CN113738965A

CN113738965A - Plug-in connection for connecting two tubular connection parts by means of a retaining clip

Info

Publication number: CN113738965A
Application number: CN202110590880.2A
Authority: CN
Inventors: M·迪德里希
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2020-05-28
Filing date: 2021-05-28
Publication date: 2021-12-03
Also published as: DE102020206677A1

Abstract

The invention relates to a plug-in coupling device comprising a tubular first coupling part, a tubular second coupling part and a retaining clip, wherein the retaining clip comprises two legs extending next to each other and an arch connecting the legs at the end. The end-side plug-in section of the first coupling part can be plugged into the end-side receptacle section of the second coupling part by a relative plug-in movement between the coupling parts until the connection position is reached. The retaining clip can be inserted onto the second coupling part until a latching position is reached, in which two legs provided as latching legs engage into the through-opening of the second coupling part and project into the interior of the second coupling part. The plug-in connection of this type is characterized in that the latching legs are temporarily elastically deflected during the plug-in movement by the contact of the plug-in section of the first connection part and the latching legs with each other at the inclined surface and engage with the latching sections in the latching recesses of the first connection part in the connecting position.

Description

Plug-in connection for connecting two tubular connection parts by means of a retaining clip

Technical Field

The invention relates to a plug-in connection, comprising: a tubular first coupling member; a tubular second coupling member; and a retaining clip comprising two legs extending side by side and an arch connecting the legs at the end sides; wherein the end-side plug-in section of the first coupling part can be plugged into the end-side receptacle section of the second coupling part by a relative plug-in movement between the coupling parts until the connection position is reached; and wherein the retaining clip can be inserted onto the second coupling part until a latching position is reached, wherein in the latching position at least one of the two legs of the retaining clip, which legs are provided as latching legs, engages into the through-opening of the second coupling part and projects here into the interior of the second coupling part.

Background

Such a plug-in coupling is known from WO2014/136014a 1. In order to connect the two coupling parts of the plug-in coupling device, it is provided that the plug-in section of the first coupling part is first inserted into the plug-in section of the second coupling part and then the retaining clip is inserted onto the second coupling part, so that the two latching legs, each with a latching projection, engage not only in the slot-shaped through-opening of the second coupling part but also in the latching recess of the first coupling part, so that the connection between the coupling parts is fixed by means of the retaining clip.

A plug-in coupling device similar to this is furthermore known from DE69525263T2, in which the retaining clip is plugged there through a first opening in the wall of the second coupling part there until the free end of the latching leg of the retaining clip projects into a second opening in the wall of the second coupling part, which is diametrically opposite the first opening. The actuating sequence during the connection of the coupling parts corresponds here to the actuating sequence as it is also provided in the plug coupling device according to WO2014/136014a 1.

The handling of the plug-in coupling according to WO2014/136014a1 or DE69525263T2 is relatively complicated, since the two coupling parts must first be plugged into one another and must be temporarily held in this position, wherein at the same time the holding clip must be plugged or plugged in order to finally fix the plug-in coupling.

Disclosure of Invention

The invention is based on the object of improving a plug coupling of this type with respect to maneuverability.

This object is achieved in a plug connection for connecting two tubular connection parts by means of a retaining clip. The method for actuating such a plug coupling is the subject matter of the following features: in order to connect the first coupling part and the second coupling part to one another, the retaining clip is first inserted onto the second coupling part until the latching position is reached and then the plug section of the first coupling part is inserted into the receiving section of the second coupling part. Advantageous embodiments of the plug-in coupling according to the invention and of the method according to the invention result from the following description of the invention.

According to the invention, a plug-in coupling device is provided, which has at least a first tubular coupling part, a second tubular coupling part and a retaining clip, wherein the retaining clip comprises two legs running side by side, preferably parallel, and an arch (B ü gel) connecting the legs on the end sides, i.e. in each case at one of the ends. The tubular coupling part can have any cross-sectional shape. Preferably, however, the cross-sectional shape may be circular. The end-side plug-in section of the first coupling part of the plug-in coupling according to the invention can be plugged into the end-side receptacle section of the second coupling part by means of a (relative) plug-in movement between the coupling parts until the connection position is reached. Furthermore, the retaining clip can be inserted from the outside onto the second coupling part until a latching position is reached, wherein in the latching position two legs, preferably at least one of the two legs, of the retaining clip, which are provided as latching legs, engage in a preferably slot-shaped through-opening in the wall of the second coupling part and project into the interior of the second coupling part. The plug-in connection of this type is characterized in that the at least one latching leg is temporarily elastically deflected during the plug-in movement by the contact of the plug-in section of the first connection part and the latching leg at least one (obliquely extending, i.e. not parallel to the plug-in direction nor perpendicular to the plug-in direction) oblique face (of the plug-in section and/or the retaining clip of the first connection part) and engages with the latching section in the latching recess of the first connection part in the connection position.

