Connection device

Abstract

Connecting device with a first connecting piece (14) and a second connecting piece (12) that can be inserted into the first connecting piece (14), wherein the connecting pieces (12, 14) each have one or more locking elements in a plugging section (18, 24) which, in a first region of the possible rotational orientations of the connecting pieces (12, 14) relative to each other, can form a positive locking connection that prevents the second connecting piece (12) from being pulled out of the first connecting piece (14), wherein this positive locking connection is released in a second region of the possible rotational orientations, and wherein detent connecting elements are included which, in several rotational orientations within the first region, form a detent connection that prevents the connecting pieces (12, 14) from being rotated relative to each other.characterized by a locking arm (46) extending circumferentially with respect to the longitudinal axis (30) of the associated connecting piece (14), which is elastically deflectable in the direction of the longitudinal axis (30) to release the locking connection.

Description

The invention relates to a connecting device with a first connecting piece and a second connecting piece that can be inserted into the first connecting piece, wherein the connecting pieces each have one or more locking elements in a plugging section, which in a first region of the possible rotational orientations of the connecting pieces relative to each other can form a positive locking connection that prevents the second connecting piece from being pulled out of the first connecting piece, wherein this positive locking connection is released in a second region of the possible rotational orientations. The invention further relates to the use of such a connecting device for connecting two fluid-carrying components of an internal combustion engine, in particular an internal combustion engine of a motor vehicle. From DE 10 2014 102 240 A1, a connection device for connecting an outlet pipe of a turbocharger to a charge air pipe is known, in which the two nested pipes are connected to each other in a tensile-resistant manner by means of a connecting element. The connecting element comprises an annular section in the inside of which recesses are formed that are complementary to locking projections of a first of the pipes, so that by sliding the connecting element onto the pipe and then partially rotating it, a bayonet-like connection can be formed with this first pipe. The connecting element further comprises a connecting web extending from the annular section towards the second pipe with a through-opening that serves to receive a screw which is screwed into an internal thread of the second pipe. WO 2014 / 056652 A1 describes a coupling device for connecting pipe sections of a fresh gas stream of an internal combustion engine, wherein a nozzle connected to one of the pipe sections can be inserted into a receptacle connected to the other pipe section and secured therein by means of locking elements in a form-fitting, tensile-resistant manner. The locking elements are part of a locking ring that can be attached to the outside of the receptacle during pre-assembly, the locking elements engaging in locking openings that extend through the radial direction and projecting inwards beyond the inside of the receptacle. When the nozzle is inserted into the receptacle, the locking elements are temporarily displaced radially outwards by an insertion chamfer on the nozzle and then, in the deformed position of the nozzle within the receptacle, engage in a circumferential locking groove of the nozzle.To release the coupling device, the locking ring on the receptacle can be rotated a short distance, causing the locking elements to run onto a ramp of the receptacle and thus disengage from the locking groove of the fitting. From EP 1 835 144 B1 a connection device for attaching an air guide element to a compressor of an exhaust gas turbocharger is known, in which two nested connecting pieces are secured by means of a locking ring, wherein the locking ring forms a bayonet closure with each of the connecting pieces. WO 01 / 61 235 A1 and US 643 358 A each disclose a connecting device with two connecting pieces which can be connected to each other by means of a bayonet connection, wherein in several rotational orientations of the connecting pieces, with an effective bayonet connection, a locking connection is effective which secures against loosening of the bayonet connection. Based on this prior art, the invention was based on the objective of providing a connecting device, in particular for the connection of two gas-conducting components of a fresh gas stream or an exhaust gas stream of an internal combustion engine, which is easy and quick to handle and at the same time is sufficiently secured against unintentional loosening. This problem is solved by means of a connecting device according to claim 1. A connecting piece for such a connecting device is the subject of claim 11. The use of such a connecting device for connecting two fluid-conducting, i.e., liquid- or gas-conducting, components of an internal combustion engine, in particular a fresh gas stream and / or an exhaust stream of an internal combustion engine, is the subject of claim 13. Advantageous embodiments of the connecting device according to the invention