DE102023133789A1 - Drain stop valve, especially for a plug connection - Google Patents

Abstract

The present invention relates to a discharge stop valve (14), in particular for a plug connection (1) for the passage of cooling liquid, with a valve tappet (24) which is axially movable in a flow channel (18, 20) of the plug connection (1) and which cooperates in a sealing manner with a valve seat (21), with a head seal (29) arranged on a valve head (28) of the valve tappet (24) for fluid-tight closing of the flow channel (18, 20) and with a closing spring (16) which acts on the valve tappet (24) on one side and can be fixed on the other side in the flow channel (18, 20). In particular, to improve the ease of assembly, it is proposed that the valve tappet (24) in a structural unit with the head seal (29) arranged on the valve head (28) is radially dimensioned and elastically deformable in such a way that an effective outer diameter during assembly in a non-deformed state (DAG29, DAG33) is larger than the diameter (DI6, DI40) of an assembly opening and in the deformed state (DAM29, DAM33) is smaller than or equal to the diameter (DI6, DI40) of the assembly opening. The invention also relates to a plug connection (1) with such a discharge stop valve (14).

Description

The invention relates to a discharge stop valve, in particular for a plug connection for the passage of cooling liquid, with a valve tappet that is axially movable in a flow channel of the plug connection and cooperates sealingly with a valve seat, with a head seal arranged on a valve head of the valve tappet for fluid-tight closing of the flow channel and with a closing spring that acts on the valve tappet on one side and can be fixed in the flow channel on the other side.

O-rings are traditionally used as head seals, which are located in a groove in the valve head. The closing spring is either located behind the valve tappet, which has an adverse effect on the flow and the overall length, or the tappet including the closing spring must be mounted from one side during assembly - and the O-ring from the other side.

Furthermore, the invention also relates to a plug connection with such a drain stop valve.

A drain stop valve of the type mentioned above is known as an insert in a plug connection comprising a plug part and a coupling part from air conditioning technology, in particular from EP 0 568 076 B1 , wherein the plug connection is provided with two drain stop valves that interact in a flow channel of the plug part and the coupling part. Such a plug connection can be used, for example, for lines for the fluidic transport of a cooling liquid.

In detail, the known plug connection has a coupling part with a socket section and a plug part. The plug part can be inserted into the socket section of the coupling part with a shaft. The plug part can be locked or is locked in the coupling part in the inserted state by means of a holding element. Furthermore, a check valve is arranged in the plug part and in the coupling part as a discharge stop valve. The two check valves are designed and arranged in relation to the other check valve in such a way that the check valves open each other when the connection is made or keep each other open when inserted and locked and are closed in a separated and/or pre-assembled state of the plug part relative to the coupling part. The closing of the check valves when the plug connection is dismantled is caused by the closing spring of the valve. Each check valve has a valve tappet that is axially movable in a flow channel and cooperates with a valve seat to form a seal. The valve tappets are arranged opposite one another along the flow channel in axial alignment in such a way that they abut one another at the front with abutting surfaces. To seal the check valve fluid-tight, a valve head of the valve tappet has a head seal and the valve seat has a correspondingly designed sealing surface. The valve seat can also be formed by an insert sleeve.

The arrangement of the check valves has the technical effect that when the coupling part is released or separated from the plug part, no fluid can escape, in particular no coolant can leak out, because the closing spring is arranged on the valve heads, which pushes the respective check valve into its closed position when the plug connection is removed. To seal, the valve head is pressed with a particularly conical sealing surface against the corresponding particularly conical sealing surface of the valve seat in the flow channel by a restoring force of the closing spring.

The present invention is based on the object of further improving a discharge stop valve of the type mentioned at the outset and a plug connection with such a discharge stop valve with regard to the disadvantages mentioned at the outset, in particular by requiring less assembly effort and being less susceptible to errors - with preferably low complexity.

This object is achieved according to the invention according to the features of claim 1 for the discharge stop valve in that the valve tappet in structural unit with the head gasket arranged on the valve head is radially dimensioned and elastically deformable in such a way that an effective outer diameter during assembly in a non-deformed state is larger than the diameter of an assembly opening and in the deformed state is smaller than or equal to the diameter of the assembly opening.

The mounting opening can preferably be formed directly in the flow channel of the socket part, the plug part or also in an insertion sleeve.

The technical measure according to the invention can be implemented on the one hand in a first embodiment on the base side of the valve tappet in that the valve tappet has arms which can be sprung radially elastically inwards and which are not behind the valve spring, in particular on a locking edge of the Valve or connector housing or on a locking edge on an insert in the valve housing, but can advantageously lock directly on the valve spring itself, preferably in that at least some of them are designed as locking arms, whereby in a preferred embodiment they end in a locking hook at their free ends. The arms can be formed, for example, by a slot in an annular collar that protrudes radially from the valve tappet, as will be described in more detail below in connection with the second embodiment.

The effective outer diameter during assembly is the largest outer diameter of a circumference of the annular collar projecting radially from the valve tappet around the radially elastically inwardly springable arms of the valve tappet.

According to the first embodiment of the invention, the head region of the valve tappet with the head seal can remain unchanged compared to the known design or can be modified in a different way in a suitable manner. For example, it can be provided that the valve head has at least one circumferential head seal groove, which is preferably open radially towards the respective valve seat, so that a conventional annular head seal can be or is arranged therein.

On the other hand, the technical measure according to the invention can be implemented in a second embodiment on the head side of the valve tappet by providing the latter with an elastic head seal which has, in particular, an external shape in the form of a truncated cone, a mushroom head, a spherical cap, a paraboloid of revolution or a similar hat-like body of revolution and an internal cavity for receiving the valve tappet.

The effective outer diameter during assembly is the largest outer diameter of the head gasket.

The base area of the valve tappet can then remain unchanged compared to its known design or can also be modified, for example with regard to the formation of abutting surfaces, at which the valve tappets in the plug connection abut against each other at the front with abutting surfaces, on an annular collar protruding radially from the valve tappet.

Specifically, it can be provided, for example, that the abutting surfaces are each formed on an annular collar projecting radially from the valve tappet, wherein the annular collar has a contact surface for the closing spring on the rear side of the abutting surface such that the respective closing springs are clamped against a restoring force between the respective contact surface and a clamping surface of the respective valve seat, at least in the inserted and locked state.

Such an embodiment results in the closing springs being arranged relative to the respective valve tappet between the annular collar or the abutment surface and the valve head, whereby the valve head can advantageously be made smaller in diameter than the valve tappet in the area of the annular collar or the abutment surface, so that the discharge stop valve can always be inserted into the flow channel of the coupling part or the plug part on one side.

