Connection device for a fluid line

Abstract

Connection device for a fluid line, comprising a connection element (5) through which a through-channel (7) is penetrated, the through-channel defining at least one axial end section an insertion recess (12) for inserting a fluid line (2) to be connected, a holding device (16) for retaining a fluid line (2) inserted into the insertion recess (12) at its outer circumference (32), and a release element (33) movable with respect to the connection element (5), which can be driven by manual actuation to a release movement (37) by which the holding device (16) can be deactivated and thus the inserted fluid line (2) can be released, enabling it to be pulled out of the insertion recess (12), wherein the connection device (1) has safety means (44) that are effective depending on the fluid pressure prevailing in the through-channel (7) and that prevent manual deactivation of the holding device (16).when an operating fluid pressure exceeding atmospheric pressure is present in the passage channel (7), characterized in that the safety means (44) have actuation-prevention means (45) that prevent manual actuation of the release element (33).

Description

The invention relates to a connecting device for a fluid line, having a connecting element through which a through-channel passes, which defines an insertion recess on at least one axial end section for inserting a fluid line to be connected, having a holding device for holding a fluid line inserted into the insertion recess on its outer periphery, and having a release element which is movable with respect to the connecting element and can be driven by manual actuation to produce a release movement by means of which the holding device can be deactivated and thus a release of the inserted fluid line which enables it to be pulled out of the insertion recess can be triggered.A connection device of this type known from DE 10 2015 000 989 A1 offers the possibility of supplying a fluidic device with the fluidic pressure medium, in particular compressed air, required for its operation. The connection device can be attached to a fluidic device and offers the possibility of detachably connecting a fluid line through which the pressure medium is passed. The connected fluid line, which is, for example, an elastic compressed air hose, is inserted into an insertion recess of the connection device and is held therein by a holding device. By manual actuation of a release element, the holding device can be deactivated, so that the inserted fluid line is released and can be pulled out. The connected fluid line communicates with a through-channel passing through a connection element of the connection device, in which channel, just as in the connected fluid line itself, the pressure medium under a predetermined operating fluid pressure can flow. If the holding device is deactivated by actuation of the release element while the operating fluid pressure is present in the through-channel, there is the risk of the fluid line being pushed out of the insertion recess, which can lead to injuries to the user and / or to damage to adjacent machine components. This hazardous scenario is particularly pronounced in the case of elastic compressed air hoses which can spring out of the connection device in a whip-like manner as a result of the operating fluid pressure prevailing.The same problem is experienced when using a connection device which is disclosed in DE 10 2011 109 787 A1.DE 38 39 612 C1 describes a pneumatic pressure indicator device which can be switched into the path of a compressed air line in order to indicate the fluid pressure prevailing therein. As a result, the user of a fluidic device can inform himself about a possible pressurization of a fluid line before he removes the fluid line from a connected fluidic device.The same applies when using a pressure indicator device known from DE 10 2014 004 205 A1, which offers the advantage of being able to be attached to a fluid line without having to cut through the fluid line. However, the fluid line is punctured when the pressure indicator device is attached, so that the fluid line can no longer be used when the pressure indicator device is subsequently removed again.From FR 2 724 710 A1 a quick coupling for the detachable connection of pipes is known, in which a body of a male element is insertable into a front end of a sleeve, which slides axially in a body of a female element to assume an axial opening position ensuring a connection between the two elements and which, provided with means for axially locking the sleeve to the body of the female element, assumes an axial opening position ensuring the connection between the two elements and which is provided with means for axially locking the sleeve.The invention is based on the object of taking measures to avoid dangerous situations caused by the release of pressurized fluid lines without impairing the functionality of the fluid line.To achieve this object, in a connection device of the type mentioned at the beginning, it is provided that the connection device has, as a function of the fluid pressure prevailing in the through-channel, effective safety means which prevent a manual deactivation of the holding device when an operating fluid pressure exceeding atmospheric pressure is present in the through-channel, and that the safety means have actuation prevention means which prevent a manual actuation of the release element.The safety means actively prevent the holding device from being manually deactivated by a user when an operating fluid pressure exceeding atmospheric pressure is present in the through channel of the connection device communicating with a connected fluid line. The safety means make it possible for the user to readily deactivate the holding device and thereby release the connected fluid line when the operating fluid pressure is present in the through-channel, which could lead to injuries or to adverse effects on the environment of the connection device. Since the safety means operate as a function of pressure, they nevertheless permit unrestricted release of the connected fluid line in the unpressurized state of the through-channel. The effect of preventing deactivation of the holding device is therefore restricted specifically to the cases in which the operating fluid pressure is present in the through-channel and consequently also in the connected fluid line. Due to the pressure-dependent functionality of the safety means, external interventions for setting the current operating state of the safety means are unnecessary, which allows a cost-effective implementation with high functional safety.Advantageous further developments of the invention are evident from the dependent claims.Preferably, the safety means are also designed for signaling the presence of the operating fluid pressure in the through-channel. In this way, the user of the connecting device is signalled when an operating fluid pressure exceeding atmospheric pressure is present in the through-channel of the connecting device communicating with a connected fluid line, which operating fluid pressure could lead to injuries or damage if the fluid line is released. This results in a further improvement in operating safety because the user can be informatively prevented from deactivating the holding device solely by the presence of the operating fluid pressure signaled to him. If the signaled presence of the operating fluid pressure is missed, for example because the signaling of the operating fluid pressure takes place at a point remote from the