In the context of the method according to the invention, such a plug-in connection device makes it possible to connect the first connection part and the second connection part to one another by first plugging the retaining clip onto the second connection part until the latching position is reached and then plugging the plug-in section of the first connection part into the receiving section of the second connection part until the connection position is reached. In the plug-in coupling device according to the invention, the final fixed connection between the coupling parts is thus achieved in that the retaining clip which has previously been plugged onto the second coupling part is already plugged together with the two coupling parts, which achieves a simple manoeuvrability of the plug-in coupling device.

In order to release the plug-in coupling device according to the invention, it can be provided that the at least one latching leg is temporarily deflected during a corresponding (relative) release movement (in which the plug-in section of the first coupling part is pulled out of the receiving section of the second coupling part) due to the mutual contact of the plug-in section and the latching leg at the at least one (further) inclined surface and is thereby disengaged from the latching recess of the first coupling part. This makes it possible to release the fixed plug coupling merely by pulling the coupling parts out of each other. However, this can be disadvantageous in that the plug-in connection can be released undesirably, so that it is preferably provided that the plug-in connection is designed in such a way that the retaining clip fixes the connection position of the connecting parts without restriction (i.e., cannot be released without destruction by merely pulling the connecting parts out of one another). Accordingly, it is possible within the scope of the method according to the invention to first pull the retaining clip at least partially out of the second coupling part and then pull the plug section of the first coupling part out of the receiving section of the second coupling part in order to release the coupled coupling parts.

According to a preferred embodiment of the plug-in connection according to the invention, it can be provided that the retaining clip is constructed at least partially, then preferably at least in the region of one or more latching feet, or particularly preferably completely from plastic, for example from polypropylene (PP). This results in a design of the retaining clip which on the one hand ensures a secure fixing of the connection between the coupling parts and at the same time can keep the insertion force required for inserting the coupling parts together and thus also for offsetting the latching leg or legs low. In particular, the retaining clip, which is completely made of plastic, can also be produced simply and cost-effectively, for example by means of an injection molding process.

Preferably, it is provided with the plug-in coupling device according to the invention that a plug-in force (directed in the plug-in direction) of at most 80N is required for inserting the plug-in section of the first coupling part into the receiving section of the second coupling part, in order to ensure a comfortable handling of the plug-in coupling device. This can be achieved in particular by a corresponding design of the retaining clip and, if appropriate, of the at least one sealing element.

Such a sealing element can in principle ensure a sealed, in particular also fluid-tight, connection between the coupling parts in the plug-in coupling according to the invention, but this usually causes an elastic deformation of the sealing element. In this case, it can be provided in particular that the preferably annular sealing element is deformed axially (i.e. in the plugging direction) and/or radially (i.e. perpendicularly to the plugging direction) when the plug section of the first coupling part is inserted into the receiving section of the second coupling part.

In a further preferred embodiment of the plug-in coupling device according to the invention, it can be provided that the contact section of the leg, preferably of at least one of the two legs, interacts with the inclined surface (extending obliquely to the plug-in direction) of the second coupling part in such a way that the leg or the legs are temporarily elastically deflected when being plugged onto the second coupling part until the latching position is reached. At least in the latched position of the retaining clip, the or the foot, which is temporarily elastically deflected during insertion, is no longer or only to a relatively small extent elastically deflected or deformed, which results in that a (continued) temporary elastic deflection has to be carried out again in order to completely pull out the retaining clip from the second coupling part. In this way, the retaining clip is fixedly retained on the second coupling part independently of whether the second coupling part is connected or not connected to the first coupling part. In this way, handling of the coupling device during the insertion of the coupling parts together can be simplified, since the fixing of the position of the retaining clip on the second coupling part takes place automatically. The inclined surface may preferably be a curved, extending section of the outer surface of the second coupling part. The contact section of the respective foot can preferably be configured as an end section of single or double bent configuration.

