 and the peripheral surface 140a of the receiving opening 108 in the control section 158. This effect is advantageously improved by at least one axially extending groove 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, as shown in FIG. 6.

The coupling part 102 or the sealing section 156 is advantageously designed in such a way that in the fully latched position, as shown in FIG. The sealing section 156 is designed such that the main seal 164 withstands a system pressure that occurs when the plug-in coupling 100 is operated in a fluidic line system and prevents fluid from escaping.

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 is at least in the fully latched position, as shown in FIGS. 7 and 8, against the peripheral surface 140a of the receiving opening 108 in the control section 158 can be elastically braced. The dirt seal 162 is expediently clamped both radially against the peripheral surface 140 of the receiving opening 108 in the control section 158 and, if necessary, 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 tension is shown in particular in FIGS. 7, 8, 12 and 13. Due to the axial tensioning of the dirt seal 162, an axial restoring force R acts on the plug part 106 in such a way that the plug part 106 is pressed against the plugging direction E. In particular, the holding edges 112a, 112b of the plug part 106 are pressed against the tooth structures 110a, 110b.

The coupling part 102 is preferably designed in such a way 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 moved into the fully locked position. Appropriately, a self-locking device can also advantageously be provided by the blocking edge 136, so that after the plug part 106 has been completely inserted and, when the insertion force acting on the plug part 106 in the plugging direction E for inserting the plug part 106 is reduced, by the restoring force R of the dirt seal 162 the plug part 106 together with the holding part 104 attached to the plug part 106 is displaced axially relative to the coupling part 102 against the plugging direction E. This advantageously brings the blocking edge 136, as shown in FIGS. 8 and 11, into a radially acting, positive blockage with the peripheral surface 140 of the receiving opening 108.

The coupling part 102 and/or the holding part 104 is preferably made of a polyamide, expediently with a glass fiber content of 15% to 45%, in particular 20% to 40%, preferably 25% to 35%. The coupling part 102 and/or the holding part 104 is advantageously produced in a casting, in particular an injection molding, process.

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 to the release position. According to the invention, the release tool 118 has an attack body 172 extending along a longitudinal axis 170 and an expansion body 174 adjoining the attack body 172. The attack body 172 is elastically deformable about the longitudinal axis 170 and essentially rigid axially of the longitudinal axis 170.

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

In particular, the release tool 118, as shown in Fig. 5, has recesses 176, which expediently create a meander shape on the top and bottom, so that the flexibility or the elastic deformation potential around the longitudinal axis 170 is provided and at the same time the axial rigidity is maintained .

The release tool 118 is thereby designed such that it is flexible in the longitudinal axis 170, thereby reducing leverage.

The use of the release tool 118 is described below with reference to FIGS. 12 and 13.

To release the connection or to remove the plug part 106 against the plug-in direction E from the receiving opening 108, the connection is in particular plugged over, so that the plug-in coupling 100 is in the plug-in position shown in FIG. 12.

In particular, the tooth contact edge 114 of the tooth structure 110a, 110b lies 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 insertion direction E is caused. 7 and 12 show how the plug part 106 has displaced the holding part 104 axially in the plugging direction E.

To plug it over, the plug part 106 is preferably pushed into the coupling part 102, in particular towards the stop, pointing in the plugging direction E. Included The holding part 104 is preferably carried axially 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 peripheral surface 140 of the receiving opening 108. From this state, the holding part 104 can be transferred radially from the locking position into the release position or the spring arms 122 can be expanded radially elastically into the tension state.

Subsequently, the release tool 118 is expediently inserted parallel to the insertion direction E and largely parallel, in particular parallel, to the longitudinal axis 170 of the release tool 118 against the insertion direction E into the insertion opening 146 of the release contour(s) 144a, 144b. In particular, in FIG. 12 the release tool 118 is shown in a pre-release position, whereas in FIG.

In particular, by means of the movement of the release tool 118, the expansion body 174 slides in particular 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 pointing release force on the connecting section 120 of the holding part 104, so that it is transferred into the release position, as shown in FIG. 13.

The release tool 118, as shown in FIG. 144b can be introduced.