and (therefore) of the connecting piece according to the invention are the subject of further claims and will become apparent from the following description of the invention. A connecting device according to the invention comprises at least a first connecting piece and a second connecting piece that can be inserted into the first connecting piece, wherein the connecting pieces each have one or more locking elements (for example in the form of a locking projection or a locking recess) in a plugging section, which can form a positive locking connection in a first area of ​​the possible rotational orientations of the connecting pieces relative to each other, securing against the second connecting piece being pulled out of the first connecting piece, wherein this positive locking connection is released in a second area of ​​the possible rotational orientations.Furthermore, such a connecting device comprises locking connecting elements which, in several rotational orientations within the first area, form a locking connection that prevents relative rotation of the connecting pieces (at least in one release direction). A locking arm extending circumferentially with respect to the insertion direction is provided, which can be elastically deflected in the direction of the corresponding longitudinal axis to release the locking connection. The connecting device according to the invention thus forms a type of bayonet lock, by which the two connecting pieces are primarily and, in particular, tensilely secured to one another, thereby enabling simple and quick connection of the connecting pieces. Additionally, when the bayonet lock is closed, the connecting device according to the invention forms a locking mechanism, by means of which the connecting pieces are further secured against rotation relative to each other and thus against unintentional loosening of the bayonet lock. By choosing a locking mechanism for the implementation of this additional securing feature, it can be achieved (in a preferred embodiment) that this locking mechanism engages automatically when the bayonet lock is closed, i.e., when the bayonet lock is closed.The locking mechanism becomes effective when the nested connecting pieces are rotated into a rotational orientation within the first range, while active and especially manual manipulation of the locking mechanism is only required to release the bayonet fitting, i.e., to rotate the still nested connecting pieces into a rotational orientation within the second range. In this way, despite the locking mechanism providing good security for the closed bayonet fitting, closing the bayonet fitting is not hindered, or only to a negligible extent.A structurally simple design for the connecting device, which can also enable relatively easy handling of the snap-fit ​​connection elements, is realized according to the invention by means of the snap arm extending circumferentially with respect to the insertion direction, which can be elastically deflected in the direction of the associated longitudinal axis to release the snap connection. A "locking connection" is understood to be a positive-locking interaction of at least two "locking connection elements" that is effective in at least one direction. This interaction occurs automatically upon appropriate positioning of the locking connection elements as a result of an elastic load on at least one of the locking connection elements. It may be designed so that the positive-locking interaction, and thus the locking connection, can only be released without active, and in particular manual, intervention of at least one of the locking elements by means of a non-functionally intended deformation and, in particular, by the destruction of one of the locking elements. Alternatively, it is also possible to design the positive-locking locking connection such that, upon exceeding a limiting release force, the locking connection is released in a defined manner, without requiring direct active, and in particular manual, intervention of at least one of the locking connection elements.For example, it can be provided that a locking projection is elastically actuated in a locking recess to form a locking connection, the depth of which decreases continuously in at least one release direction, so that through a relative movement of the locking connection elements the locking projection is completely moved out of the locking recess under increasing elastic prestress when the force causing the relative movement exceeds a limiting release force. According to the invention, a "plug-in section" is understood to be a section of the connecting pieces, wherein these (plug-in) sections are arranged coaxially to each other when the connecting device is connected, and wherein a (preferably cylindrical) outer side of the second connecting piece is located within a similarly (preferably cylindrical) inner side of the first connecting piece. The locking arm of a connecting piece according to the invention can preferably form one or more locking projections at its free end, which (each) in a corresponding rotational orientation of the connecting pieces within the first area bear against a locking edge of the other (counter-)connecting piece in order to prevent or prevent the connecting pieces from rotating in at least the direction of release. A connecting piece for a connecting device according to the invention has one or more