Connection device

Abstract

Connection device for the detachable connection of plastic pipes (5), consisting of a union screw (16) with an inner bore (17) for receiving the respective plastic pipe (5) with an inner guide section (21) and with an adjoining inner cone section (22) expanding in the screw-in direction (Y), as well as with an actuating section (23) formed on the outer circumference and with an external thread section (24) adjoining thereto in the screw-in direction (Y), and a radially elastic clamping ring (34) arranged within the inner cone section (22) with a longitudinal section (36) extending in the axial direction and at least one inner, circumferential cutting edge (37) and with an outer cone (38) which is adapted to the inner cone section (22) and cooperates with it to fix the plastic pipe (5) within the inner bore (17),wherein a cylindrical fastening extension (26) is formed at the end of the external threaded section (24) of the inner cone section (22) pointing in the screw-in direction (Y), to which a size compensation element (27) is attached by force-fit and / or form-fit or by material-fit, which consists of a receiving section (29) for the clamping ring (34) and a pipe stub (32) extending thereto in the screw-in direction (Y) via a base part (31) for a bearing of the clamping ring (34) for guiding the pipe (5) to be connected, wherein the pipe stub (32) for guiding the pipe (5) to be connected has a radially inwardly directed, annular stop (33) at its free end, against which the pipe (5) rests in the connected and inserted state.

Description

[0001] The present invention relates to a connection device.

[0002] A connection device of this type is known, for example, from EP 0 631 081 A1. In these known connection devices, the union nut and the through-hole in the associated housing part, which is designed as a shaped bore and into which the union nut is screwed, are each sized to match the outside diameter of the pipe to be connected. This also applies to the clamping ring located inside the union nut. This means that union nuts of different dimensions and shaped bores of different shapes and sizes, as well as correspondingly sized clamping rings, must be used for different pipe diameters.

[0003] DE 20 2007 013 316 U1 discloses a connection device for at least one media line, in particular for a urea-water solution for exhaust aftertreatment in a motor vehicle with an internal combustion engine, consisting of a connection part with a receptacle for the circumferentially sealed insertion of a line-side plug section and with retaining means for locking the inserted plug section against loosening. The retaining means are designed such that, starting from a normal operating position, the inserted and locked plug section can be moved relative to the connection part over a certain distance against a restoring force, in particular together with an insert, to increase the internal volume within the connection part containing the medium.

[0004] From DE 33 25 350 A1, a connection device for the detachable connection of plastic pipes is known, comprising a union screw with an internal bore for receiving the respective plastic pipe, an internal guide section, and an adjoining internal cone section that widens in the screw-in direction, as well as an actuating section formed on the outer circumference and an external threaded section adjoining this in the screw-in direction. The connection device has a radially elastic clamping ring arranged within the internal bore of the internal cone section, with at least one internal, circumferential cutting edge and with an external cone that is adapted to the internal cone section and interacts with it to fix the plastic pipe within the internal bore.

[0005] The present invention is based on the objective of creating a possibility to connect even smaller diameter pipes without changing the shaped bore, starting from a predetermined through-bore or shaped bore of the housing part, which is predetermined with regard to its shape and size, into which the union screw is screwed.

[0006] According to the invention, this is achieved by the features of claim 1 and, in an advantageous embodiment, by one or more features of the dependent claims.

[0007] The invention is based on the understanding that, through the special design of the union screw with an end-attached size compensation element, it is possible, by simultaneously adapting the union screw with respect to its inner bore, the associated inner cone section, and the clamping ring adapted thereto, to design the fastening extension with the size compensation element attached to it in such a way that existing diameter differences can be compensated for. Accordingly, the through-bore of the housing part, which is a predefined shaped bore, can remain unchanged when smaller diameter pipes are to be connected.

[0008] Advantageous embodiments of the invention are described in the exemplary embodiments and are explained in more detail with reference to the figures.