connection device, there is nevertheless no risk of adverse effects because the safety means prevent the holding device from being deactivated.The safety means are preferably designed such that the application of the operating fluid pressure in the through channel is visualized directly on the connection device itself. This visualization can be effected, for example, by the deformation state of an extensible flexible body or by the position of a pressure-dependently movable element of the safety means. Expediently, the visualization of the presence of the operating fluid pressure as well as the deactivation prevention of the holding device takes place completely non-electrically and solely by a fluid force of the pressure medium located in the through-channel.However, it is entirely possible to equip the safety means with detection means by means of which the presence of the operating fluid pressure can be signaled alternatively and preferably additionally by outputting an electrical information signal. Thus, for example, an on-site optical display directly on the connection device can be coupled with an electrical interrogation, which offers the possibility of supplying a remote device, for example an electronic control device, with a corresponding electrical information signal. The electrical interrogation can be carried out, for example, via switching contacts which are integrated, for example, in MID technology (MID=molded interconnect device), preferably including the required connection technology, into at least one plastic body of the connection device. Alternatively, the interrogation could also be effected magnetically or optically.Preferably, the safety means comprise a safety element movable relative to the connection element depending on the fluid pressure prevailing in the through-channel. The safety element can assume a basic position in the unpressurized state of the through-channel and can be moved by the operating fluid pressure present in the through-channel into a safety position in which it is prevented that the holding device can be deactivated manually.It is advantageous if the movable safety element is also designed for signaling the presence of the operating fluid pressure. In particular, it can be provided that the safety element, when it assumes the safety position, simultaneously also immediately signals the application of the operating fluid pressure. The latter can be realized most easily in that the safety position can be visually recognized from outside the connection device and can thus be directly attributed to the presence of the operating fluid pressure.A particularly reliable visual recognizability can be realized in that the safety element, in the safety position, releases a marking which is concealed in the basic position. Such a marking can be, for example, a color marking or else an alphanumeric indicator.It is advantageous if the safety element together with the connection element delimits a drive chamber which is in fluid communication with the through-channel and is thereby exposed to the fluid pressure prevailing in the through-channel. Thus, the safety element is constantly acted upon in the direction of the safety position by the fluid pressure prevailing in the drive chamber, which corresponds to the fluid pressure prevailing in the through-channel. The resulting fluid force, when the fluid pressure reaches the predetermined operating fluid pressure, is capable of moving the safety element from the initial position and the safety position.The drive chamber is preferably designed as an annular chamber coaxially enclosing the through-channel. As a result, the safety element is acted upon with the fluid pressure over a large area. In addition, a uniform application of pressure results, which counteracts tilting of the movable safety element.It is furthermore advantageous if the safety element is prestressed into the basic position relative to the connection element by spring means. As a result, the safety element is held in the basic position by the spring force of the spring means and, after previous deflection, is also moved back into the basic position again when the passage channel and consequently the drive chamber is pressureless. By means of the design of the spring means, it is possible to set at which level of an operating fluid pressure the safety means respond and the safety element is moved into the safety position. It is consequently possible to preset the sensitivity of the safety means as required by selecting suitable spring means.The safety element is expediently of sleeve-shaped design and arranged such that it encloses the connection element coaxially on the outside with at least part of its length. The user then has, among other things, the advantageous possibility of visually detecting the current position of the security element at the moment.The basic position and the safety position are expediently predefined by first and second stop surfaces arranged on the connection element, with which the safety element can alternatively cooperate. The two stop surfaces point towards each other and are expediently arranged at a distance from each other.In an advantageous embodiment, the connecting device is equipped with a manual venting valve which is connected to the through-channel and which, in particular at any time, enables manual venting of the through-channel. The user is thus provided with the advantageous possibility of venting the through-channel manually in an emergency situation in which the through-channel can no longer be vented by regular measures, in order to lower the fluid pressure prevailing therein such that the holding device can be deactivated by means of the release element for the purpose of releasing the inserted fluid line. Such a manual venting valve is preferably designed as a quick-release valve, which enables venting at a high flow rate.The manual venting valve allows venting of the through-channel at least in the safety position of the safety element and preferably in any position of the safety element.In one possible embodiment of the connection device, the safety means are designed such that they mechanically interrupt the force transmission between the release element and the holding device when the operating fluid pressure is present in the through-channel. The release element can then be driven manually to form a release movement, but this release movement does not affect the operating state of the holding device.A configuration is considered to be particularly advantageous in which the safety means have actuation prevention means which prevent manual actuation of the release element when the operating fluid pressure is present in the passage channel of the connecting device. Such an embodiment can be realized particularly simply and cost-effectively because the release element and the holding device can be configured conventionally and do not require any mutual safety adaptation.In one possible embodiment, the actuation prevention means are designed as shielding means which are capable of preventing manual actuation access to the release element. The release element is thus in principle capable of performing a release movement relative to the connection element, but cannot be acted upon manually, or not easily, because of the correspondingly positioned shielding means, in such a way that it actually performs the release movement.The release element expediently has an actuating section which is situated outside the connection element and can be manually acted upon for the purpose of its release