Connection adapter

Abstract

System (100) comprising a connection (19) and a connection adapter (0) for connecting and disconnecting a maintenance station to a service valve (1) of an external system in which a working fluid circulates in a closed circuit, in particular an air conditioning system, with a connection (19) through which pressurized working fluid from the maintenance station can be fed into the connection adapter (0) for filling or through which pressurized working fluid can be discharged, with a dead space (21) which is vented via a vent path even when the service valve (1) is coupled to the connection adapter (0), wherein the connection (19) has a rotatable connection part (47), with a servo chamber (20) which is fluidically connectable to the connection (19) and in which a servo piston (8) is accommodated for opening and closing the vent path, which is forced by an overpressure present in the servo chamber (20) towards its position closing the vent path, and with a valve spindle (10)which actuates a first valve element (10.1) and a second valve element (10.2), wherein the first valve element (10.1) is designed and positioned such that, when the valve spindle (10) moves to open the service valve (1), it fluidly connects the servo chamber (20) to the port (19), and the second valve element (10.2) is designed and positioned such that it only opens and fluidly connects the dead space (21) to the servo chamber (20) after the servo piston (8) has reached a position closing the vent path, and with a retainer (10.5) for opening the spring valve insert (29) forming a component of the service valve (1), which is designed and arranged such that it only opens the spring valve insert (29) after the servo piston (8) has reached a position closing the vent path.

Description

FIELD OF THE INVENTIONThe invention relates to a system comprising a connection and a connection adapter for docking and docking a maintenance station to a service valve according to the preamble of claim 1 or claim 2.BACKGROUND ARTSo-called connection adapters are often used for the secure production of a detachable flow path between two fluid systems, wherein usually one system is equipped with these connection adapters in each case.For example, evacuation, filling and service and maintenance stations for motor vehicle air conditioners (motor vehicle=vehicle) are equipped with such connection adapters in order to be able to safely carry out the filling with refrigerant, the discharging of the refrigerant, the evacuation or also service activities on motor vehicle air conditioners.In modern motor vehicle air conditioners, CO 2 which is often more environmentally compatible is currently used as refrigerant. The CO 2 as refrigerant for motor vehicle air conditioners is an environmentally friendly alternative to the heretofore frequently used refrigerant tetrafluoroethane (also: R134a). CO 2 is significantly more environmentally compatible here, has a high cooling power, is non-combustible, does not form decomposition products and is available economically worldwide. In refrigeration technology, the natural refrigerant carbon dioxide (CO 2) is designated by the abbreviation R744. In order to have the CO 2 available in the required liquid state, however, this must be exposed to a significantly higher pressure-in comparison with tetrafluoroethane-which can lead to dangerous conditions for operating personnel during the filling or discharging of the CO 2 as refrigerant.In general, due to the environmental damage when releasing refrigerants and / or the danger to the operating personnel by the automobile industry and the motor vehicle handpiece, high demands are placed on the properties of connection fittings such as the connection adapters addressed. The use of the environmentally compatible CO 2 as refrigerant has exacerbated these requirements once again on account of the very high pressure situation addressed. Accordingly, such connection fittings are / must be provided, for example:having a pressure relief function;a self-alignment function of the valve presser;a separate and unique function for opening and closing a service valve;when the flow path is open, it cannot be detached from the service valve;a locking mechanism for securely connecting to a service valve;- can be identified unambiguously for the assignment to the high pressure or low pressure of a fluid system to be connected;ensuring secure locking on a valve body before the hydraulic opening;a pull-off force in the locked state of more than 5,000 N;requiring a maximum force for withdrawal of less than 50 N after hydraulic closing;reliable if the service valve is not connectedensuring that no fluid (refrigerant) can leak;preventing mechanical decoupling from the service valve when the flow path is open;at least for 5,000 plugging cycles;a vent of the dead space between the connection adapter and the service valve, in order to reduce the pressure after the flow path has been interrupted and before the decoupling, and to be able to detect an incorrectly closing valve insert in the service valve;ensuring the pressure reduction via the connecting fittings or via the service device, anda defined pen depression position;a precisely defined space and path until the "seal break" and until the service valve is completely opened are maintained.These requirements require in some cases very contrary functions, so that they are not implemented in their entirety by any known solution to date.The majority of the solutions to date additionally have no durability of the sealing systems and at the same time high tightness during operation. This is particularly true even at high system pressures, which must be used to handle 2 in the case of CO. In particular, the diametrical requirement of opening and closing a flow path and venting of the dead space and the requirement that no refrigerant must escape when the service valve is decoupled result in most solutions not having a pressure relief function and venting of the dead space.At best, such connection fittings can only be used at service stations which have their own pressure relief function. Solutions which represent both functions force compromise in the dimensioning of the necessary sealing elements on account of the available path for opening / closing the flow path or venting, as a result of which durability is limited. Further solutions which meet both of the above-mentioned requirements require a second energy source.OBJECT OF THE INVENTIONAgainst this background, the object of the invention is to concretize to the effect that a connection fitting is to be specified, with which a temporary, high-pressure flow path between two fluid systems can be produced reliably and preferably without tools.SOLUTION ACCORDING TO THE INVENTIONA solution to this object is provided by the main claim 1.According to the invention, a system comprising a connection adapter and a connection is provided for this purpose.For this purpose, a connection adapter according to the invention for docking and docking a maintenance station to a service valve of an external installation, in which a working fluid circulates in an at least substantially closed circuit, in particular an air conditioning system, ideally in the form of a vehicle air conditioning system, is proposed. The mentioned maintenance station can also be an evacuation station, filling station, measuring station and / or service station, for example. For the sake of simplicity, such a station is referred to below only as a "maintenance station". In the foreign installation mentioned-particularly preferably in the form of a vehicle air conditioning system-a working fluid circulates in an at least substantially closed circuit, wherein a time-dependent leakage which exists in real installations is also always included here. In addition, such a foreign system also comprises a system in which the working fluid is not yet circulating in a closed circuit, but is intended to circulate immediately, which is the case, for example, when the foreign system is first filled with working fluid.The system according to the invention comprises a connection via which-during the filling process-pressurized working fluid can be fed from the maintenance station into the connection adapter, pressurized fluid can be discharged into the maintenance station or a reduced pressure can be generated during the evacuation process. According to the invention, the connection has a rotatable connection part.In addition, the connection adapter according to the invention comprises a dead space-preferably between the connection adapter and the service valve-which is also ventilated via a venting path when the service valve is coupled to the connection adapter; at least as long as the check valve dedicated to it is still closed. Timely venting of the dead space increases the safety during decoupling. Moreover, notice is taken early and even before something can happen if the spring valve insert should not have been expected to have closed.The connection adapter according to the invention also comprises a servo space which can be connected fluidically to the connection and can also be disconnected from the connection again. In this servo space, a servo piston for opening and closing the vent path is accommodated. This servo piston is urged in the direction of its position closing the venting path in the event of an overpressure prevailing in the servo chamber.The connection adapter according to the invention also comprises a valve spindle which actuates a first valve element and a second valve element. In this case, the valve spindle preferably itself forms the valve elements; ideally even integrally in one piece.In this case, the first valve element is designed and positioned