Furthermore, it can be provided that the contact section of the one or more latching legs interacts with the inclined surface of the second coupling part in such a way that, when the retaining clip is pulled out of the second coupling part, the latching legs are offset from the latching position to such an extent as to reach a release position (in which they additionally interact with the second coupling part) that they are (completely) moved out of the latching recesses of the first coupling part. In order to open the plug-in coupling device or to release the connection between the two coupling parts, it is not necessary to pull the retaining clip completely out of the second coupling part, which makes possible as simple a handling of the plug-in coupling device as possible. In this case, it can be particularly preferred if the contact section in the release position stops at a stop which prevents or at least hinders further pulling out of the retaining clip. This prevents the retaining clip from being pulled out of the second coupling part unintentionally completely.

In accordance with a preferred embodiment of the plug-in connection according to the invention, it can be provided that the retaining clip has a gripping section with two opposing gripping surfaces, wherein the gripping section is freely accessible in the latched position of the retaining clip. The gripping section makes it possible to pull the retaining clip out of the second coupling part relatively simply by hand.

In order to be able to exert a sufficient tensile force for the pulling-out of the retaining clip via the gripping surfaces, it can furthermore preferably be provided that at least one of the gripping surfaces, preferably both gripping surfaces, has a surface (with projections and/or recesses) with a structure.

In order to achieve the simplest possible release of the connection between the coupling parts when using a tool, such as, for example, a screwdriver, the retaining clip may preferably have a recess (i.e., a recess or a through-opening) which is accessible in the latched position by means of the tool and which is designed such that a pulling force for pulling the retaining clip out of the second coupling part can be applied by means of the tool.

In a further preferred embodiment of the plug-in connection according to the invention, it can be provided that at least one or more latching legs, preferably the entire holding clip, has a cross section whose (maximum) extent in the plug-in direction is configured in each case smaller than the extent perpendicular to the plug-in direction. The relatively large extent of the latching legs perpendicular to the plugging direction can be used to advantage to ensure that at least a plurality of the latching legs project into the interior of the second connecting part, without the need for special latching elements designed as projections of the latching legs being provided for this purpose. This allows a simple design for the retaining clip, which advantageously contributes to the manufacturability.

Preferably, it can be provided that the one or more latching legs (respectively) have a deformation section between the latching section and the bow, which deformation section has a greater (maximum) extent perpendicular to the plugging direction than the latching section. It is thereby possible to achieve that the elastic deformation of the detent leg or legs which is experienced during the insertion of the first coupling part into the second coupling part and, if appropriate, during the insertion of the retaining clip onto the second coupling part or the pulling out of the latter can be substantially limited to one or more relatively flexurally flexible deformation sections. This makes it possible in particular to design the respective latching sections of the latching leg or legs in a relatively flexurally rigid manner and to keep the maximum bending stress in the deformation section relatively low.

The plug-in coupling according to the invention is advantageously suitable for use in a motor vehicle and is particularly suitable for connecting two coupling parts which are part of a cooling system of a motor vehicle.

Drawings

The invention is explained in detail below with the aid of embodiments shown in the drawings. In the drawings:

fig. 1 shows a second coupling part of a plug coupling device according to the invention and a retaining clip in a perspective view;

FIG. 2 shows a retaining clip in perspective view;

fig. 3 shows a longitudinal section through the plug coupling in the first operating position when the coupling parts are connected;

fig. 4 shows a simplified cross-sectional view through the plug-in coupling in the region of the retaining clip in the first actuating position according to fig. 3;

fig. 5 shows a longitudinal section through the plug coupling in the second operating position when the coupling parts are connected;

fig. 6 shows a simplified cross-sectional view through the plug-in coupling in the region of the retaining clip in the second operating position according to fig. 5;

fig. 7 shows a longitudinal section through the plug coupling in a third operating position when the coupling parts are connected;

fig. 8 shows a simplified cross-sectional view through the plug-in coupling in the region of the retaining clip in the third operating position according to fig. 7;

fig. 9 shows a longitudinal section through a plug-in coupling in the connected position of the coupling part;

fig. 10 shows a simplified cross-sectional view through the plug connection in the region of the retaining clip in the connection position according to fig. 9; and

fig. 11 shows the use of a plug coupling in a cooling system of an internal combustion engine.

Detailed Description

The plug-in coupling device shown in the figures comprises a tubular first coupling part 1 (see fig. 3,5,7 and 9), a likewise tubular second coupling part 2 (see fig. 1,3,5,7 and 9 in particular), and a U-shaped retaining clip 3 which comprises two legs 4 running parallel next to one another, which are each designed as a latching leg 4, and an arch 5 connecting the latching legs on the end sides.