locking elements in a plug-in section which is provided for plugging together with a plug-in section of a complementary counter-connecting piece (of the connecting device according to the invention), wherein the locking elements are provided to form a positive locking connection effective in a first area of ​​possible rotational orientations of the connecting piece relative to the counter-connecting piece and securing against the disconnection of the connecting piece from the counter-connecting piece, wherein this positive locking connection is released in a second area of ​​possible rotational orientations.Such a connecting piece is further characterized by a locking element which, in conjunction with a locking element of the mating connecting piece, can form a locking connection within the first area in several possible rotational orientations, preventing the connecting piece from rotating relative to the mating piece. A locking arm extending circumferentially with respect to the insertion direction is provided, which can be elastically deflected in the direction of the corresponding longitudinal axis to release the locking connection. In a preferred embodiment of the connecting device according to the invention, the locking elements can be designed such that, when the connecting sleeves are rotated relative to each other from the second region to the first region, the second connecting sleeve is moved (further) into the first connecting sleeve. In this way, the joining of the connecting sleeves by the additional rotation of the connecting sleeves relative to each other, which is intended to form the bayonet lock, can at least be supported, thereby further simplifying the handling of the connecting device according to the invention. It may also be preferably provided that at least one axial contact surface (relative to the orientation of a plug axis along which the connecting pieces are plugged into each other) is provided for the connecting pieces, wherein these axial contact surfaces would preferably limit the maximum insertion depth of the second connecting piece into the first connecting piece when in contact with each other (directly or by means of an intermediate functional element, in particular a sealing element, integrated into at least one of the axial contact surfaces).This allows not only the insertion depth of the second connecting piece into the first connecting piece to be limited by the axial contact surfaces striking each other, but also a relatively good seal of the connecting device against, in particular, the escape of a product, especially a fluid (gas or liquid), through the connecting pieces in a structurally simple way. A particularly good seal can be achieved if (preferably) one or more sealing elements (especially in the form of a sealing ring) are integrated into the axial contact surface of at least one of the connecting pieces. In combination with a design of the connecting device in which the interaction of the locking elements, when the connecting pieces are rotated from the second area to the first area, moves the second connecting piece (further) into the first connecting piece, it can also be ensured that the sealing element(s) are sufficiently deformed between the axial contact surfaces of the connecting pieces as a result of this insertion movement caused by the rotation of the connecting pieces, in order to guarantee a sufficiently reliable seal despite form and positional tolerances of the components of the connecting device. In a further preferred embodiment of the connection device according to the invention, the axial contact surfaces can be located radially outside the cross-sections of the plug sections with respect to the plug axis. This allows for good stability of the closed connection device, particularly against bending loads, since such bending loads can be advantageously supported by the comparatively large contact surfaces, which are relatively far apart from the bending or plug axis. With sealing element(s) integrated into the axial contact surfaces, such a relatively large dimensioning of the axial contact surfaces can also have an advantageous effect with regard to the sealing action. It is further preferred that the length of at least one of the plug sections be at least 50% of the (largest) inner diameter of the corresponding connecting piece. Such a relatively large or long dimension of the plug sections allows them to be advantageously supported by bending loads and also ensures a relatively good seal of the connection device. Particularly with regard to the dimensions of the connection device according to the invention, it can be advantageous if the first connecting piece forms a push-fit section for a pipe on the outside of its insertion section (and especially coaxially thereto). The longitudinal extent of the first connecting piece in the area of ​​the insertion sections can thereby be advantageously used both for connecting the first connection device to the second connecting piece and to the pipe, resulting in a particularly compact design for the connection device as a whole. In a further preferred embodiment of the connection device according to the invention, it can be provided that the plug sections of the connecting pieces are each formed by a cylindrical (inner or outer) base surface, which preferably makes contact or almost makes contact over as much of the entire surface as