[0009] They show: Fig. 1 a partial longitudinal section of a connection device according to the invention in the unassembled state, Fig. 2 a connection device according to Fig. 1 in the assembled state with piping, Fig. 3. A detailed view at A in Fig. 2, Fig. 4 a detailed view according to Fig. 3, however in an alternative embodiment and Fig. 5 a detailed view according to Fig. 3, however in an alternative embodiment.

[0010] In the various figures of the drawing, identical parts are always labelled with the same reference symbols.

[0011] Regarding the following description, it should be noted that the invention is not limited to the exemplary embodiments and not to the described combinations of features; rather, each individual feature of the exemplary embodiment(s) is also significant for the subject matter of the invention independently of the described combination of features, both on its own and in other combinations with other features of the other exemplary embodiments.

[0012] As can be seen from Fig. 1 and Fig. 2, a connection device for the detachable connection of a plastic pipe 5 comprises, in particular, a housing part 1 with an internal through-bore 2. This through-bore 2 is designed as a so-called formed bore and consists of at least four bore sections, namely an upper internal threaded section 4 adjoining an insertion opening 3 of the through-bore 2 with a thread of, for example, size M8 x 1 or M10 x 1 according to DIN 13-5 of November 1999 or, in the case of a connection device made of plastic, a V-thread according to DE 295 21 493 U1, and a threadless cylindrical section 6 adjoining this internal threaded section 4, in particular with an inner diameter corresponding to the inner diameter of the threaded section 4.A cylindrical guide section 7 adjoins this cylinder section 6, extending towards the interior of the housing part 1. The inner diameter of this guide section 7 is smaller than the inner diameter of the cylinder section 6. This creates a step with an annular contact surface 8 between the cylinder section 6 and the guide section 7. The inner diameter of the guide section 7 is larger than the outer diameter of the plastic pipe 5 to be connected. At the inner end of the guide section 7, a flow bore section 11, with a smaller inner diameter than the guide section 7, connects via an annular stop 9. For example, in the case of a formed bore with an M10 x 1 internal thread, the inner diameter of the flow bore 2 is 4 mm. The annular stop 9 provides a deep insertion stop for the pipe 5.Advantageously, an insertion section 12, which widens conically up to the insertion opening 3, is formed in the through-bore 2 between the insertion opening 3 and the internal thread section 4. Furthermore, a centering section 13 of the through-bore 2, which widens conically from the guide section 7 to the contact surface 8, is advantageously located in the area of ​​the transition from the contact surface 8 to the guide section 7. The through-bore 2 has a depth T1 from the insertion opening 3 to the contact surface 8 of, in particular, T1 = 9 mm for an internal thread M10 × 1. Furthermore, a possible insertion depth T2 of the pipe 5 up to the stop 9 is a maximum of 13 mm for an internal thread M10 x 1. For an internal thread M8 x 1 according to DIN 13-5 of November 1999, the inner diameter d is... i of flow-through bore section 11 d i = 3 mm and the dimensions T1 and T2 are the same as for an internal thread M10 × 1.

[0013] According to the invention, a union screw 16 is provided which has a continuous inner bore 17, the inner diameter of which is adapted, in particular, to an outer diameter of the pipe 5 to be connected, wherein a circumferential gap is present between the circumference of the pipe 5 and the inner bore wall, which is sealed medium-tight by means of a ring seal 19 arranged in an annular groove 18 of the bore wall. In a screw-in direction Y of the union screw 16, a cylindrical guide section 21 for the pipe 5 to be connected is formed, to which an inner conical section 22, which widens conically towards the front end of the union screw 16, is connected.On its outer circumference, the union screw 16 has an actuating section 23, to which an external thread section 24 is attached, the thread diameter of which is adapted to the thread diameter of the internal thread section 4 of the housing part 1, so that the union screw 16 according to the invention can be screwed into the internal thread section 4 with its external thread section 24, as shown in . Fig. Figure 2 shows that a sealing section 25 with a ring seal 25a is located between the actuating section 23 and the external threaded section 24. A cylindrical mounting extension 26 is formed at the end of the internal cone section 22 facing in the screw-in direction and also at the end of the external threaded section 24. This mounting extension 26 projects into the cylindrical section 6 of the through-bore 2 when the union nut 16 is screwed in. A size compensation element 27 is positively and / or force-fitted to the mounting extension 26. This size compensation element 27 has a circular inlet opening 28 on an upper, hollow cylindrical receiving section 29 facing the inner threaded bore or the mounting extension 26. This receiving section 29 has a circumferential wall which, viewed in longitudinal section (i.e., a section in the direction of the longitudinal axis XX of the union nut 16), has the form of a web.The width B1 of the web and the width B2 of the fastening extension 26 are dimensioned such that the following applies:. B1+B2≤(di1−dK) / 2