actuation and which is at least partially covered by a shielding section of the safety element when the safety element is moved into the safety position. The shielding section is then preferably pushed over the actuating section of the release element in such a way that the latter is completely or partially covered on its radial outer periphery. Expediently, the shielding section has a length such that it also axially protrudes beyond the actuating section in the safety position of the safety element, so that the release element comes to lie recessed in the shielding section and is particularly difficult to access. The shielding section is in particular sleeve-shaped.In another advantageous embodiment, the actuation prevention means are designed as blocking means which mechanically block the release element when the operating fluid pressure is present in the through-channel such that the same can no longer be caused to move in the release movement.In this context, it is advantageous if a movable safety element of the safety means has a blocking section which, in the basic position, is moved away from the release element in order to enable the release movement and which, in the safety position, bears axially against the release element and supports the same in order to prevent a release movement. The blocking section is expediently designed in the form of a sleeve.There is the advantageous possibility of equipping the actuation prevention means with both shielding means and blocking means, so that the release element is both shielded from external access and blocked from execution of the release movement when the operating fluid pressure is present in the through-channel. This meets particularly high safety requirements.The release element is expediently of sleeve-shaped design and is inserted in the region of the insertion section in an axially movable manner into the passage channel of the connection element. An inserted fluid line expediently extends coaxially through the sleeve-shaped release element.A preferred embodiment of the holding device has an annular holding element arranged on the connection element coaxially with the insertion recess. The holding element has a plurality of holding claws distributed in its circumferential direction, that is to say around the through-channel, which protrude radially inward-in particular obliquely-and which are elastically deformable in the radial direction. When the holding device is activated, the holding claws bear under resilient prestress against the outer periphery of a fluid line inserted into the insertion recess and hold the same firmly. To deactivate the holding device, the release element executing the release movement presses against the holding claws in such a way that the same are lifted from the outer circumference of the inserted fluid line with radial deformation and the fluid line that is consequently no longer held and thus released can be pulled out.The invention is explained in more detail below with reference to the attached drawings. In these show: FIG. 1 shows a preferred first embodiment of the connection device according to the invention in a longitudinal section in the connected state of a fluid line fixed by an activated holding device, FIG. 2 shows the arrangement from FIG. 1 in a perspective longitudinal section, FIG. 3 shows the arrangement from FIGS. 1 and 2 in a longitudinal section with activated safety means, which here have actuation prevention means, FIG. 4 shows the arrangement from FIG. 3 in a perspective longitudinal section, FIG. 5 shows an alternative, further embodiment of the connection device according to the invention in a longitudinal section, wherein an inserted fluid line is held in place by an activated holding device, FIG. 6 shows the arrangement from FIG. 5 in a perspective longitudinal section, FIG. 7 shows the arrangement from FIGS. 5 and 6 with activated safety means, which in turn are designed as actuation prevention means, and FIG. 8 shows the arrangement from FIG. 7 in a perspective longitudinal section.The connection device, which is designated in its entirety by reference numeral 1, enables the detachable connection of a fluid line 2, which is designed for the passage of a fluidic pressure medium such as compressed air or pressure liquid. The fluid line 2 has a line channel 4 which is surrounded peripherally by a line wall 3.The fluid line 2 is preferably a flexible hose. This is particularly the case in connection with compressed air that is too conductive. However, the fluid line 2 can also be a rigid tube.The connection device 1 has a preferably rigid connection element 5 with a longitudinal axis 6. the longitudinal axis 6 preferably corresponds to the longitudinal axis of the entire connection device 1. the connection element 5 is traversed by a passage channel 7, referred to as a passage channel 7, which opens on the one hand on a front side 8 and on the other hand on a rear side 9 of the connection element 5.The front end section of the through-channel 7 assigned to the front side 8 defines an insertion recess 12 which is open on the front side 8 and into which the connected fluid line 2 is inserted by way of an end section 13.In the region of the rear side 9, the connection element 5 forms a fastening section 14, which is provided in order to fasten the connection device 1 to a fluidic device 15, which is only schematically indicated. In the embodiment of FIGS. 1 to 4, the fastening section 14 is designed as a threadless plug-in connector, in the embodiment of FIGS. 6 to 8 as a screw-in connector provided with an external thread. The plug-in connector allows fixing to the fluidic device 15 in a similar manner to the connection of a fluid line by means of a further connection device. Alternatively, the plug-in connection can also be designed for pressing into a fluidic device 15. In the embodiment of FIGS. 5 to 8, the fastening section 14 can be screwed into a threaded opening of a fluidic device 15.In the region of the insertion recess 12, the connection element 5 carries a holding device 16 designed for axially immovable retention of the fluid line 2 inserted into the insertion recess 12. The holding device 16 has an annular cross section and is, for example, of sleeve-like configuration. It is expediently arranged coaxially with the longitudinal axis 6.The holding device 16 preferably has an annular holding element 17 which is expediently arranged coaxially in the insertion recess 12. It has a plurality of resiliently bendable holding claws 18 which are arranged distributed with a mutual spacing in the circumferential direction of the through-channel 7, that is to say around the longitudinal axis 6. Expediently, the holding element 17 has a fixing ring 22 coaxial to the longitudinal axis 6, with which it is fixed directly or indirectly on the connection element 5 and from which the holding claws 18 project radially inward in the direction of the longitudinal axis 6.Each holding claw 18 is preferably inclined with respect to a plane radial to the longitudinal axis 6. This is such that each holding claw 18 extends obliquely radially inward from the fixing ring 22 and simultaneously in the direction of the rear side 9.The holding element 17 can be fixed directly to the connection element 5. However, the fastening manner realized in the exemplary embodiment is expedient, in which the holding element 17 is fixed in a fastening sleeve 23 of the holding device 16 which is separate in this respect and which is in turn inserted into the insertion recess 12 and fastened to the connection