possible in the closed state of the connection device, wherein at least one of the locking elements (or one of the locking elements of each pair of positively interlocking locking elements) is formed as a locking projection projecting from the associated base surface and at least one other of the locking elements is formed as a locking recess provided in the associated base surface.In this way, particularly good support of bending loads and good sealing of the connection device can be achieved through the plug sections of the connecting spigots as a result of a relatively large contact area formed by the base surfaces. It is further preferred that the locking recess(s) widen(s) from a locking section into which the corresponding locking projections are inserted after assembly by rotating the connecting pieces, towards the free end of the corresponding connecting piece (i.e., opposite to the insertion direction), whereby this widening can be as stepless as possible, for example, running diagonally. In this way, such a locking recess can form an "insertion funnel" for the corresponding locking projection, thereby simplifying the correct (rotational) alignment of the connecting pieces relative to each other, i.e., enabling the connection of the connecting device, even when the connecting device is still detached. In one embodiment of the connecting device according to the invention, each connecting sleeve can further be provided with a stop surface which, upon contact with one another, limits the first range of possible rotational orientations in the locking direction. This prevents the connecting sleeves from being rotated relative to each other to such an extent that the locking connecting elements are disengaged and can no longer perform their function. In a further preferred embodiment of the connection device according to the invention, a projection can also be provided on one of the connecting pieces which, when the connecting pieces are joined in a rotational orientation within the first or second region, can engage in a recess of the other connecting piece. In this way, it can be ensured, for example, that the connecting pieces are (rotationally) aligned with each other for connection in such a way that, upon subsequent rotation, not only the tensile-locking connection but also the snap-fit ​​connection is formed. The locking connection can preferably be effective in the direction of the longitudinal axis of the corresponding connecting piece; that is, the direction of the relative movement of the locking connection elements, by which the locking connection is closed or released, has at least one directional component that is coaxial or parallel to this longitudinal axis. Alternatively (or additionally with another pair of locking connection elements), it is also possible, for example, to design the locking connection as effective in the radial direction with respect to the corresponding longitudinal axis. A connecting device according to the invention is particularly suitable for connecting two fluid-conducting components (fluid: gas and / or liquid) of an internal combustion engine, especially an internal combustion engine intended for generating propulsion power for a motor vehicle, particularly a wheel-based motor vehicle (preferably passenger cars and trucks). The two fluid-conducting components can particularly preferably be two gas-conducting components of a fresh air stream and / or an exhaust stream. The ease of handling of the connecting device according to the invention, which in particular also allows for simple manual connection without visual contact, is advantageous in the generally very confined installation spaces found in the engine compartments of modern motor vehicles.The same applies to the comparatively compact dimensions that can be achieved through the inventive design of a connecting device while maintaining relatively high load-bearing capacity, particularly with regard to bending loads, and relatively good sealing. The indefinite articles (“a”, “an”, “one”, and “ones”), particularly in the patent claims and in the description generally explaining the patent claims, are to be understood as such and not as numerals. Accordingly, components specified by these articles are to be understood as existing at least once and potentially existing multiple times. The present invention is explained in more detail below with reference to an embodiment illustrated in the drawings. The drawings show: Fig. 1: a connecting device according to the invention in the connected state; Fig. 2: a detailed view of the locking connecting elements of the connecting device in the connected state (but without the gas supply line); Fig. 3: a longitudinal section through the connecting device in the connected state; Fig. 4: the connecting device in the disconnected state in a first perspective view; and Fig. 5: the connecting device in the disconnected state in a second perspective view. The drawings show a housing 10 of a compressor (not shown), which forms part of an exhaust gas turbocharger of an internal combustion engine (also not shown) of a motor vehicle. On the inlet side, the housing 10 integrates a connecting piece 12, which can be connected as a second connecting piece 12 to a first connecting piece 14 of a connection device according to the invention. The first connecting piece 14 is connected to one end of a gas supply line 16. The