such that, when the valve spindle is moved in order to initiate the impact of the service valve or by a further component for impact of the service valve, it fluidically connects the servo chamber to the connection. The "pushing open" of the service valve is preferably synonymous here with the pushing open of the spring valve insert of the service valve.The second valve element is designed and positioned in such a way that it first opens and connects the dead space fluidically to the servo space-and thus also to the connection-after the servo piston has reached a position closing the venting path.In addition, the connection adapter according to the invention comprises a hold-down device for opening the spring valve insert, which forms a component of the service valve. This hold-down device is designed and arranged in such a way that it opens the spring valve insert only after the servo piston has reached a position closing the venting path.The special arrangement of the components of the connection adapter with respect to one another enables reliable filling, but also evacuation of the external installation when using only one connection adapter. Thus, the maintenance station can be easily connected to the foreign installation. Pressure can escape in a safe manner via the venting path, if necessary. The servo piston functions here as a closure of the venting path and closes itself even independently if, for example, a corresponding pressure is present in the servo chamber. A first step can then be taken with the first valve element to connect the servo space to the dead space in order to establish the flow path.The second valve element can first open and finally fluidically connect the dead space to the servo space after the servo piston has reached a position closing the venting path.Thus, with this one connection adapter, a secure possibility can be created of connecting an external installation to the most varied evacuation, filling, maintenance and service stations, wherein this can take place independently of the type of pressure reduction. In addition, the requirements of the automobile industry and the motor vehicle handwork can also be fulfilled thereby.A further solution to this object is provided by the main claim 2.According to the invention, a system comprising a connection adapter and a connection is provided for this purpose.For this purpose, a connection adapter according to the invention for docking and docking a maintenance station to a service valve of an external installation, in which a working fluid circulates in an at least substantially closed circuit, in particular an air conditioning system, ideally in the form of a vehicle air conditioning system, is proposed. The mentioned maintenance station can also be an evacuation station, filling station, measuring station and / or service station, for example. For the sake of simplicity, such a station is referred to below only as a "maintenance station". In the foreign installation mentioned-particularly preferably in the form of a vehicle air conditioning system-a working fluid circulates in an at least substantially closed circuit, wherein a time-dependent leakage which exists in real installations is also always included here. In addition, such a foreign system also comprises a system in which the working fluid is not yet circulating in a closed circuit, but is intended to circulate immediately, which is the case, for example, when the foreign system is first filled with working fluid.The system according to the invention comprises a connection via which-during the filling process-pressurized working fluid can be fed from the maintenance station into the connection adapter, pressurized fluid can be discharged into the maintenance station or a reduced pressure can be generated during the evacuation process. According to the invention, the connection has a rotatable connection part.In addition, the connection adapter according to the invention comprises a dead space-preferably between the connection adapter and the service valve-which is also ventilated via a venting path when the service valve is coupled to the connection adapter; at least as long as the check valve dedicated to it is still closed. Timely venting of the dead space increases the safety during decoupling. Moreover, notice is taken early and even before something can happen if the spring valve insert should not have been expected to have closed.The connection adapter according to the invention also comprises a servo space which can be connected fluidically to the connection and can also be disconnected from the connection again. In this servo space, a servo piston for opening and closing the vent path is accommodated. This servo piston is urged in the direction of its position closing the venting path in the event of an overpressure prevailing in the servo chamber.The connection adapter according to the invention also comprises a valve spindle which actuates a valve element, which is also referred to herein as a second valve element. In this case, the valve spindle preferably itself forms the valve element or a plurality of valve elements; ideally even integrally in one piece.The valve element, which is also referred to herein as a second valve element, is designed and positioned in such a way that it first opens and fluidically connects the dead space to the servo space-and thus also to the connection-after the servo piston has reached a position closing the venting path.In addition, the connection adapter according to the invention comprises a hold-down device for opening the spring valve insert, which forms a component of the service valve. This hold-down device is designed and arranged in such a way that it opens the spring valve insert only after the servo piston has reached a position closing the venting path.The special arrangement of the components of the connection adapter with respect to one another enables reliable filling, but also evacuation of the external installation when using only one connection adapter. Thus, the maintenance station can be easily connected to the foreign installation. Pressure can escape in a safe manner via the venting path, if necessary. The servo piston functions here as a closure of the venting path and closes itself even independently if, for example, a corresponding pressure is present in the servo chamber.The second valve element can first open and finally fluidically connect the dead space to the servo space after the servo piston has reached a position closing the venting path.Thus, with this one connection adapter, a secure possibility can be created of connecting an external installation to the most varied evacuation, filling, maintenance and service stations, wherein this can take place independently of the type of pressure reduction. In addition, the requirements of the automobile industry and the motor vehicle handwork can also be fulfilled thereby.PREFERRED DEVELOPMENT POSSIBILITIES OF THE INVENTIONA preferred embodiment of the connection adapter is when the servo piston has at least one upper pressurized end face and at least one lower pressurized end face, the ratio of which is selected such that the servo piston is pressed sealingly against the second valve element against the force of a servo piston spring whenever a pressure which is greater than a limit pressure is present in the servo chamber, and / or - preferably: and - against the stop of a sliding sleeve. In addition, it is preferred that when a pressure is present in the servo chamber which is less than the limit pressure, the servo piston is pressed by the force of a servo piston spring against the upper stop on the valve housing.The limiting pressure mentioned can preferably be selected variably and is preferably in a range from 0.5 MPa to 10 MPa, particularly preferably in a range from 0.5 MPa to 5 MPa, here preferably 1 MPa.This ensures that the connection adapter is securely fixed to a coupled service valve at an internal system pressure that is greater than the limit pressure. On the other hand, at a system pressure that is lower than the limit pressure, it is ensured that the servo piston reliably releases the venting path.Furthermore, it is particularly preferred if the valve spindle used for valve control of the valves which connect the connection to the dead space has a first valve element, preferably designed as a cylinder-ring-shaped valve disk, and has a second valve element, preferably designed as a conical-section-preferably as a full-cone-section-valve disk, which cooperates with a valve seat on the servo piston in such a way that the servo piston can be held by the second valve element in a position which does not close the venting path when the connection adapter is fluidically coupled against a pressure in the servo space and can be pulled from its position which closes the venting path into a position which does not close the venting path when the connection adapter is fluidically coupled off. It can thus be ensured that the venting path-regardless of whether during coupling or during decoupling-can always be released so that venting is made possible. This further contributes to the working safety.In addition, it is particularly preferred if the valve spindle forms at its one end the hold-down device for opening the spring valve insert forming a component of the service valve, which spring valve insert preferably merges via a collar for self-alignment of the hold-down device into the remainder of the valve spindle. In this case, the hold-down device preferably has a first radial bore which merges via an axial bore blended therewith into a second radial bore blended therewith in the valve spindle and thus creates a fluidic connection between the space below a collar of the valve