In a preferred advantageous embodiment of the invention, the closing spring is designed as a helical spring such that it is arranged coaxially on the respective valve tappet. The closing spring expediently surrounds the valve tappet in such a way that the valve tappet forms an inner guide for the closing spring, so that breaking out of the closing spring in the event of compression is prevented or largely limited.

In a particularly advantageous variant, a spring guide can be formed by several, in particular four, webs evenly distributed over the circumference of the valve tappet. In the area of the spring guide, the closing spring is thereby forced into a coaxial position with the valve tappet. In particular, the closing spring rests on the spring guide, i.e. on the webs, surrounding the valve tappet.

According to the first embodiment, which has the arms that can be sprung radially elastically inwards, these arms can be designed according to the slotting of the annular collar that projects radially from the valve tappet, analogous to the webs distributed over the circumference of the valve tappet, and provide the spring guide.

With regard to the second embodiment of the invention, the multi-component injection molding process in particular offers advantageous possibilities for producing the elastic head gasket, because this is a manufacturing process that can be used in plastics technology when injection molded parts are to consist of two or more plastics. Completely different materials can also be combined with each other to advantage. The term multi-component injection molding covers various processes in detail, for example the sandwich molding process and the overmolding process. In both cases, at least two different melts are combined with each other.

While in the sandwich molding process the two melts are injected simultaneously, the German translation of "overmolding" means something like "overmolding", because in this case an injection molded part previously made from a first melt is overmolded with a second melt during a subsequent process step. Depending on the plastics selected, this process can be used to produce so-called hard-soft connections. These usually consist of relatively hard plastics (here: the valve tappet) which are provided with a layer of elastic, relatively soft material (here: the head gasket). The machines used to implement the overmolding process are equipped with at least two independently controllable injection units, which - like the associated control system - can already be designed for a corresponding application, whereby thermoplastic elastomers (TPE) in particular are to be used as sealing materials for the multi-component injection molding process to implement the overmolding process. Overmolding can be implemented, for example, with an EPDM-based TPE. After the valve tappet has been manufactured, a polymer sealing base material can be cold-sprayed onto it and then vulcanized to form the head gasket.

However, both embodiments of the technical measure according to the invention can also advantageously be provided together on a structural unit of the valve tappet with the head gasket arranged on the valve head.

A plug connection according to the invention is characterized in that at least one, preferably two, discharge stop valve(s) according to the invention are mounted in it.

The invention advantageously enables improved assembly to be carried out while ensuring an optimal installation length and high flow, and assembly is preferably carried out from one side only. In addition to cost-effective production and assembly, this also advantageously provides high process reliability and a low risk of dirt entering.

Furthermore, the invention also makes it possible for the respective discharge stop valve to be inserted in a modular manner into the flow channel of the plug part or the coupling part, together with the valve seat formed by an insertion sleeve. In particular, the discharge stop valve according to the invention can be designed as a press-in cartridge and particularly preferably according to the identical part principle, which means that the same discharge stop valve, for example designed as a press-in cartridge, is used or can be used both in the plug part, if the space there allows it, and in the coupling part. The discharge stop valves in the plug part and in the coupling part are therefore preferably designed identically.

The design according to the invention also makes it possible for the coupling parts, the plug parts and the drain stop valves to be manufactured as standard parts, whereby the requirements for the plug connection to be manufactured, such as flow rate or closing spring preload, are met by a relative combination of the coupling part, the plug part and the drain stop valves. The identical part principle also has the great advantage over a design without identical parts that there is always a flow balance between the two drain stop valves. This means that, for example, no differences due to diverging flow paths need to be taken into account when designing the closing springs. The use of identical parts is therefore particularly advantageous even with changing flow directions.

Furthermore, the invention takes into account the generally radially limited space requirement in the plug of a plug connection equipped with the inventive discharge stop valve. According to the inventive concept, the press-in cartridge described above can optionally be dispensed with, insofar as the valve tappet with the seal and also the closing spring can be mounted directly in the plug. In this way, both the number of required components and the assembly steps of a plug connection equipped with at least one, preferably two, discharge stop valves according to the invention are kept small, because many identical parts can be used for the plug and coupling.

An advantageous design of the sealing mechanism provides that the valve head has at least one circumferential head seal groove, which is designed to be open in particular radially to the respective valve seat, so that a head seal, expediently an annular head seal, can be or is arranged in it. The head seal is advantageously designed in such a way that the valve head is or can be sealed radially and axially against the sealing surface of the respective valve seat.

In the case of the implementation of the second embodiment, the valve tappet can be completely covered by the elastic head gasket on the head side and protrude into the cavity of the gasket. Here too, the head gasket groove or a similarly designed profile with preferably two Head gasket grooves provide positive locking to hold the gasket in place.

In both embodiments, the valve tappet can be designed as a hollow body, at least in some regions, in particular in a material-saving manner.

In order to improve the function of the discharge stop valves, in particular to avoid malfunctions, a special variant of the invention provides that the sealing surface at an end of one of the valve seats opposite the clamping surface is conical, widening in diameter in the direction away from the clamping surface. Such a conical sealing surface advantageously has the consequence that the valve tappet, in particular the valve head, can be guided better through the valve seat and jamming is avoided.

Corresponding to the conical sealing surface of the valve seat, according to an advantageous embodiment of the invention, the assembly or insertion of the valve tappet into the flow channel, in particular into and/or through the valve seat, is improved in that at least one of the valve heads has a conical converging insertion section.

In the case that the elastic head gasket has an external shape in the form of a truncated cone, a mushroom head, a spherical cap, a paraboloid of revolution or a similar hat-like body of revolution which covers the valve head, such a conical converging insertion section is advantageously already completely provided by the elastic head gasket.

A particular advantage arises in the interaction with the head gasket. The respective discharge stop valve can advantageously be closed fluid-tight by means of a sealing contact of the head gasket formed on the valve head with the conical sealing surface of the valve seat. The conical sealing surface also prevents damage to the discharge stop valve according to the invention, for example due to the seal being sheared off, and the head gasket is pressed axially and radially into the head gasket groove by means of the conical sealing surface when the discharge stop valve is transferred from the open to the closed position, which improves the sealing properties. An increase in pressure within the flow channels expediently has a reinforcing effect on the sealing potential of the respective discharge stop valve.

Further advantageous embodiments of the invention emerge from the following description of the figures and the dependent claims.