connection device thus serves to connect the gas supply line 16, which, like the compressor, is a gas-conducting component of a fresh gas stream of the internal combustion engine, to the inlet side of the housing 10 of the compressor.This connection between the gas supply pipe 16 and the housing 10 must be made both for the assembly of the internal combustion engine during the manufacture of the motor vehicle and during maintenance work, so that the connecting device should not only be able to be connected as quickly and easily as possible but also be able to be detached again without damage. The second connecting piece 12, integrally formed by the compressor housing 10, comprises a substantially hollow cylindrical plug-in section 18. On the outer surface of this section, a plurality of (here specifically three) identically dimensioned locking elements in the form of locking projections 20 are provided. These projections are arranged at uniform intervals along a closed circumferential line on the outer surface of the plug-in section 18, which forms a cylindrical base. An arrangement with non-uniform spacing is also possible and may be more advantageous, for example, to allow connection of the connecting pieces 12 and 14 only in one rotational orientation relative to each other, and / or to connect only two precisely matched connecting pieces 12 and 14 (so-called coding). The arrangement of the locking projections 20 relative to each other is identical with respect to their spacing in relation to a free, front end of the plug section 18 (or of the second connecting piece 12 as a whole) and in relation to a rear end of the plug section 18. A stop flange 22 of the second connecting piece 12 adjoins this rear end of the plug section 18. To connect the connecting device, the plug section 18 of the second connecting piece 12 interacts with a complementary, hollow cylindrical plug section 24 of the first connecting piece 14, in the inner surface of which (as a cylindrical base) a number (here: three) of identically dimensioned locking elements in the form of locking recesses 26 corresponding to the number of locking projections 20 of the second connecting piece 12 are integrated (see Fig. 5). The course of each locking recess 26, starting from a front, free end of the first connecting piece 14 towards its rear end, is approximately S-shaped and includes an insertion section 28, which extends approximately in the direction of the plug axis 30 (or...The longitudinal profile of the locking recesses 26 is aligned with the longitudinal axis 30 of the plug section 24 of the first connecting piece 14 and – in the connected state of the connecting device – also with the longitudinal axis 30 of the second connecting piece 12), wherein the width of the locking recesses 26 decreases continuously and linearly within the respective insertion section 28. The width of the locking recesses 26 at the end of the respective insertion section 28 is only slightly larger than the width (i.e., the circumferential extent) of the locking projections 20 of the second connecting piece 12. The insertion section 28 of each of the locking recesses 26 transitions into a locking section 32, which has a longitudinal profile oriented approximately circumferentially and inclined by only a few degrees (from the insertion section 28) towards the rear end (of the plug-in section 24) of the first connecting sleeve 14. The width of each of the locking recesses 26 in the region of the respective locking section 32 is at least slightly greater than the (maximum) length (i.e.,Dimensioning in the direction of the insertion axis 30 or along the longitudinal axis 30 of the second connecting piece 12) of the locking projections 20 of the second connecting piece 12, so that the locking projections 20 introduced into the insertion sections 28 of the locking recesses 26 by inserting the second connecting piece 12 into the first connecting piece 14 can be moved by rotating the two connecting pieces 12, 14 relative to each other in the locking rotation direction 34 up to the ends of the locking sections 32, in which the locking projections 20 in conjunction with the locking recesses 26 form a positive locking connection that is effective with respect to a tensile load on the connecting device. The locking sections 32 of the locking recesses 26 each transition into a run-out section 36, which terminates at the rear end of the plug section 24 of the first connecting piece 14 and advantageously enables the first connecting piece 14 to be manufactured by injection molding from plastic (e.g. PA 46), since in this way undercuts formed by the locking recesses 26 can be avoided when demolding in the direction of the longitudinal axis 30 of the first connecting piece 14. A twisting of the connecting pieces 12, 14 relative to each other to form the positive locking connection is only possible when the connecting pieces 12, 14 have been pushed together to such an extent that the connecting projections 20 are located at the ends of the insertion sections 28 of the locking recesses 26, whereby an additional (circumferential) axial contact surface 38 formed by the stop flange 22 of the second connecting piece 12 is located in relatively close proximity to an axial contact surface 42 formed by an annularly circumferential stop flange 40 of the first connecting piece 14, which is arranged at the front end of its