At its plug-in end, the first coupling part 1 forms a plug-in section 6 which is provided and accordingly formed for insertion into a receiving section 7 of the second coupling part 2. The plug-in section 6 of the first coupling part 1, which has a constant inner diameter over its entire length, comprises, starting from the plug-in-side end, a guide region 8, which is characterized by an enlarged outer diameter. This guide region 8 serves on the one hand to achieve self-centering of the first coupling part 1 when it is inserted into the second coupling part 2. Furthermore, the guide region, when the first coupling part 1 is inserted, enlarges a first sealing element 9 in the form of a conventional O-ring 9 arranged within the receiving section 7 of the second coupling part 2, so that the O-ring 9 then contacts a sealing region 10 of the plug section 6, which follows the guide region 8, with elastic enlargement. The sealing region 10 has a constant outer diameter over its length in the design example shown. Adjoining the sealing region 10 is an enlarged region 11 which is conically enlarged at the beginning and has a constant outer diameter over a relatively short distance at the end. Associated with the enlarged region 11 is a circumferential latching recess 12 which is bounded on the one hand by the end of the rear side of the enlarged region and on the other hand by a circumferential limiting projection 13. The first coupling part 1 is furthermore formed with an likewise circumferential abutment projection 14 spaced apart from the limiting projection 13, which in the connected position of the plug-in coupling device abuts against the free end side of the second coupling part 2.

The second coupling part 2 has a relatively large inner diameter and then a relatively small inner diameter in its receiving section 7, starting from the free end. The relatively large inner diameter is here slightly larger than the outer diameter of the limiting projection 13 and than the correspondingly dimensioned, largest outer diameter of the enlarged region 11 (in the section with a constant outer diameter) of the first coupling part 1. Whereas the relatively small inner diameter of the second coupling part 2 is only slightly larger than the outer diameter of the sealing region 10 of the first coupling part 1. By means of this combination of almost identical inner and outer diameters of the

coupling parts

1,2, a coaxial orientation of the

coupling parts

1,2 is ensured in the connection position of the plug-in coupling device.

In each case one slot-shaped through-opening 15, which extends in the circumferential direction in two diametrically opposite sections, is formed in the wall of the second coupling part 2 and serves in each case to accommodate one of the latching legs 4 of the retaining clip 3. In the latched position of the retaining clip 3 inserted onto the second coupling part 2 (see fig. 1), a respective inner part of the latching section 16 of the latching arch 4 or a part opposite the respective other latching leg 4 latches into the inner space 17 of the second coupling part 2 and, in the connected position of the two

coupling parts

1,2, into the latching recess 12 of the first coupling part 1. The retaining clip 3 can thereby secure the connection of the two

coupling parts

1,2 in the connected position against unintentional release.

To connect the

coupling parts

1,2, they are first oriented substantially coaxially with one another (see fig. 3 and 4) and then plugged into one another by relative movement (see fig. 5 to 10). The retaining clip 3 has been inserted onto the second coupling part 2 to the latched position.

In the operating position (as shown in fig. 5 and 6), the plug-in takes place into each other as soon as the guide region 8 of the first contact part 1 contacts the O-ring 9. The guide region 8 is already guided by a likewise annular second sealing element 18, which rests with the rear end face on the O-ring 9 and the front end face of which is provided for contact with a conical enlargement of the enlargement region 11 of the first coupling part 1 in the connected position of the

coupling parts

1,2, wherein the second sealing element 18 is then (also) elastically deformed in the axial direction. For this purpose, the end face of the second sealing element 18 has a funnel-shaped course which is complementary to the enlarged region 11 of the first coupling part 1. In the actuating position according to fig. 5 and 6, the latching section 16 of the latching leg 4 of the retaining clip 3 is also located in abutment with the sealing region 10 of the first coupling part 1, so that the latching leg 4 is not yet deflected by interaction with the enlarged region 11 of the first coupling part 1 or, in particular, with a conical enlargement of the enlarged region which acts as an inclined surface.

This offset of the detent feet 4 is present in the actuating position, as is shown in fig. 7 and 8. If, starting from this operating position, the two

coupling parts

1,2 are still slightly further plugged together until the connecting position according to fig. 9 and 10 is reached, the latching legs 4 of the retaining clip 3 latch into the latching recesses 12 of the first coupling part 1 due to their elastic deflection, so that the connection between the

coupling parts

1,2 is secured against undesired loosening. The fastening is not restricted here, since the end face of the enlarged region 11 which delimits the latching recess 12 has a perpendicular orientation with respect to the plug-in direction (which extends along the longitudinal axis 22 of the coupling parts 1,2), so that the latching legs 4 cannot be deflected and thus the connection between the

coupling parts

1,2 cannot be released without destruction merely by applying a tensile force to the

coupling parts

1, 2.