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 attack body 172, in particular a bending about the longitudinal axis 170, this Release tool 118 slips out of the release contour 144a, 144b and As a result, the holding part 104 cannot be levered out, which could lead to damage to the holding part 104 and/or the coupling part 102.

As a further measure, a height of the release contour(s) 144a, 144b was designed axially to the insertion direction E using the curves so that if excessive force is applied to the release tool 118, it is rotated out of the release contour(s) 144a, 144b, and that Holding part 104 is no longer pressed radially out of the coupling part 102.

In particular, when transferring the holding part 104 from the locking position to the release position, spring arms 122 pivot, preferably due to the control contour 128 and the axial separating web 130, 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, so that the plug part 106 can be released from the latching connection.

It has proven to be advantageous that if there is a one-sided opening of the holding part 104, in particular if a spring arm 122 expands radially, whereas the second spring arm 122 remains in the rest position, the holding part 104 due to the appropriate holding bevels 132 of the spring arms 122 and bearing edges of the coupling part 102 are opened asymmetrically, 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.

According to a further developed variant of the release tool 118, a maximum displacement path of the holding part 104 radially to the coupling part 102, which the holding part 104 requires in order 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 always brought about and in particular a 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 which protrude axially to the longitudinal axis 170 and are separated from 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 such guide contours that the release tool 118 can always be used correctly when installed. In particular, the expansion tabs 182 are designed in such a way that when the expansion tabs 182 are inserted into a release contour 144a, 144b, a mandrel 150 optionally formed on the connecting section 120 is encompassed.

The invention is not limited to the exemplary embodiments shown and described, but also includes all embodiments that have the same effect within the meaning of the invention. It is expressly emphasized that the exemplary embodiments are not limited to all features in combination; rather, each individual sub-feature can have an inventive significance in itself, even independently of all other sub-features. Furthermore, the invention has not yet been limited to the combination of features defined in claim 1, but can also be defined by any other combination of certain features of all of the individual features disclosed overall. 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.