plug-in section 24.It can be provided that a sealing element 44 in the form of a sealing ring, which is partially arranged in a circumferential receiving groove introduced into the axial contact surface 42 of the stop flange 40 of the first connecting piece 14, but which projects beyond this axial contact surface 42, already contacts the axial contact surface of the stop flange 22 of the second connecting piece 12, without, however, already being compressed to a significant degree between the axial contact surfaces 38, 42 of the stop flanges 22, 40 of the connecting pieces 12, 14.Such compression of the sealing element 44 only occurs when the connecting pieces 12, 14 are rotated relative to each other to form the positive-locking connection that secures the connecting pieces 12, 14 in tension. This is because the longitudinal orientation of the locking sections 32 of the locking recesses 26, which is slightly oriented towards the rear end of the first connecting piece 14, results in such rotation being accompanied by a slightly further insertion of the connecting pieces 12, 14. Consequently, such rotation of the connecting pieces 12, 14 relative to each other not only forms the positive-locking connection that secures the connecting pieces 12, 14 in tension, but also ensures a reliable seal of the connected device by means of the then sufficiently compressed sealing element 44. The longitudinal profile of the locking section 32 of each of the locking recesses 26 can, for example, be linear, which would also create a linear relationship between the rotation and the resulting further insertion of the connecting pieces 12, 14, and consequently the profile of the handling torque with which this rotation is effected. However, such a linear profile can lead to a relatively large handling torque at the end of the rotation, which could make connecting the device more difficult. Advantageously, a degressive profile of the handling torque can therefore be provided, which can be achieved by a corresponding arcuate longitudinal profile of the locking section 32 of each of the locking recesses 26. In principle, the contact between the rear boundary surfaces of the locking projections 20 and the front boundary surfaces of the locking sections of the locking recesses 26 and the compression and thus elastic preload of the sealing element 44 caused by this contact creates a relatively small force-locking securing of the connection against unintentional rotation of the connecting spigots 12, 14 relative to each other in the release direction (opposite to the locking direction of rotation 34). According to the invention, this force-fit locking mechanism is further supplemented by a latching connection, which is formed in a connected state of the connecting device by cooperating latching elements of the two connecting pieces 12, 14. A latching arm 46 serves as the latching element of the first connecting piece 14, one end of which extends into the outer surface of the associated stop flange 40 and which extends in an arc shape in an approximately parallel orientation to the outer surface of this connecting flange 40 along a circumferential section, with this latching arm 46 additionally extending slightly towards the front, free end of the first connecting piece 14 and thus projecting a short distance beyond this free end.At the free end of the locking arm 46, it has a plurality (here specifically two) of steps in its end face, whereby locking projections 48 are formed which can interact with a locking edge 50, which is radially aligned with respect to the longitudinal axis 30 of the second connecting piece 12 and is formed by a first end surface of a recess 52 of the stop flange of this connecting piece 12. The arrangement of the locking arm 46 on the circumference of the stop flange 40 of the first connecting piece 14 is selected such that, when the connecting pieces 12, 14 are joined (in which case the locking projections 20 are still located within the insertion sections 28 of the locking recesses 26), its free end is pressed against a section of the axial contact surface 38 of the stop flange 22 of the second connecting piece 12 that is located upstream of the recess, causing the locking arm 46 to be elastically deflected in one of the directions defined by the insertion axis 30. Only when the connecting pieces 12, 14 are rotated relative to each other into a predetermined end position,In which the locking projections 20, in conjunction with the locking recesses 26, form a positive-locking connection that secures the connecting device under tension, and the sealing element 44 is sufficiently deformed between the axial contact surfaces 38, 42 of the stop flanges 22, 40 to ensure adequate sealing, the snap-fit ​​connecting elements of the two connecting spigots 12, 14 come into operative connection with each other. Depending on the form and positional tolerances of the connecting spigots 12, 14 and the sealing element 44, as well as depending on the assembly torque manually applied for connecting the connecting device, the snap arm 46, due to its elastic deflection, engages in the recess 52 of the stop flange 22 of the second connecting spigot 12 to such an extent that the snap edge 50 either rests against one of the snap projections 48 or, as shown in Figs. 1 and 2,The locking arm 46 is fully engaged with its free end in the recess 52. This rotational alignment