• 1a ein Ausführungsbeispiel einer erfindungsgemäßen Steckvorrichtung mit einer ersten Ausführung eines erfindungsgemäßen Auslaufstoppventils in einer dreidimensionalen Explosionsdarstellung,
• 1b eine weitere Darstellung zum Ausführungsbeispiel gemäß 1a in einer dreidimensionalen Explosionsdarstellung,
• 2 die erste Ausführung eines erfindungsgemäßen Auslaufstoppventils in einer dreidimensionalen Explosionsdarstellung zusammen mit einer Einsteckhülse,
• 3 den Ventilstößel der ersten Ausführung eines erfindungsgemäßen Auslaufstoppventils in einer gegenüber 2 um 90° gedrehten Lage,
• 4 bis 6 verschiedene Montagephasen der in 2 gezeigten ersten Ausführung eines erfindungsgemäßen Auslaufstoppventils in der Einsteckhülse,
• 7 die erste Ausführung eines erfindungsgemäßen Auslaufstoppventils zu Beginn der Montage in einem Steckerteil,
• 8a und 8b die erste Ausführung eines erfindungsgemäßen Auslaufstoppventils mit komprimierter Feder während zweier aufeinander folgender Phasen der Montage im Steckerteil,
• 9 die erste Ausführung eines erfindungsgemäßen Auslaufstoppventils nach Abschluss der Montage im Steckerteil,
• 10 im Längsschnitt, die in 1a dargestellte Ausführung einer erfindungsgemäßen Steckvorrichtung im Montagezustand mit zwei geöffneten erfindungsgemäßen Auslaufstoppventilen,
• 11 in einer Darstellung wie in 10, die in 1a dargestellte Ausführung einer erfindungsgemäßen Steckvorrichtung nach einer Vormontage oder zu Beginn einer Demontage mit zwei geschlossenen erfindungsgemäßen Auslaufstoppventilen,
• 12a eine vergrößerte Einzelheit an einer speziell ausgestalteten Berührungsstelle von zwei erfindungsgemäßen Auslaufstoppventilen in einer erfindungsgemäßen Steckvorrichtung,
• 12b in einer dreidimensionalen Darstellung, ähnlich wie in 2 und 3, einen Ventilstößel eines erfindungsgemäßen Auslaufstoppventils für eine erfindungsgemäße Steckvorrichtung in einer Ausbildung nach 12a,
• 13 und 14 eine Ventilstößel-Dichtungs-Einheit einer zweiten Ausführung eines erfindungsgemäßen Auslaufstoppventils in zwei dreidimensionalen Darstellungen aus unterschiedlichen Blickwinkeln,
• 15 in Explosionsdarstellung und im Längsschnitt, die in 13 und 14 gezeigte Ventilstößel-Dichtungs-Einheit der zweiten Ausführung eines erfindungsgemäßen Auslaufstoppventils ohne Feder zusammen mit einer Einsteckhülse,
• 16 im Längsschnitt, die Ausführung einer erfindungsgemäßen Steckvorrichtung mit der zweiten Ausführung eines erfindungsgemäßen Auslaufstoppventils im Montagezustand mit zwei geöffneten erfindungsgemäßen Auslaufstoppventilen,
• 17 in einer Darstellung wie in 10, die erfindungsgemäße Steckvorrichtung in der Ausführung nach 16, nach einer Vormontage oder zu Beginn einer Demontage mit zwei geschlossenen erfindungsgemäßen Auslaufstoppventilen,
• 18 und 19 eine Montagephase der zweiten Ausführung eines erfindungsgemäßen Auslaufstoppventils in einem Steckerteil,
• 20 und 21 zwei Darstellungen von Einzelheiten einer erfindungsgemäßen Steckvorrichtung mit der zweiten Ausführung eines erfindungsgemäßen Auslaufstoppventils.

They show:

• 1a an embodiment of a plug device according to the invention with a first embodiment of a discharge stop valve according to the invention in a three-dimensional exploded view,
• 1b a further illustration of the embodiment according to 1a in a three-dimensional exploded view,
• 2 the first embodiment of a drain stop valve according to the invention in a three-dimensional exploded view together with an insert sleeve,
• 3 the valve tappet of the first embodiment of a discharge stop valve according to the invention in a 2 rotated by 90°,
• 4 to 6 different assembly phases of the 2 shown first embodiment of a discharge stop valve according to the invention in the insertion sleeve,
• 7 the first embodiment of a drain stop valve according to the invention at the beginning of assembly in a plug part,
• 8a and 8b the first embodiment of a compressed spring leak stop valve according to the invention during two successive phases of assembly in the plug part,
• 9 the first embodiment of a drain stop valve according to the invention after completion of assembly in the plug part,
• 10 in longitudinal section, which in 1a illustrated embodiment of a plug device according to the invention in the assembled state with two open discharge stop valves according to the invention,
• 11 in a representation as in 10 , which in 1a illustrated embodiment of a plug-in device according to the invention after pre-assembly or at the beginning of disassembly with two closed discharge stop valves according to the invention,
• 12a an enlarged detail of a specially designed contact point of two discharge stop valves according to the invention in a plug device according to the invention,
• 12b in a three-dimensional representation, similar to 2 and 3 , a valve tappet of an inventive discharge stop valve for a plug-in device according to the invention in a design according to 12a ,
• 13 and 14 a valve tappet-seal unit of a second embodiment of a discharge stop valve according to the invention in two three-dimensional representations from different viewing angles,
• 15 in exploded view and in longitudinal section, which are 13 and 14 shown valve tappet seal unit of the second embodiment of a drain stop valve according to the invention without spring together with a plug-in sleeve,
• 16 in longitudinal section, the design of a plug device according to the invention with the second design of a drain stop valve according to the invention in the assembled state with two open drain stop valves according to the invention,
• 17 in a representation as in 10 , the plug-in device according to the invention in the embodiment according to 16 , after pre-assembly or at the beginning of disassembly with two closed discharge stop valves according to the invention,
• 18 and 19 an assembly phase of the second embodiment of a drain stop valve according to the invention in a plug part,
• 20 and 21 two representations of details of a plug device according to the invention with the second embodiment of a drain stop valve according to the invention.

The 1a and 1b to 12a and 12b therefore refer to an embodiment of a plug device according to the invention in a first embodiment and the 13 to 22 on an embodiment of a plug device according to the invention in a second embodiment. The significant difference between the two embodiments lies - as will be explained in more detail below - in particular in the structural design of the respective discharge stop valve according to the invention, in particular of its valve tappet-seal unit.

In the various figures of the drawing, identical parts are always provided with the same reference symbols and are therefore generally described only once, unless otherwise required.