[0014] Here, d i1 the inner thread diameter of the external thread 24 of the union screw 16 and d k is the diameter of the cone section 22 at the transition to the fastening extension 26.

[0015] This ensures that the inlet opening of the cylindrical receiving section 29 is not smaller than the diameter d K , so that the inner cone section 22 is not constricted in the area of ​​its end-end enlarged outlet opening.

[0016] The receiving section 29 has an annular base 31. This base 31 transitions into a cylindrical pipe stub 32, the inner diameter of which is adapted to the outer diameter of a pipe 5 to be connected. The pipe stub 32 has a radially inwardly directed annular stop 33 at its free end, against which the pipe 5 rests when connected and inserted. The receiving section 29 serves to receive and support a clamping ring 34. The clamping ring 34 is dimensioned such that, in the incompletely assembled state, i.e., when the union screw 16 is not fully screwed into the through-bore 2, it encloses the pipe 5 to be connected in such a way that the pipe 5 can be pushed through the clamping ring 34. The clamping ring 34 has an axially and radially continuous longitudinal or radial slot at one point on its circumference.The clamping ring 34 has a discontinuity in its circumferential profile, allowing it to expand and contract radially. In its inner circumferential region, the clamping ring 34 has at least one radially inwardly projecting, circumferential cutting edge 37. The clamping ring 34 also has an outer cone 38, which interacts with the inner cone section 22 to lock the pipe 5 in such a way that when the pipe 5 is pulled against its insertion direction, the clamping ring 34 is carried along by the frictional engagement of its cutting edges 37 until its outer cone 38 comes into contact with the inner cone section 22. With further pulling, the clamping ring 34 is elastically constricted via the cones 38 and 22, so that the cutting edges 37 interact with the outer wall of the pipe 5 in a force-fit and / or form-fit manner, thus fixing the pipe 5 against being pulled out.

[0017] The receiving section 29 is dimensioned such that, when the union screw 16 is screwed in, the base part 31 rests against the contact surface 8 of the through-bore 2, while the pipe stub 32 is dimensioned such that its stop 33 does not contact the annular stop surface 9 of the through-bore 2. The receiving section 29, which has a web-like shape in longitudinal section along its wall, has – as shown in Fig. Figure 3 shows a circumferential locking section 41 which, in the assembled state, engages in an internal groove 42 of the fastening extension 26 and forms a positive locking connection. Fig. Figure 4 shows an alternative fastening method. Here, the receiving section 29, with its longitudinally ribbed wall, encompasses the fastening extension 26 on its outer circumference. The receiving section 29 has a locking bead 43 at its inner end, which, in the assembled state, engages in a circumferential groove 44 on the outer surface of the fastening extension 26, thereby also establishing a positive-locking connection. Since the size compensation element 27 according to the invention has a longitudinal slot 30 in its wall in the region of the receiving section 29 and is, in particular, made of plastic, it can be elastically deformed during assembly. Alternatively, elastic deformation can also occur via material elongation, i.e., without the longitudinal slot 40, of the size compensation element 27.

[0018] In Fig.Figure 5 shows a further embodiment of the size compensation element 27 according to the invention. Here, the receiving section 29 is pressed into the fastening extension 26 in a force-fit manner, so that a force-fit connection is established. Alternatively, a material-fit connection can also be established by gluing. In this case, the size compensation element 27 according to the invention is made in particular of metal, e.g., brass.