of the interconnected connecting pieces 12, 14 relative to each other, shown in Figs. 1 and 2, represents the absolute end position, because further rotation in the locking direction 34 is prevented at least by a stop surface 54 of a stop element 56, which projects beyond the stop flange 40 of the first connecting piece 14 towards its free end, abutting a stop surface 58 of the second connecting piece 12. This stop surface 58 of the second connecting piece 12 is formed by the second end surface of the recess 52 of the associated stop flange 22. The recess 52 thus serves as the locking connecting element of the second connecting piece 12, into which the free end of the locking arm 46 of the first connecting piece 14 engages when the absolute end position shown in Fig. 1 and Fig. 2 is reached.or the detent edge 50 formed by this recess 52 in conjunction with one of the detent projections 48 formed by the detent arm 46. The actual rotational end position of the interconnected connecting pieces 12, 14 therefore does not always have to correspond to the absolute end position shown in Fig. 2, but a positive locking connection securing the connecting pieces 12, 14 in tension is realized by the locking projections 20 and the locking recesses 26 in a first area of ​​the possible rotational orientations, while at the same time, the detent connecting elements within this first area form a detent connection that prevents the connecting pieces 12, 14 from rotating relative to each other in the release direction in several specific rotational orientations. To release the locking connection (and subsequently the connection between the connecting pieces 12, 14 formed by the locking projections 20 and the locking recesses 26), the free end of the locking arm 46 can be manually deflected towards the rear end of the first connecting piece 14. For ease of handling, the locking arm 46 has a gripping surface 70 at its free end, which is provided with serrations (see Fig. 2). The stop element 56, which projects beyond the free end of the stop flange 40 of the first connecting piece 14, in combination with the stop flange 22 of the second connecting piece 12, ensures that the connecting pieces 12, 14 can only be inserted sufficiently far together in a second area of ​​the possible rotational orientations, namely only when the stop element 56 engages in the recess 52 of the stop flange 22 of the second connecting piece 12. The plug section 24 of the first connecting piece 14 forms a mounting section 60 on its outer side, onto which a connecting section of the gas supply pipe 16 can be mounted. For a sufficiently secure hold of the connecting section of the gas supply pipe 16 on the mounting section 60 of the first connecting piece 14, the mounting section 60 forms a circumferential projection 62 at the rear end of the first connecting piece 14. This projection engages in a complementary recess on the inner side of the connecting section of the gas supply pipe when the connecting section has been pushed onto the mounting section 60 of the first connecting piece 14 until it reaches a predetermined end position (see Fig. 3).Furthermore, the outer surface of the first connecting piece 14, in the area between this circumferential projection 62 and the stop flange 40 of this connecting piece 14, is provided with circumferential grooves 64, which, in conjunction with corresponding grooves on the inner surface of the gas supply pipe 16, also improve the retention of the gas supply pipe 16 on the first connecting piece 14. Finally, this connection can be additionally secured by a separately attached hose clamp 66. A connection opening 68 for connecting a crankcase ventilation vent line of the internal combustion engine is integrated into the gas supply pipe 16. This places special demands on the sealing of the connection device, since gaseous and liquid components, which are considered pollutants, are also returned to the fresh gas stream via such a vent line and should not escape into the environment. Reference symbol list 10 Housing 12 Second connection 14 First connection 16 Gas guide pipe 18 Plug section of the second connection 20 Locking projection 22 Stop flange of the second connection 24 Plug section of the first connection 26 Locking recess 28 Insertion section of the locking recess 30 Plug axis / Longitudinal axis of the plug section of the first / second connection 32 Locking section of the locking recess 34 Locking rotation direction 36 Outlet section of the locking recess 38 Axial contact surface of the second connection 40 Stop flange of the first connection 42 Axial contact surface of the first connection 44 Sealing element 46 Detent arm 48 Detent projection 50 Detent edge of the second connection 52 Recess of the stop flange of the second connection 54 Stop surface of the first connection 56 Stop element of the first connecting piece 58 stop surface of thesecond connecting piece 60 attachment section of the first connecting piece 62 projection of the attachment section 64 groove of the attachment section 66 hose clamp 68 connection opening of the gas supply pipe 70 gripping surface

Claims