element 5 in an axially immovable manner. This axially immovable fastening is realized by way of example in that the fastening sleeve 23 inserted into the insertion recess 12 rests with its rear side against a step 24 of the insertion recess 12 and is supported at the front by an anchoring ring 25 which is anchored axially immovable on the connection element 5, in particular by being pressed positively into the insertion recess 12.In the direction toward the rear side 9, the holding device 16 is adjoined axially by a sealing ring 26, which is likewise arranged in coaxial alignment in the through-channel 7. It is preferably supported axially on the one hand on the fastening sleeve 23 and on the other hand on an annular shoulder 27 formed by a step of the insertion recess 12.The annular holding element 17 preferably represents a spring-elastic structure. The holding element 17 is expediently produced from a material with spring-elastic properties, in particular from metal, preferably spring steel.In the non-inserted state of the fluid line 2, the holding claws 18 assume a tension-neutral starting position in which the diameter bounded by them is smaller than the outer diameter of the fluid line 2. Due to the resilient restoring force which builds up in the process, the holding claws 18 then bear under prestress against the outer periphery 32 of the fluid line 2 and hold the same axially firmly. The holding device 16 assumes an activated operating state.The inserted fluid line 2 also passes through the sealing ring 26, which is thereby somewhat widened and, with sealing contact, bears with prestress all around the outer circumference 32 of the inserted fluid line 2. The sealing ring 26 is also pressed against the inner periphery of the insertion recess 12 with sealing. This results in a fluid-tight connection between the inserted fluid line 2 and the connection element 5. compressed air or another pressure medium can consequently overflow without leakage between the through channel 7 and the line channel 4.The connection device 1 has a movable release element 33, with the aid of which the holding device 16 can be temporarily deactivated, so that the inserted fluid line 2 is released and can be pulled out of the connection device 1 by applying a corresponding tensile force in the opposite direction to the insertion movement 28.The release element 33 is preferably sleeve-shaped and dips with a part of its length from the front side 8 into the insertion recess 12. The sleeve-shaped release element 33 has a through-opening 34 coaxial to the insertion recess 12, the diameter of which is slightly larger than the outer diameter of the fluid line 2, so that the fluid line 2 penetrating into the insertion recess 12 passes through the through-opening 34. When inserted into the insertion recess 12, the fluid line 2 is inserted through the through-opening 34 of the release element 33.The release element 33 has a preferably annular actuating portion 35 which lies outside the connection element 5.An actuating force can be introduced manually into the release element 33 at the actuating section 35, which results in the release element 33 being driven to a release movement 37 indicated by an arrow. The manual application is effected in particular by pressing on it by means of at least one finger of the human hand. During this release movement 37, the release element 33 is moved further axially into the insertion recess 12, so that it acts with its release section 36 on the holding claws 18 and lifts the same from the outer periphery 32 of the fluid line 2 under spring elastic deformation. This corresponds to a deactivated operating state of the holding device 16, in which the inserted fluid line 2 is detached from the holding device 16, so that it can be pulled out of the insertion recess 12 without damage.Expediently, the release section 36 is provided with a hook-like structure 38 which engages radially behind a step on the inner periphery of the fastening sleeve 23, so that the release element 33 is held in the insertion recess 12 in a captive manner.The insertion of the release element 33 into the insertion recess 12 during assembly of the connection device 1 is promoted in that the release section 36 is slotted, so that the segments of the release section 36 resulting therefrom can be bent elastically radially inward until they are latched to the fastening sleeve 23.The actuating portion 35 expediently has a larger outer diameter than the release portion 36 adjoining it. The actuating section 35 is in particular designed such that it projects radially outwards in front of a front axial end face 42 of the connection element 5. This front axial end face 42 is expediently located on a front sleeve-shaped end section 43 of the connection element 5, which peripherally encloses at least a major part of the axial length of the insertion recess 12.The connection device 1 is provided with safety means 44 which operate in dependence on the fluid pressure prevailing in the through-channel 7. The fluid pressure prevailing in the through-channel is the pressure of the fluidic pressure medium located in the through-channel 7. Preferably, the function of the safety means 44 is controlled purely as a function of the fluid pressure prevailing in the through-channel 7, i.e. in particular without an additional external effect.The safety means 44 prevent the holding device 16 from being manually deactivated when an operating fluid pressure exceeding atmospheric pressure is present in the through-channel 7.In the unpressurized state of the through-channel 7, on the other hand, the manual deactivation of the holding device 16 is enabled. The user can then execute a release movement 37 of the release element 33 at any time in order to cause deactivation of the holding device 16, which in the exemplary embodiment results in the holding claws 18 being moved away radially outwards from the longitudinal axis 6 by the release section 36 of the release element 33 in order to lift off from the outer periphery 32 of the fluid line 2.Thus, the safety means 44 can prevent intentional or unintentional loosening of the fluid line 2 inserted into the insertion recess 12 as long as a fluid pressure prevails in the through channel 7 and thus also in the line channel 4, which could result in disadvantageous consequences during a loosening process. Especially if the line wall 3 consists of a flexible material, for example of rubber or of an elastomer material, the release of the fluid line 2 effected under high fluid pressure loading can result in the fluid line 2 being abruptly pushed out of the insertion recess 12 and striking itself like a whip. This can result in injuries to persons located in the vicinity or damage to surrounding peripheral components.An advantage of the safety means 44 is that they can not only prevent the deactivation of the holding device 16, but at the same time are able to signal that the passage channel 7 is at said operating fluid pressure, which is at the same time a trigger for the safety means to be activated and prevent the inserted fluid line from being released.It is common to the illustrated embodiments that the safety means 44 have actuation preventing means 45 which, when the operating fluid pressure is present in the through channel 7, prevent a manual release actuation of the release element 33, which ultimately means that a user is prevented from driving the release element 33 to the release movement 37 already mentioned. This release movement 37 is exemplarily oriented in the axial direction of the