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

In 1a a plug connection 1 according to the invention, which is particularly suitable for the passage of cooling liquid, is shown. The plug connection 1 has a coupling part 2 with a sleeve section 4 and a plug part 8 which can be inserted into the sleeve section 4 with a shaft 6. In particular in the 10 and 11 Accordingly, different states of the plug connection 1 with the plug part 8 inserted into the socket section 4 are shown.

The plug part 8 can be locked or is locked in the coupling part 2 in the inserted state by means of a multi-part holding device 12. The holding device 12 is expediently designed to be radially elastic and engages in a form-fitting manner in an annular groove 10 of the plug part 8 for locking.

In 1a the holding device 12 is only located on the coupling part 2 with the socket section 4. An arrangement of the holding device 12 on both the coupling part 2 and the plug part 8 is in 10 and 11 shown, where 10 shows the locked state.

It is provided that a discharge stop valve 14 is designed in the plug part 8 and in the coupling part 2 and arranged in relation to the other discharge stop valve 14 in such a way that the discharge stop valves 14 open each other when plugged in and locked. A discharge stop valve 14 is in 1a (right) shown in its individual parts, another (left) as part of a valve package 15 designed as a press-in cartridge for the coupling part 2. The intended arrangement of the discharge stop valves 14, as intended for mutual interaction, is again based on 10 and 11 The 4 to 6 show the assembly of the valve package 15.

1b concerns the same version as 1a , whereby only the conditions at connector part 6 (right side of 1a) The exploded view is slightly different from that in 1a chosen insofar as it also illustrates more clearly how the discharge stop valve 14 is mounted in the plug part 6, namely by introducing a closing spring 16 from one side and introducing a valve tappet 24 from the other side. This is explained in detail below using the 7 to 9 presented in more detail.

The discharge stop valves 14 are in a separated and/or pre-assembled state of the plug part 8 relative to the coupling part 2, as in 11 shown, closed. It is provided that the closure of the outlet stop valves 14 is brought about and maintained by the closing spring 16.

As particularly in the 7 to 11 As shown, both the coupling part 2 and the plug part 8 each have a flow channel 18, 20 with a discharge stop valve 14 arranged in this flow channel 18, 20. Each of the two discharge stop valves 14 has a valve tappet 24 which is axially movable in the respective flow channel 18, 20 and sealingly interacts with a valve seat 21. The valve tappet 24 is in its first special embodiment - enlarged compared to 1a and 1b - as a single part also in 2 and 3 shown.

When the plug part 8 is inserted into the coupling part 2, the valve tappets 24 of the two discharge stop valves 14 are arranged along the flow channel 18, 20 opposite one another with respect to the longitudinal axis XX in such a way that they abut one another at the front with abutting surfaces 26. It is intended that this mutual arrangement of the valve tappets 24 of the two discharge stop valves 14 both in the pre-assembly position, with an at least partially inserted shaft 6 of the plug part 8 in the sleeve section 4 of the coupling part 2 ( 11 ), as well as in the fully inserted and locked state of the plug part 8 relative to the coupling part 2 ( 10 ) is present.

To close the discharge stop valve 14, the valve tappet 24 is provided with a valve head 28. The valve head 28 has a head seal 29, for the reception of which the at least one circumferential head seal groove 27 on the valve head 28, which opens radially outwards towards the valve seat 21, is provided. A conical introduction section 25 is arranged on the valve head 28.

A corresponding valve seat 21 has a correspondingly designed sealing surface designated by the reference number 22. To close the check valve 14, the valve tappet 24 or the valve head 28 formed on the valve tappet 24 can be moved axially relative to the respective flow channel 18, 20 in such a way that the head seal 29 of the valve head 28 and the sealing surface 22 of the valve seat 21 can be transferred into a sealing position, whereby a fluid located in the flow channel 18, 20 cannot escape through the outlet stop valve 14 from the plug part 8 or from the coupling part 2.

In particular, 10 the inserted and locked state, i.e. the inserted arrangement of the plug part 8 with its shaft 6 in the socket section 4 of the coupling part 2, wherein at the same time the plug part 8 is locked to the coupling part 2 by means of the holding device 12. The outlet stop valves 14 are open.

With regard to a pre-assembly state or a state at the beginning of a disassembly, 11 instead, it can be seen that the plug connection 1 is partially separated, so that the locking by means of the holding device 12 is released and the plug part 8 with its shaft 6 is partially pulled axially out of the sleeve section 4 of the coupling part 2, but a remaining section of the shaft 6 of the plug part 8 still remains in the sleeve section 4 of the coupling part 2.

Expediently, the axial displacement of the plug part 8 from the fully inserted state to the partially inserted pre-assembly state is sufficient for the outlet stop valves 14 to assume their closed position and prevent fluid flow or fluid leakage from the respective flow channel 18, 20. An opening gap designated by the reference numeral 31 between the coupling part 2 and the plug part 8 is in 11 in the plane of a main seal 30 arranged between the coupling part 2 and the plug part 8 (individual illustration of the main seal 30 also in 1 ) can be recognized.

According to the first embodiment of the invention, radially elastically inwardly springable arms 33 are formed on the valve tappet 24, which are located on a circumference of an annular collar 34 interrupted by slots and projecting radially from the base of the valve tappet 24. The slots are (for reasons of clarity only in 3 and 12 ) is designated by the reference numeral 32. The slots 32 advantageously make it possible to change the diameter of the annular collar 34.

In this way, in the first embodiment, the inventive concept can be realized that the valve tappet 24 (in structural unit with the head gasket 29 arranged on the valve head 28) is radially dimensioned and elastically deformable in such a way that an effective outer diameter during assembly in a non-deformed state is larger than the diameter of an assembly opening ( 6 ) and in the deformed state smaller than or equal to the diameter of the mounting hole ( 4 ) is.

According to a special embodiment, the valve seat 21 is formed in a sleeve 40, as shown by way of example in 2 to 6 as well as 10 and 11 is shown. 3 to 6 illustrate the assembly of the discharge stop valve 14 according to the invention in the insertion sleeve 40 to form a valve package 15, as is also shown in 1a is shown. 10 and 11 (upper part) show how the insert sleeve 40 with the discharge stop valve 14 mounted therein is mounted in the socket section 4 of the coupling part 2.