Connecting device with a first connecting piece (14) and a second connecting piece (12) that can be inserted into the first connecting piece (14), wherein the connecting pieces (12, 14) each have one or more locking elements in a plugging section (18, 24) which, in a first region of the possible rotational orientations of the connecting pieces (12, 14) relative to each other, can form a positive locking connection that prevents the second connecting piece (12) from being pulled out of the first connecting piece (14), wherein this positive locking connection is released in a second region of the possible rotational orientations, and wherein detent connecting elements are included which, in several rotational orientations within the first region, form a detent connection that prevents the connecting pieces (12, 14) from being rotated relative to each other.characterized by a locking arm (46) extending circumferentially with respect to the longitudinal axis (30) of the associated connecting piece (14), which is elastically deflectable in the direction of the longitudinal axis (30) to release the locking connection. Connecting device according to claim 1, characterized in that the locking elements are designed such that, when the connecting sleeves (12, 14) are rotated relative to each other, the second connecting sleeve (12) is moved into the first connecting sleeve (14) from the second area to the first area of ​​the possible rotational orientations. Connection device according to claim 1 or 2, characterized by an axial contact surface (38, 42) of each of the connection fittings (12, 14), wherein these axial contact surfaces (38, 42) limit the maximum insertion depth of the second connection fitting (12) in the first connection fitting (14) when in contact with each other. Connection device according to claim 3, characterized by a sealing element (44) integrated into the axial contact surface (38, 42) of at least one of the connection nozzles (12, 14). Connection device according to one of the preceding claims, characterized in that the first connection nozzle (14) forms a mounting section (60) for a pipe (16) on the outside of its plug section (24). Connecting device according to one of the preceding claims, characterized in that the connecting pieces (12, 14) each form a cylindrical base surface in the area of ​​their plug sections (18, 24), wherein at least one of the locking elements is designed as a locking projection (20) protruding from the associated base surface and at least one other of the locking elements is designed as a locking recess (26) provided in the associated base surface. Connecting device according to claim 6, characterized in that the locking recess(s) (26) widens / widens from a locking section (32) towards the free end of the associated connecting sleeve (12, 14). Connecting device according to one of the preceding claims, characterized by a stop surface (54, 58) of each of the connecting spigots (12, 14) which, when in contact with each other, limit the first area of ​​the possible rotational orientations in the locking rotational direction (34). Connecting device according to one of the preceding claims, characterized by a projection of one of the connecting pieces (14) which, when the connecting pieces (12, 14) are joined together in a rotational orientation within the first or second area, can engage in a recess (52) of the other connecting piece (12). Connecting device according to one of the preceding claims, characterized in that the locking arm (46) forms one or more locking projections (48) at its free end which, in a corresponding rotational orientation of the connecting sleeves (12, 14) within the first area, bear against a locking edge (50) of the other connecting sleeve (12). Connecting piece (12; 14) for a connecting device according to one of the preceding claims, wherein the connecting piece (12; 14) has one or more locking elements in a plug-in section (18; 24) which is provided for plugging together with a plug-in section (24; 18) of a complementary mating connecting piece (14; 12), wherein the locking elements are provided to form a positive locking connection effective in a first area of ​​possible rotational orientations of the connecting piece (12, 14) relative to the mating connecting piece (14; 12) and securing against the disconnection of the connecting piece (12; 14) from the mating connecting piece (14; 12), wherein this positive locking connection is released in a second area of ​​possible rotational orientations, and wherein a snap-fit ​​connecting element is included which, in conjunction with a snap-fit ​​connecting element of the mating connecting piece (14;12) in several possible rotational orientations within the first area forms a locking connection that prevents the connecting piece (12, 14) from rotating relative to the mating connecting piece (14; 12), characterized by a locking arm (46) extending circumferentially with respect to the longitudinal axis (30) of the connecting piece (14), which is elastically deflectable in the direction of the longitudinal axis (30) to release the locking connection. Connecting piece (14) according to claim 11, characterized in that the locking arm (46) forms one or more locking projections (48) at its free end which, in a corresponding rotational orientation of the connecting piece (14) relative to the counter-connecting piece (12), can bear against a locking edge (50) of the counter-connecting piece (12) within the first area. Use of a connecting device according to one of claims 1 to 10 for connecting two fluid-conducting components of an internal combustion engine.

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