longitudinal axis 6 and in principle leads to a linear movement of the release element 33 relative to the connection element 5, namely in such a way that the release element 33 is increasingly pressed further axially into the insertion recess 12.Preferably, the safety means 44 comprise a safety element 46 which is separate with respect to the connection element 5 and is movable relative to the connection element 5. The movement executable by the safety element 46 is referred to as a safety movement 47 and is preferably a pure linear movement which is oriented in particular in the axial direction of the longitudinal axis 6.The safety element 46 is thus movable in the longitudinal direction of the connection element 5 by way of example in order to carry out the safety movement 47.The safety element 46 is preferably sleeve-shaped and arranged on the connection element 5 in coaxial enclosure.Preferably, the safety element 46 has a sleeve-shaped front end section 48 assigned to the front side 8 and a sleeve-shaped rear end section 49 facing the rear side 9.While the front end section 48 of the safety element 46 overlaps the front sleeve-shaped end section 43 of the connection element 5, the rear end section 49 dips from the front side 8 into an annular space 52 which is open toward the front side 8 and is bounded by an inner wall section 54 of the connection element 5 directly delimiting the through-channel 7 and an outer wall section 53 of the connection element 5 enclosing this inner wall section 54 at a radial distance.On the rear side opposite the front side, the annular space 52 is bounded by an annular terminating wall 55 of the connection element 5, which expediently and preferably merges integrally into the fastening section 14.The rear end section 49 of the safety element 46 which dips into the annular chamber 52 from the front functions as an axially movable boundary wall of an annular drive chamber 56. this annular drive chamber 56 is bounded radially on the outside by the outer wall section 53, radially on the inside by the inner wall section 54, on the rear side by the annular boundary wall 55 and on the front side by the rear end section 49 of the safety element 56.Annular sealing means 57 ensure that the annular drive chamber 56 is sealed in the region of the safety element 46 while ensuring the displaceability of the safety element 46 in a sliding manner. By way of example, the annular sealing means 57 consist of a sealing ring which is arranged on the rear side of the safety element 46, i.e. on the front side facing the drive chamber 56. This sealing ring can only loosely abut the safety element 56 or is fixed to the safety element 46 in any desired manner, for example by adhesive bonding.One or more connecting openings 58 formed in the connecting element 5 provide a constant fluid connection between the through channel 7 and the drive chamber 56.In this way, it is ensured that the pressure medium flowing in the through-channel 7 also enters the drive chamber 56 through the connecting openings 58 and the same fluid pressure prevails in the drive chamber 56 as in the through-channel 7.The connection element 5 is preferably embodied in multiple parts and in particular in two parts. It is common to all illustrated exemplary embodiments that the connection element 5 has a front longitudinal section 62 defining the insertion recess 12 and a rear longitudinal section 63 adjoining the rear and having the fastening section 14. The inner wall section 54 is a constituent part of the front longitudinal section 62 and is inserted into a forwardly open fastening recess 64 of the rear longitudinal section 63 which is surrounded by the annular terminating wall 55. The latter belongs to the rear longitudinal section 63 like the outer wall section 53; by virtue of the end section of the front longitudinal section 62 which dips into the fastening recess 64 being slotted once or several times, the radial connecting openings 58 result for the fluid transfer between the passage channel 7 and the drive chamber 56.The two length sections 62, 63 of the connection element 5 are, for example, glued to one another or welded to one another.The axial division of the connection element 5 into two makes it possible without any problems to push the sleeve-shaped safety element 46 onto the front longitudinal section 62 from the rear side before the rear longitudinal section 63 is subsequently attached, so that the safety element 46 is captive axially between the two longitudinal sections 62, 63 of the connection element 5.Preferably, the safety element 46 can be moved, while performing the safety movement 47, between a retracted basic position, which can be seen from FIGS. 1 and 2 and FIGS. 5 and 6, and a safety position, which can be seen from FIGS. 3 and 4 and FIGS. 7 and 8, is displaced forward. The basic position is defined in that the safety element 46 bears against a first stop surface 65 of the connection element 5 which points forwardly in the direction of the insertion recess 12. The safety position is expediently defined in that the safety element 46 bears against a second stop surface 66 of the connection element 5 which points rearward in the direction of the fastening portion 14 and is arranged axially further forward on the connection element 5 than the first stop surface 65.The two stop surfaces 65, 66 are preferably of annular design. By way of example, the first stop surface 65 is formed by the end surface of the sleeve-shaped outer wall section 53, while the second stop surface 66 is formed by a rear end surface 66 aof the front sleeve-shaped end section 43 axially opposite the front axial end surface 42.In the safety element 46, the two front and rear end sections 48, 49 are preferably each sleeve-shaped. The front end section 48 radially outwardly overlaps the front sleeve-shaped end section 43 of the connection element 5 in the axial direction. The rear end section 49 dips into the annular chamber 52 from the front, as mentioned. Since the rear end section 49 has a smaller diameter than the front end section 48, namely in particular both on the outer circumference and on the inner circumference, the safety element 46 has a stepped section 67 connecting the two end sections 48, 49, This stepped section 67 forms a preferably annular first counterstop surface 68 on the outer circumference of the safety element 46 which is directed rearward and faces the first stop surface 65, and On the inner circumference of the sleeve-shaped safety element 46, the stepped section 67 forms a second counterstop surface 69 which is axially opposite the second stop surface 66 and faces it. In the basic position, the safety element 46 bears with its first counter-stop surface 68 against the first stop surface 65 of the connection element 5. In addition, in the safety position, it rests with its second counter-stop surface 69, which points forward, on the second stop surface 66 of the connection element 5.Due to the fluid pressure prevailing during use of the connecting device 1 in the drive chamber 56 preferably coaxially enclosing the through-channel 7, a fluid force is applied to the safety element 46 in the direction of the safety position. By way of example, the fluidic pressure medium acts on the annular sealing means 57 supported on the safety element 46, which transfers the pressure force to the safety element 46. In the case of a seal that is released differently, the pressure medium can also act directly on the rearward-directed rear axial end face 72 of the preferably one-piece safety element 46.The