spindle and the space inside the servo piston and inside the sliding sleeve when the service valve is coupled. As an alternative to the arrangement of these bores, the collar mentioned can also be formed on the cylinder surface with flow channels running parallel to the valve axis. Both embodiments represent a simple and reliable fluidic connection of the two spaces.In addition, it is particularly preferred if the first valve element is designed and positioned such that, in the absence of an overpressure in the servo chamber-as can occur during docking and docking for the purpose of emptying, if the connection does not lead to an overpressure-it can press the servo piston by positive locking into a position closing the venting path. Thus, even during the evacuation process, in which the servo piston is not pressed into a position closing the venting path by the prevailing overpressure, it can be otherwise brought into the corresponding position. For this purpose, a positive connection is preferably produced between the first valve element and the servo piston. This represents a simple and reliable mechanical possibility for closing the venting path in the corresponding case.A particularly preferred embodiment consists in that the valve spindle is guided in an axially displaceable manner in a preferably multipart valve housing which generally also delimits the servo chamber and the dead chamber-and for this purpose preferably at least partially delimits them on the outside-and in the ideal case also carries or can accommodate the connection. In this case, the valve housing carries a valve actuator connected to it via a thread, with the aid of which the valve spindle-which is preferably connected to the valve actuator via rolling bearings-can be moved back and forth in the axial direction relative to the valve housing. The thread is preferably a setting thread with a reduced pitch compared to the metric standard thread or a fine thread. This creates a simple possibility of being able to manually axially displace the valve spindle and to be able to set the valve positions connected thereto.Furthermore, it is particularly preferred if the valve housing carries a blocking sleeve which is axially displaceable with respect to it and which interacts positively with the valve actuator on the one hand, preferably at its one axial end which is inclined toward the valve actuator, and interacts positively with blocking balls for blocking a service valve in its connected position on the other hand, preferably at its other axial end which is inclined away from the valve actuator. They preferably interact in such a way that, as long as no service valve is connected to the connection adapter, the blocking sleeve is supported against the blocking balls in such a way that it cannot be displaced any further beyond the blocking balls in the axial direction and thus forms a stop for the valve actuator, which stops its further axial displacement in the direction of the valve housing. Thus, the connection adapter cannot be opened incorrectly if the worker is not aware, for example, that a very high pressure "leak" here, Alternatively or additionally they preferably interact with one another in such a way that, as long as a service valve is connected and the first valve element is not yet closed, the valve actuator prevents the locking sleeve from being displaced into its unlocking position, in which it allows the locking balls to be displaced in the radially outward direction. It is thus excluded that a worker, when the system is under pressure, releases the connection adapter from its locking with the service valve by appropriate displacement of the blocking sleeve, which thereupon flies explosively therefrom at a high internal pressure. When the service valve is not inserted, the blocking balls are preferably located in conical bores which become sufficiently narrow radially inward that the balls can never fall out inward-in the direction of the valve axis.It is also particularly preferred if a sliding sleeve is supported on the servo piston via a spring element, preferably in the form of a servo piston spring, which sliding sleeve has a skirt on the outer end-preferably on its axial end, which is located on the side facing the service valve-which skirt forms a ball counter bearing which, as long as no service valve is coupled to the connection adapter, blocks the blocking balls between it and the blocking sleeve in such a way that the blocking balls keep the blocking sleeve captured between itself and the valve actuator, and the sliding sleeve is displaced in the direction of the servo piston by the pushing in of the service valve to such an extent that the skirt releases the blocking balls for insertion into the corresponding blocking groove of the service valve. A simple and secure mechanical mechanism is thus created in order to be able to detect a secure coupling of the service valve in order to allow various processes only when the service valve is coupled.It is also particularly preferred if the blocking sleeve is prestressed by a spring with respect to the valve housing, preferably with respect to the valve housing lower part, wherein the configuration is such that the blocking sleeve presses the blocking balls into the blocking groove of the service valve in a radially inward direction with the aid of said spring-since the blocking sleeve is pressed downward by the spring in the direction of the sevice valve and holds them caught there as soon as the sliding sleeve has been displaced so far in the direction of the servo piston that its skirt releases the blocking balls. Thus, the spring additionally secures the service valve in a simple mechanical manner against undesired decoupling, since it presses the blocking sleeve downward in such a way that it holds the blocking balls-preferably via a shoulder-securely in the blocking groove of the service valve.Furthermore, it is particularly preferred if the sliding sleeve has a preferably hollow cylindrical section into which the servo piston sealingly dips in order to close the venting path. Thus, the servo piston is easily provided with a possibility for the closing of the venting path.A further preferred embodiment consists in that the servo piston and the sliding sleeve are mounted on one another via a rolling bearing, regularly in the form of a linear bearing. This rolling bearing is particularly preferably designed in the form of a ball or ball-circulating sleeve. This facilitates the relative axial movement between the servo piston and the sliding sleeve with respect to one another, even under high pressure. Ideally, this prevents jamming and / or jerking movements between the two components both in the upward axial direction (in the direction of the valve actuator) and in the downward axial direction (in the direction of the service valve).In addition, it is particularly preferred if the sliding sleeve forms a stop for the servo piston, which stop prevents its further axial displacement in the direction of the service valve. Thus, the freedom of movement of the servo piston can be limited in a simple manner, whereby the blocking of the venting path can take place in a defined manner.In addition, it is particularly preferred if the sliding sleeve transmits the pressure force communicated to it by the servo piston to the blocking balls. Thus, the blocking balls additionally secure the service valve in a simple mechanical manner against undesired decoupling, since the locking of the service valve is intensified in this way.A further preferred embodiment consists in the valve spindle being designed such that it passes over a latching point which, when the valve actuator is actuated, indicates haptically to the user that he now impacts the spring valve insert and / or terminates the forced opening of the spring valve insert, wherein the latching point is preferably produced by a latching ball pin, the ball of which temporarily engages in an annular groove of the valve spindle. Thus, the user can be easily notified of a haptic warning message.Furthermore, it is particularly preferred if the venting path is formed by at least one transverse bore of the sliding sleeve, at least one transverse bore in the valve housing and ideally a further part of the venting path is formed by at least one transverse bore in the blocking sleeve, wherein the transverse bore in the blocking sleeve is ideally offset with respect to the remainder of the venting path in such a way that an axial throttle gap is formed between the remainder of the venting path and the transverse bore of the blocking sleeve. This throttling of the pressure across this axial throttle gap is necessary, for example, if the spring valve insert does not close again correctly because of a fault. Then, larger amounts of working fluid, which are initially at high overpressure, are to be blown off via the aeration path. The axial throttle gap mentioned here offers a simple and reliable possibility of reducing this high pressure.Further possible embodiments, functions and advantages result from the dependent claims and / or the following description of the exemplary embodiment and / or with reference to the figures.FIGURE LISTFIG. 1 shows the connection adapter in a sectional front view without a service valve. FIG. 2 shows the connection adapter in a sectional front view with service valve which has not yet been inserted. FIG. 3 shows the connection adapter in a sectional front view during the coupling and locking of a service valve. FIG. 4 shows the connection adapter with inserted service valve in a sectional front view at the beginning of opening. FIG. 5 shows the connection adapter with inserted service valve in a sectional front view when fully opening. FIG. 6 shows the connection adapter with inserted service valve in a sectional front view at the beginning of the closing. FIG. 7 shows the connection adapter with inserted service valve in a sectional front view when fully closing. FIG. 8 shows a system comprising a connection adapter and a connection FIG. 9 shows a system comprising a connection adapter and a connection in plan viewPREFERRED EMBODIMENTThe port adapter assembly generallyFIGS. 