[0019] The inventive design of the union screw 16 with the size compensation element 27 attached to its end allows for the connection of smaller diameter pipes without altering the dimensioning of the through-hole 2 in a housing part 1 for a specific diameter of a pipe 5 to be connected. This means that, based on a specific through-hole 2, arbitrarily smaller pipe diameters can be connected using the union screw according to the invention. Furthermore, the invention provides that the clamping ring 34 used can also be adapted to the different diameter sizes of the pipe 5.

[0020] The invention is not limited to the embodiments illustrated and described, but also encompasses all embodiments that have the same effect within the meaning of the invention. It is expressly emphasized that the embodiments are not limited to all features in combination; rather, each individual feature can also have inventive significance independently of all other features. Furthermore, the invention is not yet limited to the combination of features defined in claim 1, but can also be defined by any other combination of specific features from all disclosed individual features. This means that, in principle, virtually any individual feature of claim 1 can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.

Claims

[1] Connection device for the detachable connection of plastic pipes (5), comprising a union screw (16) with an inner bore (17) for receiving the respective plastic pipe (5) with an inner guide section (21) and with an adjoining inner cone section (22) expanding in the screw-in direction (Y), as well as with an actuating section (23) formed on the outer circumference and with an external thread section (24) adjoining thereto in the screw-in direction (Y), and a radially elastic clamping ring (34) arranged within the inner cone section (22) with a longitudinal section (36) extending in the axial direction and at least one inner, circumferential cutting edge (37) and with an outer cone (38) which is adapted to the inner cone section (22) and cooperates with it to fix the plastic pipe (5) within the inner bore (17),wherein a cylindrical fastening extension (26) is formed at the end of the external threaded section (24) of the inner cone section (22) pointing in the screw-in direction (Y), to which a size compensation element (27) is attached by force-fit and / or form-fit or by material-fit, which consists of a receiving section (29) for the clamping ring (34) and a pipe stub (32) extending thereto in the screw-in direction (Y) via a base part (31) for bearing the clamping ring (34) for guiding the pipe (5) to be connected, wherein the pipe stub (32) for guiding the pipe (5) to be connected has a radially inwardly directed, annular stop (33) at its free end, against which the pipe (5) rests in the connected and inserted state. [2] Connection device according to claim 1, characterized by, that the receiving section (29) has an upper inlet opening (28) which is adapted to the inner diameter of an outlet opening of the inner cone section (22) in such a way that the inner cone section (22) is not constricted in the area of ​​its end outlet opening. [3] Connection device according to claim 1 or 2, characterized by , that the receiving section (29) has a longitudinally rib-shaped circumferential wall and is radially elastically deformable. [4] Connection device according to any one of claims 1 to 3, characterized by , that the receiving section (29) has at its free end on its outer circumference a circumferential locking section (41) which engages in an inner groove (42) of the fastening extension (26). [5] Connection device according to any one of claims 1 to 3, characterized by, that the receiving section (29) has a locking bead (43) at its inner end, with which it engages in a circumferential groove (44) on the outside of the fastening extension (26) when mounted. [6] Connection device according to one of claims 1 to 3, characterized by , that the size compensation element (27) is made in particular of a metallic material and is inserted within the fastening extension (26) in a force-fit or material-fit manner with its receiving section (29). [7] Connection device according to any one of claims 1 to 6, characterized by , that the union screw (16) can be screwed into a housing part (1) with a through hole (2), wherein in the screwed-in state the size compensation element (27) with its receiving section (29), which is attached to the fastening extension (26), is arranged in a guide section (7) of the through hole (2). [8] Connection device according to claim 7, characterized by , that when the union screw (16) is screwed into the housing part (1) the size compensation element (27) with its receiving section (29) rests against a contact surface (8) of the guide section (7) of the through bore (2) of the housing part (1).

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