To assemble the discharge stop valve 14 according to the invention in the insertion sleeve 40, the arms 33 formed on the valve tappet 24 and springable radially inward are first pushed in the direction of the 4 arrows marked with the reference symbol P - starting from a non-deformed state DAG33 of the outer diameter ( 6 ), which is larger than the inner diameter DI40 of the assembly opening in the insertion sleeve 40 - to a deformed state DAM33, where the outer diameter is smaller than or equal to the diameter DI40 of the assembly opening. In this way, the spring-loaded arms 33 formed on the valve tappet 24, which are pressed radially inward in an elastic manner, can be pushed through the insertion sleeve 40 ( 4 ) and also by the closing spring 16 ( 5 ) until they are elastically adjusted to the outside diameter in the non-deformed state DAG33 ( 6 ), whereby the arms 33 engage in particular behind the closing spring 16. As a result, the valve tappet 24 is held on one side in the insertion sleeve 40, whereby on the other side a fixation is achieved by the previously ( 4 ) head gasket 29 arranged on the valve head 28 ( 6 ). The closing spring 16 is supported on its side facing the valve head 28 on the valve seat 21 formed by the insertion sleeve 40, in which the assembly opening is also formed. A radially projecting contact surface 23 serves this purpose.

As also particularly 4 to 6 show, the arms 33 of the valve tappet 24, which can be spring-loaded radially inwards, can, in a preferred embodiment, run out at their free ends - as already mentioned - into locking hooks 36, which on their side facing away from the impact surface 26 not only provide a contact surface 37 for the closing spring 16, but can also lock with the closing spring 16. At least some of the arms 33 of the valve tappet 24, which can be spring-loaded radially inwards, are thus - and in a particularly preferred embodiment - locking arms.

As in 7 to 9 As shown, the discharge stop valve 14 according to the invention can be installed in the shaft 6 of a plug part 8 in a similar manner. To do this, the arms 33 formed on the valve tappet 24, which can be sprung radially inwards, are firstly - starting from a non-deformed state DAG33 ( 7 , 9 ) of the outside diameter which is larger than the inside diameter DI6 of the mounting hole in the shaft 6 - in the direction of 7 with the arrows marked with the reference symbol P to a deformed state radially inward, where the outer diameter DAM33 ( 8a and 8b) smaller than or equal to the diameter DI6 of the assembly opening (and also smaller than or equal to the inner diameter of the closing spring 16 designed as a helical spring). Thus, the springable arms 33 formed on the valve tappet 24 and pressed radially inward in an elastic manner can be pushed in the axial assembly direction M through the valve seat 21 in the shaft 6 and also through the closing spring 16 already placed in the shaft 6 (in the drawing above the valve seat 21) ( 8a and 8b) until they are elastically adjusted to the outer diameter in the undeformed ground state DAG33 ( 9 ), whereby the arms 33 engage behind the closing spring 16 and preferably lock with it.

As a result, the valve tappet 24 is held on one side in the insert sleeve 40 mounted in the shaft 6, while on the other side it is fixed by the previously ( 7 ) head gasket 29 arranged on the valve head 28 ( 9 ), and the closing spring 16 is supported on its side facing the valve head 28 on a contact surface 23 on the valve seat 21. 10 and 11 (lower part) show how the insert sleeve 40 with the discharge stop valve 14 mounted therein is mounted in the shaft 6 of the plug part 8.

In order to lock the plug connection 1 according to the invention ( 10 ) increased safety, for example against blockage due to undesired displacement of the parts contained therein, and in particular to prevent the valve tappet 24 from slipping in the axial direction XX after, for example, the abutting abutting surfaces 26 of the spring arms 33 rotate against each other so that the spring arms 33 of one discharge stop valve 14 engage in the slots 32 of the other discharge stop valve 14, further advantageous and technical measures can be implemented in the plug connection 1 according to the invention, which 12a and 12b illustrate explicitly.

So - as in 12a and 12b shown - wedge elements 50 arranged alternately around the circumference of the spring-loaded arms 33 on the valve tappet 24 can be provided, which prevent the valve tappets 24 of the two abutting discharge stop valves 14 from rotating against each other by engaging in the slots 32 between the radially elastically engage the inside spring-loaded arms 33 of the valve tappet 24 of the other discharge stop valve 14 and close these slots 32 again at the end.

How 12b shows, in this version - in contrast to the version in 3 There are only three spring-loaded arms 33, and these are not designed as locking arms.

Finally, according to the invention, a fluid volume lost when opening a plug connection 1 according to the invention, i.e. a dead volume between the sealing areas which drips out after the connection is opened, can be minimized. Thus, axially extending recesses 38, 39 can be provided in the valve head 28 and/or in the plug-in sleeve 40, which are opened in particular against the flow direction of the fluid, as is particularly the case 4 to 6 , but also 10 and 11 These recesses 38, 39 serve to minimize material and to avoid undesirable material accumulations. Such material accumulations would cause the respective part to warp when cooling. The fluid volume that collects in these recesses 38, 39 when the fluid flows in - either from the side of the coupling part 2 with the sleeve section 4 or from the side of the plug part 8 - can - at least if the conditions specified in 10 and 11 shown vertical installation position - if the recesses 38, 39 are on the "wet" side, i.e. the inflow side of the fluid. On the other hand, recesses would instead increase the dead volume. Even if a plug connection 1 according to the invention is not installed vertically, a lost fluid volume is minimized by the effectiveness of capillary forces in the recesses 38, 39.

The 13 to 21 The embodiment of a plug device according to the invention in a second embodiment shown has - apart from the features of the outlet stop valve 14 - the same basic structure as the one in 1a and 1b illustrated embodiment of a plug device according to the invention in the first embodiment.

The plug connection 1 has a coupling part 2 with a socket section 4 and a plug part 8 that can be inserted into the socket section 4 with a shaft 6. In particular in the 16 and 17 Accordingly, different states of the plug connection 1 with the plug part 8 inserted into the socket section 4 are shown. As these figures also illustrate, the plug part 8 can be locked or is locked in the coupling part 2 in the inserted state by means of a multi-part holding device 12. Expediently - as in the first embodiment - the holding device 12 is designed to be radially elastic and engages in the annular groove 10 of the plug part 8 in a form-fitting manner for locking ( 16 ).

As in the first embodiment, it is provided that a discharge stop valve 14 is formed in the plug part 8 and in the coupling part 2 and arranged in relation to the other discharge stop valve 14 in such a way that the discharge stop valves 14 open each other when plugged in and locked. The discharge stop valve 14 of the second embodiment differs from a discharge stop valve 14 as in 1a (right) in its individual parts, by which below, particularly with reference to 13 to 15 , explained features. This second version of the discharge stop valve 14 - just like in 1a (left) - be part of a valve package 15 designed as a press-in cartridge for the coupling part 2.

The arrangement of the discharge stop valves 14 to each other, as they are intended for mutual interaction, is based on 16 and 17 out.

18 and 19 show by way of example the special assembly phase of the second embodiment of the discharge stop valve 14 in a plug part 8, which is characteristic of the invention.