1 and 2 show the general, preferred embodiment of a connection adapter 0, wherein FIG. 2 also shows the service valve 1 for improved clarity, which is later coupled to the connection adapter 0. The coupling of the service valve 1 and the different switching positions of the connection adapter with the service valve 1 coupled will be explained step by step in the further course. However, the general configuration of the individual parts of the connection adapter 0 and the service valve 1 will be discussed first.The service valve 1 is preferably a valve of an external installation to which the connection adapter 0 is connected. This service valve 1 preferably comprises a spring valve insert 29; if this spring valve insert 29, which usually forms a type of nonreturn valve, is pressed downward-into the service valve 1-the flow path of the service valve 1 is opened. In addition, the service valve 1 preferably comprises a circumferential blocking groove 32 on its circumferential surface, into which the blocking balls 3 can later engage, which will be explained in more detail in the later course.The connection adapter 0 itself preferably comprises a valve actuator 16 at an axial end. This valve actuator 16 preferably comprises a thread 17 on its inner circumferential surface, preferably in the form of a fine thread. This thread 17 corresponds to the corresponding thread 17 of the valve housing 18. the thread 17 of the valve housing 18 is preferably attached to a shoulder at the upper axial end (in the direction of the valve actuator 16) of the valve housing 18. This shoulder serves on the one hand as a carrier for the thread 17 and on the other hand preferably also as a stop for the valve actuator 16 in the fully screwed-in state. The valve housing 18 is preferably embodied in multiple parts-in the preferred exemplary embodiment shown in two parts. The lower part 18.1 of the valve housing here carries the cone bores 12 which have already been discussed and which carry the blocking balls 3 as long as the service valve 1 is not engaged. The upper part of the valve housing 18 preferably carries, in the region in which the servo piston 8 moves, at least one transverse bore 18.2, which is part of the venting path, which is later illuminated in more detail.It is furthermore preferred that the upper part of the valve housing 18 carries a spring-loaded detent ball pin 28, preferably in a corresponding recess, which can engage in a preferably encircling, corresponding annular groove of the valve spindle 10. Likewise preferably, in the upper part of the valve housing 18 there is a preferably encircling groove for receiving a sealing element 5 between the valve housing 18 and the valve spindle 10.The valve housing lower part 18.1 additionally preferably comprises a stop element 9 or a groove in which a stop element 9 is fastened. This stop element 9 is preferably located below (axially along the valve axis 15 direction of the service valve 1) the cone bores 12.The valve housing lower part 18.1 additionally preferably comprises a shoulder on which a spring 13, preferably in the form of a compression spring, can be supported.The other side on which the corresponding spring 13 can be supported is preferably located on a shoulder of a blocking sleeve 2, which preferably at least partially encloses the valve housing 18. This shoulder mentioned preferably merges into a preferably encircling groove which additionally partially supports the locking balls 3 in the non-released state of the locking sleeve shown. In the released state of the locking sleeve 2 (see FIG. 3 ), the corresponding shoulder interacts with the stop element 9 in such a way that it provides a lower stop for the released locking sleeve 2, which is pressed downward (axial along the valve axis 15 direction of the service valve 1) by the spring force of the spring 13. In this released state (see FIG. 3 ), the shoulder additionally offers a further support of the blocking balls 3 against a radial displacement away from the valve axis 15, since the blocking balls 3 have been displaced inward (toward the valve axis 15) in the cone bores 12 in the released state of the blocking sleeve 2.FIG. 3 and this "snapping-in" of the locking sleeve 2 are explained in more detail in a later section.Preferably above (axially along the valve axis 15 direction of the valve actuator 16) the shoulder of the blocking sleeve 2, the blocking sleeve 2 comprises at least one transverse bore 2.1, which is part of the venting path. In addition, the blocking sleeve 2 preferably comprises on the inside a preferably annularly encircling recess which functions as an axial throttle gap 2.2 between the blocking sleeve 2 and the valve housing 18, wherein the axial throttle gap 2.2 is likewise part of the venting path. Preferably at the opposite axial end, at which the shoulder mentioned is located, the end of the locking sleeve 2 preferably acts as a stop for the valve actuator 16; on the one hand, in the non-triggered state of the locking sleeve 2 and, on the other hand, in the triggered state of the locking sleeve when the valve actuator 16 is fully screwed in. For this purpose, the valve actuator 16 preferably comprises a further shoulder which extends circumferentially on the outside and interacts accordingly with the locking sleeve 2.Inside the valve housing 18 there is preferably the servo piston 8, which can cover an axial movement path inside the valve housing 18. The servo piston 8 is preferably sealed off from the valve housing 18 by means of a sealing element 7. The servo piston 8 runs at least partially axially within a sliding sleeve 4, preferably within a hollow cylindrical section 33 of the sliding sleeve 4. the sealing between the sliding sleeve 4 and the servo piston 8 - when the servo piston 8 is in the corresponding position in which the venting path is blocked - preferably takes place via a sealing element 24. This at least one transverse bore 4.1 can be blocked by the servo piston 8, preferably by a shoulder of the servo piston 8, whereby the entire venting path is blocked. Preferably, a servo piston spring 14 is located between a shoulder of the servo piston 8 and the shoulder of the sliding sleeve 4; the sliding sleeve 4 also preferably comprises the valve receptacle 23 for the service valve 1 and a skirt 22, which is illuminated in more detail later.Preferably, the valve spindle 10 runs inside the servo piston 8 and the sliding sleeve 4, which can be displaced axially upward and downward (along the valve axis 15) by the valve actuator 16. The valve spindle 10 preferably comprises a first valve element 10.1, which is preferably plate-shaped. This first valve element 10.1 preferably comprises a sealing element 6, which seals the first valve element 10.1 with respect to the valve housing 18. Preferably, the servo piston 8 comprises a corresponding disk-shaped recess, in which the first valve element 10.1 can be at least partially accommodated and whereby the servo piston 8 can be moved against the spring force of the servo piston spring 14. This plate-shaped recess is preferably also part of the servo chamber 20, which will be discussed in more detail in the later sections.The servo piston 8 also preferably comprises a sealing surface 8.3, which preferably interacts with the second valve element 10.2 or a sealing element 7 on the second valve element in such a way that the servo piston 8 can be seated on the valve seat in a sealing manner on the second valve element 10.2. The sealing surface 8.3 of the servo piston 8 is preferably designed obliquely and is preferably analogous to the inclination of the second valve element 10.2. At the lower axial end (end in the direction of the service valve 1), the valve spindle 10 additionally preferably comprises a hold-down 10.5, which preferably merges via a collar 31 into the remaining valve spindle 10. This collar 31 serves the required self-alignment function of the hold-down 10.5. This "self-alignment" is preferably achieved by the interaction of the collar 31 with a constriction of the radial cross section of the sliding sleeve 4.In order to connect the space below this collar 31-which may be the dead space 21 or part of the dead space 21-virtually to the interior of the servo piston 8 and the sliding sleeve-which may be the servo space 20 or part of the servo space 20-in order to ensure the flow path there-depending on the valve positions-in a sufficient cross section to the connection 19 or also in order to carry out the venting via the venting path, the valve spindle 10 comprises a flow path in its interior. For this purpose, the holding-down device 10.5 preferably comprises a first radial bore 10.3.1, which merges via an axial bore 10.4 blended therewith into a second radial bore 10.3.2 blended therewith in the valve spindle 10 itself. Alternatively, the collar 31 can be formed with flow channels running parallel to the valve axis 15 on the cylinder surface in order to ensure the described flow channel with a sufficient cross section.A rolling bearing 34 can be provided between the servo piston 8 and the sliding sleeve 4, preferably in the form of a ball sleeve, in order to facilitate the relative movement of the two parts with respect to one another.In the following, for the sake of better clarity, individual positions and steps are also