safety means 44 preferably also include spring means 73, by means of which the safety element 46 is preferably constantly prestressed in the direction of its basic position. These spring means 73 are preferably compression spring means. The spring means 73 are in particular of a mechanical type.The spring means 73 are preferably incorporated in the region lying radially between the safety element 46 and the connection element 5. By way of example, the safety element 46 has an inner diameter along part of its length which is greater than the outer diameter of the longitudinal section of the connection element 5 which is at the same axial height, with the result that a spring receiving space 74 is formed between the safety element 46 and the connection element 5, said spring receiving space receiving the spring means 73.The spring means 73 are preferably arranged coaxially around the connection element 5. They are expediently realized in the form of a helical compression spring.By way of example, the spring means 73 are supported axially on the one hand on an annular first support shoulder 75 formed on the outer circumference of the connection element 5 and axially on the other hand on a second support shoulder 76 which is axially opposite the first support sleeve 75 and is formed on the inner circumference of the safety element 46. The spring means 73 are designed with regard to their spring force in such a way that they hold the safety element 46 in the basic position until a fluid pressure, referred to as operating fluid pressure, prevails in the drive chamber 56, which fluid pressure is an overpressure, so that it exceeds the atmospheric pressure. The operating fluid pressure is generally that fluid pressure which the pressure medium located in the through-channel 7 has, in order to enable fluid-controlled operation of the fluidic device 15 connected to the connection device 1. Such an operating fluid pressure is usually in the range between 3 and 6 bar.As soon as the operating fluid pressure is present in the through channel 7 and thus also in the drive chamber 56 continuously communicating with the through channel 7, the safety element 46 is displaced from the basic position forwards into the safety position, performing a safety movement 47 relative to the connection element 5.Since the spring means 73 are constantly active, the safety element 46 is immediately pushed back into the basic position by the spring force of the spring means 73 as soon as the fluid pressure prevailing in the through-channel 7 or in the drive chamber 56 falls below the operating fluid pressure again, which is in particular the case when the through-channel 7 is vented or depressurized by the fluidic device 15 or a venting device which is separate in this respect and is not depicted.Since the safety element 46 is visible to a person standing next to the connection device 1, the safety element 46 directly functions as an indicator means which visually signals, on the basis of its current position, whether the line channel 4 or the through channel 7 is pressureless or whether the operating fluid pressure is present.The visualization of the switching position is advantageously promoted by a marking 77, which is concealed in the basic position of the safety element 46 and is visible only in the safety position. By way of example, such a marking 77 is located as a color marking on the outer periphery of the rear end section 49 of the safety element 46, which is retracted into the annular space 52 in the basic position and is extended out of this annular space 52 in the safety position. For example, the marking 77 can be an annular colored surface extending around the security element 46, which colored, for example, in red. It is understood that another type of marking can also be provided, for example alphanumeric information.The safety means 44 may comprise detection means 78 capable of signalling the presence of the operating fluid pressure by outputting an electrical information signal. Such detection means 78 may include a pressure sensor. However, an embodiment is preferred in which the detection means 78 according to the illustrated exemplary embodiments perform a switching function dependent on the position of the safety element 46. In this context, it is advantageous if the detection means 78 contain at least one first switching contact 78 aarranged on the connection element 5 and at least one second switching contact 78 barranged on the safety element 46, wherein these switching contacts 78 a, 78 bare separated from one another in the basic position of the safety element 46 and bear against one another in an electrically conductive manner in the safety position of the safety element 46. Electrical conductors 78c leading away from the switching contacts 78a, 78b and indicated only schematically in the drawing are connected to an evaluation device, not shown in detail, so that an electrical information signal can be output when a circuit is closed by mutual contacting of the two switching contacts 78a, 78b.The electrical conductors 78 cmay be integrated into the connection element 5 and the safety element 46 in particular using what is known as MID technology (MID=molded interconnect device). These two components are preferably made of plastic material.The two switching contacts 78 a, 78 bare preferably arranged in the region of the second stop surface 66 and the second counterstop surface 69, wherein they can directly form these two surfaces. An assignment to the second stop surface 66 and to the second counterstop surface 69 has the advantage that the switching contacts 78 a, 78 bare covered toward the immediate environment by the safety element 46 having a wall which is preferably free of breakthroughs and are protected against contamination.The actuation prevention means 45 already discussed above are designed in the exemplary embodiment of FIGS. 1 to 4 as blocking means 45 athat block a manual actuation of the release element 33, and in the exemplary embodiment of FIGS. 5 to 8 as shielding means 45 bthat prevent a manual actuation access to the release element 33.The safety element 46 is in one case a component of the blocking means 45 aand in the other case a component of the shielding means 45 b.To realize the blocking means 45 a, the front end section 48 of the safety element 46 forms a preferably sleeve-shaped blocking section 83 which, in the basic position of the safety element 46, is axially offset from the release element 33 to the rear, so that the release movement 37 can be carried out if necessary. In the safety position, on the other hand, the safety element 46 with the blocking section 83 bears axially on the rear side on the release element 33 and supports the release element 33 in such a way that it is blocked against execution of the release movement 37.The blocking portion 83 advantageously interacts with the actuating portion 35 of the release element 33. The actuating portion 35 has a radial extent which corresponds at least to the diameter of the blocking portion 83 so that it is directly axially upstream of the axially oriented front end face 84 of the safety element 46 arranged on the blocking portion 83. In the basic position, the safety element 46 is retracted, so that there is a sufficient axial distance between the front end face 84 and the rear face 85, axially opposite and facing this front end face 84, of the actuating section 35 of the release element 33, in order to enable the release element 33 to move the release movement 37 when manually acted upon accordingly.Expediently, the