The discharge stop valves 14 in the plug part 8 and the coupling part 2 are in a separated and/or in a pre-assembled state of the plug part 8 relative to the coupling part 2, as shown in the 16 shown, closed. It is provided that the closure of the outlet stop valves 14 is brought about and maintained by a closing spring 16.

As in particular in 7 to 11 As shown, both the coupling part 2 and the plug part 8 each have a flow channel 18, 20 with a discharge stop valve 14 arranged in this flow channel 18, 20. Each of the two discharge stop valves 14 has a valve tappet 24 which is axially movable in the respective flow channel 18, 20 and which cooperates sealingly with a valve seat 21. The valve tappet 24 is shown in various views as an individual part, also in 13 to 15 shown.

When the plug part 8 is inserted into the coupling part 2, the valve tappets 24 of the two discharge stop valves 14 are arranged along the flow channel 18, 20 opposite one another with respect to the longitudinal axis XX in such a way that they abut one another at the front with abutting surfaces 26. It is intended that these mutual arrangement of the valve tappets 24 of the two discharge stop valves 14 both in the pre-assembly position, with an at least partially inserted shaft 6 of the plug part 8 in the socket section 4 of the coupling part 2 ( 17 ), as well as in the fully inserted and locked state of the plug part 8 relative to the coupling part 2 ( 16 ) is present.

To close the discharge stop valve 14, the valve tappet 24 is provided with a valve head 28. The valve head 28 has a head seal 29. The corresponding valve seat 21 has a sealing surface designated by the reference number 22. To close the check valve 14, the valve tappet 24 or the valve head 28 formed on the valve tappet 24 can be moved axially relative to the respective flow channel 18, 20 in such a way that the head seal 29 of the valve head 28 and the sealing surface 22 of the valve seat 21 can be transferred into a sealing position.

In particular, 16 - as well as 10 for the first embodiment - the inserted and locked state, i.e. the inserted arrangement of the plug part 8 with its shaft 6 in the socket section 4 of the coupling part 2, whereby at the same time the plug part 8 is locked to the coupling part 2 by means of the holding device 12. The outlet stop valves 14 are open.

With regard to a pre-assembly state or a state at the beginning of a disassembly, 17 - as well as 11 for the first embodiment - instead, it can be seen that the plug connection 1 is partially separated, so that the locking by means of the holding device 12 is released and the plug part 8 with its shaft 6 is partially pulled out axially from the sleeve section 4 of the coupling part 2, but a remaining section of the shaft 6 of the plug part 8 still remains in the sleeve section 4 of the coupling part 2.

Expediently, the axial displacement of the plug part 8 from the fully inserted state to the partially inserted pre-assembly state is sufficient for the outlet stop valves 14 to assume their closed position and prevent fluid flow or fluid leakage from the respective flow channel 18, 20. A stroke designated by the reference symbol H between the coupling part 2 and the plug part 8 is in 17 can be seen on each side of the closing springs 16.

In contrast to the first embodiment of the invention, no radially elastically inwardly springable arms 33 are formed on the valve tappet 24, but the annular collar 34 with the abutment surfaces 26, which protrudes radially from the valve tappet 24 at the base, is not slotted, thus has a closed circumferential contour. The abutment surfaces 26 of two discharge valves 14 according to the invention arranged complementarily to one another can thus lie against one another over their entire surface in the assembled state. Therefore, in a plug connection according to the invention, no wedge element 50 is necessary, as is optionally present in 12a and 12b shown for the first version.

The closing spring 16 is again designed as a helical spring such that it is arranged coaxially on the respective valve tappet 24. It surrounds the valve tappet 24, with the valve tappet forming an inner guide for the closing spring, so that breaking of the closing spring 14 in the event of compression is prevented or limited. In this case, the spring guide - analogous to the springable arms 33 of the first embodiment - can be implemented by several, in particular four, webs 41 evenly distributed over the circumference of the valve tappet 24, on which the closing spring 16 rests surrounding the valve tappet 24.

In the second embodiment, the inventive concept that the valve tappet 24 (in structural unit with the head seal 29 arranged on the valve head 28) is radially dimensioned and elastically deformable such that an effective outer diameter during assembly in a non-deformed state is larger than the diameter of an assembly opening and in the deformed state is smaller than or equal to the diameter of the assembly opening, is realized by the design of the head ring seal 29. In this regard, particular reference is made to 15 as well as 18 to 20 referred to.

First, however, it should be noted that in the second embodiment, according to a special embodiment, the valve seat 21 can also be formed in an insert sleeve 40, as shown by way of example in 15 as a single part and in 16 and 17 in the upper part as well as in 21 in a state mounted in the socket section 4 of the coupling part 2.

The installation of the discharge stop valve 14 according to the invention in the shaft 6 of a plug part 8 is just as possible in the second embodiment as in the first embodiment, for which reference is made in particular to 18 and 19 The assembly in a plug-in sleeve 40 and directly in the plug part 8 is carried out analogously to one another.

The second embodiment is characterized by the fact that the valve tappet 24 is provided with an elastic head seal 29 on its valve head 28. which in particular has an external shape in the form of a truncated cone, a mushroom head, a spherical cap, a paraboloid of revolution or a similar hat-like body of revolution and an internal (not further specified) cavity for receiving the valve tappet 24, in particular its valve head 28.

The conical insertion section 25 on the valve head 28 mentioned in the first embodiment is formed by the elastic head seal 29.

As already mentioned, the elastic head seal 29 can preferably be manufactured in a multi-component injection molding process with the valve tappet 24, whereby a thermoplastic elastomer (TPE) is preferably used for the head seal 29 and thus the above-mentioned advantages come into play. In this case, the "soft" elastic head seal 29 is adhesively bonded to the valve head 28, which consists of a non-elastic "hard" plastic material.

However, this can be supported in a form-fitting manner by - as in the first embodiment - at least one - in the exemplary embodiment two - circumferential head gasket groove(s) or similar other holding structures being formed on the valve head 28.

In particular in the case of two head gasket grooves, it is possible to set the best possible interlocking of the soft and hard components by optimizing their geometry, in particular their respective groove depth and width as well as their distance from one another and the height of the wall between them, with regard to the hold of the seal 29 on the valve head 28 and with regard to a high deformability in one direction required during assembly and then a low deformability in the other direction required in the assembled state. This can also prevent migration of the soft and hard components against each other in the long term.