shown when using the connection fitting 0, which describe the coupling of the service valve 1 and the opening and closing of the connection adapter 0.Coupling and locking of a service valve 1 (see FIG. 3 )Finally, FIG. 3 shows the connection adapter 0 exactly at the moment after it has been connected to the service valve 1. Directly during the connection to the service valve 1, the dead space 21 is relieved of pressure via the vent holes of the vent path arranged in series, in order to prevent the connection adapter 0 from blowing off if a corresponding pressure would cause the connection adapter 0 to do so. These venting bores are chronological the transverse bore 4.1 of the sliding sleeve 4, the transverse bore 18.2 of the valve housing 18 and the transverse bore 2.1 of the blocking sleeve 2. an axial throttle gap 2.2 is preferably located between the transverse bore 18.2 and the transverse bore 2.1 for reliable venting even at high pressures.During the insertion of the service valve 1, the sliding sleeve 4 with the valve receptacle 23 is slid along the valve axis 15 and against the force of the servo piston spring 14 into a defined position in the direction of the valve actuator 16.The sealing of the service valve 1 to the dead space 21 is preferably ensured by the valve seal 26 in that the sealing surface 25 of the sliding sleeve 4 is formed such that the service valve 1 bears against the sealing surface 25 such that the valve seal 26 can bear reliably against the circumferential surface of the service valve 1 provided for this purpose. Advantageously, the valve seal 26 can be formed as a D-ring to eliminate the risk of a spiral failure.As already mentioned, blocking balls 3 are inserted in each case in the radial cone bores 12, which are preferably introduced into the valve housing lower part 18.1 of the valve housing 18. By pushing in the service valve 1, the sliding sleeve 4-and preferably the skirt 22 of the sliding sleeve 4-releases the conical bores 12, whereby the blocking balls 3 are pressed by the sliding sleeve 4 acted upon by the force of the servo piston spring 14 into the circumferential blocking groove 32-preferably in the form of an annular groove-of the service valve 1 and are blocked in this position.If the sliding sleeve 4 were to be slid into the valve housing 18 without service valve 1 until the cone bores 12 were released, the blocking balls 3 block the insertion of the service valve 1.Because the blocking balls 3 now no longer block the blocking sleeve 2, the blocking sleeve 2 snaps in axially downward (in the direction of the service valve 1) by the spring force of the spring 13 and is also held there by the spring force. This "snapping-in" takes place axially downwards as far as the stop element 9, as a result of which the blocking balls 3 are pressed once again further into the blocking groove 32 of the service valve 1 and locked there. Generally, in this state shown, the service valve is now firmly locked to the connection adapter 0. By the "snapping in" of the locking sleeve 2, the valve actuator 16 is also released, since the latter is now first of all no longer prevented from rotating by the locking sleeve 2.Start of Opening (see FIG. 4)By rotating the valve actuator 16 preferably in the clockwise direction, the valve spindle 10 is displaced downward (direction of service valve) along the valve axis 15. In this case, rolling bearings 11, preferably in the form of ball bearings, prevent the transmission of the rotational movement of the valve actuator 16 to the valve spindle 10 with the first valve element 10.1, the second valve element 10.2, the hold-down device 10.5 and the servo piston 8.FIG. 4 shows how the first valve element 10.1 is opened by the rotation of the valve actuator 16, while the second valve element 10.2 remains closed.The force acting in the servo chamber 20 on the pressurized surface 8.1 of the servo piston 8-when the first valve element 10.1 is opened and pressure prevails in the servo chamber 20 via the connection 19-reinforces the sealing effect of the sealing element 6 on the sealing surface 8.3, while at the same time the venting bore 4.1 is securely closed by the axial, pressure-guided movement of the servo piston 8. The dead space 21 is thus hermetically encapsulated. The travel of the servo piston 8 is limited by the stop on the sliding sleeve 4, which is locked in its position by the service valve 1 attached.Due to the force acting on the pressurized surface 8.1 of the servo piston 8, the sliding sleeve 4 is pressed onto the blocking balls 3 in the cone bores 12. As a result of this force acting more strongly with increasing system pressure, the blocking balls 3 are preferably pressed permanently against the skirt 22 of the blocking sleeve 2, wherein the skirt 22 acts as a ball counter bearing, and the blocking sleeve 2 is thereby locked in this position.The ratio of the pressurized surfaces 8.1 and 8.2 of the servo piston 8 and the force of the servo piston spring 14 are advantageously selected such that the servo piston 8 is pressed against the sealing surface 8.3 of the second valve element 10.2 and / or against the stop of the sliding sleeve 4 at a system pressure which is greater than the limit pressure (preferably >=1 MPa).Complete Opening (see Figure 5)The valve spindle 10 is displaced in the direction of the service valve 1 by further rotation of the valve actuator 16 until it stops in the clockwise direction along the valve axis 15, whereby the second valve element 10.2 is also opened and the flow path between the servo chamber 20 and the dead chamber 21 is established.In the same direction, the spring valve insert 29 of the service valve 1 is pressed by the hold-down 10.5 and the flow path between the dead space 21 and the external installation which comprises the service valve 1 is thereby produced. The flow path between connection 19 via the first valve element 10.1, second valve element 10.2 and service valve 1 is thus produced for the evacuation and / or filling of an external system.Due to the advantageous configuration of the length of the blocking sleeve 2 and the possible movement space of the blocking sleeve 2 in the axial direction along the valve axis 15, decoupling from the service valve 1 can only take place if the valve actuator 16 has been brought completely-preferably by turning counterclockwise-into the end position and both valve elements 10.1 and 10.2 of the valve spindle 10 are completely closed.This results in dual safety against decoupling from a service valve 1, since in this (upper) position of the valve actuator 16 the venting path is necessarily open via the venting bores.In general, the formation of a ball counter bearing by the skirt 22 on the locking sleeve 2 is preferred. When the valve elements 10.1 and 10.2 are open and the servo piston 8 is pressurized, the frictional connection via the sliding sleeve 4, the blocking balls 3 and the ball counter bearing prevents the blocking sleeve 2 from being displaced along the valve axis 15 in the direction of the valve actuator 16, so that the locking mechanism remains fixed. If necessary, the blocking sleeve 2 can thereby also be designed in such a way that the mechanical stop on the opened valve actuator 16 can be omitted. The plugged-on service valve 1 is thereby securely coupled to the connection adapter 0.A service valve 1 which does not close correctly on a circuit which is at least partially charged with refrigerant is detected by the outflow of the refrigerant via the dead space 21 and the venting path.If the connection fitting is likewise intended to be used for evacuation, the first valve element 10.1 is to be designed in such a way that, when the connection adapter 0 is opened, the first valve element 10.1 forcibly guides the servo piston 8 downward counter to the spring force of the servo piston spring 14 in order to close the venting bore 4.1 before the evacuation process is initiated.Beginning of closing (see Fig. 6)From the fully open state shown in FIG. 5, the closing of the connection adapter 0 can now be initiated.By rotating the valve actuator 16 in the counterclockwise direction, the valve spindle 10 is displaced along the valve axis 15 in the direction of the valve actuator 16. First, the second valve element 10.2 closes.The pressurized servo piston 8 generates the necessary counter force at the sealing surface 8.3. The hold-down device 10.5 lifts from the spring valve insert 29 of the service valve 1.The flow path between dead space 21 and the connected (cold) circuit and between servo space 20 and dead space 21 is interrupted. The venting path is furthermore closed.Complete Closing (see Figure 7)By further rotating the valve actuator 16 in the counterclockwise direction until it abuts, the valve spindle 10 is displaced further along the valve axis 15 in the direction of the valve actuator 16. The second valve element 10.2 remains closed and the first valve element 10.1 also closes. The servo piston 8 is also moved upwards by the second valve element 10.2 and the transverse bore 4.1 is released. The flow path between servo space 20 and dead space 21 is interrupted. The pressure in the dead space 21 is reduced by the open venting path and a leaky spring valve insert 29 in the service valve 1 could be detected in that the pressurized medium constantly flows out of the venting path to the environment.Furthermore, conclusions can be drawn about incorrectly closing spring valve inserts 29 in the service valve 1 or about a defective sealing element 6.decoupling the service valve (when no medium flows out)Only when the valve actuator 16 has been rotated completely counter-clockwise as far as the stop can the blocking sleeve 2 be displaced manually in the direction of the valve actuator 16 