Reference character list

100 plug-in coupling

102 coupling part

104 holding part

106 connector part

108 recording opening

110a Anterior tooth structure

110b Posterior tooth structure

111 warehouse opening

112a Front holding edge

112b Rear holding edge

114 tooth contact edge

116 stop edge

118 release tool

120 connecting section

122 spring arm

124 holding projection

126 Clearance

128 tax contour

130 divider

132 holding angle

134 bearing edge

136 blockade edge

138 support surface

140 circumferential area of the receiving opening

140a circumferential surface of the receiving opening in the control section

140b circumferential surface of the receiving opening in the sealing section

142 transfer path

144a Release contour on the holding part

144b Release contour on the coupling part

146 insertion opening 48 ramp section 50 mandrel 52 recess 54 radius

156 sealing section

158 control section

159 groove

160 transition section

162 dirt seal

164 main seal

166 main seal groove

168 seal groove

170 longitudinal axis

172 attack bodies

174 spreader bodies

176 recess of the release tool

178 rounds

180 depth of the spreader body

182 expansion tabs

E Plugging direction

F direction of deformation

R restoring force

Claims

Expectations 1 . Plug-in coupling (100) for fluid 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), the plug part (106) being circumferentially sealed with a plug shaft in a receiving opening (108) of the coupling part (102) can be inserted in a plug-in direction E and via the radially elastic holding part (104), which projects 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) can be locked against loosening against the plug-in direction (E), the holding part (104) having at least two axially spaced tooth structures (110a, 110b) for gripping behind at least one on the plug part (106) to form the pre-locking position and the full locking position. designed holding edge (112a, 112b), the holding part (104) being displaceable relative to the coupling part (102) radially to the receiving opening (108) between a locking position that locks the plug part (106) and a release position that releases the plug part (106). 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), each of which extends from the connecting section (120) into one free end, the spring arms (122) protruding into the receiving opening (108) in a relaxed rest state in such a way that the plug part (106) can be locked in the pre-latching position and the fully latching 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) against the insertion 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 when the holding part (104) is displaced radially from the locking position to the release position, the spring arms (122) extend from the rest state to the radially expanded state of tension. 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) which protrude from the spring arms (122) radially to the receiving opening (108) and in at least one holding projection (124 ), in particular in each holding projection (124), the two tooth structures (110a, 110b) which are spaced apart axially to the insertion direction (E) are formed, with two holding areas being arranged on each radially elastic spring arm (122) in such a way that the spring arms (122) are mirror-symmetrical to each other in cross section. Plug-in coupling (100) according to claim 4, characterized in that the holding projections (124) have axial clearances (126) which completely penetrate the holding projections (124) axially. 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 encompassing a separating web (130) of the coupling part (102) which runs axially to the plug-in direction (E), the separating webs (130) each being designed to extend axially through a radial bearing opening (111) in the outer surface of the coupling part (102), so that the holding projections (124). 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) on the free ends of the spring arms (122) and in a beveled control contour (128) in a radially outwardly offset web section of the the respective spring arm (122), the control contour (128) pointing towards the connecting section (120), the control contours (128) being designed such that when the holding part (104) is radially displaced from the locking position to 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 expanded pointing radially outwards into the tension state. Plug-in coupling (100) according to claim 7, characterized in that the control contours (128) each have a holding bevel (132), the holding bevel (132) being designed such that in the tension state of the spring arms (122), the holding bevel (132) is vertical is aligned with the direction of the radial displacement of the holding part (104) from the locking position into the release position and in the release position on a correspondingly designed bearing edge (134) which is aligned in the tensioned state and in particular parallel to the holding bevel (132) with the spring arms (122). ) rests, so that further displacement of the holding part (104) facing 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 to the release position is blocked and/or the radially elastic deformation of the holding part (104), in particular the spring arms (122), from the rest state into the radially expanded tension state, in particular in a form-fitting manner, is blocked . Plug-in coupling (100) according to claim 9, characterized in that a blocking edge (136) is formed on the side of the frontmost tooth structure (110b) axially opposite to the plug-in direction (E), which faces axially against the plug-in direction (E). ) protrudes pointing from the tooth structure (110b), with the blocking edge (136) facing radially outwards being followed by a support surface (138) which is axially offset in the insertion direction (E), the blocking edge (136) and the support surface (138) being designed in this way are that when the plug-in coupling (100) is fully engaged, 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) and with the holding edge radially against a peripheral surface (140). 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) in a peripheral section radially adjacent to the connecting section (120) of the holding part (104). Have release contour (144a, 144b), 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). is. Plug-in coupling (100) according to claim 11, characterized in that the release contour (144a, 144b) of the holding part (104) and / or the coupling part (102) is designed such that it forms an insertion opening (146) open in the plugging direction (E). , wherein a cross section of the insertion opening (146) is reduced over a ramp section (148) pointing against the insertion direction (E), so that a release tool (118) can be inserted into the insertion opening (146) and by means of a system contact with the ramp section (148 ) a radially outwardly pointing 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 to the coupling part (102) is formed on the connecting section (120) of the holding part (104), which at least in the fully latched position in a corresponding formed recess (152) engages 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 is on one of the locking connection between the tooth structure (110a, 11 Ob) and the retaining edge (112a, 112b ) of the plug part (106) has a maximum loaded bending point a radius (154). 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 sealing section (156) which adjoins the cylindrical sealing section (156) and points against the plug-in direction (E). Control section (158), the receiving opening (108) in the control section (158) having a larger diameter 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 adjusts 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) is reduced, with axially extending grooves being formed as leakage paths in particular in the peripheral surface (140) of the control section. 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 of the plug shaft with a front facing in the plugging direction (E), in a main sealing groove ( 166) arranged main seal (164) is arranged adjacent to the control section (158), in particular also the transition section (160), and in the fully latched position of the plug shaft with the main seal (164) is arranged adjacent to 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), the control section (158), and in particular also the transition section (160), being designed such that the dirt seal (162) is at least in the Full locking position can be elastically braced against the peripheral surface (140) of the receiving opening (108). 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 to the release position, characterized in that the release tool (118) has an attack body extending along a longitudinal axis (170). (172) and an expansion body (174) adjoining the attack body (172), the attack body (172) being elastically deformable about the longitudinal axis (170) and being essentially 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 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 designed in a fork-like manner with two expansion tabs (182) projecting axially to the longitudinal axis (170) and separated from a central separating slot, which are designed in particular in such a way that 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 gripped.