blocking section 83 is retracted with respect to the front axial end face 42 of the connection element 5 in the basic position of the safety element 46, so that it does not protrude beyond this front axial end face 42 and expediently its front end face 84 is at a distance from this front axial end face 42.When, in the safety position, the safety element 46 with the blocking section 83 bears against the rear face 85 of the actuating section 35, a blocking force opposite the direction of the release movement 37 acts on the actuating section 35 and prevents a release actuation of the release element 33 from being generated with normal manual force application. The blocking force results from the fluid force of the pressure medium acting on the safety element 46 in the drive chamber 56.Preferably, the outer diameter of the safety element 46 in the region of the blocking section 43 is at least substantially the same as that of the actuating section 35 of the release element 33.According to the exemplary embodiment of FIGS. 5 to 8, the shielding means 45 bpreferably contain a shielding section 86 which is formed as a component of the safety element 46. the shielding section 86 is preferably of sleeve-shaped design and is expediently, like the blocking section 83 in the exemplary embodiment of FIGS. 1 to 4, formed by the front end section 48 of the safety element 46.The shield portion 86 has an inner diameter larger than the outer diameter of the operation portion 35 of the release member 33.In the basic position shown in FIGS. 5 and 6, the safety element 46 is moved back relative to the connection element 5 to such an extent that the release element 33 is easily accessible in order to manually actuate it in order to produce the release movement 37.It is advantageous if the shielding section 86 is positioned in the basic position of the safety element 46 in a manner comparable to the blocking section 83 in the exemplary embodiment of FIGS. 1 to 4, so that the details concerning the blocking section 83 made in this respect also apply to the shielding section 86.In the safety position displaced forward, the shielding section 86 protrudes axially beyond the connection element 5 on the front side 8 to such an extent that it extends radially outwards beyond the actuating section 35 of the release element 33. As a result, the actuating section 35 is preferably covered all the way around its radial outer periphery, i.e. completely, and is withdrawn from a pressing access. It is of course possible to design the shielding section 86 such that it only partially covers the actuating section 35 on the outer circumference, but in such a way that manual actuation access is impossible. This would be possible, for example, by virtue of the fact that the sleeve-shaped shielding section 86 is perforated or slotted. Moreover, such a configuration is also possible in principle for the blocking section 83.Preferably, the safety element 46 is designed such that, in the safety position, it also protrudes axially forward beyond the actuating section 35 of the release element 33 by its shielding section 86. Here, the release element 33 is then axially recessed with respect to the safety element 46 moved into the safety position to such an extent that the front end face 84 of the shielding section 86 is disposed at a distance upstream of the front face 87 of the release element 33 pointing in the same direction. The farther the release element 33 is overlapped by the shielding section 86 in the region of the front face 87, the more intensive the shielding function with respect to the release element 33.The release element 33 cannot be covered by the shielding section 86 on its axial front side. Since the radial distance defined between the outer circumference of the inserted fluid line 2 and the inner circumference of the shielding section 86 is relatively small, the actuating section 35 is nevertheless withdrawn from a pressing access by human fingers, so that an effective shielding function is provided.Expediently, the inner diameter of the shielding section 86 is only slightly larger than the outer diameter of the actuating section 35.In FIGS. 3 and 4 and in FIGS. 7 and 8, the displacement movement of the safety element 46 from the basic position into the safety position is indicated in each case by an arrow 47 a, which displacement movement takes place when pressure medium under the operating fluid pressure enters the drive chamber 56 according to the flow arrows 89 drawn in the same figures and exerts a fluidic actuating force on the safety element 46 which is greater than the opposing spring force of the spring means 73.All illustrated embodiments of the connection device 1 have in common an optional feature which consists of a manually illustrated vent valve 92 which is only symbolically illustrated. The manual vent valve 92 is preferably arranged in or on the connection element 5 and is preferably integrated into the connection element 5. The through-channel 7 can be vented as required by the manual venting valve 92, wherein, by way of example, venting of the through-channel 7 is associated with simultaneous venting of the drive chamber 56.The manual venting valve 92 is associated with a venting channel 93 which passes through the wall of the connecting element 5. The venting channel 93 opens at one end, in accordance with the illustrated exemplary embodiment, into the through channel 7 or alternatively, in a manner not shown, directly into the drive chamber 56.In the normally assumed closed position of the manual venting valve 92, the venting channel 93 is closed. If necessary, however, it is possible to switch the manual venting valve 92 manually into an open position, so that the through-channel 7 is vented. In the exemplary embodiment, the venting of the through-channel 7 brings about a simultaneous venting of the drive chamber 56, since the same is in fluid communication with the through-channel 7. Thus, for example, the drive chamber 56 is vented through the through channel 7.If the venting channel 93 opens into the drive chamber 56 according to the mentioned and not illustrated exemplary embodiment, it can be vented directly, i.e. bypassing the through channel 7, by actuating the manual venting valve 92. In this case, the through-channel 7 is then vented indirectly through the drive chamber 56.The manual venting valve 92 is in particular also designed for the direct venting of the through-channel 7 when the connection device 1 does not have a drive chamber 56 and the safety means 44 are actuated directly by the pressure medium located in the through-channel 7. For example, an actuating element of the safety means 44 can project into the through-channel 7 in order to be acted upon directly in the through-channel 7 by the fluid pressure prevailing therein and to prevent the deactivation of the holding device 16 when the fluid pressure has the operating pressure.Manual venting is useful in cases in which, for example, due to a fault or due to an emergency stop situation, the pressure medium in the through-channel 7 is enclosed under the operating fluid pressure, so that the fluid line 2 cannot be removed. The user then has the possibility of lowering the internal fluid pressure by actuating the manual vent valve 92 in order to enable the fluid line 2 to be released.For manual actuation, the manual vent valve 92 has a manual actuating element 94 which is accessible from the outside and is expediently arranged in a recessed manner in the connection element 5, so that it cannot be accidentally actuated.