counter to the force of the tension spring 13. The blocking balls 3 are pressed out of the blocking groove 32 of the service valve 1 by the force of the servo piston spring 14 via the frictional connection with the sliding sleeve 4. The sliding sleeve 4 presses the service valve 1 out of the connection adapter 0, so that the latter can be removed and the initial state is reached again.Some variants of service stations reduce the pressure after completion of a filling process via the service station and not via the connection adapter. For this reason, it is preferred if the connection adapter 0 can also be adapted to this embodiment.The closing of the connection adapter 0 is divided into two phases. The transition from the beginning closing phase to the final phase is preferably signaled by a noticeably recognizable, preferably haptic feedback at the valve actuator 16.The beginning phase serves to interrupt the flow path between service valve 1 and dead space 21.By rotating the valve actuator 16 in the counterclockwise direction, the hold-down 10.5 is lifted off the pin of the spring valve insert 29 in the coupled service valve 1, as a result of which the flow path to the circuit connected to the service valve 1 is interrupted. The stroke required for this is defined according to the respective refrigerant per standard.By way of example, this process is reliably concluded with the refrigerant R744 after a stroke of the valve spindle 10 with the hold-down device 10.5 of 2.5 mm. Upon reaching this point, the described feedback is preferably provided by a substantial increase in resistance to rotation of the valve actuator 16 in a counter-clockwise direction. For this purpose, a circumferential groove, preferably in the form of an annular groove 27, is preferably present on the valve spindle 10 at the defined point. The increase in resistance is caused by a ball-and-socket pin 28 which is inserted into the valve housing 18 transversely to the valve spindle 10 and presses against the shaft of the valve spindle 10.If a connection adapter 0 is connected to a maintenance station, at which the pressure is to be reduced via this maintenance station, the operator interrupts the rotational movement of the valve actuator 16 and starts venting at the connected fluid system.The flow path between the servo chamber 20 and the connection 19 is open, so that the overpressure can escape from the servo chamber 20. As the force on the first pressurized surface 8.1 of the servo piston 8 decreases, the servo piston is moved by a force acting on the second pressurized surface 8.2 and the force of the servo piston spring 14 against the upper stop.As a result, the second valve element 10.2 opens. Simultaneously, the venting bore 4.1 is released by the servo piston 8. The overpressure in the dead space 21 is reduced via the valve elements 10.1 and 10.2 to the connection 19 and via the series-connected transverse bores 4.1, 2.1 and 18.2 of the venting path.Further EmbodimentThis (further) embodiment corresponds to the previously described embodiment or the previously described embodiments and only differs in that the connection adapter 0 does not have a first valve element 10.1. The valve element 10.1 is not necessary in this embodiment. The other features or the advantageous and preferred features described in connection with the previously described embodiment or the previously described embodiments also apply to this (further) embodiment and are correspondingly advantageous or preferred and are also claimed for this further embodiment.In particular, independent protection is thus also claimed for a connection adapter 0 for docking and docking a maintenance station to a service valve 1 of a foreign installation in which a working fluid circulates in a closed circuit, in particular an air conditioning system having a connection 19, via which working fluid under pressure can be fed from the maintenance station into the connection adapter 0 for filling or via which working fluid under pressure can be discharged, having a dead space 21, which is also ventilated via a venting path when the service valve 1 is coupled to the connection adapter 0, having a servo space 20, which can be fluidically connected to the connection 19 and in which a servo piston 8 is accommodated for opening and closing the venting path, which servo space urges an overpressure present in the servo space 20 in the direction of its position closing the venting path, and having a valve spindle 10, actuating a valve element 10.2 (the valve element 10.2 is described as a second valve element in the embodiment described further above), wherein the valve spindle 10, does not actuate a valve element 10.1 (the valve element 10.1 is described as a first valve element in the embodiment described further above), which is designed and positioned such that it fluidically connects the servo chamber 20 to the connection 19 when the valve spindle 10 is moved in order to push open the service valve 1, and the valve element 10.2 (here, the second valve element 10.2) is designed and positioned such that it first opens and fluidically connects the dead chamber 21 to the servo chamber 20 after the servo piston 8 has reached a position closing the venting path, and having a holding-down device 10.5 for opening the spring valve insert 29 forming a component of the service valve 1, which is designed and arranged, This spring valve insert 29 opens only after the servo piston 8 has reached a position closing the venting path.Independent protection is also claimed for a system 100 comprising a connection 19 and a connection adapter 0 for docking and docking a maintenance station to a service valve 1 of a foreign installation, in which a working fluid circulates in a closed circuit, in particular an air conditioning system having a connection 19, via which working fluid under pressure can be fed from the maintenance station into the connection adapter 0 for filling or via which working fluid under pressure can be discharged, having a dead space 21, which is also ventilated via a venting path when the service valve 1 is coupled to the connection adapter 0, wherein the connection 19 has a rotatable connection part 47, having a servo space 20, which can be fluidically connected to the connection 19 and in which a servo piston 8 for opening and closing the venting path is accommodated, which urges an overpressure present in the servo space 20 in the direction of its position closing the venting path, and having a valve spindle 10 which actuates a valve element 10.2 (the valve element 10.2 is described as a second valve element in the embodiment described further above), wherein the valve spindle 10 actuates no valve element 10.1 (the valve element 10.1 is described as a first valve element in the embodiment described further above) which is designed and positioned such that, when the valve spindle 10 is moved in order to push open the service valve 1, it fluidically connects the servo space 20 to the connection 19, and the valve element 10.2 (here, the second valve element 10.2) is designed and positioned such that it first opens and fluidically connects the dead space 21 to the servo space 20 after the servo piston 8 has reached a position closing the venting path, and with a hold-down device 10.5 for opening the spring valve insert 29 forming a component of the service valve 1, which is designed and arranged such that it opens the spring valve insert 29 only after the servo piston 8 has reached a position closing the venting path.Advantageously, a connection adapter 0 for docking and docking a maintenance station to a service valve 1 of an external system without a valve element 10.1 is thus claimed, wherein the valve element 10.1 is described as a first valve element in the embodiment described further above. This embodiment can thus be described like the embodiment described further above, just without the first valve element 10.1.Advantageously, the valve spindle 10 of the connection adapter 0 actuates only a single valve element 10.2 (wherein the valve element 10.2 is described as a second valve element in the embodiment described further above), wherein the valve element 10.2 is designed and positioned such that it first opens and fluidically connects the dead space 21 to the servo space 20 after the servo piston 8 has reached a position closing the venting path.The servo chamber 20 is advantageously fluidically connected to the connection 19 before the valve element 10.2 first opens and fluidically connects the dead chamber 21 to the servo chamber 20 after the servo piston 8 has reached a position closing the venting path.System 100 of Connection Adapter 0 and Connection 19For all of the above embodiments, the valve housing 18 at least partially carries the connection 19 of the connected maintenance station, preferably by means of a thread.A system 100 is claimed which has a connection adapter 0 according to the invention and the connection 19. A system 100 according to the invention comprising a connection adapter 0 and the connection 19 is shown, for example, in FIGS. 8 and 9.The connection 19 has an inner base body 46 which is hollow on the inside, so that fluid can be guided to the connection adapter 0. The inner base 46 has an elongated shape. The inner base body 46 also has a lateral opening and an opening 50 on an end side (i.e. proximal to the connection adapter 0), via which the fluid is or can be conducted to the connection adapter 0. The opposite end face, i.e. the side facing away from the connection adapter 0 (i.e. distal to the connection adapter 0), is closed.The lateral opening is a round or oval opening, or advantageously an elongate opening or an opening with many small openings which extend or extend at least