In order to release the connection between the

coupling parts

1,2 in this way and thus to open the plug-in coupling, it is provided that the retaining clip 3 is pulled out of the second coupling part 2 by a distance starting from the latching position until the release position is reached, wherein in each case one contact section 19 of the latching legs 4, which is designed as an end section of the respective latching leg 4 bent doubly (in each case by 90 °), is guided along at an abutment section of the curved outer surface of the second coupling part 2, which section acts as an inclined surface, so that the latching legs 4 are offset to such an extent that the latching sections 16 of the latching legs are moved completely out of the latching recesses 12 of the first coupling part 1 when the release position is reached.

In the release position, the contact sections 19 of the latching legs are each arranged in a recess 20 of the second coupling part 2, wherein the base surfaces of the two recesses 20 facing each other run parallel to each other and thus no longer act as inclined surfaces. The retaining clip 3 is thus automatically retained in the release position, and in combination with the return action of the offset latching feet 4. Furthermore, the upper limiting surface of the recess 20, or the limiting surface provided in the pull-out direction, is designed to contact a stop 21 of the section 19, which prevents the retaining clip 3 from being pulled out of the second coupling part 2 beyond the release position.

The retaining clip 3, which is completely made of plastic, has a cross section which is limited by two parallel, relatively long flanks and by partial, circularly outwardly curved flanks which connect these parallel flanks at the end sides in each case. This results in an extension for the entire cross section of the retaining clip 3 (apart from the cross section of the contact section 19) which is significantly smaller in the plug-in direction than in the transverse direction. Thereby, a size optimized for the load of the retaining clip 3 is achieved. The relatively large dimension perpendicular to the plugging direction results here in the region of the latching section 16 of the latching leg 4: they project partially into the interior 17 of the second coupling part 2, but at the same time are also arranged within the corresponding through-openings 15 of the second housing part 2, so that an advantageous support for the latching sections 16 is achieved. In the region of the bow 5 of the retaining clip 3, the relatively large dimension perpendicular to the plugging direction leads to: a gripping section 23 is formed, which enables a relatively large-area gripping of the retaining clip 3 and thus a manual pulling out of the retaining clip 3 from the second contact part 2 or from the latching position into the release position. In order to transmit the tensile forces transmitted in this case to the retaining clip 3 with as good a force fit as possible, the gripping sections 23 or the gripping surfaces 24 of the bow 3 (which are defined by the parallel-running sides of the cross section of the bow 3) have surfaces with a structure, wherein the structure is produced by a plurality of elongate projections 25 running parallel.

The bow 5 (arranged centrally between the latching legs 4) forms, on the side adjoining the second coupling part 2, a recess 26 which is accessible in the latching position of the retaining clip 3, so that a tool, for example a screwdriver, can be inserted into this recess in order to facilitate or at least assist the removal of the retaining clip 3 from the second coupling part 2 by means of the tool.

Furthermore, the latching legs 4 of the retaining clip 3 have a deformation section 27 between the respective latching section 16 and the bow 5, which deformation section has a smaller extent perpendicular to the plugging direction than the latching section 16. As a result, a relatively high elasticity is achieved in the region of the deformation section, so that elastic deformation of the detent feet 4 during insertion and removal and in the release position occurs mainly in the region of the deformation section 27.

Fig. 11 shows a possible use of a plug coupling as part of a cooling system of an internal combustion engine 28 of a motor vehicle, wherein it is provided in particular that a cooling channel of the internal combustion engine 1 is connected by means of the plug coupling to a coolant line 29 leading to a coolant cooler (not shown) of the cooling system.

List of reference numerals

1 first coupling part

2 second coupling part

3 holding clip

4 holding clip (latch) foot

5 arcuate portion of retaining clip

6 plug-in section of the first coupling part

7 receiving section of a second coupling part

8 guide region of plug-in section

9 first sealing element/O-ring

10 sealing region of plug section

11 enlarged area of plug section

12 catch recess of the first coupling part

13 limiting projection of first coupling member

14 first coupling part abutment projection

15 through opening of the second coupling part

16 latching section of a latching bow

17 inner space of second coupling member

18 second sealing element

19 contact section of latching leg

20 recess of second coupling part

21 stop part of second coupling component

22 longitudinal axis of coupling member

23 gripping section of a retaining clip

24 gripping surface of gripping section

25 projection of retaining clip

26 void of retaining clip

27 deformation section of the detent foot

28 internal combustion engine

29 coolant lines.