Claims

Connection device for a fluid line, having a connection element (5) through which a through-channel (7) passes, which defines an insertion recess (12) on at least one axial end section for inserting a fluid line (2) to be connected, having a holding device (16) for holding a fluid line (2) inserted into the insertion recess (12) on its outer periphery (32), and having a release element (33) which can be moved with respect to the connection element (5) and can be driven by manual actuation to form a release movement (37) by means of which the holding device (16) can be deactivated and hence a release of the inserted fluid line (2) which enables the inserted fluid line (2) to be pulled out of the insertion recess (12) can be triggered, wherein the connection device (1) has, as a function of the fluid pressure prevailing in the through-channel (7), effective safety means (44) which prevent a manual deactivation of the holding device (16), when an operating fluid pressure exceeding atmospheric pressure is present in the through-passage (7), characterized in that the safety means (44) comprise actuation prevention means (45) preventing the manual actuation of the release element (33).Connection device according to claim 1, characterised in that the safety means (44) are also designed to signal the presence of the operating fluid pressure in the through-channel (7), wherein the presence of the operating fluid pressure in the through-channel (7) can expediently be visualized directly on the connection device (1) by the safety means (44).Connection device according to claim 2, characterised in that the safety means (44) have detection means (78), by means of which the presence of the operating fluid pressure can be signalled by outputting an electrical information signal.Connection device according to one of Claims 1 to 3, characterized in that the safety means (44) have a safety element (46) which is movable relative to the connection element (5) as a function of the fluid pressure prevailing in the through-channel (7) and which assumes a basic position in the unpressurized state of the through-channel (7) and which can be moved by the operating fluid pressure present into a safety position which prevents the holding device (16) from being deactivated manually.Connection device according to claim 4, characterised in that the safety element (46) occupying the safety position signals directly that the operating fluid pressure is present in the through-channel (7).Connection device according to claim 5, characterised in that the application of the operating fluid pressure in the through-channel (7) can be visually recognised directly on the basis of the safety position occupied by the safety element (46), expediently by releasing a marking (77) concealed in the basic position of the safety element (46).Connection device according to one of Claims 4 to 6, characterized in that the safety element (46) together with the connection element (5) delimits a drive chamber (56) which is in fluid communication with the through-channel (7) and is therefore exposed to the fluid pressure prevailing in the through-channel (7), the safety element (46) being acted upon in the direction of the safety position by the fluid pressure prevailing in the drive chamber (56).Connection device according to claim 7, characterised in that the drive chamber (56) is an annular chamber coaxially enclosing the through-channel (7).Connection device according to claim 7 or 8, characterised in that the safety element (46) is prestressed by spring means (73) relative to the connection element (5) into the basic position, from which it can be moved against the spring force of the spring means (73) into the safety position by the fluid pressure prevailing in the drive chamber (56), when this fluid pressure has the operating fluid pressure.Connection device according to one of Claims 4 to 9, characterized in that the safety element (46) is of sleeve-shaped design and encloses the connection element (5) coaxially.Connection device according to one of Claims 4 to 10, characterized in that the connection element (5) has two first and second stop surfaces (65, 66) which are axially spaced apart from one another and face one another, wherein the safety element (46) bears against the first stop surface (65) in the basic position and against the second stop surface (66) in the safety position.Connection device according to one of Claims 1 to 11, characterized in that a manual venting valve (92), which is designed as a constituent part of the connection device (1) and is suitable for manually venting the through-channel (7), is connected to the through-channel (7) and is expediently arranged on the connection element (5).Connection device according to one of Claims 1 to 12, characterized in that the actuation prevention means (45) are designed as shielding means (45b) which prevent manual actuation access to the release element (33).Connection device according to claim 13 in conjunction with one of claims 4 to 12, characterised in that the release element (33) has an actuating section (35) which lies outside the connection element (5) and can be manually acted upon for its release actuation, wherein the safety element (46) has an expediently sleeve-shaped shielding section (86) which, in the safety position, is pushed over the actuating section (35) of the release element (33) in such a way that the latter is at least partially covered on its radial outer periphery, wherein the actuating section (35) is expediently also axially overlapped by the shielding section (86).Connection device according to one of Claims 1 to 14, characterized in that the actuation prevention means (45) are designed as blocking means (45a) which block the manual actuation of the release element (33).Connection device according to claim 15 in conjunction with one of claims 4 to 12, characterised in that the safety element (46) has an expediently sleeve-shaped blocking section (83), which in the basic position is moved away from the release element (33), enabling the release movement (37) thereof, and which in the safety position bears axially against the release element (33) and supports the same in order to prevent a release movement (37).Connection device according to one of Claims 1 to 16, characterized in that the release element (33) is of sleeve-shaped design and, in the region of the insertion recess (12), dips coaxially into the through-channel (7) of the connection element (5) in an axially movable manner, an inserted fluid line (2) passing coaxially through the release element (33).Connection device according to one of Claims 1 to 17, characterized in that the holding device (16) has an annular holding element (17) which is arranged on the connection element (5) coaxially with the insertion recess (12) and has a plurality of holding claws (18) which are distributed in the circumferential direction and project radially inwards and which are elastically deformable, the holding claws (18) bearing under prestress on the outer circumference of a fluid line (2) inserted into the insertion recess (12) when the holding device (16) is activated and being able to be lifted from the outer circumference (32) of the inserted fluid line (2) by the release element (33) which performs a release movement (37) in order to deactivate the holding device (16).

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