partially over the radial length of the circumference of the inner base body 46. The opening 50 on the end face disposed on the side of the terminal adapter 0 is a round or oval opening, or an opening having a polygonal shape.The connection 19 further comprises an outer base body 47 in the form of a T-piece. The first part 44 of the T-piece is elongate and thinner than the second part 45 of the T-piece 47, which is arranged here substantially at an angle of 90°, The first and the second part 44, 45 of the T-piece do not have to be arranged exactly at an angle of 90° with respect to one another, but it is sufficient if the first part 44 is arranged at an angle of less than 90° and greater than 10° with respect to the second part 45. However, an angle between the first part 44 and the second part 45 of 45° to 90° is preferred.The T-piece 47 is designed to be hollow on the inside, so that fluid can be guided or conducted from the first part 44 of the T-piece 47 to the second part 45 of the T-piece 47 and via the lateral opening of the inner base body 46, through the inner hollow inner base body 46 and further via the opening 50 on the end side opening of the inner base body 46 to the connection adapter 0 or these are in fluidic contact or are continuous with one another.The outer base body 47 or the T-piece forms a connection part of the connection to which a hose can be connected in order to be able to supply the fluid.The inner hollow region of the second part 45 of the T-piece 47 is shaped or preferably designed round, such that the second part 45 can be pushed or arranged over the inner base body 46, which is preferably likewise designed round (i.e. at least in the region where the second part 45 can be pushed over the inner base body 46 or arranged above it). In particular, the outer base body 47 or the T-piece 47 arranged on the inner base body 46 can be rotated or radially rotated, as is shown in FIG. 9 with the reference symbol D. Advantageously, the rotation or radial rotation D comprises a rotational angle of 360° about the longitudinal axis of the inner base body 46, as can be easily seen in FIG. 9. However, the range of the angle of rotation does not necessarily have to be 360°, in particular an angle of rotation of 45° to 270° is generally sufficient.The outer base body 47 or the T-piece 47 is secured to the inner base body 46 by a securing means 42, as can be seen clearly in FIG. 8. The securing means 42 is a securing ring, preferably a spring steel ring or a securing disk. Thus, the outer base body 47 or the T-piece 47 cannot be detached or pulled off from the inner base body 46 in the axial direction. The axial direction here means the axial direction of the inner base body 46. Preferably, the inner base body 46 has a groove on its distal side (i.e. distal to the connection adapter 0) into which the fuse 42 is inserted, inserted or arranged.Between the outer base body 47 and the second part 45 of the T-piece 47, which are arranged or pushed one above the other, two seals 40, 41 are arranged. The gaskets 40, 41 are an upper gasket 40 and a lower gasket 41, and the upper gasket is disposed above the side opening, i.e., on the side away from the connector adapter 0 (distal side). The lower seal 41 is disposed below the side opening, i.e., on the side facing the terminal adapter 0 (proximal side). The two seals seal off the intermediate space between the inner base body 46 and the outer base body 47 or the T-piece 47 from the outside, so that no fluid can escape when it is conducted or pressed or flowed through the connection 19. As can be clearly seen in FIG. 8, the inner base body 46 preferably has in each case one groove for the upper and lower seals 40, 41 in which the seals 40, 41 are inserted, inserted or arranged, wherein one of the two grooves, i.e. the upper groove, is arranged above the lateral opening and the other of the two grooves, i.e. the lower groove, is arranged below the lateral opening. The two grooves are advantageously round, so that an O-ring can be used as seal 40, 41.Due to the two seals 40, 41, it is possible, even if the outer base body 47 or the T-piece 47 is rotated with respect to the inner base body, to nevertheless achieve a tight connection to the connection adapter 0. This is particularly advantageous if there is little space available for starting, if e.g. a rigid or rigid connecting hose has to be used, or if only access from a specific side to the connection 19 is possible or present, so that even a flexible hose could easily be kinked.For attaching the connection 19, the connection 19 optionally has a threaded connection 43, in particular a threaded connection 43, for mounting on a service coupling, in particular a service coupling of the connection adapter 0.The connection 19 is thus advantageously constructed in multiple parts and not in one piece.REFERENCE LIST0 Connection adapter 1 service valve 2 blocking sleeve 2.1 transverse bore of the blocking sleeve 2.2 axial throttle gap 3 blocking ball 4 sliding sleeve 4.1 transverse bore of the sliding sleeve 5 sealing element 6 sealing element 7 sealing element 8 servo pistons 8.1 first pressurized surface 8.2 second pressurized surface 8.3 sealing surface servo pistons 9 stop element 10 valve spindle 10.1 first valve element 10.2 second valve element 10.3.1 first radial bore (top) 10.3.2 second radial bore (bottom) 10.4 axial bore (connection of the radial bores) 10.5 hold-down 11 rolling bearing 12 cone bore 13 spring 14 servo piston spring 15 valve axis 16 valve actuator 17 thread between valve housing and valve actuator 18 valve housing 18.1 valve housing lower part 18.2 transverse bore in valve housing 19 connection 20 servo chamber 21 dead space 22 skirt (ball counter bearing) 23 valve receptacle 24 sealing element 25 sealing surface 26 valve seal 27 annular groove 28 snap-in ball pin 29 spring valve insert of the service valve 30 not allocated 31 collar for self-alignment of the hold-down device 32 locking groove of the service valve 33 hollow cylindrical section of the sliding sleeve 34 rolling bearing 40 upper seal 41 lower seal 42 securing ring 43 threaded connection 44 first part of the outer base body or T-piece 45 second part of the outer base body or T-piece 46 inner base body 47 connection part or outer base body or T-piece 50 opening or proximal opening 100 system of connection and connection adapter D rotation

Claims

System (100) comprising a connection (19) and a connection adapter (0) for docking and docking a maintenance station to a service valve (1) of a foreign installation in which a working fluid circulates in a closed circuit, in particular an air conditioning system having a connection (19) via which working fluid under pressure for filling can be fed from the maintenance station into the connection adapter (0) or via which working fluid under pressure can be discharged, having a dead space (21) which is vented via a venting path even when the service valve (1) is coupled to the connection adapter (0), wherein the connection (19) has a rotatable connection part (47), having a servo space (20) which can be fluidically connected to the connection (19) and in which a servo piston (8) for opening and closing the venting path is accommodated, which urges an overpressure present in the servo space (20) in the direction of its position closing the venting path, and having a valve spindle (10) which actuates a first valve element (10.1) and a second valve element (10.2), wherein the first valve element (10.1) is designed and positioned such that, when the valve spindle (10) is moved in order to push open the service valve (1), it fluidically connects the servo space (20) to the connection (19), and the second valve element (10.2) is designed and positioned such that it first opens and fluidically connects the dead space (21) to the servo space (20) after the servo piston (8) has reached a position closing the venting path, and having a holding-down device (10.5) for opening the spring valve insert (29) which forms a constituent part of the service valve (1), which holding-down device is designed and arranged, opening the spring valve insert (29) only after the servo piston (8) has reached a position closing the venting path.System (100) comprising a connection (19) and a connection adapter (0) for docking and docking a maintenance station to a service valve (1) of a foreign installation in which a working fluid circulates in a closed circuit, in particular an air conditioning system having a connection (19) via which working fluid under pressure for filling can be fed from the maintenance station into the connection adapter (0) or via which working fluid under pressure can be discharged, having a dead space (21) which is vented via a venting path even when the service valve (1) is coupled to the connection adapter (0), wherein the connection (19) has a rotatable connection part (47), having a servo space (20) which can be fluidically connected to the connection (19) and in which a servo piston (8) for opening and closing the venting path is accommodated, which forces an overpressure present in the servo space (20) in the direction of its position closing the venting path, and with a valve spindle (10) which actuates a valve element (10.2), wherein the valve element (10.2) is designed and positioned such that it opens first and fluidically connects the dead space (21) to the servo space (20) after the servo piston (8) has reached a position closing the venting path, and with a hold-down device (10.5) for opening the spring valve insert (29) which forms a constituent part of the service valve (1) and is designed and arranged such that it opens the spring valve insert (29) only after the servo piston (8) has reached a position closing