The effective outer diameter when assembling the second version is the largest diameter of the elastic head gasket 29. This is in a non-deformed state, as it exists before and after assembly, 13 to 17 as well as 20 and is designated with the reference symbol DAG29. The largest diameter DAG29 of the elastic head gasket 29 in the non-deformed state is larger than the diameter DI40 of the assembly opening of the insertion sleeve 40 ( 15 to 17 ) and also larger than the diameter DI40 of the mounting opening of the insertion sleeve 40 ( 15 to 17 ) and also larger than the diameter DI6 of the mounting hole in the shaft 6 of the plug part 8 ( 16 and 17 ). The mounting opening is located - as in the first version - in the valve seat 21.

In the deformed state, as it is immediately present during assembly, which in 18 and 19 for the plug part 8, but these figures are also representative of an assembly in the insertion sleeve 40, the largest diameter DAM29 of the elastic head seal 29 in the deformed state is smaller than or equal to the diameter of the assembly opening DI6 (and also DI40 in the case of the insertion sleeve 40).

When the assembly unit comprising the valve tappet 24 and head gasket 29, on which the closing spring 16 which can be mounted from the seal side is already placed, is pushed into the valve seat 21, the head gasket 29 deforms elastically in the direction of the arrows P due to the wedge effect which is exerted on the essentially conical outer shape of the head gasket 29 by the force applied for assembly M when entering the assembly opening. The diameter reduction (DAG29 to DAM29) of the gasket 29 is preferably carried out by bending a flange section 42 which rests against the outer contour of the valve head 28 during assembly M. In particular, the dimensioning of the material thickness of the flange section 42 can advantageously influence the level of force which has to be applied for assembly M.

For example, a wider groove in the vicinity of the rim section 42, as shown, which is filled with the soft component compared to the other groove in the area of the tip of the valve head 28, causes the material of the rim section 42 to be easily displaced into a free space radially above the groove during the deformation taking place for assembly M.

Instead, the other groove in the area of the tip of the valve head 28 can be narrower but deeper than the groove in the vicinity of the rim section 42, for example in the sense of a firm connection between the seal 29 and the head 28 - as shown.

After assembly, the maximum diameter DAG29, which has returned to its non-deformed state and is preferably formed on the flange section 42 of the head gasket 29, acts like a barb and prevents the head gasket 29 from moving back through the assembly opening. Bending the flange section 42 into the bend during assembly M opposite direction is not possible, so that system pressures can also be maintained. In particular, the hard component of the wall between the grooves together with the soft component in the groove in the vicinity of the flange section 42 forms a block that counteracts the seal deformation.

In addition, the valve tappet 24 is held by the closing spring 16, which can expand after assembly and which is clamped between the contact surface 37 on the valve tappet 24 on the one hand and the contact surface 23 on the valve seat 21 on the other hand.

A particular advantage of the second embodiment of the discharge stop valve 14 according to the invention is that it can be mounted completely from one side in a socket section 4 of a coupling part 2 or in a plug part 8.

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 partial feature can also have an inventive significance in itself, separated from all other partial features. For example, the two embodiments of the plug-in valve 14 according to the invention can be used together in a plug-in connection 1 according to the invention.

Furthermore, the invention is not yet limited to the combinations of features defined in the independent claims, but can also be defined by any other combination of specific features of all the individual features disclosed overall. This means that in principle practically every individual feature of the independent claims can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.

The person skilled in the art can also add further useful technical features within the scope of the claims without departing from the scope of the invention.

For example, as can be seen in particular from 20 As can be seen, the sealing surface 22 of the valve seat 21 can be conical and/or stepped in order to pre-center the valve head 28, in particular the head gasket 29 located there.

Also, for example, how 2 and 15 show, the outer peripheral surface of the insertion sleeve 40 is given a contour 60 which, as shown, is particularly suitable for holding and sealing in the flow channel 18/20 of the coupling part 2 with the socket section 4 and/or the plug part 8, in particular due to the presence of grooves and teeth. For example, a ring seal 46 can be placed at this point, as is 16 and 17 show.

Finally, it has not yet been mentioned that the insertion sleeve 40 forming a valve seat 21 is preferably arranged in the respective flow channel 18, 20 in such a way that the valve seat 21 is supported axially, at least in an inserted and locked state of the plug part 8 in the coupling part 2, on a stepped surface, which is formed in an inner circumferential surface of the flow channel 18, 20, in particular perpendicular to the flow channel 18, 20. Such stepped surfaces are in 10 and 11 as well as 16 and 17 in the socket section 4 is marked with the reference number 45.

21 further illustrates that through the structural design of the plug connection 1 according to the invention, in particular of axial lengths of the coupling part 2 with the socket section 4, optionally of the insert part 40 and/or the plug part 8, a plug-in path W of the plug shaft 6 in the socket section 4 can be provided, as well as preferably also a path limitation WB for the axial movement of the mutually abutting ( 10 , 16 ) or spaced apart ( 11 , 17 ) Drain stop valves 14 in the plug connection 1 according to the invention. For example, the end faces of the sleeve section 4, insert part 40 and/or plug shaft 6 can serve as stops for the contact surfaces 36 of the valve tappet 24 for the closing springs 16. The general advantage of such stops is that for the compressed state, i.e. when the connection is plugged in, the remaining axial play caused by stroke tolerances of the two tappets 24 under the influence of the flow forces no longer includes spring tolerances in the tolerance chain and is therefore better restricted.

List of reference symbols

1

Plug connection

2

Coupling part of 1

4

Socket section of 2

6

Shaft of 8

8

Plug part of 1

10

Ring groove of 8

12

Holding device for 2, 8

14

Drain stop valve in 1

15

Valve package of 14 and 40

16

Closing spring of 14

18

Flow channel of 2

20

Flow channel of 8

21

Valve seat in 2 / 8

22

Sealing surface of 21 for 28

23

Investment area of 21 for 16

24

Valve tappets of 14

25

Introductory section at 28

26

Impact area of 24 for 14

27

Head ring seal groove 28 for 29

28

Valve head of 14 (24)

29

Head gasket on 28

30

Main seal between 2 and 8

31

Opening gap between 2 and 8 ( 11 )

32

Slot in 34

33

Spring arms of 24 (first version of 14)

34

Ring collar at 24

36

Investment area of 24 for 16

37

Latch hook at 33

38

Recess in 28

39

Recess in 40

40

Insert sleeve for 14

41

Bridge of 24 (second version of 14)

42

Brim section of 29 with DAG29 (second version of 14)

45

Step area in 4 for 40

46

Ring seal around 40

50

Wedge element in 1 ( 12a , 12b)

60

Contour of 40

DAG29

Outside diameter of 29 in the undeformed state

DAM29

Outer diameter of 29 in deformed state

DAG33

Outside diameter of 33 in the undeformed state

DAM33

Outer diameter of 33 in deformed state

DI40

Diameter mounting hole of 40

DI6

Inner diameter of 6

H

Stroke between 2 and 8 ( 17 )