Claims

1. A plug coupling device with:

-a tubular first coupling part (1);

-a tubular second coupling member (2); and

-a retaining clip (3) comprising two legs (4) running side by side and an arch (5) connecting the legs (4) at the end sides;

-wherein an end-side plug-in section (6) of the first coupling part (1) can be plugged into an end-side receptacle section (7) of the second coupling part (2) by means of a relative plug-in movement between the coupling parts (1,2) until a connection position is reached; and is

-wherein the retaining clip (3) can be inserted onto the second coupling part (2) until a latching position is reached, wherein in the latching position at least one of the two legs (4) of the retaining clip (3) provided as latching legs (4) engages into the through-opening (15) of the second coupling part (2) and projects here into the interior space (17) of the second coupling part (2),

characterized in that said at least one locking foot (4)

-temporarily during a plugging movement, is elastically deflected at least one inclined face by the contact of the plugging section (6) of the first linking part (1) and the latching foot (4), and

-engaging with a latching section (16) into a latching recess (12) of the first coupling part (1) in the connecting position.

2. Plug coupling according to claim 1, characterized in that the design is such that the retaining clip (3) fixes the connection position of the coupling parts (1,2) unrestrictedly.

3. Plug coupling according to one of the preceding claims, characterized in that the retaining clip (3) is constructed from plastic.

4. Plug-in coupling device according to one of the preceding claims, characterized in that the contact section (19) of at least one of the legs (4) interacts with the inclined surface of the second coupling part (2) in such a way that the leg (4) is temporarily elastically deflected into the latched position when plugged onto the second coupling part (2).

5. Plug-in connection with one of the preceding claims, characterized in that one or more contact sections (19) of the at least one latching leg (4) interact with an inclined surface of the second connecting part (2) in such a way that the latching leg (4) is offset from the latching position when the retaining clip (3) is partially pulled out of the second connecting part (2) to such an extent into a release position that it is moved out of the latching recess (12) of the first connecting part (1).

6. Plug coupling according to claim 5, characterized in that the contact section (19) in the release position is stopped at a stop (21) which blocks a further withdrawal of the retaining clip (3) from the second contact part (2).

7. Plug coupling according to one of claims 4 to 6, characterized in that the contact section (19) is configured as a singly or doubly bent end section of the respective leg (4).

8. Plug connection coupling device according to one of the preceding claims, characterized by a sealing element (9,18) which is deformed axially and/or radially when the plug section (6) of the first coupling part (1) is inserted into the receiving section (7) of the second coupling part (2).

9. Plug connection coupling according to one of the preceding claims, characterized in that the design of the retaining clip (3) and, if appropriate, of the sealing element (9,18) is such that a plug force of at most 80N is required for inserting the plug section (6) of the first coupling part (1) into the receiving section (7) of the second coupling part (2).

10. Plug coupling according to one of the preceding claims, characterized in that the retaining clip (3) has a gripping section (23) with two mutually opposite gripping faces (24), wherein the gripping section (23) is freely accessible in the latched position of the retaining clip (3).

11. Plug coupling according to claim 10, characterized in that at least one of the gripping surfaces (24) has a structured surface.

12. Plug coupling device according to one of the preceding claims, characterized in that the retaining clip (3) has a recess (26) which is freely accessible in the latched position and which is designed such that a pulling force can be applied to a limiting surface of the recess (26) in order to pull the retaining clip (3) out of the second coupling part (2).

13. Plug connection coupling according to one of the preceding claims, characterized in that at least the at least one latching foot (4) of the retaining clip (3) has a cross section whose extent in the plug-in direction is in each case configured to be smaller than the extent perpendicular to the plug-in direction.

14. Plug connection coupling according to one of the preceding claims, characterized in that the at least one latching leg (4) has a deformation section (27) between the latching section (16) and the bow (5), which deformation section has a smaller extension perpendicular to the plug-in direction than the latching section (16).

15. Method for actuating a plug-in coupling device according to one of the preceding claims, characterized in that, for the mutual connection of the first coupling part (1) and the second coupling part (2), the retaining clip (3) is first plugged onto the second coupling part (2) until the latching position is reached and then the plug-in section (6) of the first coupling part (1) is plugged into the receiving section (7) of the second coupling part (2).