the venting path.System (100) according to Claim 1 or 2, characterized in that the servo piston (8) has at least one upper, pressurized end face (8.1) and at least one lower, pressurized end face (8.2), the ratio of which is selected such that the servo piston (8) is pressed sealingly against the second valve element (10.2) against the force of a servo piston spring (14) whenever a pressure which is greater than a limit pressure is present in the servo chamber (20), and / or at the stop of a sliding sleeve (4) and / or whenever a pressure which is less than a limit pressure is present in the servo chamber (20), is pressed by the force of a servo piston spring (14) against the upper stop on the valve housing (18).System (100) according to one of Claims 1 to 3, characterized in that the valve spindle (10) used for valve control of the valves which connect the connection (19) to the dead space (21) has a first valve element (10.1), which is preferably designed as a cylinder-ring-shaped valve plate, and has a second valve element (10.2), which is preferably designed as a conical-section-shaped valve plate and cooperates with a valve seat on the servo piston (8) in such a way that the servo piston (8) can be held by the second valve element (10.2) against a pressure in the servo space (20) in a position which does not close the venting path when the connection adapter (0) is coupled on, and can be pulled out of its position which closes the venting path into a position which does not close the venting path when the connection adapter (0) is decoupled.System (100) according to one of Claims 1 to 4, characterized in that the valve spindle (10) forms, at its one end, the hold-down device (10.5) for opening the spring valve insert (29) which forms a constituent part of the service valve (1), which spring valve insert merges via a collar (31) for self-alignment of the hold-down device (10.5) into the remainder of the valve spindle (10), wherein the hold-down device (10.5) preferably has a first radial bore (10.3.1), which merges via an axial bore (10.4) blended therewith into a second radial bore (10.3.2) blended therewith in the valve spindle (10) and thus, when the service valve (1) is coupled, preferably creates a fluidic connection between the space below a collar (31) of the valve spindle (10) and the space inside the servo piston (8) and inside the sliding sleeve (4).System (100) according to one of the preceding claims, characterized in that the first valve element (10.1) is designed and positioned in such a way that, in the absence of overpressure in the servo space (20), it can press the servo piston (8) by positive locking into a position closing the venting path.System (100) according to one of the preceding claims, characterized in that the valve spindle (10) is guided axially displaceably in a preferably multipart valve housing (18), which generally also delimits the servo space (20) and the dead space (21) and ideally also carries the connection (19), wherein the valve housing (18) carries a valve actuator (16) connected to it via a thread (17), with the aid of which valve actuator the valve spindle (10) - which is preferably connected to the valve actuator (16) via rolling bearings (11) - can be moved back and forth in the axial direction relative to the valve housing (18).System (100) according to one of the preceding claims, characterized in that the valve housing (18) carries a blocking sleeve (2) which is axially displaceable with respect to it and interacts in a positive-locking manner on the one hand with the valve actuator (16) and interacts in a positive-locking manner on the other hand with blocking balls (3) for locking a service valve (1) in its connected position, preferably in such a way that the blocking sleeve (2) is supported against the blocking balls (3) as long as no service valve (1) is connected to the connection adapter (0) in such a way that it cannot be displaced further beyond the blocking balls (3) in the axial direction and thereby forms a stop for the valve actuator (16), which stops its further axial displacement in the direction of the valve housing (18) and / or preferably in such a way that the valve actuator (16) is connected as long as a service valve (1) is connected and the first valve element (10.1) is not yet closed, preventing the locking sleeve (2) from being displaced into its unlocking position, in which it allows the locking balls (3) to be displaced in the radially outward direction.System (100) according to one of the preceding claims, characterized in that a sliding sleeve (4) is supported on the servo piston (8) via a spring element, preferably in the form of a servo piston spring (14), which sliding sleeve has a skirt (22) on the outer end side, which skirt forms a ball counter bearing, which, as long as no service valve (1) is coupled to the connection adapter (0), blocks the blocking balls (3) between it and the blocking sleeve (2) in such a way that they hold the blocking sleeve (2) captured between itself and the valve actuator (16), and which is displaced in the direction of the servo piston (8) by the service valve (1) being pushed in so far that the skirt (22) releases the blocking balls (3) for insertion into the corresponding blocking groove (32) of the service valve (1).System (100) according to one of the preceding claims, characterized in that the blocking sleeve (2) is prestressed with respect to the valve housing (18), preferably with respect to the valve housing lower part (18.1), by a spring (13), wherein the configuration is such that the blocking sleeve (2) presses the blocking balls (3) in the radially inward direction into the blocking groove (32) of the service valve (1) and holds them caught there as soon as the sliding sleeve (4) has been displaced so far in the direction of the servo piston (8) that its skirt (22) releases the blocking balls (3).System (100) according to one of the preceding claims, characterized in that the sliding sleeve (4) has a preferably hollow-cylindrical section (33), into which the servo piston (8) sealingly dips in order to close the venting path.System (100) according to one of the preceding claims, characterized in that the servo piston (8) and the sliding sleeve (4) are mounted on one another via a rolling bearing (34).System (100) according to one of the preceding claims, characterized in that the sliding sleeve (4) forms a stop for the servo piston (8), which stop prevents its further axial displacement in the direction of the service valve (1).System (100) according to one of the preceding claims, characterized in that the sliding sleeve (4) transmits the pressure force communicated to it by the servo piston (8) to the blocking balls (3).System (100) according to one of the preceding claims, characterized in that the valve spindle (10) is designed such that it passes over a latching point which, when the valve actuator (16) is actuated, indicates haptically to the user that he now impacts the spring valve insert (29) and / or terminates the forced opening of the spring valve insert (29), wherein the latching point is preferably produced by a latching ball pin (28), the ball of which temporarily engages in an annular groove (27) of the valve spindle (10).System (100) according to one of the preceding claims, characterized in that the venting path is formed by at least one transverse bore (4.1) of the sliding sleeve (4), at least one transverse bore (18.2) in the valve housing (18) and ideally a further part of the venting path is formed by at least one transverse bore (2.1) in the blocking sleeve (2), wherein the transverse bore (2.1) is ideally offset with respect to the remainder of the venting path in such a way that an axial throttle gap (2.2) is formed between it and the transverse bore (2.1).The system (100) according to any one of the preceding claims, characterized in that the connection (19) has an inner base body (46) and an outer base body (47), wherein the outer base body (47) is arranged above the inner base body (46).System (100) according to one of the preceding claims, characterized in that the connection part (47) of the connection (19) is a T-piece.System (100) according to one of the preceding claims, characterized in that the connection (19) is designed to be hollow on the inside.System (100) according to one of the preceding claims, characterized in that the connection (19) has two seals (40, 41) which are arranged between the inner base body (46) and the outer base body (47).System (100) according to the preceding claim, characterized in that the two seals (40, 41) are O-rings.System (100) according to either of Claims 20 and 21, characterized in that the two seals (40, 41) are arranged in grooves.System (100) according to one of the preceding claims, characterized in that the connection (19) has a threaded connection (43), in particular a threaded connection (43) for mounting on a service coupling, in particular a service coupling of the connection adapter (0).The system (100) according to any one of the preceding claims, characterized in that the connector (19) is rotatable 360 degrees.System (100) according to one of Claims 1 to 23, characterized in that the connection (19) is rotatable in a range from 45° to 270°.System (100) according to one of the preceding claims 17 to 25, characterized in that the outer base body (47) or the T-piece 47 is secured to the inner base body (46) by a securing means (42).System (100) according to Claim 26, characterized in that the securing means (42) is a securing ring, preferably a spring steel ring or a securing disc.System (100) according to one of the preceding claims, characterized in that the connection (19) is multi-part.

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