M

Mounting direction from 24 in 40 / 6 ( 4 , 7 , 18 , 19 )

P

Compression direction of 33 / 29 ( 4 , 7 , 18 , 19 )

W

Plug-in path for 6 in 4 ( 21 )

WB

Path limitation for 14 in 1

X-X

Longitudinal axis of 2, 8, 14

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• EP 0568076 B1 [0004]

Claims (14)

Discharge stop valve (14), in particular for a plug connection (1) for the passage of cooling liquid, with a valve tappet (24) which is axially movable in a flow channel (18, 20) of the plug connection (1) and which cooperates sealingly with a valve seat (21), with a head seal (29) arranged on a valve head (28) of the valve tappet (24) for fluid-tight closing of the flow channel (18, 20) and with a closing spring (16) which acts on one side on the valve tappet (24) and can be fixed on the other side in the flow channel (18, 20), characterized in that the valve tappet (24) in a structural unit with the head seal (29) arranged on the valve head (28) is radially dimensioned and elastically deformable in such a way that an effective outer diameter during assembly in a non-deformed state (DAG29, DAG33) is larger than the diameter (DI6, DI40) of a mounting opening and in a deformed state (DAM29, DAM33) is smaller than or equal to the diameter (DI6, DI40) of the mounting opening. Drain stop valve (14) after Claim 1 , characterized in that an abutment surface (26) for a further discharge stop valve (14) is formed on an annular collar (34) projecting radially from the valve tappet (24), wherein the annular collar (34), in particular on the rear side of the abutment surface (26), has a contact surface (36) for the closing spring (16) such that the closing spring (16) is braced against a restoring force between the respective contact surface (36) and a clamping surface (23) of the respective valve seat (21), at least when inserted and locked into a plug part (8) or coupling part (2) of a plug connection (1). Drain stop valve (14) after Claim 1 or 2 , characterized in that the valve tappet (24) has several, preferably four, radially elastically inwardly springable arms (33), preferably locking arms. Discharge stop valve (14) after one of the Claims 1 until 3 , characterized in that the external diameter effective during assembly is the largest external diameter (DAG33, DAM33) of a circumference of a/the annular collar (34) projecting radially from the valve tappet (24) around the radially elastically inwardly springable arms (33) of the valve tappet (24), wherein the annular collar (34) has a slot (32). Discharge stop valve (14) after one of the Claims 1 until 3 , characterized in that the effective outer diameter during assembly is the largest outer diameter (DAG29, DAM29) of the head ring seal (29). Discharge stop valve (14) after one of the Claims 1 until 5 , characterized in that the valve head (28) is provided with an elastic head seal (29), preferably consisting of a thermoplastic elastomer, which in particular has an external shape in the form of a truncated cone, a mushroom head, a spherical cap, a paraboloid of revolution or a similar hat-like body of revolution and an internal cavity for receiving the valve tappet (24). Drain stop valve (14) after Claim 6 , characterized in that a reduction of the outer diameter (DAG29) in the non-deformed state of the head gasket (29) to the diameter (DAM29) effective during assembly (M) in the deformed state is achieved by bending a flange section (42) of the head gasket (29) during assembly (M), wherein the flange section (42) rests against an outer contour of the valve head (28). Drain stop valve (14) after Claim 6 or 7 , characterized in that the head gasket (29) in the assembled state, even under the system pressure of the fluid, is prevented from moving back against the assembly direction (M) and from reducing the outer diameter (DAG29) from the non-deformed state of the head gasket (29) by a/the flange section (42) of the head gasket (29). Discharge stop valve (14) after one of the Claims 1 until 8 , characterized in that the closing spring (16) is designed as a helical spring such that it is arranged coaxially on the respective valve tappet (24). Discharge stop valve (14) after one of the Claims 1 until 9 , characterized in that a spring guide for the closing spring (16) is formed by the arms (33) which can be resiliently sprung radially inwards or by webs (41) of the valve tappet (24) which are evenly distributed over the circumference. Plug connection (1), in particular for the passage of cooling liquid, comprising a coupling part (2) with a sleeve section (4) and a plug part (8) which can be inserted into the sleeve section (4) with a shaft (6), wherein the plug part (8) is locked in the coupling part (2) in the inserted state by means of a holding device (12), wherein in each case in the plug part (8) and in the coupling part (2) a discharge stop valve (14) is designed and arranged in relation to the other discharge stop valve (14) in such a way that the discharge stop valves valve (14) open to one another in the inserted and locked state and are closed in a separated and/or pre-assembled state of the plug part (8) relative to the coupling part (2) - due to a respective closing spring (16), wherein each discharge stop valve (14) has a valve tappet (24) which is axially movable in a flow channel (18, 20) and cooperates sealingly with a valve seat (21), wherein the valve tappets (24) are arranged axially aligned opposite one another along the flow channel (18, 20) in such a way that they abut one another at the end with abutting surfaces (26), wherein for fluid-tight closing of the check valve (14) a valve head (28) of the valve tappet (24) has a head seal (29) and the valve seat (21) has a correspondingly designed sealing surface (22), characterized in that at least one discharge stop valve (14) has a Discharge stop valve (14) after one of the Claims 1 until 10 is. Plug connection (1) to Claim 11 , characterized in that at least one valve seat (21) is designed as an insertion sleeve (40) and is arranged in the respective flow channel (18, 20) in such a way that the valve seat (21), at least in an inserted and locked state of the plug part (8) in the coupling part (2), is axially supported on a step surface (45), which is formed in an inner peripheral surface of the flow channel (18, 20), in particular perpendicular to the flow channel (18, 20). Plug connection (1) to Claim 11 or 12 , characterized in that a/the mounting opening for the outlet stop valve (14) is formed by a valve seat (21) in the flow channel (18, 20) of the sleeve section (4) of the coupling part (2), the shaft (6) of the plug part (8) or in a/the insertion sleeve (40). Plug connection (1) according to one of the Claims 11 until 13 , characterized in that through the structural design of axial lengths of the coupling part (2) with the sleeve section (4), optionally the insert part (40) and/or the plug part (8), a plug-in path (W) of the plug shaft (6) in the sleeve section (4) is provided, and preferably also a path limitation (WB) for the axial movement of the discharge stop valves (14) which are adjacent to one another or spaced apart from one another, wherein in particular (the) end faces of the sleeve section (4), insert part (40) and/or plug shaft (6) form stops for (the) contact surfaces (36) of the valve tappet (24) for the closing springs (16).

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